Abstract: A pressure control system is disclosed. The control system in one embodiment includes a main body comprising a pilot chamber wherein an intake port and a discharge port are formed, and a spool comprising an upper slide and a lower slide. The spool in this embodiment is attached by a spring to the upper part of the main body. The exhaust apparatus pressure control system includes an absolute pressure sensor for detecting the pressure in the intake port and a differential pressure sensor for detecting the difference between the pressure in the intake port and atmospheric pressure; a control valve for supplying a pressure regulating gas to the pilot chamber; and a control circuit for sending switching signals to the absolute pressure sensor and the differential pressure sensor, and driving the control valve based on the output from the absolute pressure sensor or differential pressure sensor.

Abstract: An automatic transmission lubrication control system includes a modulating, spring biased spool valve and feedback circuit. One end of the spool valve is supplied with line pressure hydraulic fluid. The valve spool modulates a flow of lubricating hydraulic fluid from the cooler and its position is determined by a force balance between the line pressure, the regulated fluid output pressure to the lubrication system and the force of the biasing spring. In a reduced lubrication state, a signal from a transmission control module opens a solenoid valve to provide high pressure fluid to a three way check valve which closes the feedback circuit and applies high pressure fluid to the opposite end of the valve spool. This action moves the valve spool to a travel limit, closing off flow from the cooler. Hydraulic fluid from the torque converter feed is then routed to the lubrication system.

Abstract: A tapered face whose hole diameter is gradually reduced toward a riding-on direction is formed at a valve-seat end of a supply valve seat or an discharge valve seat where a seal member of a spool slides and rides onto from a side with a low fluid pressure to a side with a high fluid pressure, while the other valve-seat end is kept as a cylindrical surface with a constant hole diameter, by which two tapered faces are formed in a valve hole, and an inner diameter of a portion located between the two tapered faces of the valve hole is formed equal to an inner diameter of a small diameter end of the tapered face, while an inner diameter of a portion located on a hole end side rather than the two tapered faces of the valve hole is formed equal to or larger than the inner diameter of a large diameter end of the tapered face.

Abstract: A fluid flow control device for improving, for example, valve operation by reducing “error forces” occurring due to fluid communication between ports of a valve having two or more ports. Incremental pressure drop passages bleed incrementally the flow of fluid between first an second ports as the valve spool is moving between the first and second positions to decrease the pressure differential generated force exerted on the spool whereby the energy required to be applied to the spool for moving the spool between the first and second positions is decreased.

Abstract: A directly piloted valve assembly has a valve body including a bore, at least one inlet port, at least one outlet port and at least one exhaust port or second outlet port wherein the ports are all in fluid communication with the bore. A spool is received in the bore. The spool includes a wall defining a lumen. An actuator is received in the lumen. The actuator includes a shuttle seal channel. A shuttle seal is received in the shuttle seal channel. A solenoid is connected to the valve body. The wall of the spool includes at least one pilot hole in fluid communication with the lumen defined by the spool and the bore of the valve body.

Abstract: A manual valve of a hydraulic pressure control system for an automatic transmission includes: a valve body including a first exhaust passage that includes an exhausting hole and an intake hole that are communicated with a drive range port in a neutral range, such that a transmission fluid, which is supplied from the drive range port when the vehicle is shifted from drive to neutral, is exhausted; and a hydraulic pressure exhaust control unit that is disposed in the exhaust hole so as to control an exhaust amount according to an exhaust pressure.

Abstract: A flow divider includes a spool for distributing fluid from a supply flow path to priority and surplus flow paths. First and second surplus restrictions vary flow rate in accordance with the movement of the spool and restrict the flow rate to the surplus flow path respectively from first and second supply passages. The second surplus restriction is formed to restrict the flow rate in at least two steps. The spool includes a cross-sectional area changing portion located at a position corresponding to the second surplus restriction. Therefore, the circuit structure is prevented from becoming complicated and the fluid force acting as a spool urging force is suppressed.

Abstract: A spool valve system includes a valve main body with, from a first side to a second side, an input port to which an input pressure is supplied, an output port that outputs an output pressure, and a drain port that discharges the input pressure; and a spool that is structured to move freely relative to the valve main body, the spool including, from the first side to the second side, a first land, a groove that is formed adjacent to the first land, and a second land that is formed adjacent to the groove.

Abstract: A closing device for closing channels in which pressure fluid is conveyed in a housing. The closing device includes a sealing body that is designed as a sleeve member, the peripheral surface of which is arranged between the accommodating bore and the closing member for sealing purposes, and is subjected to a defined surface pressure in sections.

Abstract: A multi-way valve has a housing with a stepped bore forming two piston guiding regions and a shoulder ring with two sealing shoulders. The housing also has a first, second and central transverse bores which are spaced along the cylindrical bore. A contact piston has a piston rod and sealing members secured thereon. The guide members are pressed fit onto opposite ends of the piston rod.

Abstract: A valve (1) comprises: a body (2); a bushing (3) slidably mounted on said body; a valve spool (4) slidably mounted on said bushing; said bushing and spool having respective control edges (5) that are adapted to cooperate with one another as a function of the relative position between said bushing and spool to vary the size of a control opening therebetween; a first drive (11) operatively arranged to controllably move one of said bushing and spool relative to said body; and a second drive (12) operatively arranged to controllably move the other of said bushing and spool relative to said body; whereby said first and second drives may be selectively operated to move said bushing and spool simultaneously in opposite directions to increase the dynamic response of said valve.

Abstract: A fluid control valve comprises a ferromagnetic material portion that is formed on the spool so as to extend in the axial direction of the spool, permanent magnets that are arranged opposite each other having the middle portion therebetween in a direction orthogonal to the axial direction of the spool, form between themselves oppositely oriented magnetic fields aligned in the axial direction, and which are formed to be longer than the middle portion in the axial direction of the spool, and a coil that is arranged in a direction orthogonal to the axial direction of the spool with respect to the permanent magnets and generates a magnetic field that penetrates the opposing permanent magnets due to the conduction of electricity.

Abstract: A packing attached to a spool of a spool valve has a ring-shaped inner-peripheral seal portion provided with an inner-peripheral seal face, a ring-shaped outer-peripheral seal portion provided with an outer-peripheral seal face, and an intermediate flexible portion interposed between the both portions and curved by an action of a fluid pressure, the intermediate flexible portion has both right and left flat side faces parallel with each other, a thickness of the intermediate flexible portion is formed smaller than the inner-peripheral seal portion and the outer-peripheral seal portion, and a ring width of the intermediate flexible portion in a packing radial direction is formed equal to or larger than the thickness.

Abstract: A spool valve assembly includes a spool that is moveable by differential pressure across the spool.

Abstract: A slide valve for regulating the hydraulic pressure at a working connection to values between a low pressure and a high pressure, for which purpose a valve slide is accommodated in a hole of a housing such that it can move linearly, which housing has a low pressure connection, a high pressure connection and the working connection, for which purpose the working connection is connected to the low pressure connection in the first position of the valve slide, while the working connection is separated from the two further connections in a second position of the valve slide, and having a third position of the valve slide, in which the working connection is connected to the high pressure connection (P). A plurality of radial holes are arranged in the valve slide, through which radial holes flow can pass and which radial holes interact with a plurality of circumferential control edges in the housing which seal the valve slide in the hole in a leakfree manner by means of suitable sealing rings.

Abstract: A hydraulic control apparatus for a single action cylinder includes a switch valve for supplying fluid to and draining fluid from the cylinder, a cylinder side passage connected to the cylinder, a switch valve side passage connected to the switch valve, and a valve body accommodation chamber. The valve body accommodation chamber linearly extends between the cylinder side passage and the switch valve side passage. An on-off valve is located in a vicinity of a first end of the valve body accommodation chamber. The on-off valve defines a first back pressure chamber. A flow control valve is located in a vicinity of a second end that is opposite to the first end. The flow control valve defines a second back pressure chamber. The on-off valve and the flow control valve are separated from each other by a partitioning member.

Abstract: A fluid distribution and control valve for respiratory gas delivery systems. The valve has a body which is defined by four internal zones. Each zone is connectable to an external fluid circuit and a mobile structure. The mobile structure can move into four positions. The different positions of the mobile structure determine which of the zones are in fluid communication with each other. The valve may also be used to in a pilot's mask to supply oxygen to the pilot from a main source or from a secondary source.

Abstract: A valve section that functions as a solenoid valve device that includes a pressure adjusting section that adjusts fluid pressure supplied from a fluid pressure source; a pump section that sucks and discharges working fluid in a reservoir; and a single solenoid section that drives the pressure adjusting section and the pump section.

Abstract: A hydraulic control arrangement is disclosed for the load-independent control of a consumer with a continuously adjustable distribution valve having a pressure compensator down the line. According to the invention, the pressure compensator has a single-sided damping such that the movement in the opening direction is damped and the movement in the closing direction is substantially undamped. Furthermore, a control arrangement is disclosed in which a load-holding function is integrated in the pressure compensator.

Abstract: A spool valve and valve seat assembly disposed in the control module of a hot melt adhesive dispensing system is uniquely structured so as to effectively prevent fluid communication or “cross-talk” between a first dispensing outlet port and a second recirculation port, during those periods when the control module is effectively reciprocally cycling the spool valve between its oppositely disposed extreme conditions for alternatively permitting the hot melt adhesive material to be dispensed from the first outlet port or for re-routing the hot melt adhesive material through the recirculation passage so as to prevent the hot melt adhesive from being improperly dispensed as a result of being undesirably routed to the recirculation passage.

Abstract: In order to minimize shift shocks during R?N and D?N manual shifts, in a manual valve of a hydraulic control system of a continuously variable transmission including a valve body having one input port and two output ports and a valve spool having a first land and a second land connecting the input port with one of the two output ports or completely blocking the input port from the two output ports, each land includes slots configured such that inner ends of the slots can be connected to the output ports in a neutral state.

Abstract: An oil flow control valve (10) in a combustion engine is operated for affecting a cam phaser (26) disposed at an output side of said oil flow control valve (10). The cam phaser includes a spool (14) disposed in a spool housing (12). The method for operating the valve includes synchronising a displacement of said spool (14) in said housing (12) with combustion demands, and synchronising movement of said spool (14) with oil pressure characteristics on the output side of the oil flow control valve (10).

Abstract: An automatic transmission lubrication control system includes a modulating, spring biased spool valve and feedback circuit. One end of the spool valve is supplied with line pressure hydraulic fluid. The valve spool modulates a flow of lubricating hydraulic fluid from the cooler and its position is determined by a force balance between the line pressure, the regulated fluid output pressure to the lubrication system and the force of the biasing spring. In a reduced lubrication state, a signal from a transmission control module opens a solenoid valve to provide high pressure fluid to a three way check valve which closes the feedback circuit and applies high pressure fluid to the opposite end of the valve spool. This action moves the valve spool to a travel limit, closing off flow from the cooler. Hydraulic fluid from the torque converter feed is then routed to the lubrication system.

Abstract: An electromagnetically actuated piston slide valve (1) with proportional characteristic comprises an axially movable piston (5) for closing radial passage openings (7). So as to change, with a cross-sectional area of the fluid passage openings (7) given by the magnetic drive, a parabolic course of the pressure loss at an increasing flow rate into a largely linear to degressive course, there is provided a pressure-sensing bore (9), which connects the fluid entrance side, at which pressure P1 is present, with the fluid exit side, at which pressure P2 is present. In the pressure-sensing bore (9) is axially displaceably disposed a pressure-sensing pin (10) and pushes, when pressure P1 is greater than pressure P2, the slide piston (5) into its open position. Thereby the free cross-sectional area of the fluid passage openings (7) increases, and the pressure loss ?P=P1?P2 decreases correspondingly.

Abstract: A piston for a linear spool valve, the valve comprising a body having a inner surface. The body is made of a material with a relatively low heat expansion coefficient ?1. The piston comprises a contact member having an outer surface and being adapted to reciprocate within the body of the valve so that the outer surface is in contact with the inner surface. The contact member has at least a first layer made of a material with a heat expansion coefficient ?2 essentially greater than ?1, i.e. ?2>>?1, and at least a second layer made of a material with a heat expansion coefficient ?3 close to ?1. This causes the contact member to be adapted to behave, along said outer surface, as a material having a heat expansion coefficient essentially closer to ?1 than to ?2. One of the layers constitutes an outer layer of the contact member and comprises the outer surface.

Abstract: A manually actuated cartridge valve assembly (15) has a main body (31), a valve assembly (33), and an end assembly (35). Disposed within an internal cavity (107) of the end assembly (35) is a rotary member (109) that rotates about an axis (115) when a handle (29) is manually actuated. The axis (115) is substantially perpendicular to the axis (73) of the spool valve (49). The rotary member (109) has at least one axial end (117) that extends through the outer surface of the end assembly (35) and attaches to the handle (29). The movement of the handle (29) defines a plane of movement (147), which is selectively rotatable about the axis (73) to a desired orientation (149). A locking member (99) is selectively operably associated with the end assembly (35) to restrict rotation of the plane of movement (147).

Abstract: A valve timing control device includes a driving side rotational member, a driven side rotational member, a retarded angle chamber, an advanced angle chamber, a first control valve, a supply passage supplying the fluid to the first control valve, a first pump pumping the fluid to a vapor liquid separating portion, a second pump pumping the fluid in the vapor liquid separating portion to the first control valve, a discharge passage discharging the fluid from the first control valve toward the operational fluid reservoir, and a second control valve provided at the discharge passage and operated to switch the discharge passage between a first discharge passage is discharging the fluid discharged from the first control valve to the operational fluid reservoir and a second discharge passage flowing the fluid to be drawn into the first pump.

Abstract: An automatic transmission having at least one hydraulic valve with flow force compensation. The hydraulic valve includes a valve body having a valve bore and at least one inlet and at least one outlet adapted to provide fluid communication with a source of pressurized hydraulic fluid and a return to the source of pressure. A valve member is slidingly disposed within the valve body that includes at least one valve element having an outer diameter and a metering face. The metering face is adapted to control the flow of pressurized hydraulic fluid between the inlet and the outlet of the valve body. The metering face includes a flow force compensating annular void disposed adjacent to the outer diameter that is defined by a lead angle ? measured between the outer surface and a line intersecting the outer surface and tangential to the annular void.

Abstract: An electromagnetic hydraulic valve (1), which including an electromagnet (2) with an armature (3) and of a valve housing (4) with an axial bore (5) and a piston valve (6) located therein is provided. The valve housing (4) includes several annular grooves (8, 9, 10) in which several radial openings (11, 12, 13) are located, which open into the axial bore (5), through which the hydraulic valve (1) has a fluid connection with a pressure connection (P), a tank connection (T) and two consumer connections (A, B). The piston valve (6) is acted upon by the armature (3) of electromagnet (2) and includes two ring-shaped control sections (14, 15), which connect alternatively the pressure connection (P) and the tank connection (T) with one of the consumer connections (A, B) through axial movement of piston valve (6). According to the invention, the radial openings (11, 12, 13) in valve housing (4) are provided as windows having a rectangular cross section.

Abstract: A linear solenoid valve includes a solenoid having a coil wound around a coil bobbin, a fixed core, and a movable core for being attracted to the fixed core when the coil is energized, and a valve mechanism having a valve element for selectively bringing an inlet port and an outlet port into and out of fluid communication with each other responsive to a displacement of the movable core. The movable core has a nonmagnetic layer formed on an outer surface thereof and having a predetermined thickness.

Abstract: An automatic tool changing assembly for a machine tool has a bottom frame, a base, a cylinder block, an air motor and an air transporting device. The bottom frame is securely mounted on the machine tool and has a bottom panel, two sliding bars and a spring. The base is movably mounted on the bottom frame above the bottom panel and abutting the spring. The cylinder block is securely mounted on the base and has a piston rod, a piston disk and an air cylinder. The air motor is securely mounted on the base and has a cylinder, a jacket, a mounting groove and a cylinder tube. The air transporting device is mounted in the air motor and has a mounting tube, a first compression ring, a first sealing ring, a middle compression ring, a second sealing ring, a second compression ring, a mounting axle and an axle spring.

Abstract: To obtain a directional control valve superior in workability and maintenanceability by mounting a pilot valve, a printed circuit board and the like on a top surface of a main valve section efficiently so that easy disassembly and assembly are achieved. A valve adapter is mounted on a top surface of a housing of a main valve section with first screws, pilot valves are mounted on the valve adapter with second screws, a printed circuit board is disposed above the pilot valves, and is electrically connected thereto, a protective cover for covering the valve adapter, the pilot valves, and the printed circuit board is mounted airtightly to the top surface of the housing with third screws, a pilot supply flow channel is formed between the valve adapter and the housing, and relay holes for bringing the pilot valves into communication with pilot flow channel ports are provided on the valve adapter.

Abstract: An automatic transmission having a pressure regulator with flow force compensation. The pressure regulator includes a valve body having a valve bore and at least one inlet and at least one outlet adapted to provide fluid communication with a source of pressurized hydraulic fluid and a return to the source of pressure. A valve member is slidingly disposed within the valve body that includes at least one valve element having an outer diameter and a metering face. The metering face is adapted to control the flow of pressurized hydraulic fluid between the inlet and the outlet of the valve body. The metering face includes a flow force compensating annular void disposed adjacent to the outer diameter that is defined by a lead angle ? measured between the outer surface and a line intersecting the outer surface and tangential to the annular void.

Abstract: A spool type control valve is operated by an electrically driven pilot valve. A pilot piston is attached to the control spool. As an electrical actuator moves the pilot spool, a greater pressure is applied to one side of the pilot piston than the other side, which causes movement of the control spool. When the control spool reaches the desired position, its positional relationship to the pilot valve defines a pressure differential across the pilot piston which exerts a net force on the control spool that counterbalances a spring force acting on the control spool. This defines an equilibrium position at which the control spool remains until subsequent motion of the pilot spool occurs which alters the pressure differential across the pilot piston.

Abstract: In a solenoid valve 10, an annular oil groove 66 is formed at a portion corresponding to a spring chamber 56 on the external surface of a sleeve 19, a drain passage 68 is formed to make an upper part of the annular oil groove 66 communicate with the outside of an insertion bore 61, and a throttle hole 67 is provided at a lower part of the annular oil groove 66 for making the annular oil groove 66 communicate with the spring chamber 56. Since the annular oil groove 66 communicates with the outside of the insertion bore 61 at its upper part through the drain passage 68, it can be realized to store the operating oil to the height of the upper part of the annular oil groove 66, so that the operating oil can be reserved in the spring chamber 56 which communicates with the annular oil groove through the throttle hole 67. Further, the operating oil is supplied from a feedback port 48 next to the spring chamber 56 through a clearance between the spool valve 19 and a valve hole 18.

Abstract: A hydraulic control system for an internal combustion engine, includes a driven mechanism driven by hydraulic pressure fed through a flowing passage change-over valve. The flowing passage change-over valve includes a valve body formed with a plurality of ports which are respectively communicated with the supply passage and the oil passage, and a spool valve body slidably disposed in the valve body to open and close the plurality of ports, the ports including a supplying port communicated with the supplying passage. The maximum cross-sectional area of the supplying port is larger than a minimum cross-sectional area of the supplying passage. The flowing passage change-over valve is supplied with electric current to heat hydraulic fluid kept in the flowing passage change-over valve so as to lower a viscosity of the hydraulic fluid.

Abstract: A valve accommodating hole (11), and each of a supply port (20), discharge ports (21 and 22), and output ports (23 and 24) connected to the valve accommodating hole are formed in a valve casing (15), and a valve shaft (12) is attached to the valve accommodating hole (11) so as to be reciprocable in the axial direction. Circular rubber elastic valve elements (51 and 52) are attached to the valve shaft (12) and used for switching between a communication state where either one of the elastic valve elements is spaced away from an inner peripheral sealing surface of the valve accommodating hole (11) such that the supply port (20) and the respective output port (23 or 24) communicate with each other and a shut-off state where either one of the elastic valve elements comes in contact with the inner peripheral sealing surface such that the communication is shut off.

Abstract: A novel three-way valve comprising a valve body, a valve sleeve for adjustable position mounting within the body, and a valve stem movable so as to selectively form a pathway between line recesses in the valve sleeve. Three line recesses are used to form a three way valve and the front and rear line recesses are provided around the diameter such that an increased number of apertures may be provided while reducing the diameter of the apertures themselves to provided the necessary fluid flow with a reduced throw requirement for the valve stem. Exhaust valves are provided to relieve pressure on the unused fluid path. Preferably, the apertures are equi-spaced around the recesses diameter to create a more efficient fluid flow. The valve has a knob and/or a hex key for making fine adjustments to the position of the valve sleeve for optimal efficiency.

Abstract: A proportional pressure control valve which includes an electric first stage pilot having a single outlet port configured to provide a variable pressurized hydraulic fluid to the outlet port and at a pressure that is proportional to an electric input signal and which is variable between first and second values and further includes a second stage hydraulic valve which has a spool reciprocally moveable in a bore between first and second positions indicative of a full ON and a full OFF condition. A fluid isolation chamber is oriented in the bore and in a region between a control port and a tank port in the fluid pathway therebetween. The interior wall of the bore and the first and second diameter regions on the spool are configured to always provide a controlled volume fluid flow rate between the control port and the fluid isolation chamber.

Abstract: The present invention A hydraulic control valve with a regeneration function, including a main body formed of a supply fluid passage to which pressurized fluid is supplied, at least one port, a tank fluid passage for discharging the pressurized fluid to an outside storage tank, and a first regeneration fluid passage; a spool movably installed inside the main body for controlling the flow of the pressurize fluid, and including a second generation fluid passage formed therein; and a regeneration valve for returning only part of the pressurized fluid of the first regeneration fluid passage to the tank fluid passage to maintain pressure of the first regeneration fluid passage at a designated value, and for supplying the pressurized fluid to the second regeneration fluid passage, and if the pressure of the supply fluid passage is higher than a predetermined pressure, changing the pressure of the first regeneration fluid passage in accordance with a change of the pressure of the supply fluid passage.

Abstract: An apparatus and a method for fluid distribution and control. A valve body defines at least two pairs of chambers which are each connectable to an external fluid circuit. A mobile structure, which moves according to a controlling unit, forms an internal penetrating passage. An internal bearing surface, which is located at the first end of the internal passage, is capable of cooperating in a sliding manner with a stationary piston head. The internal bearing surface may move beyond either side of the piston head. When the mobile structure is in an extreme position, an end chamber of the valve body is in fluid communication with the internal passage. When coupled with a PSA adsorber system, the system is capable of supplying oxygen enriched air to an occupant of an aircraft.

Abstract: A tandem hydraulic valve comprising first and second axially aligned valve spools, a valve guide slidably receiving said valve spools to control, in use, the connection between respective ports of the valve guide, said first and second spools being formed as separate components and being axially interconnected, to move in unison, by an axial connection component, and, the interface of said first and second spools being connected to a predefined, external, hydraulic fluid leakage path.

Abstract: The invention relates to an assembly comprising at least one hydraulic control valve and a body for receiving said hydraulic control valve, the hydraulic control valve including flow orifices and flow control means for putting the flow orifices selectively into hydraulic communication with one another. The hydraulic control valve is in the form of an oblong cartridge, the body includes an open housing adapted to receive the hydraulic control valve in removable manner such that when the hydraulic control valve is in place in the housing, the hydraulic control valve and the housing together define isolated hydraulic chambers into which the flow orifices of the hydraulic control valve open out.

Abstract: In a hydraulic pressure control system for a vehicle automatic transmission device, an electric pump is provided in addition to a mechanical pump for generating hydraulic pressure, so that the hydraulic pressure can be continuously supplied to friction coupling elements even during the idling stop operation. A hydraulic pressure line for the electric pump is provided independently from a hydraulic pressure line for the mechanical pump. The hydraulic pressure of the electric pump is applied to the hydraulic pressure line for the mechanical pump shortly before a pressure control valve, which controls the hydraulic pressure to be applied to the friction coupling element.

Abstract: A hydraulic control arrangement is disclosed for the load pressure independent control of a consumer, comprising a distribution valve forming an inlet metering orifice, a corresponding individual pressure compensator, a stop valve provided for each consumer connection which may be released by means of a pilot valve and an anti-cavitation valve by means of which pressure medium can be drawn from a reservoir to avoid cavitation. According to the invention, the distribution valve and the stop valves are arranged along two parallel axes, while the axes of the two pilot valves are arranged perpendicularly to these two axes. The anti-cavitation valves in turn extend perpendicularly to the axes of the distribution valves, the stop valves and the anti-cavitation valves.

Abstract: A body element for a spool valve is provided that includes a body having an inner surface that defines an internal valving chamber having a longitudinal axis, and at least one transverse surface to the longitudinal axis. The transverse surface has at least one port comprising an annular flow passage, an intermediate flow passage and an outer flow passage extending outward from and in fluid communication with the inner surface of the internal valving chamber.

Abstract: A control for parallel hybrid transmission has a valve mechanism, which is operable to supply fluid pressure to a torque-transmitting mechanism with or without the operation of the vehicle engine. The valve mechanism is responsive to an electrically driven pump to supply fluid pressure whenever the engine is discontinued and the electric driven pump is operated.

Abstract: A stepped down groove 53 is provided around the peripheral surface of a rod portion 43 of a spool 40 which faces a third oil groove 33. Both the axial ends 53a and 53b of the stepped down groove 53 are located axially outside of both the axial ends 33a and 33b of the third oil groove 33 at least while the valve is in pressure-adjusting condition. Also, another stepped down groove 52 is provided around a land 42 which faces a first oil groove 31. Both the axial ends 52a and 52b of the stepped down groove 52 come, respectively, to the right and left sides of the axial end 31b of the first oil groove 31 to which end the spool 40 shifts to increase the opening of the oil groove at least while the valve is in pressure-adjusting condition.

Abstract: The invention relates to a control system, especially a hydraulic control system for a transmission, including a valve assembly, especially a directional valve assembly, designed for controlling a cooling system for a clutch and for ensuring a minimum level of pressure and suctioning function of a pump.

Abstract: A normally open hydraulic control valve includes: a linear solenoid unit; a spool driven by an output force of the linear solenoid unit to move forward; a valve body in which the spool is fitted; and a return spring for biasing the spool in a retreating direction. The valve body includes: a reaction force oil chamber for introducing hydraulic pressure, which presses the spool in a direction against a biasing force of the return spring, from the output port; and a damper oil chamber which suppresses vibration of the spool. The damper oil chamber is adjacent to the reaction force oil chamber with the third land portion of the spool therebetween. A slide gap which leaks and supplies oil from the reaction force oil chamber to the damper oil chamber is provided between the third land portion and the valve body.