JP2522732Y2 - Iron loss value measuring device - Google Patents

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to an iron loss value measuring device for online measurement of iron loss of a ferromagnetic material, particularly an electromagnetic steel sheet where magnetic properties are a problem. It is.

(Prior art) In ferromagnetic materials such as steel sheets, particularly electromagnetic steel sheets, the quality of the magnetic properties such as iron loss determines the quality. Therefore, measuring iron loss is important for quality control and operation management. is there.

As an apparatus capable of analyzing iron loss online,
An apparatus according to 49-6961 has been proposed. This device has a rectangular cylindrical iron core 31 having flanges at both ends shown in FIG.
7, a coil 33 for magnetic flux density is wound around the same axis as shown in FIG. 7, and a coil 35 for air gap compensation and a coil 34 for magnetic field are provided on the outer side surface in this order from the inside. Excitation coil 32 on the outside so that it has the same axis as iron core 31
Is wound around the detecting unit 30.

However, with this device, the excitation coil 32
Is separated from the steel plate 1 by the presence of the other coils 33, 34, 35, so that the excitation coil 32 as shown by the broken line in FIG.
The component of the magnetic field lines generated in the direction perpendicular to the surface of the steel sheet 1 becomes small, and the magnetic field lines hardly enter the steel sheet 1. For this reason, as shown in FIG. 8, the detecting section 30 needs to increase the length of the exciting coil and to increase the output of the exciting power supply in order to obtain the required length l at which the strength of the magnetic field at a certain level is obtained. was there.

And iron loss is the power loss value per unit weight,
In order to measure the thickness, it is necessary to measure the dimensions, and it is necessary to measure the thickness and width. For example, for a steel plate having a constant width, only the thickness needs to be measured. However, the thickness gauge 36 (see FIG. 7) for the measurement cannot be arranged at the same position as the detection unit 30 due to the mechanism of the detection unit 30. It is difficult to measure the power loss and the same point. To solve this, the timing of the measurement of the thickness of the steel sheet and the measurement of the power loss may be synchronized so as to measure the same portion of the steel sheet. However, in that case, there is a problem that the apparatus becomes complicated.

In order to solve such a problem, an iron loss measuring device disclosed in Japanese Utility Model Application Laid-Open No. 61-206883 proposed by the present applicant has been proposed. This is because two through-type exciting coils are used and their respective magnetic field components are 1
By providing a measuring coil for measuring the cross-sectional area of a steel plate or the like in the vicinity of the detecting coil and providing a detecting coil between them so as to form two closed magnetic paths, It is an object of the present invention to provide an iron loss measuring device capable of reducing the output, measuring the power loss and the dimension related to the cross-sectional area at substantially the same place, and accurately measuring the iron loss.

The iron loss measuring device includes two exciting coils provided so that the material to be measured penetrates at different positions in the moving direction of the long material to be measured moving in the longitudinal direction. A detection coil disposed between the excitation coils to detect a change in magnetic flux density of the material to be measured, and a measuring device provided near the detection coil and non-magnetically measuring a dimension related to a cross-sectional area of the material to be measured. And characterized in that:

(Problems to be solved by the invention) The above-mentioned electrical steel sheets are required to indicate the iron loss by an Epstein test at the time of shipment, and this Epstein test is performed at room temperature (about 23 ° C). When measuring the loss, the temperature of the magnetic steel sheet is generally not normal temperature. By the way, as shown in FIG. 4, the iron loss depends on the temperature and the silicon content of the steel sheet, and the smaller the silicon content is, the more easily the iron loss is affected (A: large silicon content, B: middle,
C: same small).

Therefore, there is a problem that the iron loss measured during operation and the iron loss obtained by the Epstein test are different for the same material to be measured. In addition, since the Epstein test is performed by cutting the product, it cannot be measured over the entire length and cannot be reflected in operation because it cannot be measured in real time.

In view of the above problems, the present invention corrects the iron loss measurement value so that the temperature during operation is the same as that of the Epstein test. It is an object of the present invention to provide an iron loss measuring device that can accurately measure (equivalent to loss) accurately and without being affected by temperature, and in real time during operation.

(Means for Solving the Problems) In order to solve the above-mentioned problems, the iron loss value measuring device of the present invention is provided at different positions in the moving area of a long measuring material moving in the longitudinal direction. Two excitation coils provided so as to penetrate the material to be measured, a detection coil disposed between the excitation coils to detect a change in magnetic flux density of the material to be measured, and provided near the detection coil A measuring device for non-magnetically measuring a dimension related to a cross-sectional area of a material to be measured; a thermometer provided near the detection coil for measuring the temperature of the material to be measured; An iron loss calculating circuit for calculating an iron loss by performing temperature correction according to the silicon content of the measurement material is provided.

(Operation) With the above-described configuration, the present invention provides a magnetic flux density of a material to be measured by a detection coil, a thickness and a width of the material to be measured by a measuring device, a temperature by a thermometer, and a silicon content at the temperature. With the corresponding correction value, the iron loss value of the material to be measured is accurately measured depending on the silicon content and the temperature.

(Example) Hereinafter, an example of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a block diagram showing an embodiment of the present invention. In FIG. 1, reference numeral 1 denotes an electromagnetic steel sheet which is transported on a production line (not shown) in the longitudinal direction (the direction of the white arrow). .

At two positions separated by an appropriate length in the transfer direction of the transfer area of the magnetic steel sheet (hereinafter simply referred to as “steel sheet”) 1, the steel sheet 1
Excitation coils 2 and 3 having an inner diameter larger than the cross-sectional dimension in the width direction of
However, both ends of each of the exciting coils 2 and 3 are connected in series to a 50 Hz or 60 Hz AC power supply 5 specified in JIS as a frequency for iron loss measurement. ing. The exciting coils 2 and 3 may be connected in parallel.

The distance between the exciting coils 2 and 3 is the second distance.
As shown in the drawing, the magnetic field lines H from the excitation coils 2 and 3 are determined so as to form a closed magnetic circuit as one loop. 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 long and longer stable magnetic flux density region E is formed.

Further, a detection coil 4 is provided by winding the steel plate 1 at, for example, a center 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.
Hz fundamental wave and waveform distortion caused by iron loss etc. of steel sheet 1.
Harmonics of about 150Hz (nx fundamental, n = 2, 3, 4, ...)
And a discontinuous movement phenomenon of the domain wall in the steel sheet 1 in the steel sheet magnetization process, that is, a signal in which three components of a high frequency (several KHz to several hundred KHz) Barkhausen noise generated by the known Barkhausen effect are mixed. The detection coil 4 is provided with a magnetic path length correction coil (not shown). The magnetic path length correction coil has a magnetic path length correction coil prepared in advance when the magnetic field distribution changes due to the transfer speed or the material of the steel sheet 1, for example. The effective magnetic path length can be determined by a steep line between the output of the coil and the effective magnetic path length.

The detection signal of the detection coil 4 is supplied 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 on the output side.
Are connected, and the attenuation rate is determined so that the input signal level from the detection coil 4 does not exceed the maximum 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 high frequency. The output signal of the low-pass filter 8 is amplified by the amplifier 9 and applied to the voltage terminal of the power meter 10. An exciting current is supplied from the AC power supply 5 to the wattmeter 10. Therefore, the detection coil 4, the low-pass filter 8, the wattmeter 10 and the AC power supply 5 have the same configuration as the Epstein test apparatus. Circuit and calculates the detected value as an iron loss calculation circuit 11.
Give to.

At positions near the detection coil 4 between the excitation coil 2 and the detection coil 4 and at positions near the detection coil between the excitation coil 3 and the detection coil 4, the influence of the lines of magnetic force from the excitation coils 2 and 3 respectively. For example, a thickness gauge 20 and a width gauge 21 using γ-ray, which can be detected without being affected by the detection signal of the detection coil 4 and without affecting the detection signal of the detection coil 4, are provided facing the steel plate 1. Is provided with a thermometer 22 for measuring the temperature of the steel sheet 1. The respective detection signals from the thickness meter 20, the width meter 21, and the thermometer 22 are input to the iron loss calculation circuit 11 together with the output signal of the power meter 10, and the iron loss calculation is performed. The circuit 11 calculates an iron loss.

First, the iron loss calculating circuit 11 calculates the iron loss W per unit weight (1 kg) by calculating the power loss P with respect to the mass of the length 1 of the steel sheet 1 corresponding to the power loss detection section (effective magnetic path length). The following formula is set to obtain: W = P / ρ · t · w · l (W / kg) where ρ: density of steel sheet t: thickness of steel sheet w: width of steel sheet Based on t and w from the width meter 21 and P from the wattmeter 10, the iron loss W is calculated based on the above equation.

Next, the iron loss calculation circuit 11 performs a temperature correction on the iron loss W calculated based on the above equation according to the detected temperature of the steel sheet 1 measured by the thermometer 22. That is, assuming that the iron loss whose temperature has been corrected is W 'and the detected temperature is T (° C.), W' = W / {1−α (T−23)} where α is the influence coefficient of the temperature on the iron loss. And the recorder 16 records the iron loss W '(w / kg) obtained by this equation. Here, the coefficient α is
As described with reference to FIG. 4, although it differs depending on the silicon content, for example, in FIG.
0.04% / ° C (large silicon content), B characteristic is -0.07% /
° C (in the silicon content), the C characteristic is -0.13% / ° C (small silicon content), and is preset according to the silicon content of the steel sheet 1.

As described above, the iron loss value can be continuously measured in real time while the steel sheet 1 is transferred on the production line (that is, online), and the value can be recorded in the recorder 16. In addition, since the iron loss value is accurately measured and recorded according to the temperature of the steel sheet 1 and the temperature correction according to the silicon content, the recorded iron loss value is determined by an Epstein test at the time of shipment. Can also be used as an iron loss value. This will be described with reference to a correlation diagram shown in FIG. 5. FIG. 5 shows a result obtained by comparing a temperature-corrected iron loss measurement value with an Epstein test value, and the iron loss measurement value at each measurement position approximates the Epstein value. This indicates that the measurement was performed with high accuracy.

(Effects of the Invention) As described above, the iron loss measuring device of the present invention uses 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 device, and the temperature by the material thermometer. The iron loss value of the material to be measured is measured by a correction value according to the silicon content at that temperature, and it can be accurately measured online in a production line depending on the silicon content and the temperature. it can. Therefore, not only can the iron loss value required at the time of shipment of the magnetic steel sheet be accurately measured in the manufacturing process, but also the measurement result can be reflected in the manufacturing conditions in real time, and the product yield can be improved, It is a very effective iron loss measurement device.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of the iron loss value measuring device of the present invention, FIG. 2 is an explanatory diagram of a path of exciting magnetic force lines of the device, FIG. 3 is an explanatory diagram showing a magnetization state of a steel sheet by the exciting coil, FIG. 4 is a characteristic diagram showing the effect of temperature on the iron loss value, FIG. 5 is a relationship diagram showing the effect of temperature correction, FIG. 6 is a perspective view of an iron core of a detection unit in a conventional example, and FIG. FIG. 8 is a cross-sectional view showing a state in which the coil is wound, and FIG. 8 is a characteristic diagram in the magnetic field state. 1 is an electromagnetic steel plate, 2 and 3 are excitation coils, 4 is a detection coil,
11 is an iron loss calculation circuit, 20 is a thickness gauge, 21 is a width gauge, and 22 is a thermometer.

Continuation of the front page (72) Inventor Shinsuke Mita 1850 Minato, Wakayama City, Wakayama Prefecture Sumitomo Metal Industries, Ltd. Wakayama Steel Works (56) References JP-A-49-6696 (JP, A) JP-A-61-206883 (JP) , U)

Claims (1)

(57) [Scope of request for utility model registration] 1. Two exciting coils provided at different positions in a moving direction of a long material to be measured moving in a longitudinal direction so as to penetrate the material, and two exciting coils provided between the exciting coils. A detection coil disposed to detect a change in magnetic flux density of the material to be measured, and a measuring device that is provided near the detection coil and non-magnetically measures a dimension related to a cross-sectional area of the material to be measured,
A thermometer which is provided near the detection coil and measures the temperature of the material to be measured, and calculates iron loss by performing temperature correction according to the temperature measured by the thermometer and the silicon content of the material to be measured. An iron loss value measuring device comprising: an iron loss calculating circuit.