Power assisted braking system for braking wheels of motor vehicle

摘要

The brake servo unit boosts the operating force of the brake actuating component based on the difference between the pressures in the vacuum chamber(27) and variable pressure chamber(28), and transmits the boosted operating force to the master brake cylinder. The servo unit has a transition point at which the boost ratio is decreased while the brake force increases before a boost limiting point is reached at which the servo unit is not ready to carry out its boost function.