Preparation method of high-strength piston pin hole bushing

Abstract

The invention relates to a preparation method of a high-strength piston pin hole bushing, which comprises the following steps of: proportioning 28.5 to 33.5 weight percent of Zn, 1.5 to 2.5 weight percent of Mn, 0.8 to 1.5 weight percent of Al, 0.6 to 1.2 weight percent of Ni, 0.7 to 1.3 weight percent of Si and the balance of Cu; copper, zinc, aluminum and silicon are added in the form of pure copper, pure zinc, pure aluminum and pure silicon, and manganese and nickel are added in the form of a CuMn30 copper-manganese intermediate alloy and a CuNi15 copper-nickel intermediate alloy; adding pure copper, pure zinc, pure aluminum, pure silicon, a copper-manganese alloy and a copper-nickel alloy into a smelting furnace for smelting, and fully stirring; the smelted copper liquid is subjected to horizontal continuous casting, and a rough ingot blank is obtained; a copper pipe ingot blank obtained after horizontal continuous casting serves as a spinning blank, spinning is conducted in a reverse spinning mode, a pair of double-conical-surface type spinning wheels are installed in a staggered mode, the gap between a core mold and the spinning wheels is 4-8 mm, the feeding ratio is 0.5-1 mm / r, and the temperature is 150-250 DEG C; and machining. The preparation method is simple in procedure and easy to operate, the prepared piston pin hole bush is high in strength and low in cost, the use requirement of the piston pin boss part can be met, the anti-fatigue performance of the piston pin boss part is improved, and the pin boss failure phenomenon is effectively avoided.

Description

technical field [0001] The invention relates to a preparation method of a piston pin hole bushing, in particular to a preparation method of a high-strength piston pin hole bushing. Background technique [0002] The piston pin hole bushing is one of the key parts of the engine. It is inserted in the piston pin hole with an interference fit and has a clearance fit with the piston pin. It is used to reduce the contact stress on the surface of the piston pin hole and improve the reliability of the pin hole. Due to the continuous high-frequency alternating stress during high-temperature operation, the working conditions of the bushing are extremely harsh. Therefore, the bushing material needs to have good hardness, strength and fatigue resistance. [0003] At present, domestic engine piston pin hole bushings are mainly made of copper alloys such as tin bronze and phosphor bronze, which are relatively expensive, and the forming methods are mostly solid bar machining or machining ...

AI Technical Summary

Problems solved by technology

[0003] At present, domestic engine piston pin hole bushings are mainly made of copper alloys such as tin bronze and phosphor bronze, which are relatively expensive, and the forming methods are mostly solid bar machining or machining after forging. higher

Moreover, the performance of the prepared piston bush is 540MPa at room temperature, and the Brinell hardness is about 170HB, which is far from that of the imported piston bush.

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