A split composite piston and its forming method

Abstract

In the split composite piston and its molding method of the present invention, the split surface of the piston head passes through the annular oil chamber, the split surface of the piston head is provided with an annular compensation port, and an annular compensation plate is arranged in the annular compensation port, and the bottom surface of the annular compensation plate is in contact with the The split surfaces on both sides form weldable surfaces, and the piston head and piston skirt are welded and connected along the weldable surfaces. The method includes S1: forming the blank of the piston head, the piston skirt and the annular compensation plate; S2: machining the annular compensation port; S3: cleaning; S4: welding the annular compensation plate and the annular compensation port; S5: splitting Decent processing to form a continuous and complete weldable surface; S6: Fit the split surface of the piston head and piston skirt and perform positioning installation; S7: Use welding along the split surface to achieve composite connection; S8: Perform post-weld heat treatment; S9: For finishing and surface treatment. The invention has the advantages of stable and reliable structure, easy molding and strong process adaptability.

Description

technical field [0001] The invention mainly relates to the molding technology of internal combustion engine steel pistons, in particular to a split composite piston and a molding method. Background technique [0002] The piston is installed in the cylinder liner. When the internal combustion engine is running, the piston reciprocates at the top and bottom dead centers. It is the power conversion and output mechanism, which undertakes the main function of converting heat energy into mechanical work, and withstands high temperature, high pressure and high-speed motion. Inertial force; at the same time, with the continuous improvement of internal combustion engines, the heat load on the piston head is higher, and the selection of steel structure pistons with better performance has become the direction of improving piston performance. The existing steel structure piston materials are mainly heat resistant. Alloy steels with poor weldability, such as: 38MnVS6 or 42CrMoA, etc. ...

AI Technical Summary

Problems solved by technology

The main welding surface is lower than the auxiliary welding surface and parallel to the horizontal plane. The main problems are: because the two welding surfaces are not on the same plane, the poor position accuracy in the process of processing makes the welding gap inconsistent and the thickness of the brazing seam is different. The weld joints on the main and auxiliary welding surfaces have poor strength, and the welding seam increases the risk of weld failure under the action of axial burst pressure; the main welding surface and the auxiliary welding surface are perpendicular to each other, the main welding surface is located in the combustion chamber, and the combustion chamber profile is The welding seam is divided, and the welding seam is exposed to the high-temperature and high-pressure gas in the combustion chamber, which increases the risk of failure during the working process of the combustion chamber; the edge of the weld seam in the annular oil chamber melts out, and the solder at the edge of the weld seam inside the annular oil chamber melts. There is a risk of falling off during the reciprocating movement of the piston and the flushing of the lubricating oil

2. The steel piston formed by split welding, the piston is divided into upper and lower parts and welded by electron beam at the pin hole position. The main problems are: the pin hole position has a wide section, relatively deep weld seam, and difficult welding process , especially when the pin-hole weld is under the action of alternating axial and radial loads, the welding defect caused by welding is likely to cause weld failure, and the failure risk of the piston increases

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