Inspection and matching before assembly of chrome hardened bar

- May 18, 2019-

1. Check the quality of the piston and connecting rod is the same multi-cylinder diesel engine. The difference of the quality of each piston should not exceed lOg; the quality of the connecting rod should not exceed 20g; the quality of the piston connecting rod assembly should not exceed 30g.


2. Selection of piston and cylinder liner The matching method in our daily practice is: wash and dry the piston and cylinder liner, apply a layer of cleaning oil on the working surface, and set the cylinder sleeve upright. Next, and put it into the cylinder liner smoothly with your right hand. If the piston slowly falls, it indicates that the piston and the cylinder sleeve have a good clearance; if it does not fall, the clearance is too tight; if it falls too fast, it indicates that the clearance is too large.


3. Selection and inspection of the chrome hardened bar clearance and ring groove The piston rod is installed in the ring groove, which can rotate freely in the electric push rod ring groove, can sink into the bottom of the ring groove, and its edge gap is 0.10~ Between 0.15mm, if it is exceeded, the gap is too large.


4. Inspection of the end face clearance of the piston rod The piston rods are placed horizontally 40 mm from the upper end of the cylinder liner, and the thickness gauge is inserted into the end gap to measure whether the gap of each ring meets the size required by the machine manual.


5. Optional piston pin and connecting rod bushing Wash and dry the piston pin and bushing, apply a layer of clean oil on each working surface, then hold the right hand near the small end of the connecting rod, and then use the left hand. Put the piston pin into the bushing positively, and push the piston pin into the bushing by the force of the right thumb. If the push is too tight and too laborious, you need to wipe the bushing; if the push is too loose, you must re-option, increase the piston pin or replace the bushing.


1. The matching of the connecting rod bearing bush and the connecting rod journal is fixed on the bearing surface of the bearing bush. The uniformity of the small point (commonly known as sesame point) is more than 75%. The torque of the connecting rod bolt is tightened to the specified standard, and the organic oil is coated on the mating surface. In the case of a slight push, it is advisable to rotate.