Process for solving problem of unqualified parallelism of die-casting piston pin hole

Abstract

The invention provides a process for solving the problem of unqualified parallelism of a die-casting piston pin hole. The process comprises the following steps that a die-casting piston blank produced by a die-casting machine is cast, the die-casting piston blank is put into a shot blasting machine, and shot blasting treatment is conducted for 20 minutes; (2), heat treatment is conducted after shot blasting is conducted on the die-casting piston blank, the die-casting piston blank is heated to 225+ / -5 DEG C in a pit furnace, and heat preservation is conducted for 8 hours; (3), the piston blank subjected to heat treatment is machined and produced, in the annular groove machining process, an inner cavity of the piston blank is jacked, a top process positioning table is machined, when the piston pin hole is machined, the top process positioning table serves as the standard and is closely matched with a fixing clamp, and the top of the inner cavity of a piston is pressed by an air cylinder, so that the piston pin hole and the peripheral part of the piston pin hole are not affected by external force; and (4), when a top plane is machined, a pin pulls an annular groove for machining, so that the piston pin hole is not stressed, and the parallelism of the die-casting piston pin hole produced by the process is below 2 microns and completely meets the standard requirement that the parallelism is below 4.5 microns.

Description

technical field [0001] The invention belongs to the technical field of piston processing, and more specifically relates to a process for solving the unqualified parallelism of die-casting piston pin holes. Background technique [0002] There are more and more die-casting pistons on small engines, such as lawn mowers and chain saws. The engines produced by world-renowned brands such as Steele, Fuji Hua, and TTI are all used in batches. Small engines are small in size and high in power. Long, the load is heavy when working, which requires the engine to have good working performance, and the corresponding piston, the core component of the engine, is required to be more excellent, which involves the strength, durability, emission and other issues of the piston. The pressure of 400 tons makes the aluminum liquid After die-casting into a piston, it has high strength, and the parallelism of the corresponding piston pin hole is not good. There is a certain interference space in the ...

AI Technical Summary

Problems solved by technology

[0002] There are more and more die-casting pistons on small engines, such as lawn mowers and chain saws. The engines produced by world-renowned brands such as Steele, Fuji Hua, and TTI are all used in batches. Small engines are small in size and high in power. Long, the load is heavy when working, which requires the engine to have good working performance, and the corresponding piston, the core component of the engine, is required to be more excellent, which involves the strength, durability, emission and other issues of the piston. The pressure of 400 tons makes the aluminum liquid After die-casting into a piston, it has high strength, and the parallelism of the corresponding piston pin hole is not good. There is a certain interference space in the cooperation with the piston pin and the connecting rod, and the durability will deteriorate, and the emission will not meet the standard. Therefore, the die-casting piston is a product with strict requirements on various indicators, especially in terms of emission, fatigue resistance and power.

[0003] The company's current share of such products has reached 30%, but the flatness of the piston pin hole is difficult to meet the technical requirements. The current production process produces fewer qualified pistons, which cannot meet the needs of existing orders. Customer complaints also cause huge losses to the company's profits

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