Piston and method for optimizing skirt profile section of piston

Abstract

The invention discloses a piston. The cross section curve of the profile meets the following ellipse-like diameter variable parametric equation shown in the specification, wherein Tn / 2 means the radial maximum spacing between the nth curve and the previous curve; alpha means the angle between the cross section and the long axis of an ellipse; J means the included angle between the starting point of the curve and the long axis of the ellipse; J' means the included angle between the terminal point of the curve and the long axis of the ellipse; mu' means a variation coefficient; and delta D means an ellipse-like diameter variation. According to the invention, because the adopted equation is a simple and harmonic curve which has a less peak acceleration and a limit phase step value and has continuous displacement, velocity and acceleration curve properties; the dynamic loading can be reduced by the acceleration, the high-speed response requirement of a cutter feed system can be relieved, and the working rotation speed in cutting can be improved; the stability of the operation of the system can be improved by the limit saltus; and the rigid shock and flexible shock in the cutting process can be avoided by virtue of the continuation of the displacement curve, the velocity curve and the acceleration curve. The invention also provides a method for optimizing a skirt profile section of a piston.

Description

technical field [0001] The invention relates to the technical field of engine pistons, in particular to a piston with a smooth outer circular cross-section and a method for optimizing the cross-sectional shape of its skirt. Background technique [0002] In order to meet the requirements of future automobiles, the degree of strengthening of the engine is increasing day by day, and the load on the piston is becoming increasingly severe. The requirements for the shape of the outer circle of the piston are also gradually increasing. The cross-sectional shape of the outer circle of the piston becomes complicated due to the influence of various factors, such as Asymmetrical ellipse, partial eccentric ellipse, several eccentric and superimposed ellipses, etc., and the lack of domestic research on the design and processing of the cross-sectional shape of the piston has caused great limitations in the design and processing of the cross-sectional shape of the piston in China. [0003]...

AI Technical Summary

Problems solved by technology

Parabolas and transition curves have acceleration jumps at their connection ends, causing tremors in the cutting process, affecting the processing quality, and the processing quality often fails to meet the design requirements

During high-efficiency machining, the machine tool runs at high speed and the acceleration is also large, which may easily cause unstable machining dimensions and large fluctuations. Therefore, the machine tool is required to have a strong response ability, and it is difficult for ordinary machine tools to meet product requirements.

Images