JPH04140529A - Frame and frame vibration removing method - Google Patents

Abstract

PURPOSE:To remove vibration transmitted from a vibration generating source loaded on a frame to the frame itself by providing a body, a support rod and a weight, and removing the vibration by swinging up the weight according to a force applied from the vibration generating source. CONSTITUTION:When a vibration generating source loaded on a fixed board part 15 is driven so that a force in the direction as shown with an arrow A can be applied to a frame 11, according to the law of inertia, a stationary weight 17 is displaced so as to swing up in the direction as shown with an inverse arrow B against the arrow A while being fixed to a support rod 16. In this way, by swinging up the weight 17 according to the force applied from the vibration generating source to the frame 11, momentum of the whole system and impulse volume acting on the frame 11 can be decreased. Furthermore, it is possible to ease and remove vibration generated by the vibration generating source loaded on the frame 11. Moreover, since the speed (v) of the weight varies according to an external force, the vibration can be always removed according to the size of the external force.

Description

DETAILED DESCRIPTION OF THE INVENTION [Purpose of the Invention (Industrial Field of Application) The present invention is directed to, for example, a pedestal supporting various devices that serve as a source of vibration, and a device that transmits vibrations from the various devices that serve as a source of vibration to the pedestal. Concerning a method for removing vibrations.

(Prior Art) For example, a pedestal on which various devices are placed and supported has been designed based on a static load such as the weight of the pedestal, or a dynamic load such as inertial force. And, as shown in Figure 2,
For example, measures to eliminate vibrations transmitted from the floor 1 to the pedestal 2 include increasing the rigidity of the pedestal 2 and using a material with high damping properties for the material of the pedestal 2.

(Problems to be Solved by the Invention) By the way, the rigidity of the pedestal 2 can be increased by providing a reinforcing member 3 as shown in FIG. 2 as a countermeasure against vibration. However, the mounting positions of the reinforcing members 3 are often determined through trial and error, which is inefficient.

Further, when a device mounted on the pedestal 2 is driven, a load that becomes a source of vibration may be applied from this device to the pedestal 2.

Since the magnitude and direction of this load change depending on how the device moves, the type of this load is not always constant. Therefore, all kinds of loads applied to the frame 2 cannot be absorbed by the reinforcing members 3, and merely providing the reinforcing members 3 is not sufficient as a countermeasure against vibration.

Furthermore, transient phenomena become a problem when starting the drive of the device or changing the force of the device, but it is not possible to sufficiently eliminate vibration 1 by simply increasing the rigidity of the pedestal 2.

Furthermore, even if the stiffness of the pedestal 2 is increased by providing the reinforcing material 3..., depending on the arrangement of the reinforcing material 3..., there may be cases where the reinforcing material 3... does not contribute in any way to vibration removal of the pedestal 2. Ru.

Furthermore, for example, a positioning device gt mount frame 2 for semiconductor manufacturing is used.
When the positioning device is placed on the mount 2, the residual vibration of the pedestal 2 may affect the characteristics of the positioning device and may lower the mounting strength of the positioning device. For this reason, the vibration of the front stand 2 is currently an obstacle to increasing the speed of the positioning device.

Furthermore, conventionally, it has been considered to prevent vibrations from the floor 1 from being transmitted to the pedestal 2, but it has not been considered to remove vibrations applied to the pedestal 2 from various devices placed on the pedestal 2. It wasn't.

The object of the present invention is to provide a mount capable of removing vibration transmitted from a vibration generation source mounted on the mount, and a mount capable of removing vibration transmitted from a vibration generation source mounted on the mount to the mount. The purpose is to provide a method.

[Structure of the Invention] (Means and Effects for Solving the Problems) In order to achieve the above object, the present invention includes a main body on which a vibration generation source is mounted and supported, and one end of which is pivotally supported on the main body. The mount includes a support rod and a weight provided at the free end of the support rod, and removes vibration by swinging up the weight in response to a force applied from a vibration source.

In addition, vibration removal for the pedestal is achieved by swinging up a weight provided at the free end of a support rod, one end of which is pivotally supported on the main body, in response to the force applied from the vibration source placed on the main body. It's in the method.

Further, the present invention makes it possible to remove vibrations transmitted to the pedestal from a vibration generation source placed on the pedestal.

(Example) An embodiment of the present invention will be described below with reference to FIG.

Components that are the same as those described in the prior art section are given the same numerals and their explanations will be omitted.

FIG. 1 schematically shows an embodiment of the present invention as a first-order model, and reference numeral 11 in the figure represents a frame. This frame 1
1 is a rectangular box-shaped main body 1 with a rigid frame structure in which each node is a rigid joint.
2, and support legs 14 for supporting the main body 12 on the floor 13.
...(only two are shown). And pedestal 1
1 has a surface plate part 15 on its upper part, and a vibration generation source such as a positioning device for semiconductor manufacturing equipment is placed on this surface plate part 15.

Furthermore, a support rod 16 made of a rigid body is provided inside the main body 12.
and a weight 17 are provided. The support rod 16 has one axial end pivotally supported at the center of the back side of the surface plate 15, and a weight 17 is fixed to the free end located on the other axial end. Then, support rod 16 and dust 1
7 is a pendulum 18 suspended vertically within the main body 12.
It consists of

The vibration generation source placed on the surface plate 15 is driven and the mount 1
1, when a force is applied in the direction shown by arrow A in the figure, the dust 17, which was stationary, follows the law of inertia and remains fixed to the support rod 16, as shown by arrow B, which is in the opposite direction to arrow A. Displaces in the direction and swings up.

In other words, considering the main body 12, support rod 16, and weight 17 as a system, the weight 17 swings up from a stationary state until the angle between the extending direction of the support rod 16 and the vertical direction is θ. think of. Then, on the pedestal 11,
Suppose that a force acting in the direction indicated by arrow A, having a magnitude F and a velocity V is applied. In addition, the moment of inertia is ignored and considered simply.

If the weight 17 swings up at a speed in the direction of arrow B as V, then the following equation, F t -MV-mv-(1) holds true from the relationship between momentum and impulse. Here, M represents the mass of the frame 11, m represents the mass of the weight 17, and t represents the time during which the force F acted.

Also, considering the mechanical energy of the system shown in Figure 1, the following equation can be obtained.

Note that solving equations (1) and (2) gives the following equation.

That is, as shown in equation (1), the support rod 1 is attached to the main body 12.
6 and a weight 17 are provided, and by swinging the weight 17 in response to the force applied to the pedestal 11 from the vibration source, the momentum of the entire system and the amount of impulse acting on the pedestal can be reduced. Then, it is possible to alleviate and eliminate the vibrations generated by the vibration source placed on the pedestal 11.

In addition, since the speed of the weight ■ changes according to the external force F,
It is possible to always remove vibrations according to the magnitude of external force.

Furthermore, when transient conditions become a problem, consider the superposition of two waves.

Y=V1+'j2 -a, 5in (ω1 to 10β1) +a2s in (ω2t+β2) -a, (sinω, tcosβ1 +cosω, tsinβl) +a2 (sinω2tcosβ2 +cosω2tstnβ2) Natural frequency ω1 of the main body 12 and natural frequency of the weight 17 ω
2 are considered to be equal (ω1-ω2-ω), and the phase difference is 1
80" (β, m O'β2-180"), equation (5) becomes
80.

m (a, -a2) s in ω t
becomes.

That is, al represents the amplitude of the main body 12, a2 represents the amplitude of the weight 17, and when al and 82 are equal, their respective natural frequencies ω.

The vibration of the pedestal 12 can be canceled regardless of ω2.

Therefore, the natural frequency ω of the main body 12 and the natural frequency ω2 of the dust 17 should be made equal, and the value of the mass m of the weight should be set so that the amplitude of the main body 12 and the amplitude of the weight 17 are equal. If these two conditions are satisfied, vibrations can be flexibly removed regardless of the magnitude of the external force F.

Here, the natural frequency ω2 of the dust 17 is expressed by the following formula, ω21J
77th g: Gravitational acceleration f! : Depends on the length of the support rod 16.

Further, the length of the support rod 16 is adjusted according to the natural frequency ω1 of the main body 12.

In this embodiment, vibrations are removed using one pendulum 18, but the present invention is not limited to this, and for example, vibrations may be removed using a plurality of pendulums.

Moreover, the present invention can eliminate vibrations regardless of the shape of the weight 17, the shape of the support rod 16, and the installation location of the pedestal 11.

"Effects of the Invention" As explained above, the present invention includes a main body on which a vibration generation source is mounted and supported, a support rod having one end pivotally supported on the main body, and a support rod provided at the free end of the support rod. equipped with a weight,
It removes vibrations by swinging up a weight in response to the force applied from the vibration source.

Further, a weight provided at the free end of the support rod, one end of which is pivotally supported on the main body, is swung up in response to the force applied from the vibration generating source placed on the main body to remove vibrations.

Therefore, the present invention has the effect of being able to remove vibrations transmitted to the pedestal from a vibration generation source placed on the pedestal.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram schematically showing one embodiment of the present invention, and FIG.
The figure is an explanatory diagram schematically showing a conventional example. 11... Frame, 12... Main body, 16... Support rod,
17... Weight.

Claims (2)

[Claims] (1) A main body on which a vibration generation source is placed and supported, a support rod having one end pivotally supported on the main body, and a weight provided at the free end of the support rod, and the vibration generation source A mount that removes vibrations by swinging up the weight in response to a force applied from the mount. (2) The feature is that vibrations are removed by swinging up a weight provided on the free end of a support rod whose one end is pivotally supported on the main body in response to the force applied from the vibration source placed on the main body. A method for removing vibrations from a stand.