Pipe joint for branch

Abstract

To provide a pipe joint for a branch which can prevent a relative movement of a case body with respect to a fluid pipe while suppressing a movement resistance when connecting split bodies.SOLUTION: In a pipe joint 1 for a branch, a case body 21 having main pipes 3a, 3b and a branch pipe 4 is constituted by a split T-shaped pipe body 31 and a split T-shaped pipe cover 32, and can be attached in a sealing manner onto an outer periphery of a fluid pipe 2 made of a synthetic resin by fastening the split T-shaped pipe body 31 and the split T-shaped pipe cover 32 by a bolt 38a and a nut 38b. The split T-shaped pipe body 31 and the split T-shaped pipe cover 32 include: a plurality of first projections 61 provided at both ends in a circumferential direction of an inner peripheral surface 34 of each of the split T-shaped pipe body 31 and the split T-shaped pipe cover 32, and extending in the circumferential direction; and a plurality of second projections 62 provided on an intermediate side of the circumferential direction from the first projections 61, and having a circumferential linear dimension L21 shorter than a circumferential linear dimension L11 of the first projection 61.SELECTED DRAWING: Figure 7

Description

Technical Field

[0001] The present invention relates to a branch pipe joint including a main pipe portion surrounding the outer periphery of a fluid pipe and a case body having a branch pipe portion branched from the main pipe portion.

Background Art

[0002] Conventionally, as a branch pipe joint capable of connecting a branch pipe, a case body having a main pipe portion surrounding the outer periphery of a fluid pipe and a branch pipe portion branched from the main pipe portion is configured by a plurality of divided bodies divided in the circumferential direction, and the divided bodies adjacent to each other in the circumferential direction are connected in the circumferential direction by a connecting means to be attached to the outer periphery of the fluid pipe in a sealed manner.

[0003] Further, in this type of branch pipe joint, for example, a plurality of first protrusions projecting from both ends in the circumferential direction on the inner circumferential surface of each divided body and extending in the circumferential direction, and a plurality of second protrusions projecting from the intermediate side in the circumferential direction on the inner circumferential surface of each divided body and extending in an oblique direction intersecting both the pipe axis direction and the circumferential direction. When the divided bodies arranged to face each other with a synthetic resin fluid pipe interposed therebetween are moved in the inner diameter direction of the fluid pipe so as to abut against each other and fastened by a connecting means, the first protrusions and the second protrusions bite into the outer circumferential surface of the fluid pipe, thereby preventing relative movement of the case body with respect to the fluid pipe in the circumferential direction and the pipe axis direction (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In the case of the branch pipe joint described in the above Patent Document 1, both the first protrusion and the second protrusion are constituted by ridges having substantially the same extension dimension, so that when each divided body moves in the inner diameter direction of the fluid pipe, it is in line contact with the outer peripheral surface of the fluid pipe. Further, particularly, the second protrusion is disposed on the intermediate side in the circumferential direction on the inner peripheral surface of the divided body, and has a larger inclination angle with respect to the moving direction of the divided body than the first protrusion. Therefore, when the divided body moves in the inner diameter direction of the fluid pipe, the moving resistance is large and it is difficult to bite into the fluid pipe. As a result, the connection work is difficult, and it is difficult to prevent the relative movement of the case body with respect to the fluid pipe in the circumferential direction and the pipe axis direction.

[0006] The present invention has been made paying attention to such problems, and an object thereof is to provide a branch pipe joint capable of suppressing the moving resistance when connecting divided bodies and preventing the relative movement of the case body with respect to the fluid pipe.

Means for Solving the Problems

[0007] In order to solve the above problems, the branch pipe joint of the present invention is a branch pipe joint having a main pipe portion surrounding the outer periphery of a fluid pipe and a branch pipe portion branching from the main pipe portion, which is constituted by a plurality of divided bodies divided in the circumferential direction, and the divided bodies adjacent to each other in the circumferential direction are connected in the circumferential direction by a connecting means so as to be attachable in a sealed manner to the outer periphery of the fluid pipe, wherein the divided body is provided with a plurality of first protrusions projecting from both ends in the circumferential direction on the inner peripheral surface of the divided body and extending in the circumferential direction, and a plurality of second protrusions projecting from an intermediate side in the circumferential direction with respect to the first protrusion and having a shorter extension dimension in the circumferential direction than the first protrusion. According to this feature, when the divided body surrounds the outer periphery of the fluid pipe, the first protrusion having a long extension dimension projecting from both ends of the divided body and slidably contacting the outer surface of the fluid pipe in the circumferential direction has a small moving resistance because it extends in the circumferential direction. On the other hand, the second protrusion has a shorter extension dimension and a smaller contact area than the first protrusion, so that it is easy to bite into the fluid pipe. Therefore, it is possible to suppress the moving resistance when connecting the divided bodies and prevent the relative movement of the case body with respect to the fluid pipe in the circumferential direction and the pipe axis direction.

[0008] The first protrusion is characterized by having an inner surface that extends rearward in the connection direction of the divided body from the connection-side end of the first protrusion. According to this feature, while the connection-side end of the first protrusion bites into the fluid pipe, the inner surface does not bite into the fluid pipe, so the movement resistance can be suppressed.

[0009] The connection-side end of the first protrusion is characterized by being formed substantially orthogonal to the connection direction of the divided body. According to this feature, relative circumferential movement of the case body with respect to the fluid pipe can be prevented.

[0010] The connection-side end of the first protrusion is characterized by having a pair of inclined surfaces that incline so as to expand toward both sides in the pipe axis direction rearward in the connection direction of the divided body. According to this feature, since the first protrusion can be easily bitten into the outer peripheral surface of the fluid pipe, the movement resistance can be suppressed.

[0011] The first protrusion is characterized by being provided at a position away from the intermediate side in the circumferential direction from the dividing surface of the divided body. According to this feature, by biting a part of the fluid pipe between the first protrusions of the divided bodies adjacent to each other in the circumferential direction so as to sandwich it in the circumferential direction, these first protrusions can cooperate to prevent relative circumferential movement.

[0012] The top of the second protrusion is characterized by being formed in a dot shape. According to this feature, the top of the second protrusion comes into point contact with the outer surface of the fluid pipe, improving the biting into the fluid pipe.

[0013] The second protrusion is characterized by being formed in a substantially conical shape. According to this feature, the top of the second protrusion formed in a substantially conical shape makes point contact with the outer surface of the fluid pipe, improving the biting-in to the fluid pipe and preventing relative movement of the case body in all directions including the axial direction and circumferential direction of the fluid pipe.

[0014] At least one of the first protrusion and the second protrusion is characterized by being inclined with respect to the connection direction of the divided body. According to this feature, when integrally molding the first protrusion and the second protrusion on the inner peripheral surface of the divided body using a mold, it becomes easier to demold in the connection direction of the divided body.

Brief Description of the Drawings

[0015]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Figure 13

Figure 14

Embodiment for Carrying Out the Invention

[0016] A mode for carrying out the branch pipe joint according to the present invention will be described below based on examples.

Examples

[0017] The branch pipe joint according to the embodiment of the present invention will be described with reference to FIGS. 1 to 14. In the following description, the lower side of FIG. 1(a) is defined as the front of the branch pipe joint, the upper side as the rear, the left side as the left, and the right side as the right for explanation.

[0018] As shown in FIGS. 1(a) and (b), at a predetermined position of the fluid pipe 2 constituting the existing flow path, a branch pipe joint 1 as an embodiment of the present invention is attached in a sealed state. The fluid in the fluid pipe 2 is tap water in this embodiment, but it is not limited thereto, and for example, it may be industrial water, agricultural water, sewage, etc., or a gas or a gas-liquid mixture of gas and liquid.

[0019] Further, the fluid pipe 2 according to the present invention is made of polyethylene and is formed in a cylindrical shape with a substantially circular cross-section in a cross-sectional view. In addition, the fluid pipe according to the present invention may be a synthetic resin pipe such as a vinyl chloride pipe or a polyolefin pipe. Furthermore, if the fluid pipe according to the present invention is softer than the first protrusion and the second protrusion described later, it may be made of metal such as ductile cast iron, other cast iron, steel, or concrete. Furthermore, the inner peripheral surface of the fluid pipe may be coated with an epoxy resin layer, mortar, plating, etc., or the inner peripheral surface of the fluid pipe may be coated with an appropriate material by powder coating.

[0020] As shown in FIG. 2, the branch pipe joint 1 includes a case body 21 having main pipe portions 3a and 3b that surround the outer periphery of the fluid pipe 2 and a branch pipe portion 4 that branches from the main pipe portion 3a. As shown in FIGS. 2 to 4, the case body 21 is composed of a split T-shaped pipe body 31 and a split T-shaped pipe cover 32 as split bodies and has a split structure that is split into two in the circumferential direction along the pipe axis T1 of the fluid pipe 2. Specifically, the split T-shaped pipe body 31 is composed of a main pipe portion 3a that surrounds the rear portion of the outer peripheral surface of the fluid pipe 2 and a branch pipe portion 4 that protrudes from the outer periphery of the main pipe portion 3a. The split T-shaped pipe cover 32 is composed only of the main pipe portion 3b that surrounds the front portion of the outer peripheral surface of the fluid pipe 2.

[0021] In addition, in this embodiment, the split T-shaped pipe cover 32 is composed only of the main pipe portion 3b, but may have a branch pipe portion. Further, the branch pipe portion may be provided so as to be dividable at the split surface of the front and rear split bodies. Furthermore, although the case body 21 of this embodiment is composed of two split bodies (split T-shaped pipe body 31 and split T-shaped pipe cover 32), it may be composed of three or more split bodies.

[0022] Also, the split T-shaped pipe cover 32 and the split T-shaped pipe body 31 are made of ductile cast iron, which has higher strength than the polyethylene fluid pipe 2, but they may also be made of other metals such as cast iron or steel, or made of concrete. They may also be made of the same polyethylene as the fluid pipe 2, or made of other synthetic resins such as vinyl chloride or polyolefin. That is, it is preferable that the split T-shaped pipe cover 32 and the split T-shaped pipe body 31 have higher strength than the fluid pipe 2, but they do not necessarily have to be higher, and the materials are not limited to those described above.

[0023] As shown in FIGS. 1(a), (b) and 2, the branch pipe portion 4 is formed in a cylindrical shape having a central axis T2 that is substantially orthogonal to the pipe axis T1 of the fluid pipe 2 and extends substantially horizontally in the front-rear direction. In addition, a branch hole (not shown) is formed at a position corresponding to the branch hole 4a (see FIG. 3(b)) of the branch pipe portion 4 in the fluid pipe 2, and the fluid pipe 2 communicates with the branch pipe 5. Further, at the open end of the branch pipe portion 4, a partition valve device 50 having a valve body 50a (see FIG. 1(b)) capable of opening and closing the inside of the branch pipe portion 4 is connected in a sealed manner. Further, the branch pipe 5 is connected to the partition valve device 50 in a sealed manner. That is, the branch pipe 5 is connected to the branch pipe portion 4 in a sealed manner via the partition valve device 50, and by opening and closing the valve body 50a of the partition valve device 50, the fluid pipe 2 and the branch pipe 5 can be put into a communicating state or a non-communicating state.

[0024] [Split T-shaped pipe] As shown in FIGS. 2 and 3(a), (b), the split T-shaped pipe body 31 forms a semi-circular arc shape when viewed from the direction of the pipe axis T1 of the fluid pipe 2, and has a semi-cylindrical main pipe portion 3a that extends in the direction of the pipe axis T1 so as to cover the rear part of the outer peripheral surface of the fluid pipe 2, and a branch pipe portion 4 that protrudes at the central position in the left-right direction on the outer periphery of the main pipe portion 3a. A branch hole 4a communicating with the branch pipe portion 4 is formed at a position corresponding to the branch pipe portion 4 in the main pipe portion 3a. A pair of flange portions 33, 33 protruding in the outer diameter direction are formed at both circumferential ends of the main pipe portion 3a.

[0025] The inner peripheral surface 34 of the main pipe portion 3a is formed as a concave curved surface having substantially the same curvature as the outer peripheral surface of the fluid pipe 2. More specifically, the inner diameter dimension L2 (see FIG. 3) of the inner peripheral surface 34 of the split T-shaped pipe body 31 is formed slightly larger than the designed outer diameter dimension L1 (see FIG. 2) of the fluid pipe 2. Further, on the left and right sides of the inner peripheral surface 34, concave packing groove portions 35, 35 capable of accommodating the seal packing 40 are extended in the circumferential direction. Further, on the left and right outer sides of the packing groove portions 35, 35, concave accommodation groove portions 36, 36 capable of accommodating the locking member 24 are extended in the circumferential direction.

[0026] On the inner diameter side of the front surface of the flange portions 33, 33 which are the split surfaces of the main pipe portion 3a, concave packing groove portions 37, 37 capable of accommodating the seal packing 40 are linearly extended along the peripheral edge of the inner peripheral surface 34 from the left packing groove portion 35 to the right packing groove portion 35. Further, on the outer diameter side of the flange portions 33, 33, a plurality of bolt insertion holes 39 (five in the front and rear directions in this example) through which bolts 38a (see FIG. 1(a)), which are fastening members for fastening the split T-shaped pipe body 31 and the split T-shaped pipe cover 32, can be inserted are formed.

[0027] As shown in FIGS. 3(a) and 3(b), the inner peripheral surface 34 formed between the left and right packing groove portions 35, 35 in the main pipe portion 3a has, at both ends in the circumferential direction (upper and lower sides), first regions 60a, 60a extending in the left-right direction, and a second region 60b provided between the first regions 60a, 60a in the circumferential direction.

[0028] In the first regions 60a, 60a, a plurality of first protrusions 61 are provided in a row at predetermined intervals in the left-right direction along the flange portions 33, 33. In the second region 60b, a plurality of second protrusions 62 are provided in a row at predetermined intervals in the left-right direction along the flange portions 33, 33, and a plurality of rows of the second protrusion groups formed of these plurality of second protrusions 62 are provided at predetermined intervals in the circumferential direction.

[0029] As shown in FIGS. 5(a) and 5(b), each first protrusion 61 is composed of a front surface 61a standing upright linearly on the inner peripheral surface 34, inclined surfaces 61b, 61b inclined left and right rearward from the front surface 61a, side surfaces 61c, 61c extending in the circumferential direction from the inclined surfaces 61b, 61b, and an inner surface 61d facing the inner diameter side. The linear dimension L11 (about 9 mm), which is the extension dimension in the circumferential direction, is longer than the left and right dimension L12 (about 4 mm) in the axial direction (L11 > L12). That is, the first protrusion 61 is configured as a linear protrusion extending in the circumferential direction as a whole shape because the length dimension in the circumferential direction of the bottom surface is longer than the length dimension in the direction of the pipe axis T1.

[0030] Also, as shown in FIG. 6, each first protrusion 61 is provided so that the inner surface 61d projects at a position a predetermined distance away from the upper and lower end sides in the circumferential direction toward the middle side in the circumferential direction on the inner peripheral surface 34, and is substantially parallel to the moving direction (front-rear direction) when connecting the split T-shaped pipe body 31 and the split T-shaped pipe cover 32. The apex angle θ1, which is the inner angle between the inner surface 61d and the front surface 61a, is about 90 degrees (θ1 = about 90 degrees). Since the front surface 61a is substantially orthogonal to the moving direction (front-rear direction) when connecting the split T-shaped pipe body 31 and the split T-shaped pipe cover 32, it is slightly inclined with respect to the radial direction. The radial protrusion dimension L13 is about 2 mm (L13 = about 2 mm), and the vertical dimension L14 of the front surface 61a is about 2.1 mm (L4 = about 2.1 mm). The vertical dimension L14 of the front surface 61a is slightly longer than the radial protrusion dimension L13 (L13 < L14).

[0031] As shown in FIGS. 5(a) and 5(c), each second protrusion 62 has a substantially circular bottom surface and is formed in a conical shape protruding toward the inner diameter direction. The linear dimension L21, which is the extension dimension in the circumferential direction, is the same as the left and right dimension L22 in the axial direction (L21 = L22).

[0032] Further, as shown in FIG. 6, each of the second protrusions 62 projects from the upper and lower end sides in the circumferential direction on the inner circumferential surface 34 toward the intermediate side in the circumferential direction (the left side in FIG. 6) such that the height from each bottom surface to the top 62a faces the inner diameter direction. Note that the second protrusion 62 in the fifth row counted from the first protrusion 61 side projects so that its height faces forward (the right side in FIG. 6). Further, the radial protrusion dimension L23 is approximately 2 mm (L23 = approximately 2 mm), and the apex angle θ2 is approximately 90 degrees (θ2 = approximately 90 degrees).

[0033] In this way, the first protrusion 61 and the second protrusion 62 have substantially the same radial protrusion dimensions L13 and L23 (L13 ≈ L23), but the circumferential linear dimension L21 of the second protrusion 62 is formed shorter than the circumferential linear dimension L11 of the first protrusion 61 (L11 > L21). That is, the first protrusion 61 is a protrusion extending linearly in the circumferential direction, whereas the second protrusion 62 has an overall shape of a dot-like protrusion because the circumferential length dimension of the bottom surface and the length dimension in the tube axis T1 direction are substantially the same.

[0034] Note that in this embodiment, the circumferential extension dimension of the first protrusion 61 is defined as the circumferential linear dimension L11, and the circumferential extension dimension of the second protrusion 62 is defined as the circumferential linear dimension L21. However, the circumferential extension dimensions of the first protrusion 61 and the second protrusion may be defined as the curved length dimensions along the inner circumferential surface 34.

[0035] Further, on the front end portion of the first protrusion 61, inclined surfaces 61b, 61b are formed so as to incline in a V shape so as to spread left and right in the circumferential direction from the front surface 61a when viewed from the inner diameter side, so that the first protrusion 61 can be easily bitten into the outer circumferential surface of the fluid tube 2.

[0036] On the other hand, as shown in FIG. 4, the split T-shaped tube cover 32 has the same configuration as the split T-shaped tube body 31 except that it does not have the branch pipe portion 4 of the split T-shaped tube body 31 described above. Therefore, in FIG. 4, the same reference numerals are given to the same configurations and parts as those of the split T-shaped tube body 31, and detailed description thereof is omitted.

[0037] In the present embodiment, regarding the arrangement of the first protrusion 61 and the second protrusion 62, as shown in FIGS. 3(b) and 4(b), a form in which the split T-shaped tube body 31 and the split T-shaped tube cover 32 have substantially the same arrangement and substantially the same alignment is illustrated. However, the present invention is not limited to this, and the split T-shaped tube body 31 and the split T-shaped tube cover 32 may be alternately arranged and aligned with each other.

[0038] Further, in the present embodiment, the first protrusion 61 and the second protrusion 62 are integrally formed with the split T-shaped tube body 31 and the split T-shaped tube cover 32 by casting. However, the present invention is not limited to this. A sheet member or the like provided with the first protrusion and the second protrusion may be provided separately from the case body, and the first protrusion and the second protrusion may be provided on the inner peripheral surface of the case body by arranging the sheet member on the inner peripheral surface of the case body.

[0039] Further, in the present embodiment, the split T-shaped tube body 31 and the split T-shaped tube cover 32 are formed by casting. When demolding, the mold is extracted from each of the split T-shaped tube body 31 and the split T-shaped tube cover 32 in a direction orthogonal to the split surface of the flange portion 33, so that the first protrusion 61 and the second protrusion 62 can be easily formed. In particular, by setting the demolding direction to be orthogonal to the split surface of the flange portion 33, the first protrusion 61 extending in the circumferential direction can be easily formed.

[0040] As shown in FIG. 7, when the flange portions 33, 33 of the split T-shaped tube body 31 and the split T-shaped tube cover 32 configured in this way are butted against each other and arranged, a cylindrical inner peripheral surface is formed by the front and rear semi-circular inner peripheral surfaces 34, 34, and the first protrusions 61, 61 and the second protrusions 62, 62 formed on each are arranged so as to face each other front and back. In particular, the first protrusions 61, 61 of each of the split T-shaped tube body 31 and the split T-shaped tube cover 32 are arranged in the vicinity of the front and rear sides of the split surface.

[0041] Next, as shown in FIG. 2, the seal packing 40 is made of an elastically deformable rubber material and is composed of semi-circular arc-shaped portions 41, 41 that are spaced apart from each other left and right, and connecting portions 42, 42 that connect the upper ends and the lower ends of the semi-circular arc-shaped portions 41, 41. The semi-circular arc-shaped portions 41, 41 can be accommodated in the packing grooves 35, 35 of the split T-shaped pipe body 31 and the split T-shaped pipe cover 32, and the connecting portions 42, 42 are formed so as to be accommodable in the packing grooves 37, 37 of the split T-shaped pipe body 31 and the split T-shaped pipe cover 32.

[0042] Also, a convex portion 43 (see FIG. 8(a)) extending in the longitudinal direction is formed on one of the connecting portions 42, 42, and a concave portion 44 (see FIG. 8(a)) extending in the longitudinal direction is formed on the other. When fastening the split T-shaped pipe body 31 and the split T-shaped pipe cover 32, the seal packing 40 provided on the split T-shaped pipe body 31 and the seal packing 40 provided on the split T-shaped pipe cover 32 abut against each other in a facing state. Therefore, the convex portion 43 of the seal packing 40 provided on the split T-shaped pipe body 31 fits into the concave portion 44 of the seal packing 40 provided on the split T-shaped pipe cover 32, and the convex portion 43 of the seal packing 40 provided on the split T-shaped pipe cover 32 fits into the concave portion 44 of the seal packing 40 provided on the split T-shaped pipe body 31. As a result, the connecting portions 42, 42 of the split T-shaped pipe body 31 and the connecting portions 42, 42 of the split T-shaped pipe cover 32 abut against each other in a sealed manner.

[0043] As shown in FIG. 2, the locking member 24 is divided into a plurality (seven in this example) in the circumferential direction, locking claws 24a are formed on the inner peripheral surface, and it is composed of an arc-shaped member made of polyacetal, which has higher strength than the fluid pipe 2 made of polyethylene, and a fixing clip (not shown) that connects the fixing bosses (not shown) protruding from both ends of each arc-shaped member. By winding the arc-shaped members connected in an endless string shape by a plurality of fixing clips in the circumferential direction and connecting both ends by an O-ring (not shown) to form an annular shape, it can be attached to the outer peripheral surface of the fluid pipe 2.

[0044] [Attachment of the case body to the fluid pipe] Next, a process of sealingly attaching a case body 21 composed of a split T-shaped pipe body 31 and a split T-shaped pipe cover 32 to the outer peripheral surface of a fluid pipe 2 will be described with reference to FIGS. 8 to 14.

[0045] To externally fit the split T-shaped pipe body 31 and the split T-shaped pipe cover 32 onto the fluid pipe 2, first, although not particularly shown, locking members 24, 24 connected in an endless string shape by a plurality of fixing clips (not shown) are wound circumferentially on both sides in the pipe axis T1 direction of the attachment positions of the split T-shaped pipe body 31 and the split T-shaped pipe cover 32 on the outer periphery of the fluid pipe 2, and both ends are connected by O-rings (not shown) to form an annular shape and attached.

[0046] Next, as shown in FIG. 8(a), a case body 21 in which seal packings 40 are accommodated and arranged in the packing groove portions 35, 37 of the split T-shaped pipe body 31 and the split T-shaped pipe cover 32 respectively is arranged with the split T-shaped pipe body 31 and the split T-shaped pipe cover 32 facing the front and rear sides of the fluid pipe 2 such that their flange portions 33, 33 face each other. Then, the split T-shaped pipe body 31 and the split T-shaped pipe cover 32 move in the inner diameter direction (front-rear direction) so as to approach each other such that the locking members 24, 24 attached to the outer peripheral surface of the fluid pipe 2 are accommodated in the accommodation groove portions 36, 36.

[0047] Here, a situation where each first protrusion 61 and each second protrusion 62 bite into the outer peripheral surface of the fluid pipe 2 will be described with reference to FIGS. 9 to 12. In the following, the first protrusions 61 and second protrusions 62 protruding from the inner peripheral surface 34 of the split T-shaped pipe body 31 will be described as an example. However, since the situation where the first protrusions 61 and second protrusions 62 protruding from the inner peripheral surface 34 of the split T-shaped pipe cover 32 bite into the outer peripheral surface of the fluid pipe 2 is the same, the description thereof will be omitted.

[0048] When the split T-shaped pipe body 31 approaches the fluid pipe 2, as shown in FIG. 9(a), first, the upper and lower end sides in the circumferential direction on the inner peripheral surface 34 of the split T-shaped pipe body 31 approach the fluid pipe 2 earlier than the intermediate side in the circumferential direction, so that the first protrusion 61 comes into contact with the outer peripheral surface of the fluid pipe 2.

[0049] Next, as shown in Fig. 9(b), when the split T-shaped tube body 31 is further moved forward, the first protrusion 61 bites into the outer periphery of the fluid tube 2. Then, since the inner peripheral surface 34 gradually approaches the intermediate side from the upper and lower end sides in the circumferential direction, the outer peripheral surface of the fluid tube 2 is sequentially contacted and bitten into by the second protrusions 62 from the second protrusion 62 close to the first protrusion 61 toward the second protrusion 62 on the intermediate side in the circumferential direction.

[0050] Next, as shown in Fig. 9(c), when the split T-shaped tube body 31 is further moved forward, all the first protrusions 61 and the second protrusions 62 bite into the outer peripheral surface of the fluid tube 2, and substantially the entire inner peripheral surface 34 abuts against the outer peripheral surface of the fluid tube 2. As a result, the flange portions 33, 33 of the front split T-shaped tube cover 32 and the rear split T-shaped tube body 31 are brought close to each other and are in a state where they can be connected (see Fig. 8(b)).

[0051] Next, the details of the situation where the first protrusion 61 bites into the outer periphery of the fluid tube 2 will be described. The two-dot chain lines in Figs. 10(a) and 10(b) indicate the regions where the first protrusion 61 is expected to bite in.

[0052] As shown in Fig. 10(a), first, the corner between the front surface 61a and the inner surface 61d of the first protrusion 61 contacts the outer peripheral surface of the fluid tube 2. At this time, the front surface 61a is substantially orthogonal to the moving direction (black arrow direction) when connecting the split T-shaped tube body 31 and the split T-shaped tube cover 32, while the inner surface 61d is substantially parallel to the moving direction (black arrow direction).

[0053] Then, as shown in Figs. 10(b) and 10(c), since the upper and lower sides of the inner peripheral surface 34 near the first protrusion 61 and the outer peripheral surface of the fluid tube 2 are only slightly inclined with respect to the moving direction of the split T-shaped tube body 31, the moving direction of the first protrusion 61 with respect to the fluid tube 2 has a larger circumferential component than the inner diameter component. Therefore, the front end portion of the first protrusion 61, which consists of the linear front surface 61a substantially orthogonal to the moving direction and the pair of inclined surfaces 61b, 61b (see Fig. 5), bites into the outer peripheral surface of the fluid tube 2 in the circumferential direction so as to split it.

[0054] Further, the first protrusion 61 extends linearly in the circumferential direction, and since the inner surface 61d is provided substantially parallel to the moving direction, while the front surface 61a and the inclined surfaces 61b, 61b bite into the outer peripheral surface of the fluid pipe 2, the inner surface 61d only makes sliding contact with the outer peripheral surface of the fluid pipe 2 and does not bite in. Therefore, compared with a linear protrusion that is obliquely arranged with respect to the circumferential direction or a linear protrusion formed such that the inner surface 61d follows the inner peripheral surface 34, the moving resistance of the split T-shaped pipe body 31 is suppressed. Further, in a state where the first protrusion 61 bites into the fluid pipe 2, since the inner surface 61d of the first protrusion 61 abuts against the outer peripheral surface of the fluid pipe 2 without a gap over substantially the entire surface, the biting state of the first protrusion 61 can be maintained.

[0055] Next, as shown in Fig. 11(a), for the second protrusion 62 adjacent to the first protrusion 61, first, the dot-like top 62a contacts the outer peripheral surface of the fluid pipe 2. Then, as shown in Figs. 11(b) and (c), since the inner peripheral surface 34 and the outer peripheral surface of the fluid pipe 2 near the second protrusion 62 have a greater inclination with respect to the moving direction of the split T-shaped pipe body 31 than the inner peripheral surface 34 and the outer peripheral surface of the fluid pipe 2 near the first protrusion 61, in the moving direction of the second protrusion 62 with respect to the fluid pipe 2, the inner diameter direction component that bites into the fluid pipe 2 becomes larger than that of the first protrusion 61. Therefore, the second protrusion 62 bites into the inner diameter direction of the outer peripheral surface of the fluid pipe 2 from the top 62a to the conical surface 62b while slightly moving in the circumferential direction of the outer peripheral surface of the fluid pipe 2.

[0056] Next, as shown in Fig. 12(a), for the second protrusion 62 on the intermediate side in the circumferential direction, first, the dot-like top 62a contacts the outer peripheral surface of the fluid pipe 2. Then, as shown in Figs. 12(b) and (c), since the inner peripheral surface 34 and the outer peripheral surface of the fluid pipe 2 near the second protrusion 62 have the largest inclination with respect to the moving direction of the split T-shaped pipe body 31 compared with the inner peripheral surface 34 and the outer peripheral surface of the fluid pipe 2 near the first protrusion 61, the biting in the moving direction of the second protrusion 62 with respect to the fluid pipe 2 becomes substantially equal to the inner diameter direction component. Therefore, the second protrusion 62 bites into the outer peripheral surface of the fluid pipe 2 in the inner diameter direction from the top 62a to the conical surface 62b.

[0057] Thus, although the inner diameter direction component of the second protrusion 62 is larger than that of the first protrusion 61, since it is formed in a conical shape, the contact area with respect to the outer peripheral surface of the fluid pipe 2 is small, so the movement resistance generated when biting into the outer peripheral surface of the fluid pipe 2 is suppressed.

[0058] Further, when the first protrusion 61 and the second protrusion 62 bite into the outer peripheral surface of the fluid pipe 2, as shown in FIG. 13, on the outer peripheral surface of the fluid pipe 2, a linear recess 71 extending in the circumferential direction is formed by the first protrusion 61 biting in, and a dot-like recess 72 is formed by the second protrusion 62 biting in. Thus, the shapes of the recesses 71 and 72 are different between the vicinity of the split surface and the location away from the split surface of the split T-shaped pipe body 31 and the split T-shaped pipe cover 32.

[0059] Even if the first protrusion 61 is formed in a dot shape, a recess 71 extending in the circumferential direction is formed in the vicinity of the split surface on the outer peripheral surface of the fluid pipe 2. However, in this recess 71, since the linear first protrusion 61 extending in the circumferential direction with respect to the outer peripheral surface of the fluid pipe 2 bites widely in the extending direction, the regulating force of the relative movement of the case body 21 in the pipe axis T1 direction with respect to the outer peripheral surface of the fluid pipe 2 increases.

[0060] Also, as shown in FIG. 14, the upper and lower first protrusions 61, 61 of the split T-shaped tube body 31 and the upper and lower first protrusions 61, 61 of the split T-shaped tube cover 32 are arranged to face each other in the circumferential direction near the split surface between the split T-shaped tube body 31 and the split T-shaped tube cover 32. As a result, at each of the upper and lower locations of the split T-shaped tube body 31, a part of the outer periphery of the fluid tube 2 is clamped between the front and rear first protrusions 61, 61. Specifically, as shown in FIG. 14, the relative rotation of the case body 21 forward with respect to the outer peripheral surface of the fluid tube 2 (clockwise in the drawing, in the direction of the solid line arrow) is restricted by a part of the outer periphery of the fluid tube 2 abutting against the front surface 61a of the upper first protrusion 61 in the split T-shaped tube body 31 and the front surface 61a of the lower first protrusion 61 in the split T-shaped tube cover 32 located substantially diagonally thereto. Conversely, the relative rotation of the case body 21 rearward with respect to the outer peripheral surface of the fluid tube 2 (counterclockwise in the drawing, in the direction of the dotted line arrow) is restricted by a part of the outer periphery of the fluid tube 2 abutting against the front surface 61a of the upper first protrusion 61 in the split T-shaped tube cover 32 and the front surface 61a of the lower first protrusion 61 in the split T-shaped tube body 31 located substantially diagonally thereto. Therefore, the relative rotation of the case body 21 in the circumferential direction with respect to the outer peripheral surface of the fluid tube 2 is prevented.

[0061] Further, by the dot-shaped second protrusions 62 biting into the outer peripheral surface of the fluid tube 2, not only the relative movement of the case body 21 in the tube axis T1 direction and the circumferential direction with respect to the outer peripheral surface of the fluid tube 2 but also the relative movement in all directions including the tube axis T1 direction and the circumferential direction is prevented. Furthermore, compared with the case where the linear first protrusions 61 are provided protruding into the second region 60b, the movement resistance when moving the split T-shaped tube body 31 and the split T-shaped tube cover 32 can be suppressed, so that the fastening operation becomes easier.

[0062] Next, as shown in FIG. 8(b), the split T-shaped tube body 31 and the split T-shaped tube cover 32 are butted against each other front and rear, a bolt 38a attached from the front to the bolt insertion hole 39 of the split T-shaped tube cover 32 is inserted into the bolt insertion hole 39 of the split T-shaped tube body 31, and a nut 38b is screwed onto the tip of the bolt 38a protruding upward from the bolt insertion hole 39, thereby fastening the split T-shaped tube body 31 and the split T-shaped tube cover 32, and the fluid tube 2 is attached to the outer peripheral surface in a sealed manner.

[0063] Further, when the first protrusion 61 and the second protrusion 62 bite into the outer peripheral surface of the fluid pipe 2, relative movement of the case body 21 composed of the split T-shaped pipe main body 31 and the split T-shaped pipe cover 32 in the pipe axis T1 direction and the circumferential direction with respect to the fluid pipe 2 is prevented.

[0064] Thereby, for example, when the fluid pipe 2, the branch pipe joint 1, and the branch pipe 5 buried in the ground are exposed due to collapse caused by heavy rain disasters, ground deformation due to liquefaction, etc., and the branch pipe 5 sinks, a force causing relative rotation in the circumferential direction of the case body 21 with respect to the fluid pipe 2 is generated. Even in such a case, since the relative rotation of the case body 21 is prevented, the case body 21 itself does not rotate to block a branch hole (not shown) formed in the fluid pipe 2, and the communication between the fluid pipe 2 and the branch pipe 5 can be maintained.

[0065] In addition, in the present embodiment, a form in which bolts 38a and nuts 38b are applied as connection means for connecting the split T-shaped pipe main body 31 and the split T-shaped pipe cover 32 is illustrated. However, the present invention is not limited to this, and connection means other than bolts and nuts, such as bolts and screw holes, may be used for connection.

[0066] [Function and Effect] As described above, in the branch pipe joint 1 as an embodiment of the present invention, a case body 21 having main pipe portions 3a, 3b that surround the outer periphery of a fluid pipe 2 made of synthetic resin and a branch pipe portion 4 that branches from the main pipe portion 3a is configured by a split T-shaped pipe body 31 and a split T-shaped pipe cover 32 that are a plurality of split bodies divided in the circumferential direction. By connecting the split T-shaped pipe body 31 and the split T-shaped pipe cover 32 adjacent to each other in the circumferential direction with bolts 38a and nuts 38b as connecting means in the circumferential direction, it can be attached to the outer periphery of the fluid pipe 2 in a sealed manner. The split T-shaped pipe body 31 and the split T-shaped pipe cover 32 are provided with a plurality of first protrusions 61 that project from both ends in the circumferential direction on the inner circumferential surface 34 of each of the split T-shaped pipe body 31 and the split T-shaped pipe cover 32 and extend in the circumferential direction, and a plurality of second protrusions 62 that project from the intermediate side in the circumferential direction on the inner circumferential surface 34 of the split T-shaped pipe body 31 and the split T-shaped pipe cover 32 rather than the first protrusions 61, and the linear dimension L21 (circumferential extension dimension) in the circumferential direction is shorter than the linear dimension L11 (circumferential extension dimension) in the circumferential direction of the first protrusions 61.

[0067] According to this, when surrounding the outer peripheral surface of the fluid pipe 2 with the split T-shaped pipe body 31 and the split T-shaped pipe cover 32, the first protrusions 61 that project from both ends of the split T-shaped pipe body 31 and the split T-shaped pipe cover 32 and have a long extension that is in sliding contact with the outer peripheral surface of the fluid pipe 2 in the circumferential direction have a small moving resistance because they extend in the circumferential direction. On the other hand, the second protrusions 62 are more likely to bite into the outer peripheral surface of the fluid pipe 2 because their extension dimension is shorter and their contact area is smaller than that of the first protrusions 61. Therefore, it is possible to prevent relative movement of the case body 21 with respect to the fluid pipe 2 in the circumferential direction and the pipe axis T1 direction while suppressing the moving resistance when connecting the split T-shaped pipe body 31 and the split T-shaped pipe cover 32.

[0068] Further, the first protrusion 61 has an inner surface 61d that extends backward from the front end portion (connection side end portion) of the first protrusion 61 in the moving direction (connection direction) of the split T-shaped pipe body 31 and the split T-shaped pipe cover 32. Therefore, the front end portion of the first protrusion 61 bites into the fluid pipe 2, while the inner surface 61d does not bite into the fluid pipe 2, so that the moving resistance can be suppressed.

[0069] Further, the front end portion (connection side end portion) of the first protrusion 61 is formed substantially orthogonal to the moving direction (connection direction) of the split T-shaped pipe body 31 and the split T-shaped pipe cover 32, thereby preventing the circumferential relative movement of the case body 21 with respect to the fluid pipe 2.

[0070] Also, on the front end portion (connection side end portion) of the first protrusion 61, a pair of inclined surfaces 61b, 61b are formed which are inclined so as to expand toward the left and right sides in the pipe axis T1 direction toward the rear in the moving direction (connection direction) of the split T-shaped pipe body 31 and the split T-shaped pipe cover 32. Thus, the first protrusion 61 can be easily bitten into the outer peripheral surface of the fluid pipe 2 as if cutting it.

[0071] Also, the first protrusion 61 is provided at a position separated from the split surface of the split T-shaped pipe body 31 and the split T-shaped pipe cover 32 toward the intermediate side in the circumferential direction. By biting a part of the fluid pipe 2 between the first protrusions 61, 61 of the split T-shaped pipe body 31 and the split T-shaped pipe cover 32 adjacent to each other in the circumferential direction so as to sandwich it in the circumferential direction, these first protrusions 61, 61 can cooperate to prevent the circumferential relative movement.

[0072] Also, the top 62a of the second protrusion 62 is formed in a dot shape. By the top 62a of the second protrusion 62 making point contact with the outer peripheral surface of the fluid pipe 2, the biting-in to the fluid pipe 2 is improved.

[0073] Also, the second protrusion 62 is formed in a substantially conical shape. By the top 62a of the second protrusion 62 making point contact with the outer peripheral surface of the fluid pipe 2, the biting-in to the fluid pipe 2 is improved, and the relative movement of the case body 21 with respect to the fluid pipe 2 in all directions including the pipe axis T1 direction and the circumferential direction can be prevented.

[0074] Further, at least one of the first protrusion 61 and the second protrusion 62 is inclined with respect to the connection direction of the split T-shaped tube body 31 and the split T-shaped tube cover 32, so that when the first protrusion 61 or the second protrusion 62 is integrally formed on the inner peripheral surface 34 of the split T-shaped tube body 31 and the split T-shaped tube cover 32 using a mold (not shown), it becomes easier to demold in the connection direction of the split T-shaped tube body 31 and the split T-shaped tube cover 32.

[0075] Specifically, it is desirable that at least one of the inclined surfaces 61b, 61b and side surfaces 61c, 61c other than the inner surface 61d of the first protrusion 61 and the conical surface 62b of the second protrusion 62 is inclined (has a draft angle) with respect to the demolding direction of the casting mold as appropriate. By doing so, when the first protrusion 61 or the second protrusion 62 is integrally formed on the inner peripheral surface 34 of the split T-shaped tube body 31 or the split T-shaped tube cover 32, it becomes easier to demold in the connection direction of the split T-shaped tube body 31 and the split T-shaped tube cover 32, and thus the formation of the first protrusion 61 and the second protrusion 62 becomes easier.

[0076] As described above, the embodiments of the present invention have been described with reference to the drawings. However, the specific configuration is not limited to these embodiments, and modifications and additions within the scope not departing from the gist of the present invention are also included in the present invention.

[0077] For example, in the above embodiment, the first protrusions 61 were arranged in only one row along the tube axis T1 on both end sides in the circumferential direction of the inner peripheral surface 34, but two or more rows may be provided in the circumferential direction. Specifically, for example, the first regions 60a, 60a may be in a range where the inclination angle of the tangent to the inner peripheral surface 34 with respect to the moving direction of the split T-shaped tube body 31 and the split T-shaped tube cover 32 is less than about 25 degrees (for example, in a range of about 15 to 25 degrees from both ends in the circumferential direction). The arrangement position and the number of arrangements of the first protrusions 61 in the tube axis T1 direction and the circumferential direction within this first region 60a are arbitrary and can be variously changed.

[0078] Further, in the above embodiment, the second protrusions 62 were arranged in a plurality of rows along the pipe axis T1 on the intermediate side in the circumferential direction on the inner circumferential surface 34. However, for example, the second region 60b may be in a range where the inclination angle of the tangent line of the inner circumferential surface 34 with respect to the moving direction of the split T-shaped pipe body 31 and the split T-shaped pipe cover 32 is about 25 degrees or more (for example, in a range of about 130 to 150 degrees in the circumferential direction, etc.). The arrangement position and the number of arrangements of the second protrusions 62 in the pipe axis T1 direction and the circumferential direction within this second region 60b are arbitrary and can be variously changed.

[0079] Further, in the above embodiment, the first protrusion 61 was linearly extended in the circumferential direction on the inner circumferential surface 34, but it may be provided with an inclination (such as the draft angle of the casting mold) with respect to the circumferential direction. In this case, the inclination angle with respect to the circumferential direction is preferably less than about 45 degrees.

[0080] Further, in the above embodiment, the form in which the first protrusion 61 is constituted by a linear protrusion and the second protrusion 62 is constituted by a dot-shaped protrusion was illustrated. However, the present invention is not limited to this. If the circumferential extension dimension of the second protrusion 62 is shorter than the circumferential extension dimension of the first protrusion 61, the first protrusion 61 does not necessarily have to be linearly configured, and the second protrusion 62 does not necessarily have to be dot-shaped.

[0081] Note that the above "circumferential extension dimension" means, for example, when the first protrusion or the second protrusion is provided with an inclination with respect to the circumferential direction, it is not the "length dimension in the longitudinal direction" of the first protrusion or the second protrusion, but the "extension dimension of the circumferential component" is sufficient. That is, it is sufficient that the extension dimension of the circumferential component of the second protrusion is shorter than the extension dimension of the circumferential component of the first protrusion.

[0082] Further, the "linear protrusion" means that the length dimension in the circumferential direction of the bottom surface is longer than the length dimension in the pipe axis T1 direction, and thus it extends in the circumferential direction as a whole shape. On the other hand, the "dot-shaped protrusion" means that the length dimension in the circumferential direction of the bottom surface and the length dimension in the pipe axis T1 direction are substantially the same, and thus it extends in substantially all directions with the same dimension as a whole shape.

[0083] In addition, in the above-described embodiment, the first protrusion 61 has been illustrated as having an inner surface 61d that extends backward in the moving direction of the split T-shaped pipe body 31 and the split T-shaped pipe cover 32. However, the present invention is not limited thereto, and the inner surface 61d may be formed in a curved shape or a planar shape along the inner peripheral surface 34.

[0084] In addition, in the above-described embodiment, the front end portion (connection side end portion) of the first protrusion 61 has been illustrated as being formed substantially orthogonal to the moving direction of the split T-shaped pipe body 31 and the split T-shaped pipe cover 32. However, the present invention is not limited thereto, and it may be formed to be inclined with respect to the moving direction, such as in the inner diameter direction.

[0085] In addition, in the above-described embodiment, a pair of inclined surfaces 61b, 61b that are inclined so as to expand toward both sides in the direction of the pipe axis T1 are formed at the front end portion (connection side end portion) of the first protrusion 61 in the backward direction of the moving direction of the split T-shaped pipe body 31 and the split T-shaped pipe cover 32. However, the present invention is not limited thereto, and it may be formed to taper toward the moving direction. Further, it may not have these inclined surfaces 61b, 61b.

[0086] In addition, in the above-described embodiment, the first protrusion 61 has been illustrated as being provided at a position away from the intermediate side in the circumferential direction from the split surface of the split T-shaped pipe body 31 and the split T-shaped pipe cover 32. However, the present invention is not limited thereto, and it may be provided in the vicinity of the split surface.

[0087] In addition, in the above-described embodiment, the second protrusion 62 has been formed in a dot shape. However, it does not necessarily have to be formed in a dot shape, and it may be formed in a linear shape having a shorter extension dimension than the first protrusion 61. Further, the second protrusion 62 is formed of a cone so that the top portion is formed in a dot shape, but it may be a protrusion in the shape of a column or a hemisphere whose top portion is not in a dot shape. Furthermore, although the second protrusion 62 is a cone, it may be a pyramid.

[0088] In the above embodiment, all of the plurality of first protrusions 61 were formed in the same shape, but they may be formed in different shapes depending on the arrangement position or the like. Also, all of the plurality of second protrusions 62 were formed in the same shape, but they may be formed in different shapes depending on the arrangement position or the like.

[0089] In the above embodiment, the branch pipe joint 1 was exemplified in a form that does not include a fluid control body capable of controlling the flow of fluid in the case body 21. However, the present invention is not limited to this, and a valve body such as a partition valve, a switching valve, or a butterfly valve capable of opening and closing a flow path, or a fluid control body such as a plug may be provided in the case body.

Explanation of Reference Numerals

[0090] 1 Branch pipe joint 2 Fluid pipe 3a, 3b Main pipe portion 4 Branch pipe portion 5 Branch pipe 21 Case body 24 Locking member 31 Split T-shaped pipe body (split body) 32 Split T-shaped pipe cover (split body) 33 Flange portion 34 Inner peripheral surface 35, 37 Packing groove portion 36 Accommodation groove portion 38a Bolt (connecting means) 38b Nut (connecting means) 40 Seal packing 50 Partition valve device 60a First region 60b Second region 61 First protrusion 61a Front surface (connecting side end portion) 61b Inclined surface 61c Side surface 61d Inner surface 62 Second protrusion 71, 72 Concave portion

Claims

1. A branch pipe joint, comprising a case body having a main pipe section surrounding an outer periphery of a fluid pipe and a branch pipe section branching off from the main pipe section, the case body being configured as a plurality of divided bodies divided in a circumferential direction, the divided bodies being circumferentially connected to each other by a connecting means, the branch pipe joint being capable of being hermetically attached to the outer periphery of the fluid pipe, The branch pipe fitting is characterized in that the split body has a first protrusion portion that protrudes in multiple places on both circumferential ends of the inner surface of the split body and extends in the circumferential direction, and a second protrusion portion that protrudes in multiple places toward the middle in the circumferential direction than the first protrusions and has a shorter circumferential extension dimension than the first protrusions.

2. 2. The branch pipe joint according to claim 1, wherein the first protrusion has an inner surface extending from a connection side end of the first protrusion toward the rear in the connection direction of the split bodies.

3. 2. The branch pipe joint according to claim 1, wherein a connecting end of the first projection is formed substantially perpendicular to a connecting direction of the divided bodies.

4. A branch pipe fitting as described in claim 3, characterized in that a pair of inclined surfaces are formed on the connection side end of the first protrusion portion, which incline so as to expand on both sides in the pipe axial direction toward the rear of the connection direction of the split body.

5. 5. The branch pipe joint according to claim 1, wherein the first protrusion is provided at a position away from the dividing surface of the split body toward the circumferential middle side.

6. 2. The branch pipe joint according to claim 1, wherein the top of the second projection is formed in a point shape.

7. 7. The branch pipe joint according to claim 6, wherein the second protrusion is formed in a substantially conical shape.

8. 2. The branch pipe joint according to claim 1, wherein at least one of the first protrusion and the second protrusion is inclined with respect to a direction in which the divided bodies are connected.

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