JP3184267B2 - Magnetic particle flaw detector - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for a magnetic flaw test, which is one of non-destructive tests performed to detect material flaws.

[0002]

2. Description of the Related Art Conventionally, welding parts of large steel structures,
For inspection of material defects in cast and forged steel products, a magnetic particle flaw detection method called a gap method is applied. In this method, as shown in FIG. 1, while a surface layer of the material 500 is magnetized with an electromagnet, a test solution in which the ferromagnetic powder 302 is suspended in water or the like is poured, and a magnetic powder pattern attached to the defective portion 510 is obtained. This is a method for detecting defects. FIG. 2 shows the method of the gap method. FIG. 2A shows an example in which an electromagnet composed of an iron core 130 and a winding 131 is excited by a power supply 110 to magnetize a test material 500, and a magnetic field 302 generated in a defect portion 510 is adsorbed by a magnetic powder 302 so that a defect is eliminated. To detect. FIG. 2 (b) shows a rotating magnetic field 123 as shown in FIG. 2 (c) by using two sets and four magnetic poles 132 to change the phase of the magnetic field of each magnetic pole. The defect is detected simultaneously. In this method, in order to facilitate the detection of defects, a fluorescent magnetic particle flaw detection method of observing the fluorescence generated when irradiating ultraviolet rays onto the magnetic powder coated with a fluorescent paint is often adopted, A non-fluorescent magnetic particle inspection method for observing with visible light has also been performed.

[0003] In any case, procedures for magnetizing the material, spraying the test solution, and observing are required, and a magnetizing device, a test solution sprayer, and a lighting apparatus are used in accordance with each procedure.
These devices are separated and independent from each other, and are manually applied by an inspector according to a test procedure and applied. Similarly, observation is performed by an inspector by directly visually observing whether or not there is a defect indication, which is a factor that greatly hinders automation, including the individual operation of the test procedure described above.

Further, in order to record the shape of the defect, there is no other choice but to take a photograph or transfer it to an adhesive tape, and there is a disadvantage that the recording property is poor.

[0005]

In the above prior arts, all procedures are performed by manual operation of an inspector. However, no consideration has been given to high efficiency due to automation and improvement of recording properties. In some cases, in addition to in-house tests, in cases where inspections by customers and witness inspections by government offices are performed, the same inspections are repeated each time, resulting in a large waste. An object of the present invention is to automate a magnetic particle flaw detection test in order to eliminate this waste. In automating the inspection, the position of an observation camera and illumination ultraviolet rays which are problematic directly or indirectly enter the camera. It is an object of the present invention to provide a magnetic particle flaw detection apparatus suitable for automation by proposing a method of preventing the camera lens from being stained by the test solution and a method of preventing the camera lens from being stained by the test solution.

[0006]

Basically the hand in the present invention, in order to solve the problems]
The stage is illuminated to the test area by the magnetizing device of the magnetic particle flaw detector.
Lighting device and magnetic powder suspended in the test area
A test solution spraying device in which the spray direction of the sprayed test solution is directed,
Position the camera so that the imaging direction is perpendicular to the center of the test area.
A magnetic particle flaw detector equipped with the obtained imaging device,
The basic means is to selectively transmit only fluorescence of a specific wavelength.
Filter on the front of the imaging device.
Have a filter that can be opened and closed further in front of the filter.
It can be suggested to provide a utter.

[0007]

According to the basic means of the present invention, a magnetizing device is provided.
The lighting device, the test liquid spraying device and the imaging device are integrated
Since individual devices can be provided on the test surface
In addition to being easier to automate than bringing them into
In addition to being easy to integrate, the imaging device is
, The imaging direction is oriented in the vertical direction.
It is said that there is little change in the field of view and viewing angle even if the attitude changes
An effect can be obtained. In addition, only the specific wavelength of fluorescence
A filter that selectively transmits light is provided on the front of the imaging device.
In addition to the action and effect,
Select the light required to clearly capture defective images, etc. with a filter
Is captured by the image pickup device and is disturbed by light of extra wavelength
The function and effect of being able to capture a clear image without
A filter that can be opened and closed further on the front than the filter
If the camera has a shutter, open it when shooting.
Closes the shutter when spraying the test liquid and captures the spray liquid.
Spray liquid adheres to the imaging device and filter even when it comes to the device side
As a result, it is possible to suppress the phenomenon that the imaging condition is deteriorated.

[0008]

An embodiment of the present invention will be described below with reference to FIG.

The magnetizing apparatus 100 shown in FIG. 3 has a magnetizing coil built into the four legs of the electromagnet, and a current is passed through the coil, so that a test surface in a range surrounded by the four legs can be formed. Magnetize to the strength required for the test. FIG. 101 shows a magnetic pole, 102 is a traveling wheel, and 104 is a wheel support plate.
The magnetizing device 100 further includes a test surface observation imaging device 200.
(Hereinafter referred to as a camera), an illumination lamp 250, and a test liquid spray nozzle 300 are integrated and integrated. According to this embodiment, the magnetizing device 100 magnetizes the test surface, the test solution spray nozzle 300 sprays the test solution on the test surface, and the illumination lamp 2.
The illumination of the test surface by 50 and the observation and recording of the test surface by the camera 200 are performed simultaneously or continuously, thereby enabling automation.

[0010] In particular, by observing the test surface with a television camera and recording it on a video tape recorder, the recordability of the test results conventionally performed by taking a photograph or transferring it to an adhesive tape can be improved. Dramatic improvements can be made, and this is the decisive factor in achieving automation.

The camera 200 is mounted so as to make a hole in the center of the iron core of the magnetizing device and to embed it in the hole.
The camera is always facing the center of the test surface 502. Less than,
The effect will be described with reference to FIGS. FIG. 5 illustrates a case where the camera 200 is mounted on the side surface of the iron core using the spacer 280. As shown in FIG. 5A, a visual field 260 is set at the center of the planar test surface 502. Also, for example, in the case of FIG.
There is an inconvenience that the center of 60 is shifted from the center of the test surface 502. According to this embodiment, as shown in FIGS. 6A and 6B, the center of the visual field can always be adjusted to the center of the test surface 502 regardless of the shape of the test surface.

The illuminating lamp 250 shown in FIG. 3 irradiates ultraviolet rays 252 to generate fluorescent light from the fluorescent magnetic powder and has a function of detecting a defect by the camera 200. However, a part of the ultraviolet rays 252 reflected by the test surface 502 is directly. It reaches the camera 200. Since this light has a high intensity, the monitor screen is covered with red-purple light to make other images invisible. In order to prevent such inconvenience, in the present invention, as shown in FIG. 4A, an optical filter 231 for transmitting the fluorescence emitted from the magnetic powder but cutting the ultraviolet light is provided on the front surface of the camera 200. As a result, harmful reflected ultraviolet rays were blocked.

In the magnetic particle flaw detection test, a test solution in which magnetic particles are suspended is sprayed on the test surface. At this time, a shutter is used to prevent the test solution droplets scattered on the test surface from adhering to the lens of the camera 200. 232 were provided. The shutter 232 is driven by the actuator 234 to open and close, and is opened when observing the test surface and closed when spraying the test liquid, thereby protecting the camera lens.

[0014]

According to the first aspect of the present invention, a magnetic particle inspection test
Easy to automate by integrating multiple means necessary for
The center of the field of view of the imaging device that can easily perform defects and image defects
Can always be maintained at the center of the test surface regardless of the shape of the test surface.
You. According to the invention of claim 2, the effect of the invention of claim 1 is obtained.
In addition to the results, the optical
The clarity of the image can be improved. According to the invention of claim 3
For example, in addition to the effect of the invention of claim 2, the test liquid is sprayed.
Measures can be resolved and the degree of clarity of imaging by the imaging device can be reduced.
Layers can be improved and obstacles in automating magnetic particle inspection
The three problems that have been addressed, namely the position of the imaging device and
Control of light at wavelengths that interfere with image clarification, such as fields and ultraviolet light,
At the same time, measures against splashing of the test solution were solved,
This opens the way for automation, eliminating individual differences and human errors in magnetic particle flaw detection testing, improving reliability, and improving recordability and improving efficiency by automating the testing process.

[Brief description of the drawings]

FIG. 1 is an explanatory view of a procedure of magnetic particle flaw detection.

FIG. 2 is a diagram illustrating the principle of magnetic particle flaw detection.

FIG. 3 is a front view (a), a plan view (b), and a side view (c) of a magnetizing device.

FIG. 4 is a side view (a) and a plan view (b) provided with an optical filter and a camera protection plate.

FIG. 5 is an explanatory diagram of a defect due to a mounting position of a camera.

FIG. 6 is an explanatory diagram showing usefulness of the position of the camera of the present invention.

[Explanation of symbols]

100: magnetizing device, 200: imaging device (camera), 23
1: optical filter, 232: movable closing plate (shutter),
233 bearing, 234 actuator, 250 ultraviolet light, 251 bracket, 502 test surface.

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Kazushi Komaki 3-2-1, Sachimachi, Hitachi-shi, Ibaraki Pref. Hitachi Engineering Co., Ltd. (56) References JP-A-55-1510 (JP, A) JP-A-60-117148 (JP, A) JP-A-51-107183 (JP, A) JP-A-1-118359 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) G01N 21 / 91 G01N 27/84

Claims (3)

(57) [Claims] 1. A test device, comprising: a magnetizing device of a magnetic particle flaw detector;
A lighting device oriented in the bright direction and a magnetic powder in the test area.
Test solution sprayer with spray direction of suspended test solution
With the imaging direction perpendicular to the center of the test area
A magnetic particle flaw detector equipped with an activated imaging device. 2. The method according to claim 1, wherein only fluorescence of a specific wavelength is used.
Filter is provided on the front of the imaging device to selectively transmit light
Magnetic particle flaw detector characterized by the above-mentioned . 3. The method according to claim 2, further comprising:
A shutter that can be opened and closed on the front is provided.
Magnetic particle flaw detector that.