Modeling and Simulation Analysis of Wet Multi-Disk Service Braking System for Heavy Vehicles

A new type of charging valve with electro-hydraulic closed-loop feedback is designed, and a wet multi-disc dual-circuit service brake is built based on AMEsim. The charging and discharging characteristics of the accumulator are studied. The results show that under the condition of a medium-flow constant current source, the dual-circuit accumulator responds quickly, and a single charging can smoothly provide multiple stable discharge output. The response to the pressure output caused by the static structural parameters of the tandem braking valve and the pedal signal is studied. The results show that: the pedal signal can significantly change the brake pressure output, but the preload of the return spring is not apparent; the change of the cross-sectional diameter of the rear axle spool will cause the spool opening lags, and the difference in the spool diameter will cause the spool closing lags. The time response performance of single-axle braking and dual-axle braking is studied. The response from environmental factors such as road adhesion coefficient, slope, load, and brake cool modes to braking distance, braking deceleration, and braking temperature is studied. We establish a parameter ranges of braking safety zone and braking safety comfort zone. This study provides a comparison and reference to the design of a new charging valve and the performance test of the service braking system of heavy vehicles.