Method of bending pipe and apparatus therefor
AssigneeYutaka Giken Co., Ltd.
InventorsHiroyuki Takahashi, Hiroshi Takada
Life of this patent
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Abstract
A movable die base (2) is moved toward a stationary die base (1). A pressing force is applied by a bending punch (21) disposed on the movable die base to a bending target portion of a pipe (A) which is placed on a die (11) provided on the stationary die base and which has inserted therein a core metal (17). At the time of this bending work, both ends of the pipe are restricted by holding them with restriction pads (22). When the pressing force is applied by the bending punch, the restriction pads are displaced to follow the pressing of the bending punch, whereby restricted state on both ends of the pipe is constantly maintained.
Claims8
1:
- A method of bending a pipe comprising the steps of:
- setting a pipe in a manner capable of giving in under a pressing force;
- inserting into the pipe a core metal having a forming section along which the pipe is to be bent, said core metal being positioned at a bending target portion of the pipe;
- applying a restricting force to both ends of the pipe as seen in a longitudinal direction of the pipe;
- and
- applying the pressing force to the bending target portion of the pie in a state of restricting the pipe such that a point of operating the restricting force displaces depending on a progress of applying the pressing force, whereby the pipe remains constantly restricted while the pressing force is being applied.
2:
- A method of bending a pipe comprising:
- moving at least one of a pair of die bases lying opposite to each other toward the other thereof;
- applying a pressing force to a bending target portion of a pipe by a bending punch disposed on one of said die bases, said pipe being placed on a die provided on the other of said die bases and having inserted therein a core metal so as to be bent along a forming section of said core metal;
- and
- holding both ends of the pipe by restricting means such that, when the pressing force is applied to the bending target portion by said bending punch, said restricting means is displaced to follow the pressing by said bending punch, whereby the pipe is bent in a state in which the restriction at both ends of the pipe is maintained.
3:
- The method according to claim 1, wherein the pipe is formed of predetermined shape of sheet metal into a cylindrical shape with both longitudinally extending free ends thereof welded together.
4:
- An apparatus for bending a pipe comprising:
- a pair of die bases lying opposite to each other;
- a bending punch for applying a pressing force to a bending target portion of a pipe, said bending punch being disposed on one of said die bases;
- a die for placing thereon the pipe, said die being disposed on the other of said die bases such that at least one of said die bases is moved toward the other thereof to apply the pressing force by said bending punch to bend the pipe along a forming section of a core metal inserted into the pipe;
- and
- restriction means for restricting the pipe by holding both longitudinal ends thereof, said restriction means being arranged to be displaceable to follow a movement of said bending punch in a pressing direction.
5:
- The apparatus according to claim 4, wherein said restriction means is a restriction pad disposed on said one of said die bases,
- wherein said die is made up of two segments, each of said segments being arranged to be swingable, under the pressing force by said bending punch, about a supporting shaft provided respectively toward each longitudinal end of the pipe, and
- wherein said restriction pad displaces to follow the swinging of each of said segments of said die.
The apparatus according to claim 4, wherein said core metal is disposed on said die in a manner to be swingable about a supporting shaft at one end of said core metal.
7:
- The method according to claim 2, wherein the pipe is formed of predetermined shape of sheet metal into a cylindrical shape with both longitudinally extending free ends thereof welded together.
8:
- The apparatus according to claim 5, wherein said core metal is disposed on said die in a manner to be swingable about a supporting shaft at one end of said core metal.
Dependencies are inferred from the claim text.