JP2514550B2 - Magnetic force type stress measurement method for non-ferrous metal materials - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic force type stress measuring method for a non-ferrous metal material, wherein a stress generated in the non-ferrous metal material is measured by using a magnetic force.

[0002]

2. Description of the Related Art According to a conventional measuring method using a magnetic force type stress meter, it is possible to measure only a magnetic metal material containing an iron component such as a steel material. For example, an exciting core and a detecting core shown in FIG. It has been widely practiced as a method for non-destructively measuring the stress that has already occurred in the magnetic metal material using the magnetic force type stress meter consisting of (for example,
Japanese Patent Publication No. 39-2178, Japanese Patent Publication No. 51-44425
Japanese Patent Laid-Open No. 60-243526, Utility Model Registration No. 1648984, Utility Model Registration No. 1648985, and Patent Registration No. 1413416 by the present inventor).

[0003]

However, since the conventional measuring method using the magnetic force type stress meter is based on the principle of detecting the amount of change in the magnetic flux due to the magnetization of the iron component contained in the material, at least the measurement of the magnetic flux If the iron content of 5% or more was not present in the measured object, it could not be practically measured. In particular, with duralumin materials containing no iron component, pure aluminum materials, copper materials, brass materials, and stainless steel materials of the type containing almost no iron component, the stress that has occurred cannot be measured at all.

According to the present invention, the stress generated in the non-ferrous metal material, which cannot be measured by the conventional magnetic force type stress meter as described above, can be measured by using the magnetic force type stress meter. The purpose is to provide.

[0005]

In order to achieve the above-mentioned object, a magnetic force type stress measuring method for a non-ferrous metal material according to the present invention is directed to a direction in which a stress occurring in the non-ferrous metal material is acting and its right angle. A means for exciting a direct current type or an alternating current type in either or both of the directions, and a means for disposing a magnetic force type stress meter between the N pole and the S pole of the excited magnetic force line in contact with the surface of the non-ferrous metal material. The stress generated in the non-ferrous metal material is measured by combining.

[0006]

[Operation] In use, place the above-mentioned magnetic force type stress meter in contact with the surface of the measuring object to be measured, and on the other hand, on both sides of the magnetic force type stress meter and in contact with the surface of the measuring object. The N-pole and the S-pole of the magnet to be excited in the direct current type or the alternating current type are placed in either or both of the direction in which the stress is applied and the direction perpendicular to the direction in which the stress is applied, and the magnet is excited. Then, the exciting magnetic flux changes according to the magnitude of the stress generated in the measured object, the result is output to the detector, and the value is read by the measuring pointer.

[0007]

EXAMPLE An example will be described with reference to the drawings.
For example, the magnetic force type stress meter 1 shown in FIG.
(There are various types as described in the above-mentioned related art, but any type can be used). In this magnetic force type stress meter 1, an exciting iron core 2 made of a U-shaped material having a high magnetic permeability, which is made of a material having almost no residual magnetism, is wound with an exciting coil 3, and magnetic poles 4 and 5 are provided at the ends thereof. The excitation coil 3 is connected to an oscillator 6 (see FIG. 5) for applying an alternating voltage of a proper frequency and a constant intensity, and further, between the magnetic poles 4 and 5 of the excitation iron core 2. In addition, magnetic poles 9 and 10 are formed on a detection iron core 8 made of a U-shaped high magnetic permeability material around which the detection coil 7 is wound, and a detector 18 for detecting the output thereof is connected to the detection coil 7. . The exciting iron core 2 and the detecting iron core 8 are arranged on two planes that intersect each other at right angles, and their magnetic poles 4, 5, 9, 10 are arranged on the same plane. The detector 18 is connected to the detection coil 7 and a circuit for amplifying its output and a reverse voltage so that the measuring pointer 11 indicates a zero point when the object to be measured 15 is an output in a stress-free state. It has a circuit for giving. Reference numeral 12 is a power switch of the oscillator 6, 13 is a zero adjustment knob of the measuring pointer 11, and 14 is an output amplification switching knob of the detection coil 7.

In measuring the stress, it is considered that almost no stress is applied in advance, or a magnetic material is applied on a plate material of the same quality as the object to be measured 15 which has been sufficiently annealed to be stress-free. The stress meter 1 is placed, and the N and S poles of the magnet 16 are placed on both sides of the stress gauge 1, and the power switch 12 of the detector 18 is turned on to switch the oscillator 6 to the exciting coil 3 of the exciting iron core 2. When an alternating voltage with a constant frequency and a constant intensity is applied, an alternating magnetic pole is generated between the magnetic poles 4 and 5, and the magnetic force lines pass through the plate material. The zero adjustment knob 13 is turned to adjust the measuring pointer 11 of the detector 18 so as to have a zero value, and this value is set to a stress-free state.

Next, as shown in FIG. 2 and FIG. 3, the magnetic force type stress gauge 1 is placed in contact with the surface of the object to be measured 15 to be measured, on both sides thereof and on the surface of the object to be measured 15. The N-pole and the S-pole of the magnet 16 are placed in either or both of the direction in which the stress is in contact with it (viewed by the arrow A-A) and the direction perpendicular thereto (viewed by the arrow BB) (this Excitation power may be either DC or AC). At this time, when the magnetic field lines 17 excited on the surface of the object to be measured 15 are added to be superposed on the action line of stress or acted in a direction perpendicular to the action line, this simulates the magnetization action on the iron component. It acts on the object to be measured 15 and causes a change in the magnetic flux to the detection coil 7 of the magnetic force type stress meter 1, and the change is output to the detector 18, and the amplification degree is adjusted by the output amplification degree switching knob 14 depending on the magnitude of the output. If adjusted, the stress value can be read by the measuring pointer 11.

Further, as shown in FIG. 2, when an error may occur when the magnetic force lines of the magnet 16 flow directly to the iron core of the magnetic force type stress meter 1, an iron plate having a thickness of about 1 mm is provided around the magnetic poles of the iron core. 19 should be attached.

Further, as shown in FIG. 4, when the object to be measured 15 is a relatively thin plate, a similar effect can be obtained by placing the exciting magnet 16 on the back surface of the plate on which the magnetic stress meter 1 is placed. Obtainable.

Table 1 shows the results of measuring the stress generated inside the aluminum material among the non-ferrous metal materials using the above means. The results are shown in FIG.

[0013]

[Table 1]

As shown in Table 1 and FIG. 6 above, the tensile stress and compressive stress values generated in the aluminum material show almost the same gradient changes as those of the metallic material, and the lines of magnetic force applied in the non-ferrous metallic material. It can be seen that has a property that is simulated as a steel material, and acts in the same way as a steel material in response to stress. The value can be measured with a sensitivity of about ½ for the same stress value. This can be detected at the same value as in the case of steel material by increasing the sensitivity of the detector 18.

As a result of the above explanation, the present invention brings about the following effects.

It has become possible to measure the stress and residual stress generated in a non-ferrous metal material, which could not be measured using the magnetic force type stress meter 1 in the past.

Since the measurement can be made only by applying the magnetic forces of the N pole and the S pole to the surface of the object to be measured, the object to be measured need not be destroyed,
Moreover, it can be easily measured.

[0017]

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of a magnetic force type stress meter.

FIG. 2 is a front view showing a usage state placed on the surface of the object to be measured.

FIG. 3 is an explanatory diagram showing an excited state of magnetic force lines.

FIG. 4 is a front view showing another embodiment of a magnet installed state.

FIG. 5 is a plan view showing a detector.

FIG. 6 is a graph showing an example of measurement results of stress values generated inside the aluminum material.

[Explanation of symbols]

 1 Magnetic force type stress meter 15 Non-ferrous metal material 16 Magnet 17 Magnetic field line

Claims (1)

(57) [Claims] 1. A non-ferrous metal material (15), in which one or both of a direction in which a stress is applied (as viewed in the direction of arrow AA) and a direction perpendicular thereto (as viewed in the direction of arrow BB), or both. , A combination of means for exciting the direct current or alternating current and means for disposing the magnetic force type stress meter 1 between the N pole and the S pole of the excited magnetic force line (17) in contact with the surface of the non-ferrous metal material (15) Thus, a magnetic force type stress measuring method for a non-ferrous metal material, wherein the stress generated in the non-ferrous metal material (15) is measured.