Precision machining method for blind holes of oil cylinder piston

Abstract

The invention discloses a precision machining method for blind holes of an oil cylinder piston. The precision machining method for the blind holes of the oil cylinder piston comprises the following steps: (1) conducting rough machining on a big piston blind hole till specification of the blind hole reaches 67mm in diameter Phi and 195mm in depth; (2) conducting predrillng on a small piston blind hole first till the following formula is completed, and the formula can be found in the specification; and then conducting semifinishing on the big piston blind hole till the following formula is completed, and the formula can be found in the specification; (3) conducting semifinishing on the big piston blind hole first till the following formula is completed, and the formula can be found in the specification, wherein the depth of the hole is 320mm, cylindricity is smaller than or equal to 0.05mm, and the surface roughness Ra is 3.2 Mu m; conducting machining on the orifice of a counter bore and the big piston blind hole Phi 71 till the runout is smaller than or equal to 0.04mm, and the surface roughness Ra is 3.2 Mu m; and then conducting semifinishing on the small piston blind hole till the following formula is completed, and the formula can be found in the specification, wherein the depth of the hole is 359mm, and concentricity with the big piston blind hole Phi 71 is smaller than orequal to 0.05mm; (4) conducting finish machining on the big piston blind hole first till the following formula is completed, and the formula can be found in the specification, wherein the depth of the hole is 320mm, the requirement of cylindricity is smaller than or equal to 0.03mm; conducting finish machining on the orifice of a counter bore Phi 235 and the big piston blind hole Phi 71 till therunout is smaller than or equal to 0.04mm, and the surface roughness Ra is 3.2 Mu m; and conducting finish machining on the small piston blind hole till the following formula is completed, and the formula can be found in the specification, wherein the depth of the hole is 359mm, concentricity of the small piston blind hole Phi 25 and the big piston blind hole Phi 71 is smaller than or equal to 0.02mm, and the surface roughness Ra is 1.6 Mu m; and (5) conducting honing on the big piston blind hole till the requirement of design size of the big piston blind hole of the oil cylinder is satisfied.

Description

technical field [0001] The invention belongs to the technical field of machining, and in particular relates to a precision machining method for a blind hole of an oil cylinder piston. Background technique [0002] The oil cylinder is an important "blind hole" pressure-bearing, sealing, wear-resistant and cushioning part with a special-shaped appearance in the valve drive mechanism of the exhaust valve assembly of a low-speed diesel engine. Degree to meet the sealing, wear resistance and realize the function under high pressure. [0003] When the precision of the blind hole of the cylinder piston is not high, it will cause high-pressure oil leakage, and the exhaust function of the exhaust valve cannot be realized. When the roughness of the piston blind hole of the oil cylinder is poor, it will cause rapid wear and tear, resulting in high-pressure oil leakage due to sealing gaps, and the exhaust function of the exhaust valve cannot be realized. It can be seen that the precis...

AI Technical Summary

Problems solved by technology

[0013] The quality of the existing process method for finishing blind holes (drilling and honing processing preparation hole quality) is poor, and the fine boring process adopts ordinary horizontal boring machine T68, the machine tool precision is low, and sometimes a positive cone with a small hole bottom and a large hole is produced. It is very difficult to honing the bottom of the blind hole on the radial drilling machine Z35; the efficiency of finishing the blind hole (drilling and honing preparation hole) is low, and the technical level of the boring workers is high.

Since the adjustment of the boring tool is manual and there is no tool calibration instrument, the control of the drilling and honing allowance of the hole is inaccurate, and the dimensional accuracy, shape accuracy, and surface roughness stability of the fine boring hole are poor, which cannot meet the requirements of drilling and honing, and sometimes the drilling and honing will occur. Waste products that cannot meet the requirements; the existing process method makes the process assurance ability of finishing the large and small piston blind holes insufficient, and the coaxiality of the two blind holes sometimes goes out of tolerance, affecting the product qualification rate or affecting the use

Images