JP2000114032A - Magnetically fixed device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make magnetic attracting surfaces to be switched to each other by providing a magnet assembly having a cylindrical internal space forming the boundary between a plurality of magnetic members and the magnetic attracting surfaces and a notched section extended in the axial direction on the outer periphery of a magnetic metallic switching member which is rotatably arranged in the internal space of the assembly. SOLUTION: A magnetically fixed device is provided with a rectangular parallelepiped magnet assembly 12, a cylindrical switching member 16 rotatably arranged in the internal space 14 of the assembly 14, and a rotating operating tool. The member 16 is formed of a magnetic metallic material, such as the soft iron, carbon steel, etc., and has a notched section 50 extended in the axial direction on the outer periphery of its main body section. The device also has a hanging ring 22 fixed to the center of the upper surface of a roof board 20 arranged on the upper surface of the assembly 12, the frontface board of the assembly 12 which blocks the front-side of the internal surface 14, and the rear-face board of the assembly 12 arranged to block the rear-side of the space 14. A first magnetic member 30 is formed in a thick plate-like shape and has magnetic attracting surfaces 44 and 46 at one end in the width wise direction. The surfaces 44 and 46 are kept in excited states.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic fixing device for holding or holding a magnetic material, and more particularly to a magnetic fixing device using a permanent magnet.

[0002] The present invention relates to a magnetic fixing device in which a switching member made of a magnetic metal material is arranged in a bore of an arranged magnet assembly.

[0003]

2. Description of the Related Art As one of magnetic fixing devices using permanent magnets, there is provided a rotating permanent magnet rotatably disposed in a bore of a magnetic circuit block, and the rotating permanent magnet is rotated by a predetermined angle to perform magnetic attraction. In some cases, the surface is selectively switched between an excited state and a non-excited state.
-39020, JP-B-64-5445, JP-B-4-16925).

As another magnetic fixing device, a permanent magnet is reinforced with a plate-like metal member made of a magnetic material to form a rotating permanent magnet assembly, and the rotating permanent magnet assembly is used as a switching member. (Japanese Utility Model Publication No. 5-10326).

[0005]

However, a rod-shaped member made of a permanent magnet material is often broken or broken. For this reason, in the former magnetic fixing device, since the rotating permanent magnet is used as the switching member, the rotating permanent magnet is broken or broken during use, and the magnetic fixing device becomes unusable.

In the latter magnetic fixing device, although the permanent magnet is reinforced by a metal member, the surface of the permanent magnet is rotated while the surface of the permanent magnet is in contact with the magnetic member forming the lumen. Breakage or breakage, and thus breakage of the switching member, cannot be completely prevented.

Therefore, in this type of magnetic fixing device, it is important that the magnetic attraction surface can be switched without causing breakage or breakage of the permanent magnet.

[0008]

A magnetic fixing device according to the present invention comprises:
A magnet assembly comprising one or more permanent magnets and a plurality of magnetic members, the magnet assembly having a columnar bore forming a boundary with the plurality of magnetic members, and a magnetic attraction surface, and rotating into the bore. And a switching member made of a magnetic metal material that is arranged as possible. The switching member has a substantially columnar shape in which a notch extending in the direction of the axis is formed on the outer peripheral portion.

When the switching member is rotated by one predetermined angle while the magnetic attraction surface is in the non-excited state, the magnetic attraction surface is switched to the excited state. On the other hand, when the switching member is rotated to the other side by a predetermined angle while the magnetic attraction surface is in the excited state, the magnetic attraction surface is switched to the non-excited state. Since the switching member is made of a magnetic metal material, there is no possibility of breakage or breakage due to its rotational movement.

According to the magnetic fixing device of the present invention, a permanent magnet for keeping the magnetic attraction surface in an excited state is incorporated in the magnet assembly, and the switching member for selectively switching the magnetic attraction surface between the excited state and the non-excited state is a magnetic metal The permanent magnet does not move even if the switching member is rotated angularly because the material is made of a material, and thus the magnetic attraction surface can be selectively switched between the excited state and the non-excited state. Does not break or break.

The plurality of magnetic members are a first magnetic member having the magnetic attraction surface of one polarity, and a first magnetic member partially abutting on one magnetic pole surface of the permanent magnet. A second abutment on the other pole face of the permanent magnet.
And a third magnetic member having the magnetic attraction surface of the other polarity and having a magnetic space separated from the first and second magnetic members. . In this case, the lumen forms the boundary with the first, second, and third magnetic members.

The plurality of magnetic members are substantially U-shaped first magnetic members having the magnetic attraction surface of one polarity, and the first magnetic member has an inner surface which is in contact with one magnetic pole surface of the permanent magnet. A third magnetic member having a magnetic member, a second magnetic member in contact with the other magnetic pole surface of the permanent magnet, and the magnetic attracting surface of the other polarity, wherein the second magnetic member A third magnetic member that is magnetically spaced. Also in this case, the lumen forms the boundary with the first, second, and third magnetic members.

The magnet assembly includes a pair of spaced apart permanent magnets, and the plurality of magnetic members are substantially U-shaped first magnetic members having the magnetic attraction surface of one polarity. A first magnetic member abutting on one magnetic pole surface of the two permanent magnets on a U-shaped inner surface, and a pair of second magnetic members each abutting on the other magnetic pole surface of the permanent magnet; A third magnetic member having the magnetic attraction surface of the other polarity, the third magnetic member being magnetically spaced from the pair of second magnetic members. Also in this case, the lumen forms the boundary with the first, second, and third magnetic members.

The magnetic fixing device may further comprise an auxiliary permanent magnet disposed in a space formed by the notch and the inner cavity, wherein the switching is performed so that one of the magnetic pole faces faces the notch. An auxiliary permanent magnet attached to the member may be included. Thus, the magnetic flux from the permanent magnet of the magnet assembly is prevented from passing through the magnetic action surface by the magnetic flux from the auxiliary permanent magnet, so that the magnetic attraction surface can be more reliably kept in the non-excited state.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIGS. 1 to 4, a magnetic fixing device 10 has a rectangular parallelepiped magnet assembly 12 and a columnar magnet rotatably disposed in a bore 14 of the magnet assembly 12. Switching member 16, an operating tool 18 for rotating the switching member 16 at an angle, and the top plate 2 disposed on the upper surface of the magnet assembly 12.
0, a suspension ring 22 fixed at the center of the upper surface of the top plate 20, a front plate 24 arranged at the front of the magnet assembly 12 to close the lumen 14 at the front side, and And a rear plate 26 disposed on the rear surface of the magnet assembly 12 so as to close on the side.

The magnet assembly 12 includes three magnetic members 30, 32, and 34 formed of a magnetic material such as soft iron and carbon steel.
, A plate-shaped permanent magnet 36 magnetized in the thickness direction, and a plurality of non-magnetic materials 38, 40, 42 are formed in a rectangular parallelepiped shape.

The first magnetic member 30 is formed in a thick plate shape, and has a magnetic attraction surface 44 at one end in the width direction.
The second magnetic member 32 is formed in a thick plate shape having a smaller width dimension than the first magnetic member 30, and is located on the other end side in the width direction of the first magnetic member 30 and has the first magnetic member 32. It is spaced from member 30 in its thickness direction.

The third magnetic member 34 is formed in a prismatic shape, and is located at one end side in the width direction of the first magnetic member 30 and is spaced apart from the first magnetic member 30 in the thickness direction. And a distance from the second magnetic member 32 in the width direction. The third magnetic member 34 has a magnetic attraction surface 46.
On the side opposite to the second magnetic member 32.

The permanent magnet 36 is formed of a plurality of rectangular plate members 36a and 36b made of a high coercive force magnet material such as a ferrite magnet. It is arranged between the magnetic members 30 and 32. The permanent magnet 36 has one and the other magnetic pole surfaces magnetically in contact with the inner surfaces of the other ends in the width direction of the first and second magnetic members 30 and 32, respectively.

In the following description, the permanent magnet 3
It is assumed that the S and N pole faces of No. 6 are in contact with the first and second magnetic members 30 and 32, respectively. But,
The N pole face may be brought into contact with the first magnetic member 30 and the S pole face may be brought into contact with the second magnetic member 30.

The non-magnetic member 38 is disposed in a magnetic space 48 between the second and third magnetic members 32 and 34, and the non-magnetic member 42 is located between the first and third magnetic members 30 and 34. Are located. The non-magnetic member 40 receives the permanent magnet 36 in the opening. The non-magnetic members 38, 40, 42
An appropriate material such as aluminum or resin can be used.

When the non-magnetic members 38, 40, and 42 are plate-like members such as aluminum, the magnetic members are joined by a non-magnetic material adhesive or a screw member.
32, 34. However, the non-magnetic member 3
When the resins 8, 40, and 42 are resins, the magnetic members can be integrally assembled to the magnetic members 30, 32, and 34 by injecting the resin between the magnetic members 30, 32, and curing the resin. .

The second and third magnetic members 32 and 34 and the non-magnetic member 38 have a cross-sectional shape of the first member which is the first member.
The magnetic member 30 is formed so as to have the same sectional shape.

The lumen 14 passes through the magnet assembly 12 in a horizontal direction at a joint where the first, second and third magnetic members 30, 32 and 34 and the non-magnetic members 38, 40 and 42 are joined. And thus form an arcuate boundary with them.

The switching member 16 is made of a magnetic metal material such as soft iron or carbon steel, and has a notch 50 extending in the axial direction on the outer periphery of the main body 16a. For this reason,
The main body 16a of the switching member 16 has a substantially semicircular cross-sectional shape. The switching member 16 also has a protrusion 16b that protrudes forward from the main body 16a through the front plate 24 (see FIG. 2).

The size of the notch 50 is determined by the size of the magnetic attraction surface 44,
When the switching member 16 is in the excited state,
And the third magnetic members 32 and 34 are magnetically short-circuited, but when the magnetic attraction surfaces 44 and 46 are in a non-excited state, the switching member 16 is switched to the second and third magnetic members 32 and 3.
4 is selected so as not to cause a magnetic short circuit.

The top plate 20, the front plate 24 and the rear plate 26
It is assembled to the magnet assembly 12 by an appropriate screw member. The operating tool 18 includes a boss 52 fitted to the projection 16 b of the switching member 16 and a handle 5 extending from the boss.
4 and is detachably attached to the switching member 16 at the boss portion 52.

In the magnetic fixing device 10, as shown in FIG. 3, when the switching member 16 is rotated so that the notch 50 is on the first magnetic member 30 side, the switching member 16
And the third magnetic members 32 and 34 are magnetically short-circuited. For this reason, the magnetic flux from the permanent magnet 36 is transmitted from the N pole to the second magnetic member 32, the switching member 16, the third magnetic member 34, the magnetic attraction surface 46, the magnetic attraction surface 44, and the first magnetic member 30. Through the path 56 leading to the S pole of the permanent magnet 36.

When the switching member 16 is rotated to the state shown in FIG. 3, a large amount of magnetic flux from the permanent magnet 36 passes through the magnetic attraction surfaces 44 and 46, so that the magnetic attraction surfaces 44 and 46 are in an excited state. . As a result, the magnetic material becomes
When the magnetic body is in contact with or near the magnetic attraction surfaces 44, 46, the magnetic material is attracted to the magnetic attraction surfaces 44, 46, and as a result, the magnetic fixing device 10 holds the magnetic material, or It is held by a magnetic material.

Contrary to the above, as shown in FIG. 4, when the switching member 16 is rotated so that the cutout 50 is located on the third magnetic member 34 and the non-magnetic member 42, the switching member 1 is rotated.
6 magnetically shorts the first and second magnetic members 30 and 32. Therefore, most of the magnetic flux from the permanent magnet 36 is
From the N pole, the second magnetic member 32, the switching member 16, and the first
Via the magnetic member 30 to the S pole of the permanent oil magnet 36.

When the switching member 16 is rotated to the state shown in FIG. 4, a large amount of magnetic flux from the permanent magnet 36 does not pass through the magnetic attraction surfaces 44 and 46, so that the magnetic attraction surfaces 44 and 46 are in the non-excited state. I will put it. Further, while the magnetic attraction surfaces 44 and 46 are in the non-excited state, a slight magnetic flux from the permanent magnet 36 passes through the magnetic attraction surfaces 44 and 46, and the magnetic flux causes the magnetic material to move to the magnetic attraction surfaces 44 and 46. This is a slight leakage magnetic flux that is insufficient to attract and hold the magnetic flux. With these, the magnetic attraction surface 4
The magnetic material adsorbed by the magnetic heads 4 and 46 is released, and as a result, the magnetic fixing device 10 releases the magnetic material or is released from the magnetic material.

When switching the magnetic attraction surfaces 44 and 46 between the excited state and the non-excited state, the switching member 16
While rotating while contacting the non-magnetic members 38, 40, 42 and the non-magnetic members 38, 40, 42, the permanent magnet 36 does not move. Therefore, according to the magnetic fixing device 10, the magnetic attraction surfaces 44, 46
Although the permanent magnet 36 can be selectively switched between the excited state and the non-excited state, breakage or breakage of the permanent magnet 36 does not occur. Further, since the switching member 16 is made of a magnetic metal material, there is no possibility that the switching member 16 will be broken or damaged due to its own rotational movement.

Referring to FIGS. 5 and 6, the magnetic fixing device 60 includes a rectangular parallelepiped magnet assembly 62 and a magnet assembly 62.
Not only is not shown, but also includes an operating tool for rotating the switching member 66 at an angle, and closing the lumen 64 on the front side, not shown. It includes a front plate and a rear plate that closes the lumen 64 on the rear side.

The magnet assembly 62 includes a first magnetic member 70,
A pair of second magnetic members 72, a third magnetic member 74, a pair of permanent magnets 76, and a plurality of non-magnetic materials 78, 78, 8
By 0,80, it is formed in a rectangular parallelepiped shape.

First, second and third magnetic members 70 and 72
And 74 are formed from a magnetic material such as soft iron or carbon steel. Each of the permanent magnets 76 is formed in a plate shape by a high coercive force magnet material, and is magnetized in the thickness direction. The non-magnetic materials 78 and 80 are made of a non-magnetic material such as aluminum and resin.

The first magnetic member 70 has a plate-like bottom 70a.
And a pair of legs 70b extending downward from both ends in the width direction, the opening has a U-shape inside, and the auxiliary pole portion 70c projecting into the opening from the bottom 70a is connected to the bottom 7a.
0a at the center inside in the width direction. The auxiliary pole part 70c extends over the entire length of the bottom part 70a in the longitudinal direction. The first magnetic member 70 has a magnetic attraction surface 44 of the same polarity at the tip of both legs 70b.

Each second magnetic member 72 is formed in a thick plate shape having a width smaller than that of the first magnetic member 70, and is located within the opening of the first magnetic member 70 and has the first magnetic member 72. It is spaced from the leg 70b of the member 70 in the thickness direction.

The third magnetic member 74 is formed in the shape of a prism, and the auxiliary pole portion 7 is provided in the opening of the first magnetic member 70.
0c. The third magnetic member 74 has the magnetic attraction surface 46 on the side opposite to the auxiliary pole portion 70c.

Each of the permanent magnets 76 is disposed between the leg 70b and the second magnetic member 72, and the N and S pole faces are respectively connected to the leg 70b and the second magnetic member 72 of the first magnetic member 70. The magnetic member 72 is magnetically contacted. Each non-magnetic member 78 is disposed behind the opening of the first magnetic member 70, and each non-magnetic member 80 is connected to the leg 7 of the first magnetic member 70.
0b and the third magnetic member 74.

The lumen 64 includes an auxiliary pole portion 70c of the first magnetic member 70, second and third magnetic members 72 and 74,
The magnet assembly 6 is attached to the assembly portion including the non-magnetic members 78 and 80.
2 are formed to penetrate in the horizontal direction, and thus form an arc-shaped boundary with them.

The switching member 66 differs from the switching member 16 in that a notch 90 formed in the outer peripheral portion of the main body 66a has a U-shaped cross section. The operation tool, front panel and rear panel are
They are the same as those of the magnet assembly 12. Magnet assembly 62
Similarly to the magnet assembly 12, the top plate 20 and the ring 22
May be provided.

The size of the notch 90 is determined by the magnetic attraction surface 44,
When the switching member 66 is in the excited state,
And the third magnetic members 72 and 74 are magnetically short-circuited, but when the magnetic attraction surfaces 44 and 46 are in the non-excited state, the switching member 66 is turned on by the second and third magnetic members 72 and 7.
4 is selected so as not to cause a magnetic short circuit.

In the magnetic fixing device 60, as shown in FIG. 5, the notch portion 90 is formed by the auxiliary pole portion 70 of the first magnetic member 70.
When the switching member 66 is rotated to the c side, the switching member 66 magnetically short-circuits the second and third magnetic members 72 and 74. Therefore, the magnetic flux from the permanent magnet 76 is transmitted from the N pole to the second magnetic member 72 and the switching member 6.
6, via the third magnetic member 74, the magnetic attraction surface 46, the magnetic attraction surface 44, and the path 96 to the S pole of the permanent magnet 76 via the first magnetic member 70.

When the switching member 66 is rotated to the state shown in FIG. 5, a large amount of magnetic flux from the permanent magnet 76 passes through the magnetic attraction surfaces 44 and 46, so that the magnetic attraction surfaces 44 and 46 are in an excited state. .

Contrary to the above, as shown in FIG. 6, the switching member 66 is set so that the notch 90 is on the third magnetic member 74 side.
Is rotated, the switching member 66 magnetically short-circuits the first and second magnetic members 70 and 72. Therefore, most of the magnetic flux from the permanent magnet 76 is transferred from the N pole to the second magnetic member 72, the switching member 66, and the auxiliary pole portion 70 of the first magnetic member.
c and a path 98 through the leg 70 b of the first magnetic member 70 to the S pole of the permanent magnet 76.

When the switching member 66 is rotated to the state shown in FIG. 6, a large amount of magnetic flux from the permanent magnet 76 does not pass through the magnetic attraction surfaces 44 and 46, so that the magnetic attraction surfaces 44 and 46 are in the non-excited state. I will put it. Further, while the magnetic attraction surfaces 44 and 46 are in the non-excited state, a slight magnetic flux from the permanent magnet 76 passes through the magnetic attraction surfaces 44 and 46, and the magnetic flux causes the magnetic material to move to the magnetic attraction surfaces 44 and 46. This is a slight leakage magnetic flux that is insufficient to attract and hold the magnetic flux.

Also in the magnetic fixing device 60, when the magnetic attraction surfaces 44, 46 are switched between the excited state and the non-excited state, the switching member 66 rotates while being in contact with the magnetic members 70, 72, 74 and the non-magnetic members 78, 80. But the permanent magnet 7
6 does not move. Therefore, the permanent magnet 76 can be selectively switched by the magnetic fixing device 60 between the magnetically attracted surfaces 44 and 46 between the excited state and the non-excited state.
Does not break or break. Further, since the switching member 66 is made of a magnetic metal material, there is no risk of breakage or breakage due to its own rotational movement.

In the magnetic fixing device 60, the auxiliary magnetic pole portion 7
Instead of providing 0c, the thickness of the bottom portion 70a may be increased, and a portion corresponding to the auxiliary magnetic pole portion 70c may be formed at the center of the bottom portion 70a. In this case, the second magnetic member 72
In addition, the width of the permanent magnet 76 can be reduced, and the cross-sectional shape of the switching member 66 can be substantially semicircular, similar to the switching member 16.

FIGS. 7 and 8 show examples in which auxiliary permanent magnets 100 and 102 are arranged in the cutouts 50 and 90 of the switching members 16 and 66 in the magnetic fixing devices 10 and 60, respectively. The auxiliary permanent magnets 100 and 102 are made of a high coercive force permanent magnet material in a plate shape, and are magnetized in the thickness direction.

In the illustrated example, since the permanent magnets 36 and 76 have their N pole faces in contact with the second magnetic members 32 and 72, the auxiliary permanent magnets 100 and 102 have the N pole faces respectively. The switching members 16 and 66 are in contact with each other. However, if the permanent magnets 36 and 76 have their S pole faces in contact with the second magnetic members 32 and 72, respectively, the S pole faces of the auxiliary permanent magnets 100 and 102 will be in contact with the switching members 16 and 66, respectively. You only need to make contact.

The auxiliary permanent magnets 100 and 102 can be located in the cutouts 50 and 90, respectively, and
And 64 are not large. For this reason,
The auxiliary permanent magnets 100 and 102 are not likely to break or break due to the rotation of the switching members 16 and 66, respectively. The auxiliary permanent magnets 100 and 102 may be covered with a material such as a resin.

As shown in FIG. 7, when the switching member 16 magnetically short-circuits the first and second magnetic members 30 and 32, the magnetic flux from the auxiliary permanent magnet 100
The magnetic flux from the permanent magnet 36 acts on the magnetic attracting surfaces 44 and 46 in a direction opposite to the magnetic flux from the magnetic attracting surface 44 and 46 via the magnetic space 48 between the second and third magnetic members 32 and 34.
Prevent reaching 4,46. Therefore, according to the embodiment shown in FIG. 7, the magnetic attraction surfaces 44 and 46 can be completely de-energized.

When the switching member 16 magnetically short-circuits the second and third magnetic members 32 and 34, the magnetic flux from the auxiliary permanent magnet 100 becomes magnetic in the same direction as the magnetic flux from the permanent magnet 36. It acts on the suction surfaces 44, 46. Thereby, the magnetic flux from the auxiliary permanent magnet 100 also
4, 46 act to be in an excited state. For this reason,
According to the embodiment shown in FIG. 7, the magnetic attraction surfaces 44 and 46 can be in a stronger excitation state.

In the embodiment shown in FIG. 8, as in the embodiment shown in FIG. 7, when the switching member 66 magnetically short-circuits the first and second magnetic members 70 and 72, the auxiliary permanent magnet The magnetic flux from 102 acts on the magnetic attraction surfaces 44 and 46 in the opposite direction to the magnetic flux from the permanent magnet 76,
The magnetic attraction surfaces 44 and 46 are completely de-energized.

Conversely, when the switching member 66 magnetically shorts the second and third magnetic members 72 and 74, the magnetic flux from the auxiliary permanent magnet 102 is in the same direction as the magnetic flux from the permanent magnet 36. Therefore, the magnetic attraction surfaces 44 and 46 are placed in a stronger excitation state.

The magnetic fixing device of the present invention can be applied to various magnetic fixing devices such as a hanging magnetic attraction device, a magnet base, and a permanent magnet chuck.

The present invention is not limited to the above embodiment. For example, the magnet assembly 12 or 62 may be arranged in a box-like case that opens to one side with the magnetic attraction surface exposed. Therefore, those skilled in the art will be able to change the above-described embodiment to various embodiments without departing from the spirit of the present invention.

[Brief description of the drawings]

FIG. 1 is a perspective view showing one embodiment of a magnetic fixing device according to the present invention.

FIG. 2 is a longitudinal sectional view of a magnet assembly and a switching member of the magnetic fixing device shown in FIG. 1;

FIG. 3 is a sectional view taken along line 3-3 in FIG. 2;

FIG. 4 is a sectional view similar to FIG. 3, showing a state where a magnetic attraction surface is in a non-excited state;

FIG. 5 is a sectional view of a magnet assembly in another embodiment of the magnetic fixing device according to the present invention.

FIG. 6 is a sectional view similar to FIG. 5, showing a state where the magnetic attraction surface is in a non-excited state in the apparatus shown in FIG. 5;

FIG. 7 is a sectional view showing an embodiment in which auxiliary permanent magnets are arranged on a switching member in the device shown in FIG. 3;

FIG. 8 is a sectional view showing an embodiment in which auxiliary permanent magnets are arranged on a switching member in the device shown in FIG. 5;

[Explanation of symbols]

 10, 60 Magnetic fixing device 12, 62 Magnet assembly 14, 64 Lumen 16, 66 Switching member 30, 70 First magnetic member 32, 72 Second magnetic member 34, 74 Third magnetic member 36, 76 Permanent Magnets 38, 40, 42, 78, 80 Non-magnetic member 44, 46 Magnetic attraction surface 50, 90 Notch 100, 102 Auxiliary permanent magnet

Claims (5)

[Claims] 1. A magnet assembly comprising one or more permanent magnets and a plurality of magnetic members, the magnet assembly having a columnar lumen forming a boundary with the plurality of magnetic members, and a magnetic attraction surface; A switching member made of a magnetic metal material rotatably disposed in the lumen, the switching member having a substantially columnar shape having a cutout extending in the direction of the axis formed on an outer peripheral portion. apparatus. 2. The magnetic member according to claim 1, wherein the plurality of magnetic members are a first magnetic member having the magnetic attraction surface of one polarity, and a first magnetic member partially contacting the one magnetic pole surface of the permanent magnet. A third magnetic member having a member, a second magnetic member in contact with the other magnetic pole surface of the permanent magnet, and the magnetic attracting surface of the other polarity, wherein the first and second magnetic members are The magnetic fixing device according to claim 1, further comprising a third magnetic member having a magnetic space between the first, second, and third magnetic members, wherein the lumen forms the boundary with the first, second, and third magnetic members. 3. The magnetic member according to claim 1, wherein the plurality of magnetic members are substantially U-shaped first magnetic members having the magnetic attraction surface of one polarity, and have an inner surface in contact with one magnetic pole surface of the permanent magnet. A third magnetic member having a first magnetic member, a second magnetic member in contact with the other magnetic pole surface of the permanent magnet, and the magnetic attracting surface of the other polarity, wherein the second magnetic member has A third magnetic member magnetically spaced from the member;
The magnetic fixation device according to claim 1, wherein the lumen forms the boundary with the first, second, and third magnetic members. 4. The magnet assembly includes a pair of spaced apart permanent magnets, and the plurality of magnetic members are substantially U-shaped first magnetic members having the magnetic attraction surface of one polarity. A first magnetic member abutting on one magnetic pole surface of the two permanent magnets on a U-shaped inner surface, and a pair of second magnetic members each abutting on the other magnetic pole surface of the permanent magnet A third magnetic member having a magnetic attraction surface of the other polarity, the third magnetic member being magnetically spaced from the pair of second magnetic members; Forming the boundary with the first, second and third magnetic members;
The magnetic fixing device according to claim 1. 5. An auxiliary permanent magnet disposed in a space formed by the notch and the lumen, and assembled to the switching member such that one of the magnetic pole faces faces the notch. Claims 1,2,2, including an attached auxiliary permanent magnet.
5. The magnetic fixing device according to 3 or 4.