JPH03190108A - magnetic fixing device - Google Patents

Abstract

PURPOSE:To prevent a permanent magnet from rotating to a non-excitation rotary position from excitation rotary position by a method wherein, in the state where a magnetic member is brought into contact with a magnetic-action working surface, two magnetic members are separated with each other in the distance with which the magnetic action, caused by the unbalance of the magnetic flux in a magnetic circuit, works in such a manner that a permanent magnet will be rotated in the direction toward the rotating position of excitation from the rotating position of non-excitation. CONSTITUTION:The engaging part 148, which is formed on the end part located on the opposite side of the protruding part of a permanent magnet 126, has two stepped parts 148a and 148b which will be selectively engaged to a stopper 136. The distance between two magnetic members 130 and 130 is set in the value with which a magnetic member will function in such a manner that the permanent magnet 126 is rotated toward an excitation rotary position from a non-excitation rotary position by the force of magnetic action in the state wherein the magnetic members 130 are brought into contact with a magnetic-action working surface 150. When the stepped parts 148a and 148b are not brought into contact with the stopper 136, the permanent magnet 126 is in an excitation rotary position, and the magnetic-action working surface 150 is in the state of excitation. On the other hand, when either of the stepped parts 148a and 148b is brought into contact with the stopper 136, the permanent magnet 126 is in the non-excitation rotary position, and as the magnetic-action working surface 150 is in the non-excitation state, the stopper 136 and the engaging part 148 work as a stopper means.

Description

[Detailed Description of the Invention] (Field of Application of Industry I) The present invention provides an LJJ that holds a magnetic material or is held therein.
This invention relates to a replaceable magnetic fixing device.

(Prior art) As one of the devices for this magnetic decoupling, there is a magnetic circuit block that opens at one end (1) and a permanent rod-shaped block placed in a rotatable manner inside the lumen. There is a device that includes a magnet and an operation knob that rotates the permanent magnet (for example, Japanese Utility Model Publication No. 58-18250, Japanese Unexamined Patent Publication No. 56-26415).
(Japanese Patent Publication No. 6046803).

As i7 [Kimizuhisa@7], a low coercive force magnet such as an alnico magnet, or a high coercive force magnet such as a flight magnet or a red earth metal magnet is used. By operating the operation knob, this permanent magnet can be selected into an energized rotational position where the pair of magnetically active surfaces of the magnetic circuit block are in an energized state, and a non-energized rotational position where the magnetically active surfaces are in a de-energized state. It can be rotated.

In this type of magnetic fixing device, for example,
As described in Japanese Patent No. 26415, the magnetic circuit is magnetically balanced when the permanent magnet is in the energized rotational position and in the non-energized rotational position. In this equilibrium state, the permanent magnet is stable. On the other hand, if the permanent magnet is located between the excited rotational position and the non-excited rotational position h7, the magnetic circuit becomes magnetically unbalanced, and as a result, the rotational force due to the unbalanced magnetic flux in the magnetic circuit That is, the magnetic force acts on the permanent magnet, and the permanent magnet is rotated in a direction that balances the magnetic flux of the magnetic circuit.

However, in conventional magnetic fixing devices of this type, the magnetic force acts to rotate the permanent magnet toward a non-excited rotational position. For this reason, conventional magnetic fixing devices include a stopper that prevents the permanent magnet from rotating from an energized rotational position to a non-excitation rotational position.

This type of stopper resists the magnetic force and prevents the permanent magnet from rotating due to the magnetic force when the permanent magnet is rotated over 90 degrees from a non-excited rotational position to an energized rotational position. , when the permanent magnet is rotated by less than 90 degrees from a non-excited rotational position to an energized rotational position, there is a device that releasably blocks the rotation of the permanent magnet due to the magnetic force against the magnetic force. .

However, in the conventional magnetic fixing device using the former stopper, the permanent magnet is slightly rotated by impact, vibration, etc. in the opposite direction to the direction of rotation blocked by the stopper, and the permanent magnet becomes magnetic. The acting force causes it to rotate to the non-excited rotational position.

In addition, conventional magnetic fixing devices using repeating stoppers are
When the rotation prevention function of the stopper is canceled due to impact, vibration, etc., the permanent magnet will be rotated to the non-excited rotational position by the magnetic force.

(Problem to be solved) As mentioned above, when a permanent magnet is rotated from an energized rotational position to a non-excited rotational position by a magnetic force, the magnetically active surface is switched from an energized state to a non-excited state. The magnetic material that is attracted to the surface will be released from the magnetically active surface.

SUMMARY OF THE INVENTION An object of the present invention is to provide a magnetic fixing device in which a permanent magnet is not rotated from an energized rotational position to a non-energized rotational position by a sudden action force.

(Solution Means, Actions, Effects) The magnetic fixing device of the present invention includes a pair of magnetic members having a fidgeting magnetically active surface and spaced apart from each other, and has a space extending between the magnetic members. a magnetic circuit block, a permanent magnet rotatably disposed in the space, and an energized rotational position where the magnetically active surface is placed in an energized state and a non-excited rotational position where the magnetically active surface is placed in a de-energized state. and an operating means for rotating the permanent magnet, the permanent magnet is a magnet with a high coercive force, and the magnetic member is arranged in a magnetic circuit in a state in which the magnetic body is brought into contact with the magnetically active surface. the permanent magnets are separated from each other by a distance such that a magnetic force due to an imbalance of magnetic flux within the permanent magnets acts to rotate the permanent magnets in a direction from the non-energized rotational position toward the energized rotational position.

When the permanent magnet is rotated to the excitation rotation position, the magnetic flux of the permanent magnet passes through the magnetically active surface, so that the magnetically active surface is in an excited state, thereby making it possible to attract a magnetic substance to the magnetically active surface. At this time, the magnetic circuit is in a magnetically balanced state.

Also, if the permanent magnet is rotated to a non-energized rotational position,
Since the magnetic flux of the permanent magnet is magnetically short-circuited by the magnetic member, the magnetically active surface is placed in a de-energized state, whereby the magnetic body attracted to the magnetically active surface is released from the magnetically active surface. At this time as well, the magnetic circuit is in a magnetically balanced state.

However, if the permanent magnet is between the energized and de-energized rotational positions, the magnetic circuit becomes magnetically unbalanced, and as a result, the rotational force or magnetic action force due to the unbalanced magnetic flux in the magnetic circuit Acts on permanent magnets. According to the magnetic fixing device of the present invention, this magnetic force acts to rotate the permanent magnet toward the excitation rotation position.

Therefore, according to the magnetic fixing device of the present invention, the permanent magnet is not rotated from the excitation rotational position to the non-excitation rotational position by the magnetic force.

In a magnetic fixing device that uses a low coercive force magnet such as an alnico magnet as a permanent magnet, even if the distance between both magnetic members is increased to the same diameter as the permanent magnet, the magnetic force will de-energize the permanent magnet. It merely acted to rotate it into a rotated position.

The magnetic circuit block may further include a non-magnetic member disposed integrally with the magnetic member between the magnetic members.

Preferably, the magnetic fixing device further includes a stopper means for preventing the permanent magnet from being rotated beyond a predetermined angle from the excitation rotation position to the non-excitation rotation position. This allows the user to easily and reliably maintain the permanent magnet in the non-energized rotational position.

Roughly speaking, when the permanent magnet is rotated over 90 degrees from the energized rotational position to the non-energized rotational position, the magnetic fixing device rotates the permanent magnet in a direction toward the next energized rotational position. It is preferable to include stopper means for resisting the magnetic force. This eliminates the need for the user to manually maintain the permanent magnet in a non-energized rotational position.

Instead of said stopper means, when said permanent magnet is rotated through an angle of less than 90 degrees from said energized rotational position towards said non-energized rotational position, rotation of said permanent magnet in the direction towards the original energized rotational position is provided. Stop means may be included for releasably blocking the magnetic force.

(Example) Referring to FIGS. 1 to 3, the magnetic fixing device 2 of the present invention
0 includes a magnetic circuit block 22. The magnetic circuit block 22 includes a pair of magnetic members 24 and a non-magnetic spacer, that is, a non-magnetic member 26 placed between the magnetic members. The magnetic member 24 and the non-magnetic member 26 are integrally bonded to each other using a bonding agent such as a brazing material. The lower portions of the opposing inner surfaces of the magnetic member 24 are inclined so as to define, together with the lower end surface of the non-magnetic member 26, a groove-shaped space having a widening cross-sectional shape.

The lower end surface of the magnetic member 24 acts as a magnetically active surface 28 for attracting a magnetic body.

The magnetic circuit block 22 has a space 30 extending in the left-right direction in the center thereof and opening at one end of the magnetic circuit block 22 in the left-right direction. In the illustrated example, the space 30 extends from one magnetic member 24 to the other magnetic member 2 via the non-magnetic member 26.
The inner lumen has a circular cross-section extending over 4, and has a similar inner diameter dimension in the axial direction.

A permanent magnet 32 having a high coercive force, such as a ferrite magnet or a rare earth metal magnet, is housed in the space 30 . The permanent magnet 32 is slightly smaller than the inner diameter of the space 30 and approximately -
It has a rod-like shape with a similar outer diameter, and is arranged within the space 30 so as to be rotatable around its axis. However, the shape of the permanent magnet 32 may be an oval shape having a flat surface with the outer peripheral portion cut away in a direction perpendicular to the magnetization direction.

The permanent magnet 32 is magnetized in its diametrical direction, so that the permanent magnet 32 has different polar surfaces (
It acts as a bar-shaped magnet that strikes (N, S).

'f, As shown in Figure 3, at both ends of the permanent magnet 32,
A recess 34 having a U-shaped cross section is formed.

The recesses 34 are opened in the end face of the permanent magnet 32, extend in the magnetization direction of the permanent magnet 32, and have the same cross-sectional shape and dimensions. Due to stiffness, the permanent magnet 32
It has a symmetrical shape with respect to its center.

A plate 36 is attached to the end surface of the magnetic circuit block 22 on the side where the space 30 is opened by a plurality of screws 38. The plate 36 has a circular hole 40 formed in the center of the plate 36, as shown in FIGS. 4 and 5.
and a substantially annular recess 42 opening on the side facing the plate 36.

A pair of protrusions 44 protrude toward the center of the hole 40 from a portion defining the outer peripheral edge of the recess, a plurality of holes 46 into which the screws 38 are received, and a protrusion protruding toward the side where the recess 42 opens. and a pair of protrusions 48 formed near the protrusion 44.

The recess 42 is formed around the hole 40 and communicates with the hole 40. The convex portion 44 is formed such that the right edge in the illustrated example in FIG. 4 coincides with a straight line passing through the center of the space 30 and the hole 40. The hole 46 and the protrusion 48 are each formed at points symmetrical with respect to the center of the hole 40.

After fitting the protrusion 48 into the hole 50 formed in the magnetic circuit block 22 and shown in FIG.
The hole 5 shown in FIG. 3 formed in the magnetic circuit block 22
2, it is attached to the magnetic circuit block 22.

An operation knob 54 for rotating the permanent magnet 32 around its axis is fitted into the recess 34 of the permanent magnet 32 on the open end side of the space 30 .

As shown in FIGS. 6 and 7, the operation knob 54 includes a disc-shaped main body 56 and a flange-shaped first protrusion integrally extending along the outer periphery of one end of the main body in the thickness direction. 58, a pair of second protrusions 60 formed on the end surface of the main body portion 56 on the side of the first protrusion 58, and a pair of second protrusions 60 protruding outward from opposing portions of the outer peripheral edge of the first protrusion 58. an arc-shaped convex portion 62;
The other end surface of the main body part 56 is provided with a knob part 64 formed by ffg.

The diameter of the main body portion 56 is smaller than the diameter of the hole 40 of the plate 36, and the diameter of the first protrusion 58 is smaller than the diameter of the hole 40 of the plate 36.
The diameter of the projection 62 is slightly smaller than that of the recess 42 of the plate 36, and the length of the knob 64 is /J% smaller than the diameter of the hole 40 of the plate 36. Sai. The thickness of the main body portion 56 is slightly larger than that of the plate 36. The second protrusion 60 is
It has dimensions that allow it to fit into the recess 34 of the permanent magnet 32.

The main body portion 56 is fitted into the hole 40 of the plate 36,
The first protrusion 58 is fitted into the recess 42 of the plate 36 at the right side in FIG. 4, the protrusion 62 is fitted into the recess 42 of the plate 36, and the second protrusion 60
is fitted into the recess 34 of the permanent magnet 32.

Instead of forming the recess 34 on the permanent magnet 32 and forming the protrusion 60 on the operating knob 54, a protrusion may be formed on the permanent magnet 32 and a recess may be formed on the operating knob 54. Further, the engagement between the permanent magnet 32 and the operating knob 54 may be achieved by other means such as a hole and a projection fitted into the hole. Further, the recess 42 that receives the first protrusion 58 and the convex portion 62 of the operation knob 54 is connected to the plate 36 of the magnetic circuit block 22.
It may be formed on the end face of the side.

The permanent magnet 32 is pushed toward the operation knob 54 by an elastic body 66 placed in the recess 34 on the inner side of the space 30 . The elastic body 66 is made of a material that can be elastically deformed in three dimensions, such as styrofoam or synthetic rubber. In the illustrated example, the elastic body 66 has a disk shape, but it may also have a cubic shape.

The thickness and diameter of the elastic body 66 are larger than the depth and width of the recess 34, respectively. However, the elastic body 66 is arranged in a compressed state in the inner part of the space 30 between the end of the permanent magnet 32 on the side opposite to the operation knob 54 and the magnetic circuit block 22, and The elastic body 66 is received in the four parts 34 in a compressed state in the width direction of the recess. As a result, the permanent magnet 32 is pressed toward the operation knob 54, and the permanent magnet 32 is pressed toward the operation knob 54, and the permanent magnet 32 is pressed toward the operation knob 54, and the permanent magnet 32 is pressed toward the operation knob 54, and the permanent magnet 32 is pressed toward the operation knob 54, and the permanent magnet 32 is pressed toward the operation knob 54, and the permanent magnet 32 is pressed toward the operation knob 54, and the permanent magnet 32 is pressed toward the operation knob 54, and the permanent magnet 32 is pressed toward the operation knob 54, and the permanent magnet 32 is pressed toward the operation knob 54, and the permanent magnet 32 is pressed toward the operation knob 54, and the permanent magnet 32 is pressed toward the operation knob 54, and the permanent magnet 32 is pressed toward the operation knob 54. :l It is prevented from displacing in the axial direction within 30.

On the plate 36, letters indicating whether the magnetically active surface 28 is in an on state '1--that is, an energized state or an off state, that is, a de-energized state, a mark of the magnetic fixing device, a manufacturer's name, etc. are written. A name plate 68 shown in dotted lines in FIG. 2 may be attached.

The magnetic fixing device 20 includes, for example, an elastic body 66 disposed in one of the four parts 34 of the permanent magnet 32, and the permanent magnet 32 placed inside the space 30 so that the elastic body 66 becomes the deep part of the space 17130 of the magnetic circuit block 22. A rotatably arranged operating knob 54
1 of the operation knob 54 or the hole 40 and the recess 42 of the fidget plate 36 .
The plate 36 can be assembled by attaching the plate 36 to the end face of the magnetic circuit block 22 with screws 38 so that the plate 36 can be inserted into the magnetic circuit block 22. Nameplate 68 is plate 36
plate 36 after attaching it to the magnetic circuit block 22.
It can be pasted on.

In the magnetic fixing device 20 assembled in this way,
The permanent magnet 32 and the operating knob 54 are rotatable within a range that engages the protrusion 62 of the operating knob 54 or the protrusion 44 of the plate 36 . Since the permanent stone 32 and the operating knob 54 are in contact with the first protrusion 58 of the operating knob 54 or the plate 36, they will not come off the magnetic circuit block 22.

Although the permanent magnet 32 may be magnetized before the assembly of the magnetic fixing device 20 is completed, it is preferable to magnetize it after the assembly is completed.

Further, as the operating knob, an operating knob 70 having a knob portion 72 having a length dimension larger than the diameter dimension of the hole 40 of the plate 36 may be used, as shown in FIG.

In the magnetic fixing device 20, the N pole face of the permanent magnet 32 and the S
The inner magnetic member 24 of the magnetic circuit block 22 as well as the pole face
When magnetically connected to the inner magnetic member 24, both polar faces
The magnetically active surface 28 is placed in a de-energized state since it is magnetically short-circuited.

For kneading, one pole face N (or S) of the permanent magnet 32
When magnetically connected to one magnetic member 24 of the magnetic circuit block 22 and magnetically connected to the other pole surface S (or N) or the other magnetic member 24, one magnetically active surface 28 or N
Since the magnetically active surface 28 acts as a magnetic pole surface and the other magnetically active surface 28 acts as an S magnetic pole surface, the magnetically active surface 28 changes to an excited state.

The non-energized rotational position of the permanent stone 32 is the convex portion 6 of the operation knob 54.
The excitation rotation position is a position between the convex portion 62 and both convex portions 44 . Therefore, the convex portions 44.62 act as a stopper means, which will be described later, when the permanent magnet 32 is at its non-excited rotational position.

To make the convex portion 44.62 act as a single stopper,
For example, the direction of the recess 34 of the permanent magnet 32, the direction of the operation knob 5, etc.
The magnetization direction of the permanent magnet 32 may be determined according to the direction of the protrusion 60 of the permanent magnet 32, the positional relationship between the protrusion 44 of the plate 36 and the protrusion 62 of the operation knob 54, etc. In the illustrated example, it is possible, for example, to magnetize the permanent stone 32 in a direction perpendicular to the direction of extension of the recess 44, as shown in FIG.

The mutual spacing of the internal magnetic members 24, ie, the thickness of the non-magnetic member 26 in the illustrated example, is greater than that of conventional magnetic fixing devices using high coercivity permanent magnets. Thereby, the magnetic force caused by the unbalance of the magnetic flux in the magnetic circuit acts to rotate the permanent magnet 32 to the excitation rotation position while the magnetic body is in contact with the magnetically active surface 28 .

Such an interval between the inner magnetic members 24, that is, the non-magnetic member 2
The thickness of 6 is determined by the size of the magnetic fixing device, especially the permanent magnet 32.
Varies depending on the diameter dimension.

As shown in FIG. 9, the height H of the magnetic circuit pro-nk 22
1 The width T of the magnetic circuit block 22, the diameter φ' of the space 30, and the diameter φ of the permanent magnet 32 are the same, but the thickness of the non-magnetic member 26, that is, the interval W between the inner magnetic members 240 is different.
A seed magnetic fixing device is manufactured, and the rotation angle θ of the permanent magnet 32 is
When the rotational resistance, that is, the rotational force was measured, the results shown in FIG. 10 were obtained. The rotational force in FIG. 10 is caused by the unbalance of the magnetic flux in the magnetic circuit, so it is the magnetic force in the present invention.

H, T, φ' and φ are each 54 mm.

They were 50 mm, 35 mm, and 34.8 mm.

The rotational force was measured with a plate-shaped magnetic body 74 having a thickness of 9 mm or more brought into contact with the magnetically active surface.

In FIG. 10, curves 80, 82, 84, and 86 have W of 12 mrn, 16 mm, and 28 mm, respectively.
Figure 3 shows the change in rotational force of 8 and 35 mm magnetic fixing devices. Further, when θ=0, the permanent magnet 32 is rotated to the non-excitation rotation position, and when θ=90, the permanent magnet 32 is rotated to the excitation rotation position.

Furthermore, when the rotational force value is positive, it indicates that a counterclockwise rotational force is acting on the permanent magnet, and when it is negative, it indicates that a clockwise rotational force is acting on the permanent magnet. .

As can be seen from FIG. 10, in the conventional magnetic fixation device shown by curve 80, the magnetic force acts to rotate the permanent magnet to a non-energized rotational position. In contrast, in the magnetic fixing device of the invention shown by curves 82, 84, and 86, the magnetic force acts to rotate the permanent magnet to the excitation rotational position.

When the rotation angle θ of the permanent magnet is in the range of 90 degrees to 180 degrees,
This curve is almost the same as the curve obtained by rotating the curves 80, 82, 84, and 86 in FIG. 10 by 180 degrees around the position of point 88 in FIG. Therefore, the rotation angle θ of the permanent magnet is
Even if the angle is in the range of 90 degrees to 180 degrees, W = 16 mm
, 28mm.

According to the 35 mm magnetic fixing device, the magnetic force acts to rotate the permanent magnet to the exciting rotation position, but W
= 12 mm In a conventional magnetic fixation device, the magnetic force acts to rotate the permanent magnet into a non-excited rotational position.

In a magnetic fixing device that uses a low coercive force magnet such as an alnico magnet as a permanent magnet, even if W is the same as the diameter of the permanent magnet, the magnetic force will excite the permanent magnet at any rotation angle position. It did not act to rotate it into a rotated position.

In FIG. 11, the above H, T, φ' and φ are each 54
The relationship between the W and rotational force in magnetic fixing devices of mm, 50 mm, 35 mm, and 34.8 mm is shown. 11th
In the figure, a white line 90 is a curve when a magnetic material is attracted, and a curve 92 is a curve when a magnetic material is not attracted.

As is clear from FIG. 11, in the case of magnetic fixing devices in which H, T, φ°, and φ are respectively 54 mm, 50 mm, 35 mm, and 34.8 mm, the magnetic acting force moves the permanent magnet to the exciting rotation position. The minimum value of W for rotating the magnetic material is 13.
4mm, but 28mm when not adsorbing magnetic material
becomes.

However, in the magnetic fixing device, when the magnetic body is attracted to the magnetically acting surface, it is sufficient to prevent the permanent magnet from being rotated to the non-excited rotational position. When the body is attracted to the magnetically active surface, the permanent magnet may be rotated to the excitation rotation position.

Referring to the magnetic fixing device 100 shown in FIG. 12, the magnetic circuit block 102 includes a pair of plate-shaped magnetic members 104 facing each other and spaced apart from each other, and the magnetic members 1
04, a pair of non-magnetic members 106 are provided at intervals in the vertical direction and are integrally arranged with the magnetic member 104.

The inner magnetic member 104 and both magnetic members 106 are arranged so as to cooperate with each other to define a space 10B having a square cross-sectional shape. One end of the space 108 is closed by an end plate (not shown) attached to a corresponding end surface of the magnetic circuit block 102.

In the space 108, a permanent magnet 110 having a high coercive force similar to the permanent magnet used in the embodiment shown in FIG. 1 is rotatably arranged. The permanent magnet 110 is connected to the magnetic circuit block 102
Exit from the other end of the space 108 is prevented by a plate and an operating knob located at the other end (both not shown).

In the magnetic fixing device 100, the polar face of the permanent magnet 110 (
The permanent magnet 110 rotates to an excitation rotation position where one of the pole faces (N, S) is magnetically connected to one magnetic member 104 and the other pole face (N, S) is magnetically connected to the other magnetic pole member 104. , the lower end surface of the magnetic member 104, that is, the magnetically acting surface 112 is placed in an excited state.

On the other hand, one of the pole faces (N, S) of the permanent magnet 110 is directed toward one non-magnetic member 106, and the other pole face (N, S) is directed toward the other non-magnetic pole member 106. When the permanent magnet 110 is rotated to the position, the magnetic member 1
The magnetically active surface 112 of 04 is placed in a de-energized state.

The magnetic fixing device 100 has a simple structure, simple machining, and easy assembly, making it inexpensive.

In the magnetic fixing device of the present invention, since the permanent magnet receives a rotational force directed toward the excitation rotation position by the magnetic force, there is no need to provide a stopper to prevent the permanent magnet from being rotated by the magnetic force. good. In this case, the permanent magnet is maintained by the user in a non-energized rotational position against said magnetic force while the magnetically active surface is to be in a non-energized state.

However, in the case of the magnetic fixing device of the present invention, even if the rotational position of the permanent magnet shifts slightly from the non-excited rotational position, the permanent magnet is likely to be rotated to the energized rotational position. Preferably, a stopper means is provided to prevent the permanent magnet from being rotated beyond a predetermined angle from the energized rotational position to the non-excited rotational position.

This allows the user to easily and reliably maintain the permanent magnet in the non-energized rotational position.

In the case of the magnetic fixing device 20 shown in FIG. 1, the convex portion 44 of the plate 36 and the convex portion 62 of the operating knob 54 can be used as the stopper means.

In this case, the convex portions 44.62 have shapes, sizes, and relative positional relationships such that no matter which convex portion 44 the convex portion 62 comes into contact with, the permanent magnet is at the non-excited rotational position. be done. As a result, while the operation knob 54 is rotated and the protrusion 62 is engaged with one of the protrusions 44, the permanent magnet 32 is maintained in the non-excited rotational position, and when the operation knob 54 is released from the hand. , a permanent magnet is rotated to an excitation rotational position by the magnetic force.

In place of the stopper means, it is preferable that the magnetic fixing device is provided with another stopper means for preventing the permanent magnet from being rotated from the excitation rotational position to the non-excitation rotational position by magnetic force.

Such other stopper means stops the rotation of the permanent magnet against the magnetic force at a position where the rotation angle of the permanent magnet exceeds 90 degrees when switching the magnetically active surface from the energized state to the de-energized state. A deterrent can be used.

For example, in the case of the magnetic fixing device 20 shown in FIG.
so as to engage with either the protrusion 62 of the operating knob 54 or the protrusion 44 of the plate 36 when rotated too far;
It can be configured by determining the shape, size, relative positional relationship, etc. of the convex portions 44.62.

In this case, when rotating the permanent magnet 32 from the non-excited rotational position to the excitation rotational position, the permanent magnet 32 is directed to the original excitation rotational position against the magnetic force, that is, the permanent magnet 32 is moved from the excitation rotational position. What is necessary is to rotate it in the opposite direction to the direction in which it is rotated to the non-excited rotational position.

Further stop means are magnetically secured for releasably blocking rotation of the permanent magnet against the magnetic force when the permanent magnet is rotated by less than 90 degrees to switch the magnetically active surface from an energized state to a de-energized state. It can be provided in the device.

The further stopper means can be configured by, for example, a stopper that releasably engages with the permanent magnet or the operating knob, and a release mechanism that releases the engagement between the stopper and the permanent magnet or the operating knob.

Referring to FIG. 13, the magnetic fixing device 120 includes a magnetic circuit block 122, a high coercivity permanent magnet 126 rotatably arranged in a cylindrical space 124 formed in the magnetic circuit block, and Operation knob 1 that rotates the magnet
28.

The magnetic circuit block 122 includes a pair of plate-shaped magnetic members 13
0 and a non-magnetic member 132 disposed between the magnetic members are integrally joined using an adhesive such as brazing material or solder. One magnetic member 130 has a space 124 from its side.
A hole 134 is formed extending deep into the hole, and a rod-shaped stopper 136 is fitted in the hole so as not to be movable.

The permanent magnet 126 is a bar magnet and is magnetized in the diametrical direction. The opposing portion of the permanent magnet 126 in the direction perpendicular to the magnetization direction is a flat surface 138 with a part of the material cut away, and therefore the permanent magnet 126 has an oval cross-sectional shape. On the front end surface of the permanent magnet 126,
A convex portion 140 extending in the magnetization direction is formed.

The operation knob 128 includes a disc-shaped main body 142 , a knob 144 that integrally continues on one side of the main body in the thickness direction, and a knob 144 that extends in the diametrical direction of the main body 142 on the other side of the main body 142 . The groove 146 is formed to extend. The operating knob 128 is attached to the magnetic circuit block 122 so as to fully receive the convex portion 140 of the permanent magnet 126, and is attached to the front end surface of the magnetic circuit block 122 with a plurality of screws (not shown). An attached end plate (not shown) prevents it from coming off the magnetic circuit block 122.

As shown in FIG. 14, a two-shaped engaging portion 148 is formed at the end of the permanent magnet 126 on the opposite side from the convex portion 140. As shown in FIG. The engaging portion 148 has two step portions 148a and 148b that are selectively engaged with the stopper 136.

In the case of this magnetic fixing device 120 as well, the interval between the inner magnetic members 130, that is, the thickness of the non-magnetic member 132 is such that when the magnetic body is in contact with the magnetically acting surface 150, the permanent magnet 126 is not held by the magnetic force. It is set as a value that acts to rotate from the excitation rotation position to the excitation rotation position.

Therefore, as shown in FIG. 14(B), the stepped portion 148a
, 148b are not in contact with the stopper 136, the permanent magnet 126 is in the energized rotational position and the magnetically active surface 150 is in the energized state. On the other hand, as shown in FIG. 14(A) or (C), the stepped portions 148a, 14
8b is in contact with the stopper 136, the permanent magnet 126 is in the non-excited rotational position, and the magnetically active surface 15
0 is placed in a de-energized state. Therefore, the stopper 13
6 and the engaging portion 148 act as the aforementioned stopper means.

Referring to FIG. 15, the magnetic fixing device 160 includes a magnetic circuit block 162 and a rod-shaped permanent magnet 166 with high coercive force rotatably disposed in a cylindrical space 164 formed in the magnetic circuit block. include. Magnetic circuit block 16
2, a pair of plate-shaped magnetic members 168 and a non-magnetic member 170 disposed between the magnetic members are integrally joined using an adhesive such as brazing material or solder.

The magnetic circuit block 162 and the permanent magnet 166 are
It has the same function as the magnetic fixing device 20 shown in the figure. Therefore, the interval between the inner magnetic members 168, that is, the distance between the non-magnetic members 170
The thickness is such that when the magnetic body is in contact with the magnetically active surface 172, the magnetic force acts to rotate the permanent magnet 166 from the non-excited rotational position to the energized rotational position. There is. Moreover, the permanent magnet 166 is magnetized in the diametrical direction.

The magnetic fixing device 160 further includes an operating means 17 for rotating the permanent magnet 166 from an energized rotational position to a non-energized rotational position.
Contains 4. Operation means 174, magnetic circuit block 162
a handle portion 176 made of a non-magnetic material attached to the handle portion 176; an operating rod 178 having one end pivotally connected to the handle portion 176; and a link 180 pivotally connecting one end to the other end of the operating rod 178.
and a rack 1 whose one end is connected to the other end of the link 180.
82 and a gear 184 coaxially secured to the permanent magnet 166 to mesh with the rack.

In this magnetic fixing device 160, when the operating rod 178 is held in the operator's hand, the permanent magnet 166 is in a non-energized rotational position. At this time, the magnetic circuit is in a magnetically unbalanced state.

On the other hand, when the operating rod 178 is released from the hand, the permanent magnet 166 is rotated counterclockwise in FIG. 15 by the magnetic force. At this time, since gear 182 is also rotated in the same direction, rack 182 and link 180 are pulled down, and the other end of operating rod 178 is pulled down.

Once the permanent magnet 166 is rotated to the energized rotational position, the permanent magnet will not rotate any further because the magnetic circuit is magnetically balanced.

When the permanent magnet 166 is in the excitation rotation position, the operating rod 1
78 is held in the operator's hand, the link 180 and the rack 182 are pulled up, so that the rack 184 is in the first position.
5, the permanent magnet 166 is rotated clockwise to a non-energized rotational position.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing an embodiment of the magnetic fixing device of the present invention, FIG. 2 is an enlarged sectional view of the magnetic fixing device of FIG. 1, and FIG. 3 is an exploded perspective view of the magnetic fixing device of FIG. 1. , FIG. 4 is an enlarged side view showing an embodiment of the plate used in the magnetic fixing device of FIG. 1, FIG. 5 is a cross-sectional view taken along line 5--5 in FIG. 4, and FIG. FIG. 7 is an enlarged front view showing one embodiment of the operating knob used in the magnetic fixing device shown in FIG. 1, FIG. 7 is a right side view of the operating knob shown in FIG. 6, and FIG. 8 is a front view showing another embodiment of the operating knob. 9 is a front view showing the dimensions of the magnetic fixing device used in the experiment, FIG. 12 is a cross-sectional view showing another embodiment of the magnetic fixing device; FIG. 13 is an exploded perspective view showing still another embodiment of the magnetic fixing device; FIG. 14 13 is a sectional view taken along line 1414H in FIG. 13 to explain the function of the magnetic fixing device shown in FIG. 13, and FIG. 15 is a sectional view showing still another embodiment of the magnetic fixing device. 20.100,120,160: Magnetic fixing device, 22.
102,122.162:! i-circuit block, 24.104, 130, 168: magnetic member, 26.10
6,132.170: Non-magnetic member, 28.122,15
0,172: Magnetic action surface, 30.108,124,16
4: Space, 32.110, 126.166: Permanent magnet,
54.70, 128: Operation knob (operation means), 44.6
2: Convex portion (stopper means), 136: Stop collar (stopper means), 148: Engagement portion (stopper means), 174: Operating means. Figure 1 8 Figure 2

Claims (5)

[Claims] (1) A magnetic circuit block comprising a pair of magnetic members each having a magnetically active surface and spaced apart from each other, and having a space extending between the magnetic members, and rotatably arranged within the space. a permanent magnet, and an operating means for rotating the permanent magnet to selectively place it in an energized rotational position in which the magnetically active surface is in an energized state and in a non-energized rotational position in which the magnetically active surface is in a deenergized state. , the permanent magnet is a high coercive force magnet, and the magnetic member is
In a state in which a magnetic body is brought into contact with the magnetically acting surface, a magnetically acting force due to unbalanced magnetic flux in the magnetic circuit rotates the permanent magnet in a direction from the non-excited rotational position to the excited rotational position. Magnetic fixing devices separated from each other by a distance that acts as follows. (2) The magnetic fixing device according to claim (1), wherein the magnetic circuit block further includes a non-magnetic member disposed integrally with the magnetic member between the magnetic members. (3) The permanent magnet further includes a stopper means for preventing the permanent magnet from being rotated by a predetermined angle or more from the excitation rotation position to the non-excitation rotation position.
2) The magnetic fixing device according to item 2). (4) Furthermore, when the permanent magnet is rotated by more than 90 degrees from the energized rotational position to the non-energized rotational position, the rotation of the permanent magnet in the direction toward the next energized rotational position is controlled by the magnetism. A magnetic fixing device according to claim 1 or 2, comprising stopper means for blocking against the acting force. (5) Furthermore, when the permanent magnet is rotated by an angle of less than 90 degrees from the excitation rotation position to the non-excitation rotation position, the rotation of the permanent magnet in the direction toward the original excitation rotation position is A magnetic fixing device according to claim 1 or 2, comprising stopper means for releasably blocking against an acting force.