Abstract: A method for manufacturing a liquid cooling jacket has a feature of using a primary joining rotary tool provided with a tip side pin and a base side pin having a taper angle larger than a taper angle of the tip side pin and comprising a first primary joining process in which inserting the tip side pin and the base side pin of the rotary tool that is rotating into the sealing body member and moving the rotary tool along the first abutted portion with an outer circumferential face of the base side pin being in contact with a front face of the sealing body member and with the outer circumferential face of the tip side pin being kept off a step side face of the peripheral wall step portion while having a second aluminum alloy of the sealing body member flow into the gap.

Abstract: A heat transfer plate manufacturing method in which a tip end-side pin of a rotation tool, as rotating, is inserted into a butt part, and friction stirring is performed with an outer peripheral surface of a base end-side pin in contact with a front surfaces of a base member and a lid plate, with the base end-side pin and a flat surface in contact with the base member and the lid plate, and with a tip end surface of a protrusion part in contact with only the base member, is provided.

Abstract: Provided is a method for manufacturing a liquid cooling jacket including a jacket body and a sealing body joined to the jacket body. The method includes steps of: preparing; placing; first primary joining with a rotary tool; and second primary joining with the rotary tool. The rotary tool includes a base end pin and a distal end pin. The distal end pin includes a flat surface and a protrusion protruding from the flat surface. In the first primary joining and the second primary joining, friction stirring is performed in a state where the jacket body and the sealing body are brought in contact with the flat surface of the distal end pin and the base end pin and only the jacket body is brought in contact with a distal end surface of the protrusion.

Abstract: Provided is a method for manufacturing a liquid-cooled jacket, to reduce the size of a recessed groove on a surface of a metal member and also to reduce roughness of a jointed surface. The method includes: a placing step of placing a sealing body on a jacket body, a first main joining step of performing friction stirring by moving a main joining rotary tool around to a first overlapped portion, and a second main joining step of performing friction stirring to a second overlapped portion. The main joining rotary tool has a base-end-side pin and a tip-end-side pin. A taper angle of the base-end-side pin is greater than a taper angle of the tip-end-side pin and a stairs-like pin step portion is formed on an outer circumferential surface of the base-end-side pin.

Abstract: Provided is a vehicle steering system that is able to restrict a travel amount of a steered shaft in a housing, that is small and that has an excellent strength. The vehicle steering system is a steer-by-wire vehicle steering system that converts rotative power of electric motors into a movement of a steered shaft in an axial direction via a ball screw mechanism. One of contact portions at respective ends of a screw shaft at an intermediate part of the steered shaft passes through a rotor based on a moving direction of the steered shaft so as to contact a corresponding one of the corresponding stoppers thereby restricting a travel amount of the steered shaft. The stoppers are made of a material different from that of the housing and having a high strength.

Abstract: Provided is a vehicle steering system that is able to restrict a travel amount of a steered shaft in a housing, that is small and that has an excellent strength. The vehicle steering system is a steer-by-wire vehicle steering system that converts rotative power of electric motors into a movement of a steered shaft in an axial direction via a ball screw mechanism. One of contact portions at respective ends of a screw shaft at an intermediate part of the steered shaft passes through a rotor based on a moving direction of the steered shaft so as to contact a corresponding one of the corresponding stoppers thereby restricting a travel amount of the steered shaft. The stoppers are made of a material different from that of the housing and having a high strength.

Abstract: Provided is a vehicle steering system that is able to restrict a travel amount of a steered shaft in a housing, that is small and that has an excellent strength. The vehicle steering system is a steer-by-wire vehicle steering system that converts rotative power of electric motors into a movement of a steered shaft in an axial direction via a ball screw mechanism. One of contact portions at respective ends of a screw shaft at an intermediate part of the steered shaft passes through a rotor based on a moving direction of the steered shaft so as to contact a corresponding one of the corresponding stoppers thereby restricting a travel amount of the steered shaft. The stoppers are made of a material different from that of the housing and having a high strength.

Abstract: A ball screw device has a plurality of spiral raceways. One end and the other end of each raceway is connected via a bridge. An annular flange of a ball nut has a plurality of mounting portions at equal intervals in a circumferential direction. A fixing screw is fitted to each mounting portion. The bridges arranged so as to overlap with the annular flange in position in an axial direction are arranged at positions different in the circumferential direction from positions at which the mounting portions are arranged, and are arranged at unequal intervals in the circumferential direction.

Abstract: There are provided a ball screw that makes it possible to prevent a situation where a large load is applied to a part of a plurality of balls, and an electric power steering system including the ball screw. The ball nut is a component that surrounds a part of the male thread groove, and has a nut inner surface and a female thread groove. The female thread groove is formed in the nut inner surface, and forms a part of the rolling path. A female thread diameter varies according to a position in an axial direction of the ball nut. The female thread diameter is larger at each axial end of the ball nut than at an axially intermediate portion of the ball nut, and the female thread diameter is larger at one axial end than at the other axial end.

Abstract: A vehicle steering system includes a steered shaft, and stoppers which restrict an amount of movement of the steered shaft in an axial direction. The steered shaft has first outer peripheral faces, second outer peripheral faces, and annular stepped portions. Each stepped portion includes a contact portion that faces a corresponding one of the stoppers in the axial direction, a first corner portion that has a concave curved sectional shape and connects the first outer peripheral face to an inner end of the contact portion, and a second corner portion that has a concave curved sectional shape with a larger curvature radius than that of the first corner portion, and connects the first outer peripheral face to the second outer peripheral face, at a position in front of or behind a central axis of the steered shaft.

Abstract: There are provided a ball screw that makes it possible to prevent a situation where a large load is applied to a part of a plurality of balls, and an electric power steering system including the ball screw. The ball nut is a component that surrounds a part of the male thread groove, and has a nut inner surface and a female thread groove. The female thread groove is formed in the nut inner surface, and forms a part of the rolling path. A female thread diameter varies according to a position in an axial direction of the ball nut. The female thread diameter is larger at each of axially ends of the ball nut than at an axially intermediate portion of the ball nut, and the female thread diameter is larger at one of the axially ends than at the other of the axially ends.

Abstract: A rear wheel steering system includes a rack shaft, a neutral position locking apparatus that restricts the movement of the rack shaft in a rack axis direction, and a pin-driving device that drives a restriction pin. The neutral position locking apparatus has the restriction pin and a pin-receiving portion formed in the rack shaft. The restriction pin has a first pin-sidewall portion slanted with respect to a pin axis and a second pin-sidewall portion parallel to the pin axis. The pin-receiving portion has a first shaft-sidewall portion that contacts the first pin-sidewall portion when the position of the rack shaft in the rack axis direction is at a neutral position, and a second shaft-sidewall portion that contacts the second pin-sidewall portion when the position of the rack shaft in the rack axis direction is at a restriction position different from the neutral position.

Abstract: Provided is a vehicle steering system that is able to restrict a travel amount of a steered shaft in a housing, that is small and that has an excellent strength. The vehicle steering system is a steer-by-wire vehicle steering system that converts rotative power of electric motors into a movement of a steered shaft in an axial direction via a ball screw mechanism. One of contact portions at respective ends of a screw shaft at an intermediate part of the steered shaft passes through a rotor based on a moving direction of the steered shaft so as to contact a corresponding one of the corresponding stoppers thereby restricting a travel amount of the steered shaft. The stoppers are made of a material different from that of the housing and having a high strength.

Abstract: A ball screw device has a plurality of spiral raceways. One end and the other end of each raceway is connected via a bridge. An annular flange of a ball nut has a plurality of mounting portions at equal intervals in a circumferential direction. A fixing screw is fitted to each mounting portion. The bridges arranged so as to overlap with the annular flange in position in an axial direction are arranged at positions different in the circumferential direction from positions at which the mounting portions are arranged, and are arranged at unequal intervals in the circumferential direction.

Abstract: A configuration is provided which includes a differential gear-type transfer ratio varying mechanism interposed between an input shaft which rotates as a steering wheel is operated and an output shaft which rotates in conjunction with operation of a steering mechanism for permitting a differential operation between both the shafts, the configuration including a transfer ratio control motor for applying a rotational force to the output shaft, a reaction force control motor for applying a rotational force to the input shaft, and a steering control unit for controlling and driving the transfer ratio control motor to obtain a rotation transfer ratio that is predetermined according to operation of the steering wheel and controlling and driving the reaction force control motor to apply a predetermined reaction force to the steering wheel.

Abstract: A variable stiffness stabilizer device (1) has a stabilizer bar (2) and actuators (3). The stabilizer bar (2) has a torsion bar (4) extending in the lateral direction (X1) of a vehicle and arms (6) connected through bend portions (5) to the ends (4a, 4b) of the torsion bar (4) and bendingly deformed according to the strokes of wheel supporting members (11). Variable bending stiffness parts (13; 130) of the arms (6) are rotatable about the axes (C1) of the arms (6), so that the bending stiffness of the arms (6) can be changed according to their rotational positions. The actuators (3) rotationally drive the variable bending stiffness parts (13; 130) about the axes (C1) to adjust the rotational positions of the variable bending stiffness parts (13; 130).

Abstract: A planet gear mechanism 19 interposed between a steering 2 and steerable wheels 4L and 4R is interposed. A torque controlling motor 25 for controlling a torque acting on the steering 2 and a transmission-rate varying motor 20 for driving the planet gear mechanism 19 are arranged coaxially (on an axial A) with the planet gear mechanism 19. This eliminates the need for arranging each motor 20 and 25 on the both ends of the axis A to face each other, and also reduces a space occupied by the motors 20 and 25 with respect to a radial direction of the axis A. As a result, reduction in the size of an apparatus can be achieved.

Abstract: There is provided a vehicle steering system which includes an electric motor for imparting a steering force to a steering mechanism of a vehicle and an automatic parking controller for executing an automatic parking control by controlling the electric motor, wherein the automatic parking controller controls an energizing voltage of the electric motor by imparting a square wave to the electric motor and increasing/decreasing a neutral point voltage of a winding of the electric motor.

Abstract: A configuration is provided which includes a differential gear-type transfer ratio varying mechanism interposed between an input shaft which rotates as a steering wheel is operated and an output shaft which rotates in conjunction with operation of a steering mechanism for permitting a differential operation between both the shafts, the configuration including a transfer ratio control motor for applying a rotational force to the output shaft, a reaction force control motor for applying a rotational force to the input shaft, and a steering control unit for controlling and driving the transfer ratio control motor to obtain a rotation transfer ratio that is predetermined according to operation of the steering wheel and controlling and driving the reaction force control motor to apply a predetermined reaction force to the steering wheel.

Abstract: A motor vehicle steering apparatus (1) has a transmission-ratio variable mechanism (8) for changing, with the use of a transmission-ratio changing motor (18), the rotational transmission-ratio between a first steering shaft (5) connected to a steering member (2) and a second steering shaft (6) connected to a steering mechanism (12). The apparatus has a counter force compensating motor (23) for compensating steering counter force of the steering member (2) caused by operation of the transmission-ratio variable mechanism (8), a hydraulic steering assist mechanism (80), and a controller (24) for controlling the transmission-ratio changing motor (18) and the counter force compensating motor (23). The controller (24) has a function of causing the counter force compensating motor (23) to generate steering assist torque.