Piston pressure limiting method for eliminating piston engine knock and piston with pressure relief function used by piston pressure limiting method

Abstract

The invention aims to provide a piston pressure limiting method for eliminating piston engine knock and a piston with a pressure relief function used by the piston pressure limiting method. The pistonpressure limiting method can limit maximum combustion pressure in a piston type engine cylinder, prevent the pressure in the engine cylinder from exceeding a set safety value, and eliminate knock possibly generated after the compression ratio of a piston type engine is increased, so that the heat efficiency of the piston type engine is remarkably improved. In order to achieve the above purpose, the following technical scheme is provided. According to the technical scheme, the piston pressure limiting method for eliminating the piston engine knock comprises the following steps that the pistonwith the pressure relief function is installed in an engine air cylinder combustion chamber, a safety pressure value in the air cylinder combustion chamber is set to be P1, and when a pressure value Pin the combustion chamber is set to be less than the safety pressure value P1, the pressure relief function of the piston is not opened; and whenever the pressure value P in the combustion chamber isset to be larger than or equal to the safety pressure value P1, the pressure relief function of the piston is opened, the combustion chamber relieves the pressure to the outside through the piston, and the pressure relief function of the piston is closed until the pressure value P in the combustion chamber is reduced below the safety pressure value P1.

Description

technical field [0001] The invention relates to a piston engine, in particular to a piston pressure limiting method for eliminating knocking of a piston engine and a piston with a pressure relief function used therefor. Background technique [0002] The reciprocating piston engine refers to a piston engine in which the piston makes a reciprocating linear motion in the cylinder, and the linear motion of the piston is converted into the rotary motion of the crankshaft through the crank connecting rod power transmission mechanism. The main function of the piston is to withstand the combustion pressure in the cylinder and ensure the reliable sealing of the working medium of the generator. Reciprocating piston engines are usually gasoline engines and diesel engines. Gasoline has poor anti-knock performance, and the mixed gas is prone to deflagration, causing the body to detonate. Therefore, the ignition and ignition method is generally used. At present, the compression ratio of ...

AI Technical Summary

Problems solved by technology

However, the variable compression ratio is based on the compression ratio control of the engine operating conditions, which cannot eliminate the knocking phenomenon that may occur due to a sudden increase in cylinder pressure under low load conditions; it is more likely to further reduce cylinders with lower pressure cycles under high load conditions pressure, leading to a decline in power and economy

There are many solutions for variable compression ratio technology, but usually require the use of complex electronic control technology and complex mechanical or hydraulic devices, which are difficult to manufacture and expensive to produce

And because its compression ratio changes slowly, it can't respond in time when the engine cycle conditions of automobiles change, and it can't prevent the cylinder pressure from rising instantly. Therefore, in order to avoid the knocking phenomenon, the technology in the art The personnel set the working pressure of the internal combustion engine relatively conservatively. Taking the gasoline engine used in the family car as an example, the normal working pressure of the engine is usually set to about 60% of the pressure when the knocking begins, so as to effectively avoid the engine from changing the vehicle load. Under the influence of factors such as fuel quality, intake air temperature and pressure, the cylinder pressure rises instantaneously and causes knocking, which obviously limits the improvement of the compression ratio of the existing engine, making it difficult to further improve the thermal efficiency of the existing engine

Images