摘要:
A hydraulic control apparatus for an automatic transmission of a motor vehicle, the transmission including a lock-up clutch, the apparatus including a lock-up clutch switching valve device which is operable for selectively placing the lock-up clutch in a fully released, a partially engaged, and a fully engaged state thereof; a hydraulic pressure producing device which produces a hydraulic pressure; an abnormality detecting device which detects an abnormality of at least one of the lock-up clutch and the lock-up clutch switching valve device; and a control device which, when the abnormality detecting device detects the abnormality, operates the hydraulic pressure producing device for one of (a) applying the hydraulic pressure, and (b) inhibiting the hydraulic pressure from being applied, to at least one of the lock-up clutch and the lock-up clutch switching valve device for forcibly placing the lock-up clutch in one of the fully released and fully engaged states thereof.
摘要:
A control system for an automatic transmission, comprising a gear transmission unit for establishing a predetermined gear stage by applying a plurality of frictional engagement elements selectively. The gear transmission unit includes a main transmission portion capable of establishing at least a reverse gear stage, and an auxiliary transmission portion capable of switching a high gear stage and a low gear stage. The auxiliary transmission portion is set to the high stage at the shifting time to the reverse stage. The reverse stage is established by controlling the application of predetermined frictional engagement elements of the main transmission portion when a reverse stage shifting command is generated. A torque-down of an engine is executed at the time of controlling the engagement of the frictional engagement elements for the reverse stage. The auxiliary transmission portion is set to the high stage by controlling the applications of predetermined frictional engagement elements of the auxiliary transmission portion when the reverse stage in the main transmission portion is detected. A signal to end the engine torque-down is sent when a shift of the auxiliary transmission portion to the high stage is detected.
摘要:
A shift control system of an automatic transmission sets a predetermined gear stage by applying a first frictional engagement element and releasing a second frictional engagement element. A pressure regulating mechanism regulates an oil pressure to be fed to or drained from the first frictional engagement element. A failure detector detects a failure of an apparatus to participate in the regulation and control of the oil pressure which is to be fed to or drained from at least one of the first and second frictional engagement elements. A gear stage inhibitor inhibits the setting of the predetermined gear stage if the failure is detected by the failure detector.
摘要:
A shift control system of an automatic transmission for setting a predetermined gear stage by applying first frictional engagement means and releasing second frictional engagement means, comprising: a pressure regulating mechanism for regulating an oil pressure to be fed to or drained from the first frictional engagement means; a failure detector for detecting a failure of an apparatus to participate in the regulation and control of the oil pressure which is to be fed to or drained from at least one of the first and second frictional engagement means: and a gear stage inhibitor for inhibiting the setting of the predetermined gear stage if the failure is detected by the failure detector.
摘要:
A control system for an automatic transmission includes a first frictional engagement element and a second frictional engagement element; and a first hydraulic servo for controlling the application/release of the first frictional engagement element and a second hydraulic servo for controlling the application/release of the second frictional engagement element. A regulator valve regulates the oil pressure to the first hydraulic servo. A signal pressure is applied to the regulator valve to establish a predetermined gear stage by switching the applied/released states of the first frictional engagement element and the second frictional engagement element by feeding/releasing oil pressure to/from the first hydraulic servo and the second hydraulic servo. The regulator valve includes a valve member having: a first pressure receiving area to which is applied the feed pressure to the first hydraulic servo as a feedback pressure in a first direction; a second pressure receiving area to which is applied the signal pressure in a second direction opposite the first direction; a fourth pressure receiving area to which is applied the feed pressure to the second hydraulic servo in the first direction, in a shift wherein the first frictional engagement element is released while the second frictional-engagement element is applied; and a third pressure receiving area to which is applied the signal pressure in the second direction, for regulation of the oil pressure only during a shift.
摘要:
A control system for use in an automatic transmission which includes a gear shift mechanism having first and second frictional engagement elements for establishing: a first gear stage with the first frictional engagement element being applied and the second frictional engagement element being released; and a second gear stage with the first frictional engagement element being released and the second frictional engagement element being applied. The control system, in turn, includes: a first oil passage for feeding an oil pressure to the first frictional engagement element; a second oil passage for feeding an oil pressure to the second frictional engagement element; and a first valve arranged in the first oil passage for regulating the oil pressure of the first oil passage. At the time of a shift from the first gear stage to the second gear stage, the oil pressure of the first oil passage is regulated by the first valve responsive to the oil pressure of the second oil passage. The control system further includes a second valve arranged in the first oil passage for selectively feeding or shutting off the oil pressure of the first oil passage to and from the first frictional engagement element.
摘要:
A shift control system is provided for an automatic transmission having, connected in series, a secondary shifting unit, capable of being shifted between a high speed stage and a low speed stage, and a primary shifting unit which provides plural speed stages including a reverse speed stage. The secondary shifting unit can be set to the high speed stage upon a shift into reverse. The shift control system is equipped with a reverse range detector for detecting a shift from neutral to reverse range, a vehicle stop detector for detecting that vehicle is stopped, and a high speed stage command device for setting the secondary shifting unit at the high speed stage when, subsequent to a shift of the primary shifting unit into reverse, the vehicle is determined by a signal from the vehicle stop detector to have substantially stopped.
摘要:
A hydraulic control system for an automatic transmission to establish a predetermined stage by applying a first frictional engagement element and releasing a second frictional engagement element, comprising: a first hydraulic servo for actuating the first frictional engagement element; a second hydraulic servo for actuating the second frictional engagement element; change-over means for switching the feed of an oil pressure to the first hydraulic servo; signal pressure generating means for generating a signal pressure; and a pressure regulator valve for regulating the pressure to be fed to the second hydraulic servo. The pressure regulator valve includes: a first valve member having a first pressure receiving area to be fed with the signal pressure in one direction; a second valve member arranged coaxially with the first valve member and adapted to come into abutment against the first valve member in the other direction, the second valve member having a second pressure receiving area to be fed with the oil pressure to the first hydraulic servo in the other direction, when the oil pressure is fed by the change-over means; and bias means so disposed at the side of the second valve member axially opposed to the first valve member as to bias the second valve member into abutment against the first valve member.
摘要:
An oil pressure controller of an automatic transmission which is capable of supplying engaging pressures to hydraulic servos of two frictional engaging elements which require different engaging pressures by a single pressure governing valve with a good pressure governing accuracy. The oil pressure controller comprises a hydraulic power source (10), hydraulic servos (70 and 80), signal pressure generating means (20), a pressure governing valve (30) for governing an oil pressure (P.sub.s) from the hydraulic power source (10) by a signal pressure (P.sub.ACC) and a control valve (40). The pressure governing valve (30)has a pressure receiving face A.sub.1 to which the signal pressure is applied, a pressure receiving face A.sub.2 to which the engaging pressure (P.sub.s) is fed back in the opposite direction and a pressure receiving face (A.sub.3) for selecting whether the feedback of the engaging pressure is present or not in order to change the control gain of the pressure governing valve (30)in response to the change of the control valve (40) for selecting the hydraulic servo (70 or 80) to which the oil pressure is supplied.
摘要:
A hydraulic control system for an automatic transmission includes a regulator valve in a hydraulic circuit for supplying pressure to a servo of a frictional engagement element. The regulator valve has an input port, an output port and a drain port. A valve member of the regulator valve includes a pressure receiving area fed with a feedback pressure from the portion of the hydraulic circuit between the regulator valve and the servo, and another pressure receiving area selectively fed with pressure from a signal pressure source. A further pressure receiving area, having a surface area different from the another pressure receiving area, is constantly fed pressure from the signal pressure source.