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Lendi Institute of Engg &Technology
Boring machineBy
Polaiah(asst prof)
Introduction
When internal surface of a hollow part is turned, a single point cutting tool is used for enlarging a hole, the operation is called BORING
The bar on which single point tool is mounted is called BORING BAR
Types of Boring Machines Horizontal Boring Machine ( HBM )1. Table type HBM2. Planer type HBM3. Floor Type HBM4. Multiple Spindle HBM Vertical Boring Machine ( VBM ) 1. Single Column VBM2. Double Column VBM
Types
Horizontal boring machine:
The work is supported on a table which is stationary and tool revolves in a
horizontal axis.
Can perform boring, reaming, turning, threading, facing, milling , grooving
and many other operations with suitable tools.
Work piece which are heavier and asymmetrical can be easily held and
machined.
Different types has been designed to suit the different purpose.
Horizontal boring machine
Horizontal boring machine
Horizontal Line Boring Machine
Vertical Boring Machine:
The work rotates on a horizontal table about a vertical axis and the tool
is stationary except for feed.
Machine may look like a vertical lathe.
Larger diameter and heavy work pieces, can be set up more quickly than
in lathe.
Multiple tooling may be adapted with its turret type tool post, increasing
the rate of production.
Vertical boring machine
Vertical boring machine
Vertical Boring Operations
Vertical Boring Operations
JIG BORING MACHINE
Jig Boring Machine It uses a single point cutting tools to machine surfaces rapidly and
accurately.
Cemented carbide and diamond tipped tools are operated at a very high
cutting speed to produce accurately sized holes with fine surface.
Jig boring machine is a precision boring machine, resembles to vertical
milling machine in construction.
Accurate positioning of holes is achieved by Lead screw method or
Mechanical / Electrical Gauging method or Optical measuring method.
Jig Boring Machine
Jig-Boring Machine a metal-cutting machine for finishing holes, planes, and
slots with a highly precise location of centers or surfaces without the use of
special attachments for tool alignment.
Jig-boring machines are used for boring, drilling, counter-sinking, reaming,
milling, and other types of finishing in individual and small-scale production
during the manufacture of cutting and measuring tools, jigs, dies, and key
components of machines and instruments. Devices with stable and adjustable
end gauges and indicator sensing units are used on jig-boring machines for
precise measurements; also used are lead screws with dials and a vernier, which
are equipped with error-elimination compensators, and graduated shafts with
optical measuring instruments.
There are two types of these machine tools: double-sided (gantry) machines with
a one-movement table and open-sided (single-sided, overhanging) machines
with a two-movement table. In open-sided machines the spindle head moves
only vertically; in the double-sided machines it moves horizon-tally along the
crosspiece, which can travel in a vertical direction.
The manufactured article and the cutting tool on the jig-boring machine are
moved relative to one another along orthogonal coordinates (with linear
displacement accuracy to 2 microns) and polar coordinates (with angular
displacement accuracy to 5 seconds of arc). Sturdy construction is a feature of
jig-boring machines, which have smooth drive motions and accurate balancing
of fast-rotating parts (to reduce vibration).
The machines are installed in insulated areas in which a constant temperature of
20°C is maintained. Jig-boring machines are operated by highly skilled workers.
Jig Boring
Jig Boring Machine Jig Boring
The boring operation can be carried out on lathe and milling machine but the need of accuracy of holes, its quality and relative position of different hole centers is demanded in jig & fixtures. To cope up with this work boring machine are need , which are called “jig boring machine”.
NEED OF JIG BORING MACHINE
The jig boring is a special type of boring process, hence its working principal is just similar to the boring process.
In this process rotating tool is passed over the stationary work. This principal is used for large work pieces, while for small size work pieces tool is kept stationary and work is moved by applying force.
The feed in this process is given with respective to the vertical axis of the hole and its radius.
WORKING PRINCIPLE OF JIG BORING PROCESS
Jig boring machine generally consists of a heavy base and a column.
A spindle head is provided at the top of this column, which is fixed on the guide ways of the column. The spindle is fixed using preloaded antifriction bearings.
The table is arranged on the saddle. It can move in different on the guide ways of the saddle.
Table provides longitudinal motion to the work piece & saddle cross movement to the work piece.
By moving the spindle head up and down, the vertical movement of the spindle is obtained.
CONSTRUCTION &MAIN FEATURES
BED:-the component which base to the machine is called bed it us made from C.I. it support the column, saddle, control penal and whole machine.
COLUMN:-it is also a hollow component made from cast iron. It is supporting the head stock , guide ways and vertical head provides axis for positioning.
head-stock:-it is also called spindle-head.it is fixed on column in front side. Spindle is supported in quill. As this quill is moving up and down side becomes like a telescopic mechanism.
MAIN COMPONENT OF JIG BORING MACHINE
TABLE AND SADLE:- table helps to clamp and hole the work piece in a fixture in required position. Hence t-shaped slots are made in it. The saddle provides possibility of longitudinal motion of the work piece.
PICK-UP DEVICES:- it is attached on the table and saddle. It is helping in controlling various machine operations automatically. Again devices are necessary for accurate measurements.
THERE ARE MAINLY TWO TYPES OF JIG BORING M/C.
Single column jig boring machine
Double column jig boring machine
TYPES OF JIG BORING MACHINE
Single column jig boring machine is used for small size of component.
It is made of plain rotary table, inclined table and square table
It looks like a vertical milling machine, hence it is called vertical milling type jig boring machine.
SINGLE COLUMN JIG BORING MACHINE
The vertical columns are provided at two sides of this machine.
This construction looks like a planer hence it is called a planer type jig boring machine.
It is used for the large weight work pieces.
DOUBLE COLUMN JIG BORING MACHINE
The jig boring machine is specified by following basis;
Distance of spindle axis from column. Maximum distance between spindle face & table. Minimum distance between spindle face & table. Diameter and taper of spindle hole Maximum diameter that can be bored. Maximum weight of work which can be placed. Dimension of working axis of table Maximum table transverse. Horse power of main motor. Horse power of table feed motor. Minimum measuring capacity of dial. Least count of venire caliper. Various spindle speeds.
SPECIFICATION OF JIG BORING MACHINE
The more accuracy is required in measurement taken by jig boring machine and in position, generally different measuring mechanisms are used for taking measurements. They are as under.
1. Precision lead screw system2. Scale and microscope system3. End measurement system4. Electro – magnetic system
SYSTEM OF MEASUREMENT
TOOLS
Based on its construction1. Forged type boring tool.2. Carbide tip tool. Based on shape1. Common type boring tool2. Haviour cut boring tool3. Special boring tool
BORING TOOL MOUNTINGS
1. Boring bar2. Cutter heads3. Facing heads
BORING TOOLS AND MOUNTINGS
For jigs, fixtures and dies. For drilling hole in jig-bushing. To produce compound and progressive
dies. For pilot hole & bushing hole for grinding &
alignment post in stripper or die-set. For grinding the hardened parts.
APPLICATION OF JIG BORING MACHINE
Thank uYours
polaiah