A hydraulic control unit (4) for an automatic transmission of a motor vehicle includes a volumetric flow rate control valve (49). The hydraulic control unit (4) is configured for delivering hydraulic fluid to an inlet (59) of the volumetric flow rate control valve (49). An outlet (31, 71) of the volumetric flow rate control valve (18, 49) is connected to a torque converter torus of the automatic transmission. In addition, the volumetric flow rate control valve (59) is configured for directing the hydraulic fluid across an orifice (66), so that the pressure of the hydraulic fluid is reduced and a constant flow of hydraulic fluid is feedable to a torque converter torus.

The “factory installed” pressure regulator valve of an automotive transmission is replaced by a pressure regulator valve having two separate valve components conjointly movable together in a bore. A protrusion or protuberance extending from the center of one end of one of the valve components defines a fulcrum which abuts against an adjacent end of the other valve component as the two valve components move conjointly and in direct contact with each other within the bore during operation of the pressure regulator valve. Preferably, an opening is provided in a land in one of the valve components to vent hydraulic fluid (transmission oil) to prevent a pressure build-up in the bore which might separate the two valve components from each other during reciprocating movement of the valve components in the bore.

An automatic transmission comprising a control valve body adapted to control oil flow within the transmission, a torque converter having a torque converter clutch operable in one of an open and an applied condition, a first control circuit between the control valve body and the torque converter and a second control circuit between the control valve body and the torque converter, a first oil path that provides a fluid connection between the first control circuit and the torque converter, a second oil path that provides a fluid connection between the second control circuit and the torque converter, a third oil path that provides a fluid connection between the second control circuit and the torque converter clutch, and an orifice that provides a fluid connection between the second control circuit and the torque converter.

A one-way valve includes: a cylindrical section, one end of which is inserted into and fixed to an inside of a pipe, the cylindrical section including a through-hole through which oil is passed in an axial direction; and a columnar section housed inside the pipe and including, in another end thereof, a plurality of lateral holes through which oil is passed, flow of oil being blocked when the other end is inserted into a one-side opening section of the cylindrical section.

A hydraulic control unit (4) includes a valve bush (12), a valve cover (15) partially closing the valve bush (12) on an end face (S1), a valve slide (13) guided in a longitudinal direction (L) within the valve bush (12), and a housing part (6). The housing part (6) includes a recess (8) matching an external contour of the valve bush (12). An intermediate plate (7) is configured to partially cover the valve cover (15). A spring (14) is arranged within the valve bush (12) and preloads the valve slide (13) in a starting position. The valve bush (12) is inserted, together with the valve cover (15), the valve slide (13), and the spring (14), into the recess (8) of the housing part (6) and jointly form a hydraulic valve (9). The valve bush (12) forms an inlet (19), and the valve cover (15) forms an outlet (31).

An automatic transmission comprising a control valve body adapted to control oil flow within the transmission, a torque converter having a torque converter clutch operable in one of an open and an applied condition, a first control circuit between the control valve body and the torque converter and a second control circuit between the control valve body and the torque converter, a first oil path that provides a fluid connection between the first control circuit and the torque converter, a second oil path that provides a fluid connection between the second control circuit and the torque converter, a third oil path that provides a fluid connection between the second control circuit and the torque converter clutch, and an orifice that provides a fluid connection between the second control circuit and the torque converter.

A vehicle power transmission device includes: a continuously variable transmission including a primary pulley, a secondary pulley, and a transmission belt wound between the primary pulley and the secondary pulley; a belt running clutch of hydraulic type for transmitting power to the continuously variable transmission; and a hydraulic control circuit controlling the continuously variable transmission and the belt running clutch. The hydraulic control circuit includes a fail-safe valve switching a communication destination of an oil supply passage for supplying a hydraulic fluid to the belt running clutch to one of a first oil passage supplied with a control hydraulic pressure and a second oil passage supplied with a hydraulic pressure higher than the control hydraulic pressure, the fail-safe valve connecting the oil supply passage with the second oil passage when the fail-safe valve is switched to a failure position. The second oil passage is provided with an orifice.

A hydraulic control valve for controlling hydraulic circuits comprises a valve housing defining a valve bore, a first spool valve slidably positioned within the valve bore and adapted to control a first hydraulic circuit, and a second spool valve slidably positioned within the valve bore and adapted to control a second hydraulic circuit. The first spool valve and the second spool valve are positioned co-axially within the valve bore and are independently slidable within the valve bore to allow the first and second spool valves to control the first and second hydraulic valves independently of one another.

A power train device for a vehicle is provided with a selector valve that is switched between a first state in which oil discharged from an electric oil pump is able to be supplied as a hydraulic fluid to an engagement hydraulic chamber of a vehicle-starting frictional engagement element, and a second state in which the oil is able to be supplied as a lubricating oil to the vehicle-starting frictional engagement element through a first lubricating oil supply circuit, depending on a magnitude of a discharge pressure of a mechanical oil pump.

A valve body for an automotive transmission includes a pressure regulator valve in the casting for controlling oil pressure within the torque converter. The valve has a bore to provide fluid communication with an exhaust circuitry in the transmission when the valve is moved by oil pressure from a first position to a second position. The regulator valve prevents excessive pressure and damage from ballooning of the torque converter housing. In an alternative non-lockup torque converter, a check ball in a modified separator plate moves to open and close an oil path in the plate to thereby control oil pressure.