Abstract: A continuously variable transmission (CVT) for a vehicle includes a hydraulically-controlled component and a pilot valve. The pilot valve includes at least one micro-electrical-mechanical-systems (MEMS) based device. The pilot valve is operably connected to and is configured for actuating the hydraulically-controlled component. The pilot valve additionally includes a regulating valve operably connected to the pilot valve and to the hydraulically-controlled component. The regulating valve is configured to direct fluid to the hydraulically-controlled component when actuated by the pilot valve.

Abstract: A method of controlling a hydraulic control system for a dual clutch transmission includes controlling a plurality of pressure and flow control devices in fluid communication with a plurality of clutch actuators and with a plurality of synchronizer actuators. The clutch actuators are operable to actuate a plurality of torque transmitting devices and the synchronizer actuators are operable to actuate a plurality of synchronizer assemblies. Selective activation of combinations of the pressure control solenoids and the flow control solenoids allows for a pressurized fluid to activate at least one of the clutch actuators and synchronizer actuators in order to shift the transmission into a desired gear ratio.

Abstract: A clutch transmission, in particular a dual-clutch transmission for a vehicle, such as a motor vehicle, includes at least one automatic transmission with a hydraulically actuatable clutch and at least one hydraulically actuatable gear actuator, and a hydraulic circuit having a tank supplying an unpressurized hydraulic medium and a pressure source supplying a pressurized hydraulic medium. For operating the respective clutch, a first pressure control valve and at least one second pressure control valve are arranged upstream of the respective coupling. At least one of the pressure control valves is connected with an upstream switching device which connects the at least one pressure control valve and a hydraulically actuatable parking lock either with the pressure source or with the tank.

Abstract: A method of controlling a hydraulic control system for a dual clutch transmission includes controlling a plurality of pressure and flow control devices in fluid communication with a plurality of clutch actuators and with a plurality of synchronizer actuators. The clutch actuators are operable to actuate a plurality of torque transmitting devices and the synchronizer actuators are operable to actuate a plurality of synchronizer assemblies. Selective activation of combinations of the pressure control solenoids and the flow control solenoids allows for a pressurized fluid to activate at least one of the clutch actuators and synchronizer actuators in order to shift the transmission into a desired gear ratio.

Abstract: A method of estimating transmission torque of a dry clutch, may include a) slowly releasing a dry clutch until a slip of the dry clutch occurs, b) acquiring and storing stroke of an actuator and torque of an engine at a starting time point at which the slip of the dry clutch occurs at step a), and c) determining the stroke of the actuator and the transmission torque of the dry clutch at the starting time point at which the slip of the dry clutch occurs, by using the stroke of the actuator and the torque of the engine stored at step b).

Abstract: A hydraulic control system for a dual clutch transmission includes a plurality of pressure and flow control devices in fluid communication with a plurality of clutch actuators and with a plurality of synchronizer actuators. The clutch actuators are operable to actuate a plurality of torque transmitting devices and the synchronizer actuators are operable to actuate a plurality of synchronizer assemblies. Selective activation of combinations of the pressure control solenoids and the flow control solenoids allows for a pressurized fluid to activate at least one of the clutch actuators and synchronizer actuators in order to shift the transmission into a desired gear ratio.

Abstract: A shift control apparatus controlling a stepped transmission. The apparatus is configured with a gear ratio setting unit, and a shift speed change determining unit. A shift speed change predicting unit predicts in advance a change of shift speed by the shift speed change determining unit based on the set gear ratio, a rate of change in the set gear ratio, and an engagement preparation time which is a time needed for engagement preparation of the friction engagement element. A shift control unit controls a hydraulic actuator so that engagement preparation of a friction engagement element to be engaged is performed when a change of shift speed is predicted, and controls the hydraulic actuator so that a hydraulic pressure needed for engaging the friction engagement element is supplied to a hydraulic servo when a change of shift speed is determined by the shift speed change determining unit.

Abstract: A hydraulic control system and method for controlling a dual clutch transmission includes a plurality of pressure and flow control devices and logic valve assemblies in fluid communication with a plurality of clutch actuators and with a plurality of synchronizer actuators. The clutch actuators are operable to actuate a plurality of torque transmitting devices and the synchronizer actuators are operable to actuate a plurality of synchronizer assemblies. Selective activation of combinations of the pressure control solenoids and the flow control solenoids allows for a pressurized fluid to activate at least one of the clutch actuators and synchronizer actuators in order to shift the transmission into a desired gear ratio.

Abstract: The present invention provides a method of operating an electro-hydraulic control system for a dual clutch transmission having seven forward speeds or gear ratios and reverse. The control system includes an oil delivery subsystem, a clutch control subsystem and a synchronizer control subsystem. All three subsystems are under the control of a transmission control module. The method of operation includes gathering data from various shaft speed, clutch position and shift actuator position sensors and utilizing pressure control (PCS) and flow control (FCS) solenoid valves and a logic valve to pre-stage and engage (and disengage) hydraulic shift actuators associated with a requested and current gear and to sequentially engage one of a pair of input clutches.

Abstract: A system for providing pressurized hydraulic fluid in a transmission of a motor vehicle includes a pump for providing pressurized hydraulic fluid having an inlet port and an outlet port. A bypass valve includes an inlet port in communication with the outlet port of the pump, a first outlet port in communication with the inlet port of the pump, and a second outlet port. The inlet port of the bypass valve is in communication with the second outlet port of the bypass valve when the bypass valve is in a first position and the inlet port of the bypass valve is in communication with the first outlet port of the bypass valve when the bypass valve is in a second position. A control device and accumulator are operatively associated with the bypass valve.

Abstract: A clutch control device for controlling a clutch installed between an engine and a transmission in a power transmission device for a vehicle includes a clutch actuator driven by a working fluid, a stroke sensor for detecting a movement of the clutch actuator, a flow rate control valve for controlling an amount of the working fluid in the clutch actuator, and a flow rate control valve control device for controlling a position of a valve body of the flow rate control valve responsive to a detection signal from the stroke sensor.

Abstract: A hydraulic control system for a transmission includes a source of pressurized hydraulic fluid that communicates with an electronic transmission range selection (ETRS) subsystem or manual valve and a clutch actuation subsystem.

Abstract: A hydraulic control system for a dual clutch transmission includes a plurality of pressure and flow control devices in fluid communication with a plurality of clutch actuators and with a plurality of synchronizer actuators. The clutch actuators are operable to actuate a plurality of torque transmitting devices and the synchronizer actuators are operable to actuate a plurality of synchronizer assemblies. Selective activation of combinations of the pressure control solenoids and the flow control solenoids allows for a pressurized fluid to activate at least one of the clutch actuators and synchronizer actuators in order to shift the transmission into a desired gear ratio.

Abstract: A hydraulic control system for a transmission includes a first source of pressurized hydraulic fluid for providing a first flow of hydraulic fluid, a second source of pressurized hydraulic fluid for providing a second flow of hydraulic fluid, and a torque converter control subsystem for controlling a torque converter and a torque converter clutch. The torque converter control subsystem includes a torque converter control valve and a solenoid. The solenoid is multiplexed to the torque converter control valve and the torque converter clutch. The torque converter control valve is operable to control a flow of hydraulic fluid to the torque converter and to other subsystems within the hydraulic control system.

Abstract: A hydraulic control system for a dual clutch transmission includes a plurality of pressure and flow control devices and logic valve assemblies in fluid communication with a plurality of clutch actuators and with a plurality of synchronizer actuators. The clutch actuators are operable to actuate a plurality of torque transmitting devices and the synchronizer actuators are operable to actuate a plurality of synchronizer assemblies. Selective activation of combinations of the pressure control solenoids and the flow control solenoids allows for a pressurized fluid to activate at least one of the clutch actuators and synchronizer actuators in order to shift the transmission into a desired gear ratio.

Abstract: A hydraulic circuit for controlling a hybrid clutch and an automatic transmission of a motor vehicle. The circuit includes an electrically-powered hydraulic pump to supply the hybrid clutch and the automatic transmission with a hydraulic medium. A pressure booster is connected downstream of the hydraulic pump and includes a pressure booster slave cylinder and a pressure booster master cylinder. A hydraulic line segment extends between the pressure booster and the hybrid clutch, with the pressure booster master cylinder connected with a hybrid clutch slave cylinder to actuate the hybrid clutch. An oil feed device is connected with the pressure booster slave cylinder and fed by it with the hydraulic medium for refilling the hydrostatic line segment with the hydraulic medium.

Abstract: A hydraulic control system for a dual clutch transmission includes a plurality of pressure and flow control devices and logic valve assemblies in fluid communication with a plurality of clutch actuators and with a plurality of synchronizer actuators. The clutch actuators are operable to actuate a plurality of torque transmitting devices and the synchronizer actuators are operable to actuate a plurality of synchronizer assemblies. Selective activation of combinations of the pressure control solenoids and the flow control solenoids allows for a pressurized fluid to activate at least one of the clutch actuators and synchronizer actuators in order to shift the transmission into a desired gear ratio.

Abstract: A hydraulic control device for a transmission is provided. The hydraulic control device regulates hydraulic pressure from an oil pressure source to generate line pressure, and selectively applies the generated line pressure to at least two kinds of controlled objects. The hydraulic control device includes: linear solenoid valves each controlling hydraulic pressure to the line pressure in accordance with electromagnetic force of a solenoid; and switching valves each selectively switching at least two kinds of controlled objects to apply the hydraulic pressure applied from the corresponding linear solenoid valve to the switched controlled object. The hydraulic control device further includes a feedback oil passage provided for each of the switching valves. The feedback oil passage is branched from one of a plurality of output oil passages of the corresponding switching valve. The feedback oil passage is connected to a feedback port of the linear solenoid valve.

Abstract: A hydraulic control system for a dual clutch transmission includes a plurality of solenoids and valves in fluid communication with a plurality of clutch actuators and with a plurality of synchronizer actuators. The clutch actuators are operable to actuate a plurality of torque transmitting devices and the synchronizer actuators are operable to actuate a plurality of synchronizer assemblies. Selective activation of combinations of the solenoids allows for a pressurized fluid to activate at least one of the clutch actuators and synchronizer actuators in order to shift the transmission into a desired gear ratio.

Abstract: A vehicle includes a motive power source, a transmission, and a clutch system. The vehicle further includes a controller that causes the clutch system to generate a generally constant clutch pressure to mechanically couple the motive power source and transmission as a line pressure associated with the transmission varies.

Abstract: An electro-hydraulic control system for a multiple speed automatic motor vehicle transmission includes main and auxiliary hydraulic pumps, a line pressure regulator, a lubrication pressure regulator, a lubrication override control valve and a torque converter control valve which is controlled by a variable force solenoid (VFS). Driver commands are provided to the system through a manual logic or spool valve which functions in conjunction with a spool or logic default valve and a default solenoid. Five solenoid valves receive various flows of hydraulic fluid and supply them to hydraulic actuators that engage and disengage four friction clutches and a selectable one-way clutch.

Abstract: The control apparatus comprises, in its version intended for a double-clutch transmission, first, second and third shift forks each movable between first and second engagement positions to engage a respective gear, of which the first shift fork is able to engage at least the first gear and the second shift fork is able to engage at least the second gear, first, second and third double-acting hydraulic actuators arranged to control each the movement of a respective shift fork between the first and second engagement position, of which the first hydraulic actuator is associated to the first shift fork and the second hydraulic actuator is associated to the second shift fork, a slide valve selectively movable into one of at least three operating positions in each of which the slide valve selects a respective hydraulic actuator, and first and second gear shift solenoid valves for controlling the supply of fluid to the hydraulic actuator each time selected by the slide valve or the connection of that actuator to a t

Abstract: A hydraulic control system for a dual clutch transmission includes a source of pressurized hydraulic fluid, first and second actuator control devices in downstream fluid communication with the source of pressurized hydraulic fluid, and first and second clutch control devices in downstream fluid communication with the source of pressurized hydraulic fluid. A first valve is in downstream fluid communication with the first and second actuator control devices. A second valve is in downstream fluid communication with the first valve, the first clutch control device and the second clutch control device, and the second valve is moveable between two positions by the first and second clutch control devices. Selective activation of combinations of the control devices allows for a pressurized fluid to engage the dual clutch and an actuator in order to shift the transmission into a desired gear ratio.

Abstract: Pairs of variable feed solenoid valves provide fluid to a pair of input clutch actuators and a pair of inlet ports of a first or logic valve. The position of the first logic valve spool is controlled by a solenoid valve. A first pair of outlet ports of the first logic valve provide fluid to a first piston which selects two speed ratios. A second pair of outlet ports of the first logic valve provide fluid to a pair of inlet ports of a second logic valve. The position of the second logic valve spool is controlled by fluid from the input clutch circuits. A first pair of outlet ports of the second logic valve provide fluid to a second piston which selects two other speed ratios and a second pair of outlet ports of the second logic valve provide fluid to a third piston which selects two additional speed ratios.

Abstract: When a predetermined time has passed without detection of engine stall and without detection of the neutral state and without detection of a vehicle starting operation, in a first control state in which a clutch is in a disengaged state, a clutch control system effects transition to a second control state in which transition to a third control state is permitted. When a vehicle starting operation is detected in the second control state B in which the clutch is in the disengaged state, a liquid pressure modulator is driven to effect transition to the third control state in which the clutch is put in the engaged state or a partially engaged state. When an engine stall or the neutral state is detected in the second control state, transition to the first control state A is effected.

Abstract: Pairs of variable feed solenoid valves provide fluid to a pair of input clutch actuators and a pair of inlet ports of a first logic valve. The position of the first logic valve spool is controlled by a solenoid valve. A first pair of outlet ports of the first logic valve provide hydraulic to a first piston which selects two speed ratio. A second pair of outlet ports of the first logic valve provide fluid to a pair of inlet ports of a second logic valve. The position of the second logic valve spool is controlled by fluid from the input clutch circuits. A first pair of outlet ports of the second logic valve provide fluid to a second piston which selects two other speed ratios and a second pair of outlet ports of the second logic valve provide fluid to a third piston which selects two additional speed ratios.

Abstract: A powertrain for a vehicle includes an engine, a transmission with an input member driven by the engine, and an output member. An electric motor is operable to drive the input member. The transmission has an electrically-actuated one-way clutch with a neutral mode in which the clutch freewheels in both directions of rotation, and a locked mode in which the clutch is locked in one direction of rotation. The transmission also has a hydraulically-actuated dual-piston clutch with a spring that biases the dual-piston clutch to an engaged state. The one-way clutch is in the neutral mode and the spring biases the dual-piston clutch to the engaged state prior to a key start of the engine. The one-way clutch is actuated to the locked state following ignition of the engine after a key start, and remains in the locked state during an autostop of the engine.

Abstract: In a control of a vehicular automatic transmission, an engaging device provided in a power transmission path between an engine and driving wheels is brought into a slipping state or a release state when a certain neutral control condition is satisfied while a shift lever is placed in a running position, the engaging device is engaged so as to increase a torque transmission capacity thereof when a certain neutral control cancellation condition is satisfied during neutral control under which the engaging device is in the slipping state or the release state, and an engaging pressure of the engaging device is held at a constant pressure level for a given period of time when an accelerator pedal is depressed while the engaging device is engaged so as to increase the torque transmission capacity thereof.

Abstract: A method for controlling a drivetrain including an automatically shifted starting clutch and gear-shift clutch and a transmission, with a non self-locking clutch actuator, a gear actuator for engaging and disengaging transmission gears and a control unit which generates control commands for the clutch actuator and gear actuator and transmits such commands to the actuators such that, when the vehicle is at rest and a gear is engaged and if the clutch actuator fails, the clutch does not inadvertently engage. When a transmission gear is engaged, a control command is generated and sent for the clutch actuator to disengage the clutch. Thereafter, the vehicle speed is determined and if the speed is essentially zero and the clutch begins to engage, a control command is sent to the gear actuator to shift the transmission to its neutral position.

Abstract: The present invention comprehends a plurality of embodiments of a hydraulic control system for various configurations of dual clutch transmissions. The hydraulic control systems all include a regulated source of pressurized hydraulic fluid including an electric pump, a filter and an accumulator, a pair of pressure control valves and a branching hydraulic circuit including pressure or flow control valves, spool or logic valves and two position valves which collectively supply and exhaust hydraulic fluid from a plurality of shift actuators. The actuators are connected to shift rails which include shift forks and are slidable to engage synchronizers and positive clutches associated with the various gear ratios.

Abstract: The present invention comprehends a plurality of embodiments of a hydraulic control system for various configurations of dual clutch transmissions. The hydraulic control systems all include a regulated source of pressurized hydraulic fluid including an electric pump, a filter and an accumulator, a pair of pressure control valves and a branching hydraulic circuit including pressure or flow control valves, spool or logic valves and two position valves which collectively supply and exhaust hydraulic fluid from a plurality of shift actuators. The actuators are connected to shift rails which include shift forks and are slidable to engage synchronizers and positive clutches associated with the various gear ratios.

Abstract: A clutch control device includes: a plurality of hydraulic clutches built into a transmission; a clutch switching pattern storage device in which a plurality of clutch switching patterns, each defining engage/release changeover timing with which the plurality of hydraulic clutches are engaged/released are stored in correspondence to individual speed change patterns adopted by the transmission; a clutch switching pattern selection device that selects a clutch switching pattern stored in the clutch switching pattern storage device in correspondence to a speed change pattern for the transmission at a time of speed change; and a hydraulic control device that executes hydraulic control for the plurality of hydraulic clutches in correspondence to the clutch switching pattern selected by the clutch switching pattern selection device.

Abstract: An integrated clutch-transmission assembly for a road vehicle; the integrated clutch-transmission assembly has a power-assisted clutch having a number of first hydraulic actuators; a power-assisted transmission having a number of second hydraulic actuators; a high-pressure pump for the hydraulic actuators; a number of solenoid valves for controlling the hydraulic actuators; a housing having a first chamber housing the clutch, and a second chamber housing the transmission; and a flat supporting plate, which is housed removably inside the housing to separate the two chambers of the housing, has a first wall fitted with the clutch, and has a second wall parallel to and opposite the first wall and fitted with the high-pressure pump and at least some of the solenoid valves.

Abstract: A vehicle drive apparatus for supplying oil pressure to a hydraulic servo at restart of an engine. The vehicle drive apparatus includes an accumulator that accumulates the oil pressure, an electromagnetic switching valve that retains oil pressure of the accumulator when an oil pump is stopped, a switching valve control unit that controls opening and closing of the electromagnetic switching valve, and a restart determining unit that determines whether or not to restart the vehicle drive source from a stopped state. When it is determined by the restart determining unit to restart the vehicle drive source, the switching valve control unit is started so as to supply the oil pressure accumulated in the accumulator to the hydraulic servo. As a result, engine friction engagement elements are quickly engaged to enable starting of a vehicle.

Abstract: An electro-hydraulic control system for a multiple speed automatic motor vehicle transmission includes main and auxiliary hydraulic pumps, a line pressure regulator, a lubrication pressure regulator, a lubrication override control valve and a torque converter control valve which is controlled by a variable force solenoid (VFS). Driver commands are provided to the system through a manual logic or spool valve which functions in conjunction with a spool or logic default valve and a default solenoid. Five solenoid valves receive various flows of hydraulic fluid and supply them to hydraulic actuators that engage and disengage four friction clutches and a selectable one-way clutch.

Abstract: A control section determines a driving state of a vehicle and controls first and second solenoid valves on the basis of the determined driving state. An oil passage length of a second oil discharge passage is shorter than that of a first oil discharge passage and a discharge end of the second oil discharge passage is opened at a lower position than that of the first oil discharge passage. The control section derives hydraulic oil, discharged from an oil chamber via a first shift valve, to the first oil discharge passage by means of a second shift valve when it is determined that the driving state is one during normal driving. The control section derives the hydraulic oil to the second oil discharge passage by means of the second shift valve when it is determined that the driving state is one required for rapid lock-up off.

Abstract: A solenoid valve device that includes a solenoid valve; a drive circuit that drives the solenoid section; a current sensor that detects a current applied to the solenoid section; and a control unit that controls, when the solenoid valve is served as the pressure control valve, the drive circuit by performing a feedback control based on the current detected by the current sensor so that a current in accordance with an output pressure command is applied to the solenoid section, and controls, when the solenoid valve is served as the solenoid pump, the drive circuit without performing the feedback control so that a pump current is applied to the solenoid section.

Abstract: A control device for and a method of controlling a gearbox having a pressure-limiting device connected to a pressure medium source. A first controllable valve device is connected downstream of the pressure-limiting device and an actuating device is connected further downstream and adjusts the gearbox. A second controllable valve device is connected directly to the pressure medium source, via a supply line, and another actuating device is connected downstream of the second controllable valve device. An electric control device is provided for actuating the controllable valve devices and a sensor is connected to the electric control device for measuring pressure of the pressure medium in the supply line. The electric control device is connected to the second controllable valve device such that the second controllable valve device and the further actuating device are controlled by the pressure of the pressure medium in the supply line.

Abstract: An agricultural vehicle and method of operating the same, where the agricultural vehicle has an engine, a continuously variable transmission, a processor, an inching controller, and a speed controller. The speed controller sends a first signal to the processor, and the processor controls the transmission to operate the vehicle at a first speed based on the first signal. The inching controller sends a second signal to the processor, and the processor controls the transmission to move the agricultural vehicle in a forward or reverse direction, depending on the second signal. If the first speed based on the first signal is zero, the second signal triggers the processor to control the transmission to move the agricultural vehicle in the forward or reverse direction a predetermined first distance. The control of the vehicle to be at zero speed or to be in a particular position is effectuated by a position control mechanism.

Abstract: A method is proposed for blocking inadmissible gearshift processes in a transmission with a plurality of shifting devices which, to carry out a shift process, are moved by actuating devices when a shift command is sent by a control unit (TCU) to the relevant actuating device. The actuating devices are connected for data exchange with one another and with the control unit (TCU) in such manner that the actuating device of the shifting device to be shifted is activated provided that clearance has been given by at least one other actuating device.

Abstract: A hydraulic control system and method for controlling a dual clutch transmission includes a plurality of pressure and flow control devices and logic valve assemblies in fluid communication with a plurality of clutch actuators and with a plurality of synchronizer actuators. The clutch actuators are operable to actuate a plurality of torque transmitting devices and the synchronizer actuators are operable to actuate a plurality of synchronizer assemblies. Selective activation of combinations of the pressure control solenoids and the flow control solenoids allows for a pressurized fluid to activate at least one of the clutch actuators and synchronizer actuators in order to shift the transmission into a desired gear ratio.

Abstract: A hydraulic control system and method for controlling a dual clutch transmission includes a plurality of pressure and flow control devices and logic valve assemblies in fluid communication with a plurality of clutch actuators and with a plurality of synchronizer actuators. The clutch actuators are operable to actuate a plurality of torque transmitting devices and the synchronizer actuators are operable to actuate a plurality of synchronizer assemblies. Selective activation of combinations of the pressure control solenoids and the flow control solenoids allows for a pressurized fluid to activate at least one of the clutch actuators and synchronizer actuators in order to shift the transmission into a desired gear ratio.

Abstract: A hydraulic control system for a dual clutch transmission includes a plurality of pressure and flow control devices and logic valve assemblies in fluid communication with a plurality of clutch actuators and with a plurality of synchronizer actuators. The clutch actuators are operable to actuate a plurality of torque transmitting devices and the synchronizer actuators are operable to actuate a plurality of synchronizer assemblies. Selective activation of combinations of the pressure control solenoids and the flow control solenoids allows for a pressurized fluid to activate at least one of the clutch actuators and synchronizer actuators in order to shift the transmission into a desired gear ratio.

Abstract: A hydraulic control system for a dual clutch transmission includes a plurality of pressure and flow control devices and logic valve assemblies in fluid communication with a plurality of clutch actuators and with a plurality of synchronizer actuators. The clutch actuators are operable to actuate a plurality of torque transmitting devices and the synchronizer actuators are operable to actuate a plurality of synchronizer assemblies. Selective activation of combinations of the pressure control solenoids and the flow control solenoids allows for a pressurized fluid to activate at least one of the clutch actuators and synchronizer actuators in order to shift the transmission into a desired gear ratio.

Abstract: A hydraulic fluid supply system includes an active pressure regulator or feed limit valve with a flow cut-off which may be used with dual clutch transmission hydraulic control systems. The supply system includes a pump, a filter, pressure relief and filter bypass valves, an accumulator, a system pressure sensor and the active feed limit valve. The active feed limit and flow cut-off valve includes an on-off solenoid valve and a spool or logic valve having an inlet port, an outlet port, a control port, a feedback port and an exhaust port. The inlet port is supplied with pressurized hydraulic fluid and the control port is supplied with hydraulic fluid from the solenoid control valve when it is energized. A valve spool having a pair of spaced-apart lands is biased toward the control port. One side of a check valve is in fluid communication with the feedback port.

Abstract: A hydraulic system for controlling a motor vehicle transmission having automated actuation of clutches. The hydraulic system includes a first valve connected downstream from a hydraulic energy source for producing a system pressure to control and/or regulate a clutch pressure. A second valve is connected downstream from the first valve and ahead of two clutches of the motor vehicle transmission to control and/or regulate the clutch pressure, wherein the second valve includes a regulating circuit to regulate the clutch pressure.

Abstract: A pressure medium-actuated control device of an automated step-by-step variable speed transmission. The device having a control valve for controlling an actively engaged disconnectable type clutch which is disposed along a power flow path between a motor and a transmission input shaft, and a self-retaining valve located in the pressure supply of the clutch control valve for a rotational speed-dependent emergency actuation of the disconnectable type clutch. An electrical switch-off actuator is connected to the self-retaining valve such that the valve piston, of the self-retaining valve, can be moved into an idle position to lock the pressure supply of the clutch control valve in a powered state of the switch-off actuator, and into an operating position determined by the applied control pressures in the power-off state of the switch-off actuator.

Abstract: A clutch control system for a vehicle includes an actuator which is configured to control a hydraulic pressure. A timer is configured to measure a time period from a timing at which a hydraulic pressure supply source starts supplying hydraulic oil to a hydraulic clutch to a timing at which the hydraulic pressure reaches a predetermined value. A clutch control compensator is configured to calculate a control compensation value of an amount of operation of the actuator based on the time period measured by the timer. A clutch controller is configured to control the actuator based on the control compensation value and the amount of operation of the actuator using a deviation between the hydraulic pressure detected by the hydraulic pressure detector and a target hydraulic pressure set according to a condition of the vehicle.

Abstract: A hydraulic control apparatus for marine reversing gear assembly for watercraft includes a pressure-reducing valve for adjusting pressure of working oil supplied from a supply pump, and supplying working oil to forward and reverse clutches; a proportional electromagnetic valve for controlling the supply of working oil to a pilot chamber of the pressure reducing valve; and a spring-type switching valve for switching to a circuit for supplying working oil to a control piston chamber for controlling a spring force of the pressure-reducing valve or to a circuit for draining working oil from the chamber; wherein a pressure output from the proportional electromagnetic valve acts upon the switching valve as a pilot pressure; and, when the pilot pressure falls below a predetermined value, the switching valve switches to the circuit for supplying the working oil to the chamber via the spring of the switching valve, fully opening the pressure-reducing valve.

Abstract: A hydraulic control unit is set up to hydraulically actuate a starting clutch of a motor vehicle and gear selectors of a transmission of the motor vehicle by use of hydraulic valves which are integrated in the hydraulic control unit and which have in each case at least one control element. The hydraulic control unit is characterized in that the integrated hydraulic valves are aligned in the hydraulic control unit in such a way that a movement direction of a vibratory element of a hydraulic valve which controls only the starting clutch differs from the movement direction of vibratory elements of the other hydraulic valves, and is aligned to a lesser extent with the longitudinal axis of the motor vehicle.