JP6068122B2 - Branch joint - Google Patents

Description

  The present invention relates to a branch joint for branching a cast iron pipe through which a fluid such as city gas flows.

Cast iron pipes made of gray cast iron or ductile cast iron (spheroidal graphite cast iron) are widely used for underground pipes such as city gas. These cast iron pipes are manufactured with a plurality of different standards depending on the pipe material and connection port shape, and even with the same nominal diameter (for example, nominal diameter 100A), the outer diameter varies depending on the pipe type. Have. For example, even for cast iron pipes made of the same ductile cast iron and having the same nominal diameter, there are a plurality of standards with slightly different pipe outer diameters. Therefore, when branching each pipe, it is necessary to use a corresponding branch joint according to the pipe type.
As a joint for branching a buried gas pipe such as a cast iron pipe, there is one described in Patent Document 1, for example. According to the joint for branching described in Patent Document 1, the first and second split joints 4 and 5 are joined to the main pipe 1 and a hole is drilled to take a branch from the second split joint 5. However, there is no allowance for the outer diameter of the main pipe, and in order to cope with each pipe type having a different pipe outer diameter, a branch joint corresponding to each pipe outer diameter must be prepared.

  In addition, it is often the first time that the type of pipe buried in the ground to be branched is known when the ground is dug up, and the installer can handle any type of pipe. Therefore, all the branch joints corresponding to each pipe type must be prepared, and the preparation is complicated. Therefore, as a branch joint that allows branching from either pipe to allow some difference in outer diameter size and also to cope with the difference in pipe material (gray cast iron pipe and ductile cast iron pipe), There is a branch joint that allows a difference in pipe outer diameter due to a difference in pipe type by using a sealant and a rubber seal member in combination, and is practically used.

JP 2003-336783 A

  However, in such a general-purpose branch joint, it is necessary to ensure sufficient rigidity of the branch joint itself in order to enable branching from a gray cast iron pipe that has a lower load resistance against bending load than a ductile cast iron pipe. In other words, the branch joint becomes very large and heavy, and it is difficult to construct the branch pipe. In recent years, there are many gas companies that do not perform branch piping from gray cast iron pipes that have a small load resistance against bending loads, and for these companies, the above-mentioned branch joints are excessively stiff and overspec. It has become. Therefore, a lightweight branch joint having excellent workability for branching work is desired. However, even in these businesses, an allowance that can cope with a slight difference in the outer diameter of the pipe is required for the branch joint.

  Therefore, the present invention has been made in view of the above-described problems of the prior art, and while being easy to handle, it can be attached to a plurality of types of pipes having different outer diameters, and branches can be taken out. An object of the present invention is to provide a branch joint for cast iron pipe having a high height.

In order to solve the above problem, the branch joint of the present invention is
An inner surface of the sleeve main body having a flange-shaped sleeve main body mounted on a main pipe through which a fluid flows, and a hollow branch portion provided so as to protrude outward from the sleeve main body; A branch sleeve member in which an annular groove is formed;
A hook-shaped push sleeve member paired with the branch sleeve member, which is attached to the outer surface of the main pipe with the main pipe sandwiched between the branch sleeve member;
A seal member mounted in the annular groove of the sleeve main body portion and sealing an outer surface of the main pipe and an inner surface of the sleeve main body portion;
A branch joint comprising the branch sleeve member and a fastening member for fastening the push sleeve member,
The branch sleeve member has wedge-shaped convex portions formed with reduced diameter taper portions so as to taper in the fastening direction with the push sleeve member, and formed at both ends in the circumferential direction of the sleeve main body portion ,
The push sleeve member is formed with a recess for receiving the wedge-shaped protrusion.
The said branch sleeve member is characterized by the said sleeve main-body part being diameter-reduced when the said wedge-shaped convex parts approach by clamping of the said branch sleeve member and the said push sleeve member.
The branch sleeve member deforms the wedge-shaped convex portions formed at both end portions in the circumferential direction of the sleeve main body portion in a direction of reducing the diameter by receiving a load in a direction of reducing the diameter by the concave portions formed in the push sleeve member .

In the branch joint of the present invention,
The annular groove is preferably provided so that the seal member is disposed on the outer side in the axial direction of the main pipe with respect to a connecting portion of the branch portion to the sleeve main body portion.
Thus, the thickness of the sleeve body can be made substantially uniform by disposing the seal member on the axially outer side of the main pipe. As a result, the stress accompanying the diameter reduction of the sleeve main body portion is dispersed, so that it is possible to prevent the stress from being concentrated on one part of the sleeve main body portion when the sleeve main body diameter is reduced. Can be uniformly deformed along the outer surface of the pipe, so that even a cast iron pipe having a different pipe outer diameter can have a sealing property.

In the branch joint of the present invention,
It is desirable that the connecting portion of the branch portion and the sleeve main body portion is provided in a shape that disperses the stress associated with the diameter reduction of the sleeve main body portion.
As described above, since the shape of the connecting portion between the branch portion and the sleeve main body portion is provided in a shape that disperses the stress accompanying the diameter reduction of the sleeve main body portion, one place of the sleeve main body portion is provided when the sleeve main body diameter is reduced. Stress can be prevented from being concentrated on the sleeve, and the sleeve body can be uniformly deformed along the outer surface of the tube, so that even a cast iron pipe having a different outer diameter can have a sealing property.

In the branch joint of the present invention,
The shape of the connecting portion is preferably provided in a tapered shape that increases in diameter from the outside toward the sleeve main body portion.
As described above, since the shape of the connecting portion is provided in a tapered shape that expands from the outside toward the sleeve main body portion, the branch sleeve member is deformed while the entire tapered portion is deformed, and the stress is concentrated on one place. Does not occur.

In the branch joint of the present invention,
The branch sleeve member is provided with a column that presses two locations in the vicinity of the hole in the main pipe surface in the same direction as the mounting direction when the branch sleeve member and the push sleeve member are mounted on the main pipe. It is desirable that
In this way, the branch sleeve member is provided with the struts that press the two locations in the vicinity of the drill hole on the main pipe surface, so that even when a bending load is applied to the main pipe and a tensile stress is generated on the main drill hole side, Stress in a direction against the bending force of the main pipe is applied by the pressing of the column.

Further, in the branch joint of the present invention, when the branch sleeve member and the push sleeve member are mounted on the main pipe, a plurality of pressing protrusions that press the outer peripheral portion of the main pipe are at both end portions of the push sleeve member. It is desirable to be provided on the inner surface.
As described above, since the plurality of pressing protrusions are provided on the inner surfaces of both ends of the pressing sleeve member, the contact pressure of the pressing sleeve member with respect to the main pipe increases. This contributes to the improvement of the bending load resistance performance when a bending load is applied to the main pipe.

  According to the present invention, the branch sleeve member is formed with the wedge-shaped convex portions formed with the tapered portions so as to taper in the fastening direction with the push sleeve member at both ends in the circumferential direction. The concave portion for receiving the wedge-shaped convex portion is formed, and the sleeve main body is reduced in diameter by bringing the wedge-shaped convex portions closer to each other by tightening the branch sleeve and the push sleeve, and along the outer periphery of the pipe to which the branch sleeve member is attached. Therefore, even for pipes having slightly different outer diameters, the same branch joint can be attached to the main pipe to take out the branch.

It is a front view (half-sectional view) which shows the state which mounted | wore the main pipe with the branch joint which concerns on this invention. It is a front view (partial sectional view) of a branch sleeve member of a branch joint according to the present invention. It is a right view of the branch sleeve member of the branch joint which concerns on this invention. It is a bottom view of the branch sleeve member of the branch joint which concerns on this invention. It is a side view of the push sleeve member of the branch joint which concerns on this invention. It is a top view of the push sleeve member of the branch joint which concerns on this invention. It is a component expanded view of the branch joint which concerns on this invention. It is a cross-sectional view which shows the construction state of the branch joint which concerns on this invention.

Hereinafter, a branch joint according to an embodiment of the present invention will be described with reference to the drawings.
As shown in FIG. 1, the branch joint 1 according to one embodiment of the present invention is paired with a branch sleeve member 2 attached to a branch pipe P and a branch sleeve member 2 and attached to the main pipe P. And a fastening member composed of a bolt 4 and a nut 5 that fasten the paired sleeve members, and a seal member 6 that hermetically seals the main pipe P and the branch sleeve member 2. Yes. Hereinafter, details of each member will be described.

  As shown in FIGS. 2 and 3, the branch sleeve member 2 includes a sleeve-shaped sleeve body 201 having an arcuate inner surface having a radius of curvature equal to or slightly larger than the radius of the outer periphery of the main pipe P, and a sleeve body. A branch portion 202 projecting outward from the center portion of the portion 201. Since the branch joint 1 is mounted on a plurality of types of main pipes P having different outer diameter specifications, the radius of curvature of the inner surface of the branch sleeve member 2 is equal to or slightly larger than the radial dimension of the main pipe P having a larger dimension. Is provided. By providing the dimensional relationship between the sleeve main body 201 and the main pipe P in this way, the branch sleeve member 2 can be easily attached to the outer peripheral portion of the main pipe P. The sleeve main body portion 201 and the branch portion 202 are a casting that is integrally formed by casting. The material is spheroidal graphite cast iron (ductile cast iron).

  A resin short pipe 203 for connecting a branch pipe (not shown) is inserted into the branch section 202 and sealed. A connecting portion 204 (base portion) of the branch portion 202 to the sleeve main body portion 201 is formed in a substantially triangular pyramid shape whose diameter increases toward the sleeve main body portion 201. As shown in FIGS. 2 and 4, two support columns 205 are formed on the inner diameter side of the base portion of the branch portion 202 so that the end surface is flush with the inner peripheral surface of the sleeve main body portion 201. . Further, a seal member accommodation groove 206 into which the seal member 6 is mounted is formed on the inner surface of the sleeve main body 201. The seal member housing groove 206 is provided outside the substantially triangular pyramid-shaped connecting portion 204 so that the seal member 6 is disposed at a position outside the outer diameter of the branch portion 202. Further, the branch sleeve member 2 is provided with a flange portion 209 for fastening with a push sleeve member 3 described later. The flange portion 209 is formed so that the inner side is wide and the width is narrowed toward the end portion, and the bolt hole 212 is similarly provided so that the inner side is wide and the end portion is narrow. In this way, the bolt hole 212 on the inner side in the axial direction of the main pipe is provided on the outer side with respect to the pipe axis, and the force point (bolt hole position) with respect to the fulcrum is moved away, so that a larger bending moment can be generated at the time of fastening. . As a result, it is possible to more reliably deform the vicinity of the branch portion of the branch sleeve body portion 201 having the highest rigidity in the branch sleeve member 2, so that the inner surface of the sleeve body portion 201 is more closely attached to the outer surface of the main pipe P. is there. Wedge-like convex portions 207 are formed at both ends in the circumferential direction of the sleeve main body portion 201 so as to protrude from the flange portion 209. The wedge-shaped convex portion 207 is provided in a taper shape having a reduced diameter tapered surface 208 on the outer side on the circumferential extension line of the sleeve main body portion 201. The sleeve main body 201 has a bottomed cylindrical perforation having a threaded portion 210 at one end inner diameter in a direction perpendicular to the paper surface of FIGS. 1 and 2 and perpendicular to the axial direction of the branching portion 202. A perforated cylindrical portion 211 is formed.

  As shown in FIGS. 5 and 6, the push sleeve member 3 has an arcuate inner surface with a radius of curvature equal to or slightly larger than the radial dimension of the outer peripheral portion of the main pipe P, like the branch sleeve member 2 described above. It consists of a push sleeve body 301 having a shape and a flange 304 for fastening to the branch sleeve member 2. In addition, it is also provided on the sleeve main body portion of the arc-shaped inner surface having a radius of curvature equal to or slightly larger than the radial dimension of the outer peripheral portion of the main pipe P having the larger outer diameter among the plurality of main pipes P that can be mounted. This is the same as the branched sleeve member. The push sleeve member 3 is also made of spheroidal graphite cast iron (ductile cast iron) in the same manner as the branch sleeve member 2.

  The push sleeve member 3 is provided with a concave portion 302 that receives the wedge-shaped convex portion 207 of the branch sleeve member 2. A tapered surface 303 corresponding to the diameter-reduced tapered surface 208 of the branch sleeve member 2 is formed outside the recess 302. The flange portion 304 has the same projected shape as the flange portion 209 of the branch sleeve member 2, and a bolt hole 305 is formed so as to correspond to the bolt hole 212 provided in the flange portion 209. Further, three pressing convex portions 306 are formed on the inner diameter side of both end portions of the pressing sleeve main body portion 301, respectively. Thus, the contact pressure at the contact location increases by providing a location that does not come into contact with the outer peripheral surface of the main pipe P (pressing convex portion 306) at the time of mounting on the inner diameter side of both ends of the push sleeve main body 301. . Further, the contact surface of the pressing convex portion 306 with the main pipe P is formed with fine irregularities, and when the branch sleeve member 2 and the pressing sleeve member 3 are tightened and attached to the main pipe P, the main pipe P Eat firmly on the outer surface. This prevents the main pipe P from slipping with respect to the branch joint 1 when a bending load is applied to the main pipe P. A plurality of reinforcing ribs 307 extending in the axial direction are formed on the outer diameter side of the push sleeve main body 301. Due to the reinforcing rib 307, the branch joint 1 has an excellent bending resistance against the main pipe P bending load.

  Moreover, the bolt 4 and the nut 5 which are fastening members for fastening the branch sleeve member 2 and the push sleeve 3 are made of ductile cast iron having sufficient strength and corrosion resistance. Specifically, it is a ductile cast iron product specified in JIS standard (JIS G 5502), and a material added with 2% Ni is used to make FCD400-15 have corrosion resistance. In the present embodiment, this material is used, but any material having both strength and corrosion resistance may be used. For example, it may be made of stainless steel such as SUS304.

  Further, the seal member 6 that seals the inner surface of the main pipe P and the branch sleeve member 2 is preferably nitrile butadiene rubber (NBR) having good sealing performance over a long period of time.

Subsequently, the construction procedure of the branch joint which concerns on one embodiment of this invention is demonstrated.
1. First, the branch sleeve member 2 and the push sleeve member 3 are prepared, and the seal member 6 is attached to the sleeve body 201. Then, the branch sleeve member 2 and the push sleeve member 3 are mounted so that the main pipe P is sandwiched between the main body portions. Then, both the sleeve members 2 and 3 are fastened and fixed by the bolt 4 and the nut 5. At this time, the wedge-shaped convex portion 207 of the branch sleeve member 2 fits into the concave portion 302 of the push sleeve member 3, and the reduced diameter tapered surface 208 is pushed by the tapered surface 303. Along with this, the wedge-shaped convex portions 207 approach each other, whereby the sleeve main body portion 201 is reduced in diameter, and the sleeve main body portion 201 satisfies the sealing performance by being deformed along the outer peripheral surface of the main pipe P. The deformation of the branch sleeve member 2 and the push sleeve member 3 at this time will be described more specifically with reference to FIG. FIG. 8A is a cross-sectional view showing a state before the fastening member is tightened, and FIG. As shown in FIG. 8A, in the state before the fastening member is tightened, the branch sleeve member 2 is fitted to the reduced diameter tapered surface 208 having the wedge-shaped convex portion 207 formed in the concave portion 302 of the push sleeve member 3. Thus, the tapered diameter surface 208 and the tapered surface 303 are in contact with each other, and the packing 6 has not been sufficiently compressed. As shown in FIG. 8B, after the fastening member is tightened, the wedge-shaped convex portion 207 is moved in the direction of the arrow A by moving the reduced diameter tapered surface 208 along the tapered surface 303 by tightening the fastening member. Move towards. Along with this, the sleeve main body 201 is similarly deformed (reduced in diameter), and the packing 6 is sufficiently compressed against the outer peripheral surface of the main pipe P, so that the main pipe P and the inner surface of the sleeve main body 201 are sealed. . For example, in the case of a branch joint according to the present invention for a ductile cast iron pipe having a nominal diameter of 100A, the sleeve body is deformed as described above for a pipe having a maximum outer diameter of 123.4 mm to a minimum outer diameter of 116.5 mm. Therefore, one type of branch joint can be used.

In the branch joint according to the present embodiment, the connecting portion 204 of the branch portion 202 has a hollow substantially triangular pyramid shape whose diameter increases toward the sleeve main body portion 201, so that the branch sleeve member generates a reaction force from the pipe. Since the part that receives the reaction force from the pipe without receiving it has a substantially uniform thickness, when deforming along the main pipe P, the stress is partially concentrated in one place of the sleeve body 201. Is prevented, and the safety against destruction of the joint is improved.

  2. Next, a drilling machine (such as a horuseau) (not shown) is attached to the drilling cylindrical portion 211 and the main pipe P is drilled.

  3. After drilling, the drilling machine is removed from the drilling cylindrical part 211, the plug 7 is attached to the screw part 210, and the construction is completed.

  Here, two struts 205 are provided on the inner diameter side of the connecting portion 204 of the branch sleeve member 2, and when the construction is completed, as shown in the cross section of FIG. Has been. Accordingly, even when bending is applied to the main pipe P in the state shown in FIG. 1 and the main pipe P protrudes upward, the vicinity of the perforated hole is pressed by the support column 205. It has sufficient strength.

P: Main pipe 1: Branch joint 2: Branch sleeve member 201: Sleeve body part, 202: Branch part, 203: Resin short pipe 204: Linking part (base part), 205: Post 206: Seal member receiving groove, 207: Wedge-shaped convex portion, 208: Reduced diameter tapered surface 209: Flange portion, 210: Screw portion, 211: Drilling cylinder portion 212: Bolt hole 3: Push sleeve member 301: Push sleeve main body portion, 302: Concavity 303: Taper Surface, 304: flange portion, 305: bolt hole 306: pressing convex portion, 307: reinforcing rib 4: bolt 5: nut 6: seal member 7: plug

Claims (6)

An inner surface of the sleeve main body having a flange-shaped sleeve main body mounted on a main pipe through which a fluid flows, and a hollow branch portion provided so as to protrude outward from the sleeve main body; A branch sleeve member in which an annular groove is formed;
A hook-shaped push sleeve member paired with the branch sleeve member, which is attached to the outer surface of the main pipe with the main pipe sandwiched between the branch sleeve member;
A seal member mounted in the annular groove of the sleeve main body portion and sealing an outer surface of the main pipe and an inner surface of the sleeve main body portion;
A branch joint comprising the branch sleeve member and a fastening member for fastening the push sleeve member,
The branch sleeve member has wedge-shaped convex portions formed with reduced diameter taper portions so as to taper in the fastening direction with the push sleeve member, and formed at both ends in the circumferential direction of the sleeve main body portion ,
The push sleeve member is formed with a recess for receiving the wedge-shaped protrusion.
The branch sleeve member is characterized in that the sleeve main body portion is reduced in diameter when the wedge-shaped convex portions approach each other by tightening the branch sleeve member and the push sleeve member. The said annular groove is provided so that the said sealing member may be arrange | positioned in the axial direction outer side of the said main pipe with respect to the connection part to the said sleeve main-body part of the said branch part. Branch fittings. The shape of the connection part with the said sleeve main-body part of the said branch part is provided in the shape which disperse | distributes the stress accompanying the diameter reduction of the said sleeve main-body part, The Claim 1 or Claim 2 characterized by the above-mentioned. Branch joint. 4. The branch joint according to claim 3, wherein a shape of the connecting portion is provided in a tapered shape that expands toward the sleeve main body portion. 5. The branch sleeve member is provided with a column that presses two locations in the vicinity of the hole in the main pipe surface in the same direction as the mounting direction when the branch sleeve member and the push sleeve member are mounted on the main pipe. branch connection according to any one of claims 1 to 4, characterized in that is. When the branch sleeve member and the push sleeve member are mounted on the main pipe, a plurality of pressing protrusions that press the outer peripheral portion of the main pipe are provided on the inner surfaces of both ends of the push sleeve. branch connection according to any one of claims 1 to 5 to.

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