Variable-frequency semi-precision part piston mechanism

The utility model discloses a variable-frequency semi-precision part piston mechanism. The device comprises a combustion cylinder, pistons, pin shafts and connecting rods, characterized in that it ischaracterized in that it comprises, a piston is connected into the combustion cylinder in a sliding fit mode. The lower ends of the pistons are rotationally connected with connecting rods through pinshafts; two air grooves and an oil groove are sequentially formed in the side wall of the piston from top to bottom. A ventilation groove is formed in the outer edge of the upper end face of the piston, a rubber block is arranged at the upper end of the outer side wall of the ventilation groove, sealing mechanisms are evenly arranged in the ventilation groove in the circumferential direction of the ventilation groove, a sealing groove is formed in the middle of the upper end face of the piston, and a transverse rod is installed in the sealing groove. According to the variable-frequency semi-precision part piston mechan