Abstract: In a four-wheel-drive vehicle, a hydraulic unit has an electric motor, to which a motor current is supplied from a control device, and a pump that is actuated by rotation of a motor shaft, and a drive force transfer device has a piston that is moved by the pressure of working oil discharged from the pump, and a friction clutch that is switchable between a transfer state and a blocked state, in which transfer of a drive force to rear wheels is allowed and blocked, respectively, in accordance with movement of the piston. The control device detects the presence or absence of an abnormality of a flow passage forming member, which forms a flow passage for working oil, in accordance with at least any of a motor current and the number of revolutions of a motor shaft at the time when the motor shaft is rotated by applying a voltage to the electric motor.

Abstract: A housing includes a case made of a resin material and having an open side, and a cover that covers the open side of the case. Screw holes that are open toward the cover are formed in a side wall of the case. Through holes are formed in the cover at positions facing the respective screw holes. The cover is fastened to the case by screwing cover bolts into the respective screw holes through the respective through holes. Insertion holes are formed to extend through the side wall in an assembly direction of the cover with respect to the case. The housing is attached to an attachment target made of a metal material, by screwing attachment bolts into respective attachment holes in the attachment target through the respective insertion holes. The attachment bolts are formed to press the cover against the side wall when inserted in the respective attachment holes.

Abstract: A four-wheel-drive vehicle including a powertrain operable to adjust a front- and rear-wheel driving force ratio that is a ratio between a driving force of front wheels and a driving force of rear wheels includes a control device that controls the powertrain and adjusts the front- and rear-wheel driving force ratio so as to reduce the driving force of the front wheels that are steered wheels, when it is detected that emergency avoidance to avoid collision with an avoidance target ahead in a traveling direction is necessary.

Abstract: A driving force distribution apparatus distributes and outputs, to a first clutch hub and a second clutch hub, a driving force input from a driving source. The driving force distribution apparatus includes a clutch housing to which a driving force is input, a first multi-disc clutch disposed between the clutch housing and the first clutch hub, and a second multi-disc clutch disposed between the clutch housing and the second clutch hub. A first pressing mechanism that presses the first multi-disc clutch includes an annular pressing portion disposed between a bottom wall portion of the clutch housing and the first multi-disc clutch, legs inserted in insertion holes formed in the bottom wall portion, and a lubricating oil introduction portion that guides lubricating oil supplied from the clearance between the first clutch hub and the bottom wall portion toward the first multi-disc clutch.

Abstract: A drive force distribution apparatus includes a clutch housing, first and second multi-plate clutches, and a center plate located between the first and second multi-plate clutches. The clutch housing includes a body member having a cylindrical portion and a bottom portion, and a tubular fixation member fixed to part of the cylindrical portion close to an open end. The cylindrical portion of the body member includes a first fit portion to which the first multi-plate clutch is fitted, a second fit portion to which the center plate is fitted, and a third fit portion to which the fixation member is fitted. The center plate is interposed between the fixation member and a step surface between the first fit portion and the second fit portion so as not to allow axial movement of the center plate relative to the body member.

Abstract: An overcurrent protection circuit includes an amplifier configured to amplify an inter-terminal voltage of a shunt resistor, an offset application circuit configured to allow the amplifier to provide an output with a predetermined offset voltage additionally applied thereto, a first comparator that compares an output voltage from the amplifier with a predetermined first reference voltage higher than the offset voltage to output a through-current sensing signal when the output voltage from the amplifier is higher than a first reference voltage, and an amplifier failure determination circuit that compares the output voltage from the amplifier with a predetermined second reference voltage that is higher than zero and lower than the offset voltage to output an amplification circuit failure determination signal corresponding to a result of the comparison.

Abstract: A cylindrical retainer configured to retain balls in a rollable manner is provided inside a ball screw nut. The retainer has retainer grooves each having a shape of an elongated hole that extends in an axial direction of a ball screw shaft so as to be inclined at a predetermined angle. A first end of the ball screw nut and a first end of the retainer, which is one of two ends of the retainer that is closer to the first end of the ball screw nut, are spaced away from each other by a distance. The terminal end of the retainer groove closest to the second end of the retainer and a ball that is closest to the second end of the ball screw nut are spaced away from each other by a distance. The distance is set equal to or larger than the distance.

Abstract: A steering control device includes a microcomputer. The microcomputer is configured to calculate a torque command value that is a target value of a motor torque, set a restricting value that is an upper limit of an absolute value of the torque command value, restrict the absolute value of the torque command value to be equal to or less than the restricting value, control driving of a motor such that the motor torque follows the restricted torque command value, calculate a steering angle restricting value that decreases based on an increase of an absolute value of a rotation angle, and an absolute value of an angular velocity, when the absolute value of the rotation angle of the rotary shaft exceeds a steering angle threshold, and set the restricting value to be a value equal to or less than the steering angle restricting value.

Abstract: A steering control apparatus includes an electronic control unit. The electronic control unit computes a first component of a command value. The electronic control unit computes a target rotation angle of a rotatable element based on an input torque. The rotatable element rotates with an operation of the steering wheel. The electronic control unit computes a second component of the command value through feedback control. The electronic control unit computes an ideal axial force based on the target rotation angle. The electronic control unit shifts the ideal axial force as a function of a cross slope, which is a slope in a direction that intersects at right angles with a road, in a specified direction with reference to a neutral value of the ideal axial force, associated with a state where the vehicle travels straight ahead.

Abstract: A control apparatus controls a steering reaction motor. The control apparatus includes an ideal axial force calculation circuit, an estimated axial force calculation circuit, an imaginary rack end axial force calculation circuit, an axial force allocation calculation circuit and a maximum value selection circuit. The calculation circuits calculate an ideal axial force based on a target pinion angle, an estimated axial force based on a current value of a steering operation motor, an imaginary rack end axial force for imaginarily limiting an operation range of a steering wheel, a mixed axial force obtained by allocating the ideal axial force and the estimated axial force at predetermined allocation ratios. The maximum value selection circuit selects the mixed axial force or the imaginary rack end axial force having a larger absolute value as an axial force to be reflected in the command value.

Abstract: A steering control device includes a control unit, and the control unit includes a target steering angle calculating unit configured to calculate a target steering angle based on a steering torque and is configured to calculate a target reaction torque based on execution of feedback control for causing the steering angle to match the target steering angle. The control unit includes a plurality of axial force calculating units configured to calculate a plurality of kinds of axial forces acting on a turning shaft based on different state quantities and a grip state quantity calculating unit configured to calculate a grip state quantity based on the plurality of kinds of axial forces. The target steering angle calculating unit is configured to calculate the target steering angle in consideration of the grip state quantity.

Abstract: An input torque fundamental component computation circuit includes: a torque command value computation circuit that computes a torque command value corresponding to a target value for steering torque that is to be input by a driver for drive torque obtained by adding the steering torque to an input torque fundamental component; and a torque F/B control circuit that computes the input torque fundamental component through execution of torque feedback control for causing the steering torque to follow the torque command value. A target steering angle computation circuit computes a target steering angle on the basis of the input torque fundamental component. A steering-side control circuit computes target reaction force torque on the basis of execution of angle feedback control for causing a steering angle to follow a target steering angle. The torque command value computation circuit computes the torque command value in consideration of the grip state amount.

Abstract: A bearing includes a cage and rollers disposed between a first raceway surface and a second raceway surface axially facing each other. The cage includes a first guide surface and a second guide surface. The first guide surface is provided on a radially outer portion of the cage, and contacts the first raceway surface when the cage is displaced toward the first raceway surface. A clearance formed between the first guide surface and the first raceway surface is smaller than a clearance at a radially inner portion of the cage. The second guide surface is provided on a radially outer portion of the cage, and contacts the second raceway surface when the cage is displaced toward the second raceway surface. A clearance formed between the second guide surface and the second raceway surface is smaller than a clearance at a radially inner portion of the cage.

Abstract: A needle roller thrust bearing includes an annular cage and a plurality of rollers. The cage includes a plurality of cage pockets that is radially disposed. The plurality of rollers is housed in the cage pockets and disposed between a first raceway surface and a second raceway surface that axially face each other. Lubricating oil flows from a radially inner side to a radially outer side in an annular space in which the cage and the rollers are provided. The cage includes inner grooves and drainage grooves. Each of the inner grooves connects a circumferentially adjacent pair of the cage pockets by connecting radially inner areas of the pair of cage pockets. Each of the drainage grooves has an opening at an outer circumferential surface of the cage to drain lubricating oil in a circumferential area including radially outer areas of the cage pockets.

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 joint structure includes: an output side transmission shaft which rotates integrally with an output shaft of a speed increaser; an input side transmission shaft which rotates integrally with an input shaft of the speed increaser; a fixed housing; a bearing; and a one-way clutch which is fitted in the fixed housing. The one-way clutch integrally rotatably connects the output side transmission shaft and the input side transmission shaft under a condition where a rotation speed of the output shaft is higher than a rotation speed of the input shaft, and releases the connection between the output side transmission shaft and the input side transmission shaft under a condition where the rotation speed of the output shaft is lower than the rotation speed of the input shaft.

Abstract: A common mode noise reduction section performs a first noise reduction process in a first system, a second noise reduction process in a second system and a third noise reduction process in the case where the two systems have a phase, a current for which that flows through a stray capacitance is not canceled out in at least one PWM cycle in a current control cycle after the first noise reduction process is performed and the second noise reduction process is performed. The third noise reduction process includes shifting a PWM count for each phase in the first system by a first predetermined amount and shifting a PWM count for each phase in the second system by a second predetermined amount such that the currents for such a phase which flow through the stray capacitances in the two systems cancel out each other in the relevant PWM cycle.

Abstract: A base current command value is calculated based on a steering torque and a vehicle speed. A desired steering angle value is a constant representing the virtual steering limit position. When a steering angle threshold is set to a value close to, and smaller than, the desired steering angle value, a first correction value is calculated so that a steering reaction force is increased rapidly when a steering angle becomes equal to or larger than the steering angle threshold. A second correction value is calculated so that the steering angle becomes equal to the desired steering angle value when the steering angle becomes equal to or larger than the steering angle threshold. The base current command value is corrected by the first correction value and the second correction value. The driver is thus restrained from turning the steering wheel to a position beyond the desired steering angle value.

Abstract: A method for adjusting a steering system and an adjustment apparatus for a steering system are provided which allow a clearance between a support yoke and a yoke plug to be appropriately set. When a yoke plug is loosened which has been temporarily fastened to a degree that a support yoke is subjected to elastic compressive deformation, the yoke plug is loosened to a position where a clearance C between the support yoke and the yoke plug reaches a target clearance using, as a reference, a position where a rate of a change in an axial position of the yoke plug with respect to an angular position of the yoke plug increases rapidly.

Abstract: A learning procedure involves generating a non-defective product learning model by conducting machine learning using non-defective product data as teacher data, and generating a defective product learning model for each defect type by conducting machine learning for each defect type using defective product data as teacher data. A calculating procedure involves calculating the likelihood of a non-defective product from output data calculated using the non-defective product learning model to which target product data is input, and calculating the likelihood of a defective product for each defect type from output data calculated using the defective product learning model to which the target product data is input. A determining procedure involves determining that the target product data is data on a defective product having an unknown defect when the likelihood of a non-defective product and the likelihood of a defective product for each defect type satisfy a predetermined requirement.