Abstract: Aiming at the problem that it was inconvenient to observe the characteristic curve in the loading and release phase of the input force of the car booster, the factors affecting the characteristic curve of the vacuum booster were studied, the influencing factors of the input force release stage in the booster characteristic curve were analyzed and summarized; a model and simulation idea of vacuum booster suitable for studying the entire process of booster input force loading and release was proposed; a universal testing machine was used to perform compression tests on the rubber reaction disk; a key component of the booster, and the force and deformation of the feedback disk under non-linear conditions were measured. The control valve model, the feedback disc model and the front and rear cavity models of the booster were established, and the influence of each component on the characteristic curve of the booster was studied by means of numerical simulation. The results indicate that the stiffness of the plunger has a significant influence on the hysteresis of the booster characteristic curve during the entire stage of the vacuum booster's release and loading, and the stiffness of the feedback disc has a greater influence on the jump value and the jump loss value. Comparing the simulation result with the theoretical calculation value, the output force is within ±10% of the theoretical design characteristic curve, which indicates that the built simulation model can be used as a design tool for the booster.

Key words: vacuum booster; AMESim; characteristic curve; numerical simulation