JPS6061655A - Nondestructive material inspection method and device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method according to the preamble of claim 1 and a device according to the preamble of claim 4.

The use of eddy currents and the use of impedance values obtained using eddy currents for pine examination and A diagnosis has been known for several years. Basically, two processes are considered. One is to place the inspection head containing the transmitter and receiver coils on top of a stationary product; the other is to place the inspection head containing the transmitter and receiver coils on a stationary product; The purpose of this process is to detect material discontinuities along the rolled product, during which the measuring device is moved in parallel with respect to the product to be inspected. This can be done by running the measuring device by itself or by guiding the wires, tubes, etc. produced while the measuring device is moving past the measuring device.

The use of an eddy current tester of the type mentioned above is sufficient here to set the change in the measured value corresponding to a certain material discontinuity, so that it is useful for technological development and practical purposes. It was the focus of the use. The basic problem in actually realizing an eddy current inspection machine is that it is very difficult to understand the theoretical relationship, and that it is possible to calculate it in principle. Accuracy number J of theoretical near future value
However, it basically depends on the boundary article ('l is 1) given in advance, and this article ('l is 1;; in fact, it hardly matches what is the theoretical basis).

It is difficult to standardize a given measurement because the measurement result is determined by a large number of interdependent parameters. In order to achieve a standardization of
913,877, in which the frequency can be approximately given a theoretical evaluation in advance due to its frequency dependence, and an equalization method for the determination and removal of certain parameters is used accordingly. (GIeicl+ungssy
sLem) is obtained.

On the one hand, from the above-mentioned problems associated with eddy current inspection, on the other hand, starting from the basic advantages, especially non-destructive + A separate inspection, the idea of the present invention is to improve the quality of each individual product. When testing, it is possible to directly and consciously detect the characteristic frequency dependence of the impedance value, which is very difficult to reproduce in theory or in practice with a suitable method (detecting the A-shaped structure, the dark blue structure, etc.). It is to be used for.

Miscellaneous; Ii3 “Metalkunde (MeLallkunde)
) J45.

1954. 166 pages Förster (PursLer)
It is basically known that the impedance value on the complex plane of the test piece being tested shows a non-circular locus depending on the frequency. The applicant's examination was a completely different test.'' or ``In 1, we basically confirmed this course. It has been found that this is very specific for the austenitic content of certain alloys or certain steels, for example.

Constructively in this regard, the present invention aims to create a method and a device that allow rapid identification of products or test specimens according to the actual requirements, a test that evaluates certain identifications.

This problem was solved by the method described in the first claim. This method of divination avoids forgetfulness and intellectual approximations, and is instead aimed at a comparative method that I discovered myself. This method of treatment has not been tested in the overwhelming number of practical applications; the feed is known to have a slight deviation from expected scratches and hardness.

Therefore, taking into account the above-mentioned difficulties, it is possible to give up on grasping the absolute value that is difficult to obtain, and instead to compare or consider the deviation given in advance very quickly. Comparisons are made with known materials. The frequency-dependent curve of the impedance value in the imaginary plane acts as a comparison characteristic.

The method according to the invention according to claim 2 is implemented particularly advantageously. Accordingly, description of products of known configuration or known construction on the output position, ie on the image receiving surface or in the image of the printer, 1. A direct comparison is possible with a product whose curve profile is not known. In this case, for example, the complete curve profile of a number of previously known products can be explained by the Autobno1 device, and together with the curve profile of the directly inspected product, so that it can be quickly and In a way, it is possible to determine to which previously known curve profile the curve profile of the product to be inspected corresponds and therefore to which the product to be inspected can be LJ in relation to the previously known product in configuration or seam. A decision is possible.

A further development of the invention according to claim 3 provides that the relevant curve course when testing a large number of different samples is broadly covered in a certain frequency range, while in another frequency range 714
Take into account the fact that the symptoms have been determined to be present. According to the invention, this frequency or frequency range for each particular output location is not detected immediately, but can be taken out in sequence for detection and detection. For this purpose, the measuring point Py'
Calculation and size JJ to be extracted at a constant frequency for each T-
5 devices (1 Yu (, hen-uni) erLun to 8 us
Bseinricb1. ung) from which a certain measured value is reduced to a sum as a predetermined value (Vorgabe), or lies outside the tolerance limits and is therefore formed to be offset from a predetermined configuration and a pregiven seam. An adjustable tolerance range is used which allows for a different schedule.

The device according to the prerequisite concept of claim 4 is useful for carrying out 4) of claims 1 to 3. A device for measuring discontinuous frequency values of the transmitting coil dynamically and continuously x + + of the measuring cycle not only makes the measurement easy to operate, but also makes the practical use of such a device possible. A long-term recorder according to claim 5, characterized by a very rapid measurement, which is an important criterion for the installation possibilities of 1. In addition to notation 1.1 of the frequency-dependent measurements of the directly tested product, the device also provides a direct comparison of the measurement curves of a number of known products, in order to enable a direct comparison and correlation of the measurement curves. Allow Q. In this case, the quite fundamental advantage of the device according to the invention is that there is no need to eliminate device-specific parameters, since the measurements of the comparison curves 1.6 can be carried out with the same device, and the measuring surface ；The deviation of z essentially means monthly fee 21
! This is because they are reverting to the deviation in their natural characteristics. In contrast, the known device lacks the comparability of different measurement curves, which is an even bigger problem, so that the dependence of the impedance measurement point on the eL number for determining the metal properties is not actually utilized.

The alarm device according to claim 6 makes it possible to visualize the complete curve course and thus to make particularly fast determinations possible. Insofar as this apparatus is designed as a picture screen, this picture screen can be equipped with a so-called electronic magnifying glass, i.e. it is particularly suitable as a reference for identification if there are no particular hits. , it is possible to enlarge the measurement points of a certain frequency value or a certain frequency range.

The graphinop l-1 sensor according to patent claim 7 allows the setting of quite individual 1' constant criteria for measuring points iJ at a constant characteristic frequency. Instead of creating an association between the image point and the marked location, the structure profile can be formed at a fixed measuring point or a group of measuring points or irregularly using an image screen and associated control equipment. In this way, it is possible to create a measuring standard on the image screen for the subsequent computing device, due to the rounding established in the tolerance area.

Further features, advantages and individual aspects of the invention are explained below by way of example with the aid of the figures.

In FIG. 1, the plane formed by the real and imaginary parts of the impedance of the product being tested is shown.

There is an impedance point on this plane! (, 1), and several points are characterized by their quantity and phase angle ρ (=J). Separate measurement points with the same sign correspond to different separated frequency values.

The curve of the measurement points of the impedance in the imaginary plane, which depends on the measurement frequency, has an asymmetric arc-shaped locus. The trajectory of this curve is characteristic of the composition of the material or seam being examined.

In order to simplify the explanation of such a measure according to the invention, the following will start from the fact that the problem lies in adequately expressing the difference between two known possible configurations of one product.

For this purpose, both known product samples are measured using the device according to the invention, the individual measurement frequencies being of course consecutive within a pre-given frequency range and the impedance values being measured being interpreted and recorded. t(1) and displayed. After it has been optically detected that the measurements of trial 4 have been carried out satisfactorily, the measured values are filed in a long-term storage device. In this way, each Two curve trajectories are obtained, indicated by circles or roses, which are characteristic for the product configuration.

Following this, a sample of unknown configuration is measured and compared with the estimated curve trajectory of one of the previously known samples, thereby relating it to the corresponding configuration. If Wil + fixed point ``square'', the curved trajectory ``Hara''
, the measurement point ``triangle'' is associated with the curve 11i1 trace ``circle''. It is known that the relationship is clearly 1':I at the frequency f6 within the range of frequencies used, r, to f8. .

In Figure 2, the range of the imaginary plane for the IIIJ constant of the in-1 knee dance L) at frequency f6 is shown in an enlarged manner.
There is. The illumination fixed points were marked in the form of separate dots. These measurement points come from a sample of a known configuration, which corresponds to a sample with the measurement values "triangle" and "circle".It is known to disperse the measurement points within the range of the ring shape.

Here the frequency f for a previously known trial or configuration
In order to be able to make a quick and proper decision regarding the relationship of one measuring point in LJ to LJ, an irregularly formed sawtolerance area is established LJ, and the tolerance area is can be given in accordance with an image screen representation of a number of measurement points of a known sample. Such a tolerance range, for example C-shaped, makes it possible to determine that measurement points with a relatively large spacing relative to a predetermined measurement point are within the tolerance range in the direction of the imaginary part. and, on the other hand, on the other hand, make it possible to detect measuring points with relatively small spacings that are inscribed at pre-given measuring points and lie outside the plan in the direction of the real part, thus e.g. automatically The corresponding display can be divided by PJ'X.

A schematic block diagram is shown in FIG.

The transmitting coil 1 serves to generate eddy currents 2 in the product 3, and the receiving coil 4 serves to receive a measured voltage 5 which may have an amplitude and phase difference with respect to the transmitted voltage 6.

In order to generate the transmitted alternating current voltage 6, a power amblifier 7 serves together with a crystal oscillator with a rectangular-to-sine converter 8 and a divider 9. This device is connected via a bus IO with a control and storage device and accordingly also serves as a device for dynamically and continuously adjusting the separated value of the frequency of the transmitting coil 1 during the measurement cycle.

A phase-controlled rectifier 11 for forming the components of the measured voltage 5 (at the measured voltages U sinρ and U CO5ρ) is connected after the receiver coil 4 .

A phase controlled rectifier 11 is coupled to the crystal oscillator and divider 9. After the phase-controlled rectifier 11 there is a bus 10
An A/D converter 12 connected to the A/D converter 12 is connected. A microprocessor 13, blockogram storage device 14, and data storage device 15 are connected to the lotus. The phase-controlled rectifier 11 and the A/D converter 12 are connected to a microprocessor 13 and a program storage device 14 and a data storage device 1.
1Q of vector impedance values measured with 5
and forming equipment for processing. Data record 1 bird device 1
In addition to 5, record the external time in the form of tape memory 5a
A device 16 is provided, and a timekeeping device is provided.
simulator interface (Univcrsalscl+n
1LLsLelle) 17.

Output devices 18 and 19 in the form of a printer and an image screen are also connected to the knee-barsal interface 17. At the same time, an input keyboard is attached to the image screen.

A graph ink processor 20 is connected to the input device on the one hand and to the hash on the other hand. This allows for almost arbitrarily formed tolerance regions of 11 words, where the graph ink processor creates logical connections between image points and their moral connections and storage locations.

[Brief explanation of the drawing]

Fig. 1 is a state diagram of impedance points in the imaginary plane depending on the frequency for various known products and products to be tested, Fig. 2 is an enlarged partial view of Fig. 1, and Fig. 3 is a diagram according to the present invention. It is a principle wiring diagram of the device. 1... Transmission coil 2... Eddy current 3... Product 4... Receiving coil 11... Rectifier 12... To/D change I history device 13...
・Microprocessor 14...Program storage device

Claims (7)

[Claims] (1) The use of a transmitting coil and a receiving coil, where the transmitting coil is operated at different frequencies to generate eddy currents in the product to be inspected, and the impedance is measured via an evaluation device. In the destructive material inspection method, the frequency of the transmitting coil is automatically varied from separated frequency values first within a pre-given frequency range, an impedance measurement is carried out at each frequency value, and the measured impedance value is stored. A non-destructive material inspection method characterized by: (2) Impedance values measured at various frequency values of the product to be directly inspected are provided to an output device that draws an imaginary impedance surface together with corresponding measured values of the product measured in advance with a known configuration. A non-destructive material inspection method according to claim 1. (3) A randomly formed tolerance region for each individual frequency value is introduced into the imaginary plane for the impedance value measured in one tested product for one or many child-known products. A non-destructive material inspection method according to claim 1 or 2, characterized in that: (4) The transmitting coil is operated with alternating currents of different frequencies to generate eddy currents in the product to be inspected (IJiIJ function), and after the receiving coil is used for impedance measurement and the real number measured including the phase angle. An evaluation device for outputting or displaying the component and the imaginary component is arranged, and in the nondestructive material inspection device including the transmitter coil and the receiver coil, the separation value of the frequency of the transmitter coil fil is measured in the measurement cycle. A non-destructive feed test characterized by: a device (9) for dynamically and continuously adjusting the frontage; and a device (11-15) for recording the measured impedance value. Manufacture. (5) The non-destructive material inspection device according to claim 4, characterized by a long-term storage device (14). (6) A nondestructive material inspection device characterized by a flat Ara 1-Puato device (18, 19>) showing an imaginary impedance surface. (7) Claims 4 to 6 characterized by a graphic processing processor (20) connected to the output device (18, 19) and the storage/processing device (11-15). A non-destructive material testing device as described in one of them.