A method for producing a shaft, which is at least partially not circular in cross-section, from a substantially cylindrical blank by means of radial forging, wherein the blank is not rotated in a final radial forging process.

A method for manufacturing a stabilizer, the stabilizer including a main body bar that is elastically deformable, and a pair of connecting plates that are separately connected to a pair of left and right suspension devices, the method including a forging step of forming the connecting plate by forging both end portions of a material tube, in which in the forging step, both end portions of the material tube are crushed in a radial direction to be formed into the connecting plate in a state where a sealing metal plate heated to a temperature equal to or higher than a melting point is disposed inside both end portions of the material tube heated to a temperature lower than the melting point.

A method for manufacturing a stabilizer, the stabilizer including a main body bar that is elastically deformable, and a pair of connecting plates that are separately connected to a pair of left and right suspension devices, the method including a forging step of forming the connecting plate by forging both end portions of a material tube, in which in the forging step, both end portions of the material tube are crushed in a radial direction to be formed into the connecting plate in a state where a sealing metal plate heated to a temperature equal to or higher than a melting point is disposed inside both end portions of the material tube heated to a temperature lower than the melting point.

A method of manufacturing a torsion bar includes cutting a stock torsion bar material to a desired torsion bar length to form the torsion bar. The method also includes forming a first end portion by removing material from the torsion bar to form a first annular groove extending circumferentially about the torsion bar. The method further includes forming a second end portion by removing material from the torsion bar to form a second annular groove extending circumferentially about the torsion bar.

Provided are a hollow drive shaft using an upsetting method and a method of manufacturing the same, in which hot forging and upsetting processes are applied to both ends of a workpiece so that an outer diameter at both ends of the workpiece is greater than an outer diameter of a middle part of the workpiece, thereby reducing a weight of the drive shaft and enabling the drive shaft to transmit higher driving power. According to the present invention, the upsetting process is applied during the hot forging process to manufacture the hollow drive shaft, portions to be substantially processed are limited to portions at both ends of the workpiece, and the number of upsetting processes is limited to a minimum number (2 or the like), such that initial investment costs and manufacturing costs are low because the number of processes is small.

Provided are a motor device and a method for manufacturing the same that can accurately and consistently provide a support shaft to a case and enhance the strength for fixing the support shaft to the case. A small-diameter part having a smaller diameter than a large-diameter part is formed through drawing. The large-diameter part and a step part are embedded in a gear case. The small-diameter part is exposed outside the gear case. The dimensional accuracy (dimensional tolerance ±α) of the external diameter of the small-diameter part is enhanced. The small-diameter part can be set, without rattling, in a lower mold for molding the gear case. Consequently, the support shaft can be accurately and consistently provided to the gear case. Because the large-diameter part and the step part are embedded in the gear case, the resistance of the support shaft against pulling from the gear case can be enhanced.

A method for simply producing components suitable for use under high loads and risks of wear and which have a core portion which consists of a metal material and a wear-resistant layer on a peripheral surface of the core portion is disclosed. A core portion blank is provided and consists of the metal material whose dimension in a first spatial direction is greater than the desired finished dimension of the core and whose second dimension is smaller than the desired finished dimension is provided. A material that forms a wear-resistant layer in the component is applied to a peripheral surface of the core portion blank. The composite body is shaped to form the component. The component may then be optionally finished.

A method for simply producing components suitable for use under high loads and risks of wear and which have a core portion which consists of a metal material and a wear-resistant layer on a peripheral surface of the core portion is disclosed. A core portion blank is provided and consists of the metal material whose dimension in a first spatial direction is greater than the desired finished dimension of the core and whose second dimension is smaller than the desired finished dimension is provided. A material that forms a wear-resistant layer in the component is applied to a peripheral surface of the core portion blank. The composite body is shaped to form the component. The component may then be optionally finished.

A method for producing a hollow shaft from a tubular preform by pressure rolling shapes each end of the preform using at least one forming roller. A tubular preform with a round or polygonal cross-section is used, and the preform is held on a workpiece holder in the central tube region during the entire production process until the hollow shaft is completed.

A shaft for a steering device has a first portion, a second portion, and a third portion that is a shaft integrated with the first portion and the second portion and couples the first portion and the second portion in a first direction. The outer diameter of the third portion is smaller than the length of the second portion in a second direction intersecting with the first direction, and is constant across a direction extending along the first direction. The hardness of the third portion is greater than the hardness of the second portion, and is constant across the direction extending along the first direction.