Abstract: A controller executes a feedback control of a transmission so that an actual speed ratio reaches a target speed ratio. The controller includes first and second phase lead compensators configured to perform phase lead compensation of a feedback primary command pressure, a lead compensation on/off determination unit configured to determine to set on or off the phase lead compensation, and an advance amount filter unit configured to smooth a change of a gain according to on/off determination of the phase lead compensation when the phase lead compensation is on/off-switched.
Abstract: The present invention relates to a control device and a control method for a vehicle in which a lockup clutch is disengaged when a rotation speed of an engine falls below a disengagement rotation speed. The device/method changes a speed ratio of a variator on the basis of a shifting map in which a primary pulley rotation speed on a coast line is set higher than a primary pulley rotation speed on a drive line and sets a target input rotation speed of the variator to a predetermined target input rotation speed higher than the primary pulley rotation speed on the drive line when an operation of an accelerator pedal is performed such that an accelerator pedal opening falls to a first predetermined opening or less. As a result, the present invention can suppress drop of fuel efficiency of the engine caused by disengagement of the lockup clutch which is a friction engagement element.
Abstract: A vehicle control device separately controls driving powers distributed to right and left wheels. The vehicle control device is configured to execute a vehicle posture control for reducing the driving powers transmitted from a driving source to the wheels by a request from a vehicle side. The vehicle control device includes a slip detection unit and a torque control unit. The slip detection unit is configured to detect a slip in the wheels. The torque control unit is configured to determine whether to perform a torque control after an operation of the vehicle posture control according to a detection result of the slip and a state of a transmission. The torque control is a control to control a torque input to the transmission by a request from the transmission side. The torque control unit is configured to execute the torque control on the basis of a determination result.
Abstract: A control device for a continuously variable transmission includes a lock-up clutch of a torque converter which is arranged to connect and disconnect a power transmission between a power source and the driving wheel, and a control section configured to output a hydraulic pressure command value. The control section is configured to control a transmission gear ratio of the continuously variable transmission and an engagement state of the lock-up clutch in accordance with a traveling state of a vehicle. The control device includes a learning control section configured to perform a learning control of the engagement state of the lock-up clutch with respect to the hydraulic pressure command value, an oil vibration sensing section configured to sense oil vibration of a line pressure, and a learning control prohibiting section configured to prohibit the learning control when the oil vibration sensing section senses the oil vibration.
Abstract: In a cooling structure in a clutch having drive plates and driven plates, a lower limit of a width of each of dot grooves is set to a width a at which a flow quantity of lubricating oil passing through each of the dot grooves becomes a minimum flow quantity at which the drive plates and the driven plates can be cooled to a temperature equal to or lower than an upper limit temperature (Tmax) and an upper limit of the width of each of the dot grooves is set to a width b at which an air content in lubricating oil passing through each of the dot grooves becomes a maximum air content at which, according to lubricating oil having the air content, the drive plates and the driven plates can be cooled to a temperature equal to or lower than the upper limit temperature (Tmax).
Abstract: An automatic transmission has an oil pump driven by a travelling driving source. An air vent structure that expels air bubbles contained in automatic transmission fluid during pump operation has an air vent hole whose one end communicates with an outlet port of the oil pump and whose other end opens toward the oil pan. An air vent tube is connected to an opening end of the air vent hole. The air vent tube is extended up to a strainer lower side gap area located between a strainer and the oil pan, and a tube opening end of the air vent tube is placed in oil of the automatic transmission fluid.
Abstract: A control device for a continuously variable transmission of a vehicle includes a shift control section being configured to perform a rough road corresponding control to increase the hydraulic pressure to a value larger than the hydraulic pressure at a smooth road judgment at which the smooth road is judged, at a rough road judgment at which the rough road is judged, and when a line-pressure-up control condition is satisfied at the rough road judgment, the line pressure control section being configured to increase the line pressure to be greater than the line pressure when the line-pressure-up control condition is not satisfied.
Abstract: A malfunction part sensing device for an automatic transmission for a vehicle which is arranged to attain a plurality of shift stages by selectively engaging a plurality of frictional engagement elements, the malfunction part sensing device includes: a shift stage monitoring section configured to monitor the shift stages before and after the shift of the automatic transmission; a malfunction sensing section configured to sense the malfunction mode from a behavior of the vehicle which is generated in accordance with the malfunction; and a malfunction part limiting section configured to limit the one of the frictional engagement elements in which the malfunction is generated, based on the malfunction mode and a shift manner by a combination of the shift stages before and after the shift.
Abstract: A controller constitutes a control device for continuously variable transmission for executing a feedback control of a transmission so that an actual speed ratio reaches a target speed ratio. The controller includes a first phase lead compensator and a second phase lead compensator configured to perform phase lead compensation of a feedback primary command pressure, and a peak value frequency determination unit configured to change a peak value frequency according to a speed ratio.
February 23, 2017
March 28, 2019
Ken OKAHARA, Kazutaka ADACHI, Yutaka KANEKO, Kenichi MORI
Abstract: When a switch condition where a shift of a continuously variable transmission is switched from a first shift that is any one of an upshift and a downshift to another second shift is satisfied, an integral term in the feedback control of the first shift is reduced to zero with a first predetermined gradient, an operation of an integral term in the feedback control of the second shift is started after the switch condition is satisfied and before the integral term in the feedback control of the first shift reaches zero, and the continuously variable transmission is shifted based on a sum of the integral term in the feedback control of the first shift and the integral term in the feedback control of the second shift.
Abstract: Provided is a lubricant guiding structure in an automatic transmission in which a baffle plate configured to regulate the movement of a lubricant agitated by a driven sprocket is provided at one side, where an oil pump is located, in the direction of a rotational axis of the driven sprocket. As viewed from the rotational axis direction, a division wall disposed to extend across a chain is provided closer to the chain than a base of the baffle plate. As viewed from the rotational axis direction, the baffle plate is provided with a guide wall extending along a torque transmission-side chain of the chain wound on the driven sprocket. As viewed from the rotational axis-direction, the guide wall includes an inclined portion inclined in the direction coming closer to the chain as the distance to the distal end side decreases.
February 10, 2017
March 21, 2019
JATCO Ltd, NISSAN MOTOR CO., LTD.
Tsutomu ITOU, Tou OU, Shinji HIGASHIDE, Yoshiteru UENO
Abstract: The controller performs shift control of the transmission such that an actual pressure of a primary pressure becomes an indicating pressure. The controller includes a phase advance compensator which performs advance compensation of the indicating pressure, and a setting unit which sets an indicating pressure on which the advance compensation is performed by the phase advance compensator as the indicating pressure, in accordance with at least one of a rotation speed of a primary pulley, an input torque to a secondary pulley, a speed ratio, or a changing rate.
Abstract: A transmission controller increases hydraulic pressure supplied to a secondary pulley and decreases hydraulic pressure supplied to a primary pulley to shift a variator to a mechanical Low speed ratio when the hydraulic pressure supplied to the primary pulley and the secondary pulley vibrates. The transmission controller shifts the variator from the mechanical Low speed ratio to a High side when a sub-transmission mechanism is downshifted during controlling a speed ratio of the variator at the mechanical Low speed ratio.
Abstract: A first target secondary pulley pressure Psteng is calculated based on an output torque Teng of an engine, and then an offset value Psteng+PO is calculated by adding a predetermined offset PO to the first target secondary pulley pressure Psteng. The first target secondary pulley pressure Psteng is outputted as a target secondary pulley pressure Ps(n) when a target secondary pulley pressure Ps(n?1) in a previous control cycle is less than or equal to the first target secondary pulley pressure Psteng; the offset value Psteng+PO is outputted as the target secondary pulley pressure Ps(n) when the target secondary pulley pressure Ps(n?1) in the previous control cycle is greater than or equal to the offset value Psteng+PO; and otherwise, the target secondary pulley pressure Ps(n?1) in the previous control cycle is outputted as the target secondary pulley pressure Ps(n), thereby suppressing an oscillation in the target secondary pulley pressure Ps(n).
Abstract: A vehicle control device includes control means for executing coasting control to disengage a friction engaging element and set a rotation speed of a rotary shaft of a drive source at zero when a predetermined condition is established, the predetermined condition including at least a condition according to which an accelerator pedal is not depressed. The control means starts the coasting control after predicting that an actual speed ratio of a continuously variable transmission will be modifiable to a target speed ratio of the coasting control during the coasting control, even in a case where the accelerator pedal is not depressed but the actual speed ratio has not yet reached the target speed ratio.
Abstract: An automatic transmission control device implements a downshift by disengagement of a clutch that is engaged in a gear position before the downshift. It is determined whether an engine state is in a predetermined region in which a change of an engine torque per a change of an accelerator pedal opening is smaller than that in another region, and the engine torque is within a predetermined range, and an engine rotational speed is within a predetermined range. It is determined whether an operating state is in a predetermined state of accelerator operation in which the accelerator pedal opening is larger than a predetermined value, and an accelerator pedal opening change rate has an absolute value smaller than a predetermined value. The downshift is inhibited in response to determination that the engine state is in the predetermined region and the operating state is in the predetermined state of accelerator operation.
Abstract: Control device for continuously variable transmission has continuously variable transmission mechanism (CVT) transmitting power with belt (7) wound around primary and secondary pulley (5, 6); torque convertor (2) having pump impeller (20), turbine runner (21) and lock-up clutch (2a); and control unit (10) controlling lock-up clutch (2a) to predetermined engagement state and controlling the CVT to predetermined transmission ratio, according to travelling condition.
Abstract: A lockup control device for a vehicle includes: a torque converter; a lockup control section configured to increase a lockup pressure difference command to an initial pressure difference when a lockup engagement condition is satisfied in a disengagement state of the lockup clutch, and then to increase the lockup pressure difference command by a ramp pressure difference by a predetermined gradient, the lockup control section being configured to determine a ramp start condition by which the lockup pressure difference command is switched from the initial pressure difference to the ramp pressure difference, based on a speed ratio which is a ratio of input and output rotation speeds of the torque converter.
Abstract: In a vehicle in which a continuously variable transmission, which is connected to an electric motor via a clutch, is operated using oil pressure of an oil pump driven by the motor, erroneous engagement of the clutch is quickly determined. The vehicle has the motor serving as a vehicle driving source, the oil pump connected to the motor, the continuously variable transmission, the clutch interposed between the motor and the continuously variable transmission, a clutch control means for controlling the clutch such that the clutch enters into a completely-engaged, slip-engaged, or release state, and a vehicle control means for controlling the motor such that the motor rotates at a target rotation speed. Also provided is an erroneous engagement handling control means that executes torque adjustment control to decrease an output torque of the vehicle driving source when the clutch is determined to be in an erroneously completely engaged state.
Abstract: A control device for a vehicle is provided, which vehicle includes a driving source, and an automatic transmission having a torque converter provided downstream of the driving source in a power transmission path and having a lockup clutch, and an engaging element provided downstream of the torque converter in the power transmission path. The device includes a control unit which engages the engaging element in a state where the lockup clutch is engaged if an accelerator opening becomes not smaller than a predetermined opening during neutral running control in which the automatic transmission is brought into a power shut-off state during running of the vehicle.