JPH0156205B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a vibration control device for reducing low frequency vibrations of traffic bridges such as road bridges and railway bridges.

Generally, a traffic bridge has a structure in which a bridge 1 is supported at both ends by piers 2, as shown in FIG. In this type of traffic bridge, as the number of vehicles running on the traffic bridge increases and the traveling speed increases, excessive external force is applied to the traffic bridge, and furthermore, as the distance between the piers increases, Coupled with the decrease in bending rigidity of bridges, extremely large vibrations are induced in traffic bridges. Depending on the situation, vibrations from bridges can generate air pressure vibrations in the atmosphere, which become low-frequency sound pressure waves, usually below 30 Hz, that propagate to the surrounding area, and manifest as so-called low-frequency pollution. There are cases. Furthermore, vibration propagation to the ground can cause nearby buildings, houses, etc. to loosen, causing shutters, glass doors, etc. to rattle, or the vibrations of the house itself can cause great discomfort to residents, resulting in vibration pollution.

Conventionally, countermeasures against the vibrations of traffic road bridges, which are the mechanism that generates noise and vibration pollution, include increasing the rigidity of bridges and piers by reinforcing them, or adding auxiliary piers to increase the support points of bridges. Efforts will be made to reduce the discomfort caused to residents by improving and changing the vibration characteristics of traffic bridges, and by installing soundproof walls, covers, etc. to insulate the low-frequency sound pressure itself that propagates into the atmosphere. was.

However, the reality is that these conventional measures have not achieved sufficient vibration and noise reduction effects.In addition, installing auxiliary piers on existing traffic bridges, reinforcing bridges, etc. requires the use of land space. However, it was often subject to physical constraints, and had drawbacks such as construction problems.

The present invention is fundamentally different from the conventional countermeasures mentioned above in terms of vibration reduction principles, and a generator motor is attached to a target structure (referred to as the target object) such as a traffic road bridge to reduce the vibration of the target object. Energy is absorbed and converted into electrical energy in a generator, thereby reducing the vibration of the object and utilizing the electrical energy, resulting in an energy saving effect. The purpose is to provide a vibration control device.

The vibration reduction principle of the present invention is that when forced force (external force) and control force act on the object, m is the mode mass of the object, c is the damping coefficient, k is the spring constant of the object, F is the external force, and U is the control force and x is the displacement of the object, the equation of motion mx¨+cx〓+kx=F−U
Assume that

Here, for example, by detecting the vibrational acceleration x¨ of the object, converting it into signals of velocity x and displacement x, and then applying these values to the above equation of motion, we can find an optimal way to attenuate the external force F. control force U
(i.e., a control force proportional to the vibration speed of the object)
I am getting .

FIG. 2 shows an embodiment of the invention. In Figure 2, 1 is the bridge, 2 is the pier, 3 is the arm attached to the bridge 1, 4 is the motor attached to the bridge 1, 5 is the connecting rod between the arm 3 and the motor 4, and 6 is attached to the rotating shaft 12 of the motor. Shows a vertical disk. FIG. 3 is a perspective view of the motor 4, connecting rod 5, and lever disk 6. The connecting rod 5 and the lever disk 6 are a conversion mechanism that converts the vibration moment into rotational torque of the rotating shaft 12.

4 and 5 show the cross-sectional structure of the motor 5. FIG.
FIG. 6 is a perspective view showing how the rotor 7 in the motor 5 is connected.

In FIG. 4, 8 is a coil, 9 is a magnetic pole surrounding this coil 8, and in FIG. 5, the coil 8 is arranged so as to surround the magnetic pole 9.

In FIG. 2, numeral 11 is a detector attached to the bridge 1 that detects the vibration speed of the bridge 1, and the detected vibration speed signal is transmitted via a signal line 15 as shown in the block diagram of FIG. 7, which will be described later. The signal is supplied to the arithmetic control circuit 13.

In one embodiment of the present invention, the vertical deflection of the bridge 1 is suppressed by the moment generated by the lateral action of the arms 3, and the expansion and contraction between the two arms is achieved by the motor 4. This is obtained by combining the rotational force (specifically, the swinging force) generated via the lever disk 6. The motor has magnetic poles 9
As shown in FIG. 4, an arbitrary control force U can be obtained by applying an arbitrary current to the coil 8 via an arithmetic circuit 13, which will be described later.

Further, the change in distance between the arms is within a range of several mm, and if the diameter of the lever disk 6 is increased to a certain extent, the rotation angle θ can be minute. In that case, compared to the pole pitch angle θp in Fig. 4, the width θc of the coil group for one pole is
If we keep θp−θc slightly smaller, that is, θp−θc
>2θ, the coil 8a is always below the N pole,
The coil 8b is always under the south pole, and each coil does not move beyond one magnetic pole, eliminating the need for commutation (rectification) of the current accompanying rotation. Therefore, the rotor lead can be realized by the flexible coil 10 shown in FIG. 6, and a slip-ring commutator is not necessary.

Here, the vibration control system will be explained.

In FIG. 7, a bridge vibration velocity signal detected by a detector 11 is supplied to an arithmetic control circuit 13. km is the spring constant of the bridge 1, and k ₂ is the spring constant of the arm. In this control circuit 13, vibration (displacement, x) and vibration acceleration are calculated from the vibration velocity signal. On the other hand, if the length of the coil 8 is 1 and the magnetic density is B, the predetermined external force is determined as F from the above equation of motion, so the control force U required to attenuate the external force F can be calculated by calculation. You can ask for it. Therefore, the current i required to output this control force U can be determined by i=U/(B1). Here, B is the magnetic flux density in the motor, and 1 is the coil length of the motor. The control force thus obtained is expressed as rotational torque of the motor 4, and is applied to the bridge 1 via the connecting rod 5 in a phase opposite to that of the vibration, so that the vibration is attenuated.

In the above explanation, an embodiment has been described in which the present invention is used for vibration control of a bridge, but the present invention can also be used for vibration control of towers, buildings, antennas, etc. as target structures.

As described above, according to the present invention, a generator-motor device is installed that absorbs and converts the vibration energy of an object into electrical energy in a generator, and this energy is used for vibration control by reducing the vibration of the object. By doing so, the effect of energy saving can be obtained.

[Brief explanation of drawings]

Fig. 1 is a schematic configuration diagram of a traffic road bridge, Fig. 2 is a configuration diagram showing an embodiment of the present invention, Fig. 3 is a configuration diagram of a motor, Figs. 4 and 5 are sectional views of the motor, and Fig. 6 The figure is a structural diagram showing the rotor of the motor, and FIG. 7 is a block diagram for explaining the present invention. In the figure, 1 is a bridge, 2 is a pier, 3 is an arm, 4 is a motor, 5 is a connecting rod, 6 is a lever disk, 7 is a rotor, 8 is a coil, 9 is a magnetic pole, and 10 is a flexible coil. In the figures, the same reference numerals indicate the same or equivalent parts.

Claims (1)

[Claims] 1. A target structure that vibrates when subjected to an external force, a detector that detects the vibration, a motor that is fixed to the target structure and has magnetic poles and a coil facing each other, and a motor that is fixed to the target structure and has magnetic poles and coils facing each other, and A rotating shaft of the attached motor, a conversion mechanism that converts the force generated by the vibration into rotational torque of the rotating shaft, and a control force for damping the vibration based on the detection signal of the detector. and a calculation control circuit that supplies a predetermined current to the coil to generate a rotational torque.