137

Answers to exercises

Exercises I

1.

a) Manufacturing industry produces goods today, using machines, computers, and automation, in such an efficient manner, that the need for hand tools has been almost eliminated.

b) Hand tools are used for making prototypes and models, and in the main­tenance of equipment

c) Maintenance work refers to the work that needs to be done, to keep ma­chines and equipment, in good working condition.

d) A centre punch may be used to mark a point on a metal, before drilling.

e) A pin punch may be used to drive in or remove, straight pins, tapered pins, and keys.

f) An offset screw driver is used to reach screws in places which cannot be reached with an ordinary screw driver.

g) A ring spanner surrounds the head of a bolt completely, and therefore has a much firmer grip on the head of a bolt than an ordinary spanner, which surrounds the head only partially.

h) A hacksaw consists of an adjustable frame, fitted with a removable blade.

i) A scraper is used to remove small amounts of metal, from high spots on a metal surface.

j) Chisels have to be ground to a definite shape, so that they work effi­ciently and do not become too hot.

138 Answers to exercises

2.

3.

a) A hammer can be used for shaping and forming sheet metal.

b) A centre punch can be used to mark a point on a piece of metal before drilling.

c) Pliers are used for many purposes, like gripping, and holding.

d) A spanner is used for tightening nuts and bolts.

e) Files are used to remove metal from the surface of an object.

f) The cut of a file refers to the distance between the teeth.

g) The important angles of a chisel are the rake angle, and the clearance angle.

h) Taps are used for cutting internal screw threads.

i) Dies are used for cutting external screw threads.

a) Although most goods are manufactured today using automatic machines, hand tools are still required for repair and maintenance work.

b) A hammer is a multi-purpose tool. One of its uses among others, is to hammer a piece of metal until it acquires the required shape.

c) An offset screw driver is a special tool. It is used for reaching screws in awkward places.

d) There are many types of spanners. When a bolt has to be gripped firmly, one uses a ring spanner or a socket spanner.

e) A metal saw which is used for cutting sheet metal is called a hacksaw. A piece of metal can be made to acquire a desired shape, by working on it first with a chisel, and then with a file.

Answers to exercises 139

Exercises ll

1.

2.

a) A workshop contains all the types of equipment which are necessary to carry out the work required.

b) A workshop bench is a table on which the work and tools can be placed, and on which work can be done.

c) Holding and clamping devices are needed to hold an object firmly, while work. is being done on it.

d) Vee-blocks are devices which are used to hold cylindrical rods and pipes, while work is being done on them.

e) Angle blocks are used when the position of the workpiece needs to be changed by 90°.

f) Marking-out equipment is used to scribe lines, circles, etc. on an object, before work is done on it.

g) A marking-out table is a strong table with a very flat metal surface.

h) Measuring devices are needed for checking the dimensions of the fm-ished work, and also during the marking-out process.

i) The usual accuracy of a micrometer is about one-thousandth of a centi-metre.

j) An engineer's square can be used to check whether two surfaces are at right angles to each other.

a) A workshop contains many types of equipment.

b) A workshop bench is a strong table on which we can place the work, and the tools, that are required.

c) A vice is clamped to the table by means ofbolts and nuts.

140 Answers to exercises

3.

d) Vee-blocks are used to hold rods or pipes, while work is being done on them.

e) Angle blocks have two surfaces which are at right angles to each other.

f) Special fixtures are used when accurate machining, welding, or assem-bly work is required.

g) Marking-out equipment is used to scribe lines on an object.

h) Measuring instruments are used for checking the dimensions of objects.

i) A micrometer is an accurate measuring instrument.

j) An engineer's square is used to check if two surfaces are at right angles to each other.

a) A mechanical workshop contains different types of equipment. Among these are holding and clamping devices, and also measuring devices.

b) It is necessary to mark out a casting by scribing lines, before work can be done on it.

c) Special fixtures are required, when accurate machining or assembly work has to be done.

d) Measuring instruments are used in the marking-out process, and also for checking the dimensions of an object after work has been done on it.

e) A micrometer is an instrument which can be used to measure lengths, to an accuracy of 1/1000 em.

f) An engineer's square is used to check whether two surfaces are at right angles to each other.

Answers to exercises 141

Exercises lll

1.

2.

a) Cans, razor blades, kitchen utensils, aeroplanes, and automobile bodies, are some of the articles that can be made of sheet metal.

b) Hand shears are used for cutting thin metal sheets, while bench shears are used for cutting thicker metal sheets.

c) Complex shapes can be cut quickly, by using presses and press tools.

d) Automatic presses are used to cut and form complicated shapes in sheet metal, quickly, and efficiently.

e) Bending rollers are used to roll sheet metal into cylindrical shapes.

f) Bending machines are usually used to make simple straight folds in metal sheets.

g) A flanging operation produces edges of various widths and angles, on flat or curved sheets.

h) Beading improves the strength, stiffness, safety, and appearance, of an article made from sheet metal.

i) In the wiring process, the edge of a piece of sheet metal is folded round a wire of suitable diameter.

j) Folded metal joints are often soldered to make them water-tight.

a) A large variety of articles are made from sheet metal today.

b) Simple tools are still used for sheet metal work, although machines do most of the work today.

c) Thick sheets of metal can be cut using bench shears.

d) A handsaw can be used to cut complex shapes from metal.

e) In large scale manufacturing industry, automatic presses are used for sheet metal work.

142 Answers to exercises

3.

t) A press tool consists of two parts, a punch, and a die.

g) Flanging produces edges of various widths and angles on metal sheets.

h) The joining of thin sheet metal is often done using folded joints.

i) In the wiring process, the edge of a piece of sheet metal is folded round a wire.

j) Bending machines make simple straight folds on metal sheets.

a) Most of the articles produced by industry today are produced by auto­matic machines. However, simple tools are still used for many purposes.

b) The cutting of thin metal sheets can be done using hand shears, but for cutting thick sheets, bench shears are needed. Complicated shapes can be cut individually using a handsaw.

c) Large scale production of metal components in industry is done by using automatic presses. Presses can also be used for punching out complicated shapes.

d) Bending rollers are used to shape metal sheets into a cylindrical form, while bending machines are used to make simple straight folds.

e) Beading is a process by which folded edges of different widths can be produced.

Answers to exercises 143

Exercises IV

1.

2.

a) Metal fasteners are used to join metal sheets or metal components by mechanical means.

b) Riveting is useful when metal sheets have to be joined together perma­nently.

c) Fasteners with screw threads are used to join components, which have to be taken apart later.

d) An additional part like a spring washer or a lock nut may be used, to prevent a bolt and nut from becoming loose.

e) Set screws often have a hexagonal hole in their head, so that they can be tightened efficiently by using a hexagonal key.

f) Studs are used in brittle materials like cast iron.

g) If a bolt is tightened excessively in a cast iron thread, the screw thread can be damaged.

h) Studs are used to hold down a cylinder head on the cylinder block of an automobile engine.

i) Studs are used to ensure water-tight joints.

j) It is not possible to use bolts and nuts when only one side of the parts to be joined is accessible.

a) Metal components can be joined together by using metal fasteners.

b) Riveting is used on ship's hulls and aircraft fuselages.

c) Metal parts can also be joined by fastening devices which have a screw thread.

d) When both sides of the parts to be joined are accessible, nuts and bolts maybe used.

144 Answers to exercises

3.

e) It is often necessary to use set screws with countersunk heads.

f) Countersunk screws often have a hexagonal hole in their head.

g) Studs are used in applications where heavy pressures are encountered.

h) Studs are used to join components to cast iron, because the tensile strength of cast iron is very low

i) The screw thread in a cast iron component may crumble if tightened ex­cessively.

j) It is necessary to remove the head of a motor car engine, when the en­gine needs overhauling.

a) Metal components and sheets can be joined in many ways. One way is by the use of metal fasteners like rivets or bolts and nuts.

b) Bolts and nuts can be used when both sides of the components to be joined are accessible. An additional part like a washer could become necessary if the parts are subject to vibration.

c) Bolts with normal heads can be used to join metal components, how­ever, it is often necessary to use bolts with countersunk heads. Such bolts have a hole of hexagonal shape in the head, which enables the bolt to be tightened very effectively using a hexagonal key.

d) Studs are used in applications where heavy pressures are encountered, and also where water-tight or gas-tight joints are needed.

e) Studs are used to join the cylinder head of an automobile engine to its cylinder block. The joint between the cylinder and the head has to be a temporary one, because it is necessary to remove the head, when the en­gine needs reconditioning.

Answers to exercises 145

Exercises V

1.

a) Soldering is the process of joining two metal objects by a third soft metal alloy, which is called solder.

b) Solder is a metal alloy which melts at a lower temperature than the met-als being soldered. Two types of solder are commonly used, soft solder, and hard solder.

c) The surfaces of the metals must be thoroughly cleaned before soldering.

d) The fluxes usually used in the workshop are acidic in character.

e) Acid fluxes are corrosive and unsuitable for electrical work, and resin is usually used as a flux instead.

f) In the brazing process much higher temperatures are reached, and the solder usually used is spelt.

g) In oxy-acetylene welding, a blowpipe through which oxygen and acety-lene gases flow in suitable amounts, is used.

h) In the electric arc welding process, the metal electrode acts as a filler rod, making the process easier to control.

i) In the resistance welding process, no filler rods or filler electrodes are required.

j) A large amount of heat is generated at the contact faces, because the re-sistance to the flow of current is large.

2.

a) The process of joining two metal surfaces by a third soft metal alloy, is called soldering.

b) Hard solder is an alloy of copper and zinc, and is called spelt or silver solder.

c) Flux removes oxides and grease from the metal surface, and allows the solder to flow freely.

146 Answers to exercises

3.

d) Fluxes used in the workshop are usually acidic in character, and are cor­rosive.

e) The solder used for electrical work is in the form of a wire with a resin core.

f) The hard soldering process uses spelt as the solder, and borax as the flux.

g) The two principal types of welding are, electric arc welding, and resis­tance welding.

h) In oxy-acetylene welding, a blowpipe through which oxygen and acety­lene gases flow through is used.

i) The filler rod melts, and a small amount of liquid metal is formed at the joint.

j) In the electric arc welding process, the metal electrode also acts as a filler rod.

a) Solder is a metal alloy, which melts at a somewhat lower temperature than the metals to be joined. Two types of solder are normally available. One type of solder which is an alloy of tin and lead, is softer than the other, which is an alloy of copper and zinc, and is called silver solder.

b) It is very important that the surfaces of the metals that have to be sol­dered, should at first be thoroughly cleaned. For this purpose, a flux which removes oxides and grease from the surface is used.

c) In the hard soldering process, another solder and more heat must be used to reach the melting point of hard solder, which is about 600°C. A hard soldered joint is considerably stronger than a soft soldered one.

d) The temperature of the flame in an oxy-acetylene blow pipe can reach a maximum value of about 3000°C. The blowpipe heats the metal parts that have to be joined, and also a filler rod which is held in the flame at the joint.

Answers to exercises 147

e) In the resistance welding process, the surfaces of the metal parts which are to be welded, are pressed against each other, and a large current is passed through the joint. During this time, a lot of heat is generated at the contact surfaces .

148 Answers to exercises

Exercises VI

1.

2.

a) Industry needs different types of materials for different purposes.

b) Wrought iron has the advantage that it can be easily bent, and formed into different shapes.

c) Mild steel is a general purpose low carbon steel that can be used for many purposes, like reinforcing concrete, making containers, car bodies, etc.

d) Carbon steels are steels with a high carbon content. Carbon steels lose their hardness when they become hot under working conditions, and are therefore unsuitable for use as metal cutting tools.

e) Alloy steels contain alloying elements like tungsten, chromium, and va­nadium, and can work at higher temperatures than carbon steel.

f) Cast iron is iron with a higher carbon content than steel, and has the ad­vantage that it can be easily cast into complex shapes.

g) The important nonferrous elements and alloys are copper and its alloys, aluminium and its alloys, and zinc and its alloys.

h) Plastic goods have the advantages of being cheap, light, and easy to manufacture.

i) Thermoplastics become soft when heated, and become hard on cool­ing.They can be moulded easily, and have the advantage that they can be repeatedly remoulded. Thermosetting plastics are harder than ther­moplastics, but can be heated and moulded only once.

j) A good example of a composite material is resin reinforced with fibre­glass. It has the advantages of high strength, and easy mouldability, at room temperature.

a) Different kinds of metals and alloys are used for different purposes.

Answers to exercises 149

3.

b) Wrought iron has the advantage of being easily bent into different

shapes.

c) Steel is an alloy composed of iron and a small amount of carbon.

d) Carbon steel can be hardened, and is used to make small tools like scis­sors, and screw drivers.

e) Metal cutting tools are made of special alloy steels called high speed

steels.

f) Tools made of alloy steels can work at higher temperatures than tools made of carbon steel.

g) Cast iron when in a liquid state, flows easily into moulds.

h) Thermosetting plastics become soft when heated, and can be moulded into different shapes.

i) Composite materials can be made from resins reinforced with glass fi­

bre.

j) Mild steel can be used for reinforcing concrete and for making car bod­ies.

a) Metal alloys and plastics are amongst the most important materials used by manufacturing industry today. Different kinds of metals and alloys are required for different applications.

b) Mild steel which contains about 0.2% carbon, is the most used type of

steel, and is used for many purposes, like the reinforcing of concrete, and the construction of water tanks. Mild steel, unlike steels with a high carbon content cannot be hardened.

c) Cast iron is a very useful material, because in liquid form it is able to flow easily into moulds. Complex shapes can be cast using cast iron. Cast iron is a hardwearing material which resists abrasion.

d) Plastics are of increasing importance, because goods made of plastics are easy to manufacture, reasonable in price, and light. Some plastics

150 Answers to exercises

become soft when heated, and hard when cooled. Such plastics can be used repeatedly.

e) Composite materials, which are made of resin and glass fibre, can be used, where high strength, and easy moulding at room temperatures, are some of the properties required.

Answers to exercises 151

Exercises VII

1.

2.

a) Casting is probably the quickest and the most economical way of pro­ducing a metal component.

b) In sand casting, the molten metal is poured into a hollow space in a box filled with sand. The hollow space has the shape of the object that has to be cast.

c) A pattern is a replica of the object to be cast, and is usually made of wood or steel.

d) The three main stages in the manufacture of a casting are, the making of the pattern, the making of the mould, and the pouring in of the metal.

e) The casting is usually made slightly larger than the final object that has to be produced, so that it can be machined to a precise size.

f) Sand casting is particularly useful for producing large complex castings, like machine beds, and engine cylinder blocks.

g) The two main die casting processes are, gravity die casting, and pressure die casting. Die castings are stronger, and better finished, than sand castings.

h) Die casting moulds are made out of steel.

i) The die casting process has the disadvantage, that it can only be used with low melting point metals and alloys.

j) Many automobile components like carburettors, fuel pumps, and engine cylinder heads, are manufactured by the die casting process.

a) The process of casting has been practiced for thousands of years.

b) In the sand casting process, the molten metal is poured into a mould.

c) The pattern which is a replica of the object to be produced, is made of wood or metal.

152 Answers to exercises

3.

d) The wooden pattern is usually made in two halves, which are joined together by dowel pins.

e) The pattern and the resulting casting, are usually made larger than the final size of the finished object.

f) The extra allowance in the size of the casting, is called a machining al­lowance.

g) The two methods of producing castings are called gravity die casting, and pressure die casting.

h) Die casting moulds are very precisely made, and the castings produced are very accurate in their dimensions.

i) The disadvantage of the die casting process is that, only low melting point metals and alloys can be used.

j) In the pressure die casting process, the molten metal is forced into the dies under pressure.

a) The process of casting is probably the quickest and easiest way to pro­duce metal objects, particularly large and complex objects.

b) In the sand casting process, the melted metal is poured into a hollow space filled with sand. The hollow space is similar in shape and size to the object that has to be cast.

c) The pattern and the casting are usually larger than the finished metal component. This extra allowance is called a machining allowance.

d) Moulds which are used in the pressure die casting process are made of steel, and can be used indefinitely. The moulds are precisely made, and the castings produced are very accurate in their dimensions.

e) The disadvantage of the pressure die casting method is that only low melting point metals and alloys, like zinc and aluminium alloys can be used in this process. However, the castings produced by this process have the advantage that they do not need to be machined.

Answers to exercises 153

Exercises Vlli

1.

a) The purpose of the heat treatment process, is to improve the properties of metals to the extent that the manufacturing process is made easier, and also to enable the metal component to be able to withstand rough usage.

b) The mechanical properties of metals, like hardness, strength, and brittle­ness, depend on the grain structure of the metal.

c) The size, shape, and orientation of the grains, affect the mechanical properties of metals.

d) Castings that are allowed to cool slowly have a coarse grain structure, while castings that are allowed to cool rapidly, have a fine grain struc­ture.

e) Objects that have a fine grain structure, are stronger than those which have a coarse grain structure.

f) Mild steel sheet is produced by a cold rolling process. This process changes the grain structure of the steel, causing the grains to become elongated.

g) Mild steel sheet is in a work-hardened state after rolling.

h) Metal pressings are initially in a work-hardened state, and very brittle. They will break easily during usage, if they are not subjected to heat treatment.

i) Stress relieving is done by heating the component to about 500°C, and allowing it to cool. It has the advantage that it is relatively cheap, and that no scale is formed on the metal surface.

j) In the annealing process, the steel component is heated to a higher tem­perature than in the normalizing process, and allowed to cool slowly. This makes the steel as soft and ductile as possible.

154 Answers to exercises

2.

3.

a)

b)

c)

d)

e)

f)

g)

h)

i)

j)

The purpose of heat treating a metal is to improve its properties.

Metals consist of a large number of small crystals interlocked together.

The mechanical properties of metals depend on the size, shape, and ori­entation of the crystals in the metal.

In the sandcasting process, the metal cools slowly, resulting in a casting with a coarse grain structure.

The pressure die casting process produces castings that are accurate, and well finished.

Mild steel sheet is produced by a process, which causes the grains in the metal to become elongated.

Metal components which are produced from mild steel sheet are in a state of stress.

Stress relieving is relatively cheap, because only a small amount of en­ergy is required for this process.

Stress relieving has the further advantage, that the surface is not spoilt by the formation of scale on it.

The annealing process goes further than the normalizing process, and makes the steel as soft and ductile as possible.

a) The heat treatment process improves the mechanical properties of a metal to the extent that the manufacturing process is made easier. In addition, a heat treated metal component is able to withstand rough us­age.

b) The mechanical properties of a metal like hardness, strength, and brit­tleness, depend on the size, shape, and orientation of the crystal grains in it.

c) When a casting is produced, the grain structure of the casting depends on the rate at which it cools when it is solidifying. If the rate of cooling

Answers to exercises 155

is slow, as in a sand casting, the crystal grains are large. On the other hand, if the rate of cooling is rapid, the crystal grains are somewhat smaller.

d) Metals are often in a highly stressed state after the manufacturing proc­ess. This stress must be removed, before the component is put into use. This can be accomplished by heating the component to a temperature of above 500°C, and allowing it to cool.

e) The process of annealing makes a metal as soft and ductile as possible. Here the metal component is heated to about 850°C as in the normaliz­ing process, but allowed to cool at a much slower rate.

156 Answers to exercises

Exercises IX

1.

2.

a) The cheapest way of producing complex metal components is by cast­ing.

b) Forged components are stronger, and less brittle, than cast components.

c) No material is wasted in the forging process, because the entire material is forced into the shape of the final component.

d) Cast iron cannot be forged, because it becomes very brittle, and breaks easily when heated to red heat.

e) A blacksmith produces forged components by using hand tools.

f) Mechanical hammers were used for forging after the beginning of the industrial revolution. They have the advantage of being able to forge large components.

g) Three ways in which a forging can be produced are, hand forging, drop forging, and upset forging.

h) The drop forging process is particularly useful, when a large number of medium-size forgings are required.

i) In the drop fotging process, the red hot metal billet is forced into the cavity between the dies.

j) In the upset forging process, a change in the cross-sectional area of the component is produced.

a) Metal components can be made cheaply, and efficiently, by the casting process.

b) Cast components are usually brittle, and break easily.

c) Forged components are stronger than cast components, or those pro­duced by machining.

Answers to exercises 157

3.

d) Forging is more economical in the use of material, because the metal is forced into shape.

e) Mild steel becomes ductile at high temperatures, and can be forced into the right shape.

t) Forged components were produced in small quantities by blacksmiths.

g) Large mechanical hammers were used to produce large forgings.

h) Two half dies are used in the drop forging process, and the red hot billet is forced into them.

i) Often, several stages of forging are needed, to produce a forged compo­nent.

j) In upset forging, the cross-sectional area of the component is changed.

a) Metal components can be produced more cheaply by casting than by forging. Components produced by casting however are very brittle, and break easily.

b) The process of forging is very economical in the use of material, be­cause the metal is pressed into the form of th(l fmal component, and no metal is wasted.

c) Steel and many metals become ductile at high temperatures, and can be pressed or hammered into the desired form. Cast iron cannot however be forged in this way.

d) The method of drop forging is particularly useful, when a large number of components need to be produced.

e) In this process two half dies are used. The pressure exerted by the upper die, forces the red hot billet into the cavity between the dies.

158 Answers to exercises

Exercises X

1.

a) Carbon steels having a carbon content of about 0.8% to 1.3% can be hardened.

b) Only the working part of a tool is usually hardened.

c) In the hardening process, a tool is heated to a temperature of about 820°C at which temperature it acquires a cherry-red colour.

d) The next stage in the process, is the quenching of the tool in water or oil.

e) The process of removing some of the brittleness is called tempering, and if this is not done, the tool will break easily.

f) Tempering reduces the hardness of the cutting edge of the tool, while increasing its toughness.

g) A hardened object can be tempered by heating it to a temperature of be-tween 230°C and 320°C.

h) When the surface of a hardened object is polished first and then tern-pered, a coloured oxide film is formed on the surface.

i) As the tempering temperature increases, the tool loses hardness, while gaining toughness.

j) Case hardened steel has a hard surface, and a tough interior.

2.

a) Tools made of high carbon steel can be hardened.

b) Only the working part of a chisel, which is its edge, is hardened.

c) The edge of the chisel is heated to a temperature of 820°C, until it be-comes cherry red in colour.

d) The chisel is quenched by plunging into water or oil.

e) The edge of the chisel will be very hard, and also very brittle.

Answers to exercises 159

3.

t) The process of tempering, toughens the edge of the chisel.

g) The colour of the surface film depends on the temperature to which it is heated.

h) As the tempering temperature is increased, the tool loses hardness, while gaining toughness.

i) The surface colour gives a good indication of the properties of the tool after tempering.

j) If mild steel is heated to 820°C, and then immersed in a carbon rich substance, it absorbs carbon on its surface.

a) When a tool like a chisel is hardened, only the working part, which is the edge of the chisel is hardened.

b) The edge of the chisel is heated to about 820°C, at which temperature it acquires a cherry red colour. After this it is immersed in water or oil.

c) The tool is now very hard, but also very brittle .It is necessary to reduce the brittleness, otherwise the chisel will break under normal conditions of use.

d) The process of reducing the brittleness is called tempering. To temper a hardened object, it must be heated to a temperature of between 230°C and 320°C, depending on the material used. The process of tempering makes the tool tougher, and ensures that it does not break under normal conditions of use.

e) It is often an advantage for an object to have a hard outer surface, and a tough interior. A case hardened component has a carbon rich outer sur­face, which can be hardened, while the interior retains its normal tough­ness.

160 Answers to exercises

Exercises XI

1.

2.

a) In rotatory motion, the object is rotating round an axis, or a point.

b)~ In reciprocating motion, the object moves along a straight line in one direction first, and then back along the same straight line, to its starting point.

c) A shaft is usually a cylindrical rod which undergoes a rotatory motion.

d) Bearings are supports in which a shaft is able to rotate.

e) Bronze or white metal are suitable materials for making plain bearings.

f) A split bearing is a plain bearing which is made in two halves.

g) The bearing on the small end of a connecting rod, is a single piece hol­low cylindrical bearing.

h) A ball bearing consists of hardened steel spheres, running between two precision ground hard cylindrical races.

i) The purpose of lubrication is to maintain a thin film of oil between two contact surfaces.

j) Two rotating shafts can be coupled together, by using gear wheels, by using a belt and pulleys, or by using a chain and sprocket wheels.

a) A rotating body is usually rotating round a point or an axis.

b) A body has linear motion when it moves in a straight line in one direc­tion.

c) The support in which a shaft rotates, is called a bearing.

d) The big end bearing of an automobile connecting rod, consists of two thin split bearings.

e) The spheres in a ball bearing are fitted between two cylindrical races.

Answers to exercises 161

3.

t) The process of maintaining a film of oil between two contact surfaces, is called lubrication.

g) Two shafts may be coupled using a belt and two pulleys.

h) The small end bearing on an automobile connecting rod is called a gudgeon pin.

i) The rollers in a roller bearing, are located between an outer cup and an inner cone.

j) Two shafts may be coupled using a chain and two sprocket wheels.

a) When a body has a rotatory motion, it usually rotates round an axis in a clockwise, or an anticlockwise sense. If the motion is linear, the body moves in a straight line.

b) A machine is composed of many parts, some of which are moving. A shaft is a cylindrical rod, which is usually made of steel, and is sup­ported by bearings in which it can rotate.

c) Bearings are usually in the form of plain bearings, ball bearings, or roller bearings. Special alloys are used to make plain bearings, for ex­ample, bronze.

d) Ball bearings are composed of steel balls located between two cylindri­cal races. The lubrication of such bearings is simple, because they only need an occasional application of grease.

e) A rotating shaft has mechanical energy. It is often necessary to transfer this energy to another shaft. This can be done by using two gear wheels, or by using two pulleys and a belt.

162 Answers to exercises

Exercises XII

1.

2.

a) Gears are used to transmit motion from one part of a mechanism to an­other.

b) The ratio of the speeds between two shafts can be changed, by changing the ratio of the number of teeth in the gear wheels. The direction of the axes of rotation can be changed, by using special gears like spiral gears.

c) Spur gears have teeth which are cut parallel to their axes of rotation. They are used to couple parallel shafts.

d) In a bevel gear, the teeth lie on a conical surface, and appear to meet at the apex of a cone.

e) Helical gears are gears whose teeth lie on the surface of a cylinder, and are inclined at an angle to the axis of rotation of the gears.

f) Spur gears are simple and cheap to make, but can only transmit motion between two parallel shafts. Bevel gears are able to transmit motion be­tween two shafts inclined at an angle to each other, but are more expen­sive to make.

g) Helical gears are placed in an oil bath, to minimize wear on their teeth.

h) A rack and pinion is a device, which converts rotatory motion into linear motion.

i) Worm gears are used for heavy duty work, where a large ratio of speeds is required.

j) Gearboxes are used, when several changes in the ratio of the speeds be­tween two shafts are required.

a) Gears transmit motion from one part of a mechanism to another.

b) A spur gear has teeth cut parallel to its axis of rotation.

Answers to exercises 163

3.

c) The larger gear wheel is called the gear, and the smaller gear wheel the pinion.

d) The teeth in a bevel gear lie on a conical surface, and appear to meet at the apex of a cone.

e) The teeth in helical gears are cut on a cylinder, and at an angle with the axis of the cylinder.

f) Helical gears are usually placed in an oil bath, in order that wear may be minimized.

g) A rack and pinion converts rotatory motion into linear motion.

h) Worm gears are used for heavy duty work, where a large ratio of speeds is required.

i) Helical gears are quieter, and smoother in operation, than spur gears.

j) When two gears mesh together, the ratio ofthe speeds of the shafts, de­pends on the ratio of the number of teeth in the gears.

a) A gear wheel when coupled with other gear wheels, transmits motion from one part of a mechanism to another.

b) In helical gears, the friction, and the resulting heat and wear generated, are greater than with other drives. These are often placed in an oil bath in order to reduce wear.

c) In a bevel gear, the teeth are cut in such a way, that they lie on a conical surface, and appear to meet at the apex of a cone.

d) The teeth of a helical gear are cut on a helical cylinder, at an angle to the axis of the drive. Helical gears are quieter, and run more smoothly,

than spur gears.

e) When two gears which are attached to two shafts are coupled together, the ratio of the speeds of the shafts, depends on the ratio of the number of the teeth on both gear wheels.

164 Answers to exercises

Exercises Xlli

1.

2.

a) Screws are used for fastening metal and other types of components.

b) A screw thread is a ridge in the form of a spiral, on the surface of a cyl­inder or a cone.

c) There are many types of screw threads, each designed for a particular type of work.

d) The pitch is the distance from a point on a screw thread, to a corresponding point on the next thread, measured parallel to the axis of the screw.

e) The lead ofthe screw, is the distance advanced by the screw, when it is rotated by one revolution. The lead is equal to the pitch multiplied by an integral number.

f) This is the distance measured radially over which a mating male and fe­male thread overlap.

g) The major diameter is the largest diameter of the screw thread, and the minor diameter is the smallest diameter of the screw thread.

h) Threads may be produced by cutting, by rolling, or by grinding.

i) Machine tools have tapered holes in their spindles, so that tapered shanks of small tools like drills, can be fitted into them.

j) The angle of a thread, is the angle between the two inclined faces of the thread.

a) Screws are commonly used for fastening metal components.

b) A screw thread is in the form of a spiral on the surface of a cylinder, or a cone.

c) There are many types of screw threads, each suitable for a different kind of work.

Answers to exercises 165

3.

d) The pitch is the distance from a point on a screw thread, to the corre-

sponding point on ,the next screw thread.

e) The lead is the distance advanced by the screw in one revolution.

f) In a double thread screw, the lead is twice the pitch.

g) The major diameter is the largest diameter of the screw thread, and the

minor diameter is the smallest diameter of the screw thread.

h) Screw threads can be cut using taps and dies, or by using a lathe.

i) Most machine tools have revolving spindles, which have tapered holes

in them.

j) The taper on the inside of a spindle matches exactly, the taper on the

outside of the tool which is fitted into the spindle.

a) An external screw thread is cut on the outside of a cylinder, while an in­

ternal screw thread is cut on the inside of a hole, like a nut.

b) There are many types of screws threads, each suitable for a particular type of work. Each screw thread is made to a definite specification, and has a special name, for example, a metric screw thread.

c) The pitch, is the distance between a point on a screw thread, to the cor­responding point on the next thread. The lead, is the distance by which the screw advances, when it is rotated through one revolution.

d) In a single thread screw, the pitch and the lead are the same. In a double

thread screw, the lead is double the pitch.

e) Most machine tools have revolving spindles with tapered holes in them, into which the tapered shanks of drills can be fitted. The taper on the

tool, matches exactly the taper on the inside of the spindle.

166 Answers to exercises

Exercises XIV

1.

2.

a) It is difficult to drill the right size of hole in the right place, because a drill usually produces too large a hole, and also because the positioning of the hole is difficult.

b) A compound table is a table which has movements at right angles to each other. The work is moved using the lead screws on the compound table, until the position of the hole is precisely located under the drilling head, after which the drilling is done.

c) A centre drill, is a short stiff drill, with a short pointed part which does not bend easily.

d) The different parts of a drill are the body, the shank, and the tang.

e) Small drills are held in a self-centering chuck.

f) Large drills are inserted into the spindle of the machine.

g) A sleeve is used, when it is necessary to use a drill with a small shank, in a machine with a large hole in its spindle.

h) A drift is a tool used to remove drills from the spifidle of a machine.

i) A reamer is used to finish a hole accurately to size.

j) Counterboring opens the end of a hole cylindrically, while countersink­ing opens the end of a hole conically.

a) The accurate drilling of a hole of the right size at the right location, can be difficult.

b) A compound table has two movements at right angles to each other.

c) A centre drill is first used to start a new hole.

d) A twist drill is made from a cylindrical piece of steel, and has got spiral grooves.

Answers to exercises 167

3.

e) Small drills have straight shanks, and are held in a self-centering chuck.

f) Larger drills have tapered shanks, and are fitted directly into the spindle of the drilling machine.

g) A tool which is used to remove a drill from a spindle is called a drift.

h) A hole can be finished precisely to the required size, by using a reamer.

i) Counterboring is the process of enlarging the end of a hole cylindrically.

j) Countersinking generates a cone shaped enlargement of the end of a hole, into which the head of a countersunk screw can fit.

a) Although drilling a hole appears to be a simple operation, the accurate drilling of a hole of the right size, and in the right place, can be very difficult. A large variety of machines, and tools, have been developed for the drilling of holes.

b) A drill is usually made from a cylindrical piece of HSS steel, and has spiral grooves. At the beginning of the drilling process, a centre drill is used to drill a small hole. Then a twist drill is used to drill the hole to the right size.

c) Small drills have cylindrical shanks, and are held in a self-centering chuck. Larger drills have tapered shanks, which enable them to be in­serted quickly into the spindle of a machine.

d) Not all tapered drills have shafts of the same size. When it is necessary to fit a drill with a small shaft into a spindle with a large hole, a sleeve is inserted between the shaft and the spindle.

e) A drill does not produce an accurately sized hole in a metal. The inside surface of the hole is rough, and is slightly oversize. This difficulty can be overcome by drilling the hole slightly undersize, and finishing the hole with a reamer.

168 Answers to exercises

Exercises XV

1.

2.

a) Many types of metal cutting machines, like lathes, and shaping ma­chines, use single point metal cutting tools.

b) The pointed part of the tool acts as a wedge which presses on the body of the metal, and tears off a chip when the metal moves relative to the tool.

c) For efficient metal cutting, the tools should be made of the right mate­rial, and have the correct cutting angles ground on their tips.

d) The important angles on a lathe tool are, the top rake angle, the side rake angle, the front clearance angle, and the side clearance angle.

e) Clearance angles are necessary to ensure that, only the edge of the tool touches the work.

f) If the angles on a tool are incorrect, more heat is generated, tool wear is increased, and the surface finish of the work is made worse.

g) The use of a cutting fluid reduces the heat generated during the cutting process, and thus increases the life of the tool.

h) Water soluble oils are cheap and efficient coolants, but do not have good lubricating properties.

i) Water soluble coolants are unsuitable for complex operations such as gear cutting.

j) Carbide tipped tools are very hard, and will maintain a sharp edge under conditions which cause ordinary tools to bum away.

a) Many metal cutting machines like lathes, and shaping machines, use single point cutting tools.

b) It is absolutely essential that the cutting angles on a tool are correct.

Answers to exercises 169

3.

c) The cutting action in which metal chips are removed, is similar to the action of a chisel.

d) The pointed part of the tool is like a wedge which presses heavily on the metal, and tears off a chip.

e) Clearance angles are necessary to ensure, that only the edge of the tool touches the work.

f) Changing tool angles has an effect on the heat generated, and on tool wear.

g) When fast spindle speeds are used, a small amount of cutting fluid is pumped over the cutting edge of the tool.

h) The cutting fluid helps to remove chips from the edge of the tool, and improves surface finish.

i) Water soluble oils are cheap and efficient coolants, and are suitable for the machining of most steel components.

j) Water soluble coolants do not have good lubrication properties, and are unsuitable for gear cutting.

a) The cutting process by which metal chips are removed from a metal, is similar to the action of a chisel.

b) For efficient metal cutting, it is absolutely necessary that the tools are made of the right material, and have the right cutting angles. The cutting angles are different for different materials, on which cutting has to be done.

c) Clearance angles are necessary to ensure that, only the edge of the tool touches the work. If there was no clearance angle, the tool would not cut, but only rub on the work.

d) The use of a coolant, reduces the heat produced during the cutting proc­ess, and this increases the life of the tool. The coolant also helps to re­move metal chips, from the cutting edge of the tool.

170 Answers to exercises

e) Water soluble oils are cheap and efficient coolants, and are suitable for machining most steel components. However they do not have good lu­bricating properties, and are unsuitable for complicated machining op­erations, like gear cutting.

Answers to exercises 171

Exercises XVI

1.

2.

a) Engineering inspection is important, because it is necessary to check whether manufactured components have the right dimensions.

b) Variations in dimensions must be kept within strict limits, to ensure the interchangeability of parts.

c) Nominal dimensions are the dimensions given on the drawing of the component.

d) The deviation from a nominal dimension is called a tolerance, and this is necessary, because it is impossible to produce a large number of components, having precisely the dimensions given in the drawing.

e) The two limits between which the dimensions of a component lie, are called the low limit, and the high limit.

f) In a clearance fit, a shaft must be able to move freely in a hole, without being loose in it.

g) When the allowed deviation or tolerance is only above, or only below, the nominal dimension, then it is called a unilateral tolerance. If the de­viation can be on both sides of the nominal dimension, then it is called a bilateral tolerance.

h) The engineering allowance is the difference in dimensions between the high limit of the shaft, and the low limit of the hole.

i) Allowances and tolerances must be kept as large as possible, otherwise the number of rejected components will be high, and this will increase the manufacturing cost.

j) An interference fit occurs when a shaft is slightly larger than a hole, and can only be forced into the hole under pressure.

a) Engineering inspection is an essential part of all manufacturing, but it is not usually possible to inspect every component.

172 Answers to exercises

3.

b) Small deviations in dimensions must be kept within strict limits.

c) Limits are necessary to ensure that components are interchangeable.

d) The dimensions of a component given in the drawing, are called nomi­nal dimensions.

e) It is impossible to produce components, which have precisely the di­mensions stated in the drawing.

f) A certain amount of deviation from the nominal dimensions must be al­lowed, and this is called a tolerance.

g) In a clearance fit, the shaft must be able to move freely in a hole, with­out being too loose in it.

h) The engineering allowance, is the difference between the high limit of the shaft, and the low limit of the hole.

i) Small tolerances, increase the cost of manufacture, and also the number of rejected components.

j) If the shaft is made slightly larger than the hole, pressure is required to force the shaft into the hole.

a) Although engineering inspection is an essential part of engineering pro­duction, it is not possible to inspect every manufactured component.

b) When a component is designed, it is given certain dimensions on the drawing which are called nominal dimensions. However it is not possi­ble to manufacture a large number of components, that have precisely the dimensions given on the drawing.

c) For this reason, a definite deviation from a nominal dimension is al­lowed, and this is called a tolerance. When a component is manufac­tured, each dimension must lie between two values, called the high and low limits.

d) For a shaft to be able to enter a hole, there must be a small difference between the upper limit of the shaft, and the lower limit of the hole. This difference is called an allowance.

Answers to exercises 173

e) In general tolerances must be kept as large as possible. Small tolerances increase the manufacturing costs, and also the number of rejected com­ponents.

174 Answers to exercises

Exercises XVII

1.

2.

a) A lathe can be used for machining cylindrical and conical surfaces, and also for cutting screw threads.

b) The accuracy of the work done on a lathe, depends on the accuracy of the lathe itself, and also on the skill and accuracy of the operator.

c) A lathe is unsuitable for production work, because a lot of time is taken for tool setting, tool changing, etc.

d) It is mainly used for the making of prototypes, and in maintenance

work.

e) The main parts of the lathe are the bed, the headstock, the tail stock, and

the carriage.

f) The headstock has a strong spindle which is driven by an electric motor through a gearbox.

g) The work is usually held in a chuck.

h) The purpose of the tool post is to hold the cutting tools, and it is fixed to the carriage.

i) Capstan and turret lathes have the same headstock and fourway toolpost as ordinary lathes. The tailstock is however replaced by a hexagonal

turret.

j) Each face of a hexagonal turret holds tools which are used successively, to perform different operations in a regular sequence.

a) Lathes can produce components that are symmetrical about an axis.

b) The accuracy of the work done on a lathe, depends on the skill and ex­perience of the operator.

c) The ordinary lathe is not suitable for production work, because a lot of time is spent on tool setting.

Answers to exercises 175

3.

d) It is only used in tool rooms and workshops for the making of proto­types and for maintenance work.

e) The lathe has a rigid bed, on which are mounted a fixed headstock, and a movable tailstock.

t) The speed of the spindle can be varied through a wide range.

g) The work to be machined is held in a chuck.

h) The work is turned down to the desired dimensions.

i) The carriage can move along the guideways of the bed, in a direction parallel to the axis of rotation of the headstock spindle.

j) The headstock contains a strong spindle, driven by an electric motor through a gearbox.

a) A lathe can be used to turn cylindrical surfaces both external and inter­nal, and also to turn conical surfaces. An additional feature of the lathe, is its ability to cut screw threads on a cylindrical surface.

b) The accuracy of the work done on a lathe depends on the skill and expe­rience of the operator. A lot of time is required for tool setting and tool changing, with the result that this type of work is not suitable for production.

c) The lathe has a rigid bed with parallel guideways, on which are mounted a fixed headstock, and a movable tailstock. In addition, it has a carriage which can be moved along the guideways, in a direction parallel to the axis of rotation of the spindle.

d) The headstock has a strong spindle, which is driven by an electric motor through a gearbox. The speed of rotation of the spindle can be varied through a wide range, to suit the work that has to be machined.

e) The work that has to be machined must be held in a device called a chuck, which is fitted to the front end of the spindle. When the spindle rotates, the work rotates with it, and can be turned down to the desired dimensions, using single point tools which are held in a tool post.

176 Answers to exercises

Exercises XVIII

1.

2.

a) A planer is primarily used to produce plane surfaces.

b) In a shaper, the work is fixed on a table, and the metal is removed by a single point metal cutting tool.

c) The time taken for the return stroke is reduced by using a quick return mechanism. The reason for doing this is to reduce the machining thne.

d) Shapers can generate flat, horizontal, vertical, or inclined surfaces. They can also generate contoured surfaces.

e) Very heavy workpieces cannot be machined on a shaper.

f) The tool in a shaper performs a reciprocating motion.

g) The fundamental difference between a shaper and a planer, is that in a shaper, the work is fixed and the tool moves, while in a planer, the tool is fixed and the work moves.

h) The most widely used type of planer is the double housing planer.

i) The rigidity of a double housing planer is ensured, by joining the two housings at the top by a cast iron member.

j) The table of the planer may be driven mechanically or hydraulically.

a) A shaper is used to produce flat surfaces.

b) In a shaper, the work is fixed on a table, and metal is removed from its surface by a single point metal cutting tool.

c) Metal is removed only during the forward cutting stroke, and not during the return stroke.

d) The time taken by the return stroke is reduced by using a quick return mechanism.

Answers to exercises 177

3.

e) A machine tool like a shaper, is used primarily to produce plane sur­faces.

f) A planer is large compared with a shaper, and is capable of machining heavy workpieces.

g) In a planer the tool is fixed, while the work performs a reciprocating motion.

h) There are many types of planers, of which the double housing planer is the most commonly used.

i) The two vertical housings are joined by a cast iron member, to ensure stability.

j) There are two more tool heads mounted on the vertical faces of the housings.

a) In a shaper, the work is fixed on a table, and is machined using a single point cutting tool. Metal is removed during the forward stroke, and no metal is removed during the backward stroke.

b) To reduce the machining time, it is necessary to reduce the time taken by the return stroke. This is ensured, by using a quick return mechanism.

c) The shaper is chiefly used to produce flat surfaces. The surfaces can be vertical, horizontal, or inclined. In addition, it can be used for producing slots, gear wheels, and irregular surfaces, using specially shaped tools.

d) A planer is used like a shaper, to produce flat surfaces. A planer is large and massive in comparison with a shaper and is able to machine work­pieces which are too heavy to be fixed on the work table of a shaper.

e) The fundamental difference between the shaper and the planer, is that in a shaper, the work is fixed and the tool moves, while in a planer, the tool is fixed and the work moves.

178 Answers to exercises

Exercises XIX

1.

2.

a) Lathes use single point cutting tools, while milling machines use mul­tipoint cutting tools.

b) The multipoint cutting tools used in milling machines, achieve fast rates of metal removal, and also produce a good surface finish.

c) Ordinary milling machines have three independent movements, longi­tudinal, transverse, and vertical.

d) Ordinary milling machines lack the rigidity required for heavy produc­tion work.

e) A horizontal milling machine receives its power from a motor, through belts, gears, and clutches.

f) On a horizontal milling machine, milling cutters are mounted on the ar­bor of the machine.

g) The vertical milling machine has a column and knee like a horizontal milling machine, but has a spindle which is vertical, and can be swiv­elled through an angle.

h) In a universal milling machine, the table can be swivelled, and moved at an angle to the milling machine spindle.

i) Accessories like dividing heads, vertical milling attachments, rotary ta­bles, etc. can be fitted to a universal machine.

j) These accessories enable the machine to produce gears, twist drills, milling cutters, etc.

a) Milling machines use single point cutting tools, and not multipoint cut­ting tools.

b) The work table has three movements, longitudinal, transverse, and vertical.

Answers to exercises 179

3.

c) Ordinary milling machines lack the rigidity required for heavy duty work.

d) The use of multipoint cutting tools, enables the machine to achieve fast rates of metal removal.

e) The spindle just projects out of the column face, and has a tapered hole in it.

f) Cutting tools and arbors, can be fitted into the hole in the machine spin­dle.

g) The overhanging arm mounted on the top of the column acts as a bear­ing support for the arbor.

h) The spindle receives power from the motor, through belts, gears, and clutches.

i) In a vertical milling machine, the head may be swivelled at an angle.

j) Milling machines are fitted with accessories like dividing heads, and ro­tary tables.

a) The use of multipoint cutting tools, enables the milling machine to achieve high cutting rates and also produce a good surface finish.

b) These machines are extremely versatile, and have three independent ta­ble movements, longitudinal, transverse, and vertical. They are used in workshops, but lack the stability required for heavy production work.

c) A horizontal milling machine has a horizontal spindle, which receives its power from a motor, through belts, gears, and clutches.

d) The spindle has a tapered hole, into which various cutting tools and ar­bors, can be inserted. The arbor is an extension of the machine spindle, and milling cutters can be mounted on it.

e) In the vertical milling machine, the spindle head is perpendicular to the work table. The spindle head can also be inclined at an angle, permitting the milling of angular surfaces.

180 Answers to exercises

Exercises XX

1.

2.

a) In the process of grinding, metal is removed from a metal surface, by a rotating abrasive wheel.

b) Grinding produces high dimensional accuracy, and a good surface finish.

c) Very little metal is removed from a surface by grinding.

d) Grinding is the only method that can be used to machine materials, that are too hard to be machined by other methods.

e) The different grinding methods available are, external and internal cy­lindrical grinding, surface grinding, and form grinding.

f) In external cylindrical grinding, the workpiece is rotated about its own axis, while it moves lengthwise in contact with a revolving grinding wheel.

g) In internal cylindrical grinding, the workpiece is rotated about its own axis, whilst the cylindrical grinding wheel rotates against the direction of rotation of the workpiece.

h) Surface grinding may be done, by using the periphery, or the end face of the grinding wheel.

i) Form grinding is used to accurately finish surfaces, that have already been machined to a special shape.

j) Aluminium oxide grinding wheels are used to grind materials of high tensile strength.

a) Grinding is a finishing operation which gives high dimensional accuracy to workpieces.

Answers to exercises 181

3.

b) Very little metal is removed from the surface in a grinding operation.

c) Surfaces which are too hard to be machined by other methods, can be machined by grinding.

d) External cylindrical grinding is used to produce cylindrical or tapered surfaces.

e) Internal cylindrical grinding is used to produce cylindrical holes, or internal tapers, on a workpiece.

f) In surface grinding, the periphery or the end face of the grinding wheel maybe used.

g) Form grinding is done with specially shaped grinding wheels to accu­rately grind surfaces which have already been machined.

h) In the centreless grinding method, the workpieces are not held and ro­tated between centres.

i) Aluminium oxide wheels are better suited for grinding materials of high tensile strength.

j) The abrasives used in grinding wheels are small grains of silicon carbide or aluminium oxide.

a) Grinding is an operation which is done using a rotating grinding wheel, and which removes metal from the surface of a workpiece.

b) Grinding is normally a finishing process, which gives high dimensional accuracy, and a good surface finish, to workpieces which have been ma­chined by other methods.

c) Materials which are too hard to be machined by other methods, can be machined by grinding. Only a small amount of metal is removed in a grinding operation.

d) External cylindrical grinding is used to produce a cylindrical or tapered surface, on the outside of a workpiece. The surface grinding process is used to generate flat surfaces, using the end face, or the periphery of the grinding wheel.

182 Answers to exercises

e) The abrasives used in grinding wheels, are small grains of silicon car­

bide or aluminium oxide. Grinding wheels are made by using a suitable

material to bond the abrasive particles together.

Answers to exercises 183

Exercises XXI

1.

2.

a) Automatic lathes are used for the production of a large number of identical components.

b) In the past, small batches of components were produced by the use of conventional machines, and skilled labour.

c) The disadvantages of the previous methods of production, were the low machine utilization time, and the high cost of production.

d) In flexible automation, a machine produces components automatically, in accordance with predetermined instructions. Only the instructions need to be changed, when another component has to be manufactured.

e) CNC machines have electrical drives which are controlled by a com­puter, unlike ordinary machines which have drives controlled by a skilled operator.

f) The machine utilization time is high, because the waiting time required for resetting the machine is small.

g) When a new batch of components has to be produced, only a change in the computer program is necessary.

h) The skill of the operator is unimportant, because the accuracy is only dependent on the accuracy of the machine and the program.

i) Each tool is held in an adaptor and stored in a magazine. The required tool is selected from a magazine, and is used to replace the one already in the machine.

j) Minimization of wear is achieved, by using rolling components, instead of sliding components.

a) Automatic lathes are used for the production of a large number of identical components.

184 Answers to exercises

3.

b) A new development has been the use of numerically controlled ma­chines for small batch production.

c) Previously, small batch production was achieved using skilled labour,

and conventional machine tools.

d) This resulted in a low machine utilization time, and a high cost of pro­

duction.

e) The operation of a CNC machine is controlled by a computer program.

f) Special tooling, like jigs and fixtures, are not required when a CNC ma­chine is used.

g) Minimization of wear in CNC machines is achieved, by using rolling components, instead of sliding components.

h) Measuring instruments give a continuous indication of the position of the cutting tool.

i) The correct tool for a particular operation is selected automatically from a magazine.

j) The massive construction of the machines, gives them the stability needed, to withstand large cutting forces.

a) Single and multispindle automatic lathes have found their greatest application, where a large number of identical components have to be

produced. A new development has been the use of computer controlled

machines, for the production of small batches of components.

b) In the past, small and large batches were produced on conventional ma­chines, using highly skilled labour. This resulted in a low machine utili­zation time, a long waiting time, and high production costs.

c) The operation of a CNC machine tool is controlled by a computer. Ma­chine tools which are used in this type of work, do not have the normal movements and drives used by conventional machines.

d) CNC machines do not need to be set up by a highly skilled operator. Only a change in the computer program is necessary to produce a new

Answers to exercises 185

batch of components. The flexibility of the system results in high ma­chine utilization times.

e) The machines are of massive construction. This gives them the stability needed to withstand large cutting forces, and the thermal effects caused by the large quantities of chips produced.

186 Answers to exercises

Exercises XXII

1.

2.

a) In an internal combustion engine, the fuel is burnt inside the engine, while in an external combustion engine, the fuel is burnt outside the en­gine.

b) The chemical energy of the fuel is converted into heat energy, and part of the heat energy is converted into mechanical energy by the engine.

c) A petrol engine has four strokes.

d) The connecting rod and the crankshaft, have the function of changing the reciprocating motion of the piston, into the rotatory motion of the crankshaft.

e) The power stroke is the only stroke in which the engine extracts energy from the fuel.

t) The four strokes of the Otto cycle are called induction, compression, ig­nition, and exhaust.

g) In the induction stroke, the inlet valve opens, and the piston moves downward. This creates a partial vacuum, that sucks in the petrol-air mixture into the cylinder, through the open inlet valve.

h) The flywheel stores the energy generated during the power stroke, and uses this energy to move the crankshaft, connecting rod, and pistons, through the other three strokes.

i) The chief difference between the two engines, lies in the different meth­ods used for introducing fuel into the cylinder, and for burning fuel in the cylinder.

j) Multicylinder engines run more smoothly and silently, than single cylinder engines.

a) In an internal combustion engine, the fuel is burnt inside the engine.

Answt<rs to exercises 187

3.

b) The chemical energy of the fuel is converted into heat energy, and part

of this energy is converted into mechanical energy by the engine.

c) The valves can be opened or closed, to allow a petrol-air mixture to en­ter or leave the cylinder.

d) The connecting rod and the crankshaft enable the reciprocating motion

of the piston to be converted into rotatory motion.

e) During the power stroke, the engine extracts energy from the fuel.

f) During the induction stroke, the inlet valve opens, and the piston moves

downward.

g) During the compression stroke, both valves remain closed, and the pis­ton moves upwards, compressing the petrol-air mixture.

h) The sprocket wheel drives the camshaft through a chain drive.

i) The difference between a petrol and a diesel engine, lies in the different methods used for introducing and burning fuel in the cylinder.

j) Diesel engines have a higher thermal efficiency than petrol engines, and

therefore consume less fuel.

a) The petrol engine and the diesel engine, are both combustion engines in which the fuel is burnt inside the engine.The chemical energy of the fuel is first converted into heat energy by combustion, and then into me­chanical energy by the engine.

b) Most petrol engines are based on the Otto four stroke principle, in

which a mixture of petrol and air is first compressed, and then ignited.

c) The petrol engine has a cylinder with a tight fitting piston, which can

undergo an up and down motion. In the head ofthe cylinder, there is an

inlet and an outlet valve.These valves can be opened or closed to allow

a petrol-air mixture, to enter or leave the cylinder.

d) In a four stroke process, the movement of the piston takes place in four stages, two upwards, and two downwards. These four strokes are called

188 Answers to exercises

induction, compression, ignition, and exhaust. Energy is extracted from the fuel, only during the ignition stroke.

e) The petrol engine and the diesel engine are similar, as far as their me­chanical components are concerned. The main difference between the engines, lies in the methods used for introducing the fuel into the engine, and for burning the fuel.

189

Vocabulary

ability Fiihigkeit f angular winkelf<irmig adj

abrasion Abrieb m, Abnutzungf anneal ausglilhen, anlassen v

abrasive Schleifmittel n anticlockwise im Gegenuhrzeigersinn

abrasive wheel Schleifscheibe f appears erscheinen v

absolutely vollkommen adv application Anwendung/

accessible zuganglich adj arbor Fraserdom m

accessory ZubehOrteil n arc Lichtbogen m

accomplish ausfiihren v asphalt Asphaltm

accordance Obereinstimmungf associated verbunden adj

accuracy Genauigkeit/ attachment Zusatzgerat n

accurate genau adj automatic automatisch adj

achieve leisten v automation Automation/

acid Sauref awkward schwer zuganglich adj

acquire erwerben v axis Achsef

action Proze6 m backlash Flankenspiel n

adaptor Aufnehmerm balance Gleichgewicht n

adopt annehmen v based on begriindet auf v

advanced fortgeschritten adj batch Menge, Losgro6e f

advantage Vorteil m bead Bordeln, Falzen v

aim richten v bearing Lagern

aircraft fuselage Flugzeugrumpf m bed Bett n

alignment Ausrichtungf belt Riemenm

allowance Spieln bend Biegen v

alloy Legierungf bevel gear Kegelrad n

although obwohl cj bilateral zweiseitig adj

amongst unter pr billet Knilppelm

angle Winkelm blacksmith Schmiedm

190 Vocabulary

blow Schlagm coke Koksm

bolt Schraubef column Siiulef

braze hartloten v combustion Verbrennungj

briefly kurzadv commonly gewohnlich adj

brittle sprod~:; adj compare vergleichen v

bum verbrennen v compensate kompensieren v

bush Lagerbuchse f completely vollstiindig adv

camshaft Nockenwellef complex komplexadj

capable flihig adj component Bestandteil m

carbon steel Kohlenstoffstahl m composed of zusammengesetzt aus v

carburettor Vergaserm composite zusammengesetzt adj

carriage Werkzeugschlitten m compound Verbindungf

case harden einsatzhiirten v compress zusammendriicken v

cast iron GuBeisenn concerned betroffen adj

casting GuBm condition Voraussetzungj

cause verursachen v cone Kegelm

chain Kettef conical kegelf<irmig adj

change wechseln v connecting rod Pleuelstange f character Eigenartf consider iiberlegen, betrachten v

cheap billig adj construction Anlage/

chemical change chemische Reaktionf contain enthalten v

chisel MeiBelm continuous stiindig adj

chromium Chromn contour Konturj

chuck Futter n conventional herkommlich adj

clamp Klemme/ conversion Umsetungf

clean reinigen v convert umwandeln v

clearance Spielraum m, Spiel n coolant Kiihlschmiermittel n

clearance angle Freiwinkel m copper Kupfern

clockwise im Uhrzeigersinn corresponding entsprechend adj

clutch Kupplungf corrosive korrodierend, iitzbar adj

coating Schichtf cost-effective kostengiinstig adj

Vocabulary 191

counterbore Zylindrische Senkungf difficult schweradj

countersink Kegel Senkungf dimension MaBn

countersunk screw Senkschraube f direction Richtungf

coupling Kupplungf discuss besprechen v

crank Kurbelf disintegration Aufspaltungf

crankshaft Kurbelwellef distance Entfemungf

create erzeugen v dividing head Universal Teilkopf m

cross member Quertriiger m dowel pin Diibelm

cross rail Querschiene f drawing technische Zeichnungf

crumble kriimeln v drift Austreiber m

crystal grain Mikrokristall n drill Bohrerm

cut schneiden v drilling bohren v

cutting schneidend, scharf adj, drive treiben v

Schneidenn drop forging Gesenkschmieden n

cylinder Zylinderm drum Trommelf

eylinderblock Zylinderblock m ductile duktil, dehnbar adj

damage schaden v economical sparsamadj

definite bestimmt adj efficiency Leistungsflihigkeitf

depend abhiingen v efficient leistungsflihig adj

depth Tiefej electrochemical elektrochemischer Vor-

description Beschreibung f process gangm

design entwerfen v electrolyte Elektrolyt n

determine bestimmen,entschei- eliminate aussondem, ausschei-

den v den v

development Entwicklungf enable ermoglichen v

deviation Abweichungf encounter begegnen v

device Geriit n energy Energief

dial gauge MeBuhrf engine Motorm

die Schneideisen n engine head Zylinderkopf m

die casting SpritzguBm enormous enorm adj

difference Unterschied m ensure sichem, sicherstellen v

192 Vocabulary

equipment Ausriistung, Einrich- fon:e into einpressen, hineintrei-

tungf benv

essential wesentlich adj form Fonnj

estimation Schlitzungj formed tool ProfilmeiBel m

exaetly genauadj fourway toolpost Vierfachhalter m

example Beispieln freely zwanglos adv

excessive iibermliBig adj friction Reibungf

exist existieren v fuel pump Benzinpumpef

experience Erfahrungf fundamental grundlegend adj

extensive umfassend adj galvanic action galvanischer Vorgang m

extent AusmaB n, GroBef gasket Dichtungj

external liuBerlich adj gearwheel Zahnradn

extract ausscheiden v generate erzeugen v

extremely sehradj glass fibre Glasfaserj

fast schnell adj granule Granulatn

fasten befestigen v grease Fettn

feature Eigenschaftj grind schleifen v

ferrous eisenhaltig adj grip greifen v

filler Fiiller m groove Nutj

finished component Fertigteil n, Fertigwaref guideways Bettfiihrungen pi

finishing operation Endverfahren n guillotine Guillotine f

fiXture Vorrichtung n, feste half (pl. halves) Hlilftej

Anlagef hardness Hlirtef

flanging bOrdeln v hardwearing widerstandsflihig adj

flat flach adj headstock Spindelstock m

flexible beweglich adj heat Hitze, Wlirme f fluid Fliissigkeitj heavy schweradj

Oute Spannutf helical gears Zahnrlider mit

flux FluBmittel n Schrligverzahnung n

flywheel Schwungrad n hexagonal sechseckig adj

hollow hohladj

Vocabulary 193

identical identisch adj knowledge Kenntnis f, Wissen n

ignite entziinden v lack mangeln, fehlen v

immerse tauchen v lathe Drehmaschine f

important wichtigadj lead Blein

impossible unmoglich adj Ieadscrew Leitspindel f

improve verbessem v linear linear adj

inclined face schiefe Ebene f lubrication Schmieren n

increase zunehmen v machining allowance Bearbeitungszugabe f

independent unabhiingig adj machining centre Bearbeitungszentrum n

indication Anzeigef maintain erhalten v

induction Einfiihrungf maintenance Instandhaltungf

inhibitor Inhibitor m major diameter Nenndurchmesser m

inspect priifen v manufacture Herstellungf

instruction Befehl m mass produce serienmiiBig herstellen v

interchangeable auswechselbar adj massive massiv adj

interfere iiberlagem v match anpassen v

interlock ineinandergreifen v material Stoffm

internal innerlich adj measurement Messungf

introduce einfiihren v mechanism Mechanismus m

involve verwickeln v mention erwiihnen v

iron Eisenn metal chips Metallspiine m

iron ore Eisenerzn method Methode/

irregular unregelmiiBig adj micrometer MeBschraube f

jennying machine Kantenbearbeitungsma- mild steel Baustahl m

schinef milling machine Friismaschine f

jig feste Anlage, Vorrich- minimum Minimumn

tung/ minor diameter Kemdurchmesser m

join verbinden v mixture Mischungf

joint Verbindungf molten metal fliissiges Metall n

key Keilm motion Bewegungf

keyway Nutf mould GieBforrnf

knee Konsolef, Knie n

194 Vocabulary

movement Bewegungf permanent dauemdadj

multipoint cutting Werkzeug mit mehreren permit erlauben v

tool Schneidenn petrol Benzinn

multipurpose mehrzweck- adj pinion Ritzeln

necessary notwendig adj pipe Rohrn

nitrocellulose Nitrocellulose f pitch of a screw Steigungf

noise Geriiusch n planer Hobelmaschine f nominal dimension NennmaBn plant Anlage/

normalize normalgliihen v pliers Zangef

nozzle Diisef polish polieren v

numerical control Numerische Steuerungf polluting medium verschmutzendes Medi-

numerous zahlreich adj umn

nut Mutter/ polycrystalline vielkristallin adj

object Gegenstand m popular beliebt adj

offset screwdriver Winkelschrauben- pour gieBen v

zieherm power Kraft/

often oft adj practice ausfiihren v

operation Verfahrenn practice Gewohnheit f

orientation Orientierungf precise genauadj

outlet valve AuBlaBventil n precisely priizise adv

overhanging arm Gegenhalter m precision Genauigkeit f

overlap iibergreifen v predetermine vorherbestimmen v

oxy-acetylene Acetylen-Sauerstoff m predictable voraussagbar adj

paint Farbef press Pressef

part Teiln press pressen v

particularly besonders adj pressure Druckm

pasty teigig adj previous vorheradj

pattern Mustern primarily hauptsiichlich adv

penetrate durchdringen v probably wahrscheinlich

perform leisten v process Vorgangm

periphery Randm produce herstellen v

Vocabulary 195

production Herstellungf repair reparieren v

profile Profil n repeat wiederholen v

projection vorspringender Teil m replace ersetzen v

prototype Mustern require erfordem v

punch Stanzwerkzeug n reservoir Reservoir n

purpose Zweckm resin Harzn

push schieben v resistance Widerstand m

quantity GrllBef return zuriickkehren v

quench abschrecken v revolution Umdrehungf

quiet ruhigadj revolving sich drehend adj

rack Zahnstange f ridge .Kammm

rack and pinion Zahnstangengetriebe n rigidity Stabilitlit j

radial radial adj rivet Nietef

rake angle Spanwinkel m rod Rundstabm

range Reihe j. Bereich m roUer Walze, Rollef

rapid schnell adj rotary table Maschinenschraubstock,

rate Rate/. MaBn urn 360° drehbar m

ratio Verhliltnisn rotatory drehbeweglich adj

reamer Reibahlef rough raub adj.

reaming reiben v rub reiben v

reciprocating pendelnde Bewegungf mst Rostm

motion sand casting SandguBm

recirculating umlaufend adj screw Schraubef

recondition iiberholen v screw thread Gewinden

reduce vermindem, reduzieren securely sicheradv

v select auswiihlen v

regulate regeln v self-centering chuck Dreibackenfutter n

reinforced concrete Eisenbeton m semi-skiUed angelemt adj

reject ausscheiden v sequence Reihenfolgef

relieve entlasten, entspannen v serve dienen v

remarkable bemerkenswert adj set screw Stellschraube f remove abtrennen v

196 Vocabulary

setting-up Einstellungf stability Stabilitiit f

severe streng adj stage Phase/

shape Form/ standard Norm/

shaper StoBmaschine f steel Stahlm

shaping machine Hobelmaschine f strand Strangm

shear scheren v strength Starke, Stabilitiit/

shears (snips) Scheref stress Spannung,Beanspru-

sheet Blechn chungf

ship's hull Schiffsrumpf m strict streng adj

shock Sto6m strip abziehen v

sideways seitwarts adv stroke Hubm

similar iihnlich adj structure Strukturf

single point tool SchneidmeiBel m stud Stiftschraube f

size GroBe/ sturdy stark adj

skill Geschicklichkeitf successively hintereinander adv

sleeve Muffe/ sufficient genug, ausreichend adj

sliding gleitend adj suitable geeignet adj

slot Schlitzm support Tragerm

smooth zUgigadj surface finish Oberflachenqualitat f

socket spanner SteckschlUssel m swivel drehen v

solder loten v tailstock Reitstock m

spanner SchraubenschlUssel m take apart zerlegen, auseinander-

spark plug ZUndkerzef nehmen v

specification Spezifizierungf tang Kegellappen m

spelt Messinghartlot n tap Gewindebohrer m

spindle Spindel/ tap hole AbfluBloch n

spiral Spiralef taper VerjUngung/

spline lange Nut/ taper shank Kegelschaft m

spring washer Unterlegscheibe f temper anlassen v

sprocket Kettenrad n temporary vorUbergehend adj

spur gear Stirnrad n tensile strength Zugfestigkeit f

thread Gewindegang m

Vocabulary 197

tight dichtadj usually gewohnlich adv

tighten festziehen v utilization Nutzungf

time Zeit/ vacuum Vakuumn

tip Spitzef vanadium Vanadiumn

tolerance Toleranzf vapour Dampfm

tool head Werkzeugschlitten m variation Veriinderung f

tool post MeiBelhalter m vernier caliper MeBschieber m

topic Theman versatile vielseitig adj

tough widerstandsfahig adj vibration Schwingung, Vibration/

toughen ziih machen v vice Schraubstock m

transition Ubergangm water-tight wasserfest adj

trepanning schiidelbohren v wedge Keilm

tungsten Wolframn welding SchweiBenn

turn drehen v wiring Drahteinlegen n

turning centre CNC Drehmaschine f work-harden kalthiirten v

type Sortef worm gear Schneckengetriebe n

unilateral einseitig adj worthwhile lohnendadj

unite vereinigen v wrought iron SchweiBstahl m

useful niitzlich adj

198

Index

A

abrasion 16

abrasion marks 16

abrasive particles 118

abrasive wheel 117

accessories 99, 112

accurate 8, 43, 122, 123

accurately 81

acid paste 25

adaptor 124

alignment 51

allowance 38, 94

alloys 33,39

aluminium 33

aluminium oxide 118

angle blocks 7

angular surface 112

annealing 44

anticlockwise 60

arbor Ill

assembly 7

automatic lathe 122

automatic presses 15

automatic production 122

automation I

automobile engine 60

automobile gear box 67

axis 60

B

back-up wheel 117

backlash 124

ball bearings 60

handsaw 15

beading 15

bearing support 111

bearings 60

bending 15

bending rollers 15

bevel gear 67, 112

bilateral tolerance 94

billet 51

blowpipe 26

blows 57

body 82

bolts 20

bond 25, 118

bonding materials 118

borax 25

boring 81

brass 33, 118

brazed joint 25

brazing 25

brittle 50, 89

brittleness 43, 56

bronze 60

c camshaft 129

capstan 99

carbide tipped tools 89

carbon steel 33, 56

carbon-rich substance 56

carburettor 39, 130

Index

carriage 99

case hardening 56

cast iron 20, 33, 118

casting 20

cavity 51

centre drill 81

centre punch 1, 81

centreless grinding 117

centres 75

ceramics 118

chain 61

chemical energy 128

cherry-red 56

chips 123

chisel 2, 56

chuck 99

clamp 7, 82

clamping device 20

clearance angle 2, 88

clearance fit 94

clockwise 60

CNC 122

cold rolling 43

column 111

combustion process 129

complex forms 33

components 20, 44, 50, 74

composite materials 34

compound table 81

compress 128

compressed mixture 129

compression stroke 129

computer 1, 122

computer program 123

computerized numerical control 122

cone 67

conical surface 67,99

counecting rod 50, 128

contoured surface 105

conventional machine tools 122

corrosion 16

corrosive action 25

cost of manufacture 95

cost of production 122

counterbore 81, 82

countersink 81

countersunk heads 20

coupling 61,99

crank 61

crankshaft 50, 61, 128

cross-sectional area 51

crystals 43

cutting 15

cutting angles 88

cutting edge 56

cutting fluid 88

cutting forces 123

cutting stroke 105

cutting tools 33

cycle 129

cylinder 60, 67

cylinder block 20

cylinder head 20

cylindrical hole 117

cylindrical surface 99

D

damage 16

depth of engagement 74

deviation 94

devices 7

diameter 7 4

die 2, 15, 75

diecasting 3 8

199

200

diesel engine 128, 130

dimensional accuracy 94, 117

dimensions 7

direction of the motion 67

dividing heads 112

double thread screw 74

dowel pins 38, 95

drift punches 1

drilling 81

drilling machine 68

drills 75

drive 122

drop forging 50

ductile 44, 50

E

electric arc welding process 26

electroplating 16

engine 20

engine balance 129

engine block 33

engine head 39

engineering materials 33

engineering production 94

estimation of costs 123

exhauststroke 129

external 67

external combustion engine 128

external cylindrical grinding 117

external screw thread 74

F

fastening devices 20

feed movement I 00

files 1

filler rod 26

film 56

finished component 43, 94

fmishing operation II 7

fixtures 7

flanging 15

flat surface 105, 117

flexibility 123

flutes 82

flux 25

flywheel 129

folded metal joints 15

folding 15

folding machines 15

force 95

forging 50

forging process 50

form grinding 117

formed tools 105

friction 60, 67

fuel pump 39, 130

G

gas-air mixture 128

gas-tight 20

gasket 20

gearbox 67, 68

gear tooth 50

gears, gear wheels 60, 67

glass fibre 34

grain structure 4 3

gravity die casting 3 8

grease 25, 60

grinding 81 , 11 7

grinding wheel 75, 117

groove 105

gudgeon pin 60

guideways I 06

Index

Index

H

hacksaw

hammer 1

hammered 50

hand tools 1

hard solder 25

hard soldering 25

harden 56

hardness 43

head 82

headstock 99

headstock spindle 99

heat treatment 15, 43

heavy-duty work 68

helical gear 67

hexagonal form 20

hexagonalkey 20

hexagonal turret 100

high carbon steels 56

high limit 94

high speed steels 33

holding and clamping devices 7

hole 94

horizontal 105

hydraulically 106

hydrochloric acid 25

I

identical components 122

ignite 128

inclined 105

inclined faces 74

induction stroke 129

inspection 94

interchangeability of components 94

interference fit 95

internal 67

internal combustion engine 128

internal cylindrical grinding 117

internal screw thread 74

internal taper 11 7

iron 33

irregular surface 105

J

jennying machines 15

joining 15

K

keyway 105, 123

knee 111

L

lacquering 16

lathe 88,99

lead 74

leadscrew 99

limit 94

linear motion 60, 68

liquid form 33

location 81

longitudinal 111

low limit 94

lubricating properties 88

lubrication 60

M

machine 1, 60

machine beds 33

machine tool 38

machine utilization time 122

machining 50

machining centre 123

magazine 124

201

202

maintenance 1, 99

manufacturing industry 94

manufacturing process 43

marking-out equipment 7

massive 105

material 2

materials 33

measuring instruments 124

mechanical components 130

mechanical energy 61, 128

mechanical hammers 50

mechanically I 06

metal alloy 25

metal billet 51

metal components 16

metal fasteners 16

metal surface

metals 2, 33

metric thread 75

mild steel 21, 33

milling cutters 112

milling machine Ill

minimization of wear 123

models I

molten metal 38

morse taper 75

motion 60

motor car engine 20

mould 33,38

movement 81, 122

multicylinder engines 129

multipoint cutting tool Ill

multispindle 122

N

nails

nominal dimensions 94

noncorrosive flux 25

normalizing 44

numerically controlled machines 122

nuts 20

nuts and bolts 20

0

oil bath 67

orientation of the grains 43, 50

Otto four stroke cycle 128

outlet valve 128

over-hanging arm Ill

oversize 82

oxide 25,56

oxy-acetylene welding 26

p

parallel guideways 99

pattern 38

performance 130

periphery 117

petrol engine 128

pin punch

pinion 67

piston 60, 128

pitch 74

plain bearing 60

planer 105

plastics 33

polishing 16

polycrystalline materials 43

power stroke 128

precise 81

predetermined program 122

pressure 95, 129

pressure die casting 3 8

production work 99, Ill

Index

Index

prototypes 1

pulleys 60

punch 1, 15

push fit 95

Q

quality of the fit 94

quenched 56

quick return mechanism 1 OS

quieter 67

R

rack and pinion 61, 68

rake angle 2, 88

ratio 68

reamer 75, 81

reciprocating motion 60

reconditioning 20

red hot metal 50

regulated 1 00

regulating wheel 118

rejected components 95

resin 25, 34

resistance welding method 26

return stroke 1 OS

revolution 129

rigid bed 99

rigidity 1 06

rivets and riveting 20

roller bearings 60

rolling components 123

rotary tables 112

rotatory motion 60, 68

s safety IS

sandcasting 38

scraper 1

screw thread 20, 74

screwdriver

screws 74

screwthread 2

self-centering chuck 82

set screws 20

shaft 60

shank 82

shape 43

shaper 105

shaping machine 88

shears 15

sheet metal 1, 15

silicon carbide 118

silver solder 25

single point cutting tool 99, 111

single thread screw 74

skilled labour 122

skilled operator 100

sleeve 82

sliding components 123

slot 105

small batches of components 122

small end 60

smoother operation 67, 129

socketspanner 51

solder 15, 25

soldering 16, 25

spanner 1, 50

spark plug 130

special tooling 123

specific type of work 74

specification 7 4

speed 67

speed reducers 68

spelt 25

203

204

spindle 111

spiral 74

splines 105

split shell bearings 60

sprocket wheel 61, 129

spur gear 67

stability 123

state of stress 43

steam engine 128

steel 33

stiffuess 15

stops 100

straight shank 82

strength 15,33,43

stress 15

stress relieving 44

stretching 15

studs 20

supports 60

surface fmish 88, Ill

surface grinding 117

swivel 112

T

T-slot 123

tailstock 99

tang 82

tap 2, 75

taper 75,99

taper shank 7 5, 82, Ill

tapered surface 11 7

tapping 81

tempering 56

tensile strength 20

thermal efficiency 130

thermoplastics 34

thermosetting plastics 34

tolerance 94

tool changing 99, 123

tool post 99

tool setting 99, 100

tool wear 88

toothed wheel 67

toughen 56

toughness 56

transition fit 95

transverse 111

trepanning 81

tungsten carbide 33

turning centre 123

turret 99

twist drill 82, 112

u unilateral tolerance 94

upset forging 51

v vee-blocks 7

versatile machine 112

vertical 105, Ill

vertical milling attachments 112

vice 7

w water soluble oil 88

water-tight 15, 20

wear 67

wedge 88

welding 7, 16,25

white metal 60

wiring 15

work rest 118

work-harden 43

Index

Index

workshop 7

workshop bench 7

workshop equipment 7

worm, worm gear 68

wrench 1

wrought iron 33, 118

z zinc chloride 25

205

Einfiihrung in die Umwelttechnik

Herausgegeben von Bertram Philipp.

1993. X, 286 Seiten mit 37 Abbildungen. Kartoniert. ISBN 3-528-04777-1

[ __:____] fPRIDPP (HRSGf) _ :==J [ ----~

~NDIE _ 4 IUMWEU IECHN~i( ]

L

-~~---~- l

Dieses Buch wendet sich an Studenten ingenieurwissen­schaftlicher Facher, die sich tor Fragen des Umweltschut­zes interessieren und an angehende ,Umweltberater". Es fuhrt in die technischen Grundlagen ein und vermit­telt auch Grundkenntnisse des Umweltrechts und okolo­gisch-wirtschaftliche Zusam­menhange.

Verlag Vieweg · Postfach 58 29 · 65048 Wiesbaden