JPH0217705Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to a pipe bending device that bends a straight pipe material, such as a gas pipe or water pipe, into a predetermined shape at an arbitrary location. .

[Technical background of the invention]

Conventional pipe bending equipment uses (1) hot treatment means to fill the pipe with sand and heat it to bend the pipe, and (2) to prevent pipe bending from cracking or collapsing. A cold treatment method is employed in which a metal core is inserted into the core and bent into a predetermined shape.

In particular, the previously proposed pipe bending apparatus using the above-mentioned cold treatment means is constructed as shown in FIGS. 3 and 4.

That is, in FIGS. 3 and 4, a bending pulley body 1 in which a circumferential groove 1a having an arcuate cross section is formed is rotatably mounted on a machine frame (not shown) by a rotating shaft 2. A movable gripping member 3 is attached to the rotating shaft 2.
is pivoted so as to grip the pipe (pipe material) W to be bent and rotate integrally with the bending pulley body 1. Note that the movable gripping member 3
The gripping portion 3a is adapted to temporarily and firmly fix the pipe W within the circumferential groove 1a of the bending pulley body 1 using an actuator such as a hydraulic cylinder (not shown).

On the other hand, a fixed pedestal 4 having a groove 4a is provided on the machine frame near the circumferential groove 1a located on one side of the movable gripping member 3. A pressing member 5 having grooves 5a having the same shape as the pressing member 5 is provided on the surface so as to press and hold the pipe W using a hydraulic cylinder (not shown). In addition, inside the pipe W in which the pressing member 5 is located, a bullet-shaped core bar 6 having approximately the same diameter as the inner diameter of the pipe W is disposed such that it can be freely inserted and removed by a guide rod 7 integrated therewith. has been done. Note that the pressing force of the gripping portion 3a is greater than the pressing force of the pressing member 5, and the pipe W is bent so that the circumferential groove 1 of the pulley body 1 is bent.
Since the pipe W is in pressure contact with the pressing member 5, the pipe W located on the pressing member 5 slides against the pressing member 5 during the bending operation.

Therefore, in the pipe bending device described above, the core bar 6 is pressed against the pressing member 5 in advance during the pipe bending process.
Position it at the tip of the tube and temporarily fix it.

Next, the straight pipe W to be bent is positioned and placed in the circumferential groove 1a of the bending pulley body 1 via the core metal 6. However, the fixed pedestal 4
The pipe W in the groove 4a is temporarily fixed by the pressing member 5, and on the other hand, the pipe W is gripped more firmly by the gripping portion 3a of the movable gripping member 3 than by the pressing member 5. After that, the bending pulley body 1
is rotated by a predetermined rotation angle in anticipation of the spring back of the pipe W.

In this way, the straight pipe W is curved into a predetermined shape.

[Problems with background technology]

However, in the above-mentioned pipe bending device, the pipe W is temporarily fixed by the fixed pedestal 4 on which the core bar 6 is located and the pressing member 5, and on the other hand, the pipe W is fixed by the bending pulley 1 and the gripping part 3a of the movable gripping member 3. Since the pipe W is curved and formed into a predetermined shape by being gripped and rotated, the pipe W located in the groove 5a of the core metal 6 and the pressing member 5 is subjected to bending stress. Not only is there a possibility that distortion and cracks may occur due to the frictional force, but there is also a possibility that the curved portion of the pipe W is eroded due to this.

[Purpose of invention]

The present invention has been made in view of the above-mentioned circumstances, and is designed to prevent distortion and distortion in the curved portion of the pipe that is formed by pushing the rear part of the pipe W in the bending direction (axial direction) in synchronization with the bending pulley body. The present invention provides a pipe bending device that aims to prevent the occurrence of cracks and at the same time improve the quality of pipes that are bent into a predetermined shape.

[Summary of the idea]

In the present invention, a bending pulley body that grips and rotates a pipe and a main drive gear integral with the bending pulley body are mounted on a machine frame, one end of a rack member is engaged with the main drive gear, and the other end of the rack member is engaged with the main drive gear. A driven gear is engaged with the driven gear, and a rack of a pushing cylinder into which the pipe is inserted is provided so as to be pushed in the axial direction of the pipe.

[Example of idea]

Hereinafter, the present invention will be described with reference to an illustrated embodiment.

In addition, the present invention will be described with the same reference numerals attached to the same constituent members as in the above-described specific example.

In FIGS. 1 and 2, reference numeral 1 denotes a bending pulley body having a circumferential groove 1a having an arcuate cross section and mounted on a machine frame (stationary member) (not shown) by a rotating shaft 2. A movable gripping member 3 is mounted on the rotating shaft 2 so as to grip a pipe (workpiece) W and rotate integrally with the bending pulley body 1. The portion 3a is configured to temporarily and firmly fix the pipe W within the circumferential groove 1a of the bending pulley body 1 using an actuator (not shown). Further, a fixed pedestal 4 having a groove 4a is provided on the machine frame side (stationary member) near the circumferential groove 1a located on one side of the movable gripping member 3. A pressing member 5 having grooves 5a having the same shape as the pressing member 5 is provided on the joint surface of the pipe W so as to press and hold the pipe W using a hydraulic cylinder (not shown). Furthermore, this pressing member 5 is configured to press and hold the pipe W using a hydraulic cylinder (not shown). Further, inside the pipe W in which the pressing member 5 is located, a bullet-shaped core bar 6 having approximately the same diameter as the inner diameter of the pipe W is provided so as to be freely insertable and removable by a guide rod 7 integrated therewith. ing.

Note that the pressing force of the gripping portion 3a is greater than the pressing force of the pressing member 5 to bend the pipe W and press it against the circumferential groove 1a of the pulley body 1, so that the pipe W located on the pressing member 5 is during bending operation,
It is adapted to slide relative to the pressing member 5.

On the other hand, a main drive gear 8 is integrally mounted on the rotating shaft 2 with the bending pulley body 1, and one end 9a of a rack member 9 is meshed with the main drive gear 8. A driven gear 10 is meshed with the other end 9b of the rack member 9, and the driven gear 10 is rotatably mounted on a support shaft 11 to the machine frame. Furthermore, a small gear 12 is integrally mounted on this support shaft 11 with the driven gear 10,
A rack 13a attached to a push cylinder 13 into which the pipe W is inserted is meshed with the small gear 12 so as to push the pipe W in the axial direction. Furthermore, the push cylinder body 13 is temporarily fixed to the pipe W by each mounting bolt 14, and the pipe W is fixed to the axis of the pipe W by the push cylinder body 13. It is now being pushed in a direction.

Therefore, when bending a pipe, the core metal 6 is positioned and temporarily fixed at the tip of the pressing member 5 in advance, and the metal core 6 is positioned directly above the driven gear 10 located behind the fixed pedestal 4. After meshing the rack 13a of the push cylinder 13 with the small gear 12, attach the push cylinder 13 to the pipe W with each mounting bolt 14.
temporarily fixed by

Next, the bending pulley body 1 is rotated by a predetermined rotation angle, taking into account the spring back of the pipe W. Then, since the main drive gear 8 coaxially integrated with the bending pulley body 1 also rotates to the right, the rack member 9 meshing therewith moves to the left in FIG. Since the driven gear 10 meshed with the other end of the rack member 9 is rotated, the small gear 12 which is integrally coaxial with the driven gear 10 is rotated. Then, this small gear 12 is connected to the rack 1 that meshes with it.
3a to the right in FIG. 1, the pushing cylinder 13 integrated with the rack 13a pushes the pipe W in the axial direction against the pressing force of the pushing member 8.

That is, although the pipe W pushed by the pushing cylinder 13 is subjected to bending stress and frictional force between the groove 5a of the pushing member 5 and the core bar 6, as described above, the pipe W is pushed by the bending pulley body. Since the pushing force similar to the rotational moment of 1 is applied by the pushing cylinder 13, the tensile force applied to the pipe W is eliminated, so that distortion and cracks do not occur in the curved part of the pipe W. This can be prevented from occurring, and the quality of the pipe can be improved.

[Effect of idea]

As described above, according to the present invention, the bending pulley body 1 that grips and rotates the pipe W and the main drive gear 8 that is integral with the bending pulley body 1 are mounted on the machine frame, and the main drive gear 8
The rack 13a of the pushing cylinder 13 has one end of the rack member 9 meshed with the rack member 9, a driven gear 10 and a small gear 10 meshed with the other end of the rack member 9, and the pipe W inserted into the small gear 10. The above pipe W
Since the pipe W is provided so as to be pushed in the axial direction, not only can the tensile stress applied to the pipe W be canceled by the rearward pushing force and prevent distortion and cracks, but also the main gear 9 and the driven gear 10 and small gear 1
By changing the gear ratio with 2, the boosting force can be adjusted freely, and since the gear mechanism is used, the power can be transmitted smoothly.

[Brief explanation of drawings]

FIG. 1 is a partially cutaway front view of a pipe bending device according to the present invention, FIG. 2 is a left side view of the same, and FIG. 3 is a partially cutaway view of a pipe bending device that has already been proposed. The cutaway front view and FIG. 4 are exploded perspective views of the same. DESCRIPTION OF SYMBOLS 1... Bending pulley body, 2... Rotating shaft, 3... Movable gripping member, 4... Fixed pedestal, 5... Pressing member, 6
... Core metal, 7 ... Guide rod, 8 ... Drive gear, 9
... Rack member, 10 ... Main drive gear, 12 ... Small gear, 13 ... Push cylinder body.

Claims (1)

[Scope of utility model registration request] A bending pulley body that grips and rotates the pipe and a main drive gear integral with the bending pulley body are mounted on a machine frame, one end of a rack member is meshed with the main drive gear, and a driven gear is attached to the other end of the rack member. A pipe bending device characterized in that the following gears are engaged with each other, and a rack of a pushing cylinder body into which the pipe is inserted is pushed in the axial direction of the pipe by the driven gear.