JPH07171726A - Chuck for permanent magnet - Google Patents

Abstract

PURPOSE:To realize the smooth switching of the working surface by making the length of the magnetic pole surface of a permanent magnet in the moving direction of the permanent magnet larger than that of a non-magnetic part in the same direction to reduce the force required for switching the working surface. CONSTITUTION:The length of the magnetic pole surface of a permanent magnet 28 in the moving direction of the permanent magnet 28 is larger than that of a non-magnetic part 18 in the same direction. The positional relationship between the non-magnetic part 18 and the permanent magnetic pole surface in the moving direction of the permanent magnet 28 is the second direction orthogonal to the first direction, and is different in a plurality of parts in the second direction parallel to the working surface. When the permanent magnet 28 is moved to the first position, the first areas of two magnetic piece assembled bodies 14 adjacent across the permanent magnet 28 are magnetically connected to the permanent magnet 28, and the magnetic flux of the permanent magnet 28 passes the edge surface of the first area, that is the opposite side to the second area, of the first area of the adjacent two magnetic piece assembled bodies 14.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a permanent magnet chuck for holding a magnetic substance by a magnetic force, and more particularly, to excite the work face by moving the permanent magnet in a direction intersecting the work face for attracting the magnetic substance. The present invention relates to a permanent magnet chuck that switches between a magnetic state and a non-excited state.

[0002]

2. Description of the Related Art As one of the permanent magnet chucks of this type, there is a magnetic chuck as disclosed in, for example, Japanese Utility Model Publication No. 5-29783.

This magnetic chuck includes a plurality of plate-shaped magnetic pole piece assemblies arranged in parallel at intervals and a side of one end of the magnetic pole piece assembly between the adjacent magnetic pole piece assemblies. A spacer made of a non-magnetic material, a connecting means for interconnecting at least the adjacent pole piece assemblies on a side opposite to the side where the spacers are arranged, and a spacer disposed between the adjacent pole piece assemblies. At least one permanent magnet disposed so as to be movable between the spacer and the connecting means in a direction orthogonal to the working surface in a state where the magnetic pole surfaces are slidably abutted on both pole piece assemblies; An operating mechanism for selectively moving the magnet to the spacer side and the connecting means side is included.

Each of the pole piece assemblies adjacent to each other with the permanent magnet in between is provided with a first region made of a magnetic material that acts as a pole piece on the spacer side, and the connection of the first region. A second region having a non-magnetic portion of non-magnetic material that extends to the side of the means. The permanent magnet is movable between a first position where its magnetic pole surface contacts only the first region and a second position where it contacts only the second region.

In the above magnetic chuck, when the permanent magnet is moved to the first position, the working surface is placed in an excited state for attracting a magnetic substance. On the other hand, the permanent magnet is the second
When the work surface is moved to the position, the work surface is placed in a non-excited state in which the attraction of the magnetic substance is released. Therefore, the working surface is
By the movement of the permanent magnet, the excitation state and the non-excitation state are selectively switched.

In the above magnetic chuck, however, the force required to move the permanent magnet when the permanent magnet passes through the non-magnetic portion of the second region to switch the working surface from the excited state to the non-excited state. Is maximum at a specific position in the relative positional relationship between the permanent magnet and the non-magnetic portion. As a result, a large force is required to move the permanent magnets, and the work surface cannot be smoothly switched. In particular, in the case of a magnetic chuck using a large amount of permanent magnets, it is difficult to switch the work surface.

The above reason has not been clarified yet, but when the magnetic pole surface of the permanent magnet passes through the non-magnetic portion of the second region so as to switch the working surface from the excited state to the non-excited state, It is considered that this is because the magnetic flux is concentrated between the magnetic pole surface and the magnetic pole piece assembly, particularly the first region.

[0008]

SUMMARY OF THE INVENTION An object of the present invention is to reduce the maximum force required for switching work surfaces and to enable smooth switching of work surfaces.

[0009]

A permanent magnet chuck according to the present invention comprises a plurality of plate-shaped magnetic pole piece assemblies arranged in parallel with each other at intervals in a first direction parallel to a work surface for attracting a magnetic body. A plurality of magnetic pole pieces each including a first region made of a magnetic material that acts as a magnetic pole piece and a second area having a non-magnetic portion that continues to the side of the first area opposite to the work surface. An assembly, a spacer made of a non-magnetic material disposed between the adjacent pole piece assemblies and on the side of the working surface, and at least the adjacent pole piece assemblies are interconnected on the side opposite to the working surface. It is possible to move between the spacer and the connecting means in a direction intersecting the working surface in a state between the connecting means and the adjacent magnetic pole piece assemblies, with the magnetic pole surfaces slidably abutting on both the magnetic pole piece assemblies. At least one permanent placed in A magnet and an operating mechanism for selectively moving the permanent magnet to a first position where most of the magnetic pole surface contacts only the first region and a second position where only the second region contacts the second region. including.

The length dimension of the magnetic pole surface of the permanent magnet in the moving direction of the permanent magnet is larger than that of the non-magnetic portion in the same direction. The positional relationship between the non-magnetic portion and the magnetic pole surface of the permanent magnet in the moving direction of the permanent magnet is the second direction orthogonal to the first direction and the second direction parallel to the work surface. Different in multiple places.

The work surface for attracting the magnetic substance is formed by the first region and the spacer, or by a face plate arranged on these.

When the permanent magnet is moved to the first position, the first regions of two adjacent pole piece assemblies that are adjacent to each other with the permanent magnet in between are magnetically connected to the permanent magnet. The magnetic flux of the magnet mainly passes through the end faces of the two adjacent pole piece assemblies on the side opposite to the first region and the second region. At this time, the amount of leakage magnetic flux passing through the ends of the first region and the second region of the two adjacent pole piece assemblies is extremely small. This leaves the work surface in an excited state.

On the other hand, when the permanent magnet is moved to the second position, both the first regions of the two adjacent pole piece assemblies with the permanent magnet in between are magnetically separated from the permanent magnet. Therefore, the magnetic flux passing through the end faces of the two adjacent pole piece assemblies on the side opposite to the second region is extremely small. This leaves the work surface in a non-excited state.

When the permanent magnet is moved from the first position to the second position, the magnetic pole surface of the permanent magnet passes through the nonmagnetic portion of the second region. At this time, the force required to move the permanent magnet is maximized.

However, according to the present invention, the positional relationship between the non-magnetic portion of the second region and the magnetic pole surface of the permanent magnet in the moving direction of the permanent magnet is different at a plurality of positions in the second direction, which is well known. The maximum force required for switching the work surface is smaller than that of the permanent magnet chuck, and as a result, the work surface can be smoothly switched.

The reason why the maximum force required for switching the work surface is reduced by the present invention has not been clarified, but the second magnetic pole surface of the permanent magnet is used to switch the work surface from the excited state to the non-excited state. When passing through the non-magnetic part of
The timing at which the magnetic pole surface of the permanent magnet reaches a predetermined portion of the non-magnetic portion differs depending on the portion of the magnetic pole surface of the permanent magnet in the second direction, which causes concentration of magnetic flux between the permanent magnet and the pole piece assembly. Since it is relaxed compared to known chucks,
it is conceivable that.

The non-magnetic portion may have one or more holes formed in the pole piece assembly, may have such holes and a non-magnetic material disposed therein, and further. It may have a non-magnetic material region extending continuously in the second direction.

In any case, the positional relationship between the non-magnetic portion and the permanent magnet in the moving direction of the permanent magnet can be made different at a plurality of positions in the second direction depending on the position and shape of the hole or the non-magnetic material portion. it can.

However, in order to make the positional relationship between the non-magnetic portion and the permanent magnet in the moving direction of the permanent magnet different at a plurality of points in the second direction, a plurality of the above-mentioned elements arranged at intervals in the second direction. The permanent magnets may be arranged such that the permanent magnets adjacent in the second direction are displaced in the moving direction.

Further, in order to make the positional relationship between the non-magnetic portion and the permanent magnet in the moving direction of the permanent magnet different at a plurality of locations in the second direction, a rectangular shape long in the direction having an angle with respect to the second direction. You may use the permanent magnet which has a magnetic pole surface.

When the non-magnetic portion has one or more holes, the plate-shaped member made of a magnetic material is formed with one or more holes to form the first member.
It is possible to manufacture a magnetic pole piece assembly in which the first and second regions are integrated, and the magnetic pole piece assembly is easier to manufacture than the case where the first and second magnetic pole pieces are separately manufactured and then joined by welding or the like. become.

Further, when the non-magnetic portion has one or more holes and the non-magnetic material arranged in the holes, it is possible to prevent the permanent magnet from being locked at the edge portion of the hole, which makes the permanent magnet easier. The permanent magnet can be prevented from being damaged.

[0023]

EXAMPLE A permanent magnet chuck 10 shown in FIGS.
The side plate portion 12 is provided between the square cylindrical case 12 made of a non-magnetic material and the pair of side plate portions 12a facing each other.
a plurality of magnetic pole piece assemblies 14 arranged in parallel with each other at a constant interval in a first direction (vertical direction in FIG. 1) extending in parallel with b. Each side plate portion 1 of the case 12
2a, 12b and each pole piece assembly 14 have a rectangular plate shape.

As shown in FIGS. 2 and 4, each of the pole piece assemblies 14 has a first region in the upper part of FIG.
And a second region extending downward from the region. The first region has a pole piece 16 made of a magnetic material. On the other hand, the second region has a non-magnetic portion 18 extending from the magnetic pole piece 16 and made of a non-magnetic material, and a magnetic portion 20 extending to the opposite side of the non-magnetic portion from the magnetic pole piece 16 and made of a magnetic material. Have. As shown in FIG. 2, each pole piece assembly 14 is formed with a pair of elongated holes 22 extending from the non-magnetic portion 18 to the magnetic portion.

The non-magnetic portion 18 is in a second direction (in FIG. 1, parallel to the side plate portion 12a and orthogonal to the first direction).
A plurality of circular holes 1 formed at intervals in the left-right direction
8a, a portion between the adjacent holes 18a, and a portion between the hole 18a and the elongated hole 22.

Adjacent holes 18a are displaced in a third direction (vertical direction in FIG. 2) orthogonal to the first and second directions. In the illustrated example, the holes 18a are formed such that their arrangement meanders in the third direction with respect to the second direction.

Between adjacent holes 18a and holes 18a, 22
Between, there is little leakage magnetic flux passing through the part between them,
In addition, the value is selected to be sufficiently small so that the magnetic flux is saturated in the region between them.

A spacer 2 made of a non-magnetic material is provided between the adjacent pole piece assemblies 14 at the end on the pole piece 16 side.
4 is provided, and a connecting member 26 made of a magnetic material is provided at the end on the magnetic portion 20 side. The case 12, the pole piece assembly 14, the spacer 24, and the connecting member 26 are fixed to each other.

As shown in FIGS. 3 and 4, the spacer 24 and the connecting member 2 are provided between the adjacent pole piece assemblies 14.
6, a plurality of permanent magnets 28 are arranged between the spacer 24 and the connecting member 26 so as to be movable in the third direction. The permanent magnets 28 are arranged such that the magnetization direction is the arrangement direction of the pole piece assemblies 14 and the pole faces of the same polarity of the permanent magnets that contact the same pole piece assembly 14 face each other.

The permanent magnet 28 is a plate-shaped or block-shaped magnet, and has a rectangular magnetic pole surface elongated in the second direction. The permanent magnet 28 is arranged at the same position in the moving direction of the permanent magnet 28 so that the upper edge and the lower edge of the magnetic pole surface are parallel to the second direction.

The permanent magnet 28 also has its magnetic pole surface in contact with the magnetic pole piece assembly 14 while the majority of the magnetic pole surface contacts only the magnetic pole piece 16 and the magnetic portions 20 in the first and second regions. Is movable to a second position in which it only contacts.

The permanent magnets 28 are formed by the adjacent pole piece assemblies 1.
4 is attached to a slider 30 which is movable between the spacer 24 and the connecting member 26. The slider 30 has a slot 22 in the slider and pole piece assembly 14.
Are connected to each other by two connecting rods 32 passing through. Both ends of the connecting rod 32 extend to a vertically extending recess 34 provided on the facing surface of the side plate portion 12a.

As shown in FIGS. 1 to 3, racks 36, which are housed in the recesses 34 so as to be movable in the same direction as the moving direction of the permanent magnets 28, are fixed to both ends of the connecting rod 32.
The racks 36 are arranged at a distance from each other and with the teeth facing each other.

Two gears 38 and 40, which mesh with the rack 36 and mesh with each other, are arranged in each recess 34. Each gear 38 meshing with one rack 36 is attached to a shaft 42 rotatably supported by the side plate portion 12a. On the other hand, the gear 40 that meshes with the other rack 36 has a shaft 44 that rotatably passes through the pole piece assembly 14.
It is attached to both ends of.

One end surface of the shaft 44 has one side plate portion 12
It is exposed to the side of the permanent magnet chuck 10 from the side surface of a. The other end of the shaft 44 is connected to the gear 40 having its end face facing the side surface of the other side plate 12a. Gear 40
A hexagonal hole 46 that is opened to the side of the permanent magnet chuck 10 is formed on the end surface that faces the side surface of the.

The illustrated permanent magnet chuck 10 includes a pole piece 1
Although the end surface on the 6 side is the work surface 48 for adsorbing the magnetic substance,
A face plate described in JP-A-61-65742 may be arranged on the surface. In addition, adjacent pole piece assemblies 1
Instead of connecting the four to each other with a connecting member 26 arranged between both pole piece assemblies, a plurality of pole piece assemblies 14 are connected with one plate member arranged on the side opposite the working surface 48. Alternatively, the box-shaped case 12 may be used, and the case 12 may be connected to each other by the bottom plate of the case.

When using the permanent magnet chuck 10, the permanent magnet 28 is inserted into the hexagonal hole 46 of the shaft 44 with a hexagonal wrench.
By rotating the gear 40, its pole face is moved to a position where it only contacts the second region and a position where said pole face contacts only the pole piece 16 of the adjacent pole piece assembly 14.

That is, the shaft 44 in FIGS.
Is rotated counterclockwise, the gear 40 is rotated in the same direction and the gear 38 is rotated clockwise, so that the rack 36 and thus the slider 30 are moved downward in FIGS. The permanent magnet is moved to a position where the pole face only contacts the second region of the pole piece assembly 14, as shown in FIG.

On the other hand, when the shaft 44 is rotated in the opposite direction from this state, the gear 40 is rotated in the clockwise direction and the gear 38 is rotated in the counterclockwise direction. 30 is moved upwards, whereby the permanent magnet is moved to a position where its pole faces only contact the pole pieces 16, as shown in FIG.

As shown in FIG. 4, when the permanent magnet 28 is moved to the first position (the position where the magnetic pole surface of the permanent magnet 28 contacts only the magnetic pole piece 16), the magnetic flux generated by the permanent magnet 28 is generated. Passes primarily through the loop 52 from the pole piece 16 of one pole piece assembly 14 through the work surface 48 to the pole piece 16 of the other pole piece assembly 14. As a result, the work surface 48 is placed in an excited state.

Therefore, according to the permanent magnet chuck 10, when the working surface 48 is in the excited state, the leakage magnetic flux passing through the lower ends of the magnetic pieces 16 of the two adjacent pole piece assemblies 14 is extremely small, and as a result, , When compared with a conventional permanent magnet chuck in which only one of the adjacent pole pieces is divided into two magnetically insulated parts, when the work surface 48 is in an excited state,
There are many magnetic fluxes that contribute to the attraction of the magnetic material to the work surface 48.

On the other hand, as shown in FIG. 5, when the permanent magnet 28 is moved to the second position (the position where the magnetic pole surface of the permanent magnet 28 contacts only the second region), the permanent magnet 2 is moved.
The magnetic flux generated by 8 mainly passes through the loop 54 from the magnetic portion 20 of the one pole piece assembly 14 to the magnetic portion 20 of the other pole piece assembly 14 via the connecting member 26. As a result, the work surface 48 is placed in a non-excited state.

In the permanent magnet 28, a part of the magnetic pole surface is in contact with the non-magnetic portion in both the first and second positions, but most of the magnetic pole surface is in the first position. May be moved so as to contact only the magnetic portion 20 and contact only the magnetic portion 20 at the second position.

According to the permanent magnet chuck 10, the upper and lower edges of the magnetic pole surface of the permanent magnet 28 are parallel to the second direction, while the adjacent holes 18a move in the third direction (movement of the permanent magnet). Direction), the maximum force required to switch the working surface from the excited state to the non-excited state or vice versa is smaller than in known permanent magnet chucks.

This is because the magnetic closed loops 52 and 54 are formed as shown in FIGS. 4 and 5 regardless of whether the work surface is in the excited state or the non-excited state, so that the magnetic pole surface of the permanent magnet is the second. When passing through the non-magnetic part of the
The timing at which the magnetic pole surface of the permanent magnet 28 reaches a predetermined portion of the hole 18a differs depending on the portion of the magnetic pole surface of the permanent magnet in the second direction, which causes a magnetic flux between the permanent magnet and the magnetic pole piece 16 or the magnetic portion 20. It is considered that this is because the concentration of is reduced as compared with the known chuck.

For example, in the permanent magnet chuck 10, at a certain timing when the magnetic pole surface of the permanent magnet 28 passes through the non-magnetic portion 18, particularly the hole 18a, a) most of the magnetic pole surface is located in the second direction. A part that contacts only the first region, b) a part contacts the non-magnetic part, and the rest the first part
There will be a site that contacts the region of c), and c) a site that mostly contacts only the second region.

On the other hand, in the known permanent magnet chuck described in the prior art, all the parts of the magnetic pole surface in the second direction simultaneously go through the above states a) to c) in that order. That is, all parts of the magnetic pole surface in the second direction pass through the nonmagnetic part at the same timing.

Therefore, as compared with the known permanent magnet chuck, the permanent magnet chuck 10 concentrates the magnetic flux between the magnetic pole surface of the permanent magnet and the first region, particularly the magnetic pole piece 16 when the working surface is switched to the excited state. And the concentration of magnetic flux between the magnetic pole surface of the permanent magnet and the second region, especially the magnetic portion 20, is alleviated when the work surface is switched to the non-excited state. As a result, the maximum force required to switch the work surface to either the excited state or the non-excited state becomes small, and the work surface can be smoothly switched.

The second part 20 as well or the second part 2
0 and the connecting member 26 may be made of a non-magnetic material. With this configuration, when the work surface is in the non-excited state, the attractive force always acts between the pole piece 16 and the permanent magnet 28, so that the work surface is changed from the non-excited state to the excited state with a small force. It can be switched.

On the other hand, since the loop 54 shown in FIG. 5 is not formed when the work surface is in the non-excited state, when the work surface is switched from the excited state to the non-excited state, the magnetic pole surface of the permanent magnet is in the non-magnetic portion. Requires a great deal of force when passing 18. However, the timing at which the magnetic pole surface of the permanent magnet reaches the predetermined portion of the non-magnetic portion differs depending on the portion of the magnetic pole surface of the permanent magnet in the second direction, and the concentration of magnetic flux between the permanent magnet and the magnetic pole piece assembly may occur. By being relaxed compared to known chucks, the force is relaxed.

In order to reduce the maximum force required to switch the working surface from the excited state to the non-excited state, the non-magnetic portion 18 (particularly the hole 18a in the illustrated example) and the permanent magnet 28 in the moving direction of the permanent magnet 28 are made permanent. The positions and shapes of the magnetic pole surface and the non-magnetic portion may be set so that the positional relationship between the magnet 28 and the magnetic pole surface is different at a plurality of positions in the second direction.

In the second embodiment of the non-magnetic portion shown in FIG. 6, a plurality of circular holes 18a are formed in a zigzag shape in the moving direction of the permanent magnet 28 with respect to the second direction, that is, meandering to form a second shape. The positional relationship between the non-magnetic portion 18 in the area and the magnetic pole surface of the permanent magnet 28 is displaced in the moving direction of the permanent magnet 28 at a plurality of positions in the second direction.

In the third embodiment of the non-magnetic portion shown in FIG. 7, a plurality of circular holes 18a are formed in a linear array inclined in the moving direction of the permanent magnet 28 with respect to the second direction. , The non-magnetic portion 18 and the permanent magnet 28 of the second region
The positional relationship with the magnetic pole surface is displaced in the moving direction of the permanent magnet 28 at a plurality of positions in the second direction.

In the fourth embodiment of the non-magnetic portion shown in FIG. 8, a plurality of circular holes 18a are formed in a mountain-shaped array inclined in the moving direction of the permanent magnet 28 with respect to the second direction. , The non-magnetic portion 18 and the permanent magnet 28 of the second region
The positional relationship with the magnetic pole surface is displaced in the moving direction of the permanent magnet 28 at a plurality of positions in the second direction.

In the fifth embodiment of the non-magnetic portion shown in FIG. 9, a plurality of circular holes 18a are divided into a plurality of hole groups spaced in the second direction, and adjacent hole groups of the permanent magnet 28 are separated. By displacing in the moving direction, the positional relationship between the non-magnetic portion 18 in the second region and the magnetic pole surface of the permanent magnet 28 is displaced in the moving direction of the permanent magnet 28 at a plurality of locations in the second direction.

In the sixth embodiment of the non-magnetic portion shown in FIG. 10, a plurality of elongated holes 18b elongated in the second direction are formed in the permanent magnet 28.
By displacing the non-magnetic portion 18 of the second region and the magnetic pole surface of the permanent magnet 28 in the second direction.
The permanent magnet 28 is displaced in the moving direction at a plurality of positions in the direction.

In the seventh embodiment of the non-magnetic portion shown in FIG. 11, a plurality of elongated holes 18b elongated in the second direction are tilted in the moving direction of the permanent magnet 28 with respect to the second direction. The positional relationship between the non-magnetic portion 18 in the area 2 and the magnetic pole surface of the permanent magnet 28 is displaced in the moving direction of the permanent magnet 28 at a plurality of locations in the second direction.

In the eighth embodiment of the non-magnetic portion shown in FIG. 12, one elongated hole 28b extending from one end to the other end of the pole piece assembly 14 in the second direction is formed in the second direction. By inclining in the moving direction of the permanent magnet 28, the positional relationship between the non-magnetic portion 18 of the second region and the magnetic pole surface of the permanent magnet 28 is displaced in the moving direction of the permanent magnet 28 at a plurality of locations in the second direction. ing.

In the ninth embodiment of the non-magnetic portion shown in FIG. 13, the permanent magnet 28 is moved in the second direction so that the two elongated holes 18b that are long in the second direction form a mountain shape. The non-magnetic portion 1 of the second region
8 and the magnetic pole surface of the permanent magnet 28 are displaced in the moving direction of the permanent magnet 28 at a plurality of positions in the second direction.

In the tenth embodiment of the non-magnetic portion shown in FIG. 14, one elongated hole 28b extending from one end to the other end of the pole piece assembly 14 in the second direction is provided with a permanent magnet in the second direction. By making it meander in the moving direction of 28,
The positional relationship between the non-magnetic portion 18 in the second region and the magnetic pole surface of the permanent magnet 28 is displaced in the moving direction of the permanent magnet 28 at a plurality of locations in the second direction.

In the eleventh embodiment of the non-magnetic portion shown in FIG. 15, the non-magnetic portion 58 extends from one end to the other end of the pole piece assembly 14 in the second direction. The nonmagnetic material zone is formed by a material zone, and the nonmagnetic material zone is made to meander in the moving direction of the permanent magnet 28 with respect to the second direction, whereby the nonmagnetic portion 58 in the second region and the magnetic pole surface of the permanent magnet 28 are positioned. The permanent magnets 28 are displaced in the moving direction at a plurality of positions in the second direction.

In the twelfth embodiment of the non-magnetic portion shown in FIG. 16, the non-magnetic portion 58 extends from one end to the other end of the pole piece assembly 14 in the second direction. The nonmagnetic material zone is formed of a material zone, and the nonmagnetic material zone is inclined in the moving direction of the permanent magnet 28 with respect to the second direction, so that the nonmagnetic portion 58 in the second region and the magnetic pole surface of the permanent magnet 28 are positioned. The relationship is displaced in the moving direction of the permanent magnet 28 at a plurality of positions in the second direction.

In the thirteenth embodiment of the non-magnetic portion shown in FIG. 17, the non-magnetic portion 58 extends from one end to the other end of the pole piece assembly 14 in the second direction. By forming the non-magnetic material zone in the shape of a mountain and forming the non-magnetic material zone in a mountain shape, the positional relationship between the non-magnetic portion 58 of the second region and the magnetic pole surface of the permanent magnet 28 is permanent at a plurality of positions in the second direction. The magnet 28 is displaced in the moving direction.

In the second embodiment of the permanent magnet shown in FIG. 18, the nonmagnetic portion 60 is made parallel to the second direction, and instead, the permanent magnets 28 adjacent to each other in the second direction are displaced in the moving direction. As a result, the non-magnetic portion 60 of the second region
And the magnetic pole surface of the permanent magnet 28 are displaced in the moving direction of the permanent magnet 28 at a plurality of positions in the second direction.

In the third embodiment of the permanent magnet shown in FIG. 19, a plurality of circular permanent magnets 62 are arranged in a mountain shape inclined in the moving direction of the permanent magnet 62 with respect to the second direction. The positional relationship between the non-magnetic portion of the area 2 and the magnetic pole surface of the permanent magnet 62 is displaced in the moving direction of the permanent magnet 62 at a plurality of locations in the second direction. In the case of this embodiment, the non-magnetic portion is the same as that of the embodiment of FIG.

In the fourth embodiment of the permanent magnet shown in FIG. 20, the two permanent magnets 28 are inclined in the moving direction of the permanent magnet 28 with respect to the second direction so that both of them have a mountain shape. The positional relationship between the nonmagnetic portion of the second region and the magnetic pole surface of the permanent magnet 28 is displaced in the moving direction of the permanent magnet 28 at a plurality of locations in the second direction. In the case of this embodiment, the non-magnetic portion is the same as that of the embodiment of FIG.

Although the permanent magnets 28 having the same position in the moving direction are used in the embodiment shown in FIGS. 1 to 17, the magnets arranged as in the embodiment shown in FIG. 18 or 20 are used. Alternatively, a magnet arranged as shown in FIG. 19 may be used. Similarly, also in the embodiments shown in FIGS. 18 to 20, the non-magnetic portions arranged as shown in FIGS. 1 to 17 may be used.

It is preferable that the holes 18a and 18b are filled with a non-magnetic material so that the contact surface between the permanent magnet 28 and the pole piece assembly 14 is a smooth surface.

[Brief description of drawings]

FIG. 1 is a plan view showing an embodiment of a permanent magnet chuck of the present invention.

2 is a cross-sectional view taken along line 2-2 of FIG.

3 is a cross-sectional view taken along line 3-3 of FIG.

4 is a cross-sectional view taken along line 4-4 of FIG.

5 is a cross-sectional view at the same position as in FIG. 4 when the work surface is in a non-excited state.

FIG. 6 is a diagram showing a second embodiment of the non-magnetic portion.

FIG. 7 is a diagram showing a third embodiment of a non-magnetic portion.

FIG. 8 is a diagram showing a fourth example of the non-magnetic portion.

FIG. 9 is a diagram showing a fifth example of the non-magnetic portion.

FIG. 10 is a diagram showing a sixth example of the non-magnetic portion.

FIG. 11 is a diagram showing a seventh example of the non-magnetic portion.

FIG. 12 is a diagram showing an eighth example of the non-magnetic portion.

FIG. 13 is a diagram showing a ninth example of the non-magnetic portion.

FIG. 14 is a diagram showing a tenth embodiment of the non-magnetic portion.

FIG. 15 is a diagram showing an eleventh embodiment of a non-magnetic portion.

FIG. 16 is a diagram showing a twelfth embodiment of the non-magnetic portion.

FIG. 17 is a diagram showing a thirteenth embodiment of the non-magnetic portion.

FIG. 18 is a diagram showing a second embodiment of arrangement of permanent magnets.

FIG. 19 is a diagram showing a third embodiment of arrangement of permanent magnets.

FIG. 20 is a diagram showing a fourth embodiment of arrangement of permanent magnets.

[Explanation of symbols]

 10 permanent magnet chuck 14 magnetic pole piece assembly 16 magnetic pole piece 18,60 non-magnetic portion 20 magnetic portion 24 spacer 26 connecting member 28,62 permanent magnet 30 slider 36 rack 38,40 gear 48 working surface 18a, 18b hole

Claims (9)

[Claims] 1. A plurality of plate-shaped magnetic pole piece assemblies arranged in parallel to each other at intervals in a first direction parallel to a work surface for attracting a magnetic body, the magnetic material acting as a magnetic pole piece. A plurality of magnetic pole piece assemblies each having a first region and a second region having a non-magnetic portion continuing from a side opposite to the work surface of the first region, and adjacent magnetic pole piece assemblies. A spacer made of a non-magnetic material, which is disposed between the adjacent magnetic pole piece assemblies, a coupling means for coupling at least adjacent magnetic pole piece assemblies to each other on the side opposite to the mechanical work surface, and an intervening magnetic pole piece assembly. And at least one permanent magnet movably arranged between the spacer and the connecting means in a direction intersecting the working surface in a state where the magnetic pole surfaces are slidably abutted on the both pole piece assemblies. Most of the magnetic pole surface is in front of the permanent magnet The first contact only with the first area
Of the magnetic pole surface of the permanent magnet in the moving direction of the permanent magnet.
It is larger than that of the non-magnetic portion in the same direction, and the positional relationship between the non-magnetic portion and the magnetic pole surface of the permanent magnet in the moving direction of the permanent magnet is a second direction orthogonal to the first direction. And a permanent magnet chuck different in a plurality of positions in a second direction parallel to the work surface. 2. The non-magnetic portion has a plurality of holes formed in the pole piece assembly at intervals in the second direction, and adjacent holes are displaced in the moving direction of the permanent magnet. The permanent magnet chuck according to claim 1, wherein: 3. The non-magnetic portion has a plurality of hole groups formed of a plurality of holes formed in the pole piece assembly at intervals in the second direction, and adjacent hole groups are the permanent holes. The permanent magnet chuck according to claim 1, wherein the permanent magnet chuck is displaced in the moving direction of the magnet. 4. The at least one non-magnetic portion is formed in the pole piece assembly at intervals in the second direction.
The permanent magnet chuck according to claim 1, wherein the permanent magnet chuck has one slot and at least one slot extending in a direction at an angle with respect to the second direction. 5. The non-magnetic portion is at least one elongated hole formed in the pole piece assembly and meanders in the moving direction of the permanent magnet with respect to the second direction in the second direction. The permanent magnet chuck of claim 1 having at least one elongated hole extending. 6. The non-magnetic portion further comprises a non-magnetic material disposed in the hole or the slot.
The permanent magnet chuck according to claim 1. 7. The non-magnetic portion has a non-magnetic material region which continuously extends in the second direction while being displaced in the moving direction of the permanent magnet with respect to the second direction. Permanent magnet chuck. 8. A plurality of permanent magnets arranged at intervals in the second direction, wherein permanent magnets adjacent to each other in the second direction are displaced in the moving direction.
The permanent magnet chuck according to claim 1. 9. The permanent magnet chuck according to claim 1, wherein a magnetic pole surface of the permanent magnet has a rectangular shape that is long in a direction having an angle with respect to the second direction.