JP2019015302A - Branch joint and branch work execution method - Google Patents

Abstract

To facilitate connection of branch piping at a piping construction site.SOLUTION: A branch joint 10 includes: a joint body 11 having cylindrical welded portions 11a, 11b which can be welded on both ends; and a cylindrical branch portion 12 integrally formed with the joint body 11, protruding radially outward of the joint body 11, and having a female screw on an inner peripheral surface thereof.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a branch joint and a branch construction method.

  Patent Document 1 discloses a saddle joint that is welded to a pipe in order to branch the flow path of the pipe. Patent Documents 2 and 3 disclose a technique for extending a peripheral portion of a hole formed on a peripheral surface of a pipe by burring to form a cylindrical branch portion.

JP 2015-36558 A Noto 3173050 gazette Japanese Patent Application Laid-Open No. 2015-124862

  Patent Document 1 discloses a branch joint in which a branch protrusion member prepared as a separate member is welded to the periphery of a hole formed on the circumference of a pipe serving as a joint body. However, since this welding is performed on the curved surface of the pipe, defects such as water leakage are likely to occur, and further, only a part on the circumference of the pipe is heated to a high temperature at the time of welding, so the pipe body is bent and correction is necessary. was there.

  Patent Document 2 discloses a branch joint in which a branch protrusion is formed by burring on a pipe serving as a joint body. Although this has an advantage that a plurality of branch portions can be formed, there is a basic problem that the length and thickness of the protruding portion are not sufficiently secured. For this reason, the screw method cannot be used for joining the pipe to the branching portion during the piping construction, and a welding work on site is required. In order to improve this point, a branch joint is also proposed in which a branch portion is protruded to the inner diameter side of the pipe at the time of burring (Patent Document 3). May cause a pressure loss of the fluid flowing through the inside, or may accumulate dust.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a branch joint that can easily connect a branch pipe at a pipe construction site, and a branch construction method using the branch joint.

  The invention disclosed in the present application in order to solve the above problems has various aspects, and the outline of typical ones of these aspects is as follows.

  (1) A branch joint according to an aspect of the present invention includes a joint body having weldable cylindrical welded parts at both ends, and a branch part formed integrally with the joint body, the diameter of the joint body And a cylindrical branch portion protruding outward in the direction and having an internal thread formed on the inner peripheral surface.

  (2) In (1), when the inner peripheral surface of the branch part having the female screw is formed with an inclined surface that is inclined so that the inner diameter of the branch part increases as it goes in the protruding direction of the branch part. Good.

  (3) In (1) or (2), the thickness of the tip portion in the protruding direction of the branch portion may be equal to or greater than the thickness of the joint body.

  (4) In any one of (1) to (3), a curved surface connecting the outer peripheral surface of the branch portion and the outer peripheral surface of the joint body in a cross section passing through the central axis of the joint body and the central axis of the branch portion. The curvature radius may be 0.5 times or less the outer diameter of the branch portion.

  (5) In any one of (1) to (4), the protruding amount of the branch portion may be 0.3 times or more the outer diameter of the branch portion.

  (6) In any one of (1) to (5), the curved surface connecting the inner peripheral surface of the branch portion and the inner peripheral surface of the joint body includes an outer peripheral surface of the branch portion and an outer peripheral surface of the joint body. It is good to follow the curved surface to connect.

  (7) The branch construction method according to one aspect of the present invention includes a step of abutting the welded portion of the branch joint according to any one of (1) to (6) against an end portion of a pipe, and the end portion. And welding along the outer peripheral surface of the welded portion, connecting the branch joint to the pipe, and forming an external thread formed on the outer peripheral surface of the branch pipe on the inner peripheral surface of the branch portion. And connecting the branch pipe to the branch portion by screwing into the female screw.

  (8) In (7), the pipe may be a fire hydrant pipe.

  According to the above aspects (1) to (8) of the present invention, branch piping can be easily connected at the piping construction site.

It is an external appearance perspective view which shows the branch joint of this embodiment. It is sectional drawing of the branch joint of this embodiment. It is a figure which shows the example of the protrusion diameter of a branch part of this embodiment, an outer diameter, thickness, and the frequent nominal diameter used with the branch piping connected to a branch part. It is process drawing for demonstrating the branch construction method in this embodiment. It is process drawing for demonstrating the branch construction method in this embodiment. It is process drawing for demonstrating the branch construction method in this embodiment.

  First, the structure of the branch joint 10 of this embodiment is demonstrated with reference to FIG. 1, FIG. FIG. 1 is an external perspective view showing a branch joint of the present embodiment. FIG. 2 is a cross-sectional view of the branch joint of the present embodiment. Specifically, FIG. 2 is a view showing a cross section passing through the central axis of the joint body 11 and the central axis of the branching portion 12. The branch joint 10 of this embodiment is a joint for branching the flow path of piping. The pipe is, for example, a fire hydrant pipe installed on the side of the road. The maximum working pressure of the applied fluid of the branch joint 10 of this embodiment is good to be about 2.0 MPa or less.

  The branch joint 10 includes a tubular joint body 11 that connects the flow paths of two pipes such as fire hydrant pipes, and a tubular branch portion 12 that protrudes radially outward of the joint body 11.

  At both ends of the joint body 11, welded portions 11a and 11b welded to the pipe are formed. The welded portions 11 a and 11 b are cylindrical and have a shape that is inclined so that the diameter becomes smaller toward the outside of the joint body 11. Since the groove processing is performed in this way, when the welded portions 11a and 11b are abutted against the pipe, a groove is formed on the outer peripheral surface to ensure the area of the welded area. can do. Note that the shape of the welded portions 11a and 11b formed by the groove processing is not limited to that shown in FIG. 2, but may be any shape as long as a groove is formed when it is abutted against the pipe. The shape may also be For example, the welded portions 11a and 11b may have a shape in which grooves such as an I shape, a U shape, and a Y shape are formed in a cross-sectional view when they are abutted against a pipe.

  A branch hole 11 c is formed in the peripheral surface of the joint body 11. The branch hole 11 c is preferably formed at a substantially central portion of the joint body 11. The branch portion 12 is formed integrally with the joint main body 11 so as to protrude outward in the radial direction of the joint main body 11 from the peripheral edge portion of the branch hole 11c. Moreover, the branch part 12 is cylindrical, The front-end | tip is opening.

  Further, as shown in FIG. 2, the inner peripheral surface 12 a on which the female thread of the branching portion 12 is formed is inclined so that the inner diameter of the branching portion 12 increases as it goes in the protruding direction of the branching portion 12. That is, a so-called taper screw is formed on the inner peripheral surface 12 a of the branch portion 12. Thereby, the tightness is improved. In addition, the structure of the inner peripheral surface 12a of the branch part 12 is not restricted to this, A so-called straight screw may be formed.

  When the branch portion 12 is formed by plastic processing, which will be described later, the protruding amount L1, the outer diameter L2, and the wall thickness L3 of the branch portion 12 depend on the outer diameter and the thickness of the raw tube before being processed. 12 may have a protruding amount, an outer diameter, and a wall thickness so that a female screw can be formed on the inner peripheral surface 12a. The protruding amount L1 of the branch part 12 is preferably 0.3 times or more the outer diameter L2 of the branch part 12. The protruding amount L1 of the branch portion 12 is a length from the outer peripheral surface of the joint body 11 to the tip of the branch portion 12 as shown in FIG. In addition, the thickness L3 of the branching portion 12 may be greater than the thickness L5 of the joint body 11. The wall thickness L3 is the thickness of the tip of the branch portion 12 in the protruding direction. Further, the curvature radius R in a cross-sectional view of the curved surface connecting the outer peripheral surface of the joint body 11 and the outer peripheral surface of the branching portion 12 is preferably 0.5 times or less of the outer diameter L2 of the branching portion 12. By satisfying such a condition, the branch portion 12 suitable for forming a female screw on the inner peripheral surface is obtained. Further, by satisfying such a condition, the curved surface connecting the inner peripheral surface of the branch portion 12 and the inner peripheral surface of the joint body 11 is along the curved surface connecting the outer peripheral surface of the branch portion 12 and the outer peripheral surface of the joint body 11. It is possible to form a female screw on the inner peripheral surface of the branching portion 12 without making the branching portion 12 project inside the joint body 11. Therefore, pressure loss such as fluid flowing in the branch joint 10 does not occur and accumulation of dust or the like does not occur. FIG. 3 shows an example of the projecting amount L1, the outer diameter L2, the wall thickness L3, and the nominal diameter that is frequently used in the branch pipe connected to the branch part. In addition, the nominal diameter shown in FIG. 3 is the dimension of the outer diameter of the steel pipe prescribed | regulated to JIS (Japanese Industrial Standards). For example, as shown in FIG. 3, when connecting a branch pipe 40 (see FIG. 4A, etc.) having a nominal diameter “1B” to the branch portion 12, as an example, the protruding amount L1 of the branch portion 12 is 19 mm, and the outer diameter L2 is 42 mm and the wall thickness L3 are preferably 7 mm. Needless to say, these numerical values are examples, and the protrusion amount L1, the outer diameter L2, and the wall thickness L3 may be values greater than or equal to those shown in FIG.

  The branch joint 10 is made of a weldable material, and at least the welded portions 11a and 11b are preferably made of a material having a carbon content of 0.3% or less. As a material of the branch joint 10, for example, a steel pipe corresponding to SGP or STPG defined in JIS may be used.

  The branch portion 12 may be formed, for example, by plastic processing a cylindrical raw tube having the same outer diameter L4 as the joint body 11. As the plastic working, for example, a so-called bulge forming is performed in which a raw pipe is arranged in a mold having a shape corresponding to the branching portion 12, the internal pressure in the raw pipe is increased, and the side surface of the raw pipe is expanded to form the branching portion 12. Processing should be done. By performing such plastic working, the branch joint 10 in which the joint body 11 and the branch portion 12 are integrally formed is formed. Moreover, the branch part 12 which has the desired protrusion amount L1, thickness L3, and curvature radius R can be formed by controlling an internal pressure. In addition, it is good to make it the dimension according to a specification, such as adjusting the thickness of the joint main body 11 by performing machining, such as boring, after bulge forming. In addition, although the branch joint which has a branch part can also be manufactured by casting or forging, when manufactured by casting, it is not suitable for welding due to a large amount of carbon contained, or when manufactured by forging. The manufacturing cost will increase.

  In the present embodiment, a three-pronged branch joint having three openings has been described. However, the present invention is not limited to this, and the branch joint is formed in two openings formed by a welded portion and an outer peripheral surface. What is necessary is just to have at least one or more branch holes.

  In the branch joint 10 of this embodiment described above, the pipe can be easily welded to the welded portions 11a and 11b. This is because the welded portions 11a and 11b have a cylindrical shape and are suitable for welding using an automatic welding machine or the like. In addition, it may be difficult to bring in large equipment such as an automatic welder at the installation site where piping is installed, and branch piping connected to the branch section 12 at the installation site can be connected by a simple method. It is preferable that In the branch joint 10 of this embodiment, a branch pipe can be easily connected to the branch portion 12. This is because a female thread is formed on the inner peripheral surface of the branching portion 12, and therefore a branch pipe can be screwed into the female thread and connected.

  Next, with reference to FIG. 2 and FIG. 4A-FIG. 4C, the branch construction method in this embodiment is demonstrated. FIG. 4A to FIG. 4C are process diagrams for explaining the branch construction method in the present embodiment, and are views showing cross sections of a pipe, a branch joint, and a branch pipe.

  First, two pipes 20a and 20b and a branch joint 10 are prepared. The pipes 20a and 20b may be, for example, fire hydrant pipes installed on the side of the road. The end portions 21a and 21b of the pipes 20a and 20b are grooved so that, when they are abutted against the branch joint 10, an inclined surface is formed so that the outer diameter increases as it goes away from the branch joint 10. It may be processed (see FIG. 4A).

  And the branch joint 10 is provided between the piping 20a and the piping 20b so that the flow path of the piping 20a and the flow path of the piping 20b may be connected. Specifically, as shown in FIG. 4A, the end 21a of the pipe 20a is abutted against the welded part 11a of the branch joint 10, and similarly, the end of the pipe 20b is against the welded part 11b of the branch 10. Match 21b. At this time, a V-shaped groove is formed in a sectional view by the inclined surface of the welded portion 11a and the inclined surface of the end portion 21a. Similarly, a V-shaped groove is formed in a sectional view by the inclined surface of the welded portion 11b and the inclined surface of the end portion 21b. These grooves are preferably formed continuously around the entire circumference of the joint body 11.

  Next, welding is performed along the outer peripheral surfaces of the welded part 11a and the end part 21a. Similarly, welding is performed along the outer peripheral surfaces of the welded part 11b and the end part 21b. Specifically, the welded portions 11a, 11b of the joint body 11 which is an arc welding rod or a welding wire and a base material, along a V-shaped groove continuously formed on the entire circumference of the joint body 11, and It is preferable to perform so-called arc welding in which the end portions 21a and 21b of the pipes 20a and 20b are melted. Thereby, as shown to FIG. 4B, the branch joint 10 and piping 20a, 20b will be connected via the welding parts 30a, 30b which fuse | melted and solidified after that. The welded portion 11a may be butted against the end 21a and then welded, and then the welded portion 11b may be butted against the end 21b and welded.

  By performing welding along the outer peripheral surfaces of the welded portions 11a, 11b and the end portions 21a, 21b, thermal stress is evenly generated in the circumferential direction, compared to the case of welding in a part of the circumferential direction, It can suppress that piping 20a, 20b bends. If the pipes 20a and 20b are bent, it takes time to correct the work, but such a problem does not occur when the branch construction method of the present embodiment is used.

  The welding of the branch joint 10 and the pipes 20a and 20b may be performed by drawing a circle along their outer peripheral surfaces, the operation is simple, and automatic operation is possible without relying on a manual operation such as a skilled welder. It is possible to use a welding machine.

  The welding between the branch joint 10 and the pipes 20a and 20b may be performed at a work place such as a factory. Thereafter, the welded branch joint 10 and the pipes 20a and 20b are moved to an installation site of the pipes 20a and 20b (hereinafter also simply referred to as an installation site). If it is difficult to carry the pipes 20a and 20b and the branch joint 10 to the installation site, they may be welded at the installation site.

  Furthermore, a branch pipe 40 having an external thread formed on the outer peripheral surface is prepared at the installation site. The branch pipe 40 is a pipe for forming a flow path F2 branched from the flow path F1 of the pipe 20a and the pipe 20b connected by the branch joint 10. Although it is difficult to carry the pipes 20a and 20b to the installation site of the pipes 20a and 20b with the branch pipe 40 connected, it is preferable to connect the branch pipe 40 at the installation site.

  The branch pipe 40 is connected to the branch portion 12 of the branch joint 10 welded to the pipes 20a and 20b installed at the installation site. Specifically, as shown in FIG. 4C, the male screw formed on the outer peripheral surface 40 a of the branch pipe 40 is screwed into the female screw formed on the inner peripheral surface 12 a of the branch portion 12, thereby On the other hand, the branch pipe 40 is connected. The branch pipe 40 may be connected to the branch portion 12 after the pipes 20a and 20b are installed at the installation site or before.

  In the branch construction method including the steps described above, the branch joint 10 and the pipes 20a and 20b are easily welded, and the branch pipe 40 is not attached to the branch joint 10 at the installation site of the pipes 20a and 20b. Connection can be made easily without using a device or the like.

  As mentioned above, although embodiment concerning this invention was described, the specific structure shown in this embodiment was shown as an example, and it is not intending limiting the technical scope of this invention to this. Those skilled in the art may appropriately modify these disclosed embodiments, and it should be understood that the technical scope of the invention disclosed herein includes such modifications.

  10 branch joint, 11 joint body, 11a, 11b welded part, 11c branch hole, 12 branch part, 12a inner peripheral surface, 20a, 20b pipe, 21a, 21b end, 30a, 30b weld part, 40 branch pipe.

Claims (8)

A joint body having weldable cylindrical welded parts at both ends;
A branching portion integrally formed with the joint body, the tubular branching portion protruding radially outward of the joint body, and having an internal thread formed on an inner peripheral surface;
A branch joint.   2. The branch joint according to claim 1, wherein an inner peripheral surface of the branch portion having the female screw is formed as an inclined surface that is inclined so that an inner diameter of the branch portion is increased in a protruding direction of the branch portion.   The branch joint according to claim 1 or 2, wherein a thickness of a tip portion of the branch portion in a protruding direction is equal to or greater than a thickness of the joint body.   The radius of curvature of the curved surface connecting the outer peripheral surface of the branch portion and the outer peripheral surface of the joint body in a cross section passing through the central axis of the joint body and the central axis of the branch portion is 0.5 times the outer diameter of the branch portion. The branch joint according to any one of claims 1 to 3, wherein:   The branch joint according to any one of claims 1 to 4, wherein an amount of protrusion of the branch portion is 0.3 or more times an outer diameter of the branch portion.   The curved surface that connects the inner peripheral surface of the branch portion and the inner peripheral surface of the joint main body is along a curved surface that connects the outer peripheral surface of the branch portion and the outer peripheral surface of the joint main body. Branch joint. A process of abutting the welded part of the branch joint according to any one of claims 1 to 6 against an end of a pipe;
Welding along the outer peripheral surface of the end and the welded portion, and connecting the branch joint to the pipe;
Connecting the branch pipe to the branch portion by screwing a male screw formed on the outer peripheral surface of the branch pipe into a female screw formed on the inner peripheral surface of the branch portion;
Branch construction method including   The branch construction method according to claim 7, wherein the pipe is a fire hydrant pipe.

Images