JPS6132180Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an improvement of a vibration isolating device that utilizes the repulsive force between magnetic poles.

This type of vibration isolator supports the equipment to be vibration-isolated in a floating state by the repulsive force acting between magnets with the same poles facing each other, so it has great compliance and good performance. Although it has an anti-vibration effect, it has the disadvantage that free vibrations caused by external shocks are not attenuated forever.

The present invention aims to eliminate the above-mentioned drawbacks while increasing the repulsion force, and the figure shows an embodiment thereof.

Reference numeral 1 denotes a ring-shaped lower magnet, which is magnetized in its axial direction as shown in the figure. The lower magnet 1 is located at the bottom 3a of a dish-shaped lower yoke 3 made of magnetic material.
The outer peripheral surface thereof faces the annular portion 3b with a ring-shaped non-magnetic spacer 2 interposed therebetween. 4 is an elastic body fixed in the center hole of the lower magnet 1, and a sleeve 5 is fixed at the center thereof.

The lower half of the lower yoke 3 is inserted into a lower case 6 made of hard rubber, and placed on the bottom surface of the lower case 6 via a cushion 8 and a metal plate 7. The side wall of the lower case 6 slidably surrounds the lower yoke 3, and a recess 9 provided therein allows the cushion 8 to deform. A cap 10 closes the central opening of the lower case 6 and is screwed onto the metal plate 7. The cap 10 is replaced with a mounting screw as necessary, thereby fixing the lower case 6 to the floor or the like.

Reference numeral 11 denotes a ring-shaped upper magnet, which is magnetized in the axial direction as shown in the figure, and is fixed within an upper yoke 13 made of a dish-shaped magnetic material via a non-magnetic spacer 12. , a sleeve 15 is held at its center via an elastic body 14. The upper yoke 13 is tightly fitted into an upper case 16 made of hard rubber, and is fixed to the upper case 16 by a non-magnetic cap 20 which is screwed into the central opening of the upper yoke.

The upper case 16 is arranged above the lower case 6 with the magnetic pole surface of the upper magnet 11 facing the magnetic pole surface of the lower magnet 1. Both magnets 1 and 11 are arranged so that the same poles face each other.

Reference numeral 21 denotes a shaft made of a magnetic material, which passes through the sleeves 5 and 15 in a slidable manner. Shaft 2
A collar piece 22 is fixed to the upper end of the cap 1, and is fitted into a cylindrical portion 23 formed on the cap 20.

Next, the operation of the device will be explained.

Place the lower case 6 on the floor and lower the upper case 16.
When a device requiring vibration isolation is placed on top, the upper case 16 is supported in a floating state by the repulsive force acting between both magnets 1 and 11, as shown in the figure.
The equipment placed on top of it is suspended from the floor surface, and vertical vibration transmission from the floor surface is prevented. Since both the upper and lower magnets 11,1 do not generate a restoring force against horizontal displacement, the opposing state of both the magnets 11,1 cannot be maintained as is. The shaft 21 is provided to maintain this state.
The shaft 21 regulates the horizontal position of both the upper and lower magnets 11, 1 so that they are coaxial.

Both yokes 3 and 13 serve to prevent the magnetic flux of both magnets 1 and 11 from leaking to the outside, and also serve to increase repulsive force. In other words, the end faces of the annular portions 3b and 13b of both yokes 3 and 13 serve as south poles, and mutual repulsive force is generated between them, so that this is added to the repulsive force of the north poles of both magnets 1 and 11. When a downward impact is applied to the upper case 16, the upper magnet 11
approaches the lower magnet 1, the repulsive force acting between them increases and pushes back the upper case 16. This upward movement goes too far due to inertia and induces a downward movement again to generate free vibration, but at this time a relative movement occurs between the shaft 21 and both cases 6 and 16. That is, due to the lowering of the upper case 16, the upper end of the shaft 21 is
The amount of protrusion of the upper yoke 13 from the bottom 13a is increased, and the lower end increases the amount of protrusion of the lower yoke 3 from the bottom 3a. Moreover, when the upper case 16 rises, the amount of protrusion decreases.

By the way, the shaft 21 has a flange piece 22, which is located within the cylindrical portion 23 of the cap 20, so that it functions as an air damper. Therefore, the relative movement of the shaft 21 with respect to the upper case 16 is suppressed thereby, and the free vibration of the upper case 16 is suppressed. Note that the air damper may be constructed from the lower end of the shaft 21 and the cap 10, or may be provided at both the upper and lower positions.

As described above, the present invention forms a flange at the tip of at least one of the protrusions of the shaft to restrict the facing state of the upper and lower magnets in a coaxial manner, and closes the upper end provided on at least one of the magnets. Since it is fitted into the cap, it acts as an air damper and can very effectively suppress the free vibration of the upper magnet.

[Brief explanation of the drawing]

The figure is a front sectional view of one embodiment of the present invention. 1...Lower magnet, 3...Lower yoke, 11...
Upper magnet, 13... Upper yoke, 21... Shaft, 22... Flange piece, 23... Cylindrical portion.

Claims (1)

[Scope of utility model registration request] In a vibration isolating device, a pair of ring-shaped magnets magnetized in the axial direction are arranged one above the other with the same polarity facing each other, and both of the magnets are each fixed to a dish-shaped yoke having an opening at the center of the bottom. , a shaft for coaxially restricting the opposed state of both magnets is inserted through the center of the pair of ring-shaped magnets, both ends of the shaft are made to protrude through the central opening of the yoke, and at least one A vibration isolating device in which a flange formed at the tip of the protruding portion is fitted into a cap provided on at least one of the two magnets, the upper end of which is closed.