| 摘要 |
A booster device is provided such that positioning with respect to the circumferential direction of shells is easily achieved. The booster device 1 is provided with: a housing 2 that is partitioned into a front chamber A and a rear chamber B by means of a front shell 3, a rear shell 4, and a center shell 5, wherein power pistons 6, 7 are respectively disposed in the front chamber A and the rear chamber B so as to partition the chambers into constant-pressure chambers A1, B1 and variable-pressure chambers A2, B2; a rod member 24 that penetrates through the housing 2, fixes a master cylinder at one end, and is connected to a vehicle at the other end; and a cylindrical member 30, through which the rod member 24 is inserted, that is fixed to the center shell 5, provides communication between variable-pressure chamber A2 of the front chamber A and variable-pressure chamber B2 of the rear chamber B. A projecting piece part 5D projecting outward in the radial direction of the center shell 5 is formed on the center shell 5 at a part of the outer circumferential edge thereof, and an axial groove 4D that opens frontward in an axial direction is formed in the rear shell 4 at a part of the outer circumferential edge thereof in order for the projecting piece part 5D to be fitted therein. |
