Abstract: At the time of a failure in the second group of engagement devices, the manner of input of oil pressures to a fail-safe valve group is changed via a priority degree switching valve on the basis of the state of engagement of engagement devices of the first group in such a manner that the predetermined degrees of priority for the supply of one of oil pressures PC4, PB1 output from linear solenoid valves SL4, SL5 to a corresponding one of a clutch C4 and a brake B1 via the fail-safe valve group are changed so as to avoid an event that the fail-safe gear stage established in order to prevent the occurrence of interlock of the automatic transmission involves a downshift of two or more stages from the speed change stage maintained immediately prior to the occurrence of the failure. Therefore, it is possible to prevent the occurrence of an uncomfortable behavior of the vehicle caused by the shift to the fail-safe gear stage.

Abstract: A control apparatus and control method of an automatic transmission that establishes a plurality of speeds of different speed ratios by selectively engaging and/or releasing a plurality of engagement devices, detects abnormal engagement of at least one of the engagement devices which causes tie-up to occur in the automatic transmission; establishes a predetermined specific speed set in advance in order to prevent tie-up from occurring in the automatic transmission, when abnormal engagement of the at least one of the engagement devices is detected; and places the automatic transmission in a neutral state when an engine speed will exceed a predetermined allowable speed if the predetermined specific speed is established.

Abstract: A lubrication groove is formed on a sliding face of a bushing, both ends of which open to the same end face of the bushing. The lubrication groove has inclined portions that extend from the openings in directions that approach each other, and a parallel portion that is in communication with the ends of the inclined portions via curved portions. Oil is guided to the lubrication groove so as to form an oil film on the sliding face. Sealability is achieved because the lubrication groove only opens to one end face of the bushing.

Abstract: A connection structure for an automatic transmission includes a drum member that includes a base portion, an outer diameter portion that extends from an outer diameter side of the base portion in an axial direction, and a collar portion that extends from an inner diameter side of the base portion in the axial direction; a base member that includes a raised portion, an outer diameter portion that extends from an outer diameter side of the raised portion in the axial direction, a boss portion that extends from an inner diameter side of the raised portion in the axial direction, and a connection portion that extends from an end of the outer diameter portion; and a ring gear of a planetary gear that includes a spline groove and a circular concave groove on an end portion of an inner peripheral face.

Abstract: At a first forward speed, the oil passage in a relay valve is switched to control the torque capacity of a lock-up clutch using a linear solenoid valve that controls the engagement pressure of a clutch that is engaged at each of fifth to eighth forward speeds. At each of second to eighth forward speeds, the oil passage in another relay valve is switched to control the torque capacity of the lock-up clutch using a linear solenoid valve that controls the engagement pressure of a brake that is engaged at the first forward speed.

Abstract: Engagement, disengagement, and slip of a lock-up clutch can be controlled using two valves that are a lock-up relay valve and a linear solenoid valve. A lock-up control valve employed in a conventional hydraulic control apparatus can be eliminated, which simplifies the configuration, and reduces the size of a hydraulic control apparatus for a torque converter with a lock-up clutch. When the lock-up clutch is engaged, hydraulic pressure output from the linear solenoid valve is supplied to a disengagement-side oil chamber of the torque converter, and a pressure difference between the engagement-side oil chamber and the disengagement-side oil chamber is applied to a spool valve element of the linear solenoid valve. Therefore, the spool valve element is driven such that an electromagnetic force applied from a linear solenoid becomes equal to the pressure difference.

Abstract: A transmission can be provided which achieves multiple speeds while maintaining good balance of gear ratio steps between gears by having a first clutch which selectively connects a first intermediate output member and a fourth rotating element RE4 together, a second clutch which selectively connects an input shaft and a second rotating element RE2 together, a third clutch which selectively connects the first intermediate output member and a first rotating element RE1 together, a fourth clutch which selectively connects the input shaft and the first rotating element RE1 together, a fifth clutch which selectively connects a second intermediate output member and the first rotating element RE1 together, a first brake which selectively holds the first rotating element RE1 to a transmission case, and a second brake which selectively holds the second rotating element RE2 to the transmission case.

Abstract: When a shift routine is not being executed in an automatic transmission and a difference between an actual turbine speed and a calculated synchronous speed is equal to, or greater than, a preset value ?, a difference ?NT between an estimated turbine speed and the actual speed when the automatic transmission is in a neutral state is calculated. When ?NT is equal to, or less than, a preset value ?, it is determined that a failure related to the neutral state of the automatic transmission has occurred. Also, when ?NT is greater than a preset value ?, it is determined that a failure related to slipping of a frictional engaging element has occurred.

Abstract: A deceleration control apparatus for controlling a deceleration value of a vehicle, including a plurality of deceleration-value setting devices, a target-deceleration-value control portion operable to change a target deceleration value of the vehicle according to an operation of each of the deceleration-value setting devices, and a brake control portion operable to control a braking force to be applied to the vehicle, according to the target deceleration value changed by the target-deceleration-value control portion, wherein the target-deceleration-value control portion is operable to successively change the target deceleration value of the vehicle in response to successive operations of one and another of the plurality of deceleration-value setting devices such that the target deceleration value changed according to the operation of the above-indicated one deceleration-value setting device is subsequently changed according to the operation of the above-indicated another deceleration-value setting device.

Abstract: A target deceleration of a vehicle is increased or decreased under given conditions and braking force is controlled in accordance with the increased or decreased target deceleration. Upon the increase or decrease in the target deceleration, the rate of change in the target deceleration is variably set.

Abstract: A control apparatus for controlling a vehicle automatic transmission including (i) a first coupling device to be engaged for establishing an emergency gear position and (ii) a second coupling device to be released for establishing the emergency gear position. The control apparatus includes: (a) first and second controller valves for controlling the respective first and second coupling devices; and (b) a fail-safe valve having (b-1) a first output port connected to a drain port of the first controller valve, (b-2) a first input port to which a working fluid is input, (b-3) a first drain port for draining the working fluid, (b-4) a second output port connected to an input port of the second controller valve, (b-5) a second input port to which the working fluid is input, and (b-6) a second drain port for draining the working fluid.

Abstract: A hydraulic control apparatus for controlling an automatic transmission which includes two hydraulically operated frictional coupling devices of a first group and a plurality of hydraulically operated frictional coupling devices of a second group, and which is arranged to establish a selected one of its gear positions, by simultaneous engaging actions of the two frictional coupling devices of the first group or simultaneous engaging actions of of one of the frictional coupling devices of the first group and one of the frictional coupling devices of the second group, the hydraulic control device including a second-group-engaging switching valve which is arranged to receive second engaging hydraulic pressures generated to engage the hydraulically operated frictional coupling devices of the second group and which is operable, upon reception of at least one of the second engaging hydraulic pressures, to generate a second-group-engaging pilot hydraulic pressure, and a fail-safe valve which is arranged to receive a

Abstract: A hydraulic control apparatus for use with a vehicle's automatic transmission, the apparatus including a fail-safe switch valve which has an escape-related output port connected to a drain port of a transmission-related solenoid valve corresponding to an escape-related frictional coupling device to establish an escape-related speed step, and additionally has an escape-related input port to which a hydraulic pressure is inputted, and a drain port from which a hydraulic fluid is drained, wherein the fail-safe switch valve is selectively switchable to a normal communication state thereof in which the escape-related output port and the drain port are communicated with each other and the escape-related input port is shut off, and to a fail-related communication state thereof in which the escape-related output port and the escape-related input port are communicated with each other, and the drain port is shut off, so that a hydraulic pressure is supplied from the escape-related output port of the fail-safe switch va

Abstract: A hydraulic control apparatus for controlling a vehicular automatic transmission including hydraulically operated frictional coupling devices which are selectively engaged and released to selectively establish gear positions having respective different speed ratios, and linear solenoid valves operable to regulate fluid pressures of the respective frictional coupling devices, each linear solenoid valve including a spool and a solenoid and being operable between a pressure-regulating state in which the spool is movable to a position of equilibrium of forces for regulating an output fluid pressure according to an electromagnetic force produced by the solenoid, and a non-pressure-regulating state in which the spool is held at a stroke end thereof at which no output fluid pressure is generated from the linear solenoid valve, each linear solenoid valve in the pressure-regulating state being operable to regulate a fluid pressure of the corresponding frictional coupling device according to the electromagnetic force,

Abstract: A control apparatus for controlling a stepped automatic transmission of a vehicle having an output shaft and an input shaft which is to be connected to an engine of the vehicle through a clutch while a shifting action is being effected in the transmission. The control apparatus includes a torque vibration restrainer operable, upon completion of the shifting action in the transmission, to restrain a torque vibration which is generated in a power transmitting path of the vehicle. The torque vibration restrainer applies an inverted-phase torque vibration which is inverted in phase with respect to the generated torque vibration, to the power transmitting path, and/or place the clutch in its slipping state or released state, for restraining the generated torque vibration.

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: 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: 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: When a shift routine is not being executed in an automatic transmission and a difference between an actual turbine speed and a calculated synchronous speed is equal to, or greater than, a preset value &agr;, a difference &Dgr;NT between an estimated turbine speed and the actual speed when the automatic transmission is in a neutral state is calculated. When &Dgr;NT is equal to, or less than, a preset value &bgr;, it is determined that a failure related to the neutral state of the automatic transmission has occurred. Also, when &Dgr;NT is greater than a preset value &bgr;, it is determined that a failure related to slipping of a frictional engaging element has occurred.