Maruti Udyog Limited is a leading car manufacturing
firm in India, in collaboration with Suzuki, Japan. The company started
it's operations in 1983. Today the market share of Maruti cars is
approximately 70% with brands like Maruti 800, Zen, Esteem, Omni vans,
Gypsy jeeps. The company has only one manufacturing unit at Gurgaon, near
New Delhi, with a production capacity of 1400 units daily, include all
the models, both domestic and export. Quality Control is a very important aspect of manufacturing.
To be competitive and stay in the market, both national and international,
the companies spend a lot in quality management. My job at Maruti Udyog
Limited was the same, to analysis and eliminate various quality problems.
Wheel Wobbling
Objective :
To analyze and eliminate the problem of wheel wobbling
in the different models of Maruti cars : * Maruti 800 (domestic) - CS * Maruti 800 (export) - CE * Maruti Zen (domestic) - YS * Alto Suzuki (export) - YE
Problem Description :
Irregularities in construction, shifting of the weight mass
from tread wear, and other problems can cause the tyre and wheel assembly
to be unbalanced.
With today's highway speeds, even a slight unbalance
can cause wheel tramp (tyre and wheel hopping up and down) or wheel shimmy
(shaking from side to side). Wheel assemblies must be in both static and
dynamic balance to avoid wheel wobbling.
Observations and Conclusions :
* 5g and 10g weights were not being used by the operator
for balancing the wheel on the wheel balancing machine. So the least weight
used was 20g, hence more error in tyre balancing.
* Weights were not fixed exactly at the calculated value
as the process was manual. Sometimes 50 and 100 angle differences was observed.
* While shifting the wheel from the place where it is
rotated to check the imbalance on the wheel balancer to the place where
weights are fixed, the wheel may rotate somewhat, which might cause error
in angles.
* Due to carelessness of the operator, wrong weights
were being fixed of the wheel sometimes.
Shower Leakage
Objective :
To study defects of shower leakage in the different
models of Maruti cars and give the feedback on the line, where the various
components of the vehicle are assembled, so as to reduce the number of
defects.
Problem Description :
Shower Leakage is a test to ensure that the rain water does
not leak inside the car. For the above test the vehicles are sprayed with
water on the outer surface from all sides of the vehicle. From visual inspection,
the faults are detected and then repaired.
Observations and Conclusions :
Shower Leakage is a common defect which occurs in Maruti
cars. It can be eliminated to the barest minimum provided -
* All due precautions are taken at the various stages
of the assembly process.
* The operators are diligent and alert.
* Proper fixing material, like grommets, trims are used.
* Sealer material should be applied properly on the holes
due to improper welding.
Wheel Noise
Objective :
To analyze and eliminate the defect of wheel noise
in the different models of Maruti cars.
Problem Description :
The disc brake assembly is more or less similar in all the
car models. It consisted of the rotor fitted to another plate with the
help of guide pins. The assembly is also provided with brake pad and dust
cover. This disc brake assembly sometimes create a noise while applying
brakes.
A study of rejected wheel showed that most of the wheel
noise cases were a result of dust cover bending, defective bearing and
mishandling of the knuckle subassembly.
Observations and Conclusions :
* Dust cover bending was the reason in most cases. On bending,
the dust cover touches the disc and thus interferes the wheel movement
giving rise to wheel noise.
* The washer of the knuckle subassembly may drop between
the plate and the disc giving rise to a shattering noise, while wheel is
rotating.
* Sometime the bearing in the subassembly was broken,
the rotor can't rotate freely and hence wheel noise.
* Loose bolts and nuts also create trouble.
Fuel Gauge Not Working
Objective :
To study and analyze the problem of Fuel Gauge not
working.
Problem Description :
Fuel gauge is an important component of the cars, which is
an indicator of the fuel level. To measure the quantity of fuel in a fuel
tank, the potentiometer (or variable resistance), arm and float are mounted
so that the float remains as close as possible to the center of the tank
for all fuel levels.
This is because modern fuel tanks are often shallow and
of uneven shape and partly because the control position is less affected
by vehicle attitude changes (such as climbing or descending a gradient).
Observations and Conclusions :
* Fuel gauge suffers from the problem of wear and poor electrical
contact.
* Sometimes problem occurs in the circuit of fuel gauge.
* Poor electrical connections of fuel gauge on instrument
panel.
Conclusion
Many of the recommendations suggested by us, were incorporated
by the company in the assembly lines of the cars. This resulted in better
quality control of the Maruti cars. The number of defects in the above
four areas started reducing. Though our contribution was very small, we
felt a sense of satisfaction.
This project was done by Ashish Adya and Apurva
Prakash, in May, 1998. (Guide : Mr. Praveen Gupta)
This page was last updated on 23rd July, 1998.