Embed Size (px)
Citation preview
131
APPENDIX 1
ONE POINT LESSON
Table A1.1 One point lesson-2
One – Point Lesson
Them
e
Peening coverage No. 02
Date of preparation
Cla
ssif
icati
on
√ Basic knowledge
Improvement cases
Trouble cases
Coverage – Less Coverage - Good Check : Visual
Good Coverage : 98 % to 100 % desired
Date executed
132
Table A1.2 One point lesson-3
One – Point Lesson
Them
e
Shot size
No. 03
Date of
preparation
Cla
ssif
icati
on √ Basic knowledge
Improvement cases
Trouble cases
The shot size should be selected such that it is 10 % to 25 % of the wire
diameter of the spring.
Shot sizes will be 0.35 to 0.45 mm
Date executed
133
Table A1.3 One point lesson-4
One – Point Lesson
Them
e Shot type
No. 04
Date of
preparation
Cla
ssif
icati
on
√ Basic knowledge
Improvement cases
Trouble cases
The shot type used are – Conditioned cut wire steel shots
Wrong method Right method
Do not use : “AS CUT” Shots
Date executed
134
Table A1.4 One point lesson-5
One – Point Lesson
Them
e Peening intensity
No. 05
Date of
preparation
Cla
ssif
icat
ion √ Basic knowledge
Improvement cases
Trouble cases
This is specified in terms of the Almen arc rise which is selected to suit
the shot size.
Example: 0.4 shot – Arc Rise 0.16 to 0.20 A mm.
Date executed
135
Table A1.5 One point lesson-6
One – Point Lesson
Them
e What is conditioned
shots?
Cut wire
No. 06
Date of
preparation
Cla
ssif
icat
ion
√ Basic knowledge
Improvement cases
Trouble cases
Date executed
136
Table A1.6 One point lesson-7
One – Point Lesson
Them
e Why conditioned shots?
Cut wire
No. 07
Date of
preparation
Cla
ssif
icat
ion √ Basic knowledge
Improvement cases
Trouble cases
Because “ as cut “ shots have sharp edges and produce ‘ sharp notches’
on the spring surface which act as stress raisers leading to crack and
break.
It is observed, shown figure the failure of spring will take place because
of cut shots. Always use conditioned shots only.
Date executed
137
Table A1.7 One point lesson-8
One – Point Lesson
Them
e Conditioned cut wire
shots (0.4mm) -
Information
No. 08
Date of
preparation
Cla
ssif
icat
ion √ Basic knowledge
Improvement cases
Trouble cases
1. Shape : Round ( cylindrical Squares – Corners Rounded )
2. Size : 0.35 to 0.45 mm
3. Chemical Analysis ( Is: 4454-ii ) : C - 0.45 – 0.75, Si – 0.10 – 0.30,
Mn – 0.6 – 1.20 –
S: 0.05 Max.
P: 0.045 Max.
4. Average Mean Hardness : Hv : 650 to 750
5. Length of 10 shots : 4.0 ± 0.50 mm
6. Height of 50 shots : 0.02 to 0.03 gms.
7. Specific height of 1 litter shots : 4.536 kg.
8. Inventory : 800 kg
9. Packing : 25 Kg / Bag
10. Source : Bakul Castings Dewas (MP)
11. Accepting Authority : Inwards Inspection – SSS
12. Procurement Time : 4 Weeks.
Date executed
138
Table A1.8 One point lesson-9
One – Point Lesson
Th
eme
Sieving of shots
No. 09
Date of
preparation
Cla
ssif
icati
on √ Basic knowledge
Improvement cases
Trouble cases
1. Remove shots from machine.
2. Pass through Sieve 1
3. What remains on top is Scrap.
4. Pass again through Sieve 2.
5. What remains on top is ‘good shots’
6. Bottom is scrap.
We get good shots of 0.6 mm
Range : 0.45 to 0.6
( Presently seiving is manual )
Date executed
139
Table A1.9 One point lesson-10
One – Point Lesson
Them
e Conditioned cut wire
shots (0.4mm) -
Information
No. 10
Date of
preparation
Cla
ssif
icat
ion
√ Basic knowledge
Improvement cases
Trouble cases
• Shot size is a parameter in the peening – process.
• Shots degrade during peening.
1. Natural wear
2. Shots break
3. Contamination.
• To maintain acceptable quality of shots sieving is necessary.
Date executed
140
Table A1.10 One point lesson-11
One – Point Lesson
Th
eme
How often is sieving
No. 11
Date of
preparation
Cla
ssif
icati
on √ Basic knowledge
Improvement cases
Trouble cases
1. Sample test : Visual
Every 8 – hours of running.
2. Sieving : Every 24 - hours of running.
Date executed
141
Table A1.11 One point lesson-12
One – Point Lesson
Them
e Shot peening : Process
control
No. 12
Date of
preparation
Cla
ssif
icati
on √ Basic knowledge
Improvement cases
Trouble cases
Sl
No
Controlled Purpose Method Frequency
1 Sieving
Shot Condition :
Size, wear broken
shots,
contamination
dust, fines
• Visual &
magnifier
10X
• Sieving 1&2
• Every 8 hours
• Every 24
hours of
running
2 Amperage
• Shots flow
kg/min
• Level of shots
in hopper
• Ammeter
current in
amps Daily
3 Arc height
• Peening in
intensity
• Velocity of
shots
• Almen strip
• Fixture
• Test gauge Weekly
4 Coverage
• 98% to 100 %
peened surface
• Exposer time
• Visual
magnifier x
10x
• Mat.Lab if in
doubt
Daily
Date executed
142
Table A1.12 One point lesson-13
One – Point Lesson
Th
eme
Belt specification
No. 13
Date of
preparation
Cla
ssif
icat
ion √ Basic knowledge
Improvement cases
Trouble cases
Belt specification :
Part no : 38166
Length : 8730 MM
Width : 100 mm
Thickness : 8 mm
No. of Buckets: 52 No’s.
• The elevator belt conveys peened Shots from bottom hopper to top
hopper.
• The belt is fitted with – 52 buckets.
• ½ of the buckets 26 carry shots.
• The belt runs (7.5 X 52) / 2 = 195 Buckets. Carry 230 kgf shots
per minute.
Date executed
143
Table A1.13 One point lesson-14
One – Point Lesson
Th
eme
Shots level in hooper
No. 14
Date of
preparation
Cla
ssif
icati
on √ Basic knowledge
Improvement cases
Trouble cases
• Minimum level of shots in hopper is marked.
• After each sieving and loading the shots: Check the level of hopper.
• Add new shots if necessary.
• Ideally, the hopper should be ¾” full of shots.
• Maintain it.
Date executed
144
Table A1.14 One point lesson-15
One – Point Lesson
Th
eme
Shots flow information
No. 15
Date of
preparation
Cla
ssif
icat
io
n
√ Basic knowledge
Improvement cases
Trouble cases
• The maximum shot flow this machine can give is 230 kgs / mins.
• The shot flow depends on current amperage.
• The no load current is 5.5 amps. ( 10 HP motor )
• The maximum amps is 14.5 A.
• The operating amperage is 9 amps.
• Hence each amperage raise gives 25.5 kgs of shots.
• It is ideal to run the machine at 14.0 amps but not exceeding 14.50
amps.
The shot flow can be adjusted by abrasive control valve.
Date executed
145
Table A1.15 One point lesson-16
One – Point Lesson
Them
e Blast pattern: How to
check/test ?
No. 16
Date of
preparation
Cla
ssif
icati
o
n
√ Basic knowledge
Improvement cases
Trouble cases
• Use a 3mm thick, 300 mm x 900 mm plate.
• Place it on the work conveyor (Mill).
• Do not run the work conveyor (Mill).
• Shot peen for 30 seconds.
• Take out the plate.
• The blast pattern shows the distribution of shots.
• The area which receives the max. shots is called the ‘hot spot’
(warm to touch and deformed )
• The location of ‘hot spot’ is about 8 from the center of rotor.
• Adjust the pattern by control cage.
Date executed
146
Table A1.16 One point lesson-17
One – Point Lesson T
hem
e How much load on work
conveyor
No. 17
Date of
preparation
Cla
ssif
icat
ion √ Basic knowledge
Improvement cases
Trouble cases
If too much weight,
• Belt sags – gap between belt and side plate
• Springs struck.
• Belt tears at holes
• Break downs.
• Belt shifts
The right quantity: by volume: 1/3, by weight: 180 kgs.
‘Do not overload’.
Date executed
147
Table A1.17 One point lesson-18
One – Point Lesson
Them
e Set up of control cage
through blast pattern
No. 18
Date of
preparation
Cla
ssif
icati
on
√ Basic knowledge
Improvement cases
Trouble cases
Fig. shows the warping of thin (3 mm) plate during the setting of hot spot.
• Test the plate for blast pattern.
• Determine the hot spot.
• Adjust the control cage for current hot spot location.
• Repeat the test for verification.
• Mark the location of control cage.
This helps in future replacements
Date executed
148
Table A1.18 One point lesson-19
One – Point Lesson
Them
e Work conveyor
information
No. 19
Date of
preparation
Cla
ssif
icat
ion √ Basic knowledge
Improvement cases
Trouble cases
Work conveyor consists of vulcanized endless rubber belt, multiple ply
construction with 8.0 ø diameter drain holes.
Work conveyor speed : 6.1 m/min, mill drive motor : 1400 rpm / 1 hp
Date executed
149
Table A1.19 One point lesson-20
One – Point Lesson
Them
e
Dust collector data
No. 20
Date of
preparation
Cla
ssif
icati
on
√ Basic knowledge
Improvement cases
Trouble cases
• Capacity : 1250 to 1700 CFM.
• Type : Motorized shanker type dust collector bag filters 3.
• Make : Vi-Ku Engineers.
• Efficiency : 99 % for 100 microns and above.
• Filter bags : 2 Nos
• Filter Area : 547 Sq.Ft.
• Bag size : 127 ø mm × 1778 mm long.
• Shanker motor : 0.5 Hp, 1400 rpm
• Dust discharge : Manual gate
Date executed
150
Table A1.20 One point lesson-21
One – Point Lesson
Them
e V- Belts, always use
correct V- belts
No. 21
Date of
preparation
Cla
ssif
icat
ion
√ Basic knowledge
Improvement cases
Trouble cases
Date executed
151
Table A1.21 One point lesson-22
One – Point Lesson
Them
e
Plant maintenance
No. 22
Date of
preparation
Cla
ssif
icat
ion √ Basic knowledge
Improvement cases
Trouble cases
• Two important reasons for plant maintenance
1. Condition of the plant.
2. Performance of the plant.
1. Condition of the Plant: Due to peening action, not only the work but
also other parts of the plant like peening cabinet, wheel housing also
Receive peening,
o Through protection is provided, still they wear.
o If unchecked, they may cause holes and leakage of shots from
unprotected parts which are not easy to replace.
2. Performance of the plant: Due to peening action, liners blades,
impeller & control cage will wear.
o If not checked they will affect the blast pattern, intensity and
coverage.
o For these two reasons, regular and periodic checks must be
made immediately.
Date executed
152
Table A1.22 One point lesson-23
One – Point Lesson
Them
e Amperage and wheel
efficiency- Importance
No. 23
Date of
preparation
Cla
ssif
icati
on
√ Basic knowledge
Improvement cases
Trouble cases
1. The ammeter reading of the motor (rotor) indicates the volume of
shots thrown.
2. Therefore the correct amperage should be maintained
3. The Operating range of our 10hp rotor motor is 9 amps i.e.,
(Max. current 14.50 A- No load current 5.5 A)
4. For maximum efficiency, it is necessary to run the machine at almost
14 amps, but not exceeding 14.5 amps (relay provided to cut off).
4. Less amperage indicates low shot flow or less shot in hopper.
5. This results in poor peening and low wheel efficiency.
6. Wheel efficiency is calculated as under :
(Running load Amps – No load Amps)
ή = ------------------------------------------------------ X 100
(Rated Max. Amps - No load Amps)
Date executed
153
Table A1.23 One point lesson-24
One – Point Lesson
Them
e
Housing keeping
No. 24
Date of
preparation
Cla
ssif
icat
ion
√ Basic knowledge
Improvement cases
Trouble cases
• It is necessary to accept the fact that spillage of shots around the
machine is inevitable.
• It is a self-detective machine.
• Shots may escape through unloading or holes and recess in the
machine.
• These holes not only risk the personnel but also damage other
machine.
• Even if a small problem is noticed, rectify it immediately.
So, It is necessary to take Immediate corrective actions
“A STICH IN TIME SAVES NINE”
Date executed
154
Table A1.24 One point lesson-25
One – Point Lesson
Them
e Adjusting and checking
blast pattern
No. 25
Date of
preparation
Cla
ssif
icat
ion
√ Basic knowledge
Improvement cases
Trouble cases
Date executed
155
Table A1.25 One point lesson-26
One – Point Lesson
T
hem
e
Principle and effect of shot peening
No. 26
Date of
preparation
Cla
ssif
icati
on √ Basic knowledge
Improvement cases
Trouble cases
Date executed
156
APPENDIX 2
KAIZEN IMPLEMENTED
Table A2.1 Kaizen case-1
Machine: Shot-peening Kaizen case - 1 Unit: Main plant
Kaizen theme : Minimum shots level
indicator/ sensor.
Target:
Counter measure : A visual shots level indicator and sensor provided and
machine stops if shots level is low.
Problem :
- No minimum shots level indicator
- Rotor runs even if shots are less
- Poor peening quality
- Rework
Before counter measure :
Benefits / results after implementation:
- Shots level in hopper – visual
- Rotor stops if shots level is low.
- Good peening quality
- No rework
Analysis: Rework, why?
Poor peening quality, why?
Not noticed
After counter measure :
Scope and plan for horizontal deployment:
----------------------
Root cause : Less shots in hopper Idea : Minimum shots level indicator/sensor provided
157
Table A2.2 Kaizen case-2
Machine: Shot-peening Kaizen case-2 Unit: Main plant
Kaizen theme: Safety guards at 5 places. Target:
Counter measure : Local safety guards provided
Problem :
- All moving parts like rotor, drive,
sprockets etc., have no guards.
- Unsafe
Before counter measure :
Benefits / results after implementation:
- Safety
Analysis :
Unsafe, why?
No protective guards
After counter measure :
Scope and plan for horizontal deployment:
Local safety guards provided at 5 places
Root cause : Unsafe Idea : Local guards
158
Table A2.3 Kaizen case-3
Machine: Shot-peening Kaizen case-3 Unit: Main plant
Kaizen theme: Development of semi-automatic.
electrical, control panel.
Target:
Counter measure: New control panel with delay timer relay with all controls
developed.
Problem :
- Manual controls.
- Only trained person can operate.
- No controls, timer, hour meter.
- No separator switch for shaker and dust
collector
Before counter measure :
Benefits / results after implementation:
- A single button press starts the
operations in sequential manner with
delay timer relay
- Timer, buzzer and safety controls
developed.
- Easy to operate
Analysis :
Only trained persons, why?
Manual controls only
After counter measure :
Scope and plan for horizontal deployment:
----------------------
Root cause : Manual controls Idea : Semi – automatic controls
159
Table A2.4 Kaizen case-4
Machine: Shot-peening Kaizen case-4 Unit: Main plant
Kaizen theme: Easy CLIT activities on top of
machine.
Target:
Counter measure: Landing platform around the machine and aluminum ladder is
provided
Problem :
- No daily CLIT
- Poor accessibility
- Unsafe
- Forced / accelerated deterioration.
Before counter measure :
Benefits / results after implementation:
- Easy CLIT activities
- Easy accessibility
- Safe ladder.
- Forced deterioration prevented
Analysis: No daily CLIT, why?
Poor accessibility, why?
Unsafe, why?
Small straight fixed ladder
After counter measure :
Scope and plan for horizontal deployment:
Can be deployed to all shot-peening machines
Root cause : Poor accessibility for CLIT Idea : Landing around machine and safe ladder
160
Table A2.5 Kaizen case-5
Machine: Shot-peening Kaizen case-5 Unit: Main plant
Kaizen theme: Arresting shot spilling from
funnel.
Target:
Counter measure: Funnel modified, so that shots do not spill out during on /off,
operation
Problem : - During on/off operation shots spillage occurs
from funnel
- Shots fall on top of the machine and floor
- Reclaiming
Before counter measure :
Benefits / results after implementation:
- Spillage is arrested
- Shots do not fall on the machine and
floor
- No reclaim
Analysis: Shots spillage from on/off, why?
Funnel height not adequate
After counter measure :
Scope and plan for horizontal deployment:
-------------------------------------
Root cause : Funnel height Idea: Funnel height increased.
161
Table A2.6 Kaizen case-6
Machine: Shot-peening Kaizen case-6 Unit: Main plant
Kaizen theme: Oil level indicator for reduction
gear box.
Target:
Counter measure: Tabular oil level indicator provided.
Problem :
- No oil level indicator for reduction gear of
mill drive
- Gear / bearing may get damage
Before counter measure :
Benefits / results after implementation:
- Prevents damage of gear box.
- Inspection made easy.
Analysis: Gears / bearing get damage, why?
Oil level in gear box is low / not there why?
No oil level indicator
After counter measure :
Scope and plan for horizontal deployment:
Can be adapted to all machines.
Root cause : Oil level inspection Idea: Visual control
162
Table A2.7 Kaizen case-7
Machine: Shot-peening Kaizen case-7 Unit: Main plant
Kaizen theme: Emergency switch provided on
machine.
Target:
Counter measure: Emergency switch is provided on the right side of the machine
Problem :
- No emergency switch
- In case, of emergency, operator has to come
out to stop the machine
- No safety
Before counter measure :
Benefits / results after implementation:
- Emergency stopping is possible.
- Safety
Analysis:
Not safe, why?
Emergency stop of machine is not possible,why?
No emergency switch
After counter measure :
Scope and plan for horizontal deployment:
------------------------------
Root cause : Emergency stopping is not possible Idea: Emergency switch
163
Table A2.8 Kaizen case-8
Machine: Shot-peening Kaizen case-8 Unit: Main plant
Kaizen theme: Arresting of conveyor belt
shifting Target:
Counter measure: Split flange is provided at both the ends of the main roller.
Problem :
- Work conveyor belt shifts
- To be realigned
- Belt gets damaged
Before counter measure :
Benefits / results after implementation:
- Belt shifting is arrested.
- Belt damage eliminated.
- Increased MTBF
Analysis: Belt gets damaged, why?
Belt shifting, why?
No guide
After counter measure :
Scope and plan for horizontal deployment:
------------------------------
Root cause : Belt shifting Idea: Flange to arrest shifting.
164
Table A2.9 Kaizen case-9
Machine: Shot-peening Kaizen case-9 Unit: Main plant
Kaizen theme: Arresting shots falling on ground
during unloading.
Target :
Counter measure: Door seating changed and toggle clamp closing provided.
Problem :
- Shots leak out from door edges
- Spread on floor.
- Personnel risk ( unsafe )
Before counter measure :
Benefits / results after implementation:
- Leakage arrested.
- Shots do not spread on floor.
- Safe working.
Analysis: Leakage from door edges, why?
Gaps between door and main frame, why?
Seating is not perfect, why?
Poor seating system.
After counter measure :
Scope and plan for horizontal deployment:
------------------------------
Root cause : Seating is not perfect Idea: Modify/change the door seating
16
5
APPENDIX 3
POKA – YOKE IMPLEMENTED
Table A3.1 Poka yoke case-1
Machine: Shot-peening Poka - yoke case-1 Unit: Main plant
Problem: If the door is open, blast motor / shots can still run * Prevent error Shut down
Solution: Limit switch is provided to door.
Detect error
* Control
Key important : 1. Safety to operator
2. No leakage of shots Alarm
Before Improvement After Improvement
Old control panel:
- Independent control
- If the door is opened blast /shots can still run
- Risk to personnel (unsafe)
- Shots leakage.
New control panel:
- Semi-auto mode
- Limit switch provided at door that is connected to control
circuit
- If door is opened, blast motors / shots will stop automatically.
- No risk and no shot leakage.
16
6
Table A3.2 Poka yoke case-2
Machine: Shot-peening Poka - yoke case-2 Unit: Main plant
Problem: If shots level is low, blast motor / shots can still run Prevent error Shut down
Solution: Proximity sensor provided at minimum shots level in
hopper
Detect error * Control
Key important : No rework Alarm
Before Improvement After Improvement
--------------No photo-----------
Old control panel:
- If shots level is low, peening still takes place.
- Poor quality
- Rework.
New control panel:
- Proximity sensor provided at minimum shots level on hopper
which gives indication to control circuit and the blast motor /
shots will be automatically switch off
- Good peening quality
- Rework reduced
16
7
Table A3.3 Poka yoke case-3
Machine: Shot-peening Poka - yoke case-3 Unit: Main plant
Problem: If the bottom mesh tray is opened, machine can
still run Prevent error * Shut down
Solution: Limit switch and toggle clamp provided at the
opening of tray. Detect error * Control
Key important : Prevent damage to machine parts Alarm
Before Improvement After Improvement
--------------No photo-----------
Old control panel:
- If the mesh tray is open, machine can still run.
- Occasionally small springs can escape to hooper and
damage the parts.
- Also shots come out from the opening
New control panel:
- Limit switch and toggle clamp closing provided to the tray
- If the tray is open by mistake the entire electrical system
shutdown.
- No damage to the machine parts
- No leakage
16
8
Table A3.4 Poka yoke case-4
Machine: Shot-peening Poka - yoke case-4 Unit: Main plant
Problem: Even after completion of peening cycle the rotor
and shots can still be on. * Prevent error * Shot down
Solution: Indicator and hooter is connected to output timer * Detect error
* Control
Key important : Quality Alarm
Before Improvement After Improvement
Old panel :
- If the mesh tray is open, machine can still run
- Occasionally small springs can escape to hooter and
damage the parts.
- Also shots come out from the opening
New panel :
- A timer, hooter and indicator provided.
- Rotor and shots will switch off immediately after the
completion of peening cycle.
- No over shot-peening.
- No scrap.
16
9
Table A3.5 Poka yoke case-5
Machine: Shot-peening Poka - yoke case-5 Unit: Main plant
Problem: Sequential operation (manual) confusion. * Prevent error Shot down
Solution: Automatic control panel. Detect error
* Control
Key important : No confusion Alarm
Before Improvement After Improvement
- All manual control.
- Operation sequence confusion
- In auto mode, one press of button starts the machine in
sequential manner
- No confusion.
![Bakul-patofisiologi Trauma [Compatibility Mode]](https://img.pdfslide.net/doc/110x75/54355eda219acdda5f8b45ca/bakul-patofisiologi-trauma-compatibility-mode.jpg)
