Aisin-warner Kabushiki Kaisha

Aisin Seiki Kabushiki Kaisha

Toyota Jidosha Kabushiki Kaisha

Aisin-warner Limited

Kazuhiko Shibata

Nobuaki Miki

Shinya Nakamura

Hiroyuki Amano

Tsuyoshi Yoshida

Kagenori Fukumura

Mutsumi Kawamoto

Seiichi Nishikawa

Yoshinori Shibayama

A transmission for a vehicle has a shift mechanism, a hydraulic actuator for operating the shift mechanism and a hydraulic control for supplying and discharging working oil to and from the hydraulic actuator to control the shift of the shift mechanism. The hydraulic control includes a flow regulating valve for regulating flow of the working oil supplied to the hydraulic actuator, as a function of pressure of the working oil supplied to the hydraulic actuator.

Hydraulic control for vehicle transmission

A hydraulic control system for an automatic transmission of a motor vehicle, which is provided with a bleed valve in a fluid chamber of a particular shift valve for restricting pressure increase when line pressure is admitted thereinto for a jumping shift to a lower gear position by bleeding part of the admitted line pressure to limit the displacement of a spool of the shift valve and to hold same in an intermediate position until solenoid pressure turns from high to low level, causing the shift valve to retain temporarily an intermediate gear position to lessen the deceleration shock which would otherwise be imposed on the vehicle body.

Shift valve with an intermediate position during a 4-2 shift

A lock-up clutch control system for automatic transmissions having a lock-up control valve supplied with said line and solenoid pressures in opposite fluid chambers for engaging and releasing a lock-up clutch, the lock-up control valve being constructed to satisfy the following conditions (5) and (7) ##EQU1## where A.sub.1 is a land area of a spool for receiving the line pressure, A.sub.2 is a land area for receiving the solenoid pressure, F is the force of a biasing spring, PL is the line pressure, and Ps is the solenoid pressure.

Lock-up clutch control system for automatic transmissions

An electronic control system is provided which controls the locking and unlocking of a variable speed automatic transmission. A hydraulic control circuit comprising a plurality of hydraulic pressure controlling valves, a plurality of flow path switching means and a plurality of solenoid valves is provided to control the engagement of the clutches and brakes of the automatic transmission. The electronic control system detects a slope, modifies a portion of standard data in a manner corresponding to the detected slope to produce shift reference data which is then written into a read-write memory, compares the actual speed stage, throttle opening and vehicle speed against the shift reference data to determine the speed stage to which the transmission is to be shifted and controls the energization of the solenoid valves to change or shift the speed stage. Additionally, the electronic control system reads the minimum vehicle speed required to establish lockup and the maximum vehicle speed for unlocking which correspond to the actual speed stage and the throttle opening from lockup controlling reference data, compares them against the actual vehicle speed to determine the necessity of lockup or unlocking and controls the energization of the solenoid valves in accordance with the determination to establish a lockup or an unlocked condition.

Lockup controlling system for variable speed, automatic transmission

A signal generator is provided which produces a signal indicative of a throttle position of an engine on a vehicle. A plurality of split electrodes are formed on a printed electrical circuit substrate, and are connected with respective output leads. A less than 360.degree. rotating shaft which is connected with a rotatable shaft of a throttle valve has secured thereto an electrically conductive slider having a plurality of radially extending legs which fixedly carry contact members disposed for contact with the plurality of split electrodes. Each contact member corresponds to only one split electrode. A lead which is connected to one of the split electrodes assumes a ground potential or a constant positive potential. Consequently, the potential of the slider is maintained at such ground or constant positive potential, while the remaining split electrodes assume the ground or the constant positive potential only when they are engaged by contact members on the slider. In this manner, the output is in the form of a bi-level signal, and the combination of outputs from the plurality of leads constitute together a code. The pattern of the plurality of split electrodes which provides a coded output is configured such that a change in the potential occurs only in one bit of the code for each rotation of the rotating shaft through a given angle. Thus, a Gray code is formed for the angle of rotation of the rotating shaft.

Growing community of inventors

Anjo, Japan

Kazuhiko Shibata