Permanent magnet cage and conveying device

Abstract

The permanent electromagnetic retainer (1) of the present invention comprises: a first magnet (3) which is a magnet with a relatively small coercive force; a second magnet (4) which is a rare earth magnet with a relatively large coercive force and is configured in an annular shape; and a coil (5) which magnetizes the first magnet by being energized, wherein the first magnet (3) is configured such that the magnetic pole faces of different magnetic poles are respectively oriented in the axial direction of the axis (α); the second magnet (4) is configured such that the magnetic pole faces of different magnetic poles are respectively oriented in the axial direction of the axis (α); and is arranged on the outside of the first magnet in the radial direction of the axis (α); the first magnet (3), the second magnet (4) and the coil (5) are configured to overlap in the radial direction of the axis (α); and the switching action of the adsorption on / off state is performed by energizing the coil (5) to switch the magnetization direction of the first magnet (3) when switching the adsorption on / off state.

Description

Technical Field

[0001] The present invention relates to a permanent electromagnetic cage and a technology of a conveying device equipped with the permanent electromagnetic cage. Background Art

[0002] Conventionally, a technology related to a permanent electromagnetic retainer having a permanent magnet and a coil is known (see Patent Document 1). The permanent electromagnetic retainer is configured to attract an object through the magnetic force of the permanent magnet and is configured to be in an "off" state when the coil is energized.

[0003] In addition, a technology related to a permanent electromagnetic adsorption device is known, which includes: a first permanent magnet, a second permanent magnet and a coil. By energizing the coil in a manner of switching the direction of power supply, the magnetization direction of the first permanent magnet is switched, thereby switching the adsorption of the adsorbed object between an on (ON) state and an off state (see patent document 2).

[0004] The permanent magnet type adsorption device has a high adsorption force and does not need to continuously energize the coil in the adsorption closed state, thereby reducing power consumption.

[0005] Prior art literature

[0006] Patent Literature

[0007] Patent Document 1: Japanese Patent Application Laid-Open No. 2019-102682

[0008] Patent Document 2: Japanese Patent Application Laid-Open No. 2017-75020. Summary of the Invention

[0009] Problems to be solved by the invention

[0010] However, in the permanent electromagnetic holder, the permanent magnets and electromagnets are arranged in a row in the height direction (a direction perpendicular to the adsorption surface), which causes a problem of increasing the size of the permanent electromagnetic holder in the height direction.

[0011] Furthermore, in the permanent electromagnetic attraction device, the first and second permanent magnets are arranged in a vertical direction (a direction perpendicular to the attraction surface). Therefore, while the permanent electromagnetic attraction device has high attraction force and reduces power consumption, it also suffers from the problem of being larger in height.

[0012] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a permanent magnet retainer that has a high suction force, reduces power consumption, and can be configured to be relatively thin.

[0013] Solutions for solving problems

[0014] The problems to be solved by the present invention are as described above. Next, a solution for solving the problems will be described.

[0015] That is, in claim 1, a permanent electromagnetic holder includes an attraction surface for attracting an object, the holder being configured to attract the object in an attraction-on state and to release the attracted object in an attraction-off state. The permanent electromagnetic holder includes: a first magnet having a relatively low coercive force; a second magnet having a relatively high coercive force and being annular; and a coil configured to magnetize the first magnet by supplying current to the first magnet. The first magnet is configured so that pole faces of different poles face the axial direction of an axis, wherein the axis is orthogonal to the attraction surface and passes through the center of the attraction surface. The second magnet is configured so that pole faces of different poles face the axial direction of the axis and is arranged radially outward of the first magnet. The coil is disposed between the first and second magnets. The first, second, and coils are arranged to overlap in the radial direction of the axis. Switching between the attraction-on and attraction-off states is performed by supplying current to the coil to switch the magnetization direction of the first magnet.

[0016] In claim 2, the permanent electromagnetic retainer has a front yoke, and the front yoke is configured to be close to the first magnet, the second magnet and the coil on the side of the attraction surface in the axial direction of the axis of the first magnet, the second magnet and the coil, and a part of the front yoke is configured to protrude to the opposite side of the attraction surface in the axial direction of the axis than the end part of the attraction surface side of the coil on the first magnet side of the coil.

[0017] In claim 3, the permanent electromagnetic retainer has a back yoke, the bottom of the back yoke is arranged on the opposite side of the adsorption surface side in the axial direction of the axis, the opening of the back yoke is arranged on the adsorption surface side in the axial direction of the axis, the first magnet, the second magnet and the coil are arranged on the inner side of the back yoke, the front yoke is arranged to cover the opening of the back yoke, and a part of the back yoke is constructed so that the end on the opposite side of the first magnet side of the coil protrudes toward the adsorption surface side in the axial direction of the axis.

[0018] In claim 4, a conveying device includes the permanent electromagnetic holder.

[0019] Effects of the Invention

[0020] The present invention has the following effects.

[0021] That is, according to the present invention, a high adsorption force is provided, power consumption can be reduced, and a thin configuration can be achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a cross-sectional view showing a permanent electromagnetic retainer according to an embodiment of the present invention.

[0023] Figure 2 (a) is a schematic top view of the first magnet, the second magnet, and the coil in the adsorption-on state of the permanent electromagnetic retainer according to the embodiment of the present invention. Figure 2 (b) is a schematic cross-sectional view showing the adsorption-on state of the permanent electromagnetic retainer according to the embodiment of the present invention.

[0024] Figure 3 (a) is a schematic top view of the first magnet, the second magnet, and the coil in the adsorption closed state of the permanent electromagnetic retainer according to the embodiment of the present invention. Figure 3 (b) is a schematic cross-sectional view showing the adsorption closed state of the permanent electromagnetic retainer according to the embodiment of the present invention.

[0025] Figure 4 It is a cross-sectional view showing a permanent electromagnetic retainer according to an embodiment of the present invention.

[0026] Figure 5 It is a cross-sectional view showing a permanent electromagnetic retainer according to an embodiment of the present invention.

[0027] Figure 6 It is a cross-sectional view showing a permanent electromagnetic retainer according to an embodiment of the present invention.

[0028] Figure 7 1 is a schematic cross-sectional view showing an adsorption-on state of the permanent electromagnetic retainer according to the embodiment of the present invention.

[0029] Figure 8 1 is a schematic cross-sectional view showing an adsorption-on state of the permanent electromagnetic retainer according to the embodiment of the present invention.

[0030] Figure 9 1 is a schematic cross-sectional view showing an adsorption-on state of the permanent electromagnetic retainer according to the embodiment of the present invention.

[0031] Figure 10 It is a schematic cross-sectional view showing the adsorption closed state of the permanent electromagnetic retainer according to the embodiment of the present invention.

[0032] Figure 11 It is a cross-sectional view showing a permanent electromagnetic retainer according to an embodiment of the present invention. DETAILED DESCRIPTION

[0033] Next, use Figures 1 to 6The permanent magnet cage 1 will be described. In the following description, the dotted lines in the drawings are described as dotted lines representing loops of magnetic field lines.

[0034] The permanent electromagnetic retainer 1 is configured to attract iron products (attractive objects 2) using magnetic force. The permanent electromagnetic retainer 1 is configured to switch between an on / off state. In the on state, the permanent electromagnetic retainer 1 attracts the attractive object 2, and in the off state, the attractive object 2 can be released.

[0035] The permanent electromagnetic retainer 1 can be used in conveying devices for conveying and transporting iron products, or in retaining devices for holding iron products while they are attached to a wall or ceiling. Specific examples of applications using the permanent electromagnetic retainer 1 include industrial robots and cranes that use magnetic force to grip and transport workpieces, aircraft such as helicopters and drones that use magnetic force to lift and transport steel bars, and wall-moving robots that move while magnetically attached to a wall.

[0036] like Figures 1 to 3 As shown, the permanent electromagnetic retainer 1 is constructed in a generally cylindrical shape and includes an attraction surface 1a for attracting an object 2, located at one end in the axial direction of the axis α. The axis α is perpendicular to the attraction surface 1a and passes through the center of the attraction surface 1a. The axial direction of the axis α represents the direction in which the axis α extends (the height direction of the permanent electromagnetic retainer 1), while the radial direction of the axis α represents the direction perpendicular to the axis α. The permanent electromagnetic retainer 1 includes a first magnet 3, a second magnet 4, a coil 5, a front yoke 6, a back yoke 7, and a spacer 8.

[0037] For convenience, the following description will be made with the direction in which the attraction surface 1 a of the attraction object 2 in the permanent electromagnetic holder 1 faces downward. However, the direction of the permanent electromagnetic holder 1 is not limited thereto.

[0038] The first magnet 3 is a magnet with a low coercive force (e.g., an alnico magnet or an iron-chromium-cobalt magnet) and is cylindrical in shape. The first magnet 3 is configured so that the magnetic pole faces (the south pole and the north pole) of different polarities are oriented in the axial direction of the axis α. The magnetic pole faces of the first magnet 3 are configured so that they are perpendicular to the axial direction of the axis α.

[0039] The second magnet 4 is a rare earth magnet (e.g., a neodymium magnet) with a relatively high coercive force and is cylindrical (annular). The height of the second magnet 4 is approximately the same as that of the first magnet 3. The second magnet 4 is configured so that the magnetic pole faces (the south pole and the north pole) of the different magnetic poles are oriented in the axial direction of the axis α. The magnetic pole faces of the second magnet 4 are configured so that they are perpendicular to the axial direction of the axis α.

[0040] The second magnet 4 is arranged radially outside the first magnet 3 (outside the first magnet 4 in the radial direction of the axis α). The second magnet 4 and the first magnet 3 are arranged coaxially.

[0041] The first magnet 3 and the second magnet 4 are arranged at the same position in the axial direction of the axis α. The first magnet 3 and the second magnet 4 are arranged to overlap in the radial direction of the axis α. The upper surface position of the first magnet 3 and the upper surface position of the second magnet 4 are aligned in the axial direction of the axis α, and the lower surface position of the first magnet 3 and the lower surface position of the second magnet 4 are aligned in the axial direction of the axis α.

[0042] The coil 5 is a solenoid coil that generates a strong magnetic flux on the axis α side (the first magnet 3 side) when energized, thereby magnetizing the first magnet 3. The magnetization direction of the first magnet 3 is switched by switching the energization direction of the coil 5.

[0043] The coil 5 is annularly arranged between the first magnet 3 and the second magnet 4. The coil 5 is arranged radially outside the first magnet 3. The coil 5 is arranged radially inside the second magnet 4. The coil 5 is configured to be close to the first magnet 3 and the second magnet 4.

[0044] The first magnet 3 , the second magnet 4 , and the coil 5 are arranged so as to overlap in the radial direction of the axis α.

[0045] The front yoke 6 is a magnetic yoke made of a material such as iron and has a generally flat disc shape. The front yoke 6 is positioned outside the first magnet 3, the second magnet 4, and the coil 5. The front yoke 6 is positioned below the first magnet 3, the second magnet 4, and the coil 5 (on the side of the attraction surface 1a in the axial direction of the axis α), so as to be close to or in contact with these magnets. The outer diameter of the front yoke 6 is approximately the same as that of the second magnet 4.

[0046] The back yoke 7 is a magnetic yoke made of a material such as iron and has a generally cylindrical shape with a bottom and an opening. The bottom of the back yoke 7 is located at the top, and the opening is located at the bottom. The inner diameter of the back yoke 7 is larger than the outer diameter of the front yoke 6.

[0047] The back yoke 7 is arranged on the outside of the first magnet 3, the second magnet 4 and the coil 5. The first magnet 3, the second magnet 4 and the coil 5 are arranged on the inside of the back yoke 7 (inside the back yoke 7). The back yoke 7 is configured to be close to or in contact with the first magnet 3, the second magnet 4 and the coil 5. The bottom of the back yoke 7 is located above the first magnet 3, the second magnet 4 and the coil 5, and the side wall of the back yoke 7 is located on the outside of the first magnet 3, the second magnet 4 and the coil 5. The lower end portion of the back yoke 7 (the lower opening portion) is located below the first magnet 3, the second magnet 4 and the coil 5. The lower end surface of the back yoke 7 is configured to be approximately flush with the lower surface of the front yoke 6.

[0048] The front yoke 6 is arranged so as to cover the opening of the back yoke 7. The lower surface of the front yoke 6 and the lower end surface of the back yoke 7 constitute an adsorption surface 1a.

[0049] The spacer 8 is made of a non-magnetic material such as aluminum and blocks the magnetic flux of the first magnet 3 and the second magnet 4. The spacer 8 is inserted between the second magnet 4 and the outer surface of the front yoke 6 and the inner surface of the back yoke 7.

[0050] By switching the direction of energization to the coil 5 , the magnetization direction of the first magnet 3 is switched, thereby switching between the attraction-on state and the attraction-off state of the attraction object 2 .

[0051] The switching operation between the attraction on / off state is performed by momentarily energizing coil 5 (turning on and then immediately turning off the power to coil 5) to switch the magnetization direction of first magnet 3. In the permanent magnet holder 1, for example, the magnetization direction of first magnet 3 (attracting the attraction on / off state) is switched within 0.01 to 0.2 seconds from the start of energizing coil 5.

[0052] In the adsorption-on state, for example, when the magnetic pole of the second magnet 4 on the adsorption surface 1a side is the north pole, the magnetic pole of the first magnet 3 on the adsorption surface 1a side is magnetized to the north pole. In this way, the first magnet 3 is magnetized in the same direction as the magnetic pole of the second magnet 4, and the adsorption-on state is achieved (see Figure 2 ).

[0053] In the attraction closed state, for example, when the magnetic pole of the second magnet 4 on the attraction surface 1a side is N-pole, the magnetic pole of the first magnet 3 on the attraction surface 1a side is magnetized to S-pole. In this way, the magnetic flux of the first magnet 3 and the second magnet 4 circulates inside the front yoke 6 and the back yoke 7, so that the magnetic flux of the first magnet 3 and the second magnet 4 does not leak to the outside of the attraction surface 1a, and the attraction closed state is achieved (see Figure 3 ).

[0054] In this manner, the first magnet 3 is configured so that its pole faces of different poles face the axial direction of the axis α, and the second magnet 4 is configured so that its pole faces of different poles face the axial direction of the axis α. The first magnet 3, the second magnet 4, and the coil 5 are arranged to overlap radially from the axis α. Switching between the attraction on / off states is achieved by energizing the coil 5 (momentarily) to switch the magnetization direction of the first magnet 3. Consequently, the permanent magnet retainer 1 exhibits higher attraction force, reduces power consumption, and is thinner than conventional permanent magnet retainers.

[0055] Furthermore, in conventional permanent magnet retainers, when the magnetic force of the permanent magnet is strong, the coil is considered to be larger to offset the magnetic force of the permanent magnet. However, if the coil is made larger in this way, the size increases in the radial direction of the attraction surface (radial direction of the axis). However, the permanent magnet retainer 1 constructed in this way has a higher attraction force than conventional permanent magnet retainers with stronger magnetic force and larger coils, while being able to suppress the size increase in the radial direction of the axis α.

[0056] Furthermore, after the permanent electromagnetic holder 1 switches the suction on / off state, the switched suction on / off state is maintained until the suction on / off state is switched again even when the coil 5 is not energized.

[0057] Therefore, the permanent electromagnetic retainer 1 can prevent, for example, the erroneous attraction of a magnetic material when the power supply is turned off and the device is accidentally de-energized, thereby enabling attraction to be turned on, as is the case with conventional permanent electromagnetic retainers. Furthermore, for example, the erroneous initiation of attraction of a magnetic material when the device is accidentally de-energized before positioning at the hanging position, as is the case with conventional permanent electromagnetic retainers, can be prevented.

[0058] like Figure 1 As shown, the front yoke 6 has a groove 6 a formed on its upper surface (the surface on the side where the first magnet 3 , the second magnet 4 , or the coil 5 is arranged in the axial direction of the axis α) and has a height difference on its upper surface.

[0059] The groove 6a of the front yoke 6 is a square groove having an annular shape when viewed from above and is formed concentrically with the first magnet 3 or the second magnet 4. The outer diameter of the groove 6a of the front yoke 6 is configured to be substantially the same as the inner diameter of the second magnet 4. The inner diameter of the groove 6a of the front yoke 6 is configured to be substantially the same as the outer diameter of the first magnet 3.

[0060] A portion (lower portion) of the coil 5 is arranged in the groove portion 6a of the front yoke 6. The lower end portion of the coil 5 (the end portion on the side of the attraction surface 1a) is arranged to be inserted into the upper portion of the front yoke 6. A portion of the front yoke 6 is configured to protrude upward (on the side of the axial direction of the axis α on which the first magnet 3, the second magnet 4, or the coil 5 is arranged (the opposite side of the attraction surface 1a in the axial direction of the axis α)) from the lower end portion of the coil 5 (the end portion on the side of the attraction surface 1a). On the outside of the coil 5 (on the side of the second magnet 4), a portion of the front yoke 6 is configured to protrude upward from the lower end portion of the coil 5.

[0061] In this manner, the end portion of the coil 5 on the side of the attraction surface 1a is configured to be inserted into the upper portion of the front yoke 6. A portion of the front yoke 6 is configured to protrude, on the first magnet 3 side of the coil 5, from the end portion on the side of the attraction surface 1a of the coil 5, toward the side opposite the attraction surface 1a side in the axial direction of the axis α. Consequently, in the permanent magnet retainer 1, the magnetic flux directed toward the axis α side (the first magnet 3 side) can be increased, allowing the first magnet 3 to be magnetized with relatively low power consumption.

[0062] The back yoke 7 has a structure in which a groove 7 a is formed on the lower surface of the bottom portion (the surface on the side where the first magnet 3 , the second magnet 4 , or the coil 5 is arranged in the axial direction of the axis α) and has a height difference on the lower surface.

[0063] The groove portion 7a of the back yoke 7 is a square groove that is annular when viewed from above and is formed concentrically with the first magnet 3 or the second magnet 4. The outer diameter of the groove portion 7a of the back yoke 7 is configured to be approximately the same as the inner diameter of the second magnet 4. The inner diameter of the groove portion 7a of the back yoke 7 is configured to be approximately the same as the outer diameter of the first magnet 3.

[0064] A portion (upper portion) of the coil 5 is arranged in the groove portion 7a of the back yoke 7. The upper end portion of the coil 5 (the end portion on the opposite side to the adsorption surface 1a side) is arranged to be inserted into the bottom portion of the back yoke 7. A portion of the back yoke 7 is configured to protrude downward (on the side in the axial direction of the axis α where the first magnet 3, the second magnet 4, or the coil 5 is arranged (on the adsorption surface 1a side in the axial direction of the axis α)) than the upper end portion of the coil 5 (the end portion on the opposite side to the adsorption surface 1a side) on the inner side of the coil 5 (the first magnet 3 side). On the outer side of the coil 5 (the second magnet 4 side), a portion of the back yoke 7 is configured to protrude downward than the upper end portion of the coil 5.

[0065] In this manner, the end portion of the coil 5 opposite the attraction surface 1a is configured to be inserted into the bottom portion of the back yoke 7. The back yoke 7 is configured such that a portion of the back yoke 7 protrudes toward the attraction surface 1a in the axial direction of the axis α, on the first magnet 3 side of the coil 5, relative to the end portion opposite the attraction surface 1a side of the coil 5. Therefore, in the permanent magnet retainer 1, the magnetic flux directed toward the axis α side (the first magnet 3 side) can be increased, allowing the first magnet 3 to be magnetized with relatively low power consumption.

[0066] The permanent magnet holder 1 does not need to be cylindrical, but may be polygonal (e.g., a quadrangular prism). Furthermore, the first magnet 3 does not need to be cylindrical, and the second magnet 4 does not need to be cylindrical. Specifically, the first magnet 3 may be polygonal (e.g., a quadrangular prism), and the second magnet 4 may be polygonal (e.g., a quadrangular tube).

[0067] The second magnet 4 may be formed by arranging a plurality of rare earth magnets of a predetermined shape (eg, fan shape) in a ring shape.

[0068] The groove portion 6 a of the front yoke 6 or the groove portion 7 a of the back yoke 7 may be formed of a circular groove, a polygonal groove, or the like.

[0069] It should be noted that, in the permanent electromagnetic cage 1, Figure 4 As shown, the front yoke 6 may have no groove 6a on its upper surface and may be formed as a flat surface. Furthermore, the back yoke 7 may have no groove 7a on its lower surface and may be formed as a flat surface. This configuration makes it easier to manufacture the permanent magnet retainer 1.

[0070] Furthermore, in the permanent electromagnetic holder 1, the height of the second magnet 4 may be configured to be different from the height of the first magnet 3. In this case, for example, Figure 5 As shown, the axial length (height) of the second magnet 4 about the axis α is shorter than the axial length (height) of the first magnet 3 about the axis α. A recess is formed on the upper surface of the front yoke 6, and a recess is formed on the lower surface of the bottom portion of the back yoke 7. The outer diameters of the recess in the front yoke 6 and the recess in the back yoke are formed to be approximately the same as the inner diameter of the second magnet 4. The first magnet 3 and the coil 5 are arranged in the recess in the front yoke 6 and the recess in the back yoke.

[0071] In addition, in the permanent magnet holder 1, the outer diameter of the front yoke 6 may be configured to be different from the outer diameter of the second magnet 4. In this case, for example, Figure 6 As shown, the outer diameter of the front yoke 6 is configured to be shorter than the outer diameter of the second magnet 4 .

[0072] Then, Figures 7 to 10 The permanent electromagnetic retainer 1 described above will be described.

[0073] It should be noted that in the description Figures 7 to 10 The permanent electromagnetic retainer 1 described above is Figures 1 to 6 The same parts of the permanent electromagnetic retainer 1 are omitted as appropriate. Figures 1 to 6 The description will focus on the different parts of the permanent magnet cage 1 described above.

[0074] like Figures 7 to 10 As shown, the permanent magnet holder 1 includes a first magnet portion 10 and a second magnet portion 20 arranged side by side in the axial direction of the axis α. The first magnet portion 10 is arranged closer to the attraction surface 1a than the second magnet portion 20 in the axial direction of the axis α.

[0075] The first magnet portion 10 includes a first magnet 13 , a second magnet 14 , a first coil 15 , a front yoke 16 , a first back yoke 17 , and a spacer 18 .

[0076] The first magnet 13 is a magnet with a low coercive force (e.g., an alnico magnet or an iron-chromium-cobalt magnet) and is cylindrical in shape. The first magnet 13 is configured so that the pole faces (the south pole and the north pole) of the different poles are oriented in the axial direction of the axis α. The pole faces of the first magnet 13 of the different poles are arranged orthogonally to the axial direction of the axis α.

[0077] Second magnet 14 is a rare earth magnet (e.g., a neodymium magnet) with a relatively high coercive force and is cylindrical (annular). The height of second magnet 14 is approximately the same as that of first magnet 13. Second magnet 14 is configured so that its pole faces (the south pole and the north pole) face the axial direction of axis α. Second magnet 14 is configured so that its pole faces are perpendicular to the axial direction of axis α.

[0078] The first magnet 13 and the second magnet 14 are arranged at the same position in the axial direction of the axis α.

[0079] The first coil 15 is a solenoid coil that generates a strong magnetic flux on the axis α side (first magnet 13 side) when energized, thereby magnetizing the first magnet 13. The magnetization direction of the first magnet 13 is switched by switching the energization direction of the coil 15.

[0080] The first coil 15 is disposed between the first magnet 13 and the second magnet 14. The first coil 15 is disposed radially outside the first magnet 13. The first coil 15 is disposed radially inside the second magnet 14. The first coil 15 is configured to be close to the first magnet 13 and the second magnet 14.

[0081] The first magnet 13 , the second magnet 14 , and the first coil 15 are arranged so as to overlap in the radial direction of the axis α.

[0082] The front yoke 16 is a magnetic yoke made of a material such as iron and is formed in a substantially flat disc shape. The front yoke 16 is arranged below the first magnet 13 , the second magnet 14 , and the first coil 15 so as to be close to or in contact with them.

[0083] The first back yoke 17 is a magnetic yoke made of a material such as iron and has a generally cylindrical shape with a bottom and an opening. The bottom of the first back yoke 17 is located at the top, and the opening is located at the bottom. The inner diameter of the first back yoke 17 is larger than the outer diameter of the front yoke 16.

[0084] The first back yoke 17 is arranged on the outside of the first magnet 13, the second magnet 14 and the first coil 15. The first magnet 13, the second magnet 14 and the first coil 15 are arranged on the inside of the first back yoke 17. The first back yoke 17 is configured to be close to or in contact with the first magnet 13, the second magnet 14 and the first coil 15. The bottom of the first back yoke 17 is located above the first magnet 13, the second magnet 14 and the first coil 15, and the side wall of the first back yoke 17 is located on the outside of the first magnet 13, the second magnet 14 and the first coil 15. The lower end portion of the first back yoke 17 (the lower opening portion) is located below the first magnet 13, the second magnet 14 and the first coil 15. The lower end surface of the first back yoke 17 is configured to be approximately flush with the lower surface of the front yoke 16.

[0085] The front yoke 16 is arranged to cover the opening of the first back yoke 17 .

[0086] The spacer 18 is made of a non-magnetic material such as aluminum and blocks the magnetic flux of the first magnet 13, the second magnet 14, the third magnet 23, and the fourth magnet 24. The spacer 18 is inserted between the outer surface of the second magnet 14 and the front yoke 16 and the inner surface of the first back yoke 17.

[0087] The second magnet portion 20 includes a third magnet 23 , a fourth magnet 24 , a second coil 25 , a second back yoke 27 , and a spacer 28 .

[0088] The third magnet 23 is a magnet with a relatively low coercive force (e.g., an alnico magnet or an iron-chromium-cobalt magnet) and is cylindrical in shape. The outer diameter of the third magnet 23 is larger than the inner diameter of the second magnet 14 and smaller than the outer diameter of the second magnet 14. The third magnet 23 is configured such that its magnetic pole faces face the axial direction of the axis α. The third magnet 23 is configured such that the magnetic pole faces of different polarities (the south pole and the north pole) are arranged orthogonally to the axial direction of the axis α.

[0089] The third magnet 23 is disposed above the first back yoke 17 so as to be close to or in contact with the upper surface of the first back yoke 17. The third magnet 23 is disposed coaxially with the first magnet 13 and the second magnet 14.

[0090] The fourth magnet 24 is a rare earth magnet (e.g., a neodymium magnet) with a relatively high coercive force and is cylindrical (annular). The height of the fourth magnet 24 is approximately the same as that of the third magnet 23. The outer diameter of the fourth magnet 24 is larger than that of the second magnet 14. The fourth magnet 24 is configured so that the magnetic pole faces (the south pole and the north pole) of the different magnetic poles are oriented in the axial direction of the axis α. The magnetic pole faces of the fourth magnet 24 are configured so that they are perpendicular to the axial direction of the axis α.

[0091] The fourth magnet 24 is positioned above the first back yoke 17, close to or in contact with the upper surface of the first back yoke 17. The fourth magnet 24 is positioned radially outward of the third magnet 23 (outward of the third magnet 23 in the radial direction of the axis α). The fourth magnet 24 is positioned concentrically with the first magnet 13, the second magnet 14, and the third magnet 23.

[0092] The third magnet 23 and the fourth magnet 24 are arranged at the same position in the axial direction of the axis α. The third magnet 23 and the fourth magnet 24 are arranged to overlap in the radial direction of the axis α. The upper surface position of the third magnet 23 and the upper surface position of the fourth magnet 24 are aligned in the axial direction of the axis α, and the lower surface position of the third magnet 23 and the lower surface position of the fourth magnet 24 are aligned in the axial direction of the axis α.

[0093] Second coil 25 is a solenoid coil that generates a strong magnetic flux on the axis α side (third magnet 23 side) when energized, magnetizing third magnet 23. By switching the energizing direction of second coil 25, the magnetizing direction of third magnet 23 is switched.

[0094] The second coil 25 is disposed between the third magnet 23 and the fourth magnet 24. The second coil 25 is disposed radially outward of the third magnet 23. The second coil 25 is disposed radially inward of the fourth magnet 24. The second coil 25 is configured to be close to the third magnet 23 and the fourth magnet 24.

[0095] The third magnet 23 , the fourth magnet 24 , and the second coil 25 are arranged so as to overlap in the radial direction of the axis α.

[0096] The second back yoke 27 is a magnetic yoke made of a material such as iron and has a generally cylindrical shape with a bottom and an opening. The bottom of the second back yoke 27 is located at the top, and the opening is located at the bottom. The inner diameter of the second back yoke 27 is larger than the outer diameter of the first back yoke 17.

[0097] The second back yoke 27 is positioned outside the first magnet unit 10 (first magnet 13, second magnet 14, first coil 15), third magnet 23, fourth magnet 24, and second coil 25. The first magnet unit 10 (first magnet 13, second magnet 14, first coil 15), third magnet 23, fourth magnet 24, and second coil 25 are positioned inside the second back yoke 27. The second back yoke 27 is configured to be close to or in contact with the third magnet 23, fourth magnet 24, and second coil 25. The bottom of the second back yoke 27 is positioned above the third magnet 23, fourth magnet 24, and second coil 25, while the sidewalls of the second back yoke 27 are positioned outside the first magnet unit 10 (first magnet 13, second magnet 14, first coil 15), third magnet 23, fourth magnet 24, and second coil 25. The lower end (lower opening) of the second back yoke 27 is positioned below the third magnet 23, fourth magnet 24, and second coil 25. The lower end surface of the second back yoke 27 is configured to be substantially flush with the lower surface of the front yoke 16 and the lower end surface of the first back yoke 17 .

[0098] The spacer 28 is made of a non-magnetic material such as aluminum and blocks the magnetic flux of the first magnet 13, the second magnet 14, the third magnet 23, and the fourth magnet 24. The spacer 28 is inserted between the fourth magnet 24 and the outer surface of the first back yoke 17 and the inner surface of the second back yoke 27.

[0099] The lower surface of the front yoke 16 , the lower end surface of the first back yoke 17 , and the lower end surface of the second back yoke 27 constitute an attraction surface 1 a .

[0100] By switching the energization direction of the first coil 15 and / or the second coil 25, the magnetization direction of the first magnet 13 and / or the third magnet 23 is switched, thereby switching the attraction-on state and the attraction-off state of the attraction object 2.

[0101] The switching operation of the attraction on / off state is performed by momentarily energizing the first coil 15 and / or the second coil 25 when switching the attraction on / off state (immediately de-energizing the first coil 15 and / or the second coil 25 after energizing the first coil 15 and / or the second coil 25). This switches the magnetization direction of the first magnet 13 and / or the magnetization direction of the third magnet 23. For example, in the permanent magnet holder 1, the magnetization direction of the first magnet 13 and / or the magnetization direction of the third magnet 23 switches within 0.01 to 0.2 seconds after the first coil 15 and / or the second coil 25 are energized.

[0102] For example, in the adsorption-on state, when the magnetic pole of the second magnet 14 on the adsorption surface 1a side is the north pole and the magnetic pole of the fourth magnet 24 on the adsorption surface 1a side is the south pole, by energizing only the first coil 15, the magnetic pole of the first magnet 13 on the adsorption surface 1a side is magnetized to the north pole. In this way, the first magnet 13 is magnetized in the same direction as the magnetic pole of the second magnet 14, and the adsorption-on state is achieved (see Figure 7 ).

[0103] Furthermore, for example, in the adsorption-on state, when the magnetic pole of the second magnet 14 on the adsorption surface 1a side is the N pole and the magnetic pole of the fourth magnet 24 on the adsorption surface 1a side is the S pole, by energizing only the second coil 25, the magnetic pole of the third magnet 23 on the adsorption surface 1a side is magnetized to the S pole. In this way, the third magnet 23 is magnetized in the same direction as the magnetic pole of the fourth magnet 24, and the adsorption-on state is achieved (see Figure 8 At this time, compared with the case where only the first coil 15 is energized to enter the attraction-on state, a stronger attraction force for attracting the attraction object 2 is generated.

[0104] Furthermore, for example, in the adsorption-on state, when the magnetic pole of the second magnet 14 on the adsorption surface 1a side is the north pole and the magnetic pole of the fourth magnet 24 on the adsorption surface 1a side is the south pole, by energizing the first coil 15 and the second coil 25, the magnetic pole of the first magnet 13 on the adsorption surface 1a side is magnetized to the north pole and the magnetic pole of the third magnet 23 on the adsorption surface 1a side is magnetized to the south pole. In this way, the first magnet 13 is magnetized in the same direction as the magnetic pole of the second magnet 14, and the third magnet 23 is magnetized in the same direction as the magnetic pole of the fourth magnet 24, and the adsorption-on state is achieved (see Figure 9 At this time, compared with the case where only the first coil 15 or only the second coil 25 is energized to enter the adsorption-on state, a stronger adsorption force for adsorbing the adsorption object 2 is generated.

[0105] In the adsorption closed state, for example, when the magnetic pole of the second magnet 14 on the adsorption surface 1a side is the north pole and the magnetic pole of the fourth magnet 24 on the adsorption surface 1a side is the south pole, the magnetic pole of the first magnet 13 on the adsorption surface 1a side is magnetized to the south pole, and the magnetic pole of the third magnet 23 on the adsorption surface 1a side is magnetized to the north pole. In this way, the magnetic flux of the first magnet 13, the second magnet 14, the third magnet 23, and the fourth magnet 24 circulates inside the front yoke 16, the first back yoke 17, and the second back yoke 27, so that the magnetic flux of the first magnet 13, the second magnet 14, the third magnet 23, and the fourth magnet 24 does not leak to the outside of the adsorption surface 1a, and the adsorption closed state is achieved (see Figure 10 ).

[0106] In this way, the first magnet portion 10 is arranged on the side of the attraction surface 1a relative to the second magnet portion 20 in the axial direction of the axis α, the first magnet 13 is configured so that the pole faces of different poles are respectively oriented in the axial direction of the axis α, and the second magnet 14 is configured so that the pole faces of different poles are respectively oriented in the axial direction of the axis α. The first magnet 13, the second magnet 14 and the first coil 15 are arranged so as to overlap in the radial direction of the axis α. The third magnet 23 is configured so that the pole faces of different poles are respectively oriented in the axial direction of the axis α, and the fourth magnet 24 is configured so that the pole faces of different poles are respectively oriented in the axial direction of the axis α. The third magnet 23, the fourth magnet 24 and the second coil 25 are arranged so as to overlap in the radial direction of the axis α. The switching operation of the attraction on / off state is performed by energizing the first coil 15 and / or the second coil 25 (momentarily energizing) when switching the attraction on / off state, thereby switching the magnetization direction of the first magnet 13 and the magnetization direction of the third magnet 23. Therefore, the permanent electromagnetic holder 1 has a higher attraction force than conventional permanent electromagnetic holders, can reduce power consumption, and can be made thinner in a configuration in which the first magnet portion 10 and the second magnet portion 20 are arranged in the axial direction of the axis α.

[0107] When switching the adsorption on / off state, the configuration allows selection of a coil energization scheme (first coil 15 and / or second coil 25) from energizing the first coil 15, energizing the second coil 25, or energizing both the first coil 15 and the second coil 25. For example, the coil energization scheme can be selected by a company employee operating an operating switch or the like.

[0108] For example, when it is desired to weaken the suction force for suctioning the suction object 2 , it is selected to energize only the first coil 15 when switching the suction on / off state.

[0109] Furthermore, for example, when it is desired to increase the suction force for suctioning the suction object 2 compared to when only the first coil 15 is energized, it is selected to energize only the second coil 25 when switching the suction on / off state.

[0110] In addition, for example, when it is desired to increase the adsorption force for adsorbing the adsorption object 2 compared to when only the first coil 15 or only the second coil 25 is energized, it is selected to energize the first coil 15 and the second coil 25 when switching the adsorption on / off state.

[0111] In this way, when switching the adsorption on / off state, the configuration is such that a scheme for energizing the coils can be selected from energizing the first coil 15, energizing the second coil 25, or energizing the first coil 15 and the second coil 25. Therefore, the setting of the adsorption force for adsorbing the adsorbed object 2 can be changed according to the specifications of the adsorbed object 2, the purpose of the permanent electromagnetic holder 1, etc.

[0112] It should be noted that, in the permanent electromagnetic holder 1 , when switching the adsorption on / off state, a configuration may be adopted in which only the first coil 15 and the second coil 25 are energized.

[0113] The front yoke 16 is configured such that a groove portion (not shown) is formed on the upper surface thereof and a height difference is formed on the upper surface thereof.

[0114] A portion (the lower portion) of the first coil 15 is positioned within the groove of the front yoke 16. The lower end portion (the end on the side of the attraction surface 1a) of the first coil 15 is configured to fit into the upper portion of the front yoke 16. A portion of the front yoke 16 is configured to protrude upward from the lower end portion (the end on the side of the attraction surface 1a) of the first coil 15 on the inner side (the side of the first magnet 13) of the first coil 15. On the outer side (the side of the second magnet 14) of the first coil 15, a portion of the front yoke 16 is configured to protrude upward from the lower end portion of the first coil 15.

[0115] In this manner, the end portion of the first coil 15 on the side of the attraction surface 1a is configured to be inserted into the upper portion of the front yoke 16. A portion of the front yoke 16 is configured to protrude, on the first magnet 13 side of the first coil 15, from the end portion of the first coil 15 on the side of the attraction surface 1a, toward the side opposite the attraction surface 1a in the axial direction of the axis α. Consequently, in the permanent magnet holder 1, the magnetic flux directed toward the axis α side (the side of the first magnet 13) can be increased, allowing the first magnet 13 to be magnetized with relatively low power consumption.

[0116] The first back yoke 17 is configured such that a groove portion (not shown) is formed on the lower surface of the bottom portion, and has a height difference on the lower surface.

[0117] A portion (upper portion) of the first coil 15 is arranged in the groove portion of the first back yoke 17. The upper end portion of the first coil 15 (the end portion on the opposite side of the adsorption surface 1a side) is arranged to be inserted into the bottom portion of the first back yoke 17. A portion of the first back yoke 17 is configured to protrude downward (on the side of the first magnet 13 or the second magnet 14 or the first coil 15 in the axial direction of the axis α (the adsorption surface 1a side in the axial direction of the axis α)) from the upper end portion of the first coil 15 (the end portion on the opposite side of the adsorption surface 1a side) on the inner side of the first coil 15 (the first magnet 13 side). On the outer side of the first coil 15 (the second magnet 14 side), a portion of the first back yoke 17 is configured to protrude downward from the upper end portion of the first coil 15.

[0118] In this manner, the end portion of the first coil 15 opposite the attraction surface 1a is configured to be engaged with the bottom portion of the first back yoke 17. The first back yoke 17 is configured such that a portion of the first back yoke 17 protrudes toward the attraction surface 1a in the axial direction of the axis α, relative to the end portion of the first coil 15 opposite the attraction surface 1a. Therefore, in the permanent magnet retainer 1, the magnetic flux directed toward the axis α (the first magnet 13 side) can be increased, allowing the first magnet 13 to be magnetized with relatively low power consumption.

[0119] The second back yoke 27 may be configured similarly to the front yoke 16 , with a groove (not shown) formed on the upper surface of the bottom portion and a height difference formed on the upper surface.

[0120] A portion (lower portion) of the second coil 25 is positioned within the groove of the second back yoke 27. The lower end portion (the end on the side of the attraction surface 1a) of the second coil 25 is configured to be snapped into the upper portion of the second back yoke 27. A portion of the second back yoke 27 is configured to protrude upward from the lower end portion (the end on the side of the attraction surface 1a) of the second coil 25 on the inner side (the side of the third magnet 23) of the second coil 25. On the outer side (the side of the fourth magnet 24) of the second coil 25, a portion of the second back yoke 27 is configured to protrude upward from the lower end portion of the second coil 25.

[0121] In this manner, the end portion of the second coil 25 on the side of the attraction surface 1a is configured to be inserted into the upper portion of the second back yoke 27. A portion of the second back yoke 27 is configured to protrude, on the third magnet 23 side of the second coil 25, from the end portion of the second coil 25 on the side of the attraction surface 1a, toward the side opposite the attraction surface 1a in the axial direction of the axis α. Consequently, in the permanent magnet holder 1, the magnetic flux directed toward the axis α side (the side toward the first magnet 13) can be increased, allowing the first magnet 13 to be magnetized with relatively low power consumption.

[0122] The second back yoke 27 may be configured to have a groove (not shown) formed on the lower surface of the bottom portion similarly to the first back yoke 17 , thereby having a height difference on the lower surface.

[0123] A portion (upper portion) of the second coil 25 is arranged in the groove portion of the second back yoke 27. The upper end portion of the second coil 25 (the end portion on the opposite side of the adsorption surface 1a side) is arranged to be inserted into the bottom portion of the second back yoke 27. A portion of the second back yoke 27 is configured to protrude downward (on the side where the third magnet 23, the fourth magnet 24, or the second coil 25 is arranged in the axial direction of the axis α (the adsorption surface 1a side in the axial direction of the axis α)) than the upper end portion of the second coil 25 (the end portion on the opposite side of the adsorption surface 1a side) on the inner side of the second coil 25 (the third magnet 23 side). On the outer side of the second coil 25 (the fourth magnet 24 side), a portion of the second back yoke 27 is configured to protrude downward than the upper end portion of the second coil 25.

[0124] In this manner, the end portion of the second coil 25 opposite the attraction surface 1a is configured to be engaged with the bottom portion of the second back yoke 27. The second back yoke 27 is configured such that a portion of the second back yoke 27 protrudes toward the attraction surface 1a in the axial direction of the axis α, on the third magnet 23 side of the second coil 25, relative to the end portion of the second coil 25 opposite the attraction surface 1a. Therefore, in the permanent magnet holder 1, the magnetic flux directed toward the axis α side (the third magnet 23 side) can be increased, allowing the third magnet 23 to be magnetized with relatively low power consumption.

[0125] It should be noted that the permanent magnet holder 1 may be configured such that, in addition to the first magnet portion 10 and the second magnet portion 20 , three or more magnet portions are arranged in the axial direction of the axis α.

[0126] The second magnet 14 or the fourth magnet 24 may be formed by arranging a plurality of rare earth magnets of a predetermined shape (eg, a fan shape) in a ring shape.

[0127] The groove portion of the front yoke 16 , the second back yoke 17 , or the second back yoke 27 may be formed of a circular groove, a polygonal groove, or the like.

[0128] In addition, in the permanent electromagnetic cage 1, as Figure 11 As shown, the coil 5 may be arranged above the second magnet 4 (on the opposite side of the adsorption surface 1a in the axial direction of the axis α) and configured to be snapped into the back yoke 7. In this case, the first magnet 3 and the second magnet 4 are arranged to overlap in the radial direction of the axis α, and the coil 5 is arranged radially outside the first magnet 3 and above the second magnet 4. The coil 5 and the second magnet 4 are arranged to overlap in the axial direction of the axis α.

[0129] With this configuration, in the permanent magnet holder 1 , the magnetic flux toward the axis α side (the first magnet 3 side) can be increased, and the first magnet 3 can be magnetized with relatively low power consumption.

[0130] Industrial applicability

[0131] The present invention is used for a permanent electromagnetic holder capable of attracting an object by utilizing magnetic force, and a conveying device including the permanent electromagnetic holder.

[0132] Description of reference numerals:

[0133] 1. Permanent electromagnetic cage;

[0134] 1a adsorption surface;

[0135] 2. Adsorb objects;

[0136] 3 first magnet;

[0137] 4 second magnet;

[0138] 5 coils;

[0139] 6 front yoke;

[0140] 6a groove;

[0141] 7. Carry the yoke;

[0142] 7a groove;

[0143] 8 spacers;

[0144] 10 first magnet portion;

[0145] 13 First Magnet;

[0146] 14 second magnet;

[0147] 15 first coil;

[0148] 16 front yoke;

[0149] 17 The first yoke;

[0150] 18 spacers;

[0151] 20 second magnet portion;

[0152] 23 third magnet;

[0153] 24 fourth magnet;

[0154] 25 second coil;

[0155] 27 The second yoke;

[0156] 28 spacers;

[0157] α axis.

Claims

1. A permanent electromagnetic retainer having an adsorption surface for adsorbing an object, configured to adsorb the adsorption object in an adsorption-on state and to release the adsorbed adsorption object in an adsorption-off state, wherein: The permanent electromagnetic cage has: The first magnet is a magnet with a relatively small coercive force; The second magnet is a rare earth magnet with a large coercive force and is formed into a ring shape; a coil, which magnetizes the first magnet by being energized; as well as A back yoke, wherein the bottom of the back yoke is arranged on the opposite side of the adsorption surface side in the axial direction of the shaft center, and the opening of the back yoke is arranged on the adsorption surface side in the axial direction of the shaft center, The first magnet, the second magnet and the coil are arranged on the inner side of the back yoke. The coil is configured to be wound around a portion of the back yoke on the inner side of the back yoke and to be engaged with the back yoke. The first magnet is configured such that the magnetic pole faces of different poles are respectively oriented in the axial direction of the axis, and the axis is orthogonal to the adsorption surface and passes through the center of the adsorption surface. The second magnet is configured such that the magnetic pole faces of different magnetic poles are respectively oriented in the axial direction of the axis, and is arranged outside the first magnet in the radial direction of the axis. The coil is disposed between the first magnet and the second magnet. The first magnet, the second magnet, and the coil are arranged to overlap in the radial direction of the axis. The switching operation of the attraction on / off state is performed by instantaneously energizing the coil when switching the attraction on / off state to switch the magnetization direction of the first magnet.

2. A permanent electromagnetic retainer having an adsorption surface for adsorbing an object, configured to adsorb the adsorption object in an adsorption-on state and to release the adsorbed adsorption object in an adsorption-off state, wherein: The permanent electromagnetic cage has: The first magnet is a magnet with a relatively small coercive force; The second magnet is a rare earth magnet with a large coercive force and is formed into a ring shape; and a coil, which magnetizes the first magnet by being energized, The first magnet is configured such that the magnetic pole faces of different poles are respectively oriented in the axial direction of the axis, and the axis is orthogonal to the adsorption surface and passes through the center of the adsorption surface. The second magnet is configured such that the magnetic pole faces of different magnetic poles are respectively oriented in the axial direction of the axis, and is arranged outside the first magnet in the radial direction of the axis. The coil and the second magnet are arranged to overlap in the axial direction of the axis. The first magnet and the second magnet are arranged to overlap in the radial direction of the axis. The switching operation of the attraction on / off state is performed by instantaneously energizing the coil when switching the attraction on / off state to switch the magnetization direction of the first magnet.

3. The permanent electromagnetic retainer according to claim 1 or 2, wherein: The first magnet is configured such that the length of the first magnet in the axial direction of the axis is shorter than the length of the first magnet in the radial direction of the axis. The second magnet is formed in an annular shape, and is configured such that the length of the second magnet in the axial direction of the shaft center is shorter than the length of the second magnet in the radial direction of the shaft center.

4. The permanent electromagnetic retainer according to claim 2, comprising: a back yoke, wherein the bottom of the back yoke is arranged on the opposite side of the adsorption surface side in the axial direction of the shaft center, and the opening of the back yoke is arranged on the adsorption surface side in the axial direction of the shaft center, in, The first magnet, the second magnet, and the coil are arranged inside the back yoke. The coil is arranged inside the back yoke so as to be wound around a portion of the back yoke and locked into the back yoke. 5 . A conveying device comprising the permanent electromagnetic holder according to claim 1 .

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