Processing method for piston rod assembly

Abstract

The invention provides a processing method for a piston rod assembly. When an annular groove of a piston is processed, a 4 mm groove cutter is used for performing rough turning firstly, then a 2mm small-sized groove cutter is used for slowly turning a groove bottom excircle through cutting for two times to eliminate chatter marks, the groove is narrowed properly under the premise that the hardness is guaranteed, so that the transverse deformation of the groove subjected to carburization and quenching is still within the common difference required; 0.4-0.5 mm allowance of the total is taken out and is subjected to completely turning firstly, then an upper grinder is assembled, so as to control the concentricity, and guarantee the overall precision; chamfers and bottom diameter dimension of the excircle required when threads are subjected to thread rolling are subjected to completely turning on a numerically controlled lathe firstly, then threads are rolled, so as to guarantee the linear type of threads while ensuring concentricity; a piston and a piston rod are assembled by a spanner, so as to guarantee that the centers of the piston and the piston rod are positioned on the same operating horizontal plane; the torque is adjusted to guarantee the torque force, and the piston and the piston rod are tightly screwed; after the piston rod assembly is completely assembled, the bending deformation during grinding is remarkably reduced when the upper grinder is subjected to overall grinding, so that the straightness and concentricity during the grinding of the integral piston rod assembly are well guaranteed.

Description

technical field [0001] The invention relates to a processing method of a piston rod assembly. Background technique [0002] The compressor is a driven fluid machine that upgrades low-pressure gas to high-pressure gas. It is the heart of the refrigeration system. It sucks low-temperature and low-pressure refrigerant gas from the suction pipe, drives the piston through the motor to compress it, and sends it to the compressor. The exhaust pipe discharges high-temperature and high-pressure refrigerant gas to provide power for the refrigeration cycle, thereby realizing the refrigeration cycle of compression→condensation→expansion→evaporation (heat absorption). The piston rod assembly is a precision part in the compressor, which can effectively control the distribution of air pressure in the compressor. If there is a deviation in the manufacturing size, it will cause the collapse of the entire compressor and cause a safety accident. [0003] Piston rod components include pistons ...

AI Technical Summary

Problems solved by technology

[0016] 1. The 11 ring grooves of the piston all need to have a hardness of HRC60-62, which makes it difficult to implement during the processing. The grooves must be cut out on the workpiece before carburizing and quenching, but after carburizing and quenching, the grooves It will also cause deformation of the original position, which makes it difficult for the CNC machine tool to grasp the original position and because the bottom of the groove also has a large hardness, vibration marks will be generated during processing;

[0017] 2. The threaded hole at the large end of the piston must have good concentricity with the small outer circle at the small end, otherwise there will be a large jump after the overall assembly with the piston rod, which is not conducive to the overall grinding after assembly

[0041] 1. The torque control during tightening and whether the coaxiality between the piston and the piston rod can be guaranteed has a great impact on the success or failure of the entire part. Once the screw is deviated or skewed, the straightness of the entire part will be greater than 0.50mm, and this data will also It is greater than the overall grinding allowance, resulting in the inability to complete subsequent processing;

[0042] 2. The problem of too long length during grinding, that is, because the method of two thimbles is used in the overall grinding process, the supporting force is not very large. During grinding, there will be more or less bending deformation in the middle section. How to eliminate it? Bending deformation is very important, the smaller the amount of bending deformation, the higher the precision of the part will be

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