JP7485563B2 - Pipe cutting method and device - Google Patents

Description

The present invention relates to a pipe cutting method and device that uses a cutter to cut a fluid pipe without interrupting the flow inside a housing that hermetically encloses the fluid pipe.

In the conventional pipe cutting method, in which a fluid pipe is cut with a cylindrical cutter in a state where the fluid flow is uninterrupted inside a housing that hermetically encloses the fluid pipe, the fluid pipe is cut and divided in the axial direction of the pipe with a cylindrical cutter of the smallest diameter possible inside a housing that is small and lightweight in order to simplify the construction.

JP2006-515406A (page 6, Figures 1-5)

However, in Patent Document 1, the housing attached to the fluid pipe is designed to be small and lightweight, and its extension dimension is therefore short. This means that the housing is unable to provide sufficient support for the fluid pipe on both sides of the cutter, and as the cylindrical cutter advances in the pipe diameter direction to cut the fluid pipe, the area near the cut part of the fluid pipe may be pressed by the cutter and elastically deformed so as to sink, or the fluid pipe may tilt. In reaction to this, the cutter may bite into the cut part of the fluid pipe, subjecting it to excessive load, which not only causes malfunctions, but also makes it difficult to ensure sealing, raising the risk of fluid leakage.

The present invention was made with a focus on these problems, and aims to provide a pipe cutting method and device that can stably support a fluid pipe and maintain a high level of sealing when cutting the fluid pipe with a cutter inside a housing, while carrying out the intended cutting process.

In order to solve the above problems, the pipe cutting method of the present invention comprises the steps of:
A pipe cutting method for cutting a fluid pipe in an uninterrupted flow state using a pipe cutting device including a housing that hermetically surrounds the fluid pipe and a cutter that cuts the fluid pipe in the housing, comprising:
This method is characterized by having an attachment process for attaching a support member to the fluid pipe, the support member consisting of a pair of attachment parts attached to the fluid pipe at a position sandwiching the housing in the pipe axis direction and an extension part spanning the attachment parts and extending in the pipe axis direction, and a cutting process for cutting the fluid pipe with the cutter inside the housing.
According to this feature, by attaching a support member consisting of a pair of mounting parts that sandwich the housing attached to the fluid pipe in the pipe axis direction and an extension part that spans between these mounting parts in the installation process, the fluid pipe to be cut by the cutter within this housing can be stably supported along the pipe axis direction, so that the fluid pipe can be cut without placing an excessive load on the cutter in this cutting process and while maintaining high sealing performance.

The support member is attached to the fluid pipe spaced apart from a support surface surrounding the fluid pipe.
According to this feature, the support member can support the fluid pipe by the extension portion that bridges the pair of mounting portions in the pipe axial direction, without receiving a supporting force from the surrounding support surfaces.

After the cutting step, a valve member capable of opening and closing the pipe flow path is disposed in the housing.
According to this feature, the installation of the valve member can be completed while maintaining a stable support state of the fluid pipe by the support member.

After the cutting step, the support member is removed from the fluid pipe.
According to this feature, by removing the support member from the fluid pipe after cutting, the surroundings of the housing attached to the fluid pipe can be simplified and the removed support member can be reused.

The mounting step is carried out after the housing is fitted onto the fluid pipe.
According to this feature, the installation process of the support member can be carried out after the housing that surrounds the cut portion of the fluid pipe is fitted, which not only makes installation easier but also improves the accuracy of the installation position.

In order to solve the above problems, the tube cutting device of the present invention comprises:
A pipe cutting device that cuts a fluid pipe in an uninterrupted flow state, the pipe cutting device comprising: a housing that hermetically surrounds a fluid pipe; and a cutter that cuts the fluid pipe in the housing,
The fluid pipe is characterized by having a support member consisting of a pair of mounting portions that are attached to the fluid pipe at positions that sandwich the housing in the pipe axis direction, and an extension portion that spans between the mounting portions and extends in the pipe axis direction.
According to this feature, by attaching a support member consisting of a pair of mounting parts that sandwich the housing attached to the fluid pipe in the pipe axis direction and an extension part that spans between these mounting parts, the fluid pipe being cut by the cutter within this housing can be stably supported along the pipe axis direction, so that the fluid pipe can be cut without placing excessive load on the cutter and while maintaining high sealing performance.

Each of the pair of mounting portions has a divided structure and is characterized by being composed of at least a first divided portion provided with the extension portion, and a second divided portion connected to the first divided portion.
According to this feature, since the mounting portion has a divided structure, it can be easily mounted at any position on the fluid pipe.

The first divided portion and the extension portion are integrally formed.
According to this feature, the pair of first divided portions and the extension portion are integrally formed, so that the rigidity of the support member can be increased.

The support member is characterized by having a plurality of second divided portions each having an inner surface corresponding to an outer surface of a different fluid pipe.
According to this feature, the second divided portion can be appropriately selected in accordance with the outer surface of the fluid pipe, thereby increasing the versatility of the support member.

1 is a partially sectional front view showing a state in which a housing and a support member in Example 1 are attached to an existing fluid pipe. FIG. FIG. 2 is a plan view similar to FIG. FIG. 2 is a side view similar to FIG. 11 is a front cross-sectional view showing a state in which a fixing flange is attached to a housing. FIG. 1 is a front cross-sectional view showing the state in which an operating valve and a drilling device are attached to a housing. 11 is a front cross-sectional view showing the state in which the existing fluid pipe has been cut with a cutter. FIG. 4 is a front cross-sectional view showing a state in which the valve member insertion device is attached to the housing. FIG. 4 is a front cross-sectional view showing a state in which a valve member is inserted into a housing. FIG. FIG. 9 is a side cross-sectional view similar to FIG. 4 is a front cross-sectional view showing the operating valve and the valve member insertion device removed from the housing. FIG. FIG. 4 is a side view showing a state in which the fixing flange is removed from the housing. 11 is a front cross-sectional view showing a state in which a support member is being removed from a housing. FIG. FIG. 2 is a front cross-sectional view showing the valve device. FIG. 14 is a side view similar to FIG. FIG. 13 is a front view showing a support member of the first modified example. FIG. 16 is a plan view similar to FIG. FIG. 16 is a side view similar to FIG. 13 is a side view showing another aspect of the support member of the first modified example. FIG. FIG. 11 is a front view showing a support member of a second modified example. FIG. 20 is a side view similar to FIG. FIG. 13 is a front view showing a support member of a third modified example. FIG. 22 is a side view similar to FIG.

The embodiment for implementing the pipe cutting method and device according to the present invention will be described with reference to Figures 1 to 22.

As shown in Figure 5, the pipe cutting device 1 according to the present invention is mainly composed of a housing 4 that hermetically surrounds an existing fluid pipe 2 (hereinafter simply referred to as fluid pipe 2), a support member 3 that is fixedly attached to the fluid pipe 2 at an installation position that sandwiches the housing 4 in the pipe axial direction, and a drilling device 70 that is connected above the housing 4 via an operating valve 60. Note that in the present invention, cutting a fluid pipe means dividing the fluid pipe 2 inside the housing 4 in the pipe axial direction, i.e., completely cutting the fluid pipe 2.

Here, the fluid pipe 2 is made of, for example, ductile cast iron for water supply buried underground, is formed in a substantially circular cross section, and has an inner circumferential surface coated with an epoxy resin layer. The fluid pipe according to the present invention may be made of other metals such as cast iron and steel, or made of concrete, polyvinyl chloride, polyethylene, or polyolefin. Furthermore, the inner circumferential surface of the fluid pipe is not limited to an epoxy resin layer, and may be coated with, for example, mortar, or an appropriate material may be coated on the inner circumferential surface of the fluid pipe by powder coating. In addition, the fluid in the fluid pipe in this embodiment is water supply, but it is not limited to water supply in this embodiment, and may be, for example, industrial water, agricultural water, sewage, gas, or a gas-liquid mixture of gas and liquid. The materials of the housing 4 and the valve member 5 may also be compatible with the above.

As shown in Figures 1 to 3, the housing 4 attached to the outer periphery of the fluid pipe 2 is a so-called split T-shaped pipe, and is structured to be divided into an upper housing part 41 and a lower housing part 42 in the radial direction of the fluid pipe 2 (vertical direction in this embodiment). In addition, on both sides of the axial direction of the housing 4, there are provided anti-detachment fittings 6, 6 that prevent the fluid pipe 2 from coming off. The anti-detachment fittings 6 are structured to be divided in the radial direction (vertical direction in this embodiment), and the inner peripheral part of the anti-detachment fittings 6 that contact the outer surface of the fluid pipe 2 has anti-detachment claws 6b built in along the circumferential direction. When the anti-detachment fittings 6 are attached, the anti-detachment claws 6b bite into the outer surface of the fluid pipe 2, preventing the fluid pipe 2 from coming off.

The upper housing portion 41 is formed with a neck portion 41a, a flange portion 41b connected to the neck portion 41a, and a housing opening portion 41d connected to the flange portion 41b and communicating with the inside of the housing. A drilling device 70 (see Figures 5 and 6), a valve member insertion device 80 (see Figures 7 to 9), etc. can be attached to the flange portion 41b via a fixed flange 51 and an operating valve 60, which will be described later.

The lower housing part 42 has a bowl-shaped housing bottom 42d, and a discharge hole 42b is formed in the center of the housing bottom 42d. A valve 49 equipped with an openable and closable discharge port 49a can be connected to the discharge hole 42b, and by operating the valve 49 as described below, cutting chips generated when the fluid pipe 2 is cut can be discharged together with the fluid via the discharge hole 42b and the discharge port 49a.

In this embodiment, the housing is described as an upper part 41, a lower part 42, etc., but the direction in which the housing is divided is not limited to the top and bottom, and may be, for example, horizontal or inclined at a predetermined angle. The number of divisions of the housing may be three or more. Similarly, the piping direction of the fluid pipe 2 is not limited to the horizontal, and may be, for example, vertical. Furthermore, the cutting direction of the cutter 72 described below is not limited to the top and bottom, and may be, for example, horizontal. In the following embodiment, an example is described in which the cutter 72 is a cylindrical cutter such as a hole saw, which has good work efficiency, but as long as it is a cutter that divides the fluid pipe 2 in the axial direction inside the housing 4, for example, a wire saw, end mill, or cutting tool may be used.

Next, the support member 3 of this embodiment will be described. As shown in Figures 1 to 3, the support member 3 is mainly composed of a pair of mounting parts 31, 32 that are attached to the outer circumferential surface of the fluid pipe 2 on both sides of the housing 4 and the anti-detachment fittings 6, 6 in the axial direction, and a number of extension parts 33, 33 that span between the mounting parts 31, 32 and extend in the axial direction like a shaft.

One of the mounting parts 31 is formed in a substantially cylindrical shape with an inner surface that contacts the outer surface of the fluid pipe 2, and has a structure divided in the radial direction of the fluid pipe 2 (in the present embodiment, the vertical direction, but it may be horizontal or oblique), and is composed of an upper mounting part 31a and a lower mounting part 31b that are connected to each other across the fluid pipe 2. The other mounting part 32 has the same shape as the mounting part 31 and is composed of an upper mounting part 32a and a lower mounting part 32b. Here, the lower mounting parts 31b and 32b in this embodiment constitute the first divided part of the present invention, and the upper mounting parts 31a and 32a constitute the second divided part of the present invention. In this way, since the mounting parts 31 and 32 have a divided structure, they can be easily attached to any position of the fluid pipe 2. Note that the inner surface of the mounting parts 31 and 32 that face the outer surface of the fluid pipe 2 may be formed with uneven parts to prevent slipping. Also, a member similar to the above-mentioned anti-detachment claw 6b may be installed inside the mounting parts 31 and 32 (the same may be done for the support member of the modified example described later).

The pair of lower mounting parts 31b, 32b and the two extension parts 33, 33 in this embodiment have an integral structure. In detail, on the lower surface of each lower mounting part 31b, 32b near the housing 4, plate-shaped flange parts 35, 35 extending outwardly and obliquely downward are provided so as to face each other in the tube axis direction, and both ends of each extension part 33, 33 are fixed by welding or the like in a state where they penetrate these flange parts 35, 35. That is, the lower mounting parts 31b, 32b and the extension parts 33, 33 in this embodiment are integrally configured. In this way, the rigidity of the support member 3 can be increased. However, this is not limited to this, and the extension parts 33, 33 and the lower mounting parts 31b, 32b may be configured separately and detachably attached by bolts or the like.

As shown in Figures 1 and 3, the extensions 33, 33 of this embodiment are arranged at approximately the same height as the lower part of the housing 4, and extend approximately symmetrically about the fluid pipe 2, approximately parallel to sandwich the housing 4 on both sides. This allows the support member 3 to support the fluid pipe 2 evenly and without bias.

Furthermore, multiple reinforcing ribs 36a, 36a are provided along the circumferential direction at both ends of the extension portion 33 and are fixed to the inner surface of the flange portion 35, 35 by welding or the like. Furthermore, reinforcing ribs 36b, 36b are provided between the outer surface of the flange portion 35, 35 and the lower surface of the lower mounting portion 31b, 32b. The extension portion 33 is configured as a relatively thick, hollow, approximately cylindrical shape with a roughly circular cross section, and further, in combination with the reinforcing ribs 36a, 36b described above, it has a high structural strength that is less prone to bending, etc.

The upper mounting parts 31a, 32a and the lower mounting parts 31b, 32b are removably attached to any position on the outer periphery of the fluid pipe 2 by fastening bolts and nuts 34 that are inserted between the opposing flange parts.

As shown in Figures 1 and 2, the pair of mounting portions 31, 32 constituting the support member 3 are spaced apart in the pipe axial direction without contacting the housing 4 and the anti-detachment fittings 6, 6. Similarly, the extension portions 33, 33 are spaced apart in the pipe radial direction without contacting the housing 4 and the anti-detachment fittings 6, 6. Furthermore, the support member 3 is attached to the fluid pipe 2 in a spaced apart state without contacting the supporting surfaces around the fluid pipe 2, such as the original ground, excavated ground, the underside and side of a retaining wall or structure (not shown), i.e., without receiving any supporting force from these supporting surfaces.

The fixed flange 51, working valve 60, and drilling device 70 are described below. As shown in Figures 4 to 10, with the housing 4 and support member 3 hermetically attached to the fluid pipe 2, the fixed flange 51, working valve 60, and drilling device 70 are attached to the flange portion 41b of the housing upper part 41.

As shown in FIG. 4, a seal member 53 is inserted between the fixed flange 51 and the flange portion 41b. Inside the fixed flange 51, a protrusion 51a is formed that protrudes inward in the circumferential direction, and a plurality of support pins 54 are attached to the lower part of the fixed flange 51 in a sealed manner in the radial direction at a predetermined interval in the circumferential direction, and the flange portion 41b of the upper part of the housing 41 and the seal member 53 are clamped from above and below by these protrusions 51a and support pins 54, so that the fixed flange 51 can be fixed to the housing 4 in a sealed manner. In addition, a plurality of fixing pins 52 are attached to the upper part of the fixed flange 51 in a sealed manner in the radial direction at a predetermined interval in the circumferential direction (see FIG. 9), so that the valve member 5 can be temporarily fixed when the valve member 5 is inserted into the housing 4, as described later.

As shown in FIG. 5, a seal member 63 is inserted between the joint surface of the working valve housing 61 of the working valve 60 and the fixed flange 51, and the joint surface is fastened by a bolt (not shown), thereby sealing the working valve 60 and the fixed flange 51. A working valve body 62 is attached in a sealed manner to the working valve housing 61 of the working valve 60, and the working valve body 62 is capable of sliding horizontally to open and close the space between the housing 4 and the drilling device 70.

A seal member 73 is inserted between the joint surface between the drilling device 70 and the working valve 60 and is fastened with a bolt 74, thereby sealing the gap between the drilling device 70 and the working valve 60. Furthermore, the drilling device 70 has a cutter 72 attached to a cutter shaft 75 attached to a drilling device housing 71 in a sealed manner so as to be movable up and down and rotatable. The cutter 72 and cutter shaft 75 can be driven up and down and rotated from outside the drilling device 70 by a drive device (not shown).

The process for installing the pipe cutting device 1, the process for cutting the fluid pipe 2, and the process for installing the valve member 5 are described below.

First, the installation process of the pipe cutting device 1 will be described. First, the area of the pipeline in which the fluid pipe 2 is configured, where the fluid pipe 2 is to be cut and the valve member 5 is to be installed (described later), is excavated to expose that area. The excavation depth is such that the support member 3 located below the housing 4 can be separated from the excavated ground without coming into contact with it, allowing installation and removal work to be performed. The outer peripheral surface of the exposed fluid pipe 2 is cleaned to remove any attached matter.

Next, as shown in Figures 1 to 3, the housing 4 is attached to the fluid pipe 2. More specifically, the fluid pipe 2 is sandwiched between the upper and lower housing parts 41 and 42 that constitute the housing 4, and these upper and lower housing parts 41 and 42 are fastened together by fastening bolts 43 inserted through opposing flanges. Sealing members 45 are provided on the opposing surfaces of the upper and lower housing parts 41 and 42, and on the inner surface that contacts the outer surface of the fluid pipe 2, and the housing 4 is attached to the fluid pipe 2 at a predetermined position in a sealed manner.

Next, the anti-detachment fittings 6, 6 are attached to both ends of the housing 4 in the tube axis direction. More specifically, the divided members 6a, 6a that make up the anti-detachment fitting 6 are fitted onto the ends of the housing 4 and are fitted over the fluid pipe 2 so as to sandwich it from above and below, and these divided members 6a, 6a are fastened together by fastening bolts 6d inserted through the flanges that face each other. This fastening causes the anti-detachment claws 6b attached inside the anti-detachment fitting 6 to bite into the outer surface of the fluid pipe 2, preventing the fluid pipe 2, which is cut as described below, from detaching from the housing 4.

Next, the support member 3 is attached so as to sandwich the above-mentioned housing 4 and the anti-detachment fittings 6, 6 in the pipe axial direction. In detail, the upper mounting parts 31a, 32a constituting the support member 3, the lower mounting parts 31b, 32b and the extension parts 33, 33 that are integrally formed are fitted to the fluid pipe 2 so as to sandwich it from above and below, and these mounting parts are fastened with the bolts and nuts 34 that face each other. By this fastening, the support member 3 is fixedly and detachably attached to the fluid pipe 2. At this time, the bolts and nuts 34 of the upper mounting parts 31a, 32a and the lower mounting parts 31b, 32b that constitute one of the pair of mounting parts 31, 32 may be loosely attached and attached so as to cover the fluid pipe 2. In this way, by performing the installation process of the support member 3 after fitting the housing 4 that surrounds the cut part of the fluid pipe 2, not only can the construction be easily performed, but the accuracy of the mounting position of the support member 3 can be improved.

Next, as shown in FIG. 4, guide pins 56 with tapered tips facing upward are removably attached in the circumferential direction to each of the multiple through holes formed in the flange portion 41b in the vertical direction. In addition, the fixed flange 51 is hermetically attached to the flange portion 41b of the housing 4, and further, as shown in FIG. 5, the working valve 60 and the drilling device 70 are hermetically attached in order from the bottom.

In this embodiment, the support member 3 is attached after the housing 4 and the anti-detachment fittings 6, 6 are attached to the fluid pipe 2, and then the fixed flange 51, the working valve 60, and the drilling device 70 are attached to the housing 4, but the order in which the support member 3 is attached is not limited to this. For example, the support member 3 may be attached to the fluid pipe 2 before the housing 4 is attached or before the anti-detachment fittings 6, 6 are attached, or the support member 3 may be attached to the fluid pipe 2 after the fixed flange 51, the working valve 60, and the drilling device 70 are attached to the housing 4.

Next, the process of cutting the fluid pipe 2 will be described. As shown in Figures 5 and 6, the cutter 72 cuts the fluid pipe 2 without interrupting the flow with the working valve body 62 open. Since the cutter 72 is cylindrical, the cut part of the fluid pipe 2 is formed in an arc shape along the cylindrical cutter 72 when viewed from the cutter shaft 75. In order to simplify this process, the housing 4 is made small and lightweight, and the cutter 72 moving through the housing 4 is formed in a cylindrical shape with a diameter at least larger than the fluid pipe 2, but as small as possible. The cutting chips generated when cutting the fluid pipe 2 are discharged together with the fluid by operating the valve 49 attached to the discharge hole 42b provided in the center of the lower part 42 of the housing.

As shown in FIG. 6, the fluid pipe 2 is gradually cut from its top by the cutter 72 that moves downward while rotating, and as a result, a downward pressure force is applied to the fluid pipe 2. However, as described above, the fluid pipe 2 is supported by the support members 3 fixed to the fluid pipe 2 on both sides of the housing 4 in the axial direction, so that the fluid pipe 2 does not sink downward during the cutter 72 cutting in the axial direction, and maintains an approximately straight shape in the axial direction.

As a result, the internal seal of the housing 4 is maintained at a high level, and the cutter 72 is not subjected to excessive load from the fluid pipe 2 being cut, allowing the cutter 72 to cut accurately and easily as designed.

Furthermore, even when the fluid pipe 2 is completely cut by the cutter 72, that is, when it is divided in the pipe axial direction, as shown in FIG. 6, the extension portion 33 is bridged across the mounting portions 31, 32 of the support member 3 attached to the divided fluid pipes 2, 2, so that the linearity of the fluid pipes 2, 2 is maintained. Therefore, even after the cutting process, the valve member described later can be inserted while maintaining the sealing property inside the housing 4. In this way, according to the pipe cutting method and pipe cutting device 1 of the present invention, by attaching the support member 3 consisting of a pair of mounting portions 31, 32 that sandwich the housing 4 attached to the fluid pipe 2 in the pipe axial direction and the extension portion 33 that is bridged between these mounting portions 31, 32 in the mounting process, the fluid pipe 2 cut by the cutter 72 in this housing 4 can be stably supported along the pipe axial direction, so that the fluid pipe 2 can be cut in this cutting process without applying an excessive load to the cutter 72 and while maintaining high sealing property.

In addition, since the support member 3 is attached to the fluid pipe 2 at a distance from the support surface, such as the original ground surrounding the fluid pipe 2, the excavated ground, or the underside or side of a retaining wall or structure, the support member 3 can support the fluid pipe 2 by the extension portion 33 that spans the pair of mounting portions 31, 32 in the pipe axial direction without receiving support force from the support surface, regardless of the surrounding environment.

After the fluid pipe 2 is cut, the cutter 72 is raised, closing the working valve body 62 in the working valve housing 61, and sealing the space between the housing 4 and the drilling device 70. The fluid in the drilling device 70 is then discharged, and the drilling device 70 is removed from the working valve 60, completing the cutting process of the fluid pipe 2.

Next, the installation process of the valve member 5 will be described. As shown in FIG. 7, the valve member insertion device 80 is attached in a sealed manner to the top of the working valve 60. This valve member insertion device 80 includes an insertion device housing 86, an insertion shaft 87, and a holding portion 83 that holds the valve member 5 attached to one end of the insertion shaft 87 by a mounting bolt 88. The other end of the insertion shaft 87 includes a threaded portion 89 that is screwed into the insertion shaft 87, and a handle 90 for rotating the threaded portion 89. The handle 90 can be rotated to raise and lower the insertion shaft 87, allowing the valve member 5 to be inserted into and removed from the housing 4.

8 and 9, when the handle 90 is rotated to lower the insertion shaft 87 and insert the valve member 5 into the housing 4, the guide pin 56 provided on the flange portion 41b of the housing 4 is inserted along the insertion hole formed in the outer lid 5d of the valve member 5, and the valve member 5 is guided relative to the housing 4 and set in a predetermined position. Next, as shown in FIG. 9, the fixing pin 52 provided on the fixing flange 51 is screwed in, and the inclined surface formed on the outer periphery of the outer lid 5d of the valve member 5 is temporarily fixed by the fixing pin 52. Thereafter, the fluid in the valve member insertion device 80 is discharged, the insertion device cover 84 is removed, the mounting bolt 88 connecting the holding portion 83 and the insertion shaft 87 is removed from the working hole 85, the valve member insertion device 80 is removed from the working valve 60, and then the holding portion 83 of the valve member insertion device 80 is removed from the valve member 5. Furthermore, the working valve 60 is removed from the fixing flange 51 (see FIG. 10).

Next, as shown in FIG. 11, the guide pin 56 is removed from the through hole of the flange portion 41b, and instead, a bolt and nut 57 is fastened through the through hole and the insertion hole of the outer cover 5d of the valve member 5. In this way, the valve member 5 is fixed to the housing 4. After that, the fixing pin 52 and the support pin 54 are loosened (see FIG. 9), and the fixing flange 51 is removed from the housing 4.

10, the valve member 5 as an insert inserted into the housing 4 after the fluid pipe 2 is cut includes a valve cover 5a that closes the housing opening 41d of the housing 4, an outer cover 5d that is connected to the flange portion 41b of the housing 4 as described above, a valve seat body 5b having a valve seat hole 5f, a valve body 5v that opens and closes the valve seat hole 5f, a valve operating shaft 5j that is connected to the upper part of the valve body 5v, and a sealing member 5e that seals between the valve seat body 5b and the housing 4. The valve device is such that the valve member 5 is inserted into the housing 4 in a sealed manner, and the valve operating shaft 5j is rotated to move the valve body 5v, so that the valve body 5v can open and close the valve seat hole 5f provided in the valve seat body 5b to control the flow of the fluid pipe 2. However, the seal between the valve body 5v and the valve seat body 5b is not limited to a packing, and may be, for example, a metal-to-metal seal.

When installing the valve member 5, the valve body 5v is raised to the top to open the valve seat hole 5f (see Figure 10). By doing this, not only can the flow path in the fluid pipe 2 be maintained without being blocked even when the valve member 5 is installed, but the valve member 5 itself is not subjected to a large fluid pressure, and can be easily installed while maintaining a separation between the valve member 5 and the cut surface of the fluid pipe 2. In addition, by installing the valve member 5 with the support member 3 attached to the fluid pipe 2, installation of the valve member 5 can be completed while maintaining a stable support state of the fluid pipe 2 by the support member 3.

Next, as shown in Figure 12, the support member 3 is removed from the fluid pipe 2. In this way, the support member 3 can be removed from the fluid pipe 2, so that the support member 3 is left on both sides of the housing 4, simplifying the area around the housing 4 without deterioration over time, and the removed support member 3 can be reused, for example, by attaching it to the construction site of another fluid pipe.

After removing the support member 3, the pressure applied when closing the valve body 5v of the valve member 5 can be received by the anti-detachment fittings 6, 6, so the support member 3 can be removed as described above.

As shown in Figures 13 and 14, the valve 49 is removed from the exhaust hole 42b of the housing 4, and a plug 48 is installed in its place. Note that the valve 49 may be removed prior to the support member 3, provided that the seal between the inner bottom of the housing 4 and the valve seat body 5b has been confirmed.

Finally, although not specifically shown, the fluid pipe 2, the housing 4, and the valve member 5 are backfilled from the state shown in Figs. 13 and 14. Note that, if necessary, a jack or the like may be placed between the lower part of the housing 4 and the excavated ground before backfilling.

Next, modified examples of the support member according to the present invention will be described with reference to Figures 15 to 22. Note that explanations of the same configuration as the previous embodiment will be omitted.

First, the support member 103 of the first modified example will be described. As shown in Figures 15 and 16, the support member 103 is mainly composed of a pair of mounting parts 131, 132 attached to the outer circumferential surface of the fluid pipe 2 at both sides sandwiching the housing 4 and the anti-detachment fittings 6, 6 in the pipe axial direction, and a number of extension parts 133, 133 that are bridged between these mounting parts 131, 132 and extend in the pipe axial direction.

One of the mounting parts 131 has a structure divided into an upper mounting part 131a formed in a substantially semi-cylindrical shape with an inner surface that contacts the outer surface of the fluid pipe 2, and a lower mounting part 131b consisting of hollow rectangular columnar tubes 138, 138 that are approximately square in cross section and extended in a direction perpendicular to the pipe axis and arranged in parallel in the pipe axis direction, and are connected to each other across the fluid pipe 2. The other mounting part 132 has the same shape as the mounting part 131 and is composed of an upper mounting part 132a and a lower mounting part 132b. Here, the lower mounting parts 131b, 132b of this modified example constitute the first divided part of the present invention, and the upper mounting parts 131a, 132a and the upper mounting part 131a' described later constitute the second divided part of the present invention. In this way, since the mounting parts 131, 132 have a divided structure, they can be easily attached to any position of the fluid pipe 2.

In addition, the lower mounting portion 131b of this modified example is configured by arranging two rectangular columnar tubes 138 side by side in the tube axis direction, but the lower mounting portion is not limited to this, and may be configured by arranging only one rectangular columnar tube or three or more rectangular columnar tubes side by side. In addition, the cross-sectional shape of the rectangular columnar tube that constitutes the lower mounting portion of this modified example is not limited to being approximately square, but may be rectangular, or may be cylindrical instead of being rectangular, and may be solid instead of being hollow.

The pair of lower mounting parts 131b, 132b and, in this embodiment, the two extension parts 133, 133 have separate structures fastened by fastening members 135. In more detail, fastening bolts constituting the fastening members 135 are inserted through through holes formed in the left and right ends of the lower mounting parts 131b, 132b in the vertical direction and through holes formed in the both ends in the axial direction of the extension part 133 in the vertical direction, and nuts are fastened to the fastening bolts, thereby connecting the pair of lower mounting parts 131b, 132b and the two extension parts 133, 133 in a fixed manner.

As shown in Figures 15 and 17, the extensions 133, 133 of this modified example are arranged at approximately the same height as the lower part of the housing 4, and extend approximately symmetrically about the fluid pipe 2, approximately parallel to sandwich the housing 4 on both sides. In this way, the support member 103 can support the fluid pipe 2 uniformly without bias.

As shown in FIG. 16, the extensions 133, 133 are connected to the lower mounting parts 131b, 132b, which extend in the left-right direction, at approximately right angles; that is, the extensions 133, 133 and the lower mounting parts 131b, 132b are configured to be well-shaped in a plan view. The extensions 133 are configured to be hollow and generally prismatic, with a generally square cross-section, the same as the prismatic tube 138, and are connected to the lower mounting parts 131b, 132b in surface contact, which makes it easy to distribute stress, and furthermore, as mentioned above, the well-shaped structure makes it difficult for bending to occur, providing high structural strength.

The upper mounting parts 131a, 132a and the lower mounting parts 131b, 132b are removably attached to any position on the outer periphery of the fluid pipe 2 by fastening bolts and nuts 134 inserted through holes formed at opposing locations. In addition, the upper surfaces of the lower mounting parts 131b, 132b are provided with concavely curved portions 137 that are configured to come into surface contact with the outer surface of the lower part of the fluid pipe 2.

As shown in FIG. 18, the extensions 133, 133 and the lower mounting parts 131b, 132b constituting the support member 103 of this modified example are configured to be attached to a fluid pipe (hereinafter referred to as a large diameter pipe 2') having a larger diameter than the fluid pipe 2. In detail, instead of the above-mentioned upper mounting parts 131a, 132a, the upper mounting part 131a' and the lower mounting part 131b are formed in a substantially semi-cylindrical shape having an inner surface that contacts the outer surface of the large diameter pipe 2', and are detachably attached to any position on the outer circumferential surface of the large diameter pipe 2' by fastening bolts and nuts 136 inserted through holes formed at opposing positions. That is, the support member 103 of this modified example has a plurality of upper mounting parts 131a, 131a' each having an inner surface having a diameter corresponding to the outer surface of the fluid pipe 2 and the large diameter pipe 2' of different outer diameters. The lower mounting parts 131b and 132b have through holes formed opposite the upper mounting part 131a' at a location different from the location opposite the upper mounting part 131a described above, for inserting the bolts and nuts 136. In this way, the extension parts 133 and the lower mounting parts 131b and 132b can be made common, thereby increasing the versatility of the support member 103.

In addition, the support member 103 of this modified example has two upper mounting parts 131a, 131a' with inner surfaces corresponding to the outer surfaces of the two types of fluid pipes 2 and the large diameter pipe 2', but the support member 103 is not limited to this and may have three or more upper mounting parts with inner surfaces corresponding to the outer surfaces of three or more types of fluid pipes.

As shown in Figures 15 and 16, the pair of mounting portions 131, 132 constituting the support member 103 are spaced apart in the pipe axial direction without contacting the housing 4 and the anti-detachment fittings 6, 6. Similarly, the extension portions 133, 133 are spaced apart in the pipe radial direction without contacting the housing 4 and the anti-detachment fittings 6, 6. Furthermore, the support member 103 is attached to the fluid pipe 2 in a spaced apart state without contacting the support surfaces around the fluid pipe 2, such as the original ground, excavated ground, the underside and side of a retaining wall or structure, not shown, i.e., without receiving support force from these support surfaces.

Next, the support member 203 of the second modified example will be described. As shown in Figures 19 and 20, the support member 203 is mainly composed of a pair of mounting parts 231, 232 attached to the outer circumferential surface of the fluid pipe 2 at both sides sandwiching the housing 4 and the anti-detachment fittings 6, 6 in the pipe axial direction, and a single extension part 233 that spans between these mounting parts 231, 232 and extends in the pipe axial direction.

One of the mounting parts 231 is formed in a generally cylindrical shape with an inner surface that contacts the outer surface of the fluid pipe 2, and has a structure divided in the radial direction of the fluid pipe 2 (up and down in this modified example, but it can also be horizontal or oblique), and is composed of an upper mounting part 231a and a lower mounting part 231b that are connected to each other across the fluid pipe 2. The other mounting part 232 has the same shape as the mounting part 231 and is composed of an upper mounting part 232a and a lower mounting part 232b. Here, the lower mounting parts 231b and 232b in this embodiment constitute the first divided part of the present invention, and the upper mounting parts 231a and 232a constitute the second divided part of the present invention. In this way, since the mounting parts 231 and 232 have a divided structure, they can be easily attached to any position of the fluid pipe 2.

The pair of lower mounting parts 231b, 232b and the one extension part 233 in this modified example have an integral structure. In detail, plate-shaped flange parts 235, 235 that extend vertically downward are provided on the lower surface of each lower mounting part 231b, 232b near the housing 4 so as to face each other in the tube axis direction, and both ends of the extension part 233 are fixed by welding or the like in a state where they penetrate these flange parts 235, 235. That is, the lower mounting parts 231b, 232b and the extension part 233 in this modified example are integrally configured. In this way, the rigidity of the support member 203 can be increased. However, this is not limited to this, and the extension part 233 and the lower mounting parts 231b, 232b may be configured separately and detachably attached by bolts or the like.

As shown in Figures 19 and 20, the extension 233 of this modified example extends approximately parallel to the fluid pipe 2 at a height position spaced approximately vertically downward from the valve 249 provided at the lower end of the housing 4. The outlet 249a opened and closed by the valve 249 of this modified example opens in a direction approximately perpendicular to the tube axis. In this way, the fluid in the housing 4 can be easily discharged through the outlet 249a facing approximately perpendicular to the tube axis without being interfered with by the extension 233 extending in the tube axis direction below the valve 249.

Furthermore, both ends of the extension portion 233 are fixed to the inner surface of the flange portion 235 by welding or the like. In addition, a reinforcing rib 236a is provided on the inner surface of the flange portion 235 so as to sandwich the extension portion 233 from above and below, and reinforcing ribs 236b, 236b are provided across the outer surface of the flange portion 235 and the lower surfaces of the lower mounting portions 231b, 232b so as to sandwich the extension portion 233 from the left and right as viewed in the tube axis direction. The extension portion 233 is configured as a relatively thick, hollow, approximately cylindrical shape with a roughly circular cross section, and further, in combination with the reinforcing ribs 236a, 236b described above, it has a high structural strength that is less likely to bend or the like.

The upper mounting parts 231a, 232a and the lower mounting parts 231b, 232b are removably attached to any position on the outer periphery of the fluid pipe 2 by fastening bolts and nuts 234 that are inserted between the opposing flange parts.

As shown in FIG. 19, the pair of mounting portions 231, 232 constituting the support member 203 are spaced apart in the pipe axial direction without contacting the housing 4 and the anti-detachment fittings 6, 6. Similarly, the extension portion 233 is spaced apart in the pipe radial direction without contacting the housing 4 and the anti-detachment fittings 6, 6. Furthermore, the support member 203 is attached to the fluid pipe 2 in a spaced apart state without contacting the support surfaces around the fluid pipe 2, such as the original ground, excavated ground, the underside and side of a retaining wall or structure, not shown, i.e., without receiving support force from these support surfaces.

Next, the support member 303 of the third modified example will be described. As shown in Figures 21 and 22, the support member 303 is mainly composed of a pair of mounting parts 331, 332 attached to the outer circumferential surface of the fluid pipe 2 at both sides sandwiching the housing 4 and the anti-detachment fittings 6, 6 in the pipe axial direction, and a number of extension parts 333, 333 that are bridged between these mounting parts 331, 332 and extend in the pipe axial direction.

One of the mounting parts 331 is formed in a generally cylindrical shape with an inner surface that contacts the outer surface of the fluid pipe 2, and has a structure divided in the radial direction of the fluid pipe 2 (up and down in this modified example, but it can also be horizontal or oblique), and is composed of an upper mounting part 331a and a lower mounting part 331b that are connected to each other with the fluid pipe 2 in between. The other mounting part 332 has the same shape as the mounting part 331 and is composed of an upper mounting part 332a and a lower mounting part 332b. Here, the upper mounting parts 331a and 332a of this modified example constitute the first divided part of the present invention, and the lower mounting parts 331b and 332b constitute the second divided part of the present invention. In this way, since the mounting parts 331 and 332 have a divided structure, they can be easily attached to any position of the fluid pipe 2.

The pair of upper mounting parts 331a, 332a and the two extension parts 333, 333 in this modified example have an integral structure. In detail, on the upper surface of each upper mounting part 331a, 331a near the housing 4, plate-shaped flange parts 335, 335 extending outwardly and obliquely upward are provided so as to face each other in the tube axis direction, and both ends of each extension part 333, 333 are fixed by welding or the like in a state where they penetrate these flange parts 335, 335. That is, the upper mounting parts 331a, 332a and the extension parts 333, 333 in this embodiment are integrally configured. In this way, the rigidity of the support member 303 can be increased. However, this is not limited to this, and the extension parts 333, 333 and the upper mounting parts 331a, 332a may be configured separately and detachably attached by bolts or the like.

As shown in Figures 21 and 22, the extensions 333, 333 of this embodiment are arranged at approximately the same height as the top of the housing 4, and extend approximately symmetrically about the fluid pipe 2, approximately parallel to sandwich the housing 4 on both sides. In this way, the support member 303 can support the fluid pipe 2 uniformly without bias.

Furthermore, both ends of the extension portion 333 are fixed to the inner surface of the flange portion 335 by welding or the like. In addition, reinforcing ribs 336a are provided on the inner surface of the flange portion 335 so as to sandwich the extension portion 333 from above and below, and reinforcing ribs 336b are provided across the outer surface of the flange portion 335 and the upper surfaces of the upper mounting portions 331a and 332a. The extension portion 333 is configured as a relatively thick, hollow, approximately cylindrical shape with a roughly circular cross section, and further, in combination with the reinforcing ribs 336a and 336b described above, it has a high structural strength that is less likely to bend or the like.

The upper mounting parts 331a, 332a and the lower mounting parts 331b, 332b are removably attached to any position on the outer periphery of the fluid pipe 2 by fastening bolts and nuts 334 that are inserted between the opposing flange parts.

As shown in FIG. 21, the pair of mounting portions 331, 332 constituting the support member 303 are spaced apart in the pipe axial direction without contacting the housing 4 and the anti-detachment fittings 6, 6. Similarly, the extension portions 333, 333 are spaced apart in the pipe radial direction without contacting the housing 4 and the anti-detachment fittings 6, 6. Furthermore, the support member 303 is attached to the fluid pipe 2 in a spaced apart state without contacting the support surfaces around the fluid pipe 2, such as the original ground, excavated ground, the underside and side of a retaining wall or structure (not shown), i.e., without receiving support force from these support surfaces.

Although the embodiments of the present invention have been described above with reference to the drawings, the specific configuration is not limited to these embodiments, and the present invention also includes modifications and additions that do not deviate from the gist of the present invention.

For example, in the above embodiment, the support member 3 supports the fluid pipe 2 while it is being cut by the cutter 72 inside the housing 4 and after it has been cut, and also supports the fluid pipe 2 when the valve member 5 is installed inside the housing 4. However, this is not limited to the above, and the support member 3 only needs to support the fluid pipe 2 at least while it is being cut and after it has been cut, and may be removed after cutting. Alternatively, the support member 3 may be attached to the fluid pipe 2 together with the housing 4 and the valve member 5 without being removed from the fluid pipe 2 after the valve member 5 is installed, and construction may be completed in that state.

For example, in the above embodiment, the pair of mounting parts 31, 32 constituting the support member 3 are spaced apart in the tube axial direction without contacting the housing 4 and the anti-detachment fittings 6, 6, and similarly, the extension parts 33, 33 are spaced apart in the tube radial direction without contacting the housing 4 and the anti-detachment fittings 6, 6, but this is not limited thereto. Intermediates may be provided between the pair of mounting parts 31, 32 and the housing 4 or the anti-detachment fittings 6, 6, or between the extension parts 33, 33 and the housing 4 or the anti-detachment fittings 6, 6, or they may be in direct contact.

In the above embodiment, the support member 3 is attached to the fluid pipe 2 in a spaced-apart state, i.e., without contacting the support surfaces around the fluid pipe 2, such as the original ground (not shown), the excavated ground, the underside and side of a retaining wall or structure, i.e., without receiving any supporting force from these support surfaces. However, this is not limited to this, and the meaning of "spaced-apart" also includes the placement of an intervening object (such as wood placed between the ground and the support member 3 without receiving any supporting force) that fills the spaced-apart gap without receiving any supporting force.

Furthermore, for example, in the above embodiment, the valve member 5 as an insert that is inserted into the housing 4 after the fluid pipe 2 is cut is described as a so-called soft seal valve, but it is not limited to this and may be a sluice valve, butterfly valve, ball valve, switching valve, or plug.

1 Pipe cutting device 2 Existing fluid pipe (fluid pipe)
2' Large diameter pipe (fluid pipe)
3 Support member 4 Housing 5 Valve member 6 Detachment prevention fitting 31, 32 Mounting portion 31a, 32a Upper mounting portion (second divided portion)
31b, 32b Lower mounting portion (first divided portion)
33 Extension portion 60 Working valve 70 Drilling device 72 Cutter 80 Valve member insertion device 103 Support member 131, 132 Mounting portions 131a, 131a', 132a Upper mounting portion (second divided portion)
131b, 132b Lower mounting portion (first divided portion)
133 Extension portion 203 Support member 231, 232 Mounting portion 231a, 232a Upper mounting portion (second division portion)
231b, 232b Lower mounting portion (first division portion)
233 Extension portion 303 Support member 331, 332 Mounting portion 331a, 332a Upper mounting portion (first division portion)
331b, 332b Lower mounting portion (second division portion)
333 Extension section

Claims (7)

A pipe cutting method for cutting a fluid pipe in an uninterrupted flow state using a pipe cutting device including a housing that hermetically surrounds the fluid pipe and a cutter that cuts the fluid pipe in the housing, comprising:
A pipe cutting method comprising: an attachment step of attaching a support member to the fluid pipe at a distance from a support surface surrounding the fluid pipe, the support member comprising a pair of attachment portions attached to the fluid pipe at a position sandwiching the housing in the pipe axial direction and an extension portion spanning the attachment portions and extending in the pipe axial direction; and a cutting step of cutting the fluid pipe with the cutter inside the housing. 2. The pipe cutting method according to claim 1 , further comprising disposing a valve member capable of opening and closing a flow passage in the pipe in the housing after the cutting step. 3. The pipe cutting method according to claim 1 , further comprising the step of removing the support member from the fluid pipe after the cutting step. A pipe cutting device that cuts a fluid pipe in an uninterrupted flow state, the pipe cutting device comprising: a housing that hermetically surrounds a fluid pipe; and a cutter that cuts the fluid pipe in the housing,
A pipe cutting device comprising a pair of mounting portions attached to a fluid pipe at a position sandwiching the housing in the pipe axial direction, and an extension portion bridging the mounting portions and extending in the pipe axial direction , and characterized in having a support member attached to the fluid pipe at a distance from a support surface surrounding the fluid pipe . 5. The tube cutting device according to claim 4, wherein each of the pair of mounting portions has a split structure and is composed of at least a first split portion provided with the extension portion and a second split portion connected to the first split portion. 6. The tube cutting device according to claim 5 , wherein the first divided portion and the extension portion are integrally formed. 7. The tube cutting device according to claim 5 , wherein the support member has a plurality of second divided sections each having an inner surface corresponding to an outer surface of a different fluid pipe.

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