Honda Giken Kogyo Kabushiki Kaisha

Hiroyuki Katano

Takahiro Eguchi

Osahide Miyamoto

Koichi Hasegawa

Daihei Teshima

Masatoshi Nishina

Kouji Shibuya

Hiroyuki Takeo

Masatoshi Shimizu

Takehiro Katakura

Yoshiaki Shuto

Hironori Fujita

A vehicular transmission including an engine, a continuously variable transmission CVT and a starting clutch. The driving force from the engine is transmitted through the continuously variable transmission CVT with a speed change to a countershaft, and the starting clutch is used to transmit this driving force from the countershaft to wheels of a vehicle. The continuously variable transmission CVT is hydraulically controlled by a control valve CV which receives control signals through a line from an electrical control unit ECU. After the vehicle has decelerated and stopped, and after the engine has stopped by an idling elimination control, the electrical current that controls the control valve CV is adjusted almost to zero.

Vehicular transmission stop control system

In a control apparatus for a hydraulically operated vehicular transmission having a plurality of speed stages to be established by a selecting operation of a plurality of hydraulic clutches, when a command to downshift to G(N-2) is issued in the course of downshifting to G(N-1) and a flag FTBD is set to 1, a control is performed to accelerate the time of completion of the downshifting control to G(N-1). When that oil temperature in the transmission which is detected by an oil temperature sensor is lower than a predetermined value, the setting of FTBD to 1 is prohibited. Therefore, at the time of low oil temperature, the downshifting to G(N-1) is performed in an ordinary manner. At the time of starting of the downshifting control from G(N-1) to G(N-2), the hydraulic pressure in the hydraulic clutch for the speed stage G(N-1) is sufficiently increased. A smooth downshifting to G(N-2) can thus be smoothly performed without the occurrence of excessive engine racing.

Control apparatus for hydraulically operated vehicular transmission

A system for controlling an automatic transmission mounted on a vehicle, including a gear system and hydraulic clutches which hold a member of the gear system stationary to produce gear reduction or reverse to transmit engine output, and a linear solenoid valve provided in the oil line which generates an oil pressure to be supplied to hydraulic clutches in response to a current supplied thereto. In the system, the current supply is initiated when the ignition switch is turned to the ON position where the engine is not started, producing a noise due to the solenoid valve operation. In order to avoid this, the current is limited to a predetermined value when the engine is not started and the vehicle is stopped. Moreover, since the predetermined value is slightly above the current at which the clutch pressure begins to rise, the automatic transmission can start its operation quickly when the engine is started.

Control system for automatic vehicle transmission

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Wako, Japan

Hiroyuki Katano