Summer Training ProjectOn

Paint Scratch Analysis

Submitted To:Mr. Manoj Mahajan

Mr. Lokesh AhujaTRIM LINE 3

Submitted By:Abhyuday Raj Sinha

B.Tech(MAE): 6th SemesterAmity University, Lucknow

Contents:1: Declaration2: Acknowledgement3: Company profile4: Products5: Tata Motors, Lucknow Plant6: Trim Line-37: Project : Paint Scratch Analysis at Trim Line 38: Conclusion

I hereby declare that the project work entitled PAINT SCRATCH ANALYSIS is an authentic record of my own work carried out at TATA MOTORS, LUCKNOW as requirements of four week summer training project, under the guidance of MR. MANOJ MAHAJAN (Senior Manager, Trim Line-3) ,during 24TH MAY 2016 to 21ST JUNE 2016.

Dated: 21.06.2016 Abhyuday Raj Sinha B.Tech(MAE)- 3rd Year

Amity University, Lucknow

Certified that the above statement made by the student is correct to the best of our knowledge and belief.

Mr. Manoj Mahajan Mr. Lokesh AhujaSenior Manager ManagerTrim Line 3 Trim Line 3Tata Motors, Lucknow Tata Motors, Lucknow

1. Declaration:

Industrial training is a crucial period in engineering curriculum since it exposes a student to the real world which he or she is going to enter after the completion of the graduation. This is the period during which an engineer actually becomes an engineer by gaining the Industrial experience. I am very thankful to God who has given me the opportunity to get training in TATA MOTORS, LUCKNOW, one among the most renowned organizations of India. I would like to express my deep gratitude to my Project Head MR. MANOJ MAHAJAN (Trim Line-3) and MR. LOKESH AHUJA(TRIM LINE-3) for having provided me with the wonderful & conductive environment to work in and realize what really industry is. They have always been helpful and supportive. I would also like to thank Mr. Prabhakar Gund, Mr. Rohit, Mr. Rajiv Mishra, Mr. Naved Anwar and Mr. Ravi Shankar for helping me throughout my training. I will always remain indebted to them for their generous ways of dealing with Summer trainees.

Abhyuday Raj SinhaB.Tech(MAE)6th Semester

Amity University, Lucknow

2. Acknowledgement:

Tata Motors Limited is India’s largest automobile company, with consolidated revenues of Rs.2.625 Trillion(USD 42 billion) in 2014-15. It is the leader in commercial vehicles in each segment, and among the top three in passenger vehicles with winning products in the compact, midsize car and utility vehicle segments. The company is the world's fourth largest truck manufacturer, and the world's third largest bus manufacturer.Tata Motors helps its employees realize their potential through innovative HR practices. The company's goal is to empower and provide employees with dynamic career paths in congruence with corporate objectives. All-round potential development and performance improvement is ensured by regular in-house and external training. The company has won several awards recognizing its training programs.Established in 1945, Tata Motors is India's largest and only fully integrated automobile company. Tata Motors began manufacturing commercial vehicles in 1954 with a 15-year collaboration agreement with Daimler Benz of Germany. Since 1969, the company's products have come out of its own design and development efforts.Today, Tata Motors is India's largest commercial vehicle manufacturer with a 59 per cent market share and ranks among the top six manufacturers of medium and heavy commercial vehicles in the areas of business Tata Motors' product range covers passenger cars, multi-utility vehicles as well as light, medium and heavy commercial vehicles for goods and passenger transport. Seven out of 10 medium and heavy commercial vehicles in India bear the most trusted TATA mark.

3. Company Profile:

MANUFACTURING UNITS

HEAD QUATERS

Commercial Vehicle Business unit (CV Unit) : The company has over 130 models of light, medium and heavy commercial vehicles ranging from two tones to 40 tones, buses ranging from 12-seaters to 60-seaters, tippers, special purpose vehicles, off-road vehicles and defense vehicles.

Passenger Car Unit :The Company’s passenger car range comprises the hatchback Indica, the Indigo sedan and the

Marina, its station wagon variant, in petrol and diesel versions. The Tata Sumo, its rural variant, the Spacio and the Tata Safari (the country's first sports utility vehicle) are the company's multi-utility offerings. The Tata Indica, India's first indigenously designed and manufactured car, was launched by Tata Motors in 1999 as part of its ongoing effort towards giving India transport solutions that were designed for Indian conditions. Currently, the company's passenger cars and multi-utility vehicles have a 16-per cent market share. . In addition to the growth opportunities in the buoyant domestic market, the company is pursuing growth through acquisitions (it acquired Daewoo Commercial Vehicles, Korea, in 2004) and alliances (it has entered into a tie-up with MG Rover, UK, to supply 1, 00,000 Indicas to be budged as City Rover) in other geographies. Research and Development :

Tata Motors invests up to 1.3 per cent of its annual turnover on research and development, with an emphasis on new product / aggregates development and technology up gradation. Its Engineering Research Center in Pune has India's only certified crash-test facility and hemi-anechoic chamber for testing of noise and vibration.

The company also draws on the resources of leading international design and styling houses like the Institute of Development in Automotive Engineering, SPA, Italy and Stile Bertoni, Italy. The company has also been implementing several environmentally sensitive technologies in manufacturing processes and uses some of the world's most advanced equipment for emission checking and control.

Environmental responsibility :Tata Motors has led the Indian automobile industry's anti-pollution efforts through a

series of initiatives in effluent and emission control. The company introduced emission control engines in its vehicles in India before the norm was made statutory. All its products meet required emission standards in the relevant geographies. Modern effluent treatment facilities, soil and water conservation programs and tree plantation drives on a large scale at its plant locations contribute to the protection of the environment

Exports : Tata Motors' vehicles are exported to over 70 countries in Europe, Africa, South

America, Middle East, Asia and Australia. The company also has assembly operations in Malaysia, Bangladesh, Kenya, South Africa and Egypt.

Passenger cars and utility vehicles

• Tata Sierra (Discontinued)• Tata Estate (Discontinued)• Tata Sumo/Spacio• Tata Sumo Grande• Tata Safari• Tata Indica• Tata Vista• Tata Indigo• Tata Manza• Tata Indigo Marina• Tata Winger• Tata Magic• Tata Nano• Tata Xenon XT• Tata Aria• Tata Venture• Tata Iris

4. Products:

Concept vehicles:• 2000 Aria Roadster

• 2001 Aria Coupe • 2002 Tata Indiva

• 2004 Tata Indigo Advent

• 2005 Tata Xover

• 2006 Tata Cliffrider

• 2007 Tata Elegante • 2009 Tata Prima

• 2010 Tata Versa

• 2010 Tata Essota

• 2011 Tata Pixel

Commercial vehicles Tata Ace Tata TL/Telcoline/207 DI Pickup Truck Tata 407 Ex and Ex2 Tata 709 Ex Tata 809 Ex and Ex2 Tata 909 Ex and Ex2

Tata 1109 (Intermediate truck) Tata 1512 (Medium bus chassis) Tata 1612/1616 (Heavy bus chassis) Tata 1618 (Semi Low Floor bus chassis) Tata 1623 (Rear Engined Low Floor bus chassis) Tata 1613/1615 (Medium truck) Tata 2515/2516 (Medium truck)

Tata Starbus (Branded Buses for city) Tata Divo (Fully built luxury coach) Tata CityRide (12 - 20 seater buses for intra-city use) Tata 3015 (Heavy truck) Tata 3118 (Heavy truck) (8×2) Tata 4018 (Heavy truck) Tata 4923 (Ultra-Heavy truck) (6×4) Tata Novus (Heavy truck designed by Tata Daewoo) Tata Prima (The World Truck designed by Tata Motors and Tata Daewoo)

Military vehicles:: Tata 4018 (Heavy truck) Tata LSV (Light Specialist Vehicle) Tata Mine Protected Vehicle (4×4) Tata 2 Stretcher Ambulance Tata 407 Troop Carrier, available in hard top, soft top, 4×4, and 4×2 versions Tata LPTA 713 TC (4×4) Tata LPT 709 E Tata SD 1015 TC (4×4) Tata LPTA 1615 TC (4×4) Tata LPTA 1621 TC (6×6) Tata LPTA 1615 TC (4×2)

5. Tata Motors Lucknow Plant

The plant, rolls out commercial vehicles and is specialized in the designing and manufacturing of a range of modern buses which includes Low-floor, Ultra Low-floor, CNG & RE Buses.

The Lucknow facility also specializes in manufacturing HCBS (High capacity Bus System) buses.

In light of Company’s aggressive growth plans, they are currently in expansion phase and production at Lucknow would grow many-fold in near future. The expansion shall be in the areas of painting, welding, vehicle assembly & testing and utility services, driven by latest technology. To achieve these plans they invite people who have good Technical Knowledge, seek Challenging Opportunities and have a Drive for Engineering Excellence to come and partner us in our journey.

Tata Motors Lucknow is one of the youngest production facilities among all the Tata Motors locations and was established in 1992 to meet the demand for Commercial Vehicles in the Indian market. The state-of-the-art plant is strongly backed by an Engineering Research Centre and Service set-up to support with latest technology and cater to the complexities of automobile manufacturing. Fully Built Vehicle business, which is one of the fast growing areas of our business, is also established in Lucknow.

Departments in TATA Motors Lucknow: Planning Technical services Central tool room Central procurement Dispatch Central logistics Factory logistics group-CV Factory logistics gear-transmission Factory logistics Gr-sumo SQIG Engineering services Central maintenance FPIG - CV factory FPIG-transmission factory Central quality (CQ) Area office, Lucknow Regional sales office (Lucknow) Service depts., Lucknow works Plant head office Manufacturing head office Human resources

Get training Business excellence Finance Internal audit ERC Lucknow Administration Construction

The part of the vehicle which constitutes the front part of vehicle and is having all the controls within the driver’s reach is known as cowl/cab. The difference between cowl and cab is that cab is covered from upside,backside & has windows, while the cowl Has only the front part with all the controls.

The cowl is received from Jamshedpur infinished condition, but is being treated heresuch as denting & painting so as to removethe defects occurred during the transportation before being sent to assembly .Now the BIW & Paint Shop’s are being erected here in the Eastern Complex to fabricate the Cowl and Cab here with the capacity of about 520 cabs per day. The models of the cabs of the trucks which are assembled here are LPS 3518 (Sleeper) and LPK 2518 (Non-sleeper). All the activities of the trim line 3 are divided into 26 stations, which are as follows-

6. TRIM LINE-3(COWL/CAB ASSEMBLY LINE):

Stations at Trim Line-3

Station No. 1: (Cab dropping) –

Cab is dropped on the peg, placed on the

slat board with the help of a hoist of 0.5

ton. Inspection card is attached and

reflector sticker is placed on the front

portion.

Station No. 2: (Tapping, Mascot and Mud-guard ) – In this station tapping , mascot and mud

guard assembly is done.

Station No. 3: (main wiring harness and wiper motor) – Main wiring harness is fitted and wiper motor is assembled.

Station No. 4: (Lower and Upper Berth) – Lower and upper berth are installed at this station.

Station No. 5: (DTV Fitment and Hand Brake) – In this station DTV (Dual Treadle Valve) for hand brake and hand brake is assembled.

Station No. 6: (Head Lamps and Blinkers) – Head lampsand blinkers are installed at this station.

Station No. 7: (Centre Panel) – Centre panel is installedin the cab at this station. All the wiring of the panel isdone in this station.

Station No. 8: (Insulation and Flange Tube) – Insulated rubber sheets and flanged tube for the suction air filter inlet are fitted in this station.

Station No. 9: (Wind Shield Glass) – Wind shield glassis fitted at this station.

Station No. 10: (Seat Belt) – Seat belts are installed atthis station.

Station No. 11: (Door Beading) – Door beading for insulation purpose is installed at this station.

Station No. 14: (Air filter) – Air filter for cab is installed inthis station. Air filter filters the air entering the air tank.This attachment is fitted at this station. Station No. 15: (Turning Window) – Turning windows areinstalled at this station.

Station No. 16: (Dash Board) – Dash boards are installedat this station.

Station No. 17: (Driver and co-driver Seats) – Fitment ofdriver’s seat co-driver’s seats takes place at this station.

Station No. 18: (Steering Column) – Steering columns areinstalled at this station. Station No. 19: (Electrical Inspection) - The variouselectrical parts such as head lamps, blinkers etc. areinspected at this station to check the wiring of cabs

Station No. 20: (Instrument Cluster Board) – Speedometer, fuel indicator, distance indicator etc. are placed on the cluster board. This is fitted in front of the driver’s seat at this station.

Station No. 21:(Steering Wheel) – Steering wheels are fitted at this station.

Station No. 22:(Auxiliary Water Tank) – Auxiliary water tanksare installed in this station.

Station No. 23:(Mechanical Inspection) – Inspection like movability of doors and other parts is done at this station.

Station No. 24:(Mechanical Inspection) – Inspection like movability of doors and other parts is done in this station.

Station No. 25:(Cab Lifting) – Cabis then lifted for further assembly.

Station No. 26:(Casting Cup) – Casting cup is fitted at the bottom of the cab to make an ease for thechassis fitment (or later casting cup gets attached with the chassis of the vehicle).

7. Project

Paint Scratch Analysis at Trim Line 3

Paint imperfections:

Paint Imperfections are classified as:

Whenever a cab is sent from the paint shop to the trim line for assembling, it definitely contains some paint imperfections which have to be removed before sending it to the next line. Sometimes, certain imperfections occur at the trim line which also have to be eliminated at the trim line itself.

Paint Scratch

Paint Rundow

n

Paint Not

Done

Paint Remove

d

I observed around hundred cabs during their assembling processes at Trim Line 3 and discovered that paint scratches generally occurred at the following locations:

Inside Central On Stay Rod Door Edge Door Inner

Panel Aperture

Near Bottom Near Door Lock Door Face Lower Edge of Corner Of The Door Central Panel

Near Master Near Door Hinge Door Inner Upper Central Panel Cylinder Near Window Lock Plate

Data Table for every defect sorted in descending order…

Defect Frequency Percentage Cumulative%

Near Door Lock(F) 77 14 14

Stay Rod(B) 74 13 27

Door Inner Upper Near Window(K) 62 11 38

Inside Central Panel(A) 62 11 49

Central Panel Lock Plate(L) 53 9 58

Door Inner Aperture(D) 48 9 67

Door Hinge(J) 43 8 75

Lower Edge of Central Panel(H) 39 7 82

Near Bottom Corner of the door(E) 37 7 88

Door Edge(C) 35 6 94

Near Master Cylinder(I) 19 3 98

Door Face(G) 11 2 100

Pareto’s Law states that 80% of the problems are caused by the top 20% defects.

So, in order to find out the top 20% scratch defects at Trim Line 3 a Pareto Chart is drawn:

Near Door L

ock(F)

Stay Rod(B)

Door Inner U

pper Near W

indow(K)

Inside Centra

l Panel(A

)

Central P

anel Lock

Plate(L)

Door Inner A

perture(D

)

Door Hinge(J)

Lower E

dge of Centra

l Panel(H

)

Near Bottom Corn

er of t

he door(E)

Door Edge(C)

Near Maste

r Cylin

der(I)

Door Face

(G)

0

100

200

300

400

500

0102030405060708090100

77 74 62 62 5348 43 39 37 35 19 11

1427

3849

5867

7582

8894 98 100

Paint Scratch Pareto

Defects

Freq

uenc

y O

f Def

ects

Cum

ulati

ve %

Analysis of Scratches from Pareto

Near Door Lock Possible Causes of Scratch: (a) & (b):1. Inappropriate size of holes.2. Carelessness done by the worker while fitting the screws.3. Hammering done on the male part of the lock to fix

it in the female part dislocates it and in that dislocation the bolts and washers fixing the lock create the scratch.

(c): 4. When the lock is not fitted properly, sometimes the edge of

the female part rubs with the door surface near the male part, when the door is closed and creates a scratch.

5. Insufficient gap at door’s inner edge.6. Depth of the striker may be inappropriate.7. Insufficient gap at door’s outer edge.

a

b

c

Validation of Causes:(a) & (b):1. Inappropriate size of holes:The appropriate diameter of holes at a & b should be 6mm according to drawing and the diameter of holes recorded, were as follows:

Cab Number Diameter of Holes at 'a' Diameter of Holes at 'b'8168 6.02mm 6.06mm

8169 6.08mm 6.02mm

8170 6.06mm 6.08mm

8171 6.04mm 6.02mm

8157 6.06mm 6.06mm

Since the diameter of holes lie within the tolerance limit of the designed diameter, this can not be the cause of scratch.

a

b

2: Carelessness done by the worker while fitting the screws: I observed around ten cabs and found that workers were fitting the screws carefully and properly. So, this can not be the cause of scratch.

3. Hammering done to fix the male part of the lock in the female part properly, shifts the male part towards the door edge which dislocates the bolts and washers fixing it and a scratch is created:

It was observed in every cab that these scratches were getting created by hammering. So, this is the root cause of scratches at a & b.

(c):1. When screws of the lock is not tightened, the edge of the

female part rubs with the door surface near the male part, when the door is closed and creates a scratch:

To check for this cause I observed five cabs between stations where the door lock was fixed and where it’s screws were tightened and tabulated as:

Cab NumberDid any scratch get created in

between the two stations?

8168 NO

8169 YES

8170 NO

8171 NO

8157 NO

c

Only 1 out of 5 cabs obtained scratch so, this can not be the root cause of scratch.

2. Insufficient gap at door’s inner edge:I checked door gap in the region ‘x’ and tabulated as:

Cab Number Door Gap At ‘x’ Occurrence of Scratch at 'c'

8168 8mm NO8169 7.5mm YES8170 8.5mm YES 8171 8mm YES8157 9mm YES8172 8.5mm NO8173 7mm YES 8174 9mm NO

Since no relation could be established between the door gap at inner edge and occurrence of scratch, it can not be the cause of scratch ‘c’.

However, when the door gap was less than 8mm, a different scratch was obtained at x due to fouling.

x

c

3. Inappropriate depth of the striker:I checked the depth of strikers in 5 cabs and tabulated them as:

Since no relation could be established between the depth of striker and occurrence of scratch, it can not be the cause of scratch ‘c’.

Cab Number Depth of Striker Occurrence of Scratch

8174 25.10mm NO

8158 25.06mm YES

8175 25.04mm NO

8176 24.84mm NO

8177 25.12mm YES

h

4. Insufficient gap at door’s outer edge:I checked door clearance in the region ‘A’, ‘B’, ‘C’ and tabulated as:

When the door gap was less than 6mm at region ‘B’, this scratch was obtained due to fouling. Hence, this is the root cause of this scratch.

C

B

A

Cab Number Door Gap At A Door Gap At B Door Gap At C Occurance of Scratch8168 6.5mm 6mm 6mm NO8169 6mm 4.5mm 6.5mm YES 8170 6.5mm 4mm 6mm YES 8171 6mm 5mm 4.5mm YES 8157 4.5mm 4.5mm 6.5mm YES 8172 6mm 6.5mm 6mm NO8173 6.5mm 4.5mm 6mm YES 8174 6.5mm 6.5mm 6mm NO8158 7mm 4.5mm 6mm YES 8175 4mm 6mm 6.5mm NO8176 6mm 7mm 4.5mm NO8177 6mm 5mm 5.5mm YES

Star Gauge used to find door gap

Prevention From Scratches:(a) & (b):

As in most of the cabs the male part does not fix inside the female part properly(Hard Locking) and hammering shifts the male part towards the outer edge which fixes it inside the female part. The gaps ‘a’ & ‘b’ which were initially almost same now changes. They were recorded as:

ba

Cab Number Gap 'a' Gap 'b'

Before

Hammering After HammeringBefore

Hammering After Hammering8168 5.06mm 2.34mm 4.86mm 7.88mm8169 5.04mm 2.46mm 5.06mm 7.64mm8170 4.92mm 2.26mm 5.02mm 7.68mm8171 5.10mm 2.28mm 5.04mm 7.86mm8157 4.94mm 2.54mm 5.08mm 7.48mm

5 mm 5 mm

5 mm

Hammering can be avoided if instead of shifting the male part we shift the female part. This can be achieved if the holes provided for screws to fit the female part are shifted radially by a small distance(around 2.5mm). Therefore total shift will be around 5mm.

A simpler method adopted by the workers is by using a hard metallic tool(screwdriver) which they fix at the end near gap ‘b’ and apply a downward force on it. This pushes the male part towards the outer door edge and decreases gap ‘a’. At the same time another worker tightens the screws and fits the lock. This prevents the scratch from getting created.For safety purpose, a rubber handle can be used to cover the metallic side of the tool.

(c):1. By providing more door gap(6mm-8mm) at the outer edge of the door.2. A wooden stopper is used at the lock fixing station to prevent the closing of door until the lock is fitted.3. The fixing and fitting of the door lock are done at the same station.

Door Gap Wooden stopper to prevent closing of

door

On Stay Rod

(a): Possible Causes of Scratch: 1: Inappropriate thickness of the stay rod.2: The stay rod holder might create scratch on it.3: No specific resting place for stay rod at the time the cab comes to Trim Line.

.

Validation of Causes: 1: Inappropriate thickness of stay rod:

The thickness of stay rod was recorded as:

Since, the thickness was according to the drawing and had no relation with the scratch, this is not a cause of scratch.

Cab Number Thickness of Stay Rod Occurrence of Scratch

8168 8.08mm YES8169 8.12mm YES8170 8.18mm NO8171 8.04mm YES8157 8.10mm NO

x

2: The stay rod holder might create scratch on it:

To check for this cause, I calculated the diameter of stay rod holder and found that:

Cab Number Diameter of Stay Rod Holder Occurrence of Scratch

8168 8.68mm YES8169 8.52mm YES8170 8.56mm NO8171 8.64mm YES8157 8.54mm NO

Since, the diameter was according to the drawing and had no relation with the scratch, this is not a cause of scratch. Further it was made up of a non metallic material, so creation of scratch was hardly possible.

3: No specific resting place for stay rod at the time the cab comes to Trim Line :

To check for this cause, I went to the dropping station and found that this scratch came from the paint shop.

In the absence of stay rod holder at the BIW shop, the stay rod is unable to rest at a particular place. When the central panel is closed, the stay rod doesn’t comes back to it’s resting place, most of the time and consequently hits the inside of the central panel.When this cab is painted in the paint shop, this hitting creates a visible scratch on the central panel.

Hence, this is the root cause of this scratch.

This is one of the most occurring scratches in the cab and can be eliminated only if the stay rod holder is fitted in the BIW shop instead of Trim Line. This will reduce one process in the trim line and will also prevent formation of such scratches in future.

Prevention From Scratch:

Central Panel Lock Plate

(a): Possible Causes of Scratch: 1: In the absence of rubber buffer near the lock plate, before reaching the trim line, the inside of the central panel hits the lock plate and creates this scratch.2: Unskilled labour. 3: For proper locking of the Central Panel, the lock plate is bended using a metallic tool which creates scratch on its edges. 4: Some lock plate might be harder than others.

.

a

Validation of Causes: 1: In the absence of rubber buffer near the lock plate, before the cab reaches the trim line, the inside of the central panel hits the lock plate and creates this scratch:

To check for this cause, I went to the dropping station. I looked for this scratch in ten cabs but found it in none. So, I concluded that this can not be a cause of this scratch.

×

2: Unskilled labour:

To check for this cause, I went to the station where bending of lock plate is done. I observed this bending in ten cabs and found that only four of them got scratches. So, I further introspected about the worker doing this job. In four days, four workers did that job. Their work is tabulated as:

Day 1 Day 2 Day 3 Day 4

Morning

ShiftEvening

ShiftMorning

ShiftEvening

ShiftMorning

ShiftEvening

ShiftMorning

ShiftEvening

Shift

Worker A Worker B Worker A Worker C Worker A Worker B Worker D Worker B

Work Experience 3 Months1.5

Months 1 Month 1.5

Months

Occurrence of Paint Scratch in 10 cabs

3 5 4 6 4 5 4 4

To some extent we can say that workers do make mistake and unskilled labour is a cause of this scratch.

2: For proper locking of the Central Panel, the lock plate is bended using a metallic tool which creates scratch on its edges:

Conventionally used tool for bending

To check for this cause, I went to the station where bending of lock plate is done. I looked for this scratch in ten cabs and found that it was getting created there only. So, I concluded that this tool is a cause of this scratch. But, not all cabs were developing the scratch. Therefore it is not the root cause of this scratch.

To check for this cause, I went to the station where bending of lock plate is done. I observed two cabs while bending was being done. One cab got the scratch and the other did not. Then, I myself tried to bend the two lock plates and felt the difference in hardness between the two. So, I tabulated my observations for the next five cabs as:

4: Some lock plate might be harder than others:

Cab Number Hard Lock PlateOccurrence of

Scratch

8174 NO NO

8158 YES YES

8175 NO NO

8176 NO NO

8177 YES YES

Since hardness of lock plate has a direct relation with occurrence of scratch, it is the root cause of this scratch.

Scratch at a can be eliminated by avoiding metal to metal contact between the tool and the lock plate.

This can be achieved by using plates of a hard non metallic material(like acrylic) in the jaws of the conventionally used metallic tool.

Prevention From Scratch:

(b):

Cause of Scratch:Due to very less space provided for fitting the shocker in sleeper cabs and due to worker’s carelessness, the shocker or the nut tightening gun sometimes rubs on this region. This scratch was found in 8 out of 100 cabs.

b

Plastic coated masking tapes can be applied in the scratch prone regions before fitting their nearby components.

Plastic Coated masking tape

Plastic coated tape can be made in line only by applying brown tape over the conventionally used masking tape.

Prevention From Scratch:

Lower Edge of Central Panel

Possible Causes of Scratch: 1: Workers’ carelessness during fitment of parts near central panel.2: Height of some pegs might not be appropriate.3: In some cabs the gap at the top edge of central panel might be more than needed.4: Some cabs might not properly rest over the peg which cause them to lean down from the front.

Validation of Causes: 1: Workers’ carelessness during fitment of parts near central panel:I observed the fitments near central panel in five cabs and found that workers were not responsible for this scratch.Hence, it was not a cause of this scratch.

2: Height of some pegs might not be appropriate which might bring them to the level of central panel:To check for this cause, I checked the height of ten pegs and tabulated them as:

The height of all the pegs had impact on the formation of scratch to some extent. But, in some cabs(mainly LPS) the height was more than required but still the scratch didn’t create. Therefore this can be a cause of this scratch, but not the root cause.

Height Of Peg Occurrence of Scratch60.4cm NO58.5cm NO60.8cm NO62.2cm YES62.6cm YES61.5cm NO62.3cm YES59.2cm NO61.5cm YES61.7cm NO

3: In some cabs the gap at the top edge of central panel might be more than needed. This lowers the central panel and might bring it to the height of the peg:In some cabs it might be possible that the gap provided at the top edge of central panel be more than it should be. So, I checked for this cause in five cabs and tabulated as:

There was no relation between the gap at the top edge and the formation of scratch. Therefore, I concluded that this was also not a cause of this scratch.

Gap 'x'Occurrence of

Scratch156mm NO

154mm NO

160mm NO

154mm NO

158mm YES

x

4: Some cabs might lean down more from the front than others:Resting points of sleeper and non sleeper cabs were different which caused the non sleeper(LPK) cabs to lean down more from the front than sleeper(LPS) cabs.

Resting point of LPK

Resting point of LPS

To check whether this might be the cause of this scratch, I observed three LPK cabs and three LPS cabs and tabulated as follows:

This cause was observed in all the cabs that had this scratch and hence is the root cause of this scratch.

h

LPK LPSCab

Number Height 'h'Cab

Number Height 'h'

8173 125.8cm 8157 128.2cm

8174 124.8cm 8158 127.8cm

8175 126.2cm 8159 128.6cm

On an average this height ‘h’ should be more than the sum of heights of central panel and the peg individually to avoid the formation of scratch.

Average Height of Central Panel(65cm) + Average Height of Peg(60cm) = 125cm

Therefore cabs having height ‘h’ less than or equal to 125 will obtain the scratch.

This scratch can be avoided if we raise the cab to a height that under no conditions the central panel touches the peg.

This has been implemented by using rubber pads below the acrylic plates fitted at points where the cab rests on the peg. This adjustment raises the cab to 1.0-1.5cm more height above the peg.

Prevention From Scratch:

A permanent solution to this problem is by replacing all the currently used acrylic plates with thicker plates, so that they produce the same effect as the combination of currently used plates and rubber pads have.

However, not all pegs have this adjustments. In some, either the rubber pads have been damaged or have got removed due to poor maintenance.

Door Face Possible Causes of Scratch:(1): If door cover is not applied, scratches can be caused by any metallic object coming in its way.(2): If metal dust get stuck to the magnets on the inner side of the covers, they rub with the door face.

Prevention From Scratch:

(1): Proper door covers should be applied throughout the line. Further, care should be taken by workers that no metallic object rubs the door. Cotton-made watch covers and belt covers should be worn by the workers before coming to the line.×

(2):

Normal door cover attracts dust of metal which sooner or later creates scratches.

Masking tapes areused to avoid thesticking of metallic dust.

However, masking tapes are not completely reliable and some metallic dust still stick over it. So, they are required to be brushed at regular intervals.

Plastic coated masking tapes do not allow metal dust to stick on it and hence are preferable.

Door Inner Upper Near Window

Causes of Scratch: (1) Worker’s carelessness during (2) For fitting the channel inside the window hammering is inserting the channel. done at the corners of the channel. Since there is hardly any clearance provided between the channel and window, the

channel while fitting inside creates scratches on the window.

Prevention From Scratch:(1): Worker should carefully insert the channel inside the window, taking care that it does not touches the window.

(2): This scratch can be prevented by avoiding hammering and that will be possible if we provide some clearance between the window and channel.

Further, if we use a proper hammer then also this scratch can be prevented to some extent.

Damaged Hammer Proper Hammer

×

8. Conclusion:1. Assembling

processes will be more efficient after

improvements.

2. No extra process for fixing the

scratches will be required.

3. Time consumption will

be less.

4. Quality of work will be improved.

5. It will decrease the total cost of

production.