Cutting-out / cleaving tool

Abstract

To provide a cutting-out / cleaving tool with safety preventing damage on a supply network and the like for the other lifelines arranged outside of an installation section of an existing pipe upon replacement with a pipe to be newly installed through cutting and enlarging the existing pipe.SOLUTION: A cutting-out / cleaving tool is provided with: cutting-out groove forming parts K1, K2 forming grooves in a pipe wall of an existing pipe along a traction direction through traction toward the front of the traction direction; a cutting-out / cleaving part KA arranged behind the cutting-out groove parts K1, K2 in the traction direction to be fitted in the cutting-off groove formed with the cutting-out groove forming parts K1, K2 and adding force in a direction where a pair of cut-out surfaces opposite to each other are separated apart; and an enlarging part KK arranged behind the cutting-out / cleaving part KA in the traction direction to enlarge the existing pipe cleaved with the cutting-out / cleaving part KA.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a notch and cleavage tool that is pulled from rear to front along a pulling direction along the axis of an existing buried pipe, cuts the inner wall of the existing pipe along the pulling direction to expand the diameter of the existing pipe, and pulls a new pipe connected to the rear into the interior of the existing pipe. [Background technology]

[0002] Conventionally, a cutting and cleaving tool that cuts an existing buried pipe in the axial direction of the pipe to expand its diameter has been known, as described in Patent Document 1, which is equipped with a cutting section having multiple rotary blades, including a first rotary blade that makes an incision in the existing pipe and a second rotary blade that completely cuts the existing pipe along the incision made by the first rotary blade. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 3261400 Summary of the Invention [Problem to be solved by the invention]

[0004] In the technique disclosed in the above Patent Document 1, a first rotary blade makes an incision in an existing pipe, and a second rotary blade cuts the existing pipe completely along the incision made by the first rotary blade. In this configuration, when cutting an existing pipe, the cutting edge of the second rotating blade becomes exposed from the inside of the existing pipe to the outside, and if there are supply networks related to other lifelines (e.g., power lines, communication lines, water pipes, etc.) outside the existing pipe to be cut, there is a risk that the power lines, etc. will be damaged, leaving room for improvement.

[0005] The present invention has been made in consideration of the above-mentioned problems, and its purpose is to provide a highly safe notching and cleaving tool that, when cutting and expanding an existing pipe to replace it with a new pipe, does not damage supply networks, etc. related to other lifelines that are installed outside the installation site of the existing pipe. [Means for solving the problem]

[0006] The notch and cleavage jig for achieving the above object is as follows: A cutting and cleaving tool that is pulled from the rear to the front along a pulling direction along the axis of an existing buried pipe, cuts the inner wall of the existing pipe along the pulling direction to expand the diameter of the existing pipe, and pulls the new pipe connected to the rear into the inside of the existing pipe. The cutting and cleaving tool has the following characteristics: a notch groove forming portion that is pulled toward the front in the pulling direction and forms a notch groove along the pulling direction in the inner wall of the existing pipe; a notch groove cleaving portion that is provided behind the notch groove forming portion in the pulling direction and fits into the notch groove formed by the notch groove forming portion and applies a force in a direction in which a pair of opposing notch surfaces of the notch groove are separated from each other; and an expansion section that is provided rearward of the notched groove cleavage section in the pulling direction and expands the diameter of the existing pipe that has been cleaved at the notched groove cleavage section.

[0007] According to the above characteristic configuration, when cutting open an existing pipe and replacing it with a new pipe, first a notch groove is formed in the inner wall of the existing pipe along the towing direction by the notch groove forming section, and then the notch groove cleaving section fits into the notch groove and applies force in a direction in which the pair of opposing notch surfaces of the notch groove move apart, so that the existing pipe can be cleaved along the notch groove without cutting it with a rotating blade. In other words, according to the above-mentioned characteristic configuration, the existing pipe is split along the notch groove by applying a pressing force to the notch groove by the notch groove cleaving portion, so there is no need to cut the existing pipe with a rotating blade whose cutting edge is exposed from the inside to the outside of the existing pipe, as in the conventional method, and even if there is a supply network related to lifelines around the existing pipe, the existing pipe can be safely split without damaging the supply network, etc. Furthermore, by expanding the diameter of the existing pipe after it has been split using the expansion section provided behind the cut groove split section, the new pipe can be smoothly pulled into the area where the existing pipe was installed. As a result, it is possible to realize a highly safe existing pipe cleaving tool that does not damage the supply networks, etc. related to other lifelines installed outside the installation site of the existing pipe when cutting and expanding the diameter of the existing pipe and replacing it with a new pipe.

[0008] Further characteristic configurations of the notch and cleavage jig include: A cleaving body portion having the notch groove forming portion and pulled in the pulling direction is provided, In a pulling direction view, which is a view along the pulling direction, The splitting body is provided with the notch groove forming portion and a running wheel that runs on the inner wall of the pipe in a direction perpendicular to the pulling direction, the notch groove forming portion and the running wheel are provided in such a way that the main body axis of the splitting body is sandwiched between the notch groove forming portion and the running wheel that runs on the inner wall of the pipe in a direction perpendicular to the pulling direction, In the perpendicular direction, the distance between the tip of the notched groove forming portion that cuts into the inner wall of the pipe and the ground contact portion of the running wheel that touches the inner wall of the pipe is smaller than the outer diameter of the existing pipe.

[0009] According to the above characteristic configuration, in a towing direction view that is a view along the towing direction, the distance between the tip of the notch groove forming part that cuts out the pipe inner wall and the grounding part of the running wheel that touches the pipe inner wall in a direction perpendicular to the towing direction is configured to be smaller than the outer diameter of the existing pipe, so that the tip of the notch groove forming part is not exposed from the inside of the existing pipe to the outside. This makes it possible to suitably prevent damage to a supply network related to a lifeline provided outside the existing pipe by the notch groove forming part when the notch groove forming part forms a notch groove in the inner peripheral wall of the existing pipe.

[0010] Further characteristic configurations of the notch and cleavage jig include: A cleavage body portion having the notch groove cleavage portion and being pulled in the pulling direction is provided, The notch groove cleavage portion is When viewed in the pulling direction, which is a direction along the pulling direction, the cleavage main body has a narrow portion that gradually becomes narrower toward the tip side away from the main body axis in a direction perpendicular to the pulling direction, and has a chamfered portion in which the end portion on the tip side in the perpendicular direction is chamfered; The chamfered portion is provided farther from the main body axis in the orthogonal direction toward the rear side in the pulling direction.

[0011] As described above, when viewed in the pulling direction, which is a direction along the pulling direction, the notch groove cleavage portion has a narrow-shaped portion that gradually narrows in width in a direction perpendicular to the pulling direction toward the tip side away from the main body axis of the cleavage main body portion.Therefore, the narrow-shaped portion of the notch groove cleavage portion gradually fits into the notch groove from the tip side and can be cleaved by pressing against a pair of notch surfaces. Furthermore, the notch groove cleavage portion has a chamfered portion where the end portion on the tip side in the orthogonal direction is chamfered, and the chamfered portion is located farther from the main body axis in the orthogonal direction as it is further rearward in the towing direction. Therefore, as the chamfered portion is pulled from the rear to the front in the towing direction, the notch groove can be cleaved well, and even if the chamfered portion is exposed from the portion where the notch groove is cleaved, the chamfered portion does not have a sharp shape, so that it is possible to prevent damage to the supply network related to the lifeline outside the existing pipe at the chamfered portion.

[0012] Further characteristic configurations of the notch and cleavage jig include: When viewed in the pulling direction, In the perpendicular direction, the notch groove cleavage portion and a running wheel that runs on the inner wall of the pipe are provided on the cleavage main body in a manner sandwiching the main body axis of the cleavage main body, In the perpendicular direction, the distance between the tip chamfer portion of the chamfered portion that is farthest from the main body axis and the ground contact portion of the running wheel that contacts the inner wall of the pipe is greater than the outer diameter of the existing pipe.

[0013] According to the above characteristic configuration, the distance in the orthogonal direction between the tip chamfered portion that is farthest from the main axis among the chamfered portions and the ground contact portion where the running wheel contacts the inner wall of the pipe is greater than the outer diameter of the existing pipe, so that the cutout groove can be properly cleaved by the passage of the tip chamfered portion in the towing direction, while the cutout groove cleavage portion that may be exposed from the cutout groove after being cleaved is chamfered, so that it is possible to effectively prevent damage to the supply network etc. related to the lifeline outside the existing pipe by the exposed portion. [Brief description of the drawings]

[0014] [Figure 1] 1 is a schematic diagram showing a wire blade method for replacing an existing pipe with a new pipe using a notch and cleavage jig according to an embodiment. FIG. [Diagram 2] FIG. 2 is a side view of the notch and cleavage jig according to the embodiment. [Diagram 3] FIG. 2 is a bottom view of the notch and cleavage jig according to the embodiment. [Figure 4] FIG. [Diagram 5] FIG. 13 is a diagram showing the process of cutting and then splitting an existing pipe. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] The notching and cleaving tool according to an embodiment of the present invention is highly safe when cutting and expanding an existing pipe to replace it with a new pipe, without damaging the supply networks, etc. related to other lifelines installed outside the installation site of the existing pipe.

[0016] The notching and cleaving jig 200 according to this embodiment is suitably used in the wire blade method shown in FIG. In the wire blade method, first, as shown in Figure 1(a), a first pit PT1 is formed at one end of the portion of the existing pipe P to be replaced that is buried underground by excavating the ground G and removing the existing pipe P from the excavated portion, and a second pit PT2 is similarly formed at the other end of the portion of the existing pipe P to be replaced.

[0017] 1(b), a traction device 100 that traction the wire W from rear to front in the traction direction (the direction of the arrow Y in FIG. 1) is installed in the first pit PT1, and the base end (the end on the base side of the arrow Y in the traction direction) of the wire W that is installed so as to be towable by the traction device 100 is sent into the inside of the existing pipe P. Note that the tip end (the end on the tip side of the arrow Y in the traction direction) of the wire W after being towed by the traction device 100 is wound around a drum D installed near the first pit PT1 and collected.

[0018] Finally, a notch and cleavage tool 200 that cuts and cleaves the inner wall of the existing pipe P along the pulling direction is connected to the base end of the wire W, and a new pipe PE made of polyethylene or the like is connected behind the notch and cleavage tool 200 in the pulling direction.The wire W is then pulled by a pulling device 100, and the existing pipe P is replaced with the new pipe PE.

[0019] Now, in the above-mentioned wire blade method, when the existing pipe P is cut in the towing direction using a notching and splitting tool, if there are other supply networks related to lifelines (e.g., power lines, communication lines, water pipes, etc.) outside the existing pipe P when the existing pipe P is cut, there is a risk of damaging the power lines, etc. Therefore, as shown in FIG. 1 or FIG. 2, the notch and cleavage jig 200 according to the embodiment is provided in a form in which the jig is pulled from the rear to the front along a pulling direction along the pipe axis (not shown) of the buried existing pipe P, the pipe inner wall Pa of the existing pipe P is cut along the pulling direction to expand the diameter of the existing pipe P, and the new pipe PE connected to the rear is pulled into the inside of the existing pipe P. The jig is pulled forward in the pulling direction to form a notch groove KR (FIG. 5) formed in the existing pipe P, a notch groove opening portion KA is provided behind the notch groove forming portions K1, K2 in the towing direction and fits into the notch groove KR formed by the notch groove forming portions K1, K2 and applies force in a direction in which a pair of opposing cutout surfaces KRa (shown in FIG. 5) of the notch groove KR move apart, and an expansion portion KK is provided behind the notch groove opening portion KA in the towing direction and expands the diameter of the existing pipe P that has been cleaved by the notch groove opening portion KA.

[0020] To further explain, the notch cleaving jig 200 is provided with a wire connection part YK to which the wire W can be connected by crimping at the front end in the towing direction, and the wire connection part YK, the cleavage main body part H, the notch groove cleavage part KA, and the enlarged diameter part KK are provided in the order described from the front to the rear in the towing direction, in a form in which they are connected to each other with bolts B. The enlarged diameter part KK is provided with a connection part R on the rear side in the towing direction for hanging a hook (not shown) provided on the newly installed pipe PE.

[0021] The cleaving body H has an internal space NK extending along the towing direction, and a first rotary blade K1 and a second rotary blade K2 as notch groove forming parts and a notch groove cleaving part KA are provided in the order described from front to rear in the towing direction with a part of the blade being inserted into the internal space NK. The rotation axes of the first rotary blade K1 and the second rotary blade K2 are provided along a first orthogonal direction (the direction of the arrow X in Figs. 2 and 3) that is orthogonal to the towing direction, and the notch groove cleaving part KA is fixed to the cleaving body H by a plurality of bolts B whose bolt axes extend along the first orthogonal direction.

[0022] In the side view shown in Figure 2, the first rotary blade K1 and the second rotary blade K2 are partially exposed from the cleaving main body H to the base end side of the arrow Z in a second orthogonal direction (a direction along the arrow Z in Figure 2: an example of an orthogonal direction) that is perpendicular to both the pulling direction and the first orthogonal direction, and the exposed amount (extension) of the second rotary blade K2 is greater than the exposed amount (extension) of the first rotary blade K1.

[0023] Furthermore, the cleaving main body H is provided with a plurality of traveling wheels T, which are partially exposed on the opposite side (the tip side of the arrow Z in the second orthogonal direction) from the side where the first rotary blade K1 and the second rotary blade K2 are exposed (the base end side of the arrow Z in the second orthogonal direction) in the side view shown in Fig. 2. The plurality of traveling wheels T are rotatable while being placed on the inner pipe wall Pa of the existing pipe P with their ground contact parts Ta, and in this embodiment, three traveling wheels are provided at equal intervals in the towing direction, and the amount of exposure (protrusion) from the cleaving main body H is all the same.

[0024] That is, in the side view shown in Figure 2 (or the towing direction view, which is a view in the direction along the towing direction), the cleaving main body H has, in the first orthogonal direction, the first and second rotating blades K1 and K2, which are notch groove forming parts, and the running wheel T, which are arranged on either side of the main body axis H1 of the cleaving main body H, and in the second orthogonal direction, the distance L1 between the tip K2a of the second rotating blade K2, which cuts out the pipe inner wall Pa, and the ground contact portion Ta of the running wheel T, which contacts the pipe inner wall Pa, is configured to be smaller than the outer diameter (not shown) of the existing pipe P. This prevents the second rotating blade K2, which is a notch groove forming portion and has a particularly large protrusion, from being exposed to the outside of the existing pipe P when it forms the notch groove KR (shown in Figure 5) in the inner wall Pa of the existing pipe P and damaging lifelines such as power lines outside the existing pipe P.

[0025] The notch groove cleavage portion KA has a flat plate shape, a portion of which is fitted into the internal space NK formed in the cleavage main body portion H along the towing direction, as shown in Figure 2, Figure 3, or Figure 4. In the side view shown in Figure 2 (or the towing direction view, which is a view along the towing direction (shown in Figure 4)), it has a narrow-shaped portion KA2 that gradually becomes narrower toward the tip side away from the main body axis H1 of the cleavage main body portion H in a second orthogonal direction (direction along arrow Z: an example of the orthogonal direction) perpendicular to the towing direction, and has a chamfered portion KA1 in which the end portion on the tip side in the second orthogonal direction is chamfered, and the chamfered portion KA1 is arranged in a form in which it is further away from the main body axis H1 in the second orthogonal direction as it moves further rearward in the towing direction.

[0026] To further explain, in the second orthogonal direction, the notch groove cleavage portion KA and the running wheel T are provided on the cleavage main body portion H in such a way that they sandwich the main body axis H1 of the cleavage main body portion H, and in the second orthogonal direction, the distance (L2 in Fig. 2) between the tip chamfered portion KA1a (the rearmost portion of the chamfered portion KA1 in the towing direction) which is the furthest from the main body axis H1 of the chamfered portion KA1 and the ground contact portion Ta of the running wheel T which contacts the pipe inner wall Pa is configured to be larger than the outer diameter of the existing pipe P. The outer diameter of the enlarged diameter portion KK is configured to be even larger than the distance (L2 in Fig. 2) between the tip chamfered portion KA1a and the ground contact portion Ta of the running wheel T which contacts the pipe inner wall Pa. Although detailed illustration is omitted, in order to prevent damage to power lines and the like outside the existing pipe P, the corner KA3 at the boundary between the narrow-width portion KA2 and the chamfered portion KA1 is chamfered as shown in Figure 4.

[0027] Hereinafter, the process of cutting and cleaving the inner wall Pa of the existing pipe P will be described with reference to FIG. When the notch and cleaving tool 200 is pulled into the interior of the existing pipe P by the traction device 100, as shown in Figure 5(a), first, a notch groove KR is formed in the inner wall Pa of the existing pipe P by the first rotary blade K1 and the second rotary blade K2 (only K2 is shown in Figure 5(a)) which serve as notch groove forming parts. Furthermore, as the notch cleaving jig 200 is pulled further, as shown in Figure 5 (b), the notch groove cleaving portion KA fits into the formed notch groove KR, and the narrow-shaped portion KA2 presses the pair of opposing notch surfaces KRa of the notch groove KR in a direction separating them, separating the pair of notch surfaces KRa. Furthermore, as the notch opening and splitting jig 200 is pulled further, the tip chamfered portion KA1a of the chamfered portion KA1 is exposed to the outside of the existing pipe P, and the pair of notch surfaces KRa are pushed wide open by the narrow-shaped portion KA2, as shown in Figure 5(c), thereby splitting the existing pipe P. Thereafter, the existing pipe P, which has been split by the notch and splitting jig 200, is expanded in diameter by the expanded diameter portion KK, and the new pipe PE is pulled in.

[0028] [Another embodiment] (1) In the above embodiment, the notch groove forming portions K1 and K2 are configured by two rotary blades having different rotation diameters. However, the notch groove forming portions K1 and K2 may be formed of one rotary blade, or may be formed of three or more rotary blades. Furthermore, the pair of rotary blades may have the same diameter, and may have the same protrusion from the cleaving main body H in the side view shown in FIG.

[0029] Furthermore, the configurations disclosed in the above embodiments (including other embodiments, the same applies below) can be applied in combination with configurations disclosed in other embodiments, provided that no contradiction arises. Furthermore, the embodiments disclosed in this specification are merely examples, and the embodiments of the present invention are not limited thereto, and can be appropriately modified within the scope that does not deviate from the purpose of the present invention. [Industrial Applicability]

[0030] The existing pipe splitting tool of the present invention can be effectively used as a highly safe existing pipe splitting tool that does not damage supply networks, etc. related to other lifelines installed outside the installation site of the existing pipe when cutting and expanding the diameter of the existing pipe and replacing it with a new pipe. [Explanation of symbols]

[0031] 100: Traction device 200: Notch and cleavage jig H: Cleavage main body H1: Body axis K1: Notched groove forming section K2a: Tip KA: Notched groove cleavage section KA1: Chamfered area KA1a: Tip chamfering area KA2: Narrow shape part KK: Expanded diameter part KR: Notched groove KRa: Notch surface P: Existing pipe Pa: pipe inner wall Ta: Grounding part W: Wire

Claims

1. A cutting and cleaving tool that is pulled from the rear to the front along a pulling direction along the axis of an existing buried pipe, cuts an inner wall of the existing pipe along the pulling direction to expand the diameter of the existing pipe, and pulls a new pipe connected to the rear into the inside of the existing pipe, a notch groove forming portion that is pulled toward the front in the pulling direction and forms a notch groove along the pulling direction in the inner wall of the existing pipe; a notch groove cleaving portion that is provided behind the notch groove forming portion in the pulling direction and fits into the notch groove formed by the notch groove forming portion and applies a force in a direction in which a pair of opposing notch surfaces of the notch groove are separated from each other; a notch and cleaving jig provided behind the notch and cleaving portion in the pulling direction and configured to enlarge the diameter of the existing pipe cleaved at the notch and cleaving portion.

2. A cleaving body portion having the notch groove forming portion and pulled in the pulling direction is provided, In a pulling direction view, which is a view along the pulling direction, The splitting body is provided with the notch groove forming portion and a running wheel that runs on the inner wall of the pipe in a direction perpendicular to the pulling direction, the notch groove forming portion and the running wheel are provided in such a way that the main body axis of the splitting body is sandwiched between the notch groove forming portion and the running wheel that runs on the inner wall of the pipe in a direction perpendicular to the pulling direction, A notch and cleavage jig as described in claim 1, wherein the distance in the perpendicular direction between the tip of the notch groove forming portion that cuts into the inner wall of the pipe and the ground contact portion of the running wheel that contacts the inner wall of the pipe is smaller than the outer diameter of the existing pipe.

3. A cleavage body portion having the notch groove cleavage portion and being pulled in the pulling direction is provided, The notch groove cleavage portion is When viewed in the pulling direction, which is a direction along the pulling direction, the cleavage main body has a narrow portion that gradually becomes narrower toward the tip side away from the main body axis in a direction perpendicular to the pulling direction, and has a chamfered portion in which the end portion on the tip side in the perpendicular direction is chamfered; The notch and cleavage jig according to claim 1 or 2, wherein the chamfered portion is provided farther from the main body axis in the orthogonal direction toward the rear side in the pulling direction.

4. When viewed in the pulling direction, In the perpendicular direction, the notch groove cleavage portion and a running wheel that runs on the inner wall of the pipe are provided on the cleavage main body in a manner sandwiching the main body axis of the cleavage main body, A notch and cleavage jig as described in claim 3, wherein the distance in the perpendicular direction between the tip chamfered portion of the chamfered portion that is farthest from the main body axis and the ground contact portion of the running wheel that contacts the inner wall of the pipe is greater than the outer diameter of the existing pipe.

Images