JPS63218854A - Flaw detection apparatus using magnetic powder - Google Patents

Abstract

PURPOSE:To dispense with flaw detection by manual work, by integrally supporting four magnetic poles provided at a predetermined interval, a magnetic powder scattering nozzle and a marking apparatus. CONSTITUTION:A magnetizing apparatus 10 having four magnetic poles at a predetermined interval is fixed to a support stand 11 and handles 15, 17 are regulated to set the apparatus 10 at the optimum position of an object to be inspected. A truck 13 is moved forwardly and rearwardly to bring the apparatus 10 into contact with the object 1 to be inspected under pressure and fixed by a handle 20. The spring 39 in the support stand 11 presses the apparatus 10 to the object 1 to be inspected under definite pressure to bring the same into contact with said object 1 under pressure so as to hold a definite interval from the surface thereof through a roller 41. The object 1 to be inspected is rotated and a current is supplied to an exciting coil 40 and a pump 21 is operated to inject the magnetic powder liquid in a tank 18 to the flaw detection surface of the object 1 to be inspected. Further, an ultraviolet lamp 43 is allowed to light and a TV camera is operated. The image of the camera 42 is monitored and an operation panel 19 is operated when the image of a flaw is received to mark the flaw by an apparatus 45. By this constitution, magnetic powder flaw detection can be performed by one inspector and flaw detection by manual work becomes unnecessary.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a magnetic particle flaw detection device, and particularly to a magnetic particle flaw detection device suitable for automating magnetic particle flaw detection.

[Conventional technology]

A pressure vessel as shown in FIGS. 12 and 13 is made by welding a cylindrical body and a semicircular side end.

Since such a test object 1 is used with its interior under high pressure, if cracks, welding errors, etc. occur in the thick portions, accidents may occur.

Therefore, a thorough product inspection is performed on the object 1, and magnetic particle flaw detection is used as a means for this inspection.

During this flaw detection, as shown in FIG.
was placed on four rotating rollers 2, and two workers mainly welded the welded parts a and b shown in FIG.

Inspect C. - A human worker (A) holds the magnetized part 3 (for example, having an electromagnetic structure) which is a flaw detector with one hand, and brings this magnetized part 3 into contact with the surface of the subject 1. In addition, holding a cylinder-shaped magnetic powder liquid container 4 in the other hand, the magnetic powder liquid is sprayed into the gap between the magnetized part 3 and the subject 1 in the energized state. The other person (B) points the ultraviolet lamp 5 held at this spraying part and irradiates it with ultraviolet light.

When the rotating roller 2 is rotated in this state, the subject 1 rotates. Worker A injects the magnetic powder liquid from the magnetic powder liquid container 4 onto the inspection part while contacting the welding part a (b or C). Magnetic flux is generated from the leg ends of the U-shaped magnetized portion 3, and a magnetic circuit passing through the inside of the subject 1 is formed.

The magnetic resistance of this magnetic circuit changes if there is a crack or the like in the subject 1. That is, if there is an air layer in the magnetic circuit, the larger the area and gap, the higher the magnetic resistance. If there is such a magnetoresistance change part, the sprayed magnetic powder liquid will concentrate there.

Fluorescent paint is mixed in the magnetic powder liquid, and the areas where the magnetic particles are attached emit light when irradiated with ultraviolet rays, making it easy to detect defective areas. Since the magnetic resistance change is weak in the longitudinal direction of cracks, etc., the detection sensitivity is weak. Therefore, it is desirable to perform flaw detection while rotating the magnetized part 3 by nearly 90 degrees.

As shown in FIG. 14, the pressure vessel is provided with a nozzle 6 for connecting to other equipment. As shown in FIG. 15, this nozzle stub 6 is welded in an annular manner at the connection point. Flaw detection for such parts is carried out in the 14th
Since the welding part is bent unlike in the case shown in the figure, the welding is carried out while appropriately rotating the magnetized part 3 within a range of 90 degrees. This makes it possible to reliably detect defective locations.

FIG. 16 is an explanatory diagram when inspecting the inner surface of a longitudinal welded steel pipe. Workers A and B enter the pipe, and as in the case of Fig. 14, worker A holds the magnetized part 3 and magnetic powder liquid container 4, and worker B holds the ultraviolet lamp 5, and performs flaw detection while lying on his stomach. implement.

[Problem that the invention seeks to solve]

However, conventional magnetic particle flaw detection devices have the following problems.

(1) The magnetized part is heavy, making continuous flaw detection difficult for long periods of time by humans.

(2) Two people are always required for flaw detection work.

(3) Inspecting the inner surface of longitudinal welded steel pipes requires very hard work due to poor working posture and poor work efficiency.

(4) Continuous energization is not possible due to temperature rise in the magnetized part.

(5) The handle of the magnetization device is located in the center, so the field of view for testing is narrow.

(6) Since the position of the ultraviolet lamp and the amount of magnetic powder applied vary depending on the inspector, the test conditions for the position of the ultraviolet lamp and the amount of magnetic powder applied vary.

(7) The welded part of the nozzle head is inspected twice or more in two directions using a magnetization device, resulting in poor work efficiency.

An object of the present invention is to provide a magnetic particle flaw detection apparatus that automates magnetic particle flaw detection and eliminates the need for flaw detection work by an operator.

[Means for solving problems]

In order to solve the above-mentioned problems, the present invention provides a magnetic particle flaw detection apparatus for flaw detection of pressure vessels, small diameter pipes, etc., which includes a magnetized part having four magnetic pole parts arranged at predetermined intervals, and A magnetizing device including a nozzle for dispersing magnetic powder on a flaw detection surface, a marking device for marking a defect detection part, and a support member for integrally supporting each of the above-mentioned members is provided.

[Effect]

According to the above means, the support member moves the magnetic pole part of the magnetizing device while bringing it into close contact with the object to be inspected, and automatic flaw detection is possible by spraying magnetic powder liquid onto the flaw detection surface, which eliminates the need for manual flaw detection operations. Can configure devices.

Hereinafter, one embodiment of the present invention will be described based on the drawings.

Fig. 1 is a side view showing a magnetic particle flaw detection device according to the present invention;
3 are a plan view and a side view showing details of the magnetizing device 10 shown in FIG. 1, and FIG. 4 is a rear view thereof.

A magnetizing device in which magnetic poles are provided on each side of a quadrilateral, and polarities are set to be different between opposing magnetic poles or between magnetic poles on diagonal sides.
O is fixed to a support stand 1), and this support stand 1) is rotatably connected to a height adjustment member 12. The height adjustment member 12 is fitted into a column 14 fixed to a movable truck 13, and its height can be adjusted by a vertical adjustment handle 15 provided on the column 14.

Further, an angle adjustment mechanism 16 is provided between the support base 1) and the height adjustment member 120 to adjust the angle between them.
Using the handle 17, it is possible to easily adjust the angle so that the positional relationship between the magnetization device 10 and the subject 1 is optimized.

A magnetic powder liquid tank 18 and an operation panel 19 are installed on the truck 13, and a fixed installation handle 20 for locking the movement of the truck 13 is provided on the side. The magnetic powder liquid tank 18 is filled with magnetic powder liquid, which is stirred and transferred to the magnetization device 10.
A pump 21 is provided to supply the water. Further, the magnetic powder liquid tank 18 is provided with a magnetic powder liquid stirring valve 22 and a magnetic powder liquid supply valve 23. The magnetic powder liquid sent out by the pump 21 is supplied to a nozzle described later through a magnetic powder liquid supply pipe 24. Further, the operation panel 19 is connected to an AC power source, and its output is supplied to the magnetization device 10 via a power cable 25.

The operation panel 19 can turn on/off the power, select magnetic poles, control the current direction, and the like.

Next, the magnetizing device 10 will be explained in detail with reference to FIGS. 2 to 4.

As shown in FIG. 2, a spring guide 31 is fixed within the tip of the support base 1), a bolt 32 is fitted into the guide 31, and a nut 33 is attached to the end opposite to the subject. Furthermore, a nut 34 is attached to the end of the bolt 32 on the subject side.
A spring 35 is fitted around the bolt 32 between the nut 34 and the spring guide 31.

An angle 36 is disposed between the nut 34 and the spring 35, and the angle 36 is constantly pressed toward the subject 1 by the spring 35.

A holder 37 having a U-shaped cross section is attached to the angle 36 by a wing nut 38, and four magnetic poles 39 are arranged in, for example, a square shape on this holder 37.
An excitation coil 40 is wound around each of the magnetic poles 39 . A roller 41 that rolls on the subject 1 is attached to the tip of the magnetic pole 39 . This roller 41 prevents the surface of the magnetic pole 39 from coming into direct contact with the subject 1 .

Furthermore, as shown in FIG.
It is installed on 7. The holder 37 is also equipped with an ultraviolet lamp 43 that irradiates the viewing range of the television camera 42 with ultraviolet rays, and a magnetic powder dispersion nozzle 44 that sprays magnetic powder liquid onto the surface of the subject 1 within the viewing range of the camera 42.

In addition, a marking device 45 is installed in the holder 37 near the television camera 42, and by operating the operation panel 19, it is possible to mark with chalk or the like near the defect occurrence area on the surface of the subject 1. . Note that this marking is performed by recognizing the defect from the image obtained by the television camera 42, and using the marking device 45 based on this.
Automatic marking is also possible.

Holder 37 shown in FIGS. 2 and 3. Magnetic pole 39° excitation coil 40. Roller 41. A configuration including a television camera 42, an ultraviolet lamp 43, and a magnetic powder dispersing nozzle 44 constitutes a magnetizing device 10, which can be detachably attached to the support base 1) using a wing nut 38. By allowing the magnetization device 10 to be used alone, it is possible to perform flaw detection on longitudinal welded steel pipes and the like.

Next, the operation of the embodiment of the present invention with the above configuration will be explained as follows.
This will be explained with reference to the figures.

First, when performing flaw detection on the circumferential surface of a pressure vessel, etc., the magnetization device IO is fixed to the support stand 1), and the height adjustment handle 15 is
and the angle adjustment handle 17, the magnetization device 10
is located at the optimum position relative to the subject 1. Furthermore, the trolley 13 is moved forward and backward relative to the subject 1, and positioned so that the magnetization device 10 comes into pressure contact with the subject 1 with an appropriate pressing force, and then the trolley 13 is fixed using the fixed installation handle 20. In this state, the spring 39 in the support base 1) presses the magnetization device IO toward the subject 1 with a constant pressure, and while maintaining a constant distance from the surface of the subject 1 via the roller 41. It is crimped.

During flaw detection, rotate the object 1 in the direction of the arrow and press the operation panel 1.
9 to energize the excitation coil 40, and further operate the pump 21 to inject the magnetic powder liquid in the tank 18 onto the test surface of the object 1. Further, the ultraviolet lamp 43 is turned on and the television camera 42 is turned on. As a result, flaw detection of the object 1 to be inspected is performed continuously. The inspector monitors the image captured by the television camera 42 on a monitor television (not shown),
When a defect is imaged, the operation panel 19 is operated to activate the marking device 45 to perform marking.

As described above, according to the present invention, all magnetic particle flaw detection can be performed by one inspector, and there is almost no need for the inspector to perform any operations during the flaw detection.

Next, flaw detection on the inner surface of the longitudinal welded steel pipe 50 will be explained with reference to FIG.

First, the wing nut 38 is removed to separate the magnetizing device 10 from the angle 36, and it is attached to the fixing jig 4 of the manipulator 46 that runs by itself inside the tube (installed with the welding line directly below).
7 and secure with bolts. Magnetic powder liquid supply pipe 2
4 and a power cable 25 including the output cable of the television camera are drawn out of the pipe and connected to respective devices installed outside the pipe. The output cable of the television camera 42 is connected to a monitor television 48 via the operation panel 19.

The manipulator 45 uses a motor as a driving source, and has an operation panel 19.
It runs on its own due to the power provided by it. The magnetization device 10 is mounted facing the free-running surface, the roller 41 runs while rolling on the inner wall surface of the tube, and the magnetic pole 39 detects flaws while maintaining a constant interval on the inner surface of the tube.

When the manipulator 45 starts running, the ultraviolet light 43
is turned on, the coil 40 is energized, and the magnetic powder liquid is ejected from the nozzle 44.

Thereafter, flaw detection is performed in the same manner as in the case of FIG.

As is clear from the conventional flaw detection method shown in FIG. 16, the present invention does not require an inspector to enter the pipe, and all operations necessary for flaw detection are performed automatically.

Next, flaw detection of the nozzle 6 will be explained with reference to FIG.

For this flaw detection, the magnetizing device IO is removed from the state shown in FIG. 1 or FIG. 5. At this time, if the top of the nozzle 6 cannot be exposed from the center of the magnetizing device 10,
The television camera 42 is removed and installed as shown in FIG. Thereafter, the coil 40 is energized and the magnetic powder liquid is injected onto the flaw detection surface.

In this state, the magnetization device IO is manually rotated around the nozzle stand 6.

At this time, since the direction in which defects occur is not constant, the polarity generated in the magnetic pole 39 is changed to facilitate defect detection.

That is, as shown in FIG. 7, the magnetic fluxes generated by the four magnetic poles 39 are made parallel, or as shown in FIG. 8, the direction of magnetic flux generation is changed by 90 degrees. This operation allows defects to be detected reliably.

FIG. 9 shows the temperature rise characteristics of the magnetic poles with respect to the energization time. In this example, as a result of doubling the number of magnetic poles compared to the conventional one,
The core area is about three times as large, and as is clear from FIG. 9, even if the current is continuously applied, the coil 40 will not be overheated or damaged. In the figure, characteristics A, B, and C indicate an infinite interval (101) and a zero interval (that is, a close contact state), respectively.

Further, in the present invention, since the positions of the ultraviolet lamp and the magnetic powder supply nozzle can be fixed, the positions of the ultraviolet rays and the magnetic powder application conditions can be made uniform, and the flaw detection conditions can be made constant. As a result, as is clear from the solid line characteristics in FIG. 10, the leakage magnetic flux density becomes high, and the flaw detection sensitivity can be increased. Incidentally, the conventional characteristics are shown by broken lines.

Furthermore, in the conventional configuration, since it was necessary to hold and operate the magnetizing part, it was necessary to provide a handle on the magnetizing part.
In the present invention, this is not necessary and a television camera can be installed in this area (or it can be directly observed without installing a television camera), so the field of view for the flaw detection surface is as shown in Figure 1). It can be enlarged (portion C is the viewing range according to the present invention, and portion D is the viewing range according to the conventional method).

[Effects of the Invention] As explained above, according to the present invention, the magnetic powder supply nozzle, the magnetization part, etc. are integrated and made detachable, so automatic flaw detection can be carried out with high sensitivity and efficiency on nine different shapes of specimens. can be done.

[Brief explanation of the drawing]

Fig. 1 is a side view showing a magnetic particle flaw detection device according to the present invention;
, 3 and 4 are a plan view, a side view and a rear view showing details of the magnetization device 10 shown in FIG. 1, FIG. 7 and 8 are explanatory diagrams of the polarity change of the magnetic pole in the present invention, FIG. 9 is a temperature rise characteristic diagram of the magnetic pole part, and FIG. Conventional leakage magnetic flux density characteristic diagram, Figure 1) is a comparison diagram of the viewing range of the present invention and the conventional one, Figures 12 and 13 are side and front views showing the shape of the pressure vessel, and Figure 14 is the conventional magnetic powder. FIG. 15 is an explanatory diagram of flaw detection using a flaw detection device, FIG. 15 is an explanatory diagram of conventional flaw detection of a nozzle welded part, and FIG. 16 is an explanatory diagram of conventional flaw detection of a longitudinal welded pipe. 1-...-Subject, 10--...Magnetization device, 1)
---Support stand, 12---Height adjustment member, 13--
Trolley, 14-...- Support column, 16-- Angle adjustment mechanism, 18-- Magnetic powder liquid tank, 19-...-
---One operation panel, 21-...-Pump, 32-...
-Bolt, 35--Spring, 36--11-11 angle, 37--1-Holder, 38--
- Butterfly nut, 39...-Magnetic pole, 40...---1--
Excitation coil, 41---Roller, 42---
--- Television camera, 43-- Ultraviolet lamp, 44-
--Magnetic powder dispersion nozzle, 45 --- Marking device, 46 --- Manipulator, 47 ---
-----Fixing metal fittings, 48-...-Monitor TV. 1st FIJ Fig. 2 I Fig. 4'a5 Fig. 6 Fig. 7 Fig. 8s 9th garden electricity gate C minute) → torm To the slit (mm) - 111 - llFF section

Claims (3)

[Claims] (1) In a magnetic particle flaw detection device that detects flaws in pressure vessels, small diameter pipes, etc., there is a magnetized part equipped with four magnetic pole parts arranged at predetermined intervals, and magnetic powder is applied to the flaw detection surface by the magnetized part. A magnetic particle flaw detection device comprising a magnetization device including a nozzle for dispersing particles, a marking device for marking a defect detection portion, and a support member for integrally supporting each of the members. (2) The magnetic particle flaw detection device according to claim (1), wherein a television camera is attached to the magnetization device. (3) Claim No.
The magnetic particle flaw detection device according to paragraphs 1) and 2).