JP2009012068A - Rotary draw bending apparatus of pipe - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rotary draw bending apparatus with a back-tension mechanism, which does not require a pre-working (drilling, crushing, screwing, etc.) for forming a grabbable shape part which enables fixing by a grabbing tool of a drawing means at the end part of a pipe to be bent and improves the producibility of working. <P>SOLUTION: The back-tension supplying mechanism 5, which makes the pre-working unnecessary, is provided with a taper collet 6 which enlarges/reduces in the radial direction of the pipe to be able to press the inner peripheral surface of the pipe, an outer cylindrical ring 8 which holds the taper collet to be able to contact with the outer peripheral surface of the pipe, an expander 7 which penetrates the outer cylindrical ring and the taper collet and moves in the axial direction of the pipe to make the taper collet enlarge/reduce in the radial direction of the pipe, a cylinder 12 for a pipe-end cramp which moves a rod 11 connected with the expander in the axial direction of the pipe, and a pipe-axial tension loading hollow cylinder 13 which makes the rod penetrate to connect it with the cylinder for the pipe-end cramp and the outer cylindrical ring and moves these in the axial direction of the pipe. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a pipe rotary draw bending machine, and more particularly to a pipe rotary draw bending machine having a rear tension mechanism.

In a rotary drawing process with a relatively large bending radius, a simple rotary drawing machine that does not generate wrinkles on the inner side of a thin-walled pipe has a rear tension mechanism (see, for example, Patent Document 1).
JP 2006-88178 A

  In the conventional rotary pull bending machine having the rearward tension mechanism, in order to form a grippable shape that enables the rear tensioning mechanism to be locked by a gripping tool at the pipe end portion used for bending, Processing (hole drilling, crushing, screw processing, etc.) needs to be performed, and this pre-processing step has a problem that it is difficult to improve the productivity of processing by a rotary bending machine having a rear tension mechanism.

The present invention solves the above-mentioned problems by devising a rear tension mechanism that can apply a rear tension to a pipe end of a pipe without pre-processing the pipe end.
That is, the present invention
A rotatable bending die having an outer peripheral portion corresponding to the bending shape of the pipe, a clamp for fixing the front end portion of the pipe to the bending die, and the pipe in the tube axis direction in cooperation with the bending die. In a rotary bending machine for a pipe having a movable pressing die and pressing die supporting means for supporting the pressing die against the pipe while pressing it,
Furthermore, a taper collet capable of pressing the inner peripheral surface of the rear end portion by expanding and contracting in the tube radial direction of the rear end portion, and holding the taper collet and contacting the outer peripheral surface of the tube of the rear end portion. An outer cylinder ring, an expander that passes through the outer cylinder ring and the taper collet and moves in the tube axis direction to expand and contract the taper collet in the tube radial direction, and a rod connected to the expander is connected to the tube axis A tube end clamping cylinder that moves in the direction, and a tube axis tension hollow cylinder that passes through the rod and is connected to the tube end clamping cylinder and the outer ring to move them in the tube axis direction. It is a pipe rotary drawing and bending machine (present invention machine) characterized by having a rear tension mechanism.

  In the machine according to the present invention, the tapered collet is a split mold divided in the pipe circumferential direction, and each of the divided split molds can slide in the pipe axis direction along the expander, and from the expander The outer cylinder ring includes a separable inner member and an outer member, and the inner member and the outer member. It is preferable to have a structure in which the flange of the taper collet is suppressed and the movement of the taper collet in the tube axis direction is suppressed.

  According to the present invention, in the rotary bending machine having a rear tension mechanism, a pre-processing step for forming a grippable shape at the pipe end of the pipe is not required, and the productivity of the rotary drawing process is improved.

  FIG. 1 is a schematic diagram showing an example of the present invention machine. The bending die 1 has an outer peripheral portion corresponding to the bending shape of the pipe 10 and can rotate around the rotation center point O. The clamp 2 is a means for fixing the front end portion of the pipe 10 to the bending die 1. The pressing die 3 can move in the direction of the tube axis while sandwiching the pipe 10 in cooperation with the bending die 1. Here, the pipe axis direction means the length direction of the pipe axis of the straight pipe part (unbent straight pipe part) of the pipe 10 (the same applies hereinafter).

The pressing mold support means 4 is a means for supporting the pressing mold 3 while pressing it against the straight pipe portion of the pipe 10. This pressing force opposes the bending reaction force. The distance in the tube axis direction between the force point at which the pressing die support means 4 pushes the pressing die 3 and the point at which the pipe 10 abuts against the bending die 1 is larger than the outer diameter D of the pipe 10.
The rear tension mechanism 5 unique to the device of the present invention comprises a taper collet 6, an outer cylinder ring 8, an expander 7, a rod 11, a tube end clamping cylinder 12, and a tube axis tension loading hollow cylinder 13.

  The taper collet 6 can expand and contract in the radial direction of the pipe at the rear end of the pipe 10 and can press the inner peripheral surface of the pipe at the rear end. In this expansion / contraction operation, the contraction is spontaneous, and the expansion is due to forced expansion from the inner diameter side. The outer cylinder ring 8 can hold the taper collet 6 and contact the outer peripheral surface of the pipe at the rear end. The expander 7 is a member that expands and contracts the taper collet 6 in the radial direction of the tube by changing the diameter of the portion penetrating the outer cylinder ring 8 and the taper collet 6 and moving in the tube axis direction and inscribed in the taper collet 6. The rod 11 is detachably coupled to the tip of the rod 11 by a screwing method so that a plurality of different diameters can be easily used.

The cylinder 12 for pipe end clamping has its front end connected to the rear end of the rod 11 and transmits the reciprocating motion of the piston 12A driven by the pump 21 and the directional control valve 20 to the expander 7 at the tip of the rod 11. This is moved (advanced or retracted) in the direction of the tube axis.
The tube-tension load hollow cylinder 13 has a hollow portion of the hollow piston 13A passing through the rod 11, the front end of the piston 13A is connected to the outer cylinder ring 8 through the guide tube 9, and the rear end of the piston 13A is the guide The cylinder 13A is connected to the tube end clamping cylinder 12 through the cylinder 9A, and the reciprocating motion of the piston 13A driven by the pump 23 and the direction control valve 22 is applied to the outer cylinder ring 8 at the front end of the guide cylinder 9 and the pipe at the rear end of the guide cylinder 9A. This is transmitted to the end clamping cylinder 12 (and also to the expander 7 connected to the pipe end clamping cylinder 12 by the rod 11), and these are simultaneously moved (advanced or retracted) simultaneously in the tube axis direction.

  As a result, the pipe wall is strongly clamped by the taper collet 6 on the pipe inner peripheral surface side and the outer cylinder ring 8 on the pipe outer peripheral surface side against the rear end portion of the pipe 10 that is not pre-processed, and the pipe rear end due to this clamping pressure This makes it possible to maintain a firm gripping state of the part even when a rear tension is applied, and the pre-processing step can be omitted. In addition, it can be completed in a short time from pipe setting to the start of the clamping pressure and from the completion of the bending process to the release of the clamping pressure, and the work efficiency in the preparation stage before bending and the final stage after bending is improved. improves.

Next, the procedure for using the present invention machine will be described with reference to FIGS. FIG. 2 shows a preparation stage, and FIG. 3 shows a rotational drawing process or a subsequent cleanup stage.
Preparation [1] (FIG. 2 (a)): The pipe 10 is arranged at a predetermined pipe set position between the bending die 1 and the pressing die 3, and the pipe 10 is clamped by the cooperation of the bending die 1 and the pressing die 3. Then, the front end portion of the pipe 10 is fixed to the bending die 1 with the clamp 2.

Preparation [2] (FIG. 2 (b)): The tube end clamping cylinder 12 is operated in the extrusion mode, the expander 7 is moved forward in the tube axis direction, the diameter of the taper collet 6 is urged, and the outer cylinder. A tube-thickness-receiving space capable of storing the thickness of the pipe 10 at the rear end is formed between the ring 8 and the ring 8.
Preparation [3] (FIG. 2 (c)): The tube tension load hollow cylinder 13 is operated in the extrusion mode, and the outer cylinder ring 8, the taper collet 6 and the expander 7 are simultaneously moved forward in the tube axis direction. The tube meat at the rear end of the pipe 10 is accommodated in the tube meat accommodating gap.

Preparation [4] (FIG. 2 (d)): The tube end clamping cylinder 12 is operated in the retract mode, the expander 7 is moved backward in the tube axis direction, the diameter of the taper collet 6 is expanded, and the outer cylinder ring 8 The rear end of the pipe 10 is gripped by pinching the tube in the tube housing space in cooperation.
Rotating pull bending process (FIG. 3 (a)): While the bending die 1 is rotated, the pressing die support means 4 supports the pressing die 3 while pressing it against the pipe 10, and at the same time, the tube end clamping cylinder 12 and the tube shaft tension load hollow The cylinder 13 is operated in the pull-in mode, and a pipe shaft tension is applied to the pipe 10 while ensuring the gripping state of the rear end of the pipe 10.

Rear end [1] (FIG. 3 (b)): The expander 7 is moved forward by operating the tube end clamping cylinder 12 in the extrusion mode, and the diameter of the taper collet 6 is urged to reduce the tube at the rear end of the pipe 10. Release the pinching force of meat.
Cleanup [2] (Fig. 3 (c)): The tube cylinder tension load hollow cylinder 13 is operated in the retract mode, and the outer cylinder ring 8, the taper collet 6 and the expander 7 are simultaneously moved backward in the tube axis direction. The pipe 10 is separated from the rear end portion.

  Further, the taper collet and the outer cylinder ring can be configured as follows. That is, the taper collet is a split mold divided in the pipe circumferential direction, and each of the divided split molds can slide in the pipe axis direction along the expander, and can be separated from the expander. The outer ring is composed of an inner member and an outer member that can be divided, and the outer member is separated by the inner member and the outer member. In this configuration, the flange of the taper collet is suppressed to suppress the movement of the taper collet in the tube axis direction.

  An example of this form is shown in FIGS. In this example, the taper collet 131 is a split mold 131a, 131b, 131c, 131d divided into four in the pipe circumferential direction, but it may be divided into two, three, or more than five. In this example, a dovetail structure is employed as a structure in which each of the divided split molds can slide along the expander 132 and can be prevented from being separated from the expander 132. The dovetail structure (male type) and the dovetail groove (female type) of the dovetail structure are slidable in the length direction of each other with an appropriate clearance between them. In this example, the male type is provided on the taper collet 131 side and the female type is provided on the expander 132 side, but this may be reversed.

Each of the split dies 131a, 131b, 131c, and 131d can press the inner peripheral surface of the pipe 10, and the expander 132 can slide along the expander 132 so that the contact surface with the expander 132 can slide in the tube axis direction. The surface has the same taper as the 132 taper.
Further, the outer cylinder ring 133 has a structure in which the inner member 133a and the outer member 133b can be divided, and the inner member 133a and the outer member 133b suppress the flanges 131aa, 131ba, 131ca, and 131da of the taper collet 131, The movement of the taper collet 131 in the tube axis direction is suppressed. However, the holding force of the flange is adjusted to such an extent that the movement of the taper collet 131 in the pipe radial direction is not hindered. It should be noted that the inner member 133a and the outer member 133b may be integrated with a restraining plate (not shown) so as to prevent separation during tension loading.

  According to such a configuration form of the taper collet and the outer cylinder ring, the rear end portion of the pipe can be gripped more reliably and with a higher work efficiency, so this form is preferable.

  Using the machine of the present invention shown in FIG. 1, the rotary drawing bending process having the following specifications was performed according to the procedure shown in FIGS. The productivity evaluated in terms of the number of treatments per predetermined time in this processing is the same as the conventional performance (the same predetermined in processing using a rotary bending machine having a conventional rear tension mechanism that requires a pre-processing step of the pipe rear end. Compared with the productivity evaluated by the number of treatments per hour), it was improved by about 2 times.

Material: Carbon steel ERW steel pipe STKM13A, STKM15A, STKM17A
Outer diameter D × wall thickness t (mm): φ89.1 × t2.0, φ76.3 × t1.6 (t / D = 2.2, 2.1%)
Bending radius R (mm): 500, 600, 650 (R / D = 5.6 to 8.5), bending angle: 90 °

It is a schematic diagram which shows an example of this invention machine. It is a schematic diagram which shows an example of the use procedure of this invention machine. It is a schematic diagram showing an example of the procedure for using the machine of the present invention. It is a three-dimensional schematic diagram which shows an example of the divided | segmented taper collet. It is a cross-sectional schematic diagram which shows the pipe rear end part holding state using the taper collet of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Bending type | mold 2 Clamp 3 Push type | mold 4 Push type | mold support means 5 Back tension mechanism 6 Taper collet 7 Expander 8 Outer cylinder ring 9, 9A Guide cylinder
10 Pipe (pipe, steel pipe)
11 sticks
12 Pipe end clamping cylinder
12A, 13A piston
13 Pipe shaft tension load hollow cylinder
20, 22-way control valve
21, 23 Pump (hydraulic pump)
131 Taper collet
132 Expander
133 Outer ring O Rotation center point of bending mold

Claims (2)

A rotatable bending die having an outer peripheral portion corresponding to the bending shape of the pipe, a clamp for fixing the front end portion of the pipe to the bending die, and the pipe in the tube axis direction in cooperation with the bending die. In a rotary bending machine for a pipe having a movable pressing die and pressing die supporting means for supporting the pressing die against the pipe while pressing it,
Furthermore, a taper collet capable of pressing the inner peripheral surface of the rear end portion by expanding and contracting in the tube radial direction of the rear end portion, and holding the taper collet and contacting the outer peripheral surface of the tube of the rear end portion. An outer cylinder ring, an expander that passes through the outer cylinder ring and the taper collet and moves in the tube axis direction to expand and contract the taper collet in the tube radial direction, and a rod connected to the expander is connected to the tube axis A tube end clamping cylinder that moves in the direction, and a tube axis tension hollow cylinder that passes through the rod and is connected to the tube end clamping cylinder and the outer ring to move them in the tube axis direction. A rotary pull bending machine for a pipe, characterized by having a rear tension mechanism.   The taper collet is a split mold divided in the pipe circumferential direction, and each of the divided split molds can slide in the pipe axis direction along the expander and can be prevented from being separated from the expander. The outer ring is composed of an inner member and an outer member that can be divided, and the tapered collet is formed by the inner member and the outer member. 2. The rotary bending machine for pipes according to claim 1, wherein the pipe has a structure that suppresses the flange and suppresses the movement of the taper collet in the tube axis direction.

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