2. Valliammai Engineering College
Mechanical Engineering Department
Main Project - Review Presentation
(Batch No: 13)
PREVENTION OF WRONG THREAD FORMATION IN DI ROTOR
(SIMPSON & JCB)
INDUSRIAL PROJECT AT DELPHI-TVS
Team members
C.THENAPPAN (42210114061)
M.SATHISH KUMAR (42210114056)
M.SRINATH (42210114058)
L.PALANIYAPPAN (42210114046)
Project Guide
S.Karthikeyen (Asst.Professor
Department of Mechanical Engg, VEC.)
3. Introduction
• The serious problem faced by today’s industry is material wastage.
• Material wastage mainly occurs due to machining of component in the
wrong operative cycle process.
• The scrap rate for manufacturing any component while machining should
be at the lower rate.
• Every industry always aim for material optimization while manufacturing.
• Material wastage contributes a great loss to the industry by both money and
time.
4. TASK GIVEN TO US
• To reduce scrap formation in quality line.
• To construct a Poka-Yoke System, by which
scrap rate reduces to ‘0’
• There by to eliminate Wastage Cost
incurring per month.
6. Problem with the existing system:
• In the existing system, the typical rotor types considered are Simpson
rotor and JCB rotor.
• Both rotors look identical in their physical identity, but anyhow they have
different parametric state.
• For example, Simpson rotor requires right hand thread cutting while JCB
requires left hand thread cutting.
• While thread grinding operation is to be performed, the operator may get
confused with Simpson and JCB rotor and may perform RH thread
grinding in JCB instead of in Simpson or vice versa.
• Due to wrong thread formation in rotors, it ultimately leads to the material
wastage for the industry.
• In order to overcome this problem new methodology thus been
implemented.
7. Objective
• The objective of the project is to detect the wrong thread formation in the
rotor and also to avoid the wrong thread formation.
• In order to perform this job, new methodology should be implemented.
• The method should be able to differentiate the two rotors based on its
parameter.
• Also it should be able to provide feedback signal to CNC machine to
indicate the wrong component placed in the workplace.
8. Calculation
• The wastage factor is consider of the calculation of the total profit made by
the industry.
• The wastage factor helps in deciding the total estimated quantity to be
manufactured annually.
• Wastage factor is calculated by means initial raw material quantity and wastage
incurred.
The total finished product manufactured per month = 2000 units
The waste material formed per month = 106 units
Wastage factor = (Waste material quantity/Total finished quantity)
9. Wastage Factor = 106/2000
= 0.053 or 5.3%
This wastage factor is used to calculate the estimated quantity.
Estimated Quantity = Raw quantity *(100% + Wastage Factor%)
= 2000*( 100% + 5.3%)
= 2106.
Based on the estimated quantity, the total estimated quantity per
annum is calculated.
The annual total estimated quantity = 2106*12
= 25272 units.
Thus the estimated raw material quantity value is obtained.
10. The loss incurred due to wastage in manufacturing process is calculated
in order to check the expenses.
The manufacturing cost for fabricating a rotor = Rs 2500/unit
The total cost spend for the estimated quantity = 2500*25272
= Rs
6,31,80,000.
The cost of material wastage for the rotor = 2500*106
= Rs 2,65,000
The cost of wastage of Material/Month is Rs 2,65,000/-
11. Scrap rate because of wrong thread in
DI rotor
0
10
20
30
40
50
60
Jul-13 Aug-13 Sep-13 Oct-13 Nov-13
JCB
Simpson
12. Rotor hard stage flow diagram
Buffing OD grinding Tang grinding
Thread grindingHoningHP washing
Screw fitting Line exit
13. Comparison of two rotors
Simpson rotor:
• Right hand thread grinding.
• Plunger bore angle is at 60°.
• No groove is present on the
cylindrical surface.
JCB rotor :
• Left hand thread grinding.
• Plunger bore angle is at 90°.
• A rectangular shape groove
is present on the cylindrical
surface.
15. Two types of threads for DI rotors
Simpson rotor
• Right hand thread rotor
JCB rotor
• Left hand thread rotor
16. Two types of threads for DI rotors
Simpson Rotor JCB Rotor
17. Project idea
• The main difference between the two rotors is the Plunger bore angle.
• The plunger bore angle for Simpson is 60° and for JCB is 90°.
• Using the above parameter, the wrong thread formation is detected and it is
also avoided.
• Hence the pneumatic cylinder with electric feedback is used to identify the
rotor plunger bore angle.
18. Poka - Yoke
• The term "poka-yoke" comes from the Japanese words "poka" (inadvertent
mistake) and "yoke" (prevent).
• Poka- yoke is a quality assurance technique developed by Japanese
manufacturing engineer Shigeo Shingo.
• The aim of poka - yoke is to eliminate defects in a product by preventing or
correcting mistakes as early as possible.
• Poka-yoke has been used most frequently in manufacturing environments.
19. Steps to be followed to implement
Poka – Yoke
• Step 1: Describe the defect (or potential defect).
• Step 2: Determine where the defect is discovered or where it is made.
• Step 3: Detail the sequence of events in the documented standard.
• Step 4: Observe the process and detail the steps that differ from the
standard.
• Step 5: Identify contributing conditions (tools, training, etc).
Refer to step 4 observations; ask the 5 ‘whys’ to determine root cause.
• Step 6: Identify the mistake-proof device necessary to prevent the defect.
21. Methodology
• The system consist of,
1. double acting pneumatic cylinder,
2. probe,
3. feedback circuit.
• The double acting cylinder is attached to work plane of the system.
• The probe is attached to one end of the double acting cylinder in such a
way that the probe axis lies on the central axis of the plunger bore hole.
• The double acting cylinder is connected to the feedback circuit which in
turn is connected to CNC machine.
22. Hardware used
• Double acting pneumatic cylinder with Probe.
• Feedback circuit.
• Air compressor.
• Thread grinding machine.
• CNC machine.
• 5/2 DC Valve.
• Magnetic Reed Switches.
23. Process flow chart
Air compressor sends air to
the double acting cylinder
Probe in the cylinder is
extended
Probe passes through the
plunger bore (JCB)
Feedback valve is given as
‘1’
Program continues and
thread is formed
Probe strikes the rotor
surface (SIMPSON)
Feedback valve is given as
‘0’
Error is detected and
program terminates
24. CNC Coding Before Poka - Yoke
02324 (GRING PRG FOR E-2 @ SIMPSON) ;
G 98 ;
G 10 P10000 X0 Z0 ;
G54 T0 ;
G01 (356.9 F5000) ;
G4 X 0.5 ;
IF [#1005 EQ 1] GOTO 4950 ;
#940 = 420.65 ;
#5262 = #940 ;
25. CNC After Poka - Yoke
02324 (GRING PRG FOR E-2 @ SIMPSON) ;
G 98 ;
G 10 P10000 X0 Z0 ;
G54 T0 ;
G01 (356.9 F5000) ;
M 93 (PY FWD) ;
G4 X 0.5 ;
IF [#1005 EQ 1] GOTO 4950 ;
M94 (PY RVS) ;
#940 = 420.65 ;
#5262 = #940 ;
28. Working
• Double acting cylinder actuated by Pressurized Air
• Forward Motion and Retraction Controlled by Single
Solenoid 5/2 DCV
• When JCB Rotor fixed in the machine, Probe in the
Cylinder enters passes through the Plunger Hole
during forward motion
• The Feedback is given as ‘1’ , CNC Reads and
threading operation takes place
• In case of Simpson Rotor, Probe hits the rotor surface
sending the feedback as ‘0’
• Threading Operation terminates with the message
“ Wrong Rotor Inserted”
30. TIME STUDY RESULTS
After Implementation of Poka-Yoke
53
0
0
10
20
30
40
50
60
BEFORE POKA - YOKE AFTER POKA - YOKE
Qtyinno’s
Wrong Thread reduction(Average/Fortnight)
32. Work Allocation
SL
NO:
NAME OF THE
STUDENT
WORK DONE WORK TO BE
DONE
1.
THENAPPAN.C
M.SRINATH
1. Design and
Fabrication of
the system
2. Review of the
rotor
manufacturing
cell unit
1. Analysis study of
the rotor production
unit
2.
M.SATHISH
KUMAR
L.PALANIYAPPAN
1. Design and
Fabrication of
the system
1. Methodological
study of the rotor
production unit
