Honda Giken Kogyo Kabushiki Kaisha

Keiichi Ishikawa

Masakazu Maezono

Sadanori Nishimura

Takashi Aoki

Yoshimi Sakurai

Noboru Sekine

Satoshi Terayama

Hideo Furukawa

Kazuma Hatakeyama

Satoru Sunada

Hiroyuki Shimada

Shoji Asatsuke

Hiroshi Yoshizawa

Koichi Funatsu

Hiroshi Ishikawa

Hideo Fukushi

Takeyuki Shimizu

Toshihiko Yoshino

Takabumi Sakai

Tatsuyuki Ohhashi

Takafumi Maruyama

A control system of a vehicle automatic transmission in which an engine load and a vehicle speed are detected and used to determine a vehicle acceleration in accordance with the pre-established characteristics. An actual vehicle acceleration is at the same time calculated in response to the detected vehicle speed. The difference therebetween is then calculated and the calculated value is added to a difference calculated earlier to obtain an average therebetween. Five gear shifting scheduling maps, for example, one for moderate hill climbing, one for level-road running, one for steep hill descent, are pre-established and in response to the average obtained, one of the maps is selected. A gear shifting is controlled based on the selected map. In a pre-determined condition, such as when the engine load changes abruptly, braking is in progress and so on, the map selection is suspended and the control is carried out using the map selected earlier.

Control system for vehicle automatic transmission

It is an object of the present invention to provide a method of controlling the automatic transmission of a vehicle, in which the vehicle can be smoothly started on a low frictional coefficient road by requiring the concurrent operation of the brake pedal and the acceleration pedal. An up-shift operation will occur when both the brake and acceleration pedals are operated when the vehicle speed is less than a predetermined value.

Method of controlling the automatic transmission of a vehicle

Holding device for holding the selector gear servo valve in the reverse position when the manual valve is in the neutral or parking position and when the manual valve is moved to a forward position, hydraulic pressure in the servo valve overcomes the holding to move the servo valve to a forward position. Additionally, a control valve is provided for binding the servo valve in the reverse position even when the manual valve is moved to the forward position until hydraulic pressure of the hydraulic clutch for the second transmission train reaches a predetermined level.

Holding means and binding means for selector gear servo valve in a

Hydraulically operated transmission having plural gear trains each selectively established by engagement of an associated hydraulic clutch. Each hydraulic clutch has an outer member and an inner member with the inner member being divided into at least a first inner part and a second inner part engaged in parallel with the outer member. A one-way clutch is interposed between the first inner part and the second inner part of each hydraulic clutch. The first inner part of each clutch is directly coupled to a member on one of the input side and the output side of the hydraulic clutch. The second inner part is connected to that member through the one-way clutch so that the one-way clutch allows overrotation of the second inner part when the member is on the input side and overrotation of the member when it is on the output side.

Hydraulically operated transmission with reverse torque limiter

Apparatus for controlling at least three shift valves operating four hydraulic clutches in a hydraulically operated vehicular transmission. The shift valves are serially located and alternately switched to establish successive first through fourth-speed transmission trains. Each shift valve is urged to one position by a respective spring and has an oil chamber at its opposite for oil pressure to urge it to its other position. Additionally, the first shift valve has another oil chamber at its spring end. A first electromagnetic open-air pressure dump valve is connected to a first oil passage through which oil is inputted to the first oil chamber of the first shift valves and the oil chamber of the second shift valve. A second electromagnetic open-air pressure dump valve is connected to a second oil passage through which oil is inputted to the other oil chamber of the first shift valve and the oil chamber of the third shift valve. An electronic microcomputer controls the first and second electromagnetic valves to operate the shift valves by permitting or dumping oil pressure to the oil chambers.

Control apparatus for hydraulically operated vehicular transmissions

A vehicular transmission having a fluid torque converter of the type in which a clutch is provided for mechanically connecting the input and output sides of a fluid torque converter above certain vehicle speeds for improved operation and economy and in which the clutch is operated within a predetermined vehicular speed range by such a relatively low engaging force as to allow slippage of said clutch for minimizing vibration. A control system causes the engaging force of the clutch to be increased more than that which is normally established below a reference value of small throttle valve opening for providing a braking effect by the engine. The control system also may provide for stopping the increase in engaging force at small throttle valve openings when the r.p.m. of the output side of the fluid torque converter falls below the r.p.m. at the input side, such as during a transition from a steep downward slop to a gentle downward slope, or when low oil temperature and high oil viscosity would cause operation too abruptly.

Control for the clutch of a fluid torque converter in a vehicular

An apparatus for controlling a multi-speed, oil pressure operated type vehicle transmission connected to an engine through a torque converter wherein each drive train includes an oil pressure operated clutch and the low speed drive train also includes a one-way clutch engagement element, such as an oil pressure clutch or the like, interposed in each of said driving trains such that each driving train is established by oil supply to each said clutch. The apparatus includes a holding device for the highest speed drive train which is actuated when the brake operation is detected and the vehicle is stopped, which actuation provides a pressurized oil supply to the highest speed oil pressure operated clutch interposed in said high speed drive train to minimized the torque transmitted from the engine even though the pressurized oil is continuously supplied to the low speed oil pressure clutch interposed in said low speed driving train.

Brake and speed responsive controlled transmission

A clutch operation control system for a fluid torque converter of a vehicular transmission in which the fluid torque converter is equipped with a clutch for mechanically connecting the input side and output side of said torque converter. The clutch has its clutch plate supplied at its one side with oil pressure in a control chamber to release the clutch and at its other side with the torque converter oil pressure in said fluid torque converter for operating the clutch by the differential pressure across the clutch plate. An oil line leading to the control chamber is connected at a vehicular speed equal to or higher than a predetermined level to an oil drain port by means of a control valve to operate the clutch with an engaging force of the torque converter pressure. The clutch plate has an orifice for providing communication between the two sides of said clutch plate. The control valve is formed with a throttle portion for throttling the communication passage between the oil line to the control chamber and said drain port in a relatively low vehicular speed range equal to or higher than said predetermined level for allowing some slippage of the clutch.

Clutch operation control system for fluid torque converter of vehicular

An operation control system for a hydraulically operated clutch of a fluid torque converter wherein the clutch mechanically couples the input and output of the torque converter under certain conditions. Pressure chambers on either side of the clutch plate are pressurized to operate the clutch. An orifice through the clutch plate allows flow from one chamber to the other. A regulator valve is connected to both pressure chambers and is responsive thereto. The regulator valve is also responsive to external signals such as vehicle speed and throttle opening to regulate the pressure difference in the two chambers for operation of the clutch.

Clutch operation control system for fluid torque converters

An hydraulic transmission interposed between an engine and the wheels of a vehicle is controlled by hydraulic circuits and hydraulically-operated clutches. A shift valve assembly is supplied with oil pressure in accordance with the extent of opening of the throttle of the engine, as well as vehicle governor pressure acting as a vehicle speed signal. The shift valve assembly not only functions to control operation of hydraulic clutches but also acts as a malfunction-preventive valve which operates to impede engagement of the reverse transmission clutch during forward running of the vehicle at a speed higher than a predetermined vehicle speed, irrespective of the throttle valve opening.

Growing community of inventors

Utsunomiya, Japan

Keiichi Ishikawa