Fixture for Steel Pipe Connection

Abstract

To provide a steel pipe connection fixture for reducing a work load of a worker when linearly connecting a steel pipe driven into the natural ground by push-in engagement in an auxiliary construction method of tunnel construction.SOLUTION: A steel pipe connection fixture 30 is provided on a guide cell 23 of a driving-in drill jumbo 20. A fixed steel pipe receiver 31 of the steel pipe connection fixture 30 is fixed to a tip of the guide cell 23. A holding part 32 is advanceably / retreatably provided on a front part of the fixed steel pipe receiver 31 via an extensible guide 40. A steel pipe 10B to be added is held relatively immobile and releasable by the holding part 32. An advancing / retreating driving part 50 advances / retreats the holding part 32.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a jig for connecting steel pipes in a straight line in an auxiliary method for mountain tunnel construction, and particularly to a steel pipe connection jig applied to steel pipes connected by press-fitting rather than screw connection.

Background Art

[0002] When constructing a mountain tunnel by the NATM (New Australian Tunneling Method), auxiliary methods such as the AGF (all ground fasting) method and the mirror bolt method may be implemented to reinforce the ground being excavated. In this type of auxiliary method, for example, a machine such as a drill jumbo is used to drive steel pipes into the ground. A plurality of steel pipes are sequentially connected in a straight line to make them longer. Generally, the steel pipes are connected by screw connection (see Patent Document 1, etc.). The newly added steel pipe is mounted on the guide cell of the drill jumbo and arranged to be aligned in a straight line with the already driven steel pipe. Then, an operator uses tools such as a pipe wrench or a chain tong to manually pull out and rotate the added steel pipe to screw-connect it to the end of the already driven steel pipe. Such a screw connection method takes time because it is necessary to rotate the added steel pipe. In addition, the screw connection part becomes structurally weak.

[0003] Therefore, it has been proposed to connect steel pipes by press-fitting instead of screw connection (see Patent Document 2, etc.). A plurality of locking claws arranged in a ring are formed at the end of one steel pipe of the press-fitting method. An annular locking groove is formed at the end of the other steel pipe. When the added steel pipe is pushed straight along the pipe axis toward the already driven steel pipe, the locking claws are elastically deformed and fitted into the locking groove to be locked. Thereby, the steel pipes can be connected with one touch only by linear movement.

Prior Art Documents

Patent Documents

[0004] Patent Document 1 Japanese Unexamined Patent Application Publication No. 2016-12144 Patent Document 2 Japanese Unexamined Patent Application Publication No. 2020-111880 Summary of the Invention Problems to be Solved by the Invention

[0005] However, in the above-mentioned push-fit method, the steel pipe on the added side has to be strongly pushed in to elastically deform the locking claws, and for example, a force of about 1 kN is required. Therefore, even when using tools such as pipe wrenches and chain tongs, the workload is excessive with only manual labor. In addition, since the work is usually carried out on a high work platform such as a drill jumbo's man gauge, the footing is poor and it is difficult to brace and difficult to obtain reaction force, and the working conditions are often more difficult. It was not easy to join using the existing mechanism of the drill jumbo as it was. In view of such circumstances, an object of the present invention is to reduce the workload of workers when connecting steel pipes driven into the ground in a straight line by a push-fit method in an auxiliary method for tunnel construction. Means for Solving the Problems

[0006] In order to solve the above problems, the inventor conceived of applying a pushing force to the steel pipe on the added side on behalf of the worker using a steel pipe connection jig. The present invention has been made based on such a concept, and is a steel pipe connection jig used in an auxiliary method for tunnels in which a plurality of steel pipes connected in a straight line by push-fitting are driven into the ground, having a slide receiver that slidably receives the steel pipe to be added in the pipe axis direction, and a fixed steel pipe receiver fixed to the tip of the guide cell of the drill jumbo for driving, a holding portion provided in the front of the fixed steel pipe receiver so as to be able to advance and retreat, and holding the steel pipe to be added in a non-relative movable and releasable manner, and an advancing / retreating drive portion that advances and retreats the holding portion It is characterized by comprising

[0007] Preferably, the holding part includes a moving steel pipe receiver having a receiving part for the steel pipe to be spliced, and a clamp for clamping the steel pipe to be spliced.

Advantages of the Invention

[0008] According to the present invention, in the auxiliary construction method for tunnel construction, the working load of workers when connecting steel pipes driven into the ground in a straight line by the pushing and fitting method can be reduced.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Figure 3

Figure 4

Modes for Carrying Out the Invention

[0010] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows a tunnel 1 under construction by the NATM method. The ground 2 is excavated and the tunnel 1 is being constructed. In the construction, as an auxiliary construction method for ground reinforcement, for example, a large number (only one is shown in the figure) of long front support steel pipes 9 (ground reinforcement pipes) are driven into the ground in front of the face by the AGF method. A drill jumbo 20 is used for driving. The long front support steel pipe 9 is composed of a plurality (for example, about 4) of steel pipes 10. These steel pipes 10 are connected in a straight line.

[0011] As shown in Fig. 1, at the end 10e of the steel pipe on the tip side (left in Fig. 1) and the tip 10f of the steel pipe on the rear end side (right in Fig. 1) in two adjacent steel pipes 10, a one-touch connection part 11 is formed. As shown in Fig. 2(a), the one-touch connection part 11 includes an annular locking groove 12 formed on the inner peripheral surface of the end 10e of the steel pipe on the tip side and a locking claw 13 formed on the tip 10f of the steel pipe on the rear end side. For example, the locking groove 12 is formed in a wedge-shaped concave cross-sectional shape. The locking claw 13 is formed in a wedge-shaped convex cross-sectional shape (see Patent Document 2). The locking claw 13 forms an annulus and is divided into a plurality of locking claw parts 13a by a slit 14. The locking claw part 13a and thus the locking claw 13 are locked in the locking groove 12. By inserting the tip 10f of the steel pipe on the rear end side into the inside of the end 10e of the steel pipe on the tip side, the locking claw 13 is fitted into the locking groove 12.

[0012] The end 10e and the tip 10f including the locking groove 12 and the locking claw 13 in the steel pipe 10 are preferably made of high-tensile steel. The intermediate part excluding the end 10e and the tip 10f of the steel pipe 10 may be made of ordinary steel.

[0013] Note that a drilling rod 24 (only shown in Fig. 1) is inserted into the inside of the leading steel pipe 9. A drilling bit 25 is provided at the tip of the drilling rod 24. The rear end of the drilling rod 24 is connected to a drifter 26 on a guide cell 23 of a drill jumbo 20.

[0014] As shown in Fig. 1, a steel pipe connection jig 30 is prepared for connecting the steel pipes 10. The steel pipe connection jig 30 is incorporated in the drill jumbo 20. A boom 22 extends from the body 21 of the drill jumbo 20, and a guide cell 23 is provided at the tip of the boom 22. The steel pipe connection jig 30 is attached to the tip of the guide cell 23. Preferably, the steel pipe connection jig 30 is attachable and detachable with respect to the guide cell 23.

[0015] As shown in FIGS. 2(a) and 2(b), the steel pipe connection jig 30 includes a fixed steel pipe receiver 31, a holding portion 32, a telescopic guide 40 (guide member), and a forward and backward drive portion 50. The fixed steel pipe receiver 31 is composed of a thick steel plate. The fixed steel pipe receiver 31 is oriented so as to be orthogonal to the longitudinal direction (front - rear direction) of the guide cell 23 and is abutted against and fixed to the front end surface of the guide cell 23. As shown in FIG. 3, the fixed steel pipe receiver 31 has a pair of convex plate portions 31a, 31b. The convex plate portions 31a, 31b project upward from the left and right sides of the bottom of the fixed steel pipe receiver 31. The upper end heights of the left and right convex plate portions 31a, 31b are different from each other. A slide receiving portion 31c is formed between these convex plate portions 31a, 31b. The slide receiving portion 31c penetrates the fixed steel pipe receiver 31 in the front - rear direction and has a U - shaped hole shape opened at the upper end of the fixed steel pipe receiver 31, and receives the steel pipe 10B to be joined so as to be slidable in the longitudinal direction of the guide cell 23. The axial direction of the steel pipe 10B is oriented in the longitudinal direction of the guide cell 23. The steel pipe centering device provided in the guide cell 23 may be used as the fixed steel pipe receiver 31.

[0016] As shown in FIG. 3, the telescopic guide 40 projects forward from the front end of the guide cell 23. The telescopic guide 40 includes a cylindrical fixed guide portion 41 and a cylindrical movable guide portion 42 that is one size smaller than it, and has a double - cylinder structure. The axial direction of the telescopic guide 40 is oriented in the longitudinal direction of the guide cell 23. The cross - sections of the fixed guide portion 41 and the movable guide portion 42 are square, but are not limited to this, and may be circular. The rear end portion of the fixed guide portion 41 is fixed to the fixed steel pipe receiver 31. As shown in FIGS. 2(b) and 4(a), the movable guide portion 42 is axially received in the fixed guide portion 41 so as to be movable forward and backward. By the forward and backward movement of the movable guide portion 42, the telescopic guide 40 is telescoped in the axial direction (front - rear direction).

[0017] A holding portion 32 is disposed in front of the fixed steel pipe support 31 (to the left in FIG. 2(b)) via a telescopic guide 40. The holding portion 32 can move forward and backward in the front-rear direction due to the telescopic movement of the telescopic guide 40. Moreover, the holding portion 32 holds the steel pipe 10B in a non-relative-movable and releasable manner with respect to the holding portion 32.

[0018] Specifically, as shown in FIG. 2(a), the holding portion 32 includes a moving steel pipe support 33 and a clamp 34. Similar to the fixed steel pipe support 31, the moving steel pipe support 33 is constituted by a thick steel plate. The moving steel pipe support 33 is oriented so as to be orthogonal to the longitudinal direction (front-rear direction) of the guide cell 23 and is abutted against and fixed to the front end surface of the movable guide portion 42. As shown in FIG. 3, the moving steel pipe support 33 has a pair of convex plate portions 33a, 33b. The convex plate portions 33a, 33b protrude upward from the left and right side portions at the bottom of the moving steel pipe support 33. The upper end heights of the left and right convex plate portions 33a, 33b are different from each other, and moreover, the height relationship is reversed left and right with respect to the convex plate portions 31a, 31b of the fixed steel pipe support 31. A receiving portion 33c is formed between the convex plate portions 33a, 33b. The receiving portion 33c penetrates the moving steel pipe support 33 in the front-rear direction and has a U-shaped hole shape reaching the upper end of the moving steel pipe support 33. The receiving portion 33c receives the steel pipe 10B. The moving steel pipe support 33, and thus the holding portion 32, and the fixed steel pipe support 31 face each other in the front-rear direction and are connected via the telescopic guide 40 so as to be able to approach and separate.

[0019] As shown in FIGS. 2(a) and (b), a clamp 34 is disposed in front of the moving steel pipe support 33. Preferably, the clamp 34 is abutted against the front surface of the moving steel pipe support 33. The clamp 34 is detachably attached to the outer periphery of the portion of the steel pipe 10B that is in front of the moving steel pipe support 33.

[0020] As shown by the solid line in FIG. 3, the clamp 34 includes a pair of clamp members 34a and a tightening tool 34b. Each clamp member 34a is formed in a semi-circular shape. The pair of clamp members 34a are rotatably connected via a hinge 34c. As shown by the two-dot chain line in FIG. 3, these clamp members 34a sandwich the steel pipe 10B from both sides. The ends of the clamp member 34a that are 180 degrees opposite to the hinge 34c are separably connected by the tightening tool 34b. The tightening tool 34b includes, for example, a bolt or the like. When the tightening tool 34b is tightened, the clamp 34 is fixed to the outer periphery of the steel pipe 10B. By loosening and removing the tightening tool 34b, the clamp 34 is separated from the steel pipe 10B.

[0021] As shown in FIG. 2(a), the advancing / retreating drive unit 50 includes a pair of hydraulic cylinders 51. The pair of hydraulic cylinders 51 are arranged on the left and right sides (up and down in FIG. 2(a)) with the telescopic guide 40 sandwiched therebetween. The cylinder part 52 of each hydraulic cylinder 51 is connected to and supported by the side of the guide cell 23. The tip of the piston rod 53 of the hydraulic cylinder 51 is connected directly or via a bracket (not shown) to the moving steel pipe receiver 33. Although not shown, some hydraulic hoses of the drill jumbo 20 are connected to the hydraulic cylinder 51. Thereby, the hydraulic driving force of the hydraulic cylinder 51 is supplied from the drill jumbo 20. By the telescopic drive of the advancing / retreating drive unit 50 composed of the pair of hydraulic cylinders 51, the telescopic guide 40 is telescoped and the holding unit 32 advances and retreats.

[0022] The steel pipe connection jig 30 is used as follows. <Driving-in process> As shown in FIG. 1, the leading steel pipe 9 is driven into the ground 2 by the drill jumbo 20. Before the last steel pipe 10A of the leading steel pipe 9 is completely buried in the ground 2, the driving-in is stopped and the end 10e is projected into the tunnel 1.

[0023] <Steel pipe installation process> Subsequently, as shown in FIG. 3, the steel pipe 10B to be added is installed so as to straddle from the moving steel pipe receiver 33 to the fixed steel pipe receiver 31 of the steel pipe connection jig 30. The steel pipe connection jig 30 is inserted into and supported by the receiving portion 33c of the moving steel pipe receiver 33 and is also inserted into and supported by the slide receiving portion 31c of the fixed steel pipe receiver 31. <Drilling rod addition process> Before and after the above steel pipe installation process, the drilling rod 24 (FIG. 1) is added by the length of the steel pipe 10B.

[0024] <Clamp mounting process> As shown in FIGS. 2(a) and 2(b), a clamp 34 is mounted and clamped on the front portion of the moving steel pipe receiver 33 in the steel pipe 10B. The steel pipe 10B is clamped from both sides by a pair of clamp members 34a, and the clamp 34 is fixed to the steel pipe 10B by tightening the tightening tool 34b. Preferably, the clamp 34 is abutted against the front surface of the moving steel pipe receiver 33.

[0025] <Positioning process> Subsequently, as shown in FIGS. 2(a) and 2(b), by operating the boom 22 of the drill jumbo 20, the pipe axis of the steel pipe 10B is made to coincide with the pipe axis of the receiving steel pipe 9 previously driven, and the tip 10f of the steel 10B is brought close to the end 10e of the immediately preceding steel pipe 10A. Preferably, a worker A different from the operator (not shown) of the drill jumbo 20 is arranged near the connection planned portion of the steel pipes 10A and 10B on the elevated work platform 27, and the positioning is performed while the worker A checks.

[0026] <Pushing-in process> Next, the hydraulic cylinder 51 of the reciprocating drive unit 50 is driven to extend, and the moving steel pipe receiver 33 is advanced. Then, as shown in FIG. 4(a), together with the moving steel pipe receiver 33, the clamp 34 abutted against the moving steel pipe receiver 33 is advanced, and the steel pipe 10B fixed to the clamp 34 is advanced. The steel pipe 10B slides on the slide receiving portion 31c. The telescopic guide 40 is extended.

[0027] The tip 10f of the advancing steel pipe 10B is pushed into the end 10e of the steel pipe 10A, and the locking claw 13 is elastically deformed and engaged with the locking groove 12 to be locked. As a result, the tip 10f of the steel pipe 10B is connected to the end 10e of the steel pipe 10A with one touch, and the steel pipe 10B can be added to the leading pipe 9 during driving. The pushing force can be obtained by the advancing / retreating drive unit 50, and it is not necessary for the operator A to push it in manually. Therefore, the operator A only needs to perform the positioning process. As a result, the burden on the operator A can be significantly reduced.

[0028] <Retreat process> Thereafter, by loosening the tightening tool 34b, the steel pipe 10B is released from the clamp 34. Preferably, the clamp 34 is removed from the steel pipe 10B. Further, as shown in FIG. 4(b), by contracting the hydraulic cylinder 51, the moving steel pipe receiver 33 is retracted (retreated), and the telescopic guide 40 is contracted. At this time, the receiving portion 33c is slid along the steel pipe 10B.

[0029] <Resumption of driving process> Subsequently, the drifter 26 (FIG. 1) is advanced along the guide cell 23 and connected to the end of the steel pipe 10B, and the driving of the leading pipe 9 by the drill jumbo 20 is resumed. By retreating (retreating) the moving steel pipe receiver 33 (FIG. 4(b)), it is possible to avoid the steel pipe connection jig 30 becoming an obstacle to steel pipe driving. Therefore, when resuming driving, it is not necessary to remove the entire steel pipe connection jig 30 from the guide cell 23 as long as only the clamp 34 is removed.

[0030] The above operations are repeated for the number of steel pipes 10 that make up the leading pipe 9. As a result, the leading pipe 9 having a predetermined length can be driven into the ground 2.

[0031] The present invention is not limited to the above-described embodiment, and various modifications can be made. For example, the movable steel pipe support 33 may integrally have a clamp for fixing the steel pipe 10B. The receiving portion 33c of the movable steel pipe support 33 may be a clamp that releasably clamps the steel pipe 10B. In this case, in the steel pipe installation process, when supporting the steel pipe 10B to be added to the movable steel pipe support 33, the steel pipe 10B is clamped by the clamp integral with the movable steel pipe support 33. Subsequently, in the pushing-in process by the forward and backward drive unit 50, the movable steel pipe support 33 and the clamp integral therewith are advanced, so that the steel pipe 10B is advanced and connected to the steel pipe 10A. Thereafter, during the retraction process, the clamp integral with the movable steel pipe support 33 is loosened, the clamp is released from the steel pipe 10B, and then the movable steel pipe support 33 and the clamp integral therewith are retracted. The telescopic guide 40 may integrally have the forward and backward drive unit 50.

Industrial Applicability

[0032] The present invention is applicable to an auxiliary method for ground reinforcement in the construction of mountain tunnels.

Explanation of Signs

[0033] 1 Tunnel 2 Ground 9 Long tip receiving steel pipe 10 Steel pipe 10B Steel pipe to be added 10e End 10f Tip 11 One-touch connection part 12 Locking groove 13 Locking claw 13a Locking claw part 14 Slit 20 Drill jumbo 21 Machine body 22 Boom 23 Guide cell 24 Drilling rod 25 Drilling bit 26 Drifter 30 Steel pipe connection jig 31 Fixed steel pipe support 1c Slide receiving portion 32 Holding part 33 Moving steel pipe support 33c Receiving part 34 Clamp 34a Clamp member 34b Tightening tool 34c Hinge 40 Telescopic guide 50 Forward and backward drive part 51 Hydraulic cylinder 52 Cylinder part 53 Piston rod

Claims

1. A steel pipe connection jig used in a tunnel auxiliary construction method for driving a plurality of steel pipes linearly connected by press-fitting into the ground, having a slide receiver that slidably receives the steel pipe to be added in the pipe axis direction, a fixed steel pipe receiver fixed to the tip of the guide cell of the drilling jumbo for driving, and a holding part provided to be movable forward and backward in front of the fixed steel pipe receiver, holding the steel pipe to be added in a non-relative movable and releasable manner, a forward and backward drive part for moving the holding part forward and backward, characterized by comprising the above. A steel pipe connection jig.

2. The steel pipe connection jig according to claim 1, characterized in that the holding part includes a movable steel pipe receiver having a receiving part for the steel pipe to be added, and a clamp for clamping the steel pipe to be added.

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