Abstract: A fluid pressure control device comprising: an inlet valve which is provided in a supply path for connecting a fluid pressure apparatus and a fluid pressure source and is opened so as to increase fluid pressure of the fluid pressure apparatus; and an outlet valve which is provided in a discharge path for discharging working fluid from the fluid pressure apparatus and is opened so as to reduce the fluid pressure of the fluid pressure apparatus; wherein the inlet valve is formed by a solenoid selector valve effecting only a fully open operation and a fully closed operation; wherein the outlet valve is formed by a flow control valve in which one-to-one correspondence exists between quantity of drive current applied thereto and flow rate of the working fluid flowing therethrough.

Abstract: A flow control valve having a housing having a first port and a second port and a spool mounted in the housing. A first fluid chamber and a second fluid chamber which impart a fluid pressure to both ends of the spool communicate with each other through a fluid passage formed with an orifice. As the spool moves, thrust to the spool produced by a difference in pressure at both ends of a spool balances with a biasing force produced by the biasing mechanism. The flow control valve is provided with an annular seal made of an elastic material together with a seal member. When the edge of the land portion on the outer periphery of the spool is brought into contact with the annular seal, the first port is completely shut off from the second fluid chamber. Thus, leakage will become zero when the valve portion is closed.

Abstract: The present invention provides a flow control valve which makes it possible to prevent the leakage of hydraulic fluid when the valve is closed while continuously controlling the flow rate. An axially slidable piston (12) housed in a housing (11) provided with a first port (13) and second port (16) is urged by an electromagnet (20). A first closing valve (14) for connecting and isolating the first port (13) and first fluid chamber (A), with a valve seat portion (14C) opened opposite one end portion of the piston (12) in the first fluid chamber (A) and a valve body (14B) which is seated in and separated from the valve seat portion in accordance with the axial displacement of the piston (12), is provided between the first port (13) and the first fluid chamber (A). An orifice (15) is provided in the conduit connecting the first fluid chamber (A) and the second fluid chamber (B).

Abstract: A hydraulic pressure control apparatus comprising: an introducing valve provided on a supply duct connecting to each other a hydraulic source and a control chamber for controlling a fluid-operated equipment or increasing or decreasing the hydraulic pressure of the fluid-operated equipment; and a discharge valve provided on a discharge duct discharging hydraulic fluid from the fluid-operated equipment or the control chamber. The introducing valve and/or the discharge valve are disposed in series on the supply duct or the discharge duct; at least one of a plurality of the introducing valves and/or the discharge valves consists of a flow rate-variable valve capable of changing the flow rate of the hydraulic fluid continuously according to the intensity of electric current; and the other introducing valves and/or discharge valves consist of electromagnetic change-over valves fully opened or fully closed.

Abstract: A solenoid valve has a valve seat mounted in a passage for pressure fluid formed in a housing, an armature, and a valve body integral with the armature for opening and closing the valve seat. The armature is moved in a direction to open or close the valve seat by an electromagnetic coil. The solenoid valve is mounted in the housing to enclose the armature liquid-tightly in a pressure fluid chamber defined by the solenoid valve and the housing.

Abstract: An anti-lock hydraulic control device is composed of a front-wheel brake and rear-wheel brake for effecting brake control through a hydraulic system which is connected with a master cylinder and circulates hydraulic fluid; a front-wheel side control valve and rear-wheel side control valve between the master cylinder and front-wheel brake, and master cylinder and rear-wheel brake respectively; a reserve between the front-wheel side control valve and rear-wheel side control valve; a proportioning valve between the master cylinder and rear-wheel side control valve; and a pump connected to the reserve and provided with a discharge opening connected between the proportioning valve and the rear-wheel control valve. When anti-lock control starts, the pump operates and discharges hydraulic fluid to the rear-wheel side control valve, thus increasing rear-wheel brake fluid pressure, and so avoiding the problem of insufficient braking power in the rear-brakes during anti-lock control, and increasing braking efficiency.

Abstract: A proportional pressure control valve having a sleeve having a high-pressure source port, a low-pressure source port and an outlet port and a spool mounted in the sleeve kept in slide contact with the sleeve. Annular seals made of a resilient material are inserted in an annular groove formed in the inner surface of the sleeve. A spring is provided for biasing the spool axially. Valve portions are formed by shoulder portions on the annular seals and shoulder portions on the spool to open and close communication between the high-pressure source port and the outlet port and between the outlet port and the low-pressure source port as the spool moves. They are positioned so that when the spool moves in one direction, communication between the high-pressure source port and the outlet port opens and communication between the outlet port and the low-pressure source port is closed.

Abstract: A flow control valve includes a sleeve formed with an inlet port and an outlet port and a spool slidably mounted in the sleeve. A fluid passage having an orifice connects a high-pressure end and a low-pressure end of the spool. An annular seal is liquid-tightly fitted in an annular groove formed in the inner periphery of the sleeve and extends into an annular groove formed in the outer periphery of the spool with a gap left therebetween. A biasing elements is provided to bias the spool in a direction opposite to the direction in which the fluid pressure differential between both ends of the spool tends to urge the spool. A seal can be effected by the annular seal and a shoulder portion of the spool defining the annular groove thereof. The seal, however allows fluid communication from the inlet port toward the outlet port through the orifice to be established with the movement of the spool.

Abstract: A brake system has a manually controlled brake pressure generator, independent controlled brake circuits each having a wheel brake and a flow control valve for electronically controlling the pressure of the wheel brake, a dynamic pressure source necessary for the pressure control by the flow control valve, a reservoir, a sensor such as a wheel speed sensor, and an electronic control unit. A pair of check valves for introducing and returning fluid are provided in parallel to each other between an output circuit of the brake pressure generator and each controlled brake circuit. A solenoid changeover valve for antilock is provided between the output circuit of the brake pressure generator and the check valves for introducing fluid to close the line during antilock control.

Abstract: A fluid pressure controller having a housing having a first port and a second port, and a spool axially slidably mounted in the housing. First and second chambers are defined between opposing ends of the spool between the spool and the housing. The controller further has an electricity/power converter for applying to the spool an axial driving force corresponding to the magnitude of an electric command, and a spring for holding the spool in its initial position when the value of the electric command to the converter is zero. A variable-size orifice is provided to separately control communications between the first chamber and the first port depending upon the axial position of the spool. The second chamber normally communicates with the second port. A fixed-size orifice and a relief valve are provided parallel to each other in passages connecting the first and second chambers.

Abstract: A fluid pressure controller has a houisng including an input port, a discharge port and an output port, and a spool is axially slidably mounted in the housing. First and second chambers are defined at opposing ends of the spool by the spool and the housing. Ring valve members are mounted on the spool at axial spaced locations to define oppositely oriented variable-size orifices for pressure increase and pressure reduction. They are adapted to separately control communications between the first chamber and the input port and between the first chamber and the discharge port depending upon the axial position of the spool and to close both communications when the spool is in its closed position. Thus the pressure controller can be freely changed between providing pressure increase, pressure reduction and pressure hold.

Abstract: A flow control valve for an antilocking device in a vehicle brake system prevents a locking of the wheels during a brake application. The flow control valve includes a pressure reducing chamber (115) regularly connected with an outlet port (111) through a passage by way of a fixed orifice (125). An inlet port (110) is normally connected with the outlet port (111) through a small passage. Therefore, even if a spool (116) is fixed in a position closing a large passage, working fluid introduced into the inlet port (110) flows to the outlet port (111) through the small passage, whereby it is possible to apply pressure to a wheel brake without wheel locking.

Abstract: A flow control valve for use in an antilock control device includes a housing having inlet and outlet ports communicating with a pressure source and a wheel brake, respectively, and a spool slidably mounted in the housing and formed with a channel including an orifice. When the spool is in a first position, a large-flow passage is formed between the inlet and outlet ports. When in another position, a restricted-flow passage is formed between the inlet and outlet ports through the orifice while the large-flow passage is closed. A piston is mounted in the housing on top of the spool. Every time the brake is applied, the piston is adapted to move up and down, thus allowing the spool to slide in the same direction to the first position. Instead of the piston, a sleeve may be disposed between the inner periphery of the housing and the outer periphery of the spool so as to be slidable relative to both the housing and the spool.

Abstract: A fluid pressure control device for antilock control includes a housing having inlet and outlet ports communicating with a master cylinder and a wheel brake, respectively, and a spool mounted in the housing so as to be slidable between two positions. When the spool is in one of the two positions, a large-flow channel is formed between the inlet and outlet ports, whereas in the other position, a small-flow channel is formed therebetween. When in an intermediate positon, both the large-flow and small-flow channels are closed. A bypass channel branches off from the small-flow channel so as to extend to the outlet port. A check valve is provided in this channel. Even if the spool should get stuck and immovable at an intermediate position between the above two positions, hydraulic oil can be fed from the inlet port to the outlet port through this bypass channel.

Abstract: A brake pressure control device for vehicles is arranged in a pipeline connecting a master cylinder (22) and a wheel brake (23) with an electromagnetic directional control valve (24) which is switchable to any one of a plurality of valve positions by electromagnetic force. The electromagnetic directional control valve (24) is switched between a first valve position and a second valve position. Bidirectional flow of fluid is allowed when the electromagnetic directional control valve is in the first valve position. Unidirectional flow of the fluid is allowed but a reverse flow of the fluid is prevented when the electromagnetic directional control valve is in the second valve position.

Abstract: A flow control valve for antilock control includes a housing having inlet, outlet and discharge ports communicating with a master cylinder, a wheel brake and a reservoir circuit, respectively, and a spool mounted in the housing so as to be slidable between two positions. When the spool is in one of the two positions, a large-flow channel is formed between the inlet and outlet ports, whereas in the other position, a restricted-flow channel is formed therebetween. In an intermediate position, both of the channels are closed by edge portions formed on the spool. A throttled bypass channel is formed so as to branch off from the restricted-flow channel so as to be connected to the outlet port. Even if the spool should get stuck in any intermediate position between the above two positions, hydraulic oil can be fed from the inlet port to the outlet port through this throttled channel.

Abstract: An anti-lock brake control system for an automobile vehicle includes an anti-lock modulator having a single housing structure, which accommodates plural sets of flow control valves and solenoid-operated discharge valves, a plurality of plunger pumps and a plurality of reservoirs. The valves in each set are disposed in line with and in series-connected fashion with each other. The valve sets and an electric motor having an eccentric drive shaft for driving the plunger pumps are disposed on respective sides of the longitudinal axis of the plunger pumps. All of the longitudinal axis of each valve set, that of each plunger pump and that of the eccentric drive shaft are laid perpendicular to one another.

Abstract: An antilock mechanism for use in a hydraulic brake system including a hydraulic pressure source, a wheel brake, and a drain channel, includes a flow control valve and a drain valve provided in the drain channel. The flow control valve has an inlet port connected with the hydraulic pressure source, a first outlet port connected with the wheel brake, and a second outlet port connected with the drain channel. A spool is slidably inserted in the housing. The spool comprises first axial conduit and a second axial conduit separated by a wall having a fixed orifice formed therein, and is biased by a return spring. The drain valve is located adjacent the open end of the housing such that the second outlet port of the flow control valve and a valve member of the drain valve are connected straight.

Abstract: A brake pressure control device for vehicles is provided in a pipeline connecting a master cylinder (22) and a wheel brake (23) with an electromagnetic directional control valve (24) which is switched in a plurality of valve positions by electromagnetic force. The electromagnetic directional control valve (24) is switched between a first valve position and a second valve position. Bidirectional flow of fluid is allowed when the electromagnetic directional control valve is in the first valve position. Unidirectional flow of the fluid is allowed but reverse flow of the fluid is prevented when the electromagnetic directional control valve is in the second valve position.

Abstract: A throttle opening control actuator is provided between a throttle (2) which is regularly urged by a return spring (5) in a direction for decreasing its opening in order to regulate engine output of a vehicle and an acceleration pedal (1) which is coupled to the throttle (2) by a cable (7).