JP3022610B2 - Rotary magnetic damper device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary magnetic damper for applying a load to the movement of various devices, and more particularly to a rotary magnetic damper having an improved braking force.

[0002]

2. Description of the Related Art A magnetic damper device of this type is disclosed in the literature, for example, “Transactions of the Japan Society of Mechanical Engineers, No. 890.
−26 ”provides the theoretical basis.
3A and 3B show a basic model of a conventional rotary magnetic damper device. The magnetic damper device in the figure includes disk-shaped yokes 1 and 2 opposed vertically,
A plurality of pairs of permanent magnets 3 and 4 having a pair of N poles and S poles respectively arranged on upper and lower opposing surfaces of the yokes 1 and 2 and a gap having a high magnetic flux density between the yokes 1 and 2 and a disk-shaped conductive plate 5 rotatably arranged in a non-contact state in the inner space d. A plurality of permanent magnets 3 and 4 are arranged at predetermined intervals in the circumferential direction of the same yokes 1 and 2, and the adjacent permanent magnets 3 and 4 have different polarities along the rotation direction of the conductor plate 5. ing.

In the above arrangement, when the conductor plate 5 rotates in the direction of arrow A at a predetermined speed v, the magnetic flux in the gap d is cut off, so that an electromotive force is induced in the conductor plate 5 and as a result, as shown in FIG.
An eddy current flows between adjacent magnets 3 and 4 as shown by arrows in FIG. The eddy current causes the conductor plate 5 to generate a braking force in the direction opposite to the direction of the arrow A by the action of the magnetic field.

[0004] This braking force applies a load to the movement of various devices (not shown) connected to the shaft or the yokes 1 and 2 provided on the conductor plate 5, and the damping force is very accurately proportional to the movement speed. It has advantages such as stability by acting on contact and little change with temperature, so that it can be applied to various uses.

[0005] However, in the conventional rotary magnetic damper device, since adjacent magnets on the same surface are spaced apart from each other, there are practical problems described below.

[0006]

That is, the eddy current flows between the adjacent magnets 3 and 4 in a loop as shown in FIG. 3B, but the distance between the magnets 3 and 4, that is, the air gap is large. As a result, a loop is formed around each of the magnets 3 and 4 as indicated by arrows, and as a result, eddy currents cancel each other between the adjacent magnets 3 and 4, so that the braking force is reduced.

An object of the present invention is to solve the above-mentioned problems, and an object of the present invention is to provide a rotary damper device in which eddy currents cancel each other out and the braking force is increased.

The present invention has been made to achieve the above object.
Is specified by the following items (1) to (6)
is there. (1) For a rotating plate that rotates around an axis perpendicular to the plate surface
Rotary magnetic damper that gives a rotational braking force without contact
Device. (2) The rotating plate is made of a plate material having good electrical conductivity. (3) opposing both surfaces of the rotating plate and disengaging them
A pair of yokes are provided so as to be sandwiched by touch. (4) The rotating plate on at least one of the yokes
A plurality of magnets are arranged on the surface facing
The resulting magnetic flux penetrates the rotating plate. (5) In the arrangement of the plurality of magnets, the rotation of the rotating plate
There is a part where N pole and S pole are alternately arranged in the circumferential direction
Exist. (6) In the alternate arrangement of the N pole and the S pole,
N-pole and S-pole located next to each other without a pump
I do.

[0009]

In the rotary magnetic damper device having the above-described structure, the magnetic path is shortened between adjacent magnets having no air gap, so that the magnetic flux density is also increased. In addition, the path of the eddy current generated during the rotation of the conductor is shortened, and the eddy current flows more easily because there is no cancellation.

[0010]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 shows a first embodiment of the present invention. Note that the arrangement relationship in the cross section of the yoke, the magnet, and the conductor plate in the embodiment is the same as that of the related art in FIG.

That is, a pair of permanent magnets 10 and 12 in which a plurality of pairs of different poles are in close contact with each other are arranged at predetermined intervals along the circumferential direction on the surface of a yoke (not shown). Further, a plurality of pairs of permanent magnets having different magnetic poles opposite to the above-mentioned arrangement are arranged on the opposing surface of a yoke (not shown) located on the upper side, and the conductor plate 14 can rotate in a non-contact state therebetween. It is provided in.

Therefore, according to the above configuration, each magnet 1
Since the magnetic flux path between the pair of 0 and 12 where there is no air gap is short, the magnetic flux density is high, which is effective for a braking force proportional to the square of the magnetic flux density. The conductor plate 14
Rotates in the direction of arrow A at a predetermined speed v, the conductor plate 14
In order to cut off the magnetic fluxes of the magnets facing each other across the, an electromotive force is induced in the conductor plate 14 by Fleming's right-hand rule,
As a result, three eddy currents flow in the conductor plate 14 in a loop. This eddy current causes the conductor plate 14 to generate a braking force in the direction opposite to the direction of the arrow A by the action of the magnetic field, and is connected to the shaft 14a of the conductor plate 14 or the conventional yokes 1 and 2 in FIG. In this embodiment, each magnet 1
The eddy current (a) mainly indicated by the solid line at the center of the pair of 0 and 12 mainly flows, and the eddy current (b) directed outward by the left and right chain lines becomes smaller than that at the center.

This is because the eddy current generated in the conductor plate 14 (A)
In this case, the flow path becomes shorter than before, and more flow occurs because there is no cancellation. Therefore, the braking force is improved. Further, since the left and right eddy currents (b) are less likely to flow in a wide range, interference of the eddy currents between the pair of adjacent magnets 10 and 12 is eliminated, and the reduction in efficiency due to this is also prevented.

FIG. 2 shows a second embodiment of the present invention. A permanent magnet in which different poles are alternately arranged in a ring shape over the entire circumference in a circumferential direction on a surface of a yoke (not shown). 2
0,21 pairs are arranged. Further, a pair of ring-shaped permanent magnets whose magnetic poles are opposite to this arrangement are arranged on the surface of the yoke located on the conductor plate 14. The magnets 20 and 21 may be a plurality of magnets arranged in a ring shape or a ring-shaped block multi-polarized. In this embodiment, when the conductor plate 14 rotates in the direction of the arrow A, an eddy current (a) shown by a solid line in the figure is generated between all adjacent poles, so that the braking efficiency can be further increased.

[0015]

As described in detail in the above embodiments, in the rotary magnetic damper device according to the present invention,
Since the magnetic path between adjacent magnets without an air gap is short, the magnetic flux density is high. In addition, the path of the eddy current generated during the rotation of the conductor is shortened, and furthermore, there is no cancellation, so that the flow becomes easier. As a result, more eddy currents can be generated, so that a strong braking force can be secured.

[Brief description of the drawings]

FIG. 1 is a plan view according to a first embodiment of the present invention.

FIG. 2 is a plan view according to a second embodiment of the present invention.

FIG. 3A is a side view showing a basic model of a conventional rotary magnetic damper device. FIG. 4B is a plan view showing an eddy current generation state when the conductor plate is moved.

[Explanation of symbols]

 1, 2, yoke 10, 12, 20, 21 permanent magnet 14 conductor plate

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Kazuo Matsui 5-36-11 Shimbashi, Minato-ku, Tokyo Inside Fuji Electric Chemical Co., Ltd. (56) References JP-A-62-80318 (JP, A) (58) ) Field surveyed (Int.Cl. ⁷ , DB name) F16F 15/03 F16F 6/00

Claims (1)

(57) [Claims] (1) The method is specified by the following items (1) to (6).
Invention. (1) For a rotating plate that rotates around an axis perpendicular to the plate surface
Rotary magnetic damper that gives a rotational braking force without contact
Device. (2) The rotating plate is made of a plate material having good electrical conductivity. (3) opposing both surfaces of the rotating plate and disengaging them
A pair of yokes are provided so as to be sandwiched by touch. (4) The rotating plate on at least one of the yokes
A plurality of magnets are arranged on the surface facing
The resulting magnetic flux penetrates the rotating plate. (5) In the arrangement of the plurality of magnets, the rotation of the rotating plate
There is a part where N pole and S pole are alternately arranged in the circumferential direction
Exist. (6) In the alternate arrangement of the N pole and the S pole,
N-pole and S-pole located next to each other without a pump
I do.