A method of manufacturing a flaring-processed metal pipe from a hollow shell including a plurality of portions having different deformation resistances in a circumferential direction is provided, the method includes: among the plurality of portions, specifying a portion having a relatively small deformation resistance as a low deformation resistance section, and a portion having a relatively large deformation resistance as a high deformation resistance section; and press-fitting a pipe expansion punch into the hollow shell such that a thickness reduction rate of the low deformation resistance section is smaller than a thickness reduction rate of the high deformation resistance section.

A method of manufacturing a flaring-processed metal pipe from a hollow shell including a plurality of portions having different deformation resistances in a circumferential direction is provided, the method includes: among the plurality of portions, specifying a portion having a relatively small deformation resistance as a low deformation resistance section, and a portion having a relatively large deformation resistance as a high deformation resistance section; and press-fitting a pipe expansion punch into the hollow shell such that a thickness reduction rate of the low deformation resistance section is smaller than a thickness reduction rate of the high deformation resistance section.

Some embodiments disclosed herein are directed to a tubular member including a central axis, a first end, a second end opposite the first end, an upset region between and axially spaced from the first end and the second end, and a first outer diameter axially spaced midway between the first end and the upset region. The upset region includes a second diameter which is larger than the first diameter, does not include a weld joint, and includes redistributed material from the tubular member.

The disclosure aims to provide a structural member made of an extruded material that effectively helps to reduce weight while ensuring strength and rigidity. The structural member has a varied wall thickness along an extrusion direction.

The disclosure aims to provide a structural member made of an extruded material that effectively helps to reduce weight while ensuring strength and rigidity. The structural member has a varied wall thickness along an extrusion direction.

A system for manufacturing a tubular member includes a mandrel configured to be inserted within a throughbore of the tubular member to engage with an inner diameter of the throughbore. In addition, the system includes a die assembly comprising a cavity. The die assembly is configured to be disposed about an outer surface of the tubular member such that a central portion of the tubular member is aligned with the cavity. Further, the system includes a ram configured to apply a load to the tubular member along a central axis of the tubular member to expand the central portion of the outer surface of the tubular member into the cavity to form an upset region along the tubular member.

A hollow shaft includes a cylindrical main body part and an extremity drawn part that is integrally connected to one end of the main body part on the same axis and whose diameter is made smaller than a diameter of the main body part by drawing processing, wherein an inner peripheral face of the main body part and an inner peripheral face of a base portion, which is continuous with one end side of the main body part, of the extremity drawn part are formed as cut faces that are subjected to cutting processing before the drawing processing, and an inner peripheral face of a tip portion, which is continuous with an extremity side of the base portion, of the extremity drawn part is a non-cut face. Accordingly, the hollow shaft can be molded with high shape precision while maintaining a low drawing ratio for an extremity drawn part.

A hollow shaft includes a cylindrical main body part and an extremity drawn part that is integrally connected to one end of the main body part on the same axis and whose diameter is made smaller than a diameter of the main body part by drawing processing, wherein an inner peripheral face of the main body part and an inner peripheral face of a base portion, which is continuous with one end side of the main body part, of the extremity drawn part are formed as cut faces that are subjected to cutting processing before the drawing processing, and an inner peripheral face of a tip portion, which is continuous with an extremity side of the base portion, of the extremity drawn part is a non-cut face. Accordingly, the hollow shaft can be molded with high shape precision while maintaining a low drawing ratio for an extremity drawn part.

A method and an apparatus for axially shaping a tube use a mandrel guided in the tube and an annular die guided on the outside of the tube. The tube is clamped in a clamping device. The outer diameter of the tube is reduced by moving the annular die in a pushing direction. In order to form undercuts on the outside and inside of the tube the method uses the following steps: Reversing the direction of movement of the die and the mandrel upon reaching an end position from the pushing direction to an opposite pulling direction. In a first setting step, the die and the mandrel are then moved in relation to one another to a first preset annular-gap setting, and in a subsequent first shaping step, the die and the mandrel are moved in the pulling direction, while maintaining the preset annular gap.

A method and an apparatus for axially shaping a tube use a mandrel guided in the tube and an annular die guided on the outside of the tube. The tube is clamped in a clamping device. The outer diameter of the tube is reduced by moving the annular die in a pushing direction. In order to form undercuts on the outside and inside of the tube the method uses the following steps: Reversing the direction of movement of the die and the mandrel upon reaching an end position from the pushing direction to an opposite pulling direction. In a first setting step, the die and the mandrel are then moved in relation to one another to a first preset annular-gap setting, and in a subsequent first shaping step, the die and the mandrel are moved in the pulling direction, while maintaining the preset annular gap.