JPH0214514B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a vibration control device that controls vibration by moving a movable mass using a feed screw.

BACKGROUND ART In recent years, architectural structures such as buildings have become increasingly taller and larger in scale, but due to the sophistication of design methods, they are becoming more flexible and lighter. Therefore, disturbances such as strong winds and earthquakes cause vibrations as shown by the dotted lines in Figure 1. Such vibrations cause discomfort to building occupants, and can be especially severe during earthquakes. May cause large vibrations. A vibration control device shown in FIG. 2 has been conventionally used to solve such problems. This vibration control device is installed on a floor near the roof of a high-rise building 1 shown in FIG.
A feed screw 4 that reciprocates through a nut 3 fixed to the end thereof, a drive motor 5 that rotates the feed screw 4, a controller 6 that applies a control current to the drive motor 5, and a high-rise building 1. It consisted of a vibration sensor 7 that detects vibrations and causes the controller 6 to generate a corresponding control current, and a spring (not shown) interposed between the movable mass 2 and the high-rise building 1.

In the conventional vibration control device having such a configuration, when the high-rise building 1, which is a vibrating object, attempts to vibrate in the vibration direction shown in the figure, the vibration sensor 7 detects the vibration. A control current corresponding to this detection signal is applied to the drive motor 5 by the controller 6, and acts on the movable mass 2 via the feed screw 4 and the nut 3 as a control force proportional to the vibration speed. was movable in the opposite direction to the vibration direction, and its inertial force suppressed the vibration.

However, in the conventional vibration control device, each time the direction of action of the control force is reversed, there is a backlash between the feed screw 4 and the nut 3, so that the rotational movement of the feed screw 4 and the reciprocating movement of the movable mass 2 are However, due to this backlash, the vibration control becomes unstable in some cases.

The present invention has been made to eliminate the above-mentioned drawbacks, and provides a vibration control device that is stable and has high control effects by offsetting backlash. An embodiment of the present invention will be described below with reference to the drawings.

FIG. 3 shows a vibration control device composed of two feed screws, etc., and related devices that need to be identified are given subscripts A and B. The drive motor 5 is fixed to a mount 16, and a drive gear 13 is attached to its output shaft 9 using a key or the like to prevent it from slipping.
The driving gear 13 has two driven gears 14A and 14B.
are in mesh with each other, and the respective gear shafts 15A, 1
The shaft ends of feed screws 4A and 4B having the same lead direction and the same pitch are attached to the feed screw 5B using a key or the like to prevent them from slipping. Gear shaft 15
Bearings 10A, 10 are fixed to the mount 8 near the ends A and 15B are attached to the feed screws 4A and 4B using a key etc. so as not to slip.
B is rotatably held, and feed screws 4A,
Nuts 3A and 3B are screwed onto 4B. These nuts 3A and 3B are attached to the feed screws 4A and 3B at the time of assembly.
The above two feed screws are moved in the axial direction of the feed screws so as to cancel out the backlashes between the nuts 4B and the nuts 3A and 3B, and the backlashes between the drive gear 13 and the driven gears 14A and 14B. Nut 3 to create preload
A and 3B are fixed to the movable mass 2 by applying a predetermined amount of initial rotational force to them. Therefore, the shafts of the two feed screws 4A and 4B are driven by the motor 5.
A movable mass 2 having a linear bearing 12 at its lower end assembled so as to be able to move smoothly on a rail 11 by rotating it in the same direction by a movable mass 2.
can smoothly reciprocate from front to back.

Next, the operation of the vibration control device according to the present invention will be explained. When the high-rise building 1 attempts to vibrate in the vibration direction shown in the figure, the vibration sensor 7 detects the signal and sends an acceleration signal to the controller 6. The controller 6 receives this signal, integrates it, converts it into a speed signal, and then sends a current corresponding to the speed signal to the drive motor 5.
The drive motor 5 generates a torque T corresponding to the vibration speed, and transmits the torque T/2 to each of the driven gears 14A and 14B via the drive gear 13.
As a result, the vibration directions of the feed screws 4A, 4B, which are attached to the gear shafts of the driven gears 14A, 14B using a key or the like to prevent them from slipping, and the nuts 3A, 3B screwed thereto, are determined in the same direction. U/2=2π×T/2/L L: The control force for the lead length of the feed screw is transmitted in the opposite direction. Backlashes interposed between the feed screws 4A, 4B and the nuts 3A, 3B, respectively, as well as the drive gear 13 and the driven gears 14A, 1
Since the backlashes between the nuts 3A and 4B are canceled out in advance, if the direction of torque action of the drive motor 5 is reversed, the control force applied to the nuts 3A and 3B is also reversed. Therefore, Natsuto 3A, 3
The movable mass 2 to which B is fixed has nuts 3A,
Since it moves in unison with 3B, the vibrations of the high-rise building 1 are attenuated, and stable and highly effective vibration control is realized.

The equation of motion at this time is expressed by the following formula.

_{m 1} X¨ ₁ + _{k 1 X 1} + _{k 2 ( X 2 −} CX〓 ₁ ...(3) Here m ₁ ; Modal mass of the high-rise building k ₁ ; Spring constant of the high-rise building m ₂ ; Mass of the movable mass k ₂ ; Spring constant between the movable mass and the high-rise building X ₁ , X〓 ₁ , X¨ ₁ ; Displacement, _velocity , and acceleration _of the high-rise building. X ₂ , Although an example in which the vibration control device of the present invention is applied to a high-rise building has been described, it goes without saying that it can also be applied to other vibrating objects, such as ordinary houses, towers, bridges, etc.

[Brief explanation of drawings]

Fig. 1 is a perspective view of a high-rise building, Fig. 2 is a diagram showing a conventional example of a vibration control device, and Fig. 3 is a configuration diagram of a vibration control device according to the present invention.
5 is a feed screw, 5 is a drive motor, 6 is a controller, and 7 is a vibration sensor. In addition, the same reference numerals are given to the same or corresponding parts in the figures.

Claims (1)

[Claims] 1. A vibration sensor that detects vibration, a controller that receives a signal detected by this vibration sensor and flows a corresponding current, a drive motor that receives a control current from this controller and rotates, and a gear connected to this drive motor. In a vibration control device consisting of two feed screws that are driven by the two feed screws, and a movable mass that is fixed to a nut screwed onto each of the two feed screws and reciprocates in the axial direction of the feed screws, the two feed screws are is assembled to a movable mass by applying a predetermined amount of initial rotational force to each nut so as to generate preload in the axial direction of the feed screw.