JP2019036581A - Electric magnet - Google Patents

Abstract

To provide an electric magnet which allows for downsizing of a device and reduction of mechanical interference, does not has a residual magnetic field and can output a magnetic field in any direction without moving the electric magnet.SOLUTION: The electric magnet comprises: two X-axis coils 1 in each of which coil axes 1C are in parallel with each other, and which are disposed axially symmetrically to each other around a central axis CL in parallel with a Z direction and; two Y-axis coils 2 in each of which coil axes 2C are in parallel with each other and which are disposed axially symmetrically to each other around the central axis CL; and one Z-axis coil 3 in which a coil axis 3C is matched with the central axis CL and disposed at a more outer peripheral side than the two X-axis coils 1 and the two Y-axis coils 2. An X direction and a Y direction are orthogonal to each other. A yoke that is a soft ferromagnetic substance is not disposed in a magnetic field generation region generated by all the coils 1 to 3. A magnetic field in any direction can be applied onto the central axis CL by changing current caused to flow to each of the coils 1-3.SELECTED DRAWING: Figure 1

Description

  The present disclosure relates to an electromagnet.

  Processing devices using electromagnets such as magnetoresistance measuring device, vibrating sample magnetometer, electromagnet for various magnetic property measuring devices including MRAM / evaluation device, heat treatment device in magnetic field, magnetization demagnetization processing device, saturation magnetostriction measuring device From the magnetic application industry to the semiconductor industry, and the medical and biotechnology fields, technologies using magnetic fields have been put into practical use in many fields.

  In the above-mentioned fields, the magnetic field is applied in a desired direction to measure the characteristics of the object to be measured in the magnetic field, or the object to be processed is disposed in the desired magnetic field and subjected to heat treatment or the like. In order to change the magnetic characteristics, an electromagnet is used to apply a magnetic field in a desired direction by current control, rotation of the electromagnet, or the like.

JP 2013-36941 A Japanese Patent No. 4761383

  Japanese Unexamined Patent Application Publication No. 2013-36941 discloses a magnetic sensor inspection apparatus using a three-axis Helmholtz coil that applies a magnetic field to the magnetic sensor in order to inspect and evaluate a three-axis magnetic sensor, for example. In the Helmholtz coil, a pair of coils whose coil axes are coaxial are arranged apart from each other, and a magnetic field is applied to an object arranged between the pair of coils. Three sets of coils are provided to generate x-axis, y-axis, and z-axis magnetic fields. However, in such an electromagnet using a Helmholtz coil, a magnetic field generation region is set inside each coil. Therefore, if the device arranged in the magnetic field generation region is large, the entire inspection apparatus must be enlarged. Since mechanical interference with the Helmholtz coil occurs, mechanical operation is restricted.

  Japanese Patent No. 4761483 discloses an electromagnet having a magnetic field application region only on one side of the apparatus and avoiding mechanical operation restrictions and apparatus enlargement. However, since a magnetic field is formed radially from the central first yoke to the surrounding second yoke, the position of the object must be changed according to the direction to be applied, such as the x-axis, y-axis, and z-axis.

  As another requirement, there are cases where measurement and evaluation with high response are required by changing the strength and direction of the magnetic field to be generated. In this case, if a residual magnetic field is generated in the electromagnet itself or if there is hysteresis, a difference is generated between the current control to the coil and the actually generated magnetic field. Therefore, it is desirable that the residual magnetic field and the hysteresis are not generated.

  The present disclosure has been made paying attention to such a problem, and the object thereof is to reduce the size of the apparatus and reduce mechanical interference, and there is no residual magnetic field, and an arbitrary without moving the electromagnet. An electromagnet capable of outputting a magnetic field in a direction is provided.

  In order to achieve the above object, the present disclosure takes the following measures.

That is, the electromagnet of the present disclosure is
Two X-axis coils, each coil axis being parallel to or crossing each other, and each coil axis is arranged at a position that is axially symmetric with respect to a central axis parallel to the Z direction. An X-axis coil;
Two Y-axis coils, each coil axis being parallel or crossing each other, and each coil axis being arranged at a position that is axially symmetric with respect to the central axis When,
One Z-axis coil, which has a coil axis that coincides with the central axis and is arranged on the outer peripheral side of the two X-axis coils and the two Y-axis coils. When,
With
An X direction orthogonal to the central axis and passing through the coil axes of the two X axis coils and a Y direction orthogonal to the central axis and passing through the coil axes of the two Y axis coils are orthogonal to each other. ,
All of the coils overlap each other at least partially when viewed along a direction orthogonal to the central axis,
In the magnetic field generation region by all the coils, a yoke that is a soft ferromagnet is not disposed,
By changing the current passed through each coil, a magnetic field in an arbitrary direction can be applied on the central axis.

According to this configuration, since the coil axis of the X-axis coil is arranged symmetrically with respect to the central axis, a magnetic flux in the X direction is generated on the central axis by energizing the two X-axis coils. Since the coil axis of the Y-axis coil is arranged symmetrically about the central axis, a magnetic flux in the Y direction is generated on the central axis by energizing the two Y-axis coils. By energizing the Z-axis coil, a magnetic flux in the Z direction is generated on the central axis. Since the arrangement centers of all the XYZ coils coincide, a magnetic flux in a desired direction is generated on the central axis, and a magnetic field in any direction can be applied without moving the electromagnet relative to the object. It becomes.
In addition, since the yoke, which is a soft ferromagnet, is not disposed in the magnetic field generation region of all the coils, the magnetic field disappears immediately when the current is turned off, so there is no residual magnetic field and no hysteresis is generated.
Furthermore, since all the coils overlap each other at least partially when viewed along the direction orthogonal to the central axis, the size in the Z direction can be suppressed and downsizing can be pursued. Since the space on one side can be used as a magnetic field application space, mechanical interference can be reduced.
Further, since the Z-axis coil is arranged on the outer peripheral side of the X-axis coil and the Y-axis coil, the strength of the Z-axis coil is matched to the strength of the magnetic field of the X-axis coil and the Y-axis coil. The magnetic field can be applied in a balanced manner with respect to the three directions of XYZ.

The top view which shows the electromagnet of this indication. It is AA site | part sectional drawing of FIG. 1, and explanatory drawing regarding X direction magnetic field generation | occurrence | production. It is BB site | part sectional drawing of FIG. 1, and explanatory drawing regarding a Y direction magnetic field generation | occurrence | production. It is AA site | part sectional drawing of FIG. 1, and explanatory drawing regarding Z direction magnetic field generation | occurrence | production. The typical sectional view showing a modification. The typical sectional view showing a modification. The typical sectional view showing a modification.

  Hereinafter, an electromagnet according to an embodiment of the present disclosure will be described with reference to the drawings.

  As shown in FIGS. 1 and 2A to 2C, the electromagnet is used to apply a magnetic field, and two X-axis coils 1, two Y-axis coils 2, and one Z-axis coil 3 are used. Have. In the present embodiment, the X-axis coil 1, the Y-axis coil 2, and the Z-axis coil 3 are formed by winding a non-magnetic conductor such as an enamel conductor in a cylindrical shape.

  As shown in FIG. 2A, the coil axes 1C of the two X-axis coils 1 are parallel to each other. As shown in FIG. 1, the coil axes 1 </ b> C are arranged at positions that are axially symmetric with respect to a central axis CL that is parallel to the Z direction. The coil shafts 1C are arranged at positions that are symmetric with respect to each other on a virtual circumference VC around a central axis CL extending in the Z direction parallel to the coil shafts 1C. In the present embodiment, the two X-axis coils 1 are formed in the same size. The shaft end surfaces 1a on one side of the two X-axis coils 1 are arranged on the same plane PS. The two X-axis coils 1 are arranged so that all the portions overlap each other when viewed along a direction orthogonal to the central axis CL (for example, the X direction and the Y direction) (so-called side by side).

  As shown in FIG. 2A, when an X-axis excitation current Xi having different current directions is supplied to the two X-axis coils 1, a magnetic flux mf1 from one coil 1 toward the other coil 1 is developed. Since each coil axis 1C of the two X-axis coils 1 is parallel but not coaxial, unlike the Helmholtz coil, magnetic flux along the X direction is expressed in a region outside the shaft end surface 1a of the X-axis coil 1. Can be made. In the present embodiment, since one shaft end surface 1a of the two X-axis coils 1 is arranged on the same plane PS, the shaft end surface 1a on one side of the two X-axis coils 1 is suppressed while suppressing the height. The magnetic flux along the X direction can be expressed in the vicinity of.

  As shown in FIG. 2B, in each of the two Y-axis coils 2, each coil axis 2C is parallel to the central axis CL. Each coil shaft 2 </ b> C is disposed at a position that corresponds to each other around the central axis CL. Each coil axis 2 </ b> C is disposed at a position that is axially symmetrical with each other on the virtual circumference VC. In the present embodiment, the two Y-axis coils 2 are formed in the same size as the X-axis coil 1. The shaft end surfaces 2a on one side of the two Y-axis coils 2 are arranged on the same plane PS. The two Y-axis coils 2 are arranged so that all the portions overlap each other when viewed along a direction orthogonal to the central axis CL (for example, the X direction and the Y direction) (so-called side by side).

  As shown in FIG. 2B, when a Y-axis excitation current Yi having different current directions is passed through the two Y-axis coils 2, a magnetic flux mf2 from one coil 2 toward the other coil 2 appears. Since the coil axes 2C of the two coils 2 are parallel but not the same, unlike the Helmholtz coil, a magnetic flux along the Y direction can be expressed in a region outside the shaft end surface 2a of the Y-axis coil 2. it can. In the present embodiment, since one shaft end surface 2a of the two Y-axis coils 2 is disposed on the same plane PS, the shaft end surface 2a on one side of the two Y-axis coils 2 is suppressed while suppressing the height. The magnetic flux along the Y direction can be expressed in the vicinity of.

  The X direction perpendicular to the central axis CL and passing through the coil axes 1C of the two X-axis coils 1 and the Y direction perpendicular to the central axis CL and passing through the coil axes 2C of the two Y-axis coils 2 are mutually Orthogonal. With this structure, the direction of the magnetic flux generated in the X-axis coil 1 is orthogonal to the direction of the magnetic flux generated in the Y-axis coil 2.

  As shown in FIG. 2C, the Z-axis coil 3 is arranged on the outer peripheral side with respect to the two X-axis coils 1 and the two Y-axis coils 2 with the coil axis 3C coinciding with the central axis CL. As shown in FIG. 2C, when a Z-axis excitation current Zi is passed through the Z-axis coil 3, the coil axis 3C coincides with the central axis CL, and thus a magnetic flux mf3 that passes through the central axis CL appears. In the structure in which the Z-axis coil 3 is disposed on the inner peripheral side of the X-axis coil 1 and the Y-axis coil 2, the z-direction magnetic flux by the Z-axis coil 3 becomes weaker. If the strength is increased, the Z-axis coil 3 is increased, the X-axis coil 1 and the Y-axis coil 2 are separated, and the strength of the magnetic flux in the X direction and the Z direction is decreased. If the Z-axis coil 3 is on the outermost peripheral side, the strength of the magnetic flux by the Z-axis coil 3 can be adjusted by the number of turns and dimensions, and the strength of the magnetic flux by the X-axis coil 1 and the Y-axis coil 2 can be adjusted. Accordingly, it is possible to provide an electromagnet which can be adjusted in strength and can output the magnetic flux intensity in the xyz direction in a balanced manner.

  In this embodiment, the X-axis coil 1, the Y-axis coil 2, and the Z-axis coil 3 are formed by winding a conducting wire in a cylindrical shape, and the height along the Z direction is the same, but this is not limitative. Not. For example, the coil may be formed in a polygonal cylindrical shape or an elliptical shape, and the heights along the Z direction may not be the same.

  A yoke, which is a soft ferromagnetic material, is not disposed in the magnetic field generation region of all the coils 1, 2, and 3. For this reason, when the current is turned off, the magnetic field disappears immediately, there is no residual magnetic field, and no hysteresis occurs. In order to realize this configuration, a support portion 4 that supports the X-axis coil 1, the Y-axis coil 2, and the Z-axis coil 3 is provided. In the present embodiment, the support portion 4 has a structure in which the coils 1 to 3 are bolted to a disk-shaped base plate and top plate and the periphery is surrounded by a side wall plate. As an example, it is possible to hold the upper part in a suspended state with the upper part as a scaffold, attach a prober to the lower part, and set an arbitrary place of the central axis CL as the magnetic field application region P. Of course, the present disclosure is not limited to this. In any case, the support portion 4 is formed of a nonmagnetic material such as aluminum or plastic. In this way, by changing the current flowing through each of the coils 1 to 3, a magnetic field in an arbitrary direction can be applied to the predetermined region P on the central axis CL without relatively moving the electromagnet.

  Since all the coils (X-axis coil 1, Y-axis coil 2 and Z-axis coil 3) overlap each other when viewed along the direction orthogonal to the central axis CL, the coils The dimension of the device including the Z direction can be suppressed, and the space on one side in the Z direction can be used as the magnetic field application space. Of course, the present invention is not limited to this embodiment, and all the coils (the X-axis coil 1, the Y-axis coil 2, and the Z-axis coil 3) are at least one when viewed along a direction orthogonal to the central axis CL. It is only necessary that the parts overlap each other.

  In the present embodiment, the shaft end surfaces 1a, 2a, 3a on one side of the X-axis coil 1, the Y-axis coil 2, and the Z-axis coil 3 are on the same plane PS, but the present invention is not limited to this. For example, as shown in FIG. 3A, the shaft end surfaces 1a and 2a on one side of the X-axis coil 1 and the Y-axis coil 2 are arranged on the same plane PS, and the shaft end surface 3a on one side of the Z-axis coil 3 is placed. However, the X axis coil 1 and the Y axis coil 2 may be disposed on the other side in the axial direction from the same plane PS on which the shaft end surfaces 1a and 2a on one side are disposed.

  As in the example of FIGS. 1 and 2, the coil axes 1 </ b> C and 2 </ b> C are arranged in parallel for the two X-axis coils 1 and the two Y-axis coils 2 so that the coil axes cross each other. This is because, when arranged, the end portions on one side in the axial direction of the coil are open, and the device is enlarged. Of course, as shown in FIG. 4, the two X-axis coils 1 and the two Y-axis coils 2 may be arranged so that the coil axes intersect each other. If the coil axes cross each other, they are not coaxial. Therefore, unlike a Helmholtz coil, magnetic flux can be expressed in a region outside the end face of the coil. As shown in FIG. 4, the angle α between the coil axis 1C (2C) and the central axis CL is 45 degrees or less, preferably 20 degrees or less, more preferably 10 degrees or less, and further preferably 5 degrees or less.

As described above, the electromagnet of the present embodiment is the two X-axis coils 1, and the coil axes 1 </ b> C are parallel to or intersecting each other, and each coil axis 1 </ b> C is a central axis CL parallel to the Z direction. Two X-axis coils 1 disposed at positions that are axially symmetric with respect to each other,
Two Y-axis coils 2, each coil axis 2C being parallel or crossing each other, and each coil axis 2C is disposed at a position that is axially symmetric with respect to the center axis CL. A coil 2 for shafts;
One Z-axis coil 3, wherein the coil axis 3 </ b> C coincides with the central axis CL, and is arranged on the outer peripheral side of the two X-axis coils 1 and the two Y-axis coils 2. Coil 3 for
Have
The X direction perpendicular to the central axis CL and passing through the coil axes 1C of the two X-axis coils 1 and the Y direction perpendicular to the central axis CL and passing through the coil axes 2C of the two Y-axis coils 2 are mutually Orthogonal.
All the coils 1 to 3 overlap each other at least partially when viewed along a direction orthogonal to the central axis CL.
A yoke that is a soft ferromagnet is not disposed in the magnetic field generation region of all the coils 1 to 3.
A magnetic field in an arbitrary direction can be applied on the central axis CL by changing the current flowing through the coils 1 to 3.

According to this configuration, since the coil axis 1C of the X-axis coil 1 is arranged symmetrically with respect to each other about the central axis CL, energization of the two X-axis coils 1 causes an X direction on the central axis CL. The magnetic flux is generated. Since the coil axis 2C of the Y-axis coil 2 is arranged symmetrically with respect to each other about the central axis CL, a magnetic flux in the Y direction is generated on the central axis CL by energizing the two Y-axis coils 2. By energizing the Z-axis coil 3, a magnetic flux in the Z direction is generated on the central axis CL. Since the arrangement centers of all the XYZ coils coincide with each other, a magnetic flux in a desired direction is generated on the center axis CL, and a magnetic field in an arbitrary direction is applied without moving the electromagnet relative to the object. It becomes possible.
In addition, since the yoke, which is a soft ferromagnet, is not disposed in the magnetic field generation regions of all the coils 1 to 3, since the magnetic field disappears immediately when the current is turned off, there is no residual magnetic field and no hysteresis is generated.
Furthermore, since all the coils 1 to 3 overlap each other at least partially when viewed along the direction orthogonal to the central axis CL, it is possible to reduce the size in the Z direction while pursuing miniaturization. In addition, since the space on one side in the Z direction can be used as the magnetic field application space, mechanical interference can be reduced.
Further, since the Z-axis coil 3 is disposed on the outer peripheral side of the X-axis coil 1 and the Y-axis coil 2, the Z-axis is adjusted in accordance with the magnetic field strength of the X-axis coil 1 and the Y-axis coil 2. The strength of the coil 3 can be set, and a magnetic field can be applied in a balanced manner with respect to the three directions of XYZ.

  In the present embodiment, the coil axes 1C of the two X-axis coils 1 are parallel to each other, and the coil axes 2C of the two Y-axis coils 2 are parallel to each other.

  According to this configuration, since the coil does not expand as compared with the configuration in which the coil axes cross each other, it is possible to pursue downsizing of the device.

  In the present embodiment, the shaft end surfaces 1a and 2a on one side of the X-axis coil 1 and the Y-axis coil 2 are on the same plane PS, and the shaft end surface 3a on one side of the Z-axis coil 3 is for the X-axis. The coil 1 and the Y-axis coil 2 are on the same plane PS as the axial end faces 1a and 2a on one side, or are disposed on the other side in the axial direction from the same plane PS.

  According to this configuration, the strengths of the magnetic fields of the X axis and the Y axis can be easily matched. The Z-axis coil 3 can be arranged so as not to interfere with the XY-axis magnetic field application region.

  In this embodiment, it has the support part 4 which supports the X-axis coil 1, the Y-axis coil 2, and the Z-axis coil 3, and the support part 4 is formed of a nonmagnetic material.

  Thus, since the support part 4 is a nonmagnetic material, there is no residual magnetic field and no hysteresis occurs.

  In the present embodiment, the X-axis coil 1, the Y-axis coil 2, and the Z-axis coil 3 are formed by winding a conducting wire in a cylindrical shape, and have the same height along the Z direction.

  If there is a cylindrical space, all the coils 1 to 3 can be accommodated, so that a compact electromagnet can be provided.

  As mentioned above, although embodiment of this invention was described based on drawing, it should be thought that a specific structure is not limited to these embodiment. The scope of the present invention is shown not only by the above description of the embodiments but also by the scope of claims for patent, and further includes all modifications within the meaning and scope equivalent to the scope of claims for patent.

  In the example of FIGS. 1 and 2, the shaft end surfaces 1 a, 2 a, 3 a on one side of the X-axis coil 1, the Y-axis coil 2, and the Z-axis coil 3 are arranged on the same plane PS. Not. For example, as shown in FIG. 3B, the shaft end surface 1a on one side of the X-axis coil 1, the shaft end surface 2a on one side of the Y-axis coil 2, and the shaft end surface 3a on one side of the Z-axis coil 3 However, it may be slightly off. The shaft end surface 1a on one side of the X-axis coils 1 is on the same plane, the shaft end surface 2a on one side of the Y-axis coils 2 is on the same plane, and the one side of the Z-axis coils 3 is on one side. This is because, if the shaft end surface 3a is on the same plane, it can be adjusted by the flowing current.

  The structure employed in each of the above embodiments can be employed in any other embodiment. The specific configuration of each unit is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention.

DESCRIPTION OF SYMBOLS 1 ... Coil for X axis 1C ... Coil axis 2 ... Coil for Y axis 2C ... Coil axis 3 ... Coil for Z axis 3C ... Coil axis 4 ... Support part CL ... Center axis VC ... Virtual circle

Claims (5)

Two X-axis coils, each coil axis being parallel to or crossing each other, and each coil axis is arranged at a position that is axially symmetric with respect to a central axis parallel to the Z direction. An X-axis coil;
Two Y-axis coils, each coil axis being parallel or crossing each other, and each coil axis being arranged at a position that is axially symmetric with respect to the central axis When,
One Z-axis coil, which has a coil axis that coincides with the central axis and is arranged on the outer peripheral side of the two X-axis coils and the two Y-axis coils. When,
With
An X direction orthogonal to the central axis and passing through the coil axes of the two X axis coils and a Y direction orthogonal to the central axis and passing through the coil axes of the two Y axis coils are orthogonal to each other. ,
All of the coils overlap each other at least partially when viewed along a direction orthogonal to the central axis,
In the magnetic field generation region by all the coils, a yoke that is a soft ferromagnet is not disposed,
An electromagnet capable of applying a magnetic field in an arbitrary direction on the central axis by changing a current flowing through each coil.   2. The electromagnet according to claim 1, wherein coil axes of the two X-axis coils are parallel to each other, and coil axes of the two Y-axis coils are parallel to each other. The axial end surfaces on one side of the X-axis coil and the Y-axis coil are on the same plane,
The shaft end surface on one side of the Z-axis coil is on the same plane as the shaft end surface on one side of the X-axis coil and Y-axis coil, or is disposed on the other side in the axial direction from the same plane. The electromagnet according to claim 1 or 2. A support portion for supporting the X-axis coil, the Y-axis coil, and the Z-axis coil;
The electromagnet according to claim 1, wherein the support portion is formed of a nonmagnetic material.   The X-axis coil, the Y-axis coil, and the Z-axis coil are formed by winding a conducting wire in a cylindrical shape, and have the same height along the Z direction. Electromagnet.

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