Bending method for pipe material
AssigneeSango Co., Ltd.
InventorYutaka Sekido
Life of this patent
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Abstract
In a method of bending a pipe material, in order to use an apparatus, such as a press, and prevent the pipe material from being made thin and cracks from being generated, one side of a cylindrical pipe material is firmly held by a first clamp and another side thereof is loosely held by a second clamp. The clamp is relatively moved downward with respect to the clamp. At this time, pressing force is applied to the pipe material in an axial direction from both ends thereof. The pipe material is plastically deformed by being guided by one quarter spherical surface of a first mandrel and one quarter spherical surface of a second mandrel, whereby two bent portions and an intermediate straight portion are formed.
Claims10
A method of bending a pipe material, comprising:
- firmly holding a pipe material by a first clamp which is one of at least two clamps arranged in a longitudinal direction of the pipe material and loosely holding the pipe material by a second clamp;
- arranging first and second mandrels inserted from opposite ends of the pipe material within the pipe material so as to be brought into contact with each other or closely confront each other near a boundary surface between the first and second clamps, thereby fixing the mandrels so as not to relatively move with respect to the first and second clamps;
- and
- relatively moving the first and second clamps parallel to the boundary surface in an opposite direction to each other while maintaining the fixing state, whereby two bent portions and an intermediate straight portion are formed in the pipe material.
Dependencies are inferred from the claim text.