Toyota Jidosha Kabushiki Kaisha

Akio Sugawara

Yuji Yasuda

Masaru Morise

Hideki Miyata

Hiroaki Takeuchi

Ryosuke Ikemura

Kunihiko Usui

Keisuke Ushida

Hiromichi Kimura

Masami Kondo

Keigo Matsubara

Norifumi Takada

Shuntaro Shinohara

Akihito Hayasaka

A drive control system for a hybrid vehicle configured to prevent backward coasting on an uphill grade even when an engine torque cannot be delivered to drive wheels. When the hybrid vehicle is propelled by delivering engine torque to rear wheels on an uphill grade, the drive control system determines an occurrence of a failure in which the torque cannot be delivered from the engine to the rear wheels. If the occurrence of the failure is determined, the drive control system executes a hill hold control to deliver torque to establish a required drive force from a motor to front wheels while disengaging an engagement device.

Drive control system for hybrid vehicle

A drive force control system for a vehicle configured to allow a driver to find out a steering angle at which a wheel grips a road surface. In the vehicle, a torque distribution ratio to a pair of wheels turned by a steering wheel and another pair of wheels is changeable. A controller restricts a control to change the torque distribution ratio in the event of a slip of the pair of wheels, if a steering angle of the pair of wheels is changed to allow the pair of wheels to grip a road surface.

Drive force control system for vehicle

A control system for a four-wheel drive vehicle configured to improve energy efficiency by avoiding selection of a four-wheel drive mode more than necessary. The control system comprises a controller that shifts an operating mode between a two-wheel drive mode and a four-wheel drive mode. When a control of the prime mover is terminated, the controller detects the operating mode selected by a switch before restarting the control of the prime mover. If the two-wheel drive mode or the four-wheel drive mode was selected by the switch before restarting the control of the prime mover, the controller selects the two-wheel drive mode when restarting the control of the prime mover.

Control system for four-wheel drive vehicle

A transmission gear control apparatus for a vehicle is provided. The vehicle includes an automatic transmission, a torque converter, and an accelerator operation amount sensor. The torque converter is disposed between the engine and the automatic transmission. The transmission gear control apparatus includes an electronic control unit. The electronic control unit is configured to: (i) control switching of a transmission gear stage of the automatic transmission at least on a basis of a change in vehicle speed of the vehicle; (ii) control lockup of a lock-up clutch of the torque converter on a basis of a state of the vehicle; and (iii) control the automatic transmission when the accelerator operation amount is equal to or larger than a specified value such that an upshift of the automatic transmission is performed at a higher vehicle speed as a rotation difference between input and output of the torque converter is reduced.

Transmission gear control apparatus for vehicle

A control apparatus for automatic-transmission provided with input-clutch through which drive force generated by engine is input to automatic-transmission, released-side frictional coupling device being placed in released state to perform shifting action of automatic-transmission, and engaged-side frictional coupling device being placed in engaged state to perform shifting action, control apparatus including: first shifting mode control means including slipping means for placing input-clutch in released state, engaging means for placing input-clutch in engaged state, and releasing/engaging switching control means for controlling shifting action of automatic-transmission being performed in first shifting mode wherein released-side frictional coupling device is brought into released state, and engaged-side frictional coupling device is brought into engaged state, while input-clutch is placed in released or slipping state under control of slipping means, and input-clutch is then brought into engaged state under control of engaging means, with a change of operating speed of engine connected to input-shaft of automatic-transmission.

Control device for automatic transmission

A hydraulic control apparatus for an automatic transmission provided with a friction engaging element that operates using hydraulic pressure includes a range pressure oil passage which is connected to the friction engaging element; a manual valve which is connected to the range pressure oil passage; a drain port which is formed in the manual valve and which drains hydraulic pressure of the range pressure oil passage; a drain oil passage which is connected to the drain port; and a drain pressure controller which is connected to the drain oil passage and which performs control so as to change a decreasing rate of drain pressure of the drain oil passage.

Hydraulic control apparatus for automatic transmission

A hydraulic control circuit for an automatic transmission of a vehicle, the transmission including hydraulically operated coupling devices at least one of which is selectively operated to establish a corresponding one of speed steps, the hydraulic control circuit including electromagnetic valve devices which output respective hydraulic pressures to operate the hydraulically operated coupling devices, respectively, an all-fail detecting and switching valve device which is switched, based on an all-fail state of the electromagnetic valve devices in which none of the electromagnetic valve devices output the respective hydraulic pressures, to an operation state corresponding to a fail position to output, as a first hydraulic pressure, a source hydraulic pressure to a first hydraulically operated coupling device out of the plurality of hydraulically operated coupling devices, and an operation-state memory valve which is switched, based on a state of the vehicle before the all-fail state occurs, from a non-running position indicating that the vehicle is not running, to a running position indicating that the vehicle is running, which is kept at one of the non-running position and the running position, and which supplies an operating hydraulic pressure to one of a second and a third hydraulically operated coupling device out of the plurality of hydraulically operated coupling devices that corresponds to the one of the non-running position and the running position at which the operation-state memory valve is kept.

Hydraulic control circuit for automatic transmission of vehicle

A hydraulic control apparatus for an automatic transmission includes a first SL linear solenoid, a second SL linear solenoid, a third SL linear solenoid, and a fourth SL linear solenoid, which are normal closed type, and a sequence valve. The sequence valve connects the first SL linear solenoid to a servo of a C1 clutch, the second SL linear solenoid to a servo of a C2 clutch, and the fourth SL linear solenoid to a servo of a B3 brake at normal time. The sequence valve selectively connects a D range oil passage to the servo of the C1 clutch and the servo of the C2 clutch, and connects the D range oil passage to the servo of the B3 brake, when an electric failure gas occurred.

A hydraulic control apparatus for switching an operation of a hydraulically operated mechanical apparatus, by selectively operating two frictional engagement elements of a first, a second, a third, and a fifth frictional engagement elements, the hydraulic control apparatus including a first control valve which, in association with an event that respective hydraulic pressures to operate the first and second frictional engagement elements are both produced, drains one of the third and fifth frictional engagement elements and outputs a control hydraulic pressure; and a second control valve which, when at least two hydraulic pressures of (a) the control hydraulic pressure and (b) respective hydraulic pressures to operate the third and fifth frictional engagement elements are supplied to the second control valve, drains the other of the third and fifth frictional engagement elements.

Hydraulic control apparatus for hydraulically operated mechanical apparatus

There is provided a hydraulic pressure control apparatus for a vehicular hydraulic power transmission device with a lock-up clutch, in which an increase in the temperature of hydraulic oil in an engagement side oil chamber is suppressed, durability of frictional material is improved, and the lock-up clutch is appropriately controlled. A switching control valve (a lock-up relay valveand a lock-up control valve) switches between connection and disconnection between each of two oil passages that communicate with an engagement side oil chamberand each of a high pressure oil passage and a low pressure oil passage, according to the operating state of the lock-up clutchFor example, when the lock-up clutch is completely engaged, the hydraulic oil is supplied to both the two oil passages from the high pressure oil passage, hydraulic pressure PON in the engagement side oil chamberis increased, and a sufficient transmission torque capacity of the lock-up clutchis obtained. When the lock-up clutchis in the slip state, one of the two oil passages is connected to the high pressure oil passage, and the other oil passage is connected to the low pressure oil passage such that the hydraulic oil is circulated in the engagement side oil chamberTherefore, an increase in the temperature of the hydraulic oil is suppressed, the lock-up clutchis cooled, and the durability of the frictional materialis improved.

Hydraulic pressure control apparatus for vehicular hydraulic power transmission device with lock-up clutch

A friction apply device, from among each pair of friction apply devices that are applied to achieve a speed from first speed to fourth speed, that is to be placed in a slipping state is selected based on a heat load when a neutral control is executed. As a result, it is possible to continue to execute the neutral control without the durability of the friction apply device being impaired by the heat load, for example, thereby increasing a fuel efficiency effect and the like achieved by the neutral control.

Neutral control for vehicular automatic transmission

A fluid pressure control circuit includes a fluid pressure device which is operated by a fluid pressure; a control valve which is connected to the fluid pressure device via a connecting passage, and which changes a flow rate of predetermined fluid that is to be supplied to the fluid pressure device or that is to be discharged from the fluid pressure device according to a position of a valve element; and a pressure difference reflecting device which moves the valve element based on a difference in the fluid pressure between predetermined two different portions in the connecting passage and which changes the flow rate of the fluid that is to be supplied or to be discharged through the control valve according to the fluid pressure difference. With this fluid pressure control circuit, it is possible to obtain excellent responsiveness during supply/discharge of the fluid, change in the fluid pressure or the like, without increasing the amount of the fluid to be consumed.

Fluid pressure control circuit

A pair of feedback chambers is provided in a supply/discharge switching control valve, and the hydraulic pressure is introduced from a portion on the upstream side of the orifice provided in the communication passage through the second feedback passage, and is introduced from a portion on the downstream side of the orifice provided in the communication passage through the first feedback passage. Therefore, the responsiveness is enhanced, compared with the case where only the first feedback chamber is provided. Also, the overshoot and the undershoot of the fluid pressure, and the pressure fluctuation are effectively suppressed, compared with the case where only the second feedback chamber is provided. Also, by appropriately setting the pressure receiving area of the spool in the first feedback chamber and the pressure receiving area of the spool in the second feedback chamber, and the circulation cross sectional areas of the orifices, it is possible to easily tune the responsiveness, and the overshoot and the undershoot of the fluid pressure, the pressure fluctuation and the like, according to the performance required of the hydraulic pressure device.

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Toyota, Japan

Akio Sugawara