TYRE MECHANICSBY :- RAGHAVENDRA.R.GVIII Semester
Mechanical Department PESIT
OUTLINE OF TYRE MECHANICS
INTRODUCTION HISTORY BEHIND TYRE EVOLUTION MANUFACTURING TYRES PROPERTIES WEAR AND TEAR CONCLUSION AND REFRENCES
A TYRE is termed as a steel ring which forms the periphery of a running wheel it is shrunk , bolted , riveted or otherwise fastened around a wheel center Tyres are rolled from blooms of bessemer steel whose section is that of frustrum of a cone , the center being punched out and the shape being imparted by rolling on open end rolls.
HISTORYCHARLES GOODYEAR invented vulcanised rubber in 1844 that was later used in tyres. In 1888 JOHN DUNLOP invented pneumatic tyres which were used in bicycles. In 1895 ANDRE MICHELIN was the first person to use pneumatic tyres on automobile but was not successful In 1911 PHILIP STRAUSS invented the first tyre which was a combination of tyre and air filled inner tube
In 1903 P W LICHFIELD of goodyear company patented the first tubeless tyre which was never expolited commerciallyIn 1908 FRANK SIEBERLING invented grooved tyres which improved road traction In 1910 B F GOODRICH invented long life tyres by adding carbon to the rubber GOODRICH was the person who invented synthetic tyres in 1937
CHARLES GOODYEAR WAS THE FIRST PERSON TO INVENT THE TECHNIQUE OF ADDING SULPHUR TO HARDEN THE RUBBER POPULARLY KNOWN AS VULCANISATION WHICH GAVE AN OPENING TO THE FIELD OF RUBBER MECHANICS
MANUFACTURING TYRESThere are basically 10 steps involved in the manufacturing of tyres:Bead wires are set as applicators, bead joints are set in the right place to avoid imbalance.Carcass Building
Inner liner is rotated at one drum and rotated around the drum at one turn , the joint is cut with a hot knife so that the diagonal end is at the top. Cord ply mountings are set and rotated around the drum at one end the cord is cut by a wire by overlapping 2-5 wires
Body Ply: Mounting
Bead Wire Mounting and Turn-Up
Bead mounting is done automatically , edges are turned up with bladders and over the beads and stitched tightly Sidewalls are set around the drum in one end and rotated in one turn , sidewall is set and seam is attached to it manually
Sidewall Mounting and Joining
Steel belt tables go down to the drum automatically and is cut by a hot knife setting it manually The end of nylon cap ply is set at the drum in the middle of steel belts , bandage is wound on the steel belts 1-2 times
Cap Ply: Mounting and Joining
Tread is pulled onto to the drum automatically and joined to the end Carcass(1st stage) and tread(2nd stage) are joined together automatically , carcass and tread are pressurized to the flange and then stitched together automatically
First and Second Stage Coupling
After preparing the green tyre it is further subjected to painting where anti blemish chemicals are used.
Aspect Ratio and Rim / Pan Width. Aspect ratio =Section height/ Section width The actual dimensions of a tyre are dependent on the rim on which it is mounted. The dimension that changes the most is the tyre's section width; a change of about 0.2" for every 0.5" change in rim width. The ratio between the section width and the rim width is pretty important. If the rim width is too narrow, you pinch the tyre in and cause it to balloon more in crosssection. If the rim width is too wide, you run the risk of the tyre ripping away at high speed.
Aspect ratio is, as you know if you read the bit above, the ratio of the tyre's section height to its section width. The aspect ratio is sometimes referred to as the tyre 'series'. So a 50-series tyre means one with an aspect ratio of 50%. The maths is pretty simple and the resulting figure is stamped on all tyres as part of the sizing information:
WEAR AND TEAR
With use of tyres, all cars will show signs of wear and tear and this is allowed for under the Scheme. Hence we have provide some advice to help you ensure your car remains safe and in good working condition. Unavoidable minor damage caused by a wheelchair, or other mobility aid, will be accepted as fair wear and tear. If you want to protect an area of your car ensure smooth driving
I HEREBY THANK ALL THE STAFF MEMBERS AND STUDENTS OF MECHANICAL DEPARTMENT FOR GIVING ME AN OPPURTUNITY TO PRESENT MY SEMINAR