JP3227466B2 - Damping device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vibration damping device, and more particularly to a vibration damping device configured to reduce vibration of a vibrating body due to displacement of an additional mass.

[0002]

[Prior art]

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

[0003] This type of vibration damping device adopts a configuration in which an additional mass having a predetermined weight mainly corresponding to the mass of a building is displaced in accordance with the vibration state of the building to dampen vibration generated in the building. Have been.

As a conventional vibration damping device, for example, an additional mass is slidably supported by a linear bearing or the like, and a transmission mechanism such as a ball screw for adjusting to the additional mass is driven by a motor or a hydraulic actuator so that the additional mass is horizontal. Devices configured to be reciprocated in one direction are contemplated.

[0005]

[Problems to be solved by the invention]

In the above vibration damping device, the additional mass is set so as to always reciprocate with the stroke center of the ball screw as a reference point. That is, the additional mass is stationary at this reference point when there is no vibration, slides horizontally around this reference point when vibration occurs, and returns to the reference point again when the vibration stops. It is configured.

[0006] In such a control device, when the additional mass is subjected to the vibration control, if a minute vibration is performed for a long time or a state where the additional mass is stopped for a long time, a load is always applied to the same place, and the additional mass is reduced. The problem is that the bearings supported may cause fatigue damage due to fretting, or the ball screw is always screwed into the additional mass at the same location, which is likely to wear out, which may cause problems in the durability and reliability of the vibration damping device. is there.

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

[Means for Solving the Problems]

According to the first aspect of the present invention, there is provided an additional mass having a predetermined weight and being displaceably provided, a driving unit for reciprocatingly driving the additional mass around a reference point in a displaceable range, and the driving unit. In the vibration damping device, the control means includes a reference point moving means for moving the reference point in a long cycle.

Further, the invention according to claim 2 is characterized in that the reference point moving means always moves the reference point in a long cycle.

[0009]

[Action]

Therefore, according to the first aspect of the present invention, since the control means is provided with the reference point moving means for moving the reference point in a long cycle, fatigue damage due to fretting of the bearing to which the load of the additional mass acts and the drive mechanism are provided. Can be prevented, and the durability and reliability of the device can be improved.

According to the second aspect of the present invention, since the reference point is always moved in a long cycle, the frictional resistance at the time of startup such as an earthquake becomes not a static friction but a dynamic friction, and the resistance due to the friction is reduced and the additional mass is reduced. Can be started smoothly, and responsiveness when vibration occurs can be improved.

[0011]

【Example】

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 a roof 2 a of a building 2. This building 2 has 12 floors and is constructed like a tower structure in which the depth of the side is smaller than the width of the front. A vibration state detection sensor 3 for detecting the state of vibration of the floor surface, pillars, or the like is provided on each of the floors 3, 6, 9, 12 of the building 2, for example.
(3 ₁ , 3 ₂ , 3 ₃ ...) Are provided, and an earthquake sensor 4 for detecting an earthquake is buried under the building 2. An anemometer 5 is installed on the roof of the building 2.

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

The building 2 shown in FIG. 1 has a structure in which, for example, when an earthquake occurs or when wind pressure acts, vibration is likely to occur in a narrow direction (arrow X direction) with a small depth. For this reason, the vibration damping device 1 shown in FIG. 2 is installed to dampen vibration generated in the direction of the arrow X. The vibration damping device 1 has a configuration in which a ball screw mechanism 7 is provided on the additional mass 6 and the rotational driving force of the AC servomotor 8 is transmitted to the ball screw mechanism 7 to slide the additional mass 6 in the direction of the arrow X. ing.

In FIG. 1, when a building 2 vibrates due to an earthquake,
Each vibrating state detection sensor 3 ₁ to 3 ₄ and seismic sensors 4, the detection signal from the wind speed the wind direction meter 5 is inputted to the control unit 9 vibrated, vibration control circuit 9 calculates the vibration state by these signals, the Based on the calculation result, the displacement direction, displacement amount,
Calculate the displacement speed, acceleration, etc.

As shown in FIGS. 2 and 3, the main body 1 a of the vibration damping device has a fixing portion 1 b protruding from both sides from the bottom portion, and is fixed to the roof 2 a by fixing bolts 12. A concave portion 13 into which the additional mass 6 is displaceably inserted is formed in the upper surface 1c of the main body 1a. The additional mass 6 has a T-shaped cross-sectional shape as shown in FIG. 3, and the lower portion 6a is inserted into the recess 13 and the arms 6b and 6c on both sides face the upper surface 1c of the peripheral edge of the recess 13. Overhanging. The arms 6b and 6c of the additional mass 6 and the main body 1
Linear bearings 14, 15 are provided between the upper surface 1c and the upper surface 1c.

The AC servomotor 8 is fixed to the upper surface 1c of the main body 1, and its output shaft 8a has a male screw 17 screwed into the ball screw mechanism 7 via the coupling 16 as shown in FIG. Is joined to. One end of the male screw 17 is supported by a first bearing portion 18 fixed to the upper surface 1c, and the other end extending through the additional mass 6 is supported by a second bearing portion 19.

Note that the additional mass 6 has an intermediate device of a male screw 17 as a reference point, and reciprocates in the X direction around this reference point.

As shown in FIG. 4, the first bearing portion 18 is provided on the upper surface 1c of the main body 1a.
, Fixed to the housing 18a, angular contact ball bearings 20, 21 fitted in the housing 18a, and a stopper 18b for holding the angular contact ball bearings 20, 21.

The inner rings 20a, 21a of the angular contact ball bearings 20, 21 are fitted to the fitting portion 17a of the male screw 17, and the outer rings 20b, 21b are
It fitted in 18a of the holes 18 in the _al. The inner races 20a and 21a are fixed to the male screw 17 by tightening a nut 23 which is fitted to the threaded portion 17c of the male screw 17 in relation to the step 17b of the male screw 17 and the washer 22.

The angular contact ball bearings 20 and 21 have a structure capable of withstanding loads not only in the radial direction but also in the thrust direction (the direction of arrow X).

As shown in FIG. 5, the ball screw mechanism 7 provided on the additional mass 6 is held by the mounting portion 6 d of
And 7a, the more the ball 7b is fitted into the space between the spiral groove 17d of the spiral groove 7 _al Tooneji 17 of the female screw portion 7a. Since the rotation of the male screw 17 is transmitted to the female thread portion 7a via the rolling friction of the ball 7b, the transmission efficiency of the ball screw mechanism 7 is higher than that of other transmission means, and the rotational driving force of the AC servomotor 8 is transmitted to the ball screw mechanism 7 by a transmission loss. Can be transmitted to the additional mass 6 in a state where the weight is small.

Returning to FIG. 2, the description will be continued. The other end of the output shaft 8a of the AC servomotor 8 has an electromagnetic brake mechanism 24 fixed to the upper surface 1c.
Is inserted inside. When the power supply is lost due to a power failure due to an earthquake, etc.
The output shaft 8a is automatically braked. The male screw 17 cannot rotate due to the braking operation of the electromagnetic brake mechanism 24. Therefore, the additional mass 6 is stopped and is prevented from operating in an uncontrollable state.

Reference numeral 30 denotes a position detecting mechanism for detecting the moving position of the additional mass 6, and in this embodiment, a working transformer type displacement meter is used. The position detecting mechanism 30 includes a coil 30a and an iron core 30b inserted in the coil 30a. Coil 30a
Is provided so as to extend in the horizontal direction (X direction) on the second bearing portion 19 while being supported by the bracket 31.

The iron core 30 b has one end inserted into the coil 30 a and the other end supported by a bracket 32 erected from the additional mass 6. Therefore, when the additional mass 6 is driven in the X direction, the relative position between the coil 30a and the iron core 30b changes, and the output voltage of the coil 30a changes accordingly.

As shown in FIG. 2, the vibration control device 9 includes an amplifier 33, an adding circuit 34, an A / D converter 35, an arithmetic device 36, and a servo controller 3.
7, an A / D converter 38 and a waveform generator 39. The waveform generator
39 functions as a reference point moving means and constitutes a main part of the present invention, and generates a sine wave signal having an extremely long cycle (for example, about several hours to several tens of hours) as described later.

Here, the operation of the vibration damping device 1 configured as described above will be described.

For example, due to the occurrence of an earthquake or the action of wind pressure, the building 2
When vibrating in the direction, vibrations of different displacement amounts and accelerations occur on each floor of the building 2. Such, the vibration state is the vibration of the building 2 detecting sensor 3 ₁ to 3 ₄ and seismic sensors 4, is detected by the wind wind pressure meter 5, the detection signal is A / D converter 38
Is input to the arithmetic unit 36 via the. Then, the displacement direction, displacement amount, speed, acceleration, and the like of the additional mass 6 are calculated by the arithmetic unit 36 based on the signal from each sensor. The servo controller 37 supplies a drive current to the AC servomotor 8 according to a command from the arithmetic unit 36.

Since the AC servomotor 8 is always in a standby state with a weak current applied thereto, the AC servomotor 8 rotates the male screw 17 simultaneously with the supply of the drive current. When the male screw 17 rotates, the rotational force is transmitted to the ball screw mechanism 7, and is converted to the displacement of the additional mass 6 efficiently as described above. Although the additional mass 6 has an appropriate mass according to the mass of the building 2, the load at the time of starting is reduced because it is supported by the linear bearings 14 and 15.

Therefore, the additional mass 6 can slide in the direction of the arrow X with good responsiveness to the supply of the drive current from the servo controller 37. Thereby, the vibration generated in the building 2 is damped by the displacement of the additional mass 6.

In the vibration control device 9, the position detection mechanism 30
The output signal fed back from the coil 30a is amplified by the amplifier 33 and input to the adding circuit. Adder circuit 34
Then, the long-period displacement component from the waveform generation circuit 39 and the displacement amount of the additional mass 6 from the reference point are added, and the output signal from the addition circuit 34 is input to the arithmetic unit 36 via the A / D converter 35. Is done. For this reason, the arithmetic unit 36 controls the additional mass 6 by applying an excitation frequency component to the vibration component of the building 2 to control the vibration of the building 2 on the displacement component having a long period.

Conventionally, as shown in FIG. 6A, the additional mass 6 reciprocates in the X direction about the reference point to suppress the vibration of the building 2. Then, when there is no earthquake or wind, the additional mass 6 stops at the reference point position. In the case of a small earthquake or wind, it moves slightly near the reference point.

Therefore, the ball 7 b of the ball screw mechanism 7 is almost fitted to the same position of the male screw 17 and is easily worn, and the load is applied to almost the same position in the first and second bearing portions 18 and 19. Fretting fatigue was likely to occur.

On the other hand, in the vibration damping device 1 of the present invention, as shown in FIG. 6B, a long-period sine wave from the waveform generator 39 is added to the displacement signal a of the additional mass 6 based on the signal from each sensor. The signal b is added by the adding circuit 34, and the combined signal c is added to the arithmetic unit 36.
Is input to As a result, the additional mass 6 slides in the X direction so as to suppress the vibration of the building 2, and the reference point position is gradually moved by the sine wave signal b. The sine wave signal b is a long-period signal as described above, and the additional mass 6 moves with a slow motion that does not hinder the vibration damping operation for damping the vibration of the building 2.

Therefore, even when the building 2 does not vibrate at all, the reference point of the additional mass 6 is gradually moved in the X direction by the sine wave signal b.

As described above, since the reference point of the additional mass 6 always moves little by little, the ball 7 b of the ball screw mechanism 7 and the male screw 17
And the screwing position slightly shifts, so that the screwed portion of the male screw 17 at the reference point can be prevented from being locally worn. Also, the bearings 20, 21 provided in the first and second bearing portions 18, 19 are prevented from being damaged by fretting fatigue.

Further, since the additional mass 6 moves little by little even in the normal state as described above, when the additional mass 6 is activated when damping the vibration of the building 2, the frictional resistance becomes dynamic friction instead of static friction. As a result, the startup of the additional mass becomes smooth, and the response during the vibration control operation can be improved.

The signal generated by the waveform generator 39 may not be a sine wave signal, and may be an intermittent signal at predetermined time intervals instead of a continuous signal. In short, the signal for moving the reference point of the additional mass 6 may be a signal having a long period that does not affect the vibration suppression control.

In FIG. 2, even if the level of the reference point (point 0) adjusting section of the amplifier 33 is electrically varied in a long cycle without using the waveform generator 39, the same effect as in the above embodiment can be obtained. can get.

FIG. 7 shows a modification of the present invention. In the AC servo transmission path in FIG. 7, a rotary encoder (shown by a broken line in FIG. 7) 41 is provided as position detection means directly connected to the output shaft 8a of the motor 8.

The rotary encoder 41 detects the amount of rotation of the male screw 17 connected to the output shaft 8a, and the position of movement of the additional mass 6 can be obtained from the detected amount of rotation pulse. Therefore, the rotation pulse from the rotary encoder 41 is counted by the addition / subtraction counter 42 of the vibration control device 9.

Therefore, the output signal of the added mass 6 and the long-period sine wave signal from the digital waveform generator 46 are added by the adder 43 by the addition / subtraction counter 42, and the signal from the adder 43 is sent to the arithmetic unit 44. Is entered. This is the same as in the previous embodiment
The AC servo 8 is driven and controlled by the servo controller 45, and the additional mass 6 moves in the X direction to suppress vibration. At the same time, the reference point of the additional mass 6 moves in a long cycle by the sine wave signal from the digital waveform generator 46.

In the above embodiment, the rotational driving force of the motor 8 is transmitted to the additional mass 6 via the ball screw mechanism 7.
It goes without saying that the present invention can be applied to a vibration damping device having a transmission mechanism other than the ball screw mechanism 7.

[0044]

【The invention's effect】

As described above, according to the first aspect of the present invention, since the control means is provided with the reference point moving means for moving the reference point in a long cycle, the bearing of the driving means to which the load of the additional mass acts is subjected to fretting fatigue. Damage can be prevented.
Further, since a transmission mechanism such as a ball screw used in the driving means can be prevented from being locally worn, the durability of the device can be improved, and the reliability of the vibration damping operation can be enhanced.

According to the second aspect of the present invention, since the reference point is always moved in a long cycle, the frictional resistance at the time of starting, such as when an earthquake occurs, becomes not dynamic friction but dynamic friction, and the resistance due to friction is reduced and added. The mass can be started smoothly, and the responsiveness at the time of vibration can be improved.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing a state in which an embodiment of a vibration damping device according to the present invention is installed in a building.

FIG. 2 is a diagram illustrating a configuration of a vibration suppression device and a vibration control device.

FIG. 3 is a cross-sectional view of the vibration damping device.

FIG. 4 is a vertical cross-sectional view of a bearing portion for bearing a male screw.

FIG. 5 is a longitudinal sectional view of a ball screw mechanism provided for an additional mass.

6A is a waveform diagram of an input signal to an arithmetic device by a conventional device, and FIG. 6B is a waveform diagram of an input signal to an arithmetic device by the device of the present invention shown in FIG. 2;

FIG. 7 is a block diagram showing a modification of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Vibration suppression device 3 ... Vibration state detection sensor 4 ... Earthquake sensor 5 ... Wind speed anemometer 6 ... Additional mass 7 ... Ball screw mechanism 8 ... AC servomotor 9 ... Vibration control device 14, 15 Linear bearings 17 Male screw 18 First bearing 19 Second bearing 20,21 Angular contact ball bearing 30 Position detector 34 Adder circuit 36 Calculation Equipment 37 Servo controller 39 Waveform generator 41 Rotary encoder 42 Addition / subtraction counter 46 Digital waveform generator.

Claims (2)

(57) [Claims] An additional mass having a predetermined weight and being displaceably provided; a driving means for reciprocatingly driving the additional mass around a reference point in a displaceable range; and a control for controlling the driving means. A damping device comprising: means for moving the reference point in a long cycle in the control means. 2. The vibration damping device according to claim 1, wherein said reference point moving means always moves the reference point in a long cycle.