| 摘要 |
PROBLEM TO BE SOLVED: To reduce the cost of a rear shell (a press molding of a steel plate) constituting a portion of a housing of a negative pressure type booster.SOLUTION: A rear shell constituting a portion of a housing of a negative pressure type booster is formed by pressing a steel plate. The rear shell has a tapered flange part having a large-diameter part at an opening end, and also has a stepped cylinder part which has a small-diameter part in a region connecting with the small-diameter part of the flange part. A power piston is assembled at the cylinder part through an annular seal member, and a boot covering an outer periphery of the power piston is assembled at the flange part. The flange part has a cut made at least at one place in a peripheral direction. |
