JPH0333529A - Vibration isolator - Google Patents

Abstract

PURPOSE:To stabilize vibration isolating performance by connecting a load carrying platform and a base to be loaded with machinery to each other through a series of suspension members respectively engaging with both parts and having small flexural rigidity, and further arranging damping elements utilizing friction between the load carrying platform and the base. CONSTITUTION:Vibration isolators 3 and damping elements 30 are mounted between a base 1 and a load carrying platform (or flame), and the base 1 is constituted to be suspended on the load carrying platform 3 through the vibration isolators 3. The outside case 4 and the inside case 5 of the device 3 are connected each other through a series of suspension members 6 respectively engaging with both parts and having small flexural rigidity. Consequently, the load generated by placing a heavy article is actuated on the suspension members 6 nearly uniformly. When vibration of low frequency in the horizontal direction is actuated on the load carrying platform 2 at starting or stopping of a vehicle, as friction members 33, 34 are pressed to each other with a spring 32, the base 1 is not vibrated until the vibrating force is over the static friction force, the vibration is reduced by the static friction force, and generation of impulsive force by collision of the load carrying platform can be prevented.

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 consists of an outer case 4, an inner case 5, and a hanging member 6A with low bending rigidity that connects the two cases.The outer case 4 is attached to the base 1, the inner case 5 is attached to the waiting area (floor surface) 2, They are each fixed with bolts 7. Precision instruments are then 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 load 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 cannot reduce the low frequency and large displacement vibrations that occur when starting or stopping, and when the supporting legs collide with the foundation, the impact force is applied to the supported object. It may work.

(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, if this device is used in a transportation vehicle, there is a problem that it cannot reduce the low-frequency vibrations that occur when starting or stopping, and if the displacement becomes large and there is a collision, an impact force will be applied to the device. .

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, and - 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 member, and even when low frequency vibrations are applied, no impact force is applied to the equipment.

(Embodiment) An embodiment of the present invention will be described below with reference to FIGS. 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 hanging member 6 are connected by a connecting fitting 10. That is, the equipment 8 is loaded on the loading platform 2 via the vibration isolating device 3.

Further, the damping element 30 is composed of a spring sasaeco 1, 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 l is suspended from the loading platform 2 by six vibration isolators 3. For this reason, equipment 8
The load generated by loading the suspension member 6 acts almost equally on the suspension member 6.

Further, when the length of the hanging member is Flood and the gravitational acceleration is g, the natural frequency f of such a system is expressed by a linear equation.

f = (1/2 x) ・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.

In addition, when horizontal low-frequency vibrations act on the loading platform when the vehicle starts or stops, since the friction members 33 and 34 are held down by the springs 32, the base 1 will not move until these static frictional forces are exceeded. does not vibrate. Normally, the low-frequency vibration acceleration that occurs on the loading platform when a vehicle starts or stops is about 0.1 or 0.2G, so this static friction force can reduce vibrations and reduce the impact caused by collisions with 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.

〔Effect 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 alternating hanging members with low bending rigidity, and a damping element using friction is provided between the loading platform and the base. , the load can be applied evenly to the hanging 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 the construction drawing, and Fig. 3 is a block diagram of the damping element shown in Fig. 1. , FIG. 4 is a block diagram of a vibration isolator showing a different embodiment of the present invention, FIG. 5 is a cross-sectional view of a conventional vibration isolator, and FIG. 6 is a block diagram of a conventional vibration isolator. 1. Base, 2. Seedling stand (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.