JPH058398Y2 - - Google Patents

Description

[Detailed explanation of the idea]

[Industrial Application Field] The present invention relates to a clamp device for attaching a service cable to a branch pipe when the branch pipe is taken out from a gas or water pipe buried underground. [Prior Art] As shown in FIG. 6, this type of clamp conventionally consists of saddles 01 and 02 which are divided into upper and lower parts, which are straddled over a pipe and fastened with bolts 03 and nuts 04, and a branch extraction hole 05 is formed in the upper saddle 01. An O-ring groove 06 is provided around the branch take-out hole 05 on the inner surface of the upper saddle, which is in close contact with the surface of the tube 09, and an O-ring 07 is attached to the tube 0.
A hole 08 was formed on the surface of the tube 9 to branch out the fluid inside the tube. [Problems that the invention aims to solve] There are many cases where buried pipes corrode and leak due to stray current from the tracks and the structure of macro cells between concrete and soil due to the use of concrete in roads and buildings. It will be done. For this reason, resin-coated steel pipes whose piping surfaces are coated with synthetic resin and joints whose joint surfaces are also coated with resin have come to be used, but there is no appropriate anti-corrosion measure for the branch extraction clamps, and The only methods available were to wrap an anti-corrosion cover over the extraction joint and cut the edge from the buried soil, which was incomplete. In addition, in the above-mentioned conventional clamp, even if the pipe 09 is a resin-coated pipe, when the clamp is attached and a hole 08 is made in the pipe with a punching machine, chips from making the hole will flow into the pipe 09 in the branch extraction hole 05.
The chips 10 adhere to the surface of the pipe 09, the upper saddle 01, and the branch pipe connected to it become conductive, and the macro cell current generated in the branch pipe is conducted to the pipe 09, causing rapid corrosion in one of the buried pipes. is likely to progress. [Means for Solving the Problems] In order to solve the above-mentioned problems, the present invention is designed to completely protect the piping from corrosion by making it possible to isolate the clamping device connected to the branched piping from the buried environment, as well as providing an electrical insulation function to the connection part. The structure of the present invention will be explained below.A sleeve is provided on the end side in the axial direction of the upper and lower saddles, and the sleeve is made of the synthetic resin that surrounds the outer peripheral surface of the tube and whose inner surface is enlarged toward the end. At the axial joint of the upper and lower saddles, an interlocking part of a recess and a protrusion made of the coated synthetic resin is provided where the upper and lower saddles engage with each other, and between the inner surface of the sleeve and the outer circumferential surface of the tube, and between the interlocking part and the outer circumferential surface of the tube. This clamp device is characterized in that a viscous sealant is filled between the two. [Example] Hereinafter, an example of the present invention will be described based on the drawings. Fig. 1 is a front sectional view showing the clamping device of the present invention assembled to the pipe 9, Fig. 2 is a side view of the assembled state, Fig. 3 is a plan view and bottom view of the upper saddle 1, and Fig. The figures are a plan view and a bottom view of the lower saddle 2, and FIG. 5 is a partial sectional view showing the packing 3. The lower saddle 2 is constructed by screwing fastening bolts 4 into threaded holes 22 on both sides of a lower saddle body 21 made of malleable cast iron, and a synthetic resin coating layer 23 is formed by injection molding on the entire surface of the lower saddle body 21 except for the outer periphery of the bolt 4. It is coated and molded. The resin coated portion of the bolt 4 has a chamfer 41 for preventing rotation, and when the synthetic resin coat layer 23 is formed, the bolt 4 is fixed to the lower saddle body 21. The upper saddle 1 is also composited by injection molding on the entire surface of the upper saddle body 11 except for the insertion hole 16 of the bolt 4, the seat surface 17 of the nut 5, and the part from the packing groove 12 on the inner surface of the upper saddle to the inner surface of the branch outlet connection port 14. A resin coating layer 13 is coated and molded, and a synthetic resin sleeve 15 is provided at the upper end of the branch outlet connection port 14.
is formed protrudingly. Furthermore, half sleeves 18 and 28 are provided on the axial end sides of the upper and lower saddles 1 and 2, and are made of the synthetic resin that surrounds the outer peripheral surface of the tube and whose inner surfaces are enlarged toward the ends. At the joint in the direction, when the upper and lower saddles 1 and 2 are combined, there are a concave part 19 and a convex part 2 made of the coated synthetic resin that engage with each other.
9 meshing parts are provided. The packing 3 is provided around the branch outlet connection port 14 on the inner surface of the upper saddle 1, and is attached to the part facing the branch outlet connection port 14 from the packing groove 12. And an O-ring part 31 and a cylindrical part 32 as shown in FIG.
It is formed into an annular elastic packing 3 that is integrated with the following. The bolt tightening flange part of the upper and lower saddle bodies is
It is necessary to prevent deformation of the flange portion due to excessive tightening, so the dimension α between the upper and lower flanges is set as small as possible when the bare pipe is tightened to regulate the amount of bolt tightening. The radius of the inner surface of the upper and lower saddles that clamps the outer circumferential surface of the tube is set to an inner diameter approximately halfway between the outer diameter of the outer resin-coated steel tube and the outer diameter of the bare tube, and when the upper and lower saddles are attached to the outer resin-coated steel tube, The radial side surfaces of the circular inner surfaces of the upper and lower saddles dig into the resin coating layer of the coated resin steel pipe, preventing the saddles from rotating or sliding even if an external force is applied to the piping system after the upper and lower saddles are connected. . In addition, experiments have shown that the resin coating layer of the coated steel pipe does not break even when forced to rotate or slide, so the watertight treatment using butyl rubber tape, which will be described later, is not required when assembling the pipe to the coated steel pipe. It was found that complete watertightness can be achieved with both. The outer circumference of the bolt 4 should be pre-installed with the bolt 4 before assembly with the upper saddle 1.
An O-ring 6 is attached around the
When the upper saddle 1 is assembled to the lower saddle 2, it is closed off from the gap between the mating surfaces of the upper saddle and the lower saddle, thereby cutting off the connection of the bolt 4 with the external environment. The results of an experimental investigation of the rotation and slide blocking force of this clamp device are described below. Test conditions: Pipe diameter 50A, coated steel pipe outer diameter 64.1φ, bare tube outer diameter 60.5φ, clamp tightening bolt M16 x 2, bolt tightening torque 6Kgf・m

[Table] When assembling the clamping device of the present invention, it is necessary to install the clamp in advance, especially for juute-wrapped steel pipes that are bare pipes, because if they are directly assembled, there will be a problem with the sealing performance of the packing 3. Remove the jute on the pipe surface of the removed part, then determine the connection position of the saddle on the pipe surface of the removed part, mark both ends of the axial sleeve 18, and trace from the base point 181 on the inner surface of both sleeves to the juute winding part of the pipe. Then wrap the anti-corrosion tape in a spiral, overlapping layers. Next, over the anti-corrosion tape, a solvent-free, unwashed butyl rubber tape that does not have a negative effect on the synthetic resin coated on the saddle is wrapped in the circumferential direction, and from above, the mating surfaces of the upper and lower saddles are wrapped around the mating surfaces of the upper and lower saddles. The upper and lower saddles 1 and 2, whose insides are filled with butyl rubber 103, are aligned and assembled to the part where the butyl rubber is wrapped. In addition, when assembling to a steel pipe whose outer surface is coated with resin, the present clamping device can be set on the pipe as it is after checking that the surface of the pipe to which it is to be assembled is not damaged. After assembling to the pipe 9, the nut 5 is screwed onto the fastening bolt 4 protruding from the surface of the upper saddle 1 and fastened, and a cap 8 having a female thread 81 on the inner surface is covered from the outside of the fastened nut 5. Then screw the female thread 81 of the cap onto the head 43 of the bolt 4. 1 and 3 between the end of the cap 8 and the upper surface of the upper saddle 1.
As shown in the figure, a seat seat 102 with a gear-shaped inner periphery is provided on the synthetic resin surface covered with the upper saddle 1, and a seat padkin is provided with a gear-shaped outer periphery to prevent rotation and twisting of the seat seat. 7 is interposed, and the cap 8 is tightened and sandwiched between it and the seat seat 102 made of synthetic resin. In this way, the nut 5 and bolt head 43 are also isolated from the external corrosive environment. The lower surface 82 of the cap 8 is formed into an annular chevron-shaped protrusion, which applies local surface pressure to the seat packing 7 to improve sealing performance. Further, the tightening part 83 on the outside of the cap has the same face-to-face dimension as the outside of the nut 5 inside, so that the same fastener as that used to tighten the nut can be used. [Effect] This clamp device has the above configuration, so the tube 9
After installation as described above, attach a drilling machine using the female thread of the branch connection port 14, and make a hole 91 on the surface of the pipe 9. Even if chips 10 from drilling stick to the surface of the pipe 9, Main body 1 of upper saddle 1 by packing 3
1 and the surface of the main tube 9 are electrically isolated and can maintain an insulated state. Furthermore, the entire clamping devices 1 and 2 including the fastening bolt portions are covered with synthetic resins 13 and 23, and the mating surfaces of the upper and lower saddles are also coated with viscous material inside the meshing portion between the recess 19 and the protrusion 29 provided in the axial direction. A sealant is attached to the ends of the upper and lower saddles, and half sleeves 18 surrounding the outer circumference of the tube are installed.
Since a viscous sealant is attached to the inner surface of the clamp 28 to achieve sealing, it can be completely isolated from the external environment, and there is no need to wrap the outer periphery of the conventional clamp device with anti-corrosion tape or cover it. It can provide excellent corrosion protection. In addition, synthetic resin coating layer 1
3 and 23 are formed by injection molding, so they can be formed into the same exact shape as the injection mold, and there is no problem such as deformation of the pipe clamping part due to distortion of conventional castings, and the outer diameter of the pipe 9 can be adjusted. A matched, highly accurate and stable clamping device can be obtained.

[Brief explanation of drawings]

FIG. 1 is a front sectional view showing the state of the embodiment of the present invention after assembly and drilling, FIG. 2 is a partially sectional side view of FIG. 1, and FIG. 3 is a plan view and bottom view of the upper saddle 1.
Figure 4 is a top view and bottom view of the lower saddle 2;
The figure is a partial cross-sectional view of the packing 3, and FIG. 6 is a partial cross-sectional view showing a conventional clamp device. 1... Upper saddle, 11... Upper saddle body, 2...
...Lower saddle, 21...Lower saddle body, 3...Packskin, 4...Tightening bolt, 5...Nut, 6...
O-ring, 8...Cap, 9...Pipe, 13,2
3...Synthetic resin coating layer, 19...Concave portion, 29...
Convex portion, 18, 28... Half sleeve, 103...
Butyl rubber.

Claims (1)

[Scope of utility model registration request] The lower saddle has a fastening bolt buried in it and its entire surface is covered with injection molded synthetic resin, and the upper saddle has its entire surface covered with injection molded synthetic resin except for the nut seat and the inner packing groove to the connection hole for branch extraction. A packing is attached to the part of the inner surface of the upper saddle facing the connecting hole for branch extraction from the packing groove, and a cylindrical packing is attached to the joint between the upper and lower saddles that spans the pipe around the outer circumference of the fastening bolt, and The upper and lower saddles that span the pipe are screwed and fastened to bolts protruding from the surface of the upper saddle with nuts, and a cap having a female thread that is threadedly engaged with the fastening bolt is attached from the outside of the nut, and the axial ends of the upper and lower saddles are attached. A sleeve made of the synthetic resin that surrounds the outer circumferential surface of the tube and whose inner surface is enlarged toward the end is provided on the side of the tube, and a synthetic resin coated sleeve with which the upper and lower saddles engage with each other is provided at the joint in the axial direction of the upper and lower saddles. 1. A clamp device comprising: a mating part of a concave part and a convex part, and a viscous sealing agent is filled between the inner surface of the sleeve and the outer circumferential surface of the tube, and between the mating part and the outer circumferential surface of the tube.