Nissan Motor Company Limited

Jatco Corporation

Aichi Machine Industry, Ltd.

Tateki Jozaki

Tatsuo Ochiai

Masato Koga

Hideaki Suzuki

Masaaki Uchida

Seiichiro Takahashi

Mamiko Inoue

Ryousuke Nonomura

Ryoji Kadono

Shigeru Ishii

Yoshihide Shinso

Hiroyasu Tanaka

Yusuke Kimura

Masahiro Yamamoto

Shigeki Shimanaka

Tatsuo Wakahara

Naoya Inoue

Mitsuru Watanabe

Satoshi Takizawa

Hideshi Wakayama

Hirofumi Okahara

Kenji Yoneda

Akito Suzuki

Midori Yamaguchi

Masayoshi Nakasaki

Masatoshi Akanuma

Junya Takayama

Youhei Ishikawa

Yuichi Asai

Takeshi Chibahara

Yoshinori Ishimori

Jun Shiomi

Jun Shimoi

A transmission controller permits a 2-1 shift, in which a gear position of a subtransmission mechanism is changed from a second speed to a first speed, when an accelerator pedal has been depressed to or above a predetermined opening. The gear position of the subtransmission mechanism is changed from the second speed to the first speed when an actual through speed ratio passes a mode switch line from a High side to a Low side while the 2-1 shift is permitted in the subtransmission mechanism.

Continuously variable transmission and control method thereof

A control apparatus for an automatic transmission includes a stepwise variable transmission mechanism; a power ON/OFF state judging section; and a shift control section configured to control the stepwise variable transmission mechanism to a target rotational speed by disengaging the first engagement portion and engaging the second engagement portion in accordance with a torque inputted to the stepwise variable transmission mechanism, the shift control section being configured to engage one of the first engagement portion and the second engagement portion which has a function to suppress a variation of an input rotational speed of the stepwise variable transmission mechanism which is generated by a switching of the power ON/OFF state when the power ON/OFF state is switched at the shift control of the stepwise variable transmission mechanism, and to disengage the other of the first engagement portion and the second engagement portion.

Control apparatus and method for automatic transmission

A control system of an automatic transmission including a stepwise variable transmission section and a continuously variable transmission section makes a speed change control of the continuously variable transmission section cooperate with a change of an input rotation speed of the stepwise variable transmission section and is configured to judge, during the shift change of the stepwise variable transmission section, whether a delivery of a torque from one of a plurality of disengaging side frictional elements to one of a plurality of engaging side frictional elements is completed, and to start the speed change control of the continuously variable transmission section upon judgment that the delivery of the torque is completed and that an inertial phase has started.

Control system of automatic transmission

The transmission controller changes the gear position of the subtransmission mechanism and varies the speed ratio of the variator in an opposite direction to a speed ratio variation direction of the subtransmission mechanism when the actual through speed ratio passes a predetermined mode switch line. When the improvement in the shift response of the continuously variable transmission is determined to be required and the actual through speed ratio passes the mode switch line from a Low side to the High side, the transmission controller increases a shift speed of the subtransmission mechanism compared with a normal coordinated shift.

A control apparatus for an automatic transmission system having a serial arrangement of a stepwise variable automatic transmission mechanism and a continuously variable automatic transmission mechanism, the control apparatus being disposed in the automatic transmission system and performing a shift control of the continuously variable automatic transmission mechanism in accordance with variation in transmission ratio of the stepwise variable automatic transmission mechanism, the control apparatus including a control section configured to execute a retardation processing upon shift control of one of the continuously variable transmission mechanism and the stepwise variable transmission mechanism which has a smaller response delay of an actual transmission ratio from a target transmission ratio than that of the other transmission mechanism.

Control apparatus and method for automatic transmission system

In control apparatus and method for an automatic transmission, a gear shift state of a stepwise variable transmission mechanism is controlled to a target gear shift state by releasing a first engagement section according to a reduction in a capacity of the first engagement section and, simultaneously, by engaging a second engagement section according to an increase in the capacity of the second engagement section, in accordance with a torque inputted to the stepwise variable transmission mechanism and, during an inertia phase, either one of the first and second engagement sections functions as a gear shift state control side engagement section and the capacity of a gear shift state non-control side engagement section which is the other engagement section is increased when determining that it is impossible to make the gear shift state follow up the target gear shift state at the gear shift state control side engagement section.

A continuously variable transmission includes a variator capable of varying a speed ratio continuously, and a subtransmission mechanism provided in series with the variator. On the basis of an operating condition of a vehicle, a transmission controller sets a destination through speed ratio, which is an overall speed ratio of the variator and the subtransmission mechanism to be realized in accordance with the operating condition, and controls the variator and the subtransmission mechanism on the basis thereof. When shifts are prohibited in the subtransmission mechanism, the destination through speed ratio is limited to a speed ratio range that can be realized only by a shift in the variator.

A control apparatus of an automatic transmission has an engagement part, a power-ON/OFF state judgment section and a control section controlling a capacity of the engagement part. The control section compares an actual input revolution speed difference absolute value of an absolute value of a difference between an input revolution speed when engaged and an actual input revolution speed with a target input revolution speed difference absolute value of an absolute value of a difference between the input revolution speed when engaged and a target input revolution speed, then a deviation is determined by subtracting the target input revolution speed difference absolute value from the actual input revolution speed difference absolute value. When the deviation is positive, the capacity is increased. When the deviation is negative, the capacity is reduced. When the deviation is zero, a previous capacity that is set before the comparison of the both absolute values is maintained.

Control apparatus of automatic transmission

A continuously variable transmission includes a variator capable of varying a speed ratio continuously, and a subtransmission mechanism provided in series with the variator. When an actual through speed ratio passes a predetermined mode switch speed ratio, a transmission controller performs a coordinated shift in which a gear position of the subtransmission mechanism is changed and a speed ratio of the variator is varied in an opposite direction to a speed ratio variation direction of the subtransmission mechanism. When the rapid deceleration is determined to be underway, the transmission controller decreases a speed ratio variation amount of the variator in the direction of a High side accompanied by a downshift of the subtransmission mechanism compared with the coordinated shift.

A control device for controlling a continuously variable transmission () is disclosed. The control device has an oil pressure control unit () which supplies an oil pressure to a primary pulley () and secondary pulley () based on a command signal indicative of a target speed-reduction ratio, a sensor () which detects a rotation speed (Np) of the primary pulley (), and a controller () which transmits the command signal indicative of the target speed-reduction ratio to the oil pressure control unit (). The controller is programmed to set the target speed-reduction ratio to a first speed-reduction ratio (R); calculate a first predetermined rotation speed (N) of the primary pulley at which the V-belt reaches a first limiting temperature (T) at the first speed-reduction ratio (R); calculate a first elapsed time after the detected rotation speed (Np) of the primary pulley exceeds the first predetermined rotation speed (N); maintain the first speed-reduction ratio (R) when the first elapsed time is equal to or less than a first predetermined time; and set the target speed-reduction ratio to a second speed-reduction ratio (R) smaller than the first speed-reduction ratio (R) when the first elapsed time exceeds the first predetermined time. At the second speed-reduction ratio (R), the temperature of the V-belt should become equal to or less than the first limiting temperature (T) throughout the permitted rotation speed region of the primary pulley. Thus, starting acceleration performance of the continuously variable transmission is enhanced.

Control device for controlling V-belt continuously variable transmission

There are provided with a determination means for determining whether or not the correlation between the pressure value detected by the primary pressure sensor and the pressure value detected by the secondary pressure sensor is an actually impossible relation (Step), and a switchover means for switching over to an open control while prohibiting a feedback control when the correlation is determined to have become a relation actually impossible by the determination means (Step). Presence or absence of a fault to the primary pressure sensor or the secondary pressure sensor (particularly, fault of fixed output voltage) is judged based on the correlation between the output voltage of the primary pressure sensor and the output voltage of the secondary pressure sensor to prohibit the control of a primary pressure and a secondary pressure using the hydraulic pressure sensors when it is judged that there is a fault.

Transmission controller of V-belt type continuously variable automatic transmission

In a system for controlling an automatic transmission, at the time of ultra-low temperature start with the oil temperature of &#x2212;20&#xb0; C. or less, control is carried out such that when the state that the actual line pressure is equal to or greater than an ultra-low set value continues for a period longer than a line-pressure low-pressure control command set time, it is determined that the line pressure is under regulation, maximizing an indicated value of the line pressure.

System and method of controlling automatic transmission

A hydraulic clutch transmits driving torque in a power train of a vehicle. An oil pressure supply unit supplies oil pressure for engagement to the clutch and a controller controls the unit. The controller causes the unit, prior to engagement of the clutch, to precharge the interior of the clutch with hydraulic fluid. The controller counts an elapsed time since the last release of the clutch and shortens the precharge period as the elapsed time decreases, thereby optimizing the precharge state of the clutch.

Hydraulic clutch control of vehicle power train

A speed change ratio control unit for a continuously variable transmission that uses a step motor as a driving actuator of a speed change control valve that compares a variable ASTP representing a step position of the step motor and a step position BSTP of the step motor that is necessary for realizing a desired speed change ratio at every predetermined operation cycle, and if ASTP&#x2260;BSTP is satisfied determines that a step-out has occurred on the step motor.

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Yokohama, Japan

Tateki Jozaki