Large-cylinder-diameter integrally-forged steel piston

Abstract

The invention relates to a large-cylinder-diameter integrally-forged steel piston. A piston skirt part and a piston head part are both forged parts, the top of the piston skirt part and the piston head part are fixed to form a piston body, a closed cooling oil cavity or two communicated double cooling oil cavities is / are formed in the piston body, and a skirt part annular part is fixed to the lower end of the piston skirt part; and the cross section of a corresponding oil annular groove lower annular bank on the outer wall of the top of the piston skirt part is in an oval shape with the long axis parallel to the direction of a piston pin hole, and the annular bank and the skirt part annular part jointly participate in guiding of a piston body. Blanks of the piston head part and the pistonskirt part are separately forged and machined, so that the forging process is simplified, and the requirements and investment on equipment, cutters and the like are reduced. The piston skirt part annular part is independently machined, the forging depth of the piston body skirt part is reduced, the piston production difficulty is reduced, and the piston production efficiency is improved. The piston skirt part annular part and the oil annular groove lower annular bank jointly participate in piston guiding, stable operation of an engine is facilitated, the eccentric wear phenomenon of the pistonis reduced, and use safety and reliability of the piston are improved.

Description

technical field

[0001] The invention relates to the technical field of pistons, in particular to an integral forged steel piston with a large cylinder diameter. Background technique

[0002] The piston is the "heart" of the engine, which bears alternating mechanical loads and thermal loads, and is one of the key components in the engine with the worst working conditions. The function of the piston is to withstand the gas pressure, and transmit it to the connecting rod through the piston pin to drive the crankshaft to rotate. The failure of the piston will cause the engine to lose power, and even cause the entire engine to be scrapped.

[0003] Now large bore pistons (pistons with a bore greater than 150mm) are made of aluminum alloy, cast iron, steel top aluminum skirt, and steel top iron skirt. With the increase in engine power, aluminum pistons can no longer meet the requirements, and cast iron pistons are due to molding reasons. , There are inevitable defects such as san...

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