关键词: 商用车；制动气室；压力传感器；四回路保护阀

Abstract: The pneumatic braking system of heavy commercial vehicles is a safety item in the whole vehicle, and its characteristics under certain conditions are sometimes easily overlooked by designers. Therefore, this paper takes the pneumatic braking system as the research object, analyzes the stress of internal components of the four-circuit protection valve when the residual pressure of each air storage chamber is different due to various reasons, and observes the corresponding relationship between inflation pressure and time through basic air pressure test. The final result shows that the pneumatic braking system with four-circuit protection valve is obviously different from the ordinary pneumatic braking system in certain conditions: the smaller the residual air pressure, the less easy it is to inflate, but the larger the residual air pressure, the higher the inflation priority. It is hoped that the research results of this article can bring some enlightenment to designers to avoid the occurrence of problems related to pneumatic braking.

Key words: Commercial vehicles; Brake air chamber; Pressure sensor; Four-circuit protection valve