Jatco Corporation

Nissan Motor Company Limited

Hironori Nihei

Tetsuya Izumi

Seonjae Kim

Masato Koga

Takashi Matsuda

Toshiji Iida

Fumito Shinohara

Takayuki Tanaka

Toshiyuki Shibuya

Kwang-ho Lee

Kiyotaka Sawano

Naohiro Hoshi

Takeshi Chibahara

Takuya Numata

Toru Koga

Kwang-Ho Lee

An engine is restarted in response to an idle stop OFF command at tso that a gear shift control purpose hydraulic pressure is raised according to a working oil from an engine driven oil pump. An idle stop release time control of the engine is allowed according to a torque down unnecessary determination when a gear shift control purpose hydraulic pressure has reached to a set hydraulic pressure at t. In a case where this allowance causes an engine torque Te to be raised from a torque down value toward a driving operation corresponding value by a predetermined gradient &#x394;Te, a command value of a starting frictional element engagement pressure Pis set to a control maximum value during the idle stop control including during the idle stop release time control.

Fastening pressure control device for starting friction element at time of controlling idle stop of vehicle

At vehicle stop judgment time t, a first engine automatic-stop control permission judgment, based on idle stop permission conditions by which an instant permission judgment can be possible, is carried out. If a result of the first engine automatic-stop control permission judgment at time tis 'permitted', the second engine automatic-stop control permission judgment, based on an idle stop permission condition which requires a certain time for the judgment, is initiated, and an electric oil pump ON (drive) command (the test drive command) is issued. At time tat which an actual drive of the electric oil pump in response to the test drive command is detected, it is judged that a failure of an electric system of the electric oil pump and a foreign matter-biting failure of the electric oil pump do not occur, then a failure judgment of the electric oil pump becomes 'normal'. This judgment is completed before time tat which the second engine automatic-stop control permission judgment ends, and both of &#x201c;permitted&#x201d; of a result of the second engine automatic-stop control permission judgment and &#x201c;normal&#x201d; of the failure judgment of the electric oil pump, an idle stop ON command is not outputted.

Trouble-deciding device for electric oil pump to be used in transmission of vehicle having engine automatic-stop control device

In an idling-stop cancellation control apparatus of a vehicle driving system of an idling-stop control device equipped automotive vehicle capable of running by a power produced by an engine and transmitted via a transmission whose shift is controlled by a hydraulic pressure produced by an engine-driven oil pump during operation of the engine, a controller is configured to execute, based on engine speed, idling-stop cancellation control by which the vehicle driving system is put into an output torque state suited for vehicle-driving operation, when a hydraulic pressure sensor system provided for detecting a hydraulic pressure used for shift control of the transmission is failed. The controller is further configured to execute, based on the hydraulic pressure, idling-stop cancellation control by which the vehicle driving system is put into an output torque state suited for vehicle-driving operation, when the hydraulic pressure sensor system is unfailed.

Idling-stop cancellation control apparatus of vehicle driving system

In a speed ratio control device for a belt continuously variable transmission according to this invention, when a speed ratio is subjected to feedback control on the basis of a difference between an actual speed ratio and a target speed ratio, pressure supplied to a primary pulley is corrected through feedforward (S, S) in order to suppress variation in the groove width of the primary pulley caused by a rapid variation in an input torque into the primary pulley (S) while traveling in a fixed speed ratio mode (S) in which the target speed ratio is held at a fixed value.

Speed ratio control device and method for belt type continuously variable transmission

In a line pressure control device for a belt type continuously variable transmission according to this invention, when a line pressure is feedback-controlled to equal a target line pressure which is equal to or greater than the larger of oil pressures supplied to a primary pulley and a secondary pulley (S), and it is determined that the target line pressure has fallen below a first low pressure, leading to a divergence between the target line pressure and the actual line pressure (S), the target line pressure is restricted such that the target line pressure does not fall below a lower limit value (S).

Line pressure control device and method for belt type continuously variable transmission

A positional deviation ERRstep of a step motoris calculated on the basis of a reference model step StepMdl, an actual speed ratio-corresponding step Bstep, and an added value obtained by adding together a target deviation GTstep, calculated in accordance with a transmission input torque Ti, and a starting learned value Gstep. When the transmission input torque Ti is large, the target deviation GTstep is increased in accordance with the transmission input torque Ti. A line pressure PL is then controlled on the basis of the positional deviation ERRstep obtained as a result.

Continuously variable transmission and control method thereof

When a line pressure PL serving as a source pressure of a primary pulley () and a secondary pulley () is controlled on the basis of a control deviation &#x394;Step, which is the deviation between a step count StepMdl of a step motor () corresponding to a target speed ratio I (o) and a value obtained by adding a target deviation GTstep and a starting learned value Gstep to a step count Bstep of the step motor () corresponding to an actual speed ratio ip, the engine torque varies dramatically beyond the range of a predetermined value Tand a predetermined value Tduring a predetermined time period t, a learning error determination relating to the starting learned value Gstep is prohibited for a predetermined time period t

In a line pressure control apparatus of a belt-drive CVT, a shift is achieved by varying V- groove widths of primary and secondary pulleys by a differential pressure between primary and secondary pulley pressures, originating from line pressure. The differential pressure is created by bringing a shift actuator, such as a step motor, into a control position corresponding to a target transmission ratio. The target transmission ratio is calculated based on a theoretical transmission ratio based on engine-and-vehicle operating conditions, taking account of a hardware response delay and a disturbance. The target transmission ratio is converted into a reference-model operative position, corresponding to a reference-model number-of-steps of the shift actuator. An actual transmission ratio is converted into an actual-transmission-ratio related operative position. Line pressure is corrected in a manner so as to reduce the positional deviation between the reference-model operative position and the actual-transmission-ratio related operative position.

Line pressure control apparatus for belt-drive continuously variable transmission

A belt continuously variable transmission includes a primary pulley (), a secondary pulley (), a belt (), a hydraulic pump (), a speed ratio control valve () that regulates hydraulic pressure from the hydraulic pump () and supplies the hydraulic pressure to the primary pulley () and the secondary pulley (), a motor () that drives the speed ratio control valve (), a controller () that controls the motor (), and an oil temperature sensor () that detects the temperature of a working fluid. The controller () stops energization to the motor () when the temperature of the working fluid becomes greater than a first predetermined temperature while the vehicle is at rest in an idling state.

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Zama, Japan

Hironori Nihei