Booster shell reinforcing structure in a vacuum booster

摘要

In a booster shell reinforcing structure in a vacuum booster which makes a booster shell rigid enough to withstand the load applied thereto during operation and reduces the weight thereof, a reinforcement member includes an outer peripheral portion corresponding to a coupling angular portion between the flat portion and the tapered portion in a front shell half of the booster shell, being laid on an inner surface of the flat portion. The reinforcement member has a plurality of cuts formed in the outer peripheral portion at predetermined angular intervals so that each of the cuts is opened outside the reinforcement member and closed with inner edges of the cuts in the radial direction of the booster shell, and a plurality of main reinforcing portions which are located between the cuts. The front shell half includes a plurality of raised portions corresponding in position to the cuts, each of the raised portions having a sloped plate portion interposing between the cylindrical portion and the flat portion near the respective inner edges of the cuts, being substantially U-shaped in section perpendicular to the radial direction, and opening towards a master cylinder.