| 摘要 |
865,389. Fluid-pressure servomotor-control systems. GARRETT CORPORATION. March 28, 1958 [April 1, 1957], No. 10095/58. Class 135. A cylindrical plug valve 14, Fig. 1, regulates pressure from an inlet 11 to a coaxial outlet 12 of a tubular valve body and is connected to a coaxial piston 24 having the same cross-sectional area as the valve seat 15 and having its upstream side connected at 40 to the downstream side of the valve and its downstream side 25 able to be connected through a three-way solenoid valve 33 to the upstream side of the valve and when thus balanced is actuated against a spring 52 through a lever 46 by a diaphragm 56 having one side 63 exposed at 70 to outlet pressure and having the other side 68 supplied with pressure, which may be from the inlet, through a restriction 75 and three-way solenoid valve 73 with a vent 76 and having a leak-off at 80, Fig. 2, controlled by a piston-valve 81 set by a cam 132 positioned by a motor 133 and actuated in response to inlet pressure acting via pipes 130, 31 through the three-way valve 33. Cam 132, loaded by spring 123, positions a rod 121 abutting a flange 113 on the piston valve 104 while inlet pressure acts via passages 130, 134, 126, 136 on the end 120 of the piston valve. Any increase in the required pressure set up in chamber 68 acts via 80 to move the piston housing 103, sealed to the casing by a diaphragm 94, downwards against spring 107 to relieve the pressure increase after which openings 106 will relap with the piston valve. Vibration of the piston valve seat 103 is damped by a resilient tube 108 surrounding spring 107. The piston valve may be replaced by a lift valve. When solenoid valve 33 is de-energized passage 36 opens to atmosphere and upstream pressure closes the valve, the increased pressure produced in chamber 68 being relieved to atmosphere past a diaphragm valve 85 loaded by spring 91 and by the pressure in chamber 63 acting via pipe 71. Chamber 68 may also be vented through solenoid valve 73. |
