JP3029701B2 - 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 magnetic damper device for attenuating vibrations of various devices and for applying a load to motion, and more specifically for controlling a braking force for applying such loads and the like. To plan.

[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.
6A and 6B show a basic model of the conventional translational magnetic damper device. The magnetic damper device in the figure has yokes 1 and 2 having one end connected in a U-shape and the other end facing up and down, and arranged on upper and lower opposing surfaces of the yokes 1 and 2, respectively. The permanent magnet includes opposing permanent magnets and a conductor plate arranged in a non-contact state in a gap having a high magnetic flux density in a magnetic circuit formed by the permanent magnets.

In the above arrangement, when the conductor plate 5 relatively moves in the direction of the arrow at a predetermined speed v, the magnetic flux in the air gap d is cut off, so that an electromotive force E is generated in the conductor plate 5 by the principle of electromagnetic induction. An eddy current flows as shown by a dashed line in FIG. 2B, which is a view taken along line BB of FIG. 2A (the same applies to the case where a plan view is drawn hereinafter). 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 damping and movement of vibrations of various devices and structures (not shown) connected to the conductor plate 5 or the yokes 1 and 2, and the damping force is very accurately proportional to the speed of movement. It has the advantages of being stable and acting without contact, and having little change with respect to temperature. For example, it is used for high-precision positioning of a table apparatus disclosed in JP-A-61-131841. , Can be applied to various uses.

[0005]

However, the conventional magnetic damper device has the following problems. That is, when the conductor plate 5 moves, the braking force received by the conductor plate 5 is proportional to the moving speed v of the conductor plate 5, and the permanent magnets 3, 4
Is proportional to the square of the strength of the magnetic field generated by the
In the conventional magnetic damper device, since the strength of the magnetic field and the resistivity of the conductive plate 5 are constant, the braking force is proportional only to the moving speed.

Accordingly, when the magnetic damper device is connected to various devices and used as a vibration damping device for preventing the vibration of the device, the vibration applied to the device has various relative moving speeds at the time of vibration. There is, but besides that,
Since there are various vibration magnitudes (amplitudes) and vibration frequencies, there is ultimately a vibration damping force for a specific vibration magnitude (amplitude) and vibration frequency. I could not control the vibration efficiently.
SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of this type of magnetic damper device is to provide a magnetic damper device capable of reliably damping and damping vibrations having different amplitudes and frequencies. The purpose is.

[0007]

In order to achieve the above object, in a magnetic damper device according to the present invention, a magnetic circuit constituted by arranging a magnet on one or both of opposing surfaces of a yoke, In a magnetic damper device having a conductor arranged in a non-contact state in a gap having a high magnetic flux density of a circuit and cutting off magnetic flux generated from the magnet by relative movement between the conductor and the magnet, the same yoke surface There are two or more magnetic poles of the magnet to be arranged, and at least one adjacent magnetic pole is formed as a different pole, and the magnet is rotatable in a substantially parallel plane of the conductor. The angle formed between the boundary line and the direction of the relative movement can be changed.

[0008]

In the magnetic damper device having the above construction, there are a plurality of directions of the magnetic field in the air gap having a high magnetic flux density, and when the conductor plate relatively moves, the adjacent directions are opposite to each other according to the number of poles of the magnet. Is generated, more eddy current flows in the conductor plate in the high magnetic flux density gap, the eddy current toward the outside decreases by that much, and the eddy current in the gap can be increased. it can. When the magnet is rotated by a predetermined angle, the orientation of the magnet, more strictly, the boundary between mutually different magnetic poles intersects at a predetermined angle with respect to the direction of relative movement of the conductor plate. Then, a part of the electromotive force generated corresponding to each magnetic pole due to the movement cancels each other, and the amount of generated eddy current also varies depending on the degree of the cancellation. As a result, the magnitude of the braking force determined by the eddy current and the strength of the magnetic field in the high magnetic flux density region changes. Therefore, by adjusting the amount of movement in the different direction, the amplitude of various vibrations Effective damping and braking are performed according to the frequency.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a preferred embodiment of a damper device according to the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 shows a first embodiment in which a bipolar pole arrangement, which is a basic configuration of the present invention, is applied to a translation type magnetic damper device for linearly moving a conductor plate. ) Is a perspective view showing an example of such a damper device, and FIG.
BB line of FIG.

As shown in FIG. 1, a pair of permanent magnets 14 (S-poles) of different poles are provided on opposite surfaces of upper and lower yokes 10 and 12 each having one end made of a magnetic material and connected in a U-shape. , 1
6 (N-pole), 18 (N-pole), and 20 (S-pole) are opposed to each other.
A magnetic circuit is formed between 4, 16, 18, and 20 by a bidirectional magnetic field from the north pole to the south pole indicated by an arrow in the figure.
In the gap d having a high magnetic flux density of the magnetic circuit, a conductor plate 22 made of a non-magnetic material, which is an electrically good conductor such as an aluminum plate in a non-contact state, is arranged, and a translation type magnetic damper device is configured. ing. That is, the conductor plate 2
2 moves straight.

Here, in the present invention, the pair of permanent magnets 1
4, 16 and 18, 20 are arranged rotatably in a horizontal plane. The specific configuration is as follows. For convenience of description, only the yoke 10 located above will be described. A window hole 24 that penetrates vertically at a predetermined position of the yoke 10 is provided. A projecting ring-shaped engaging ridge 26 is formed. Above the window hole 24, a substantially disk-shaped dial member 28 is rotatably inserted and arranged. Two concave portions 30, 30 are formed on the upper surface of the dial member 28 at radially opposite positions. By inserting a finger or the like into the concave portions 30, 30, the dial member 28 is pinched and rotated by a predetermined amount. I can do it. The lower part of the dial member 28 has a shape in which the diameter is reduced by one step so as to match the engaging ridge 26.

On the other hand, a disk-shaped base member 32 is rotatably inserted below the window hole 24, and the upper surface of the base member 32 and the lower surface of the dial member 28 are joined and integrated. As a result, the dial member 28 and the base member 32 are undetachably mounted in the window holes 24.

Further, the pair of permanent magnets 14 and 16 are fixed to the lower surface of the base member 32. Thereby, by rotating the dial member 28,
The permanent magnets 14, 16 integrated therewith are rotated.

The base member 32 and the dial member 28 are preferably made of a magnetic material, and are more preferably formed of the same material as the yokes 10, 12. Further, in this example, since the line connecting the concave portions 30 provided in the dial member 28 is disposed so as to be orthogonal to the joining surface of the pair of permanent magnets 14 and 16, the position of the concave portions 30 and 30 with respect to the axial direction of the yoke 10 is provided. By looking at the angle, the orientation of the permanent magnets 14, 16 can be determined.

The mechanism for rotating the permanent magnets 18 and 20 provided on the lower yoke 12 has the same structure as that of the permanent magnets 14 and 16 provided on the upper yoke 10, and thus the same reference numerals are used. Thus, the description thereof will be omitted.

In the above configuration, FIG.
As shown in (A), a state in which the boundary line between the pair of permanent magnets 14, 16 and 18, 20 is located in a direction orthogonal to the moving direction of the conductive plate 22 (this state is referred to as “0 °” for convenience). In this case, when the conductor plate 22 is moved at a constant speed in the direction of the arrow, the conductor plate 22 cuts off the magnetic flux in the gap d, so that the electromotive forces E1, E2 are generated by the Fleming's right-hand rule. As a result, three eddy currents flow on the conductive plate 22 as shown in the figure.

At this time, the eddy current causes a braking force in the direction opposite to the direction of the arrow to be generated in the conductor plate 22 by the action of the magnetic field, and various devices (not shown) connected to the conductor plate 22 or the yokes 10 and 12 side. In this embodiment, the eddy current ia indicated by the solid line at the center mainly flows, and the eddy current ib directed outward by the dashed lines on the left and right corresponds to the ia. Does not flow more.

This is because the electromotive forces E of the opposite directions are adjacent to each other.
1, E2 is generated, so that adjacent magnets 14, 16, 1
The eddy current shown by the solid line between 8 and 20 becomes easier to flow, and does not flow to the left and right. Therefore, the eddy current in the air gap d having a high magnetic flux density has twice the electromotive force as compared with the conventional one, and the flowing path is shortened, so that the eddy current is more effectively used for the braking force. In addition, the area of the conductor plate 22 can be reduced by the amount that the left and right eddy currents hardly flow over a wide range.

Next, the dial member 28 is rotated, and as shown in FIG.
The boundary between the lines 8 and 20 is inclined by a predetermined angle (20 degrees) with respect to the moving direction of the conductive plate 22. In this state, when the conductor plate 22 moves in the direction of the arrow, the electromotive force E based on each of the permanent magnets 14, 16, 18, 20 as described above.
1 and E2 are generated on the conductive plate 22, and the eddy currents ia ', i
Since b 'is also a direction orthogonal to both the direction of the magnetic field and the moving direction of the conductive plate 22, it is generated as shown in the figure.

By the way, looking at the whole inside of the high magnetic flux density region formed by the permanent magnet, the portion N near the boundary of the permanent magnet is considered.
In this case, the direction of the electromotive force is reversed and is canceled. Therefore, actually, an electromotive force is generated only in a portion other than the above N, and based on this, an eddy current flows as indicated by an arrow in the figure. Therefore, in this state, FIG.
Since the induced electromotive force is small and the eddy current is small as compared to the case shown in FIG.

When the dial member 28 is further rotated so that the boundary line and the moving direction of the conductor plate 22 are substantially coincident with each other as shown in FIG. , The two electromotive forces E1, E2 are completely opposite to each other and cancel each other. Therefore, the eddy current ic
Also, as shown in the figure, only small flow occurs at both ends of the high magnetic flux density region, and almost no braking force is generated.

As described above, in this embodiment, the dial member 2
8, that is, by rotating the permanent magnets 14, 16, 18, and 20, the relative angular positional relationship between the boundary line of the permanent magnet and the moving direction of the conductor plate is changed from the state shown in FIG. By changing it, an arbitrary braking force can be obtained, and effective vibration suppression and braking are performed according to the amplitude and frequency of various vibrations. FIG. 2B shows an example in the middle between FIGS. 2A and 2C, and it goes without saying that the angle of the boundary line can be arbitrarily set. Further, the dial member 28 may be rotated in the middle of the movement of the conductor plate by interlocking with another machine. With this configuration, the braking force can be changed during the movement of the conductor plate.

FIG. 3 shows a second embodiment of the present invention.
In this embodiment, an example is shown in which the present invention is applied to a rotary magnetic damper device, unlike the above-described embodiment. First, the basic configuration of the rotary magnetic damper device will be described. A pair of upper and lower disc-shaped yokes 32, 34 are mounted on a shaft 30, and permanent magnets are arranged at predetermined positions on the opposing surfaces of the yokes 32, 34. Is established. Then, the magnetic poles of the permanent magnets arranged vertically opposite each other are made different. In the conventional general rotary magnetic damper device, the permanent magnets disposed on the same yoke are disposed one by one at predetermined intervals, but in this embodiment, the permanent magnets are disposed on the surface of one yoke. Are disposed at predetermined intervals along the circumferential direction, two permanent magnets 36 and 38 in which a plurality of pairs of different poles are in close contact with each other. Further, on the opposing surface of the other yoke, a plurality of pairs of different-polarity permanent magnets whose magnetic poles are opposite to those of the above-described permanent magnets 36 and 38 are disposed to face each other, and a disc-shaped conductor plate 40 is interposed therebetween. It is provided rotatably in a non-contact state.

Here, in the present invention, similarly to the first embodiment, the permanent magnets 36, 34 are provided on the lower surface of a base member 44 rotatably provided in window holes 42 provided at predetermined positions of the yokes 32, 34. At the same time, the permanent magnets 36 and 38 are rotatable via a dial member 46 fixed and adhered to the upper surface of the base member 44.

Therefore, according to the above configuration, the magnetic flux density is increased between the permanent magnets 36 and 38 since there is no air gap between the permanent magnets, so that the magnetic flux density increases and is proportional to the square of the magnetic flux density. This is effective for braking force. When the conductor plate 40 rotates at a predetermined speed v at a speed v in the direction of the arrow, the electromotive force is applied to the conductor plate 40 by Fleming's right-hand rule in order to cut off the magnetic flux of each of the permanent magnets facing each other across the conductor plate 40. As a result, a predetermined eddy current flows through the conductor plate 40 in a loop shape. Then, by rotating the dial member 46, an arbitrary control is performed from a state where the maximum braking force can be generated as shown in FIG. 4A to a state where the minimum braking force is generated as shown in FIG. 4B. Power can be obtained. In addition, other configurations and actions are as follows.
Since this is the same as in the first embodiment, detailed description will be omitted.

FIG. 5 shows a third embodiment of the present invention. In the present embodiment, a rotary magnetic damper device using a disk-shaped conductor plate 50 that rotates similarly to the second embodiment is described.
The yoke and the permanent magnet constituting the magnetic circuit are the same as those used in the first embodiment. In other words, a pair of permanent magnets 56 and 58 having different polarities are respectively opposed to opposing surfaces of a pair of upper and lower yokes 52 and 54 connected in a U-shape, and the permanent magnets 56 and 58 are attached to the yokes 52 and 54. The braking force is controlled by rotating through a dial member 60 provided. The other configurations and operations are the same as those of the above-described embodiments, and thus detailed description is omitted.

In each of the above embodiments, the permanent magnet is used as the magnet constituting the magnetic circuit. However, an electromagnet may be used depending on the application, for example, it is necessary to control the braking force. May be provided with a magnet. The number of magnetic poles provided in one yoke is not limited to two as in the above-described embodiment, but may be three or more. Further, a plurality of magnetic poles may be formed by a plurality of magnets. By performing desired magnetization on the magnetic material, a plurality of magnetic poles may be formed on one magnet, which is optional.

Further, in each of the above embodiments, an example was described in which a metal electric good conductor such as an aluminum plate was used as the conductor plates 22, 40, and 50. However, the present invention is not limited to this. A good electrical conductor made of a non-metallic material may be used. Further, the material is not limited to a solid but may be a liquid. However, in the case of a liquid, it goes without saying that a predetermined case (either a conductor or a non-conductor) for accommodating the liquid is required.

[0029]

As described above, in the magnetic damper device according to the present invention, there are a plurality of directions of the magnetic field in the air gap having a high magnetic flux density, and when the conductor plate moves relatively, it corresponds to the number of poles of the magnet. Since an electromotive force is generated in the opposite direction to each other, more eddy current flows in the conductor plate in the high magnetic flux density gap, and the eddy current toward the outside decreases by that much,
The eddy current in the gap can be increased, and the area of the conductor plate can be reduced. In addition, there are two or more magnetic poles of the magnet arranged on the same yoke surface, and at least one adjacent magnetic pole is formed as a different pole, and the magnet is formed in a substantially parallel plane of the conductor plate. , The amount of eddy current flowing in the conductor plate can be changed by changing the positional relationship between the relative movement direction of the conductor plate and the direction of the magnetic pole. As a result, the magnitude of the braking force determined by the eddy current and the strength of the magnetic field in the high magnetic flux density region can be controlled, and effective vibration suppression and braking can be performed in accordance with various vibration amplitudes and frequencies. It is possible to do.

[Brief description of the drawings]

FIG. 1A is a perspective view showing a first embodiment of a magnetic damper device according to the present invention. (B) is a sectional view taken along line BB.

FIG. 2 is a diagram for explaining the operation of the magnetic damper device shown in FIG.

FIG. 3 is a partially broken front view showing a second embodiment of the magnetic damper device according to the present invention.

FIG. 4 is a diagram for explaining the operation of the magnetic damper device shown in FIG.

FIG. 5 is a partially broken front view showing a third embodiment of the magnetic damper device according to the present invention.

FIG. 6A is a front view showing a basic model of a conventional translation type magnetic damper device. (B) is an explanatory view showing a state of occurrence of an eddy current when the conductor plate is moved.

[Explanation of symbols]

 10, 12 Yoke 14, 16 Permanent magnet 22 Conductor plate

──────────────────────────────────────────────────続 き Continuation of front page (72) Inventor Kazuo Matsui 5-36-11 Shimbashi, Minato-ku, Tokyo Inside Fuji Electric Chemical Co., Ltd. (56) References JP-A-3-47379 (JP, A) JP 61-286635 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) F16F 15/03 F16F 6/00

Claims (1)

(57) [Claims] 1. A magnetic circuit comprising magnets arranged on one or both of opposing surfaces of a yoke, and a conductor arranged in a non-contact state in a gap having a high magnetic flux density of the magnetic circuit. In a magnetic damper device configured to cut off a magnetic flux generated from a magnet by a relative movement between a conductor and the magnet, there are two or more magnetic poles of the magnet arranged on the same yoke surface, and at least one adjacent magnetic pole is provided. The magnet is rotatable in a plane substantially parallel to the conductor, and an angle between a boundary between the different poles and the direction of the relative movement can be changed. And a magnetic damper device.