Reduced-diameter steel piston forming device and forming method

Abstract

In the reduced-diameter steel piston and its forming device and method of the present invention, the piston skirt of the steel piston is provided with a piston inner cavity and a pin hole, and the piston inner cavity is set in a reduced-diameter structure. The device includes an upper mold, a lower mold and a diameter-reducing mold core. The diameter-reducing mold core includes a force applying member, a wedge and a pair of diameter-reducing blocks. A wedge-shaped cavity is formed between the two diameter-reducing blocks. The wedge is matched with the wedge-shaped cavity. The outer diameter of each reducing block gradually decreases from the middle position to both ends, one end of the force applying member is connected with the upper die, and the other end presses on the top of the wedge. The method includes S1: forming the blank of the steel piston body; S2: placing the steel piston body between the upper mold and the lower mold and positioning it on the lower mold; S3: positioning the reducing block and the wedge in the inner cavity of the piston; S4: Start the upper die and press down, so that the diameter of the piston inner cavity gradually decreases from the middle to both ends; S5: remove the wedge and the diameter reducing block; S6: carry out finishing and surface treatment. It has the advantages of simple and reasonable structure, high rigidity of the overall structure, easy demoulding and light weight.

Description

technical field [0001] The invention mainly relates to the skirt forming technology of internal combustion engine steel pistons, in particular to a reducing diameter steel piston forming device and forming method. Background technique [0002] The piston is installed in the cylinder liner, which is the power conversion and output mechanism. It undertakes the main function of converting heat energy into mechanical work, and bears the inertial force generated by high temperature, high pressure and high-speed movement. With the continuous improvement of the internal combustion engine, the structure is compact and more High explosion pressure and higher power density have become the direction for continuous improvement of internal combustion engine performance, while improving the piston structure and selecting alloy steel pistons with better performance are important technical directions to meet the continuous performance of internal combustion engines. [0003] When the intern...

AI Technical Summary

Problems solved by technology

The piston blank is forged, and the upper part of the piston skirt is thicker and the lower part is thinner. The machining method reduces the thickness of the skirt, which takes a long time and costs a lot, and destroys the metal flow line of the skirt.

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