Aisin Seiki Kabushiki Kaisha

Kazuo Ishikawa

Noboru Murakami

Koichiro Hirosawa

Keiichi Yamamoto

Hiroaki Maeda

Tsunehiko Ogasawara

Yuzo Masuda

Norishige Yoshikawa

Tsunehiko Ogasahara

Yoshinori Nishi

A direct-coupled clutch for a torque converter 10 has a front cover 11, a piston clutch plate 12 having a frictional facing 12a, a turbine 13, a driven plate 14, secured to the piston clutch plate 12 for rotation in unison with the piston clutch plate, a disk 16 circumferentially movably arranged between the piston clutch plate 12 and the driven plate 14, a first resilient member 17 and a second resilient member 18 arranged between the piston clutch plate 12 and the turbine 13. The driven plate 14 has a first receiving part 15a and a second receiving part, formed radially more inwardly than the first receiving part, for carrying the second resilient member. The driven plate 14 has a first pawl for circumferentially compressing the second resilient member and a second pawl 14b formed radially more inwardly than the first pawl 14a. The disk 16 has a retainer 16a for circumferentially compressing the first resilient member 17. The clutch has a simplified structure.

Direct-coupled clutch for torque converter

An automatic transmission includes a torque converter with a directly coupled clutch. A plurality of rotational speed sensors are used in the control of a lockup and a shifting operation. The invention provides an arrangement to detect any abnormality associated with such sensors. Under the lockup condition of the torque converter, a speed Ve detected by an engine rotational speed sensor, and speeds Vsp1 and Vsp2 detected by a first and a second vehicle speed sensor and a speed ratio K.sub.1 of a change gearing are used to detect any abnormality associated with the three sensors. All of the sensors are determined to be properly functioning when the equalities Ve=K.sub.1 .multidot.Vsp1 and Ve=K.sub.1 .multidot.Vsp2 apply. The first vehicle speed sensor is determined to be faulty when the former equation applies while the latter equation does not apply, and the second vehicle speed sensor is determined to be faulty when the former equality applies while the latter does not apply. When the both equalities do not hold, the engine rotational speed sensor is determined to be faulty.

Control system for automatic transmission

A lockup control system for a torque converter with a directly coupled clutch is disclosed. A gear ratio of the torque converter is detected as is a throttle valve opening. A gear ratio data (as a reference data) which is previously assigned to a throttle valve opening is read from ROM, and is compared against the detected gear ratio. If the latter is equal to or greater than the former, a lockup command is provided, and a prevailing vehicle speed is written into a register. When a lockup condition is established, the current vehicle speed is compared against the vehicle speed stored in the register, and whenever the former becomes equal to or less than the latter from which .DELTA.V is subtracted, the lockup is terminated. Reference data is provided in three groups corresponding to three temperature regions of the torque converter. A group corresponding to the actual temperature of the torque converter is selected, and reference data in the group which corresponds to a particular throttle opening is read from ROM. .DELTA.V is a function of the throttle opening, and assumes a smaller value for an increased throttle opening and assumes a greater value for a reduced throttle opening.

Lockup control system for automatic transmission

A lock-up clutch of an automatic transmission is controlled by an electronic control unit using a gear shift diagram and a lock-up clutch changeover diagram each having vehicle velocity plotted along identical abscissa and throttle opening plotted along identical ordinate. Changeover of the lock-up clutch is controlled upon setting a changeover line in the changeover diagram in accordance with which the lock-up clutch is changed over from OFF to ON state, and changeover of transmission gear ranges is controlled upon setting a transmission gear range changeover point in the gear shift diagram. The changeover line is set in such a manner that it will not intersect a region in the gear shift diagram where the shift position is 2nd gear range or less and the throttle opening is less than a predetermined value. Thus, the lock-up clutch is not engaged in a case where the transmission is in 2nd gear range or less and, moreover, the throttle opening is less than a predetermined value.

Lock-up clutch control method in automatic transmissions for automotive

A hydraulic control system for a 4 drive speed automatic transmission, comprising:

Hydraulic control system for automatic transmission

An automatic power transmission including a torque converter and a planetary type multiple stage gear transmission unit. The torque converter is provided with a lock up clutch for mechanically connecting the converter pump with the turbine so that the engine output torque is directly transmitted to the gear transmission unit. The engagement of the lock up clutch is controlled by the difference between the governor pressure which represents the vehicle speed and the throttle valve kickdown pressure which indicates whether or not the engine throttle valve is in or substantially in the full open position so that the lock up clutch can be engaged at a relatively low speed under a normal operation.

Vehicle automatic power transmission having a lock up clutch

A clutch control system for a manual transmission comprises a servo cylinder for selectively engaging a clutch engagement mechanism, and a shift valve for connecting a source of oil pressure to the servo cylinder upon shifting of the transmission to operate the servo cylinder and for connecting the servo cylinder to an oil reservoir after shifting of the transmission to release the operation of the servo cylinder. The control system further comprises a thermostatically operated valve associated with the shift valve for controlling the flow of oil discharged from the servo cylinder to the oil reservoir in accordance with changes of the oil temperature.

Clutch control system with thermostatic regulator valve

Automatic transmission for automobiles including a hydraulic torque converter and a transmission gear mechanism which has a plurality of friction devices such as clutch and brakes whereby a plurality of different driving stages can be provided through selective actuation of the friction devices. Trimmer valve is provided for each actuator of the friction device to provide a supply of gradually increasing hydraulic pressure. The trimmer valve is applied at its return port with a pressure corresponding to the engine throttle valve position so that the initial pressure to be applied to the actuator is determined in accordance with the engine throttle valve position.

Automatic transmission for automobiles

Automatic transmissions for automobiles include a hydraulic torque converter and a transmission gear mechanism which has a plurality of friction devices such as a clutch and brakes whereby a plurality of different driving stages can be provided through selective actuation of the friction devices. The automatic transmissions further include an over-drive system comprising at least an OD shift valve and a Low-High shift valve. The OD shift valve is applied through the L-H shift valve with a pressure sufficient to shift gear devices to a high speed position or a low speed position. A kick-down valve is disposed between the engine throttle position valve and the L-H shift valve to enable the pressure in the throttle line to increase when the kick down operation takes place.

This invention relates to a fluid pressure supplying method for fluidically actuating a frictional engaging apparatus in a vehicle transmission, including the steps of supplying high pressure to actuate the frictional engaging apparatus, reducing the high pressure to a lower pressure when the frictional engaging apparatus is initially engaged, and increasing the fluid pressure to line pressure in the frictional engaging apparatus after the frictional engaging apparatus is fully engaged, thereby smoothly engaging the frictional engaging apparatus without giving a shock to the apparatus and reducing the engaging time of the frictional engaging apparatus.

Fluid pressure modulating apparatus for a fluidically actuated

An improved internal combustion engine exhaust brake control device for use in conjunction with an automatic transmission, of the type in which the actuation of manual and throttle-connected switches energize a valve retarding the engine exhaust gas flow and creating back pressure which imparts a braking action on the engine, wherein the improvement comprises a switching device actuated by the manual down-shifting of the transmission that, in conjunction with actuation of the throttle-connected switch, automatically activates the exhaust brake device.

Engine exhaust brake controlled by transmission and accelerator

A hydraulic control system for a vehicle transmission including a plurality of hydraulically operated functional brake and clutch devices for providing a plurality of driving stages of different speed ratios, the system comprising a pressure regulator valve for providing a regulated line pressure and shift valves for transmitting the line pressure to selected ones of the frictional devices. Pressure control valves are provided between the shift valves and the brake or clutch devices which are operated in low speed range of the transmission to provide a time delay in the increase of the pressure for actuating the devices. The pressure regulator valve is provided with pressure increasing chambers which receive the outlet pressure from the pressure control valves to increase the line pressure when the transmission is shifted to the low speed range such as the first and second speed forward drive stage and the reverse drive stage.

Growing community of inventors

Hoi, Japan

Kazuo Ishikawa