JPH0362504A - Magnetic levitation apparatus for magnetic plate - Google Patents

Abstract

PURPOSE:To support a magnetic plate approximately horizontally against the gravity and prevent said magnetic plate from warping by installing magnets with specific intervals above and in the horizontal side of the ends of said magnetic plate arranged so that the plane thereof may be approximately horizontal. CONSTITUTION:A magnetic plate 1 is arranged so that the plane 1a thereof may be approximately horizontal. Upper magnets 2 are arranged above both ends 1b of the plate 1 with specific intervals. Horizontal-side magnets 3 are arranged in the horizontal side of both the ends 1b of the plate 1 with specific intervals. The cores 3a of the magnets 3 are connected to the cores 2a of the magnets 2. When currents are passed through the coils 2b and 3b, magnetic circuits each consisting of the core 2a, the gap between the core 2a and the plate 1, the plate 1, the gap between the plate 1 and the core 3a, and the core 3a are formed. Thereby the plate 1 is supported approximately horizontally and the ends 1b thereof are attracted to prevent the plate 1 from warping.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a magnetic levitation device for magnetic plates that levitates magnetic plates by magnetic attraction without contacting them.

[Prior Art] This type of magnetic levitation device for magnetic plates is used to support magnetic plates without touching them during transport, and to hold the tip of a steel plate without touching it in a steel plate painting line. .

A conventional magnetic levitation device for a magnetic plate, for example, as shown in FIG. 5, includes an attraction electromagnet 11 placed above the plane of the magnetic plate 1 with a gap G3 therebetween, and a distance sensor 12 that detects the gap G3. and the core 11 of the attraction electromagnet 11
A control power source 13 is provided for passing an excitation current through a coil 11b around which the coil 11b is wound. The magnetic plate 1 is supported horizontally in a fixed position without contacting the magnetic plate 1.

By the way, when the attraction force of the attraction electromagnet 11 is adjusted to ':A, the magnetic plate material 1 is attracted by the attraction electromagnet 11 and the smaller the gap G3, the stronger the attraction force Fc becomes. Since the magnetic plate material 1 will come into contact with the electromagnet 11, in order to prevent this, it is necessary to control the attraction force corresponding to the gap G3.

[Problem to be solved by the invention] However, the conventional magnetic levitation device for magnetic plate material has a gap G
The change in the attraction force F of the attraction electromagnet 11 with respect to the change in , is very large, and if magnetic saturation and magnetic leakage are ignored, with constant excitation, it changes in inverse proportion to the square of the gap G3. There is a drawback that it is troublesome to control the suction force Fc to follow the change in G3.

Furthermore, conventional magnetic levitation devices for magnetic plates have the disadvantage that when the magnetic plates are thin or wide, they bend due to their own weight due to their elasticity.

SUMMARY OF THE INVENTION An object of the present invention is to provide a magnetic levitation device for a magnetic plate that does not require control of the attractive force of a magnet to the magnetic plate and can prevent the magnetic plate from deflecting.

[Means for Solving the Problems] The present invention provides an upper magnet disposed at a predetermined interval above an end of a magnetic plate arranged so that its plane is substantially horizontal; horizontal direction side magnets arranged at predetermined intervals on the horizontal direction side.

[Function] According to the present invention, the upper magnet supports the magnetic plate material against gravity so that the plane becomes substantially horizontal, and the horizontal magnet prevents the magnetic plate material from deflecting.

[Example] Next, an example of the present invention will be described in detail based on the drawings.

In FIG. 1, reference numeral 1 indicates a magnetic plate material. This magnetic plate 1 is arranged so that its plane 1a is substantially horizontal. A predetermined gap G is provided above the ends 1b and lb on both sides of the magnetic plate 1, and the upper magnet 2
, 2 are arranged. In the embodiment shown in FIG. 1, these upper magnets 2, 2 are constituted by electromagnets consisting of a core 2a and a coil 2b.

Horizontal magnets 3.3 are arranged on the horizontal sides of both end portions 1b, 1b of the magnetic plate 1, with a predetermined gap G2 therebetween. These horizontal side magnets 3
, 3 is 2 In the illustrated embodiment, the core 3a and the coil 3
It consists of an electromagnet consisting of b. The cores 3a, 3a of these horizontal side magnets 3, 3 are connected to the upper side magnets 2, 2.
The cores 2a, 2a are connected to each other. The coil 2b.

When a current is supplied to 3b, magnetic flux exits the core 2a, passes through the gap G1, enters the magnetic plate 1, and enters the primary gap G.
A magnetic circuit is constructed which enters the core 3a through the core 2 and then returns to the core 2a.

When this magnetic circuit is configured, the upper magnet 2゜2
Attract the magnetic plate 1 upward in the vertical direction with an attractive force F, and support the magnetic plate 1 within a predetermined range against gravity without contacting the magnetic plate 1 so that the plane 1a is almost horizontal, and ,
The horizontal side magnet 3°3 is located at the end 1b of the magnetic plate 1,
lb is the suction force F.

to prevent the magnetic plate material 1 from deflecting.

The gap G1 is formed by the magnetic plate 1 formed by the upper magnet 2.2.
It is set within a range that allows vertical position changes.

Also, the end portion 1b of the magnetic plate material 1 is inserted through the gap G2.
, the core 3a of the horizontal side magnets 3, 3 facing the end face of lb,
The end faces of 3a are narrowed down to a facing area corresponding to the thickness of the magnetic plate 1.

As a result, the magnetic flux density in the gap G2 is increased, and the attractive force F of the horizontal magnet 3°3 to the magnetic plate 1 is increased.
We are trying to increase the number of people.

The reason why the deflection of the magnetic plate 1 can be prevented will be explained in detail.

When the center of the end surface of the magnetic plate 1 is on the same level as the center of the end surface (magnetic pole) of the cores 3a, 3a of the water direction magnet 3°3 (when the level of the magnetic plate 1 is 0), the magnetic plate 1, the attraction force F of the horizontal side magnet 3.3 acts in the horizontal direction.

The component force in the vertical direction is O.

When the magnetic plate 1 is lowered by a distance from the same level as the horizontal magnet 3 (when the level of the magnetic plate 1 is −L), as shown by the solid line in FIG. Since the attractive force F of the horizontal side magnet 3 acts in an upward diagonal direction forming an angle θ with the horizontal line, an upward component force F, (Fv-F, X5lnθ) as shown in Fig. 3 is generated. .

On the other hand, as shown by the small-dotted chain line in FIG. 2, when the level of the magnetic plate 1 is higher than the level of the horizontal magnet 3 by a distance (when the level of the magnetic plate 1 is +L), As shown in Fig. 3, downward component force Fv (F, -F
a xsinθ) occurs.

The attractive force F of the upper magnet 2 against the magnetic plate 1 always acts only upward.

Now, ignoring magnetic saturation and magnetic leakage, let Φ be the effective number of magnetic flux passing through the magnetic plate 1 and passing through the upper magnet 2 and the horizontal magnet 3, and the effective opposing area of the horizontal magnet 3 and the upper magnet 2. respectively Ag1. If it is Ag2.

So, F,, F, is proportional to the square of Φ, and.

It is inversely proportional to Ag+ and Ag2.

From the relationship of equations (1) and (2> above, as shown in FIG. 3, when F acts upward, θ is +, and
If θ is - when F acts downward, the total supporting force F acting on one end of the magnetic plate 1 is expressed by the following equation.

Therefore, by selecting the values of Ag+ and Ag2, the total supporting force F can be set to the value shown by the curve within the range surrounded by curves A and B in Fig. 4 (within the shaded range).
The horizontal side magnet 3 is arranged so that the ends 1b, 1b of the magnetic plate 1 are arranged at a level corresponding to the center of the horizontal side magnet 3, that is, so as to prevent the magnetic plate 1 from bending.
causes a restoring force to act on the magnetic plate 1.

Note that the curve C in FIG. 4 indicates the total supporting force F acting on the magnetic plate 1 in the conventional magnetic levitation device for magnetic plates shown in FIG. Curve C shows that no force is available to restore the voltage to the reference level.

As shown in FIG. 3, the magnetic plate 1 of the horizontal side magnet 3
The attractive force F on the magnetic plate always has a horizontal component F, and this horizontal component F also prevents the magnetic plate 1 from deflecting.

Note that by controlling the magnitude of the current supplied to the coil 2a of the upper magnet 2 and the coil 3a of the horizontal magnet 3,
There is no need to control the attraction force to the magnetic plate 1. Therefore, it is not necessary to connect the core 2a of the upper magnet 2 and the core 3b of the horizontal magnet 3, and the upper magnet 2 and the horizontal magnet 3 may be made of permanent magnets.

[Effects of the Invention] The present invention does not require control of the attraction force of the magnet to the magnetic plate, and can prevent the magnetic plate from deflecting.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram showing an embodiment of the present invention, and the second diagram and FIG. 5 are schematic diagrams showing a conventional magnetic levitation device for magnetic plate material. ...Magnetic plate material. 2... Upper magnet. 3...Horizontal side magnet. Figure 2 2 L in Figure 4 Level of magnetic plate L Figure 3

Claims (1)

[Claims] (1) An upper magnet placed at a predetermined interval above the end of a magnetic plate arranged so that its plane is almost horizontal, and an upper magnet placed at a predetermined interval above the end of the magnetic plate in the horizontal direction. What is claimed is: 1. A magnetic levitation device for magnetic plate material, comprising: a horizontal side magnet arranged therein.