JPH04157234A - Vibration damper - Google Patents

Abstract

PURPOSE:To prevent high frequency vibration from being transmitted to a vibrator so as not to give any unpleasant feeling to residents by interposing a vibration isolating member capable of absorbing vibration generated in a device main body between the bottom portion of the device main body and the upper surface of the vibrator. CONSTITUTION:A plurality of vibration isolating members 12 (121-12n) are interposed between the lower surface 1b of a main body 1a and the upper surface of a fixing recess portion 2b, for absorbing vibration generated in a vibration damper 1. Laminated rubber members 13, 14 are interposed between the side surfaces 1c, 1d of the main body 1a and the inner side walls of the fixing recess portion 2b, respectively. The laminated rubber members 13, 14 are adapted to transmit force in the direction of displacement of an additional mass 6 to the inner walls of the fixing recess portion 2b by the use of rigidity thereof, wherein relative displacement with respect to the fixing recess portion 2b can be allowed when the main body 1a is displaced vertically and vertical vibration can be absorbed by shearing force. Therefore, vibration of a vibrator can be damped, and vibration generated in a vibration damper can be prevented from being transmitted to the vibrator.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a vibration damping device, and more particularly to a vibration damping device configured so that vibrations of the damping device are not transmitted to a vibrating body.

2. Description of the Related Art For example, in a structure such as a building, when vibration occurs due to an earthquake or wind pressure, a vibration damping device is provided on the roof of the building or the like to damp the vibration.

This type of vibration damping device mainly employs a configuration in which an additional mass having a predetermined weight corresponding to the mass of the building is displaced in accordance with the vibration state of the building to damp the vibrations generated in the building. .

The additional mass is slidably provided on the main body of the device fixed on the roof of the building, and is moved in a direction to damp vibrations upon transmission of the driving force of an actuator such as a servo motor.

Problems to be Solved by the Invention However, in conventional vibration damping devices, the main body of the device is directly fixed to the roof of a building, so an actuator for moving the additional mass or a transmission mechanism for transmitting driving force to the additional mass is required. The problem is that the high-frequency vibrations generated by the building are difficult to transmit to the building, causing discomfort to the occupants of the building.

Therefore, an object of the present invention is to provide a vibration damping device that solves the above problems.

Means for Solving the Problems The present invention provides an additional mass having a predetermined weight in a slidable manner within a device main body installed on a vibrating body, and the vibration of the vibrating body is reduced by displacement of the additional mass. A vibration damping device for damping vibrations, comprising: a vibration isolating member provided between a bottom of the device main body and a top surface of the vibrating body to absorb vibrations from the device main body; provided between a side surface of the device main body and a side surface of the vibrating body opposite to the side surface so as to allow displacement in a direction perpendicular to the direction and transmit inertia force due to displacement of the additional mass to the vibrating body. and a transmission member.

By blocking vibrations from the operating device main body with the vibration isolating member, further allowing displacement of the additional mass of the device main body in a direction perpendicular to the sliding direction, and transmitting the inertia force due to the displacement of the additional mass to the vibrating body, This damps the vibration of the vibrating body and prevents the vibration generated by the vibration damping device from being transmitted to the vibrating body.

Embodiment FIGS. 1 and 2 show an embodiment of a vibration damping device according to the present invention.

In both figures, a vibration damping device 1 is installed on the roof 2a of a building (vibrating body) 2. This building 2 has 12 floors and is constructed like a tower structure with a smaller side depth than the front width. For example, each of the 3rd, 6th, 9th, and 12th floors of the building 2 is provided with a vibration state detection sensor 3 (3, 3, 3,...) that detects the state of vibration of the floor surface, pillars, etc. An earthquake sensor 4 for detecting earthquakes is buried in the basement of the building 2. Further, a wind speed anemometer 5 is installed on the roof of the building 2.

The vibration state detection sensor 3 may be a displacement sensor that detects displacement when the building 2 vibrates, or may be a speed sensor that detects the speed when vibration occurs, or an acceleration sensor that detects acceleration.

Building 2 shown in Figure 1 is located in the narrow direction (X direction) where, for example, an earthquake occurs or wind pressure acts.
The structure is prone to vibration. Therefore, the second
The vibration damping device 1 shown in the figure is installed so as to control vibrations occurring in the X direction. This control device 1 is generally configured such that a ball screw mechanism 7 is provided on an additional mass 6, and the rotational driving force of an AC servo motor 8 is transmitted to the ball screw mechanism 7 to cause the additional mass 6 to slide in the X direction. .

In Figure 1, when building 2 vibrates due to an earthquake,
Each vibration state detection sensor 3. 34 and the detection signals from the earthquake sensor 4 are input to the A/D converter 9 and converted into digital signals. The arithmetic device 1o, into which the signal from the A/D converter 9 is input, receives the measurement signal from the wind speed anemometer 5 and the A/D converter 9.
Rotation detector built into C servo motor 8 (not shown)
The vibration state is calculated based on the signals from the vibration state detection sensors 3I to 34, the earthquake sensor 4, the wind speed anemometer 5, etc., and based on the calculation results, the direction of displacement of the additional mass 6, A program for calculating displacement amount, displacement speed, acceleration, etc. is input. Then, a servo controller 11 connected within the arithmetic device 10 supplies a drive current to the AC servo motor 8 in response to a command from the arithmetic device 10.

Here, the control device 1, which is the main part of the present invention, will be explained in detail.

The device main body (hereinafter simply referred to as main body) Ia of the control device 1 is installed in a concrete mounting recess 2b provided on the roof 2a of the building 2, as shown in FIGS. 2 and 3.

Furthermore, a plurality of vibration isolating members 12 (only three are shown in FIG. 2) are provided between the lower surface 1b of the main body 1a and the upper surface of the mounting recess 2b.
~12n) are present. The vibration isolating member 12 is made of, for example, rubber with increased elasticity to absorb vibrations generated by the vibration damping device 1, and the upper and lower base portions are the main body 1a.

It is fixed in the mounting recess 2b.

Furthermore, a laminated rubber member (transmission member) 13, 14 is interposed between the side surfaces 1c, ld of the main body 1a and the inner wall of the side surface of the mounting recess 2b.

The laminated rubber members 13 and 14 are constructed by alternately stacking a plurality of metal plates whose surfaces are coated with rubber and disc-shaped rubber plates, and hold them together. . The laminated rubber members 13 and 14 have a structure that damps vibrations by their elastic shear force, and are oriented vertically to allow the main body 1a to be displaced upwardly and downwardly, with bases at both ends facing the sides of the main body 1a. 1c, 1d and the inner wall of the mounting recess 2b.

That is, the laminated rubber members 13 and 14 transmit the force in the direction in which the additional mass 6 is displaced to the inner wall of the mounting recess 2b due to their rigidity, but when the main body 1a is displaced upward or downward, the force in the direction of displacement of the additional mass 6 is transmitted to the inner wall of the mounting recess 2b.
The shearing force absorbs vibrations in the upward and downward directions.

A recess 1e into which the additional mass 6 is displaceably inserted is formed inside the main body 1a. As shown in FIG. 3, the additional mass 6 has a T-shaped cross section, and its lower part 6a is inserted into the recess 1e, and the arms 6b and 6c on both sides face the upper surface 1f of the periphery of the recess 1e. It's sticking out like that. Linear bearings 15a and 15b are provided between the arm portions 6b and 6c of the additional mass 6 and the upper surface 1f of the main body 1a.

Therefore, the weight of the additional mass 6 is equal to the weight of the linear bearings 1 on both sides.
5a and 15b, the weight of the additional mass 6 is hardly applied to the aforementioned ball mechanism 7.

Further, the AC servo motor 8 is fixed in the recess 1e of the main body 1a, and its output shaft 8a is coupled to a male screw 17 screwed into the ball screw mechanism 7 via a coupling 16 as shown in FIG. has been done.

One end of the male thread 17 is supported by a first bearing part 18 fixed to the bottom surface 1g of the recess 1e, and the other end, which extends through the additional mass 6, is supported by a second bearing part 19.

As shown in FIG. 4, the first bearing section 18 includes a housing 18a fixed to the bottom surface 1g of the main body 1a, and a housing 18a fixed to the bottom surface 1g of the main body 1a.
Angular contact ball bearing 20.2 that fits inside 8a
1, and a stopper 18b that holds an angular contact ball bearing 20.21.

Inner ring 20a of angular contact ball bearing 20.21,
21a fits into the fitting portion 17a of the male thread 17, and the outer ring 20
b, 21b fit into the hole 18a1 of the hanging 18a. In addition, the inner ring 20a.

21a is fixed to the male thread 17 between the stepped portion 17b of the male thread 17 and the washer 22 by tightening a nut 23 that is screwed into the threaded portion 17c of the male thread I7.

The angular contact ball bearings 20 and 21 have a structure that can withstand loads not only in the radial direction but also in the thrust direction (X direction). That is, in FIG. 4, the angular contact ball bearing 2° on the left side can receive a load in the X direction, and the angular contact ball bearing 21 on the right side can receive a load in the X direction.
It can bear loads in one direction. This is because when the additional mass 6 is driven in the X direction, a force in the opposite direction to the moving direction of the additional mass 6 acts on the screw 17.

The second bearing part 19 may have the same configuration as the first bearing part 18, or the end of the male thread 17 may be supported by a normal radial bearing that does not receive thrust loads. .

As shown in FIG. 5, the ball screw mechanism 7 provided on the additional mass 6 has a nut 7a held on the mounting portion 6d of the additional mass 6, a spiral groove 7a of the nut 7a, and a spiral groove 17d of the male thread 17. It consists of a ball 7b that fits into the space. In the ball screw mechanism 7, the rotation of the male screw 17 is transmitted to the nut 7a via the rolling friction of the ball 7b, so the transmission efficiency is higher than other transmission means, and the rotational driving force of the AC servo motor 8 is transmitted with less loss. can be transmitted to the additional mass 6 in the state.

Here, the operation of the vibration damping device 1 having the above configuration will be explained.

For example, when the building 2 vibrates in the X direction due to an earthquake or the action of wind pressure, vibrations with different amounts of displacement and acceleration occur on each floor of the building 2. Such vibrations of the building 2 are detected by each of the vibration state detection sensors 3I to 34, and are further detected by the earthquake sensor 4. Based on the signal from the wind speed anemometer 5, the displacement direction, displacement amount, speed, acceleration, etc. of the additional mass 6 are calculated by the calculation device IO. The servo controller 11 supplies a drive current to the AC servo motor 8 according to a command from the arithmetic device 10 .

Since the AC servo motor 8 is constantly supplied with a weak current and is in a standby state, the AC servo motor 8 rotates the male screw 17 at the same time as the drive current is supplied. Note that the energy consumption due to the weak current is small, so there is little waste.

When the male screw 17 rotates, the rotational force is transmitted to the pole screw mechanism 7, and as described above, the additional mass 6
is converted into a displacement of Although the additional mass 6 has a considerable mass corresponding to the mass of the building 2, the linear bearing 14.
15, the load upon starting is reduced.

Therefore, the additional mass 6 can slide in the X direction with good responsiveness to the drive current supplied from the servo controller 11. As a result, vibrations generated in the building 2 are suppressed by the displacement of the additional mass 6. Moreover, the vibration damping device 1
In this case, since the additional mass 6 can be driven with a relatively light force, even high frequency vibrations can be suppressed well.

In this way, when the additional mass 6 slides in the X direction, vibrations are likely to occur in the AC servo motor 8 that drives the additional mass 6 and the drive transmission mechanism such as the pole screw mechanism 7, and these vibrations are transmitted to the main body 1a. be done. In this way, the main body 1a
The vibration generated from the main body 1a is a high-frequency vibration of about 50 Hz or more, whereas the vibration frequency of the building 2, which is damped by the additional mass 6, is about 10 Hz at maximum, which is very low compared to the frequency from the device body 1a. It is the frequency of vibration. The laminated rubber members 13 and 14 are provided so as to utilize this difference in vibration frequency to absorb only high frequency vibrations.

That is, the inertial force in the X direction when the additional mass 6 slides is transmitted to the inner wall of the mounting recess 2b via the laminated members 13, 14, and the same vibration damping effect as in the conventional case can be obtained. however,
High frequency vibrations generated by the AC servo motor 8, ball screw mechanism 7, etc. are transmitted to the vibration isolating member 12 and the laminated rubber member 13.1.
It is absorbed by the elasticity of 4.

For example, when upward and downward vibrations occur in the main body 1a, the laminated members 13 and 14 allow the upward and downward movements of the main body 1a, and the vertical vibrations are caused by the elasticity of the vibration isolating member 12 and the laminated rubber member 13.
Absorbed by a shear force of 14. Furthermore, even if vibration occurs in a direction perpendicular to the X direction other than the upward and downward directions, it is absorbed in the same way.

Therefore, vibrations from the main body 1a are not transmitted to the building 2,
When moving the additional mass 6, the occupants of the building 2 will not feel uncomfortable.

In the above embodiment, a rubber vibration isolating member is provided at the bottom of the main body 1a, but the present invention is not limited to this, and it is of course possible to provide a buffer member such as an air damper.

Further, in the above embodiment, the laminated rubber members 13, 14 are provided on the side surfaces 1c, ld of the main body 1a, but the invention is not limited to this, and the laminated rubber members 13, 14 act as a rigid body in the sliding direction of the additional mass 6, and are perpendicular to the sliding direction. Other members may be used as long as they are configured to allow movement of the main body 1a in this direction.

Further, in the above embodiment, the additional mass 6 is moved via the ball screw mechanism 7, but it goes without saying that the additional mass 6 may be moved using another drive mechanism.

Effects of the Invention As described above, the vibration damping device of the present invention suppresses vibrations of a vibrating body by sliding the additional mass, for example, when high-frequency vibrations generated in the drive system that drives the additional mass are transmitted to the main body of the device. Even if the high-frequency vibrations occur, the high-frequency vibrations can be absorbed by the vibration isolating member provided between the device main body and the vibrating body and can be prevented from being transmitted to the vibrating body, thereby eliminating the discomfort of the occupant. Furthermore, since the inertia force due to the sliding of the additional mass is transmitted to the vibrating body via the transmission member, the vibration of the vibrating body can be effectively suppressed.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram showing a state in which an embodiment of the vibration damping device according to the present invention is installed in a building, FIG. 2 is a front view of the vibration damping device,
FIG. 3 is a longitudinal sectional view of the vibration damping device, FIG. 4 is a longitudinal sectional view of a bearing portion that supports a male screw, and FIG. 5 is a longitudinal sectional view of a pole screw mechanism provided on the additional mass. 1... Vibration damping device, 2... Building, 3. ~34... Vibration state detection sensor, 4... Earthquake sensor, 6... Additional mass, 7... Ball screw mechanism, 8... AC servo motor, 11... Servo controller, 12. ... Vibration isolation member, 13.14... Laminated rubber member, 15a, 15b
...Linear bearing. Patent applicant Obayashi Himo Co., Ltd.

Claims (1)

[Scope of Claims] A vibration control device in which an additional mass having a predetermined weight is slidably provided in a device main body installed on a vibrating body, and vibrations of the vibrating body are suppressed by displacement of the additional mass. In the vibration device, a vibration isolating member is provided between the bottom of the device main body and the top surface of the vibrating body and absorbs vibrations from the device main body, and the device main body is oriented perpendicular to the sliding direction of the additional mass. a transmission member provided between a side surface of the device main body and a side surface of the vibrating body opposite to the side surface so as to allow the additional mass to be displaced and to transmit the inertia force due to the displacement of the additional mass to the vibrating body; A vibration damping device comprising: