VACUUM BRAKE BOOSTER

摘要

A vacuum brake booster (10) having sound absorbing members (70', 270, 70), affixed to the front (12) and rear (14) shells to attenuate sounds caused by air movement in the brake booster. The front shell (12) is joined to the rear shell (14) to define the housing for the brake booster (10). The housing is divided into a first chamber (18) and a second chamber (20) by a wall structure (22). The first (18) and second (20) chambers in a first mode of operation are designed to be in communication with a first source of fluid (vacuum) having a first fluid pressure while in a second mode of operation the second chamber (20) is in communication with a second source of fluid (atmospheric air) at a second fluid pressure. In the second mode of operation, a pressure differential is created across the wall structure (22) to produce an output force corresponding to an input force associated with a desired braking application. A first sound absorbing member (70, 270) is urged into engagement with the rear shell (14) for attenuating and dampening sounds produced by the communication of the second source of fluid in the second mode of operation while a second sound absorbing member (70') is urged into engagement with the front shell (12) for attenuating and dampening sounds produced by the evacuation of the second source of fluid from the second chamber (20) to return to the first mode of operation.