Abstract: In a vehicular belt-driven continuously variable transmission, belt squeezing force is inhibited from becoming excessive and a safety factor, with respect to belt slip, of belt squeezing force applied to a transmission belt (48) is reduced to a value that is less than or equal to 1.5 by reducing a pressure receiving area (SOUT) of an output side hydraulic cylinder (46c). As a result, a centrifugal hydraulic pressure canceller chamber on a secondary pulley side (46) can be eliminated thus simplifying the structure of the vehicular belt-driven continuously variable transmission, while belt squeezing force can be appropriately controlled.

Abstract: A hydraulic control system of a vehicle power train having a belt-type continuously variable transmission, and a hydraulic lock-up clutch, includes: a line pressure control valve; first and second control valves; first, second and third electromagnetic valves; and a fail-safe valve. The fail-safe valve is switched to a fail position in which a line pressure is supplied to one of a drive pulley and a driven pulley when a rapid deceleration state is likely to occur in the belt-type continuously variable transmission, the fail-safe valve is switched to a normal position in which a hydraulic pressure output from the first control valve is supplied to the one of the drive pulley and the driven pulley during times other than the above, and the fail-safe valve is switched by a combination of a hydraulic pressure controlled by the second electromagnetic valve and a hydraulic pressure controlled by the third electromagnetic valve.

Abstract: A clutch apply control valve switches between a first position and a second position based on a control pressure PDS1 and a control pressure PDS2. When both the control pressure PDS1 and the control pressure PDS2 are output, the clutch apply control valve switches from the first position to the second position and outputs the control pressure PDS2. As a result, a lockup control valve switches to an OFF position. Accordingly, a dedicated solenoid valve for controlling operation of the clutch apply control valve can be eliminated, thus reducing both size and cost while enabling a lockup clutch to be released even if there is an ON failure of a solenoid valve.

Abstract: A hydraulic control circuit that shuts off an oil passageway so that the ratio between the shift pressure and the belt clamping pressure is not caused to be in a predetermined relationship even when a speed change ratio control valve and/or a speed change ratio control valve are not supplying/discharging hydraulic oil. Therefore, even if the speed change ratio control valve and/or the speed change ratio control valve cease supplying/discharging the hydraulic oil, the action of a thrust ratio control oil pressure P? output from a thrust ratio control valve on a primary hydraulic cylinder is avoided. Thus, impairment of the continuity of control at the time of a shift of the continuously variable transmission is prevented.

Abstract: In one embodiment, an oil pressure control apparatus includes a belt-driven continuously variable transmission, a lockup clutch provided in a torque converter, a primary regulator valve that regulates a line oil pressure that becomes a source pressure of oil pressure of various parts, and a lockup control valve that performs switching when controlling engagement/release of the lockup clutch. Control of the primary regulator valve and control of the lockup control valve are performed with a single linear solenoid valve. In this case, control of the primary regulator valve and control of the lockup control valve are performed in different ranges.

Abstract: In one embodiment, an oil pressure control apparatus includes a belt-driven continuously variable transmission, a lockup clutch provided in a torque converter, a primary regulator valve that regulates a line oil pressure that becomes a source pressure of oil pressure of various parts, and a clamping oil pressure control valve that supplies a clamping oil pressure to a driven-side pulley of the belt-driven continuously variable transmission. Control of the primary regulator valve is performed with a control oil pressure of a linear solenoid valve that controls the clamping oil pressure control valve, and a control oil pressure of a linear solenoid valve that controls engagement/release of the lockup clutch.

Abstract: An oil pressure control apparatus includes a belt-driven continuously variable transmission, a primary regulator valve that regulates a line oil pressure that becomes a source pressure of oil pressure of various parts, and a gear oil pressure control valve that supplies gear oil pressure to a driving-side pulley of the belt-driven continuously variable transmission. A failsafe valve is provided between the gear oil pressure control valve and the driving-side pulley. When the gear oil pressure control valve or a linear solenoid valve that controls the gear oil pressure control valve fails, the failsafe valve is switched so as to supply the line oil pressure to the driving-side pulley, and other than during such the gear oil pressure control valve's failure or the electromagnetic valve's failure, the failsafe valve is switched so as to supply the gear oil pressure to the driving-side pulley.

Abstract: An oil pressure control circuit includes an oil pump for outputting an oil pressure from each of a first port and a second port, a lockup control valve for making a switchover between a state in which a secondary pressure is supplied to an engagement-side oil chamber of a torque converter and a state in which a secondary pressure is supplied to a release-side oil chamber of the torque converter, in accordance with an oil pressure supplied from a first solenoid valve, a garage shift control valve for maintaining a supply source of an oil pressure when an oil pressure is supplied from the first solenoid valve, and a port switchover valve for shutting off the first port of the oil pump from a line-pressure oil passage when an oil pressure is supplied from each of both the first solenoid valve and a second solenoid valve.

Abstract: A first orifice is provided in a first fluid passage upstream of a cooler, and a second orifice is provided in a second fluid passage. The flowrates of hydraulic fluid flowing through the first and second fluid passages are regulated by the first and second orifices, respectively, and are thus suppressed from becoming excessive. Also, the downstream side of the second fluid passage is connected to the first fluid passage between the first orifice and the cooler, and a lubrication passage is connected to the first fluid passage downstream of the cooler. Accordingly, the lubrication passage is a single passage and the cooler and the lubrication passage are arranged in series so the cooler flowrate and the lubrication flowrate are the same. As a result, the flowrate of hydraulic fluid that flows out from a secondary regulator valve to the upstream side of an oil pump can be increased.

Abstract: A clutch apply control valve switches between a first position and a second position based on a control pressure PDS1, and a control pressure PDS2. When both the control pressure PDS1, and the control pressure PDS2 are output, the clutch apply control valve switches from the first position to the second position and outputs the control pressure PDS2. As a result, a lockup control valve switches to an OFF position. Accordingly, a dedicated solenoid valve for controlling operation of the clutch apply control valve can be eliminated, thus reducing both size and cost while enabling a lockup clutch to be released even if there is an ON failure of a solenoid valve.

Abstract: A hydraulic control circuit that shuts off an oil passageway so that the ratio between the shift pressure and the belt clamping pressure is not caused to be in a predetermined relationship even when a speed change ratio control valve and/or a speed change ratio control valve are not supplying/discharging hydraulic oil. Therefore, even if the speed change ratio control valve and/or the speed change ratio control valve cease supplying/discharging the hydraulic oil, the action of a thrust ratio control oil pressure P? output from a thrust ratio control valve on a primary hydraulic cylinder is avoided. Thus, impairment of the continuity of control at the time of a shift of the continuously variable transmission is prevented.

Abstract: The line oil pressure PL that is a basic pressure of a needed Pin pressure and a Pd pressure is set by line oil pressure setting device on the basis of the higher oil pressure of the oil pressure values obtained by adding reference margin values EX to the needed Pin pressure and the to Pd pressure. Therefore, a requirement minimum line oil pressure PL with respect to the needed Pin pressure needed for shifting and the Pd pressure needed for the belt clamping pressure is appropriately set so that good shifting performance and good belt clamping pressure are secured.

Abstract: The line hydraulic pressure setting portion sets the line hydraulic pressure PL, which is the base pressure for the required shift control pressure Pin and the required belt clamping pressure Pd, based on the higher of the required pressures Pin and Pd. At this time, if the continuously variable transmission is to be shifted up, the required Pin calculating portion calculates the required shift control pressure Pin based on one of the target speed ratio ?* and the actual speed ratio ? with which the required shift pressure Pv is calculated to be higher than with the other. As such, the required shift control pressure Pin is set to the minimum necessary level for shifting up the continuously variable transmission and the line hydraulic pressure PL is appropriately set to a level for obtaining the required shift control pressure Pin.

Abstract: A hydraulic control system for a vehicular drive system including a hydraulically operated belt-and-pulley type continuously variable transmission and a hydraulically operated frictional coupling device engaged for running of a vehicle, the hydraulic control system including: a first solenoid valve for regulating a belt-tensioning hydraulic pressure for tensioning a belt of the transmission, a second solenoid valve for regulating a transient coupling hydraulic pressure to be applied to the frictional coupling device in the process of an engaging action, a line-pressure regulating valve for regulating a line pressure used for hydraulically operated devices of the mechanism, and a hydraulic-circuit switching device operable to apply a control pressure of the second solenoid-operated valve to the line-pressure regulating valve after the frictional coupling device has been placed in a fully engaged state, and to apply a first control pressure of the first solenoid-operated valve to the line-pressure regulating va

Abstract: A hydraulic circuit cleaning apparatus has a hydraulic circuit that includes an oil pump, an oil passage to which the oil pressure ejected from the oil pump is supplied, and a pressure regulator device connected to the oil passage for regulating the oil pressure in the oil passage. The apparatus cleans the hydraulic circuit by using a cleaning liquid. A discharge oil passage is connected to a discharge port of the pressure regulator device, so that the cleaning liquid is discharged out of the hydraulic circuit via the discharge oil passage.

Abstract: A hydraulic circuit cleaning apparatus has a hydraulic circuit that includes an oil pump, an oil passage to which the oil pressure ejected from the oil pump is supplied, and a pressure regulator device connected to the oil passage for regulating the oil pressure in the oil passage. The apparatus cleans the hydraulic circuit by using a cleaning liquid. A discharge oil passage is connected to a discharge port of the pressure regulator device, so that the cleaning liquid is discharged out of the hydraulic circuit via the discharge oil passage.

Abstract: A control apparatus for a vehicle includes a power transmitting system between an engine and wheels. The transmitting system has a continuously variable transmission (CVT) and a motor-generator actuated in one of a regenerating operation mode and an assisting operation mode. The motor-generator serves as a generator in a regenerating operation mode and as a motor in an assisting operation mode. The apparatus includes an electric control unit (ECU) that determines a shift of engine speed, computes the total amount of torque of the engine, the CVT and the motor-generator and selects one of the operation modes and actuates the motor-generator base on the selected operation mode to corrects the engine speed.

Abstract: A hydraulic control apparatus for controlling a vehicle power transmitting system including a belt-and-pulley type continuously variable transmission and a torque converter provided with a lock-up clutch. The transmission includes a pair of hydraulic actuators one of which receives a belt tensioning pressure for controlling a tension of a transmission belt.

Abstract: A hydraulic control apparatus for controlling a belt-and-pulley type continuously variable transmission of a motor vehicle having an engine, which transmission includes a pair of hydraulic actuators one of which receives a belt tensioning pressure for controlling a tension of a transmission belt. The hydraulic control apparatus includes an engine-output detecting valve for generating an engine output pressure indicative of a currently required output of the engine, a solenoid-operated valve for regulating a modified engine output pressure based on the engine output pressure generated by the engine-output detecting valve, and a pressure regulating valve for regulating the belt tensioning pressure based on at least the modified output pressure. The modified engine output pressure is obtained so that the belt tensioning pressure is controlled to an optimum level.

Abstract: A hydraulic control apparatus for controlling a continuously variable transmission of a motor vehicle, which transmission includes a first and a second shaft, a pair of variable-diameter pulleys provided on the first and second shafts, respectively, a transmission belt connecting the pulleys, and a pair of hydraulic actuators one of which receives a belt tensioning pressure for controlling a tension of the belt. The hydraulic control apparatus includes a reversal detecting device for determining whether a rotating direction of the pulleys has been reversed or not, and a pressure increasing device for temporarily increasing the belt tensioning pressure when the reversal detecting device detects reversal of the rotating direction of the pulleys.