A spinning machine includes: a main shaft which includes a chuck holding a cylindrical material having a bottom and a regulation member; a mandrel which is inserted inside from an opening side end portion of the material; and a press roller which presses the opening side end portion of the material. The spinning machine molds a circumferential groove portion on the opening side end portion so that an inner diameter of the opening side end portion of the material is smaller than an inner diameter of a body of the material by pushing a press roller while rotating the material around the axial center of the main shaft, and at least a portion of the inserted mandrel is formed so that a gap is provided between the portion and an inner circumferential surface after the opening side end portion of the material is plastically deformed.

A device for manufacturing a metal wheel (1) from a pre-form, with stretching rolls (3) engaging on the rim region of the pre-form, by means of which rolls a rim (1.1) is end-formed which, for forming a rim flange (1.7). Freely rotatable rolls (4) are arranged underneath the stretching rolls (3) and cooperate with them. A method for manufacturing a metal wheel (1) from a pre-form, the pre-form of the metal wheel (1) to be manufactured is placed on a clamping mandrel (2) and is caused to rotate, stretching rolls (3) engage an axially outer side of a rotation-symmetrical jacket of the pre-form with the exertion of radial pressure, and move along the jacket wall of the pre-form with compression and stretching of the jacket wall to form a rim (1.1) with a main movement component parallel with the axis of rotation (2.1) of the pre-form.

A device for manufacturing a metal wheel (1) from a pre-form, with stretching rolls (3) engaging on the rim region of the pre-form, by means of which rolls a rim (1.1) is end-formed which, for forming a rim flange (1.7). Freely rotatable rolls (4) are arranged underneath the stretching rolls (3) and cooperate with them. A method for manufacturing a metal wheel (1) from a pre-form, the pre-form of the metal wheel (1) to be manufactured is placed on a clamping mandrel (2) and is caused to rotate, stretching rolls (3) engage an axially outer side of a rotation-symmetrical jacket of the pre-form with the exertion of radial pressure, and move along the jacket wall of the pre-form with compression and stretching of the jacket wall to form a rim (1.1) with a main movement component parallel with the axis of rotation (2.1) of the pre-form.

A method of manufacturing a preliminary formed body includes an ironing step and a thickening step. In the ironing step, a predetermined range of a plate is formed into a tapered shape in such a manner that while rotating the plate, a transform target portion of the plate is locally heated by induction heating, and a processing tool is pressed against the transform target portion. In the thickening step, a peripheral portion that is a distal end of the tapered shape of the plate is expanded inward in such a manner that while rotating the plate, the peripheral portion is locally heated, and a forming roller is pressed against the peripheral portion to push the peripheral portion in a direction orthogonal to a thickness direction of the peripheral portion.

According to a spinning forming device, while a plate is rotated by a rotating shaft, a transform target portion of the plate is pressed by a processing tool and locally heated by a heater that performs induction heating. The heater includes a coil portion having a doubled circular-arc shape and is inclined by an inclining device relative to a direction from the rotating shaft toward the processing tool. A measuring unit measures distances each from the coil portion to an outer peripheral original portion of the plate at a plurality of measurement points distributed in a circumferential direction of the rotating shaft. A controller controls the inclining device based on a measurement result of the measuring unit such that an angle difference between the coil portion and the outer peripheral original portion becomes not more than a predetermined angle.

According to a spinning forming device, while a plate is rotated by a rotating shaft, a transform target portion of the plate is pressed by a processing tool and locally heated by a heater that performs induction heating. The heater includes a coil portion having a doubled circular-arc shape and is inclined by an inclining device relative to a direction from the rotating shaft toward the processing tool. A measuring unit measures distances each from the coil portion to an outer peripheral original portion of the plate at a plurality of measurement points distributed in a circumferential direction of the rotating shaft. A controller controls the inclining device based on a measurement result of the measuring unit such that an angle difference between the coil portion and the outer peripheral original portion becomes not more than a predetermined angle.

In a spinning forming method, a plate including a peripheral portion at which a ring-shaped projection is provided is used, the projection projecting in a thickness direction of the plate. Further, while rotating the plate, a transform target portion of the plate is locally heated, and a processing tool is pressed against the transform target portion to transform the plate. According to this configuration, a heat capacity of the peripheral portion of the plate can be increased. With this, when heating the vicinity of the peripheral portion of the plate, the peripheral portion can be prevented from becoming high in temperature. As a result, deformation of the peripheral portion of the plate can be suppressed.

In a spinning forming method, a plate including a peripheral portion at which a ring-shaped projection is provided is used, the projection projecting in a thickness direction of the plate. Further, while rotating the plate, a transform target portion of the plate is locally heated, and a processing tool is pressed against the transform target portion to transform the plate. According to this configuration, a heat capacity of the peripheral portion of the plate can be increased. With this, when heating the vicinity of the peripheral portion of the plate, the peripheral portion can be prevented from becoming high in temperature. As a result, deformation of the peripheral portion of the plate can be suppressed.

A method for forming an end part of a tube, such as a hollow shaft for use as a vehicle axle, is described. A rolling body having a rolling surface with an inwardly-curved contour rotates around a longitudinal axis with a first rotational speed and a second rotational speed. The rolling body and the tube rotate in the same direction. The longitudinal axis of the rolling body is arranged eccentrically to a longitudinal axis of the tube by a predetermined normal distance. The rolling body and the tube are brought into contact such that the rolling surface contacts the end part of the tube at a contact surface situated on an inner tube wall. The rolling body transfers a force to the inner tube wall by a relative movement between the rolling body and the tube such that the end part of the tube is formed radially outward.

A spinning forming device includes: a receiving jig supporting a central portion of a plate to be formed; and a rotating shaft to which the receiving jig is attached. The spinning forming device also includes: a heater configured to locally heat a transform target portion of the plate by induction heating; and a processing tool configured to press the transform target portion to transform the plate. The spinning forming device further includes a pair of holding rollers configured to sandwich an outside portion of the plate, the outside portion being located outside the transform target portion.