JPH0614098Y2 - Air spring type vibration isolation device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to an air spring type vibration damping device for reducing the transmission of vibrations from the floor and for supporting precision instruments such as various measuring instruments. Is.

(Prior Art and Problems) Conventionally, an air spring type vibration damping device has been used in order to prevent vibration from the surroundings, particularly from the floor, and maintain or improve the measurement accuracy of precision equipment.

As shown in FIG. 3, the air spring type vibration damping device is provided to support a surface plate 1 carrying precision equipment at an arbitrary position, and its structure is such that the surface plate 1 is carried. An upper metal fitting 2, a bellows 3 having a central portion attached to the upper metal fitting 2, and an outer periphery of the bellows 3 attached to the bellows 3.
And a lower metal fitting 5 which forms an air chamber 4 in cooperation with the lower metal fitting 5.

When the supply pressure is P and the height of the air chamber is h, It is known that, in general, the vibration isolation (vibration isolation) performance can be improved by reducing the natural frequency fn. As is clear from the above equation, in order to reduce the natural frequency fn, if the ratio of the weight W to the effective diameter d of the bellows 3 is kept constant and the air pressure P is kept constant, the height of the air chamber, that is, the height of the lower metal fitting. It is sufficient to increase h. However, if the height h of the air chamber (lower metal fitting) is increased, the air spring type vibration damping device itself is largely displaced by a slight amount outside, which deteriorates the stability and workability of the vibration damping device. was there.

As a solution to this problem, as shown in FIG. 4 of the related art, a damping fluid 6 having a proper viscosity, such as silicon oil or magnetic fluid, is stored in an air chamber, and a damping plate 7 is immersed in the fluid. The suspension plate 8 is connected to the damping plate 7 and the upper fitting 2.
Although this method could add an appropriate damping function to the vibration isolator and improve the stability and workability of the vibration isolator, it is necessary to store the damping fluid in the air chamber 8, that is, the lower metal fitting. For this reason, when the height h of the air chamber is increased, the length of the suspension shaft 8 becomes long, which often results in a useless structural design.

In addition, since the air piping for the air chamber must be provided above the liquid level of the damping fluid 6, when it is not possible to provide a sufficient space below the surface plate 1 due to conditions such as the installation environment of the vibration isolator. Is subject to a great deal of restrictions such as a limited space for providing air piping.

If the diameter of the air chamber is increased instead of the height of the air chamber, it is wasteful to fill the air chamber with damping fluid more than necessary.

(Object of the Invention) Therefore, the object of the present invention is to reduce the length of the suspension shaft that connects the damping plate and the upper metal fitting, and to increase the degree of freedom of installation of the air pipe for the air chamber. It is to provide a spring type vibration damping device.

(Means for Solving Problems) The above object is achieved by the air spring type vibration damping device according to the present invention. In summary, the present invention is an upper metal fitting for supporting a load,
A bellows having a central portion attached to the lower surface of the upper metal fitting, a bellows attaching means for sandwiching the outer periphery of the bellows, and the bellows attaching means attached to an upper end opening, and the main air chamber in cooperation with the bellows. In the air-spring type vibration damping device having a lower metal member forming a damper, a damping tank in which damping fluid is stored is arranged above the air chamber, and the damping fluid liquid level in the damping tank and the bellows are A damping tank air chamber is formed therebetween, and the damping tank air chamber and the main air chamber are communicated with each other by a plurality of ventilation holes formed in a wall of the damping tank, and further, in the damping fluid. In the air spring type vibration damping device, the damping plate attached to the upper fitting is immersed.

(Example) Next, the air spring type vibration damping device according to the present invention will be described in more detail with reference to the drawings.

Referring to FIG. 1, an air spring type vibration damping device according to the present invention includes an upper metal fitting attached to a surface plate 1 for carrying precision equipment, and a bellows 13 having a central portion attached to a lower surface of the upper metal fitting 12. And a bellows mounting means 1 including upper and lower flanges 14a and 14b for sandwiching the outer periphery of the bellows 13.
4 and a lower metal fitting 15 having the bellows attaching means 14 attached to the upper end opening. The lower metal fitting 15 and the bellows 13 cooperate to form a main air chamber 16.

According to the invention, a damping tank 17 is arranged in the main air chamber 16, in particular above the main air chamber. Dumping tank 17
Can have any shape, but in the present embodiment, it is a cylindrical container having an upper opening, and the upper end of the opening is fixed to the bellows attaching means 14. In the damping tank 17, a damping fluid 18 having an appropriate viscosity, such as silicon oil or magnetic fluid, is stored. Further, a damping tank air chamber 19 is formed between the liquid level of the damping fluid in the damping tank 17 and the bellows, and the damping tank air chamber 19 and the main air chamber 16 are formed in the wall of the damping tank 17. The plurality of ventilation holes 20 communicate with each other. Furthermore,
The damping plate 21 is immersed in the damping fluid, and the damping plate 21 and the upper fitting 12 are connected by a suspension shaft 22. In this embodiment, the damping plate 21 has a box shape, and the hanging shaft 2 is attached to the bottom plate portion 21a.
Although the two are connected to each other, a plurality of blade-like vertical members 21 that vertically project from the bottom plate instead of the box shape are formed.
It is also possible to form b by being fixed to the bottom plate portion 21a.

With such a structure, when the floor vibrates and a relative motion occurs between the lower metal fitting 15 and the upper metal fitting 12, first, the damping tank air chamber 19 and the main air chamber 16 work together to provide the main vibration damping effect. And the damping fluid 18 in the damping tank 17 is achieved.
With the action of the damping plate 21 connected to the upper metal fitting 12, a horizontal and vertical vibration isolation action is added. As a result, the generated vibration from the floor is rapidly attenuated by the good vibration isolation performance of the present device.

Further, according to the present device, as shown in FIG. 1, the air piping port 23 of the main air chamber 16 can be suitably arranged below the lower metal fitting 15. That is, for example, even when the surface plate 1 is large and a sufficient space cannot be provided below, the installation of the air pipe and other work can be performed in the lower portion of the lower metal fitting 15, and the workability is extremely excellent. ing.

FIG. 2 shows another embodiment of the air spring type vibration damping device according to the present invention. According to this embodiment, although the device is substantially the same as the device shown in FIG. 1, the damping plate 21 is directly connected to the upper fitting 12, so that the upper fitting and the damping plate are connected to each other in the previous embodiment. The difference is that there is no suspension shaft 22 connecting the two. In addition, although not limited, in the present embodiment, the damping plate 2
The reference numeral 1 extends upward from the bottom plate so as to surround the upper metal fitting 12, and the upper end thereof is configured to project above the liquid surface of the damping fluid. Furthermore, it is possible to use the upper metal fitting and the bellows portion that have penetrated into the damping fluid as the damping plate without providing the damping plate as a separate component.

The vibration isolator of this embodiment also operates similarly to the device of the previous embodiment.

(Effect of the Invention) As described above, in the air spring type vibration damping device according to the present invention, the damping tank is installed above the lower metal fitting to perform the damping action. It is possible to shorten the length of the suspension shaft that connects the air pipes, and it is possible to install the air piping for the air chamber at almost any height of the lower metal fittings that compose the air chamber. There is an advantage that the degree of freedom is high.

[Brief description of drawings]

FIG. 1 is a sectional view of an embodiment of an air spring type vibration damping device according to the present invention. FIG. 2 is a sectional view of another embodiment of the air spring type vibration damping device according to the present invention. FIG. 3 is a sectional view of a conventional air spring type vibration damping device. FIG. 4 is a sectional view of another conventional air spring type vibration damping device. 12: Upper metal fitting 13: Bellows 14: Bellows mounting means 16: Main air chamber 18: Damping fluid 19: Damping tank air chamber 20: Vent hole 21: Damping plate 22: Suspended shaft

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-60-159429 (JP, A) real-open Sho-49-16683 (JP, U) real-open Sho-60-8539 (JP, U) real-open Sho-60- 21049 (JP, U) Actually open Sho 61-54532 (JP, U)

Claims (3)

[Scope of utility model registration request] 1. An upper metal fitting for supporting a load, a bellows having a central portion attached to a lower surface of the upper metal fitting, a bellows attaching means for holding an outer periphery of the bellows, and the bellows attaching means at an upper end opening portion. In an air spring type vibration damping device provided with a lower metal fitting which is mounted and cooperates with the bellows to form a main air chamber, a damping tank storing a damping fluid is disposed above the air chamber, A damping tank air chamber is formed between the liquid surface of the damping fluid in the damping tank and the bellows, and the damping tank air chamber and the main air chamber are a plurality of vent holes formed in the wall of the damping tank. And a damping plate attached to the upper fitting is immersed in the damping fluid. 2. The utility model registration claim 1 in which the damping plate is composed of a bottom plate portion and a vertical portion projecting vertically from the bottom plate portion, and the bottom plate portion and the upper metal fitting are connected by a suspension shaft. The air-spring type vibration damping device described. 3. The air spring type vibration damping device according to claim 1, wherein the damping plate is integrally formed with the upper metal fitting.