JPH09323128A - Bending device for tube made of metal - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the occurrence of a wrinkle at the time of bending by swelling and deforming a rubber member by a deforming means after inserting a wrinkle preventing jig to the working point of the tube, and making the rubber member be in press-contact with the inside wall of the tube. SOLUTION: After inserting the wrinkle preventing jig 21 to the working point of the tube 3 from a pressing fitting 41 side, the tube 3 is clamped on a bending die 7 by a clamping die 9. Next, by pressing down the outer periphery of the tube 3 by a pressure die 11, and by pulling a wire 31 by a hydraulic cylinder 45 in the arrow E direction, the press-fit of the rubber member 25 is strongly performed to a receiving fitting 43. It follows that the rubber member 25 is swelled and deformed, its press-fit is performed to the inside wall of the tube 3, and outward pressures F by the rubber member 25 are uniformly dispersed in the tube 3 by the spheres 35 of a core material 23. In this state, when rotating the bending die 7 in the arrow B direction while moving a pressure die 11 in the arrow A direction, the bending of the tube 3 along with the peripheral surface of the bending die 7 is performed, and the occurrence of the wrinkle is prevented by the rubber member 25 being in press-contact with the inside wall of the tube 3.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a bending apparatus for a metal pipe.

[0002]

2. Description of the Related Art As a bending apparatus for a metal pipe, the one shown in FIG. 3 is conventionally known. In this bending apparatus 1, a metal cored bar (wrinkle prevention jig) 5 is inserted at a processing point of the pipe 3, and the metal cored bar 5 is clamped by a clamp die 9 on a circular bending die 7 and then the pipe 3 The outer periphery is suppressed by a pressure die 11, which is moved in the direction of arrow A, and the bending die 7 is rotated in the direction of arrow B, so that the pipe 3 along the peripheral surface of the bending die 7 is rotated.
The clamp die 9 is a bending die 7
It is configured to be able to move back and forth in the directions of arrows C and D along the guide base 13 connected to the clamp die 9, and the clamp die 9 that clamps the pipe 3 rotates in the direction of arrow B together with the bending die 7. ing.

A groove 15 having an arcuate section is formed on the outer circumference of the bending die 7 so as to match the outer circumference of the pipe 3. Further, the clamp die 9 and the pressure die 11 are also provided with similar grooves 17 and 19. Is formed on the pressure contact surface with.

[0004]

Generally, when bending a metal pipe, the inside of the bent portion receives a compressive force. Therefore, when a pipe having a small bending radius or a thin wall is bent, There is a problem that wrinkles occur in the processing part.

Therefore, as described above, conventionally, when bending the pipe, a metal cored bar is inserted as a wrinkle prevention jig into the processing point of the pipe to prevent the generation of wrinkles.
Since it is difficult for this kind of metal cored bar to make close contact with the inner wall of the pipe, it was not possible to reliably prevent the generation of wrinkles. Also, to prevent wrinkles during bending,
There is known a method of bending a pipe by sealing water, oil, sand or the like in the pipe, as disclosed in JP-A-53-108873, instead of the core metal.

According to this method, therefore, the core metal is used because water, oil, sand, etc. generate outward pressure in accordance with the bending of the pipe and adhere to the inner wall of the pipe. It is possible to reliably prevent the generation of wrinkles as compared with the case. However, these methods using water, oil, sand, etc. require large-scale equipment and are cumbersome to process, which is not suitable for bending a large amount of pipes.

The present invention has been devised in view of such circumstances, and it is possible to reliably prevent the generation of wrinkles during bending of a pipe, and even when water, oil, sand or the like is used. An object of the present invention is to provide a bending apparatus for a metal pipe, which has a low equipment cost, a simple structure, and excellent workability.

[0008]

In order to achieve the above object, the invention according to claim 1 clamps a metal pipe in which a wrinkle preventing jig is inserted into a rotatable bending die with a clamp die, In a metal pipe bending apparatus that bends a metal pipe along the circumference of the bend die by rotating the bend die, the wrinkle prevention jig has an outer diameter shorter than the inner diameter of the metal pipe. It is characterized in that it is constituted by a cylindrical rubber member which is molded and has a flexible core member axially mounted therein, and a deforming means for bulging and deforming the rubber member.

The invention according to claim 2 is based on claim 1.
In the bending apparatus for a metal pipe according to the above, the deforming means is attached to a tension member that is inserted through the core member and an end portion of the rubber member that is inserted into the metal pipe, and one end side of the tension member is connected. A push metal fitting, a receiving metal fitting attached to the other end side of the rubber member, through which the tension member is inserted, and an actuator attached to the receiving metal fitting and connected to the other end side of the tension member. The invention according to claim 3 is claim 1
Alternatively, in the apparatus for bending a metal pipe according to claim 2, the core material is formed by alternately connecting a plurality of spheres in which the through holes of the tension members are formed and a substantially cylindrical spacer. Is characterized by.

(Operation) According to the bending apparatus of the first aspect, when the wrinkle prevention jig is inserted into the processing point of the pipe and the rubber member is bulged and deformed by the deforming means, the rubber member becomes the inner wall of the pipe. It will be pressed against to prevent the generation of wrinkles during bending. In the invention according to claim 2, when the tension member is pulled by the actuator and the rubber member is firmly pressed against the metal fitting, the rubber member is bulged and deformed and pressed against the inner wall of the pipe.

According to the third aspect of the invention, when the rubber member is bulged and deformed, the sphere uniformly distributes the pressure to the outside of the rubber member, and is used for bending a pipe having a small bending radius. Also has sufficient flexibility.

[0012]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 shows an embodiment of a bending apparatus according to claims 1 to 3, in which 21 is a wrinkle preventing jig inserted in a metal pipe 3 and is a wrinkle preventing jig. As shown in FIG. 2, the tool 21 has a core material 23 that is formed with an outer diameter dimension shorter than the inner diameter dimension of the pipe 3 and has flexibility inside.
A cylindrical rubber member 25 mounted in the axial direction,
The rubber member 25 is configured to be deformed by bulging and deforming.

The rubber member 25 is formed by molding a rubber made of ester polyurethane having a hardness Shore A of about 50 into a cylindrical shape having a predetermined wall thickness, and is bulged and deformed by the operation of the deforming means 27 to make the pipe 3 It adheres to the inner wall of the. Then, the core material 2 is inserted into the core material insertion hole 29 provided at the center thereof.
3 is press-fitted. The core member 23 is a wire 31 described later.
A plurality of metal spheres 35 each having an insertion hole 33 formed therein,
Substantially cylindrical spacers 37 having a diameter slightly smaller than this and having substantially the same diameter as the core material insertion hole 29 are formed so as to be alternately connected to each other, and an insertion hole 39 for inserting the wire 31 is also formed in the spacer 37. It is provided in the direction. Both ends of each spacer 37 are shaped along the sphere 35 so that they are in spherical contact with each other.

The deforming means 27 for bulging and deforming the rubber member 25 is attached to the wire 31 inserted through the insertion holes 33 and 39 and the insertion side end 25a of the rubber member 25 into the pipe 3. Then, the metal push fitting 41 to which one end of the wire 31 is connected, the metal receiving fitting 43 which is attached to the other end 25b side of the rubber member 25, and through which the wire 31 is inserted, is attached to the receiving fitting 43. Hydraulic cylinder 45
It is composed of

The push fitting 41 is formed in a substantially U-shaped cross section, and a cylindrical receiving member 49 for receiving the spherical body 35 is housed in a recess 47 provided in the center thereof so as to be slidable in the arrow direction. Has been done. This receiving member 49 has an insertion side end portion inserted into the core material insertion hole 29, and an insertion hole 51 through which the wire 31 is inserted is formed at the center, and the insertion hole 51 is inserted as shown in the drawing. It gradually expands in the direction of the side end portion and spherically contacts the spherical body 35 at the opening. And
The wire 31 is connected to the push metal fitting 41 through the insertion hole 53 provided coaxially with the insertion hole 51 and the fixing tool 55.

Reference numeral 57 in the drawing denotes a coil spring mounted in the recess 47. On the other hand, the receiving fitting 43 is also formed in a substantially U-shaped cross section, and the piston rod 61 of the hydraulic cylinder 45 is arranged in the recess 59. And
The wire 31 is connected to the tip of the piston rod 61 through the insertion hole 63 provided in the receiving fitting 43.
When the hydraulic cylinder 45 is driven to pull the wire 31 in the direction of the arrow E, the push fitting 41 moves in the same direction and presses the rubber member 25 against the fitting 43, so that the rubber member 2
5 bulges and deforms and comes into pressure contact with the inner wall of the pipe 3, and the spherical body 35 of the core material 23 uniformly disperses the outward pressure F of the rubber member 25.

A receiving portion 65 having substantially the same shape as that of the receiving member 49 is integrally formed in the receiving metal fitting 43 to form a core material insertion hole 29.
The sphere 35 of the core member 23 is supported by the receiving portion 65. The bending apparatus 67 according to the present embodiment suppresses the wrinkle prevention jig 21 and the circular bending die 7 as described above, and the clamp die 9 for clamping the pipe 3 to the bending die 7 and the outer circumference of the pipe 3. Pressure type 1
However, since the structures of these molds 7, 9 and 11 are the same as those of the conventional example shown in FIG. 3, their structural description will be omitted.

Since the bending apparatus 67 according to this embodiment is constructed in this way, in order to bend the pipe 3 using the bending apparatus 67, first, the pressing metal fitting 4 is used.
The wrinkle prevention jig 21 is inserted into the processing point of the pipe 3 from the 1 side, and the pipe 3 is clamped to the bending die 7 by the clamp die 9. The rubber member 25 is molded with a certain hardness so as to be in a straight upright state as shown in FIG. 2 when the wrinkle prevention jig 21 is inserted into the pipe 3. When the tip side is bent due to weight, the hydraulic cylinder 45 is actuated to slightly pull the wire 31, and the rubber member 31 is pressed against the receiving metal fitting 43 and stands straight.

Then, the outer circumference of the pipe 3 is held down by the pressure die 11, and the wire 31 is pulled in the direction of arrow E by the hydraulic cylinder 45 to firmly press the rubber member 25 against the metal fitting 43, so that the rubber member 25 expands. It deforms to come into contact with the inner wall of the pipe 3 under pressure, and the spherical body 35 of the core member 23 uniformly distributes the outward pressure F of the rubber member 25 to the pipe 3.

Then, in this state, the pressure die 11 is moved in the direction of arrow A, and the bending die 7 is rotated in the direction of arrow B, so that the pipe 3 is bent along the peripheral surface of the bending die 7. At this time, a compressive force is applied to the inside of the bent portion of the pipe 3, and the rubber member 25 slightly expands as the pipe 3 is bent, but the rubber member 25 pressed against the inner wall of the pipe 3 causes wrinkles. Prevent.

Therefore, according to the present embodiment, it is possible to reliably prevent the generation of wrinkles during bending of the pipe 3, and the equipment cost is still higher than that of the conventional example using water, oil, sand or the like. It is cheap and has a simple structure, which improves workability.
The wrinkle prevention jig 21 is flexible in all directions, and the spherical body 33 of the core member 23 and the spacer 37 are in spherical contact with each other, so that the pipe 3 having a small bending radius is used.
Even in the bending process, it is possible to reliably prevent the generation of wrinkles.

In the above embodiment, the wire 31 is used as the pulling member of the deforming means 27, but such wire 31 is used.
Instead of this, a chain may be used, and the core member 23 does not necessarily have to be attached to the central portion of the rubber member 25.
Further, the structure of the core member 23 is not limited to the above embodiment, and may be any structure having flexibility that can be used for bending the pipe 3 having a small bending radius.
Although not shown, the rubber member 25 is replaced with a split structure composed of, for example, three cylindrical split rubber members, and the split rubber member at the center is made softer than the split rubber members on both sides. It can be changed.

As the actuator for operating the pulling member such as the wire 31, an air cylinder or a motor may be used instead of the hydraulic cylinder 45.

[0025]

As described above, according to the apparatus for bending a metal pipe according to each of the claims, it is possible to reliably prevent the generation of wrinkles during bending of the pipe, and to prevent water and Compared with the conventional example that uses oil, sand, etc., the equipment cost is lower and the structure is simple, and the workability is improved.

Further, according to the invention of claim 3, since the spherical body of the core material uniformly disperses the outward pressure by the rubber member, it is possible to more reliably prevent the generation of wrinkles and to bend it. It has sufficient flexibility even when bending a pipe having a small radius.

[Brief description of drawings]

FIG. 1 is a sectional view of an essential part showing bending of a pipe according to an embodiment of a bending apparatus according to claims 1 to 3.

FIG. 2 is a cross-sectional view of a main part of an embodiment of a wrinkle prevention jig.

FIG. 3 is a side view of a conventional apparatus for bending a metal pipe.

[Explanation of symbols]

 3 Pipe 7 Bending Type 9 Clamping Type 11 Pressure Type 21 Wrinkle Prevention Jig 23 Core Material 25 Rubber Member 27 Deformation Means 31 Wire 33, 39, 51, 53, 63 Insertion Hole 35 Sphere 37 Spacer 41 Pushing Metal Fitting 43 Receiving Metal Fitting 45 Hydraulic Pressure Cylinder 67 Bending machine

Claims (3)

[Claims] 1. A rotatable bending die (7) is provided with a wrinkle prevention jig (21) inserted into a metal pipe (3) while being clamped by the clamping die (9), while the bending die (7) is rotated. In a metal pipe bending apparatus for bending a metal pipe (3) along the peripheral surface of a bending die (7), the wrinkle prevention jig (21) is attached to the inner diameter of the metal pipe (3). A cylindrical rubber member (25) having an outer diameter dimension smaller than the dimension and having a flexible core member (23) axially mounted therein, and bulging and deforming the rubber member (25). Deformation means (2
7) A bending apparatus for a metal pipe, characterized in that 2. The deforming means (27) is attached to a tension member which is inserted through the core member (23) and an end portion (25a) of the rubber member (25) which is inserted into the metal pipe (3). A push metal fitting (41) to which one end side of the tension member is connected, a metal fitting (43) which is attached to the other end (25b) side of the rubber member (25) and through which the tension member is inserted, and the metal fitting (43). The bending apparatus for a metal pipe according to claim 1, characterized in that the bending apparatus comprises a mounting member and an actuator to which the other end of the tension member is connected. 3. The core member (23) is an insertion hole (3) for a tension member.
The bending process for a metal pipe according to claim 1 or 2, wherein a plurality of spherical bodies (35) formed with 3) and a substantially cylindrical spacer (37) are alternately connected. apparatus.