JPH03204120A - Pipe bending device - Google Patents

Abstract

PURPOSE:To bend the pipe to the combined R shape by forming the bent part with plural curved surfaces of different radius of curvature and moving the pressing die following the dimension variation in radius direction of the bending die. CONSTITUTION:The one part of pipe 20 is fixed with the clamper 5 to the bending die 3, and the pipe 20 is pressed with the pressing die 6 to the bending die 3 with the prescribed force by extending the rod 9a of cylinder 9. The bending die 3 is rotated to the arrow mark R direction, while pressing the pipe 20 with the pressing die 6 to the bending die 3. One part of the pipe 20 is bent in the state of being wound around the bend working part 4 of the bending die 3 and the pressing die 6 moves downward following the movement of the pipe 20, and moves while contracting the rod 9a of cylinder 9 following the variation of radius dimension of the bending die 3. The required part of the pipe 20 is bent in the state of being wound around the bending die 3 by rotating the bending die 3 further. Therefore, the pipe 20 is bent to the combined R shape of combination of the circular arc of radius r1 and the circular arc of radius r2 smaller than the above.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a pipe bending device.

[Prior Art] For example, when manufacturing pipe frames for motorcycles, in order to bend pipe parts into a desired shape, a sixth
, a pipe bending device as shown in Fig. 7 is used.

This pipe bending device A has a device main body B and a bending mold C, and the bending mold C has a disk shape and is supported by the device main body B so as to be rotatable about a point 0. .

In addition, a semicircular groove C' as a bending part is formed on the circumferential surface of this bending die C over the entire circumference. Clamper D
is provided.

A pressure mold E is provided on the side of the bending mold C,
This pressure mold E is supported by a holder F so as to be movable along the vertical direction in FIG. It is installed so that it can be moved freely along the Further, the position of this holder F can be adjusted by operating a push screw G screwed onto a bracket B' of the main body B of the apparatus.

To bend a pipe, first, a part of the straight pipe P before bending is fixed to the bending die C using a clamper D located at the initial position shown by the chain line in FIG. By operating the push screw G and moving the pressure die E, the pipe P is pressed against the bending die C with a predetermined pressure.

Next, by rotating the bending die C in the direction of arrow R in FIG. 6, the pipe P is bent into a shape that follows the semicircular groove C' (bending part) of the bending die C. .

[Problem to be solved by the invention] By the way, in the pipe bending device A having the above configuration, the pipe P
During the bending process, in other words, during the rotating operation of the bending die C,
The pressure mold F does not move in the radial direction of the bending mold C.

For this reason, the bending die C has a perfect circular shape with a constant radius centered at the 0 point so as not to interfere with the pressure die F, and the semicircular groove C' as the bending part also has the above-mentioned shape. It has a shape along the circumference centered on the 0 point.

As a result, the pipe bending apparatus A having the above configuration can only bend a pipe into an arc shape having a single radius of curvature along the circumference of a perfect circle.

Therefore, when bending a pipe into a shape that combines multiple circular arcs with different radii of curvature (hereinafter referred to as a compound R shape), multiple pipe bending machines each equipped with bending dies with different radii are required. However, the pipe had to be bent multiple times, making the work extremely complicated.

SUMMARY OF THE INVENTION In view of the above-mentioned circumstances, an object of the present invention is to provide a pipe bending device that can easily bend a pipe having a compound R shape.

[Means for Solving the Problems] Therefore, in the present invention, the bending part is formed by a plurality of curved surfaces with different radii of curvature, and the pressure mold is moved while following the dimensional change in the radial direction of the bending mold during rotation operation. The above object has been achieved by providing a biasing means for causing this.

[Function] According to the above configuration, due to the fact that the bending part is formed of a plurality of curved surfaces with different radii of curvature, the bending part can be easily resistant to changes in the dimensions of the bending die in the radial direction during the pipe bending operation.
Since the pressure mold moves to follow the circumferential surface of the bending mold by the action of the biasing means, the pipe can be bent into a compound R shape that follows the bending portion of the bending mold.

[Embodiment] Hereinafter, a specific configuration of the present invention will be explained in detail based on the drawings showing one embodiment.

1 to 4 show a pipe bending device 1 according to the present invention, and this pipe bending device 1 includes a device body 2 and a bending device rotatably supported on the device body 2 with It has type 3.

The bending die 3 has a substantially disk shape, and as shown in FIG. 4, a semicircular groove 4 serving as a bending portion is formed on the circumferential surface of the die 3 over the entire circumference.

As shown in FIG. 1, the semi-circular groove 4 has a curved surface on almost half its circumference that forms a compound R shape, which is a combination of a circular arc with a radius of "1" and a circular arc with a smaller radius r2. It is formed.

Further, as is clear from FIGS. 1 to 3, due to the fact that a part of the semicircle l@4 is formed with a curved surface forming a compound R shape, the rotation center point 0 of the bending die 3 The radius dimension from to the semi-circular groove 4 differs depending on the location of the semi-circular groove 4.

Further, the bending die 3 is provided with a clamper 5 for fixing a part of the pipe. This clamper 5 has a pair of clamping blocks 5a and 5b, and a push screw 5c for moving the clamping block 5b toward and away from the block 5a.

On the other hand, a pressure die 6 extending perpendicularly to the rotation axis of the bending die 3 is disposed in a side area of the bending die 3 . As shown in FIG. 4, this pressure mold 6 is formed with a semicircular groove 7 that extends opposite to the semicircular groove 4 of the bending mold 3, and furthermore, the pressure mold 6 is formed with a semicircular groove 7 as shown in FIGS. It is movably supported by the holder 8 along the vertical direction inside.

The holder 8 has a guide groove 2a formed in the device main body 2.
(See FIG. 4), and is installed so as to be movable along the radial direction of the bending die 3.

A hydraulic cylinder 9 as a biasing means is interposed between the back of the holder 8 and the bracket 2b projecting from the device main body 2. This hydraulic cylinder 9 is installed with its axis along the radial direction of the bending mold 3,
By extending and retracting the rod 9a, the pressure mold 6 moves toward and away from the bending mold 3 via the holder 8. Further, the hydraulic cylinder 9 is connected to a hydraulic power source 1 via a hydraulic control unit 10, which will be described later.

In order to bend a pipe using the pipe bending device 1 having the above-mentioned configuration, first, a part of the straight pipe 20 before bending is moved by the clamper 5 which is in the initial foot position shown by the solid line in FIG. While fixing it to the bending mold 3,
The rod 9a of the hydraulic cylinder 9 is extended and the pipe 20 is pressed against the bending die 3 by the pressure die 6 with a predetermined pressure.

At this time, the pipe 20 is held by the semicircular groove 4 of the bending die 3 and the semicircular groove 7 of the pressure die 6.

Next, while the pipe 20 is pressed against the bending die 3 by the pressure die 6, the bending die 3 is rotated in the direction of arrow R in the figure. As a result, as shown in FIG. 2, the pipe 20
A part of the pipe 20 is wrapped around the bending part 4 of the bending die 3 and bent, and the pressure die 6 moves downward in the figure as the pipe 20 moves.

Further, at this time, the pressure die 6 follows the change in the radius dimension from the rotation center point O of the bending die 3 to a portion facing the pressure die 6 as the bending die 3 rotates, and the hydraulic cylinder While retracting the rod 9a of No. 9, it moves to the right in the figure. At this time, the hydraulic cylinder 9 is controlled by the hydraulic control unit 10 so that the pressure force applied to the pipe 20 by the pressure mold 6 is always constant.

That is, the pressure mold 6 follows the radial dimensional change of the bending mold 3 during pipe bending work, in other words, while the bending mold 3 is rotating, due to the action of the hydraulic cylinders and the hydraulic control unit 10. While moving, the pipe 20 is always pressed against the bending die 3 with a constant force.

Note that the hydraulic control unit 10 is a pressure type 6
As long as the pressure applied to the pipe 20 is controlled to be constant at all times, various means such as an automatic pressure regulating valve can be used.

The bending die 3 is moved from the position shown in FIG.
By rotating the pipe 20 to the position shown in the figure, the required portion of the pipe 20 is wrapped around the bending die 3 and bent. Also at this time, the pressure die 6 follows the dimensional change of the bending die 3 in the radial direction. While moving, the pipe 20 is pressed against the bending die 3 with a constant force.

After rotating the bending die 3 to the position shown in Fig. 3,
By removing the pipe 20 from the pipe bending device 1, the pipe bending work is completed.

As a result of the above-mentioned bending work, the knob 20 has a shape that follows the bending part 4 of the bending die 3, as shown in FIG. It is bent into a composite R shape consisting of a combination of

In this example, a configuration is illustrated in which a pipe is bent into a composite R shape formed by combining two circular arcs with different radii of curvature. It goes without saying that the apparatus according to the present invention can also be effectively used when bending a pipe into an R shape.

Further, in this embodiment, a hydraulic cylinder is used as the biasing means, but it goes without saying that a hydraulic cylinder or a pneumatic cylinder can be used instead of the hydraulic cylinder, and rubber, springs, etc. can be used as the biasing means. It is also possible to use the 911-isomer of

Furthermore, it goes without saying that the pipe bending device according to the present invention is not only used when manufacturing motorcycle-width pipe frames, but can also be effectively used when bending various pipe parts.

[Effects of the Invention] As described in detail above, in the pipe bending device according to the present invention, the bending portion is formed by a plurality of curved surfaces with different radii of curvature, and the bending part is formed by a plurality of curved surfaces having different radii of curvature. A biasing means is provided to move the pressure mold while following the pressure mold.

According to this configuration, since the bending portion is formed of a plurality of curved surfaces having different radii of curvature, the biasing means can be applied even to changes in the dimensions of the bending mold in the radial direction during the pipe bending operation. Because the pressure mold moves to follow the circumferential surface of the bending mold, the pipe can be bent into a compound R shape that follows the bending portion of the bending mold.

Therefore, according to the pipe bending apparatus of the present invention, bending of a pipe forming a compound R shape, which conventionally required multiple steps, can be easily performed in one step.

[Brief explanation of drawings]

1 to 3 are conceptual plan views showing the operation mode of the pipe bending device related to the present invention in order, FIG. 4 is a sectional view taken along the line IV-IV in FIG. 1, and FIG. A plan view of a pipe bent by the pipe bending device according to the invention, FIG. 6 is a conceptual plan view of a conventional pipe bending device, and FIG. 7 is a cross-sectional view taken along the line ■-■ in FIG. be. 1...Pipe bending device, 2...Device body, 3...
・Bending mold, 4... Half-round groove (bending part), 5...
Clamper, 6...pressure type, 8...holder, 9.
... Hydraulic cylinder (biasing means), 10... Hydraulic control unit, 11... Hydraulic source, 20... Pipe. Figure 4 Figure 3 Figure 5

Claims (1)

[Scope of Claims] A bending mold that is rotatably supported by a device body and has a bending portion on its circumferential surface that corresponds to a desired bending shape of the pipe, and a part of the pipe is fixed to the bending mold. The pipe bending device includes a clamper and a pressure die that presses the pipe against the bending die, and bends the pipe into a shape that follows the bending part of the bending die by rotating the bending die. The bending part is formed by a plurality of curved surfaces having different radii of curvature, and a biasing means is provided for moving the pressure die while following a change in the dimensions of the bending die in the radial direction during rotational operation. A pipe bending device featuring: