JP2011027475A - Magnetic measurement sensor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a magnetic measurement sensor that can obtain accurate magnetic characteristics, without separating an insulating cover of an electromagnetic steel plate, reduces the size of coil, and improves the measurement accuracy. <P>SOLUTION: The magnetic measurement sensor includes a sensor base, four probes and two coils. The sensor base includes four holes. Springs are housed in the holes. The base end sections of the probes are inserted into the holes housing the springs. Spiral grooves are formed on inner peripheral surfaces of the holes. Screws are formed on the outer peripheral surfaces of the base end sections of the probes so that the screws are threadedly engaged with the spiral grooves. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to a magnetic measurement sensor used for obtaining magnetic characteristics in a two-dimensional plane of a plate-shaped magnetic body.

In order to save energy, increasing the energy efficiency of electrical equipment is being studied. As a means for achieving high energy efficiency of this electrical equipment, it is necessary to reduce the magnetic loss of the electrical steel sheet used for the iron core material such as an electric motor and a transformer. For this purpose, it is necessary to accurately grasp the local magnetic characteristics of the electrical steel sheet.
In order to measure this local magnetic characteristic, a magnetic sensor using a two-dimensional vector magnetic characteristic is used.
As shown in Non-Patent Document 1, the conventional magnetic measurement sensor includes two sets of probes for measuring the magnetic flux density in the X direction and the Y direction, and a coil in each direction for measuring the magnetic field strength. Have. Each of these probes has a spring and reliably contacts the sample by applying pressure.

Gion, Fujiyama, Yodogawa "Local two-dimensional magnetic property distribution of a three-phase induction motor model core" IEICE Transactions, Vol.119, No.11, 1336-1341

However, according to the invention described in Non-Patent Document 1, the magnetic steel sheet is provided with an insulating coating, and an ordinary probe cannot penetrate the insulating coating. Therefore, it was necessary to peel off the insulation coating when measuring with a conventional magnetic sensor.
Furthermore, the coils used in conventional magnetic measurement sensors are large in size. However, in order to obtain sufficient sensitivity, it has been difficult to downsize the coil, that is, downsize the magnetic measurement sensor.

  Therefore, an object of the present invention is to provide a magnetic measurement sensor with improved measurement accuracy. It is another object of the present invention to provide a magnetic measurement sensor that can obtain accurate magnetic characteristics without peeling off the insulation coating of the electromagnetic steel sheet and achieves downsizing of the coil.

  According to the first aspect of the present invention, there are provided a sensor base, four probes protruding from the tip of the sensor base with the same length so that each probe is positioned at the apex of the quadrilateral, and a tip plane of the sensor base. And two coils held so that the angle formed by each winding direction is 90 degrees, and two sets of probes located at diagonal positions are used as one set of measurement units. A measuring unit is configured, and the two probes of each measuring unit are connected to one end of two wires at the tip plane of the sensor base, respectively, and the other end of these wires is connected to the voltage detecting unit. A measurement sensor, wherein four holes are provided in the tip plane of the sensor base, springs are respectively stored in these holes, and base ends of the probes are respectively inserted into the holes. Is biased by the spring so that it protrudes from the hole In addition, a magnetic measurement sensor in which a spiral groove is formed on the inner peripheral surface of the hole and a screw is formed on the outer peripheral surface of the proximal end portion of the probe so as to be screwed into the spiral groove. is there.

According to the first aspect of the present invention, there are two coils held so that the angle formed by each winding direction is 90 degrees. For this reason, the magnetic field in the X direction and the Y direction of the electrical steel sheet can be detected.
This magnetic measurement sensor has four probes. These probes protrude with the same length so as to be located at the apex of the quadrangle. Two sets of measuring units are configured by using two probes at diagonal positions as one set of measuring units. By comprising in this way, the magnetic flux density in the X direction and the Y direction of a magnetic steel plate, and a magnetic field strength can be measured.
In measuring this magnetic flux density, the present invention is connected to a position close to the tip of the probe, that is, the tip plane of the sensor base. For this reason, a measurement error can be made smaller than before by measuring from a position near the electromagnetic steel sheet.
In addition, spiral grooves are formed in the four holes formed in the sensor base. A screw is formed on the outer peripheral surface of the proximal end portion of the probe so as to be screwed into the spiral groove. A probe is inserted into this hole. For this reason, when the probe is pressed, the probe is rotated by the spiral groove and screw. When the probe rotates, the probe can penetrate the insulating coating and contact with the magnetic steel sheet by the lever principle.
A spring is housed in the hole. For this reason, when the pressing is released, the probe rotates backward, and the probe is returned to the state before the pressing.

にて求めることができる。 The probe is provided to obtain the magnetic flux density in the electromagnetic steel sheet. A probe is brought into contact with a conductive plate-like magnetic steel plate. Thereafter, the magnetic steel sheet is AC-excited. At this time, an eddy current is generated in the steel plate. By measuring this eddy current, the magnetic flux density can be calculated.
The coil is provided to obtain the magnetic field strength in the electromagnetic steel sheet. When the magnetic steel sheet is AC-excited, it is induced from the magnetic field on the surface of the magnetic steel sheet, and electricity flows through the coil. By measuring the voltage, the magnetic field strength can be calculated.
In the case of the cross-sectional area Sc of the lead wire, the electric voltage Vc flowing through the coil having N turns, the cross-sectional area Sp [m ² ] of the probe, and the potential difference Vp [V] between the probes, the magnetic flux density B and the magnetic field between the probes Strength H is

It can ask for.

  According to a second aspect of the present invention, there is provided a flexible substrate on the front end plane of the sensor base, and a conductive pattern for electrically connecting the probe and the voltage detecting portion is formed on the flexible substrate. 1. The magnetic measurement sensor according to 1.

  As the material of the flexible substrate, phenol, epoxy, polyimide, polystyrene, or the like can be used. Preferred are polyimide and polystyrene. These materials have low dielectric loss and can reduce the influence of noise caused by the substrate.

  A third aspect of the present invention is the magnetic measurement sensor according to the first or second aspect, wherein the two coils are formed of enameled wires having an outer diameter of 0.03 mm or less.

  According to invention of Claim 3, the outer diameter of the enamel wire which the said coil uses is 0.03 mm or less, and uses a very fine wire. For this reason, even if the number of turns of the coil increases, the coil does not increase in size, and as a result, the magnetic measurement sensor can be reduced in size.

  According to the magnetic measurement sensor of the present invention, the measurement accuracy can be improved. In addition, accurate magnetic characteristics can be obtained without peeling off the insulation coating of the electromagnetic steel sheet, and the coil can be miniaturized.

It is a disassembled perspective view of the magnetic measurement sensor which concerns on the Example of this invention. It is a longitudinal cross-sectional view of the magnetic measurement sensor which concerns on the Example of this invention. It is a left view of the magnetic measurement sensor which concerns on the Example of this invention. It is an enlarged view of the longitudinal cross-section of the magnetic measurement sensor which concerns on the Example of this invention. It is explanatory drawing which shows the relationship between the probe in the front-end | tip part of the magnetic measurement sensor which concerns on the Example of this invention, and a flexible substrate.

As shown in FIG. 1, the magnetic measurement sensor 10 according to the embodiment of the present invention is provided with a flexible substrate 14 on a sub base 12 fitted in a main base 11. A coil base 15 is provided on the sub-base 12, and a coil 16 is attached to the coil base 15.
Four probe insertion holes 13a, 13b, 13c, and 13d are provided in the four probe insertion holes formed in the main base 11 and the sub base 12 so as to protrude by the same length.

The main base 11 is a rectangular parallelepiped member made of plastic. The front end of the main base 11 is formed with a quadrangular recess 11a in plan view, and four probe insertion holes 11b are formed in the peripheral portion of the recess 11a. A spiral groove is formed on the inner wall of the probe insertion hole 11b. A spring 11d is accommodated in the probe insertion hole 11b.
Moreover, the 1st cable penetration through-hole 11c is formed in the center part of this recessed part.

The sub-base 12 is a substantially rectangular parallelepiped member made of plastic. A second cable insertion through hole 12c is formed at the center of the sub-base 12. A probe insertion through hole 12b is formed at a position overlapping the probe insertion hole 11b.
The sub-base 12 is formed approximately equal to the size of the recess 11a.
The sub base 12 is fitted into the recess 11a. When the sub-base 12 is fitted into the recess, the first cable insertion through hole 11c and the second cable insertion through hole 12c are provided at overlapping positions. It becomes a through hole. And since the said probe insertion through-hole 12b and the said probe insertion hole 11b are provided in the position which overlaps, the four probe insertion hole parts are formed.

The probes 13a, 13b, 13c, and 13d are formed of four metal rods having the same length. These probes 13a, 13b, 13c, and a3d are provided so as to be positioned at the apexes of a quadrangle whose diagonal is 90 degrees. These probes 13a, 13b, 13c, and 13d are inserted into the probe insertion holes, respectively.
Screws are formed on the outer peripheral surfaces of the probes 13a, 13b, 13c, and 13d. This screw is screwed into a spiral groove formed on the inner wall of the probe insertion hole 11b. For this reason, when the main base 11 is pressed, the screws formed in the probes 13a, 13b, 13c, and 13d and the grooves formed in the probe insertion hole 11b are screwed together, whereby the probes 13a, 13b, 13c, and 13d rotate.
One of the probes 13a and the probe 13b that exists diagonally with respect to the probe 13a are used as a set as one measuring unit 13A. The remaining probes 13c and 13d are used as the other measurement unit 13B. That is, one measurement unit 13A is used as a measurement unit that measures magnetic characteristics in the horizontal direction (X direction) of the electrical steel sheet that is the measurement target, and the other measurement unit 13B is used in the longitudinal direction (Y direction) of the electrical steel sheet. It is used as a measuring unit that measures the magnetic characteristics of

The flexible substrate 14 is a substrate in which four wirings are formed by etching or metal plating the copper foil on the surface of a copper-clad plate obtained by bonding a copper foil to a polyimide film. These wirings constitute two sets of wiring sections 14c and 14d by forming two sets of wiring sections 14c and 14d. One end of the wiring of one wiring part 14c is connected to the probes 13a and 13b constituting one measuring part 13A. Specifically, the flexible substrate 14 has four holes provided so as to be located at the vertices of a quadrangle whose diagonal is 90 degrees, and the probes 13a and 13b are provided in these holes. Each is inserted. The probe and the wiring are connected with solder at a position where the probes 13a and 13b are in contact with one end of the wiring. Similarly, one end of the wiring of the other wiring portion 14d is connected to the probes 13c and 13d constituting the one measuring portion 13B.
The other end of the wiring of the one wiring portion 14c is connected to a voltmeter (not shown).

  The coil 16 is formed by winding a 0.03 mm lead wire on the outer peripheral surface of a square ceramic plate in plan view. The coil 16 includes a Hx coil 16a wound in a square horizontal direction and a Hy coil 16b wound in a square vertical direction. That is, the angle formed by the winding direction of the Hx coil 16a and the winding direction of the Hy coil 16b is 90 °. As the number of turns of the lead wire between the Hx coil 16a and the Hy coil 16b increases, the error in magnetic characteristics can be reduced.

The magnetic measurement sensor 10 composed of the above members is assembled as follows.
First, the sub base 12 is fitted into the recess 11 a of the main base 11. Thereafter, the probes 13a, 13b, 13c, and 13d are inserted into the four probe insertion holes formed by the main base 11 and the sub base 12, respectively. Thereafter, the probes 13 a, 13 b, 13 c and 13 d are inserted into the holes formed in the flexible substrate 14 and brought into contact with the sub-base 12. It fixes to the location where the end of the wiring formed in the flexible substrate 14, and the probe 13a, 13b, 13c, 13d contact. The other end of the wiring is connected to a voltmeter provided outside using a cable insertion through hole formed in the main base 11 and the sub base 12.
Thereafter, the coil base 15 is attached to the sub base 12, and the coil 16 is attached to the coil base 15. The lead wire of the coil 16 passes through the cable insertion through hole and is connected to a voltmeter (not shown).

A method for performing magnetic measurement of an electromagnetic steel sheet using the magnetic sensor 10 will be described.
First, alternating current excitation is applied to an electromagnetic steel sheet with an insulating coating. Next, the probes 13a, 13b, 13c, and 13d are brought into contact with the surface of the electromagnetic steel sheet. Thereafter, the magnetic measurement sensor 10 is pressed. At this time, the probes 13a, 13b, 13c, and 13d rotate and penetrate the insulating coating. The probes 13a, 13b, 13c, and 13d are in contact with the conductive portions of the electromagnetic steel sheet.
An eddy current and a magnetic field are generated on the surface of an electromagnetic steel plate excited by alternating current. When the magnetic steel sheet is brought into contact with the probes 13a, 13b, 13c, 13d, electricity due to eddy current flows between the probes. The electricity voltage is measured with a voltmeter. At the same time, electricity flows through the coil due to the magnetic field on the surface. The electricity voltage is measured with a voltmeter. By calculating the voltage measured by these voltmeters using an arithmetic device (not shown), the magnetic flux density and magnetic field strength between the probes 13a, 13b, 13c, and 13d of the electromagnetic steel sheet can be obtained.

10 Magnetic measurement sensor,
11 Main base,
12 Subbase,
13a, 13b, 13c, 13d
14 Flexible substrate,
16 Coil.

Claims (3)

A sensor base,
Four probes protruding at the same length from the tip of the sensor base so that each probe is positioned at the apex of a rectangle;
Two coils held so that the angle formed by each winding direction is 90 degrees on the tip plane of the sensor base,
Two sets of measuring units are configured by using two probes located at diagonal positions as one set of measuring units.
The two probes of each measurement unit are connected to one end of two wires at the tip plane of the sensor base, respectively, and the other ends of these wires are respectively magnetic measurement sensors connected to the voltage detection unit,
Four holes are provided in the tip plane of the sensor base, and springs are respectively stored in these holes.
The proximal ends of the probes are respectively inserted into the holes, and the probes are biased by the springs so as to protrude from the holes,
A spiral groove is formed on the inner peripheral surface of the hole,
A magnetic measurement sensor in which a screw is formed on the outer peripheral surface of the proximal end portion of the probe so as to be screwed into the spiral groove. A flexible substrate is provided on the tip plane of the sensor base,
The magnetic measurement sensor according to claim 1, wherein a conductive pattern for electrically connecting the probe and the voltage detection unit is formed on the flexible substrate.   The magnetic measurement sensor according to claim 1 or 2, wherein the two coils are made of enameled wires having an outer diameter of 0.03 mm or less.

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