Magnetic field alignment device and magnetic field alignment unit

Abstract

To provide a magnetic field orientation device that is easy to install. [Solution] A magnetic field orientation device 32 includes a pair of magnet parts 16 arranged with opposite poles facing each other in a first direction D1, and a yoke 34 that holds the pair of magnet parts 16. The yoke 34 has a pair of first yoke parts 34a to which the magnet parts 16 are respectively fixed, and a second yoke part 34b that connects the pair of first yoke parts 34a. When viewed from the first direction D1, the outer edge of the magnet parts 16 is positioned inside the outer edge of the first yoke part 34a. Each magnet part 16 includes a plurality of magnet rows 161-164, and each magnet row 161-164 includes a plurality of magnets 16a. The plurality of magnets 16a of one magnet row among the plurality of magnet rows 161-164 and the plurality of magnets 16a of another magnet row adjacent to the one magnet row are arranged to be offset from each other.

Description

[Technical field]

[0001] The present invention relates to a magnetic field orientation device that applies a magnetic field to a sheet-like (band-like) workpiece, and a magnetic field orientation unit equipped with the same. [Background technology]

[0002] Known methods for applying a magnetic field to a sheet-like workpiece include a method using a coil and a method using a magnet.

[0003] When applying a magnetic field to a workpiece using a coil, the magnetic field strength can be adjusted by adjusting the voltage applied to the coil. Therefore, a high-strength magnetic field can be easily applied to the workpiece. However, when using a coil, a power supply device for applying voltage to the coil and a cooling device as a countermeasure against heat generation are required, making the device configuration large-scale.

[0004] On the other hand, when applying a magnetic field to a workpiece using magnets, it is possible to arrange magnets on both sides of the workpiece (in Patent Document 1, a strip-shaped non-magnetic support body coated with magnetic paint) so that the different poles face each other, as in the magnetic field orientation device disclosed in Patent Document 1, and apply a magnetic field to the workpiece while transporting it. When applying a magnetic field to a workpiece using magnets in this way, a power supply unit and a cooling unit are not required, so the device configuration can be simplified. However, since the magnetic field strength cannot be adjusted as in the case of using coils, a strong magnet must be used when applying a high-strength magnetic field to the workpiece. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2011-54230 A Summary of the Invention [Problem to be solved by the invention]

[0006] In order to apply a magnetic field appropriately to the workpiece while transporting the workpiece, it is necessary to generate a magnetic field over a sufficient range in the direction of transport of the workpiece. For this purpose, for example, it is conceivable to use a magnet with a large size, but it is difficult to form a strong magnet with a large size. Therefore, for example, it is conceivable to arrange multiple magnets so that they are lined up in the direction of transport of the workpiece.

[0007] However, after investigations by the inventors, it was found that if one attempts to arrange powerful magnets in a line in the direction of work transport, a large repulsive force will be generated between adjacent magnets, making it difficult to install the magnets.

[0008] Therefore, an object of the present invention is to provide a magnetic field orientation device that is easy to install and a magnetic field orientation unit including the same. [Means for solving the problem]

[0009] In one aspect of the present invention, a magnetic field orientation device is A pair of magnet sections arranged apart from each other so that opposite poles face each other in a first direction; a yoke for holding the pair of magnet portions; The yoke is a pair of first yoke portions provided outside the pair of magnet portions in the first direction and to which the magnet portions are respectively fixed; a second yoke portion that is provided on the outer side of the pair of magnet portions in a second direction perpendicular to the first direction and connects the pair of first yoke portions, When viewed from the first direction, an outer edge of the magnet portion is positioned more inward than an outer edge of the first yoke portion, the magnet section includes a plurality of magnet rows arranged in a third direction perpendicular to the first direction and the second direction, Each of the magnet rows includes a plurality of magnets arranged in the second direction, The magnets of one magnet row among the plurality of magnet rows and the magnets of another magnet row adjacent to the one magnet row are arranged so as to be shifted from each other in the second direction.

[0010] In another aspect of the present invention, the magnetic field orientation unit includes a pair of magnet sections arranged at a distance from each other so that opposite poles face each other in a first direction, and a yoke that holds the pair of magnet sections. The yoke is a pair of first yoke portions provided outside the pair of magnet portions in the first direction and to which the magnet portions are respectively fixed; a second yoke portion that is provided on the outer side of the pair of magnet portions in a second direction perpendicular to the first direction and connects the pair of first yoke portions, When viewed from the first direction, an outer edge of the magnet portion is positioned more inward than an outer edge of the first yoke portion, The plurality of magnetic field orientation devices are arranged to be aligned in a third direction perpendicular to the first direction and the second direction, The magnet portion of each of the magnetic field orientation devices includes a plurality of magnets arranged in the second direction, The magnets of one of the plurality of magnetic field orientation devices and the magnets of another magnetic field orientation device adjacent to the one of the plurality of magnetic field orientation devices are arranged so as to be shifted from each other in the second direction. Effect of the Invention

[0011] According to the present invention, it is possible to obtain a magnetic field orientation device that is easy to install and a magnetic field orientation unit including the same. [Brief description of the drawings]

[0012] [Figure 1] FIG. 1 is a diagram for explaining the contents of the study by the present inventors. [Diagram 2] FIG. 2 is a schematic diagram showing equipment equipped with the magnetic field orientation device according to Reference Example 1. As shown in FIG. [Diagram 3]FIG. 3 is a perspective view showing a magnetic field orientation unit. [Figure 4] FIG. 4 is a diagram showing a magnetic field orientation device. [Diagram 5] FIG. 5 is a diagram showing an example of the strength of the magnetic field generated in the magnetic field orientation unit. [Figure 6] FIG. 6 is a diagram showing the analysis results. [Figure 7] FIG. 7 is a diagram showing the relationship between the ratio of the lengths of the magnet section and the first yoke section in the third direction and the mass of the magnetic field orientation device. [Figure 8] FIG. 8 is a perspective view showing a magnetic field orientation unit equipped with a magnetic field orientation device according to Reference Example 2. As shown in FIG. [Figure 9] FIG. 9 is a view of the magnetic field orientation device viewed from a third direction. [Figure 10] FIG. 10 is a diagram showing a magnetic field orientation device according to an embodiment of the present invention. [Figure 11] FIG. 11 is a diagram showing a magnetic field orientation device according to the third reference example. [Figure 12] FIG. 12 is a perspective view showing a magnetic field orientation unit including a magnetic field orientation device according to a modified example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] (Study by the inventor) The present inventor has studied a method of applying a magnetic field to a workpiece using a magnet. FIG. 1 is a diagram for explaining the contents of the study by the present inventor. Specifically, FIG. 1 shows equipment for applying a magnetic field to a sheet-like workpiece W. The equipment 1 shown in FIG. 1 includes a conveying device 100 for conveying the workpiece W, and a plurality of magnet units 200 for applying a magnetic field to the workpiece W.

[0014] The conveying device 100 includes a plurality of rollers 102 and a conveying belt 104 supported by the plurality of rollers 102. The conveying belt 104 is driven by a driving source (not shown) to convey a workpiece W on the conveying belt 104 in a direction indicated by an arrow A (hereinafter referred to as conveying direction A).

[0015] The magnet units 200 are arranged in a line in the conveying direction A. Each magnet unit 200 has a pair of magnets 202, 204. The magnet 202 is provided on one side of the conveying belt 104, and the magnet 204 is provided on the other side of the conveying belt 104. In each magnet unit 200, the magnets 202, 204 are arranged so that the opposite poles face each other. This generates a magnetic field in one direction between the magnets 202 and 204 (for example, a direction from the magnet 204 toward the magnet 202).

[0016] 1, a unidirectional magnetic field can be applied to the workpiece W using a plurality of magnet units 200 while the workpiece W is being transported by a transport device 100. However, as a result of studies by the present inventors, it has been found that when strong magnets (for example, magnets generating a magnetic flux of about 1 T) are used as the magnets 202, 204, a large repulsive force is generated between adjacent magnets in the transport direction A, and each magnet unit 200 cannot be easily installed.

[0017] Therefore, the present inventor attempted to control the flow of magnetic flux generated by magnets 202, 204 by providing a yoke to connect magnets 202, 204. However, simply providing a yoke to connect magnets 202, 204 was not enough to sufficiently reduce the repulsive force generated between magnets adjacent to each other in conveying direction A.

[0018] The inventors further investigated providing a yoke to sandwich magnets 202, 204 from above and below. As a result, they found that by appropriately adjusting the positional relationship between the magnets and the yoke, it is possible to sufficiently reduce the repulsive force generated between adjacent magnets in the conveying direction A. Specifically, they found that by holding a pair of magnets with a yoke so that they are sandwiched between them from above and below so that the pair of magnets do not protrude from the yoke in the conveying direction A, it is possible to sufficiently reduce the repulsive force generated between adjacent magnets in the conveying direction A.

[0019] Based on the above findings, the present inventors produced a magnetic field orientation device according to Reference Example 1 described below, and a magnetic field orientation unit including the same.

[0020] (Reference example 1) Fig. 2 is a schematic diagram showing an equipment equipped with a magnetic field orientation device according to Reference Example 1. Equipment 10 shown in Fig. 2 differs from equipment 1 shown in Fig. 1 in that equipment 10 includes a magnetic field orientation unit 12 instead of multiple magnet units 200.

[0021] Fig. 3 is a perspective view showing the magnetic field orientation unit. As shown in Figs. 2 and 3, the magnetic field orientation unit 12 includes a plurality of magnetic field orientation devices 14 arranged in a line in the conveying direction A of the workpiece W. Fig. 3 shows a first direction D1, a second direction D2, and a third direction D3 that are perpendicular to each other. The third direction D3 is a direction parallel to the conveying direction A. The first direction D1, the second direction D2, and the third direction D3 are also shown appropriately in other drawings.

[0022] A hollow portion is formed in the center of each magnetic field orientation device 14 to allow passage of the conveyor belt 104 and the workpiece W (see FIG. 2) supported by the conveyor belt 104. The magnetic field orientation device 14 will be specifically described below.

[0023] 4 is a diagram showing the magnetic field orientation device 14, where (a) is a diagram of the magnetic field orientation device 14 seen from the third direction D3, and (b) is a diagram of the magnetic field orientation device 14 seen from the first direction D1. As shown in Fig. 3 and Fig. 4(a), the magnetic field orientation device 14 includes a pair of magnet parts 16 and a yoke 18 that holds the pair of magnet parts 16.

[0024] The pair of magnet parts 16 are magnetized in a first direction D1. The pair of magnet parts 16 are arranged so that the opposite poles face each other in the first direction D1 and are spaced apart from each other. As a result, a unidirectional magnetic field (hereinafter, referred to as a unidirectional magnetic field) is generated between the pair of magnet parts 16 from one magnet part 16 to the other magnet part 16. In this reference example 1, when the workpiece W (see FIG. 2) passes through the gap between the pair of magnet parts 16, a magnetic field is applied to the workpiece W. The distance between the pair of magnet parts 16 in the first direction D1 is appropriately adjusted depending on the type, application, etc. of the workpiece W. In this reference example 1, the distance between the pair of magnet parts 16 is set to, for example, 10 mm.

[0025] In this reference example 1, the magnet part 16 is formed in a rectangular parallelepiped shape so as to extend in the second direction D2. As shown in FIG. 4(a), in this reference example 1, the magnet part 16 is composed of a plurality of rectangular parallelepiped magnets 16a arranged in a line in the second direction D2. A known permanent magnet can be used as the magnets 16a. Specifically, for example, a rare earth magnet such as a neodymium magnet or a samarium cobalt magnet, or a ferrite magnet or an alnico magnet can be used as the magnets 16a. In this reference example 1, the magnets 16a adjacent to each other in the second direction D2 are fixed to each other by, for example, an adhesive.

[0026] In this reference example 1, the yoke 18 is provided so as to surround the pair of magnet portions 16. A hollow portion 19 penetrating in the third direction D3 is formed in the center of the yoke 18. In this reference example 1, the yoke 18 has a rectangular cylindrical shape. The length of the yoke 18 in the second direction D2 is longer than the length of the yoke 18 in the first direction D1. The yoke 18 is made of a magnetic material such as steel. Specifically, the material of the yoke 18 may be SS400, SUS430, SUS403, or the like, as specified by the JIS standard.

[0027] In this reference example 1, the yoke 18 includes a pair of first yoke parts 18a and a pair of second yoke parts 18b. In FIG. 4(a), the boundary between the first yoke parts 18a and the second yoke parts 18b is indicated by a dashed line. The pair of first yoke parts 18a are provided outside the pair of magnet parts 16 in the first direction D1. The magnet parts 16 are fixed to the pair of first yoke parts 18a, respectively. In this reference example 1, the magnet parts 16 are fixed to the first yoke parts 18a by, for example, an adhesive.

[0028] In this reference example 1, the portions of the yoke 18 on one side and the other side of the pair of magnet portions 16 in the first direction D1 are referred to as first yoke portions 18a. The pair of second yoke portions 18b are provided outside the pair of magnet portions 16 in the second direction D2 and connect the pair of first yoke portions 18a.

[0029] As shown in FIG. 4(b), when viewed from the first direction D1, the outer edge of the magnet portion 16 is positioned inside the outer edge of the first yoke portion 18a. In other words, the first yoke portion 18a protrudes further in both sides in the third direction D3 than the magnet portion 16. In this reference example 1, the length b of the first yoke portion 18a in the third direction D3 is preferably 1.1 times or more, and more preferably 1.6 times or more, the length a of the magnet portion 16. In this reference example 1, the length of the second yoke portion 18b in the third direction D3 is set to be the same as the length b of the first yoke portion 18a. In this reference example 1, the length c of the first yoke portion 18a in the first direction D1 is preferably set to be 0.5 to 3.5 times the length b of the first yoke portion 18a in the third direction D3. Moreover, the length d of the second yoke portion 18b in the second direction D2 is preferably set to 0.5 to 3.5 times the length of the second yoke portion 18b in the third direction D3.

[0030] (Effects of Reference Example 1) In the magnetic field orientation device 14 according to the present reference example 1, the outer edge of the magnet part 16 is positioned inside the outer edge of the first yoke part 18a when viewed from the first direction D1. This makes it possible to suppress radial leakage of magnetic flux from the end face of the magnet part 16 on the first yoke part 18a side (the end face fixed to the first yoke part 18a). As a result, when multiple magnetic field orientation devices 14 are arranged in the conveying direction A, it is possible to prevent a large repulsive force from being generated between the magnetic field orientation devices 14 adjacent to each other in the conveying direction A. This makes it easy to install the magnetic field orientation devices 14 close to each other.

[0031] Fig. 5 is a diagram showing an example of the strength of the magnetic field generated by the multiple magnet sections 16 in the magnetic field orientation unit 12 shown in Fig. 3. Specifically, the horizontal axis of Fig. 5 indicates the position in the conveying direction A, and the vertical axis indicates the magnetic flux density in the first direction D1. Note that the magnetic flux density shown in Fig. 5 indicates the magnetic flux density of the magnetic field at the center of the magnetic field orientation unit 12 in the second direction D2.

[0032] In the magnetic field orientation unit 12 shown in FIG. 3, four magnetic field orientation devices 14 are arranged in line in the conveying direction A. Therefore, as shown in FIG. 5, the magnetic flux density of the magnetic field generated by the magnetic field orientation unit 12 changes to show four peaks. Here, as shown in the area surrounded by the dashed line in FIG. 5, on one side and the other side of the magnetic field orientation unit 12 in the conveying direction A, a portion in which the magnetic flux flows in the opposite direction to the above-mentioned unidirectional magnetic field is generated. That is, a demagnetizing field is generated on the inlet side and the outlet side of the magnetic field orientation unit 12. In this regard, in the magnetic field orientation device 14 according to this reference example 1, as described above, it is possible to suppress the radial leakage of magnetic flux from the end face of the magnet part 16 on the first yoke part 18a side. This allows the strength of the demagnetizing field to be sufficiently low. As a result, the unidirectional magnetic field can be appropriately applied to the workpiece W.

[0033] There is no particular restriction on the purpose of applying a magnetic field to the workpiece W. There is also no particular restriction on the workpiece W. Examples of the workpiece W include a rubber magnet, a magnetic paint, a magnetic fluid, a semiconductor wafer, a polymer slurry containing magnetic particles, and a film-like electrode. In the above-mentioned Reference Example 1, the workpiece W is transported by the transport belt 104, but when a magnetic field is applied to a strip-shaped workpiece, the workpiece may be passed through the magnetic field orientation unit 12 while being supported by the rollers 102.

[0034] (simulation) The present inventor investigated the influence of the dimensions of the yoke 18 on the strength of the magnetic field, etc., of the magnetic field orientation unit 12 described above by a simulation using electromagnetic field analysis software (JMAG manufactured by JSOL Corporation). Specifically, referring to FIG. 4, the magnetic field analysis was performed by changing the length b of the first yoke part 18a in the third direction D3, the length c of the first yoke part 18a in the first direction D1, and the length d of the second yoke part 18b in the second direction D2. Then, the magnetic flux density of the demagnetizing field (see FIG. 5), the magnetic flux density (peak value) of the unidirectional magnetic field generated in the magnetic field orientation unit 12, and the repulsive force generated between the magnetic field orientation devices 14 adjacent to each other in the third direction D3 (transport direction A) were obtained. Note that the cross-sectional area of ​​the first yoke part 18a perpendicular to the second direction D2 and the cross-sectional area of ​​the second yoke part 18b perpendicular to the first direction D1 were constant (5600 mm 2 ) The dimensions of the magnet section 16 and the cavity 19 were also constant. Specifically, the magnet section 16 was configured with eleven magnets 16a (neodymium magnets) arranged in the second direction D2. The length of the magnet section 16 in the first direction D1 was 24 mm, the length of the second direction D2 was 396 mm, and the length a in the third direction D3 was 36 mm. The length of the cavity 19 in the first direction D1 was 58 mm, and the length of the second direction D2 was 420 mm. The material of the yoke 18 was SS400.

[0035] Table 1 below shows the dimensions and analysis results of the analysis model. In Table 1 below, a to d of the magnet and yoke indicate the lengths a to d in FIG. 4, and b / a of the yoke indicates the ratio of the length b to the length a. The mass indicates the mass of the magnetic field orientation device 14 (the total mass of the pair of magnet parts 16 and the yoke 18) calculated from the dimensions of each part. The demagnetizing field ratio is the ratio of the magnitude (absolute value) of the magnetic flux density of the demagnetizing field to the magnitude (absolute value) of the magnetic flux density of the unidirectional magnetic field, expressed as a percentage. The analysis model of analysis No. 1 does not include the yoke 18. The analysis model of analysis No. 1 has a configuration in which multiple magnet parts 16 are arranged in the third direction D3 (transport direction A) like the magnets 202, 204 of the multiple magnet units 200 shown in FIG. 1. In addition, in the analysis models of analysis Nos. 2 and 3, the magnet parts 16 protrude from the first yoke part 18a on both sides in the third direction D3. In the analysis models of Analysis Nos. 1 to 3, the magnet parts 16 adjacent in the third direction D3 (transport direction A) are in contact with each other. On the other hand, the analysis models of Analysis Nos. 4 to 10 correspond to the above-mentioned Reference Example 1. In the analysis models of Analysis Nos. 4 to 10, the yokes 18 adjacent in the third direction D3 (transport direction A) are in contact with each other. Note that, in Analysis No. 1, the mass indicates the total mass of a pair of magnet parts 16, and the repulsive force indicates the repulsive force generated between the magnet parts 16 adjacent in the third direction D3 (transport direction A).

[0036] [Table 1]

[0037] The above analysis results are shown in a graph in Fig. 6. Specifically, Fig. 6 is a graph showing the relationship between the ratio of the length b of the first yoke portion 18a to the length a of the magnet portion 16 and the repulsive force generated between adjacent magnetic field orientation devices 14 in the third direction D3 (between the magnet portions 16 for analysis No. 1). Fig. 7 shows the relationship between the ratio of the length b to the length a and the mass of the magnetic field orientation device 14.

[0038] As shown in Table 1 and FIG. 6, in the analyses Nos. 4 to 10 corresponding to the above-mentioned Reference Example 1, the repulsive force generated between the magnet parts 16 adjacent to each other in the conveying direction A could be reduced. That is, it was found that the repulsive force generated between the magnet parts 16 adjacent to each other in the conveying direction A could be reduced by positioning the outer edge of the magnet part 16 on the inside of the outer edge of the first yoke part 18a as viewed from the first direction D1. In addition, it was found that, from the viewpoint of reducing the repulsive force, the value of the ratio of the length b to the length a is preferably 1.1 or more, and more preferably 1.6 or more. Furthermore, as shown in Table 1 and FIG. 7, it was found that, from the viewpoint of reducing the mass of the magnetic field orientation device 14, the value of the ratio of the length b to the length a is preferably 1.1 or more, and more preferably 1.6 or more.

[0039] Furthermore, as shown in Table 1, in analyses Nos. 4 to 10 corresponding to the above-mentioned Reference Example 1, the magnetic flux density of the unidirectional magnetic field could be sufficiently increased while the magnetic flux density of the demagnetizing field could be sufficiently reduced. That is, it was found that by positioning the outer edge of magnet portion 16 on the inside of the outer edge of first yoke portion 18a as viewed from first direction D1, the magnetic flux density of the unidirectional magnetic field could be sufficiently increased while the magnetic flux density of the demagnetizing field could be sufficiently reduced.

[0040] As described above, it was confirmed that when the magnetic field orientation unit 12 is configured using the magnetic field orientation device 14 according to Reference Example 1, multiple magnetic field orientation devices 14 can be easily installed in close proximity to each other while appropriately applying a unidirectional magnetic field to the workpiece W. Meanwhile, the present inventors have considered reducing the weight of the magnetic field orientation device in order to make the installation of the magnetic field orientation device even easier. Specifically, they have considered reducing the weight of the magnetic field orientation device (yoke) by making the yoke smaller.

[0041] However, if the yoke is simply made smaller, the amount of magnetic flux passing through the yoke decreases, and there is a risk that the magnetic flux density of the unidirectional magnetic field cannot be sufficiently secured. Therefore, the present inventor conducted detailed studies on a configuration for reducing the weight of the yoke while suppressing the decrease in the magnetic flux density of the unidirectional magnetic field. In the course of this study, the present inventor examined the magnetic flux density distribution generated in the yoke 18 by the pair of magnet parts 16 through magnetic field analysis using the above-mentioned electromagnetic analysis software. As a result, it was found that almost no magnetic flux flows in the center of the yoke 18 in the second direction D2 and both ends in the first direction D1 (a pair of regions 181 shown by dashed lines in FIG. 4(a)) and the four corners (four regions 182 shown by dashed lines in FIG. 4(a)). From this result, the present inventor thought that by removing the above-mentioned parts through which almost no magnetic flux flows from the yoke, it is possible to reduce the weight of the yoke while suppressing the decrease in the magnetic flux density of the unidirectional magnetic field.

[0042] The present invention has been completed based on the above findings. A magnetic field orientation device according to Reference Example 2 and a magnetic field orientation unit including the same will be described below.

[0043] (Configuration of magnetic field orientation device and magnetic field orientation unit according to Reference Example 2) Fig. 8 is a perspective view showing a magnetic field orientation unit equipped with a magnetic field orientation device according to Reference Example 2. As shown in Fig. 8, the magnetic field orientation unit 30 according to Reference Example 2 is configured to be able to apply a magnetic field to the workpiece W (see Fig. 2) transported by the transport belt 104, similar to the magnetic field orientation unit 12 described in Fig. 2.

[0044] Specifically, the magnetic field orientation unit 30 includes a plurality of magnetic field orientation devices 32 arranged in line in the transport direction A of the workpiece W. Note that Fig. 8 shows a first direction D1, a second direction D2, and a third direction D3 that are perpendicular to each other. The third direction D3 is a direction parallel to the transport direction A. The first direction D1, the second direction D2, and the third direction D3 are also shown appropriately in other drawings.

[0045] A hollow section 35 is formed in the center of each magnetic field orientation device 32 to allow the conveyor belt 104 and the workpiece W (see FIG. 2) supported by the conveyor belt 104 to pass through. In this Reference Example 2, the conveyor belt 104 and the workpiece W pass between a pair of magnet sections 16 arranged in the hollow section 35. The magnetic field orientation device 32 will be specifically described below. Note that, among the components of the magnetic field orientation device 32, components having substantially the same functions as the components of the magnetic field orientation device 14 according to the above-mentioned Reference Example 1 will be denoted by the same reference numerals and description thereof will be omitted.

[0046] 9 is a view of the magnetic field orientation device 32 viewed from the third direction D3. As shown in FIGS. 8 and 9, the magnetic field orientation device 32 includes a pair of magnet parts 16 and a yoke 34 that holds the pair of magnet parts 16. The yoke 34 is provided so as to surround the pair of magnet parts 16. A hollow part 35 that penetrates in the third direction D3 is formed in the center of the yoke 34. The length of the yoke 34 in the second direction D2 is longer than the length of the yoke 34 in the first direction D1. The yoke 34 is made of the same material as the yoke 18 described above.

[0047] The yoke 34 includes a pair of first yoke parts 34a and a pair of second yoke parts 34b. In this reference example 2, the pair of first yoke parts 34a and the pair of second yoke parts 34b are each formed by separate members. Note that, as in the yoke 34 shown in FIG. 10 described later, the pair of first yoke parts 34a and the pair of second yoke parts 34b may be integrally formed. That is, although the yoke 34 is formed by a plurality of members in this reference example 2, the yoke 34 may be formed by a single member.

[0048] As shown in Figs. 8 and 9, in Reference Example 2, the pair of first yoke parts 34a are provided outside the pair of magnet parts 16 in the first direction D1. The magnet parts 16 are fixed to the pair of first yoke parts 34a, respectively. In Reference Example 2, the magnet parts 16 are fixed to the first yoke parts 34a by, for example, an adhesive. The pair of second yoke parts 34b are provided outside the pair of magnet parts 16 in the second direction D2 and connect the pair of first yoke parts 34a. The pair of first yoke parts 34a and the pair of second yoke parts 34b are fixed to each other by, for example, an adhesive.

[0049] A recess 36 recessed toward the magnet portion 16 in the first direction D1 is formed in the center of each first yoke portion 34a in the second direction D2. In this reference example 2, the recess 36 is formed such that the length of the first yoke portion 34a in the first direction D1 increases with increasing distance from the center of the magnet portion 16 in the second direction D2. In this reference example 2, the surface 34c (see FIG. 9) to which the magnet portion 16 is fixed in the first yoke portion 34a is flat and extends in a direction perpendicular to the first direction D1. As a result, in the portion where the recess 36 is formed, the area of ​​the cross section perpendicular to the second direction D2 of the first yoke portion 34a increases with increasing distance from the center of the magnet portion 16 in the second direction D2.

[0050] In this reference example 2, corners 34d (outer corners in the first direction D1) at both ends in the second direction D2 of each first yoke portion 34a are cut out in a C-shaped shape, so that the length in the first direction D1 of both ends of the yoke 34 in the second direction D2 becomes smaller toward the outside in the second direction D2.

[0051] As in the magnetic field orientation device 14 according to the above-mentioned Reference Example 1, the outer edge of the magnet portion 16 is positioned inside the outer edge of the first yoke portion 34a when viewed from the first direction D1. In other words, the first yoke portion 34a protrudes further in the third direction D3 than the magnet portion 16. As in the above-mentioned Reference Example 1, in the present Reference Example 2, the length of the first yoke portion 34a (corresponding to the length b in FIG. 4(b)) in the third direction D3 is preferably 1.1 times or more, more preferably 1.6 times or more, of the length of the magnet portion 16 (corresponding to the length a in FIG. 4(b)). Note that, in the present Reference Example 2, the length of the second yoke portion 34b in the third direction D3 is set to be the same as the length of the first yoke portion 34a.

[0052] (Effects of Reference Example 2) In the magnetic field orientation device 32 according to the present reference example 2, as in the magnetic field orientation device 14 according to the above-mentioned reference example 1, the outer edge of the magnet part 16 is positioned inside the outer edge of the first yoke part 34a when viewed from the first direction D1. This makes it possible to suppress radial leakage of magnetic flux from the end face (the end face fixed to the first yoke part 34a) of the magnet part 16 on the first yoke part 34a side. As a result, when a plurality of magnetic field orientation devices 32 are arranged in the conveying direction A, it is possible to prevent a large repulsive force from being generated between the magnetic field orientation devices 32 adjacent to each other in the conveying direction A. This makes it easy to install the magnetic field orientation devices 32 close to each other. In addition, since the leakage of magnetic flux can be suppressed as described above, the strength of the demagnetizing field generated on the inlet side and the outlet side of the magnetic field orientation unit 30 can be sufficiently reduced. This makes it possible to appropriately apply a unidirectional magnetic field to the workpiece W.

[0053] In this reference example 2, a recess 36 recessed toward the magnet part 16 in the first direction D1 is formed in the center of each first yoke part 34a in the second direction D2. As described with respect to the yoke 18 shown in FIG. 4, the amount of magnetic flux passing through the center of the first yoke part 18a (see FIG. 4) to which the magnet part 16 is fixed is smaller than the amount of magnetic flux passing through other parts of the first yoke part 18a. Therefore, in this reference example 2, even if the cross-sectional area of ​​the center of the first yoke part 34a is reduced by forming the recess 36 in the center of the first yoke part 34a, the flow of magnetic flux in the yoke 34 is not obstructed. That is, in this reference example 2, the volume of the yoke 34 (first yoke part 34a) can be reduced without obstructing the flow of magnetic flux. This allows the magnetic field orientation device 32 to be made lighter without deteriorating the performance of the magnetic field orientation device 32. As a result, the installation of the magnetic field orientation device 32 becomes even easier.

[0054] In this reference example 2, the magnetic flux generated by the pair of magnet parts 16 flows in the first yoke part 34a from the inside to the outside in the second direction D2 (or from the outside to the inside in the second direction D2). Therefore, the amount of magnetic flux passing through the first yoke part 34a (more specifically, the outer part of the magnet part 16 in the first direction D1) increases as it moves away from the center of the magnet part 16 in the second direction D2. Therefore, in this reference example 2, the recess 36 is formed so that the length of the first yoke part 34a in the first direction D1 increases as it moves away from the center of the magnet part 16 in the second direction D2. Thereby, the cross-sectional area (area of ​​the cross section perpendicular to the second direction D2) of the part of the first yoke part 34a outside the magnet part 16 in the first direction D1 increases as it moves away from the center of the magnet part 16 in the second direction D2. As a result, the magnetic flux can flow smoothly in the first yoke part 34a (yoke 34).

[0055] In this reference example 2, the corners 34d of each first yoke part 34a are cut out in a C-shaped shape so that the length in the first direction D1 of both ends of the yoke 34 in the second direction D2 becomes shorter toward the outside in the second direction D2. As described with the yoke 18 shown in FIG. 4, the amount of magnetic flux passing through the four corners of the yoke 18 is smaller than the amount of magnetic flux passing through other parts of the first yoke part 18a (see FIG. 4). Therefore, in this reference example 2, even if the corners 34d of each first yoke part 34a are cut out, the flow of magnetic flux in the yoke 34 is not obstructed. That is, the volume of the yoke 34 can be reduced without obstructing the flow of magnetic flux. This allows the magnetic field orientation device 32 to be further lightened without deteriorating the performance of the magnetic field orientation device 32.

[0056] 9, the recesses 36 are formed so that the length of the first yoke portion 34a in the first direction D1 increases continuously with increasing distance from the center of the magnet portion 16 in the second direction D2, but the shape of the recesses is not limited to the above example. For example, the recesses may be formed so that the length of the first yoke portion 34a in the first direction D1 increases stepwise with increasing distance from the center of the magnet portion 16 in the second direction D2.

[0057] 9, the corners 34d of the first yoke portion 34a are cut out in a C-shaped manner, but the shape of the corners 34d is not limited to the above example. For example, the corners 34d may be cut out in a R-shaped manner.

[0058] 8, the multiple magnetic field orientation devices 32 are provided so as to be in contact with each other in the conveying direction A, but a gap may be provided between adjacent magnetic field orientation devices 32 in the conveying direction A. In this case, however, it is preferable to adjust the distance between the magnetic field orientation devices 32 so as to prevent a demagnetizing field from being generated between the adjacent magnetic field orientation devices 32 in the conveying direction A.

[0059] In the above-mentioned reference examples 1 and 2, the magnet unit 16 is configured by a plurality of magnets 16a arranged in a line, but in one embodiment of the present invention, the magnet unit 16 is configured by a plurality of magnets arranged in multiple rows. That is, the plurality of magnets are arranged so as to be lined up in multiple rows in the third direction D3. Hereinafter, a specific description will be given with reference to the drawings.

[0060] (Magnetic field orientation device according to the embodiment) 10 is a diagram for explaining a magnetic field orientation device according to an embodiment of the present invention, in which (a) is a perspective view showing the magnetic field orientation device, and (b) is a view showing the magnet part from the first direction D1. In this embodiment, the pair of first yoke parts 34a and the pair of second yoke parts 34b of the yoke 34 are integrally formed.

[0061] 10, in this embodiment, each magnet section 16 includes a plurality of magnet rows 161-164 aligned in the third direction D3. Each of the plurality of magnet rows 161-164 is composed of a plurality of rectangular parallelepiped magnets 16a aligned in the second direction D2. That is, in this embodiment, the plurality of magnets 16a are arranged in a plurality of rows in the third direction D3.

[0062] In each of the magnet rows 161-164, boundaries 16b between magnets 16a adjacent to each other in the second direction D2 exist so as to extend in the third direction D3. In this embodiment, in each of the magnet rows 161-164, a plurality of boundaries 16b extending in the third direction D3 exist so as to be aligned in the second direction D2.

[0063] The magnets 16a of one of the magnet rows 161-164 and the magnets 16a of the other magnet rows adjacent to the one are arranged so as to be offset from each other in the second direction D2. In other words, the magnets 16a of the magnet unit 16 are arranged in a staggered pattern. In this embodiment, the magnets 16a of each of the magnet rows 161-164 are arranged so as to be offset from the magnets 16a of the other magnet rows in the second direction D2. For example, the magnets 16a of the magnet row 161 are arranged so as to be offset from the magnets 16a of the other magnet rows 162-164 in the second direction D2. As a result, the boundaries 16b of one of the magnet rows 161-164 and the boundaries 16b of the other magnet rows of the magnet rows 161-164 are offset from each other in the second direction D2.

[0064] Since the magnet 16a is a hard metal part, when the magnet 16a has a rectangular parallelepiped shape, chipping is likely to occur at the ridges of the magnet 16a. If chipping occurs at the ridges of the magnet 16a, the plating applied to the surface of the magnet 16a will peel off, and rust may occur from the peeled off portion. For this reason, it is preferable to chamfer the ridges of the magnet 16a. On the other hand, by chamfering the ridges of the magnet 16a, the multiple boundaries 16b of the magnet part 16 become recessed compared to other parts. In the parts where these recesses are formed, the magnetic force of the magnet part 16 is slightly reduced. This causes magnetization unevenness to occur in the workpiece W (FIG. 2).

[0065] In this embodiment, as described above, the magnets 16a of one of the magnet rows 161-164 and the magnets 16a of another magnet row adjacent to the magnet row are arranged to be shifted from each other in the second direction D2. This makes it possible to prevent the portion (boundary portion 16b) where the magnetic force is reduced in the magnet section 16 from being continuously present in the third direction D3 across the magnet rows 161-164. In other words, the portion (boundary portion 16b) where the magnetic force is reduced in one of the magnet rows 161-164 can be compensated for by the magnetic force of the magnets 16a of the other magnet row adjacent to the magnet row. As a result, it is possible to prevent the portion where the magnetization state is weak from being continuously extended in the third direction D3 (work transport direction) in the work W (FIG. 2), and to reduce the magnetization unevenness of the work W.

[0066] 10, the positions in the second direction D2 of the multiple magnets 16a of one magnet row 161 facing the first direction D1 are equal to the positions in the second direction D2 of the multiple magnets 16a of the other magnet row 161. The same applies to the positional relationship in the second direction D2 between the multiple magnets 16a of one magnet row 162-164 facing the first direction D1 and the multiple magnets 16a of the other magnet row 162-164. However, the multiple magnets 16a of one magnet row facing the first direction D1 and the multiple magnets 16a of the other magnet row may be arranged to be shifted in the second direction D2.

[0067] In addition, when the magnet section 16 is composed of a plurality of magnets 16a arranged in a row, it is preferable that the plurality of magnets 16a of one of the plurality of magnetic field orientation devices 32 and the plurality of magnets 16a of another magnetic field orientation device 32 adjacent to that magnetic field orientation device 32 are arranged so as to be shifted from each other in the second direction D2. This makes it possible to reduce magnetization unevenness of the workpiece W, similar to the case where the magnetic field orientation device 32 shown in FIG. 10 is used.

[0068] (Other reference examples) Also, the magnet unit 16 may be configured by arranging rectangular parallelepiped magnets extending in the second direction D2 in the third direction D3. Also, in the above embodiment, the magnet unit 16 is configured by a plurality of magnets 16a, but the magnet unit 16 may be configured by a single magnet.

[0069] FIG. 11 is a diagram showing a magnetic field orientation device 32 according to Reference Example 3. FIG. 11 shows the magnetic field orientation device 32 as viewed from the first direction D1. The magnetic field orientation device 32 shown in FIG. 11 differs from the magnetic field orientation device 32 shown in FIG. 8 in that the length of the first yoke portion 34a in the third direction D3 is shorter at the center in the second direction D2. In this way, the length of the first yoke portion 34a in the third direction D3 may be shorter depending on the position in the second direction D2. In addition, when the length of the first yoke portion 34a in the third direction D3 or the length of the magnet portion 16 in the third direction D3 changes depending on the position in the second direction D2, the length of the first yoke portion 34a in the third direction D3 is preferably 1.1 times or more, more preferably 1.6 times or more, of the length of the magnet portion 16 in the third direction D3 in a cross section perpendicular to the second direction D2 and passing through the magnet portion 16 and the first yoke portion 34a, regardless of the position in the second direction D2. Therefore, in the magnetic field orientation device 32 shown in FIG. 11, in both the BB cross section and the CC cross section, the length of the first yoke portion 34a in the third direction D3 is preferably 1.1 times or more, and more preferably 1.6 times or more, the length of the magnet portion 16 in the third direction D3.

[0070] (Modification) Fig. 12 is a perspective view showing a magnetic field orientation unit equipped with a magnetic field orientation device according to a modified example. As shown in Fig. 12, the magnetic field orientation unit 20 according to this modified example is equipped with a plurality of magnetic field orientation devices 22. The plurality of magnetic field orientation devices 22 are arranged in a line in the conveying direction A of the workpiece W (see Fig. 2), similar to the above-mentioned plurality of magnetic field orientation devices 14.

[0071] Each magnetic field orientation device 22 includes a pair of magnet parts 24 and a yoke 26 that holds the pair of magnet parts 24. The pair of magnet parts 24 are magnetized in a first direction D1. The pair of magnet parts 24 are arranged so that the opposite poles face each other in the first direction D1 and are spaced apart from each other. As a result, a unidirectional magnetic field is generated between the pair of magnet parts 24 from one magnet part 24 to the other magnet part 24. In this modification, when the workpiece W (see FIG. 2) passes through the gap between the pair of magnet parts 24, a magnetic field is applied to the workpiece W. The distance between the pair of magnet parts 24 in the first direction D1 is appropriately adjusted depending on the type, application, etc. of the workpiece W. The magnet part 24 can be configured in the same manner as the magnet part 16 described above, so a detailed description of the magnet part 24 will be omitted.

[0072] The yoke 26 is made of a magnetic material such as steel, similar to the above-described yoke 18. In this modification, the yoke 26 has a C-shape (U-shape) when viewed from the third direction D3. Specifically, the yoke 26 includes a pair of first yoke portions 26a and a second yoke portion 26b. Each of the pair of first yoke portions 26a is supported in a cantilever manner by the second yoke portion 26b. In FIG. 12, the boundary between the first yoke portion 26a and the second yoke portion 26b is indicated by a dashed line.

[0073] In this modification, the first yoke portion 26a has a uniform portion 61 and a decreasing portion 62 in this order from one side in the second direction D2. In this modification, the uniform portions 61 of the pair of first yoke portions 26a are connected to each other by the second yoke portion 26b. The uniform portion 61 is a portion of the first yoke portion 26a in which the area of ​​a cross section perpendicular to the second direction D2 is uniform. The decreasing portion 62 is a portion in which the area of ​​a cross section perpendicular to the second direction D2 decreases continuously from the second yoke portion 26b (uniform portion 61) side toward the tip portion 63 of the first yoke portion 26a. In this modification, the length of the decreasing portion 62 in the third direction D3 decreases stepwise from the second yoke portion 26b side toward the tip portion 63, and the length of the decreasing portion 62 in the first direction D1 decreases continuously from the second yoke portion 26b side toward the tip portion 63.

[0074] The magnet portions 24 are fixed to the pair of first yoke portions 26a, respectively. The second yoke portions 26b are provided outward of the pair of magnet portions 24 in the second direction D2, and connect the pair of first yoke portions 26a.

[0075] As with the above-described magnetic field orientation device 14, in the magnetic field orientation device 22 according to this modification, the outer edge of the magnet portion 24 is positioned more inward than the outer edge of the first yoke portion 26a when viewed from the first direction D1. As with the above-described magnetic field orientation device 14, the length of the first yoke portion 26a in the third direction D3 is preferably 1.1 times or more, and more preferably 1.6 times or more, the length of the magnet portion 24. Also in this modification, the length of the second yoke portion 26b in the third direction D3 is set to be the same as the length of the first yoke portion 26a.

[0076] (Action and effect) In the magnetic field orientation device 22 according to this modification, the outer edge of the magnet part 24 is positioned inside the outer edge of the first yoke part 26a as viewed from the first direction D1. This makes it possible to suppress radial leakage of magnetic flux from the end face of the magnet part 24 on the first yoke part 26a side (the end face fixed to the first yoke part 26a). As a result, when multiple magnetic field orientation devices 22 are arranged in the conveying direction A, it is possible to prevent a large repulsive force from being generated between the magnetic field orientation devices 22 adjacent to each other in the conveying direction A. This makes it easy to install the magnetic field orientation devices 22 close to each other. Also, similar to the above-mentioned magnetic field orientation device 14, the strength of the demagnetizing field can be sufficiently reduced.

[0077] Moreover, the magnetic field orientation device 22 according to this modification has a yoke 26 having a C-shape (U-shape) when viewed from the third direction D3. This allows the magnetic field orientation device 22 to be fitted into the conveyor belt 104 from the side of the conveyor belt 104, for example, making it easier to install the magnetic field orientation device 22. Furthermore, when arranging a plurality of magnetic field orientation devices 22, one of the magnetic field orientation devices 22 and another magnetic field orientation device 22 can be fitted into the conveyor belt 104 from the opposite side in the second direction D2. This improves the degree of freedom in arranging the magnetic field orientation devices 22.

[0078] In the magnetic field orientation device 22 according to this modification, the first yoke portion 26a is supported by the second yoke portion 26b in a cantilevered manner. In this case, the amount of magnetic flux passing through the tip portion 63 side of the first yoke portion 26a is smaller than the amount of magnetic flux passing through the second yoke portion 26b side of the first yoke portion 26a. Therefore, even if the cross-sectional area of ​​the tip portion 63 side of the first yoke portion 26a is made smaller than the cross-sectional area of ​​the second yoke portion 26b side of the first yoke portion 26a, the flow of magnetic flux is not hindered. Therefore, in this modification, a reduced portion 62 is provided on the tip portion 63 side of the first yoke portion 26a. This makes it possible to reduce the volume of the first yoke portion 26a without hindering the flow of magnetic flux. As a result, it is possible to reduce the weight of the magnetic field orientation device 22 without deteriorating the performance of the magnetic field orientation device 22.

[0079] In the above-described modified example, in the reduced portion 62, the area of ​​the cross section perpendicular to the second direction D2 decreases continuously from the second yoke portion 26b side toward the tip portion 63, but the area of ​​the cross section perpendicular to the second direction D2 may decrease stepwise from the second yoke portion 26b side toward the tip portion 63. [Industrial Applicability]

[0080] According to the present invention, it is possible to obtain a magnetic field orientation device that is easy to install and a magnetic field orientation unit including the same. [Explanation of symbols]

[0081] 1,10 equipment 12,20,30 Magnetic field alignment unit 14, 22, 32 Magnetic field alignment device 16,24 Magnet section 18,26,34 York 18a, 26a, 34a First yoke section 18b, 26b, 34b Second yoke section

Claims

1. A pair of magnet portions arranged apart from each other so that opposite poles face each other in a first direction; a yoke for holding the pair of magnet portions; The yoke is a pair of first yoke portions provided outside the pair of magnet portions in the first direction and to which the magnet portions are respectively fixed; a second yoke portion that is provided on an outer side of the pair of magnet portions in a second direction perpendicular to the first direction and connects the pair of first yoke portions, When viewed from the first direction, an outer edge of the magnet portion is positioned more inward than an outer edge of the first yoke portion, the magnet unit includes a plurality of magnet rows arranged in a third direction perpendicular to the first direction and the second direction, Each of the magnet rows includes a plurality of magnets arranged in the second direction, A magnetic field orientation device, wherein the plurality of magnets in one magnet row among the plurality of magnet rows and the plurality of magnets in another magnet row adjacent to the one magnet row are arranged so as to be offset from each other in the second direction.

2. The magnetic field orientation device according to claim 1 , wherein the second yoke portion is provided on one side and the other side of the pair of magnet portions in the second direction.

3. the yoke has a C-shape when viewed from a third direction perpendicular to the first direction and the second direction, The magnetic field orientation device according to claim 1 , wherein each of the pair of first yoke portions is supported by the second yoke portion in a cantilever manner.

4. 4. The magnetic field orientation device of claim 3, wherein when the end of the first yoke portion opposite the second yoke portion in the second direction is defined as the tip portion, the first yoke portion includes a decreasing portion in which the area of ​​a cross section perpendicular to the second direction decreases continuously or stepwise from the second yoke portion side toward the tip portion.

5. 2. The magnetic field orientation device according to claim 1, wherein in a third direction perpendicular to the first direction and the second direction, a length of the first yoke portion is 1.1 times or more a length of the magnet portion.

6. 2. The magnetic field orientation device according to claim 1, wherein in a third direction perpendicular to the first direction and the second direction, a length of the first yoke portion is 1.6 times or more a length of the magnet portion.

7. The magnetic field orientation device according to claim 1 , wherein in a third direction perpendicular to the first direction and the second direction, a length of the second yoke portion is longer than a length of the magnet portion.

8. A plurality of magnetic field orientation devices each having a pair of magnet parts arranged so that opposite poles face each other and are spaced apart from each other in a first direction, and a yoke that holds the pair of magnet parts, The yoke is a pair of first yoke portions provided outside the pair of magnet portions in the first direction and to which the magnet portions are respectively fixed; a second yoke portion that is provided on an outer side of the pair of magnet portions in a second direction perpendicular to the first direction and connects the pair of first yoke portions, When viewed from the first direction, an outer edge of the magnet portion is positioned more inward than an outer edge of the first yoke portion, The plurality of magnetic field orientation devices are arranged to be aligned in a third direction perpendicular to the first direction and the second direction, The magnet portion of each of the magnetic field orientation devices includes a plurality of magnets arranged in the second direction, A magnetic field orientation unit, wherein the plurality of magnets of one of the plurality of magnetic field orientation devices and the plurality of magnets of another magnetic field orientation device adjacent to the one magnetic field orientation device are arranged so as to be offset from each other in the second direction.

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