JP2006274730A - End pipes for steel pipes - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pre-receiver steel pipe which can prevent a parting at the time of driving into a natural ground and can easily cut off a part of the pre-received steel pipe from other parts after being driven into the natural ground.
A prior steel pipe 1 includes a first pipe member 11 and a second pipe member 12. Notches 11A, 11B, and 11C are formed at the rear end of the first pipe member 11, and a protrusion 12A that engages with the notches 11A, 11B, and 11C at the tip of the second pipe member 12. , 12B, 12C are provided. A collar member 14 is fixed to the outer peripheral surface of the rear end portion of the first pipe member 11 with screws. The distal end portion of the second pipe member 12 is inserted from the opening surface of the collar member 14 and is fixed to the collar member 14 by welding at a position where it is engaged with the first pipe member 11. Further, the collar member 14 is formed with a groove-like fragile portion along the circumferential direction.
[Selection] Figure 5

Description

  The present invention relates to a terminal pipe in a steel receiving pipe that is used in a long tip receiving method or the like for reinforcing a natural ground around a tunnel.

  When a tunnel is constructed in a natural ground with poor geological conditions, a so-called prior construction method is sometimes used to stabilize the natural ground around the tunnel. In this tip receiving method, the tip receiving steel pipe is driven along the outer periphery of the tunnel arch, the hardener supplied from the end of the tip receiving steel pipe is discharged from the tip, and the hardener is injected into the ground, thereby A reinforcement arch is formed in the ground in front.

  Such a pre-receiving method includes a widening method in which a tunnel to be constructed is widened to dispose a pre-received steel pipe, and a non-widening method in which a pre-receiving steel pipe is disposed without widening the tunnel. In the non-widening method, since the pre-received steel pipe is drilled and inserted obliquely forward from the face, after the pre-received steel pipe is driven, the rear end portion of the pre-received steel pipe protrudes into the tunnel. If you try to install a support in this tunnel, the rear end of the receiving steel pipe will get in the way, so after you finish driving the receiving steel pipe, the rear end of the terminal pipe that forms the rear end of the receiving steel pipe The part is cut off from the other part of the terminal tube.

Thus, since the rear end portion of the terminal pipe is cut off from the other part of the pre-receiver steel pipe, it is desired to facilitate the cutting work. As described above, there is an injection pipe (a prior steel pipe) disclosed in Japanese Patent Application Laid-Open No. 2000-145398 as a prior steel pipe that can be easily cut off. This injection tube is provided with a node for dividing the injection tube in a part in the longitudinal direction of the injection tube. By providing such a node between the end portion (cut-off portion) of the injection tube and other portions, the injection tube can be easily divided by striking the injection tube in the radial direction. .
JP 2000-145398 A

  By the way, when the injection pipe is driven into the natural ground, a large rock drill or the like is used, and a large striking force or rotational force is applied to the injection pipe itself. The direction of the striking force applied to the injection tube is along the axial direction of the injection tube, and the direction of the rotational force is centered on the axial direction of the injection tube. However, since the injection tube is warped or bent in the process of being inserted into the natural ground, in reality, a force component is also generated in the direction along the radial direction of the injection tube. Here, if a node such as the injection tube described in Patent Document 1 is provided, the injection tube may be disconnected from the portion of the node while the injection tube is being inserted into the ground. There was a problem that there was. In particular, when the friction coefficient between the natural ground and the injection pipe is increased, this problem becomes remarkable.

  Therefore, an object of the present invention is to prevent the splitting at the time of driving into the natural ground, and after receiving the natural ground, it is possible to easily cut off a part of the receiving steel pipe from other parts. It is to provide a terminal pipe in a steel pipe.

  A terminal pipe of a pre-received steel pipe according to the present invention that has solved the above-mentioned problem is a terminal pipe in a pre-received steel pipe that is embedded in a natural ground in front of the tunnel excavation direction prior to tunnel excavation, and has the same diameter A pipe member and a second pipe member, the ends of the first pipe member and the second pipe member are connected to each other in a state of facing each other, and the connection end of the first pipe member with the second pipe member and the first pipe member The connection end of the two pipe member with the first pipe member is provided with a first engagement portion and a second engagement portion where the connection end of the second pipe member and the connection end of the first pipe member are engaged with each other. An outer cylinder member protruding in the longitudinal extension direction of the first pipe member is fixed to the connection end portion of the pipe member, and the connection end portion of the second pipe member is inserted from the open end side of the outer cylinder member to be the first bite. Meshes fit portion and the second engaging portion with each other, the outer tubular member, in which notched circumferentially weakened portion is formed.

  The terminal pipe in the pre-receiver steel pipe according to the present invention has a first pipe member and a second pipe member, and meshing portions are formed at both ends thereof and are in mesh with each other. For this reason, when a rotational force is applied to the tip receiving steel pipe, the rotational force is suitably transmitted by the meshing portion, so that the radial force component generated by the rotational force can be absorbed by the meshing portion. Further, the striking force applied in the axial direction of the pre-receiver steel pipe is transmitted between the first pipe member and the second pipe member. For this reason, the influence of the rotational force and impact force with respect to an outer cylinder member can be made small. Since the second pipe member is inserted in the outer cylinder member and the weakened portion is formed in the outer cylinder member, it is possible to prevent the division due to the rotational force and the striking force. In addition, after the receiving steel pipe has been driven into the ground, the striking force is transmitted almost directly to the weak part by applying a striking force directly in the radial direction with a hammer or the like. The two pipe member can be separated from the first pipe member. Therefore, it is possible to easily cut off part of the pre-receiver steel pipe and other part.

  Here, the contact surfaces of the first meshing portion and the second meshing portion may be formed along the radial direction of the pipe member.

  Thus, the contact surfaces of the first meshing portion and the second meshing portion are each formed along the radial direction of the pipe member. For this reason, since the slip between the 1st meshing part and the 2nd meshing part is prevented, the force of a rotation direction can be transmitted still more reliably.

  In addition, a through hole is formed in the outer cylinder member, and a hole is formed in the second pipe member at a position that overlaps the position where the through hole is formed when the first meshing portion and the second meshing portion are engaged. It is also possible to adopt a mode in which a pin penetrating the through hole is disposed in the hole.

  If the axial direction of an outer cylinder member and the axial direction of a 2nd pipe member have shifted | deviated, the force added to the axial direction of a 2nd pipe material will act on the radial direction of an outer cylinder member. When the force acting in the radial direction of the outer cylinder member is applied to the fragile portion, the fragile portion is likely to be divided. On the other hand, the pin passing through the through-hole formed in the outer cylinder member is disposed in the hole of the second pipe member, so that the axial direction of the outer cylinder member and the axial direction of the second pipe member are matched. Can be maintained. Therefore, generation | occurrence | production of the force which faced the radial direction of the outer cylinder member can be prevented, and the division | segmentation in a weak part can be prevented.

  Furthermore, it can also be set as the aspect by which the through-hole and the hole part are welded and the 2nd pipe member is being fixed to the outer cylinder member.

  Thus, the second pipe member to which the through hole and the hole are welded is fixed to the outer cylinder member, whereby the second pipe member can be easily and firmly fixed to the outer cylinder member.

  In addition, one of a male screw or a female screw corresponding to the male screw is provided outside the end of the first pipe member fixed to the outer cylinder member, and the end of the outer cylinder member fixed to the first pipe member The other of the male screw and the female screw is provided, and the outer cylinder member can be fixed to the first pipe member by screwing the male screw into the female screw.

  As described above, the first pipe member 1 and the outer cylinder member are fixed by screwing, whereby the first pipe member 1 and the outer cylinder member can be firmly fixed.

  Further, an outer cylinder member fixing hole is formed at a position of the first pipe member where the outer cylinder member is fixed, and the first pipe member fixing hole is positioned at the position of the outer cylinder member corresponding to the outer cylinder member fixing hole. A through hole is formed, and a pin that penetrates the first pipe member fixing through hole is disposed in the outer cylinder member fixing hole, and the outer cylinder member is fixed to the first pipe member via the pin. It can also be set as the aspect which is.

  Thus, by setting it as the aspect to which a 1st pipe member and an outer cylinder member are fixed via a pin, a 1st pipe member and an outer cylinder member can be easily connected by a simple process.

  According to the end pipe in the pre-receiver steel pipe according to the present invention, it is possible to prevent parting at the time of driving into the natural ground and to easily remove a part of the pre-received steel pipe from the other part after the driving into the natural ground is completed. Can be cut off.

  Hereinafter, a first embodiment of the present invention will be described with reference to the drawings. In the description of the drawings, the same elements are denoted by the same reference numerals, and redundant description is omitted. Further, the dimensional ratios in the drawings do not necessarily match those described. FIG. 1 is a side view of a pre-receiver steel pipe according to the present embodiment, and FIG. 2 is a cross-sectional view of a tunnel into which the pre-receiver steel pipe is driven.

  As shown in FIG. 1, a pre-receiver steel pipe 1 according to this embodiment includes a leading pipe 2, a first intermediate pipe 3, a second intermediate pipe 4, and a terminal pipe 5. The first pipe 2, the first intermediate pipe 3, the second intermediate pipe 4, and the terminal pipe 5 have the same diameter in the respective pipe portions, and the entire receiving steel pipe 1 is formed as the same diameter pipe. Has been.

  The leading pipe 2 is a portion that is first driven into a natural ground, and a bit member is attached to the tip thereof. While excavating the natural ground with this bit member, the steel receiving pipe 1 is driven into the natural ground.

  A male screw portion is formed at the rear end portion of the leading tube 2, and a female screw portion corresponding to the male screw portion formed at the rear end portion of the leading tube 2 is formed at the tip portion of the first intermediate tube 3. . The first intermediate pipe 3 is fixed to the first pipe 2 by screwing the female screw part formed at the tip of the first intermediate pipe 3 into the male screw part formed at the rear end of the first pipe 2. Yes.

  A male screw portion is formed at the rear end portion of the first intermediate tube, and a female screw portion corresponding to the male screw portion formed at the rear end portion of the first intermediate tube 3 is formed at the front end portion of the second intermediate tube 4. Is formed. The internal thread portion formed at the front end portion of the second intermediate tube 4 is screwed into the external thread portion formed at the rear end portion of the first intermediate tube 3, thereby the second intermediate tube 4 with respect to the first intermediate tube 3. Is fixed.

  The terminal pipe 5 is configured by connecting three pipe members 11 to 13. It has the 1st pipe member 11, the 2nd pipe member 12, and the 3rd pipe member 13, and is arrange | positioned in this order sequentially from the 2nd intermediate pipe 4 side, and is mutually fixed. A male screw portion is formed at the tip of the first pipe member 11, and a female screw portion corresponding to the male screw formed at the tip of the first pipe member 11 is formed at the rear end of the second intermediate tube 4. Is formed. When the female thread portion formed at the front end portion of the first pipe member 11 is screwed into the male thread portion formed at the rear end portion of the second intermediate tube 4, the first pipe member 11 is inserted into the second intermediate tube 4. Is fixed. Thus, the terminal pipe 5 is fixed to the second intermediate pipe 4.

  A rock drill (not shown) can be attached to the rear end portion of the terminal pipe 5, and the tip receiving steel pipe 1 is attached to the rock drill through the terminal pipe 5. This rock drilling machine has a striking force generated by applying vibration along the axial direction of the first steel pipe 1 and a rotational force generated by rotation applied around the central axis along the longitudinal direction of the first steel pipe 1. It transmits with respect to the attached receiving steel pipe 1. FIG. The tip receiving steel pipe 1 transmits this striking force and rotational force to the natural ground, excavates the natural ground with a bit member provided at the tip, and is driven into the natural ground G as shown in FIG. In the ground, after the driving of the steel pipe 1 has been completed, tunnel excavation has progressed, and the terminal pipe 5 has been cut off.

  As shown in FIG. 3, the rear end portion of the first pipe member 11 and the front end portion of the second pipe member 12 in the terminal pipe 5 of the receiving steel pipe 1, and the rear end portion and the third pipe member of the second pipe member 12. The 13 tip portions are connected and fixed in the same configuration. This aspect will be described by taking the rear end portion of the first pipe member 11 and the front end portion of the second pipe member 12 as an example. 4 is an exploded perspective view of a connecting portion between the first pipe member and the second pipe member, FIG. 5 is a side sectional view thereof, FIG. 6A is a rear view of the first pipe member, and FIG. It is a front view of a 2nd pipe member.

  As shown in FIGS. 4 and 5, the notch portions 11 </ b> A, 11 </ b> B, and 11 </ b> C are formed at the rear end portion of the first pipe member 11 so as to be spaced apart at equal intervals along the circumferential direction. Has been. The rear end portion of the first pipe member 11 including these notches 11A, 11B, 11C is the first meshing portion of the present invention. A male screw portion 11D is formed on the outer peripheral surface of the rear end portion of the first pipe member 11 including the portion where the notches 11A, 11B, and 11C are formed.

  On the other hand, protrusions 12A, 12B, and 12C that engage with the notches 11A, 11B, and 11C formed in the first pipe member 11 are provided at the tip of the second pipe member 12. The rear end portion of the second pipe member 12 including these projecting portions 12A, 12B, and 12C is the second meshing portion of the present invention.

  The opening widths of these notches 11A, 11B, and 11C and the widths of the protrusions 12A, 12B, and 12C are the same. For this reason, protrusion part 12A, 12B, 12C can be engage | inserted with respect to notch part 11A, 11B, 11C, respectively. The protrusions 12A, 12B, and 12C are fitted into the notches 11A, 11B, and 11C, respectively, so that the rear end portion of the first pipe member 11 and the front end portion of the second pipe member 12 are engaged with each other. ing.

  Further, as shown in FIG. 6A, the side surfaces of the notches 11 </ b> A, 11 </ b> B, and 11 </ b> C in the first pipe member 11 are formed along the radial direction of the first pipe member 11. Similarly, as shown in FIG. 6B, the side surfaces of the protrusions 12 </ b> A, 12 </ b> B, and 12 </ b> C in the second pipe member 12 are formed along the radial direction of the second pipe member 12. These side surfaces are the contact surfaces of each other.

  A collar member 14 that is an outer cylinder member of the present invention is fixed to the outer peripheral surface at the rear end portion of the first pipe member 11. The collar member 14 has a cylindrical shape, and the inner diameter thereof is substantially the same as the outer diameter of the pipe members 11 and 12. As shown in FIG. 5, a female screw portion 14 </ b> A is formed at the distal end portion of the collar member 14. The female screw portion 14 </ b> A is formed to correspond to the male screw portion provided at the rear end portion of the first pipe member 11, and the male screw portion 11 </ b> D of the first pipe member 11 is screwed into the female screw portion of the collar member 14. Thus, the collar member 14 is fixed to the first pipe member 11. Thus, the collar member 14 is provided so as to protrude in the longitudinal extension direction of the first pipe member 11.

  Furthermore, when the collar member 14 is fixed to the first pipe member 11, a weakened portion 14 </ b> B cut out along the circumferential direction of the inner side surface is formed at a portion protruding from the first pipe member 11. Yes. By forming the fragile portion 14B, the collar member 14 is bent from the fragile portion 14B when a large force is applied to the collar member 14 in a direction orthogonal to the axial direction. Further, a through hole 14C is formed at a position farther from the first pipe member 11 than the portion where the fragile portion 14B is formed.

  The distal end portion of the second pipe member 12 is inserted into the collar member 14 from the opening surface of the collar member 14 opposite to the side on which the first pipe member 11 is fixed. The second pipe member 12 is inserted into the collar member 14, and the first pipe member 11 and the second pipe member 12 are engaged with each other inside the collar member 14.

  Further, in the state where the second pipe member 12 is engaged with the first pipe member 11, a through hole 12 </ b> D is formed in the second pipe member 12 corresponding to the through hole 14 </ b> C formed in the collar member 14. A through hole 12 </ b> D formed in the second pipe member 12 has a smaller diameter than the through hole 14 </ b> C formed in the collar member 14.

  Pins 15 are attached to these through holes 12D and 14C so as to penetrate therethrough. The pin 15 has an outer diameter that is the same as the inner diameter of the through hole 12D formed in the second pipe member 12, and is inserted into the through hole 14C from the outside of the collar member 14, and further into the second pipe member 12. It is fitted into the formed through hole 12D. An air gap remains in the through hole 14 </ b> C formed in the collar member 14 through which the pin 15 is inserted. The collar member 14 is welded Y to the second pipe member 12 by utilizing this gap portion. Further, the rear end portion of the collar member 14 is welded Y along the outer peripheral surface of the second pipe member 12. The collar member 14 is fixed to the second pipe member 12 by these welds Y.

  Next, the procedure at the time of driving in the pre-receiver steel pipe according to this embodiment will be described.

  The purpose of drilling is to form a plurality of excavation holes around the formation position of the tunnel T as shown in FIG. The steel receiving pipe 1 is inserted to prevent the collapse of the natural ground around the tunnel. The tipping steel pipes 1 in the plurality of excavation holes formed by the excavating device are each filled with a hardener or the like, and a reinforcing material is formed in an arch shape in the ground in front of the face, thereby preventing the collapse of the natural ground. To prevent.

  When driving the receiving steel pipe 1, first, the bit member provided at the leading end portion of the leading pipe 2 of the receiving steel pipe 1 is pressed against the ground at the upper end portion of the face of the tunnel T, and the end pipe 5 A striking force and a rotational force are applied to the receiving steel pipe 1 by a rock drill from the rear end. The ground is excavated by a bit member attached to the front end of the leading pipe 2 by the striking force and rotational force given by the rock drill, and the tip receiving steel pipe 1 is sequentially driven into the ground.

  Here, when driving the receiving steel pipe, the receiving steel pipe 1 is given a large striking force and rotational force from the rock drill. In the receiving steel pipe 1, this striking force and rotational force are transmitted to the bit member at the tip. In the terminal pipe 5, the striking force and the rotational force are transmitted from the second pipe member 12 toward the first pipe member 11. Since these striking force and rotational force are directly transmitted at the joint between the second pipe member 12 and the first pipe member 11, they are reliably transmitted. In particular, the side surfaces of the protrusions 12A, 12B, and 12C in the second pipe member 12 and the side surfaces of the notches 11A, 11B, and 11C in the first pipe member 11 are formed along the radial direction. For this reason, when the protrusions 12A, 12B, and 12C of the second pipe member 12 push the side portions of the notches 11A, 11B, and 11C of the first pipe member 11 and apply the rotational force, the rotational force is reliably transmitted. can do.

  On the other hand, in the terminal pipe 5, when the impact force and the rotational force are transmitted from the second pipe member 12 to the first pipe member 11, there is a concern about the division of the fragile portion 14 </ b> B in the collar member 14. On the other hand, in the terminal pipe 5 according to the present embodiment, the striking force and the rotational force are transmitted mainly at the meshing portions of the pipe members 11 to 13. For this reason, since the force transmitted to the collar member 14 decreases, it is possible to prevent the fragile portion 14B from being divided.

  At this time, the pin 15 passes through the through hole 14C formed in the collar member 14 and the through hole 12D formed in the second pipe member 12, respectively, and the axial direction of the collar member 14 and the second pipe member The state where the twelve axial directions coincide is maintained. For this reason, it is possible to prevent the axial striking force applied to the second pipe member 12 from acting in the radial direction of the collar member 14, thereby effectively preventing the fragile portion 14 </ b> B from being divided.

  When the receiving steel pipe 1 is embedded in the natural ground in this way, most of the receiving steel pipe 1 is embedded in the natural ground except for the end portion of the terminal pipe 5 as shown in FIG. It will be in the state. As shown in FIG. 7, a plurality of these pre-receiving steel pipes 1 are embedded in an arch shape at the progress destination when the tunnel T is dug. At this time, the hardened material flows into the pre-receiver steel pipe 1 and is filled in the natural ground to harden the natural ground.

  In this way, when the steel pipe 1 is embedded, the tunnel T is dug. Thereafter, as shown in FIG. 8B, when the tunnel T is dug up to a predetermined position, an H-section steel 20 is provided in the tunnel T as a support. At this time, since the tunnel T has been dug, the end pipe 5 in the receiving steel pipe 1 protrudes into the tunnel T, and this end pipe 5 becomes an obstacle when the H-section steel 20 is provided. . In order to eliminate this obstruction, a part of the terminal pipe 5 is cut off from the other part of the first steel pipe 1 as shown in FIG.

  At this time, the first pipe member 11 and the second pipe member 12 in the terminal pipe 5 are connected via the collar member 14, and a fragile portion 14 </ b> B is formed in the collar member 14. Since the fragile portion 14B is formed, the collar member 14 can be easily cut off by the fragile portion 14B by hitting the second pipe member 12 with a hammer or the like. Then, as shown to Fig.9 (a), the H-section steel 20 used as a support work is provided in the tunnel T. As shown in FIG. Then, as shown in FIG. 9B, the next receiving steel pipe 1 is driven.

  As described above, in the receiving steel pipe according to the present embodiment, even when a large force is applied by a rock drill, the terminal pipe can be prevented from being divided, while the driving of the receiving steel pipe is completed. After that, the terminal pipe 5 can be easily cut off. For this reason, for example, when a pilot steel pipe is driven into a natural ground, even if anhydrous drilling is performed without supplying liquid or with a very small supply amount, it is ensured that the steel pipe is not broken. You can drive into the natural ground.

  Next, a second embodiment of the present invention will be described. In this embodiment, compared with said 1st embodiment, the connection aspect of a 1st pipe member and a collar member mainly differs. FIG. 10 is a side sectional view of a connection portion between the first pipe member and the second pipe member according to the present embodiment. As shown in FIG. 10, the external thread is not formed in the outer periphery of the connection part with the 2nd pipe member 12 in the 1st pipe member 30 which concerns on this embodiment. Instead, a collar member fixing through hole 31 is formed at the end of the first pipe member 30. In addition, a female thread portion is not formed in the connection portion of the collar member 40 with the first pipe member 30, and instead, the first pipe member fixing portion is located at a position corresponding to the collar member fixing through hole 31. A through hole 41 is formed. A pin 35 is disposed through the through holes 31 and 41 and is fixed by welding Y. About another part, it has the same structure as said 1st embodiment.

  In the terminal pipe according to the present embodiment, through holes 31 and 41 are formed in the first pipe member 30 and the collar member 40, respectively, and pins 35 are inserted into these through holes 31 and 41 and fixed by welding Y. . For this reason, since it is not necessary to provide a male screw part and a female screw part at the ends of the first pipe member 30 and the collar member 40, respectively, the manufacturing becomes easy, and the cost for manufacturing can be reduced.

  The preferred embodiment of the present invention has been described above, but the present invention is not limited to the above embodiment. For example, in the above-described embodiment, the notch portion of the first pipe member and the protrusion portion of the second pipe member are provided in three places, but this may be provided in two places, four places, or the like. . Moreover, these notch parts and protrusion parts should just be formed so that both may mesh, for example, it can also be set as the aspect currently formed in the circumferential direction of the pipe member at unequal intervals. Furthermore, in the said embodiment, although a terminal pipe has three pipe members, a 1st pipe member-a 3rd pipe member, it can also be set as the aspect which has 2 or 4 or more pipe members.

It is a side view of a receiving steel pipe. It is side sectional drawing of the tunnel which struck in advance exchange. It is a side view of a terminal pipe. It is a disassembled perspective view of the connection part of a 1st pipe member and a 2nd pipe member. It is a sectional side view of the connection part of a 1st pipe member and a 2nd pipe member. (A) is a rear view of a 1st pipe member, (b) is a front view of a 2nd pipe member. It is a typical perspective view around the tunnel which provided the reinforcing material. It is process drawing for demonstrating the process of excavating a tunnel, driving in a receiving steel pipe. It is process drawing for demonstrating the process following FIG. It is a sectional side view of the connection part of the 1st pipe member and the 2nd pipe member in a terminal pipe concerning a second embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Pre-receiving steel pipe 2 ... Lead pipe 3 ... 1st intermediate pipe 4 ... 2nd intermediate pipe 5 ... Terminal pipe 11, 30 ... 1st pipe member 11A, 11B, 11C ... Notch part 11D ... Male thread part 12 ... Second Pipe member 12A, 12B, 12C ... Projection part 12D ... Through hole 13 ... Third pipe member 14, 40 ... Collar member 14A ... Female thread part 14B ... Fragile part 14C ... Through hole 15, 35 ... Pin 20 ... H-section steel G ... Ground mountain T ... Tunnel Y ... Welding

Claims (6)

Prior to tunnel excavation, a terminal pipe in a receiving steel pipe embedded in a natural ground in the forward direction of the tunnel,
Having a first pipe member and a second pipe member of the same diameter, and connected to each other in a state where the ends of the first pipe member and the second pipe member face each other;
The connection end of the first pipe member with the second pipe member and the connection end of the second pipe member with the first pipe member are respectively connected to the connection end of the second pipe member and the first pipe member. A first meshing portion and a second meshing portion that mesh with each other at the connection end are provided;
An outer cylinder member protruding in the longitudinal extension direction of the first pipe member is fixed to the connection end of the first pipe member,
The connection end of the second pipe member is inserted from the open end side of the outer cylinder member, and the first engagement portion and the second engagement portion are engaged with each other,
A terminal pipe in a pre-receiver steel pipe, wherein the outer cylinder member is formed with a weakened portion cut out along a circumferential direction.   2. The terminal pipe in the steel pipe according to claim 1, wherein contact surfaces of the first meshing portion and the second meshing portion are formed along a radial direction of the pipe member. A through hole is formed in the outer cylinder member, and the second pipe member has a hole portion at a position overlapping with the position where the through hole is formed when the first meshing portion and the second meshing portion are meshed with each other. Is formed,
The terminal pipe in the tip receiving steel pipe according to claim 1 or 2, wherein a pin penetrating the through hole is disposed in the hole.   The terminal pipe in a pre-receiver steel pipe according to claim 3, wherein the through hole and the hole are welded, and the second pipe member is fixed to the outer cylinder member. One of a male screw or a female screw corresponding to the male screw is provided on the outside of the end portion of the first pipe member fixed to the outer cylinder member,
The other end of the male screw or the female screw is provided at the end of the outer cylinder member that is fixed to the first pipe member,
The terminal in the steel pipe according to any one of claims 1 to 4, wherein the outer cylinder member is fixed to the first pipe member by screwing the male screw into the female screw. tube. An outer cylinder member fixing hole is formed at a position of the first pipe member where the outer cylinder member is fixed, and the first pipe member is positioned at the position of the outer cylinder member corresponding to the outer cylinder member fixing hole. A fixing through hole is formed,
A pin penetrating the first pipe member fixing through hole is disposed in the outer cylinder member fixing hole, and the outer cylinder member is fixed to the first pipe member via the pin. The terminal pipe in the tip-receiving steel pipe according to any one of claims 1 to 4.

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