关键词: 制动踏板感；真空助力器；制动器效能因数；杠杆比

Abstract: The brake pedal feeling is the key indicator of the driver's subjective perception of a car, and a good pedal feeling can improve the driver's driving comfort. In this paper, combined with the problem of low braking confidence of drivers due to the soft brake pedal and long braking stroke of a commercial vehicle, the factors affecting the pedal feeling of the vacuum-assisted hydraulic braking system are analyzed. On the basis of theoretical calculations, the parameters of the key components of the commercial vehicle braking system are changed and optimized in combination with the actual situation. The relationship between pedal stroke, pedal force and braking deceleration of the original scheme and the optimized scheme is verified by the test. The test verification proves that the optimization scheme can effectively improve the pedal feeling, and the loading effect of the scheme is validated by the subjective feelings of the driver and the customer. It provides reference for the adjustment of brake pedal sense for commercial vehicles with the same braking form.

Key words: pedal feeling; vacuum booster; braking efficiency factor; pedal ratio