JP2017031621A - Extraction prevention tool of hole keeping pipe and installation method of hole keeping pipe of using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an extraction prevention tool of a hole keeping pipe and an installation method of the hole keeping pipe of using the same, capable of biting in a drilled hole inner surface, by surely expanding a diameter, when disconnected from a hole drilling pipe, while restraining resistance when inserting the hole keeping pipe into the hole drilling pipe.SOLUTION: An extraction prevention tool comprises a body part installed on the tip of a hole keeping pipe and a flexible anchor part arranged in a plurality at an interval in the circumferential direction in the body part and connected so as to expand toward the rear outside from the body part, and the anchor part is formed so as to become small in flexural rigidity toward the rear from a connection part with the body part.SELECTED DRAWING: Figure 2

Description

  The present invention forms a horizontal hole (drilled hole) in a natural ground with a drilled pipe, and when the bored pipe is pulled out after inserting the retained hole pipe (water collecting pipe, etc.), the retained pipe becomes the drilled pipe. In addition, the present invention relates to a retaining tube pull-out prevention tool that is attached in advance to the end of the hole-holding tube and a hole-holding tube installation method using the same.

  Conventionally, as a pull-out prevention tool to be attached to the tip of a hole-holding tube, an instrument has been proposed in which a seat plate is fixed with bolts by fixing a flat plate spring with a bent base end in a radial manner to a cone formed into a head cone. (For example, refer to Patent Document 1). As shown by a solid line in FIG. 3, when the pull-out preventing tool T is inserted into the drilled tube D, the leaf spring S comes into contact with the inner surface of the drilled tube D on the rear end side so as to be constricted into a curved shape. However, when the hole drilling tube D is pulled out from the side hole, the leaf spring S detached from the hole drilling tube D is restored and expanded in diameter as shown by a one-dot chain line in FIG. It is intended to prevent the inconvenience that the hole holding pipe P is pulled out at the same time by causing the tip to bite into the inner surface of the hole H.

Japanese Patent No. 4092287

  By the way, the leaf spring of the conventional retaining tube pull-out prevention tool is inserted into the drilled tube, and the bending moment caused by being narrowed against the inner surface is received by the conical surface of the head cone. It becomes the largest at the supported root part. As a result, as shown by a solid line in FIG. 4, the leaf spring S can be bent with the rear end edge E of the conical surface as a fulcrum. Even if it is removed from the drilling tube D, the diameter cannot be sufficiently increased, and the tip of the leaf spring cannot be caused to bite into the inner surface of the drilling hole H.

  On the other hand, it is conceivable that the elastic coefficient of the leaf spring S is set to be large so that bending is unlikely to occur, but it is pushed forward when or when the hole-holding pipe P is inserted into the drilling pipe D. On the contrary, the necessary amount of constriction cannot be secured unless the leaf spring S is forcibly bent in advance at the portion corresponding to the rear end edge E of the conical surface.

  In addition, the conventional pull-out prevention device has a problem that the number of parts is large, and it takes time and effort to weld or assemble them.

  In view of such circumstances, the present invention suppresses the resistance when inserting the hole-holding tube into the hole-drilling tube, and can reliably expand the diameter when it is detached from the hole-drilling tube and bite into the inner surface of the hole. An object of the present invention is to provide a hole tube pull-out prevention tool and a hole-holding tube installation method using the same.

  The invention according to claim 1 is configured such that a plurality of main body parts attached to the tip of the hole-holding tube and a plurality of the main body parts are arranged at intervals in the circumferential direction so as to spread outward from the main body parts. A flexible anchor portion, wherein the anchor portion is formed so that bending rigidity decreases from a connecting portion with the main body portion toward the rear. Providing prevention tools.

  According to a second aspect of the present invention, there is provided the retaining tube pull-out prevention device according to the first aspect, wherein the main body portion and the anchor portion are integrally formed of a hard synthetic resin having flexibility. .

  According to a third aspect of the present invention, in the connecting portion, a V-shaped space sandwiched between the main body portion and the anchor portion is provided with a surplus portion that connects the surfaces of the main body portion and the anchor portion facing each other. 3. A retaining tube pull-out preventing device according to claim 2, wherein:

  According to a fourth aspect of the present invention, the anchor portion is formed of a hard synthetic resin having flexibility in a blade shape having a certain lateral width, and is formed so that the thickness decreases from the connecting portion toward the rear. The retaining tube pull-out preventing device according to any one of claims 1 to 3, wherein the retaining tube pull-out preventing device is provided.

  The invention according to claim 5 is characterized in that the connecting portion is located radially inside the outer diameter of the hole-holding tube to which the main body portion is attached. Provide a tube pull-out prevention device.

  According to a sixth aspect of the present invention, the retaining tube pull-out preventing device according to any one of the first to fifth aspects is attached to the tip of the hole retaining tube, and the hole retaining tube is inserted into the hole forming tube in which the hole is formed. A hole-holding tube installation method is provided, wherein the hole-drilling tube is pulled out.

  According to the present invention, in the retaining tube pull-out preventing device attached to the tip of the retaining tube, the bending rigidity of the flexible anchor portion extending from the main body portion toward the rear outer side is reduced at the connecting portion with the main body portion. Since it was made larger and made smaller from there, it was bent slightly so that it would not be plastically deformed at the connecting portion when the hole-holding tube was inserted into the drilled tube, On the other hand, the amount of squeezing required to be greatly bent and accommodated in the drilled pipe as the entire anchor portion can be ensured. As a result, while reducing the resistance when inserting the hole-holding tube into the hole-drilling tube and securing the insertability, when it comes off from the hole-drilling tube, the anchor part surely expands and bites into the hole inner surface, A reliable pull-out preventing effect can be obtained.

  In the present invention, the main body portion and the anchor portion are integrally formed of a hard synthetic resin having flexibility, so that the welding and assembling operations of the parts, such as the conventional pull-out prevention tool, are not required. In particular, by integrally forming a surplus part that connects the opposing surfaces of the main body part and the anchor part, the anchor part functions as a stopper to prevent the anchor part from falling down, and the anchor part is more reliably prevented from bending. The effect of biting into the drilling surface when expanding the diameter is ensured. If the anchor portion is formed in a blade shape, the catching area with respect to the drilling surface is increased, so that the effect of preventing pulling out can be further improved.

  Furthermore, in the present invention, the distance from the root of the anchor portion to the inner surface of the drilled tube on which the anchor portion is placed is determined by positioning the connecting portion radially inward from the outer diameter of the hole-holding tube to which the main body portion is attached. By taking large, the bending when the anchor portion is narrowed is reduced, thereby preventing the anchor portion from being broken.

BRIEF DESCRIPTION OF THE DRAWINGS (a) The figure seen from the front, (b) The figure seen from the side, (c) The figure seen from back. Sectional drawing which shows the use condition which attached the pull-out prevention tool of the hole-holding tube which concerns on embodiment of this invention to a hole-holding tube, and inserted in the hole-drilling tube. Sectional drawing explaining the drawing-out prevention tool of the conventional hole-holding pipe. Sectional drawing explaining the problem of the drawing-out prevention tool of the conventional hole-holding pipe.

  Hereinafter, a retaining tube pull-out preventing tool according to an embodiment of the present invention will be described with reference to the accompanying drawings. FIG. 1A is a front view, FIG. 1B is a side view, and FIG. 2C is a rear view of a retaining tube pull-out prevention device 1 according to an embodiment of the present invention. It is sectional drawing which shows a state. As shown in FIGS. 1 and 2, the retaining tube pull-out prevention tool 1 is attached to the main body portion 2 and a substantially cylindrical main body portion 2 that is attached by inserting the rear end side into the front end of the retaining tube P. It is an instrument provided with a plurality of anchor portions 3 which are arranged at intervals in the circumferential direction and extend from the main body portion 2 toward the rear outer side. The main body 2 and the anchor 3 are formed by integrally molding a flexible hard synthetic resin (for example, hard polyethylene, hard vinyl chloride, etc.) with a mold.

  When the hole-holding pipe P is installed, when the hole-holding pipe P attached to the tip of the hole-holding pipe pull-out prevention tool 1 is inserted into the hole-drilled pipe drilled in the ground, the anchor portion 2 As shown in FIG. 2, it comes into contact with the inner surface of the tube, is narrowed by its flexibility, is accommodated in the drilled tube, and can be pushed forward to advance. Then, after inserting the hole-holding pipe P to the innermost part of the hole (drilling pipe) and then pulling out the hole-drilling pipe D while pushing the hole-holding pipe P forward, the anchor portion 2 is moved backward. The hole is removed from the hole tube and larger than the outer diameter of the hole drilling tube D, and bites into the inner surface of the hole formed substantially the same diameter as the outer diameter of the hole drilling tube D. After that, the hole-holding pipe P is not pulled out even if it is not pressed, and only the hole-drilling pipe can be easily pulled out.

As shown in FIG. 1, the main body 2 is formed by integrally forming a generally cylindrical barrel portion 21 and a hollow cone portion 22 provided so as to close the front side of the barrel portion 21. The outer peripheral surface of the body portion 21 is formed such that the outer diameter φ _{21 at the} front end is smaller than the outer diameter φ _P of the hole-holding tube P to be inserted, and further the outer diameter from the front end toward the rear end toward the rear. Is gradually tapered, and when the main body 2 is inserted into the hole-holding tube P, as shown in FIG. It is fixed in a state of being fitted to the periphery. If there is a concern about the detachment of the barrel portion 21, a hole penetrating the hole holding tube P and the barrel portion 21 with a drill or the like may be provided and fastened with a screw or the like, or both may be bonded, welded, or screwed. You may fix by making it equal.

  As shown in FIG. 1, five anchor portions 3 are arranged at equal intervals in the circumferential direction with respect to the main body portion 2, and one end thereof is connected to the outer peripheral surface of the front end of the body portion 21. Are provided so as to extend radially outward toward the rear outer side so as to be continuous with the conical inclined surface of the cone portion 22. As shown in FIG. 1 (a) or (c), the anchor portion 3 has a blade shape having a constant wide width W in the circumferential direction orthogonal to the radial direction, and has a thickness as shown in FIG. 1 (b). Is formed so as to become thinner at a substantially constant rate from the connecting portion (front end) to the body portion 21 toward the rear (rear end).

  The surface where the trunk portion 21 and the anchor portion 3 are opposed to each other behind the connecting portion where the V-shaped space A (FIG. 1B) is formed by the anchor portion 3 and the trunk portion 21 intersecting obliquely. The surplus part 4 which connects is provided. Since the front end of the anchor portion 3 is thick and, of course, the connecting portion also has high bending rigidity, even if it receives a large bending moment by being constricted for insertion of the drilled tube D, it can be easily plastically deformed. Absent. However, in order to prevent the crease at the base of the anchor part 3 more reliably, the surplus part 4 is sandwiched between the base of the anchor part 3 and the trunk part 21 as a stopper for supporting the anchor part 3. It is provided.

Further, the front end of the body portion 21 to which the anchor portion 3 is connected is formed such that the outer diameter φ ₂₁ of the outer peripheral surface thereof is smaller than the outer diameter φ _{P of the} retaining tube P. By positioning the inner side in the direction, the distance from the connecting portion of the anchor portion 3 to the inner surface of the drilled tube D with which the anchor portion 3 abuts is increased, and when the anchor portion 3 is narrowed, the root portion is This is to reduce the burden.
(Modification of the above embodiment)

  In the above embodiment, the anchor portion 3 is formed in a blade shape having a constant lateral width W, and the thickness of the blade is decreased from the front end toward the rear end at a constant rate, but from the front end toward the rear end. Other shapes may be adopted as long as the bending rigidity is reduced. For example, the thickness may be constant from the front end to the rear end of the anchor portion, while the lateral width may decrease from the front end to the rear end, or the thickness and the thickness from the front end to the rear end of the anchor portion may be reduced. You may form so that both width may become small.

  In the above embodiment, the anchor portion 3 is formed so that the bending rigidity is reduced over the entire length from the front end to the rear end, but it is not necessary to provide a change in bending rigidity over the entire length of the anchor portion. For example, when inserted into the drilling tube as shown in FIG. 2, the anchor portion 3 is deformed so as to bend actually from the connecting portion with the body portion 21, and abuts against the inner surface of the drilling tube D. Therefore, it may be changed from the front end of the anchor portion to the rear so that the bending rigidity is reduced only in the section.

  Specifically, the thickness of the anchor portion is gradually reduced in the section from the connecting portion toward the rear as in the above-described embodiment, but contacts the outside of the section, that is, the inner surface of the drilled pipe. The thickness (bending rigidity) may be constant at the rear portion of the point. This is because if the bending rigidity is reduced over the entire length of the anchor portion, the rear end of the anchor portion becomes too easy to bend, and there is a concern about a decrease in the biting force with respect to the drilling hole.

DESCRIPTION OF SYMBOLS 1 Pull-out prevention tool of hole-holding pipe 2 Main part 3 Anchor part 4 Remaining part P Hole-holding pipe D Hole-drilling pipe

  The present invention forms a horizontal hole (drilled hole) in a natural ground with a drilled pipe, and when the bored pipe is pulled out after inserting the retained hole pipe (water collecting pipe, etc.), the retained pipe becomes the drilled pipe. In addition, the present invention relates to a retaining tube pull-out prevention tool that is attached in advance to the end of the hole-holding tube and a hole-holding tube installation method using the same.

  Conventionally, as a pull-out prevention tool to be attached to the tip of a hole-holding tube, an instrument has been proposed in which a seat plate is fixed with bolts by fixing a flat plate spring with a bent base end in a radial manner to a cone formed into a head cone. (For example, refer to Patent Document 1). As shown by a solid line in FIG. 3, when the pull-out preventing tool T is inserted into the drilled tube D, the leaf spring S comes into contact with the inner surface of the drilled tube D on the rear end side so as to be constricted into a curved shape. However, when the hole drilling tube D is pulled out from the side hole, the leaf spring S detached from the hole drilling tube D is restored and expanded in diameter as shown by a one-dot chain line in FIG. It is intended to prevent the inconvenience that the hole holding pipe P is pulled out at the same time by causing the tip to bite into the inner surface of the hole H.

Japanese Patent No. 4092287

  By the way, the leaf spring of the conventional retaining tube pull-out prevention tool is inserted into the drilled tube, and the bending moment caused by being narrowed against the inner surface is received by the conical surface of the head cone. It becomes the largest at the supported root part. As a result, as shown by a solid line in FIG. 4, the leaf spring S can be bent with the rear end edge E of the conical surface as a fulcrum. Even if it is removed from the drilling tube D, the diameter cannot be sufficiently increased, and the tip of the leaf spring cannot be caused to bite into the inner surface of the drilling hole H.

  On the other hand, it is conceivable that the elastic coefficient of the leaf spring S is set to be large so that bending is unlikely to occur, but it is pushed forward when or when the hole-holding pipe P is inserted into the drilling pipe D. On the contrary, the necessary amount of constriction cannot be secured unless the leaf spring S is forcibly bent in advance at the portion corresponding to the rear end edge E of the conical surface.

  In addition, the conventional pull-out prevention device has a problem that the number of parts is large, and it takes time and effort to weld or assemble them.

  In view of such circumstances, the present invention suppresses the resistance when inserting the hole-holding tube into the hole-drilling tube, and can reliably expand the diameter when it is detached from the hole-drilling tube and bite into the inner surface of the hole. An object of the present invention is to provide a hole tube pull-out prevention tool and a hole-holding tube installation method using the same.

The invention according to claim 1 is configured such that a plurality of main body parts attached to the tip of the hole-holding tube and a plurality of the main body parts are arranged at intervals in the circumferential direction so as to spread outward from the main body parts. A flexible anchor portion, and the main body portion and the anchor portion are integrally formed of a hard synthetic resin having flexibility, and the anchor portion is rearward from a connecting portion with the main body portion. A retaining tube pull-out prevention tool is provided which is formed so that the bending rigidity decreases toward the bottom.

According to a second aspect of the present invention, in the V-shaped space sandwiched between the main body portion and the anchor portion in the connecting portion, a surplus portion connecting the surfaces of the main body portion and the anchor portion facing each other is provided. The retaining tube pull-out preventing device according to claim 1 is provided.

According to a third aspect of the present invention, the anchor portion is formed by forming a flexible hard synthetic resin into a blade shape having a certain lateral width, and is formed so that the thickness decreases from the connecting portion toward the rear. The retaining tube pull-out preventing device according to claim 1 or 2 , wherein the retaining tube pull-out preventing device is provided.

The invention of claim 4, wherein the coupling parts, Juana according to any one of claims 1 to 3, characterized in that located inside the outer diameter of the radial Juana tube the body portion is attached Provide a tube pull-out prevention device.

According to a fifth aspect of the present invention, the retaining tube pull-out prevention device according to any one of the first to fourth aspects is attached to the tip of the hole-holding tube, and the hole-holding tube is inserted into the hole-drilling tube in which the hole is formed. A hole-holding tube installation method is provided, wherein the hole-drilling tube is pulled out.

  According to the present invention, in the retaining tube pull-out preventing device attached to the tip of the retaining tube, the bending rigidity of the flexible anchor portion extending from the main body portion toward the rear outer side is reduced at the connecting portion with the main body portion. Since it was made larger and made smaller from there, it was bent slightly so that it would not be plastically deformed at the connecting portion when the hole-holding tube was inserted into the drilled tube, On the other hand, the amount of squeezing required to be greatly bent and accommodated in the drilled pipe as the entire anchor portion can be ensured. As a result, while reducing the resistance when inserting the hole-holding tube into the hole-drilling tube and securing the insertability, when it comes off from the hole-drilling tube, the anchor part surely expands and bites into the hole inner surface, A reliable pull-out preventing effect can be obtained.

  In the present invention, the main body portion and the anchor portion are integrally formed of a hard synthetic resin having flexibility, so that the welding and assembling operations of the parts, such as the conventional pull-out prevention tool, are not required. In particular, by integrally forming a surplus part that connects the opposing surfaces of the main body part and the anchor part, the anchor part functions as a stopper to prevent the anchor part from falling down, and the anchor part is more reliably prevented from bending. The effect of biting into the drilling surface when expanding the diameter is ensured. If the anchor portion is formed in a blade shape, the catching area with respect to the drilling surface is increased, so that the effect of preventing pulling out can be further improved.

  Furthermore, in the present invention, the distance from the root of the anchor portion to the inner surface of the drilled tube on which the anchor portion is placed is determined by positioning the connecting portion radially inward from the outer diameter of the hole-holding tube to which the main body portion is attached. By taking large, the bending when the anchor portion is narrowed is reduced, thereby preventing the anchor portion from being broken.

BRIEF DESCRIPTION OF THE DRAWINGS (a) The figure seen from the front, (b) The figure seen from the side, (c) The figure seen from back. Sectional drawing which shows the use condition which attached the pull-out prevention tool of the hole-holding tube which concerns on embodiment of this invention to a hole-holding tube, and inserted in the hole-drilling tube. Sectional drawing explaining the drawing-out prevention tool of the conventional hole-holding pipe. Sectional drawing explaining the problem of the drawing-out prevention tool of the conventional hole-holding pipe.

  Hereinafter, a retaining tube pull-out preventing tool according to an embodiment of the present invention will be described with reference to the accompanying drawings. FIG. 1A is a front view, FIG. 1B is a side view, and FIG. 2C is a rear view of a retaining tube pull-out prevention device 1 according to an embodiment of the present invention. It is sectional drawing which shows a state. As shown in FIGS. 1 and 2, the retaining tube pull-out prevention tool 1 is attached to the main body portion 2 and a substantially cylindrical main body portion 2 that is attached by inserting the rear end side into the front end of the retaining tube P. It is an instrument provided with a plurality of anchor portions 3 which are arranged at intervals in the circumferential direction and extend from the main body portion 2 toward the rear outer side. The main body 2 and the anchor 3 are formed by integrally molding a flexible hard synthetic resin (for example, hard polyethylene, hard vinyl chloride, etc.) with a mold.

  When the hole-holding pipe P is installed, when the hole-holding pipe P attached to the tip of the hole-holding pipe pull-out prevention tool 1 is inserted into the hole-drilled pipe drilled in the ground, the anchor portion 2 As shown in FIG. 2, it comes into contact with the inner surface of the tube, is narrowed by its flexibility, is accommodated in the drilled tube, and can be pushed forward to advance. Then, after inserting the hole-holding pipe P to the innermost part of the hole (drilling pipe) and then pulling out the hole-drilling pipe D while pushing the hole-holding pipe P forward, the anchor portion 2 is moved backward. The hole is removed from the hole tube and larger than the outer diameter of the hole drilling tube D, and bites into the inner surface of the hole formed substantially the same diameter as the outer diameter of the hole drilling tube D. After that, the hole-holding pipe P is not pulled out even if it is not pressed, and only the hole-drilling pipe can be easily pulled out.

  As shown in FIG. 1, the main body 2 is formed by integrally forming a generally cylindrical barrel portion 21 and a hollow cone portion 22 provided so as to close the front side of the barrel portion 21. The outer peripheral surface of the body portion 21 is formed such that the outer diameter φ21 of the front end is smaller than the outer diameter φP of the hole-holding tube P to be inserted, and the outer diameter gradually increases from the front end toward the rear end. When the main body 2 is inserted into the hole holding tube P, as shown in FIG. 1 (b), the middle portion of the taper of the trunk portion 21 is formed on the inner peripheral edge of the hole holding tube P. It is fixed in the fitted state. If there is a concern about the detachment of the barrel portion 21, a hole penetrating the hole holding tube P and the barrel portion 21 with a drill or the like may be provided and fastened with a screw or the like, or both may be bonded, welded, or screwed. You may fix by making it equal.

  As shown in FIG. 1, five anchor portions 3 are arranged at equal intervals in the circumferential direction with respect to the main body portion 2, and one end thereof is connected to the outer peripheral surface of the front end of the body portion 21. Are provided so as to extend radially outward toward the rear outer side so as to be continuous with the conical inclined surface of the cone portion 22. As shown in FIG. 1 (a) or (c), the anchor portion 3 has a blade shape having a constant wide width W in the circumferential direction orthogonal to the radial direction, and has a thickness as shown in FIG. 1 (b). Is formed so as to become thinner at a substantially constant rate from the connecting portion (front end) to the body portion 21 toward the rear (rear end).

  The surface where the trunk portion 21 and the anchor portion 3 are opposed to each other behind the connecting portion where the V-shaped space A (FIG. 1B) is formed by the anchor portion 3 and the trunk portion 21 intersecting obliquely. The surplus part 4 which connects is provided. Since the front end of the anchor portion 3 is thick and, of course, the connecting portion also has high bending rigidity, even if it receives a large bending moment by being constricted for insertion of the drilled tube D, it can be easily plastically deformed. Absent. However, in order to prevent the crease at the base of the anchor part 3 more reliably, the surplus part 4 is sandwiched between the base of the anchor part 3 and the trunk part 21 as a stopper for supporting the anchor part 3. It is provided.

Further, the front end of the body portion 21 to which the anchor portion 3 is connected is formed such that the outer diameter φ21 of the outer peripheral surface thereof is smaller than the outer diameter φP of the retaining tube P. By placing the anchor portion 3 on the inner side, a large distance is required from the connecting portion of the anchor portion 3 to the inner surface of the drilled tube D with which the anchor portion 3 abuts, and the burden on the base portion when the anchor portion 3 is narrowed. It is intended to reduce this.
(Modification of the above embodiment)

  In the above embodiment, the anchor portion 3 is formed in a blade shape having a constant lateral width W, and the thickness of the blade is decreased from the front end toward the rear end at a constant rate, but from the front end toward the rear end. Other shapes may be adopted as long as the bending rigidity is reduced. For example, the thickness may be constant from the front end to the rear end of the anchor portion, while the lateral width may decrease from the front end to the rear end, or the thickness and the thickness from the front end to the rear end of the anchor portion may be reduced. You may form so that both width may become small.

  In the above embodiment, the anchor portion 3 is formed so that the bending rigidity is reduced over the entire length from the front end to the rear end, but it is not necessary to provide a change in bending rigidity over the entire length of the anchor portion. For example, when inserted into the drilling tube as shown in FIG. 2, the anchor portion 3 is deformed so as to bend actually from the connecting portion with the body portion 21, and abuts against the inner surface of the drilling tube D. Therefore, it may be changed from the front end of the anchor portion to the rear so that the bending rigidity is reduced only in the section.

  Specifically, the thickness of the anchor portion is gradually reduced in the section from the connecting portion toward the rear as in the above-described embodiment, but contacts the outside of the section, that is, the inner surface of the drilled pipe. The thickness (bending rigidity) may be constant at the rear portion of the point. This is because if the bending rigidity is reduced over the entire length of the anchor portion, the rear end of the anchor portion becomes too easy to bend, and there is a concern about a decrease in the biting force with respect to the drilling hole.

DESCRIPTION OF SYMBOLS 1 Pull-out prevention tool of hole-holding pipe 2 Main part 3 Anchor part 4 Remaining part P Hole-holding pipe D Hole-drilling pipe

Claims (6)

A main body part attached to the front end of the hole-holding tube, a plurality of the anchor parts arranged at intervals in the circumferential direction in the main body part and connected so as to spread outward from the main body part, and With
The anchor tube pull-out prevention tool according to claim 1, wherein the anchor portion is formed so that bending rigidity decreases from a connecting portion with the main body portion toward the rear.   2. The retaining tube pull-out prevention device according to claim 1, wherein the main body portion and the anchor portion are integrally formed of a hard synthetic resin having flexibility.   The surplus part which connects the surface which the said main-body part and the said anchor part oppose is provided in the V-shaped space pinched | interposed by the said main-body part and the said anchor part in the said connection part. The retaining tube pull-out prevention tool as described.   The anchor portion is formed by forming a flexible hard synthetic resin into a blade shape having a certain lateral width, and is formed so that the thickness decreases from the connecting portion toward the rear. 4. A retaining tube pull-out preventing device according to any one of claims 1 to 3.   5. The retaining tube pull-out preventing device according to claim 1, wherein the connecting portion is located radially inside the outer diameter of the hole-holding tube to which the main body portion is attached.   6. A retaining tube pull-out prevention device according to claim 1 is attached to a tip of the retaining tube, the retaining tube is inserted into a drilled tube having a drilled hole, and the drilled tube is pulled out. A hole-holding tube installation method characterized by this.

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