Variable-compression ratio piston of combustion engine

Abstract

The invention provides a variable-compression ratio piston of a combustion engine, comprising a piston top and a piston skirt. A compression ratio adjusting device is arranged between the piston top and the piston skirt and provided with an adjusting device shell. The adjusting device shell is composed of a round platen, an inner cylinder and an outer cylinder, wherein the round platen is fixedlyconnected on the bottom surface of the piston top; the inner cylinder is arranged below the round platen and fixedly connected on the top surface of the piston skirt; and the outer cylinder is in threaded connection with the inner cylinder; the opening of the outer cylinder is provided with a inner stop ring; and the round platen can be embedded between the opening end surface of the inner cylinder and the inner stop ring of the outer cylinder in an axial displacement. The adjusting device is internally provided with a mechanically elastic deformation mechanism which is used for controlling the axial displacement of the round platen; and the initial pretightening force of the mechanically elastic deformation mechanism keeps close matching of the upper part of the outer edge of the round platen and the inner stop ring of the outer cylinder, and maintains that a flexible gap delta is formed between the lower part of the outer edge of the round platen and the opening end surface of the inner cylinder. The compression ratio can make rapidly adaptive variance along with the working condition of the combustion engine. The invention is especially suitable for an automobile engine.

Description

technical field [0001] The invention relates to a piston of an internal combustion engine, in particular to a variable compression ratio piston of an internal combustion engine. Background technique [0002] The cylinder compression ratio has a great influence on the performance of the internal combustion engine. Variable compression ratio technology means that the engine has a higher compression ratio under low-load conditions, and can control the excessively high gas pressure in the cylinder by adjusting the compression ratio under high-load conditions. At present, according to the response speed of the compression ratio changing with the engine operating conditions, the variable compression ratio technology mainly falls into the following two categories: [0003] 1. The compression ratio changes slowly with the engine operating conditions [0004] Typical examples of the compression ratio changing slowly with the engine operating conditions include: 1. A variable compre...

AI Technical Summary

Problems solved by technology

For the hydraulic deformation mechanism, due to the high pressure during the actual combustion of the engine, this puts forward high requirements for the hydraulic mechanism and its control system. The existing hydraulic mechanism has complex structures, poor high-temperature sealing performance, and short service life. Defects such as slow response speed and other defects make it difficult to quickly reset the piston after deformation

As far as the elastic deformation element is concerned, the existing elastic deformation elements often use ordinary compression springs, and the stiffness of ordinary compression springs cannot change rapidly with the load conditions in the cylinder, and there is a gap between the upper and lower parts of the piston. Arranging a compression spring to withstand huge gas pressure in the narrow space between them requires very high performance, and there is no compression spring that can meet the above requirements at present. It can be seen that the selection of elastic deformation elements is also very difficult.

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