JP2017133834A - Nondestructive inspection device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a technique that especially electrical contact resistance can be reduced, in a nondestructive inspection device for inspecting the presence or absence of defects of an inspected pipe without destructing the inspected pipe.SOLUTION: A nondestructive inspection device 10 includes a cylindrical body 20 and two winding mechanisms 30. The cylindrical body 20 is a member as a matrix of the nondestructive inspection device 10, and a pipe is inserted into it. The winding mechanisms 30 wind conducting wires around the cylindrical body 20 or rewind them, and are provided at each of right and left end parts of the cylindrical body 20.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a nondestructive inspection apparatus that inspects the presence or absence of defects in a pipe to be inspected without destroying the pipe to be inspected, and more particularly to a technique that can reduce electrical contact resistance.

Many pipes are used in factory facilities and industrial facilities called plants.
Such a pipe usually has a structure in which a steel pipe serving as a base pipe is coated with a heat insulating material such as calcium silicate or rock wool, and an outer sheet metal is coated on the outside thereof.
Such pipes show defects such as corrosion, fatigue and cracks in the steel pipe over time, and it is necessary to periodically inspect the presence or absence of such defects to ensure safety.
As such an inspection method, it is common to peel the heat insulating material and the outer sheet metal and visually inspect them. However, since it takes time and effort to peel off the heat insulating material and the defect is often not found as a result of the inspection, it is desirable that the heat insulating material can be inspected as it is without being peeled off.

In response to such a request, a technique has been proposed in which the presence or absence of a piping defect is inspected using pulse magnetism without destroying the piping (see Patent Document 1).
Specifically, a pair of exciting coils are wound around the piping, a pulse voltage is applied to the exciting coils, the generated magnetic field is detected by a magnetic sensor, the detected magnetic field is analyzed, and the piping is based on the analysis result. It is inspected for defects.
In particular, in Patent Document 1, in the inspection apparatus (1-3), the coil connection connectors (11-1, 11-2) are provided, and the exciting coils (3-3, 3-4) are separated at predetermined positions on the circumference. There has been a proposal that an exciting coil can be separated and attached to a pipe at any part of the pipe (see Example 3 and FIG. 8).
Also in Patent Document 2, the probe housing (112) and the coil (120) are configured to be separable, and the connector (130) and the connector (132) are connected to the joint surface of the divided housing (112a, 112b). Is proposed to connect the split coils (120a, 120b) to form a coil (see paragraphs 0036 to 0039 and FIG. 6).

JP-A-2014-44087 JP 2011-185827

However, in the configuration as in Patent Documents 1 and 2, since the electrical contact is formed in the exciting coil for the number of turns, a contact resistance is generated at the electrical contact, resulting in power supply to the exciting coil. The amount may increase or the power supply may become unstable. Further, in the electrical contact, contact failure may occur, and a situation may occur in which a necessary current due to the pulse voltage does not flow to the exciting coil.
Therefore, a main object of the present invention is to provide a nondestructive inspection apparatus that can inspect whether there is a defect in any part of the piping, reduce contact resistance in the exciting coil, or prevent contact failure. There is.

In order to solve the above problems, according to the present invention,
A cylinder that is detachable from the pipe;
A conductive wire wound around the cylinder and constituting an exciting coil;
A winding mechanism for winding the conductive wire around the cylindrical body, or winding it;
A non-destructive inspection apparatus is provided.

According to the present invention, the cylindrical body is detachable from the pipe and is provided with a winding mechanism. Therefore, when attaching to the pipe, the exciting coil can be formed by winding the conductive wire around the cylindrical body without separating the conductive wire. It is possible to take up the conductor from the periphery of the cylinder without separating the conductor even when it is detached from the coil, and no electrical contact is formed on the exciting coil in any situation.
Therefore, it is possible to inspect whether there is a defect in any part of the piping, and it is possible to reduce contact resistance in the exciting coil or prevent contact failure.

It is the schematic which shows the basic composition of a pulse magnetic inspection system. It is a perspective view which shows schematic structure of a nondestructive inspection apparatus. FIG. 3 is a partially enlarged view of FIG. 2. FIG. 4 is a side view and a partial cross-sectional view of FIG. 3. It is a figure which shows roughly the winding aspect to the bobbin of conducting wire. It is a figure which shows roughly the connection aspect of a conducting wire and a bobbin. It is a perspective view which shows roughly the open / close state of a nondestructive inspection apparatus. It is a figure which shows the modification of FIG. It is a block diagram which shows roughly the control structure of a nondestructive inspection apparatus. It is a figure which shows roughly the suspended state of piping.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a schematic diagram showing a basic configuration of a pulse magnetic inspection system 1.
The pulse magnetic inspection system 1 is a nondestructive inspection system that inspects the presence or absence of defects in the pipe 2 by applying a pulse voltage to the pipe 2 to be inspected and detecting a change in the magnetic field flowing through the pipe 2. The apparatus mainly includes a nondestructive inspection device 10, a control device 12, a pulse power supply 14, and a power supply switching circuit 16.

  The pipe 2 is a cylindrical pipe to be inspected for defects by the pulse magnetic inspection system 1. The pipe 2 includes a steel pipe 4 having a thickness of 7.2 mm, for example. The periphery of the steel pipe 4 is covered with, for example, a heat insulating material 6 having a thickness of 50 mm, and the periphery of the heat insulating material 6 is covered with, for example, a molten zinc iron plate 8 having a thickness of 0.3 mm (see FIG. 4).

The nondestructive inspection device 10 is a device that detects a change in the magnetic field transmitted through the pipe 2 by a magnetic sensor by generating a magnetic field by receiving a pulse voltage applied by the exciting coil 62 while the pipe 2 is inserted. .
The control device 12 is connected to the nondestructive inspection device 10 and the pulse power source 14 and controls these operations.

  The pulse power supply 14 can apply a pulse voltage to at least one of the pair of exciting coils 62 of the nondestructive inspection apparatus 10. The pulse power source 14 can output a square wave and can be driven at a predetermined repetition rate and a duty ratio. The pulse power supply 14 is electrically connected to the power supply switching circuit 16.

  The power supply switching circuit 16 switches the current direction of one excitation coil and the other excitation coil of the pair of excitation coils 62 of the nondestructive inspection apparatus 10 to the same direction or the opposite direction, respectively, or the pair of excitation coils 62 The circuit can be switched so that only one of them is driven. The power supply switching circuit 16 can select the direction of the current flowing through the pair of exciting coils 62 and operating both or only one of them. Here, if the current directions of both exciting coils 62 are operated in the same direction, a pulse magnetic field in the same direction can be applied to the pipe 2.

As shown in FIG. 2, the nondestructive inspection apparatus 10 is mainly composed of a cylindrical tube 20 and two winding mechanisms 30.
The cylindrical body 20 is a member that becomes a base body of the nondestructive inspection apparatus 10, and the pipe 2 is inserted therethrough.
The winding mechanism 30 is a mechanism that winds or winds the conductive wire 60 around the cylindrical body 20, and is provided at both left and right ends of the cylindrical body 20.
The winding mechanism 30 is a mechanism configured symmetrically, and the following description will be made centering on one winding mechanism 30.
2 and other drawings, the left-right direction coincides with the axial direction of the nondestructive inspection apparatus 10 and the cylindrical body 20 (and the bobbin 46 of the winding mechanism 30), and the up-down direction is orthogonal to the left-right direction.

As shown in FIG. 3, the winding mechanism 30 has two rotating mechanisms 32 and 34. The rotation mechanism 32 is arranged around the cylinder 20, and the rotation mechanism 34 is arranged at a position separated from the cylinder 20.
The rotation mechanism 32 includes a motor 40, a shaft 42, a gear 44 (gear), and a bobbin 46. The motor 40 is supported by the support column 22 and is fixed to the cylindrical body 20. The bobbin 46 is a cylindrical member around which the conducting wire 60 is wound. A gear 48 is provided at the end of the bobbin 46, and the gear 48 and the gear 44 are engaged with each other. The motor 40 is an example of a power source for rotating the bobbin 46, and the power is transmitted to the bobbin 46 via the shaft 42 and gears 44 and 48. The shaft 42 and the gears 44 and 48 are examples of a transmission mechanism, and a friction wheel may be adopted for the transmission mechanism instead of the gears 44 and 48.
On the other hand, the rotation mechanism 34 includes a motor 50, a shaft 52, and a bobbin 54. The motor 50 is supported by the support 24 and is fixed to the cylindrical body 20. The bobbin 54 is a cylindrical member for winding the conducting wire 60 from the bobbin 46. The motor 50 is an example of a power source for rotating the bobbin 54, and the power is transmitted to the bobbin 54 via the shaft 52. The shaft 52 is an example of a transmission mechanism, and the transmission mechanism may include a gear and a friction wheel like the rotation mechanism 32.

As shown in FIG. 4, when the motor 40 is operated, the power is transmitted to the bobbin 46 through the shaft 42 and the gears 44 and 48, and the bobbin 46 is rotationally driven. As the bobbin 46 is driven to rotate, the conducting wire 60 is drawn out from the bobbin 54 and wound around the bobbin 46 to form an exciting coil 62. The bobbin 54 follows (rotates) the bobbin 46 through a conducting wire 60 spanned between the bobbin 46.
Conversely, when the motor 50 is activated, the power is transmitted to the bobbin 54 via the shaft 52, and the bobbin 54 is rotationally driven. As the bobbin 54 rotates, the conducting wire 60 of the exciting coil 62 is wound around the bobbin 54 from the bobbin 46. The bobbin 46 follows (rotates) the bobbin 54 through a conducting wire 60 that is spanned between the bobbin 54.

  When winding or winding the conducting wire 60, both the motors 40 and 50 may be operated. In such a case, winding or winding can be performed in a state in which a certain slack is formed on the conducting wire 60 spanned between the bobbins 46 and 54, and deterioration or disconnection of the conducting wire 60 can be prevented.

  The rotation mechanism 32 may be provided with a rotation speed detection mechanism 49 (see FIG. 9) that detects the rotation speed of the motor 40. In this case, the number of turns of the exciting coil 62 can be grasped from the rotation speed ratio between the motor 40 and the gear 48, and the conducting wire 60 can be wound with the specified number of turns.

In the winding mechanism 30, one of the motors 40 and 50 may be used as the other, and the bobbins 46 and 54 may be rotationally driven by one motor.
For example, a gear may be installed at the end of the bobbin 54 and meshed with the gear 48 to transmit the power of the motor 40 to the bobbins 46 and 54. Conversely, the power of the motor 50 may be transmitted to the bobbins 54 and 46. It may be transmitted.
In such a case, it is preferable to grasp the gear ratio between the gear 48 of the bobbin 46 and the gear of the bobbin 54 and adjust the rotation pitch of the bobbins 46 and 54.
Even when one of the motors 40 and 50 is also used as the other, a friction wheel may be adopted as a part of the transmission mechanism instead of the gears 44 and 48 and the gear installed at the end of the bobbin 54. .

About the winding aspect of the conducting wire 60, as shown to Fig.5 (a), the moving mechanism 70 (refer FIG. 9) is provided in the bobbin 54, the bobbin 54 is reciprocated along the left-right direction, and the conducting wire 60 is wound. Also good.
As shown in FIG. 5B, a guide mechanism 72 is provided on the bobbin 46, the guide mechanism 72 is reciprocated along the left-right direction, and the winding position of the conducting wire 60 from the bobbin 54 to the bobbin 46 is guided. The conducting wire 60 may be wound.
As shown in FIG. 5C, the conducting wire 60 may be wound by embedding the conducting wire 60 in a long film 74 and winding the film 74 around the bobbin 46.

About the connection aspect of the conducting wire 60, the following structures can be employ | adopted.
As shown in FIG. 6A, one end portion of the conducting wire 60 is fixed to the bobbin 54, and the other end portion of the conducting wire 60 is used as it is as a wiring (endlessly), and is connected to the power supply switching circuit 16 and the pulse power source 14. Also good.
As shown in FIG. 6B, a conductive portion 80 (wiring) that conducts to the power supply switching circuit 16 and the pulse power supply 14 is built in the bobbin 46, and one end of the conductive wire 60 is fixed to the bobbin 54. The end portion may be detachably connected to the conductive portion 80 via the connection terminal 64.
In this case, as shown in FIG. 6B, the connection terminal 64 may be attached to and detached from the conductive portion 80 in the left-right direction, or as shown in FIG. 6C, the connection terminal 64 is connected in the vertical direction to the conductive portion. You may make it attach or detach with 80.
As shown in FIG. 6D, a conductive holding member 82 that can be opened and closed is provided on the bobbin 46, one end of the conducting wire 60 is fixed to the bobbin 54, and the other end of the conducting wire 60 is held by the holding member 82. You may connect to the electroconductive part 80. FIG.
In particular, according to the connection mode shown in FIGS. 6B, 6C, and 6D, since the conducting wire 60 has the connecting end, the conducting wire 60 wound around the bobbin 54 can be collected together with the bobbin 54. The conductor 60 (and the bobbin 54) can be handled or processed as a consumable item, and the worn conductor 60 can be easily replaced with a new conductor 60.

As shown in FIG. 4 (lower right cross section), the bobbin 46 and the cylinder 20 are in contact with each other to the extent that they can slide, the contact portion 46a of the bobbin 46 with the cylinder 20, and the bobbin 46 of the cylinder 20 One or both of the contact portion 20a and the contact portion 20a are made of a lubricious material.
The lubricating material is preferably a self-lubricating resin, a lubricating filler-containing resin, a solid lubricant-containing sintered nonmagnetic metal, a solid lubricant-embedded nonmagnetic metal, or an oil-containing sintered nonmagnetic metal.
Examples of the self-lubricating resin include polyacetal and polytetrafluoroethylene.
The lubricating filler-containing resin is a resin to which a filler that provides a lubricating action is added. Examples of the filler include graphite, boron nitride, molybdenum disulfide, and polytetrafluoroethylene powder.
The solid lubricant-containing nonmagnetic metal is a sintered nonmagnetic metal in which a solid lubricant is uniformly dispersed in the structure. Examples of the solid lubricant include graphite, molybdenum disulfide, and manganese sulfide.
The solid lubricant embedded nonmagnetic metal is a nonmagnetic metal embedded with a solid lubricant, and examples of the solid lubricant include graphite and molybdenum disulfide.
The oil-impregnated sintered nonmagnetic metal is a nonmagnetic metal containing an oil component. When the contact portions 46a and 20a are made of an oil-impregnated sintered nonmagnetic metal, it is preferable that an oil supply device is installed to supply oil to the contact portions 46a and 20a.

As shown in FIG. 4 (upper left cross-sectional portion), a magnetic sensor 90 is installed between the two winding mechanisms 30 at the center of the cylindrical body 20.
As the magnetic sensor 90, in addition to a magnetoresistive element (MR element), a magnetic sensor capable of measuring magnetic signals from extremely low frequencies such as a magnetic impedance element, a Hall element, a flux gate, and a superconducting quantum interference element (SQUID). used.

As shown in FIG. 7A, the cylinder 20 and the winding mechanism 30 are formed with two separation portions 100 and 102 (cuts). Hinges 26 and 28 are provided on the separation part 102 of the cylindrical body 20, and a hinge 36 is provided on the separation part 102 of the winding mechanism 30. The separation parts 100 and 102 extend in the left-right direction.
As shown in FIG. 7B, the cylindrical body 20 and the winding mechanism 30 are separated by the separation unit 100 through the hinges 26, 28, and 36 of the separation unit 102 so as to be freely opened and closed.
As shown in FIG. 8 (a), three separation parts 100, 102, 104 are formed in the cylinder 20 and the winding mechanism 30, and as shown in FIG. 8 (b), the cylinder 20 and the winding mechanism 30 However, the separation unit 100 may be opened and closed freely through the hinges 26, 28, and 36 of the separation units 102 and 104.
From such a configuration, the cylindrical body 20 and the winding mechanism 30 are detachable from the pipe 2.
7 and 8, the motor 40, the shaft 42, the gear 44, the motor 50, the shaft 52, and the bobbin of the winding mechanism 30 are described in an easy-to-understand manner to describe the opening and closing states of the cylindrical body 20 and the winding mechanism 30. Members such as 54 are omitted.
Further, the cylinder 20 is provided with a self-propelled mechanism 110 (see FIG. 9), and the nondestructive inspection apparatus 10 is movable in the left-right direction.

In the above nondestructive inspection apparatus 10, as shown in FIG. 9, the motor 40, the rotation speed detection mechanism 49, the motor 50, the moving mechanism 70, the guide mechanism 72, the magnetic sensor 90, the self-running mechanism 110, etc. are connected to the control device 12. Has been.
The control device 12 controls the operation of these members or receives detection results from these members.
In particular, the control device 12 applies a pulse voltage from the pulse power supply 14 to the exciting coil 62 of the nondestructive inspection device 10, causes the magnetic sensor 90 to detect the magnetic field generated thereby, and analyzes the response of the magnetic field detected by the magnetic sensor 90. It is supposed to be.

  Next, an inspection method for the pipe 2 using the pulse magnetic inspection system 1 will be described.

In a state where the conducting wire 60 is wound around the bobbin 54 of the rotating mechanism 34, the cylinder 20 and the winding mechanism 30 are opened and closed by the separation unit 100, the nondestructive inspection device 10 is attached to the pipe 2, and the pipe 2 is connected to the cylinder 20. To be inserted.
Thereafter, the motor 40 of the rotating mechanism 32 is operated, and the conductive wire 60 is wound around the bobbin 46 to form a pair of exciting coils 62.
Thereafter, the pulse power supply 14 is operated to apply a pulse voltage to the exciting coil 62 to generate a magnetic field for the pipe 2. In this state, the magnetic sensor 90 detects a magnetic field generated by the exciting coil 62 and parallel to the horizontal direction of the pipe 2.

Then, the pulse intensity and signal time attenuation in the output signal of the magnetic sensor 90 are analyzed by the control device 12, and the presence or absence of a defect in the pipe 2 is inspected.
For example, the signal attenuation is faster in the defective heat insulating pipe 2 than in the pipe 2 which is a normal pipe. This is because the thickness of the steel pipe 4 is reduced as a defect structure. Thus, the defective part of piping 2 can be specified by changing a pulse response characteristic by the existence of a defect.

  Thereafter, when removing the nondestructive inspection apparatus 10 from the pipe 2, the motor 50 of the rotating mechanism 34 is operated, the conductive wire 60 is wound around the bobbin 54, and the cylindrical body 20 and the winding mechanism 30 are opened and closed by the separating unit 100. Just do it.

According to the present embodiment described above, the cylindrical body 20 and the winding mechanism 30 are opened and closed by the separation unit 100 and can be freely attached to and detached from the pipe 2, and the bobbin 54 to the bobbin 46 of the conducting wire 60 by the winding mechanism 30. Therefore, when the non-destructive inspection apparatus 10 is attached to the pipe 2, the exciting coil 62 can be configured without separating the lead wire 60. Even when the non-destructive inspection apparatus 10 is detached from the pipe 2, it is possible to wind the conductor 60 without separating it, and no electrical contact is formed on the exciting coil 62 in any situation.
For example, as shown in FIG. 10, even when the pipe 2 is suspended from above (or supported from below) by the support member 120, the nondestructive inspection apparatus 10 is attached in the vicinity of the support member 120. Or it can be removed and this situation can be addressed.
From the above, the presence or absence of defects can be inspected in any part of the pipe 2, and the contact resistance in the exciting coil 62 can be reduced or the contact failure can be prevented.

  Further, when the conductive wire 60 is wound, it is difficult to separate the cylindrical body 20 and the winding mechanism 30 by the separation unit 100 if the power of the motor 40 is transmitted to the bobbin 46 by a belt or a chain. However, in this embodiment, since the power of the motor 40 is transmitted from the shaft 42 and the gear 44 to the bobbin 46 via the gear 48, the cylindrical body 20 and the winding mechanism 30 are separated from each other. The nondestructive inspection device 10 can be attached to the pipe 2 by opening and closing at 100.

  Further, when the conductive wire 60 is wound, the contact part 46a of the bobbin 46 with the cylinder 20 and the contact part 20a of the cylinder 20 with the bobbin 46 are made of a lubricious material. Even if the contact portion 46a slides with respect to the contact portion 20a with driving, the friction of the slide portion is reduced, the rotation of the bobbin 46 can be stabilized, and the configuration accuracy of the exciting coil 62 is reduced. Can be prevented.

DESCRIPTION OF SYMBOLS 1 Pulse magnetic inspection system 2 Piping 4 Steel pipe 6 Heat insulating material 8 Molten zinc iron plate 10 Nondestructive inspection apparatus 12 Control apparatus 14 Pulse power supply 16 Power supply switching circuit 20 Cylindrical body 20a Contact part 22, 24 Post | support 26, 28 Hinge 30 Winding mechanism 32 , 34 Rotating mechanism 36 Hinge 40 Motor 42 Shaft 44 Gear 46 Bobbin 46a Contact part 48 Gear 49 Rotation speed detecting mechanism 50 Motor 52 Shaft 54 Bobbin 60 Conductor 62 Exciting coil 64 Connection terminal 70 Moving mechanism 72 Guide mechanism 74 Film 80 Conducting part 82 Clamping member 90 Magnetic sensor 100, 102, 104 Separating part 110 Self-propelled mechanism 120 Support member

Claims (12)

A cylinder that is detachable from the pipe;
A conductive wire wound around the cylinder and constituting an exciting coil;
A winding mechanism for winding the conductive wire around the cylindrical body, or winding it;
A nondestructive inspection apparatus comprising: In the nondestructive inspection device according to claim 1,
The winding mechanism is
A first rotation mechanism disposed around the cylinder;
A second rotation mechanism disposed at a position spaced from the cylindrical body,
The conductor is bridged between the first rotating mechanism and the second rotating mechanism;
One of the first rotation mechanism and the second rotation mechanism is rotationally driven with respect to the other, and the non-destructive inspection apparatus is characterized in that In the nondestructive inspection device according to claim 2,
The first rotation mechanism is driven to rotate;
The non-destructive inspection apparatus, wherein the second rotation mechanism is driven by the first rotation mechanism through the conducting wire. In the nondestructive inspection device according to claim 2,
The second rotation mechanism is driven to rotate;
The nondestructive inspection apparatus, wherein the first rotation mechanism is driven by the second rotation mechanism through the conductive wire. In the nondestructive inspection device according to any one of claims 2 to 4,
The first rotation mechanism is
A first bobbin around which the conducting wire is wound;
A first power source for rotating the first bobbin;
A first transmission mechanism for transmitting power from the first power source to the first bobbin;
A nondestructive inspection apparatus characterized by comprising: In the nondestructive inspection device according to claim 5,
The first rotation mechanism is
A motor as the first power source;
A rotational speed detection mechanism for detecting the rotational speed of the motor;
A nondestructive inspection apparatus characterized by comprising: In the nondestructive inspection device according to claim 5 or 6,
At least one of the contact portion of the first bobbin with the cylinder or the contact portion of the cylinder with the first bobbin is a self-lubricating resin or a lubricating filler-containing resin. A nondestructive inspection apparatus comprising a solid lubricant-containing sintered nonmagnetic metal, a solid lubricant-embedded nonmagnetic metal, or an oil-containing sintered nonmagnetic metal. In the nondestructive inspection device according to any one of claims 2 to 7,
The second rotation mechanism is
A second bobbin for winding the conducting wire;
A second power source for rotating the second bobbin;
A second transmission mechanism for transmitting power from the second power source to the second bobbin;
A nondestructive inspection apparatus characterized by comprising: The nondestructive inspection apparatus according to claim 8,
A nondestructive inspection apparatus comprising: a moving mechanism for reciprocating the second bobbin along the axial direction of the first bobbin. The nondestructive inspection apparatus according to claim 8,
A nondestructive inspection apparatus comprising a guide mechanism for guiding a winding position of the conducting wire from the second bobbin to the first bobbin. In the nondestructive inspection device according to any one of claims 8 to 10,
One of the first power source and the second power source is used as the other one. In the nondestructive inspection device according to any one of claims 1 to 11,
The first bobbin has a built-in conductive portion that is electrically connected to a pulse power source,
One end of the conducting wire is fixed to the second bobbin,
The non-destructive inspection apparatus, wherein the other end portion of the conducting wire is detachably connected to the conductive portion via a connection terminal.

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