摘要:
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.
摘要:
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.
摘要:
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.
摘要:
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.
摘要:
In a hydraulic control apparatus for a vehicular automatic transmission, if it is determined that there is a failure that may cause tie-up in an automatic transmission, communication is provided between a first output port and a first drain port in a switching valve. As a result, a hydraulic frictional engagement device, which should be disengaged when there is a failure, is disengaged. Also, a specific shift speed is achieved by controlling the switching valve. Therefore, it is not necessary to select a shift speed that is achieved on the condition that the hydraulic frictional engagement device, which should be disengaged when there is a failure, is engaged. Thus, it is possible to prevent a shift that may impair driveability when there is a failure that may cause tie-up in the automatic transmission.
摘要:
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.
摘要:
In a hydraulic servo for a clutch, a cancel plate is disposed on a second clutch drum that undergoes the same rotation as a second clutch drum provided with a cylinder portion, in such a fashion that the cancel plate is restricted from moving to a side opposite from a return spring in an axial direction. The first clutch drum is disposed, as a separate member, on the second clutch drum. A step portion of the second clutch drum prevents the first clutch drum from moving to a side opposite from the cancel plate. Due to the spring force of the return spring, the oil pressure in the cancel oil chamber and the oil pressure in the operating oil chamber, the force that presses the first clutch drum to the step portion is always greater than the force that presses the first clutch drum to the cancel plate side.
摘要:
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.
摘要:
In a hydraulic control apparatus for a vehicular automatic transmission, if it is determined that there is a failure that may cause tie-up in an automatic transmission, communication is provided between a first output port and a first drain port in a switching valve. As a result, a hydraulic frictional engagement device, which should be disengaged when there is a failure, is disengaged. Also, a specific shift speed is achieved by controlling the switching valve. Therefore, it is not necessary to select a shift speed that is achieved on the condition that the hydraulic frictional engagement device, which should be disengaged when there is a failure, is engaged. Thus, it is possible to prevent a shift that may impair driveability when there is a failure that may cause tie-up in the automatic transmission.
摘要:
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.