Tata Motors

PRESENTED BY• SAURABH SINGH• ANURAG AMBASTHA• AKASH PANDEY

GUIDED BYMr Rakesh CheeliManager- MaintenanceFrame Factory

Company ProfileTATA MOTORS is India’s largest automobile company. It is the leader by

far in commercial vehicle, and the second largest in passenger car

market with winning products in the compacts, mid-size car, and utility

vehicle segments. The company is the world fifth largest and medium

and heavy bus manufacturer

• Company was established in 1945, TATA MOTORS present indeed cuts

across the length and breadth of India. Over 4 million TATA MOTOR vehicle

ply on Indian roads, since the first rolled out in 1954. The company’s

manufacturing base is spread across Jamshedpur, Pune, Pantnagar,

Sanand and Lucknow, supported by a nation-wide dealership, sales,

services and spare parts network comprising about 3500 touch points. The

company also has a strong auto finance operation, TATA MOTORS finance.

Frame

It is the structural centre of the vehicle for carrying load, to furnish supports for transmission system, the body, and other units such as shock absorbers, springs, shackles

Auxiliary parts required for load carrying and vehicle transmission are fastened to frame.

Diagram representing a typical frame

Above figure shows the longitudinal members A and the cross members B for a general vehicle.C are the brackets supporting the body. E1 are the dumb irons to act as bearings for spring shackles.Brackets E are meant for mounting the springs. The extension of the chassis frame ahead of the front axel is called front overhang ,whereas its extension beyond the rear axel is called the rear overhang.

FIXE

DHydraulic connection

PUSHERSEXPANDERS

movableHEFT CABIN FIXTURE(Line 1)

• Every pusher has two connections for hydraulic system. • Expanders are movable horizontally as well as laterally..• One side of the pushers is fixed and the other side is movable.• Here the cylinder used is a Double acting cylinder*.

• Double Acting Cylinder: It is a cylinder in which the working fluid acts alternately on both side of the piston.

HEFT CABIN FIXURE CONSTRUCTION

Bend in frames• During the assembling of frame, there may be some deviation from

what we require and may cause some functional defects.• In frames, they are usually characterised by exceeding of tolerance

beyond a certain level.• In our case the acceptable tolerance is from -5mm to +5mm.The possible causes for bending may be:• The side members may be bent.• Cross members may be buckled.• Some rivets may be loose or broken.

PROJECT

Problem Statement

Synchronization hydraulic cylinders of *Heft Cabin Fixture in order to eliminate problem of bend in frames

*Heft Cabin Fixture : Here long members, cross members and reinforcements are fasten together through nuts, bolts and rivets

Sr. No Possible Causes Validation Method Result

1. Different suppliers provide cross-members with different tolerances

Self-observation and operators’ interview

These defects contribute to bending

2. Different placement of frame on the fixture

Self-observation Workers adjust the machines accordingly and have no effect on bending

3. Use of plates to ensure contact between pushers and long members

Self-observation and operators’ interview

They do not contribute significantly to bending

4. Over tightening of bolts Self-observation and operators’ interview

It does not have major effect on bending.

5. Unskilled workers Self-observation and operators’ interview

Attributed to some new and unexperienced workers

6. Lack of knowledge on WIS Workers’ interview It contribute to bending

7. Single common valve for all pushers Analysis of hydraulic system It is a major reason so separate DC valves for different pusher should be used

8. Elasticity of spring reduces with time Operators’ interview Lead to non-synchronization of cylinders which in turn results into bending

Corrective Measures• Following measures can be suggested to counter the problem of non

synchronization of hydraulic cylinders:1.Using external mechanical hardware

• This will include racks and pinions, crankshafts, cables and pulleys and chains and sprockets.• Accuracy will depends on strength of hardware and the position of

the load• They can operate at any place without getting out of phase

2.Using Servo valve• Most accurate method• Independently control each cylinder with electronic position feedback

and compare each actuator’s position with others• Also works well with cylinders that never go to a home position

3.Installation of separate flow control valve for different pushers

Use of flow control valves

Use of external Mechanical Hardware

• Complicated and cumbersome method• Labour intensive

Use of servo valves

• More accurate• Very expensive

• Simpler method• Economical• Accurate

Having a look on the pros and cons of all three methods of synchronising hydraulic cylinders of the Heft Cabin Fixture, use of flow control valve is a best option by the virtue of being simpler and economical with appreciable accuracy. It has been implemented and is under observation.