Magnetic gathering type double-shaft fluxgate sensor probe

Abstract

The invention discloses a magnetism gathering type double-shaft fluxgate sensor probe, which comprises a magnetic core, an excitation coil, a detection coil and a detection coil skeleton, the magnetic core is square and is formed by processing a magnetic conductive sheet, four corners of the square protrude outwards to form ear shapes, the excitation coil is wound on the magnetic core, and the detection coil skeleton is wound on the detection coil. A groove matched with the magnetic core in shape is machined in one side of the detection coil framework, the magnetic core wound with the excitation coil is installed in the groove, the detection coils of the two shafts are perpendicularly wound in the middle of the detection coil framework, and the magnetic core and the detection coil framework are concentrically arranged. According to the double-shaft fluxgate probe, the magnetic measurement sensitivity and precision of the double-shaft fluxgate probe can be effectively improved, the complexity of winding and assembling is reduced, the two shafts are ensured to be perpendicular to each other, the consistency of the measuring shaft and the mounting shaft is ensured, and the reliability of a double-shaft fluxgate sensor is improved.

Description

Technical Field

[0001] The invention relates to the technical field of fluxgate magnetic field detection, and in particular to a magnetic field focusing type dual-axis fluxgate sensor probe. Background Art

[0002] The fluxgate is a magnetic field component sensor with excellent comprehensive performance. When measuring a planar magnetic field, two single-axis fluxgates need to be installed perpendicularly to each other to form a dual-axis fluxgate sensor. How to ensure that the two fluxgate sensors are perpendicular to each other, make the fluxgate easy to process and wind, and improve its accuracy, sensitivity, reliability, and maintainability are key technical issues that need to be solved by the dual-axis fluxgate. Summary of the invention

[0003] The object of the present invention is to provide a magnetic field-concentrating dual-axis fluxgate sensor probe which can improve magnetic measurement sensitivity and reliability and is convenient for winding in view of the deficiencies in the prior art.

[0004] The objective of the present invention is achieved through the following technical solutions:

[0005] A magnetic concentrating dual-axis fluxgate sensor probe comprises a magnetic core, an excitation coil, a detection coil and a detection coil frame. The excitation coil is wound on the magnetic core, and the detection coil is wound on the detection coil frame. The magnetic core is square and is formed by a magnetic conductive sheet. The four corners of the square protrude outward to form an ear shape. A groove matching the shape of the magnetic core is processed on one side of the detection coil frame. The magnetic core wound with the excitation coil is installed in the groove. The detection coils of the two axes are wound perpendicularly to each other in the middle part of the detection coil frame, and the magnetic core and the detection coil frame are placed concentrically.

[0006] Furthermore, the dumbbell-shaped magnetic core is formed by stacking a plurality of magnetic conductive sheets with the same thickness and size.

[0007] Furthermore, the pickup coil frame is in a square ring shape, the four corners of the square ring are rectangular bodies, and the detection coil is wound around the outside of the elongated portion between the two rectangular bodies on the detection coil frame.

[0008] Furthermore, threaded holes are processed on four rectangular bodies at the corners of the detection coil frame for fixing the detection coil frame with the magnetic core.

[0009] Furthermore, the material of the magnetic core is Permalloy or amorphous soft magnetic material.

[0010] Compared with the prior art, the present invention has the following effects:

[0011] (1) Since the size of the magnetic core of the fluxgate probe of the present invention is widened at the corner of the square, the magnetic flux change value at the detection coil can be increased under the premise that the size of the detection coil is determined, thereby improving the sensitivity and accuracy of the fluxgate sensor.

[0012] (2) The fluxgate probe of the present invention uses a single magnetic core to measure magnetic field components in two different directions, and the dual-axis detection coils are wound perpendicularly on the same magnetic core, which can ensure that the measuring axis is consistent with the installation axis, and the winding and assembly are convenient, thereby improving the reliability of the fluxgate dual-axis sensor measurement.

[0013] (3) The fluxgate probe of the present invention has a simple structure and is easy to manufacture, install and maintain. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a structural schematic diagram of the dual-axis fluxgate probe of the present invention;

[0015] Figure 2 It is a schematic structural diagram of the magnetic core of the dual-axis fluxgate probe of the present invention;

[0016] Figure 3 for Figure 2 The schematic diagram of the structure after the magnetic core is wound with the excitation coil;

[0017] Figure 4 It is a schematic structural diagram of the detection coil skeleton of the dual-axis fluxgate probe of the present invention;

[0018] Figure 5 Schematic diagram of the cross section selected to detect the change in magnetic flux in the coil.

[0019] Figure 6 It is a schematic diagram of the induced electromotive force in the detection coil of the ear-shaped magnetic core and the ring-shaped magnetic core of the present invention, wherein the four figures from top to bottom respectively represent the excitation voltage and excitation current, magnetic permeability, ear-shaped magnetic core pickup, and ring-shaped magnetic core pickup.

[0020] Markings in the figure: 1, magnetic core; 2, excitation coil; 3, detection coil; 4, detection coil skeleton; 41, groove; 42, threaded hole. DETAILED DESCRIPTION

[0021] like Figure 1-Figure 5As shown, the magnetic concentrating dual-axis fluxgate sensor probe provided in this embodiment includes a magnetic core 1, an excitation coil 2, a detection coil 3 and a detection coil skeleton 4. The magnetic core 1 is square, and the four corners of the square protrude outward to form an ear shape. The magnetic core 1 of the present invention is a deformed design based on a ring-shaped magnetic core, and the purpose is to increase the magnetic concentrating effect of the magnetic core 1. In this embodiment, the magnetic core 1 is made of multiple Permalloy magnetic conductive sheets, and the thickness and size of each magnetic conductive sheet are the same. Multiple turns of the excitation coil 2 are wound around the entire magnetic core 1 to form a closed magnetic circuit. One side of the detection coil skeleton 4 is processed with a groove 41 that matches the shape of the magnetic core 1, and the magnetic core 1 with the excitation coil 2 is installed in the groove 41. The shape of the detection coil skeleton 4 corresponds to the shape of the magnetic core 1, and is a square ring. The four corners of the square ring are rectangular bodies, and the rectangular body is processed with threaded holes 42 for fixing the detection coil skeleton 4. The detection coils 3 of the two axes are perpendicular to each other and are wound on the outside of the elongated part between the two rectangular bodies on the detection coil skeleton 4. The magnetic core 1 and the detection coil skeleton 4 are placed concentrically.

[0022] The shape of the magnetic core 1 of the present invention has a greater magnetic flux change at the detection coil than the annular magnetic core of the same size. According to Faraday's law of electromagnetic induction, the flux gate of the magnetic core has a higher sensitivity. A uniform external environmental magnetic field of B=5000nT along the Z axis is created in the simulation software, and the magnitude of the magnetic flux change at the Z axis detection coil when the magnetic core of the present invention and the annular magnetic core switch from the magnetic conduction state to the magnetic saturation state is calculated respectively. The cross section of the selected detection coil is as follows: Figure 5 As shown in the figure, the results show that the detla*le-6 value of the annular magnetic core is 4.69, and the detla*le-6 value of the magnetic core of the present invention is 6.77, which proves that the magnetic core of the present invention can make the magnetic flux change value larger. In addition, the above two magnetic cores were tested to observe the induced electromotive force pulse amplitude in the detection coil of the two magnetic cores, as shown in FIG. Figure 6 As shown, the results show that under the same external excitation and magnetic field environment, the amplitude and width of the induced electromotive force in the detection coil of the annular magnetic core are smaller than the amplitude and width of the induced electromotive force in the detection coil of the magnetic core of the present invention, which is consistent with the simulation results analysis.

[0023] The present invention measures the magnetic field components in two different directions by winding mutually orthogonal detection coils 3 in the vertical direction of the magnetic core 1. The two independent detection coil channels correspond to different axes respectively, which can realize accurate measurement of the magnetic field in a specific direction. It can not only reduce the complexity of winding and assembly, but also ensure the mutual perpendicularity between the two axes and the consistency of the measuring axis and the installation axis, thereby improving the reliability of the dual-axis fluxgate sensor.

[0024] The working principle and working process of the present invention are as follows: the sensor probe of the present invention is placed in the magnetic field environment to be detected, and the excitation coil 2 is excited by a square wave voltage of a certain frequency, so that the magnetic permeability of the magnetic core 1 is periodically changed between the two states of magnetic conduction and magnetic saturation. In the magnetic conduction state, the magnetic permeability of the magnetic core 1 is relatively high, the magnetic lines of force gather at the magnetic core 1, and the magnetic induction intensity in the detection coil 3 becomes stronger; in the magnetic saturation state, the magnetic permeability of the magnetic core 1 is close to the magnetic permeability of the air, the magnetic lines of force spread from the magnetic core 1, and the magnetic induction intensity in the detection coil 3 becomes weaker. In one excitation cycle of the square wave voltage, the magnetic induction intensity in the detection coil 3 changes four times, so that the detection coil 3 generates four induction pulses (pickup1, pickup2, pickup3, pickup4), the amplitudes of the four induction pulses depend on the environmental magnetic field, and the components of the external magnetic field in two axial directions can be obtained by measuring and processing the induced electromotive force in the detection coil 3.

[0025] The above description is only a preferred implementation manner of the present invention, but the protection scope of the present invention is not limited thereto, and any modification and replacement based on the technical solution and inventive concept provided by the present invention should be included in the protection scope of the present invention.

Claims

1. A magnetic field-concentrating dual-axis fluxgate sensor probe, comprising a magnetic core (1), an excitation coil (2), a detection coil (3) and a detection coil skeleton (4), wherein the excitation coil (2) is wound on the magnetic core (1), and the detection coil (3) is wound on the detection coil skeleton (4), characterized in that: The magnetic core (1) is square and is formed by processing a magnetic conductive sheet. The four corners of the square protrude outward to form an ear shape. A groove (41) matching the shape of the magnetic core (1) is processed on one side of the detection coil skeleton (4). The magnetic core (1) wound with the excitation coil (2) is installed in the groove (41). The detection coils (3) of the two axes are wound perpendicularly to each other in the middle part of the detection coil skeleton (4). The magnetic core (1) and the detection coil skeleton (4) are placed concentrically.

2. The magnetic field-concentrating dual-axis fluxgate sensor probe according to claim 1, characterized in that: The magnetic core (1) is formed by stacking a plurality of magnetic conductive sheets of the same thickness and size.

3. The magnetic field-concentrating dual-axis fluxgate sensor probe according to claim 1, characterized in that: The detection coil frame (4) is in the shape of a square ring, the four corners of the square ring are rectangular bodies, and the detection coil (3) is wound around the outside of the elongated part between the two rectangular bodies on the detection coil frame (4).

4. The magnetic field-concentrating dual-axis fluxgate sensor probe according to claim 3, characterized in that: Threaded holes (42) are processed on four rectangular bodies at the corners of the detection coil frame (4) and are used to fix the detection coil frame (4) on which the magnetic core (1) is installed.

5. The magnetic field-concentrating dual-axis fluxgate sensor probe according to claim 1, characterized in that: The material of the magnetic core (1) is Permalloy or amorphous soft magnetic material.

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