JP2003254487A - Clamp for branching - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a clamp for branching which prevents easy deformation of both flange parts of an upper clamp body and a lower clamp body due to clamping force, and also minimizes deformation of a boss part. <P>SOLUTION: The clamp for branching is characterized in that the flange parts 4 and 5 are formed so as to protrude outward in parallel with each other at positions respectively separated a predetermined length toward clamp body centers from both mutually facing upper and lower end rims 2a and 3a of the upper clamp body 2 and the lower clamp body 3. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fluid transportation pipeline for water, gas, etc., when a branch is required from the midway of a newly laid pipeline, or to branch from an already buried pipeline. The present invention relates to a branching clamp used when new piping is needed.

[0002]

2. Description of the Related Art Opportunities for constructing new pipes branched from existing pipelines for underground such as water and gas are frequent. At this time, a part of the pipeline at the point where the branch is planned is excavated from the ground, a branch hole of a desired size is drilled in the existing pipe, and the branch end of the new pipe is joined to this branch hole. It is necessary to construct the contents that form the road.

The left half of FIG. 7 (B) shows a reinforcing clamp (hereinafter referred to as "conventional clamp") which has been conventionally used as a material for extracting the branch pipe. This conventional clamp 01 has a substantially semi-cylindrical upper mold clamp body 02 and a lower mold clamp body 03 that are vertically divided into two parts. The upper mold clamp body and the lower mold clamp body are opposed to each other in the vertical direction. Mounting flange portions 04 and 05 are formed on both edges so as to project outward and substantially parallel to each other. Bolt insertion holes 06 and 07 are formed in the flange portion, and bolt nuts 08 and 09 that fasten both clamp bodies are attached. The upper clamp body 02 and the lower clamp body 03 are fastened and integrated with each other by the bolts and nuts to hold the existing pipe 016 and cover the outer peripheral surface thereof.

A boss 011 perpendicular to the pipe axis is provided at the center of the upper clamp body 02, and an internal thread for attaching a branch pipe (branch tee) is provided at the opening of the boss. Further, an annular groove (recess) 012 for inserting the rubber ring 013 is provided on the inner peripheral surface of the upper die clamp main body 02 surrounding the perforated portion (branch hole) 017 of the existing pipe 016, and the existing pipe and the clamp are connected to each other. It has a structure that can maintain airtightness. The installation procedure is to fasten the upper clamp body 02 and the lower clamp body 03 of the conventional clamp 01 to the existing pipeline 016 using the hexagon bolts and nuts 08 and 09, and the boss portion of the upper clamp body 02.
After installing a punch in 011 and opening a branch hole in the existing pipe,
The branch pipe is screwed into the female screw on the inner surface of the boss portion 011 to take out the branch.

By the way, in the conventional clamp, when the bolt 08 is inserted into the bolt insertion holes 06 and 07 and the nut 09 is tightened at the time of mounting, the upper clamp body 02 is clamped.
Both the flange portions 04 and 05 provided at the upper and lower end edges of the lower clamp body 03 and the lower clamp body 03 tend to fall toward each other and are easily deformed, which causes a problem in strength. Moreover, the load applied to both the flange portions 04 and 05 largely acts on the boss portion 011 in the center of the upper mold clamp body 02, and the boss portion is greatly deformed as shown in FIG. 7 (A), There is also a problem that the installation of the branch pipe may be hindered.

[0006]

SUMMARY OF THE INVENTION Therefore, the present invention solves the above-mentioned conventional problems, and it is difficult for the flanges of the upper mold body and the lower mold clamp body to be deformed by a tightening force, and the boss is not deformed. It is an object of the present invention to provide a branching clamp that can minimize the deformation of a part.

[0007]

In order to achieve the above object, the invention of claim 1 is such that, when a branch pipe is attached to a part of a pipe line that requires a branch, the branch part is vertically moved in the pipe axial direction. In a branching clamp which is covered with a half-cylindrical upper mold body and a lower mold body that are divided into two parts, and which is clamped by a fastening member to support a branch pipe, the upper mold body and the lower mold body face each other. It is characterized in that the flange portions are formed so as to project outward substantially in parallel to the clamp body from the upper and lower end edges thereof at positions separated by a predetermined length toward the center of the clamp body. Preferred as the fastening member are fastening bolts and nuts.

According to a second aspect of the present invention, in the first aspect, a plurality of bolt insertion holes for mounting the fastening bolts and nuts are provided in the length direction of the flange portion so as to face each other. It is characterized in that the thickness of the flange portion provided with the bolt insertion hole is formed uniformly in the length direction of the flange portion. According to a third aspect of the present invention, in the second aspect, the bolt locking ribs are provided on both sides of the flange portion of the upper clamp body or the lower clamp body so as to sandwich the bolt insertion hole. It is characterized in that the side surface of the head formed in a square shape of the bolt is locked.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a plan view of a branching clamp attached to a branching portion of an existing pipe, FIG. 2 is a front view of the right half portion of FIG. 1, and FIG. 3 is a sectional view taken along the line AA of FIG. [Fig. 2] is a cross-sectional view taken along the line BB (left half) and the line CC (right half) in Fig. 1, respectively. In these figures, reference numeral 1 is a branching clamp (hereinafter referred to as “improved clamp”), which comprises a substantially semi-cylindrical upper mold clamp body 2 and lower mold clamp body 3 which are vertically divided into two in the tube axis direction. The upper and lower clamp body 2 and the lower clamp body 3 have flanges 4 and 5 for mounting outwardly at positions separated by a predetermined length from the upper and lower opposite edges 2a and 3a facing each other toward the center of the clamp bodies 2 and 3, respectively. It is formed so as to extend substantially parallel to. These flange parts 4,
A plurality of bolt insertion holes 6 and 7 are formed in the length direction of 5 so as to face each other, and fastening bolt nuts 8 and 9 are mounted. Reference numeral 11 denotes a boss portion provided at the center of the upper die clamp body 2 perpendicularly to the pipe axis, and 12 denotes an annular portion provided at the intermediate portion between both lower end edges 2a and the boss portion 11 on the inner peripheral surface of the upper die clamp body 2. An airtight rubber ring 13 is mounted in the groove (recess). In FIG. 3, reference numeral 15 is a branch pipe provided by screwing into the opening of the boss portion 11, 16 is an existing pipe, and 17 is a perforated portion provided in the branch portion.

Upper mold clamp body 2 and lower mold clamp body 3
The thickness (tube thickness) of is as shown in the right half of FIG.
The thickness T of the conventional clamp 01 on the left half is, for example, 8 to
If it is 10 mm, it is 1 mm thinner than this. This reduces the weight of the clamp as a whole, facilitates the mounting work, and improves the workability. That is, conventional clamp
When the thickness of 01 is T, the thickness t of the upper die clamp body 2 and the lower die clamp body 3 has a relationship of t = T-1 mm. In the case of the thickness of 8 to 10 mm as described above, if the thickness t of the upper and lower clamp bodies 2 and 3 is reduced by 1 mm as described above, a weight reduction of about 12% can be achieved. Further, the radius r for chamfering the root of the boss 11 of the upper clamp body 2 is smaller than that R of the conventional clamp 01. As a result, the mass as a whole becomes small.

The thickness of the flange portions 4 and 5 in which the bolt insertion holes 6 and 7 are formed is uniform in the length direction of the flange portions, as is particularly apparent from FIG. As a result, the flange surfaces of the flange portions 4 and 5 become flat (uniform height), so two types of bolts 8 to be attached are required as in the conventional clamp 01 (in the case of the conventional clamp 01, the flange portion is
Both ends of 04, 05, that is, the four corners are formed with a large thickness,
In that sense, the thickness of the flange had a two-tiered structure, so the bolts 08 that are inserted into the bolt insertion holes 06 and 07 that are formed therethrough also require two types of different sizes, large and small. However, it is possible to use one type having the same length, which facilitates inventory management of the bolts 8.

Further, as shown in FIGS. 5 (A) and 5 (B), a rib 21 for preventing bolt rotation having a square cross section is inserted in the bolt insertion hole 7 in the lateral direction of the flange portion 5 of the lower clamp body 3. Bolts 8 are provided on both sides of the rib 21 on the side surface.
The side surface of the head formed in a square shape is locked so that it does not rotate together. The range of the A dimension in which the hexagon bolt used in the conventional clamp 01 shown in FIGS. 5C and 5D does not cause co-rotation is B <A <C. For example, in the case of a M22 (spare diameter) bolt, B = 32 m for a conventional hexagon bolt.
Since m and C = 37.0mm, the range of A dimension is 32mm <A <37m
It becomes m, and the difference is only 5 mm. However, with the square bolt adopted this time in the improved clamp 1, B = 32 mm, C = 45.2
Since it is mm, the range of A dimension is 32mm <A <45.2mm,
The difference is 13.2 mm. Since the dimensional tolerance can be made looser as the dimension A has a margin, the post-casting process becomes easier and the man-hours such as working and maintenance can be reduced. This makes it possible to safely prevent co-rotation, reduce the cost of machining and maintenance, and improve the workability when tightening the clamp.As with the hexagonal bolt of the conventional clamp 01, the width of the bolt head and the distance between the ribs 21 are reduced. It is possible to solve the problem that there is little margin and that co-rotation occurs when riding on the rib 21.

As described above, since the upper die clamp body 2 and the lower die clamp body 3 are made thin, the cross-section coefficient of the clamp itself is reduced and the reinforcement effect is expected to be reduced. As shown on the mold clamp body 2 side, the position of the flange portion 4 is at the bottom, that is, the upper mold clamp body 2
By lowering the bolt fastening interval in the cross-sectional direction of the pipe from the lower end edge 2a in the vertical direction (P1> P2, e1> e2), the tilting of the flange portion 4 is reduced (y1> y).
2) As a result, the reinforcement of the clamp 1 can be secured. The same applies to the lower clamp body 3 side. Since the force (moment) for deforming the flange portion in FIG. 6 is F · e, the smaller the value of e, the smaller the deformation of the flange portion.

For reference, a confirmation test of the clamp reinforcing property is performed by using a GMII type ductile pipe as the existing pipe 16 as shown in FIG. 8, and clamp 1 or 01 (downward facing the perforated portion) at the branch portion.
Is attached, and a predetermined distance L (1 m) from both pipe support points 23 and 24
The results of applying a loading load W to the above are shown in FIG. 9 as the relationship between the tube thickness and the breaking strength (bending moment) of the test tube. As is clear from this figure, it was confirmed that the conventional clamp 01 and the improved clamp 1 have approximately the same level of reinforcement.

Upper mold clamp body 2 and lower mold clamp body 3
Since the radial dimension of the inner surface of the pipe in the direction of the pipe center is matched with the maximum outer diameter that can be expected from the variation in the outer diameter of the existing pipe 16 to be attached, the upper die clamp body 2 and the lower die are usually used. The inner surface of the clamp body 3 has a larger radius. By mounting the clamp 1 on the existing pipe 16 and tightening the bolt nuts 8 and 9, the upper mold body 2 and the lower mold body 3 are deformed toward the center of the existing pipe 16 to cover the outer peripheral surface of the existing pipe 16 ( (See right half of Figure 7B). When the upper clamp body 2 and the lower clamp body 3 are deformed, the boss portion 11 is also deformed, contracting in the pipe axis direction and increasing in the direction orthogonal to the pipe axis into a so-called elliptical shape (see FIG. 7A). The boss portion 11 is deformed. If the deformation of the boss portion 11 becomes too large, a problem will occur in the airtight performance of the joint portion (screw joint) with the branch pipe 15. In the improved clamp 1, the upper clamp body 2 and the lower clamp body 3 are thinner than the conventional clamp 01 (T> t), and the chamfer dimension (R) of the upper clamp body 2 and the root of the boss portion 11 (R
By reducing the size (R> r), the deformation of the boss portion 11 when tightening the clamp can be considerably suppressed,
The reliability of the airtight performance could be significantly improved.

The flange portions 4 and 5 shown in the above embodiment
The formation position of is only an example, and in the case of implementation, it is set at an optimum position in consideration of the upper and lower end edges 2a, 3a of the upper mold clamp body 2 and the lower mold clamp body 3 which face each other. Further, the numbers of the bolt insertion holes 6 and 7 and the bolt nuts 8 and 9 formed in the flange portions 4 and 5 are arbitrary, and are not limited to those illustrated.

[0017]

As described above, according to the present invention, a flange portion is provided at a position separated from the upper and lower end edges of the upper and lower clamp bodies facing each other by a predetermined length toward the center of the clamp body. Since it is formed so as to project outwards almost in parallel, it is possible to make the flanges of the upper and lower clamp bodies less likely to be deformed by the tightening force while maintaining the same level of reinforcement. it can. Further, the deformation of the boss portion can be made as small as possible, and the reliability of the airtight performance of the joint portion (screw joint) with the branch pipe can be remarkably improved. Claim 2,
In addition to the above effects, the invention of No. 3 has an excellent effect that only one type of bolt and nut for fastening is required and the bolt rotation preventing effect is great.

[Brief description of drawings]

FIG. 1 is a plan view of a branching clamp attached to a branching portion of an existing pipe showing an embodiment of the present invention.

FIG. 2 is a front view of the right half section of FIG.

3 is a cross-sectional view taken along the line AA of FIG.

FIG. 4 is a cross-sectional view taken along line BB (left half portion) and CC line (right half portion) of FIG.

5A and 5B are drawings for explaining the range of the A dimension in which the bolts do not rotate together; FIG. 5A is a partial bottom view of a square bolt, FIG. 5B is a longitudinal sectional view of the square bolt, and FIG. A partial bottom view in the case of a bolt, (D) is the longitudinal cross-sectional view.

FIG. 6 is a view for explaining the collapse of the flange portion in the conventional clamp and the improved clamp.

FIG. 7 is a drawing for explaining the deformation of the boss portion in the conventional clamp and the improved clamp, (A) shows the degree of deformation,
FIG. 1B is a cross-sectional view of a conventional clamp (left half portion) and an improved clamp (right half portion) taken along the line DD of FIG. 1 (boss portion).

FIG. 8 is a diagram for explaining a method for confirming the clamp reinforcing property.

FIG. 9 is a graph showing the results of the same test as the relationship between the tube thickness of the test tube and the breaking strength (bending moment).

[Explanation of symbols]

1 Branch clamp 2 Upper die clamp body 3 Lower clamp body 4,5 Flange 6,7 bolt insertion hole 8, 9 Fastening bolts and nuts 11 Boss 12 Annular groove (recess) 13 rubber ring 15 Branch pipe (branch tee) 16 Existing pipe 17 Perforated part 21 ribs

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Shinichi Endo             1-12-19 Kitahorie, Nishi-ku, Osaka City, Osaka Prefecture             Kurimoto Iron Works Co., Ltd. (72) Inventor Shunji Motooka             4-1-2 Hirano-cho, Chuo-ku, Osaka-shi, Osaka Prefecture               Within Osaka Gas Co., Ltd. F-term (reference) 3H019 BA05 BB01 BD05                 3J022 DA12 DA15 EA37 EB14 EC17                       EC22 ED23 FA02 FB04 FB06                       FB12 FB17 GA04 GA13 GA22                 3J039 AA08 BB01 CA02 CA15

Claims (3)

[Claims] 1. When a branch pipe is attached to a part of a pipe line that requires branching, the upper and lower clamp bodies having a substantially semi-cylindrical shape are divided into upper and lower parts in the axial direction of the branch part. In a branching clamp which is covered with and is clamped by a fastening member to support a branch pipe, a position separated by a predetermined length from the upper and lower opposite edges of the upper clamp body and the lower clamp body toward the center of the clamp body, respectively. A branching clamp characterized in that a flange portion is formed so as to project outwardly in a substantially parallel manner. 2. A plurality of bolt insertion holes for mounting fastening bolts and nuts in the lengthwise direction of the flange portion are formed facing each other, and a flange portion formed with these bolt insertion holes is formed. The branching clamp according to claim 1, wherein the flange has a uniform thickness in the length direction of the flange. 3. A bolt locking rib is provided on both sides of a flange portion of either the upper clamp body or the lower clamp body so as to sandwich the bolt insertion hole, and the rib has a quadrangular shape on the side surface. The branching clamp according to claim 2, wherein a side surface of the formed head is locked.