Patent classifications
F16H2061/6615
SHIFT CONTROL DEVICE
A shift control device has stepless and stepped shift modes in which a transmission gear ratio of a continuously variable transmission is controlled in stepless and stepwise fashions, respectively, and includes a mode setting unit that switches the shift mode to the stepped shift mode if an engine rotation speed in the stepless shift mode exceeds a switch threshold, a correction-value setting unit that sets a correction value based on the engine rotation speed if the shift mode is to be switched to the stepped shift mode, a shift-threshold setting unit that sets a shift threshold by adding the correction value to the switch threshold if the shift mode is to be switched to the stepped shift mode, and an upshift controller that switches the transmission gear ratio toward a higher side when the engine rotation speed in the stepped shift mode reaches the shift threshold.
SHIFT CONTROL DEVICE
A shift control device includes: a stepless shift controller executing a stepless shift mode and controlling a transmission gear ratio of a continuously variable transmission in a stepless fashion; a stepped shift controller executing a stepped shift mode and controlling the continuously variable transmission using fixed transmission gear ratios; a mode setting unit switching the shift mode to the stepped shift mode when a vehicle is to be accelerated; and a transmission-gear-ratio setting unit setting an initial transmission gear ratio in the stepped shift mode when the shift mode is to be switched to the stepped shift mode. The transmission-gear-ratio setting unit estimates a variation in an engine rotation speed when the shift mode is to be switched to the stepped shift mode, and sets a fixed transmission gear ratio, at which the variation is greater than or equal to a lower limit value, as the initial transmission gear ratio.
CONTROL DEVICE FOR CONTINUOUSLY VARIABLE TRANSMISSION AND CONTROL METHOD FOR CONTINUOUSLY VARIABLE TRANSMISSION
A continuously variable transmission is mounted in a vehicle, and includes a primary pulley, a secondary pulley, and a belt, wherein the belt is wound around the primary pulley and the secondary pulley. A control device performs a low speed position return control by a feedback control employing a control input integral component. The low speed position return control is to control a transmission ratio to a final target transmission ratio for lower speed position while the vehicle is decelerating. The control device performs a limiting control in response to a condition that the transmission ratio has reached the final target transmission ratio during the low speed position return control. The limiting control is to limit the control input integral component based on thrust balance between the primary pulley and the secondary pulley so as to maintain the transmission ratio at the final target transmission ratio.
Transmission control method and transmission control device for continuously variable transmission
A transmission control method has a normal stepless manner transmission mode and a pseudo-stepped downshift mode for controlling a continuously variable transmission connected to an input side of an engine. A downshift target rotational speed and a lower-limit target rotational speed used for the pseudo-stepped downshift are set to values in an engine rotational speed region in which an engine output becomes greater than or equal to a prescribed value. When a mode transition condition is satisfied during deceleration by selecting the normal transmission mode, the mode is shifted to the pseudo-stepped downshift mode to start the pseudo-stepped downshift. When the pseudo-stepped downshift is initiated, an increase to the downshift target rotational speed and a decrease to the lower-limit target rotational speed of the primary rotational speed are repeated, until the mode cancellation condition, including the re-acceleration request, is satisfied.
EXCAVATOR AND METHOD OF CONTROLLING EXCAVATOR
An excavator includes a lower travelling body; an upper turning body mounted on the lower travelling body; a hydraulic pump installed in the upper turning body; a travelling hydraulic motor that is a variable displacement type motor configured to move the lower travelling body by being driven by hydraulic oil discharged by the hydraulic pump; and a control device configured to control a motor capacity of the travelling hydraulic motor so as to be switchable between a plurality of levels. The control device switches the motor capacity to a low rotation setting upon detecting that an operation for changing a travelling direction of the lower travelling body is performed.
VEHICLE CONTROL DEVICE
A vehicle control device is provided which is capable of properly satisfying an acceleration request from a driver even when the driver performs a step-on operation of an accelerator pedal in the implementation of an ACC mode. The vehicle control device is capable of: a front car follow-up travel mode, in which a driving force and a transmission ratio are controlled based on a first accelerator position (AP1) for an inter-vehicle distance to a preceding vehicle to be a target inter-vehicle distance; and an override mode, in which the driving force and the transmission ratio are controlled based on a second accelerator position (AP2) determined by an operation of an accelerator operator performed by a driver. Compared with a second transmission characteristic selected in the override mode, in a first transmission characteristic selected in the front car follow-up travel mode, a threshold of the accelerator position at which at least downshift of a transmission (TM) occurs is set to a higher value or an amount of change of the transmission ratio along with the downshift of the transmission (TM) is set to a lower value.
Automatic transmission and control method therefor
In a vehicle having a continuously variable transmission, a controller selectively performs a first control mode in which a transmission ratio is controlled in a stepless manner, and a second control mode in which the transmission ratio is controlled in a stepwise manner to perform an upshift after a vehicle speed has increased. When the second control mode is selected in response to a driver's acceleration request, the controller continuously downshifts the transmission ratio until the upshift is performed.
Control apparatus for vehicle
The control apparatus for a vehicle includes a determination unit that determines whether or not a start condition is established, the start condition including when a torque converter is in a lockup state, and when the vehicle is in an accelerating state; and a display control unit that causes an acting number of rotations to be displayed on a tachometer instead of an actual number of rotations when it is determined by the determination unit that the start condition is established. The display control unit calculates the acting number of rotations based on a target value of an input number of rotations of a continuously variable transmission, and varies the acting number of rotations with a rate of change having an absolute value that is greater than an absolute value of a rate of change of the actual number of rotations upon an abrupt change in the target value.
HYBRID VEHICLE
In a hybrid vehicle, when the engine is started and caused to make a transition from a stopped state into an operating state, the control device performs an operation control of the rotary machine and an output control of the engine to increase the rotation speed of the engine so that the rotation speed reaches a target rotation speed after the transition of the engine into the operating state, determined by the shifting control, and during increasing the rotation speed, when suppression conditions further including a condition that a vehicle speed is equal to or lower than a predetermined vehicle speed, and a condition that an output request amount by a driver is smaller than a predetermined output request amount, are satisfied, the control device suppresses an increase rate of the rotation speed until a predetermined time elapses from an initiation of starting of the engine are not satisfied.
Control device and control method for continuously variable transmission
A speed change ECU for a CVT sets a target input rotational speed (Nin*) such that the speed ratio of the CVT is varied stepwise a plurality of times consecutively to the downshift side in response to an operation to depress a brake pedal by a driver, and sets the target input rotational speed (Nin*) such that the time interval between consecutive downshifts becomes longer as the number of times of execution of downshifts is increased on the basis of intershifting times (tint(1)), (tint(2)), . . . while downshifts in which the speed ratio is varied stepwise are executed consecutively.