JPH0730844B2 - Double structure pipe sealing device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention is for fixing a small diameter pipe when a small diameter pipe is further inserted into a large diameter pipe to form a double structure pipe. The present invention relates to a sealing device for use in, particularly, a pipe having improved rust prevention performance and sealing performance.

(Prior art) When gas, oil, water, steam, etc. are buried underground to transport gas, oil, water, or steam, etc., if a river, road, or railroad must be crossed, it must be underground before protection. A so-called double piping structure is adopted in which a sheath pipe is buried and the main pipe is inserted and fixed in the sheath pipe.

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

In this sealing device, as shown in FIG. 4, the main pipe 1 is inserted into the sheath pipe 2, and the main pipe 1 is inserted into and out of the sheath pipe 2 respectively.
It is a device for fixing water and preventing water and the like from entering the sheath pipe 2, and as shown in FIG. 5, has an annular shape having openings 4a, 5b which substantially correspond to the outer shape of the main pipe 1. The two rubber rings 4 and 5 are made to face each other.
Annular flanges 6 and 7 are attached by bolts 8 and nuts 9 so as to sandwich 4 and 5 from both sides.

Further, each of the rubber rings 4 and 5 has a dish-shaped half section, and a space S is formed when the two rubber rings 4 and 5 are opposed to each other in a so-called "centering" manner. I am trying. Then, the plurality of bolts 8 are attached to the nuts 9
When the main pipe 1 is inserted into the openings 4a and 5a with the bolts 8,8 ... tightened with the sealing device 3 inserted into the sheath pipe 2, the rubber ring 4, 5 is the radial direction, that is, the outer peripheral edges of the rubber rings 4,5 are in contact with the inner peripheral surface of the sheath tube 2, and the inner peripheral edges of the rubber rings 4, 5 are in contact with the outer peripheral surface of the main pipe 1, respectively. By the main 1
Is fixed to the sheath tube 2, and at the same time, water and the like can be prevented from entering the sheath tube.

(Problems to be Solved by the Invention) However, in the conventional sealing device 3, if the center of the sealing device 3 and the center of the main pipe 1 or the sheath pipe 2 do not coincide with each other, the flanges 6 and 7 become the sheath pipe 2 or It comes into contact with the main pipe 1, which may induce an electrochemical corrosion reaction due to a metal touch.

Further, when replacing the sealing device, there is a problem that the metal flange cannot be removed and installed unless the main pipe is cut once.

The present invention has been made in view of the above-mentioned problems of the prior art. It firmly fixes the main pipe and is rich in sealing property, and is excellent in rust prevention performance, while not affecting the main pipe. It is an object of the present invention to provide a sealing device for a double structure pipe that can be attached and detached with the.

[Means for Solving the Problems] (Means for Solving the Problems) The present invention for achieving the above-mentioned object provides a double structure pipe installed between a sheath pipe and a main pipe inserted into the sheath pipe. In the sealing device, made of insulating and flexible material,
A plurality of insertion holes through which the screw shafts of the plurality of bolts are respectively inserted, a recessed portion that is continuously provided in the insertion holes and includes the head of the bolt, and a recess that is embedded coaxially with the insertion hole and that is larger than the outer diameter of the bolt. A base portion having a nut adapted to a large diameter, a seal portion axially opposite to the base portion and having an annular groove formed therein, and an annular body having an opening through which the main pipe is inserted,
An annular protrusion made of an insulating material and having a width wider than that of the annular groove, a cap nut embedded in a position corresponding to the insertion hole of the annular main body, into which the bolt is screwed, and an opening through which the main pipe is inserted. And a ring-shaped fitting member having a section, wherein the ring-shaped groove of the ring-shaped body is fitted with the ring-shaped projection of the fitting member and tightened by the bolt. is there.

(Operation) In the present invention thus configured, the main pipe is inserted into the opening while the annular projection of the fitting member is fitted in the annular groove of the annular main body and the two are temporarily tightened with bolts. If the bolt is further tightened after inserting the sealing device into the sheath tube or the like, the annular groove formed in the seal portion of the annular body expands and comes into pressure contact with the main tube and the sheath tube, respectively. As a result, the main pipe is firmly fixed in the sheath pipe by pressure contact in a wide range in the width direction, and even if the main pipe and the sheath pipe are slightly eccentric, the seal is excellently achieved.

On the other hand, the base with high rigidity without grooves is hardly affected by the deformation even if the annular groove is expanded by tightening the bolts, so the overall shape of the annular main body does not wavy. Assures a reliable seal due to the uniform expansion of the annular groove.

Here, with a plurality of bolts, the male screw of the bolts is screwed into the cap nut embedded in the fitting member, and the head is tightened so as to be included in the recess of the annular main body. As a result, there is no risk that the metal portion will come into direct contact with the main pipe or the sheath pipe.

Even if the insulating material is peeled off, it is separated without using a continuous metal fitting like the conventional one, so
Sparks due to static electricity are not generated, the risk of inducing an electrochemical corrosion reaction is also avoided, and rust prevention performance is improved.

When removing the sealing device, another bolt suitable for the diameter of the nut embedded coaxially in the insertion hole of the annular body is screwed in. As a result, the cap nut is pressed, and the fitted annular body and fitting member are easily separated.

Further, if the annular body and the fitting member are respectively cut in the axial direction and the cut portions are shifted by a predetermined pitch to fit the two, the sealing property is secured, so that the main pipe is not cut. The sealing device can be removed and installed.

(Embodiment) An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a half sectional view showing an embodiment of the present invention, FIG. 2 is a Y arrow view of FIG. 1 showing a half front view, and FIG. 3 is a main part showing a use state of the embodiment. FIG.

As shown in FIG. 1, the annular main body 12 includes a plurality of insertion holes 18 through which the screw shafts of the plurality of bolts 16 are respectively inserted, and a recess 22 that is continuous with the insertion holes 18 and includes the head of the bolt 16. And a base as a structure provided with. Further, the annular main body 12 has a seal portion on the opposite side in the axial direction from the base portion, in which an annular groove 11 is formed, and an opening portion 10 through which the main pipe 1 is inserted. The opening end 19 of the annular groove 11 is opened in a tapered shape, and is bored to a depth such that an annular protrusion 14 of a fitting member 15 described later can be fitted by a predetermined amount. Further, a fixed portion sealing surface 20 that contacts a fixed material such as the sheath pipe 2 is formed on the outer peripheral surface of the annular groove 11, while the inner peripheral surface of the annular groove 11 contacts the main pipe 1. The main pipe sealing surface 21 is formed.

Further, in this embodiment, the fitting member 15 and the annular main body 12 to be described later are tightened by six fastening means, that is, the bolt 16 and the nut 17, but the bolt head
A recess 22 is formed at the base of the annular main body 12 in order to avoid the metal touch with the main pipe 1 or the sheath pipe 2 by including 16a therein. Further, the diameter of the insertion hole 18 of the bolt 16 is
The outer diameter is larger than the outer diameter, and the nut 23 adapted to the diameter of the insertion hole 18 is embedded.

The annular body 12 is made of an insulating and flexible material typified by a rubber material or a resin material.

An annular fitting member 15 having an opening 13 through which the main pipe 1 is inserted is formed with a tapered annular projection 14 that fits in the annular groove 11 of the annular main body 12, and further the bolt of the annular main body 12 is formed. 16
The cap nut 17 is embedded at a position corresponding to. The cap nut 17 is composed of a female screw portion 17a with which the bolt 16 is screwed, and a large diameter portion 17b having an inner diameter larger than the female screw portion 17a, and a blind lid 24 is attached to the bottom portion.

In addition, when tightening a plurality of bolts 16, 16 ..., if the tightening amount of each bolt 16 is constant, there is no particular problem, but for example, depending on the tightening work, only one bolt is overtightened. It is possible that the fitting member 15 is inclined with respect to the annular body 12. In order to deal with such a problem, in the present embodiment, the female screw portion 17a of the cap nut 17 described above is made as short as possible, and a large diameter portion 17b that is not screwed into the male screw of the bolt 16 is formed. , So that some inclination can be absorbed.

Nut 23 and fitting member embedded in the annular body 12 described above.
The cap nut 17 embedded in the ring 15 is formed by the annular body 12 and the fitting member.
It can be easily embedded by inserting it when molding 15. The blind lid 24 is a lid for preventing a material from entering the inside of the cap nut 17 when the cap nut 17 is insert-molded.

The width of the annular groove 11 of the annular body 12 and the annular protrusion 14 of the fitting member 15
The width of the annular projection 14 needs to be wider in the state before the both 11 and 14 are fitted to each other. It can be appropriately selected depending on the size of the tube diameter with 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. However, the fitting member 15 is flexible like the material forming the annular main body 12. Gender is not always necessary.

Next, the operation will be described.

First, the annular protrusion 14 of the fitting member 15 is inserted into the annular groove 11 of the annular body 12.
Is fitted and both the bolt 16 and the cap nut 17 are temporarily tightened, the main pipe 1 is inserted into the openings 10 and 13, and the sealing device is inserted into the sheath pipe 2 and the like. Then the six bolts 16,16 ...
When tightened further, as shown in Fig. 3, the annular body
The annular groove 11 formed in the seal portion 12 expands, and the main pipe sealing surface 21 and the fixed portion sealing surface 20 come into pressure contact with the main pipe 1 and the sheath pipe 2, respectively. On the other hand, the base portion as a highly rigid structure without grooves is hardly affected by the deformation even if the annular groove 11 is expanded by tightening the bolt 16, so that the entire annular main body 12 is not affected. The shape ensures a reliable seal due to the uniform expansion of the annular groove 11 without waviness. When tightening the plurality of bolts 16, it is preferable to gradually tighten each bolt 16 in order to align the shaft center of the sealing device with the shaft centers of the main pipe 1 and the sheath pipe 2.

As a result, the main pipe 1 is firmly fixed to the sheath pipe 2 and the sealing property is ensured, but the contact portion between the main pipe 1 and the sheath pipe 2 of the sealing device 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.

Further, when the sealing device of this embodiment is attached to the main pipe 1 and the sheath pipe 2, when removing the sealing device, first, the bolt 16 is loosened and removed, but the annular main body 12 and the fitting member 15 are removed. Since the annular groove 11 and the annular protrusion 14 are tightly fitted to each other, both of them 12 and 15 try to maintain the same state. Then, a large-diameter bolt that matches the screw diameter of the nut 23 embedded in the annular body 12 (for example, if the bolt 16 is 8 mm, another bolt of 10 mm) is tightened. Then, this large-diameter bolt is not screwed into the cap nut 17 embedded in the fitting member 15, but abuts on the cap nut 17 to move the fitting member 15 to the third position.
Press to the right in the figure. This makes it possible to easily remove the annular body 12 and the fitting member 15.

Furthermore, when replacing the removed sealing device, the annular main body 12 and the fitting member of the used sealing device are replaced.
Cut and remove 15. 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 by a cutter or the like even in the field work.

Then, first, an annular main body 12 and a fitting member 15 of the new sealing device to be replaced are each formed with an axial cut, and the main body 1 is fitted with the cut open.
Then, when the cut ends of the annular main body 12 and the cut ends of the fitting member 15 are displaced by a predetermined pitch in the circumferential direction and both 12 and 15 are fitted and tightened, the annular main body 12 and the fitting member 15 are described above. As described above, the diameter expanding action also acts in the radial direction, but on the other hand, it also extends in the circumferential direction to firmly compress the cut.

Therefore, in the state where the annular body 12 and the fitting member 15 are tightened, the sealing device of the present embodiment does not impair the sealing property and the replacement work can be easily performed.

In addition, in the above-described embodiment, the present invention has been described 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, and is not fixed. If the material is circular, it can be applied, and for example, it can be used for any structure such as a wall surface of a building.

EFFECTS OF THE INVENTION As described above, according to the present invention, the male screw of the bolt is screwed into the cap nut embedded in the fitting member, and the head is enclosed in the recess of the annular main body. Since the bolts are used for tightening, it is possible to prevent metal parts such as bolts and nuts from directly contacting the main pipe or the sheath pipe.

Moreover, even if the insulating material is peeled off and the bolts and the like are exposed, since each bolt and the like are separated without using a continuous annular metal flange as in the conventional case, the No sparks will occur. Therefore, it is possible to surely avoid the risk of inducing an electrochemical corrosion reaction due to the metal touch, and the anticorrosion performance becomes extremely excellent.

Further, since the annular projection of the fitting member is fitted into the annular groove of the annular body and tightened by the bolt, the annular groove is expanded and brought into pressure contact with the main pipe and the sheath pipe, so that a wide range in the axial direction is obtained. The main pipe can be firmly fixed in the sheath pipe by pressing with, and the sealing property becomes extremely good even if the main pipe and the sheath pipe are slightly eccentric. On the other hand, the base, which has no groove and has high rigidity, is hardly affected by the deformation even if the bolt is tightened to expand the annular groove, so that the entire shape of the annular main body is undulated. Assures a reliable seal by uniformly expanding the annular groove without hitting.

Moreover, the annular groove of the seal portion is set to have a predetermined axial width according to the diameters of the main pipe and the sheath pipe, and the annular projection is formed to have a width wider than the width of the annular groove. It can be used for a wide variety of pipe diameters.

Furthermore, since a nut adapted to a diameter larger than the outer diameter of the bolt for fastening is embedded coaxially with the insertion hole formed in the annular body, if another bolt adapted to the diameter of this nut is screwed in, It is possible to easily remove the sealing device by separating the fitted annular body and fitting member.

On the other hand, since the configuration is such that the annular main body and the fitting member are fastened with the bolts and the number of parts is small, it is possible to perform the work quickly and with good preparation on site.

Further, as mentioned above, since the continuous metal fittings are not used and the bolts etc. are arranged separately, the annular main body and the fitting member can be relatively easily axially installed even after the sealing device is installed. It can be removed by cutting it into the main body, and if a new annular main body and a fitting member cut in the axial direction are installed with the cut ends displaced, the main pipe will not be cut, and replacement work will not be compromised. It can be performed.

[Brief description of drawings]

FIG. 1 is a half sectional view showing an embodiment of the present invention, FIG. 2 is a Y arrow view of FIG. 1 showing a half front view, and FIG. 3 is a main part showing a use state of the embodiment. Sectional views and FIGS. 4 to 5 are a perspective view and a sectional view showing a conventional sealing device. 1 ... main pipe, 2 ... sheath pipe (fixed material), 10 ... opening,
11 …… annular groove, 12 …… annular body, 13 …… opening, 14 ……
Annular protrusion, 15 ... Fitting member, 16 ... Bolt (fastening means), 17 ... Cap nut (fastening means).

Claims (1)

[Claims] 1. A double-structured pipe sealing device installed between a sheath pipe (2) and a main pipe (1) inserted into the sheath pipe (2), comprising an insulating and flexible material. Consists of multiple bolts (16)
A plurality of insertion holes (18) through which the screw shafts of
A recess (22) that is connected to the insertion hole (18) and encloses the head of the bolt (16), and a diameter that is embedded coaxially with the insertion hole (18) and is larger than the outer diameter of the bolt (16). An annular main body (12) having a base having a nut adapted to, a seal part axially opposite to the base and having an annular groove, and an opening (10) for inserting the main pipe (1). An annular projection (14) made of an insulating material and having a width wider than that of the annular groove (11); and the bolt embedded in a position corresponding to the insertion hole (18) of the annular body (12). (16)
And an annular fitting member (15) having an opening (13) through which the main pipe (1) is inserted, and the annular groove (11) of the annular body (12). The fitting member (1
A sealing device for double-structured pipe, wherein the annular projection (14) of 5) is fitted and tightened with the bolt (16).