29-08-2014, 11:21 AM
I am submitting our six months industrial training report, which we have done at Swaraj Engine Limited(SEL) Phase 9 Mohali. We have completed the project under the guidence of Er.Avinash Sood and Er.Amritpal Singh.We have done project on bumping. It is the process of adjusting the clearance between piston and T.D.C. of cylinder by inserting the shims.During this we have learned many new technical subjects, acquired a number of new technical skills and improved another group of existing skills.
Bumping is used to provide proper clearance between Piston and cylinder head. Generally piston comes above or below the T.D.C. of engine while rotation of crank shaft during assembly and when this happens it means it will result in head noise. In order to avoid this shims according to need, of desired thickness are introduced between liner and cylinder head. By this process all cylinders of engine have the same clearance value.
Step 1 : To Study Bumping in Engine
Theory: Bumping is a process in which T.D.C. of engine cylinder or clearance between piston and cylinder head is set by placing shims between liner and cylinder head.
Why Bumping is used: Bumping is used to provide proper clearance between Piston and cylinder head. Generally piston comes above or below the T.D.C. of engine while rotation of crank shaft during assembly and when this happens it means it will result in head noise. In order to avoid this shims according to need, of desired thickness are introduced between liner and cylinder head. By this process all cylinders of engine have the same clearance value.
• To maintain required compressed volume of Air
• To avoid Piston touching Cylinder Head, which results in damage and head noise.
• For better performance of engine
Tools and Gauges used in BUMPING:
BUMPING TOOL- It is in the form of a rectangular bar which is placed over liners with the help of studs and pressed with help of runners so that liner should be properly fitted during the movement of piston.
BUMPING GAUGE- It measures the distance that how much piston is above or below the engine T.D.C. during its upward stroke and displays the reading on its digital panel when piston moves above the T.D.C.
Shims are the spacer of big size which is inserted between liners and cylinder head in order to lift the cylinder head to avoid head noise.
The table for proper shim thickness is shown below:
READING Thickness of shim
For positive reading 1.2mm
0 to -0.10 1.2mm
-0.10 to-0.20 1.2mm
-0.20 to-0.30 1.3mm
-0.30 to-0.40 1.4mm
-0.40 to-0.50 1.5mm
Step 2: Identification and Observation of Problem
Problem: Before shims are inserted on liners, oil is applied on shims in order to prevent rusting. Then these shims are placed on a inclined rod. In this arrangement shims get stick to each other. When they are inserted on liners then sometimes worker put two shims instead of one. This results in rejection of engine during testing. The naming of positions of different shims on stand was also not done properly
Step 3: Finding a Solution
Solution:
1.We have made a new arrangement of shims in which stand is not inclined, it becomes vertical and rods becomes long and horizontal and a stopper is fixed at the free end of rod. The naming of positions of different shims on stand is done properly.
2.We have used a pressure gun in order to apply air pressure on shims arrangement on horizontal stand so that their stickiness should not take place. By using these methods in arrangement of shims, the rejection of engine is decreased up to a great extent as shown in graph.
Reading Shim Thickness
-0.30 to-0.40 1.4mm
-0.40 to-0.50 1.5mm
Bumping is used to provide proper clearance between Piston and cylinder head. Generally piston comes above or below the T.D.C. of engine while rotation of crank shaft during assembly and when this happens it means it will result in head noise. In order to avoid this shims according to need, of desired thickness are introduced between liner and cylinder head. By this process all cylinders of engine have the same clearance value.
Step 1 : To Study Bumping in Engine
Theory: Bumping is a process in which T.D.C. of engine cylinder or clearance between piston and cylinder head is set by placing shims between liner and cylinder head.
Why Bumping is used: Bumping is used to provide proper clearance between Piston and cylinder head. Generally piston comes above or below the T.D.C. of engine while rotation of crank shaft during assembly and when this happens it means it will result in head noise. In order to avoid this shims according to need, of desired thickness are introduced between liner and cylinder head. By this process all cylinders of engine have the same clearance value.
• To maintain required compressed volume of Air
• To avoid Piston touching Cylinder Head, which results in damage and head noise.
• For better performance of engine
Tools and Gauges used in BUMPING:
BUMPING TOOL- It is in the form of a rectangular bar which is placed over liners with the help of studs and pressed with help of runners so that liner should be properly fitted during the movement of piston.
BUMPING GAUGE- It measures the distance that how much piston is above or below the engine T.D.C. during its upward stroke and displays the reading on its digital panel when piston moves above the T.D.C.
Shims are the spacer of big size which is inserted between liners and cylinder head in order to lift the cylinder head to avoid head noise.
The table for proper shim thickness is shown below:
READING Thickness of shim
For positive reading 1.2mm
0 to -0.10 1.2mm
-0.10 to-0.20 1.2mm
-0.20 to-0.30 1.3mm
-0.30 to-0.40 1.4mm
-0.40 to-0.50 1.5mm
Step 2: Identification and Observation of Problem
Problem: Before shims are inserted on liners, oil is applied on shims in order to prevent rusting. Then these shims are placed on a inclined rod. In this arrangement shims get stick to each other. When they are inserted on liners then sometimes worker put two shims instead of one. This results in rejection of engine during testing. The naming of positions of different shims on stand was also not done properly
Step 3: Finding a Solution
Solution:
1.We have made a new arrangement of shims in which stand is not inclined, it becomes vertical and rods becomes long and horizontal and a stopper is fixed at the free end of rod. The naming of positions of different shims on stand is done properly.
2.We have used a pressure gun in order to apply air pressure on shims arrangement on horizontal stand so that their stickiness should not take place. By using these methods in arrangement of shims, the rejection of engine is decreased up to a great extent as shown in graph.
Reading Shim Thickness
-0.30 to-0.40 1.4mm
-0.40 to-0.50 1.5mm