JPH0369864A - Seal device for double structure pipe - Google Patents

Abstract

PURPOSE:To ensure the seal between a main pipe and a sheath pipe by inserting an insulative flexible annular body between the main pipe and the sheath pipe, by fitting an annular bead of an insulative fitting member in an annular groove formed in the annular body and by fastening the annular body and the fitting member together while enlarging the diameter of the annular body. CONSTITUTION:In such condition that an annular bead 14 on a fitting member 15 is fitted in an annular groove 14 in an annular fitting member 15 is fitted in an annular groove 14 in an annular body 12, and the annular body 12 and the fitting member 15 are temporarily fastened by a bolt 16 and a blind nut 17, a main pipe 1 is inserted through openings 10, 13, and then is inserted into a sheath pipe 2. As the bolt is further fastened, the diameter of the annular groove 11 is enlarged by the annular bead 14 so that the annular body is made into press-contact with both main pipe 1 and sheath pipe 2. Accordingly, the main pipe 1 and the sheath pipe 2 are firmly fixed together while the sealing ability therebetween being ensured. Further, since the annular body is made of flexible and insulative materials such as rubber or the like, it is possible to prevent the main pipe 1 and the sheath pipe 2 from being corroded, and further the seal device can be replaced with new one, easily, by unfastening the bolt 16.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention provides a method for fixing small-diameter piping when the small-diameter piping is further inserted into the large-diameter piping to form a double-structure piping. Regarding sealing devices used in

(Prior art) When pipes are buried underground to transport gas, oil, water, steam, etc., pipes that must cross rivers, roads, or railways are buried underground in advance to protect the main pipes. A so-called double piping structure is adopted in which a sheath pipe is buried and a main pipe is inserted and fixed into the sheath pipe.

As a means of fixing the main pipe to this sheath pipe, for example,
A sealing device disclosed in Japanese Patent No. 0-110,820 is known.

As shown in FIG. 4, this sealing device is constructed by inserting a main pipe 1 into a sheath pipe 2, and then inserting the main pipe 1 at the entrance and exit of the sheath pipe 2.
It is a device for fixing the main pipe 1 and preventing water from entering into the sheath pipe 2, and has openings 4a and 5b corresponding to the outer shape of the main pipe 1, as shown in FIG. The annular rubber rings 4゜5 are opposed to each other, and the annular flange 6 is arranged so as to sandwich the two rubber rings 4゜5 from both sides.
．． 7 is attached with bolts 8 and nuts 9.

Further, the rubber rings 4 and 5 each have a half-section shaped like a plate, and a space S is formed when these two rubber rings 4 and 5 are opposed to each other in a so-called "middle alignment". That's what I do. Then, with the plurality of bolts 8 temporarily tightened to the nuts 9, the main pipe 1 is inserted into the openings 4a, 5a, and with this sealing device 3 inserted into the sheath pipe 2, each bolt 8, 8. As the rubber rings 4 and 5 are tightened, the rubber rings 4 and 5 move in the radial direction, that is, the rubber rings 4 and 5 tighten.
The outer peripheral edge of 5 is attached to the inner peripheral surface of the sheath tube 2, and the rubber ring 4,
The inner circumferential edges of the tubes 5 come into contact with the outer circumferential surface of the main tube 1, thereby fixing the main tube 1 to the sheath tube 2 and preventing water from entering the sheath tube.

(Problem to be Solved by the Invention) However, in the conventional sealing device 3, if the center of the sealing device 3 does not coincide with the center of the main pipe 1 or the sheath pipe 2, the flange 6.7 It came into contact with main pipe 1, and there was a risk of inducing an electrochemical corrosion reaction due to metal touch.

Furthermore, when replacing the sealing device, there is a problem in that the metal flange cannot be removed or installed without first cutting the main pipe.

The present invention has been made in view of the problems of the prior art, and provides a method that firmly fixes the main pipe, has excellent sealing properties, and has excellent button-proof performance. An object of the present invention is to provide a sealing device for double-structure piping that can be installed and removed without any trouble.

[Structure of the Invention (Means for Solving the Problems) The present invention to achieve the above objects is made of an insulating and flexible material, has an opening through which a main pipe is inserted, and has an annular groove formed therein. The fitting member is made of an annular body, and is made of an insulating material, has an opening through which the main pipe is inserted, and has an annular protrusion wider than the width of the annular groove, and is fitted into the annular groove of the main body. This is a sealing device for double-structure piping, characterized in that annular protrusions of members are fitted and tightened by a fastening means.

(Function) In the present invention configured as described above, the main pipe is inserted into the opening with the annular protrusion of the fitting member fitted into the annular groove of the annular main body and temporarily fastened together by the fastening means. However, when the fastening means is further tightened after inserting the sealing device into the sheath pipe or the like, the annular groove of the main body expands and comes into pressure contact with the main pipe and the sheath pipe, respectively.

As a result, the main pipe is firmly fixed to the sheath pipe and sealing performance is ensured, but since the contact part of the sealing device with the main pipe and the sheath pipe is composed of an insulator, the main pipe and the sheath pipe are It can prevent corrosion of pipes.

In addition, by cutting the annular body and the fitting member in the axial direction and fitting the two by shifting the cut portions by a predetermined pitch, sealing performance is ensured, so there is no need to cut the main pipe. Seal devices can be removed and installed.

(Example) Hereinafter, one embodiment of the present invention will be described based on the drawings.

FIG. 1 is a half-sectional view showing an embodiment of the present invention, FIG. 2 is a view taken along the Y arrow in FIG. FIG.

First, as shown in the first prisoner, the opening 1 through which the main pipe 1 is inserted
0, an annular groove 11 is formed in the annular body 12, and insertion holes 18 for bolts 16 are bored at predetermined intervals. The open end 19 of this annular groove 11 is tapered open and is bored to a depth that allows a predetermined amount of engagement with an annular protrusion 14 of a fitting member 15, which will be described later. Further, the outer peripheral surface of this annular groove 11 is formed with a fixed part sealing surface 20 that contacts the fixed member such as the sheath pipe 2, while the inner peripheral surface of the annular groove 11 is formed to contact the main pipe 1. A main sealing surface 21 is formed.

In addition, in this embodiment, the fitting member 15 and the annular body 12, which will be described later, are connected by six fastening means, that is, bolts 1
6 and a nut 17, a recess 22 is formed in the annular main body 12 in order to contain the bolt head 16a and avoid metal contact with the main pipe 1 or the sheath pipe 2.

Furthermore, the diameter of the insertion hole 18 of the bolt 16 is
The diameter of the insertion hole 18 is larger than the outer diameter of the hole 18, and a nut 23 matching the diameter of the insertion hole 18 is embedded therein.

The annular main body 12 is made of an insulating and flexible material, such as a rubber material or a resin material.

A fitting member 15 having an opening 13 through which the main pipe 1 is inserted is formed with a tapered annular protrusion 14 that fits into the annular groove 11 of the annular body 12, and is further provided with a tapered annular projection 14 that fits into the annular groove 11 of the annular body 12. Cap nuts 17 are buried in corresponding positions. This cap nut 17 consists of a female threaded portion 17a into which the bolt 16 is screwed, and a large diameter portion 17b having an inner diameter larger than the female threaded portion 17a, and a blind cover 24 is attached to the bottom.

Note that when tightening a plurality of bolts 16, 16, there is no particular problem if the amount of tightening of each bolt 16 is constant, but for example, depending on the work, tightening may be It is also conceivable that only one bolt may be tightened too much, causing the fitting member 15 to be inclined with respect to the annular main body 12. In order to deal with such a problem, in this embodiment, the female screw portion 17 of the aforementioned cap nut 17 is
A is made as short as possible, and a large diameter portion 17b that is not screwed into the male thread of the bolt 16 is formed to absorb some inclination.

The nut 23 embedded in the annular main body 12 and the cap nut 17 embedded in the fitting member 15 described above can be easily embedded by inserting them when molding the annular main body 12 and the fitting member 15. Further, the blind lid 24 is a lid for preventing material from entering into the cap nut 17 when the cap nut 17 is insert-molded.

The relationship between the width of the annular groove 11 of the annular body 12 and the width of the annular protrusion 14 of the fitting member 15 is such that the annular protrusion 14 is wider than the annular protrusion 14 before the two parts 11 and 14 are fitted together. Although necessary, the main pipe 1 to which the sealing device of this embodiment is attached is
It can be appropriately selected depending on the size of the pipe diameter of the sheath pipe 2 and the sheath pipe 2.

The fitting member 15 is made of a rubber material, a resin material, or the like, and any other insulating material can be used, but a flexible material like the material constituting the annular body 12 may be used. Gender is not necessarily required.

Next, the action will be explained.

First, with the annular projection 14 of the fitting member 15 fitted into the annular groove 11 of the annular main body 12 and both the bolt 16 and the cap nut 17 temporarily tightened, the main pipe 1 is inserted into the opening 10° 13. , insert the sealing device into the sheath tube 2 or the like. Next, when the six bolts 16, 16... are further tightened, the third
As shown in the figure, the annular groove 11 of the annular main body 12 expands and comes into pressure contact with the main pipe 1 and the sheath pipe 2, respectively. Note that when tightening these bolts 16, each bolt 16 may be tightened little by little in order to align the axis of the sealing device with the axes of the main pipe 1 and the sheath pipe 2. preferable.

As a result, the main pipe 1 is firmly fixed to the sheath pipe 2 and sealing performance is ensured, but the contact portion of the sealing device with the main pipe 1 and the sheath pipe 2 is made of an insulator such as a rubber material. Therefore, corrosion of the main pipe 1 and the sheath pipe 2 can be prevented.

In addition, when removing the sealing device of this embodiment from the state where it is attached to the main pipe 1 and the sheath pipe 2, the bolt 16 is first loosened and removed.
Since the annular groove 11 and the annular protrusion 14 of the fitting member 15 and the fitting member 15 are firmly fitted, both 12 and 15 tend to maintain the same state. Next, a large diameter bolt (for example,
If the bolt 16 is 8 mm, tighten another 10 mm bolt. Then, this large diameter bolt is inserted into the fitting member 15.
Do not screw into the cap nut 17 buried in the cap nut 1.
7 and presses the fitting member 15 to the right in FIG. Thereby, the annular main body 12 and the fitting member 15 can be easily removed.

Further, when replacing the removed sealing device, the annular body 12 and fitting member 15 of the used sealing device are cut and removed. In this case, since the sealing device of this embodiment is made of a rubber material or a resin material, it can be easily cut with a cutter or the like during field work.

Next, first, a cut is formed in the annular body 12 and the fitting member 15 of the new sealing device to be replaced in the axial direction, and the seal is fitted into the main pipe 1 with the cut opened. Then, when the annular body 12 and the fitting member 15 are fitted and tightened with the cut ends of the annular body 12 and the fitting member 15 shifted by a predetermined pitch in the circumferential direction, the annular main body 12 and the fitting member 15 are As shown, the diameter expands in the radial direction, but it also expands in the circumferential direction, strongly compressing the cut end.

Therefore, when the annular main body 12 and the fitting member 15 are tightened, the sealing device of this embodiment does not impair its sealing performance in any way and can be easily replaced.

In addition, in the above-mentioned embodiment, the present invention was explained as a sealing device used when inserting and fixing the main pipe 1 into the sheath pipe 2, but the present invention is not limited to this embodiment. If the material is circular, it can be applied to any structure, such as the wall of a building.

[Effects of the Invention] As described above, according to the present invention, since the main pipe is attached to the material to be fixed such as a sheath pipe without using a metal flange, the main pipe can be firmly fixed and the sealing performance is improved. It is possible to provide a sealing device for double-structured piping that is rich in properties and has excellent anti-caking performance.

Furthermore, the sealing device can be easily attached and removed without cutting the main pipe.

[Brief explanation of drawings]

FIG. 1 is a half-sectional view showing an embodiment of the present invention, FIG. 2 is a view taken along the Y arrow in FIG. 4 and 5 are a perspective view and a sectional view showing a conventional sealing device. 1... Main pipe, 2... Sheath pipe (fixed material), 10...
Opening portion, 11... Annular body, 12... Annular body, 13
... opening, 14... annular projection, 15... fitting portion, 16... bolt (fastening means), 17... cap nut (fastening means). Figure 1

Claims (1)

[Claims] An annular body (12) made of an insulating and flexible material and having an opening (10) through which the main pipe (1) is inserted and an annular groove (11) formed therein; It has an opening (13) to be inserted therethrough and the annular groove (1).
1), and a fitting member (15) formed with an annular protrusion (14) wider than the width of the main body (12).
11) A sealing device for double structure piping, characterized in that the annular protrusion (14) of the fitting member (15) is fitted into the fitting member (15) and tightened by fastening means (16, 17).