JPH026396B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an insulated pipe joint that connects pipes while electrically insulating them from each other.

[Conventional technology and its problems]

Various types of insulated pipe fittings have been developed and used in the past, but all of these have been made by directly screwing or directly welding the pipe into the insulated pipe fitting, so it is difficult to install buried pipes. In such cases, the workability is extremely poor.

On the other hand, the Gas Business Law stipulates the technical details of gas facilities based on the provisions of the ministerial ordinance specifying the technical standards for gas facilities (MITSU No. 439).
No. 86 as a method for joining buried conduits of less than Kgf/ ^cm
Mechanical bonding methods shown in Figures o to u in Article D are listed, but none of these have an insulating function.

[Purpose of the invention]

The present invention has been made in view of the above circumstances, and its purpose is to eliminate the conventional welding or screwing methods for joining insulated pipe joints to pipes, and to eliminate the need for joining pipes with insulated pipe joints. An object of the present invention is to provide an insulated pipe joint for underground burial, which improves workability by having a structure that does not use any fastening bolts. Another object of the invention is to provide an insulated pipe joint for underground burial, which can be joined in accordance with the mechanical joining method of the above-mentioned notification, has excellent sealing performance and effectiveness against external stress, and has a complete electrical insulation function. Our goal is to provide the following.

[Means for solving problems]

In order to achieve such an object, the present invention provides a joint body that is disposed in an externally fitted manner between the ends of the pipes to be connected, and an inner circumferential surface of the joint body and an outer circumferential surface of the end of the pipe to be connected. an insulator disposed between the joint body and the opposing faces of the ends of the pipes to be connected and insulating between the joint body and the pipes to be connected and between the pipes to be connected; a tightening mechanism that enters between the joint body and the pipe from the open end by screwing with the inner peripheral surface of the open end and fixes them; and a tightening mechanism that is interposed between the tightening mechanism and the insulator, and a sealing member compressed by the entry of the mechanism, the tightening mechanism having a threaded portion threadedly engaged with the inner circumferential surface of the opening end of the joint body, and having a progressively larger inner diameter on the inner circumferential surface of the front end. an annular stop having a tapered surface; an outer peripheral surface has an inclined surface that abuts the tapered surface of the stop; and a rear end of the inclined surface has an inner peripheral surface of the stop and the connection The lock spacer has an extending portion interposed between the outer circumferential surface of the pipe to be removed, and further includes an annular insulating lock spacer having a groove formed in the axial direction in the main body portion on which the inclined surface is formed. It is something.

[Effect]

In the insulated pipe joint for underground burial according to the present invention constructed as described above, the insulating lock spacer is inserted between the joint body and the pipe, and then the threaded portion of the stopper is screwed into the open end of the joint body. However, the joint body and the pipe can be joined by simply inserting the taper into the insulating lock spacer. At this time, since the insulating lock spacer has a groove formed in its main body, the diameter of the insulating lock spacer tries to reduce by entering the taper of the stopper, thereby holding the outer circumferential surface of the pipe, and as a result, the fitting body will be firmly fixed to the tube. Moreover, as the sealing member is pressed and compressed by the insulating lock spacer as the stopper enters, the sealing member tightly adheres to the outer circumferential surface of the pipe and the inner circumferential surface of the joint body. Furthermore, external stresses can be absorbed over almost the entire joint body by the insulating material and the tightening mechanism.

〔Example〕

Hereinafter, one embodiment of the present invention will be described with reference to FIG. 1 and FIGS. 2A and 2B.

In FIG. 1, 1 and 1 are pipes to be connected, 2 is a cylindrical joint body disposed between the ends of the pipes 1 and 1, and 3 is an inner circumferential surface of the joint body 2. An annular insulator made of an insulating synthetic resin disposed between the outer circumferential surface of the end of the tube 1, 1, and both sides thereof are formed with tapered surfaces 3a, 3a that gradually slope inward. In addition, a protrusion 3b that protrudes inward is integrally formed at the center of the inner circumferential surface, and this protrusion 3b is arranged between the opposing surfaces of the ends of the tubes 1, 1. This prevents the end surfaces of the tubes 1, 1 from coming into contact with each other and provides insulation.

Further, 4, 4 is a seal ring made of rubber (NBR), and tapered surfaces 4a, 4a are formed at the tips thereof, and these tapered surfaces 4a, 4a are connected to the tapered surfaces 3a, 3a of the insulator 3. By entering the taper and abutting each other, the outer circumferential surface of the pipes 1, 1 of the seal rings 4, 4 and the tapered surface 3a of the insulator 3,
This provides better sealing with 3a.

Further, 5, 5 is an annular washer that is in contact with the rear end surface of the seal rings 4, 4, and when this is in contact with the outer circumferential surface of the pipe 1 and the inner circumferential surface of the joint body 2 as in the case shown in the figure, Of course, it is formed of an insulating material, but it is preferable to form it of an insulating material in other cases as well.

Furthermore, 6 and 6 are the joint body 2 and the pipe 1,
This is a tightening mechanism that fixes 1 and 1.

The tightening mechanisms 6, 6 have male screw portions 7a, 7a on the outer peripheral surface that are screwed into female screw portions 2a, 2a on the inner peripheral surface of the open end of the joint body 2, and have a gradually larger inner diameter on the inner peripheral surface of the front end. It has an annular metal stopper 7, 7 having tapered surfaces 7b, 7b, and sloped surfaces 8a, 8a abutting against the tapered surfaces 7b, 7b of the stoppers 7, 7 on the outer peripheral surface, and its slope 8
an extending portion 8 interposed between the inner circumferential surface of the stopper 7, 7 and the outer circumferential surface of the tube 1, 1 at the rear end portion of a, 8a;
Nylon or polyacetal as shown in FIG. 2A, which has four dividing grooves 8d in the axial direction on the main body portions 8c, 8c on which the inclined surfaces 8a, 8a are formed. or other annular insulating lock spacers 8 made of a slightly flexible synthetic resin such as FRP. It should be noted that the insulating lock spacers 8, 8 can also function satisfactorily even if they are half-shaped with a groove 8d' provided at one location parallel to the axial direction, as shown in FIG.

The joint body 2 and the pipe 1 by this tightening mechanism 6, 6,
1, first use the insulating lock spacers 8, 8.
are inserted into the washers 5, 5 side, and then while screwing the male threaded parts 7a, 7a of the fasteners 7, 7 into the female threaded parts 2a, 2a of the joint body 2, This is done by tapering the tapered surfaces 7b, 7b into the inclined surfaces 8a, 8a of the insulating lock spacers 8, 8 to a desired position.
In this case, the main body portions 8c, 8c on which the inclined surfaces 8a, 8a of the insulating lock spacers 8, 8 are formed have split grooves 8d.
7 into the inclined surfaces 8a, 8a of the insulating lock spacers 8, 8, the main body 8 of the insulating lock spacers 8, 8.
c, 8c are reduced in diameter and hold the outer circumferential surfaces of the tubes 1, 1, so that the tubes 1, 1 are restricted from coming out of the joint body 2, and the tubes 1, 1 and the joint body 2 are
is a bonded state.

Note that when the stoppers 7, 7 are tapered into the insulating lock spacers 8, 8, the stoppers 7,
The seal rings 4, 4 disposed between the washers 5, 5 and the insulator 3 are strongly compressed by the pressing action of the insulating lock spacers 8, 8 of 7. Due to the close contact with the outer peripheral surfaces of the tubes 1, 1 and the close contact with the tapered surfaces 3a, 3a of the insulator 3 due to compression, the fluid within the tubes 1, 1 is reliably sealed, and there is no leakage to the outside. .

Therefore, with such a configuration, when joining the joint body 2 and the pipes 1, 1, the insulating lock spacers 8, 8 are inserted into the washer 5, 5 side,
Next, it is only necessary to taper the fasteners 7, 7 into the insulating lock spacers 8, 8 while screwing the male threaded parts 7a, 7a into the female threaded parts 2a, 2a of the joint body 2, so that the joint body 2 and the pipe are connected. 1,1
This makes the joining work very easy, and even when applied to buried pipes, the joining work can be done very easily and quickly.

Moreover, in this way, no threaded portion is formed on the pipes 1, 1 themselves, and the joint body 2 is tightened by the tightening mechanisms 6, 6.
The structure is such that the seal rings 4, 4 are pressed and compressed to seal the fluid inside the tubes 1, 1, and therefore, it is the method of International Trade No. 439 mentioned at the beginning. This results in a bonded state that conforms to the mechanical bonding method disclosed in 2007, and provides very good sealing of the fluid within the tubes 1, 1, and satisfies reliability.

Furthermore, when the male threaded portions 7a, 7a of the fasteners 7, 7 are screwed into the female threaded portions 2a, 2a of the joint body 2, the tightening mechanisms 6, 6 can be tightened.
The diameter of the insulating lock spacers 8, 8 inserted into the joint body 2 is reduced by the taper penetration of 7, so that the insulating lock spacers 8, 8 hold the outer peripheral surfaces of the pipes 1, 1, and the insulation Since the extending portions 8b, 8b formed on the lock spacers 8, 8 are interposed between the inner circumferential surfaces of the stoppers 7, 7 and the outer circumferential surfaces of the tubes 1, 1, one of the tubes 1 to the other tube 1 through the stop 7 or the fitting body 2, the current flowing from the tube 1 to the other tube 1 is also reliably insulated by the insulating lock spacers 8, 8, so that the tightening mechanism 6, 6 is While satisfying the mechanical bonding method according to Publication No. 439, it can also provide an insulation function.

It should be noted that the present invention is not limited to the above-mentioned embodiments, but can of course be applied to, for example, those shown in FIGS. 3 to 7. In the explanation of the embodiments shown in FIGS. 3 to 7, only the parts that are different from the previous embodiments will be explained, and those with the same configuration as the above embodiments will be denoted by the same reference numerals in the drawings and the explanation will be omitted. I decided to.

The insulated pipe joint shown in FIG. 3 has a joint main body 10 divided into two parts, left and right, and the inner peripheral surface, tip end surface, and outer peripheral surface of the joint end 11a of the left joint main body 11 are coated with soft resin or other plastic. It has an insulating coating layer 13 consisting of a lining or coating, and an insulating cap 14 made of plastic is disposed between opposing surfaces of the end portions of the tubes 1, 1, and the insulating coating layer 13 and the insulating cap 14 are used to form the joint. It serves as an insulator 3 for insulating the main body 10 and the pipes 1, 1 or the pipes 1, 1 to be connected, and the joining of the left and right joint bodies 11, 12 is the joining of the left joint main body 11. The joint end 12 of the right joint main body 12 is attached to the end 11a.
Cover the right joint body 12 in this state.
This is done by crimping the joint end portions 12a of the joints in the circumferential direction. Note that 15 is the left and right joint body 1
This is an O-ring that seals between the joint ends 11a and 12a of Nos. 1 and 12. In this way, the insulation between the tubes 1, 1 can be achieved even if the insulation lock spacers 8, 8 do not have insulation properties, but it is still necessary to make the insulation lock spacers 8, 8 have insulation properties. Accordingly, the insulation effect can be further enhanced, and reliability can be improved.

In addition, the insulated pipe joint shown in FIG.
An insulating coating layer 22 made of fluorine resin or other synthetic resin is formed on the inner circumferential surface of the joint body 20, including the inner surface of the recessed portion 21, and the insulating coating layer 22 is formed on the inner surface. Recessed part 21
The split type insulating ring 23 is disposed between the opposing surfaces of the end portions of the tubes 1, 1 in a state where the split type insulating ring 23 is fitted and fixed, and these insulating coating layer 22 and the split type insulating ring 23 are fitted and fixed. The insulating ring 23 also serves as an insulator 3.

In addition, the insulated pipe joint shown in FIG.
A convex portion 24b is formed at one place on the outer circumferential surface of the split type insulator 3 having a diameter of 1.a, and this convex portion 24b is formed in the center of the inner circumferential surface of the joint body 2 as shown in FIG.
b, which facilitates attachment of the insulator 3 to the joint body 2 and prevents displacement.

Furthermore, the insulated pipe joint shown in FIG. 6 is the same as the insulated pipe joint shown in FIG. 3, except that the insulating cap 14 of the insulator 3 is replaced with the split type insulating ring 23 shown in FIG. , in addition to the stopper 7,
Projections 7c, 7c are integrally formed at the tip of the seal ring 7, and the pressing force of the stopper is applied directly to the seal rings 4, 4 by the projections 7c, 7c. Effectively seal ring 4,4
is compressed to improve the degree of sealing of the fluid within the tubes 1,1. In addition, such a stopper 7, 7 has a protrusion 7.
It is of course possible not only to form the seal rings 4, 7c integrally and to apply the pressing force of the stoppers 7, 7 directly to the seal rings 4, 4, but also in the case of the first embodiment.
The present invention can also be applied to the embodiments described with reference to FIGS. 5 to 5 and the embodiment of FIG. 7, which will be described later.

Also, the insulated pipe joint shown in FIG. 7 is the same as the insulated pipe joint shown in FIG.
3, but in this case, in particular, the main body parts 8c, 8c of the insulating lock spacers 8, 8
By forming recesses 8e, 8e with a concave cross section on the inner circumferential surface of the pipes 1, 1, and fitting split metal rings 25, 25 whose inner circumferential surfaces are serrated into the recesses 8e, 8e, This increases the frictional resistance with the outer circumferential surface and more effectively prevents the tubes 1, 1 from slipping out. It should be noted that such a configuration for preventing slippage is of course applicable not only to this embodiment but also to the embodiments described in FIGS. 1 to 6 above.

Moreover, FIGS. 8A to 8E show various examples of shapes of the split metal rings 25, 25 explained in FIG. An example in which the inner circumferential surface 25a is brought into contact with the outer circumferential surface of the tubes 1, 1 without forming a saw blade, B shows a notch 25 on the inner circumferential surface 25a.
This is an example of a case in which a plurality of b... are provided so that a local load is applied to the outer circumferential surfaces of the tubes 1, 1. In the case of the embodiment B, an anticorrosive coating layer is formed on the outer circumferential surfaces of the tubes 1, 1. Pipe 1 with a thick anti-corrosion coating layer,
This has the effect of increasing the pulling resistance of No. 1. Also,
H to H show examples of the longitudinal cross-sectional shapes of the split metal rings 25, 25, and the inner circumferential surfaces 25a of the split metal rings 25, 25,
25a increases the frictional resistance between the outer circumferential surfaces of the tubes 1, 1, and effectively
The inner peripheral surface shapes of C to H can be applied to the split metal ring 25 in A and the split metal ring 25 in B, respectively.

〔Effect of the invention〕

As is clear from the above explanation, according to the insulated pipe joint for underground burial according to the present invention, the joint body and the pipe can be connected by simply screwing the stopper of the tightening mechanism fitted onto the pipe onto the insulating lock spacer. Since it can be joined, the joining work is extremely easy. Furthermore, the sealing member is pressed and compressed by the insulating lock spacer as the stopper is screwed together, thereby improving the sealing ability. Furthermore, as the fastener is screwed together, the joint body and pipe are firmly fixed, and almost the entire joint body can receive external stress, so it has high strength against such external stress, and when buried underground. It also has the advantage of being highly reliable.

[Brief explanation of drawings]

Figures 1 and 2 show one embodiment of the present invention. Figure 1 is a sectional view showing the upper half of an insulated pipe joint, and Figures 2A and 2B are perspective views of an insulating lock spacer. , FIGS. 3 to 8 show other embodiments of the present invention, and FIGS. 3 to 7 are cross-sectional views showing the upper half of the insulated pipe joint, and FIGS. are respectively plan views of the split metal rings, and FIGS. 8A to 8H are longitudinal cross-sectional views of the split metal rings, respectively. 1...Pipe, 2,10,20...Joint body, 3...
...Insulator, 4...Seal ring (sealing member),
6... Tightening mechanism, 7... Stopper, 7a... Threaded part of stopper, 7b... Tapered surface of stopper, 8... Insulating lock spacer, 8a... Inclined surface of insulating lock spacer, 8b... Extending portion of insulating lock spacer, 8c... Main body of insulating lock spacer, 8d... Division groove of insulating lock spacer.

Claims (1)

[Claims] 1. A joint body disposed in an external fit between the ends of the pipes to be connected, and a gap between the inner peripheral surface of the joint body and the outer peripheral surface of the end of the pipe to be connected or of the pipe to be connected. This is achieved by screwing an insulator disposed between opposing surfaces of the ends and insulating between the joint body and the pipes to be connected, and between the pipes to be connected, and the inner circumferential surface of the open end of the joint body. a tightening mechanism that enters between the joint body and the pipe from the open end and fixes them; interposed between the tightening mechanism and the insulator;
a sealing member that is compressed by the entry of the tightening mechanism, and the tightening mechanism has a threaded portion that is threadedly engaged with the inner circumferential surface of the opening end of the joint body, and the tightening mechanism has a threaded portion that is threaded into the inner circumferential surface of the front end portion. An annular stop having a tapered surface with a large inner diameter, an inclined surface that abuts the tapered surface of the stop on its outer peripheral surface, and an inner peripheral surface of the stop at the rear end of the inclined surface. and an annular insulating lock spacer having an extending part interposed between the pipe and the outer peripheral surface of the pipe to be connected, and further having a groove formed in the axial direction in the main body part on which the inclined surface is formed. An insulated pipe joint for underground burial, characterized by comprising: