JPS58140655A - Iron loss measuring method and stress measuring device utilizing method - Google Patents

Abstract

PURPOSE:To measure iron loss with high precision regardless of the dimensions of a gap between an inside iron core and a magnetic material, by providing the inside core and an outside iron core so that magnetic flux flows in the magnetic material, and nearly eliminating the magnetic flux flowing to the inside iron core. CONSTITUTION:The inside iron core 13 and outside iron core 16 are so provided that the magnetic flux flows in the magnetic material 19; the inside iron core 13 is provided with a voltage coil 14 and a detecting coil 15 and the outside iron core 16 is provided with an energizing coil 17. Magnetic flux shunt from this outside iron core 16 to the inside iron core 13 cancels magnetic flux which is produced by the voltage coil 14 and flows in the inside iron core 13 to nearly eliminate the magnetic flux at the detection coil 15. Consequently, the voltage of the voltage coil 14 and the current of the energizing coil 17 are inputted to a wattmeter 7, whose production output is the iron loss of the magnetic material 9. Thus, the magnetic flux of the detection part 15 of th inside iron core 13 is nearly eliminated to measure the iron loss of the magnetic material 9 with high precision all the time regardless of the dimensions of the gap between the end surface of the inside iron core and the magnetic material 9.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for measuring iron loss in a magnetic material and a stress measuring device for a magnetic material using this method.

One of the conventional methods for measuring iron loss of magnetic materials is a method using a magnetic sensor l as shown in FIG. This magnetic sensor l is made of iron t0 with an X-shaped cross section.
2, a negative-order coil (excitation filter) 3R and a secondary coil (output secondary voltage coil) 4, and a negative-order coil 3
is connected to the wattmeter 7 via an alternating current voltage #ls and an amplifier, and the secondary coil 4 is connected to the power needle 7 via an amplifier 8. Now, 1 of 9 magnetic materials! ! Magnetic sensor on the surface
When the iron core opening 410 and 11tl are brought into contact and the -order coil 3 is excited by the AC current #isK, magnetic flux flows from the iron core 2 through the magnetic material 9 to 5 as shown by the arrow,
A magnetic path returning to the iron core 2 is formed again, and a voltage of 1 is generated in the secondary filter 4 by this magnetic flux. Increase this voltage l1liI
The voltage is amplified by the voltage generator and output to the power needle 7 as an output voltage. In the power needle 7, the output voltage from the secondary coil 4 and the Jl! of the negative secondary coil 3 are measured. Input 1 Ma current and multiply these values to display the iron loss of the magnetic material 9 and the iron core 2. In this case, if the iron loss of the iron core 2 is made sufficiently smaller than that of the magnetic material, the iron loss displayed on the power needle 7 will be d
It is a good idea to consider the iron loss of rm material 9.

However, in this case, if there are irregularities on the surface of the magnetic material 90,
When the open ends 10 and 11 of the core 2 of the magnetic sensor l are brought into contact with the surface of the magnetic material 9, a gap is created between the end faces 10 and 11 of the core of the magnetic sensor l and the contact surface of the magnetic material 9. , the magnetic flux leaks as the magnetic resistance increases, and the magnetic material 9
The magnetic flux density of the magnetic flux flowing inside decreases. -According to experimental examples, if there is a gap of 0.01 degrees, the material becomes magnetic! The magnetic flux density within 49 decreases by approximately IL1%. In general, since iron loss is proportional to the X square of the magnetic flux density, negative magnetic flux has a great influence on the accuracy of iron loss measurement. Therefore, in the conventional iron loss measurement method described above, magnetic material 9 and magnetic sensor End face 1G of iron core 2 of 1
, 11 f) If a gap is formed in the @, the iron loss adjustment accuracy will be lowered due to leakage magnetic flux, resulting in a large error in the iron loss measurement of the 1Mi material 9, which is a drawback.

In general, the relationship between stress acting on magnetic materials and iron loss is N-
There is a tangential relationship with vI, and the relationship between the stress acting on the magnetic material and the iron loss is expressed by K as shown in Fig. 2, where the tensile stress and compressive stress are expressed as transverse @, and the iron loss is expressed as lR@. When compressive stress acts on a magnetic material: The crushing stress and iron loss are KIN
[Since it is related to a linear circle, if this relationship is used to determine the core loss of a magnetic material on which compressive stress is acting, the compressive force can be determined with high accuracy. Now, in Figure 2, the iron loss when no compressive stress is acting on the magnetic material is W.
o.

If the iron loss when compressive stress is applied is Wi, then the crushing stress is proportional to (Wl - W@)K. Therefore.

When the ratio g4 constant is α, the compressive stress C acting on the m-type material is g = (1(Wi − Wo) ・
It can be determined from ... It is decided.

Therefore, if we define the iron loss W when no compressive stress is acting on the magnetic material and the iron loss wtvii when compressive stress is acting, then from equation (1) above, The compressive stress I can be determined. However, in the conventional iron loss measuring method as shown in FIG. This has the disadvantage that the adjustment accuracy is reduced and a large error occurs in defining the compressive stress acting on the magnetic material IK.

The present invention has been made to eliminate the above-mentioned drawbacks, and includes an iron loss measuring method and iron loss measuring method that can measure iron loss with high accuracy even if there is a gap between the contact surfaces of a magnetic sensor and a magnetic material. A stress measuring device using this iron loss measuring method is provided.

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

43- is an explanation of one embodiment of the method for measuring iron loss of magnetic materials of the present invention-1. Fig. 4 is a diagram of another embodiment of the method of determining iron loss 1 of magnetic materials of the present invention, and Fig. FIG. 2 is a block diagram of JlliN, which is a stress measuring device for magnetic materials that utilizes the iron loss measuring method.

In addition,#! 1 and 3#A to 5, the same numbers indicate the same members.

In @311i1, the voltage coil 14 wound around the inner core 13 and the detection coil 1 wound around the inner core 13 and its J11mlIK41
5, an outer core 16 provided outside the inner core 13 and having a U-shaped cross section, and an excitation coil 17 mounted on the outer core 16.

The inner core 13 has an X-shaped cross section, and protrusions taj, , , 13'' are provided between the voltage coil 14 and the detection coil 150 from each leg to the inside 11, respectively. The darkness of the protrusion 13', 13" of ~ has a -ki resistance of llI
4. A gap is provided for alignment. Then, the voltage coil 14 is connected to the AC power supply i and the power needle 7, and the detection coil 1
5 is increased -1i) 1@ and the excitation filter 17 is connected to the power needle yecH7Ic via the current needle 20, respectively. A number of acid pressure needles 111 for measuring the voltage of the voltage coil 14 are connected in parallel to the voltage coil 14 .

Now, the magnetic sensor 12 is placed on the magnetic material 90 ImK,
When the voltage coil 14 is excited with a constant voltage from the alternating current 11sK, the magnetic flux moves inside the inner core 13 in the direction of the arrow Kr1L, and a portion of the magnetic flux flows from the protrusion 13' through the gap and returns to the first inner side through the protrusion 13'. The other part forms a #E2 inner magnetic path that flows from one leg of the inner #1 iron core 13 through the magnetic material 9 in the direction of the arrow and returns to the other leg of the inner core 13. Form B. The magnetic flux flowing through the second inner magnetic path B causes a voltage of 1 to be generated in the detection filter 15 . The extremely large voltage applied to this detection coil 15 is increased by an amplifier 18, and then passed through the power needle 7 and current needle 20 to this detection coil 1s.
When a voltage of 1 car is applied to the excitation coil 17 in a direction that cancels it out, the excitation filter 17Kllfi flows, magnetic flux flows from the outer core 16 through the magnetic material 9, and a portion of the magnetic flux is shown at 5 as shown by the arrow. Inner I11 Enters from one leg of the iron core 13, flows inside the inner iron core 13, and enters the inner @ iron core 13.
comes out from the other leg of , flows through the magnetic material 9,
An outer magnetic path C returning to the outer core 16 is formed. in this case,
Maximize the increase rate of 1 dollar of the intensifier. When the magnetic flux of the detection filter 15s becomes almost zero, the magnetomotive force of each leg of the inner core 13 becomes almost zero, and the protrusions 13", 13 of each leg of the inner core 13
1 and the magnetomotive force between snow points X and Y in the vicinity of 2J:LU-
The magnetomotive force between V becomes equal. Therefore, if the voltage of the voltage coil 14 at this time and the current of the excitation filter 17 are input to the power needle 7 and multiplied, the multiplication result is
It becomes a railway between V. In this case, if the magnetic flux of each leg of the inner core 13 is made almost zero, the end face of the inner core 13 and
Regardless of the size of the air gap between the magnetic materials 9, the iron loss of the magnetic materials 9 can be determined with high tVc accuracy.

Also, the 41st i! 1 shows another embodiment of the iron loss measuring method of the present invention, in which K is used instead of the magnetic sensor 12 in FIG.
, is exactly the same as FIG. 3 except that the magnetic sensor 21 is used. The magnetic sensor 21 has an inner core 2 with a Y-shaped cross section.
2, and a voltage coil 1 wound around the back s of this inner core 22.
4 and its legs sK, a detection coil 1s, an outer core 16 with a Y-shaped cross section provided outside K so as to cover the inner core 22, and an excitation coil wound around this outer core 16. It consists of 17. Therefore, the magnetic sensor 21 is placed on the surface of the magnetic material 90, and the voltage coil 14
When excited with a constant voltage by an AC electric fi5, the magnetic flux flows from the inner core 22 through the magnetic material in the direction of the arrow, forming an inner magnetic path that returns to the inner core 22, and the detection coil ISK voltage 1 will be raised. 1 for this detection coil 15
When the generated voltage is increased by the intensifier 18 and applied to the Kkk4im coil 17 in a direction that cancels the voltage generated in the detection coil 1sKa through the power needle 7 and the ammeter 20, the exciting coil 1TK current flows, magnetic flux flows from the outer core 16 through the magnetic material 9, and a portion of the magnetic flux enters from one 811 section of the inner core 22, flows through the inner core 22, as shown by the arrow, and flows through the inner core 22. forming an outer magnetic path E which exits from the other leg of the magnetic material 9 and flows through the magnetic material 9 and returns to the outer core 16. In this case, the amplification @III is made extremely large, and the magnetic flux shunted into the inner core 22 cancels out the magnetic flux generated by the excitation 41iiK of the voltage coil 14 and flowing inside the inner core 22, and the detection filter 15
When K is applied so that the magnetic flux at
Detection coil IS and voltage coil 14 dark 2 points on each leg of
The magnetomotive force of the 'Y' cabinet and the electromotive force of the peak U-V in the magnetic material II49 facing the end face of each leg of the internal iron core 82 become equal. Therefore, if the voltage of the voltage coil 14 at this time and the current of the excitation coil 17 are input to the power needle 7 and multiplied, the multiplication result becomes the UV dark iron f- of the magnetic material 9, and the third As in the case shown in the figure, the iron loss of the magnetic material 9 can be measured with high accuracy in tK, regardless of the size of the gap between the end face of the inner core 2 and the magnetic material 90.

In addition, by using the above-mentioned iron loss measurement method, it is possible to measure the difference between the surface of the magnetic material and the end face of the inner core of the magnetic sensor.
! Even if there is ill, the crushing stress acting on the magnetic material 9 can always be measured with accuracy regardless of the size of the void 4.

@SwA is a diagram showing an example of a stress measuring device for measuring the stress of this magnetic material. That is, the stress measuring device 23 performs iron loss measurement s24 and stress measurement s24.
25 and an instruction section 26.

The iron loss measurement unit 24 is configured to keep the iron loss of the magnetic material constant using the above-mentioned iron loss adjustment method, and is configured to keep the iron loss of the magnetic material constant using the above-mentioned iron loss adjustment method.
1, AC power supply, amplifier ##18, power needle 7, voltage needle 19
and an ammeter 20. Below, magnetic sensor 12
Explain what happens when it rains.

The magnetic sensor +12 includes an internal iron core 13, a voltage coil 14 wound around the back 11 of this inner iron core 13, a detection coil IB wrapped around its legs, and an internal iron core! 3, and an outer core 16 provided on the outside so as to cover the outer core t@.
The excitation coil 17 has an excitation coil 17, and the sun wire of each of these coils is normally configured to be connectable to external devices, instruments, etc. The voltage coil 14 is connected to the AC power supply S and the wattmeter 1, the detection coil 15 is connected to the wattmeter 7 via the amplifier 18, and the exciting coil 17 is connected to the wattmeter 7 via the ammeter 2. There is. Further, a voltage needle 19 is connected in parallel to the voltage coil 14 to keep the voltage of the voltage coil 14 constant.

The stress calculation s2s is to calculate the compressive stress acting on the magnetic material by manually inputting the iron loss Wl, which has been fixed by the iron loss measurement 524, from the power needle 7, and calculates the compressive stress acting on the magnetic material.
It is composed of a proportional constant setter 28 and a stress calculator 29.

In the initial value setting @2'lK, the iron loss WO when no stress is acting on the magnetic material is set, and the proportional constant setter 28
A proportionality constant α is set for converting iron loss into stress (
Above (1) 2nd M), stress calculation! ! 29 is the power needle 7
Iron loss Wl is set to normal value tS wealth and proportional constant! ! Input the WO warp α from 28 and calculate the above (
The crushing stress acting on the magnetic material is calculated using the formula, and the calculation result is outputted to the instruction $26.

The indicator SZS has an indicator switch 30 and an indicator needle 31,
By switching the indication off side IO, the iron fi4Wt of the output of the power needle 1 or the compressive stress C of the output of the stress calculator 2i1 can be changed.
to be indicated by the indicator needle.

Next, the operation of the stress measuring device 230 having the above configuration will be explained.

First, connect the indicator switch 30 to the power needle (F side),
Set the proportional constant 92 mK and the proportional constant a, place the magnetic sensor 12 between IN and IN of the magnetic material on which no stress is applied, and set the voltage coil! 4 is excited by an AC voltage #SK at a constant voltage, the indicator 31 indicates the iron loss W when no stress is acting on the sensitive material by adding it up as in the case of the iron loss adjustment method described above. Ru. This iron loss W. is set in the initial value setting device 27. Next, compressive stress is applied to the magnetic material, a magnetic sensor 12 is placed at the constant 11, and the voltage coil 14 is excited with a constant voltage from an AC voltage. The iron loss Wi when compressive stress is applied to the material is
An instruction is given to the indicator 31 via the wattmeter 7. In addition, this iron-Wi is inputted into the stress calculation ◆ 211 [, and in the stress calculator = 9, the iron loss step, W manually entered from the initial value setter 27, and manually entered from the proportional constant setting 528. The compressive stress acting on the magnetic material from the proportional electric current α −=
Calculate a (Wi − Wa ).

In this case, the m-air sensor 12 is placed in one of the measuring parts of the magnetic material, and the iron fllW indicated by the indicator needle 31 is
When i is OL at maximum 1IIIiK, m shows tZllIi1
I on the 30&fi force calculator 29 side (G 匈)! When controlled, the maximum compressive stress acting on the magnetic material is indicated on the indicator needle 31.

If the iron loss W @ when no stress is acting on the 111 magnetomotive material is known, omit the constant iron loss We mentioned above and set the known iron loss Wo as the initial value @ 2'lK, and create a compressive stress acting on the magnetic material as described above.

Furthermore, since the stress measuring device of the present invention utilizes the iron loss measuring method of the present invention, even if there is a gap between the surface of the magnetic material and the inner core of the magnetic sensor, the size of the gap can be determined. Since the iron loss of the magnetic material can be measured with high accuracy regardless of the current, the compressive stress of the magnetic material can always be measured with high accuracy without causing a definition error due to the void 111.

Therefore, the bolts at the time of fastening or the fastening image, sometimes the bolt order sK
Measurement of axial stress or axial force acting on bolts with raised letters, hardening depth and stress of steel bars, steel plates, -1, rails, etc.
If the stress measurement device of the present invention is used to measure internal defects, etc., even if there is a gap between the lN direction of the magnetic material and the end face of the inner core of the magnetic sensor, it will be possible to measure internal defects with high accuracy regardless of the size of the gap. Since the above-mentioned measurement can be continued, the error rate is improved, and a great effect can be exerted on bolt axial stress or axial force management, quality control of steel materials, etc.

[Brief explanation of drawings]

Fig. 1 is an explanatory diagram of the conventional iron loss measuring method, Fig. 2 is a characteristic showing 14Igk of stress acting on a magnetic material and iron loss, and Fig. 3 is an implementation of the iron loss measuring method of the present invention. Example af! A
FIG. 4 is an explanatory diagram of another embodiment of the iron loss measuring method of the present invention, and FIG. S is a block diagram of an embodiment of the stress measuring device of the present invention. 5... AC power supply, 7... Power needle, 9-... Magnetic material, 12.21... Magnetic sensor, 18.22-... Inside@
Iron core, 13', 13''--Protrusion, 14--Voltage coil, 15--Detection coil, 16... External iron core, 17
...Exciting coil, 18...m width meter, 1s...voltage needle, 20...-ammeter, 23...-stress measuring device, 24
... Iron loss measurement section, 25 ... Stress calculation section, 26 ...
Indicator section, 27... Initial value setter, 28... Proportional constant setter, 29... Stress calculator. 30...Indicator switch, 31...-Indicator needle. Patent applicant Shibaura Seisakusho Co., Ltd.

Claims (1)

[Claims] (Re) An inner core and an outer core are provided so that magnetic flux flows within the magnetic material, a voltage coil and a detection coil are provided in the inner core, and an excitation filter is provided in the outer core, When an AC voltage is applied to the voltage fill, a current is applied to the excitation coil, and the magnetic flux passes through the #1itEi material from the outer core to the inner core [dL], and an AC voltage is applied to the voltage coil. The flux flowing through the inner iron core generated in the above is canceled out, and the magnetic flux of the detection coil section becomes S: zero, and from the product of the 1 voltage of the voltage coil and the current of the excitation coil at that time, The iron loss mj/ze method is characterized by determining the iron loss of materials with predistribution characteristics. Place tL on the surface of the material, apply an alternating voltage to the voltage fill, and amplify the voltage exceeded by the coil by the bundle 6a flowing within the inner core and the negative material.
Increase by. −] is applied to the excitation coil in a direction to cancel the voltage induced in the detection coil, and the outside 94! The magnetic flux flowing through the magnetic material and the inner iron core, which occurs when an alternating current voltage is applied to the voltage fill, cancels out the magnetic flux flowing through the iron core, causing the spinning The voltage of the voltage coil at that time and the iron loss W*'t from the side of the excitation filter device are adjusted so that the voltage of the detection coil becomes zero.
A power needle for calculating t, an initial power setting device for setting the iron loss WO'4 of the magnetic material when no stress is applied, and a ratio fIJ constant a for converting the measured iron loss of the magnetic material into stress.
The stress acting on the magnetic material is calculated by inputting Wi, W@, and - respectively from the proportional tm setting device for setting, the front electromotive force needle, and the initial 11 set value proportional voltage setting device. A stress measuring device comprising: a stress calculator; and an instruction section that instructs the output of the power needle or the output of the stress calculator.