JPH021623B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a magnetic chuck using permanent magnets.

In addition to magnetic chucks that require energization, there are also so-called permanent magnetic chucks that utilize the magnetic force of permanent magnets. This permanent magnetic chuck has an upper plate made of a magnetically permeable material with separators inserted at appropriate intervals to form a predetermined number of magnetic poles, and a permanent magnet placed below this upper plate and a magnetically conductive material that are the same as the magnetic poles. It is composed of a movable magnet section provided in pitches. Both the upper plate and the movable magnet part are separated into a case made of a non-magnetic material, and the movable magnet part can be moved in parallel to the upper plate by a handle provided in the case.

The permanent magnets sandwich a magnetically conductive material and the same poles or different poles face each other, and when the opposite poles match the magnetic pole position, the permanent magnetic chuck is turned on, and when the opposite poles match the separator position, the permanent magnet turns on. The permanent magnetic chuck is turned off.

In such a permanent magnetic chuck, since a permanent magnet is used, there is a problem in that magnetic flux acts even when the chuck is turned off, making it difficult to turn it off completely. On the other hand, there is a desire to avoid complicating the configuration in order to perfect countermeasures against magnetic effects during the off-time.

As a conventional permanent magnetic chuck,
As shown in No. 16149 and Utility Model No. 35-20585, there are devices in which a permanent magnet is also provided on the upper plate, but these have complicated upper plate configurations in terms of magnetic performance. In addition, as shown in Japanese Patent Publication No. 37-13842, there is a device in which a groove for a magnetic gap is provided on the surface of the bottom plate facing the permanent magnet, but the structure is relatively simple in that no permanent magnet is provided on the top plate. The problem is that the magnetic flux effect during off-time cannot be eliminated.

The present invention has been made in view of the above points, and the upper plate of the chuck is provided with magnetic poles made by dividing a magnetically conductive material with separators, while the chuck body is provided with permanent magnets and magnetically conductive materials alternately arranged. The permanent magnet part is divided into two parts, fixed and movable, and a permanent magnetic chuck is constructed in which the movable permanent magnet part is moved to add to or offset the fixed permanent magnet part magnetically. It is.

An embodiment of the present invention will be described below with reference to the accompanying drawings.

1 and 2 show a front cross section of a permanent magnetic chuck according to the present invention, with FIG. 1 showing the chuck-off state and FIG. 2 showing the chuck-on state. Figures 3 and 4 are partially sectional plan views of the same permanent magnetic chuck, with Figure 3 showing the chuck-off state as in Figure 1, and Figure 4 showing the chuck-off state as in Figure 2. Each shows the check-on status.

As shown in these figures, in the upper plate, magnetic poles 1 made of a magnetically permeable material are divided by separators 2 to form a predetermined number of mutually independent magnetic poles. A permanent magnet 3 and a magnetic pole 4 made of magnetically permeable material are arranged at the same pitch as the magnetic poles on this upper plate.
is provided on the chuck body side. The permanent magnet 3 and the magnetic pole 4 constitute a permanent magnet part that cooperates with the upper plate side magnetic pole 1, and this permanent magnet part has a part fixed to the chuck body, a handle 5, and a crankshaft 6.
The chuck consists of a movable part that moves in the left-right direction in the figure in accordance with the rotation of the chuck, and the movable part is supported by a member 7 made of a non-magnetic material so as to be movable within the chuck body. The movable parts are represented by the subscript a, the permanent magnets are represented by 3a, the magnetic poles are represented by 4a, and the fixed parts are similarly represented by 3b and 4.
It is expressed as b.

This permanent magnet part is made of a bottom plate 8 made of a non-magnetic material (in the case of a magnetically conductive material, it is necessary to insert a non-magnetic material between the magnetic poles 4a, 4b and the bottom plate 8 to isolate it from magnetism).
It is housed in a case consisting of an end plate 9 and a side plate 10 made of a non-magnetic material. The side plate 10 may be omitted.

In this permanent magnetic chuck, when the movable part of the permanent magnet part and the fixed part of the different polarities are aligned, the state shown in FIGS. 1 and 3 is achieved, and the permanent magnet 3a of the movable part and the permanent magnet 3b of the fixed part forms a closed magnetic path via the upper plate magnetic pole 1. Therefore, even if an object to be attracted is placed on the upper plate, it will not be magnetically attracted. In other words, it is a check-off.

Next, when the same poles of the movable part and the fixed part of the permanent magnet part are aligned, the states shown in FIGS. 2 and 4 are obtained, and the movable part of the permanent magnet part and the fixed part Magnetic flux from the same magnetic pole is applied, and the magnetic paths of both permanent magnets 3a and 3b are opened.
Therefore, if an object to be attracted is placed so as to straddle the upper magnetic poles 1, a closed magnetic path will be formed through the object. In other words, it becomes a check-on.

FIG. 5 shows the off-state cross-sectional shape of an embodiment of the present invention taken along the line V--V in FIG. 3. As can be seen from the state of magnetic flux drawn in this cross-sectional view, for example, permanent magnet 3
The magnetic flux that exits a reaches the upper plate magnetic pole 1 via the magnetic pole 4a, further reaches the permanent magnet 3b via the magnetic pole 4b, and finally returns to the permanent magnet 3a.

Therefore, by operating the handle 5, the positional relationship between the movable part and the fixed part of the permanent magnet part can be checked or turned on depending on whether the positional relationship is between different polarities or the same polarity. can be switched.

Note that depending on the material of the object to be attracted, residual magnetism may affect the chuck-off and make it unclear, so in order to improve this by slightly reverse excitation,
The movable part of the permanent magnet part may be made larger than the fixed part, or the magnet of the fixed part may be made weaker. For example, a partition plate made of a non-magnetic material may be inserted between the upper magnetic pole 1 and the fixed part of the permanent magnet part.

As described above, the present invention provides a chuck main body with a permanent magnet section consisting of two parts, a fixed section and a movable section, and a top plate provided to close the upper end opening of the main body that is magnetically connected to the permanent magnet section. By providing cooperating magnetic poles, it is possible to avoid complicating the structure such as attaching a permanent magnet to the top plate, and the permanent magnet part on the main body side has two sets of permanent magnets combined to prevent magnetic flux from acting upon chuck-off. It can also be prevented. Moreover, in the permanent magnet of the present invention, the fixed part and the movable part are arranged horizontally, so the height of the chuck can be reduced, and the magnetic path length of the magnetic circuit consisting of the permanent magnet part, the magnetic pole of the upper plate, and the workpiece can be reduced. Since it can be shortened, a magnetic chuck with good magnetic efficiency can be provided.

[Brief explanation of drawings]

1 and 2 are front sectional views of the permanent magnetic chuck according to the present invention, and FIGS. 3 and 4 are partially sectional plan views. FIG. 5 is taken along the line V-V in FIG. 3. FIG. DESCRIPTION OF SYMBOLS 1...Top plate magnetic pole, 2...Separator, 3...Permanent magnet, 4...Magnetic pole, 5...Handle, 6...Crankshaft, 7...Connecting member, 8...Bottom plate, 9...
End plate, 10...side plate.

Claims (1)

[Scope of Claims] 1. A main body having a space therein; a fixed permanent magnet section in which permanent magnets and magnetically permeable materials are arranged horizontally and alternately at a predetermined pitch along the magnetization direction of the permanent magnets; The permanent magnets and the magnetically conductive material are arranged side by side in a direction parallel to the horizontal direction at the same pitch as the predetermined pitch so that the same poles of the permanent magnets face each other with the magnetically conductive material in between, and the fixed permanent magnet part and A movable permanent magnet part is arranged to move in the horizontal direction while facing each other, and the fixed permanent magnet part and the movable permanent magnet part are divided by a separator at the same pitch as the predetermined pitch, and the fixed permanent magnet part and the movable permanent magnet part are magnetically connected through the workpiece. and a top plate disposed above the main body, the fixed permanent magnet part and the movable permanent magnet part, and the movable permanent magnet part has the same polarity as the fixed permanent magnet part. A magnetic chuck that is placed in an adsorption operating state by aligning the two poles, and is placed in a non-adsorption operating state by aligning the opposite poles. 2. The magnetic chuck according to claim 1, wherein the fixed permanent magnet portion is used as a side plate for forming the main body. 3. The chuck according to claim 1, wherein a non-magnetic or magnetically conductive partition plate is inserted between the fixed permanent magnet portion and the upper plate.