JPH06104505B2 - Magnetic levitation device for magnetic plates - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a magnetic levitation device for magnetic plate materials, and more particularly to a magnetic levitation device for magnetic plate materials in which the floating position of the magnetic plate material can be easily controlled.

[Prior Art] This type of magnetic levitation apparatus for magnetic plate materials is used for non-contact support during transfer of the magnetic plate material, or for holding the tip of the non-contact plate in a steel plate coating line.

A conventional magnetic levitation apparatus for magnetic plate materials is, for example, as shown in FIG. 3, a steel plate suction upper electromagnet 2 arranged above a steel plate 1 with a gap G1 therebetween, and a distance sensor for detecting the gap G1. 4, a control power supply 5 for supplying an exciting current to the electromagnetic coil 3 that winds the core of the steel plate attracting upper electromagnet 2, and the output signal from the distance sensor 4 to maintain the gap G1 at a predetermined distance. And a control unit (not shown) for controlling the exciting current so as to maintain the steel sheet 1 in a fixed position in a horizontal and non-contact manner.

By the way, in the adjustment of the attraction force of the electromagnet, the steel sheet is attracted by the electromagnet, and the smaller the gap G1, the stronger the attraction force Fc becomes. The suction force control corresponding to the gap G1 is required to prevent such contact.

Moreover, the gap attraction force Fc of the electromagnet changes inversely proportional to the square of the gap G1 under constant excitation, ignoring magnetic saturation, magnetic leakage, etc., so that the excitation current of the electromagnet is greatly controlled. Need to be fast, also the gap G1
It is necessary to reduce the change rate of to minimize the fluctuation of suction force.

[Problems to be Solved by the Invention] However, in the conventional magnetic levitation apparatus for magnetic plate materials, in order to suppress the fluctuation of the attractive force Fc as much as possible, it is not possible to increase the gap G1 and relatively reduce the rate of change. On the contrary, it requires a suction force Fc corresponding to the weight of the steel sheet to counter the drastic decrease in the suction force Fc, and the electromagnet itself must be upsized as compared with a general steel material transport electromagnet. In other words, it goes against the demand for a lighter and smaller device.

Further, increasing the size of the electromagnet also increases the size of the exciting coil and increases the inductance, which deteriorates the followability with respect to the feedback signal from the distance sensor or the like. As a result, the controllability of the attraction force Fc of the electromagnet is reduced, which makes it difficult to control the attraction force corresponding to the gap G1.

That is, in the conventional magnetic levitation device for magnetic plate materials,
The fluctuation suppression of the gap G1 and the controllability of the suction force are in a trade-off relationship with each other, and an effective solution has not yet been found.

Further, as a problem peculiar to the steel plate sucked and supported from above, when the steel plate becomes thin or wide, there is also a problem that, in combination with its elasticity, the steel plate itself may be sagged due to bending in the width direction. .

Therefore, the technical problem of the present invention is, in view of the above drawbacks, to simultaneously improve the variation control of the gap G1 and the controllability of the suction force, and to a steel plate magnetic levitation device that does not cause sagging or the like due to the deflection of the steel plate. Is to provide.

[Means for Solving the Problems] According to the present invention, the attraction electromagnet portion disposed on the upper side of the magnetic plate member arranged so that the plane is horizontal, the attraction electromagnet portion, and A distance sensor that detects a distance from the magnetic plate member, and an exciting current control that controls an exciting current to the attraction electromagnet unit so as to maintain the distance constant based on an output signal from the distance sensor. A magnetic levitation device for a magnetic plate material, each of which is provided with a side surface magnet portion of FIGS. 1 and 2 which is substantially horizontally separated from a pair of side surfaces of the magnetic plate material facing each other, A magnetic levitation device for a magnetic plate material is obtained in which magnetic poles are formed on the pair of side surfaces by the first and second side surface magnet portions, respectively.

[Embodiment] Next, an embodiment of the present invention will be described with reference to the drawings.

As shown in FIG. 1, in the magnetic levitation device for steel sheet according to the present embodiment, first, as in the conventional case, the upper electromagnet 2 for attracting a steel sheet, which is arranged above the plane of the steel sheet 1 with a gap G1, and the gap, Based on the output signal from the distance sensor 4 for detecting G1, the control power supply 5 for supplying an exciting current to the upper electromagnetic coil 3 winding the core of the upper electromagnet 2 for drawing steel plate, and the output signal from the distance sensor 4, the gap G1 And a control unit (not shown) for controlling the exciting current so as to maintain the distance between them at a predetermined separation distance. Furthermore, the first and third side magnet units 6 and 6 according to the present invention have improved level control. For the purpose of use, it is provided in a substantially horizontal direction from a pair of side surfaces of the steel sheet 1 facing each other, with a gap G2 therebetween.

The first and second side surface magnet portions 6, 6 will be described in detail with reference to FIG.

The first and second side surface magnet portions 6, 6 are composed of a core body 7 having a U-shaped cross section and a side surface electromagnetic coil 8 winding the core body 7, and each of them is made of steel plate 1. Magnetic circuits are formed on both side surfaces.

The core body 7 has a bottom portion 9 whose one end faces the side surface of the steel sheet 1 through the gap G2, a column portion 10 extending upward from the other end of the bottom portion 9 and standing upright, and a steel sheet from the upper end of the column portion 10. And a body surface portion 12 extending from the tip of the upper side portion 11 to face the upper surface of the steel sheet 1 via a gap G3.
The side electromagnetic coil 8 is wound around the bottom portion 9.

That is, the steel plate 1 has first and second side surface magnet portions 6, 6 with side surface magnetic poles formed on the side surfaces facing the bottom portion 9 and upper surface magnetic poles formed on the upper surface facing the body surface portion 12. Of each magnetic circuit.

Here, the gap G3 is set in a range that allows a vertical level change of the steel plate 1 by the steel plate attracting upper electromagnet 2.

The bottom portion 9 of the steel sheet 1 which faces the side surface via the gap G2 has its end portion narrowed to an opposing area corresponding to the thickness of the steel sheet 1, thereby increasing the magnetic flux density with the side magnetic poles of the steel sheet 1. To increase the suction force for the steel plate 1.

The facing portion 12 that extends to face the upper surface of the steel sheet 1 through the gap G3 is formed wide so as to have a large facing area with the upper surface of the steel sheet 1, and as a result, with the upper magnetic pole of the steel sheet 1. The magnetic flux density is lowered to facilitate the passage of magnetic flux.

Next, the operating state of this embodiment will be described.

Referring to FIG. 2, based on the output signal from the distance sensor 4, an exciting current is passed from the control power source 5 to the upper electrode coil 3 so as to maintain the gap G1 at a predetermined distance, and the steel plate 1 is Surface.

At this time, the side surfaces of the steel plate 1 are the first and second side surface magnet portions.
When the magnetic pole centers of 6 and 6 are at the same level, the attractive force between the gaps G2 acts in the horizontal direction, and the component force becomes zero.

Further, as indicated by the solid line in the figure, when the level of the steel plate is lowered by the L dimension from the side surface magnetic pole due to the weight of the steel plate, the attractive force F acts in the upward oblique direction, and therefore the upward component force.
Fv (Fv = F × sin θ) is generated.

On the contrary, as indicated by the broken line in the figure, when the level of the steel plate 1 is higher than the center of the magnetic pole by the dimension L, the component force Fv acts downward.

That is, the both side surfaces of the steel plate 1 have the first and second side magnet portions 6,
Armed force Fv will be received as a restoring force in the direction of returning to the center level position of the side magnetic pole with 6. Therefore, with respect to the level fluctuation of the steel plate 1 from the -L dimension to the + L dimension, the steel sheet 1 autonomously returns to the side surface magnetic pole center level by the component force Fv, so that the upper electromagnet 2 accompanying the fluctuation of the gap G1.
The followability of the suction force control is compensated.

Since both side surfaces of the steel plate 1 are also subjected to the horizontal tensile stress Fh at the same time, the sagging in the width direction of the thin plate and the wide steel plate is prevented.

[Advantages of the Invention] As described above, according to the present invention, the first and second side surface magnet portions are provided separately from the pair of side surfaces of the magnetic material, and the magnetic material is provided in the first and second sides. Since the level is autonomously restored to the center of the magnetic pole of the side magnet portion, it is possible to secure the followability in controlling the attraction force of the upper electromagnet. At the same time, since the first and second side magnet parts pull the pair of side surfaces of the magnetic material in the horizontal direction, it is possible to prevent sagging in the width direction of the thin plate and the wide steel plate.

[Brief description of drawings]

FIG. 1 is a conceptual view showing an embodiment according to the present invention, FIG. 2 is a partially cutaway sectional view of a side magnet portion in the embodiment shown in FIG. 1, and FIG. 3 is a conventional magnetic plate material. It is a levitation device. DESCRIPTION OF SYMBOLS 1 ... Steel plate, 2 ... Upper electromagnet for attracting steel plate, 3 ... Electrode coil, 4 ... Distance sensor, 4, 5 ... Control power supply, 6 ... 1st
And second side magnet portion, 7 ... core body, 8 ... electromagnetic coil, 9 ... bottom portion, 10 ... pillar portion, 11 ... upper side portion, 12 ... body surface portion.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kazuhiro Suzuki 3 Hikari, Kashima-cho, Kashima-cho, Kashima-gun, Ibaraki Sumitomo Metal Industries, Ltd. Kashima Steel Works (72) Inventor Kuma Watanabe 5-2 Sokai-cho, Niihama-shi, Ehime Sumitomo Heavy Industries Machinery Co., Ltd. Niihama Works (72) Inventor Yoshitaka Machida 5-2 Sokai-cho, Niihama-shi, Ehime Sumitomo Heavy Industries Machinery Co., Ltd. Niihama Works (56) Reference JP 63-87106 (JP, A) ) JP-A-62-77883 (JP, A) JP-A-61-178328 (JP, A) JP-A-59-19714 (JP, A) Actually-laid-open Sho-63-44603 (JP, U)

Claims (1)

[Claims] 1. A distance for detecting a suction electromagnet portion arranged on an upper side with respect to a magnetic plate member arranged so that a plane is horizontal, and a separation distance between the suction electromagnet unit and the magnetic plate member. Magnetic levitation device for magnetic plate material, which includes a sensor and an excitation current control unit that controls an excitation current to the attraction electromagnet unit so as to maintain the separation distance constant based on an output signal from the distance sensor. The first and second side surface magnet portions are substantially horizontally separated from a pair of side surfaces of the magnetic plate member facing each other, and the first and second side surface magnet portions are respectively, One end side faces each of the pair of side surfaces of the magnetic plate member, while the other end side includes a core facing the upper surface of the magnetic plate member, and substantially forms a closed magnetic path together with the magnetic plate member. For magnetism Above apparatus.