Abstract: A vehicle transmission having a valve body disposed adjacently to and in parallel with a side cover covering a front or rear side or a side surface of a transmission case in a vehicle width direction in a vehicle-mounted state, the side cover connected to the transmission case, in which an electromagnetic valve is included on the side cover side of the valve body, when viewed in a direction horizontal and parallel to mating surfaces of the transmission case and the side cover, a strainer for removing a foreign material in a hydraulic oil is disposed between the side cover and the valve body to overlap with at least a portion of the electromagnetic valve, and the strainer has an inflow portion for allowing the hydraulic oil to flow in disposed vertically above an oil surface.

Abstract: In a seal device for a hydraulic circuit, in which an oil passage that supplies hydraulic oil to or discharges the hydraulic oil from a hydraulic actuator operated by hydraulic pressure is formed over at least two members that relatively move, and a seal member that seals a gap between the two members in a liquid-tight manner is disposed in an interior of a groove section that is formed in at least either one of the two members, a communication section that allows the groove section to communicate with any portion of the oil passage such that the hydraulic oil in the interior of the groove section moves along with supply of the hydraulic oil to or discharge of the hydraulic oil from the hydraulic actuator is formed.

Abstract: A hydraulic control unit configured to improve energy efficiency is provided. The hydraulic control unit is comprised of: a feeding passage that delivers fluid from at least any of an oil pump and an accumulator storing hydraulic pressure to an actuator; a draining passage that discharge the fluid from the actuator to a drain spot; and a discharging means that is configured to selectively discharge the fluid from the actuator to the accumulator through the feeding passage, if the fluid has to be discharged from the actuator and a pressure of the accumulator is lower than that of the actuator.

Abstract: A hydraulic control device where the engagement pressure which is supplied from the first solenoid valve is supplied to the synchronization mechanism in the case where the signal pressure is not supplied to the switching valve, and the engagement pressure which is supplied from the first solenoid valve is supplied to the engagement element and the source pressure is supplied to the synchronization mechanism as the engagement pressure in the case where the signal pressure is supplied to the switching valve.

Abstract: A hydraulic control device for an automatic transmission where the spool is locked at the first position and the switching pressure can regulate the belt holding force of the primary pulley or the secondary pulley without switching a position of the spool when the engagement pressure is supplied to the second working oil chamber, and the spool is not locked at the first position and the switching pressure can switch the spool to the second position against the urging member when the engagement pressure is not supplied to the second working oil chamber.

Abstract: A vehicle hydraulic device is provided with an electric motor-driven oil pump and a shuttle valve, so that a vane pump operates smoothly, even at the start, with a backpressure applied from the electric motor-driven oil pump to the vanes. Even when the oil pressure of a working fluid discharged from the vane pump exceeds the backpressure inside vane housing grooves, the working fluid flows from a vane pump discharge oil passage to a backpressure oil passage, so that the vanes are not pushed into the housing grooves. Thus, it is possible to reduce the fluctuations in discharge amount of the vane pump due to fluctuations in oil pressure of the vane pump discharge oil passage during operation of the vane pump.

Abstract: A check valve provided makes it possible to operate a vane pump smoothly even at the start of the vane pump by maintaining an oil pressure in backpressure oil passages inside the vane pump while the vane pump is stopped. The check valve opens at the point in time when an oil pressure control device, to which a working fluid is supplied from the vane pump, has been filled with the working fluid and the oil pressure in discharge oil passages communicating with the oil pressure control device has risen and exceeded the oil pressure in the backpressure oil passages. Thus, the check valve is prevented from opening and closing repeatedly, so that the durability of the check valve is improved.

Abstract: A hydraulic control device has: a modulator valve using oil pressure from a hydraulic source for adjusting a modulator pressure; driving and driven-side hydraulic actuator control valves controlling hydraulic oil from the source to driving and driven-side hydraulic actuators; a driving-side control oil pressure adjusting electromagnetic valve using the modulator pressure for outputting a control oil pressure controlling the driving-side control valve; and a driven-side control oil pressure adjusting electromagnetic valve for outputting a control oil pressure controlling the driven-side control valve, the hydraulic control device including a failsafe valve switched from a normal to a failure position based on a failure disabling electric control for the driving-side and driven-side electromagnetic valves, the modulator valve making the modulator pressure lower than a value at the normal position based on an output switching pressure generated due to switching the failsafe valve from the normal to the failure p

Abstract: A hydraulic control unit is provided. A valve is comprised of a piston having a valve element, a cylinder holding the piston while allowing to reciprocate axially, a positive pressure chamber formed on one side of the piston to which pressure to open the valve is applied, a back pressure chamber formed on the other side of the piston to which the pressure to close the valve is applied, and a connection passage for differentiating pressures in the positive pressure chamber and the back pressure chamber. A pilot valve selectively connects the back pressure chamber with a site where the pressure is lower than that of the back pressure chamber. Hydraulic pressure lower than that applied to positive pressure chamber is applied to a low pressure section.

Abstract: A hydraulic circuit and a hydraulic control system for preventing fluid leakage and power loss resulting from jamming of contaminants. A first circuit section has an accumulator for storing hydraulic pressure, and a control valve for controlling a passage for delivering fluid from the accumulator to an actuator. Fluid discharged from an oil pump is delivered continuously to a second circuit section. A first filter is disposed on a passage for delivering the fluid from the oil pump to the accumulator for the purpose of removing contaminants finer than those in the fluid to be delivered to the second circuit section from the fluid to be delivered to the accumulator.

Abstract: A hydraulic pressure control device for a transmission, which operates a hydraulic apparatus by hydraulic pressure generated by an pump driven during operation of a driving force source, for which automatic stop control is performed, accumulates the hydraulic pressure in a pressure accumulator, and supplies the hydraulic pressure accumulated in the pressure accumulator to the hydraulic apparatus when the driving force source is automatically stopped is provided. The automatic stop control includes control to stop the driving force source when the vehicle speed is equal to or higher than a prescribed vehicle speed; and the hydraulic pressure control device performs a control to control an accumulated oil amount in the pressure accumulator and the automatic stop control in a manner to increase the accumulated oil amount of the pressure accumulator when the driving force source is automatically stopped.

Abstract: A switch valve which is configured such that a plurality of land sections and a valley section between the land sections are formed in a valve element that advances or retreats in an axial direction according to a manual operation, a plurality of port sections opened are provided in a cylinder section in which the valve element is inserted so as to be capable of advancing and retreating, and the prescribed port sections are made to communicate with each other via the valley section according to a position of the valve element in the axial direction or be blocked by the land section, the switch valve includes a seal section that seals a space between portions on both sides in the axial direction across either one of the land sections in a liquid-tight manner.

Abstract: A hydraulic control system stably controls pressure in a hydraulic chamber of a pulley accommodating a belt by controlling a feeding valve and a discharging valve. The control system reduces a control amount of the feeding valve to be smaller than that calculated based on a pressure difference in a case other than one in which pressure in the hydraulic chamber is increased by delivering oil to another chamber, in case the pressure in the hydraulic chamber is increased by delivering the oil to the other chamber. The control system reduces a control amount of the discharging valve to be smaller than that calculated based on the pressure difference in a case other than one in which pressure in the hydraulic chamber is lowered by discharging the oil from the other chamber, in case the pressure in the hydraulic chamber is lowered by discharging the oil to the other chamber.

Abstract: A hydraulic control system comprises: a regulator valve, which regulates a fluid pressure established by an oil pump to an operating pressure required in a control circuit; a signal pressure establishing valve, which applies a signal pressure to the regulator valve to determine a level of the fluid pressure to be established by the regulator valve; and an accumulator, which accumulates the operating pressure to be applied to the control circuit.

Abstract: The present invention relates to a hydraulic control system having a feeding passage to a control object, a draining passage from the control object, and a control valve disposed on one of the passages is provided. The valve is adapted to deliver or drain the fluid to/from the control object in accordance with an applied current calculated based on a difference between a target pressure and an actual pressure of the control object. The hydraulic control system is configured to calculate a desired fluid volume to adjust the actual pressure to the target pressure based on said pressure difference, and to calculate a current value to achieve the desired fluid volume based on a relation between a current value applied to the control valve and an outflow rate of the fluid.

Abstract: A hydraulic control unit configured to improve energy efficiency is provided. The hydraulic control unit is comprised of: a feeding passage that delivers fluid from at least any of an oil pump and an accumulator storing hydraulic pressure to an actuator; a draining passage that discharge the fluid from the actuator to a drain spot; and a discharging means that is configured to selectively discharge the fluid from the actuator to the accumulator through the feeding passage, if the fluid has to be discharged from the actuator and a pressure of the accumulator is lower than that of the actuator.

Abstract: A hydraulic control unit is provided. A valve is comprised of a piston having a valve element, a cylinder holding the piston while allowing to reciprocate axially, a positive pressure chamber formed on one side of the piston to which pressure to open the valve is applied, a back pressure chamber formed on the other side of the piston to which the pressure to close the valve is applied, and a connection passage for differentiating pressures in the positive pressure chamber and the back pressure chamber. A pilot valve selectively connects the back pressure chamber with a site where the pressure is lower than that of the back pressure chamber. Hydraulic pressure lower than that applied to positive pressure chamber is applied to a low pressure section.

Abstract: A hydraulic control system for an automatic transmission, in which a belt is applied to at least one pair of pulleys, and in which widths of belt grooves of the pulleys, or pressures to clamp the belt by the pulleys are controlled by hydraulic pressures applied to hydraulic chambers of the pulleys. The hydraulic control system is comprised of: a control valve that controls a delivery and a drainage of hydraulic fluid to/from the hydraulic chamber; and a drive frequency setting means that determines a drive frequency of a drive signal for actuating the control valves in such a manner that a phase of a local maximum value of amplitude of the drive signal is shifted from a phase of a local maximum value of amplitude of vibrations resulting from rotating the pulleys.

Abstract: A sealing structure capable of reducing oil leakage while preventing the oil from being deteriorated by a temperature rise of the oil. The sealing structure is configured to seal a clearance between two members tightly by a seal ring interposed therebetween. The seal ring is provided with a slidable structure, which is configured to seal the clearance between the two members by a hydraulic pressure applied thereto, and to unseal the clearance between the two members by a relative movement thereof resulting from a thermal expansion thereof.

Abstract: A hydraulic control system for an automatic transmission. The hydraulic control system is applied to an automatic transmission adapted to vary a torque capacity of a transmission member by an actuator. The hydraulic control system includes: a discharging device configured to discharge compressible gas entrained in the hydraulic fluid in the actuator; an interrupting device that interrupts power transmission; and a controller configured to determine an entrainment of the compressible gas in the hydraulic fluid, disconnect the power transmission via the interrupting device in a case that an entrained compressible gas is determined, and cause the entrained compressible gas to be removed from the hydraulic fluid by rotating the actuator while interrupting the power transmission.