| 摘要 |
PURPOSE:To obtain a small-sized solenoid by adjusting the flow passage of a variable orifice formed in the atmosphere passage of the first pressure chamber of a piston according to the magnitude of the magnetic force of the solenoid, installing an orifice in the negative pressure passage of the first pressure chamber, and obtaining the control pressure by introducing the atmosphere into the second pressure chamber by a valve mechanism. CONSTITUTION:Inside the second pressure chamber 52 between the first and the second pressure chambers 51 and 52 of the piston 42 of a control valve 24, the piston 42 is urged upwardly by a spring 53 and put into a nonoperative position. A valve body 57 is shifted upward by the magnetic force of a solenoid 43, and a variable orifice 59 is opened, and the atmosphere is introduced into the inside of the first pressure chamber 51. At this time, inside the first pressure chamber 51, a portion of the atmosphere is discharged into the first pressure chamber, because of the negative pressure due to an orifice 54, and the atmosphere is introduced into the first pressure chamber 51. The piston 42 is lowered by the differential pressure in the first and the second pressure chambers 51 and 52, and the atmosphere is introduced into a tandem brake booster device 1 through the second and the first passages 41b and 41a and a conduit 23. |
