JPS6353331A - Vibration control device - Google Patents

Abstract

PURPOSE:To support part of the weight of a movable mass, reduce the effect of the friction force, and improve the vibration reducing effect by fitting magnets to the movable mass and a vibrating body and generating a magnetic force applied to the movable mass in the same direction. CONSTITUTION:The vibration speed of a vibrating body 4 is detected by an acceleration meter 5, and a movable mass 1 is fitted to the vibrating body 4 via a spring 2, an actuator 3, and bearings 11. A control unit 6 detects the vibration speed of the vibrating body 4 and controls the actuator 3 so as to generate an opposite control force proportional to it. A pair of magnets 12 are fitted to the movable mass 1 and the vibrating body 4 so that both magnetic forces are affected each other. Accordingly, the effect of the friction force is effectively reduced, the vibration reducing effect is improved, the life of bearings and others supporting the weight of the movable mass can be extended.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application] The present invention relates to a vibration control device for reducing the imaging of a structure such as an elevated passageway, and particularly to a reduction in the dead zone of its control force.

[Conventional technology]

Mass dampers are generally used to reduce vibrations generated in vibrating bodies. Figure 3 shows an example of this. In the figure, fl+ is a movable mass, supported by a bearing housing, and movably attached to the vibrating body (4) via a spring (2) and an actuator (31). 151 is an accelerometer, the integrator (7) of the controller (6) calculates the vibration velocity of the vibrating body (4), and the force amplifier +S+ calculates the vibration velocity of the actuator (31) which is proportional to the vibration velocity wave. It generates the divided iAt force in the direction. (9) is a fixed core.

Configure the actuator (3) together with the movable core ULJ.

The 5th v is a model diagram 1 that explains the operation of the mass damper.
Ml is the mass of the vibrating body (II, Kl is the spring definition,
CQ is a reduction formula, M2 is the weight of the movable mass (1), + K2 is the spring constant of the mass damper spring (2). Here, xl is the displacement of the vibrating body (4),
If x2 is taken as the displacement of the movable page il+, the equation of motion becomes as follows.

M, xI +C0X1 4x, + K2 (x, -
X2) = F −V−(1)M? X2 + 2 (
X2

A force V proportional to the desire is generated in the following form, assuming that the gain constant is Cm.

■2CmX1 ・・・・・・・・・・・・
...(3+Equation) Substituting 31 into Equation (1) yields the following.

From equation (4), in the conventional mass damper, the apparent damping of the vibrating body (41) can be changed from co to (CI
]0cm), it can be seen that an effective retention reduction effect can be achieved.

[Problem that the invention seeks to solve]

The size of the movable mass constituting the mass damper is typically a few percent of the amount of the vibrating body, but it is acceptable if the vibrating body itself is a huge structure! E! ! The actual amount is 107ON
It may even be larger than that. In such cases, horizontal bearings are often used to move the movable mass smoothly, but when the movable mass becomes large, friction in this bearing becomes a problem.

For simplicity, assume that this friction is a "Coulomb" festival.

When the weight of the movable mass is W and the friction coefficient due to the bearing is μ, the friction force P is expressed by a 9th-order equation.

P-μW・・・・・・・・・
・・・・・・・・・ (51 also. The stiffness friction force P is the formula 9 (
Since it acts in the opposite direction to the force shown by the mountain that tries to act on the movable mass, the control force when there is a Kishi force is as follows.

Figure 5 shows the vibrational confusion in the case of 31 without debris.

FIG. 6 is a graph of the control force against the equation (vibration speed anti-X in the case of ti+), considering friction.

From formula t61, in the dry range of lc and l≦p, a so-called dead zone occurs where the movable mass does not move due to frictional force and no control force is generated, and the vibration level cannot be controlled below this level. This has caused problems such as making the control system unstable.

This invention was made to solve this problem, and aims to reduce the weight of the movable mass that is applied to the bearing part, which is the source of frictional force, and to obtain a vibration control device with a small dead zone. .

[Means for solving problems]

The vibration control device according to the present invention uses a magnet acting in the direction of the vehicle force to reduce the weight of the movable mass applied to the bearing portion and reduce the frictional force.

[Effect]

In this invention, the nine stones cancel out the amount of N of the movable mass added to the bearing part.

# It can greatly reduce the vibration force, reduce the risk of injury, and further enhance the vibration reduction effect.

〔Example〕

FIG. 1 is a diagram showing an embodiment of the present invention.

(1) to αB are completely the same as the above conventional device. α2 is a magnet provided on the movable mass and the vibrating body,
A magnet with like poles facing each other.

Now, if the repulsive force exerted by the above-mentioned pair of magnets on each other is R, then the frictional force Q when using 5ii stones is:

It will look like this:

Q-μ(w-n) ・・・・・・・・・・・・
...(7) Therefore, for example, 9 repulsive force R is the weight W of the movable mass
If 9/10 is selected, it is also possible to make the frictional force Q when using an ei stone 1/10 of the conventional #vibration force P.

In this way, the vibration control device configured as shown in Fig. 1 uses the same movable mass as the conventional imaging control device, but
It is possible to make the magnitude of the frictional force negligible.

Furthermore, since the load applied to supporting devices such as bearings is reduced, their lifespan can be significantly extended.

FIG. 2 shows another embodiment of the present invention, in which two sets of magnets are used so as to exert an attractive force on each other.

In addition, the embodiments shown in FIGS. 1 and 2.

It is clear that the same effect can be expected if an electromagnet is used for one or both of the magnets, or if the embodiment shown in FIG. 2 is characterized by a magnet on either side.

〔Effect of the invention〕

As explained above, this invention effectively eliminates the effect of friction force V, which has a negative impact on vibration control at low vibration levels, by using a very easy-to-implement method of supporting part of the weight of a movable mass by magnetic force. 4 less.

It has the effect of improving the vibration reduction effect of vibration-side equipment and extending the life of bearings, etc. that support the weight of the movable mass.

[Brief explanation of drawings]

Fig. 1 is a diagram showing one embodiment of this invention, Fig. 2 is a diagram showing another embodiment of this invention, and Fig. 3 is a diagram showing a conventional swing! ! I]
? Figure 4 shows the principle of the til control device, Figure 4 shows the principle of the vibrating side tilting device, Figure 5 shows the tilt force characteristics when there is no friction, and Figure 6 shows the characteristics when shore shaking force is considered. It is a figure showing controllability. In the figure, ill is a movable mass, (2) is a spring, (31 is an actuator, (4) is a fitted body, (5) is an acceleration, (
61 is a controller. Note that the same reference numerals in Figure 9 indicate the same or corresponding parts.

Claims (2)

[Claims] (1) Vibration detection means for detecting the vibration of a vibrating body that vibrates in response to an external force, a movable mass that moves back and forth in the vibration direction of the vibrating body, and a movable mass that is attached to the movable mass and the vibrating body and that acts on the movable mass. a magnet that generates magnetic force in a direction; an actuator fixed to the vibrating body that drives the movable mass; and controlling the actuator so that it can output a braking force proportional to the vibration speed of the vibrating body detected by the vibration detection means. A vibration control device comprising: a controller for controlling vibrations; (2) The vibration control device according to claim (1), characterized in that when the movable mass and the magnets attached to the vibrating body exert an attractive force on each other, one side is made of a magnetic material.