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 control valve switches between the (A) state where the first oil passage to which a hydraulic pressure obtained by decreasing a line pressure is supplied is in communication with the fifth oil passage for supplying the hydraulic pressure to a forward clutch or a reverse brake and the third oil passage to which a hydraulic pressure controlled by an SLP linear solenoid valve is supplied is in communication with the sixth oil passage for supplying the hydraulic pressure to a primary pulley, and the (B) state where the second oil passage to which a hydraulic pressure controlled by an SLT linear solenoid valve is supplied is in communication with the fifth oil passage and the fourth oil passage for supplying the hydraulic pressure to a secondary pulley is in communication with the sixth oil passage. The fourth oil passage has an orifice.

Abstract: An oil passage structure of a chain-driven oil pump includes three lines of oil passages for supplying oil from the center support to the torque converter, a first oil passage for supplying oil to the torque converter through the inside of an input shaft of the torque converter, a second oil passage for supplying oil to the torque converter through a space defined by the outer periphery surface of the input shaft and the inner periphery surface of a stator shaft, and a third oil passage for supplying oil to the torque converter by bypassing the drive sprocket. The third oil passage is provided on the outer periphery side of the drive sprocket and in a position where it does not interfere with the operation of a chain. Accordingly, it is possible to utilize the flex lock-up to a maximum extent, and to reduce the diameter of the sprocket.

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: A hydraulic control system of continuously variable transmission includes: a first sheave pressure regulating valve (17) that regulates a line pressure (Pl), which is used for hydraulic control as a source pressure, to obtain a first sheave pressure (Pin); a fail-safe valve (19) that selects and outputs any one of the first sheave pressure (Pin) or a fail-safe hydraulic pressure (second sheave pressure Pout) that is applied to a drive pulley (21) at the time of a failure due to an excessive first sheave pressure (Pin) to the drive pulley (21); and a first regulator valve (12) and a second regulator valve (13) that regulate the line pressure (Pl). An output pressure (Psf) of the fail-safe valve (19) is supplied to the first and second regulator valves (12 and 13) in a feedback manner as a drive pulley (21) side hydraulic pressure to thereby regulate the line pressure (Pl).

Abstract: A hydraulic control system of continuously variable transmission includes: a first sheave pressure regulating valve (17) that regulates a line pressure (Pl), which is used for hydraulic control as a source pressure, to obtain a first sheave pressure (Pin); a fail-safe valve (19) that selects and outputs any one of the first sheave pressure (Pin) or a fail-safe hydraulic pressure (second sheave pressure Pout) that is applied to a drive pulley (21) at the time of a failure due to an excessive first sheave pressure (Pin) to the drive pulley (21); and an orifice (25) that is provided in an oil passage (24) between the fail-safe valve (19) and the drive pulley (21). Then, a hydraulic pressure in the oil passage (24) on the drive pulley (21) side of the orifice (25) is supplied to the first sheave pressure regulating valve (17) as a feedback pressure.

Abstract: In a hydraulic control system for a transmission, line pressure Pl is adjusted in accordance with a second solenoid pressure Psls if the ratio of a first sheave pressure Pin with respect to a second solenoid pressure Psls is equal to or less than the gain ?. If not so, the line pressure Pl is adjusted in accordance with the first sheave pressure Pin. Consequently, the gain ? of the first sheave pressure Pin with respect to a first solenoid pressure Pslp at a first sheave pressure adjustment valve 16 and the gain ? of a second sheave pressure Pout with respect to the second solenoid pressure Psls at a second sheave pressure adjustment valve 17 can be individually set while the line pressure Pl can be suppressed to the substantially requisite minimum in the entire control region.

Abstract: A control valve switches between the (A) state where the first oil passage to which a hydraulic pressure obtained by decreasing a line pressure is supplied is in communication with the fifth oil passage for supplying the hydraulic pressure to a forward clutch or a reverse brake and the third oil passage to which a hydraulic pressure controlled by an SLP linear solenoid valve is supplied is in communication with the sixth oil passage for supplying the hydraulic pressure to a primary pulley, and the (B) state where the second oil passage to which a hydraulic pressure controlled by an SLT linear solenoid valve is supplied is in communication with the fifth oil passage and the fourth oil passage for supplying the hydraulic pressure to a secondary pulley is in communication with the sixth oil passage. The fourth oil passage has an orifice.

Abstract: In an oil pressure control device equipped with a plurality of solenoid valves, and foreign matter discharge means, the foreign matter discharge means carries out the foreign matter discharge treatment for a treatment period composed of a first period T1 in which a current smaller than a predetermined value is supplied to one of the solenoid valves and a second period T2 in which a current equal to or larger than the predetermined value is supplied to the one of the solenoid valves, and the foreign matter discharge means makes timings for varying the current values different from one another so as to start supplying a current equal to or larger than the predetermined current value to another at the beginning of the first period T1, and start supplying a current smaller than the predetermined value to the another one at the beginning of the second period T2.

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: 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 pressure control apparatus includes a primary regulator valve that regulates a pressure discharged from an oil pump to form a line pressure that is used as an original pressure for a hydraulic pressure that is supplied to each element, and a secondary regulator valve that regulates a hydraulic pressure downstream of the primary regulator valve to form a secondary pressure. Two pilot pressures (first modulator hydraulic pressure, control hydraulic pressure from a duty solenoid) are supplied to the secondary regulator valve. The secondary regulator valve is configured in such a manner that when one of the pilot pressures changes, a change in the one of the pilot pressures is absorbed by the other pilot pressure.

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: 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 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 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: 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