A method for testing the orientation direction of magnetic materials

Abstract

The invention discloses a method for testing the orientation direction of a magnetic material. A moving plane is pre-arranged and X, Y, and Z axes are set. Two energized coils under the same setting conditions are arranged with the X axis as the central axis. The testing method includes: step one, taking the magnetic material to be tested and determining the optimal magnetization direction under the setting; step two, placing the magnetic material to be tested on the moving plane so that the optimal magnetization direction under the setting is placed along the X axis, the Y axis, or the Z axis; step three, making the magnetic material to be tested pass through two energized coils in sequence along the X axis, after passing through the first energized coil, rotate 90°, and then pass through the second energized coil; step four, recording the induction data U1 and U2 when the magnetic material to be tested passes through the two energized coils in sequence; step five, judging whether the orientation of the magnetic material to be tested is correct or not by the values ​​of U1 and U2. The invention has the advantages of simple and easy detection process, low detection equipment cost, and high detection accuracy.

Description

Technical Field

[0001] The invention relates to the technical field of magnetic materials, in particular to a method for testing the orientation direction of a magnetic material. Background Art

[0002] In the manufacture of NdFeB magnets, anisotropic magnetic materials are obtained after multiple processes. The magnetic materials are non-magnetic after manufacture. Only in the final packaging and shipment stage are they magnetized or not magnetized according to customer requirements. For anisotropic magnetic materials, their magnetization direction (i.e. magnetic field orientation direction) is the key characteristic of the product. Only magnetization along the magnetization direction can maximize the performance of the magnetized magnet. In other words, if the magnetization direction of the magnetic material is wrong, it will directly lead to unqualified magnet products.

[0003] Generally speaking, the best magnetization direction of magnetic materials is set before manufacturing, which depends on the shape and size of the product. For example, for cylindrical magnetic materials, the best magnetization direction is generally set along the axis of the cylinder. For another example, for sheet magnetic materials with a rectangular cross-section, the best magnetization direction is generally set to be perpendicular to the rectangular sheet surface. In addition, some magnetic materials whose best magnetization direction cannot be determined from the appearance will generally have the magnetization direction marked on the material so that customers can directly magnetize it after purchasing.

[0004] However, in the mass production process of magnetic materials, the actual optimal magnetization direction of some products will deviate from the set optimal magnetization direction. Take rectangular sheet magnetic materials as an example. The set magnetization direction is perpendicular to the rectangular sheet surface, but due to processing errors, the actual optimal magnetization direction may be parallel to the rectangular sheet surface. If the error is not detected before leaving the factory, the customer will magnetize along the set optimal magnetization direction after purchase, and the final magnetic steel product will be unqualified.

[0005] Therefore, for anisotropic magnetic materials, it is very important to detect their orientation before leaving the factory to avoid products with wrong magnetization directions entering the market and causing losses.

[0006] At present, there are many methods for testing the orientation of magnetic materials. The most primitive method is to use magnetic tooling to adsorb and detect it. This method easily makes the magnetic material magnetic and has been gradually eliminated. In addition, there is a method for testing the orientation of magnetic materials, such as patent publication number CN111025208 A. This patent uses the difference in thermal diffusion rate to detect the orientation of magnetic materials. Although the effect is good, the determination method is relatively complicated and the equipment cost is relatively high. Another example is a method for detecting the magnetization direction of unmagnetized anisotropic magnetic steel disclosed in patent publication number CN104020425 A. This patent uses an eddy current detector to detect reactance and resistance, selects one piece with correct and incorrect magnetization directions, and makes an impedance plane drawing ellipse of the magnetic steel. The subsequent detection is based on whether it falls into the ellipse to determine whether it is qualified. The judgment is also relatively complicated. Another example is the magnetic material orientation detection device disclosed in patent numbers CN203909257U and CN204255399U. By setting a powered transmitting coil and a non-powered receiving coil, the product passes through the two coils and uses the principle of electromagnetic induction to determine the orientation of the magnetic material. There is also a risk of magnetizing the magnetic material, and the detection accuracy is not high. Since the induced current in the receiving coil is generated by the magnetic material cutting the magnetic flux lines, the requirements for the placement of the magnetic material are extremely high, and there will be large errors in measuring the induced current value alone. In addition, there are testing methods such as magnets, eddy current sensors, and eddy current coils, but these methods are easy to magnetize the magnetic material, are complicated to operate, and are time-consuming.

[0007] Therefore, there is an urgent need to develop a simple and easy method to test the orientation direction of magnetic materials to improve the defects in the current testing methods. Summary of the invention

[0008] The purpose of the present invention is to provide a method for testing the orientation direction of a magnetic material, which has the advantages of simple and easy detection process, low detection equipment cost and high detection accuracy.

[0009] The technical solution of the present invention is a method for testing the orientation direction of a magnetic material. A motion plane is pre-arranged, an X-axis and a Y-axis perpendicular to each other are set on the motion plane, the direction perpendicular to the motion plane is set as the Z-axis, and two energized coils under the same setting conditions are coaxially arranged with the X-axis as the central axis. The testing method comprises the following steps:

[0010] Step 1: Take the magnetic material to be tested and determine the optimal magnetization direction set during its processing;

[0011] Step 2: Place the magnetic material to be tested on the moving plane so that the optimal magnetization direction is along the X-axis, Y-axis or Z-axis;

[0012] Step 3: Make the magnetic material to be tested pass through two energized coils in sequence along the X-axis. After passing through the first energized coil, the magnetic material to be tested rotates 90° about any straight line parallel to the Z-axis as the rotation axis, and then passes through the second energized coil;

[0013] Step 4: Record two sets of transient induction data U1 and U2 on each energized coil when the magnetic material to be tested passes through the two energized coils in sequence;

[0014] Step 5: Determine whether the optimal magnetization direction of the magnetic material to be tested is its actual optimal magnetization direction by using the values ​​of the two sets of sensing data U1 and U2.

[0015] When the optimal magnetization direction of the magnetic material to be tested in step 2 is placed along the X-axis, if the relationship between U1 and U2 satisfies U1>U2 and |U1-U2|>the first threshold, the optimal magnetization direction of the magnetic material to be tested is its actual optimal magnetization direction, and the product inspection is qualified;

[0016] When the optimal magnetization direction of the magnetic material to be tested in step 2 is placed along the Y axis, if the relationship between U1 and U2 satisfies U1<U2 and |U1-U2|>the second threshold, the optimal magnetization direction of the magnetic material to be tested is its actual optimal magnetization direction, and the product inspection is qualified;

[0017] When the optimal magnetization direction of the magnetic material to be tested in step 2 is placed along the Z axis, if the relationship between U1 and U2 satisfies |U1-U2|<the third threshold, the optimal magnetization direction of the magnetic material to be tested is its actual optimal magnetization direction, and the product inspection is qualified.

[0018] Compared with the prior art, the beneficial effects of the present invention are as follows: the present invention is based on the principle that when a magnetic material passes through an energized coil, the energized coil will generate a transient induction data. When the same magnetic material passes through the energized coil in different orientations, the transient induction data generated by the energized coil will also be different. Therefore, the present invention allows the magnetic material with three orientations to pass through two energized coils under the same conditions in sequence, and the magnetic material to be tested is rotated 90° after passing through the first energized coil, and then passes through the second energized coil, and two groups of induction data are obtained before and after. By calculating the initial placement position of the magnetic material to be tested and the two groups of induction data values, it is determined whether the optimal magnetization direction set during product processing is the actual optimal magnetization direction, thereby testing whether the product is qualified or not. The whole process is simple and easy to implement. The equipment used for detection is mainly two energized coils, and the overall investment cost is low. Moreover, only by comparing the two groups of induction data values ​​with each other and comparing the absolute value of the difference between the two groups of induction data values ​​with the threshold value, it is possible to detect whether the optimal orientation (optimal magnetization direction) of the three orientations of the magnetic material is correct. The overall accuracy of the detection is also high, and it is not easy to make mistakes.

[0019] In the aforementioned magnetic material orientation direction testing method, the magnetic material to be tested is in the shape of a rectangular parallelepiped. During the test, it is made to slide down an inclined plane, with the ideal magnetization direction placed along the X-axis, and one of the two side surfaces opposite to each other along the Z-axis direction is attached to the inclined plane. The magnetic material to be tested passes through two energized coils under the same set conditions in turn. After passing through the first energized coil, the side surface of the magnetic material to be tested is still kept attached to the inclined plane, and the magnetic material to be tested is rotated 90° along the center of the side surface, and then passes through the second energized coil to obtain induction data U1 and U2 respectively. If U1>U2 and |U1-U2|>the first threshold value, the product inspection is qualified; if U1≤U2 and / or |U1-U2|≤the first threshold value, the product inspection is unqualified.

[0020] In the aforementioned magnetic material orientation direction testing method, the magnetic material to be tested is in the shape of a rectangular parallelepiped. During the test, it is made to slide down an inclined plane, with the ideal magnetization direction placed along the Y-axis, and one of the two side surfaces opposite to each other along the Z-axis direction is attached to the inclined plane. The magnetic material to be tested passes through two energized coils under the same set conditions in turn. After passing through the first energized coil, the side surface of the magnetic material to be tested is still kept attached to the inclined plane, and the magnetic material to be tested is rotated 90° along the center of the side surface, and then passes through the second energized coil to obtain induction data U1 and U2 respectively. If U1<U2 and |U1-U2|>the second threshold value, the product inspection is qualified; if U1≥U2 and / or |U1-U2|≤the second threshold value, the product inspection is unqualified.

[0021] In the aforementioned magnetic material orientation direction testing method, the magnetic material to be tested is in the shape of a rectangular parallelepiped. During the test, it is made to slide down an inclined plane, and the ideal magnetization direction is placed along the Z axis, and one of the two side surfaces opposite to each other in the ideal magnetization direction is attached to the inclined plane. The magnetic material to be tested passes through two energized coils under the same setting conditions in turn. After passing through the first energized coil, the side surface of the magnetic material to be tested is still kept attached to the inclined plane, and the magnetic material to be tested is rotated 90° along the center of the side surface, and then passes through the second energized coil to obtain induction data U1 and U2 respectively. If |U1-U2|<the third threshold value, the product inspection is qualified; if |U1-U2|≥the third threshold value, the product inspection is unqualified.

[0022] In the aforementioned method for testing the orientation direction of magnetic materials, the induction data U1, U2 and the first threshold, the second threshold and the third threshold are induced voltage values. The first threshold, the second threshold and the third threshold are all values ​​obtained based on the comparison between qualified products and unqualified products. They need to be determined after testing multiple identical products in practice, and are related to factors such as the material, shape, size of the product, the parameters of the energized coil, and the speed at which the product passes through the energized coil.

[0023] In the aforementioned method for testing the orientation direction of a magnetic material, the circuit in which the two energized coils are located is a bridge circuit.

[0024] In the aforementioned method for testing the orientation direction of a magnetic material, a redirection mechanism for rotating the magnetic material to be tested is provided on the inclined plane between the two energized coils. The magnetic material to be tested slides down the inclined plane under the action of gravity, and when it slides to the location of the redirection mechanism, it is rotated 90° under the action of the redirection mechanism. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a structural schematic diagram of the device of the present invention;

[0026] Figure 2 yes Figure 1 A partial enlarged view of point A.

[0027] Figure numerals: 1 - inclined plane, 2 - slideway, 3 - first energized coil, 4 - second energized coil, 5 - tip. DETAILED DESCRIPTION

[0028] The present invention is further described below in conjunction with the accompanying drawings and embodiments, but they are not intended to limit the present invention.

[0029] Example 1: A method for testing the orientation direction of a magnetic material, wherein the structure of the detection device used is as follows: Figure 1 and Figure 2 As shown, it includes an inclined surface 1, a slideway 2 is arranged on the inclined surface 1, a first energized coil 3 and a second energized coil 4 are arranged on the periphery of the inclined surface 1, and a redirection mechanism is arranged on the side wall of the slideway 2. In this embodiment, the redirection mechanism is an outwardly protruding pointed head 5.

[0030] In this embodiment, the magnetic material to be tested is a square sheet of 40 mm*40 mm*3.5 mm, and the optimal magnetization direction set during processing is perpendicular to the plane of the square of 40 mm*40 mm.

[0031] The magnetic material orientation direction testing method includes the following steps:

[0032] Before the test, a motion plane, i.e., inclined plane 1, needs to be arranged in advance. On the motion plane, mutually perpendicular X-axis and Y-axis are set. The length direction of inclined plane 1 is X-axis, and the width direction of inclined plane 1 is Y-axis. The direction perpendicular to the motion plane (inclined plane 1) is set as Z-axis. Two energized coils under the same setting conditions are coaxially arranged with X-axis as the central axis, i.e., the first energized coil 3 and the second energized coil 4.

[0033] Step 1: Take the magnetic material to be tested and determine the optimal magnetization direction set during processing, that is, the direction perpendicular to the 40mm*40mm square plane;

[0034] Step 2: Based on the shape and size of the magnetic material to be tested, in order to enable the product to slide smoothly along the inclined plane 1, in this embodiment, the magnetic material to be tested is placed on the top of the inclined plane 1 so that the optimal magnetization direction is set along the Z-axis direction, that is, the 40mm*40mm square plane of the product is attached to the inclined plane 1;

[0035] Step 3: During the test, the magnetic material to be tested is made to slide down the slideway 2 on the inclined plane 1, and the magnetic material to be tested sequentially passes through the first energized coil 3 and the second energized coil 4 under the same setting conditions. After passing through the first energized coil 3, the magnetic material to be tested is still kept attached to the side of the slideway 2, and the magnetic material to be tested is rotated 90° along the center of the side, and then passes through the second energized coil 4;

[0036] The reason why the magnetic material to be tested rotates is that a pointed tip 5 for redirecting the magnetic material to be tested is provided on the side wall of the slideway 2 between the two energized coils. The magnetic material to be tested slides down the slideway 2 under the action of gravity, and after sliding to the position of the pointed tip 5, it hits the pointed tip 5 to achieve a 90° rotation.

[0037] Preferably, the circuit in which the two energized coils are located is a bridge circuit.

[0038] Step 4: Record two sets of transient induction data U1 and U2 on each energized coil when the magnetic material to be tested passes through the two energized coils in sequence;

[0039] Preferably, U1 and U2 are both induced voltage values.

[0040] Step 5: Subtract U1 from U2, and compare the absolute value of the difference with the third threshold.

[0041] If |U1-U2|<the third threshold, the optimal magnetization direction under setting is the actual optimal magnetization direction of the product, and the product is qualified;

[0042] If |U1-U2|≥the third threshold, the optimal magnetization direction set is not the actual optimal magnetization direction of the product, and the product test fails.

[0043] If the orientation direction of the product is correct, that is, the set optimal magnetization direction is its actual optimal magnetization direction, then the actual optimal magnetization direction of the product when passing through the two energized coils and the positional relationship between the energized coils will not change, and the induced voltage values ​​U1 and U2 should be close; if the orientation direction of the product is wrong, that is, the set optimal magnetization direction is not its actual optimal magnetization direction, then the actual optimal magnetization direction of the product when passing through the two energized coils and the positional relationship between the energized coils will change, and the induced voltage values ​​U1 and U2 will differ greatly.

[0044] Example 2: A method for testing the orientation direction of a magnetic material, the detection equipment used is the same as that of Example 1.

[0045] In this embodiment, the magnetic material to be tested is a rectangular sheet of 60 mm*40 mm*3.5 mm, and the optimal magnetization direction set during processing is parallel to the plane of the 60 mm*40 mm rectangle, specifically, along the direction of the long side.

[0046] The magnetic material orientation direction testing method includes the following steps:

[0047] Step 1: Take the magnetic material to be tested and determine the optimal magnetization direction set during its processing, that is, the direction parallel to the rectangular plane of 60mm*40mm and along the long side;

[0048] Step 2: Based on the shape and size of the magnetic material to be tested, in order to enable the product to slide smoothly along the inclined plane 1, in this embodiment, the magnetic material to be tested is placed on the top of the inclined plane 1 so that the optimal magnetization direction is set along the X-axis direction, that is, the rectangular plane of the product with a size of 60 mm*40 mm is attached to the inclined plane 1, and the long side is along the X-axis direction;

[0049] Step 3: During the test, the magnetic material to be tested is made to slide down the slideway 2 on the inclined plane 1, and the magnetic material to be tested sequentially passes through the first energized coil 3 and the second energized coil 4 under the same setting conditions. After passing through the first energized coil 3, the magnetic material to be tested is still kept attached to the side of the slideway 2, and the magnetic material to be tested is rotated 90° along the center of the side, and then passes through the second energized coil 4;

[0050] Step 4: Record two sets of transient induction data U1 and U2 on each energized coil when the magnetic material to be tested passes through the two energized coils in sequence;

[0051] Preferably, U1 and U2 are both induced voltage values.

[0052] Step 5: Compare U1 and U2, and then compare the absolute value of the difference between U1 and U2 with the second threshold.

[0053] If U1>U2 and |U1-U2|>first threshold, the optimal magnetization direction under setting is the actual optimal magnetization direction of the product, and the product is qualified;

[0054] If U1≤U2 and / or |U1-U2|≤the first threshold, the optimal magnetization direction under setting is not the actual optimal magnetization direction of the product, and the product inspection fails.

[0055] If the orientation direction of the product is correct, that is, the set optimal magnetization direction is its actual optimal magnetization direction, then when the product passes through the first energized coil 3, the actual optimal magnetization direction is consistent with the movement direction. At this time, the induced voltage value U1 is larger. When it rotates 90° and passes through the second energized coil 4, the induced voltage value U2 is smaller.

[0056] Example 3: A method for testing the orientation direction of a magnetic material, the detection equipment used is the same as that of Example 1.

[0057] In this embodiment, the magnetic material to be tested is a rectangular sheet of 60 mm*40 mm*3.5 mm, and the optimal magnetization direction set during processing is parallel to the plane of the 60 mm*40 mm rectangle, specifically, along the direction of the short side.

[0058] The magnetic material orientation direction testing method includes the following steps:

[0059] Step 1: Take the magnetic material to be tested and determine the optimal magnetization direction set during its processing, that is, the direction parallel to the 60mm*40mm rectangular plane and along the short side;

[0060] Step 2: Based on the shape and size of the magnetic material to be tested, in order to enable the product to slide smoothly along the inclined plane 1, in this embodiment, the magnetic material to be tested is placed on the top of the inclined plane 1 so that the optimal magnetization direction is set along the Y-axis direction, that is, the rectangular plane of the product with a size of 60 mm*40 mm is attached to the inclined plane 1, and the short side is along the Y-axis direction;

[0061] Step 3: During the test, the magnetic material to be tested is made to slide down the slideway 2 on the inclined plane 1, and the magnetic material to be tested sequentially passes through the first energized coil 3 and the second energized coil 4 under the same setting conditions. After passing through the first energized coil 3, the magnetic material to be tested is still kept attached to the side of the slideway 2, and the magnetic material to be tested is rotated 90° along the center of the side, and then passes through the second energized coil 4;

[0062] Step 4: Record two sets of transient induction data U1 and U2 on each energized coil when the magnetic material to be tested passes through the two energized coils in sequence;

[0063] Preferably, U1 and U2 are both induced voltage values.

[0064] Step 5: Compare U1 and U2, and then compare the absolute value of the difference between U1 and U2 with the second threshold.

[0065] If U1<U2 and |U1-U2|>the second threshold, the optimal magnetization direction under setting is the actual optimal magnetization direction of the product, and the product is qualified;

[0066] If U1≥U2 and / or |U1-U2|≤the second threshold, the optimal magnetization direction under setting is not the actual optimal magnetization direction of the product, and the product inspection fails.

[0067] If the orientation direction of the product is correct, that is, the set optimal magnetization direction is its actual optimal magnetization direction, then when the product passes through the first energized coil 3, the actual optimal magnetization direction is perpendicular to the movement direction, and the induced voltage value U1 is small at this time. When it rotates 90° and passes through the second energized coil 4, the actual optimal magnetization direction is consistent with the movement direction, and the induced voltage value U2 is large at this time.

[0068] The above are only preferred embodiments of the present invention, and the protection scope of the present invention is not limited to the above embodiments. All technical solutions under the concept of the present invention belong to the protection scope of the present invention. It should be pointed out that for ordinary technicians in this technical field, some improvements and modifications without departing from the principle of the present invention should also be regarded as the protection scope of the present invention.

Claims

1. A method for testing the orientation direction of a magnetic material, characterized in that: A motion plane is pre-arranged, an X-axis and a Y-axis perpendicular to each other are set on the motion plane, the direction perpendicular to the motion plane is set as the Z-axis, and two energized coils under the same setting conditions are coaxially arranged with the X-axis as the central axis. The test method includes the following steps: Step 1: Take the magnetic material to be tested and determine the optimal magnetization direction set during its processing; Step 2: Place the magnetic material to be tested on the moving plane so that the optimal magnetization direction is along the X-axis, Y-axis or Z-axis; Step 3: Make the magnetic material to be tested pass through two energized coils in sequence along the X-axis. After passing through the first energized coil, the magnetic material to be tested rotates 90° about any straight line parallel to the Z-axis as the rotation axis, and then passes through the second energized coil; Step 4: Record two sets of transient induction data U1 and U2 on each energized coil when the magnetic material to be tested passes through the two energized coils in sequence; Step 5: Determine whether the optimal magnetization direction of the magnetic material to be tested is its actual optimal magnetization direction by using the values ​​of the two sets of sensing data U1 and U2. When the optimal magnetization direction of the magnetic material to be tested in step 2 is placed along the X-axis, if the relationship between U1 and U2 satisfies U1>U2 and |U1-U2|>the first threshold, the optimal magnetization direction of the magnetic material to be tested is its actual optimal magnetization direction, and the product inspection is qualified; When the optimal magnetization direction of the magnetic material to be tested in step 2 is placed along the Y axis, if the relationship between U1 and U2 satisfies U1<U2 and |U1-U2|>the second threshold, the optimal magnetization direction of the magnetic material to be tested is its actual optimal magnetization direction, and the product inspection is qualified; When the optimal magnetization direction of the magnetic material to be tested in step 2 is placed along the Z axis, if the relationship between U1 and U2 satisfies |U1-U2|<the third threshold, the optimal magnetization direction of the magnetic material to be tested is its actual optimal magnetization direction, and the product inspection is qualified.

2. A method for testing the orientation direction of a magnetic material according to claim 1, characterized in that: The sensing data is an induced voltage value.

3. A method for testing the orientation direction of a magnetic material according to claim 1, characterized in that: The magnetic material to be tested is in the shape of a rectangular parallelepiped. During the test, it is made to slide down an inclined plane, with the ideal magnetization direction placed along the X-axis, and one of the two side surfaces opposite to each other along the Z-axis direction is attached to the inclined plane. The magnetic material to be tested passes through two energized coils under the same setting conditions in turn. After passing through the first energized coil, the side surface of the magnetic material to be tested is still kept attached to the inclined plane, and the magnetic material to be tested is rotated 90° along the center of the side surface, and then passes through the second energized coil to obtain induction data U1 and U2 respectively. If U1>U2 and |U1-U2|>the first threshold value, the product inspection is qualified; if U1≤U2 and / or |U1-U2|≤the first threshold value, the product inspection is unqualified.

4. A method for testing the orientation direction of a magnetic material according to claim 1, characterized in that: The magnetic material to be tested is in the shape of a cuboid. During the test, it is made to slide down an inclined plane, with the ideal magnetization direction placed along the Y-axis, and one of the two side surfaces opposite to each other along the Z-axis direction sticking to the inclined plane. The magnetic material to be tested passes through two energized coils under the same setting conditions in turn. After passing through the first energized coil, the side surface of the magnetic material to be tested is still kept sticking to the inclined plane, and the magnetic material to be tested is rotated 90° along the center of the side surface, and then passes through the second energized coil to obtain induction data U1 and U2 respectively. If U1<U2 and |U1-U2|>the second threshold value, the product inspection is qualified; if U1≥U2 and / or |U1-U2|≤the second threshold value, the product inspection is unqualified.

5. A method for testing the orientation direction of a magnetic material according to claim 1, characterized in that: The magnetic material to be tested is in the shape of a rectangular parallelepiped. During the test, it is made to slide down an inclined plane, with the ideal magnetization direction placed along the Z axis, and one of the two side surfaces opposite to each other in the ideal magnetization direction sticking to the inclined plane. The magnetic material to be tested passes through two energized coils under the same setting conditions in turn. After passing through the first energized coil, the side surface of the magnetic material to be tested is still kept sticking to the inclined plane, and the magnetic material to be tested is rotated 90° along the center of the side surface, and then passes through the second energized coil to obtain induction data U1 and U2 respectively. If |U1-U2|<the third threshold value, the product inspection is qualified; if |U1-U2|≥the third threshold value, the product inspection is unqualified.

6. A method for testing the orientation direction of a magnetic material according to any one of claims 1 to 5, characterized in that: The circuit in which the two energized coils are located is a bridge circuit.

7. A method for testing the orientation direction of a magnetic material according to claim 3, 4 or 5, characterized in that: A redirection mechanism for rotating the magnetic material to be tested is provided on the inclined plane between the two energized coils. The magnetic material to be tested slides down the inclined plane under the action of gravity, and when it slides to the location of the redirection mechanism, it is rotated 90° by the action of the redirection mechanism.

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