JPH0333530A - Vibration isolator - Google Patents

Abstract

PURPOSE:To stabilize vibration isolating property by fitting an inside case on either a load carrying platform or a base to be loaded with machinery and an outside case on the other one, and connecting these cases each other through suspension members having small flexural rigidity. CONSTITUTION:A vibration isolator 3 is provided with an outside case 4 having a beam-like member 41 on the upper end part, and an inside case 5 having a beam-like member 51 on the lower end part, and these cases 4, 5 are connected to each other through a series of suspension members 6 respectively engaging with the member 41 of the case 4 and the member 51 of the case 5 and having small flexural rigidity. Further, the beginning end and the ending end of the suspension member 6 are connected to each other with a connecting metal piece 10. Namely, a heavy article placed on a base 1 is loaded on a load carrying platform 2 through the vibration isolator 3. In this case, the base 1 is suspended on the load carrying 2 through six vibration isolators 3. Hereby, the load generated by placing a heavy article 8 is nearly uniformly actuated on the suspension members 6. The natural frequency of this system is independent of the weight of the heavy article, but only dependent on the length lof the member 6, therefore adjustment is easy.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Field of Industrial Application) The present invention relates to a vibration isolating device with improved characteristics against low frequency vibrations.

(Prior Art) Conventionally, for the purpose of protecting buildings from disasters caused by vibrations such as earthquakes, and protecting precision equipment from road vibration during transportation, Japanese Patent Application Laid-Open No. 63-72936, etc. This is a vibration isolating device as shown in FIGS. 5 and 6.

In this device, a vibration isolating device 3 is arranged between a base 1 and a loading platform or a floor surface 2. This device uses an outer case 4, an inner case 5, and a hanging member 6A with low bending rigidity that connects both cases. , are fixed by bolts 7, respectively. Then, precision instruments are placed on the base 1.

However, in this conventional device, each hanging material 6A is provided independently, so a specific hanging material 6A is provided independently.
There is a risk that excessive waiting weight will be applied to A.

Therefore, the hanging material 6A needs to be large in order to obtain sufficient strength. As a result, the bending rigidity of the hanging member 6A increases, and the vibration insulation performance deteriorates.

Furthermore, when this device is used in a transportation vehicle.

There is a problem in that it is not possible to reduce low-frequency, large-displacement vibrations that occur when starting or stopping, and when the supporting legs and the foundation collide, an impact force may be applied to the supported object.

(Problem to be solved by the invention) As described above, in the conventional vibration isolating device, each hanging member was provided independently, so it was not possible to apply a uniform load to the hanging members. .

Additionally, when this device is used in transportation vehicles, there is a problem in that it cannot reduce low-frequency vibrations that occur when starting or stopping, and in the event of a collision due to large displacement.
Impact forces act on the equipment.

The present invention was developed in consideration of the above points, and an object of the present invention is to provide a vibration isolating device having stable vibration isolating performance.

[Structure of the invention]

(Means for Solving the Problems) In order to achieve the above object, in the present invention, a loading platform and a base on which equipment is loaded are connected by a series of hanging members having low bending rigidity that are connected alternately. Furthermore, a damping element using friction is placed between the cargo platform and the base.

(Function) With this configuration, it is possible to apply a load evenly to the hanging members, and even when low frequency vibrations are applied, no impact force is applied to one device.

(Example) An example of the present invention will be described below with reference to FIGS. 1 to 3. That is, a vibration isolator 3 and a damping element 30 are installed between the heavy object and the carrier (or frame) 2 of the transport vehicle.

This vibration isolating device 3 includes an outer case 4 having a beam-like member 41 at its upper end, and an inner case 5 having a beam-like member 51 at its lower end. The outer case 4 and the inner case 5 are connected by a series of hanging members 6 having low bending rigidity, which are alternately connected to the beam-like members 41 of the outer case 4 and the beam-like members 51 of the inner case 5. The starting end and the ending end of the +i% sliding member 6 are connected by a connecting fitting 10. That is, loading platform 2
A device 8 is placed on top via a vibration isolation device 3.

Further, the damping element 30 is arranged on the spring sill 31. It consists of a spring 32, friction members 33, 34 and a cover 35.

Here, the effects of the configuration of this embodiment will be explained. In this embodiment, the base 1 is suspended from the loading platform 2 by six vibration isolators 3. For this reason, equipment 8
The load generated by placing the hanging member 6 acts almost equally on the hanging member 6.

Further, assuming that the length of the hanging member is the length of the hanging member and the gravitational acceleration is g, the natural frequency f of such a system is expressed by the following equation.

f = (1/2 π) ・J g / Q
(1) That is, the natural frequency of the system does not depend on the weight of the equipment and is determined only by the length of the hanging member 6. Therefore, there is an advantage that the natural frequency of the system can be easily shifted from the frequency of the vibration to be isolated.

Furthermore, when low-frequency horizontal vibrations act on the loading platform when starting or stopping the vehicle, since the friction members 33 and 34 are held in place by the springs 32, the base 1 will not move until these static friction forces are overcome. Does not vibrate. Normally, the low frequency vibration acceleration that occurs on the loading platform when the vehicle starts or stops is about 0.1 or 0.2G, so this static friction force can reduce the vibration, and the WrF caused by collision of the loading platform. This has the advantage of preventing force generation.

Note that the present invention is not limited to the above embodiments. For example, as shown in FIG. 4, the same effect can be expected even if it is placed inside a vibration isolating device.

[Effects of the Invention] As explained above, in the present invention, the upper end of the outer case and the lower end of the inner case are connected by hanging members with low bending rigidity that are connected alternately, and the space between the loading platform and the base is Since a damping element utilizing friction is disposed in the suspension member, a load can be applied evenly to the suspension member, and a stable vibration isolating device can be provided even when low frequency vibrations are applied.

[Brief explanation of drawings]

Fig. 1 is a block diagram of a vibration isolating device showing an embodiment of the present invention, Fig. 2 is a partial block diagram of the vibration isolating device shown in Fig. 1, and Fig. 3 is a block diagram of a damping element shown in Fig. 1. , FIG. 4 is a configuration diagram of a vibration isolating device showing a different embodiment of the present invention, FIG. 5 is a sectional view showing a conventional vibration isolating device, and FIG. 6 is a configuration diagram showing a conventional vibration isolating device & It is. . L・Base, 2・Logging platform (or frame),

Claims (1)

[Claims] In a vibration isolating device that is installed between the loading platform and a base on which the equipment is loaded when precision equipment is installed on the loading platform of a transportation vehicle, The inner case is attached to one side and the outer case is attached to the other, and these cases are connected by a hanging member with low bending rigidity. Furthermore, a damping element using friction is installed between the loading platform and the base. Features a vibration isolation device.