JPH0493184A - Bending jig for pipe member - Google Patents

Abstract

PURPOSE:To enable bending of a pipe member at a constant curvature in the constant direction at all times along the curved groove of a shoe main body, by fitting a fixture which fixes the shoe main body to a worker with its winding on the knee part of the worker to the recessed curve face of the shoe main body. CONSTITUTION:A shoe main body 1 recessed curved face 3 is fixed with a fixture 6 being wound on the knee after fitting it to the knee front face side of a worker. The both end sides of a pipe member are then pressed to the rear side of the knee part after engaging the pipe member with the center part in the longitudinal direction of a curved groove 2. The pipe member can thus be subjected to bending at a constant curvature in a constant direction while engaging it with the curved groove 2 gradually toward the both ends from the medium thereof. The radius of curvature of the above recessed curved face is set so that the radii of curvature of both end sides become smaller than that of the medium part thereof, moreover the width of the recessed curved face of the shoe main body is set larger than the width of the side where the curved groove is provided.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a pipe bending jig suitable for use in bending pipe materials in narrow spaces such as the ceiling or under the floor of a building. .

[Prior Art] Conventionally, as a jig for bending pipe materials such as coated steel pipes, for example, a bending tool is attached to the tip of one of two rod-shaped handles that are rotatably provided with respect to each other. A support member is provided to support the unprocessed pipe material on two fulcrums appropriately spaced apart, and the support member is provided at the tip of the other handle to reciprocate in the axial direction of the one handle as the handle is rotated. A shoe body is provided, and a curved groove curved in an arc is formed on the front side in the direction of movement of the shoe body, and the handle can be rotated with the pipe material being passed between the supporting members. A pipe bender is known in which the shoe body is pressed against the middle of the pipe material to curve and bend the pipe material along the curved groove of the shoe body.

[Invention or problem to be solved] By the way, such a pipe venter has at least 3~
Because it weighs 5 kg, it is difficult to carry it into narrow spaces such as under floors or ceilings, and when bending in such places, the worker must use his or her own knees without using a jig. In many cases, the bending process was performed using the own blade. That is, the pipe material is bent at an arbitrary angle by pressing the middle of the pipe material against the knee of the worker and pressing both ends of the pipe material toward the back side of the worker's knee.

However, when bending is performed by the worker himself without a jig, regardless of whether the worker is skilled or not, a torsional load acts on the pipe material at the same time as the bending load, causing the pipe to move in an unexpected direction. Or, during the bending process, a concentrated load is applied to the contact area between the front side of the knee and the pipe material, and the radius of curvature of that area becomes significantly smaller, causing the pipe material to be flattened. It was difficult to perform the bending process with a certain quality.

Above all, there was a drawback that the repeated bending process was likely to injure the worker's knees.

This invention was made against this background, and is a method for bending pipe materials that can be easily transported into narrow spaces and that can be bent with a constant quality without requiring special skill. The purpose is to provide jigs.

1. Means for Solving the Problem] In order to solve the above problem, the bending jig of the present invention has a curved groove extending in a convex arc formed on one side of the shoe body made of a hard material. , -] On the other side of the U body described in Section 22, a concave curved surface portion is formed that curves in the same direction as the curved groove and fits into the knee part of the worker, and this concave curved surface portion has the following features:
A fixing device is attached that wraps around the worker's knee and fixes the shoe body to the worker.

Here, in order to securely fix the shoe body to the operator, the radius of curvature of the concave curved surface part should be set so that the radius of curvature at both ends is smaller than that at the middle part. It is preferable that the width of the part is set to be larger than the width of the side of the shoe body where the -J2 curved groove is provided.

Further, in order to ensure that the pipe material and the curved groove are engaged, it is preferable that the groove width of the curved groove is set so that the width of the curved groove is larger at both ends than at the middle portion in the longitudinal direction. Furthermore, a cushioning material may be fixed to the surface of the concave curved portion to relieve the load applied to the operator.

1 Effect] According to the above configuration, the concave curved surface portion of the shoe body is fitted to the knee surface side of the worker. By engaging the pipe material in the center and pushing both ends of the pipe material toward the rear side of the knee part, the pipe material is gradually engaged with the curved groove from the middle toward both ends and moved in a certain direction. It is possible to bend it at a constant curvature.

[Example] Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

In FIGS. 1 to 3, reference numeral 1 indicates the shoe body. This shoe body I is for bending unbent pipe material, such as coated copper pipe, to a constant curvature.
It is made of a hard material such as aluminum alloy or plastic that can sufficiently withstand the load when bending pipe material, and is formed into an approximately circular arc shape in appearance, with a central angle θ1 of approximately 120°.
It is stipulated in

The outer circumferential side of the shoe body 1 has a curved line extending in a convex arc along the longitudinal direction of the shoe body 1. 2 is formed. This curved groove 2 engages with the pipe material,
It regulates the bending direction of the pipe material that is being bent, and its cross-sectional shape is as shown in Figures 2 and 3.
It has a shape in which two wall surfaces 2b extend linearly from both ends of the bottom surface 2a, which is an arcuate surface with a radius r, toward the frontage end.

The groove widths S8 and S2 of the curved groove 2 and the radius of curvature r of the bottom surface 2a may be changed as appropriate depending on the material and outer diameter of the knob material to be bent. mm), the radius of curvature r is set to D/2 over the entire length of the curved groove 2, and the groove width is set to the groove on the middle side of the shoe body 1. Width S1 is (D-1-
0.5m+n), whereas the shoe body 1
Groove width S in a specific range (section A in Figure 1) from both ends of
, or (D+15 mm), which is set slightly larger than the intermediate side.

Increasing the groove width at both ends of the curved groove 2 in this way is as follows:
When the pipe material is gradually bent and deformed from the middle to both ends, the cross-sectional shape of the pipe material deforms into a slightly elliptical shape at the end of the process, so by widening the groove width accordingly, This is to ensure that the knob material is engaged with the curved groove 2. By the way, the outer diameter of the coated steel pipe is 19.5 m.
m, the groove width of the curved groove 2 is S l on the intermediate side
-20 mm, S, = 2] mm at both ends, and the radius of curvature of the bottom surface 2a is set to r = lQ mm.

Furthermore, the radius of curvature in the longitudinal direction of the curved groove 2 is appropriately determined according to the bending radius of the pipe material, and in the illustrated example, the radius of curvature R8 at the center position of the bottom surface 2a (see FIG. 1)
or 100mm.

- On the inner peripheral side of the shoe body 1, a concave curved surface portion 3 is formed which curves in the same direction as the curved groove 2. This concave curved surface portion 3 is fitted into the front side of the worker's knee to support the shoe body 1, and its radius of curvature is either the radius R1 at the middle side of the shoe body 1 or the curvature at both ends of the shoe body 1. The curvature radii R1 and R2 are determined as appropriate depending on the physique of the worker. In the illustrated example, R1 = 60 mm, R2-55 mm on both ends
is set to . Further, the width W1 of the concave curved surface portion 3 is set larger than the width W of the side of the body 1 where the curved groove 2 is provided.

Here, the reason why the radius of curvature of the concave curved surface portion 3 is changed as described above is to match the characteristics of the line portion. In other words, since the linear portion of the human body has a planar shape that protrudes in an almost arc shape on the front side, and recedes slightly inward on the side surface, it is recommended that the radius of curvature of the concave curved surface portion 3 is made constant. , both ends of the concave curved surface portion 3 are separated from the line portion, making it impossible to stably support the shoe body 1. Therefore, the radius of curvature on both ends of the concave curved surface portion 3 is reduced and narrowed toward the center.
This improves the adhesion between both ends of the concave curved surface portion 3 and the line portion.

Further, a cloth belt 4 is fixed to the concave curved surface portion 3 using a fixing means such as an adhesive. This cloth bell l-/l is
It has a band-like shape with approximately the same width as the concave curved surface portion 3, and both ends thereof extend largely outward in the circumferential direction from both ends of the concave curved surface portion 3. Connecting members 5 for connecting both ends of these cloth healds 4 are attached to both ends of the cloth bell l-4, and the fixing member 6 of this embodiment is connected by these connecting members 5 and the cloth belt 4. It is configured. Here, as the connecting member 5, a well-known connecting means such as a fastener may be used, but in the illustrated example, a large number of hooks are provided on the surface of one tape 5a, and a number of hooks are provided on the surface of the other tape 5b. So-called magic tape is used, which connects and connects each tape by engaging and disengaging a large number of provided loops.

In addition, the cloth health mentioned above! - A band-shaped cushioning material 7 that is slightly longer than the concave curved surface portion 3 is fixed to the surface of the concave curved surface portion 3 . The cushioning material 7 is used to relieve the load applied to the knee during bending, and may be made of various flexible materials such as rubber or hard sponge.

Further, two marks 8 are formed near the opening of the curved groove 2 on the surface of the shoe body 1.

These marks 8 serve as indicators of the bending angle, and their central angle θ2 is 90°.

In order to bend a pipe material using the bending jig configured as shown below, first, as shown in Fig. 4,
- Fit the concave curved surface 3 of the main body 1 to the front side of the worker's knee, then wrap the cloth heald 4 around the knee and connect both ends with the connecting member 5. Fasten to the knee. Then, while holding the straight pipe material P at both ends thereof, engage it with the center part of the curved groove 2 of the knee body 1, and then bend both ends of the pipe material toward the rear side of the knee. Press down firmly. Thereby, the pipe material P is deformed along the curved groove 2 and bent into a predetermined shape.

As shown in L below, when bending is performed using the bending jig of this embodiment, the pipe material P gradually engages with the curved groove 2 from the center of the shoe body 1 toward both ends. It gradually deforms into an arc shape. Therefore, the bending direction and bending radius of the pipe material P are regulated by the curved groove 2, and as a result, it is possible to perform bending in a certain direction at a constant curvature without requiring special skill. Moreover, if the mark 8 on the shoe body 1 is used as a guideline for the bending angle, the bending angles of the pipe materials can be made to match approximately 90 degrees.

Further, since the bending load applied to the pipe material is dispersed in the longitudinal direction of the curved groove 2 by the engagement between the pipe material and the curved groove 2, the pipe material is not crushed flat in the middle thereof. Incidentally, when bending of a pipe material was attempted using the bending jig of this example, the oblateness of the pipe after bending was 15% or less. Note that the oblateness here refers to a value obtained by dividing the difference between the major axis and the minor axis of a pipe material that has been deformed into an elliptical cross-sectional shape by the original pipe diameter.

Furthermore, according to the bending and pressing jig of this embodiment, the bending load is not concentrated at a constant level (it is moderately distributed, so there is no risk of hurting the worker's knees even if the bending load is repeated).

Moreover, in this embodiment, the area of the concave curved surface section 3 is expanded by setting the width of the concave curved surface section 3 to be larger than the side of the knee body 1 on which the curved groove 2 is provided.
The shoe body 1 is supported more stably, the load applied to the worker is further dispersed, and the shock absorber 7 is provided on the concave curved surface portion 3, so that the risk of hurting the knee is more reliably eliminated. Ru.

In addition, since the bending jig of this embodiment has a simple structure that only combines the shoe body 1 and the fixture 6,
It is significantly lighter and heavier than the conventional pipe bender, which is equipped with a moving mechanism for the shoe body, a handle, etc., and can be carried while attached to the worker's lap, making it easier to use in narrow spaces such as ceilings or under floors. It can be easily transported to a location and used for bending.

Note that this embodiment is merely an example, and the central angle 01 of the shoe body 1, the height of the shoe body 1, etc. may be changed as appropriate.

[Effects of the Invention] As explained above, according to the present invention, the bending process is performed by engaging the curved groove of the shoe body with the pipe material while the shoe body is fixed to the worker's knee using the fixture. By doing this, the pipe material can always be bent in a certain direction and at a constant curvature along the curved groove, and since the bending load on the pipe material is distributed, the pipe material will not be crushed. This provides an excellent effect in that bending can be performed with a constant quality without requiring special skill.

Furthermore, it has a much simpler structure and is much lighter in weight than conventional pipe venters, so it can be easily carried into narrow spaces such as ceilings by being carried while attached to the worker's lap. It is possible to bend the material by bending it.

In addition, especially when the radius of curvature at both ends of the concave curved surface section is made smaller than that at the middle section, the adhesion between both sides of the concave curved surface section and the worker's knees can be improved. If the width of the concave curved surface part is larger than the width of the curved groove side of the shoe body, the knee body can be supported more stably, and the knee part of the worker can be supported more reliably. By dispersing the applied load, you can eliminate the risk of hurting your knees. Furthermore, if a cushioning material is attached to the concave curved surface portion, the risk of hurting the knees can be more reliably eliminated. Furthermore, by making the groove width on both ends of the curved groove larger than the groove width on the middle part side, the pipe material can be reliably engaged with the curved groove from the start of bending to the end of bending.

[Brief explanation of drawings]

Fig. 1 is a plan view showing one embodiment of the present invention, and Fig. 2 is a plan view showing an embodiment of the present invention.
3 is a sectional view taken along line 11-1'l in the figure, FIG. 3 is a sectional view taken along line nl-In in FIG. 1: Shoe body; 2: Curved groove; 3: Concave curved surface portion; 6: Fixture; pipe material.

Claims (5)

[Claims] (1) A curved groove extending in a convex arc is formed on one side of the shoe body made of a hard material, and a curved groove extending in the same direction as the curved groove is formed on the other side of the shoe body to allow the operator to kneel. A concave curved surface part that fits into the part is formed, and in this concave curved surface part,
A bending jig for pipe material, which is equipped with a fixture that wraps around the worker's knee and fixes the shoe body to the worker. (2) The pipe material bending jig according to claim 1, wherein the radius of curvature of the concave curved surface portion is determined such that the radius of curvature at both ends is smaller than that at the intermediate portion. (3) The pipe according to claim 1 or 2, wherein the width of the concave curved surface portion of the shoe body is set to be larger than the width of the side of the shoe body where the curved groove is provided. Material bending jig. (4) The pipe material bending jig according to claim 1, 2 or 3, wherein the groove width of the curved groove is set larger at both ends than at a longitudinally intermediate portion thereof. . (5) A pipe material bending treatment according to any one of claims 1 to 4, characterized in that a cushioning material is fixed to the surface of the concave curved portion to relieve the load applied to the worker. Ingredients.