methods for improving processes and increasing efficiency

Plant-IX Aurangabad Electricals Ltd.

Fasteners Division

Methods for improving processes and

increasing efficiencyThe three main ideas I have stressed upon are:

Increasing energy efficiency of plant

Method for sorting nuts and bolts of unequal dimensions

Increasing safety of centre less grinding machines

Increasing energy efficiency of the plant


The TPM policy of the various plants of all the plants stress on

energy conservation.

It was observed that the lights in the finished goods area of

plant 9 are kept on throughout the day, whether or not

someone is present there.

Mostly, workers carry lots of products and find it difficult to turn

the lights on and off.

Designed a layout for motion sensing switches to reduce

wastage of power.


As soon as someone steps into any red area, the lights in the area

around the person turn on and turn off again once the person has left.


Current Usage

96 tube lights x 24 hours x 28 watt

64.512 kWh or Rs. 451.854

Monthly, this amounts to 1935.36

kWh or Rs. 13547.52

After installation of sensors

96 tube lights x 6 hours x 28 watt +

44 sensors x 1 watt *24 hours

16.656 kWh or Rs.116.592

Monthly, this amount to 499.68 kWh

or Rs. 3497.76

Cost of installation = 800 * 22

= Rs. 17600

Cost recovered from savings in less

than 2 months


By using these motion

sensing switches for lights,

the power used in the

finished goods section

drops by 74% and the

power can be used for

more productive purposes.

1935.36 kWh

499.68 kWh

0

500

1000

1500

2000

2500

Before sensors After sensors

Power usage per month in finished goods area


To compare the power wasted

everyday, we can compare it

against other day to day in plant

processes.

64.512 Kwh per day

Running an M8 forging machine

for three hours (enough time to

forge three rolls ~ 30000 pieces).

Running a rolling machine for six

and a half hours (enough time to

roll ~ 80000 pieces).

Running entire array of plating

machinery for 20 minutes

Method for sorting nuts and bolts of unequal

dimensions


dimensions Many times, nuts and bolts of similar sizes and

specification, differing in one or two things get mixed up due to

their apparent similarity.

Test case: two nuts of same external diameter, internal

diameter, material, grade and exterior finish had different

pitches of thread. One was 1.5mm and the other was 1.25mm.


dimensions This error was reported to the plant by the customers and the

lot was sent back to the plant.

Sadly, currently such issues are resolved by employing manual

labour.

They have to tighten each bolt on a nut of specified pitch and

decide whether the bolt fits or not.


dimensionsA possible way to easily sort the different products is to use

computers. Using MATLAB and its image processing

capabilities, we can take images of the bolts, decide whether

they have all the correct dimensions or not, and pass or reject the

product.


dimensionsMATLAB processes black and white picture, to determine where

the edges are by observing changes in color


dimensionsNow, by using the

histogram function of

MATLAB, we can count the

number of times that an

edge is encountered in a

specified length

interval, thus indicating

pitch of the object.


dimensionsFor separating bolts, the loading

machine can be used to guide the

bolts towards a cog that will hold

the bolt for the camera array to

examine. Depending on whether

the bolt is as per the correct

requirements, the computer can

make the cog spin clockwise or

counter clockwise, sending the bolt

into the correct bin.


dimensionsFor separating nuts, the nuts can

be loaded into the tapping machine.

As they come down the guides, the

camera take pictures. The

computer then decides whether the

bolt is correct, and accordingly

open or closes the chutes so that

the nuts are collected or stopped


dimensionsAs an added advantage, the machines can also be used to help

the final inspection. This will reduce the load on the workers and

the inspection can be done quickly and more effectively as

compared to manual checking. This is because currently, only

one in every 100 bolts from the smaller sizes is done. Using

this, every bolt can be checked in the same or lesser time.

Increasing safety of centre less grinding

machines


machines The centre less grinding machines are a major source of

worker injuries.

The injuries mostly occur when the workers are pulling out the

bolts from between the wheels.

This is a place, where wearing safety gloves, actually

increases the risk of losing a limb, as if the glove is even

slightly loose, it may get caught in the wheels and pull off the

workers arm.


machines Thankfully, no major incidents have ever occurred here.

But minor injuries are very common in this section because of

how close a workers hand comes to the wheels while removing

the bolts.

The injuries not only hamper the factory productivity, but also

leave the worker temporarily unemployed, since he cannot

work till he recovers completely


machines To reduce this hazard, a system can be put in place which

automatically pushes the bolt out a little bit, say by 4 inches, so

that the worker can easily pull it out without putting himself at

risk of getting injured.

The machine will only allow grinding once the bolt is properly in

place


machines The modification involves

adding a motor to the stopper

rod.

The bolt will push the rod

against a switch, which will

allow the machine to start

Once the grinding is

done, the motor will push out

the rod, moving out the

bolt, making it safe to

remove.


machines This system will make the bolt easier and safer to remove from

the machine.

A second advantage is that unless the bolt is of the correct

size, within tolerances, the machine will not allow the part to be

ground, reduces waste of effort on wrong bolts.