JPH038820Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to a vibration isolating device that provides anti-vibration support for precision equipment.

[Technical background of the invention and its problems] In a vibration isolator equipped with a bellows, one of the challenges to obtain the required vibration isolation performance is to lower the natural frequency in the horizontal direction.

As a conventional vibration isolating device of this type, one shown in FIG. 2 has been devised. That is, the additional tank 2 of the air spring 1 is fitted into a case 3 with an open top, and the bottom of the additional tank 2 is lifted up by a plurality of hanging rods 4 swingably suspended from the top of the case 3. and further in case 3,
It is configured to contain a damping liquid 5 into which the bottom of the additional tank is immersed. When using this vibration isolator, three to four units are arranged at appropriate intervals, and precision equipment to be supported in vibration isolation is placed on top of these. By lifting the additional tank 2 with the hanging rod 4, the natural frequency in the horizontal direction can be reduced in proportion to the length of the hanging rod 4.

However, in such a conventional vibration isolator, the case 3 is large in size and requires a large space factor because the additional tank 2 is fitted therein, and the top surface of the case 3 is open, which prevents dust from entering the case 3. It had the disadvantage of being easy.

(Purpose of the invention) The present invention was made in order to eliminate the above-mentioned drawbacks, and an object of the invention is to provide a vibration isolator that can be downsized and can reduce the natural frequency in the horizontal direction.

(Summary of the invention) That is, the vibration isolator of the invention includes a case containing a damping liquid inside, a bellows provided to seal the top surface of the case, and a hemispherical projection on the top surface. a lower metal fitting placed on the lower metal fitting, an upper metal fitting having a hemispherical recess corresponding to the hemispherical protrusion of the lower metal fitting, and a vibration isolating rubber disposed and bonded between the hemispherical protrusion and the hemispherical recess; The present invention is characterized by comprising a hanging shaft whose upper part is connected to the lower metal fitting and hangs down, and whose lower part is equipped with a damping plate that is immersed in the damping liquid.

(Embodiments of the invention) Hereinafter, embodiments of the invention will be described with reference to the drawings.
FIG. 1 is a diagram showing an embodiment of the present invention. In the figure, a case 10 with an open top has a bellows 11 disposed on the top, and the top surface is sealed by pressing the outer edge of the bellows with a ring-shaped holding fitting 12 and a holding bolt 13. A lower metal fitting 14 having a hemispherical protrusion 14a on its upper surface is disposed on the bellows 11. An upper metal fitting 16 is disposed on the protrusion 14a of the lower metal fitting 14 with a vibration isolating rubber 15 interposed therebetween.
A hemispherical recess 16a is provided on the surface of the upper metal fitting 16 that corresponds to the hemispherical protrusion 14a. The vibration isolating rubber 15 is vulcanized and bonded to the hemispherical protrusion 14a and the hemispherical recess 16a, respectively. A surface plate 17 is attached to the upper surface of the upper metal fitting 16. A hanging shaft 18 is coupled to the center of the lower surface of the lower metal fitting 14.
The upper part of the hanging shaft 18 passes through the bellows 11 and a presser plate 19 that presses the bellows, and is screwed into the lower metal fitting 14. Further, a damping plate 21 immersed in a damping liquid 20 housed in the case 10 is attached to the lower part of the hanging shaft. The damping plate 21 consists of a horizontal plate 22 and a vertical plate 23, and the horizontal plate 22 is provided with a through hole 22a. The damping liquid 20 preferably has a suitable viscosity, such as silicone oil.

A stopper plate 24 is attached to the lower part of the upper metal fitting 16. This stopper plate 24 is arranged at an appropriate distance from the presser metal fitting 12 and the lower metal fitting 14, and has the role of suppressing excessive vibration of the upper metal fitting 16.

Next, the operation of the vibration isolating device configured as described above will be explained. As shown in FIG. 1, a horizontal force F is applied between the case 10 and the surface plate 17 due to vibration, causing a relative horizontal movement, and the case 1
0 is fixed and the surface plate 17 moves to the left in the figure, the lower metal fitting 14 and the upper metal fitting 16 move around the rotation centers 01 and 02 due to the horizontal force F and the vertical force (support load) W. Rotate around the anti-vibration rubber 1
5, twisting deformation occurs. Therefore, in the vibration isolator of the present invention, the torsional deformation of the vibration isolating rubber 15 is added in series to the shear deformation of the bellows 11, and as a result, the spring action in the horizontal direction becomes soft.

Further, when the lower metal fitting 14 moves such as swinging, the movement is quickly damped by the damping plate 21 and the damping liquid 20.

(Effect of the invention) As described above, according to the vibration isolator of the present invention, the vibration isolator has a hemispherical surface between the lower metal fitting 14 placed on the bellows and the upper metal fitting 16 placed below the surface plate 17. 15, the natural frequency in the horizontal direction can be reduced.

Furthermore, since the container containing the damping liquid is completely sealed, dust does not get mixed into the container, and the entire device can be made smaller.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view showing an embodiment of the vibration isolator of the present invention, and FIG. 2 is a front view showing a conventional vibration isolator. 10...Case, 11...Bellows, 14...
Lower metal fitting, 14a...Semispherical projection, 15...Vibration isolating rubber, 16...Upper metal fitting, 16a...Semispherical recess, 1
8... Hanging shaft, 20... Damping liquid, 2
1...Dumping plate.

Claims (1)

[Scope of utility model registration request] A case containing a damping liquid inside, a bellows provided to seal the upper surface of the case, a lower metal fitting having a hemispherical projection on the upper surface and placed on the bellows, and a hemispherical projection of the lower metal fitting. an upper metal fitting having a hemispherical recess corresponding to the hemispherical recess; a vibration isolating rubber disposed and bonded between the hemispherical protrusion and the hemispherical recess; an upper part connected to the lower metal fitting and hanging down;
A vibration isolating device comprising: a hanging shaft having a damping plate attached to a lower part thereof to be immersed in the damping liquid.