JP2013053493A

JP2013053493A - Steel pipe set

Info

Publication number: JP2013053493A
Application number: JP2011193881A
Authority: JP
Inventors: Mikio Umeoka; 美喜男梅岡
Original assignee: Individual
Current assignee: Individual
Priority date: 2011-09-06
Filing date: 2011-09-06
Publication date: 2013-03-21

Abstract

PROBLEM TO BE SOLVED: To provide a steel pipe set which dispenses with a welding operation on a job site, can be easily and firmly connected without being affected by the weather, and comprises two or more steel pipes capable of being inexpensively manufactured.SOLUTION: A steel pipe set S1 includes a first steel pipe P1 which has a first screwing member 3 welded to an edge of an upper end of a steel pipe body 2, and a second steel pipe P2 which has a second screwing member 8 welded to an edge of a lower end of the steel pipe body 2. The first screwing member 3, which is formed in a flat cylindrical shape from cast steel, has a thread groove 7 provided on an inner peripheral surface. The second screwing member 8, which is formed in a flat cylindrical shape from cast steel, has an outer peripheral surface provided with a thread 14 for being screwed into the thread groove 7.

Description

本発明は、軟弱地盤の改良工事等に用いられる相互接続可能な２つ以上の鋼管からなる鋼管セットに関するものである。 The present invention relates to a steel pipe set including two or more interconnectable steel pipes used for improvement work of soft ground.

軟弱地盤を強固な地盤に改良するための方法として、セメントミルクを流し込んだ穴の中に筒状の鋼管（あるいは鋼管杭）を立て込む方法が開発されている。かかる鋼管の立て込みによる軟弱地盤の改良には、１０ｍを超えるような長尺な鋼管が必要とされることもあるが、汎用の鋼管は、４〜６ｍ程度の長さのものが多い。したがって、上記したような軟弱地盤の改良工事においては、鋼管を立て込んだ後に、その鋼管の上方に、同一径の別の鋼管を溶接によって接続した後にさらに深く立て込む方法が広く採用される。 As a method for improving a soft ground to a solid ground, a method of standing a tubular steel pipe (or steel pipe pile) in a hole into which cement milk has been poured has been developed. In order to improve the soft ground by standing the steel pipe, a long steel pipe exceeding 10 m may be required, but general-purpose steel pipes are often about 4 to 6 m long. Therefore, in the improvement work of the soft ground as described above, after the steel pipe is set up, another steel pipe having the same diameter is connected to the upper side of the steel pipe and then deeply set up.

そのような鋼管の溶接による接続の際には、上下の鋼管の長手方向を精度良く合致させることが必要であるため、立て込んだ鋼管の内部に、鋼管の内径より若干小径で幅が４０〜１００ｍｍ程度の扁平な内接管を嵌入して仮止めし（部分的に溶接し）、その内接管の上側部分に、継ぎ足す別の鋼管を外嵌し、上下２つの鋼管を溶接するという方法が採用されている。さらに、上下の鋼管を溶接する場合には、上下の鋼管の間に数個のスペーサを挟んで、上下の鋼管の間に所定の間隙（３〜６ｍｍ程度）を設ける必要がある。 When connecting such steel pipes by welding, it is necessary to match the longitudinal direction of the upper and lower steel pipes with high accuracy, so that the inner diameter of the steel pipe is slightly smaller than the inner diameter of the steel pipe and the width is 40 to 100 mm. A method is adopted in which a flat inscribed pipe is inserted and temporarily fixed (partially welded), another steel pipe to be added is externally fitted to the upper part of the inscribed pipe, and two upper and lower steel pipes are welded. Has been. Further, when the upper and lower steel pipes are welded, it is necessary to provide a predetermined gap (about 3 to 6 mm) between the upper and lower steel pipes by sandwiching several spacers between the upper and lower steel pipes.

それゆえ、上下の鋼管の間にスペーサを挟む作業の煩わしさを解消するために、特許文献１の如く、扁平な円筒状の支持体から複数のピンを放射方向へ突出させた鋼管接続用治具を、上下の鋼管の内部に嵌め込み、ピンを挟み込むことによって形成される上下の鋼管の隙間を利用して溶接を行う接続方法も提案されている。 Therefore, in order to eliminate the troublesome work of sandwiching the spacer between the upper and lower steel pipes, as shown in Patent Document 1, a steel pipe connecting jig in which a plurality of pins protrudes radially from a flat cylindrical support. There has also been proposed a connection method in which welding is performed by using a gap between the upper and lower steel pipes formed by fitting the tool into the upper and lower steel pipes and sandwiching the pins.

また、現場での溶接作業を要せず鋼管を接続する方法として、特許文献２の如く、円筒状体の略中央の外周に環状突起を設けた継手部材を利用し、その継手部材の上下のボス部（円筒状部分）を片方の鋼管の上端部と他方の鋼管の下端部とに嵌め込み、継手部材の両ボス部に装着された管固定用ネジの基部で、上下に位置した各鋼管の端部の内面を押圧することによって２つの鋼管を接続する方法も提案されている。 In addition, as a method of connecting steel pipes without requiring on-site welding work, as in Patent Document 2, a joint member provided with an annular protrusion on the substantially central outer periphery of a cylindrical body is used. The boss part (cylindrical part) is fitted into the upper end of one steel pipe and the lower end of the other steel pipe, and the base of the pipe fixing screw attached to both bosses of the joint member. A method of connecting two steel pipes by pressing the inner surface of the end has also been proposed.

特開２００４−６８５０３号公報JP 2004-68503 A 特開２００５−９７９１０号公報JP 2005-97910 A

しかしながら、特許文献１の如き鋼管の接続方法は、いずれも鋼管の立て込み作業現場での溶接作業が不可欠であるため、雨天時、強風時や寒冷時には特別な保護仮設なしに鋼管を接続することができない、という不具合がある。 However, all of the methods for connecting steel pipes as described in Patent Document 1 require that the steel pipes be welded at the site where the steel pipes are set up. Therefore, the steel pipes should be connected without special protective provisions during rainy weather, strong winds, or cold weather. There is a problem that can not be.

また、特許文献２の如き鋼管の接続方法は、作業現場での溶接作業は不要となるものの、現場における２つの鋼管の接続作業が容易ではない上、十分な接続強度を確保しにくい。さらに、継手部材の構造が複雑である上、２つの鋼管の端部の加工を必要とするため、継手部材や鋼管の加工に、多大なコストと手間がかかる。 Moreover, although the steel pipe connection method as in Patent Document 2 does not require welding work at the work site, it is not easy to connect the two steel pipes at the work site, and it is difficult to ensure sufficient connection strength. Furthermore, since the structure of the joint member is complicated and the end portions of the two steel pipes are required to be processed, the processing of the joint member and the steel pipe requires a great deal of cost and labor.

本発明の目的は、上記従来の鋼管の接続方法が有する問題点を解消し、鋼管の立て込み工事（杭打ち工事）等の現場での溶接作業が不要で、天候に左右されることなく、容易かつ強固に接続することができる上、非常に安価に製造することが可能な２本以上の鋼管からなる鋼管セットを提供することにある。 The object of the present invention is to eliminate the problems of the above-mentioned conventional methods for connecting steel pipes, and eliminates the need for welding work at the site, such as steel pipe standing work (piling work), without being affected by the weather, An object of the present invention is to provide a steel pipe set including two or more steel pipes that can be easily and firmly connected and can be manufactured at a very low cost.

本発明の内、請求項１に記載された発明は、回転圧入式の鋼管杭として互いに接続した状態で使用される同一径で円筒状の二つの鋼管からなる鋼管セットであって、鋼鉄または鋳鋼によって扁平な円筒状に形成されており内周面にネジ溝を設けてなる第一螺合部材を、鋼鉄によって長尺な円筒状に形成された管本体の上端縁際に嵌め込んで溶接してなる第一鋼管と、鋼鉄または鋳鋼によって扁平な円筒状に形成されており前記ネジ溝と螺合するネジ山を外周面に設けてなる第二螺合部材を、鋼鉄によって長尺な円筒状に形成された管本体の下端縁際に溶接してなる第二鋼管とからなることを特徴とするものである。なお、第一螺合部材または第二螺合部材の材料として利用可能な鋳鋼とは、炭素鋼を鋳物にしたもので、炭素成分が２％以下であり、鋳鉄よりも融点が高いもの（約１５５０℃以上）をいう。 Among the present inventions, the invention described in claim 1 is a steel pipe set comprising two cylindrical pipes having the same diameter and being used as a rotary press-fit type steel pipe pile, wherein the steel or cast steel The first threaded member formed in a flat cylindrical shape with a thread groove on the inner peripheral surface is fitted and welded to the upper edge of the tube body formed in a long cylindrical shape with steel. The first steel pipe and the second threaded member formed in a flat cylindrical shape with steel or cast steel and provided with a screw thread to be screwed into the screw groove on the outer peripheral surface are made into a long cylindrical shape with steel. It consists of the 2nd steel pipe welded to the edge of the lower end of the pipe main body formed in this. The cast steel that can be used as the material of the first screw member or the second screw member is a cast steel made of carbon steel, has a carbon component of 2% or less, and has a higher melting point than cast iron (about approx. 1550 ° C. or higher).

請求項２に記載された発明は、請求項１に記載された発明において、前記第一螺合部材が、前記第一鋼管の管本体の外径と同じ外径を有するリング状のフランジ部の下側に、第一鋼管の管本体の内径と同じ外径を有する円筒状の嵌入部を連設し、それらのフランジ部と嵌入部の内壁にネジ溝を設けてなるものであるとともに、前記第二螺合部材が、前記第二鋼管の管本体の外径と同じ外径を有するリング状のフランジ部の上側に、第二鋼管の管本体の内径と同じ外径を有する扁平な円筒状の嵌入部を連設し、フランジ部の下側に、前記ネジ山を外周面に設けた筒状の螺合部を連設してなるものであり、前記第一螺合部材の嵌入部と前記第二螺合部材の螺合部とを螺合させて前記第一鋼管と前記第二鋼管とを接続した場合に、２つの鋼管の外周よりも外側に突出する部分が実質的に形成されないことを特徴とするものである。 The invention described in claim 2 is the invention described in claim 1, wherein the first threaded member is a ring-shaped flange portion having the same outer diameter as the outer diameter of the pipe body of the first steel pipe. On the lower side, a cylindrical insertion portion having the same outer diameter as the inner diameter of the tube body of the first steel pipe is continuously provided, and a thread groove is provided on the inner wall of the flange portion and the insertion portion, and A flat cylindrical shape in which the second screwing member has an outer diameter equal to the inner diameter of the pipe main body of the second steel pipe, on the upper side of the ring-shaped flange portion having the same outer diameter as the outer diameter of the pipe main body of the second steel pipe And a cylindrical threaded portion provided with the screw thread on the outer peripheral surface is continuously disposed on the lower side of the flange portion, and the fitted portion of the first threaded member; When the first steel pipe and the second steel pipe are connected by screwing the threaded portion of the second threaded member, the outer circumferences of the two steel pipes Portion projecting remote outside is characterized in that not substantially formed.

請求項３に記載された発明は、請求項１、または請求項２に記載された発明において、前記第一鋼管の肉厚に対する前記第一螺合部材の嵌入部の肉厚の割合（肉厚比）が１．１５以上２．００以下に調整されているとともに、第二螺合部材の螺合部の肉厚が第一螺合部材の嵌入部の肉厚より厚くなっていることを特徴とするものである。すなわち、第一螺合部材の嵌入部の肉厚が第一鋼管の肉厚の１．１５倍を下回ると、第一鋼管と第二鋼管との接続部分に大きなねじりや曲げ応力が加わったときに、第一螺合部材の嵌入部が損傷し易いので好ましくない。反対に、上記肉厚比が２．００を上回ると、第一螺合部材の嵌入部の肉厚に合わせて第二螺合部材の螺合部の肉厚を過大にする必要が生じるため不経済であり、好ましくない。 According to a third aspect of the present invention, in the first or second aspect of the present invention, the ratio of the thickness of the fitting portion of the first threaded member to the thickness of the first steel pipe (thickness) Ratio) is adjusted to 1.15 or more and 2.00 or less, and the thickness of the screwing portion of the second screwing member is thicker than the thickness of the fitting portion of the first screwing member. It is what. That is, when the thickness of the fitting portion of the first screwing member is less than 1.15 times the thickness of the first steel pipe, when a large torsion or bending stress is applied to the connection portion between the first steel pipe and the second steel pipe In addition, the insertion portion of the first screwing member is easily damaged, which is not preferable. On the other hand, if the thickness ratio exceeds 2.00, the thickness of the screwed portion of the second screwed member needs to be increased in accordance with the thickness of the fitting portion of the first screwed member. It is an economy and is not preferable.

請求項１に係る鋼管セットによれば、第一鋼管の上端際の第一螺合部材に設けられたネジ溝に、第二鋼管の下端際の第二螺合部材に設けられたネジ山を螺合させるだけで、現場での溶接作業を必要とすることなく、第一鋼管と第二鋼管とをきわめて容易に接続することができる。また、ネジを締める方向と、繋いだ鋼管を回転圧入させる場合の回転方向とを合致させることができるため、回転圧入時に接続部分が緩む事態を生じさせない。さらに、第一螺合部材、第二螺合部材が溶接可能な鋼鉄や鋳鋼によって形成されており、第一鋼管、第二鋼管の管本体との接続強度が高いので、鋼管を回転圧入する場合に発生するねじり応力や引張応力に対して高い耐力を発現するように強固に接続することができる。加えて、第一螺合部材、第二螺合部材を鋳鋼によって形成する場合には、安価に製造することが可能となる。 According to the steel pipe set according to claim 1, the screw groove provided in the first screwing member near the upper end of the first steel pipe is threaded on the second screwing member near the lower end of the second steel pipe. By simply screwing together, the first steel pipe and the second steel pipe can be connected very easily without requiring an on-site welding operation. Moreover, since the direction in which the screw is tightened can be matched with the rotational direction in the case where the connected steel pipe is rotationally press-fitted, a situation in which the connecting portion is not loosened during rotational press-fitting is not caused. Furthermore, when the first screw member and the second screw member are formed of weldable steel or cast steel and the connection strength between the first steel pipe and the second steel pipe is high, the steel pipe is rotationally press-fitted. Can be firmly connected so as to exhibit a high yield strength against torsional stress and tensile stress generated in the wire. In addition, when the first screw member and the second screw member are formed of cast steel, it can be manufactured at low cost.

請求項２に係る鋼管セットは、第一鋼管、第二鋼管の製造時に、第一螺合部材、第二螺合部材の嵌入部を管本体に嵌入した状態で各螺合部材と管本体とを管外周からの溶接で接続できるので、製造作業が非常に容易である。また、第一鋼管と第二鋼管との接続位置に、外向きの突出部分が形成されないので、接続された２つの鋼管を、地盤の内部に非常にスムーズに押し込んだり、回転圧入したり、立て込んだりすることが可能となる。 The steel pipe set according to claim 2 is configured such that, when the first steel pipe and the second steel pipe are manufactured, each screw member and the pipe main body are in a state where the fitting portions of the first screw member and the second screw member are fitted into the pipe main body. Can be connected by welding from the outer periphery of the pipe, so that the manufacturing work is very easy. Moreover, since the outward projecting portion is not formed at the connection position between the first steel pipe and the second steel pipe, the two connected steel pipes can be pushed into the ground very smoothly, or can be rotationally pressed or stowed. It is possible to hang up.

請求項３に係る鋼管セットは、第一鋼管と第二鋼管との接続部分がフランジにより平面で接している上、第一鋼管の肉厚に対する第一螺合部材の嵌入部の肉厚の割合が所定の値に調整されているため、大きなねじり応力、曲げモーメントや圧縮力が加わっても、接続部材が損傷しにくい。その上、第二螺合部材の螺合部の肉厚が第一螺合部材の嵌入部の肉厚より厚くなるように設計されているため、無駄にコストをかけることなく非常に経済的に製造することができる。 In the steel pipe set according to claim 3, the connecting portion of the first steel pipe and the second steel pipe is in contact with the flat surface by the flange, and the ratio of the thickness of the fitting portion of the first screwing member to the thickness of the first steel pipe Is adjusted to a predetermined value, the connection member is hardly damaged even when a large torsional stress, bending moment or compressive force is applied. In addition, since the thickness of the screwing portion of the second screwing member is designed to be thicker than the thickness of the fitting portion of the first screwing member, it is very economical without wasting costs. Can be manufactured.

第一鋼管と第二鋼管とからなる鋼管セットを示す斜視図である。It is a perspective view which shows the steel pipe set which consists of a 1st steel pipe and a 2nd steel pipe. 第一鋼管の形成材料である第一螺合部材および管本体を示す斜視図である。It is a perspective view which shows the 1st screwing member which is a forming material of a 1st steel pipe, and a pipe main body. 第一螺合部材および管本体を示す正面図である。It is a front view which shows a 1st screwing member and a pipe | tube main body. 第一螺合部材および管本体を示す鉛直断面図である。It is a vertical sectional view showing the first screwing member and the pipe body. 第一鋼管の正面図（ａ）および平面図（ｂ）である。It is the front view (a) and top view (b) of a 1st steel pipe. 第二鋼管の形成材料である管本体および第二螺合部材を示す斜視図である。It is a perspective view which shows the pipe main body and the 2nd screwing member which are the formation materials of a 2nd steel pipe. 管本体および第二螺合部材を示す正面図である。It is a front view which shows a pipe | tube main body and a 2nd screwing member. 管本体および第二螺合部材を示す鉛直断面図である。It is a vertical sectional view showing a pipe body and a second screwing member. 第二鋼管の正面図（ａ）および平面図（ｂ）である。It is the front view (a) and top view (b) of a 2nd steel pipe. 第一鋼管と第二鋼管とを接続した状態の正面図である。It is a front view of the state which connected the 1st steel pipe and the 2nd steel pipe. 第一螺合部材の変更例を示す鉛直断面図である。It is a vertical sectional view showing a modification of the first screwing member.

以下、本発明に係る鋼管セットの一実施形態を、図面に基づいて詳細に説明する。 Hereinafter, one embodiment of a steel pipe set concerning the present invention is described in detail based on a drawing.

＜鋼管セットの構成＞
［実施例１］
図１は、鋼管セットを示したものである。鋼管セットＳ１は、管本体２の上端際に第一螺合部材３を溶接してなる第一鋼管Ｐ１と、管本体２の下端際に第二螺合部材８を溶接してなる第二鋼管Ｐ２とによって構成されている。 <Configuration of steel pipe set>
[Example 1]
FIG. 1 shows a steel pipe set. The steel pipe set S1 includes a first steel pipe P1 formed by welding the first screwing member 3 at the upper end of the pipe main body 2, and a second steel pipe formed by welding the second screwing member 8 at the lower end of the pipe main body 2. And P2.

図２〜図４は、管本体２と第一螺合部材３とを溶接する前の第一鋼管Ｐ１を示したものである。第一鋼管Ｐ１の管本体２は、鋼鉄（ＳＳ４００）によって、外径約１１４．３ｍｍ（内径約１０５．３ｍｍ）、厚さ４．５ｍｍ、長さ６，０００ｍｍの長尺な円筒状に形成されている（なお、管本体２の厚みを、Ｔ１とする）。 2 to 4 show the first steel pipe P1 before the pipe main body 2 and the first screwing member 3 are welded. The pipe body 2 of the first steel pipe P1 is formed of steel (SS400) into a long cylindrical shape having an outer diameter of about 114.3 mm (inner diameter of about 105.3 mm), a thickness of 4.5 mm, and a length of 6,000 mm. (The thickness of the tube body 2 is T1).

一方、第一螺合部材３は、管本体２と同様に、鋼鉄（ＳＳ４００）によって形成されている。そして、高さ約３１ｍｍの扁平な円筒状の嵌入部４の上端際に、高さ約９ｍｍのリング状のフランジ部５を連設した形状を有しており、全体の高さ（長さ）が約４０ｍｍになっている。 On the other hand, the first screwing member 3 is made of steel (SS400), similar to the tube main body 2. And it has the shape which connected the ring-shaped flange part 5 of about 9 mm in height at the upper end of the flat cylindrical insertion part 4 of about 31 mm in height, and the whole height (length) Is about 40 mm.

第一螺合部材３の嵌入部４の外径は、約１０５．０ｍｍであり、管本体２の内径と略同一になっている。一方、フランジ部５の外径は、約１１４．３ｍｍであり、管本体２の外径と同一になっている。また、嵌入部４とフランジ部５との境界（フランジ部５の下側の部分）は、下側から上側にかけて次第に大径になるように、所定の角度だけ傾斜した（水平面に対して４５°以上傾斜した）テーパ面６になっている。 The outer diameter of the fitting portion 4 of the first screwing member 3 is about 105.0 mm, which is substantially the same as the inner diameter of the tube body 2. On the other hand, the outer diameter of the flange portion 5 is about 114.3 mm, which is the same as the outer diameter of the tube body 2. Further, the boundary between the fitting portion 4 and the flange portion 5 (the lower portion of the flange portion 5) is inclined by a predetermined angle so as to gradually increase in diameter from the lower side to the upper side (45 ° with respect to the horizontal plane). The taper surface 6 is inclined.

また、第一螺合部材３の内径（最も小さい部分の径）は、約８４．０ｍｍになっており、深さ３．５ｍｍで幅（上下幅）４ｍｍのネジ溝７が螺旋状（８ｍｍピッチ）に刻設されている。それゆえ、嵌入部４の肉厚（Ｔ２）は、最も薄い部分で７ｍｍとなっている。 Further, the inner diameter (the diameter of the smallest part) of the first screwing member 3 is about 84.0 mm, and the screw groove 7 having a depth of 3.5 mm and a width (vertical width) of 4 mm is spiral (8 mm pitch). ). Therefore, the thickness (T2) of the insertion portion 4 is 7 mm at the thinnest portion.

第一鋼管Ｐ１は、上記した第一螺合部材３の嵌入部４を管本体２の上端際に嵌入させ、嵌入部４の上端を管本体２の上端と合致させた状態で、第一螺合部材３のテーパ面６と管本体２の上端面とからなる開先部分を利用して、第一螺合部材３と管本体２とを溶接することによって一体的に形成されている。図５は、管本体２と第一螺合部材３とを溶接した後の第一鋼管Ｐ１を示したものであり、当該溶接後の第一鋼管Ｐ１においては、管本体２の外周面と、第一螺合部材３のフランジ部５の外周面とが面一になっている（なお、図１、図５において、Ｙは溶接部分を示している）。 The first steel pipe P1 is inserted into the first screw member 3 in the state where the fitting portion 4 of the first screwing member 3 is fitted at the upper end of the pipe main body 2 and the upper end of the fitting portion 4 is aligned with the upper end of the pipe main body 2. The first screwing member 3 and the tube main body 2 are integrally formed by welding the groove portion formed by the tapered surface 6 of the combined member 3 and the upper end surface of the tube main body 2. FIG. 5 shows the first steel pipe P1 after welding the pipe body 2 and the first screwing member 3. In the first steel pipe P1 after welding, the outer peripheral surface of the pipe body 2, The outer peripheral surface of the flange portion 5 of the first screwing member 3 is flush with the outer peripheral surface (Y in FIGS. 1 and 5 indicates a welded portion).

一方、図６〜図８は、管本体２と第二螺合部材８とを溶接する前の第二鋼管Ｐ２を示したものである。第二鋼管Ｐ２の管本体２は、第一鋼管Ｐ１の管本体２と同じものである。また、第二螺合部材８は、第一螺合部材３と同じ鋼鉄（ＳＳ４００）によって形成されている。そして、高さ約７ｍｍのリング状のフランジ部９の上側、下側に、それぞれ、高さ約２ｍｍの扁平な円筒状の嵌入部１０と、高さ約４０ｍｍの筒状の螺合部１１を連設した形状を有しており、全体の高さ（長さ）が約４９ｍｍになっている。そして、直径５９．０ｍｍの貫通孔１２が、嵌入部１０、フランジ部９、螺合部１１の中心（軸方向の中心）を貫通した状態になっている。 On the other hand, FIGS. 6-8 shows the 2nd steel pipe P2 before welding the pipe main body 2 and the 2nd screwing member 8. FIG. The pipe body 2 of the second steel pipe P2 is the same as the pipe body 2 of the first steel pipe P1. The second screwing member 8 is formed of the same steel (SS400) as the first screwing member 3. Then, on the upper side and the lower side of the ring-shaped flange portion 9 having a height of about 7 mm, a flat cylindrical fitting portion 10 having a height of about 2 mm and a cylindrical screwing portion 11 having a height of about 40 mm are respectively provided. It has a continuous shape, and the overall height (length) is about 49 mm. And the through-hole 12 with a diameter of 59.0 mm has penetrated the center (axial center) of the insertion part 10, the flange part 9, and the screwing part 11. FIG.

また、第二螺合部材８の嵌入部１０の外径は、約１０５．０ｍｍであり、管本体２の内径と同一になっている。一方、フランジ部９の外径は、約１１４．３ｍｍであり、管本体２の外径と同一になっている。さらに、嵌入部１０とフランジ部９との境界（フランジ部９の上側の部分）は、上側から下側にかけて次第に大径になるように、所定の角度だけ傾斜した（水平面に対して４５°以上傾斜した）テーパ面１３になっている。 Further, the outer diameter of the fitting portion 10 of the second screwing member 8 is about 105.0 mm, which is the same as the inner diameter of the tube body 2. On the other hand, the outer diameter of the flange portion 9 is about 114.3 mm, which is the same as the outer diameter of the tube body 2. Further, the boundary between the fitting portion 10 and the flange portion 9 (the upper portion of the flange portion 9) is inclined by a predetermined angle so as to gradually increase in diameter from the upper side to the lower side (at least 45 ° with respect to the horizontal plane). It is an inclined taper surface 13.

また、第二螺合部材８の螺合部１１の外径（最も大きい部分の径）は、約９０．０ｍｍになっている。そして、当該螺合部１１の外周面は、深さ３．５ｍｍで幅（上下幅）４ｍｍのネジ溝を螺旋状（８ｍｍピッチ）に刻設することによって、螺旋状のネジ山１４が形成された状態になっている。それゆえ、螺合部１１の肉厚（Ｔ３）は、最も薄い部分で約１２ｍｍとなっている。 Moreover, the outer diameter (the diameter of the largest part) of the screwing part 11 of the second screwing member 8 is about 90.0 mm. The outer peripheral surface of the screwing portion 11 is formed with a screw thread 14 having a depth of 3.5 mm and a width (vertical width) of 4 mm in a spiral shape (8 mm pitch), thereby forming a helical thread 14. It is in the state. Therefore, the thickness (T3) of the screwing portion 11 is about 12 mm at the thinnest portion.

第二鋼管Ｐ２は、上記した第二螺合部材８の嵌入部１０を管本体２の下端際に嵌入させ、嵌入部１０の上端を管本体２の上端と合致させた状態で、第二螺合部材８のテーパ面１３と管本体２の下端面とからなる開先部分を利用して、第二螺合部材８と管本体２とを溶接することによって一体的に形成されている。図９は、管本体２と第二螺合部材８とを溶接した後の第二鋼管Ｐ２を示したものであり、当該接合後の第二鋼管Ｐ２においては、管本体２の外周面と、第二螺合部材８のフランジ部９の外周面とが面一になっている（なお、図９において、Ｙは溶接部分を示している）。 The second steel pipe P2 is inserted into the second threaded member 8 in a state where the fitting portion 10 of the second screwing member 8 is fitted to the lower end of the pipe main body 2 and the upper end of the fitting portion 10 is aligned with the upper end of the pipe main body 2. The second screwing member 8 and the tube main body 2 are integrally formed by welding the groove portion formed by the tapered surface 13 of the combined member 8 and the lower end surface of the tube main body 2. FIG. 9 shows the second steel pipe P2 after the pipe main body 2 and the second screwing member 8 are welded. In the second steel pipe P2 after the joining, the outer peripheral surface of the pipe main body 2, The outer peripheral surface of the flange portion 9 of the second screw member 8 is flush with the outer peripheral surface (Y in FIG. 9 indicates a welded portion).

上記の如く構成された実施例１の鋼管セットＳ１においては、第一鋼管Ｐ１の肉厚（最も薄い部分の肉厚：Ｔ１＝４．５ｍｍ）に対する第一螺合部材３の嵌入部４の肉厚（最も薄い部分の肉厚：Ｔ２＝７ｍｍ）の割合（肉厚比：Ｔ２／Ｔ１）が約１．５６に調整されている。加えて、実施例１の鋼管セットＳ１においては、第二螺合部材８の螺合部１１の肉厚（最も薄い部分の肉厚：Ｔ３＝１２ｍｍ）が第一螺合部材３の嵌入部４の肉厚（最も薄い部分の肉厚：Ｔ２＝７ｍｍ）より厚くなっている。 In the steel pipe set S1 of Example 1 configured as described above, the thickness of the fitting portion 4 of the first screwing member 3 with respect to the thickness of the first steel pipe P1 (thickness of the thinnest portion: T1 = 4.5 mm). The ratio (thickness ratio: T2 / T1) of the thickness (thickness of the thinnest portion: T2 = 7 mm) is adjusted to about 1.56. In addition, in the steel pipe set S1 of the first embodiment, the thickness of the screwing portion 11 of the second screwing member 8 (thickness of the thinnest portion: T3 = 12 mm) is the fitting portion 4 of the first screwing member 3. (Thickness of the thinnest part: T2 = 7 mm).

＜鋼管セットの接続方法＞
上記した第一鋼管Ｐ１、第二鋼管Ｐ２からなる鋼管セットＳ１の接続は、地盤改良工事の現場において地盤に鉛直に立て込んだ第一鋼管Ｐ１の上部に第二鋼管Ｐ２を接続して継ぎ足す、というような態様等にて実施される。鋼管セットＳ１を接続する場合には、第一鋼管Ｐ１の上端際の第一螺合部材３の開口部に、第二鋼管Ｐ２の下端際の第二螺合部材８の螺合部１１を押し当て、第二鋼管Ｐ２を所定の方向（時計回り）に回転させることによって、第二螺合部材８の螺合部１１のネジ山１４を第一螺合部材３の嵌入部４のネジ溝７に螺合させる。 <Connection method of steel pipe set>
The connection of the steel pipe set S1 composed of the first steel pipe P1 and the second steel pipe P2 described above is performed by connecting the second steel pipe P2 to the upper part of the first steel pipe P1 vertically standing on the ground at the site of the ground improvement work. It is carried out in such a manner. When the steel pipe set S1 is connected, the screwing portion 11 of the second screwing member 8 at the lower end of the second steel pipe P2 is pushed into the opening of the first screwing member 3 at the upper end of the first steel pipe P1. When the second steel pipe P2 is rotated in a predetermined direction (clockwise), the thread 14 of the screwing portion 11 of the second screwing member 8 is turned into the screw groove 7 of the fitting portion 4 of the first screwing member 3. Screwed on.

図１０は、第一鋼管Ｐ１と第二鋼管Ｐ２を接続した状態を示したものであり、そのように接続（螺着）された第一鋼管Ｐ１と第二鋼管Ｐ２は、回転圧入時のねじりに対して高い耐力を発現させる。また、第一鋼管Ｐ１と第二鋼管Ｐ２との接続位置に外方への突出部分が形成されないので、きわめてスムーズに地盤中に押し込んだり、回転圧入したり、立て込んだりすることができる。 FIG. 10 shows a state in which the first steel pipe P1 and the second steel pipe P2 are connected, and the first steel pipe P1 and the second steel pipe P2 thus connected (screwed) are twisted during rotational press-fitting. High tolerance is expressed. Moreover, since the outward projecting portion is not formed at the connection position between the first steel pipe P1 and the second steel pipe P2, it can be pushed into the ground, rotationally press-fitted, or stood very smoothly.

＜鋼管セットの耐屈曲性評価＞
上記の如く接続した鋼管セットＳ１（第一鋼管Ｐ１および第二鋼管Ｐ２）の両端をそれぞれ把持し、接続部分にねじり応力を加えて、鋼管セットＳ１の座屈性を評価した。その結果、実施例１の鋼管セットＳ１は、鋼管元来のねじり強さ（ねじり耐力）である１１，１３０ｋＮ・ｍの力を加えた場合でも、接続部分が屈曲することはなかった。 <Evaluation of bending resistance of steel pipe set>
Both ends of the steel pipe set S1 (the first steel pipe P1 and the second steel pipe P2) connected as described above were respectively gripped, and a torsional stress was applied to the connection portion to evaluate the buckling property of the steel pipe set S1. As a result, in the steel pipe set S1 of Example 1, even when a force of 11,130 kN · m, which is the original torsional strength (twisting strength) of the steel pipe, was applied, the connecting portion was not bent.

［実施例２〜７］
第一鋼管Ｐ１の外径、管本体２の肉厚（Ｔ１）、第一鋼管Ｐ１の第一螺合部材３の嵌入部４の肉厚（最も薄い部分の肉厚：Ｔ２）、第二鋼管Ｐ２の第二螺合部材８の螺合部１１の肉厚（最も薄い部分の肉厚：Ｔ３）、第二鋼管Ｐ２の外径、管本体２の肉厚（Ｔ４）を、下記の表１の如く変更した以外は、実施例１と同様にして、実施例２〜７の鋼管セットＳ２〜Ｓ７を得た。しかる後、実施例１と同様にして、実施例２〜７の鋼管セットＳ２〜Ｓ７の耐屈曲性を評価した。その結果、鋼管セットＳ２〜Ｓ７は、いずれも、実施例１の鋼管セットＳ１と同様に、約１１，１３０ｋＮ・ｍの力を加えた場合でも、接続部分が屈曲することはなかった。 [Examples 2 to 7]
The outer diameter of the first steel pipe P1, the thickness of the pipe body 2 (T1), the thickness of the fitting portion 4 of the first screw member 3 of the first steel pipe P1 (thickness of the thinnest portion: T2), the second steel pipe Table 1 below shows the thickness of the threaded portion 11 of the second threaded member 8 of P2 (thickness of the thinnest portion: T3), the outer diameter of the second steel pipe P2, and the thickness (T4) of the tube body 2. Except having changed like this, it carried out similarly to Example 1, and obtained steel pipe set S2-S7 of Examples 2-7. Thereafter, in the same manner as in Example 1, the bending resistance of the steel pipe sets S2 to S7 of Examples 2 to 7 was evaluated. As a result, in the steel pipe sets S2 to S7, as in the case of the steel pipe set S1 of Example 1, even when a force of about 11,130 kN · m was applied, the connection portion was not bent.

［参考実施例１］
第一鋼管Ｐ１の外径、管本体２の肉厚（Ｔ１）、第一鋼管Ｐ１の第一螺合部材３の嵌入部４の肉厚（最も薄い部分の肉厚：Ｔ２）、第二鋼管Ｐ２の第二螺合部材８の螺合部１１の肉厚（最も薄い部分の肉厚：Ｔ３）、第二鋼管Ｐ２の外径、管本体２の肉厚（Ｔ４）を、下記の表１の如く変更した以外は、実施例１と同様にして、参考実施例１の鋼管セットＳ’を得た。しかる後、実施例１と同様にして、参考実施例１の鋼管セットＳ’の耐屈曲性を評価した。その結果、鋼管セットＳ’は、約１１，１３０ｋＮ・ｍの力を加えた場合には、第一螺合部材３と第二螺合部材８との接合部分にわずかに座屈現象が見られた。 [Reference Example 1]
The outer diameter of the first steel pipe P1, the thickness of the pipe body 2 (T1), the thickness of the fitting portion 4 of the first screw member 3 of the first steel pipe P1 (thickness of the thinnest portion: T2), the second steel pipe Table 1 below shows the thickness of the threaded portion 11 of the second threaded member 8 of P2 (thickness of the thinnest portion: T3), the outer diameter of the second steel pipe P2, and the thickness (T4) of the tube body 2. A steel pipe set S ′ of Reference Example 1 was obtained in the same manner as Example 1 except for the change. Thereafter, in the same manner as in Example 1, the bending resistance of the steel pipe set S ′ of Reference Example 1 was evaluated. As a result, in the steel pipe set S ′, when a force of about 11,130 kN · m is applied, a slight buckling phenomenon is observed at the joint portion between the first screw member 3 and the second screw member 8. It was.

＜鋼管セットの効果＞
鋼管セットＳ１〜Ｓ８，Ｓ’は、上記の如く、扁平な円筒状に形成されており内周面にネジ溝７を設けてなる第一螺合部材３を、鋼鉄によって長尺な円筒状に形成された管本体２の上端縁際に嵌め込んで溶接してなる第一鋼管Ｐ１と、扁平な円筒状に形成されておりネジ溝７と螺合するネジ山１４を外周面に設けてなる第二螺合部材８を、鋼鉄によって長尺な円筒状に形成された管本体２の下端縁際に溶接してなる第二鋼管Ｐ２とからなるものである。したがって、鋼管セットＳ１〜Ｓ８，Ｓ’によれば、第一鋼管Ｐ１の第一螺合部材３のネジ溝７に、第二鋼管Ｐ２の第二螺合部材８のネジ山１４を螺合させるだけで、現場での溶接作業を必要とすることなく、第一鋼管Ｐ１と第二鋼管Ｐ２とをきわめて容易に接続することができる。また、ネジを締める方向と、繋いだ鋼管を回転圧入させる場合の回転方向とを合致させることができるため、回転圧入時に接合部が緩む事態を生じさせない。さらに、第一螺合部材３、第二螺合部材８が、溶接可能な鋼鉄によって第一鋼管Ｐ１、第二鋼管Ｐ２の外周部から容易に溶接できるように形成されており、第一鋼管Ｐ１、第二鋼管Ｐ２の管本体２との接続強度が高いので、鋼管を回転圧入する場合に発生するねじり応力や引張応力に対して高い耐力を発現するように強固に接続することができる。 <Effect of steel pipe set>
As described above, the steel pipe sets S1 to S8, S ′ are formed in a flat cylindrical shape, and the first screwing member 3 provided with the screw grooves 7 on the inner peripheral surface is formed into a long cylindrical shape with steel. A first steel pipe P1 that is fitted and welded to the edge of the upper end of the formed pipe body 2 and a screw thread 14 that is formed in a flat cylindrical shape and that engages with the screw groove 7 are provided on the outer peripheral surface. The second screwing member 8 is composed of a second steel pipe P2 formed by welding the second screw member 8 to the lower edge of the pipe body 2 formed in a long cylindrical shape with steel. Therefore, according to the steel pipe sets S1 to S8, S ′, the screw thread 14 of the second screwing member 8 of the second steel pipe P2 is screwed into the screw groove 7 of the first screwing member 3 of the first steel pipe P1. Thus, the first steel pipe P1 and the second steel pipe P2 can be very easily connected without requiring welding work on site. In addition, since the direction in which the screw is tightened and the rotation direction in the case where the connected steel pipe is rotationally press-fitted can be matched, a situation in which the joint portion is not loosened during the rotational press-fitting will not occur. Furthermore, the first screw member 3 and the second screw member 8 are formed so as to be easily weldable from the outer peripheral portions of the first steel pipe P1 and the second steel pipe P2 by weldable steel, and the first steel pipe P1. Since the connection strength between the second steel pipe P2 and the pipe body 2 is high, the second steel pipe P2 can be firmly connected so as to exhibit a high proof stress against torsional stress and tensile stress generated when the steel pipe is rotationally press-fitted.

また、鋼管セットＳ１〜Ｓ８，Ｓ’は、第一螺合部材３が、第一鋼管Ｐ１の管本体２の外径と同じ外径を有するリング状のフランジ部５の下側に、第一鋼管Ｐ１の管本体２の内径と同じ外径を有する円筒状の嵌入部４を連設し、それらのフランジ部５と嵌入部４の内壁にネジ溝７を設けてなるものであるとともに、第二螺合部材８が、第二鋼管Ｐ２の管本体２の外径と同じ外径を有するリング状のフランジ部９の上側に、第二鋼管Ｐ２の管本体２の内径と同じ外径を有する扁平な円筒状の嵌入部１０を連設し、フランジ部９の下側に、ネジ山１４を外周面に設けた筒状の螺合部１１を連設してなるものである。したがって、鋼管セットＳ１〜Ｓ８は、第一螺合部材３の嵌入部４、第二螺合部材８の嵌入部１０を管本体２に嵌入した状態で第一螺合部材３、第二螺合部材８と管本体２とを溶接できるので、製造作業が非常に容易である。また、第一鋼管Ｐ１と第二鋼管Ｐ２との接続位置に、外向きの突出部分が形成されないので、接続された２つの鋼管Ｐ１，Ｐ２を、地盤の内部に非常にスムーズに押し込んだり、立て込んだりすることができる。 Further, the steel pipe sets S1 to S8, S ′ have a first screw member 3 on the lower side of the ring-shaped flange portion 5 having the same outer diameter as the outer diameter of the pipe body 2 of the first steel pipe P1. A cylindrical fitting portion 4 having the same outer diameter as the inner diameter of the pipe body 2 of the steel pipe P1 is continuously provided, and a screw groove 7 is provided on the inner wall of the flange portion 5 and the fitting portion 4, and the first The two screwing member 8 has the same outer diameter as the inner diameter of the pipe main body 2 of the second steel pipe P2 on the upper side of the ring-shaped flange portion 9 having the same outer diameter as the outer diameter of the pipe main body 2 of the second steel pipe P2. A flat cylindrical fitting portion 10 is continuously provided, and a cylindrical screwing portion 11 having a thread 14 provided on the outer peripheral surface is continuously provided below the flange portion 9. Therefore, the steel pipe sets S <b> 1 to S <b> 8 are configured so that the first screwing member 3 and the second screwing are engaged in a state where the fitting part 4 of the first screwing member 3 and the fitting part 10 of the second screwing member 8 are fitted into the pipe body 2. Since the member 8 and the pipe body 2 can be welded, the manufacturing operation is very easy. Moreover, since the outward projecting portion is not formed at the connection position between the first steel pipe P1 and the second steel pipe P2, the two connected steel pipes P1 and P2 are pushed into the ground very smoothly or stood up. Can be drunk.

さらに、実施例１〜７の鋼管セットＳ１〜Ｓ７は、第一鋼管Ｐ１の嵌入部４の肉厚に対する第一螺合部材３の嵌入部４の肉厚の割合（Ｔ２／Ｔ１）が１．１５以上２．００以下に調整されているため、第一鋼管Ｐ１と第二鋼管Ｐ２との接続部分に大きなねじり応力が加わっても、当該接続部材が損傷しにくい。その上、第二螺合部材８の螺合部１１の肉厚（Ｔ３）が第一螺合部材３の嵌入部４の肉厚（Ｔ２）より厚くなるように設計されているため、無駄にコストをかけることなく非常に経済的に製造することができる。 Further, in the steel pipe sets S1 to S7 of Examples 1 to 7, the ratio of the thickness (T2 / T1) of the fitting portion 4 of the first screwing member 3 to the thickness of the fitting portion 4 of the first steel pipe P1 is 1. Since it is adjusted to 15 or more and 2.00 or less, even if a large torsional stress is applied to the connecting portion between the first steel pipe P1 and the second steel pipe P2, the connecting member is hardly damaged. In addition, since the thickness (T3) of the screwing portion 11 of the second screwing member 8 is designed to be thicker than the thickness (T2) of the fitting portion 4 of the first screwing member 3, uselessly. It can be manufactured very economically without cost.

＜鋼管セットの変更例＞
なお、本発明に係る鋼管セットの構成は、上記実施形態の態様に何ら限定されるものではなく、第一鋼管、第二鋼管の管本体、第一螺合部材、第二螺合部材等の形状・構造等の構成を、本発明の趣旨を逸脱しない範囲で、必要に応じて適宜変更することができる。 <Example of steel pipe set change>
In addition, the structure of the steel pipe set which concerns on this invention is not limited to the aspect of the said embodiment at all, such as a 1st steel pipe, the pipe main body of a 2nd steel pipe, a 1st screwing member, a 2nd screwing member, etc. The configuration such as shape and structure can be appropriately changed as necessary without departing from the spirit of the present invention.

たとえば、第一螺合部材や第二螺合部材は、上記実施形態の如く、テーパ面を形成したものに限定されず、テーパ面を形成していないものでも良い。なお、上記実施形態の如く、第一螺合部材あるいは第二螺合部材にテーパ面を形成した場合には、テーパ面を形成した螺合部材と管本体との溶接が容易となる上、溶接強度が高いものとなる、というメリットがある。 For example, the first screwing member and the second screwing member are not limited to those having a tapered surface as in the above embodiment, and may be those having no tapered surface. In addition, when the tapered surface is formed on the first threaded member or the second threaded member as in the above embodiment, the threaded member formed with the tapered surface and the pipe body are easily welded and welded. There is an advantage that the strength is high.

また、第一螺合部材は、上記実施形態の如く、内壁の上端から下端までネジ溝を螺刻したものに限定されず、図１１の如く、上端際の部分にネジ溝を設けないものでも良い。かかる構成を採用することによって、溶接時の熱によるネジ溝の変形を防止することが可能となる。 Further, the first screwing member is not limited to the one in which the screw groove is screwed from the upper end to the lower end of the inner wall as in the above embodiment, and the first screwing member may not be provided with a screw groove at the upper end as shown in FIG. good. By adopting such a configuration, it is possible to prevent deformation of the thread groove due to heat during welding.

一方、第一鋼管は、上記実施形態の如く、単純な円筒形状のものに限定されず、円形フランジ状の螺旋翼を先端に設けたものや、掘削用のバイトを先端に付設したもの等に変更することも可能である。加えて、第二鋼管も、上記実施形態の如く、単純な円筒形状のものに限定されず、基端に回転押込み用プレートを設けたもの等に変更することも可能である。 On the other hand, the first steel pipe is not limited to a simple cylindrical shape as in the above embodiment, but is provided with a circular flange-shaped spiral blade at the tip, a drilling tool attached to the tip, or the like. It is also possible to change. In addition, the second steel pipe is not limited to a simple cylindrical shape as in the above-described embodiment, and can be changed to one having a rotation pushing plate at the base end.

また、本発明に係る鋼管セットは、上記実施形態の如く、第一螺合部材および第二螺合部材を鋼鉄によって形成したものに限定されず、第一螺合部材、第二螺合部材の内の少なくとも一方を鋳鋼（たとえば、ＳＣ４１０：炭素成分０．３％以下）によって形成したものでも良い。かかる構成を採用した場合には、第一螺合部材、第二螺合部材を非常に安価に形成することができるため、結果的に鋼管セットを安価に製造することが可能となる。 Moreover, the steel pipe set according to the present invention is not limited to the first screwing member and the second screwing member formed of steel as in the above-described embodiment, and the first screwing member and the second screwing member At least one of them may be formed of cast steel (for example, SC410: carbon component 0.3% or less). When such a configuration is adopted, the first screw member and the second screw member can be formed at a very low cost, and as a result, the steel pipe set can be manufactured at a low cost.

本発明に係る鋼管セットは、上記の如く、優れた効果を奏するものであるから、軟弱な地盤の改良工事等に用いる２つ以上の鋼管（鋼管群）として好適に用いることができる。 Since the steel pipe set according to the present invention has excellent effects as described above, it can be suitably used as two or more steel pipes (steel pipe group) used for soft ground improvement work or the like.

Ｓ１・・鋼管セット
２・・管本体
３・・第一螺合部材
４・・被覆部
５・・フランジ部
８・・第二螺合部材
９・・フランジ部
１０・・嵌入部
１１・・螺合部
Ｐ１・・第一鋼管
Ｐ２・・第二鋼管
Ｙ・・溶接部分 S1 ·· Steel pipe set 2 ·· Tube body 3 ·· First screwing member 4 ·· Covering portion 5 ·· Flange portion 8 ·· Second screwing member 9 ·· Flange portion 10 ·· Insertion portion 11 ·· Screw Joint P1 ・・ First steel pipe P2 ・・ Second steel pipe Y ・・ Welding part

Claims

It is a steel pipe set consisting of two cylindrical steel pipes of the same diameter and used as a rotary press-fit type steel pipe pile,
A first threaded member that is formed into a flat cylindrical shape with steel or cast steel and that has a thread groove on the inner peripheral surface is fitted into the upper edge of the tube body that is formed into a long cylindrical shape with steel. A first steel pipe welded with
A second threaded member formed in a flat cylindrical shape by steel or cast steel and provided with a screw thread to be threadedly engaged with the thread groove on the outer peripheral surface is used for a tube body formed in a long cylindrical shape by steel. A steel pipe set comprising a second steel pipe welded at the edge of the lower end.

The first screw member is a cylindrical shape having the same outer diameter as the inner diameter of the pipe body of the first steel pipe, on the lower side of the ring-shaped flange portion having the same outer diameter as the outer diameter of the pipe body of the first steel pipe. In addition to providing a threaded groove on the flange wall and the inner wall of the fitting part,
A flat cylinder having the same outer diameter as the inner diameter of the tube main body of the second steel pipe, on the upper side of the ring-shaped flange portion where the second screwing member has the same outer diameter as the outer diameter of the pipe main body of the second steel pipe A cylindrical insertion portion is provided continuously, and a cylindrical threaded portion provided with the thread on the outer peripheral surface is provided below the flange portion,
When the fitting portion of the first screwing member and the screwing portion of the second screwing member are screwed together to connect the first steel pipe and the second steel pipe, they are outside the outer circumferences of the two steel pipes. The steel pipe set according to claim 1, wherein a portion that protrudes is substantially not formed.

The thickness ratio of the fitting portion of the first screwing member to the thickness of the first steel pipe is adjusted to 1.15 or more and 2.00 or less, and the thickness of the screwing portion of the second screwing member The steel pipe set according to claim 1 or 2, wherein is thicker than a thickness of the fitting portion of the first screwing member.