Nissan Motor Company Limited

Katsuyoshi Ogawa

Atsuhiro Mori

Shunichi Mitsuishi

Tetsu Takaishi

Makoto Morita

Eigo Sakagami

Egio Sakagami

A vehicle control device includes a sensor, a transfer case and a controller. The sensor detects a yaw rate of a vehicle. The transfer case distributes a drive force from a motive power source to front wheels and rear wheels. The controller determines a road surface friction coefficient to be low upon detecting an absolute value of the yaw rate during forward travel of the vehicle to be equal to or greater than a prescribed value other than zero, determines the road surface friction coefficient to be high upon detecting the absolute value is less than prescribed value, and controls a distribution amount of the transfer case based on a determination result of the road surface friction coefficient.

Vehicle control method and vehicle control device

A vehicle control device includes sensors that detect pulse signals corresponding to rotation of front wheels and of rear wheels of a vehicle, and a controller that increases a count at a rise and a fall of the pulse signals. The controller estimates a road surface friction coefficient based on a time rate of change of a difference between a value counted up using the front wheels and a value counted up using the rear wheels.

Control method of vehicle, and control device of the vehicle

A vehicle clutch control device is provided for switching from a two-wheel drive traveling to a four-wheel drive traveling. The vehicle clutch control device includes a dog clutch that separates a rear wheel drive from a front wheel drive by releasing the dog clutch, an electronically controlled coupling that distributes a driving force of a transverse engine to left and right rear wheels in accordance with a clutch connection capacity, and a four-wheel drive control unit. The four-wheel drive control unit switches the drive mode to one of a disconnect two-wheel drive mode in which the dog clutch and the electronically controlled coupling are released, a connect four-wheel drive mode in which the dog clutch and the electronically controlled coupling are engaged, and a stand-by two-wheel drive mode in which the dog clutch is engaged while the electronically controlled coupling is released.

Clutch control device for four-wheel-drive vehicle

A clutch control device is provided for a four-wheel drive vehicle for transmitting drive force to the rear wheels. The clutch control device includes a dog clutch and a friction clutch, and a 4WD control unit that controls the engagement and disengagement of the dog clutch and the friction clutch. The 4WD control unit is switchable between a two-wheel drive mode and a four-wheel drive mode. The 4WD control unit is programmed to control engagement of the dog clutch so that the dog clutch is engaged after the friction clutch is engaged and the dog clutch is synchronized. During engagement of the dog clutch, the 4WD control unit is programmed to reduce a transmission torque of the friction clutch when the dog clutch engagement standby state is detected.

Clutch control device for four-wheel drive vehicle

A clutch control device is provided for a four-wheel drive vehicle for transmitting drive force to the rear wheels. The clutch control device includes a dog clutch and a friction clutch, and a controller that controls the engagement and disengagement of the dog clutch and the friction clutch. In this clutch control device, when there is a request to engage the dog clutch from a disengaged state, the controller, during the engagement control of the friction clutch, first controls the engagement of the friction clutch, monitors the change gradient of the clutch rotational speed difference of the dog clutch and starts engagement of the dog clutch upon determining that the gradient of the clutch rotational speed difference is no longer decreasing.

Clutch control device for 4-wheel drive vehicle

A clutch control device is provided for a four-wheel drive vehicle for transmitting drive force to the rear wheels. The clutch control device includes a dog clutch and a friction clutch, and a 4WD control unit that controls the engagement and disengagement of the dog clutch and the friction clutch. The 4WD control unit has as two-wheel drive modes, a disconnected two-wheel drive mode in which the dog clutch and the friction clutch are released, and a standby two-wheel drive mode in which the dog clutch is engaged and the friction clutch is released. The 4WD control unit is programmed to switch to the standby two-wheel drive mode when uphill movement is detected during the disconnected two-wheel drive mode.

A clutch control device is provided for a 4-wheel drive vehicle. The clutch control device includes a 4WD control unit that controls the engagement and release of a friction clutch and a dog clutch which are arranged separately in the two paths. The 4WD control unit has a synchronization speed control unit, and at a time of transition from a disconnected, two-wheel drive mode, in which the friction clutch and the dog clutch are released, to a connected, four-wheel drive mode, in which the friction clutch and the dog clutch are engaged, the synchronization speed control unit reduces a synchronization speed of the dog clutch more during vehicle deceleration than when the vehicle is not decelerating.

A clutch control device is provided for a four-wheel drive vehicle for transmitting drive force to the rear wheels. The clutch control device includes a dog clutch and a friction clutch, and a controller that controls the engagement and disengagement of the dog clutch and the friction clutch. In this clutch control device, the four-wheel drive hybrid vehicle includes a disconnected, two-wheel drive mode and a connected, four-wheel drive mode. When a driver's foot is lifted off an accelerator in a low-speed region when the connected, four-wheel drive mode is selected, the 4WD control unit maintains the connected, four-wheel drive mode while the brakes are not depressed, and shifts the mode to the disconnected, two-wheel drive mode when the brakes are depressed.

A clutch control device is provided for a four-wheel drive vehicle for transmitting drive force to the rear wheels. The clutch control device includes a dog clutch and a friction clutch, and a controller that controls the dog clutch and the friction clutch. The controller starts the engagement of the dog clutch, after placing the dog clutch in a rotationally synchronized state by engaging the friction clutch and increasing an output rotation thereof, when there is a request to engage the dog clutch. In this clutch control device, the controller sets the engagement start timing of the friction clutch when a transition is made to the connected, four-wheel drive mode to an earlier timing compared to when a transition is made to the standby two-wheel drive mode, when there is a request to engage the dog clutch while in a state in which the disconnected, two-wheel drive mode is selected.

A clutch control device is provided for a four-wheel drive vehicle. The clutch control device is able to suppress the elevation of the temperature of the oil supplied to a friction clutch during two-wheel drive travel when the friction clutch is released. The clutch control device includes a dog clutch and an electronic control coupling. The friction clutch is housed in a coupling case. When the dog clutch and the friction clutch are released, a two-wheel drive mode is selected. The coupling case has a passage opening that is closed to retain lubrication oil in an oil chamber with respect to a clutch chamber that houses the friction clutch. When oil stirring conditions are met thereafter, the passage opening is opened and the lubrication oil is allowed to flow into the clutch chamber from the oil chamber.

A drive force distributing device includes first and second rollers rotatable jointly with main a drive wheel system and a subordinate drive wheel system, respectively. Control of the drive force distribution between the main drive wheels and the subordinate drive wheels is performed by adjusting an inter-roller pressing force. A structural body suppresses turning of one of the first and second rollers at a predetermined position. A reference position setting mechanism turns either one of the first and second rollers to turn in one direction, detects a position at which the turn is suppressed by the structural body, and sets a reference position based on the detected position. A turning amount of one of the first and second rollers is detected with respect to the reference position set by the reference position setting mechanism and the control of drive force distributing is performed based on the detected turning amount.

Drive force distributing apparatus

A friction gearing has housing and a unit housed in the housing, the unit including a first roller, a second roller and rotatable support plates. The first roller and the second roller are in frictional engagement with each other under a radial pressing force. The radial pressing force is variable in response to a change in the radial distance between the first and the second roller. The rotatable support plates support the first and the second rollers and receive a resisting force that is generated when the first and the second rollers come in contact under the pressing force. The unit is received in the housing with the axis of rotation of the first roller radially fixed while the first roller is rotatably supported by the housing.

Friction gearing

A vehicle drive force distributing apparatus includes an irreversible transmission mechanism, an operating state determining component and a command value resolution switching component. The irreversible transmission mechanism prevents a radially oriented pressing force, generated between first and second rollers based on an inter-roller radial pressing force command value, from decreasing during a period while command value is constant to maintain the radially oriented pressing force at a prescribed value without operating an inter-roller radial pressing force generating source. The operating state determining component determines whether first or second vehicle operating states exists during which a first or a lower second precision level of drive force distribution control, respectively, is to occur between main and subordinate drive wheels. The command value resolution switching component provides the inter-roller radial pressing force command value at a constant value for a longer period during the second vehicle operating state.

Growing community of inventors

Kanagawa, Japan

Katsuyoshi Ogawa