| 摘要 |
PROBLEM TO BE SOLVED: To improve seal inspection precision of an annular seal part without changing shape of a guide part and booster shell of a negative pressure type booster device.SOLUTION: In a diaphragm 21d of a movable barrier wall in a negative pressure type booster device, a through part in which a tie rod bolt (30d) penetrates in air tight manner is provided with a tubular guide part 21b2 which abuts with an annular flange part 30b provided at the tie rod bolt when a power piston moves frontward, and an annular seal part 21b3 which is provided behind the guide part 21b2 to shield communication between a negative pressure chamber R1 and a variable pressure chamber R2. The guide part 21b2 is provided with a communication part Po which, even in a state where the guide part 21b2 abuts with the annular flange part 30b, makes a negative pressure chamber side space Ro in which a front surface of the seal part 21b3 is exposed communicate with the negative pressure chamber R1. |
