JP2016191213A - Metal pipe strut - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for connecting tapered metal pipes in upper and lower tiers simply with a bolt and nut, thus mitigating labor for installation and absorbing displacement in a vertical direction especially of the tapered metal pipe in the upper tier.SOLUTION: When joining tapered metal pipes 10, 20 of which a diameter gradually widens in a downward direction, the tapered metal pipe 10 in an upper tier is inserted into the tapered metal pipe 20 in a lower tier from above, so as to hold an inner surface 10a of the tapered metal pipe 10 in the upper tier and an outer surface 20a of the tapered metal pipe 20 in the lower tier in a surface-contacting state. A bolt 12 is inserted through a long hole 11 extending vertically and formed in a surface-contacting area of the tapered metal pipe 10, and the bolt 12 is screwed into any one of a plurality of circular holes 25 formed in a vertical direction in a surface-contacting area of the tapered metal pipe 20, such that a circumferential surface of the circular hole 25 is plastically deformed into a female screw form, for screwing the bolt 12 thereinto.SELECTED DRAWING: Figure 7

Description

  The present invention relates to a metal pipe column applied to a lightning rod, a base station, or the like installed on the rooftop of a building, or a utility pole installed on the ground, and particularly against a bending load applied by wind force or seismic force. In addition, the present invention relates to a metal pipe column suitable for reducing the construction labor.

  A lightning rod, a base station, or the like installed on the rooftop of a building or a utility pole installed on the ground is required to have a considerable height, and the total weight increases accordingly. For this reason, after dividing the metal tube struts into a plurality of tapered metal tubes, they are transported to the site, thereby facilitating the transport operation and joining them together on the site to form a single metal tube strut. There are many cases.

  As an example of such a metal pipe support, for example, a technique disclosed in Patent Document 1 is disclosed. In this example of the metal tube strut, for each tapered metal tube that is spliced up and down, the diameter is increased in a taper shape from the upper end to the lower end. Then, the upper taper metal tube is inserted into the lower taper metal tube from above to hold them. At this time, the inner surface of the upper tapered metal tube and the outer surface of the lower tapered metal tube are held in surface contact. By realizing such a surface contact, it is possible to suitably counter a bending load caused by wind force or the like that is applied to the metal pipe column.

  However, the disclosed technique disclosed in Patent Document 1 requires a special fitting for connecting the upper tapered metal tube and the lower tapered metal tube. That is, since it is necessary to prepare this coupling fitting separately by manufacturing or purchasing it, a new preparation cost is required. Further, in order to fix the coupling fitting at a predetermined position in the tapered metal pipe, an additional work such as inserting a rod-shaped hammer and applying an impact is necessary, so that the burden of connecting work is increased.

  For this reason, a metal tube column that can realize the connection between the upper taper metal tube and the lower taper metal tube with only bolts and nuts without requiring any special coupling metal fittings has been desired. It was rare.

  Patent Document 2 discloses a technique that can realize the connection between an upper metal tube and a lower metal tube using only bolts and nuts. According to the technology disclosed in Patent Document 2, the lower metal pipe is formed with a steel pipe insertion pipe that extends upward from the upper end of the tapered portion with the same diameter. One bolt insertion hole is formed in the steel pipe insertion pipe, and a nut is provided on the inner surface side thereof. The upper metal pipe is provided with a bolt insertion long hole on a side surface of a steel pipe body having the same diameter. The steel pipe main body in the upper metal pipe is fitted into the steel pipe insertion pipe in the lower metal pipe, and the bolt is inserted into the bolt insertion long hole and the bolt insertion hole. Then, the screw portion of the inserted bolt is engaged with a nut provided on the inner surface side of the bolt insertion hole.

JP-A-4-143380 JP 2011-111769 A

  According to the technology disclosed in Patent Document 2 described above, the lower end of the steel pipe main body of the upper metal pipe is in contact with the tapered portion at the entire circumference thereof, so that most of the gravity from the steel pipe main body is received by the entire tapered portion. It is like that. In addition, since the lower end of the steel pipe body of the upper metal pipe is supported via the tapered portion of the lower metal pipe, the height of the lower end of the upper metal pipe is almost specified. As a result, the height of the lower end of the steel pipe body of the upper metal pipe is hardly displaced in the vertical direction. Therefore, one bolt insertion hole is formed in the lower metal pipe, a nut is provided on the inner surface side thereof, and a bolt insertion long hole is formed on the side surface of the upper metal pipe, so that the insertion holes are mutually inserted during bolt insertion. There is almost no misalignment between the two.

  However, as shown in Patent Document 1, when the inner surface of the upper taper metal tube and the outer surface of the lower taper metal tube are held in surface contact, due to slight manufacturing errors, the upper metal tube The height of the lower end may be shifted in the vertical direction. In such a case, as shown in Patent Document 2, in the configuration in which one bolt insertion hole is formed in the lower metal pipe and the bolt insertion long hole is formed in the side surface of the upper metal pipe, such vertical displacement is not achieved. There was a problem that it could not be absorbed.

  Therefore, the present invention has been devised in view of the above-mentioned problems, and the object of the present invention is to make surface contact between the inner surface of the upper tapered metal tube and the outer surface of the lower tapered metal tube. In the metal pipe struts that are joined together by holding, it is possible to connect the upper and lower taper metal pipes simply by using bolts and nuts. An object of the present invention is to provide a metal tube strut that can absorb water.

  In order to solve the above-described problems, the metal tube strut according to the present invention expands in a tapered shape toward the lower portion of each tapered metal tube, and forms the inner surface of the upper tapered metal tube and the lower tapered metal tube. In order to hold the outer surface of the upper tapered metal tube in surface contact and absorb the vertical displacement of the upper tapered metal tube, the upper tapered metal tube is passed through a long hole extending vertically. By inserting the bolt, the vertical displacement of the upper tapered metal tube is absorbed.

  A metal tube strut according to a first aspect of the present invention is a metal tube strut configured by joining a plurality of tapered metal tubes, and each of the tapered metal tubes is expanded in a tapered shape downward, By inserting the lower taper metal tube into the taper metal tube, the inner surface of the upper taper metal tube and the outer surface of the lower taper metal tube are held in surface contact, and the upper taper metal tube A long hole extending vertically is formed in the surface contact region of the tube, and a circular surface whose circumferential surface is plastically deformed into a female screw shape by a bolt to be screwed in the surface contact region of the lower tapered metal tube. A plurality of holes are formed in the vertical direction, and the bolt inserted through the elongated hole is screwed to the female screw formed in any one of the circular holes.

  According to a second aspect of the present invention, there is provided the metal tube support column according to the first aspect, wherein the lower tapered metal tube is screwed between the bolt and the female screw without providing a nut on the inner surface of the circular hole. It is possible to fix to the upper tapered metal tube via the above.

  According to a third aspect of the present invention, in the first or second aspect, the tapered metal pipe is characterized in that the diameter of each tapered metal pipe is increased in a tapered shape from the upper end to the lower end.

  According to a fourth aspect of the present invention, there is provided the metal tube column according to any one of the first to third aspects, wherein the elongated hole is formed by allowing the bolt to be screwed into any one of the circular holes. It is characterized in that it is possible to absorb the vertical misalignment that occurs when the inner surface of the tapered metal tube and the outer surface of the lower tapered metal tube are held in surface contact.

  A method of assembling a metal tube strut according to a fifth invention is a method of assembling a metal tube strut configured by joining together a plurality of tapered metal tubes, and each of the above-mentioned diameters expanded in a tapered shape downward. Prepare a plurality of taper metal tubes, and insert the upper taper metal tube into the lower taper metal tube from above, so that the inner surface of the upper taper metal tube and the outer surface of the lower taper metal tube are A bolt is inserted through a long hole formed in the surface contact region of the upper taper metal tube and vertically extended in the surface contact region of the lower taper metal tube. The bolt is screwed into any one of a plurality of circular holes so that the circumferential surface of the circular hole is plastically deformed into a female screw shape and screwed to the bolt.

  According to the present invention having the above-described configuration, the stress concentration is applied to the bending load based on wind force, seismic force, etc. by holding the inner surface of the tapered metal tube and the outer surface of the tapered metal tube in surface contact. While making use of the advantage that can be suitably countered without occurring, it is possible to absorb the vertical misalignment between the tapered metal tubes during construction. In particular, according to the present invention, the connection between these tapered metal tubes can be realized with only bolts, and it is not necessary to weld many nuts to the inner surface of the tapered metal tube. Become.

  In addition to this, according to the present invention, based on the bending load due to wind force or seismic force, a shear stress acts between the inner surface of the upper tapered metal tube and the outer surface of the lower tapered metal tube, Such shear stress acts on the bolt. However, according to the present invention, it is possible to allow the bolt to move relative to the long hole based on the shear stress by adopting a configuration in which the bolt is inserted into the long hole. As a result, the shear stress acting on the bolt can be reduced.

It is a perspective view which shows the whole structure of the metal pipe support | pillar to which this invention is applied. It is a figure for demonstrating the structure of the taper metal pipe of the upper stage in the metal pipe support | pillar to which this invention is applied. It is a figure for magnifying and explaining the neighborhood of a slot in an upper taper metal tube. It is a figure for demonstrating the structure of a lower taper metal pipe in the metal pipe support | pillar to which this invention is applied. It is a figure for magnifying and explaining the neighborhood of a circular hole in a lower taper metal pipe. It is a figure for demonstrating the example which twists a volt | bolt with respect to a circular hole. It is a figure which shows the example which joins an upper taper metal pipe and a lower taper metal pipe mutually. It is sectional drawing which shows the state which screwed the volt | bolt with respect to the taper metal pipe. It is a figure which shows the state which visually recognized from the head side the bolt screwed with respect to the taper metal pipe. It is a figure for demonstrating the mechanism which absorbs the position shift of the up-down direction between an upper taper metal pipe and a lower taper metal pipe. It is another figure for demonstrating the mechanism which absorbs the position shift of the up-down direction between an upper taper metal pipe and a lower taper metal pipe.

  Hereinafter, the form for implementing the metal pipe support to which the present invention is applied is explained in detail, referring to drawings.

  FIG. 1 is a perspective view showing the overall configuration of a metal tube support 1 to which the present invention is applied. The metal pipe column 1 is applied to, for example, a lightning rod, a base station, a lighting column, or a power pole installed on the ground, for example, on a rooftop of a building, and a plurality of tapered metal tubes 10, 20, 30 are joined together. It is constituted by.

  The tapered metal tubes 10, 20, and 30 are metallic tube bodies such as steel and aluminum, and are expanded in a tapered shape downward. When the tapered metal tubes 10, 20, and 30 are made of steel, for example, the surface may be hot dip galvanized.

  In the example of FIG. 1, the taper metal tube 20 is joined by inserting the taper metal tube 20 on the lowermost taper metal tube 30, and the taper metal tube 10 is further joined by inserting the taper metal tube 10 on the taper metal tube 20. An example will be described. However, the present invention is not limited to the case where the tapered metal pipes 10, 20, and 30 are joined together over three stages as shown in FIG. May be.

  The base plate 34 is fixed to the ground with anchor bolts 35. A ground plate 32 is attached to the lower side surface of the tapered metal tube 30. The base plate 34 is provided with a raised portion 31 that rises upward, and a base plate 34 is provided at the lower end of the raised portion 31.

  Further, a top plate 41 is provided at the upper end of the tapered metal tube 10 located at the uppermost stage, and a lightning rod 42 is erected on the top plate 41. Incidentally, when this metal tube support column 1 is applied to a base station, this tapered metal tube 10 is provided with an antenna. In addition, when the metal tube support 1 is applied to a utility pole, the top plate 41 is provided with a member for supporting an electric wire. As described above, the top plate 41 is provided with various configurations and members depending on what the metal tube support 1 is applied to.

  Next, the configuration in which the upper and lower tapered metal pipes 10, 20, and 30 are joined together will be described in detail. Hereinafter, the case where the upper tapered metal tube 10 and the lower tapered metal tube 20 are joined together will be described as an example.

  As shown in FIGS. 1 to 3, the upper tapered metal tube 10 is provided with a long hole 11 extending in the vertical direction in the vicinity of the lower end. FIG. 2B is a cross-sectional view taken along the line AA ′ in FIG. 2A, but the tapered metal tube 10 is substantially circular in plan view, and the long holes 11 are 180 ° from each other in plan view. It is provided at intervals. The long hole 11 is configured to penetrate from the outer surface to the inner surface of the tapered metal tube 10. The long hole 11 is configured to have a size into which the bolt 12 can be inserted. The long hole 11 may be provided not only at one place but at a plurality of places at other positions separated in the vertical direction.

  The inclination angle of the side surface of the tapered metal tube 10 shown in FIG. 3 with respect to the vertical direction is hereinafter referred to as a taper angle θ.

  As shown in FIGS. 1 and 4, the lower tapered metal tube 20 is provided with a long hole 21 extending in the vertical direction in the vicinity of the lower end, and a bolt 22 is inserted and fixed thereto. The long hole 21 is used for joining with the tapered metal tube 30 positioned further below, and the detailed configuration thereof is the same as that of the long hole 11 described above. The tapered metal tube 20 is formed with a plurality of circular holes 25 in the vicinity of the upper end and spaced apart from each other in the vertical direction. 4B is a cross-sectional view taken along the line BB ′ in FIG. 4A. The tapered metal tube 20 is substantially circular in a plan view, and the circular holes 25 are 180 ° from each other in the plan view. It is provided at intervals. The circular hole 25 is configured to penetrate from the outer surface to the inner surface of the tapered metal tube 10. FIG. 5 is an enlarged view of a plurality of circular holes 25 formed at intervals in the vertical direction. The diameter of the circular hole 25 is R, and the distance between the centers of the circular holes 25 adjacent vertically is a. The diameter R of the circular hole 25 is determined from the viewpoint described below.

  Note that the interval between the long holes 11 in the plan view of the tapered metal tube 10 and the interval between the circular holes 25 in the plan view of the tapered metal tube 20 are both set to 180 °, but this is not limitative. However, both may be set at 90 ° intervals.

  The outer diameter of the upper end of the tapered metal tube 20 needs to be smaller than the inner diameter of the lower end of the tapered metal tube 10. Thereby, the tapered metal tube 20 can be inserted into the tapered metal tube 10.

  As shown in FIG. 5, the inclination angle of the tapered metal tube 20 with respect to the vertical direction is hereinafter referred to as a taper angle θ ′. The taper angle θ ′ of the taper metal tube 20 is substantially the same as the taper angle θ of the taper metal tube 10.

  FIG. 6 shows an example in which the bolt 12 is actually screwed into the circular hole 25. Initially, the diameter R of the circular hole 25 is configured to be smaller than the diameter of the threaded portion 12a of the bolt 12, as shown in FIG. At this time, the diameter R of the circular hole 25 may be substantially the same as the diameter of the valley portion in the screw portion 12a. Thereby, even if it is going to insert the volt | bolt 12 in the circular hole 25 in the initial stage, since the diameter R is small, it is in the state which cannot implement | achieve smoothly.

  Thus, the screw part 12a in the bolt 12 is screwed into the circular hole 25 having the diameter R set. As a result, the bolt 12 (screw portion 12a) causes the circumferential surface 25a of the circular hole 25 to be plastically deformed into a female screw shape as shown in FIG. 6B, and so-called tapping is possible. In this way, the formed female thread-like circumferential surface 25a and the threaded portion 12a of the bolt 12 can be screwed together. The diameter R of the circular hole 25 described above may be configured to have any diameter as long as it can be tapped by plastic deformation into a female screw shape when the bolt 12 is screwed.

  Actually, when the upper taper metal tube 10 and the lower taper metal tube 20 are joined together, the taper metal tube 10 is inserted above the taper metal tube 20 from the lower end side as shown in FIG. As described above, since the taper angle θ ′ of the tapered metal tube 20 is substantially the same as the taper angle θ of the tapered metal tube 10, the inner surface 10 a of the tapered metal tube 10 and the outer surface of the tapered metal tube 20 are used. 20a is held in surface contact. In this way, the height of the lower end of the tapered metal tube 10 is specified. Stress concentration does not occur with respect to a bending load caused by wind force or the like applied to the metal tube column 1 via a contact surface between the inner surface 10a of the tapered metal tube 10 and the outer surface 20a of the tapered metal tube 20. It becomes possible to compete suitably.

  In this state, the circular hole 25 through which the bolt 12 can be inserted through the long hole 11 is searched. Since the long holes 11 and the circular holes 25 are provided at an interval of 180 ° in a plan view, the directions in the plan view coincide with each other. Since the height of the lower end of the tapered metal tube 10 is also specified as described above, the circular hole 25 into which the bolt 12 can be inserted is inevitably specified at the height of the long hole 11. Also in the example shown in FIG. 7, one circular hole 25 that exactly overlaps the long hole 11 is specified among a plurality of circular holes 25 provided vertically. The bolt 12 is inserted into the long hole 11 and the circular hole 25. When the bolt 12 is inserted, the screw portion 12a of the bolt 12 is screwed into the circular hole 25, and the circumferential surface 25a of the circular hole 25 is plastically deformed into a female screw shape as shown in FIG. 6B. Thus, they are screwed together.

  FIG. 8 is a cross-sectional view showing a state where the bolt 12 is screwed in this manner, and FIG. 9 is a view showing a state viewed from the head side of the bolt 12.

  A washer 28 is interposed between the head of the bolt 12 and the tapered metal tube 10. The washer 28 is developed wider than the left and right edges of the long hole 11. The washer 28 is configured to press the washer 28 with the head of the bolt 12 by screwing and fixing the threaded portion 12a of the bolt 12 to the female threaded circumferential surface 25a of the circular hole 25. As a result, the washer 28 is locked at the left and right edges of the long hole 11. The washer 28 may be formed integrally with the head of the bolt 12 as long as the bolt 12 is securely locked in the long hole 11.

  In this way, the upper tapered metal tube 10 and the lower tapered metal tube 20 are fixed by the bolts 12. This prevents the upper taper metal tube 10 from coming out of the lower taper metal tube 20 when a bending load due to wind force, seismic force, or the like is applied, by applying frictional force and resistance to shearing force. Can do. Further, the twist generated between the tapered metal tubes 10 and 20 due to such wind force or seismic force can be prevented by applying the frictional force and resistance to the shearing force by being fixed by the bolt 12.

  In addition to this, shear stress acts between the inner side surface 10a of the tapered metal tube 10 and the outer side surface 20a of the tapered metal tube 20 based on a bending load caused by wind force or the like, and the shearing force applied to the bolt 12 as well. Stress will act. However, according to the present invention, it is possible to allow the bolt 12 to move relative to the long hole 11 based on the shear stress by adopting a configuration in which the bolt 12 is inserted into the long hole 11. As a result, the shear stress acting on the bolt 12 can be reduced.

  According to the present invention, the taper angle θ ′ of the taper metal tube 20 is substantially the same as the taper angle θ of the taper metal tube 10, but both the taper angles θ and θ ′ are small and 1 ° or less. It is. Therefore, in the present invention in which the inner side surface of the tapered metal tube 10 and the outer side surface of the tapered metal tube 20 are held in surface contact, there is a slight manufacturing error or the like at such a small taper angle θ, θ ′. In this case, the height of the lower end of the upper tapered metal tube 10 may be shifted in the vertical direction. In such a case, the positional relationship of the circular hole 25 with respect to the long hole 11 as shown in FIG. As an example when the height of the lower end of the upper tapered metal tube 10 is shifted in the vertical direction, there may be a positional relationship of the circular hole 25 with respect to the long hole 11 as shown in FIG. 10, for example, FIG. In some cases, the circular hole 25 may be positioned relative to the long hole 11 as shown in FIG.

  Even in such a case, according to the present invention, the elongated holes 11 are configured to extend in the vertical direction, and the circular holes 25 are provided at a plurality of locations at intervals in the vertical direction. Even if this occurs, as shown in FIGS. 10 and 11, one of the circular holes 25 is always caught by the long hole 11. For this reason, the upper taper metal tube 10 and the lower taper metal tube 20 must be fixed to each other by joining the single circular hole 25 captured by the long hole 11 with the bolt 12 as described above. Is possible. Incidentally, in order to make sure that one circular hole 25 is always captured by the long hole 11, it is necessary that the length of the long hole 11 in the vertical direction be a + R or more.

  Therefore, according to the metal tube strut 1 to which the present invention is applied, the long hole 11 enables the bolt 12 in any one of the circular holes 25, so that the inner surface of the tapered metal tube 10 and the tapered metal tube 20 are formed. It is possible to absorb the positional deviation in the vertical direction that occurs when the outer surface is held in surface contact. By holding the inner surface of the taper metal tube 10 and the outer surface of the taper metal tube 20 in surface contact, it is possible to suitably counteract bending stress based on wind force or the like without causing stress concentration. While making the best use of it, the vertical displacement between the tapered metal tubes 10 and 20 can be absorbed during construction. In particular, according to the present invention, the connection between the tapered metal pipes 10 and 20 can be realized only by the bolts 12, and the construction labor can be reduced.

  Further, the tapered metal tube 20 can be fixed to the tapered metal tube 10 through screwing between the bolt 12 and a female threaded circumferential surface 25a in the circular hole 25. Therefore, it is not necessary to dispose a nut continuing to the circular hole 25 on the inner surface of the tapered metal tube 20 as in the disclosed technique of Patent Document 2. Therefore, since all the operations associated with the arrangement of the nut on the inner surface of the tapered metal tube 20 can be omitted, the manufacturing effort can be further reduced. In particular, according to the present invention, a plurality of circular holes 25 are provided in the vertical direction of the tapered metal tube 20, but it is not necessary to provide nuts for all the circular holes 25, and the effect of reducing the labor is very large. It becomes.

  In the above-described embodiment, the connection between the tapered metal tubes 10 and 20 has been described as an example. However, the same configuration can be applied to the connection between the tapered metal tubes 20 and 30 as well. is there. Of course, the connection structure between the tapered metal tubes 10 and 20 can be applied even if the metal tube support 1 is configured to join the tapered metal tubes having four or more stages.

  In the above-described embodiment, as an example of the tapered metal pipes 10 and 20, the case where the diameter is uniformly increased in a tapered shape from the upper end to the lower end has been described, but the present invention is not limited to this. is not. It suffices that at least the surface contact area where the inner surface 10a of the tapered metal tube 10 and the outer surface 20a of the tapered metal tube 20 are in surface contact with each other is expanded in a tapered shape downward. About the area | region, you may be comprised by the tubular body extended in the up-down direction in the state of the same diameter in which the taper is not formed.

  The present invention may be embodied in a method for assembling the metal tube strut 1 as well as being applied to the configuration of the metal tube strut 1 as described above. In such a case, by preparing a plurality of tapered metal tubes 10, 20, 30 and inserting the upper tapered metal tube 10 into the lower tapered metal tube 20 from above, the inner surface 10 a of the tapered metal tube 10, The outer surface 20a of the tapered metal tube 20 is held in surface contact. Next, the bolt 12 is inserted through the long hole 11 formed in the surface contact region of the tapered metal tubes 10 and 20 and extending vertically. Next, the circumferential surface 25a of the circular hole 25 is plastically deformed into a female screw shape by screwing the bolt 12 into any one of the circular holes 25 formed in the vertical direction in the surface contact region of the tapered metal tube 20. And screwed to the bolt 12.

  By performing these assembling methods for all the tapered metal pipes to be added, one metal pipe column 1 is finally completed.

DESCRIPTION OF SYMBOLS 1 Metal pipe support | pillar 10, 20, 30 Tapered metal pipe 11, 21 Long hole 12, 22 Bolt 25 Circular hole 28 Washer 31 Upright part 32 Ground plate 34 Base plate 35 Anchor bolt 41 Top plate 42 Lightning rod

Claims (5)

A metal tube strut constructed by splicing a plurality of tapered metal tubes,
Each taper metal tube is expanded in a taper shape downward,
By inserting the lower taper metal tube into the upper taper metal tube, the inner surface of the upper taper metal tube and the outer surface of the lower taper metal tube are held in surface contact,
In the surface contact region in the upper taper metal tube, a long hole extending up and down is formed,
In the surface contact region of the lower tapered metal tube, a plurality of circular holes whose upper surface is plastically deformed in the circumferential surface by a bolt to be screwed are formed in the vertical direction, and inserted through the elongated holes. A metal pipe column, wherein the bolt is screwed to the female screw formed in any one of the circular holes. The lower taper metal tube can be fixed to the upper taper metal tube through screwing between the bolt and the female screw without providing a nut on the inner surface of the circular hole. The metal pipe support according to claim 1, wherein The diameter of each said taper metal pipe is expanded in the taper shape from the upper end to the lower end, The metal pipe support | pillar of Claim 1 or 2 characterized by the above-mentioned. In the long hole, the inner surface of the upper tapered metal tube and the outer surface of the lower tapered metal tube are held in surface contact by allowing the bolt to be screwed into any one of the circular holes. The metal pipe column according to any one of claims 1 to 3, wherein a vertical position shift caused by this is absorbed. A method of assembling a metal pipe column constituted by joining a plurality of tapered metal pipes,
Prepare a plurality of each of the above taper metal pipes that are expanded in a tapered shape downward,
By inserting the upper taper metal tube into the lower taper metal tube from above, the inner surface of the upper taper metal tube and the outer surface of the lower taper metal tube are held in surface contact,
Insert a bolt through a long hole extending in the vertical direction formed in the surface contact area in the upper tapered metal tube,
In the surface contact region of the lower tapered metal tube, the bolt is screwed into any one of the circular holes formed in the vertical direction to plastically deform the circumferential surface of the circular hole into a female screw shape. A method of assembling a metal tube strut characterized by being screwed to a bolt.

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