JPH09201733A - Variable magnetic field generator - Google Patents

Abstract

(57) [Abstract] (Correction) [PROBLEMS] To provide a variable magnetic field generator that is stronger in an on state and can completely eliminate magnetic field strength in an off state. In a variable magnetic field generator having a magnetic circuit composed of permanent magnets and magnetic pole members, two magnet rows in which permanent magnets and magnetic pole members are periodically alternately arranged are arranged in close proximity to each other, and one magnet is arranged. A variable magnetic field generator characterized in that the magnetic field strength on the surface of the magnet array is changed by phase shifting the array.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a variable magnetic field generator.

[0002]

2. Description of the Related Art A variable magnetic field generator is used for an insertion light source device for causing an electron beam of an electron accelerator to meander to generate radiated light, a magnet / chuck for fixing a processed product of a magnetic material, and the like. The structure is as shown in FIG.
And a magnetic pole material (iron or the like) 12, and a row of magnets 13 is arranged under a magnet row 15 in which permanent magnets 11 and magnetic pole materials 12 are alternately arranged, and a plate of a magnetic body 14 is arranged under the row. Is.

[0003]

However, in this conventional variable magnetic field generator, in order to completely eliminate the magnetic field strength in the off state, the magnetic field strength in the on state must be lowered. If the magnetic field strength in the off state is set to zero, a generator having a very high magnetic field strength in the on state cannot be obtained. The present invention is intended to realize a variable magnetic field generator which is stronger than the conventional variable magnetic field generator in the ON state and can completely eliminate the magnetic field strength in the OFF state.

[0004]

That is, according to the present invention, in a variable magnetic field generator having a magnetic circuit composed of permanent magnets and magnetic pole members, two permanent magnets and magnetic pole members are alternately arranged in a row. The gist of a variable magnetic field generator is characterized in that the magnetic field strength on the surface of the magnet array is changed by arranging them in close proximity to each other and phase-shifting one magnet array. This will be described in detail below.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION An example of an embodiment of the present invention will be described below. The variable magnetic field generator of the present invention shown in FIG. 1 is configured by two rows of magnets in which magnets 1 and magnetic pole members 2 are alternately and periodically arranged. The respective magnet rows 15 are arranged so that the magnetic pole materials alternate in the same cycle. FIG.
The type 1 of the variable magnetic field generation device shown in (a) is one in which these magnet rows are arranged side by side in the left-right direction.
In the type 2 shown in (1), a permanent magnet and a magnet array of magnetic poles are arranged vertically adjacent to each other.

The bottom magnet array is movable in the longitudinal direction and has a moving mechanism (not shown) for that purpose. By moving the bottom magnet row, the magnetic field strength can be made variable. Examples of the moving mechanism include a fluid cylinder, a rack and pinion, and a linear guide.

The variable magnetic field strength by such a mechanism will be described with reference to FIGS. 2 (a) and 2 (b). First, assuming the state as shown in FIG. 2A, the magnetic flux of the magnet array is concentrated on the magnetic poles. Since the bottom movable magnet row also has the same magnetization direction as the top magnet row, it concentrates on the magnetic poles. The magnetic flux from the magnetic pole flows into the space above the upper magnet row, is absorbed by the adjacent magnetic pole, and a magnetic field is generated in the space. This is the ON state. Next, one of the movable magnet arrays is moved by a half cycle to obtain the state shown in FIG. The magnetic flux of the upper magnet array is concentrated on the magnetic poles as described above. However, in the case of FIG. 2B, since the magnetic poles of the bottom magnet row are opposite in polarity to the magnetic poles of the top magnet row, the magnetic flux of the top magnet row flows to the bottom magnet row. Therefore, since the magnetic flux does not flow in the space above the upper magnet array, the magnetic field strength becomes zero. This is the off state. As a result, at a distance of 8 mm above the magnet row in the ON state
A variable magnetic field generator that generates a magnetic field strength of 1000 G to 3000 G can be obtained.

Magnet 1 used in the variable magnetic field generator of the present invention
An example of the material is a NdFeB magnet, and an example of the material of the magnetic pole material 2 is SUY. Further, if the number of magnets in the magnet array is less than a few, it cannot be changed, so 10 or more is preferable. The smaller the gap between the magnet rows, the wider the variable range. However, to actually make it, 0.5-1
mm is preferred.

Examples of the application of the variable magnetic field generator of the present invention include a magnet chuck and an insertion light source device. If the variable magnetic field generator of the present invention is used, the magnetic chuck is stronger than before when attracted, the magnetic field can be made almost zero when it is in the off state, and the gap is variable in the insertion light source device. Since the mechanism for doing so is unnecessary, the gantry structure is simple and easy to make, and it can be used for photo CVD, X-ray exposure of LSI, and the like.

Further, in the present invention, two rows of magnets on the side of the air gap are placed in a vacuum vessel, and a pair of magnets for phase shifting are arranged outside the wall of the vacuum vessel so as to move the magnets for phase shifting. The magnetic field in the vacuum container can be made variable by driving in the same phase. An example of the use of this type of variable magnetic field generator is a vacuum-sealed insertion light source device and the like. Since this vacuum-sealed insertion light source device has no movable part inside the vacuum container, it can be easily manufactured.

[0011]

EXAMPLES Examples of the present invention will be described below. Example A permanent magnet 1 made of NdFeB having dimensions of 10 mm × 10 mm × 40 mm
a, 24 mm x 10 mm x 40 mm NdFeB permanent magnet 1
b, SUY magnetic pole material 2a having a size of 10 mm × 10 mm × 40 mm, and 24 mm × 10 mm × 40 mm SUY magnetic pole material 2b.
Fig. 2 (a) showing the magnetization direction of the permanent magnet
When a variable magnetic field generator was manufactured by arranging them closely with a distance of 0.5 mm as in (ON state) and adhering with an adhesive, the magnetic field strength was 2240 G at a distance of 8 mm above the magnet array 15. Met. Next, when one of the magnet rows was phase-shifted (OFF state) using a linear guide as shown in FIG. 2B, a magnetic field intensity of 0 G was shown.

[0012]

According to the present invention, it is possible to reduce the residual suction force when the variable magnetic field generator is released and to have a strong suction force at the time of suction.

[Brief description of drawings]

FIG. 1 is a schematic diagram of a variable magnetic field generator of the present invention.
(A) is a type 1 ON state. (B) is an ON state of another type, type 2.

FIG. 2 is a schematic diagram of a magnetic circuit according to the present invention.
(A) is an on state. (B) is an off state.

FIG. 3 is a schematic diagram of an on state of a conventional variable magnetic field generator.

[Explanation of symbols]

 1, 1a, 1b, 11 Permanent magnets 2, 2a, 2b, 12 Magnetic pole materials 13 Magnets 14 Magnetic bodies 15 Magnet arrays

Claims (1)

[Claims] 1. A variable magnetic field generator having a magnetic circuit composed of permanent magnets and magnetic pole members, wherein two magnet rows in which the permanent magnets and the magnetic pole members are periodically alternately arranged are arranged in close proximity to each other. A variable magnetic field generator characterized in that the magnetic field strength on the surface of the magnet array is changed by shifting the phase of the magnet array.