Abstract: An oil pressure control device has bypass drain oil passages that bypass a control valve and that are capable of draining the engaging pressure K from a hydraulic servo of a clutch when releasing the clutch. A drain-prohibiting check ball blocks a drain path between a manual valve and an input port.

Abstract: In an oil pressure control device, a clutch apply control valve is provided in an oil passage between a control valve and a linear solenoid valve. The clutch apply control valve is changed between a first position where an input port and an output port are connected so as to supply a control pressure to a control oil chamber, and a second position where another input port and the output port are connected so as to supply the control oil chamber with a D range pressure, instead of the control pressure. Therefore, the clutch apply control valve makes it possible to reliably supply an engaging pressure to a clutch even in the case of a failure of the control valve or the like to ensure good responsiveness of the clutch.

Abstract: A hydraulic control system for an automatic transmission includes a 3-4 shift valve that outputs a source pressure through a first path for shift speeds lower than a fourth shift speed established by directly connecting an input shaft with an output shaft of the automatic transmission, i.e., third shift speed. The hydraulic control system further includes a clutch apply control valve that outputs a source pressure through a second path at a shift speed higher than the fourth shift speed, i.e., fifth speed. The 3-4 shift valve and the clutch apply control valve serve to interrupt supply of the source pressure through the first path and the second path, respectively, in the fourth speed or the lock-up stage.

Abstract: Second and third clutches are axially aligned so that the back side of the second clutch and the front side of the third clutch oppose each other, and a first clutch is positioned radially inward of the second and third clutches. Further, a clutch drum is extended so as to be used in common by the second and third clutches, the second clutch is engaged and disengaged from the axial front side by a second piston of a second oil pressure actuator, and the third clutch is engaged and disengaged from the axial rear side by a third piston of a third oil pressure actuator. The first through third clutches are positioned in a compact manner and can be independently operated.

Abstract: Automotive vehicle control apparatus including a running stability control device for reducing engine output and/or applying brake to vehicle wheels for improving vehicle running stability, a shift control device for shifting an automatic transmission by engagement of at least one hydraulically operated frictional coupling device, depending upon a detected vehicle running condition as compared with a predetermined shift boundary pattern, a running stability control detecting device for detecting an operation of said running stability control device, and one of (a) a coupling pressure control device for controlling a hydraulic pressure of the frictional coupling device to be engaged to shift the automatic transmission, such that a rate of rise of the hydraulic pressure is lower when the operation of running stability control device is detected by the running stability control detecting device, than when the operation of the running stability control device is not detected, and (b) a shift point changing device

Abstract: Automotive vehicle control apparatus including a running stability control device for reducing engine output and/or applying brake to vehicle wheels for improving vehicle running stability, a shift control device for shifting an automatic transmission by engagement of at least one hydraulically operated frictional coupling device, depending upon a detected vehicle running condition as compared with a predetermined shift boundary pattern, a running stability control detecting device for detecting an operation of said running stability control device, and one of (a) a coupling pressure control device for controlling a hydraulic pressure of the frictional coupling device to be engaged to shift the automatic transmission, such that a rate of rise of the hydraulic pressure is lower when the operation of running stability control device is detected by the running stability control detecting device, than when the operation of the running stability control device is not detected, and (b) a shift point changing device

Abstract: An apparatus for controlling an engine of a motor vehicle, and a lock-up clutch disposed between the engine and an automatic transmission for direct connection therebetween. The apparatus includes a lock-up clutch control device for engaging the lock-up clutch during deceleration of the motor vehicle, a vehicle deceleration detector for detecting a decelerating state of the motor vehicle, and an engine deceleration restrictor for restricting a rate of decrease of the engine speed for a period following detection of the decelerating state of the vehicle, so as to facilitate an engaging action of the lock-up clutch during deceleration of the vehicle.

Abstract: A shift timing detecting system for detecting the start of a shift of an automatic transmission A in terms of a change in the R.P.M. of a predetermined rotary member after a shift command has been outputted. The shift timing detecting system comprises: a detector for detecting a change in the output R.P.M. of the automatic transmission; an arithmetic processor for arithmetically processing the change in the output R.P.M. with different coefficients to determine two processed values: a comparator for comparing the two processed values: and a shift start decider 5 for deciding the start of the shift on the basis of the result of the comparison. Since the shifting situation can be grasped from the change in the output torque accompanying the start of the shift and the change in the output R.P.M. caused by the former change, the start of the shift can be accurately detected without any time delay.