1.0 Introduction:
1.1 History
The origin of Ashok Leyland can be traced to the urge for self-reliance, felt by' independent India. Pandit Jawaharlal Nehru, India's prime minister persuaded Mr. Raghunandan saran, an industrialist, to enter auton10tive manufacturing.
In 1948, Ashok motors were set up in Chennai, for the assembly of Austin cars. The company's destiny and nature changed soon with equity participation by British Leyland and Ashok Leyland commenced Manufacture of commercial vehicles in 1955. Since then Ashok Leyland has been a major presence in India's commercial vehicle industry with a tradition of technological leadership, achieved through tie-ups with international technology leaders and through vigorous in-house R&D. Responding to the operating conditions and practices in the company, the company made its vehicles strong, over-engineering them with extra metallic muscles. "Designing durable products that make economic sense to the customer, using appropriate technology", became the design philosophy of the company, which in turn has molded consumer attitudes and the brand personality. The 5, 00,000 vehicles we have put on the roads have considerably eased the additional pressure place on road transportation in independent India.
In the populous Indian metro's, four out of the five State Transport Undertaking (STU) buses come from Ashok Leyland. Some of them like the double-decker and vestibule buses are unique models from Ashok Leyland, tailor made for high-density routes in 1987; the overseas holding by Land Rover Leyland International Holdings Limited (LRLIH) was taken over by a joint venture between the Hindu Group, the Non-Resident Indian tradition group and IVECO.
1.2 About Manufacturing Plant
At Hosur, there are three manufacturing units Plant-I located at 35 km from Bangalore on the area of 41.5 hectares (102 acres) and Plant-Il 15 km further away on the National Highway on an area of 121 hectares. In this plant, referred as Hosur Plant-I, facilities have been created for production of special vehicles and engines meeting specific customer requirements apart from regular models of commercial vehicles and engines while corporate engineering and quality control headquarters are located at Chennai (Ennore), local engineering and quality control departments to support these functions are available at Hosur.
The products of the company are well received in the market and they have a reputation for durability and high reliability. The engines produced in the plant are for industrials, marine and other application besides automotive application. The engines manufactured in the plant are being exposed to a number of countries.
The customers for the product of Ashok Leyland, Hosur include large goods and passenger fleet operators including state transport undertaking, individual truck/bus operators, and defense mining and other users in the country. This plant has been certified for ISO 14001 in the year 2014 and ISO/TS 16949 in the year 2016
1.3 Vision
1.4 Environment Policy
Ashok Leyland is committed to protecting the environment and will.
Towards fulfilling the objectives, we prorogate our environmental policy and our commitment to climate change mitigation, to all our stakeholders’ viz., employees, suppliers, customers and our neighbors. We will also strive towards enhancing our environmental sustainability.
1.5 Gemba
Cost and Gemba in Japanese means the place where all activities are actually taking place; in other words, the place where value is added. In case of the manufacturing industry, Gemba is the shop floor; for the hotel industry, it is the place where food is actually cooked; and in case of the service industry, it is everywhere. Gemba is thus the most precious place for the management. An empowered Gemba team, armed with skills and information takes full responsibilities for quality and delivery.
1.6 Nine Initiatives
1.7 Layout
1.8 Inhouse Facilities
The Ashok Leyland, Hosur Unit-I is spread over approximately hundred acres having 3 machine shops, 2 Engine assembly shops, sophisticated Engine R&D centers. In one engine assembly shop Hino engines are assembled. In the second shop 680 and other AL models of engines are assembled which are used for industrial purpose, marine applications, and special applications.
1.9 The Functions of Machine Shops
Shop 1 – H-series head and block and P-15 head and block Machining ZD30 assembly, metrology.
Shop 2 – H-series and P-15 engine assembly, testing and lacquering.
Shop 3 – Heat Treatment/Tool Room Maintenance
Shop 4 – H series block, camshaft, gears.
Shop 5 – Heat Treatment
Shop 6 – Engine Stores
Shop 7 – Logistics
2.MACHINE SHOP I
2.1 H-SERIES CYLINDER BLOCK
It is a single casting, which acts as the base of the engine above which cylinder head is placed. Cylinder block forms the basic framework of the engine. It provides a rigid framework for various parts of the engine. It provides a block house for the combustion bores. Block house forms a part of lubrication system. It supports the lubrication oil passage. it has six faces.
2.1.1 SPECIFICATIONS
2.1.2 HEAD FACE
2.1.3 SUMP FACE
2.1.4 LH FACE
2.1.5 RH FACE
2.1.6 Front Face
2.1.7 REAR FACE
2.2 H-SERIES CYLINDER BLOCK LAYOUT
2.3 H-SERIES CYLINDER BLOCK PLATFORM
Sl.
NO LA
NO OP MIC DESCRIPTIO LINE BAY
I 9653 010 MILL & DRILL LML*M446 HCB 1B
2 4078 020 MILLING 2SP LML*M189 HCB 1B
3 4013 030 MILLING SPL VER NOTCH LML *M183 HCB 1B
4 9814 040 DUPLEX MILLING LML*LM457 HCB 1B
5 4128 050 BORING ROUGH XLO*650337 HCB 1B
6 4049 060 DRILL 2 WAY MULTI SP
XLO*650324 HCB 1B
7 8641 070 SPM MILLING BFW*8038020/97255 HCB 1B
8 '4109 080 HB 800 PAL HCB 1B
9 11402 090 LML SPM LM 662 HCB 1B
10 8642 IOO SPM MILLING BFW I-ICB 1B
11 4033 110 5 SP LINEAR INDEX TICO*M136 HCB 1B
12 10131 120 BFW HM
C HCB 1B
13 4269 130 DRILL CNTR TICO TH25*Ml 71 HCB 1B
14 9880 140 CNC MULTI DRILLING
&REAMING HCB 1B
15 8405 150 MULTI TAPPING HCB 1B
16 8551 160 SPM 2 STN DRILLING TCO*M242 HCB 2B
17 8547 170 SPM 2 STN TAPPING TCO*M243 HCB 2B
18 4268 180 DRILL CNTR TICO TH25*M 170 HCB 2B
19 8710 190 SPM 8STN DRILLING LML*LM356 HCB 2B
20 4055 210 DRILL 5 SPM HORZ LML*M186 HCB 2B
21 4058 220 DRILL 3 SPINDLE TICO*M142 HCB 2B
22 4059 230 DRILL 5 SPINDLE TICO*M143 HCB 2B
23 8438 240 DRILL I OSP TICO*M235 HCB 2B
24 4032 250 SPYI 2 SPINDLE TICO*M135 HCB 2B
25 9648 260 MILLING BEW SPM HCB 2B
26 4077 270 BORER WAY ROUGH HCB 2B
27 4463 280 HMT RD HCB 2B
28 8560 290 DRILLING HMT RD HCB 2B
29 4097 300 DRILL 3 SPINDLE 'ITO*M 149 HCB 2B
30 10687 310 DRILL SPM HCB 2B
31 4083 320 DRILL 4 SPINDLE HCB 2B
32 9607 330 DRILLING SPM HCB 2B
33 8257 340 DRILL 12 SPINDLE MMT*M200 HCB 2B
34 4144 350 TAPPING 9 SPINDLE MMT HCB 2B
35 4146 360 MMT 10 SPINDLE*M203 HCB 2B
36 9093 380 OGPT SPM INDIA HCB 3B
37 8584 390 MILLING & BROACH LML*M300 HCB 3B
38 8863 400 SPM MILLING DUPLEX
LML*M353 HCB 3B
39 11417 410 LML PCN OPN HCB 3B
40 4031 420 HB 800 PAL*73006 HCB 3B
41 9663 430 CNC DRILLING HCB 3B
42 8864 440 BORING FACING HMT*13465 HCB 3B
43 4900 450 DRILL 2 SP 6 STN LML*M221 HCB 3B
44 10033
460 BFW ENNORE LML VML 1200
VMC HCB 3B
45 10418 480 BOLT TIGHTENING M/C HCB 3B
4313 490 BORER 2 WAY LML*M221 HCB 3B
47 10000 500 GROOVING HORZ*Y3562 HCB 3B
48 9971 510 LML SPM HCB 3B
49 4191 520 MILLING SPL VERT LML*M210 HCB 3B
50 4464 530 BORER FINISH XLO*650382 HCB 4B
51 9398 540 BORER FINISH LML HCB 4B
52 9868 550 REAMING EMT*E511 HCB 4B
53 4564 560 HONING GEHEING z 600-
125*0009 HCB 4B
54 4575 570 HORI DEBURR SPM HCB 4B
55 9687 630 CAM BUSH PRESS HCB 4B
56 9688 640 WELGE PLUG PRESS HCB 4B
57 9690 650 WELGE PLUG PRESS HCB 4B
58 9689 660 WELGE PLUG PRESS HCB 4B
59 9621 680 OP TEST RIG HCB 4B
60 4466 710 LINER PROJECTION HCB 4B
3.0 MACHINING OPERATIONS
3.1 DRILLING
Drilling is process of making hole or enlarging a hole in an object by forcing a rotating tool called 'Drill'. The drill is generally called 'twist drill', since it has a sharp twisted edge formed around a cylindrical tool provided with a helical groove along its length to allow the cut material to escape through it. The sham edges of the conical surfaces ground at the lower end of the rotating twist drill cut the material by peeling it circularly layer by layer when forced against a work piece.
The removed material chips get curled and escape through the helical grooves provided in the drill. A liquid coolant is generally used while drilling to remove the heat of friction and obtain a better finish for the hole.
3.2 DRILLING MACHINE
Drilling machine is one of the simplest, moderate and accurate machine tool used in production shop and tool room. It consists of a spindle which imparts rotary motion to the drilling tool, or mechanism for feeding the tool into the work, a table on which the work rests and a frame.
Specifically, the various types of drilling machines are specified as follows:
3.3 REAMING
Reaming is the operation of finishing an existing hole very smoothly and accurately in size. A drill will not produce a hole having sufficiently good qualities of finish and accuracy for many purposes. Therefore, when a very accurate, smooth hole is required the hole is first drilled a little undersize. Then it is reamed to the correct size. The accuracy to be expected is within ± 0.005 mm.
A reamer is a multi-tooth cutter which rotates and moves linearly into an already existing hole. The reamers are of following types:
3.4 BORING
It is an operation of enlarging an existing hole. When a suitable size drill is not available, initially a hole is drilled to the nearest size and using a single point cutting tool made of HSS or carbide, the size of the hole is increased. By lowering the tool while it is continuously rotating, the size of the hole is increased to its entire depth. Boring machines are one of the largest of the machine tools and are able to machine work pieces weighing up to 180 kN.
3.5 MILLING
Milling is a process in which metal is removed by means of a revolving cutter with many teeth, each tooth having a cutting edge which removes metal from a work piece. Milling machines are used to produce parts having flat as wells as curved shapes. Intricate shapes, which cannot be produced on the other machine tools, can be made on the milling machines. Generally, there are two types of milling process, namely:
The milling machines are broadly classified as follows:
3.6 COUNTERBORING
It is an operation of enlarging a drilled hole particularly that IS for a specific length generally done to accommodate the socket head screws or grooved nuts or round head bolts. The counter boring forms a large sized recess or a shoulder to the existing hole. The speeds for counter boring must be two thirds of the drilling speed of the corresponding size of the chilled hole.
3.7 HONING
Honing is an abrasive Machining process that produces a precision surface on a metal work piece by scrubbing an abrasive stone against it along a controlled path. Honing is primarily used to improve the geometric form of a surface but may also improve the surface texture.
Typical applications are the finishing of cylinders for internal combustion engines, air bearing spindles and gears. There are many types of hones, but all consist of one or more abrasive stones that are held under pressure against the surface they are working on.
3.8. TAPPING The tapping is a highly efficient threading process. This method offers productive and economical threading especially for smaller threads through reduced machine down time, higher cutting speeds and long tool life.Forming taps and cutting taps come in different designs. The material, coating and geometry of the tap are very important features to be considered for each tap style. A material or application may not be working effective for another material or application.
4.0 MEASURING INSTRUMENTS
4.1 Threaded plug gauge:
This gauge is used to check whether the diameter of thread is within the given range or not.
Method of use:
o the product and on thin walled parts, be especially aware that the gage may be more easily forced into or over the product distorting the product.
Result of inspection:
Note:
The inspection has to be made only after properly cleaning the surface
5.0 SCOPE OF THE PROJECT
5.1 SCOPE
In this project an attempt is made to reduce scrap and rework in tapping (LA 8547) and drilling operations (LA 4058 & LA 4032) of H-series cylinder block in Machine shop-1.
5.2 OBJECTIVES
Tapping:
Drilling:
LA 8547 – RH Tap
LA 4032 – HF 7mm water hole
LA 4058 – HF 4mm water hole
LA 4191 – HF finish milling
LA 8405 – FE Tap
LA 4033 – HF angular 6.8mm water hole
LA 9880 – FE /RE drill
LA 4463 – Dipstick hole drill
LA 4564 – Honing
Project Planning:
Gantt Chart: It is a tool used to plan the project ahead of time and helps to complete the project with in schedule. The Gantt chart has been attached as follows.
6.0 Root Cause Validation:
6.1 L 8547 – MULTI TAP ON RH PROBLEM
PROBLEM:
No proper tapping is provided for all the holes. The tap is either incomplete or it is not at all made.
COLLECTING DETAILS ON LA 8547:
Speed Clamping pressure Types of tap made
300-340 rpm 40-50 Kg/sq.cm M8 × 1.25 and M10 ×1.5
ON VISUAL MONITERING:
POSITIVES:
NEGATIVES:
SORTING OUT THE REASONS:
CHAMFERING IS NOT PROPER
Chamfering for those holes on the RH side is made in LA 8551 using the sub land drill tool which simultaneously produces the hole and chamfers it.
USAGE OF FLOAT TAPPING
Float taping is used so that it prevents the tool from breakage. If there is any axial load experienced by the tool the spring takes it and reverts the tool back which leads to improper tapping.
BURR NOT REMOVED
If burr is not removed from the holes it may act as an obstruction to the tapping tool and result in improper tap. So, for all three reasons we need to know about the machine that drills these holes
6.2 LA 8551- DRILLING ON RH SIDE
PROBLEM
ON OBSERVATION
Details of LA 8551
Spindle speed Cutting feed
6.8 DRILL 590-610 RPM 6.8 DRILL 170-180 mm/min
EXPERIMENTATION:
REGULAR PROCESS:
ON CLEANING:
6.3 LA 4032 AND 4058 – DRILL ON HF
PROBLEM:
Frequent breakage of drill bit which significantly adds up in the no of components to be reworked.
ON OBSERVATION:
Details of LA 4032
Spindle speed Cutting feed
810 RPM 100-110 mm/min
Details of LA 4058
Spindle speed Cutting feed
610 RPM 65-80 mm/min
6. BRAIN STORMING
FOR LA 8547
Sl.No IDEAS GENERATED
1 Tap length less
2 Tap wear
3 Tap setting fault
4 Presence of burr in the hole
5 Clamping pressure less
6 Insufficient coolant provided
7 Not enough torque produced in machine
8 Improper budding of job
9 Chamfer less
10 Improper shape of hole
11 Power cut
12 Usage of floating tap setup
13 Absence of jig
For LA 4058 and LA 4032
Sl.NO IDEAS GENERATED
1 Tool material
2 Tool life
3 Tool total length
4 Tool flank length
5 Tool shank length
6 Spindle speed
7 Feed rate
8 Jig/bush design
9 Proper coolant provided
10 Proper removal of chips
11 Clamping pressure
12 Power cut
13 Overheating of tool
7. FISH BONE DIAGRAM FOR DRILLING:
7.1 FISHBONE DIAGRAM FOR TAPPING:
8. Root Cause Validation for LA 8547
Sl.No Potential causes Verification Validation of the causes Action plan
1 Tap length Measured using
Vernier caliper No Tap length should be verified frequently
2 Presence of burr in hole Visual Yes Should be removed by coolant or manually by using blowers
3 Chamfer less Using thread gauge Yes Sub land drill
4 Absence of jig Visual Yes Jig should be provided to guide the tapping tool
5 Improper shape of hole Using gauge No The holes should be checked with gauge frequently.
9. VALIDATION OF CAUSES FOR LA 4032 AND LA 4058
Sl.No Potential causes Verification Validation of the causes Action plan
1 Drill total length Measured using
Vernier caliper Yes Total length of the drill bit should be made for the prescribed length by the machine builder.
2 Improper bush design Visual Yes Should be removed by coolant or manually by using blowers
3 Spindle speed Non-contact tachometer No Monitoring the spindle speed regularly
4 Cutting feed Stopwatch No Monitoring the cutting feed regularly
5 Improper cooling system Visual No Period
ic check on air flow rate
9. ROOT CAUSE CONSOLIDATION:
TAPPING:
9.1. CHAMPER IN THE HOLE
The chamfer produced in the predrilled hole is not proper, so the tapping tool is not guided towards the hole properly.
9.2 REMOVAL OF BURR
The burr produced during the drilling operations is not completely removed because of the insufficient amount of force given to the coolant in the drilling operations which eventually acts as a disturbance during tapping process and results in partial tap.
DRILLING:
9.3. TOOL LIFE
The tool life of the drilling machine is more when compared with other machines which leads to premature drill bit breakage and results in rework/scrap.
9.4. BUSH DESIGN
The bush design is in such a way that the gap between the block and the bush is large. more the gap, less is the support given to the drill bit and a small force acting on it may break the drill bit
10. ACTION FOR ROOT CAUSE ELIMINATION
OLD BUSH DESIGN:
WHY WE CHANGED THE BUSH DESIGN?
The new bush design is made based on the consideration of support to be given to the bush without disturbing the removal of chips during drilling operation.
ADVANTAGES OF NEW BUSH:
The new bush design is given below.
CHANGED BUSH DESIGN:
11.FEASIBILITY STUDY
For LA 4058 AND 4032
Action plan Technical Economical Operational
To change the flute length of the tool Yes No Yes
To reduce the overhanging of the tool Yes No Yes
To change the drill bit material Yes No Yes
To provide coating for the drill bit Yes No Yes
To increase the frequency of tool change span of drill bit Yes Yes Yes
To change the bush design thereby reducing the gap between bush and the job Yes Yes Yes
For LA 8547
Action plan Technical Economical Operational
To change the attachment of tapping setup frequently Yes No No
To remove the burr in the hole before tapping operation Yes No Yes
To manually clean the hole before tapping using blower Yes Yes No
To provide proper coolant system in drilling machine to remove all the burr produced Yes No Yes
To make the coolant flow in advance in tapping machine to remove the burr in hole No Yes Yes
12. IMPLEMENTATION
WHAT WHY WHERE HOW
Change the bush design by increasing the length of the bush To increase the support given to the tool and to maintain proper removal of chips LA 4032 By machining a new bush for increased length and changing the old bush with the new one
To decrease the frequency of tool change period from 240 to 100 Comparing with other similar operation machines the frequency of tool change period is inappropriate LA 4032 By requesting EHWA to change the tool for every 100 blocks
To decrease the frequency of tool change period from 240 to 100 Comparing with other similar operation machines the frequency of tool change period is inappropriate LA 4058 By requesting EHWA to change the tool for every 100 blocks
13. RECOMMENDATION
WHAT WHY WHERE HOW
To remove the burr in the drilled hole before tapping operation. The burr present in the hole during tapping causes disturbances to the tapping setup thereby reverting the tool back to its initial position without tapping the hole completely LA 8547 *To provide the coolant properly in drilling operation to remove the burr
*To provide the coolant in advance in tapping machine to remove the burr before tapping operation starts
14. PROJECT OUTCOMES
For LA 4058
Before Lean Implementation:
NO OF COMPONENTS IN MONITERED NO OF COMPONENTS SENT FOR REWORK PERCENTAGE OF REWORK COMPONENTS
4500 14 0.311
After Lean Implementation:
NO OF COMPONENTS MONITERED NO OF COMPONENTS SENT FOR REWORK PERCENTAGE OF REWORK COMPONENTS
(%) % OF REWORK REDUCED
(%)
515
0
0
100
For LA 4032
Before Implementation
NO OF COMPONENTS MONITERED NO OF COMPONENTS SENT FOR REWORK PERCENTAGE OF REWORK COMPONENTS
(%)
4500
20
0.44
After Implementation
NO OF COMPONENTS MONITERED NO OF COMPONENTS SENT FOR REWORK PERCENTAGE OF REWORK COMPONENTS
(%) % OF REWORK REDUCED
(%)
490
1
0.2
54.54
For LA 8547
Without Cleaning with blower
Component No M10 M8
Fully tapped Nos Partially tapped Nos Fully tapped Nos Partially tapped Nos
AZ 971 4 3 12 6
AZ 966 3 4 11 7
AZ 967 5 2 13 5
AZ 969 3 4 13 5
AZ 847 4 3 12 6
AZ 845 2 5 15 3
AZ 848 3 4 14 4
AZ 854 5 2 13 5
AZ 880 2 5 16 2
AFTER CLEANING WITH BLOWER
Component No M10 M8
Fully tapped Nos Partially tapped Nos Fully tapped Nos Partially tapped Nos
AZ 962 6 1 18 0
AZ 963 5 2 18 0
AZ 964 7 0 17 1
AZ 965 6 1 18 0
AZ 968 6 1 16 2
AZ 950 5 2 17 1
AZ 951 7 0 16 2
AZ 953 6 1 18 0
AZ 956 6 1 17 1
TOTAL NO OF COMPONENTS TOTAL M8 HOLES FULLY TAPPED TOTAL M10 HOLES FULLY TAPPED
9
162 UNCLEANED CLEANED
63 UNCLEANED CLEANED
119 155 32 54
15. BENEFITS
For LA 4058
For LA 4032
15.1 COST ESTIMATION FOR A REWORK
1.LA 4032
Approx. working time – 30 mins/block Tool cost = Rs 1.8/block
MAN ASSOCIATE – Rs 215 / Hr.
ASSISTANT – Rs 42 /Hr.
MACHINE DRILLING MACHINE – Rs 72/ Hr.
SPARK MACHINE – Rs 60/Hr.
TOTAL COST FOR A BLOCK = 389/2 + tool cost = Rs 196.3
BEFORE IMPLEMENTATION:
TOTAL NO OF REWORK COMPONENTS FOR 4500 BLOCKS -20
TOTAL COST FOR 20 COMPONENTS = 20 X 196.3 = Rs 3926
AFTER IMPLEMENTATION:
TOTAL NO OF REWORK COMPONENTS FOR 4500 BLOCKS – 9
TOTAL COST FOR 16 COMPONENTS = 9 X 196.3 = Rs 1766.7
INVENTORY COST
Inventory cost for one block = Rs 12,000
BEFORE IMPLEMENTATION:
TOTAL NO OF REWORK COMPONENTS FOR 4500 BLOCKS -20
TOTAL INVENTORY COST FOR 16 COMPONENTS = 20 X 12000= Rs 2,40,000
AFTER IMPLEMENTATION:
TOTAL NO OF REWORK COMPONENTS FOR 4500 BLOCKS – 9
TOTAL INVENTORY COST FOR 16 COMPONENTS = 9 X 12000 = Rs 1,08,000
2.LA 4058
Approx. working time – 30 mins/block Tool cost = Rs 1.8/block
MAN ASSOCIATE – Rs 215 / Hr.
ASSISTANT – Rs 42 /Hr.
MACHINE DRILLING MACHINE – Rs 72/ Hr.
SPARK MACHINE – Rs 60/Hr.
TOTAL COST FOR A BLOCK = 389/2 + tool cost = Rs 196.3
BEFORE IMPLEMENTATION:
TOTAL NO OF REWORK COMPONENTS FOR 4500 BLOCKS -14
TOTAL COST FOR 20 COMPONENTS = 14 X 196.3 = Rs 2748.2
AFTER IMPLEMENTATION:
TOTAL NO OF REWORK COMPONENTS FOR 4500 COMPONENTS – 0
TOTAL COST FOR 16 COMPONENTS = Rs 0
INVENTORY COST
Inventory cost for one block = Rs 12,000
BEFORE IMPLEMENTATION:
TOTAL NO OF REWORK COMPONENTS FOR 4500 COMPONENTS -14
TOTAL INVENTORY COST FOR 16 COMPONENTS = 14 X 12000 = Rs 1,68,000
AFTER IMPLEMENTATION:
TOTAL NO OF REWORK COMPONENTS FOR 4500 COMPONENTS – 0
TOTAL INVENTORY COST FOR 16 COMPONENTS = 0 X 12000 = Rs 0
Break Even Analysis:
BEP = 32 Units.
16. LIMITATIONS
17. SCOPE FOR FURTHER IMPROVEMENT
For LA 4058 and LA 4032
17.1 CHANGING THE TOOL MATERIAL OR PROVIDING THE COATING TO THE TOOL
By providing coating or by changing the tool material the life of the drill
bit is increased thereby the tool breakage and the rework components will be reduced
REFERENCE: Material science and engineering by William D Callister
17.2 BY REDUCING THE FLUTE AND TOOL LENGTH OF THE TOOL
By reducing the flute or the total length of the tool, the overhung distance of the tool is reduced and the forces acting on the tool is minimized, and the drill breakage is reduced.
17.3 PROPER COOLING SYSTEM SHOULD BE PROVIDED
Now air is used as a coolant for these machines, usage of coolant removes burr completely and also cools the drill bit which decreases the risk of drill breakage.
REFERENCE: Contemporary drill design by Kenneth M Snoeck
18.LEARNING
19.CONCLUSION
This project is started because of more number rework/scrap components produced in drilling (LA 4032 and LA 4058) and tapping (LA 8547) operations on H-Series cylinder block at Machine Shop – I. For increasing the productivity of the shop, the following implementations and recommendations are given and successfully tested.
IMPLEMENTIONS:
RECOMMENDATION:
The burr produced while drilling in RH face should be removed either by coolant or by blowers to reduce the partial tapping problem thereby reducing the tap breakage during manual tapping process.
20. BIBILIOGRAPHY