Abstract: A four-wheel-drive vehicle includes: an engine as a driving source; a right front wheel and a left front wheel as main driving wheels and a right rear wheel and a left rear wheel as sub-driving wheels that are driven by a driving force of the engine; a driving force transmission device that transmits part of the driving force of the engine to the right rear wheel and the left rear wheel; and a control device that controls the driving force transmission device. The control device is configured to, when the four-wheel-drive vehicle moves straight forward, adjust the driving force transmitted to the right rear wheel and the left rear wheel by the driving force transmission device so as to maintain a state where the magnitude of a front-rear force generated in the right front wheel and the left front wheel is greater than zero.

Abstract: A driving force transmission control device includes a driving force transmission device configured to press a friction clutch by an actuator and a controller configured to control the driving force transmission device. The controller calculates a torque command value indicating a driving force to be transmitted from a rotating member on an input side to a rotating member on an output side based on information of a vehicle. The controller sets an electric current command value according to a magnitude and an amount of time change of the torque command value. The electric current command value is a target value of an electric current. The controller performs electric current feedback control such that an electric current corresponding to the calculated electric current command value is supplied to the actuator.

Abstract: A driving force transmission device includes an input rotation member and output rotation member, a multiple-disc clutch, a pressing mechanism, and a control device that includes a current supply circuit. The control device is configured to compute a torque command value based on a state of a vehicle, the torque command value being a driving force that needs to be transmitted by the multiple-disc clutch, to compute a current command value, to correct the current command value, and to control the current supply circuit such that an electric current depending on the current command value is supplied to the pressing mechanism. The control device is configured to perform the correction so as to increase or decrease the current command value by a correction amount depending on a change rate of the torque command value.

Abstract: A four-wheel drive vehicle includes right and left main drive wheels and right and left auxiliary drive wheels, and a drive force transmission system configured to constantly transmit a drive force of a drive source to the right and left main drive wheels and to transmit the drive force to the right and left auxiliary drive wheels depending on a vehicle state. The drive force transmission system includes a differential device, a propeller shaft, a drive force transmission device configured to adjust the drive force that is transmitted from the propeller shaft to the right and left auxiliary drive wheels, and an electronic control unit configured to control the drive force transmission device.

Abstract: A vehicle control device mounted on a four-wheel drive vehicle including a driving force transmission system includes an electronic control unit. The electronic control unit calculates a command torque based on vehicle information. The electronic control unit estimates a temperature of a heat generating location in the driving force transmission system based on the command torque. The electronic control unit estimates the temperature of the heat generating location based on an estimated value of a driving force input to an input rotating member, when it is not possible for the driving force corresponding to the command torque to be transmitted to auxiliary drive wheels due to a magnitude of the driving force generated by a drive source or occurrence of a wheel slip.

Abstract: A driving force transmission device includes an input rotation member, an output rotation member, a multiple-disc clutch, a pressing mechanism, and a control device including a current supply circuit. The control device is configured to compute a torque command value, to compute a current command value, to correct the current command value, and to control the current supply circuit such that an electric current depending on the current command value is supplied to the pressing mechanism. The control device is configure to correct the current command value by a correction amount in a constant-torque state after the torque command value changes, the constant-torque state being a state where a change rate of the torque command value is in a predetermined range, the correction amount depending on a duration of the constant-torque state.

Abstract: A driving force transmission control device includes a driving force transmission device configured to press a friction clutch by an actuator and a controller configured to control the driving force transmission device. The controller calculates a torque command value indicating a driving force to be transmitted from a rotating member on an input side to a rotating member on an output side based on information of a vehicle. The controller sets an electric current command value according to a magnitude and an amount of time change of the torque command value. The electric current command value is a target value of an electric current. The controller performs electric current feedback control such that an electric current corresponding to the calculated electric current command value is supplied to the actuator.

Abstract: A vehicle control device mounted on a four-wheel drive vehicle including a driving force transmission system includes an electronic control unit. The electronic control unit calculates a command torque based on vehicle information. The electronic control unit estimates a temperature of a heat generating location in the driving force transmission system based on the command torque. The electronic control unit estimates the temperature of the heat generating location based on an estimated value of a driving force input to an input rotating member, when it is not possible for the driving force corresponding to the command torque to be transmitted to auxiliary drive wheels due to a magnitude of the driving force generated by a drive source or occurrence of a wheel slip.

Abstract: A driving force transmission device includes an input rotation member and output rotation member, a multiple-disc clutch, a pressing mechanism, and a control device that includes a current supply circuit. The control device is configured to compute a torque command value based on a state of a vehicle, the torque command value being a driving force that needs to be transmitted by the multiple-disc clutch, to compute a current command value, to correct the current command value, and to control the current supply circuit such that an electric current depending on the current command value is supplied to the pressing mechanism. The control device is configured to perform the correction so as to increase or decrease the current command value by a correction amount depending on a change rate of the torque command value.

Abstract: A driving force transmission device includes an input rotation member, an output rotation member, a multiple-disc clutch, a pressing mechanism, and a control device including a current supply circuit. The control device is configured to compute a torque command value, to compute a current command value, to correct the current command value, and to control the current supply circuit such that an electric current depending on the current command value is supplied to the pressing mechanism. The control device is configure to correct the current command value by a correction amount in a constant-torque state after the torque command value changes, the constant-torque state being a state where a change rate of the torque command value is in a predetermined range, the correction amount depending on a duration of the constant-torque state.

Abstract: A four-wheel drive vehicle includes right and left main drive wheels and right and left auxiliary drive wheels, and a drive force transmission system configured to constantly transmit a drive force of a drive source to the right and left main drive wheels and to transmit the drive force to the right and left auxiliary drive wheels depending on a vehicle state. The drive force transmission system includes a differential device, a propeller shaft, a drive force transmission device configured to adjust the drive force that is transmitted from the propeller shaft to the right and left auxiliary drive wheels, and an electronic control unit configured to control the drive force transmission device.

Abstract: A driving force control apparatus includes a first torque calculator configured to calculate turning radius correspondence torques indicating the magnitudes of the driving forces to be transmitted to a right rear wheel and a left rear wheel based on a turning radius, a second torque calculator configured to calculate steering velocity response torques based on a steering velocity of a steering wheel and a vehicle speed, a corrector configured to calculate a corrected torque by correcting a turning radius correspondence torque of at least one of wheels on an inner side of turning and on an outer side of turning in accordance with the steering velocity response torque, and a current controller configured to supply currents to torque couplings so that driving forces based on the corrected torque are transmitted.

Abstract: A four-wheel drive vehicle includes a dog clutch that selectively interrupts transmission of a drive force to a propeller shaft, first and second multi-plate clutches that selectively interrupt transmission of the drive force from the propeller shaft to left and right rear wheels, first and second pistons that press the first and second multi-plate clutches, and a hydraulic circuit that supplies hydraulic oil to first and second cylinder chambers. During a transition to a four-wheel drive mode, torque transmitted through the first multi-plate clutch increases the speed of rotation of the propeller shaft so as to engage the dog clutch, and the second multi-plate clutch is kept from transmitting torque to the propeller shaft.

Abstract: A driving force transmission control apparatus includes: a driving force transmission device that includes an electromagnetic clutch mechanism configured to generate a frictional force between clutch plates by energization of an electromagnetic coil and transmits a driving force by actuating the electromagnetic clutch mechanism; and a control device that controls the driving force transmission device.

Abstract: A drive force control device, which controls a drive force distribution device that distributes a drive force to right and left rear wheels at variable distribution ratios, computes a steering angle-based turning radius determined in accordance with a steering angle, computes a limit turning radius, which is a minimum value of the turning radius with which the vehicle is turnable while keeping a stable travel state, in accordance with a vehicle speed, sets the larger one of the steering angle-based turning radius and the limit turning radius as a target turning radius, computes target rotational speeds for the right and left rear wheels on the basis of the target turning radius and the vehicle speed, and adjusts the ratios of distribution of the drive force to the right and left rear wheels such that actual rotational speeds of the right and left rear wheels approximate the target rotational speeds.

Abstract: A control apparatus for a four-wheel drive vehicle includes a current detector configured to output a detection signal in accordance with the magnitude of an actual control current, a target current value calculator configured to calculate a target current value that is a target value of the control current, and a current controller configured to control a current output circuit to output the control current having the target current value calculated by the target current value calculator based on a result of detection performed by the current detector. When the four-wheel drive vehicle is in a two-wheel drive mode in which first and second friction clutches are released, the current controller performs zero-point adjustment for adjusting a zero point of the control current to be output from the current output circuit.

Abstract: A controller for a driving force transmitting apparatus mounted in a four-wheel-drive vehicle, includes: a driving force controller configured to calculate a command torque indicating a driving force to be transmitted to the sub-drive wheels via the driving force transmitting apparatus based on a traveling state of the four-wheel-drive vehicle and a road surface condition, and to control the driving force transmitting apparatus based on the command torque; and a road surface condition determiner configured to determine that the road surface condition is a high-? condition when a duration of a non-slipping state where a vehicle speed is equal to or higher than a prescribed value and a slip ratio of each of both the main drive wheels is lower than a prescribed value has become equal to or longer than a prescribed time.

Abstract: A control device mounted on a four-wheel drive vehicle includes: a slip ratio calculating unit that obtains a slip ratio of main driving wheels based at least on wheel speeds; a smoothing unit that smooths the slip ratio by filtering; and a driving force control unit that controls a driving force transmission device so that a driving force that is transmitted to auxiliary driving wheels increases as the slip ratio smoothed by the smoothing unit increases.

Abstract: A driving force transmission control apparatus includes: a driving force transmission device that includes an electromagnetic clutch mechanism configured to generate a frictional force between clutch plates by energization of an electromagnetic coil and transmits a driving force by actuating the electromagnetic clutch mechanism; and a control device that controls the driving force transmission device.

Abstract: A driving force control apparatus includes a first torque calculator configured to calculate turning radius correspondence torques indicating the magnitudes of the driving forces to be transmitted to a right rear wheel and a left rear wheel based on a turning radius, a second torque calculator configured to calculate steering velocity response torques based on a steering velocity of a steering wheel and a vehicle speed, a corrector configured to calculate a corrected torque by correcting a turning radius correspondence torque of at least one of wheels on an inner side of turning and on an outer side of turning in accordance with the steering velocity response torque, and a current controller configured to supply currents to torque couplings so that driving forces based on the corrected torque are transmitted.