WO2007135873A1

WO2007135873A1 - Branch tube connection device and branch tube connection method

Info

Publication number: WO2007135873A1
Application number: PCT/JP2007/059758
Authority: WO
Inventors: Yasushi Yano; Gou Horikawa
Original assignee: Waterworks Technology Development Organization Co., Ltd.
Priority date: 2006-05-22
Filing date: 2007-05-11
Publication date: 2007-11-29
Also published as: JP2007309474A; JP4916769B2

Abstract

A branch tube connection device to which a branch tube can be connected and that has a branch case (1) made up of split bodies capable of being water-tightly installed on an existing tube (K) and also has a gate valve (2) connected to the branch case (1), incorporating a valve body, and connectable to the branch tube. The branch case (1) is rotatably installed on the existing tube (K). Split surfaces of the branch case (1) are connected to each other by flanges, and the split surfaces are laid in the direction of the axis of the branch tube, or in a substantially horizontal direction, and fastened by a fastener (3). The fastener (3) connects the branch case (1) and the gate valve (2) with a seal member (5) in between them.

Description

Branch pipe connection device and branch pipe connection method

Technical field

[0001] The present invention relates to a branch pipe connection device and a branch pipe connection method, and more specifically, a branch case having a split body strength that can be water-tightly attached to an existing pipe, and a branch that connects to the branch case and incorporates a valve body. The present invention relates to a branch pipe connecting device and a branch pipe connecting method that have a gate valve that can be connected to a pipe and can connect the branch pipe.

Background art

[0002] When forming a branch pipe from the middle of an existing fluid pipe such as a water pipe, a branch pipe is formed after drilling a hole in the existing pipe by a continuous water method using a branch pipe connecting device equipped with a gate valve or the like. A method of attaching the base is often used (for example, Patent Document 1). This is because it is not necessary to cut off the water when forming the branch pipe, so it is highly convenient for tap water users.

[0003] When a branch pipe is formed on an existing pipe by the continuous water method, it is generally performed using a work gate valve (hereinafter also referred to as a "gate valve") as shown in FIGS. In other words, the split case 51 is attached to the outer periphery of the existing pipe K in a watertight state. Then, in order to connect the branch case 51 and the gate valve 52, the flange portion 51a of the branch case 51 and the flange 52a of the gate valve 52 are connected by bolts and nuts.

[0004] Next, in order to connect the piercing device 53 to the other end side of the gate valve 52, the flange 52b on the other end side of the gate valve 52 and the flange portion 53a of the piercing device 53 are fixedly attached with bolts and nuts. To do. After mounting the piercing device 53, the valve body of the gate valve 52 is retracted upward to open the inside of the gate valve 52 in a connected state, and a predetermined portion of the existing pipe K is punched by the piercing device 53.

[0005] Although not shown, the drilling device 53 has a cylindrical hole saw with a blade tip provided at the tip, and a center located at the center of the cylinder and protruding forward from the cutting tip of the hole saw. Built-in drill. Then, the handle 54 provided on the rear side of the drilling device 53 is rotated to feed the hole saw to the existing pipe K side, and the existing drill is rotated while the hole saw and the center drill are rotated by a separate drive unit (not shown). Drill a predetermined part of tube K. [0006] When the drilling is completed, the rotation of the hole saw is stopped, and the drilling device 53 is moved backward while rotating the handle 54 in the reverse direction. A part of the cut-out existing pipe is caught and discharged by the central drill as the drilling device 53 moves backward.

[0007] When the hole saw and the center drill are sufficiently retracted, the valve body of the gate valve 52 that has been retracted upward is lowered to close the communication state. After that, as shown in FIG. 14, the punching device 53 is removed, and instead, the flange portion 52b of the gate valve 52 and the flange 56a of the connecting pipe 56 having the receiving rod are connected by bolts and nuts, The leading end of the branch pipe 55 is inserted into the receiving port of the connection pipe 56 to terminate the connection, and the branch pipe 55 can be used.

[0008] Patent Document 1: Japanese Patent Application Laid-Open No. 2002-154004

Disclosure of the invention

Problems to be solved by the invention

However, in the above prior art, the connection between the members is a flange connection, and the connection between the flange portions is located in a direction perpendicular to the branch pipe to which the connection is made. When a large load force S is applied to the branch pipe or existing pipe due to aging, etc., if the flange part at the connection point, especially the flange part at the connection point with the branch pipe close to the existing pipe, is easily opened, piping from the flange part There is a problem that internal fluid leaks. Since piping is usually in the soil, countermeasures that are difficult to detect even if it leaks tend to be delayed, and the loss associated with the outflow of fluid was small.

[0010] For this reason, there is a case where a method is adopted in which the entire connection portion is covered with concrete and hardened. However, in this case as well, cracking occurs in the concrete or leakage from the concrete. There was a problem that maintenance work could not be performed because inspection was not possible, and there was a strong request for improvement.

[0011] Therefore, the object of the present invention is to provide a connection between the existing pipe and the branch pipe, even if a large load is suddenly applied or a large load force is gradually applied due to secular change. It is an object of the present invention to provide a branch pipe connecting device in which fluid is not easily leaked and a branch pipe connecting method using the same.

Means for solving the problem

[0012] The above object is achieved by the inventions described in the claims. That is, the component according to the present invention. The characteristic structure of the manifold connection device has a branch case with a split body strength that can be watertightly attached to an existing pipe, and a gate valve that is connected to this branch case and has a built-in valve body that can be connected to the branch pipe. Thus, in the apparatus that enables connection of the branch pipe, the branch case is mounted on the existing pipe and is rotatable, and the split surfaces of the branch case are flange-connected to each other and flange-connected. The dividing surface is positioned in a substantially horizontal direction with respect to the axial direction of the branch pipe and is fastened by a fastener, and by fastening the fastener, the branch case and the gate valve are connected via a sealing material. There is.

[0013] According to this configuration, the split surface of the branch case connected to the flange is positioned in a substantially horizontal direction with respect to the axial center direction of the branch pipe and is fastened by the fastener, so that a large load is applied to the connected branch pipe. Even if this occurs, the split surface is not positioned in the opening direction, so that a large load force S is not applied to the fastener that fastens the split surface, and it is difficult to apply a load in the direction in which the fastener, for example, a bolt, extends. Therefore, it is possible to reliably and effectively prevent the fluid inside the pipe from leaking through the dividing surface. Therefore, it is not necessary to solidify the entire connection area with concrete to prevent fluid leakage from inside the pipe. According to the present invention, the branch case is mounted on the existing pipe and can be rotated. Therefore, when excavating a pit, the branch case can be attached to the existing pipe only by securing a space in the depth direction. In order to install the branch pipe connecting device of the present invention in order to enable the drilling of the existing pipe and subsequent branch pipe connection work by attaching and rotating the branch case and the gate valve. The space around the necessary connection points can be reduced, and branch pipe connection work can be performed in a place where a wide surrounding space cannot be secured, and construction work (for example, pit formation work with wide space securing) can be done in a short time. It can be done and work efficiency is increased.

[0014] As a result, even if a large load is suddenly applied to the connection point between the existing pipe and the branch pipe or a large load is gradually applied due to aging, the fluid inside the pipe can be easily connected from the connection point. It was difficult to leak, and a branch pipe connection device could be provided.

[0015] On the inner peripheral surface of the branch valve side end portion of the branch case, one or a plurality of recesses having an inclined surface that is inclined in an enlarged diameter and opens outward are formed, and are fitted into the recesses. Preferably, one or a plurality of protrusions are provided on the outer peripheral surface in the vicinity of the existing pipe side end of the gate valve, and the inclined surface of the recess and the inclined surface of the protrusion are capable of surface contact. [0016] According to this configuration, when connecting the branch case and the gate valve, the relative rotation is prevented to facilitate the construction work, and the connection between the two is strengthened by the surface contact. The

[0017] As the fastener is tightened, the contact area between the inclined surface of the recess of the branch case and the inclined surface of the projection of the gate valve increases, and the inclined surface of the branch case presses the inclined surface of the protrusion. In addition, the groove can be operated in a direction away from the branch case, and a concave groove is formed in the inner peripheral surface of the other end side of the branch case. And the overhang formed on the existing pipe side end face of the gate valve come into contact with each other, so that the gate valve can be stopped from moving away from the branch case! / I prefer to do that!

[0018] According to this configuration, the connection between the branch case and the gate valve is strengthened by the surface contact between the projection having the inclined surface and the concave portion, and the wedge effect is generated. Even when such a sudden and heavy load is applied or when displacement occurs due to secular change, the connection point can be held firmly.

[0019] In consideration of the fact that the connection between the branch case and the gate valve is performed by fastening the fastener, the bolt is inserted into a bolt hole formed in the vicinity of the other end of the branch case. U, prefer to make a connection between the case and the gate valve.

[0020] According to this configuration, the connection between the branch case and the gate valve can be surely and strengthened.

[0021] It is preferable that the existing pipe side end surface of the gate valve has a concave shape that can contact the outer peripheral surface of the existing pipe.

[0022] According to this configuration, the work of attaching the gate valve to the existing pipe can be performed stably, the work becomes easier, and the work efficiency increases accordingly.

[0023] The characteristic structure of the branch pipe connection method according to the present invention is that a partition valve that incorporates a valve body and can be connected to a branch pipe is mounted at a predetermined position on the upper surface of an existing pipe, and has a flange surface. A branch case having split force is attached to the existing pipe so as to be held by the existing pipe, and the flange surfaces of the split bodies of the branch case are fastened with fasteners, and the branch case and the gate valve are connected to each other. The top of the gate valve is connected so as to be positioned upward, and the flange-connected dividing surface is positioned substantially in the horizontal direction with respect to the axial direction of the branch pipe. By using the fasteners V and further tightening the split cases

The branch case and the gate valve are firmly connected, a punching device is connected to the gate valve, a predetermined portion of the existing pipe is punched, and after the drilling by the punching device is completed, the punching device is removed, The branch pipe is connected to the gate valve.

[0024] According to this configuration, even if a large load is suddenly applied to the connection portion between the existing pipe and the branch pipe or a large load force is gradually applied due to secular change, the fluid in the pipe from the connection portion However, it is difficult to leak, and a branch pipe connection method using a branch pipe connection device can be provided.

[0025] The connection between the branch case and the gate valve has an inclined surface that is formed on the inner peripheral surface of the branch valve side end of the branch case and that is inclined outwardly and opens outward. The inclined surface of each of the recesses and the inclined surface of one or a plurality of protrusions fitted in the recess and provided on the outer peripheral surface near the existing pipe side end of the gate valve are in surface contact with each other. It is preferable.

[0026] According to this configuration, it is easy to perform the connection construction work between the branch case and the gate valve, and the connection between the two is strengthened.

[0027] When the fastener is tightened, the contact area between the inclined surface of the concave portion of the branch case and the inclined surface of the projection of the gate valve increases, and the inclined surface of the branch case makes the inclined surface of the protrusion Pressing and acting in a direction to move the gate valve away from the branch case, and an inner ridge wall of a concave groove formed to fit a sealing material on the inner peripheral surface of the other end of the branch case; and It is preferred that the branch case force is stopped by coming into contact with the overhang formed on the existing pipe side end face of the gate valve, and the branch valve is stopped from moving away! /, .

[0028] According to this configuration, since the wedge effect is generated in the connection between the branch case and the gate valve, the connection portion can be firmly held.

[0029] In consideration of the fact that the connection between the branch case and the gate valve is performed by fastening the fastener, a bolt is inserted into a bolt hole formed in the vicinity of the other end of the branch case. Connect the case to the gate valve. According to this configuration, the connection between the branch case and the gate valve can be made securely and firmly.

Brief Description of Drawings FIG. 1 is a partial cross-sectional view showing a state where a branch pipe connection device according to an embodiment of the present invention is mounted on an existing pipe.

[Figure 2] Partial cross-sectional view showing a state where a branch case is installed

[Fig.3] Partial cross-sectional view showing the state where the branch case is rotated

[Fig.4] Similar to Fig.3 showing the fasteners tightened

[Figure 5] A—A view of Figure 4

[Fig. 6] A view similar to Fig. 4 showing a state in which the fastener is further tightened.

[Fig.7] A—A view of Fig. 6

[Fig.8] Similar to Fig.4 showing the state where the fastener has been tightened

[Figure 9] A—A view of Figure 8

[Figure 10] Plan view showing the state where the fastener has been tightened

[Figure 11] Left side view of Figure 10

FIG. 12 is a view similar to the enlarged view in the circle of FIG. 4 for explaining a modification of the connection process between the branch case and the gate valve.

[Fig. 13] Cross-sectional view explaining the conventional branch pipe connection method

[Fig.14] Cross-sectional view explaining the conventional branch pipe connection method

Explanation of symbols

1 branch case

1A, 1B segment

lb recess

lbl concave inclined surface

lc inner ridge wall

2 Gate valve

2a Overhang

2d protrusion

2dl protrusion inclined surface

3 Fastener

5 Seal material K Existing pipe

BEST MODE FOR CARRYING OUT THE INVENTION

[0032] One embodiment of a branch pipe connection device and a branch pipe connection method according to the present invention will be described in detail with reference to the drawings, taking as an example the case of connecting a branch pipe to an existing water pipe. 1 to 9 show a branch pipe connection method for connecting a branch pipe to an existing pipe using the branch pipe connection device according to the present embodiment.

[0033] This branch pipe connecting device includes a branch case 1 having a split surface that can be water-tightly attached to an existing pipe, and a branch that is connected to the branch case 1 and has a built-in valve body so as to communicate with the branch pipe. The point of having the valve 2 is the same as the prior art, but the split surface of the branch case 1 that is rotatably attached to the existing pipe and is connected to the flange is substantially horizontal to the axial direction of the branch pipe. In this position, it is fastened by a fastener 3 such as a bolt and a nut, and when the fastener 3 is tightened, the branch case 1 and the gate valve 2 are connected via the sealing material 5. Have In the following, a branch pipe connection method for connecting a branch pipe to an existing pipe using this branch pipe connection apparatus will be described.

First, as shown in FIG. 1, the gate valve 2 is mounted at a predetermined position on the upper surface of the existing pipe (temporary placement). Existing pipes are usually buried in the soil, and pits are formed by excavating the periphery of the place where the branch pipes are connected. The gate valve 2 has a protruding portion 2a in the circumferential direction of one end side edge placed on the upper surface of the existing pipe, and the other end side is a receiving portion 2b whose diameter is increased, and the gap between both ends is A communicable passage is formed, and this passage is rotated by attaching a jig (not shown) to the top portion 2c, so that the passage can be shut off by leaving and exiting the passage (not shown). ) Is built-in.

[0035] One or a plurality of protrusions 2d in the circumferential direction are inclined on the outer peripheral surface of the gate valve from the one end side overhanging portion 2a toward the other end. In the embodiment, two are provided at equal distances), and as shown in FIG. 2 and subsequent figures, when the branch case 1 and the gate valve 2 are connected, their relative rotation is prevented. Make the construction work easier and strengthen the connection between them. In addition, one end side of the gate valve 2 placed on the upper surface of the existing pipe K has a curved surface with a radius of curvature substantially the same as the outer circumference of the existing pipe K so that its end face can be placed along the outer peripheral face of the existing pipe K. It has a concave shape. In this way, the existing pipe K Since the temporary placement at a predetermined position on the upper surface of the plate becomes stable, the work can be easily performed and the workability can be improved.

Then, as shown in FIG. 2, the branch case 1 is mounted from below the existing pipe K so as to hold the existing pipe K, and the branch case 1 is connected to the gate valve 2. . The branch case 1 has a split T-tube shape. In the state shown in Fig. 2, it is in force with the left and right split parts 1A and 1B, and the gate valve 2 does not have a flange connection with the gate valve 2. It is located and connected so as to be fitted on the outer peripheral surface in the vicinity of one end side.

[0037] That is, the inner peripheral surface of the other end portion of the branch case 1 that is externally fitted to the gate valve 2 is inclined so as to be expanded in diameter and has a concave portion lb having an inclined surface lbl that opens outward (in this embodiment In the same manner as the projection 2d, two are provided), and the inclined surface 2dl of the projection 2d and the inclined surface lb 1 of the recess lb are formed on the outer peripheral surface of the gate valve 2. It is slidable in surface contact. In this case, since the protrusion 2d is fitted into the recess lb, as described above, when the branch case 1 and the gate valve 2 are connected, they are prevented from rotating relative to each other to facilitate the construction work. . At this stage, the bolt 3a and the nut 3b, which are the fasteners 3 for fastening the split end portion of the branch case 1, are temporarily fixed without being sufficiently tightened. When the fastener 3 is further tightened, as will be described later, it is connected in a watertight manner by the sealing material 4 built in the split end portion and the sealing material 5 fitted on the outer peripheral surface of the gate valve 2, and branched. Case 1 and gate valve 2 are firmly connected. The connection between the branch case 1 and the gate valve 2 will be described later.

Next, as shown in FIG. 3, the branch case 1 is rotated about 90 ° to the right so that the top 2c of the gate valve 2 is positioned upward. In this case, the board 6 is placed on the ground so that the leg la of the branch case 1 and the overhanging portion of the other end receiving portion 2b of the gate valve 2 are substantially in the same horizontal plane. By rotating in this way, the connection location of the split case 1 in the shape of a split T-tube, which was split in the left and right directions in FIG. Direction)) to be positioned. Therefore, even when a branch pipe is connected to the existing pipe K, even if a large load is suddenly applied to the connection point or a large load is gradually applied due to secular change, the flange connection is applied. A structure that can reliably and effectively prevent leakage of fluid inside the piping due to a large extension load applied to the bolt at the split end connection part of the branch case 1 and opening of the flange connection part. [0039] In addition, when a pit is formed by excavating the periphery of an existing pipe K connecting a branch pipe, there is an existing building in the vicinity, and thus it is not possible to secure a wide surrounding space. By forming the pit somewhat deeply and attaching the branch case 1 to the existing pipe, it is possible to connect the branch pipe and to perform construction work, for example, pit formation work with a large space in a short time. It can be done and work efficiency is increased.

[0040] Further, when the fastener 3 is tightened, the other end of the branch case 1 is shown in FIG. 4 (hereinafter, the wood 6 is omitted) as shown in an enlarged view of the connection point between the branch case 1 and the cutoff valve 2. The inclined surface lbl in the surface comes into surface contact with the inclined surface 2dl of the protrusion 2d provided on the outer peripheral surface of the gate valve 2. In this case, as shown in FIG. 5 showing the A—A arrow structure in FIG. 4 (the existing pipe K is indicated by a two-dot chain line for the sake of convenience), the inclined surface lbl of the branch case 1 and the gate valve 2 The protrusion 2d's sloping surface 2dl contacts. In this case, the sealing material 5 has a closed circular shape that is fitted in a concave groove formed on the inner peripheral surface of the other end side of the branch case 1.

[0041] When the fastener 3 is further tightened, the inclined surface lbl of the branch case 1 and the protrusion 2d of the gate valve 2 at two locations, as shown in FIGS. Makes further contact and increases the contact area. When the contact area increases, the inclined surface lbl of the branch case 1 presses the inclined surface 2dl of the protrusion 2d and acts in a direction to move the gate valve 2 away from the branch case 1.

[0042] Further, as shown in Figs. 8 and 9, the fastener 3 is further tightened so that the contact area between the inclined surface lbl of the branch case 1 and the protrusion 2d of the gate valve 2 is increased. The contact surface is maximized, and the inclined surface lbl of the branch case 1 presses the inclined surface 2dl of the protrusion 2d, acts in a direction to move the gate valve 2 away from the branch case 1, and is a recess in which the seal material 5 is fitted. The inner rib wall lc of the groove and the overhanging portion 2a of the gate valve come into contact with each other to stop the gate valve 2 from moving away from the branch case 1, and the fastening by the fastener 3 is completed. Because of this structure, even if a large load is applied after connecting the branch pipe, the fluid leaks because the connection between the branch case 1 and the gate valve 2 is strong. Effectively prevent.

[0043] Then, as shown in FIGS. 10 and 11, the other fastening points of the split case 1 having a split T-tube shape are fastened using the bolts and nuts that are the fasteners 7 and 8, and are attached to the existing pipe K. The watertightness of the attached branch case 1 is ensured. Reference numeral 9 is a reinforcing rib, and the fastener 8 is fastened and fastened from the upper surface of the reinforcing rib 9 in the longitudinal direction. [0044] After connecting the branch case 1 and the gate valve 2, a punching device (not shown) is connected to the receiving portion 2b on the other end side of the gate valve 2 in the same manner as in the prior art. After retracting the valve body upward to open the inside of the gate valve 2 in a communicating state, a predetermined portion of the existing pipe K is drilled by a punching device.

[0045] When the drilling is completed, the rotation of the hole saw built in the drilling device is stopped, the drilling device is retracted, and a part of the cut existing pipe is discharged as the drilling device is retracted, The punching device is removed, and instead, the tip of the branch pipe (not shown) is inserted into the receiving portion 2b of the gate valve 2 to terminate the connection, and the branch pipe can be used.

[Another embodiment]

(1) In the above embodiment, the connection between the branch case 1 and the gate valve 2 is fastened by the fastener 3, and as the fastener 3 is tightened, the inclined surface lbl of the recess of the branch case and the protrusion of the gate valve The contact area of the 2d inclined surface 2dl increases, and the inclined surface lb 1 of the branch case presses the inclined surface 2dl of the protrusion, and the connection is performed by moving the gate valve 2 away from the branch case 1. However, the bolt 10 may be interposed as shown in FIGS. 12 (a) to 12 (d) in which the connection between the branch case 1 and the gate valve 2 should be strengthened.

That is, a bolt hole having a female screw is formed at a position between the inclined groove lbl formed on the inner peripheral surface of the other end side of the branch case 1 and into which the sealing material 5 is inserted. By screwing bolt 10 into the bolt hole, the connection between branch case 1 and gate valve 2 is further strengthened. In this case, as shown in FIGS. 4 to 8, as the fastener 3 is tightened, the inclined surface lbl of the branch case presses the inclined surface 2dl of the protrusion as shown in FIGS. Then, after the inner rib wall lc of the branch case 1 and the overhanging portion 2a at one end of the gate valve come into contact with each other and stop, as shown in FIG. To do. The bolt 10 may be screwed at one place or a plurality of places. Further, the bolt 10 may be connected so as to act in the direction of moving the gate valve 2 away from the branch case 1 by directly pressing the inclined surface 2dl of the protrusion. However, when such a bolt 10 is interposed, the inclined surface lbl of the branch case presses the inclined surface 2dl of the projection, and the connection is made by moving the gate valve 2 away from the branch case 1. The branch case 1 and the gate valve 2 may be connected by tightening the fastener 3 and screwing the bolt 10. [0048] (2) In the above embodiment, the tap water is taken as an example of the fluid inside the pipe. However, the present invention is not limited to this and can be applied to fluids such as various liquids and gases.

(3) In the above embodiment, two protrusions 2d are provided in the circumferential direction of the outer peripheral surface of the gate valve 2, and the inner peripheral surface of the other end of the branch case 1 also corresponds to the protrusion 2d. In this example, two recesses lb are provided. However, the combination of the protrusion 2d and the recess lb may be one or more than three.

Claims

The scope of the claims

[1] A branch case with a split body strength that can be water-tightly attached to an existing pipe, and a gate valve that is connected to this branch case and has a built-in valve body that can be connected to the branch pipe. In the branch pipe connection device that enables

The branch case is mounted on the existing pipe so as to be rotatable, and the split surfaces of the branch case are flange-connected to each other, and the split surfaces connected to the flange are substantially the same as the axial direction of the branch pipe. A branch pipe connecting device, characterized in that the branch case and the gate valve are connected to each other through a sealing material by being fastened by a fastener located in the horizontal direction.

[2] On the inner peripheral surface of the branch valve side end portion of the branch case, one or a plurality of recesses having an inclined surface that is inclined in an enlarged diameter and opens outwardly are formed, and are fitted into the recesses. 2. The projection according to claim 1, wherein one or a plurality of protrusions are provided on an outer peripheral surface in the vicinity of the existing pipe side end of the gate valve, and the inclined surface of the recess and the inclined surface of the protrusion are in surface contact. Branch pipe connection device.

[3] As the fastener is tightened, the contact area between the inclined surface of the concave portion of the branch case and the inclined surface of the protrusion of the gate valve increases, and the inclined surface of the branch case presses the inclined surface of the protrusion. In addition, the groove can be operated in a direction away from the branch case, and a concave groove is formed in the inner peripheral surface of the other end side of the branch case. An inner ridge wall that constitutes the wall and an overhang portion formed on an existing pipe side end surface of the gate valve come into contact with each other, so that the gate valve can be stopped from moving away from the branch case. Item 2. The branch pipe connecting device according to item 2.

[4] In addition to the connection between the branch case and the gate valve being performed by fastening the fastener, the branch case is inserted by inserting a bolt into a bolt hole formed near the other end of the branch case. 2. The branch pipe connecting device according to claim 1, wherein the branch valve is connected to the gate valve.

5. The branch pipe connecting device according to claim 1, wherein the existing pipe side end face of the gate valve has a concave shape that can contact the outer peripheral face of the existing pipe.

[6] At the predetermined upper surface of the existing pipe, a valve is built in and a gate valve that can be connected to the branch pipe is mounted, and a branch case having a flanged surface having a flange surface is held by the existing pipe. To attach to the existing pipe,

The flange surfaces of the split body of the branch case are fastened by a fastener, and the branch case and the gate valve are connected so that the top of the gate valve is located above, and the split-connected split is performed. So that the surface is positioned substantially horizontally with the axial direction of the branch pipe,

By further tightening the split bodies of the branch case using the fastener V, the branch case and the gate valve are firmly connected,

Connecting a piercing device to the gate valve, piercing a predetermined portion of the existing pipe, removing the piercing device after completion of piercing by the piercing device;

A branch pipe connection method for connecting the branch pipe to the gate valve.

[7] After the branch case and the gate valve are connected, the branch case and the gate valve are rotated together so that the top of the gate valve is positioned upward, and the branch case and Inclined surface of one or a plurality of recesses having an inclined surface that is formed on the inner peripheral surface of the branch valve side end of the branch case and that opens to the outside. 7. The branch according to claim 6, wherein the branching is carried out by being in surface contact with one or a plurality of inclined surfaces provided on the outer peripheral surface in the vicinity of the existing pipe side end of the gate valve. Pipe connection method.

[8] When the fastener is tightened, the contact area between the inclined surface of the concave portion of the branch case and the inclined surface of the projection of the gate valve increases, and the inclined surface of the branch case becomes the inclined surface of the protrusion. Pressing and acting in a direction to move the gate valve away from the branch case, and an inner ridge wall of a concave groove formed to fit a sealing material on the inner peripheral surface of the other end of the branch case; and 8. The branch according to claim 7, wherein the branch case force is stopped by coming into contact with an overhanging portion formed on an existing pipe side end surface of the gate valve to stop the branch valve from moving away. Pipe connection method.

[9] In consideration of the fact that the connection between the branch case and the gate valve is performed by fastening the fastener, the bolt is inserted into a bolt hole formed in the vicinity of the other end of the branch case. The branch pipe connection method according to claim 6, wherein the case and the gate valve are connected.