JP6885827B2 - Grooving device and method for metal pipes - Google Patents

Description

The present invention relates to a groove processing device and a method for forming a groove extending from the end of a metal pipe in the longitudinal direction of the pipe at a plurality of places spaced apart from each other in the circumferential direction of the outer surface at the end of the metal pipe.

For example, when a square steel pipe column of a steel structure building structure is bolted to an upper and lower beam, generally, a mounting plate with a bolt hole is welded and fixed to the end of the square steel pipe, and this mounting plate is bolted to the beam. Although the structure is to be joined, in that structure, the outer shape of the mounting plate is wider than the outer shape of the square steel pipe, which may cause inconvenience in relation to the surroundings.
Therefore, the end of the square steel pipe is crushed by press working to form a cross-shaped cross section (crushed shaft-shaped part), and a mounting plate with bolt holes having the same shape as the outer shape of the square steel pipe is welded and fixed to the end face. The mounting plate is bolted to the beam (Patent Documents 1 and 2).

Further, in Patent Document 3, the crushing method of Patent Documents 1 and 2 which simply crushes by pressing requires a large pressing force, which makes the equipment larger and heavier, and also has a cross-shaped cross section (crushed shaft-shaped portion). ), Since cracks may occur in the mountain folds and valley folds, processing is performed when the end of the square steel pipe is crushed by press working to form a cross-shaped cross section (crushed shaft-shaped part). A method of pressing a square steel pipe in a heated state in the range of 450 to 650 ° C. is shown so that cracks do not occur in the portion.

Japanese Patent Application Laid-Open No. 10-292556 JP-A-11-324225 JP 2001-71070

According to Patent Document 3, by heating at the time of pressing, the problem that a large pressing force is required and the equipment becomes large and heavy, and the problem that cracks may occur are solved, but heating is performed. Since what is required is not advantageous in terms of equipment, workability, etc., it is possible to form a cross section (or a grooved cross section if it is not a cross section) without the need for heating. desired.

The present invention has been made in order to eliminate the above-mentioned conventional drawbacks, and when forming a concave groove portion having a cross-shaped cross section or the like at the end portion of a metal tube, the equipment can be enlarged without requiring heating. It is an object of the present invention to provide a method and apparatus for grooving a metal pipe which does not cause a problem of weight increase or a problem of cracking or the like.

The invention of claim 1 for solving the above-mentioned problems is a groove processing apparatus for a metal pipe, which forms concave grooves extending from the pipe end in the pipe longitudinal direction at a plurality of locations at the end of the metal pipe at intervals in the circumferential direction of the outer surface. And
On the central axis side of the rotating body, a plurality of solo van ball-shaped rotating bodies having a cross-sectional shape that is thick and tapered toward the tip in the radial direction and has a narrow flat surface or concave surface on the tip surface are formed on the outer surface of each pipe. Provided at intervals in the circumferential direction in the manner of pressing
Contact with a protruding portion formed between two adjacent concave groove portions formed in a metal tube by being pushed by two abacus ball-shaped rotating bodies adjacent to each other in the circumferential direction among the plurality of abacus ball-shaped rotating bodies. It is characterized in that a shape guide for suppressing the swelling is provided.

2. The second aspect of the present invention is the groove processing apparatus for a metal pipe according to the first aspect.
A plurality of rotating body holders that rotatably hold each of the solo van ball-shaped rotating bodies, and a housing in which the plurality of rotating body holders are provided corresponding to the circumferential positions of the outer surface of the metal tube to which the concave groove should be formed. The housing is provided with a reduction adjusting means for adjusting the reduction of the rotating body holder.

A third aspect of the present invention is the groove processing apparatus for a metal pipe according to the first or second aspect.
It has a recessed portion and a protruding portion that match the contour of the inner surface of the pipe end when the plurality of concave grooves and ridges are formed at the end of the metal pipe, and a concave groove is formed at the end of the metal pipe. It is characterized by having a core arranged so as to be located in the pipe when it is made.

A fourth aspect of the present invention is the groove processing apparatus for a metal tube according to any one of claims 1 to 3.
The shape guide is a triangular columnar body, and each of the two base corner portions of the shape guide is formed with a concave surface having a shape substantially along the surface of the tapered tip side portion of the abacus ball-shaped rotating body. The bottom portion sandwiched between the bottom corner portions having the concave surface is characterized in that it has an outer shape formed in such a manner that a narrow bottom surface remains in the center of the bottom portion.

The invention of claim 5 uses the groove processing apparatus for a metal pipe according to any one of claims 1 to 4 to extend the pipe length from the pipe end to a plurality of places at the end of the metal pipe at intervals in the circumferential direction of the outer surface. It is a method of processing a groove of a metal pipe that forms a groove extending in a direction.
The plurality of solo van ball-shaped rotating bodies and shape guides and the metal tube to be processed are opposed to each other in the longitudinal direction of the metal tube, and the solo van ball-shaped rotating body and the metal tube are driven relatively close to each other to drive the end portion of the metal tube. It is characterized in that a plurality of concave grooves are formed on the outer surface of the.

The invention of claim 6 extends from the end of the metal pipe in the longitudinal direction of the pipe to a plurality of places at the end of the metal pipe at intervals in the circumferential direction by the groove processing apparatus for the metal pipe according to claim 3 or 4. It is a method of processing a groove of a metal pipe that forms a groove.
The plurality of solo van ball-shaped rotating bodies and cores and the metal tube to be processed are opposed to each other in the longitudinal direction of the metal tube, and the solo van ball-shaped rotating bodies and the core and the metal tube are driven relatively close to each other to drive the metal tube. It is characterized in that a plurality of concave grooves are formed on the outer surface of the end portion of the.

7. The method of grooving a metal tube according to claim 5 or 6, wherein the groove processing method is performed.
When the metal tube is a polygonal metal tube, the tip surface of the solo van ball-shaped rotating body is positioned so as to hit a corner portion of the polygonal metal tube, and the solo van ball-shaped rotating body and the polygonal metal tube are separated from each other. It is characterized in that it is driven relatively close to each other to form concave grooves having a number of corners on the outer surface of the end portion of the polygonal metal tube.

8. The eighth aspect of the present invention is the method for processing a groove in a metal tube according to the seventh aspect.
When the metal tube is a quadrangular metal tube, the tip surface of the solo van ball-shaped rotating body is positioned so as to hit the four corners of the quadrangular metal tube, and the solo van ball-shaped rotating body and the quadrangular metal tube are relative to each other. It is characterized in that four concave grooves are formed on the outer surface of the end portion of the quadrangular metal pipe by being driven in close proximity to form a cross-shaped cross section at the end portion of the quadrangular metal pipe.

9. The method of grooving a metal tube according to claim 5 or 6, wherein the groove processing method is performed.
When the metal tube is a round tube, the tip surfaces of the solo van ball-shaped rotating body are positioned at four positions at equal intervals in the circumferential direction of the outer surface of the round tube, and the solo van ball-shaped rotating body and the round tube are formed. Is relatively close to each other to form four concave grooves on the outer surface of the end of the round tube, and a cross-shaped cross section is formed at the end of the round tube.

10. The method for grooving a metal tube according to any one of claims 5 to 9.
The metal pipe to be processed is a steel pipe used as a pillar material of a building structure made of a quadrangular steel pipe or a round steel pipe.

According to the groove processing apparatus for a metal pipe of the present invention, the outer surface of the metal pipe is spaced in the circumferential direction by pushing the outer surface of the metal pipe with a plurality of solo van ball-shaped rotating bodies spaced apart in the circumferential direction. A plurality of recesses can be formed. Therefore, unlike the conventional processing method using a press, there are no problems such as increase in size and weight of equipment, cracks in concave grooves (valley folds), and no heating is required. It is possible to form a concave groove at the end of the.

Further, since the outer surface of the metal pipe is pushed by a solo van ball-shaped rotating body, a deep concave groove can be formed in the metal pipe, whereby the concave groove and the protruding portion are alternately formed in the circumferential direction at the end of the metal pipe. It is possible to form a circumferential concavo-convex cross section (cross-shaped cross section (cross tube section) when the metal pipe is a square square steel pipe) with and, and at the same time, due to the presence of the shape guide, two adjacent concave grooves It is possible to prevent the protruding portion formed between them from bulging more than necessary.
Therefore, it is possible to secure a good circumferential concavo-convex cross-sectional shape without a protrusion protruding from the contour of the original pipe (metal pipe before processing) on the outer surface of the circumferential concavo-convex cross-section formed at the end of the metal pipe. ..
The shape guide can be used not only when eliminating the protruding portion protruding from the contour of the original pipe, but also when obtaining a protruding portion recessed from the contour of the original pipe.

According to claim 3, since it has a core having a cross-sectional shape that matches the contour of the inner surface of the pipe end when a plurality of concave grooves are formed at the end of the metal pipe, the solo van ball-shaped rotating body outside the pipe and the inside of the pipe Since the concave groove is processed with the core, it is possible to form an accurate circumferential concave-convex cross-sectional shape at the end of the metal tube.

A large load acts on the bulging holding surface of the shape guide that suppresses the bulging of the protruding portion.
It is located in a narrow space between two adjacent abacus ball-shaped rotating bodies, and the shape guide that contacts the ridge and suppresses the swelling has a narrow cross section near the swelling holding surface, ensuring rigidity. Although it is difficult to do so, a shape guide having an outer shape as in claim 4 can secure sufficient rigidity to withstand a large load.

According to the method for grooving a metal pipe according to the fifth aspect of the present invention, the grooving method for a metal pipe of the present invention can be effectively and efficiently performed by the grooving apparatus. That is, as described above, unlike the conventional processing method using a press, there is no problem of increasing the size and weight of the equipment, and there is no need for heating.

When the metal tube is a polygonal metal tube such as a quadrangular metal tube, the tip surface of the solo van ball-shaped rotating body is positioned so as to hit the corner portion of the polygonal metal tube as in claim 75 or 86. The effect of preventing the occurrence of cracks in the concave groove portion (valley fold portion) is particularly remarkable.

When the metal pipe is a square metal pipe or a round pipe as in claim 8 or 9, it is a square steel pipe pillar or a circle having a cross-shaped cross section at an end as a pillar material of a building structure having a steel frame structure. The merit is especially great when manufacturing steel pipe columns.

A groove processing apparatus for a metal tube according to an embodiment of the present invention is shown, where (a) is a side view of the concave groove processing apparatus, and (b) is a frame body 32, a core base 31 and a shape guide in (a). It is a front view which showed by removing the holder 52 (however, the code | symbol of a core 30 is omitted). (A) is an enlarged view showing only the main part in FIG. 1 (b), (b) is an enlarged view of the vicinity of the tip surface of the abacus ball-shaped rotating body in (a), and (c) is the tip. It is a figure which shows the other embodiment of the shape of a surface. (A) is an enlarged view of the main part in FIG. 1 (a), (b) is a cross-sectional view taken along the line AA of (a) (shown excluding the shape guide holder 52), and (c) is an end portion. It is a front view which looked at the metal tube which was grooved with a groove from the end side. Is. It is a perspective view of the core in FIGS. 1 to 3. It is a perspective view which showed only the four shape guides of FIGS. 1 to 3 in the installation positional relationship. In FIG. 5, one shape guide is shown. FIG. 5A is a front view, FIG. 5B is a plan view, FIG. 5C is a right side view, and FIG. 5D is a sectional view taken along line BB. In the figure which supplementarily explains the mutual positional relationship between the square steel pipe 8, the solo van ball-shaped rotating body 2, the shape guide 51, and the core 30 in the concave groove processing apparatus of the illustrated example, (b) is a diagram in which FIG. 3 (b) is 45 degrees. The figure shown in the rotated state (however, the content of the display is slightly changed), (a) is the plan view corresponding to (b) (however, the figure shown excluding the solo van ball-shaped rotating body on the left side). is there. It is a figure which supplementarily explains the mode in which the shape guide is arranged between two abacus ball-shaped rotating bodies adjacent in the circumferential direction. It is a perspective view of the square steel pipe having a cruciform cross-sectional end end manufactured by the said metal pipe groove processing apparatus. FIG. 3 is a diagram for explaining that when a cruciform cross section is formed on a square steel pipe without arranging a shape guide, a protruding portion formed between two adjacent concave grooves bulges. It is a figure corresponding to (b). It is a figure explaining the difference between FIG. 3 (b) and FIG. 10, and (a) and (b) are the cases where the shape guide is used, and (c) and (d) are the cases where the shape guide is not used, respectively. Explanatory drawing, (e) is a figure explaining the difference in the cross-sectional shape (protruding state) of (b) and (d). It is a figure explaining the corner deformation behavior when the corner part of a square steel pipe is pushed in to form a concave groove, and (a) is the figure which pushed the corner part by the solo van ball-shaped rotating body of this invention which has a flat surface at the tip. In the case, (b) is an explanatory view when a corner portion is pushed by a solo van ball-shaped rotating body having an arc surface at the tip, and (c) is a view showing a cross section of a square steel pipe. A processing procedure will be described when two of the above-mentioned metal pipe concave groove processing devices are installed in parallel to form, for example, a cross-shaped cross section (cross pipe portion) at both ends of a metal pipe pillar material of a building structure. It is a figure. It is a figure explaining the processing procedure at the time of installing the above-mentioned metal pipe concave groove processing apparatus in series, for example, forming a cross pipe part at both ends of the metal pipe pillar material of a building structure. It is a figure explaining one use example of the steel pipe column which formed the cross-shaped cross section at both ends of the square steel pipe by the concave groove processing apparatus of the metal pipe of this invention, (a) is a side view, (b) is a plan view. , (C) is a cross-sectional view taken along the line CC. It is an embodiment in the case where the metal pipe is a round pipe and is a view corresponding to FIG. 4, (a) is a side view, (b) is a DD arrow cross-sectional view (c) of (a) is an end. It is a front view which looked at the metal tube which was processed into a concave groove from the end side. The grooving apparatus for the metal pipe of the example using the core 40 different from the core 30 in the first embodiment is shown, and (a) is a diagram corresponding to FIG. 3 (a) (however, the metal pipe is illustrated). (B) and (b) are cross-sectional views taken along the line EE of (a) (however, the left and right abacus ball-shaped rotating bodies and the shape guide holder 52 are not shown). (A) is a perspective view showing the core in FIG. 17 alone, and (b) is a front view of the core in (a).

Hereinafter, a method for forming a groove in a metal tube and a mode for carrying out the apparatus of the present invention will be described with reference to the drawings.

FIG. 1 shows an embodiment of a groove processing device for a metal tube of the present invention, (a) is a side view of the concave groove processing device 10, and (b) is a frame 32 and a shape described later in (a). It is a front view which showed by removing the guide holder 52 (however, the code | symbol of the core 30 which will be described later is omitted). FIG. 2 (a) is an enlarged view showing only the main part in FIG. 1 (b) in an enlarged manner. FIG. 3 (a) is an enlarged view of the main part in FIG. 1 (a), and FIG. 3 (b) is an enlarged view of the main part in FIG. 1 (b).
In this embodiment, a cruciform cross section is formed at both ends of a quadrangular square steel pipe 8 (hereinafter, in the case of a quadrangular square steel pipe, simply referred to as a square steel pipe).
The groove processing device 10 is provided with four groove forming mechanisms 1 in the housing 7 corresponding to the four corners of the square steel pipe 8 to be processed.
Each concave groove forming mechanism 1 includes a solo van ball-shaped rotating body 2 provided in a manner of pushing the outer surface of the pipe to form a concave groove, and includes a rotating body holder 3 that rotatably holds the solo van ball-shaped rotating body 2. The rotating body holder 3 is moved and adjusted toward the center of the device to provide a reduction adjusting mechanism 11 for adjusting the reduction of the solo van ball-shaped rotating body 2.
The abacus ball-shaped rotating body 2 has a cross-sectional shape that is thick on the central axis side (side of the central axis m) and narrows in a tapered shape toward the tip in the radial direction, and has a narrow flat surface 2a on the tip surface. As described above, the rotating body holder 3 is rotatably held. As shown in FIG. 2C, the cross-sectional shape may have a concave concave surface 2a'with a narrow width on the tip surface.
The solo van ball-shaped rotating body 2 does not have a rotating shaft, and the rotating body holder 3 is adapted to directly receive the load acting on the solo van ball-shaped rotating body 2 by the oilless metal (manuscript note 1: shape guide). Since it is difficult to draw (draw) the lid of the rotating body holder 3 so as to prevent the solo van ball-shaped rotating body from coming off, detailed explanation is omitted (Fig. 3 (a) in the manuscript drawing of NS2905). Drawing is omitted).

The housing 7 includes a housing body 7a that slidably accommodates the four rotating body holders 3, an outer lid 7b, and a base portion 7a'that also serves as an inner lid.
The reduction adjustment mechanism 11 only rotates the reduction screw 11a rotatably connected to the upper surface of the rotating body holder 3, the adjustment nut (double nut in the figure) 11b screwed into the reduction screw 11a, and the adjustment nut 11b. It is composed of a nut holding portion 11c that can be fixed to the housing body 7a. The reduction can be adjusted by turning the adjusting nut 11b to adjust the position of the rotating body holder 3 (the position of the abacus ball-shaped rotating body 2). However, the reduction adjustment mechanism in the present invention is not limited to the reduction adjustment mechanism 11 of the embodiment, and various mechanisms can be adopted. For example, it can also be adopted by a scroll chuck method or the like. In this case, the reduction adjustment of the plurality of rotating body holders can be performed at the same time.
The housing body 7a of the housing 7 is integrated with the base portion 7a'which also serves as the inner lid, and slidably accommodates the four rotating body holders 3 as described above. The outer lid 7b is fixed to the housing body 7a with bolts. In FIG. 1 (a), the upper and lower parts of the base portion 7a'and the lid 7b are shown in cross section, but the structure for holding the rotating body holder 3 so as to be slidable is omitted. ..
Although the details of the base portion 7a'of the housing body 7a are omitted, the base portion 7a'is fixed to a rotating face plate 13 which is rotatably attached to the device stand 12 indicated by a two-dot chain line, and is also attached to the base portion 7a'. A metal tube guide 14 for guiding the metal tube 8 to be processed is fixed. In the illustrated example, the metal tube guide 14 is fixed to the base portion 7a'on both sides orthogonal to the paper surface of FIG.

In the present invention, the protruding portion 8b formed between the two adjacent concave groove portions 8a formed in the metal tube 8 by being pushed by the two abacus ball-shaped rotating bodies 2 adjacent to each other in the circumferential direction is brought into contact with the protruding portion 8b. It is provided with a shape guide 51 that suppresses swelling.
In this embodiment in which the cross-sectional portion 8c is formed, four shape guides 51 are provided, and each shape guide 51 has FIGS. 1 (b), 2 (b), 3 (b), 7 (b), and 8 (b). As shown in each figure of the above, four abacus ball-shaped rotating bodies 2 are arranged between adjacent abacus ball-shaped rotating bodies 2, respectively.
The four shape guides 51 are fixed to the shape guide holders 52 attached to the front and rear surfaces of the housing body 7a of the housing 7 with, for example, bolts 53. A concave portion (seat) matching the cross-sectional shape of the end portion of the shape guide 51 is formed on the shape guide holder 52 side, and the end portion of the shape guide 51 is placed in this concave portion (triangular concave portion in the embodiment) in the form of an inro. It may be fixed.

As shown in FIGS. 5, 6, 8 and the like, each shape guide 51 of the embodiment is provided on each of the two triangular base corners 51c of the right-angled triangular columnar body on the tapered tip side of the solo van ball-shaped rotating body 2. A concave surface 51a having a shape substantially along the surface of the portion is formed, and a narrow triangular bottom surface (a surface having a cross-sectional shape of a drum in the illustrated example) 51b remains in the center of the base of the triangle between the concave surfaces 51a on both sides. It has a right-angled outer shape.
A large load acts on the bulging holding surface of the shape guide that suppresses the bulging of the protruding portion, but it is located in a narrow space between two adjacent solo van ball-shaped rotating bodies and comes into contact with the protruding portion. Since the vicinity of the swelling holding surface in the shape guide for suppressing swelling has a narrow cross section, it is difficult to secure rigidity. However, in the case of the outer shape guide as in claim 4, the vicinity of the swelling holding surface 51b Has a wide cross section (a cross section that becomes thick), so that sufficient rigidity to withstand a large load can be ensured.
Although the shape guide 51 of the embodiment is based on a right-angled triangular columnar body, it is not limited to the right-angled triangular columnar body and may be another isosceles triangular columnar body. Any shape may be used as long as it is arranged in a shape capable of contacting a protruding portion 8b formed between two adjacent concave groove portions 8a and suppressing the swelling thereof.

As shown in FIGS. 1 to 3, the groove processing apparatus 10 of this embodiment is located at the center position of the four abacus ball-shaped rotating bodies 2 arranged in the circumferential direction of the outer surface of the metal pipe in the longitudinal direction of the pipe. A short rod-shaped core 30 extending to is arranged. That is, not only the abacus ball-shaped rotating body 2 that pushes the outer surface of the metal tube from the outside, but also the core 30 that receives the portion pushed by the abacus ball-shaped rotating body 2 of the metal tube during processing is located in the metal tube. It is arranged like this.

As shown in the perspective view of FIG. 4, the core 30 has four recesses 30a facing each other in the radial tip side of each abacus ball-shaped rotating body 2, and projects between the adjacent recesses 30a. It has a portion 30b and has a cross section. That is, the entire longitudinal direction has a cross section.
A core having a uniform cross section as a whole, such as the core 30, is called a straight caliber core.
In FIG. 4, the horizontal portion and the vertical portion of the core 30 having a cross section are shown in a horizontal and vertical posture.
The core 30 is attached to the housing body 7a via the frame 32 as shown in FIG. That is, the frame body in which, for example, a rectangular plate-shaped core base 31 is integrally fixed to the end surface of the core 30 when viewed from the longitudinal direction of the core, and the core base 31 is attached to the front surface of the housing body 7a in the housing 7. By fixing it to 32 with a bolt, it is fixed to the housing body 7a in a horizontal state.
The lid body 7b of the housing body 7a in this embodiment is cut out at the upper and lower ends to shorten the length, and the upper and lower parts of the frame body 32 are fixed to the upper and lower parts of the housing body 7a.

When a cross-shaped cross section is formed at the end of a square steel pipe 8 by the concave groove processing device 10, for example, in FIG. 1 (a), a pushing device using, for example, a hydraulic cylinder (not shown) is used to push left as shown by an arrow. When the square steel pipe 8 is pushed into the space surrounded by the four solo van ball-shaped rotating bodies 2 of the recessed groove processing device 10, the sizing (forming) process action (or cold roll forming) in the electric pipe production line is performed. (Action), as shown in FIGS. 3 (a), (b), and (c), a concave groove portion (recessed groove) formed by crushing four corner portions of a square steel pipe with four solo van ball-shaped rotating bodies 2. 8a and a projecting portion 8b that remains in a protruding state without being crushed on the surface of the square steel pipe are formed, and a circumferential concavo-convex cross section having concave groove portions 8a and projecting portions 8b alternately in the circumferential direction (this implementation). In the example, a cross section (cross section) 8c is formed. FIG. 9 is a perspective view showing a square steel pipe 8 having a circumferentially uneven cross-sectional portion (cross pipe portion) 8c formed at an end portion.
When the circumferential concavo-convex cross-sectional portion 8c is formed, the shape guide 51 arranged between the two adjacent abacus ball-shaped rotating bodies 2 has a protruding portion 8b formed between the two adjacent concave groove portions 8a. Since the protrusion is suppressed by contacting with, it is possible to prevent the protruding portion 8b from bulging more than necessary.
FIG. 10 is a diagram corresponding to FIG. 3 (b) when the shape guide 51 is not used, but as shown in the drawing, when the four corners of the square steel pipe are crushed by the four abacus ball-shaped rotating bodies 2. , The surface of the square steel pipe is not crushed and remains in a protruding state to form a protruding part, but the protruding part is a protruding part 8b'that protrudes from the contour of the original pipe (metal pipe before processing). Become.
FIG. 11 is a diagram for comparing and explaining the difference between FIG. 3 (b) and FIG. 10, and (a) and (b) are the cases of the above embodiment using the shape guide 51, and (c) and (d) are The square steel pipe when the shape guide 51 is not used is shown, (a) and (c) are side views, (b) and (d) are cross-sectional views of the circumferentially uneven cross-sectional portion 8c, and (e) is (e). It is a figure explaining the difference of the cross-sectional shape (protruding state) of b) and (d).
As described above, by providing the shape guide 51, there is no protrusion protruding from the contour of the original pipe (metal pipe before processing) on the outer surface of the circumferentially uneven cross section formed at the end of the metal pipe. It is possible to secure an uneven cross-sectional shape (cross-sectional portion in this embodiment) 8c in the circumferential direction.
The shape guide 51 can be used not only when eliminating the protruding portion protruding from the contour of the original pipe, but also when obtaining a protruding portion recessed from the contour of the original pipe.

In the above-described embodiment, the end portion of the square steel pipe 8 is pushed into the concave groove processing device 10 installed in a fixed manner to form a circumferentially uneven cross section. However, the square steel pipe is fixed and the concave groove processing is performed. It is also possible to push and drive the device 10 toward the end side of the fixed square steel pipe to form a concave groove at the end of the square steel pipe. In short, it suffices if it can be driven relatively close to each other.

When forming a deep groove having a cross section on the outer surface of a square steel pipe, the general idea of the sizing process in an electric pipe manufacturing line is to taper the width toward the tip in the radial direction as a sizing roll. A roll profile is adopted so that the tip surface becomes an arc surface, but in the present invention, the tip surface has a narrow flat surface 2a or concave surface 2a'. This is the shape adopted as a result of the following experiments.
As shown in FIG. 12B, in an experiment in which a corner portion of a square steel pipe was pushed in as shown by an arrow with a roll M having a convex tip surface, cracks were often generated at the corner portion. Therefore, after considering various causes, as shown in Fig. 12 (a), an experiment was conducted in which the corners were pushed in as shown by the arrows with a roll K having a flat (or concave) tip surface, and cracks occurred. No more to do.
The following are considered as the reasons why cracks occur when the corners are pushed by a roll whose tip surface is an arc convex surface.
When a round steel pipe is formed into a square steel pipe in the sizing process of the electric resistance pipe production line, a large plastic deformation occurs at the corner part (the hatched part of FIG. 12 (c)) of the square steel pipe, and it becomes a total plastic region, which is remarkable. Work hardening has occurred. Therefore, as shown in FIG. 12 (b), when the convex R portion having a convex tip arc surface is pushed in, the convex R portion having a narrow range of the corner portion is pushed, so that the work-hardened convex R portion having a narrow range of the corner portion is pushed. Is liable to crack due to severe deformation that bends and deforms into a concave R shape in the opposite direction.
On the other hand, as shown in FIG. 12A, when the corner portion is pushed by the roll K whose tip surface is a flat surface (or concave surface), the convex R portion in a narrow range of the corner portion is bent into a concave R shape in the opposite direction. Instead of being deformed, a slightly wide portion including both side portions was pushed in and deformed while maintaining the convex shape of the convex R portion in a narrow range to some extent. Therefore, the deformation of the work-hardened convex R portion in a narrow range is reduced and cracks do not occur.
In FIGS. 12A and 12B, the arc convex roll M is bent and deformed in the order of M1, M2, and M3 and then pushed in, and the roll K on the flat tip surface is pushed in the order of K1, K2, and K3. It is shown that. K1 and M1 indicate the time when they come into contact with the corners, and K2 and M2 shown by solid lines indicate the time when the corners begin to dent and the difference in deformation behavior between the two appears characteristically.

When the above-mentioned concave groove processing device 10 is used to manufacture a metal pipe having a cross-shaped cross section at both ends of the metal pipe, the production efficiency is high when two concave groove processing devices 10 are installed and manufactured. .. In that case, it is efficient to adopt the method of FIG. 13 or FIG.
FIG. 13 shows a case where two recessed groove processing devices 10A and 10B are installed on opposite sides of a metal tube 8 in a parallel manner (installed by shifting rather than facing each other). In this case, pushing devices 20A and 20B using, for example, a hydraulic cylinder are arranged so as to face each other.
In FIG. 3A, the metal pipe 8 is pushed toward the groove processing device 10A by the pushing device 20A, so that the cross-sectional portion 8c is formed at one end as shown in (B).
When the metal pipe is conveyed between the grooving device 10B and the pushing device 20B as shown in (c) and pushed to the concave grooving device 10B side by the pushing device 20B, it is pushed to the other end as shown in (d). A cross section 8c is formed, whereby a metal tube 8 having a cross section 8c formed at both ends is obtained.

FIG. 14 shows a case where two recessed groove processing devices 10A and 10B are manufactured in a series system in which two recessed groove processing devices 10A and 10B are installed at opposite positions sandwiching a metal tube 8. In this case, the pushing devices 20A and 20B are arranged behind the respective recessed groove processing devices 10.
In (a) of FIG. 14 [I], the abacus ball-shaped rotating body 2 of the concave groove processing device 10A is kept in an open state, and the pushing portion of the pushing device 20A is passed through the recessed groove processing device 10A in the open state. By pushing the metal tube 8 toward the groove processing device 10B, a cross-shaped cross-sectional portion 8c is formed at one end as shown in (b).
Next, as shown in (c) of FIG. 14 [II], the solo van ball-shaped rotating body 2 of the recessed groove processing device 10B is kept in an open state, and the pushing portion of the pushing device 20B is recessed in the open state. By passing the device 10B and pushing the metal tube 8 toward the groove processing device 10A, a cruciform cross-section 8c is formed at the other end as shown in (d), and a cruciform cross section 8c is formed at both ends. A metal tube 8 is obtained.
In the case of the series method of FIG. 14, the metal pipe 8 may be fixed and the groove processing device 10 may be pushed into the metal pipe side by the pushing device 20. In that case, the cruciform cross-section 8c is naturally formed at the end opposite to the cruciform cross-section 8c shown in FIG. 14 (the end on the pushed-in concave groove processing device 10 side). Become.

When a square steel pipe having a cross-shaped cross section 8c formed at both ends is used as a column material of a building structure, a mounting plate for bolting with a beam material is welded and fixed to the end surface of the square steel pipe column material 8.
FIG. 15 shows only the lower part of the pillar material. For example, a square mounting plate 16 having the same vertical and horizontal dimensions as the square steel pipe is welded and fixed to the lower end surface of the cross section 8c of the square steel pipe pillar material 8. In the illustrated example, it is placed on the lower H-shaped steel beam 17, and the mounting plate 16 and the flange of the H-shaped steel beam 17 are joined by a bolt 18.
Since there are spaces on all four sides of the cross-shaped cross section 8c, it can be fixed with bolts 18 in the four spaces, and the side of the square steel pipe and the flange of the beam can be joined to the beam in a parallel state.
The same applies to the joint with the upper beam. However, it is natural that a cruciform cross section is formed only in the lower part or only in the upper part.
The columns joined in this way are also excellent in aesthetic appearance as columns, and are therefore suitable as column materials for building structures.
When the side of the square steel pipe is crushed to form a cross-shaped cross section at the pipe end, the protruding part becomes the corner part of the square steel pipe, and two of the spaces in the four sides of the cross-shaped cross section are H. Since it comes to the position of the web of the shaped steel beam 17, it cannot be bolted to the H-shaped steel beam 17 so as to have an excellent appearance as a column. Therefore, especially when it is used as a column material of a building structure and the beam is H-shaped steel, it is possible to push (crush) the corner portion of the square steel pipe to form a cross-shaped cross section as in the embodiment. You will need it.
However, except when it is used as a column material of a building structure and the beam is H-shaped steel as described above, even if the side portion of the square steel pipe is pushed (crushed) to form a cross section. Good. For example, it can be applied to, for example, a pile material for civil engineering, a pile material for a fence, and various other uses, and is particularly suitable for a pile material for civil engineering, a pile material for a fence, and the like.

Although the quadrangular metal tube has been described in the above-described embodiment, it can also be applied to a case where a polygonal metal tube such as a pentagon or a hexagon is targeted.
In that case, instead of the four solo van ball-shaped rotating bodies 2, the shape guide 51, the rotating body holder 3, and the reduction adjustment mechanism 11 in the above-mentioned concave groove processing device 10, the number of solo van balls corresponding to the number of corners By providing the shape rotating body 2, the shape guide 51, the rotating body holder 3, and the reduction adjustment mechanism 11, it is possible to form a concave groove according to the number of corners at the end of the polygonal metal tube. The metal tube guide 14 is adapted to the cross-sectional shape of the polygonal metal tube.
Further, in the above-described embodiment, an example in which the core is arranged so as to be located in the metal pipe has been described, but it can be carried out without the core, and a concave groove processing device that does not use the core. Alternatively, the concave groove processing method is also included in the present invention.

When the metal tube is a round tube and a cross-shaped cross section is formed at the end, the groove processing apparatus itself may be substantially the same as that shown in FIG. However, the metal tube guide 14 is adapted to the cross-sectional shape of the round tube.
FIG. 16 shows a main part of the grooving apparatus 10'of the embodiment when the metal pipe is a round pipe 18. FIG. 3 is a view corresponding to FIG. 3, (a) is a side view, (b) is a front view, and (c) is a front view of a metal pipe with a grooved end as viewed from the end side. .. The concave groove portion is indicated by 18a, the protruding portion is indicated by 18b, and the cross-sectional portion is indicated by 18c.
In the case of a round tube, the circumferential position of the abacus ball-shaped rotating body 2 is not particularly limited.

FIG. 17 shows a main part of the groove processing device 10 ”of the metal pipe of still another embodiment of the present invention. In this embodiment as well, the target metal pipe is a square steel pipe as in the first embodiment.
17 (a) and 17 (b) are views corresponding to FIGS. 3 (a) and 3 (b), and are views for explaining the concave groove processing device 10 "by showing only the main part thereof, and (a) is a side surface. (B) is a cross-sectional view taken along the line CC of (a) (however, the left and right two abacus ball-shaped rotating bodies 2 of the four abacus ball-shaped rotating bodies 2 are not shown).

Similar to the first embodiment, the concave groove processing device 10 ”of this embodiment extends in the longitudinal direction of the pipe at the center position of the four abacus ball-shaped rotating bodies 2 arranged in the circumferential direction of the outer surface of the metal pipe. A short rod-shaped core 40 is arranged.
As shown in FIG. 18, the core 40 has four recessed portions 40a facing each other in the radial tip side portion of each of the solo van ball-shaped rotating bodies 2, and a protruding portion 40b between the adjacent recessed portions 40a. It has a cross-sectional portion 40c forming a cross shape, but has a cross-sectional shape portion 40d in the pipe along the inner surface of the pipe, which is not a cross-section in the entire longitudinal direction. Then, it has a curved transition concave surface 40e that smoothly connects the corner portion of the in-pipe cross-sectional shape portion 40d to the straight concave portion 40a in the longitudinal direction along the radial tip side shape of the abacus ball-shaped rotating body 2. ..
A core 40 having such a cross-sectional shape portion 40d in a pipe, a curved transition concave surface 40e, and a cross-sectional portion 40c is called a total caliber core.
In FIG. 18, the horizontal portion and the vertical portion of the cross section of the core 40 are shown in a horizontal and vertical posture.

This Example 3 is different from the Example 1 only in that the core 40 is basically a total caliber core, but the core 40 has an in-pipe cross-sectional shape portion 40d and a curved transition concave surface 40e. As a result, the recessed portion 40a is smoothly formed by the abacus ball-shaped rotating body 2 and the core 40, and it becomes easy to secure the shape accuracy.
In FIGS. 17 and 18, basically the same parts as those in FIGS. 1 to 8 are designated by the same reference numerals and the description thereof is omitted.

1 Concave groove forming mechanism 2 Abacus ball-shaped rotating body 2a Flat surface 2a'Concave surface 3 Rotating body holder m Central axis 7 Housing 7a Housing body 7a'(inside the housing body) Base 7b (Housing) Lid 8 Square steel pipe (Metal tube)
18 Round steel pipe (metal pipe)
8a, 18a concave groove (concave groove part)
8b, 8b', 18b Protruding parts 8c, 8c', 18c Cross section 10, 10', 10 "Metal pipe groove processing device 11 Reduction adjustment mechanism 11a Reduction adjustment mechanism 11b Adjustment nut 11c Nut holding part 12 Device stand 13 Rotating face plate 14 Metal pipe guide 16 Mounting plates 20A, 20B Pushing device 30 Core (straight caliber core)
40 core (total caliber core)
30a, 40a Recessed part 30b, 40b Protruding part 40c Cross-section part 40d In-pipe cross-sectional shape part 40e Curved transition concave surface 31 Core base 32 Frame body 51 Shape guide 52 Shape guide holder 53 Bolt

Claims (10)

It is a groove processing device for a metal pipe that forms concave grooves extending from the pipe end in the pipe longitudinal direction at a plurality of locations at the end of the metal pipe at intervals in the circumferential direction of the outer surface.
On the central axis side of the rotating body, a plurality of solo van ball-shaped rotating bodies having a cross-sectional shape that is thick and tapered toward the tip in the radial direction and has a narrow flat surface or concave surface on the tip surface are formed on the outer surface of each pipe. Provided at intervals in the circumferential direction in the manner of pressing
Contact with a protruding portion formed between two adjacent concave groove portions formed in a metal tube by being pushed by two abacus ball-shaped rotating bodies adjacent to each other in the circumferential direction among the plurality of abacus ball-shaped rotating bodies. A groove processing device for a metal pipe, characterized in that a shape guide for suppressing the swelling is provided. A plurality of rotating body holders that rotatably hold each of the solo van ball-shaped rotating bodies, and a housing in which the plurality of rotating body holders are provided corresponding to the circumferential positions of the outer surface of the metal tube to which the concave groove should be formed. The recessed groove processing device for a metal pipe according to claim 1, further comprising a reduction adjusting means for adjusting the reduction of the rotating body holder, which is provided in the housing. It has a recess and a protrusion that match the contour of the inner surface of the pipe end when the plurality of concave grooves and ridges are formed at the end of the metal pipe, and the concave groove is formed at the end of the metal pipe. The recessed groove processing apparatus for a metal pipe according to claim 1 or 2, wherein the core is provided so as to be located in the pipe when the pipe is used. The shape guide is a triangular columnar body, and each of the two base corner portions of the shape guide is formed with a concave surface having a shape substantially along the surface of the tapered tip side portion of the abacus ball-shaped rotating body. Any one of claims 1 to 3, wherein the bottom portion sandwiched between the bottom corner portions having the concave surface has an outer shape formed in such a manner that a narrow bottom surface remains in the center of the bottom portion. The grooving apparatus for metal pipes according to. The groove processing apparatus for a metal pipe according to any one of claims 1 to 4 forms concave grooves extending from the pipe end in the pipe longitudinal direction at a plurality of locations at the end of the metal pipe at intervals in the circumferential direction of the outer surface. It is a method of machining a groove in a metal pipe.
The plurality of solo van ball-shaped rotating bodies and shape guides and the metal tube to be processed face each other in the longitudinal direction of the metal tube, and the solo van ball-shaped rotating body and the metal tube are driven relatively close to each other to drive the end portion of the metal tube. A method for processing a groove in a metal tube, which comprises forming a plurality of grooves in a metal tube. By the groove processing apparatus for a metal pipe according to claim 3 or 4, a metal pipe that forms concave grooves extending from the pipe end in the pipe longitudinal direction at a plurality of locations at the end of the metal pipe at intervals in the circumferential direction of the outer surface. It is a method of processing the concave groove of
The plurality of solo van ball-shaped rotating bodies and cores and the metal tube to be processed are opposed to each other in the longitudinal direction of the metal tube, and the solo van ball-shaped rotating body and the core and the metal tube are relatively close to each other to drive the metal tube. A method for processing a concave groove of a metal pipe, which comprises forming a plurality of concave grooves on the outer surface of the end portion of the metal tube. When the metal tube is a polygonal metal tube, the tip surface of the solo van ball-shaped rotating body is positioned so as to hit a corner portion of the polygonal metal tube, and the solo van ball-shaped rotating body and the polygonal metal tube are separated from each other. The method for processing a concave groove in a metal pipe according to claim 5 or 6, wherein the concave groove having a number of corners is formed on the outer surface of the end portion of the polygonal metal pipe by being driven relatively close to each other. When the metal tube is a quadrangular metal tube, the tip surface of the solo van ball-shaped rotating body is positioned so as to hit the four corners of the quadrangular metal tube, and the solo van ball-shaped rotating body and the quadrangular metal tube are relative to each other. The metal pipe according to claim 7, wherein four concave grooves are formed on the outer surface of the end portion of the quadrangular metal pipe, and a cross-shaped cross section is formed at the end portion of the quadrangular metal pipe. Concave groove processing method. When the metal tube is a round tube, the tip surfaces of the solo van ball-shaped rotating body are positioned at four positions at equal intervals in the circumferential direction of the outer surface of the round tube, and the solo van ball-shaped rotating body and the round tube are formed. 5 or 6, wherein four concave grooves are formed on the outer surface of the end portion of the round pipe, and a cross-shaped cross section is formed at the end portion of the round pipe. Concave groove processing method for metal pipes. The metal pipe to be processed by the method for processing a concave groove of a metal pipe according to any one of claims 5 to 9 is a steel pipe used as a pillar material of a building structure made of a square steel pipe or a round steel pipe. Concave groove processing method.

Images