JPS62274252A - Inspecting method for pipe internal surface by spherical body - Google Patents

Abstract

PURPOSE:To simplify an operation process and to improve operation efficiency by incorporating an electric detecting means in an insulating spherical body and inserting it into a pipe from its opening, closing the opening part so that a lead wire is movable, and sending air in through an air intake provided to the closure part and moving the spherical body of the inspection of the pipe inside. CONSTITUTION:The insulating spherical body 2 where the electric detecting means is incorporated is inserted into the pipe 1 to be inspected from its opening 1a. Its lead wire is run through the insertion part 5 of a closing lid 4 and the opening 1a is closed, The air is sent in the pipe 1 under specific pressure from an air compressor 9 through the air intake 8. The spherical body 2 moves in the pipe 1 because of the wind pressure and the electric detecting means detects the state of the film in the pipe 1 and sends electric variation due to the abnormality of the film to a detection part 7, so that the abnormality is detected.

Description

[Detailed Description of the Invention] 3. Detailed Description of the Invention [Field of Industrial Application] The present invention is applicable to water pipes and drainage pipes buried below the road surface, or existing ones installed in structures such as buildings. This method relates to a method of inspecting the painted state of the inner surface of the pipe after lining the inner surface of the pipe, and is used for inspecting the pipe after repair work.

[Conventional technology]

Conventionally, methods for inspecting the coating condition of the inner surface of water pipes, drainage pipes, etc. after rehabilitation work include an optical inspection method in which a small television camera is moved within the pipe to show the internal condition, and an electrode brush or electromagnetic inspection method. A method is known in which an abnormal portion is detected by electrical changes by moving a coil.

Then, in order to move these detection objects within the pipe, a wire is inserted into the pipe from the end opening on the side in the direction of movement of the pipe, the detection object is connected to this, and this wire is inserted from the end opening side. It is towed and moved at a predetermined speed.

[Problems to be solved by the present invention]

However, since the conventional method uses a wire to move the detection object, it has the following drawbacks.

(a) Because the wire being pulled stretches in a straight line.

Can only be used if the pipe is straight and of a certain length. In other words, in the case of a single bend, the wire being pulled rubs against the inner surface of the pipe on the bending side, often damaging the coating on this inner surface.For this reason, the bent pipe section in particular must be cut and inspected, and then inspected. Repairs were being made again.

In addition, even in straight pipe sections, if the wire is long, it will sag due to its own weight and damage the coating on the inner surface before inspection, so there is a limit to the length of the pipe to be tested.

(b) Since the wire is pulled in the direction of travel from the end opening of the pipe, and it is impossible to send the object to be detected backwards, inspection of the inner surface of the pipe is also a one-way, temporary process, which reduces reliability. Missing.

(c) Before starting the inspection, it is necessary to insert a wire into the pipe from the end opening of the pipe, which requires time and effort for preparation and does not improve work efficiency.

[Means for Solving the Problems] [The present invention aims to solve all of the above-mentioned problems.It is an object of the present invention to solve all of the above-mentioned problems. Insert the detection means through one opening of the pipe, close the opening so that the lead wire can move, and send air at a predetermined pressure from an air inlet provided in the closed part, It is characterized in that the inner surface of the pipe is inspected by the detection means by moving the spherical body.

[For production]

In the present invention, the connection lead wire of the electrical detection means incorporated in the spherical body is electrically connected to a detection section installed outside, and a detection signal from this detection section is used to generate an alarm device such as a conventional buzzer or the like. The recording device is now activated. Also, leave the end opening of the pipe to be tested open to allow some air to blow through. “In this way, a spherical body is inserted into one opening of the pipe to close it, and air is sent in at a predetermined pressure from the air inlet of the blocked part, and the spherical body moves inside the pipe under the wind pressure. go.

At this time, some air will blow through from between the circumferential surface of the spherical body and the inner surface of the pipe to the end opening of the pipe to be tested, so if the pipe is straight, the spherical body will move inside the pipe along the direction of the air flow. to the distal opening.

In addition, in the case of branched or bent pipes such as cheese piping, close the end opening of the straight pipe in the direction of travel, and leave the end opening of the bent pipe open. Then, the introduced air blows through to the end opening of the bent tube, and the spherical body also enters the bent tube and moves inside the bent tube along with the flow of air.

In response to the movement of the spherical body, the lead wire connected to the electrical detection means is drawn into the pipe, so by using a long lead wire, even a fairly long pipe can be inspected over its entire length. .

Furthermore, during the movement of the spherical body, the electrical detection means detects abnormal points in the coating on the inner surface of the pipe, such as pinholes.

When an imbalance in the coating thickness is detected, the electrical change is detected by the detection section through the lead wire, and the detection signal activates an alarm device or a recording device.

In this way, the inspection may be terminated when the spherical body reaches the end opening of the pipe to be inspected, but in addition, the opening through which air has been supplied up to now is unblocked, the end opening is closed, and the If air is pumped in, the spherical body is sent back inside the pipe, so it can be inspected on the return trip. In this case, it goes without saying that the lead wire can be wound up and recovered.

〔Example〕

FIGS. 1 and 2 are conceptual diagrams of an embodiment embodying the present invention.

In the figure, 1 is a pipe to be tested, and 2 is a spherical body made of insulating soft synthetic resin, rubber, etc., with a diameter slightly smaller than the inner diameter of the pipe to be tested 1, with an electrical detection means built inside and a lead. Connected to line 3.

Reference numeral 4 denotes a closing lid that is detachably attached to one opening of the pipe, and is provided with an insertion portion 5 through which the lead wire 3 is inserted movably while maintaining airtightness. 3 is connected to a detection unit 7 via a take-up roll 6. Further, the closing lid 4 is provided with an air inlet 8, through which air is introduced from a near compressor 9 at a predetermined pressure.

In the inspection method of the present invention, the spherical body 2 is inserted into the pipe through one opening 1a of the pipe 1 to be inspected, and the lead wire 3 is inserted into the pipe.
is inserted into the insertion part 5 of the blocking lid 4, the end opening of the pipe 1 to be inspected is opened, and air is sent in at a predetermined pressure from the near compressor 9, and the spherical body 2 moves inside the pipe due to the wind pressure. Go. During this movement, the electrical detection means detects the state of the coating film on the inner surface of the pipe, and if an electrical change occurs due to an abnormality in the coating film, it is electrically connected to the detection section 7 and detected.

Figure 2 shows the case of curved pipes such as cheese pipes.
When the end opening 1c of the pipe, which is straight in the direction of travel, is closed with the closing aM4', the air will blow through to the bent pipe 1b side as described above, so the spherical body 2 will also move inside the bent pipe 1b according to the air flow. and move to its distal opening.

FIG. 3 shows an embodiment of the electrical detection means, in which an electrode brush 10 is built into the spherical body 2, and the tip of each filament 10a is slightly recessed from the surface of the spherical body 2 to expose it. . In this case, the electrode brush 1o inside the pipe is electrically connected to the negative side through the lead wire 3, and a positive voltage is applied to the pipe 1 to be tested. Although this voltage varies depending on the material of the paint used, it is desirable to set it below the dielectric breakdown voltage of the paint film.

As a result, when the spherical body 2 moves and comes into contact with the pinhole (P) remaining in the paint film on the inner surface of the pipe, a discharge is generated from the tip of the electrode brush closest to the pinhole (P), and the charged voltage is transferred to the detection section. Detected at 7.

4 and 5 show other embodiments of the electrical detection means, in which a plurality of magnetic coils 11 are included in one spherical body 2, and the iron core tips 12 and 13 are arranged in the traveling direction of the spherical body 2. Both ends of the coil windings are connected to respective lead wires 3 so that a predetermined current is applied.

Therefore, due to the movement of the spherical body 2, the core tip 12.
13 is in contact with the coating film (m) on the inner surface of the pipe.

It moves while forming a magnetic circuit with the magnetic pipe 1, but if the thickness of the non-magnetic coating (m) changes, the resistance value in the magnetic circuit also changes, causing a change in the current flowing through the coil. Therefore, the amount of change is converted into the thickness of the coating film by the detection unit 7 and detected.

Furthermore, as another embodiment, the lead wire 3 is provided with a reading device 13 having a length that is drawn into the pipe, and the pinhole or abnormal point of uneven coating thickness is recorded in synchronization with the detection signal. It can be displayed in the section. In this case, there is an advantage that the abnormal point can be immediately identified by the length of the pipe from the opening 1a.

〔effect〕

As described above, according to the present invention, (a) an electrical detection means is incorporated into a flexible and elastic spherical body, and this spherical body is moved by air; Even if the lead wire is long, the inner coating will not be damaged, and the pipe can be inspected in a non-destructive manner without having to be cut, unlike conventional methods.Furthermore, if the lead wire is set long, the pipe within that range will be long. (b) Since the air supply can be reversed and the spherical body can be sent backwards, the inner surface of the pipe can be inspected reciprocally, ensuring reliable inspection and increasing accuracy. (C) Before inspection, all you have to do is insert the spherical body into the pipe, close it with a blocking lid, and then introduce air, which simplifies the work process and increases work efficiency. achieved.

[Brief explanation of the drawing]

Figures 1 and 2 are conceptual diagrams of one embodiment of the present inspection method, Figure 3 is an explanatory diagram of an embodiment of the electrical detection means, and Figures 4 and 5 are other embodiments of the electrical detection means. It is an explanatory diagram of an aspect. 1...Test pipe, 2...Spheroidal body. 3... Lead wire, 4... Closure lid, 5... Insertion part, 7... Detection part, 8... Air inlet,
10... Electrode brush, 11... Electromagnetic coil,
12.13... Core tip, 14... Reading device, P... Pinhole, m... Paint film.

Claims (4)

[Claims] (1) An electrical detection means is built into an insulating spherical body having a smaller diameter than the inner diameter of the pipe and has flexible elasticity, and the detection means is inserted through one opening of the pipe and its lead wire can be moved. A pipe made of a spherical body, characterized in that the opening is closed, air is sent in at a predetermined pressure from an air inlet provided in the closing part, the spherical body is moved, and the inner surface of the pipe is inspected by the detection means. Inner surface inspection method. (2) An electrode brush is incorporated in the spherical body and electrically connected to the negative side, and a positive voltage is applied to the pipe to be inspected to detect pinholes on the inner surface of the pipe by the charged voltage. A method of inspecting the inner surface of a pipe using a spherical body. (3) The spherical body according to claim 1, wherein a magnetic coil having a core tip arranged linearly in the traveling direction is incorporated in the spherical body, and the coating thickness is detected by a change in current in the magnetic circuit. Method of inspecting the inner surface of a pipe. (4) A method for inspecting the inner surface of a pipe using a spherical body according to claim 1, which includes a reading device for reading the length of a lead wire that enters the pipe, and displays this in synchronization with a recording section.