| 摘要 |
PURPOSE:To improve rapidly braking performance of an equipment in which braking force is altered through changes in air pressure within a control chamber by arraigning so that braking force is changed in accordance with the degree of strength in the operational physical force of a manual switch. CONSTITUTION:A brake booster 1 pushes a plunger 5 forward owing to the stamping on a braking pedal BP, thereby inducing air into a working pressure chamber B through a passage 6 and causing the leftward movement of a power piston 2 because of difference in pressure between the chamber B and a constant pressure chamber A, which is communicated with vacuum source through a connection opening 3, with the pressing force of the power piston 2 driving a master cylinder MC. In this case, an air space 9 is formed within the power piston 2, with the air space 9 being further divided into a constant pressure chamber C and a working pressure chamber D by means of a controlling piston 10. And the constant pressure chamber C is made to communicate with the chamber A, while the working pressure chamber D is linked to air or vacuum source through electromagnetic valves 14, 15 with the two valves 14, 15 put into a state controllable though a controller 27 in line with the manipulation of a switch 19. |
