摘要:
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.
摘要:
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.
摘要:
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.
摘要:
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.
摘要:
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.
摘要:
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.
摘要:
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 valve while the frictional coupling device is in the process of the engaging action.
摘要:
An oil pressure control device includes a plurality of solenoid valves, and a foreign matter discharge unit which carries out 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 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 one of the solenoid valves at the beginning of the first period T1, and to start supplying a current smaller than the predetermined value to the another one of the solenoid valves at the beginning of the second period T2.
摘要:
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.
摘要:
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 valve while the frictional coupling device is in the process of the engaging action.