Aisin-warner Kabushiki Kaisha

Aisin Aw Co., Ltd.

Toyota Jidosha K.k.

Aisin-warner K.k.

Toyota Jidosha Kabushiki Kaisha

Aisin Aw Kabushiki Kaisha

Aisin-warner Limited

Yoshinari Kuwayama

Masakatsu Miura

Fumitomo Yokoyama

Kunio Morisawa

Yoshihiro Yamada

Yoichi Hayakawa

Youichi Hayakawa

Masahiko Ando

Koujiro Kuramochi

Tatsuo Kyushima

Jiro Nishiwaki

Mitsugu Tatsuta

Youichi Hatakawa

An accumulator fluid control system for a hydraulic servo in a vehicular automatic transmission includes an accumulator having a cylinder, a piston, a return spring, a chamber disposed in the cylinder, a first and second input ports connected to a first passage, an output port connected to a second passage, and a check valve for controlling the connection between the first and second passages through the second input port.

Accumulator device of hydraulic fluid control system

A check valve and an orifice are situated in a feeder oil passage to an accumulator so that influence of drained oil from the accumulator is eliminated when a hydraulic servo is drained. The hydraulic pressure is supplied to the servo through the orifice, and to the accumulator with the feeder oil passage separate from the oil passage to the hydraulic servo with the check valve being opened. When draining, the hydraulic pressure in the hydraulic servo is drained quickly, however, the hydraulic pressure in the accumulator is drained gradually because the check valve is closed.

Hydraulic control device for an automatic transmission

A sequence valve for the first brake (B.sub.1) is installed, and the forward four speed modes are attained by two solenoid valves. At in the second speed mode of D range, hydraulic pressure is applied to the second brake hydraulic servo to restrain certain rotating element through the one-way clutch. After the application to the second brake hydraulic servo is completed, then the hydraulic pressure is applied to the sequence valve for the first brake, and through the sequence valve, the hydraulic pressure is applied to the first brake hydraulic servo. Accordingly, when up shifting from the first speed mode to the second speed mode, the shifting is conducted smoothly by the engagement of the second brake, after that the first brake is engaged. When up shifting from the third speed mode to the fourth speed mode, the first brake hydraulic servo is swiftly drained by the 3-4 shift valve. Consequently, the second clutch is engaged under the operation of the one-way clutch operated by the engagement of the second brake.

An automatic transmission hydraulic controller having a multiplicity of hydraulic servos for respectively controlling a multiplicity of frictional engagement elements. A hydraulic pressure to be supplied to the hydraulic servos is applied to accumulator chambers of a multiplicity of accumulators. A line pressure to be supplied to the hydraulic servos is produced by a primary regulator valve and an engine output pressure control valve is controlled by an electrical signal from a control section to produce a hydraulic pressure corresponding to the engine output. Each of at least two particular ones of the multiplicity of accumulators has a back pressure chamber formed at the rear of a piston. The pressure receiving area of this back pressure chamber and that of the corresponding accumulator chamber are substantially equal to each other. Only one of the frictional engagement elements operated by the hydraulic servos communicating with the particular accumulators is changed over from a released state to an engaged state while the other frictional engagement elements are not changed over from a released state to an engaged state, when the transmission is shifted to a predetermined speed. There is no substantial influence of a change in the line pressure upon the operating state of the other frictional engagement elements.

Hydraulic controller for an automatic transmission

A hydraulic controller for an automatic transmission, having a band brake having a large stopping force based on a self-boosting effect against rotation in a self-binding direction and having a comparatively small stopping force against rotation in the unbinding direction, a modulator valve for producing a modulator pressure by reducing a line pressure, a band brake hydraulic servo having a brake engaging hydraulic chamber and a brake releasing hydraulic chamber. A line pressure is supplied to the band brake hydraulic servo to stop rotation in the self binding direction when a predetermined transmission speed is selected. The line pressure is also supplied the band brake hydraulic servo to stop rotation in the unbinding direction when another transmission speed is selected. A modulator pressure is supplied to the brake engaging hydraulic chamber to stop the rotation in the self-binding direction of the band brake and to allow the rotation in the unbinding direction when an intermediate speed is selected. The risk of any shift from the predetermined speed to another speed via the intermediate speed is eliminated, thereby enabling the transmission to be shifted always correctly while reducing shift shocks.

The first and second emergency control valves are a back up device in case all solenoid valves are in failure (non electrified). When the first and second solenoid valves are all off due to wire disconnection and the like in case the manual valve is at the 3 range, a 1-2 shift valve is constrained by the first emergency control valve, so that the hydraulic control device becomes the third speed mode. In case t#e manual shift lever is at the 2 range and a 2-3 shift valve, the 2-3 shift valve are constrained by the first and the second emergency control valves, so that the hydraulic control device becomes the second speed mode. In case the manual shift lever is at the 1 range, the first emergency control valve is constrained, and the 2-3 shift valve is constrained by the second emergency control valve, so that the hydraulic control device becomes the first speed mode. When the manual valve is at the D range, the fourth speed mode is attained in case the first and second solenoid valves are all off.

Fail-safe hydraulic control valves in an automatic transmission

Reverse shift control device on automatic transmission

An orifice is installed on an oil passage to a hydraulic servo for a direct clutch. In forward high speed running, a line pressure from the D range port of a manual valve is supplied to the hydraulic servo through an oil passage used for forward high speed running and a three way cock (non manual type). Then comparatively large amount of oil is supplied to the servo in accordance with the high speed running. In reverse running, the line pressure from the R range port of the manual valve is supplied to the servo through the orifice and the three way cock. Consequently, comparatively small amount of oil is supplied to the hydraulic servo.

Hydraulic control device for automatic transmission

Hydraulic servo regulating systems in an automatic transmission

Manual valve in an automatic transmission

A strainer is mounted in an oil passage within a valve body constituting the hydraulic control unit of an automatic transmission. The strainer includes a frame (4) fitted into the oil passage, a reticulate member (5) secured to the frame (4) so as to form a barrier across the oil passage, and a permanent magnet (8) secured by press-fitting or by bonding to frame at a position ahead of the reticulate member (5) in terms of the direction of working oil flow. Foreign matter contained in the working oil is removed by the reticulate member (5) while extremely small contaminants exhibiting a magnetic property, such as ferrous chips, that cannot be removed by the reticulate member (5) are removed by the magnet (8).

Magnetic oil strainer

A governor valve for a hydraulic controller in an automatic transmission, which is disclosed herein, comprises an adapter having a line pressure supply bore made therethrough, a cylindrical governor rotary shaft loosely fitted into the adapter sleeve and having a line pressure supply port made therein, the port including notches intersecting the axis at right angles, a centrifugal weight mounted on one end of the governor rotary shaft and having a return spring, and a spool adapted to slide within the governor rotary shaft with the weight being urged against one end thereof. In this governor valve, there are provided dirt and dust collecting means for preventing dirt and dust separated by a centrifugal action from collecting in the line pressure supply port during the stoppage of the governor rotary shaft so as to make the shaft stick.

Governor valve

An automatic transmission locking mechanism for parking, including a cam rod provided in the front portion thereof with a cam of a predetermined shape and interlocked at the rear end thereof with a manual shift lever, a sleeve supporting and guiding the cam rod for smooth axial movement and a pawl provided with a detent which made to engage with the parking gear of an automatic transmission by the axial movement of the cam rod when the manual shift lever is shifted to place the automatic transmission in the parking range.

Growing community of inventors

Tokoname, Japan

Yoshinari Kuwayama