JPH0517580U - Iron loss measuring device - Google Patents

Abstract

(57) [Summary] [Purpose] To enable accurate measurement online on the manufacturing line depending on the material of the material to be measured. [Structure] The magnetic flux density of the material to be measured 1 by the detection coil 4, the plate thickness and width of the material to be measured by the thickness meter 20 and the width meter 21, and the iron loss in the longitudinal direction and the width direction according to the material of the material to be measured. The iron loss ratio correction value based on the difference between the values is input to the iron loss calculation circuit 11 to calculate the iron loss.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an iron loss measuring device for online measuring the iron loss of a ferromagnetic material, especially an electromagnetic steel sheet in which the quality of magnetic properties is a problem.

[0002]

[Prior Art]

 Since the quality of magnetic properties such as iron loss affects the quality of ferromagnetic materials such as steel sheets, especially electromagnetic steel sheets, measuring iron loss is important for quality control and operation control.

An apparatus according to Japanese Patent Laid-Open No. 49-6961 has been proposed as an apparatus capable of analyzing iron loss online. In this device, a magnetic flux density coil 33 is wound on the outer side of an iron core core 31 of a rectangular tube shape having flanges at both ends as shown in FIG. 6 so as to have the same axis as shown in FIG. An air gap compensating coil 35 and a magnetic field coil 34 are provided in this order from the inner side, and further, an exciting coil 32 is wound on the outer side so as to be coaxial with the iron core 31. ..

However, in the case of this apparatus, since the exciting coil 32 is separated from the steel plate 1 by the presence of the other coils 33, 34, 35, the exciting coil 32 is generated from the exciting coil 32 as shown by the broken line in FIG. The component of the generated magnetic force lines in the direction perpendicular to the surface of the steel plate 1 becomes small, and the magnetic force lines hardly penetrate into the steel plate 1. Therefore, as shown in FIG. 8, the detection unit 30 lengthens the exciting coil length in order to obtain the required length L ′ which is a constant level magnetic field strength, and increases the output of the exciting power source. Had to let.

Iron loss is a power loss value per unit weight, and when measuring it, it is necessary to measure the thickness, width, etc. in order to measure the dimensions. For example, for a steel plate with a constant width, only the thickness needs to be measured, but the thickness gauge 36 (see FIG. 7) for the measurement cannot be arranged at the same position as that of the detection unit 30 because of the mechanism, and therefore the steel plate It was difficult to measure the thickness and power loss at the same location. In order to solve this, it is sufficient to synchronize the timing of measuring the thickness of the steel sheet and the measurement of the power loss so that the same location of the steel sheet is measured, but in that case the device becomes complicated. ..

Then, what was made in order to solve such a problem is the iron loss measuring device disclosed in Japanese Utility Model Laid-Open No. 61-206883 previously proposed by the applicant of the present application. This is provided by using two through-type exciting coils and separating them so that the respective magnetic field components due to them form one closed magnetic circuit, and by placing a detecting coil between them and further in the vicinity of the detecting coil. Equipped with a measuring instrument for measuring dimensions related to the cross-sectional area of steel plates, etc., the output of the excitation power supply can be reduced, and it is possible to measure the power loss and the dimensions related to the cross-sectional area at approximately the same location. An object of the present invention is to provide an iron loss measuring device capable of accurately measuring loss.

The iron loss measuring device is provided with two iron loss measuring devices, which are provided so that the material to be measured penetrates at different positions in the moving direction in the moving region of the long material to be measured moving in the longitudinal direction. An exciting coil, a detecting coil that is arranged between the exciting coils and detects a change in the magnetic flux density of the material to be measured, and a detection coil that is provided in the vicinity of the detecting coil. And a measuring device for measuring. At the time of shipment of the above-mentioned magnetic steel sheet, it is required to display the iron loss by an Epstein test. This Epstein test is carried out at normal temperature (23 ° C) in a state of no tension, whereas when measuring iron loss during operation, it is carried out at a high temperature and under tension in the electrical steel sheet. Become. Due to this effect of temperature and tension, there is a problem that the iron loss value measured during operation and the iron loss measured by the Epstein test are different even for the same magnetic steel sheet. In order to solve these problems, the applicant of the present application has previously proposed an iron loss measurement by temperature correction and an iron loss measurement by tension correction (Practical application No. 2-125886 and No. 3-7305). ).

[0008]

[Problems to be solved by the device]

 By the way, the sample material in the Epstein test at the time of shipping the electromagnetic steel sheet is cut into the same number of rectangles in the longitudinal direction and the width direction of the steel sheet, because the iron loss values in the longitudinal direction and the width direction are different. However, the iron loss measuring device in the conventional line can measure only the iron loss value in the longitudinal direction of the steel sheet and ignores the difference from the iron loss value in the width direction (iron loss difference) under the present circumstances. is there.

[0009] Therefore, there has been a problem that the iron loss value measured by the iron loss measuring device in the line during operation is different from the iron loss value measured by the Epstein test for the same steel sheet to be measured. In addition, since the Epstein test is performed after cutting the product, there is a problem that it cannot be reflected in the operation because it cannot be measured over the entire length and cannot be measured in real time.

Here, focusing on the iron loss values in the longitudinal direction and the width direction of the above-mentioned steel sheet, the iron loss value in the width direction is larger than the iron loss value in the longitudinal direction, and the iron loss value in the width direction is different depending on the material. Table 3 shows specific numerical values for each of the three types of materials A, B, and C.

[0011]

[Table 1]

As described above, although there is a difference between the iron loss values in the longitudinal direction and the width direction, and both of them are reflected in the Epstein test value, the iron loss value in the line during operation is measured only in the longitudinal direction. Is the measurement of. Therefore, Fig. 4 shows the relationship between the iron loss ratio due to the difference between the iron loss values in the longitudinal direction and the width direction and the Epstein test value. The horizontal axis shows the Epstein test value and the vertical axis shows the iron loss ratio. It shows the relationship. The relationship in FIG. 4 shows that the Epstein test value and the measured value of the iron loss measuring device do not match.

In view of the above-mentioned conventional problems, the present invention pays attention to the iron loss ratio in the longitudinal and width directions, and corrects the iron loss ratio according to the material during operation to measure the iron loss value. As a result, the iron loss at the time of shipment of the material to be measured (that is, equivalent to the iron loss during the Epstein test) can be accurately measured without being affected by the iron loss ratio, and can be continuously measured in real time during operation. It was made for the purpose of providing a measuring device.

[0014]

[Means for Solving the Problems]

 In order to solve the above problems, the iron loss measuring device of the present invention is provided so that the material to be measured penetrates at different positions in the moving range of the long material to be measured moving in the longitudinal direction. Two exciting coils, a detecting coil arranged between the exciting coils to detect a change in magnetic flux density of the material to be measured, and a measuring coil which is provided in the vicinity of the detecting coil and is related to the cross-sectional area of the material to be measured. A magnetic measuring device and an iron loss calculation circuit that calculates the iron loss by correcting the iron loss ratio in the longitudinal and width directions according to the material of the material to be measured based on the relationship shown in Fig. 4. It is equipped with.

[0015]

[Action]

 According to the present invention, the magnetic flux density of the material to be measured by the detection coil, the plate thickness and width of the material to be measured by the measuring instrument, and the iron loss in the longitudinal direction and the width direction depending on the material of the material to be measured are configured by the above-mentioned configuration. With the iron loss ratio correction value due to the difference, the iron loss value of the ratio measuring material can be accurately measured as shown in FIG. 5 depending on the iron loss ratio in the longitudinal direction and the width direction depending on the material. Become.

[0016]

【Example】

 An embodiment of the present invention will be described below in detail with reference to FIGS. FIG. 1 is a block diagram showing an embodiment of the present invention installed on the outlet side of a continuous annealing furnace. In FIG. 1, 1 is transferred on a manufacturing line (not shown) in its longitudinal direction (arrow direction). It is a magnetic steel sheet.

At two positions separated by an appropriate length in the transfer direction of the transfer area of this electromagnetic steel plate (hereinafter simply referred to as “steel plate”) 1, an exciting coil 2 having an inner diameter larger than the cross-sectional dimension in the width direction of the steel plate 1, 3 is provided so as to penetrate the steel plate 1, and both ends of the exciting coils 2 and 3 are connected in series to a 50 Hz or 60 Hz alternating current power source 5 which is specified in JIS as the frequency for iron loss measurement. It is connected. The exciting coils 2 and 3 may be connected in parallel.

The separation distance between the exciting coils 2 and 3 is set so that the magnetic force lines H from the exciting coils 2 and 3 respectively form a closed magnetic path as one loop as shown in FIG. As a result, when the steel sheet 1 passes through the exciting coils 2 and 3, it is AC-magnetized in the longitudinal direction by the exciting coils 2 and 3, and a constant magnetic flux density is required between the exciting coils 2 and 3 as shown in FIG. A stable magnetic flux density region E having a length equal to or longer than the length is formed.

A detection coil 4 is provided by winding the steel plate 1 at a central position between the excitation coils 2 and 3, and the detection coil 4 is 50 Hz or 60 Hz based on the frequency of the AC power supply 5. And the harmonics of about 150 Hz (n × fundamental wave, n = 2, 3, 4, ...) Caused by the waveform distortion due to iron loss of the steel plate 1 and the magnetic domain inside the steel plate 1 during the magnetization process of the steel plate. A signal in which three components, that is, a discontinuous movement phenomenon, that is, high-frequency (several KHz to several hundred KHz) Barkhausen noise generated by the known Barkhausen effect are mixed is detected. The detection coil 4 is provided with a magnetic path length correction coil (not shown). The magnetic path length correction coil is provided with a magnetic path previously designed when, for example, the magnetic field distribution changes due to the transfer speed or material of the steel sheet 1. The effective magnetic path length can be determined by the calibration curve between the output of the length correction coil and the effective magnetic path length.

The detection signal of the detection coil 4 is given to the attenuator 6 and the current control circuit 7. The current control circuit 7 adjusts the output voltage of the AC power supply 5 based on the detected input signal, and adjusts the strength of the magnetic field generated from the exciting coils 2 and 3. On the other hand, the attenuator 6 has a low-pass filter 8 connected on the output side, and the attenuation rate is set so that the input signal level from the detection coil 4 does not exceed the maximum allowable input voltage of the low-pass filter 8.

The low-pass filter 8 has a cutoff frequency of, for example, 100 Hz so as to remove the third harmonic. The output signal of the low-pass filter 8 is amplified by the amplifier 9 and given to the voltage terminal of the power meter 10. An exciting current is supplied from the AC power source 5 to the power meter 10. Therefore, the detection coil 4, the low-pass filter 8, the power meter 10 and the AC power source 5 have the same structure as that of the Epstein test apparatus, and the power meter 10 loses power from the excitation current signal and the voltage signal from the amplifier 9. Is detected and the detected value is given to the iron loss calculation circuit 11.

At the position between the exciting coil 2 and the detecting coil 4 close to the detecting coil 4 and the position between the exciting coil 3 and the detecting coil 4 close to the detecting coil, the exciting coils 2 and 3 are located respectively. A thickness gauge 20 and a width gauge 21 using, for example, γ-rays, which can be detected without being affected by the magnetic field lines and without affecting the detection signal of the detection coil 4, are provided facing the steel plate 1. The detection signals from the thickness gauge 20 and the width gauge 21 are input to the iron loss calculation circuit 11 together with the output signal of the power meter 10. Is calculated.

First, the iron loss calculation circuit 11 calculates the iron loss W ₁ per unit weight (1 kg) of the steel plate 1 length L ′ corresponding to the power loss detection section (effective magnetic path length). The following formula 1 for determining the power loss P with respect to the mass is set.

[0024]

[Formula 1] W ₁ = P / ρ · t · w · L ′ (W / kg) where ρ: density of steel plate t: thickness of steel plate w: width of steel plate

Therefore, by inputting t and w from the thickness meter 20 and the width meter 21 and P from the power meter 10, the iron loss W ₁ is calculated based on the above mathematical formula 1. Next, the iron loss calculation circuit 11 corrects the iron loss W ₁ calculated based on the above Equation 1 in the longitudinal direction and the width direction according to the material of the steel plate 1. That is, if the corrected iron loss value is W ₂ , W ₂ can be obtained by the following mathematical formula 2.

[0026]

[Equation 2] W ₂ = W (L + C) · W ₁ where W (L + C) is the iron loss ratio in the longitudinal direction and width direction of the steel sheet, which was obtained in advance for each material shown in FIG. 4.

Then, the iron loss W ₂ (W / kg) obtained by the equation 2 is recorded in the recorder 12. Here, W (L + C) varies depending on the material of the steel sheet 1, and it can be preset and corrected as shown in FIG. 4 described above.

As described above, in the present invention, the iron loss value of the steel sheet 1 is continuously measured in real time while being transferred on the production line (that is, online), and the value is recorded in the recorder 12. Is what you can do. Moreover, since the iron loss value is accurately measured and recorded by correcting the iron loss ratio in the longitudinal direction and the width direction according to the material of the steel plate 1, the recorded iron loss value is the value at the time of shipment. It can also be used as an iron loss value by the Epstein test. This can be explained using the correlation diagram shown in Fig. 5, which shows the results of comparing the iron loss measurement values corrected for the iron loss ratio with the Epstein test values. The iron loss measurement values at each measurement position approximated the Epstein value. It shows that the measurement was performed with high accuracy.

[0029]

[Effect of the device]

 As described above, the iron loss measuring device of the present invention is capable of measuring the magnetic flux density of the material to be measured by the detection coil, the thickness and width of the material to be measured by the measuring instrument, and the iron loss according to the material of the material to be measured. The ratio correction value is used to measure the iron loss value of the material to be measured, which can be accurately measured online in the manufacturing line depending on the material. Therefore, it is not only possible to accurately measure the iron loss value required for shipping electrical steel sheets in the manufacturing process, but also the measurement results can be reflected in the manufacturing conditions in real time, improving the yield rate of products. It is a very effective iron loss measuring device.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of the iron loss measuring device of the present invention.

FIG. 2 is an explanatory view of a path of exciting magnetic force lines of the device.

FIG. 3 is an explanatory view showing a magnetized state of a steel sheet by the exciting coil.

FIG. 4 is a characteristic diagram showing a relationship between an iron loss ratio and an Epstein test value according to a material.

FIG. 5 is a relationship diagram showing an effect of iron loss ratio correction.

FIG. 6 is a perspective view of an iron core of a detection unit in a conventional example.

FIG. 7 is a cross-sectional view showing a state in which the coil is wound.

FIG. 8 is a characteristic diagram in the same magnetic field state.

[Explanation of symbols]

 1 Electromagnetic Steel Plate 2, 3 Excitation Coil 4 Detection Coil 11 Iron Loss Calculation Circuit 20 Thickness Meter 21 Width Meter

Claims (1)

[Scope of utility model registration request] 1. Two exciting coils provided so that the material to be measured penetrates at different positions in the moving direction in the moving range of the long material to be measured moving in the longitudinal direction, and between the exciting coils. A detection coil for detecting a change in magnetic flux density of the material to be measured, a measuring device provided near the detection coil for non-magnetically measuring a dimension related to a cross-sectional area of the material to be measured, and a material to be measured. An iron loss measuring device, comprising: an iron loss calculating circuit for calculating the iron loss by correcting the iron loss ratio in the longitudinal direction and the width direction according to the material of the.