JP2016125526A - Spacer for sheath pipe jacking method, and sheath pipe jacking method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a spacer for a sheath pipe jacking method easy to handling and excellent in nonslip effect, and a sheath pipe jacking method using the spacer.SOLUTION: A spacer 3 for a sheath pipe jacking method is mounted on the outer periphery of an insertion pipe 2 inserted into a sheath pipe 1, and provided with a gap between the sheath pipe 1 and the insertion pipe 2. The spacer includes: an annular body part 31 attached so as to surround the outer periphery of the insertion pipe 2; a plurality of projection parts 32 projecting from the outer periphery of the body part 31 toward radially outside in a radial manner; a locking part 33 projecting from the inner periphery of the body part 31 toward radially inside, and locked to the outer peripheral surface of the insertion pipe 2; and a pressing part 34 pressing the locking part 33 toward radially inside.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a spacer used in a sheath tube propulsion method and a sheath tube propulsion method using the spacer.

  As a method of laying a fluid pipe line such as a ductile cast iron pipe, a sheath propulsion method is known. According to this construction method, a pipe is laid by sequentially inserting new pipes (insertion pipes) having a smaller diameter into the sheath pipe buried in the ground. The sheath propulsion method is particularly useful under conditions where it is difficult to secure the excavation range such as densely populated areas and intersections, and is widely used in so-called pipe-in-pipe construction where old pipes are renewed. Patent Documents 1 to 3 disclose instruments for smoothly inserting an insertion tube without damaging it.

  The spacer described in Patent Document 1 is a resin band member having a large number of convex portions on the surface, and is inserted around the insertion tube by providing a gap between the sheath tube and the insertion tube. Propulsion resistance at the time can be reduced. Conventionally, an anti-slip rubber sheet or an adhesive tape is wound around the insertion tube and the spacer is mounted on the outer periphery thereof. However, the anti-slip effect may not be sufficient. Further, when the diameter of the insertion tube is small, it is necessary to bend the spacer greatly along the outer peripheral surface of the insertion tube, and handling is complicated.

  Patent Document 2 describes a band member including a roller that rolls on the inner surface of a sheath tube. Furthermore, Patent Document 3 describes a flange including a caster that rolls on the inner surface of the sheath tube. Any of these contributes to the smooth insertion of the insertion tube, but the structure is more complicated than that of the spacer, and the handling is not easy.

European Patent Application No. 1783412 JP 2003-202093 A JP 2001-248770 A

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a sheath for pipe sheath construction method that is easy to handle and has an excellent anti-slip effect, and a sheath sheath construction method using the sheath spacer. .

  The above object can be achieved by the present invention as described below. That is, the sheath for the sheath propulsion method according to the present invention is a sheath for the sheath propelling method that is attached to the outer periphery of the insertion tube inserted into the sheath tube and provides a gap between the sheath tube and the insertion tube. An annular main body portion that is attached to surround the outer periphery of the insertion tube, a plurality of convex portions that project radially outward from the outer periphery of the main body portion, and a diameter from the inner periphery of the main body portion. A locking portion that protrudes inward in the direction and locks to the outer peripheral surface of the insertion tube, and a pressing portion that presses the locking portion inward in the radial direction.

  According to this spacer, a clearance is provided between the sheath tube and the insertion tube to reduce the thrust resistance during insertion, and the insertion tube can be smoothly inserted without being damaged. Moreover, since the structure is simple, handling is easy. Nevertheless, since the engaging portion that engages with the outer peripheral surface of the insertion tube is configured to be pressed by the pressing portion, the anti-slip effect is excellent, and the spacer can be appropriately prevented from being displaced relative to the insertion tube.

  It is preferable that the tip of the convex portion is formed by a resin cap that is detachably attached. Protrusion resistance at the time of insertion can be reduced satisfactorily because the tip of the convex portion in contact with the inner surface of the sheath is made of resin. Moreover, in this case, it is preferable that the cap is provided with a drop-off preventing portion that prevents the cap from dropping off.

  As one embodiment of the spacer, the pressing portion is configured by a pressing bolt screwed to the main body portion, the locking portion is configured by a tip portion of the pressing bolt, and the pressing bolt is radially inward. What is comprised so that the front-end | tip part of the said volt | bolt may press against the outer peripheral surface of the said insertion pipe by moving it toward is mentioned. According to such a configuration, a strong anti-slip effect is exerted by strongly pressing the tip of the push bolt against the outer peripheral surface of the insertion tube, and the positional displacement of the spacer with respect to the insertion tube can be more effectively prevented.

  As one embodiment related to the spacer, the pressing portion is configured by a pressing bolt screwed into the main body portion, and the locking portion is configured by a retaining member having a claw protruding radially inward. In addition, there is a configuration in which the claw bites into the outer peripheral surface of the insertion tube by pressing the retaining member toward the radially inner side with the tip of the push bolt. According to such a configuration, the claw of the retaining member pressed by the tip of the push bolt bites into the outer peripheral surface of the insertion tube, so that a strong anti-slip effect is exhibited, and the positional displacement of the spacer with respect to the insertion tube is more effectively performed. Can be prevented.

  In addition, the sheath tube propulsion method according to the present invention is the above-described book in the sheath tube propulsion method in which a plurality of insertion tubes are inserted into the sheath tube while being sequentially joined to each other. The spacer of the invention is attached to the insertion tube, and a gap is provided between the sheath tube and the insertion tube inserted into the sheath tube via the spacer. Thereby, it is possible to insert smoothly without damaging the insertion tube by using the above-mentioned spacer that is easy to handle and has an excellent anti-slip effect.

  In the sheath pipe propulsion method, the spacer is attached to each of the pair of insertion pipes in a pipe joint provided as an earthquake-resistant pipe joint that can be expanded and contracted in the axial direction between the insertion openings. It is preferable to restrict expansion and contraction of the pipe joint at the time of insertion by connecting with a member. By restricting the expansion and contraction of the pipe joint at the time of insertion in this way, it is possible to construct by the sheath tube propulsion method while securing the expansion and contraction allowance of the earthquake-resistant pipe joint.

The side view which shows an example of the spacer for sheath pipe propulsion methods concerning this invention AA sectional view of FIG. BB sectional view of FIG. Sectional drawing which expands and shows the X section in FIG. Side view showing a pipe joint where expansion and contraction is regulated using a spacer Sectional drawing which shows the principal part of the spacer in other embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 shows a sheath tube 1 in the sheath tube propulsion method, an insertion tube 2 inserted into the sheath tube, and a sheath tube sheath spacer (hereinafter simply referred to as “spacer”) attached to the outer periphery of the insert tube 2. 3). The insertion tube 2 is a new tube having a smaller diameter than the sheath tube 1 and is, for example, a ductile cast iron tube. A gap through a spacer 3 is provided between the sheath tube 1 and the insertion tube 2 inserted therein. In the sheath tube propulsion method, a plurality of insertion tubes 2 are inserted into the sheath tube 1 while being sequentially joined, whereby a conduit is laid in the sheath tube 1. Usually, the insertion direction of the insertion tube 2 is the P direction with the insertion opening in the front.

  In order to smoothly insert the insertion tube 2 without damaging it, it is effective to provide such a gap between the sheath tube 1 and the insertion tube 2, so that such a gap is appropriately provided. A plurality of spacers 3 are attached to the insertion tube 2. As shown in FIGS. 1 to 4, the spacer 3 includes an annular main body 31 that is attached so as to surround the outer periphery of the insertion tube 2, and a plurality of protrusions that protrude radially outward from the outer periphery of the main body 31. A portion 32, a locking portion 33 that protrudes radially inward from the inner periphery of the main body 31 and locks to the outer peripheral surface of the insertion tube 2, and a pressing portion that presses the locking portion 33 radially inward 34.

  By using such a spacer 3, a clearance is provided between the sheath tube 1 and the insertion tube 2 to reduce the thrust resistance during insertion, and the insertion tube 2 can be smoothly inserted without being damaged. In addition, since the structure of the spacer 3 is simple, it is easy to handle. Nevertheless, since the engaging portion 33 that engages with the outer peripheral surface of the insertion tube 2 is configured to be pressed by the pressing portion 34, the anti-slip effect is excellent, and the displacement of the spacer 3 with respect to the insertion tube 2 is appropriately prevented. be able to.

  In the present embodiment, the main body 31 is formed in a flange shape. Moreover, the main-body part 31 is comprised by the annular body continuous along the circumferential direction. In order to fix the relative position of the insertion tube 2 and the spacer 3 in the axial direction, it is necessary to increase the contact resistance of the locking portion 33 with respect to the outer peripheral surface of the insertion tube 2, and therefore the locking portion 33 is made of metal. Preferably there is. Furthermore, the pressing portion 34 that presses the locking portion 33 is also preferably made of metal, and the main body portion 31 is also preferably made of metal. Holes 31 a are formed in the body portion 31 at a plurality of locations in the circumferential direction.

  The convex portion 32 is provided corresponding to a metal push bolt 35 attached to the main body portion 31. The tip of the convex portion 32 is formed by a resin cap 36 that is detachably attached. Since the tip of the convex portion 32 in contact with the inner surface of the sheath 1 is made of resin, the propulsion resistance at the time of insertion can be reduced well. Examples of the resin forming the cap 36 include hard resins such as hard polyethylene. In the example of FIG. 2, caps 36 are attached to all the convex portions 32, but only a part of the convex portions 32 (for example, the lower half convex portion 32) that can contact the inner surface of the sheath 1 are targeted. Also good. In FIG. 1 and the like, the head of the push bolt 35 can be seen through the cap 36, but the cap 36 may be either transparent or opaque.

  As shown in FIGS. 3 and 4, the cap 36 is provided with a drop-off preventing portion 37 that prevents the cap 36 from falling off. The dropout prevention portion 37 of the present embodiment is configured by a set screw screwed to the cap 36. When the set screw is rotated and protrudes largely inward, the tip end portion of the set screw engages with the head of the push bolt 35, and the cap 36 is prevented from falling off. However, the structure of the drop-off prevention part 37 is not limited to this. For example, the inner surface of the cap 36 may be locally raised, and the raised portion may be engaged with the head of the push bolt 35, or a method using the attractive force of a magnet may be considered.

  In the present embodiment, the pressing portion 34 is constituted by a push bolt 35 screwed to the main body portion 31, and the locking portion 33 is constituted by a tip portion of the push bolt 35. The push bolt 35 moves along the radial direction of the insertion tube 2 by the rotation operation. Then, as shown in FIGS. 3 and 4, by moving the push bolt 35 inward in the radial direction, the distal end portion (that is, the locking portion 33) of the push bolt 35 is strongly pressed against the outer peripheral surface of the insertion tube 2. It is configured to hit. As a result, a strong anti-slip effect is exhibited, and displacement of the spacer 3 with respect to the insertion tube 2 can be effectively prevented.

  When the pipe joint portion 20 formed by joining the insertion pipes 2 is provided as an earthquake-resistant pipe joint that can be expanded and contracted in the axial direction between the receiving opening, the pipe joint portion 20 as shown in FIG. It is preferable to restrict the expansion and contraction of the. In the example of FIG. 5, the spacer 3 is attached to each of the pair of insertion tubes 2 in the tube joint portion 20, and the expansion and contraction of the tube joint portion 20 at the time of insertion is restricted by connecting the spacers 3 with a shaft member 38. ing. Thereby, the extinction of the expansion / contraction allowance accompanying the promotion of the insertion tube 2 can be prevented, and the expansion / contraction allowance of the earthquake-resistant pipe joint can be secured. Therefore, it is useful for constructing a pipeline including a seismic resistant joint by the sheath tube propulsion method.

  The shaft member 38 is inserted into a hole 31 a formed in the main body 31 and is fixed by a nut 39. The nut 39 is screwed onto the shaft member 38 on both sides of the main body 31 and is firmly tightened so as to sandwich the main body 31. The shaft member 38 is attached to a plurality of locations in the circumferential direction. The strength of the shaft member 38 is set so as not to be broken by a propulsive force when the insertion tube 2 is inserted, but to be broken when an external force exceeding that (for example, an external force accompanying the occurrence of an earthquake) is applied. In addition, the expansion and contraction function of the earthquake-resistant pipe joint is not hindered. The strength of the shaft member 38 can be set by appropriately selecting the material and thickness thereof.

  The main part of the spacer in other embodiment of this invention is shown in FIG. Since the configuration other than that described below is the same as that of the above-described embodiment, common points will be omitted and differences will be mainly described. In addition, the same code | symbol is attached | subjected to the site | part same as the site | part demonstrated in the above-mentioned embodiment, and the overlapping description is abbreviate | omitted.

  In the example of FIG. 6, the pressing portion 34 is constituted by a push bolt 45 screwed to the main body portion 31, and the locking portion 33 is constituted by a retaining member 49 having a claw 49 a protruding radially inward. Has been. The main body 31 serves as a housing that houses the retaining member 49. The claw 49a is configured to bite into the outer peripheral surface of the insertion tube 2 by moving the push bolt 45 radially inward and pressing the retaining member 49 radially inward with the tip of the push bolt 45. Has been. As a result, a strong anti-slip effect is exhibited, and the displacement of the spacer 3 with respect to the insertion tube 2 can be more effectively prevented.

  In the example of FIG. 6, the upper surface of the retaining member 49 is formed by an inclined surface having a smaller diameter in the insertion direction of the insertion tube 2, and the tip of the push bolt 45 is also inclined in the same direction. Therefore, when the driving force at the time of insertion acts, the retaining member 49 is pressed radially inward by the wedge effect. As a result, the contact resistance of the locking portion 33 with respect to the outer peripheral surface of the insertion tube 2 can be increased, and the anti-slip effect of the spacer 3 can be enhanced.

  The present invention is not limited to the embodiment described above, and various improvements and modifications can be made without departing from the spirit of the present invention.

  For example, in the above-described embodiment, the example in which the main body portion 31 of the spacer 3 is configured by an annular body that is continuous in the circumferential direction has been described. However, the present invention is not limited to this, and the division is performed at one or more locations in the circumferential direction. A main body having a structure may be used. The main body portion having such a split structure is reduced in diameter by tightening a fastener including a bolt and a nut attached to the divided portion, and the distance between the main body portion and the insertion tube can be adjusted by operating the fastener.

  In the above-described embodiment, the example in which the pressing portion 34 is configured by the pressing bolts 35 and 45 is shown, but the present invention is not limited thereto. For example, in the case where the main body portion having the split structure as described above is used, if the locking portion is constituted by a retaining member as shown in FIG. 6, the retaining member is directed radially inward by tightening the fastener. Since it is pressed, the push bolt can be omitted. In such a configuration, the portion of the main body that faces the upper surface of the retaining member becomes the pressing portion. It is preferable that the portion of the main body portion serving as the pressing portion is inclined in the same direction as the upper surface of the retaining member so that the wedge effect can be exhibited.

DESCRIPTION OF SYMBOLS 1 Sheath pipe 2 Insertion pipe 3 Spacer 20 Pipe joint part 31 Main body part 32 Convex part 33 Locking part 34 Press part 35 Push bolt 36 Cap 37 Fall-off prevention part 38 Shaft member 39 Nut 45 Push bolt 49 Retaining member 49a Claw

Claims (7)

A sheath for a sheath propelling method, which is attached to the outer periphery of an insertion tube to be inserted into a sheath tube and provides a gap between the sheath tube and the insertion tube,
An annular main body attached to surround the outer periphery of the insertion tube;
A plurality of protrusions projecting radially outward from the outer periphery of the main body,
A locking portion that protrudes radially inward from the inner periphery of the main body portion and locks to the outer peripheral surface of the insertion tube;
And a pressing portion that presses the engaging portion toward the inside in the radial direction.   The sheath pipe propulsion method spacer according to claim 1, wherein a tip of the convex portion is formed by a resin cap attached in a detachable manner.   The spacer for a sheath pipe propulsion method according to claim 2, wherein the cap is provided with a drop-off preventing portion for preventing the cap from dropping off. The pressing part is constituted by a pressing bolt screwed into the main body part,
The locking portion is constituted by a tip portion of the push bolt,
The sheath according to any one of claims 1 to 3, wherein the sheath is configured such that the distal end portion of the push bolt is pressed against the outer peripheral surface of the insertion tube by moving the push bolt toward a radially inner side. Spacer for pipe propulsion method. The pressing part is constituted by a pressing bolt screwed into the main body part,
The locking portion is constituted by a retaining member having a claw protruding radially inward,
The said nail | claw is comprised so that the said nail | claw may bite into the outer peripheral surface of the said insertion pipe | tube by pressing the said retaining member toward the radial inside with the front-end | tip of the said push bolt. Spacer for pipe sheath construction method. By inserting a plurality of insertion tubes into a sheath tube while sequentially joining them, in the sheath tube propulsion method of laying a pipeline in the sheath tube,
A sheath according to any one of claims 1 to 5, wherein the spacer is attached to the insertion tube, and a gap is provided between the sheath tube and the insertion tube inserted therein via the spacer. Pipe propulsion method.   At the time of insertion by attaching the spacer to each of a pair of the insertion pipes in a pipe joint provided as an earthquake-resistant pipe joint that can be expanded and contracted in the axial direction between the insertion openings, and connecting the spacers by a shaft member. The sheath pipe propulsion method according to claim 6, wherein the expansion and contraction of the pipe joint portion is regulated.

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