Permanent electromagnetic adsorption device

Abstract

To provide a permanent electromagnetic adsorption device that can adjust the reach of magnetic flux within an object to be attracted with a simple configuration.SOLUTION: A permanent electromagnetic adsorption device 10 includes a magnetic force generating unit 12 including a coil 20, a first magnet 22 that is magnetized in a first direction or a second direction along an axial direction X depending on the direction of current flow through the coil 20, and a second magnet 24 whose magnetization direction is fixed, and a yoke unit 14 that houses the magnetic force generating unit 12 and has an attraction surface 14a that attracts an object 100 to be attracted. The attraction surface 14a is switchable between a state in which it attracts the object to be attracted and a state in which it does not attract the object to be attracted, depending on the magnetization direction of the first magnet 22. The yoke unit 14 includes a recess 46b recessed from the attraction surface 14a for adjusting the area of the attraction surface 14a.SELECTED DRAWING: Figure 8

Description

[Technical Field]

[0001] The present invention relates to a permanent electromagnetic attraction device that can be switched between a state in which an object is attracted by the magnetic force of a permanent magnet and a state in which the object is not attracted. [Background technology]

[0002] Conventionally, in steelworks, steel processing plants, and the like, devices for attracting steel plates have been used to suspend and transport the steel plates. For example, a lifting device disclosed in Patent Document 1 includes multiple electromagnetic coils arranged in a nested manner. The multiple electromagnetic coils are arranged so that the maximum magnetic flux amount of the electromagnetic coil on the innermost layer is smaller than the maximum magnetic flux amount of the electromagnetic coil on the outermost layer.

[0003] Patent Document 1 describes that with the lifting device having the above configuration, the electromagnetic coils can be used selectively or in appropriate combination, making it possible to control the magnetic flux penetration depth with high precision according to the number of steel plates being lifted. Patent Document 1 also describes that by controlling the voltage applied to the electromagnetic coils, it is possible to control the number of steel plates being lifted with high precision. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 7287479 Summary of the Invention [Problem to be solved by the invention]

[0005] As described in Patent Document 1, it is believed possible to control the number of steel plates suspended by selectively using an electromagnetic coil or by controlling the voltage applied to the electromagnetic coil. However, there is a need for a simpler configuration to adjust the number of steel plates suspended.

[0006] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a permanent electromagnetic attraction device that can adjust the reach of magnetic flux within an object to be attracted with a simple configuration. [Means for solving the problem]

[0007] A permanent electromagnetic suction device according to one aspect of the present invention comprises: a magnetic force generating unit including a coil, a first magnet that is magnetized in a first direction along the axial direction of the coil or a second direction opposite to the first direction depending on the direction of current flow through the coil, and a second magnet whose magnetization direction is fixed; a yoke portion that houses the magnetic force generating portion and has an attraction surface that attracts an object to be attracted, the attraction surface is switched between a state in which it attracts the attraction target and a state in which it does not attract the attraction target, depending on the magnetization direction of the first magnet; The yoke portion has a recess that is recessed from the suction surface and that adjusts the area of ​​the suction surface. [Effects of the Invention]

[0008] According to the present invention, a permanent electromagnetic attraction device can be obtained that has a simple configuration and is capable of adjusting the reach distance of magnetic flux within an object to be attracted. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a perspective view showing a permanent electromagnetic chucking device according to an embodiment of the present invention. [Figure 2] FIG. 2 is a view of the permanent electromagnetic chucking device as seen from one side in the axial direction. [Figure 3] FIG. 3 is a schematic cross-sectional view showing a portion AA in FIG. [Figure 4] FIG. 4 is a diagram showing the permanent electromagnetic chucking device when the chucking surface is in a state of being chucking the object to be chucking. [Figure 5] FIG. 5 is a diagram showing the permanent electromagnetic attraction device when the attraction surface is not in a state where it is attracted to the object to be attracted. [Figure 6]FIG. 6 is a conceptual diagram showing the relationship between the size of the recess and the reach of the magnetic flux within the object to be attracted. [Figure 7] FIG. 7 is a diagram showing a yoke main body and a plurality of second yoke components. [Figure 8] FIG. 8 is a schematic diagram showing a case where a steel plate is suspended as an object to be attracted by a permanent electromagnetic attraction device. [Figure 9] FIG. 9 is a diagram showing another example of a method for adjusting the area of ​​the adsorption surface. [Figure 10] FIG. 10 is a diagram showing a modified example of a permanent electromagnetic chucking device. [Figure 11] FIG. 11 is a perspective view showing an example of a permanent electromagnetic chucking device provided with a plurality of magnetic force generating units. [Figure 12] 12 is a view of the permanent electromagnetic chucking device of FIG. 11 as viewed from one side in the axial direction X. FIG. [Figure 13] FIG. 13 is a schematic cross-sectional view showing a portion BB in FIG. DETAILED DESCRIPTION OF THE INVENTION

[0010] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A permanent electromagnetic chucking device according to an embodiment of the present invention will now be described with reference to the drawings.

[0011] (Basic configuration of a permanent electromagnetic suction device) Fig. 1 is a perspective view showing a permanent electromagnetic chucking device according to an embodiment of the present invention. In Fig. 1, an arrow X indicates a direction parallel to the axial direction of a coil 20 (see Fig. 3), which will be described later. Hereinafter, the direction parallel to the axial direction of the coil 20 will be simply referred to as the axial direction X. Fig. 2 is a view of the permanent electromagnetic chucking device as seen from one side in the axial direction X. Fig. 3 is a schematic cross-sectional view showing the AA portion of Fig. 2.

[0012] Although details will be described later, the permanent electromagnetic attraction device 10 according to this embodiment is configured to be switchable between a state in which it attracts an object made of a magnetic material and a state in which it does not attract the object. The permanent electromagnetic attraction device 10 is used, for example, in industrial robots, unmanned transport systems, drones, etc. to attract and hold iron products, etc. However, the uses of the permanent electromagnetic attraction device 10 are not limited to these uses and can be used for various purposes in which it attracts an object made of a magnetic material.

[0013] 1 to 3, a permanent electromagnetic chucking device 10 according to this embodiment includes a magnetic force generating unit 12 (see FIG. 3) and a yoke unit 14 that houses the magnetic force generating unit 12. As shown in FIG. 3, the magnetic force generating unit 12 includes a coil 20, a columnar or disk-shaped first magnet 22, and a cylindrical or ring-shaped second magnet 24. In this embodiment, the first magnet 22 and the second magnet 24 are provided on one side of the coil 20 in the axial direction X.

[0014] The coil 20 is electrically connected to an external power supply (not shown). The coil 20 is a solenoid coil. In this embodiment, the coil 20 magnetizes the first magnet 22 when energized.

[0015] The first magnet 22 is disposed coaxially with the coil 20. In this embodiment, the first magnet 22 is disposed so as to be located inside the coil 20 when viewed from the axial direction X. In this embodiment, the first magnet 22 has a cylindrical shape. The first magnet 22 is magnetized in a first direction X1 along the axial direction X or a second direction X2 opposite to the first direction X1, depending on the direction of current flow through the coil 20. In other words, the magnetization direction of the first magnet 22 switches depending on the direction of current flow through the coil 20 when the first magnet 22 is magnetized by the coil 20. Note that in this specification, the magnetization direction of a magnet means the direction from the south pole to the north pole. In the state shown in FIG. 3, the first magnet 22 is magnetized in the first direction X1.

[0016] As the first magnet 22, for example, an alnico magnet, an iron-chromium-cobalt magnet, or the like can be used. In this embodiment, the first magnet 22 has a shape in which the length in the axial direction X is shorter than the length in the direction perpendicular to the axial direction X (in this embodiment, the diameter), but the length in the axial direction X may be longer than the length in the direction perpendicular to the axial direction X. Also, in this embodiment, the length of the first magnet 22 in the axial direction X is shorter than the length of the coil 20, but the length of the first magnet 22 in the axial direction X may be longer than the length of the coil 20.

[0017] The second magnet 24 is arranged coaxially with the coil 20. In this embodiment, the second magnet 24 is arranged so as to be located outside the first magnet 22 when viewed from the axial direction X. In this embodiment, the second magnet 24 has a cylindrical shape. The magnetization direction of the second magnet 24 is fixed. In this embodiment, the second magnet 24 is magnetized in a direction along the axial direction X. More specifically, the second magnet 24 is magnetized in a first direction X1. The coercive force of the second magnet 24 is greater than that of the first magnet 22. As the second magnet 24, for example, a neodymium magnet is used.

[0018] The magnetic force generating unit 12 is housed in a yoke unit 14. The yoke unit 14 is made of a magnetic material such as iron. In this embodiment, the yoke unit 14 has a cylindrical shape. The yoke unit 14 is provided with an attraction surface 14a that attracts an object to be attracted. The attraction surface 14a is provided on one side of the first magnet 22 and the second magnet 24 in the axial direction X.

[0019] In this embodiment, the yoke portion 14 has a first yoke component 42, a second yoke component 46, a third yoke component 40, and a fourth yoke component 44. In this embodiment, the third yoke component 40 has a cylindrical shape and houses the coil 20. The first magnet 22 is provided on one side of the third yoke component 40 in the axial direction X so as to be supported by the third yoke component 40. In this embodiment, the first magnet 22 is fixed to the third yoke component 40.

[0020] The first yoke component 42 has a cylindrical shape and is provided on one side of the third yoke component 40 in the axial direction X so as to surround the first magnet 22. The first yoke component 42 is fixed to the third yoke component 40. In this embodiment, an end surface 42a on one side of the first yoke component 42 in the axial direction X corresponds to the first attraction surface. Hereinafter, the end surface 42a of the first yoke component 42 will be referred to as the first attraction surface 42a.

[0021] A ring-shaped spacer 26 is provided between the first magnet 22 and the first yoke member 42. The spacer 26 is made of, for example, a magnetic material. The second magnet 24 is provided on one side of the spacer 26 in the axial direction X so as to be supported by the spacer 26.

[0022] The fourth yoke component 44 has a hollow cylindrical shape. In this embodiment, a screw hole 44a is formed in the center of the fourth yoke component 44. The fourth yoke component 44 is provided on one side of the first magnet 22 and the second magnet 24 in the axial direction X so as to be supported by the first magnet 22 and the second magnet 24. In this embodiment, the first yoke component 42, the third yoke component 40, and the fourth yoke component 44 form a yoke main body 48.

[0023] The second yoke component 46 has a hollow cylindrical shape. In this embodiment, a through-hole 46a is formed in the center of the second yoke component 46, through which a fastening member 30 (described later) is inserted. A recess 46b is formed in the center of one end face 47 of the second yoke component 46 in the axial direction X. In this embodiment, an annular region 47a on the end face 47, which is outside the recess 46b, corresponds to the second suction surface. Hereinafter, the region 47a on the end face 47 of the second yoke component 46 will be referred to as the second suction surface 47a. In this embodiment, the first suction surface 42a and the second suction surface 47a form the suction surface 14a. In this embodiment, the suction surface 14a (the first suction surface 42a and the region 47a) is formed in a planar shape so as to extend in a direction intersecting the axial direction X. In this embodiment, the suction surface 14a is provided so as to extend in a direction perpendicular to the axial direction X.

[0024] A cylindrical spacer 28 is provided inside the first yoke component 42, on one side of the spacer 26 in the axial direction X. The spacer 28 is provided so as to surround the second magnet 24, the fourth yoke component 44, and the second yoke component 46, and to extend to the attraction surface 14a. In this embodiment, the spacer 28 separates the first attraction surface 42a and the second attraction surface 47a. The spacer 28 is made of a non-magnetic material such as resin. In this embodiment, the spacer 28 corresponds to the non-magnetic portion. Note that in this embodiment, the first yoke component 42, the second yoke component 46, and the spacer 28 are provided so that one end face of the spacer 28 in the axial direction X is flush with the first attraction surface 42a of the first yoke component 42 and the second attraction surface 47a of the second yoke component 46.

[0025] In this embodiment, the spacer 28 is formed with a flange portion 28a facing one side in the axial direction X and a flange portion 28b facing the other side in the axial direction X. In this embodiment, the flange portion 28a is hooked onto the first yoke component 42, thereby preventing the spacer 28 from falling off to one side in the axial direction X. The flange portion 28b is hooked onto the fourth yoke component 44, thereby preventing the fourth yoke component 44 from falling off to one side in the axial direction X. If the fourth yoke component 44 can be prevented from falling off by means other than the spacer 28 (for example, an adhesive, a fastening member, etc.), the spacer 28 need not be provided. In this case, the air in the cylindrical gaps between the first yoke component 42 and the second magnet 24, the fourth yoke component 44, and the second yoke component 46 functions as a nonmagnetic portion.

[0026] The second yoke component 46 is fixed to the fourth yoke component 44 by fastening members 30. Screws can be used as the fastening members 30. In this embodiment, the second yoke component 46 is fixed to the fourth yoke component 44 (yoke main body 48) by screwing the fastening members 30 into threaded holes 44a in the fourth yoke component 44. In this embodiment, the fastening members 30 are preferably made of, for example, a magnetic material. In this case, the fastening members 30 can function as part of the yoke component 14.

[0027] (Basic operation of the permanent electromagnetic suction device) In the permanent electromagnetic attraction device 10 according to this embodiment, the magnetization direction of the first magnet 22 is switched by changing the current flow direction of the coil 20, thereby switching the state of the attraction surface 14a between a state in which it attracts the attraction target 100 and a state in which it does not attract the attraction target 100. The time for which current is passed through the coil 20 when switching the state of the attraction surface 14a as described above is, for example, about 0.01 to 0.2 seconds. Note that the method for switching the magnetization direction of the first magnet 22 is the same as in conventional permanent electromagnetic attraction devices, and therefore a detailed description thereof will be omitted.

[0028] Fig. 4 is a diagram showing the permanent electromagnetic attraction device 10 when the attraction surface 14a is in a state where it attracts the attraction target 100. Note that the following will describe a case where the attraction target 100 is suspended by the permanent electromagnetic attraction device 10. In Fig. 4 and Fig. 5 described later, one side in the axial direction X is the lower side, and the other side in the axial direction X is the upper side. In Figs. 4 and 5, the flow of magnetic flux is simplified and shown by thick lines.

[0029] 4, the magnetization direction of the first magnet 22 is set to the first direction X1, similar to that of the second magnet 24. In this case, the magnetic flux generated by the first magnet 22 and the second magnet 24 flows from the fourth yoke member 44 to the object to be attracted 100 via the second attraction surface 47a, and then flows from the object to be attracted 100 to the first yoke member 42 via the first attraction surface 42a. As a result, the object to be attracted 100 is attracted to the attraction surface 14a.

[0030] 5 is a diagram showing the permanent electromagnetic attraction device 10 when the attraction surface 14a is not attracting the attraction target 100. In the example shown in FIG. 5, the magnetization direction (second direction X2) of the first magnet 22 and the magnetization direction (first direction X1) of the second magnet 24 are opposite. In this case, even if the attraction target 100 comes into contact with the attraction surface 14a, the magnetic flux generated by the first magnet 22 and the second magnet 24 does not flow, or barely flows, through the attraction target 100 and the first yoke member 42. Therefore, the attraction target 100 is not attracted to the attraction surface 14a.

[0031] (Adjusting the reach of magnetic flux to the object being attracted) As shown in FIG. 4 , in the permanent electromagnetic attraction device 10 according to this embodiment, a recess 46b is formed in the yoke portion 14 so as to be recessed from the attraction surface 14a. Research by the present inventors has revealed that by adjusting the size (area as viewed in the axial direction X) of the recess 46b and thereby the area of ​​the attraction surface 14a, it is possible to adjust the length in the axial direction X (the length from the attraction surface 14a in the axial direction X) of a portion of the attraction target 100 where a predetermined magnetic flux density (e.g., 1 T) or higher is achieved. The recess 46b was formed based on the above-described findings of the present inventors. That is, the recess 46b is provided to adjust the reach (distance from the attraction surface 14a in the axial direction X) of the magnetic flux generated by the magnetic force generation unit 12 within the attraction target 100. The recess 46b will be described in more detail below.

[0032] FIG. 6 is a conceptual diagram showing the relationship between the size of the recess 46b (the area as viewed from the axial direction X) and the reach of a magnetic flux of a predetermined strength (for example, a magnetic flux density of 1 T or more) within the object to be attracted 100. Note that the relationship shown in FIG. 6 does not faithfully represent the relationship between the size of the recess 46b and the reach of the magnetic flux. As shown in FIG. 6, by increasing the area of ​​the recess 46b, the reach of the magnetic flux within the object to be attracted 100 becomes shorter. Furthermore, as a result of research by the present inventors, it has been found that the force (attraction force) of the permanent electromagnetic attracting device 10 to attract the object to be attracted 100 tends to decrease as the reach of the magnetic flux within the object to be attracted 100 becomes shorter.

[0033] Therefore, in this embodiment, the yoke main body 48 is configured to selectively secure multiple second yoke components having recesses 46b of different sizes (areas as viewed in the axial direction X). FIG. 7 is a diagram showing the yoke main body and multiple second yoke components. FIG. 7 shows the yoke main body 48 and multiple second yoke components 461-463 that are selectively secured to the yoke main body 48. In this embodiment, as described above, the second yoke components 461-463 can be selectively secured to the fourth yoke component 44 of the yoke main body 48 by the fastening members 30. The depth of the recesses 46b need only be sufficient to block the flow of magnetic flux.

[0034] FIG. 8 is a schematic diagram illustrating a case where a steel plate is suspended as an object to be attracted by the permanent electromagnetic attraction device 10. As described above, the larger the size of the recess 46b (the area as viewed from the axial direction X), the shorter the reach of the magnetic flux within the object to be attracted. Therefore, for example, as shown in FIG. 8(a), when a single steel plate 100a is suspended as an object to be attracted by the permanent electromagnetic attraction device 10, a second yoke component 461 having a large recess 46b is attached to the yoke main body 48. Also, for example, as shown in FIG. 8(b), when multiple steel plates 100a are suspended as objects to be attracted by the permanent electromagnetic attraction device 10, a second yoke component 463 having small recesses 46b is attached to the yoke main body 48. In this way, in this embodiment, by changing the size of the recess 46b and adjusting the area of ​​the attraction surface 14a, a desired number of steel plates 100a can be suspended without excess or deficiency.

[0035] As described above, in this embodiment, the reach of the magnetic flux within the object to be attracted can be adjusted by changing the size of the recess 46b to adjust the area of ​​the attraction surface 14a. That is, in this embodiment, the reach of the magnetic flux within the object to be attracted can be adjusted with the simple configuration of changing the size of the recess 46b, without electrical control.

[0036] (Variation) In the above embodiment, the recess 46b has been described as having a circular shape when viewed in the axial direction X, but the shape of the recess is not limited to a circular shape. For example, the recess may be elliptical or polygonal when viewed in the axial direction X. Furthermore, the shape of the yoke portion 14 is not limited to a cylindrical shape. For example, the yoke portion may be prismatic.

[0037] In the above embodiment, the case where one recess 46b is formed in the second yoke component 46 has been described, but a plurality of recesses may be formed in the second yoke component.

[0038] In the above embodiment, the second yoke component 46 (461-463) is fixed to the yoke main body 48 by the fastening members 30, but the second yoke component 46 may also be fixed to the yoke main body 48 by an adhesive.

[0039] In the above embodiment, three second yoke components 461 to 463 are selectively fixed to the yoke main body 48 as the second yoke component 46. However, two yoke components having recesses of different sizes may be prepared as the second yoke components selectively fixed to the yoke main body 48, or four or more yoke components having recesses of different sizes may be prepared.

[0040] In the above embodiment, the area of ​​the attraction surface 14a is adjusted by selectively fixing multiple second yoke components 461-463 having recesses 46b of different sizes. However, the method for adjusting the area of ​​the attraction surface 14a is not limited to the above example. Specifically, the area of ​​the attraction surface 14a of the yoke component 14 may be adjusted by utilizing the recesses 46b of the second yoke component 46. FIG. 9 illustrates another example of a method for adjusting the area of ​​the attraction surface. For example, as shown in FIG. 9, a ring-shaped yoke component 32 made of a magnetic material may be fitted into the recess 46b. In this case, the attraction surface 14a is formed by the end surface 32a of the yoke component 32 on one side in the axial direction X, in addition to the first attraction surface 42a and the second attraction surface 47a. The yoke component 32 is disposed so that the end surface 32a and the second attraction surface 47a are flush with each other. The yoke component 32 may be fixed to the second yoke component 46 by a fastener (not shown) or by an adhesive. In this embodiment as well, the area of ​​the attraction surface 14a can be adjusted by selectively fixing a plurality of yoke members 32 of different dimensions to the second yoke member 46. That is, in this embodiment, the reach of the magnetic flux within the object to be attracted can be adjusted with the simple configuration of fixing the yoke member 32 to the recess 46b.

[0041] Although not shown in the figures, for example, one or more screws made of a magnetic material may be removably attached to the first yoke member or the second yoke member, and the area of ​​the adsorption surface may be adjusted by removing the screws.

[0042] In the above-described embodiment, the fourth yoke component 44 and the second yoke component 46 are provided on one side of the first magnet 22 and the second magnet 24 in the axial direction X. However, the permanent electromagnetic attraction device may be configured so that a second yoke component having a recess can be fixed to the yoke main body 48. FIG. 10 illustrates a modified example of the permanent electromagnetic attraction device. For example, as shown in FIG. 10, a second yoke component 45 having a recess 46b may be provided on one side of the first magnet 22 and the second magnet 24 in the axial direction X. In this embodiment, the yoke main body 48 is formed by the first yoke component 42 and the third yoke component 40. In this embodiment, for example, the second yoke component 45 can be fixed to the yoke main body 48 by fixing the second yoke component 45 to the third yoke component 40 via the first magnet 22, the second magnet 24, and the spacer 26. In this embodiment, the reach of the magnetic flux within the object to be attracted can be adjusted by selectively fixing multiple second yoke components 45 having recesses 46b of different sizes to the yoke main body 48. Furthermore, for example, by selectively fixing a plurality of yoke members 32 (see FIG. 9) having different dimensions to recessed portion 46b of second yoke member 45, the area of ​​adsorption surface 14a can be adjusted.

[0043] In the above embodiment, the first magnet 22 and the second magnet 24 are provided on one side of the coil 20 in the axial direction X, but the configuration of the magnetic force generating unit 12 is not limited to the above example, and the configuration of the magnetic force generating unit of a known permanent electromagnetic chucking device (permanent electromagnetic holder) can be used. For example, the first magnet 22 may be provided inside the coil 20 and the second magnet 24 may be provided outside the coil 20 so that the first magnet 22, the second magnet 24, and the coil 20 overlap each other when viewed in the radial direction of the coil 20. Also, for example, the coil 20 may be provided outside the second magnet 24.

[0044] In the above-described embodiment, the second magnet 24 is magnetized so that one side in the axial direction X is a north pole and the other side is a south pole, but the magnetization direction of the second magnet 24 may be opposite to that in the above-described embodiment. In this case, too, by matching the magnetization direction of the first magnet 22 with the magnetization direction of the second magnet 24, the attraction surface 14a is in a state in which it attracts the object to be attracted, and by making the magnetization direction of the first magnet 22 opposite to the magnetization direction of the second magnet 24, the attraction surface 14a is in a state in which it does not attract the object to be attracted.

[0045] In the above-described embodiment, the yoke portion 14 is described as being composed of multiple yoke members, but the number of yoke members constituting the yoke portion is not limited to the above-described example, and the yoke portion may be composed of two or six or more yoke members.

[0046] In the above embodiment, the first magnet 22 has a cylindrical shape, but the first magnet 22 may have a rectangular prism shape. Also, in the above embodiment, the second magnet 24 has a cylindrical shape, but the second magnet 24 may have a rectangular tubular shape.

[0047] In the above embodiment, the permanent electromagnetic attracting device 10 has been described as having one magnetic force generating unit 12, but the permanent electromagnetic attracting device may also have multiple magnetic force generating units. Fig. 11 is a perspective view showing an example of a permanent electromagnetic attracting device having multiple magnetic force generating units. Fig. 12 is a view of the permanent electromagnetic attracting device of Fig. 11 as seen from one side in the axial direction X. Fig. 13 is a schematic cross-sectional view showing part BB of Fig. 12. In Fig. 12, the position of the coil 20 of the magnetic force generating unit 12 is indicated by a dashed line.

[0048] As shown in Fig. 12, the permanent electromagnetic chucking device 10a according to this embodiment includes a plurality of (six in this embodiment) magnetic force generating units 12 arranged adjacent to each other in the radial direction of the coil 20. The plurality of magnetic force generating units 12 are housed in a yoke unit 140. The configuration of the magnetic force generating units 12 is similar to the configuration of the magnetic force generating unit 12 shown in Fig. 3, and therefore a description thereof will be omitted. Furthermore, although a detailed description thereof will be omitted, each magnetic force generating unit 12 is provided with a spacer 26, a spacer 28, a second yoke member 46, a fourth yoke member 44, and a fastening member 30 shown in Fig. 3.

[0049] 13 , in this embodiment, the yoke portion 140 includes a first yoke portion 52 and a third yoke portion 50 in addition to a plurality of second yoke portions 46 and a plurality of fourth yoke portions 44 provided corresponding to the plurality of magnetic force generators 12, respectively. In this embodiment, the third yoke portion 50 has a cylindrical shape and houses the plurality of coils 20 of the plurality of magnetic force generators 12. The first magnets 22 of each magnetic force generator 12 are provided on one side of the third yoke portion 50 in the axial direction X so as to be supported by the third yoke portion 50. In this embodiment, the first magnets 22 are fixed to the third yoke portion 50.

[0050] The first yoke component 52 is provided on one side of the third yoke component 50 in the axial direction X. The first yoke component 52 is fixed to the third yoke component 50. The first yoke component 52 has a plurality of through holes 52a formed therethrough in the axial direction X to correspond to the plurality of magnetic force generators 12. The first magnets 22 and second magnets 24 of each magnetic force generator 12, as well as the spacers 26, 28, second yoke component 46, fourth yoke component 44, and fastening members 30 corresponding to each magnetic force generator 12, are provided in each through hole 52a.

[0051] In this embodiment, the yoke main body 58 is formed by the first yoke component 52, the third yoke component 50, and the multiple fourth yoke components 44. In this embodiment, the end surface 52b of the first yoke component 52 on one side in the axial direction X corresponds to the first suction surface. Hereinafter, the end surface 52b of the first yoke component 52 will be referred to as the first suction surface 52b. Similarly to the above-described embodiment, the annular area outside the recess 46b on the end surface 47 of each second yoke component 46 is the second suction surface 47a. In this embodiment, the first suction surface 52b and the multiple second suction surfaces 47a form the suction surface 140a. The suction surface 140a is formed in a planar shape extending in a direction intersecting the axial direction X.

[0052] In the permanent electromagnetic attracting device 10a according to this embodiment, as in the above-described permanent electromagnetic attracting device 10, the reach of the magnetic flux within the attracting object can be adjusted by changing the size of the recesses 46b by replacing each second yoke member 46 and adjusting the area of ​​the attracting surface 140a. That is, in this embodiment as well, the reach of the magnetic flux within the attracting object can be adjusted with the simple configuration of changing the size of the recesses 46b of each second yoke member 46.

[0053] In this embodiment, by controlling the current supplied to the coils 20 of the multiple magnetic force generating units 12, it is possible to place one of the multiple magnetic force generating units 12 in a state in which it attracts the object to be attracted, and the other magnetic force generating units 12 in a state in which it does not attract the object to be attracted. In this way, by selectively placing the multiple magnetic force generating units 12 in a state in which it attracts the object to be attracted or a state in which it does not attract the object to be attracted, it is possible to adjust the attracting force of the permanent electromagnetic attracting device 10a. For example, the number of magnetic force generating units 12 that are in a state in which they attract the object to be attracted may be adjusted depending on the weight of the object to be attracted, etc.

[0054] Furthermore, in this embodiment, the dimensions of the recesses 46b of any one of the multiple second yoke components 46 may be different from the dimensions of the recesses 46b of the other second yoke components 46. For example, the dimensions of the recesses 46b of half of the multiple second yoke components 46 (hereinafter referred to as the first group of second yoke components 46) may be different from the dimensions of the recesses 46b of the other half of the second yoke components 46 (hereinafter referred to as the second group of second yoke components 46). In this case, the first group of second yoke components 46 or the second group of second yoke components 46 can be selectively placed in a state in which they attract the object to be attracted, depending on the thickness of the object, thereby allowing the permanent electromagnetic attracting device 10a to more appropriately suspend the object to be attracted.

[0055] Although detailed description will be omitted, similar to the permanent electromagnetic attracting device 10 described above, the shape of each part of the permanent electromagnetic attracting device 10a is not particularly limited. Furthermore, the number of yoke members constituting the yoke section is also not particularly limited. Similarly to the attracting surface 14a in the permanent electromagnetic attracting device 10 described above, the area of ​​the attracting surface 140a can be adjusted using various means. For example, the area of ​​the attracting surface may be adjusted by fixing a ring-shaped yoke member to the recess 46b of each second yoke member 46, or the area of ​​the attracting surface may be adjusted by removably attaching one or more screws made of a magnetic material to the first yoke member or the second yoke member and removing the screws.

[0056] In this embodiment, the permanent electromagnetic attraction device is configured so that the second yoke member having the recessed portion can be fixed to the yoke main body. Therefore, for example, one second yoke member having the recessed portion 46b may be provided on one side of the first magnet 22 and the second magnet 24 in the axial direction X.

[0057] Furthermore, in the above-described embodiment, the permanent electromagnetic suction device 10a is described as having six magnetic force generating units 12, but the number of magnetic force generating units provided in the permanent electromagnetic suction device may be five or less, or seven or more. [Industrial Applicability]

[0058] According to the present invention, a permanent electromagnetic attraction device can be obtained that has a simple configuration and is capable of adjusting the reach distance of magnetic flux within an object to be attracted. [Explanation of symbols]

[0059] 10,10a Permanent electromagnetic adsorption device 12 Magnetic force generating unit 14,140 York 14a,140a Adsorption surface 20 coils 22 First magnet 24 Second magnet 32, 40, 42, 44, 45, 46, 50, 52 Yoke members 46b Recess 48,58 Yoke body

Claims

1. a magnetic force generating unit including a coil, a first magnet that is magnetized in a first direction along the axial direction of the coil or a second direction opposite to the first direction depending on a direction of current flow through the coil, and a second magnet whose magnetization direction is fixed; a yoke portion that houses the magnetic force generating portion and has an attraction surface that attracts an object to be attracted, the attraction surface is switched between a state in which it attracts the object to be attracted and a state in which it does not attract the object to be attracted, depending on the magnetization direction of the first magnet; The yoke portion has a recess that is recessed from the attraction surface and that adjusts the area of ​​the attraction surface.

2. the yoke portion has a yoke main body portion including a first yoke member having a first suction surface that attracts the object to be attracted, and a second yoke member that is a separate member from the first yoke member and has a second suction surface that attracts the object to be attracted, The permanent electromagnetic chucking device according to claim 1 , wherein the recess is provided in the second yoke member.

3. 3. The permanent electromagnetic chucking device according to claim 2, wherein a plurality of second yoke members having recesses of different sizes can be selectively fixed to the yoke main body.

4. 4. The permanent electromagnetic chucking device according to claim 2, wherein the second yoke member is detachably fixed to the yoke body.

5. 3. The permanent electromagnetic chucking device according to claim 1, wherein the size of the recess is adjustable.

6. a cylindrical non-magnetic portion provided within the yoke portion so as to surround the second magnet; the non-magnetic portion is provided so as to extend to the attraction surface, 4. The permanent electromagnetic attracting device according to claim 2, wherein the second yoke member is provided inside the non-magnetic portion so that the first attracting surface and the second attracting surface are separated by the non-magnetic portion.

7. the second magnet has a cylindrical shape, is provided outside the first magnet when viewed from the axial direction, and is magnetized in a direction along the axial direction, the first magnet and the second magnet are provided coaxially with the coil, the attraction surface is provided on one side of the first magnet and the second magnet in the axial direction, 3. The permanent electromagnetic chucking device according to claim 1, wherein the recess is positioned on the axis of the coil when viewed from the axial direction.

8. a plurality of the magnetic force generating units provided adjacent to each other in a radial direction of the coil, 2. The permanent electromagnetic chucking device according to claim 1, wherein the yoke portion houses the plurality of magnetic force generating portions and has a plurality of the recesses provided corresponding to the plurality of magnetic force generating portions.

9. the yoke portion includes a yoke main body portion including a first yoke member having a first suction surface that attracts the object to be attracted, and a plurality of second yoke members that are separate members from the first yoke member and each have a second suction surface that attracts the object to be attracted, the plurality of second yoke members are provided corresponding to the plurality of magnetic force generating units, The permanent electromagnetic chucking device according to claim 8 , wherein the recessed portion is provided in each of the plurality of second yoke members.

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