JP4674987B2 - 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 is known as a deformed tube with a plurality of uneven portions in the circumferential direction parallel to the tube axis, a deformed tube in which a plurality of uneven portions are formed in the circumferential direction spirally with respect to the tube axis direction, etc. It has been.
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 having protrusions corresponding to the concave portions attached to the peripheral surface of the roll 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]
Further, in order to improve the cross-sectional shape of the manufactured deformed pipe, it is necessary that the convex portion outer surface radius of curvature R of the deformed pipe P shown in FIG. 4 is uniform in the circumferential direction. In order to obtain uniformity in the circumferential direction of the convex portion outer surface radius of curvature R of the deformed pipe P, it is necessary to form with the forming roll 1 having the width W between the raised portions of the optimum dimension. Until now, the optimum dimensions have been obtained by performing molding experiments using several types of molding rolls, but the problem is that the roll cost is high and the efficiency is low.
[0006]
The present invention has been devised to solve such a problem. A roll division position is set at the boundary between a lower roll portion of a certain forming roll and a raised portion of an adjacent forming roll, and the roll division position is set. By forming a raw tube with a preliminary stand and a forming stand in which a plurality of forming rolls having a spacing obtained by a predetermined formula as a value obtained by a predetermined formula are arranged in the circumferential direction of the raw tube without causing a collapse of the cross-sectional shape An object of the present invention is to efficiently produce a deformed tube having a good cross-sectional shape with excellent shape symmetry.
[0007]
[Means for Solving the Problems]
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. In the preforming stand in which the roll dividing position is set, the width between the raised portions of the roll dividing position is set to the value of the following formula (1), and the plurality of preforming rolls are arranged in the circumferential direction of the raw tube After preforming the raw tube and attaching a concave portion corresponding to the concave portion to the raw tube, a similar roll dividing position having the same raised portion position and the width between the raised portions set by the following formula (1) Finishing with multiple finish forming rolls Characterized by forming finished mother tube target shape under molding stand.
[0008]
W2 = wa (1)
Here, w is the width of the convex portion of the required deformed pipe, W2 is the width between the raised portions of the forming roll at the roll dividing position, and a is a value set in advance in consideration of the gap between the rolls that is widened during forming.
In addition, 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 spiral undulation is attached in the pipe axis direction. A modified tube is produced.
[0009]
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 roll bottom. A roll split position is set at the boundary between the roll bottom of the roll and the adjacent ridge of the forming roll, and the width between the ridges at the roll split position is set in advance by considering the spread of the roll interval during molding. It is smaller than the required convex portion width of the deformed tube, and the plurality of forming rolls are arranged in the circumferential direction of the raw tube.
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 base pipe.
[0010]
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. 5) 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. Third and fourth molding stands may be further arranged between the preforming stand 10 and the finish molding stand 20.
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. 6a). On the peripheral surface of the preforming rolls 11-14, a number of raised portions 11p-14p (eight in the case of FIG. 6) 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.
[0011]
Similarly, the finishing molding stand 20 is also provided with four finishing molding rolls 21 to 24 with a narrow gap G (FIG. 6b). 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 24p of the finish forming rolls 23 and 24 adjacent to the preform forming stand 21 and 22, respectively. 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. 7). 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.
[0012]
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 raw 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. 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 | transformation 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. 8) with good shape accuracy is manufactured.
[0013]
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 reduction 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 e overlaps with the preforming stand 10, eight sets with small height difference are provided. Are formed on the tube M (FIG. 9). 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.
[0014]
Further, as a result of various studies on the uniformity of the outer surface curvature radius R of the deformed pipe P in the circumferential direction, the present inventors have changed the dimensions of the forming roll shown in FIG. In consideration of the rigidity of the molding stand when molding into a width, the width between the raised portions at the roll splitting position is taken into account of the widening of the gap between the rolls during molding, and the width of the convex portion of the deformed pipe that is required in advance by that amount. I found that it was better to keep it small.
[0015]
The uniformity in the circumferential direction of the convex portion outer surface radius of curvature R of the deformed pipe P shown in FIG. 4 is that the height of the raised portion of the forming roll 1 is higher than the maximum possible deformation height of the convex portion p. The reduction amount r _T that actually acts on M is constant in the circumferential direction, and the convex portion p is deformed in the region of the widths W1 and W2 between the raised portions of the forming roll 1, so that the circles with the widths W1 and W2 between the raised portions are formed. It depends on the uniformity in the circumferential direction. If the widths W1 and W2 between the raised portions are uniform in the circumferential direction when forming the deformed pipe P, the convex outer surface curvature radius R of the manufactured deformed pipe P is also the same in the circumferential direction, and the shape symmetry A good product.
[0016]
Since the gap G is generated between the forming rolls 1 due to the rigidity of the forming stand when the raw tube M is formed, the width W1 between the protruding portions is set between the protruding portion width W2 and the other protruding portions. It is necessary to make the width W1 different. In other words, the width W1 between the raised portions may be the required convex portion width w of the deformed pipe P, but the width W2 between the raised portions at the roll dividing position is generated due to the rigidity of the forming stand when the raw tube M is formed. It is necessary to make the value subtracted from the convex portion width w of the deformed pipe P that requires the gap G between the forming rolls 1. Since the rigidity of the molding stand depends on the deflection of the roll shaft and the gap between the bearing and the roll shaft or roll, the rigidity is unique to the molding stand. Generally, the rigidity of the forming stand when manufacturing steel pipes of the same size is not much different, and a reduction value of about 0.3 mm is sufficient. However, as the plate thickness of the pipe to be formed increases, the force that pushes the roll increases, so the reduction value must also be increased.
The reduction value a is preferably set to the following level when expressed as a function of the sheet thickness t to be formed.
0.0625t + 0.1 <a <0.0625t + 0.2
This makes it possible to efficiently determine the roll dimensions, which have been obtained by forming experiments using several types of forming rolls, at low cost.
[0017]
In the deformed pipe P provided with irregularities parallel to the pipe axis direction, a roll support mechanism 30 (FIG. 7) 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. 10) 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.
[0018]
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. In the case where 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 base pipe M.
[0019]
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. In addition, 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.
[0020]
[Example 1]
A steel pipe STKM13B with an outer diameter of 54 mm and a plate thickness of 1.6 mm is used as a raw pipe, and a deformed pipe with an outer diameter of 50.4 mm having eight sets of irregularities in the circumferential direction is formed in-line in the raw pipe making pipe. did. The forming apparatus (FIG. 5) arranged in the pipe making line has a two-stage forming stand structure, and in each stand 10, 20, a forming roll 13, which is adjacent to the roll bottoms 11b, 12b of the forming rolls 11, 12, 21 and 22, Roll division positions are set at boundaries between the raised portions 13p, 14p and 23p, 24p of 14 and 23, 24, and rolls 11-14, 21-24 having a total of 8 raised portions 11p-14p, 21p-24p It was used. In order to form uneven portions at equal intervals in the circumferential direction of the pipe M, the opening angle α (FIG. 6a) of the rolls 11, 12, 21, and 24 with respect to the pipe M was set to 120 degrees.
[0021]
In the first-stage molding, the need for the deformed pipe P and the convex portion width w are 19 mm and uniform in the circumferential direction. A value of 0.25 mm was obtained in advance from the roll shaft deflection and the gap between the bearing and the roll shaft. From the value a, the width W2 between the raised portions at the roll dividing position was 18.75 mm, and the width W1 between the other raised portions was 19 mm.
Further, in the second stage molding, since the required convex portion width w of the deformed pipe P is set to 16.6 mm, a is 0.3 mm, so that the width W2 between the raised portions at the roll dividing position is 16.3 mm. The width W1 between the other raised portions was 16.6 mm.
[0022]
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.
As a result of molding under this condition, a deformed pipe P having an outer diameter of 50.4 mm and a convex height of 6 mm can be molded, and the convex width w is 16.6 mm, which is very large in the circumferential direction as shown in FIG. Thus, a deformed tube P having a small variation was obtained. Further, the convex portion outer surface curvature radius R was also good in uniformity as shown in FIG.
[0023]
[Example 2]
Except that the forming rolls 11 to 14 and 21 to 24 are attached to the roll chock 43 (FIG. 10) 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 has a spiral angle of 5 degrees and an outer diameter of 50.4 mm, and the protrusion width w is very small in the circumferential direction of the deformed pipe P as shown in FIG. 11 with respect to 16.6 mm. It became a variation. Further, the convex portion outer surface curvature radius R was also good in uniformity as shown in FIG.
[0024]
[Comparative example]
Except that a = 0 mm, the distance between the raised portions of the first-stage forming rolls 11 to 14 is 19 mm, and the width between the raised portions of the second-stage forming rolls 21 to 24 is 1 = 0 mm, where a = 0 mm. The modified pipe P was manufactured under the same conditions as in Example 1. In this case, since the width W2 between the raised portions at the roll dividing position is larger than the set value, the convex portion width w of the deformed pipe P varies greatly with respect to 16.6 mm. In addition, the variation in the outer radius of curvature R of the convex portion was increased, and the uniformity of the cross-sectional shape in the circumferential direction was greatly broken.
[0025]
【The invention's effect】
As described above, in the present invention, the optimal position obtained from the calculation formula in consideration of the rigidity of the molding stand by setting the roll dividing position at the boundary between the roll bottom of the molding roll and the roll bulge of the adjacent molding roll. The target deformed pipe is formed by a forming roll having a wide width between raised portions. 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 direction of deformation of the raw tube is regulated by the recesses formed by the preforming, so that the cross-sectional shape does not collapse greatly. Further, it is not necessary to obtain the optimum dimensions of the forming roll by experiments with several kinds of forming rolls. Therefore, a deformed tube having a plurality of highly concavo-convex portions in the circumferential direction is manufactured at low cost and high efficiency.
[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 an explanatory view showing the state of the forming roll before forming (a) and during forming (b). FIG. 5 is a schematic side view of the manufacturing apparatus according to the present invention. FIG. ) And a schematic view of the forming roll of the finish forming stand (b) as seen from the pipe axis direction of the raw pipe. FIG. 7 is a schematic view of a roll support mechanism that enables the forming roll to advance and retreat with respect to the center of the raw pipe. FIG. 8 is an explanatory view showing that a deformed tube having a good cross-sectional shape is manufactured. FIG. 9 is a cross-sectional shape of a raw tube with overlapping plate ends. FIG. 10 is an uneven portion spiraled in the tube axis direction. Roll support mechanism used for manufacturing deformed pipes with ribs [Fig. 11] Convex width w Distribution in the circumferential direction of the deformed pipe P [Fig. 12] Distribution in the circumferential direction of the deformed pipe P having the outer radius of curvature R [Explanation of symbols]
10: Preliminary forming stand 20: Finishing forming stands 11-14, 21-24: Forming rolls 11p-14p of the pre-forming stand and finishing stand, 21p-24p: Raised portion 11b attached to the forming rolls of the pre-forming stand and finishing stand -14b, 21b-24b: Molding roll bottom M of the preforming stand and finishing stand M: Elementary pipe P: Deformed pipe p: Convex part b: Concave part θ: Spiral angle D: Roll gap G: Gap between forming rolls t: Deformation The convex part vertex α of the pipe: The split angle of the forming roll e: The plate end w on the unwelded part of the raw pipe w: The required convex part width of the deformed pipe W1: The width between the raised parts other than the roll split position W2: The roll split position Width between ridges r: set reduction amount r _T : reduction amount actually applied to the raw tube a: coefficient determined by the rigidity of the forming stand, etc. 1: forming roll 2: lower part of the forming roll 30, 4 0: roll support mechanism 31, 45: roll shaft 32, 43: roll chock 33: reduction screw 41: roll accommodation space 44: collar

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. The roll dividing position of a plurality of preforming rolls having a roll bottom between the raised portions is set at the boundary between the roll bottom of a certain preforming roll and the protruding portion of the adjacent preforming roll, and the roll dividing The width between the raised portions of the position is set to the value of the following formula (1), and the raw tube is preformed with a preforming stand in which the plurality of preforming rolls are arranged in the circumferential direction of the raw tube to correspond to the concave portion. A plurality of finish forming rolls arranged at the same roll division position having the same raised portion position and the width between the raised portions set by the following formula (1). The raw tube into the target shape with a finished molding stand Method for producing a deformed pipe, characterized in that the raised molding.
W2 = wa (1)
Here, w is the width of the convex portion of the required deformed pipe, W2 is the width between the raised portions of the forming roll at the roll dividing position, and a is a value set in advance in consideration of the gap between the rolls that is widened during forming.  The manufacturing method of the deformed pipe | tube of Claim 1 which shape | molds a raw | natural pipe | tube with the preforming roll which made the roll axis | shaft inclined with respect to the surface orthogonal to the pipe axis | shaft of a raw | natural pipe | tube, and a finish forming roll. 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 gap between the raised portions is the roll bottom, boundary between the raised portion of the molding to set the roll split position in the which the ridges between the width of the roll dividing position as the value of the following expression (1), the circumferential direction of base pipe the plurality of preformed roll And a plurality of finish forming rolls arranged at the same roll division position with the same raised portion position and the width between the raised portions set at the roll division position set by the following formula (1). An apparatus for manufacturing deformed pipes equipped with a finishing stand.
W2 = wa (1)
Here, w is the width of the convex portion of the required deformed pipe, W2 is the width between the raised portions of the forming roll at the roll dividing position, and a is a value set in advance in consideration of the gap between the rolls that is widened during forming.  The deformed pipe 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 pipe axis of the raw pipe.

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