Nissan Motor Company Limited

Unisia Jecs Corporation

Atsuhiro Mori

Katsuyoshi Ogawa

Shunichi Mitsuishi

Tetsu Takaishi

Makoto Morita

Eigo Sakagami

Takashi Murasugi

Masanori Koda

Shouichi Tsuchiya

Takeshi Yamamoto

Hirotaka Kusukawa

Shinichi Suzuki

Tatsuya Morishita

Takeshi Kariya

Katsuhiko Sando

Shinji Kiyohara

Takuma Hayashi

In the present invention, when a road surface condition is determined based on information acquired by a camera installed in a vehicle, a route of a host vehicle is predicted and the is determined. A road surface condition determination method and device determines a road surface condition of a predicted route based on information acquired by a camera installed in a host vehicle. A controller predicts a route of the host vehicle by determining a road surface friction coefficient of the predicted route based on information acquired by the camera. The determining of the road surface friction coefficient of the predicted route includes: dividing an ahead-of-vehicle image acquired by the camera in a left-right direction and determining a road surface condition for each of the determination areas, and determining the road surface friction coefficient in the determination areas through which the predicted route will pass.

Road condition determination method and road condition determination device

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 driving force distribution device includes a first friction roller that rotates together with a rotating member constituting a torque-transmitting path to the main driving wheel; a second friction roller that rotates together with a rotating member constituting a torque-transmitting path to the auxiliary driving wheel; and an inter-roller radial press section that presses the first and second friction rollers in radial directions of the first and second friction rollers into pressing contact with one another, to allow torque transmission between the first and second friction rollers, wherein the inter-roller radial press section sets a radial pressing force between the first and second friction rollers to limit torque input to the auxiliary driving wheel by allowing slippage between the first and second friction rollers when a maximum torque is inputted to the driving force distribution device under a condition that torque distribution to the auxiliary driving wheel is maximized.

Driving force distribution device

A torque distributor includes a friction-drive mechanism having a first roller rotatable together with a first rotary member, partly constituting a torque-transmission path to primary drive wheels, and a second roller rotatable together with a second rotary member, partly constituting a torque-transmission path to secondary drive wheels. Also provided is an eccentric-crank mechanism for revolving the second roller in a direction opposite to a rotation direction of power transmission of the second roller around an eccentric-shaft axis displaced from a second-roller rotation axis to produce a displacement of the second roller from a non-power-transmission position of non-frictional-contact with the first roller, thereby ensuring high-precision torque-distribution control with no reversal of a polarity of moment acting on a rotational-position-control system for eccentric cranks.

Torque distributor

[Problem] A two-wheel&#x2192;four-wheel drive switching for a traction-transmitting part time four-wheel drive vehicle in which a gear clutch for separating one of auxiliary driving wheels from a drive train is equipped can be carried out under a shock reduction. [Means for solving problem] In a case where a two-wheel&#x2192;four-wheel drive switching request occurs during a traveling of the vehicle (step Sand step S), an operation of switching a traction-transmitting transfer from a non-transmitting state to a transmitting state is preceded (step Sand step S) and, thereafter, the gear clutch is engaged (step Sand step S) when a revolution speed difference &#x394;Vw between main and auxiliary driving wheels is 0&#x3c;&#x394;Vw&#x3c;&#x3b1; along with an advance of the state switching of the transfer so that large shock and abnormal sound are not generated even if the gear clutch is switched from a released state to an engagement state.

Growing community of inventors

Kanagawa, Japan

Atsuhiro Mori