Jatco Corporation

Kousuke Abe

Hiroyasu Tanaka

Takuichiro Inoue

Hideki Oshita

Masahiro Yamamoto

Youhei Ishikawa

When gear ratio is abnormally increased due to failure of a secondary pulley rotation sensor or slip in a V belt, demand torque of an engine is rapidly reduced, and after upper limit regulation of a target secondary pulley pressure is performed for a second predetermined time, control of the target secondary pulley pressure according to an output torque of the engine is performed. Thereby, since an actual torque of the engine does not exceed a belt capacity capable of holding a belt by a secondary pulley pressure which is actually generated, when the secondary pulley rotation sensor fails, no slip occurs in the V belt.

Hydraulic control system of belt-type continuously variable transmission for vehicle

The shift control apparatus for a continuously-variable transmission includes a primary pulley; a secondary pulley connected with the primary pulley by a belt; a shift actuator that varies a speed ratio; a line pressure adjusting that adjusts a line pressure; a secondary-pressure adjusting section that adjusts a secondary pressure; and a control section that controls the shift actuator, the line pressure adjusting section, and the secondary-pressure adjusting section. Moreover, the control section includes a fail determining section that determines whether the shift actuator is under a failed condition. The control section carries out a fail-safe shift-actuator fixing control to fix the shift actuator, when the fail determining section determines that the shift actuator is under the failed condition, and carries out a fail-safe hydraulic control to bring the line pressure to its upper limit pressure and bring the secondary pressure to its maximum pressure, when a control-start criterion predetermined to secure driving performance of the vehicle is satisfied under the failed condition.

Shift control apparatus and method for continuously variable transmission

A transmission controller commands a demand torque of an engine to an engine controller according to an actual secondary pulley pressure that is detected by a secondary pulley pressure sensor when a vehicle speed is 0 km/h and a state wherein gear ratio is equal to or higher than a predetermined gear ratio is continued for a first predetermined time or more. Thereby, since an input torque corresponding to a secondary pulley pressure which is actually generated is inputted to a primary pulley even when a failure occurs in the secondary pulley rotation sensor, engine performance of a vehicle can be ensured.

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Fuji, Japan

Kousuke Abe