A rotary flow forming apparatus for producing light alloy rims contains a main spindle with a clamping apparatus for a rim blank. An outer pressure roller is provided and is deliverable radially from the outside in and is movable parallel to the spindle axis, for producing an outer contour of the light alloy rim. The apparatus does not require massive internal dies and thereby significantly reduces the production costs and significantly improves the efficiency of rim production, which is achieved by the fact that the rotary flow forming apparatus has an inner pressure roller for generating an inner contour of the light alloy rim, which is arranged in the region of the inner side of the rim blank opposite the outer pressure roller and is mounted so as to be movable parallel to the spindle axis, rotatable, and deliverable radially from the inside outward to the rim blank.

A spinning forming device includes: a rotating shaft that rotates a plate to be formed; a processing tool that presses a front surface of the plate while being moved outward in a radial direction of the rotating shaft; and a heater that is moved so as to be located on the same circumference as the processing tool and locally heats the plate by induction heating. The spinning forming device further includes a cooling device that cools the front surface of the plate.

A spinning forming device includes: a rotating shaft that rotates a plate to be formed; a processing tool that presses a front surface of the plate while being moved outward in a radial direction of the rotating shaft; and a heater that is moved so as to be located on the same circumference as the processing tool and locally heats the plate by induction heating. The spinning forming device further includes a cooling device that cools the front surface of the plate.

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.

A tube flanging method includes the steps of: disposing a tube such that an edge thereof is exposed to the outside of a forming mold while the tube is inserted into the forming mold; applying an external force to the exposed edge of the tube to expand the exposed edge of the tube; applying an external force to the expanded edge to bend the expanded edge toward an outer surface of the forming mold; and applying an external force to the bent edge to form a flange, the flange having a linearly integrated cross section and being perpendicular to the longitudinal direction of the tube. With this configuration, it is possible to bend the tube to form the flange at a uniform thickness.

A tube flanging method includes the steps of: disposing a tube such that an edge thereof is exposed to the outside of a forming mold while the tube is inserted into the forming mold; applying an external force to the exposed edge of the tube to expand the exposed edge of the tube; applying an external force to the expanded edge to bend the expanded edge toward an outer surface of the forming mold; and applying an external force to the bent edge to form a flange, the flange having a linearly integrated cross section and being perpendicular to the longitudinal direction of the tube. With this configuration, it is possible to bend the tube to form the flange at a uniform thickness.

A spinning method includes supporting a supported portion of a cylindrical work by a work supporting portion; pressing a first roller of a spinning head against a processed portion of the work while revolving the first roller; and performing a forming process that points a tube axis of the processed portion of the work in a given direction by pressing the first roller and a second roller in which a plane of revolution thereof is provided in a different position, in a rotational axis direction of a spindle of the spinning head, than a plane of revolution of the first roller, while revolving the first roller and the second roller, and moving the work supporting portion relative to the spinning head or moving the spinning head relative to the work supporting portion, while the first roller and the second roller work in cooperation with each other to retain the work.

A spinning method includes supporting a supported portion of a cylindrical work by a work supporting portion; pressing a first roller of a spinning head against a processed portion of the work while revolving the first roller; and performing a forming process that points a tube axis of the processed portion of the work in a given direction by pressing the first roller and a second roller in which a plane of revolution thereof is provided in a different position, in a rotational axis direction of a spindle of the spinning head, than a plane of revolution of the first roller, while revolving the first roller and the second roller, and moving the work supporting portion relative to the spinning head or moving the spinning head relative to the work supporting portion, while the first roller and the second roller work in cooperation with each other to retain the work.

A tube diameter expanding method includes: rotating a tube having one end fixed to a turntable about a center axis of the tube; inserting a rod-like roller which extends in an axial direction of the tube into the tube from another end of the tube, and bringing the rod-like roller into contact with a forming region extending from the other end to a predetermined position of the tube; heating the forming region of the tube; cooling at least a section located near the forming region and within a non-forming region extending from the predetermined position to the one end of the tube; and moving the rod-like roller in a state of contacting the forming region of the tube, in a direction from the one end of the tube toward the other end of the tube and outward in a radial direction of the tube.