JP4066404B2 - Manufacturing method and manufacturing apparatus for deformed pipe - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to a method and an apparatus for manufacturing a deformed pipe having a plurality of uneven portions in the circumferential direction.
[0002]
[Prior art]
The deformed pipe is used as a decorative building material in place of the conventional circular pipe, utilizing the design and the distinctiveness derived from the shape. This type of deformed tube includes a deformed tube with a plurality of uneven portions in the circumferential direction, a deformed tube with uneven portions parallel to the tube axis, a deformed tube with a spiral uneven portion in the tube axis direction, etc. It has been known.
A deformed pipe having a plurality of uneven portions in the circumferential direction has been conventionally produced by various methods such as a drawing method using a die and a roll forming method. In the method of drawing a raw tube with a die (Japanese Patent Laid-Open No. 63-248515), a deformed tube having a good cross-sectional shape is manufactured, but the die needs to be changed according to the dimensions and the shape of the deformed tube. Therefore, productivity is low.
[0003]
A roll forming method (Japanese Patent Laid-Open No. 57-142715) for producing a deformed tube with a rolling mill combined with a perforated roll or a flat roll is highly productive, and it is possible to use a spiral guide or die provided on the outlet side of the rolling mill. It is also possible to manufacture a deformed pipe having a plurality of projections and depressions with a spiral undulation in the pipe axis direction. However, since the convex portion is formed by allowing the material of the raw tube M to flow into the gap G of the forming roll 1 (FIG. 1a), when applied to in-line forming incorporated in the pipe making line where the raw tube M is manufactured. Even if the material flows into the gap G of the forming roll 1 at the unwelded portion and the welded portion passes through the forming stand, the cross-sectional shape may be lost, and the unevenness of the required shape may not be formed (FIG. 1b). In addition, when a spiral pattern is applied, it is a disadvantage that the guide and the die are easily worn.
[0004]
[Problems to be solved by the invention]
When manufacturing a deformed pipe having a plurality of concave and convex portions in the circumferential direction by a highly productive roll forming method, considering the deformation at the time of forming the unwelded portion (FIG. 1b), the gap across the entire circumferential length of the base pipe M A roll arrangement in which G is small is preferable. Therefore, in the manufacture of a deformed pipe with eight sets of concave and convex portions in the circumferential direction, the forming roll 1 with protrusions corresponding to the concave portions attached to the roll peripheral surface is used, and the forming roll 1 is divided by 180 degrees (FIG. 2a). Alternatively, two or four pieces are arranged in the circumferential direction of the raw tube M in a 90-degree division (FIG. 2b).
However, since the diameter of the raw tube M is larger than that of the roll gap D, when the raw tube M is inserted into the roll gap D, a gap G is generated between the forming rolls 1. The gap G is generated at a position corresponding to the apex t of the convex portion p where the deformation amount of the raw tube M is the largest in the forming roll 1 combined in the 180 degree division (FIG. 3a) and the 90 degree division (FIG. 3b). Therefore, the material flows into the gap G in a concentrated manner, making it difficult to manufacture a deformed pipe having a required shape.
[0005]
[Means for Solving the Problems]
The present invention has been devised to solve such a problem, and a plurality of forming rolls arranged in a circumferential direction of a raw tube with a narrow gap are formed into a raw tube using a preforming stand and a finish forming stand. Accordingly, an object of the present invention is to produce a deformed tube having a good cross-sectional shape with excellent symmetry without causing the cross-sectional shape to collapse.
[0006]
In order to achieve the object, the present invention, when manufacturing a deformed tube having a plurality of sets of recesses and projections in the circumferential direction from a cylindrical tube, is arranged in the circumferential direction of the tube, A plurality of preformed rolls having a total number of raised portions corresponding to the number and having a roll bottom between the raised portions are separated from a roll bottom of a certain preformed roll and a raised portion of an adjacent preformed roll. After the preform tube is preformed with a preforming stand that is set in the circumferential direction of the workpiece tube and the concave portion corresponding to the recess is attached to the blank tube, a similar roll having a similar raised portion is provided. It is characterized in that the blank pipe is finished and formed into a target shape by a finish forming stand provided with a plurality of finish forming rolls arranged at the division positions.
When forming a raw pipe with a preforming roll and a finish-forming roll in which the roll axis is inclined at a predetermined helical angle with respect to a plane perpendicular to the pipe axis of the raw pipe, a variant with a spiral undulation in the pipe axis direction. A tube is manufactured.
[0007]
The modified pipe manufacturing apparatus includes a multi-stage forming stand having at least a preforming stand and a finish forming stand. The preforming stand and the finish forming stand are formed by molding a plurality of forming rolls in which the same total number of raised portions as the concave portions to be attached to the raw tube are formed on the roll peripheral surface, and between the raised portions is the bottom of the roll. A roll dividing position is set at the boundary between the bottom of the roll and the raised portion of the adjacent forming roll, and the rolls are arranged in a circumferential direction with a narrow gap. For the production of a deformed pipe with a helical undulation, the roll axis of the forming roll is inclined at a predetermined helical angle with respect to a plane perpendicular to the pipe axis of the raw pipe.
[0008]
Embodiment
In manufacturing the deformed pipe according to the present invention, an apparatus in which a plurality of molding stands are arranged in tandem is used. Here, an apparatus having two stages of molding stands (FIG. 4) will be described as an example.
The raw tube M is preformed by the preforming stand 10 and then formed into a deformed tube P having a target shape by the finish molding stand 20. Between the preforming stand 10 and the finish forming stand 20, third and fourth forming stands may be further arranged.
The preforming stand 10 combines four preforming rolls 11 to 14 in an arrangement in which the gap G between the rolls is very narrow (FIG. 5a). On the peripheral surface of the preforming rolls 11-14, a number of raised portions 11p-14p (eight in the case of FIG. 5) corresponding to the number of recesses on the peripheral surface of the target deformed pipe P are formed. The division positions of the preforming rolls 11 to 14 are set at the boundary between the roll bottom portions 11b and 12b of the preforming rolls 11 and 12 and the raised portions 13p and 14p of the preforming rolls 13 and 14 adjacent to each other.
[0009]
Similarly, the finishing molding stand 20 is also provided with four finishing molding rolls 21 to 24 with a narrow gap G (FIG. 5b). The number of raised portions 21p to 24p corresponding to the number of recesses on the peripheral surface of the target deformed pipe P is also formed on the peripheral surfaces of the forming rolls 21 to 24. The dividing positions of the forming rolls 21 to 24 are set at the boundary between the roll bottom portions 21b and 22b of the finish forming rolls 21 and 22 and the raised portions 23p and 23p of the adjacent finish forming rolls 23 and 24 in the same manner as the preforming stand 10. Has been.
Both the preforming stand 10 and the finish forming stand 20 rotate and support the rolls 11 to 14 and 21 to 24 with the same roll support mechanism 30 (FIG. 6). The roll support mechanism 30 includes a roll chock 32 that rotatably supports the roll shafts 31 of the rolls 11 to 14 and 21 to 24. Four sets of roll chock 32 are arranged in the circumferential direction of the pipe M corresponding to each of the rolls 11 to 14 and 21 to 24, and are movable toward the center of the pipe M. By adjusting the amount of movement of the roll chock 32 with the reduction screw 33, the reduction amount of the raw tube M is set.
[0010]
When the raw tube M is passed through the preforming stand 10 in which the preforming rolls 11 to 14 are combined in this way, the portion corresponding to the convex portion p of the deformed tube P is preformed by the roll bottom portions 11b to 14b, and the portion corresponding to the concave portion is raised. It is preformed at the portions 11p to 14p. When the blank tube M is sent from the preforming stand 10 to the finish forming stand 20, the parts preformed by the roll bottom portions 11b to 14b are finish-molded by the roll bottom portions 21b to 24b of the finish forming rolls 21 to 24, and the convex portion p is formed. Then, the part preformed by the raised portions 11p to 14p is formed by the raised portions 21p to 24p of the finish forming rolls 21 to 24 to become the recess b.
In both the preliminary molding and the finish molding, a gap G is generated between the preforming rolls 11 to 14 and the finishing molding rolls 21 to 24. However, each roll 11-14, 21-24 is not divided | segmented by the vertex t (FIG. 3) of the convex part p with the largest deformation amount of the raw pipe M, and also the amount of rolling down of the raw pipe M is reduced at each step. The gap G can be narrowed because of the multistage molding that can be performed. Therefore, the material inflow to the gap G is suppressed, and the deformed pipe P (FIG. 7) with good shape accuracy is manufactured.
[0011]
This method is also effective in in-line molding in which a modified pipe P is manufactured by being incorporated in a normal pipe making line. That is, since the rolling amount of each of the stands 10 and 20 is small and the gap G between the rolls 11 to 14 and 21 to 24 is narrow, even if the plate end portion e overlaps with the preforming stand 10, eight sets with a small difference in height. Are provided on the tube M (FIG. 8). In the unwelded portion of the raw tube M, the deformation direction of the raw tube M is determined by the uneven portion due to the formation of the concavo-convex portion. Therefore, even if the welded portion of the raw tube M reaches the preforming stand 10, Eight sets of uneven portions are formed. The formed concavo-convex portions are finish-molded into the concave portion b and the convex portion p, respectively, by the finish molding stand 20.
In the deformed pipe P provided with irregularities parallel to the pipe axis direction, a roll support mechanism 30 (FIG. 6) holding the roll axis 31 in parallel with the direction perpendicular to the pipe axis of the base pipe M is used. In place of the roll support mechanism 30, when using a roll support mechanism 40 (FIG. 9) that supports the roll shaft 45 at a predetermined spiral angle θ in the tube axis direction, the irregularities spirally wavy along the tube axis direction. A deformed pipe P having the following structure is manufactured.
[0012]
The roll support mechanism 40 has a roll chock in which the roll housing space 41 is inclined at a helical angle θ with respect to the tube axis direction of the raw tube M and the roll shaft hole 42 is inclined at a helical angle θ with respect to the direction orthogonal to the tube axis of the raw tube M. 43. A collar 44 is interposed between the rolls 11 to 14 and 21 to 24 and the roll chock 43, and the rolls 11 to 14 and 21 to 24 are positioned by the collar 44. By supporting the roll shaft 45 of the rolls 11 to 14 and 21 to 24 with the roll chock 43, the rolls 11 to 14 and 21 to 24 are pressed against the base tube M at the spiral angle θ, and the convex portion p at the spiral angle θ. And the deformed pipe P in which the recessed part b wave | undulated is manufactured. When the roll support mechanism 40 is incorporated in the pipe making line and the deformed pipe P is formed in-line, the preforming stand 10 and the finish forming stand 20 are rotated in the circumferential direction of the raw pipe M.
[0013]
The above has described the production of the deformed pipe P with eight sets of uneven portions, but the present invention is not limited to this, and the same applies to the deformed tube P having a plurality of uneven portions in the circumferential direction. Applies to The spiral angle θ is preferably set to 45 degrees or less in order to hinder the rotation of the rolls 11 to 14 and 21 to 24 and the travel of the raw tube M or the deformed tube P if excessively large. Further, each of the molding stands 10 and 20 can incorporate three or five or more molding rolls instead of the four rolls 11 to 14 and 21 to 24.
[0014]
[Example 1]
A raw tube M having an outer diameter of 54 mm was manufactured from a steel strip STKM13B having a plate thickness of 1.6 mm by a roll forming method, and fed to a forming apparatus (FIG. 4) arranged in the same pipe forming line. Each of the stands 10 and 20 is divided into rolls at the boundary between the roll bottoms 11b and 12b of the forming rolls 11 and 12 and 21 and 22 and the raised portions 13p and 14p and 23p and 24p of the adjacent forming rolls 13, 14, and 23, 24. The positions were set, and rolls 11 to 14 and 21 to 24 having eight raised portions 11p to 14p and 21p to 24p as a whole were used. In order to form uneven portions at equal intervals in the circumferential direction of the tube M, the opening angle α (FIG. 5a) of the rolls 11, 12, 21, and 24 with respect to the tube M was set to 120 degrees.
[0015]
The rolling tube M that is sent at a speed of 70 m / min is set with a reduction amount of the forming rolls 11 to 14 of the preforming stand 10 set to 1.5 mm and a reduction amount of the forming rolls 21 to 24 of the finish forming stand 20 set to 2 mm. The surface was uneven. The rotation of the forming rolls 11 to 14 and 21 to 24 was driven rotation by rubbing with the raw tube M.
When the shape of the formed deformed tube P was measured, it was a deformed tube having an outer diameter of 50.8 mm in which 8 mm unevenness with a depth of 3 mm was assembled in the circumferential direction, and the unevenness symmetry was also good.
[0016]
[Example 2]
Example except that the forming rolls 11 to 14 and 21 to 24 are attached to the roll chock 43 (FIG. 9) at a spiral angle θ = 5 degrees, and the raw tube M is formed while the preforming stand 10 and the finish forming stand 20 are rotated. A modified tube P was produced under the same conditions as in 1. The obtained deformed pipe P was a deformed pipe having an outer diameter of 50.8 mm, in which unevenness having a helical angle of 5 degrees and a depth of 3 mm was assembled in the circumferential direction, and the symmetry of the unevenness was also good.
[0017]
[Comparative example]
A deformed pipe P was manufactured under the same conditions as in Example 1 except that the raw pipe M was formed using four forming rolls 1 (FIG. 2 b) divided 90 degrees with respect to the circumferential direction of the raw pipe M. In this case, since the four forming rolls 1 were divided by 90 degrees, the unwelded portion of the raw pipe P was positioned at the center of the roll bottom 2. In this case, when the unwelded portion of the raw pipe P passes through the finishing molding stand 20, the roll splitting position is located at the apex t of the convex portion p where the deformation amount of the raw pipe M is the largest, and therefore flows into the gap G. There was much material (FIG. 3b), and the shape of the raw tube M collapsed. The collapse of the shape continued even after the welded portion of the base tube M passed through the stands 10 and 20. As a result, a deformed pipe P having a good cross-sectional shape could not be manufactured.
[0018]
【The invention's effect】
As described above, in the present invention, after forming the same number of concave portions as the number of concave and convex portions of the target deformed pipe in the circumferential direction of the raw pipe, the roll raised portion of the forming roll adjacent to the roll bottom of the forming roll Finishing molding is performed in which the concave portion is reduced with a forming roll having a roll dividing position set at the boundary. In addition, since the forming stands are arranged in multiple stages, the amount of reduction at each stage can be reduced, so that the gap between the rolls can be reduced. When this method is used, the deformation direction of the raw tube is regulated by the recesses formed by preforming, so that the deformed tube with a plurality of highly symmetrical uneven portions in the circumferential direction is highly productive without greatly losing the cross-sectional shape. Manufactured by.
[Brief description of the drawings]
BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows a conventional cross section of rolls (b) used when manufacturing irregularly shaped pipes with 8 sets of irregularities and a defective cross-sectional shape (b) that tends to occur when an irregularly shaped pipe is manufactured in-line by a conventional method. )
[Fig. 2] Arrangement of forming rolls divided by conventional 180 degree division (a) or 90 degree division (b) [Fig. 3] Description showing that shape deformation occurs when deformed pipe P is manufactured by conventional roll arrangement FIG. 4 is a schematic side view of the production apparatus according to the present invention. FIG. 5 is a schematic view of the forming rolls of the preforming stand (a) and the finish forming stand (b) as seen from the tube axis direction of the raw pipe. 6] Schematic diagram of a roll support mechanism that enables the forming roll to move forward and backward with respect to the center of the raw pipe. [FIG. 7] An explanatory view showing that a deformed pipe having a good cross-sectional shape is manufactured. [FIG. Cross-sectional shape of element tube with overlapping ends [Fig. 9] Roll support mechanism used for manufacturing deformed tube with irregularities spiraled in the tube axis direction
10: preformed Stand 20: finish forming stand 11-14: forming roll 11 _p ~14 _p, 21~24 _p: ridges 11b~14b imparted to the forming roll, 21b to 24b: between ridges Roll bottom M: Elementary pipe P: Deformed pipe p: Convex part b: Concave part θ: Spiral angle D: Roll gap

Claims (4)

When manufacturing a deformed tube having a plurality of sets of recesses and projections in the circumferential direction from a cylindrical tube, it is arranged in the circumferential direction of the tube and has a total number of raised portions corresponding to the number of the recesses. A plurality of preformed rolls having a roll bottom between the ridges are set at the boundary between the roll bottom of a certain preform roll and the ridge of the adjacent preform roll, and the raw tube A plurality of finish forming rolls having the same raised portion and arranged at the same roll dividing position after preforming the preform tube with a preforming stand arranged in the circumferential direction and attaching a recess corresponding to the recess to the elementary tube. A method for producing a deformed pipe, comprising finish-molding an element pipe into a target shape with a finish-forming stand having a shape. The manufacturing method of Claim 1 which shape | molds a raw material pipe | tube with the preforming roll and inclination molding roll which inclined the roll axis | shaft with the predetermined spiral angle with respect to the surface orthogonal to the pipe axis of a raw material pipe | tube. A plurality of preformed rolls, in which the same total number of raised portions as the concave portions to be attached to the raw tube are formed on the peripheral surface of the roll and the gaps between the raised portions are the roll bottom, are preliminarily adjacent to the roll bottom of a certain preform. A pre-molding stand that is positioned in the circumferential direction of the blank tube with a narrow gap set at the boundary with the forming ridge, and the same total number of ridges are formed on the roll peripheral surface. A plurality of finish forming rolls with a roll bottom, and a roll splitting position is set at the boundary between the roll bottom of one finish forming roll and the ridges of the adjacent finish forming roll, and the circular tube of the blank tube is narrow. An apparatus for manufacturing a deformed pipe, comprising a finishing molding stand arranged along a circumferential direction. The manufacturing apparatus according to claim 3, wherein the roll axes of the preforming roll and the finish forming roll are inclined at a predetermined spiral angle with respect to a plane perpendicular to the tube axis of the raw pipe.

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