JPH07239068A - Water leakage detection type flexible pipe joint - Google Patents

Abstract

PURPOSE:To provide a water leakage detection type flexible pipe joint which can carry out sooner detection of water leakage from the pipe circumference wall part with high reliability and can be easily produced. CONSTITUTION:A cylindrical electric conductor 7 is buried along the pipe circumference wall part of a flexible pipe joint, and the electric conductor 7 is partially exposed on opposed flanges 5 pressure contact faces arranged in the end parts of the flexible pipe joint. The electric conductor 7 is connected to lead wires 15 via the opposed flanges 5 brought into pressure contact with the conductor 7.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water leakage detecting type flexible pipe joint, and more particularly to a flexible pipe joint capable of detecting water leakage from a peripheral wall of a pipe at an earlier stage.

[0002]

2. Description of the Related Art In a water pipe such as a drain pipe, a flexible pipe joint having a relatively short length is used at a bent portion or a rising portion on the ground or in the ground, or a connecting portion to equipment of various devices. It is used. Such a flexible pipe joint is usually formed by annularly forming synthetic rubber or an elastic flexible material, and a tire cord for reinforcement or a spiral metal wire is embedded in the peripheral wall of the pipe. , In order to improve flexibility, the tube may be formed into a bellows shape. However, a flexible pipe joint made of a material such as rubber is apt to cause deterioration such as corrosion and cracks in the peripheral wall of the pipe, and is particularly used for a piping system that allows passage of a corrosive liquid or hot water. This tendency is remarkable in some cases. Although such corrosion and cracks in the peripheral wall of the pipe gradually progress and eventually lead to water leakage, if left unknowingly, it will cause serious damage to surrounding equipment.

Therefore, in order to solve such a problem, various methods for detecting water leakage in a flexible pipe joint have been conventionally proposed, and a typical method for electrically detecting an electric leak is to use a conductor. Are known. In this method, two conductors are arranged on the surface of the peripheral wall of a flexible pipe joint, the ends of the conductors are connected to an alarm device, and the alarm device is activated by conduction between the conductors due to water leakage. .

[0004]

However, the above method has a problem that the leak cannot be detected until the surface of the peripheral wall portion of the flexible pipe joint has reached the surface of the leak, and the repair or replacement work has no room. It was Further, since it is necessary to lay a bare conductor wire on the surface of the peripheral wall of the flexible pipe joint, there is a problem that the conductor wire itself is easily corroded and damaged, resulting in low reliability. Therefore, the present inventor has already proposed a water leakage detection type flexible pipe joint of Japanese Patent Application No. 5-267933. This is because the conductor is embedded along the peripheral wall of the pipe, and when a fluid penetrates inside due to a crack, electrical conduction occurs between the conductor and the conductor, and the alarm circuit is activated. It is made to compose. However, in a flexible pipe joint that is fastened and fixed to a metal pipe that is a connected pipe via a companion flange,
There has been a drawback that the structure of the connecting portion for connecting the internal conductor and the lead wire has to be relatively complicated. Therefore, an object of the present invention is to provide a water leakage detection type flexible pipe joint in which lead wires can be easily connected and which has high reliability, and the following configuration is adopted to achieve the purpose.

[0005]

In a water leakage detection type flexible pipe joint of the present invention, flange portions 1 and 1 are integrally provided on outer circumferences of both axial ends, and the axial tip of the flange portion 1 is formed. Surface 2
Is pressed against the end face of the pipe 3 to be connected, and the axial rear end face 4 of the flange portion 1 is pressed against the companion flange 5, in the flexible pipe joint, along the pipe peripheral wall portion 6 of the pipe joint,
The conductor 7 is embedded in the pipe peripheral wall portion 6 in a tubular shape, a basket shape, or a net shape, and at least a part of the conductor 7 is exposed on a joint surface pressed against the companion flange 5. .

[0006]

The flexible pipe joint of the present invention, when the deterioration such as the crack progresses from the inside to the position of the conductor 7 embedded along the peripheral wall of the pipe, the flexible pipe joint slightly passes through the crack. The conductor 7 and the internal liquid are electrically connected to each other using the liquid that oozes out as a medium. Therefore, by connecting the lead wire to the metal pipe which is the connected pipe connected to the flexible pipe joint and monitoring the conduction state between the lead wire and the companion flange 5 to which the conductor 7 is exposed and pressure-welded. The progress of deterioration such as cracks can be detected at an early stage. As described above, by using the flexible pipe joint of the present invention, the progress of deterioration can be detected before water leaks from the surface of the pipe peripheral wall portion of the flexible pipe joint. Further, since the conductor 7 is embedded inside the pipe peripheral wall portion of the flexible pipe joint, the conductor itself is less corroded and damaged, and the reliability of water leakage detection is extremely high.

Further, since a part of the buried conductor 7 is exposed on the joint surface pressed against the companion flange 5,
It is extremely easy to connect a lead wire connected to an alarm device or the like through the companion flange 5 that is pressure-contacted therewith, and it is possible to provide a leak detection type flexible pipe joint that has high reliability of an electric circuit and is easy to handle. That is, as an example, the metallic companion flange 5
A reliable alarm circuit can be easily constructed by fixing the lead wire terminal to the outer surface of the.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a water leakage detection type flexible pipe joint of the present invention will be described below with reference to the drawings. FIG. 1 is a longitudinal sectional view showing a state where an example of the flexible pipe joint of the present invention is used in a piping system. FIG. 2 is an exploded perspective view of the flexible pipe joint, showing a state in which the companion flange 5 is removed from the flange portion 1 of the joint. 3 is an exploded vertical sectional view of the flange portion 1 and its vicinity. The flexible pipe joint is made of an elastic flexible material such as synthetic rubber, and is integrally formed with a bellows-shaped pipe peripheral wall portion 6 and elastic flange portions 1 provided at both ends thereof. . In this joint, synthetic rubber and tire cords are laminated in multiple layers, and a cylindrical conductor 7 is embedded in the center of the laminated body. The conductor 7 is
It is a flexible conductive rubber plate material or a bendable metal wire formed in a basket shape or a net shape. The overall shape of the joint may be a straight shape or a simple shape with one or two peaks other than the bellows shape.

In this embodiment, the conductors 7 are provided on the axial rear end surfaces 4 of the respective flange portions 1 provided at both ends of the pipe peripheral wall portion 6.
The edge of is exposed. The flexible pipe joint having such a structure is
In the conventional molding process of the flexible pipe joint, it suffices to use a flexible conductor as the laminated material of the intermediate portion, and the conventional manufacturing method can be followed almost as it is, and the manufacturing is easy. That is,
The conductor 7 is laminated in the middle of the laminating work so that both ends thereof are exposed on the surface of the flange portion. In the flange portion, new lamination may not be performed on the exposed outer circumference of the conductor. A groove portion for fitting a companion flange 5 to be described later is formed in advance on the axial rear end surface 4 side of the flange portion 1 of this flexible pipe joint. A detailed manufacturing method of the flexible pipe joint is publicly known and therefore omitted, but a wire is circumferentially embedded in the flange portion 1 and the central portion of the peripheral wall portion 6 for reinforcement.

Next, the metallic companion flange 5 pressed against the axial rear end faces 4 of the pair of flange portions 1 has an inner peripheral portion aligned with the root portion of the flange portion 1 and has a pipe 3 to be connected. The outer periphery is substantially aligned with the flange, and the bolt hole 14 is formed at a position aligned with the bolt insertion hole of the connected tube 3. The inner peripheral edge portion is formed in a stepped shape so as to be aligned with the axial rear end surface 4 of the flange portion 1. Further, in this embodiment, a small bolt hole 16 is formed on the facing surface side of the pipe 3 to be connected, and the shaft portion of the insulating spacer 8 is screwed and fastened thereto. As the insulating spacer 8, a synthetic resin material, a metal material whose surface is covered with an insulating material, or the like is used. Further, a screw hole for attaching the terminal 9 of the lead wire 15 is formed on the outer periphery of the companion flange 5. The companion flange 5 thus formed can be fitted to the axial rear end face 4 side while deforming the flange portion 1 of the flexible pipe joint. Alternatively, the flexible pipe joint may be joined to the axial rear end face 4 side of the flange portion 1 in advance. In any case, the conductor 7 exposed on the axial rear end surface 4 contacts the front surface of the companion flange 5.

The companion flange 5 thus mounted on the flexible pipe joint and the pipe 3 to be connected are fastened via insulating bolts 10 and nuts 11 as shown in FIG. Instead of the insulating bolt, an insulating collar (not shown) may be attached to the bolt hole 14 of the metallic companion flange 5 and a normal bolt may be used. The insulating spacer 8 regulates the fastening amount of the insulating bolt 10 and the nut 11 so that the flange portion 1 is not excessively closed. At the same time, the companion flange 5 and the connected pipe 3 are electrically separated. The insulating bolt 10 may be made of a plastic material or a metal material with an insulating coating. Then, the terminal 9 provided at the tip of the lead wire 15 is fixed to the outer periphery of the companion flange 5 via a screw. Next, as shown in FIG. 1, the other end of the lead wire 15 is connected to the connected tube 3 via the alarm device 13 and the power supply 12. In this embodiment, a circuit of the alarm device 13 is connected to each of the pair of companion flanges 5 so that even if one of them fails, the other can compensate for it. The alarm device 13 can be configured by a buzzer, a lamp or the like.

In this way, the flexible pipe joint is connected between the ends of the pair of pipes 3 to be connected. Then, both ends of the conductor 7 and the companion flange 5 inevitably come into pressure contact with each other, and the two are electrically and surely conducted. Next, the operation of the flexible pipe joint shown in the embodiment will be described. First, in FIG. 1, when the deterioration of the pipe peripheral wall portion 6 of the flexible pipe joint progresses and a crack is generated on the inner peripheral surface thereof, the liquid inside reaches the conductor 7 through the gap of the crack. . Then, the liquid in the flexible pipe joint and the conductor 7 are electrically connected. On the other hand, the lead wire 15 is connected to the connected pipe 3 via the alarm device 13 and the power source 12, so that an electrically closed circuit is formed through the liquid inside.
The alarm device 13 operates and issues an alarm. That is, it is possible to know when a crack occurs in the inner circumference before the water leaks from the outer peripheral wall of the flexible pipe joint. 3 is a partially enlarged view of the flange portion 1 of the present flexible pipe joint. In this figure, a tire cord 17 and a wire 18 are embedded in the flange portion 1 to reinforce the flange portion 1.

Next, FIG. 4 shows a second embodiment of the present invention.
In this embodiment, the conductor 7 and the tire cord 17 are wound around the outer periphery of the cross section of the flange 1, and the tip of the conductor 7 is exposed only at the root of the flange 1. Then, the root portion comes into contact with the companion flange 5. Therefore, when the companion flange 5 is fastened, it and the exposed portion of the conductor 7 are strongly pressed against each other. Next, FIG. 5 shows a third embodiment of the present invention, in which the flange portion 1 of this embodiment is projectingly provided in an L-shape having the same thickness in cross section with respect to the pipe peripheral wall portion 6 of the joint. The flat annular ring 18a for reinforcement is embedded in the flange portion 1, the conductor 7 and the tire cord 17 are arranged along the outer periphery thereof, and the tip end of the conductor 7 is only on the root surface of the flange portion 1. It is exposed, and the exposed portion is configured to contact the companion flange 5. As in the embodiment shown in FIGS. 4 and 5, the flange portion 1
When the conductor 7 is exposed at the root portion of, the cracks at all parts of the flange portion where cracks are particularly likely to occur can be detected. At the same time, it is possible to provide a joint with high strength that is extremely easy to manufacture and is mass producible. That is, the tire cord 17 can be sufficiently arranged on the outer circumference of the flange,
The tip of the conductor 7 can be easily guided to the flange.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a state where an example of a flexible pipe joint of the present invention is used in a piping system.

FIG. 2 is a partially cutaway perspective view showing a state in which one companion flange 5 portion in FIG. 1 is removed.

FIG. 3 is a partially enlarged view of a flange portion 1 of the flexible pipe joint of the present invention.

FIG. 4 is a partially enlarged view of the flange portion 1 of the flexible pipe joint of the second embodiment of the present invention.

FIG. 5 is a partially enlarged view of the flange portion 1 of the flexible pipe joint of the third embodiment of the present invention.

[Explanation of symbols]

 1 Flange part 2 Axial tip face 3 Connected pipe 4 Axial rear end face 5 Phase flange 6 Pipe peripheral wall part 7 Conductor 8 Insulation spacer 9 Terminal 10 Insulation bolt 11 Nut 12 Power supply 13 Alarm device 14 Bolt hole 15 Lead wire 16 Small bolt hole 17 Tire cord 18 Wire 18a Annular ring

Claims (1)

[Claims] 1. Flanges 1, 1 on the outer circumference of both axial ends
Is integrally projecting, the axial end surface 2 of the flange portion 1 is in pressure contact with the end surface of the connected pipe 3, and the axial rear end surface 4 of the flange portion 1 is in pressure contact with the companion flange 5. In the flexible pipe joint, along the pipe peripheral wall portion 6 of the pipe joint, a conductor 7 is embedded in the pipe peripheral wall portion 6 in a tubular shape, a cage shape, or a net shape, and at least a part of the conductor 7 is A water leakage detection type flexible pipe joint, which is exposed on a joint surface that is pressed against the companion flange 5.