Aisin Seiki Kabushiki Kaisha

Toyota Jidosha Kabushiki Kaisha

Kabushiki Kaisha Toyota Chuo Kenkyusho

Choji Furusawa

Toshiaki Ishiguro

Noboru Murakami

Shigeki Goto

Isamu Minemoto

Toshiyuki Inagaki

Satoshi Maruchi

Kunio Morisawa

Hiroyuki Yamaguchi

Shigeo Takahashi

Masato Shimei

Katsuhiko Hattori

Hiromi Hasegawa

Norikatsu Ishikawa

A speed change control apparatus for an automatic transmission having a plurality of friction elements in which a gear stage is established by engaging one of the friction elements and disengaging one of the others. The speed change control apparatus includes control valves connected to respective ones of the friction elements, a duty solenoid valve connected to each oil line supplying a respective one of the control valves with control hydraulic pressure, and control means for engaging one friction element by outputting an engagement duty signal to one duty solenoid valve to control the control hydraulic pressure, and disengaging one of the other friction elements correspondingly by outputting disengagement duty signals to one of the other duty solenoid valves to control the control hydraulic pressure.

Speed change control apparatus for automatic transmissions

In an automatic transmission having a torque converter, a planetary gear mechanism receiving an output from the torque converter and including brakes and clutches, and a hydraulic pressure circuit for actuating the brakes and clutches. An arrangement is provided for varying servo hydraulic pressure, which is for achieving low gear, in dependence upon vehicle velocity.

Automatic transmission control system incorporating an exhaust brake

An apparatus for controlling a transmission comprises a power transmission assembly for transmitting power from an engine, an input member connected to an output side of the power transmission assembly, a first power train connected to the input member and having at least two different speed-change ratios, a second power train communicating with the first power train and including a dog clutch for cutting off or changing over power, a brake assembly for locking the input member, and a clutch assembly for engaging and disengaging the input member with the first power train. A control system is provided for engaging the brake assembly in response to a signal indicative of changing-over of the second power train when the clutch assembly is in the disengaged state.

Transmission for four-wheel drive vehicles

An exhaust brake control system includes an input switch for commanding actuation of an exhaust brake, a throttle sensor for sensing that an accelerator pedal has been depressed in excess of a predetermined angle, a control unit for outputting a control signal in dependence upon output signals from the input switch and throttle sensor, and a valve means for opening and closing an exhaust passageway in dependence upon a control signal produced by the control unit. The control unit includes a shift sensor for sensing at least an L-range shift of an automatic transmission, and a servo hydraulic pressure sensor for sensing servo hydraulic pressure that actuates a servo piston for establishing 1st speed range. When the shift sensor senses that the automatic transmission has been shifted to the L range, the control unit outputs a control signal for actuating the valve means to open the exhaust gas passageway at such time that the servo hydraulic pressure sensor outputs a signal indicative of a value greater than a predetermined value. Exhaust braking is applied following attainment of a sufficiently high servo hydraulic pressure immediately after a downshift, thus preventing the engine from stopping at application of exhaust braking. The same is applied to downshifting to '2' range.

Exhaust brake control system

A transmission control system for automatic transmission having a mechanism for detecting the engine condition, the vehicle speed and the vehicle load and a control mechanism for automatically calculating and setting an appropriate gear ratio of the transmission basing upon the detected values. The control mechanism is so designed that the judgment on whether or not the start at a high speed gear ratio is allowable can be made before the vehicle stops, and the setting of the gear ratio at the time of vehicle stop is made automatically to a high speed gear ratio or a low speed gear ratio according to the above judgment.

Transmission control system for automatic transmission

A throttle valve assembly for displacing the plungers of at least two contiguous throttle valves in correspondence with the degree of throttle opening of an engine includes a first cam rotatably mounted on a stationary bracket fixed to the throttle valve bodies and having a cam face for displacing the plunger of the first throttle valve and an axially extending boss, a second cam rotatably mounted on the bracket and having a cam face for displacing the plunger of the second throttle valve and an axially extending boss, the first and second cams being coupled via coupling means formed on the opposing bosses, and a cable operatively associated with the engine torque demand for rotating the cams. The cam faces of the cams are formed to have a shape capable of providing the desired throttle pressure characteristic, the shapes of the cam faces differing from each other in order to obtain the optimum speed-change performance.

Throttle valve assembly

A clutch pressure modulator valve device for controlling pressure applied to a clutch of power transmission, the device including an accumulator chamber and a secondary accumulator chamber communicated with the accumulator chamber. The secondary accumulator chamber is formed so as to change the maximum expansive volume thereof by operation of an operating member disposed exterior of the power transmission whereby the modulating characteristic of the clutch pressure is adjustable to a desired value.

Clutch pressure modulator valve device

An inching control apparatus comprising a hydraulic pressure source, a plurality of clutches and, in a hydraulic circuit connecting the clutches to the hydraulic pressure source, a pressure regulating valve, an inching valve which receives output pressure from the pressure regulating valve for delivering inching control pressure, and a selector valve which receives control pressure from the inching valve for selecting engaging and disengaging the frictional engaging means. The inching valve delivers the output pressure from the pressure regulating valve directly when an inching pedal is not depressed by the driver's foot, and delivers a control pressure, which diminishes as the amount of pedal depression increases, when said amount of depression exceeds a predetermined amount. The inching valve controls the output pressure from the pressure regulating valve by operating an inching spool which is pushed through a first spring by an inching rod operatively associated with the pedal and biased by a second spring against the first spring, and which is equipped with first and second pressure-receiving portions operating against one another.

Inching control apparatus

A hydraulically operative clutch type transmission especially for industrial and loading vehicles comprises a casing accommodating shift gear mechanism therein, a housing connected to the casing, an input shaft journalled to the housing, a main shaft connected to the input shaft, a gearing member, a hydraulically operative clutch device which comprises a clutch drum connected to the main shaft and a clutch hub connected to the gearing member, a washer plate interposed between the gearing member and sleeve end of the clutch drum, the main shaft including a large diameter portion having a notch with a plain surface, and a small diameter portion, a gear member of the gearing member being rotatably supported on the large diameter portion, the clutch drum mounted on the small diameter portion, and the washer plate including a fasting portion which is engaged with the notch.

Hydraulically operative clutch type transmission

The stator assembly of a torque converter includes a stator wheel, a one-way brake for connecting the stator wheel to a stator shaft, a thrust washer provided on each side of the one-way brake and a pair of snap rings fixed to the stator wheel for locating the thrust washers. A gap is provided between the outer circumference of the thrust washer and the stator wheel to prevent undesirable engagement therebetween which would adversely effect the operation of the one-way brake.

Growing community of inventors

Okazaki, Japan

Choji Furusawa