JPH08229613A - Method for correcting roundness of pipe and device therefor - Google Patents

Abstract

PURPOSE: To provide a method and device for maintaining the roundness of a pipe for supplying the pipe having high roundness at a low cost. CONSTITUTION: Inner spinning rolls 5 and an outer spinning rolls 6 are alternately arranged so as to be respectively brought into contact with the inner periphery and outer periphery of the pipe 11 and the inner spinning rolls 5 and outer spinning rolls 6 are revolved along cocentric circular arcs. In this way, the pipe 11 is alternately flexurally deformed from the inner and outer peripheral sides with the inner spinning rolls 5 and outer spinning rolls 6. Then, residual stress of the pipe 11 is reduced and the roundness of the pipe 11 is corrected.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pipe circularity straightening method and apparatus, and more particularly to a pipe circularity straightening method and apparatus for providing a pipe having a high roundness at low cost.

[0002]

BACKGROUND OF THE INVENTION Pipes are widely used to produce various mechanical parts. In general, pipes, whether they are seamless pipes or welded pipes, are subject to considerable plastic deformation in the process of processing and are subjected to additional strain, so that the pipe precision, especially the roundness, is slightly reduced. For this reason, when a pipe with high roundness is required for machine parts,
The pipe supplied from the material manufacturer is secondarily processed to correct the roundness of the pipe.

In the case of correcting the roundness of a pipe, a method by mechanical working and a method by plastic working are known. In the case of machining, since the pipe is turned, chips are generated and the processing speed is slow. Therefore, in consideration of productivity, it is preferable to correct the roundness of the pipe by plastic working. For plastic working,
There is known a method of expanding a pipe by an expanding process or reducing the pipe by a swaging process to correct the roundness of the pipe.

However, when straightening the roundness of a pipe by expanding or swaging, an expanding tool or swaging tool suitable for various sizes of pipe diameters is required, which results in manufacturing cost and production control. Is also not preferable. Therefore, there is a demand for a roundness straightening device that can provide a pipe with high roundness at low cost and that is easy to manage in production.

On the other hand, in order to correct the roundness of the pipe by plastic working, it is necessary to securely clamp the pipe during plastic working. For small-diameter pipes, you can use a 3-jaw chuck or a 5-jaw chuck that is used on lathes, but if the pipe has a large diameter, it is difficult to apply the jaw chuck, and tighten the pipe with a chain to tighten the pipe. It is clamped. In this case, the pipe is deformed by additional strain caused by tightening the chain or the like.

In order to prevent the deformation of the pipe, a tool for tensioning is attached to the inside of the pipe, or a tool for preventing the deformation of the pipe is attached from the outside of the pipe by a block, and when the chain is clamped by clamping. It prevents deformation of the pipe and prevents the roundness of the pipe from decreasing.

[0007]

However, these methods require tools adapted to various sizes of pipe diameters, require a skilled technician at the time of clamping, and require a long setup time. It is not preferable in terms of cost and production control. Therefore, an object of the present invention is to solve the problems of the above-mentioned prior art, to provide a pipe with high roundness at a low cost, and to provide a pipe roundness correction method and device which are easy to manage in production. To provide.

[0008]

In order to achieve the above object, the present invention has an inner spinning roll and an outer spinning roll which are alternately arranged so as to be in contact with the inner circumference and the outer circumference of a pipe. And to correct the circularity of the pipe by revolving the outer spinning roll along a concentric arc and alternately bending and deforming the pipe from the inner peripheral side and the outer peripheral side with the inner spinning roll and the outer spinning roll. It is a feature. Further, in order to achieve the above object, a pipe to be processed is placed on a plurality of rolls rotatably supported at predetermined intervals, and a plurality of struts erected on both left and right sides of the pipe. Abutting both left and right sides of the pipe,
It is characterized in that a flexible tightening member is hung on the outer circumference of the pipe and is connected to the plurality of columns to hold the pipe.

[0009]

According to the present invention, the inner spinning roll and the outer spinning roll are alternately arranged so as to contact the inner circumference and the outer circumference of the pipe, respectively, and the inner spinning roll and the outer spinning roll are revolved along the concentric arc. Thereby, the pipe can be alternately bent and deformed from the inner peripheral side and the outer peripheral side by the inner spinning roll and the outer spinning roll, the residual stress of the pipe is reduced, and the circularity of the pipe is corrected.

According to another aspect of the present invention, the pipe is placed on a plurality of rolls which are rotatably supported at a predetermined interval, and a plurality of stanchions erected on both left and right sides of the pipe are installed on the pipe. The pipe is held by being in contact with both right and left sides, by hanging a flexible tightening member on the outer periphery of the pipe, and connecting it to a plurality of columns. As a result, when tension is applied to the tightening member,
The pipe is pressed against the support roll by the pressing force of the tightening member, the pipe is pressed inward in the radial direction by the pressing force from the support roll, and at the same time, the pipe is pressed by the pressing force from the support column. Therefore, by balancing these pressing forces in a balanced manner, the pipe can be clamped without deformation.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A pipe roundness correcting method and device according to the present invention will be described below with reference to the drawings. In FIG. 1, a pipe roundness correcting device, generally designated by reference numeral 1, comprises a processing means 2 and a clamping means 3. The processing means 2 includes a rotating body 4, an inner spinning roll 5 and an outer spinning roll 6, and the rotating body 4 has a drive disk 7.
The drive disk 7 is connected to a rotary drive source (not shown) and also to an axial moving means. The rotary drive source rotates the drive disk 7, and the moving means moves the drive disk 7 in the axial direction.

A shaft 8 is coaxially fixed to the center of the drive disk 7, and the shaft 8 is provided with three arms 9, 9 ,.
It is radially fixed at intervals of 20 °. The inner spinning rolls 5, 5, ... Are rotatably supported at the tips of these arms 9, 9. These inner spinning rolls 5, 5, ... Are arranged concentrically and contact the inner peripheral surface of the end 11a of the pipe 11 to be straightened. Further, the inner spinning rolls 5, 5, ... Can be supported movably along the arms 9, 9 ... In a direction toward and away from the shaft 8 (that is, in a radial direction).

An arm 12 is extended and fixed to the shaft 8 in the radial direction, and an outer spinning roll 6 is rotatably supported at the tip of the arm 12. In this case, the outer spinning roll 6 is arranged outside the inner spinning rolls 5, 5, ... And comes into contact with the outer peripheral surface of the end 11 a of the pipe 11. Further, the outer spinning roll 6 can be supported so as to be movable along the arm 12 in a direction approaching the shaft 8 and a direction moving away from the shaft 8 (that is, a radial direction).

FIG. 4 shows a clamp device 3 for a pipe to be straightened. The clamp device 3 has a supporting roll 13 and a support 14 which come into rolling contact with the outer peripheral surface of the pipe, and a tightening member 15 such as a belt and a chain. It consists of and. The support rolls 13, 13, ... Are the support brackets 1.
It is rotatably supported by the table 16 via 7, 17, .... Further, as is apparent from FIG. 5, the support rolls 13, 13 ... Are arranged at equal intervals in positions symmetrical with respect to the center 0 of the pipe 11.

Pipes 11 are placed on the left and right support rolls 13, 13, .... The support rolls 13, 13 ... Are arranged at both ends of the pipe 11 as shown in FIG. On both the left and right sides of the pipe 11, columns 14, 14 ...
Is erected on the table 16 in a state of being in contact with. The support columns 14, 14 ... Are located at both ends of the pipe 11 similarly to the support rolls 13, 13. A tightening member 15 is connected to the upper ends of the columns 14, 14 in a stretched state, and the tightening member 15 contacts and presses the outer periphery of the upper side of the pipe 11. As a result, the clamp means 3 uses two sets of the support rolls 13, the columns 14 and the tightening members 15 to make the pipe 11
Clamp both ends of.

As described above, when the tightening member 15 is fixed to the upper ends of the columns 14, 14 while the tension is being applied to the tightening member 15, the pipe 11 presses the pressing force P of the tightening member 15.
(See FIG. 5) and pressed against the outer circumference of the support rolls 13, 13. In this case, the contact point m between the pipe 11 and the left support roll 13 is on the line connecting the center of the pipe 11 and the center of the left support roll 13, and the contact point n between the pipe 11 and the right support roll 13 is the pipe 11 Is on the line connecting the center of the support roll 13 and the center of the right side support roll 13. Therefore, the pipe 11 is pressed radially inward by the pressing force R by the left and right support rolls 13, 13. At the same time, the pressing force Q is applied to the pipe 11 by the columns 14, 14 ...
Works.

Here, if the pressing forces P, Q and R are balanced in good balance, the pipe 11 can be clamped without being deformed. Then, as a result of the mechanical numerical analysis, in order to balance the pressing forces P, Q, and R in a balanced manner, the contact points m and n between the support roll 13 and the pipe 11 are
It has been found that the optimum angle 2α between the center 0 of the pipe 11 and the pipe 0 is about 52 °. However, at the time of actual clamping, it is difficult to set the angle 2α strictly to about 52 °, so the support roll 13 is arranged so that the angle 2α is 50 ° to 55 °. Further, it was found that the length a from the center position of the pipe 11 of the support column 14 to the upper end of the support column 14 was calculated by the following equation (1) as a result of dynamic numerical analysis. However, a: the length from the central position of the pipe 11 of the strut 14 to the upper end of the strut 14 r: the outer radius of the pipe 11 2α: the contact points A, B between the support roll 13 and the pipe 11 and the center of the pipe 11 Angle A: (1) A = 2b / 3 (when the lower end of the strut 14 is fixed to the table 16 with bolts, etc.) (2) A = b (the lower end of the strut 14 is pinned to the table 16) B): from the center position of the pipe 11 of the column 14 to the table 16
Length k: constant determined by radius r of pipe 11 (1) k = (2.2541 / 10 ⁴ ) r + 1.119
3 (when the lower end of the column 14 is fixed to the table 16 with a bolt or the like) (2) k = 1.185 (the lower end of the column 14 is the table 1)
6 When it is rotatably supported by pins etc.)

Next, the operation of the roundness correcting device for a pipe constructed as described above will be described. First, the pipe 11 is clamped by the clamp device 3. That is, when tension is applied to the tightening member 15 shown in FIGS. 3 and 4, the pipe 11 is pressed by the pressing force P of the tightening member 15 so that the support rolls 13, 13 ...
Is pressed against the outer circumference of. As a result, the pipe 11 is pressed radially inward by the pressing force R by the left and right support rolls 13, 13 ...
The pressing force Q acts by 4, 14, ....

Here, using the above equation (1), the outer diameter radius is 6
The graph of FIG. 3 shows the result of calculating the deformation rate of the pipe 11 of 08 mm (the maximum roundness of the circularity of the pipe per unit tension of the tightening member 15: unit mm). As is apparent from FIG. 3, when the angle 2α is set to 50 ° to 55 °, the pipe 11 is hardly deformed. In FIG. 3, a curve A shows the case where the lower end of the column 14 is fixed to the table 16 with bolts, and a curve B shows that the lower end of the column 14 is rotatably supported on the table 16 by a pin or the like. Indicates the case.

In this way, the pipe 11 is clamped by the clamping means 3
After being clamped by, the roundness of the pipe 11 is corrected by the processing means 2. First, the inner spinning rolls 5, 5, ... Are moved to the outside by a small amount and positioned slightly outside the inner diameter D of the end 11a of the pipe 11. Next, the moving means is actuated to move the inner spinning rolls 5, 5 ... And the outer spinning rolls 6 in the direction of the arrow (see FIG. 1) so that the inner spinning rolls 5, 5 ... The outer spinning roll 6 is brought into contact with the outer periphery of the end 11a of the pipe 11 (see FIG. 2).

Then, the rotary drive source is operated to revolve the inner spinning rolls 5, 5, ... And the outer spinning roll 6 around the shaft 8. This allows the pipe 1
The end portion 11a of No. 1 is bent from the inner peripheral side to the outer side by the inner spinning rolls 5, 5 ... And is bent back from the outer peripheral side to the inner side by the outer spinning roll 6. In this case, since the inner spinning rolls 5, 5, ... And the outer spinning roll 6 revolve around the shaft 8, bending from the inner peripheral side to the outer side by the inner spinning rolls 5, 5 ,. The bending back from the outer peripheral side to the inner side due to is alternately repeated.

Therefore, the residual stress at the end 11a of the pipe 11 is reduced, and the end 11a of the pipe 11 is corrected to have the same diameter as the arc on which the inner spinning rolls 5, 5 ... improves. In this case, assuming that the inner diameter of the end 11a of the pipe 11 after correction is d, the end 11a of the pipe 11 is expanded by the inner spinning rolls 5, 5, ... The present invention can be applied to all general metal materials, but the present invention can also be applied to any metal material.

In the above-described embodiment, the case where the diameter of the end portion 11a of the pipe 11 is expanded by the inner spinning rolls 5, 5, ... Of the processing means 2 has been described, but the invention is not limited to this. Even if the diameter of 11a is reduced, the same effect can be obtained. In this case, the outer spinning roll 6 is moved inward by a small amount, and the end portion 1 of the pipe 11 is moved.
It is located slightly inside the outer shape of 1a.

Further, by using the processing means 2, the pipe 11
It is also possible to correct the roundness in the state of the diameter D without expanding or reducing the diameter of the end portion 11a. In this case, the inner spinning rolls 5, 5, ... And the outer spinning roll 6 are positioned so that the finished inner diameter of the end 11a of the pipe 11 becomes D. In addition, the pipe 11 is expanded or reduced in diameter before processing, and the end portion 1 of the expanded or reduced pipe 11 is processed.
The roundness may be corrected by returning 1a to the inner diameter D by the inner spinning rolls 5, 5, ..., And the outer spinning roll 6.

By correcting the roundness without changing the diameter of the end portion 11a of the pipe 11 as described above, product design and production management are facilitated. In addition, after the roundness of the end portion 11a of the pipe 11 is corrected by the inner spinning rolls 5, 5, ...
1 may be expanded or contracted to return the inner diameter of the end 11a of the pipe 11 to D.

Further, if the inner spinning rolls 5, 5 ... And the outer spinning roll 6 of the processing means 2 can be moved radially by NC control and can be positioned at arbitrary positions, they can be applied to pipes of various sizes. can do. Although the case where one outer spinning roll 6 of the processing means 2 is used has been described in the above embodiment, the present invention is not limited to this, and six outer spinning rolls 6 may be used as shown in FIG. In FIG. 3, the same members as those of the above-mentioned embodiment are designated by the same reference numerals, and the description thereof will be omitted.

In the above embodiment, the case where the tightening member 15 of the columns 14, 14 ... Of the clamp means 3 is fixedly connected to the upper end portion of the tightening member 15 has been described, but the present invention is not limited to this, and the tightening member 15 is tightened. The position connected to 15 may be slidable. Accordingly, in actual work, the length from the center position of the pipe 11 of the support column 14 to the upper end portion of the support column 14 can be easily set to be a. Also, the support roll 1 of the clamp means 3
May be rotatably connected to a servo motor (not shown). Thereby, for example, when a weld bead is attached to the pipe 11 in the axial direction and it is desired to position the weld bead at a predetermined position, the support roll 13 is rotated by the servo motor to move the weld bead to the predetermined position. It can be easily positioned.

Further, the tightening member 15 of the clamp means 3
The tension of the fastening member 15 may be controlled by detecting the tension of the strain gauge with a strain gauge or the like. Thereby, it is possible to prevent the tension from being excessively applied to the tightening member 15 and the deformation of the pipe 11 to increase, resulting in deterioration of the roundness. Further, in the case of the above-mentioned embodiment, the support roll 13 of the clamp means 3 and the support 1
4 and the two fastening members 15 are used to clamp both ends of the pipe 11, but the present invention is not limited to this, and the support roll 1 may be used when the length of the pipe 11 is short.
3, the support 14 and the tightening member 15 may be used as one set, and if the length of the pipe 11 is long, three or more sets may be used. As a result, the pipe 11 can be reliably clamped and the bending of the pipe 11 in the axial direction can be reduced. Further, in the case of the above embodiment,
The case where the support rolls 13, 13 of the clamp means 3 are arranged at equal intervals on the left and right sides of the center 0 of the pipe 11 has been described, but the present invention is not limited to this, and the support roll 13 is provided below the center 0 of the pipe 11. You may distribute another one. Thereby, when the tension of the tightening member 15 is large,
The deformation of the pipe 11 can be further suppressed.

[0029]

As is apparent from the above description, according to the pipe roundness correcting method and device of the present invention, the inner spinning roll and the outer spinning roll are revolved along a concentric arc, and the inner spinning roll is revolved. And, the pipe is alternately bent and deformed from the inner peripheral side and the outer peripheral side by the outer spinning roll. Therefore, the residual stress of the pipe is reduced and the roundness of the pipe is corrected, whereby a pipe with high roundness can be supplied at low cost. Further, according to the invention, when tension is applied to the tightening member, the pipe is pressed against the support roll by the pressing force of the tightening member, and the pipe is pressed inward in the radial direction by the pressing force from the support roll. At the same time, the pipe is pressed by the pressing force from the column. Therefore, by balancing these pressing forces in a balanced manner, the pipe can be clamped without deformation. This allows
Since the pipe can be processed without degrading the roundness of the pipe, the pipe with high roundness can be supplied at low cost.

[Brief description of drawings]

FIG. 1 is a perspective view showing a processing means of a roundness correcting device for a pipe according to an embodiment of the present invention.

FIG. 2 is a transverse cross-sectional view showing a state cut along the line AA in FIG.

FIG. 3 is a schematic view showing another embodiment of the processing means of the roundness correcting device for a pipe according to the present invention.

FIG. 4 is a perspective view showing a clamp means of the roundness correcting device for a pipe according to the present invention.

FIG. 5 is a front view showing a clamp means of the roundness correcting device for a pipe according to the present invention.

FIG. 6 is a graph for explaining the effect of the clamp means of the roundness correcting device for a pipe according to the present invention.

[Explanation of symbols]

 5 Inner Spinning Roll 6 Outer Spinning Roll 11 Pipe 13 Roll 14 Strut 15 Tightening Member

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hiroshi Hinataya 2-1, Ukishima-cho, Kawasaki-ku, Kawasaki-shi, Kanagawa Inside the Toshiba Hamakawasaki Plant (72) Inventor, Riki Shinoda Ukishima, Kawasaki-ku, Kawasaki-shi, Kanagawa Town No. 2 1 Incorporated company Toshiba Hamakawasaki factory (72) Inventor Masayuki Ishikawa No. 1 Toshiba-cho, Fuchu-shi, Tokyo Inside Toshiba Fuchu factory (72) Inventor Fujio Takahashi New Isogo-ku, Yokohama-shi, Kanagawa Isogocho 33 Stock Company Toshiba Research Institute

Claims (8)

[Claims] 1. An inner spinning roll and an outer spinning roll are alternately arranged so as to come into contact with an inner peripheral surface and an outer peripheral surface of a pipe to be straightened, and the inner spinning roll and the outer spinning roll are arranged along a concentric arc. And a circularity of the pipe is corrected by alternately bending and deforming the pipe from the inner peripheral side and the outer peripheral side with the inner spinning roll and the outer spinning roll. . 2. The method of straightening a roundness of a pipe according to claim 1, wherein the inner spinning roll bends and deforms an inner circumference of the pipe so that the diameter of the pipe increases. 3. The method of straightening a roundness of a pipe according to claim 1, wherein the outer spinning roll bends and deforms an outer periphery of the pipe so that the diameter of the pipe is reduced. 4. The method of straightening a roundness of a pipe according to claim 1, wherein the inner spinning roll and the outer spinning roll are supported so as to be movable in a radial direction. 5. An inner spinning roll capable of rolling the inner peripheral surface of a pipe to be straightened, an outer spinning roll capable of rolling the outer peripheral surface of the pipe, and these inner and outer spinning rolls formed into concentric arcs. A method of straightening a circularity of a pipe, comprising: a device for rotatably supporting the pipe. 6. A pipe to be straightened is placed on a plurality of rolls rotatably supported at predetermined intervals, and a plurality of columns are erected on both left and right sides of the pipe so as to abut the pipe. A roundness correcting device for a pipe, characterized in that a flexible tightening member is hung on the outer periphery of the pipe and is connected to the plurality of columns to hold the pipe. 7. A pipe to be straightened is placed on two rolls, and an angle connecting a contact point between the pipe and each roll and a center of the pipe is within a range of 50 ° to 55 °. The roundness correcting device for a pipe according to claim 6, wherein: 8. The roundness correcting device for a pipe according to claim 6, wherein the flexible tightening member is connectable to an arbitrary position of the column.