Abstract: A hydraulic control system includes a linear solenoid valve, an ON-OFF solenoid valve and a hydraulically-operated frictional engagement device. A first hydraulic pressure is regulated by the linear solenoid valve within a predetermined pressure-regulation control range, and is supplied to the frictional engagement device. In a state in which the frictional engagement device is placed in a predetermined engaged state based on the first hydraulic pressure, a second hydraulic pressure, which is higher than the pressure-regulation control range, is supplied from the ON-OFF solenoid valve to the frictional engagement device, such that the frictional engagement device is placed in a fully engaged state with a high engaging torque based on the second hydraulic pressure.

Abstract: A hydraulic control system includes a linear solenoid valve, an ON-OFF solenoid valve and a hydraulically-operated frictional engagement device. A first hydraulic pressure is regulated by the linear solenoid valve within a predetermined pressure-regulation control range, and is supplied to the frictional engagement device. In a state in which the frictional engagement device is placed in a predetermined engaged state based on the first hydraulic pressure, a second hydraulic pressure, which is higher than the pressure-regulation control range, is supplied from the ON-OFF solenoid valve to the frictional engagement device, such that the frictional engagement device is placed in a fully engaged state with a high engaging torque based on the second hydraulic pressure.

Abstract: In a coasting control process, an ECU increases line pressure PL of a hydraulic path to predetermined pressure P1 such that discharge pressure of an MOP becomes higher than that before a C1 clutch is disengaged at timing when an executing condition of coasting control is satisfied (time t=t1). According to such coasting control process, driving torque of the MOP increases, so that deceleration (deceleration G) caused by driving of the MOP by a drive wheel becomes larger than that in conventional coasting control in which the discharge pressure of the MOP is not increased. As a result, it is possible to inhibit a driver from feeling discomfort due to free-running feeling generated during the coasting control.

Abstract: The hydraulic control device includes: a mechanical variable-capacity oil pump; and an electronic control unit configured to calculate a target discharge volume of the mechanical variable-capacity oil pump using a plurality of parameters of the transmission, and control the mechanical variable-capacity oil pump based on the target discharge volume.

Abstract: A control system of a vehicle includes an engine, a continuously variable transmission, drive wheels, a clutch, and an electronic control unit. The electronic control unit is configured to release the clutch and stop the engine when a predetermined execution condition is satisfied during traveling, such that the vehicle performs coasting. The electronic control unit is configured to keep the continuously variable transmission at a speed ratio established at start of the coasting, during the coasting of the vehicle. The electronic control unit is configured to restart the engine that has been stopped and perform downshift of the continuously variable transmission, when a predetermined return condition is satisfied during the coasting. The electronic control unit is configured to engage the clutch after the downshift is started, such that the vehicle returns from the coasting.

Abstract: A hydraulic control circuit of a transmission includes a first oil passage, supplying hydraulic oil from an oil pump to a torque converter, and a second oil passage branching off from the first oil passage and having an oil pressure lower than that in the first oil passage; a selection valve switching between the hydraulic oil in the first and the second oil passages to the torque converter; an oil-pressure adjustment valve provided on the first oil passage and adjusting an oil pressure of the hydraulic oil of the first oil passage; and a switching valve provided on the first oil passage and switching between interruption and supply of hydraulic oil to the selection valve. Further, the switching valve is provided on a downstream side of the branching position of the second oil passage in the first oil passage and on an upstream side of the oil-pressure adjustment valve.

Abstract: The hydraulic control device includes: a mechanical variable-capacity oil pump; and an electronic control unit configured to calculate a target discharge volume of the mechanical variable-capacity oil pump using a plurality of parameters of the transmission, and control the mechanical variable-capacity oil pump based on the target discharge volume.

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 circuit of a transmission includes a first oil passage, supplying hydraulic oil from an oil pump to a torque converter, and a second oil passage branching off from the first oil passage and having an oil pressure lower than that in the first oil passage; a selection valve switching between the hydraulic oil in the first and the second oil passages to the torque converter; an oil-pressure adjustment valve provided on the first oil passage and adjusting an oil pressure of the hydraulic oil of the first oil passage; and a switching valve provided on the first oil passage and switching between interruption and supply of hydraulic oil to the selection valve. Further, the switching valve is provided on a downstream side of the branching position of the second oil passage in the first oil passage and on an upstream side of the oil-pressure adjustment valve.

Abstract: A control system of a vehicle includes an engine, a continuously variable transmission, drive wheels, a clutch, and an electronic control unit. The electronic control unit is configured to release the clutch and stop the engine when a predetermined execution condition is satisfied during traveling, such that the vehicle performs coasting. The electronic control unit is configured to keep the continuously variable transmission at a speed ratio established at start of the coasting, during the coasting of the vehicle. The electronic control unit is configured to restart the engine that has been stopped and perform downshift of the continuously variable transmission, when a predetermined return condition is satisfied during the coasting. The electronic control unit is configured to engage the clutch after the downshift is started, such that the vehicle returns from the coasting.

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: In a coasting control process, an ECU increases line pressure PL of a hydraulic path to predetermined pressure P1 such that discharge pressure of an MOP becomes higher than that before a C1 clutch is disengaged at timing when an executing condition of coasting control is satisfied (time t=t1). According to such coasting control process, driving torque of the MOP increases, so that deceleration (deceleration G) caused by driving of the MOP by a drive wheel becomes larger than that in conventional coasting control in which the discharge pressure of the MOP is not increased. As a result, it is possible to inhibit a driver from feeling discomfort due to free-running feeling generated during the coasting control.

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 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.