JP2841487B2 - Structure damping device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention is mounted on the upper part of a structure such as a suspension bridge tower, a super-high-rise building, a tower, a steel tower, or the like, and the vibration or wind load (air force) of these structures is reduced. The present invention relates to a structure damping device used to suppress vibration amplitude due to an earthquake and to attenuate vibration at an early stage.

[Prior Art] Conventionally, as this kind of structure vibration damping device, for example, as shown in FIG. 6, a tank c having a large number of laterally partitioned insides by a wire mesh b is installed at the top of a structure a. A required amount of liquid d such as water is placed in the tank c, and the swing of the structure a is controlled by a sloshing phenomenon caused by the liquid d in the tank c moving right and left while passing through the wire mesh b. Shaking [“Building Tower” (19
Textbook entitled "Technological development of vibration control and seismic isolation structures" at the New Building Structural Technology Seminar at the Japan Building Center Information Exchange Meeting (issued in December 1988) (published by the Japan Building Center in October 1988) Or the seventh
As shown in the figure, a laminated rubber e, which is a multilayer laminated in the vertical direction, is installed on the top of the structure a, and the weight f is supported on the upper end of the laminated rubber e. Has been proposed in which vibration is damped by vibrating a weight f via a laminated rubber e.

[Problems to be Solved by the Invention] However, of the above conventional methods, the liquid d in the tank c
In the example shown in FIG. 6 in which sloshing is performed, (I) Since the liquid d is used as a vibration control weight,
(II) The liquid d moves through the wire mesh b in the tank c, but it is difficult to change the attenuation rate. (III) The natural period of the structure a It is difficult to tune the natural period of the device itself, (IV) the response is poor, and (V) a large stroke is not possible. In the case of the example shown in FIG. 7 in which the weight f is combined, (I) the weight f is supported by the laminated rubber e, so that the mass of the device cannot be increased so much. (II) The damping rate is determined by the laminated rubber. Because
(III) it is difficult to tune the natural period of the device itself to the natural period of the structure a, (IV) the life is short because the laminated rubber e is deteriorated, (V) Large amplitude cannot be obtained.

Therefore, the present invention solves the above-mentioned problems of the conventional system, and attempts to reduce the vibration of the structure by changing the vibration energy given to the structure to the kinetic energy of the weight and efficiently attenuating it. Is what you do.

[Means for Solving the Problems] In order to solve the above problems, the present invention provides a weight having upper and lower surfaces curved in an arc shape so as to perform single string vibration on a top of a structure. An arc-shaped rack extending in the vibration direction is directly provided on the upper surface of the weight, and the input shaft portion of the reduction gear is mounted on a fixed position shaft having a pinion that meshes with the rack. And a damper connected to the output shaft of the speed reducer, and a flywheel provided on the shaft.

In addition, a weight whose upper and lower surfaces are curved in an arc shape so as to be able to perform single string vibration is arranged on the upper part of the structure so as to be swingable via a support roller, and a vibration direction is provided on the upper surface of the weight. A variable drive type rotating device is connected to a fixed position shaft having a pinion that meshes with the rack, and a damper is connected to the variable drive type rotating device.
Further, a configuration in which a flywheel is provided on the shaft may be adopted.

[Operation] When a vibration occurs in a structure, the vibration energy is converted into vibration energy of a weight, and the vibration energy is indirectly transmitted to a damper through a rack, a pinion, a shaft, a reduction gear, or a variable drive type rotating device. It is consumed and the vibration of the structure can be effectively suppressed. Also, even if a deviation between the single string vibration of the weight and the natural period of the structure is likely to occur,
Tuning can be achieved by the action of an on-axis flywheel.

[Example] Hereinafter, an example of the present invention will be described with reference to the drawings.

1 to 3 show an embodiment of the present invention.
A base 2 is provided on the top of a structure 1 that vibrates in response to an external force, and a weight 3 as a vibration damping body having upper and lower surfaces curved in an arc shape so as to perform a pendulum motion is provided on the base 2. 2 is arranged so as to oscillate in a single string in the swinging direction of the structure 1 via the support roller 4 provided on the upper surface 2, thereby forming a spring system by a restoring force using gravity, and at both ends of the side of the weight 3. The vibrating region of the weight 3 is restricted within a range in which the provided projections 5 abut on the left and right buffers 7 on the gantry 6 installed at a position sandwiching the weight 3 in front and rear. An arc-shaped rack 8 is directly provided on the upper surface along the vibration direction, and a shaft 9 is disposed above the rack 8 so as to be orthogonal to the rack 8. And rotatably supported via the shaft 9 and meshed with the rack 8 at an intermediate portion of the shaft 9. As the mounting pinion 11, the vibrational energy of the governor weight 3 rack 8, as transmitted as rotational energy to the shaft 9 via the pinion 11,
Further, one end of the shaft 9 is connected to an input shaft of a speed reducer 13 installed on another stand 12, and a lever 14 that protrudes left and right is fixed to an output shaft of the speed reducer 13. At the same time, an oil damper 15 is interposed between the left and right ends of the lever 14 and the base 2 as an attenuator, and the rotational energy of the shaft 9 input to the reducer 13 is transmitted through the reducer 13. The oil is damped by the oil damper 15. Note that 16
Is a flywheel for giving inertial force to the rotation of the shaft 9.

In the above configuration, when the weight 3 is considered as a pendulum as shown in FIG. 4, its natural vibration period T is determined by the vibration radius R of the center of gravity G. That is, Further, assuming that the mass of the weight 3 is m and the horizontal displacement is x, the vertical displacement y is Can be obtained as

Next, the principle of vibration suppression control according to the present invention will be described with reference to FIG. 5, reference numeral 21 denotes a vibrating table which is vibrated by an actuator 22, 17 denotes a test piece movably mounted on the vibrating table 21 (corresponding to the structure 1 in FIG. 1), and 18 denotes a weight ( The brackets 19 and 20 correspond to the weight 3 in FIG. 1). Now, let P be the aerodynamic force (wind load) acting on the specimen 17, M be the mass of the specimen 17, K be the converted spring constant of the specimen 17, and be the damping coefficient of the specimen 17 (additional damping constant: 2Mhω). C,
Let X be the amount of linear displacement (absolute coordinates) of the specimen 17 in the horizontal direction, m be the mass of the weight 18, k be the spring constant of the weight 18, and 18 be the weight.
Assuming that p is a control force for controlling the vibration of the weight and x is a horizontal linear displacement of the weight 18 (relative coordinates with respect to the specimen 17),
The equation of motion of the specimen 17 and the weight 18 is as follows: M + CX + KX + m (+ m) = Pcosωt (1) (ω: natural frequency, t: time) m + m + kx = p (t) (2) Assuming that the weight 17 and the weight 18 make a single-string motion, X = Asinωt (3) (A: amplitude) x = Bsin (ωt + α) (4) (B: amplitude, α: ωt At this time, there is a relationship between the spring constants K and k and the specimen 17 and the weight 18 as follows: K = (M + m) ω ² (5) k = mω ² (6) . Therefore, the terms including the mass and the spring constant in the equations (3) and (4) are always zero as follows.

(M + m) + KX = − (M + m) Aω ² sinωt + (M +
m) Aω ² sinωt = 0 (7) m + kx = −mBω ² sin (ωt + α) + mBω ² sin (ωt +
α) = 0 ...... (8) (7), (8) Equation (1), (if substituted into 2), Pcosωt = CX + m = 2MhAω 2 cosωt-mBω 2 sin (ωt + α) ...... (9) p (t) = m = −mAω ² sinωt (10) Here, when the phase of the first term and the second term on the right side are the same, the attenuation of the specimen 17 and the weight 18 It is shown that the force due to the movement is balanced with the aerodynamic force P. That is, when the movement of the weight 18 is operated in a form delayed by 90 ° (−90 °) with respect to the movement of the specimen 17, the force acts in the same direction as the attenuation of the specimen 17 to try to stop the vibration. You can see that. Thus, Rewriting equation (9) as α = -90 °, Pcosωt = 2MhAω 2 cosωt + mBω 2 cosωt = (2MhA +
mB) ω ² cos ωt (11) From the equation (11), the amplitude B of the weight 18 is given by m · B = (P / ω ² ) −2 MhA (12)

It is clear from these equations that the vibration control device can be either an active type or a passive type. Therefore, the force p (t) shown by the expression (10) is the controlling force in the case of the active type, In the case of the passive type, it can be considered as a damping force.

The following is an expression of the principle described above in words.

The force of the damping device for suppressing the vibration of the structure is obtained by the movement of the mass of the damping device.

A stable vibration is obtained by giving a control force or a damping force to the vibration damping device in the opposite direction having the same magnitude as the force entering the structure.

Therefore, in a state where the structure damping device of the present invention configured as described above is installed on the top of the structure 1,
When a vibration occurs in the structure 1 due to aerodynamic force or the like, the vibration energy is transmitted to the weight 3, and the weight 3 starts single-string vibration with a delay of 90 ° with respect to the vibration of the structure 1. At this time, since the rack 8 provided on the upper surface of the weight 3 and the pinion 11 on the shaft 9 fixedly disposed above the weight 3 are engaged, the vibration energy of the weight 3 is as described above. Rotational energy is given to the shaft 9 via the rack 8 and the pinion 11. When rotational energy is given to the shaft 9, the speed reducer 13 is connected to one end of the shaft 9, and the rotation of the shaft 9 is reduced by the speed reducer 13. Oil damper on output shaft of reducer 13
Since the oil damper 15 is provided, the oil damper 15 is oscillated via the speed reducer 13, and the rotational energy of the shaft 9 is attenuated. As a result, the swaying of the structure 1 is suppressed. That is, in the present invention, energy such as aerodynamic force entering the structure 1 is converted into kinetic energy of the weight 3,
The swing of the structure 1 can be quickly suppressed by an indirect energy consumption type in which the oil is consumed by the oil damper 15 via the rack 8, the pinion 11, the shaft 9, and the speed reducer 13.

In the above, the vibration damping force on the structure 1 can be changed by selecting the vibration stroke and the mass of the weight 3. The damping rate can be changed by adjusting the pressure of the oil damper 15, but can also be changed arbitrarily by changing the gear ratio of the speed reducer 13. It can be given as an optimal condition. In addition, the speed reducer 13 can output the operation amount of the input from the input shaft portion to the output shaft portion as a smaller operation amount, so that even when the weight 3 has a large stroke, the small oil damper 15 can be used. Can respond. Further, since the weight 3 is made to oscillate in a single string, it can be easily synchronized with the natural period of the structure 1. However, even if the period is likely to be shifted, the weight on the shaft 9 is not changed. Synchronization can be achieved by the action of the flywheel 16, and further, an arc-shaped rack 8 extending in the vibration direction is directly provided on the upper surface of the weight 3, and a pinion meshed with the rack 8.
Since the position-fixed shaft 9 having the position 11 is arranged above the weight 3 that vibrates in a single string, the arrangement position of the weight 3 is lowered to reduce the height of the entire apparatus. Can be.

In the above embodiment, the case where the oil damper 15 is used as an attenuator for attenuating the vibration energy of the weight 3 is shown. However, instead of the oil damper 15, an air damper, a spring damper, or a hydraulic damper is used. Although it is possible to use an elastic damper or the like, and in the embodiment, the case where the speed reducer 13 is used to operate the damper has been described,
Instead of the speed reducer 13, a variable drive type rotating device such as a generator, a hydraulic motor, and a water pump can be used. In the case of the generator, by changing the field current, the hydraulic motor or the water pump can be used. In the case of, the attenuation rate can be arbitrarily changed by changing the discharge flow rate and the discharge pressure, and it is needless to say that various changes can be made without departing from the gist of the present invention.

[Effects of the Invention] As described above, according to the structure vibration damping device of the present invention,
On the upper part of the structure, a weight whose upper and lower surfaces are curved in an arc shape so as to be able to perform a single string vibration is arranged swingably via a support roller, and extends on the upper surface of the weight in the vibration direction. An arc-shaped rack is directly provided, and an input shaft portion of the speed reducer is connected to a fixed position shaft having a pinion that meshes with the rack, and an attenuator is connected to an output shaft portion of the speed reducer. Since the configuration is such that a flywheel is provided thereon, or a configuration in which a variable drive type rotating device is used in place of the speed reducer, the following excellent effects are exhibited.

(I) Since the swing energy of the structure can be easily converted into the kinetic energy of the weight, and this can be used as the optimal damping force by the damper, the swing of the structure can be suppressed quickly.

(Ii) The damping rate can be arbitrarily changed by adjusting the speed reducer and the variable drive type rotating device, so that the structure can be given an optimal state. Since the input operation amount can be output to the output shaft as a smaller operation amount, even when the vibration stroke of the weight is large, it is possible to cope with a small damper.

(Iii) Since the weight uses single-string vibration, it is easy to move, and can be matched with the natural period of the structure. Even if the period is likely to shift, the action of the flywheel on the shaft This makes it possible to easily perform the cycle adjustment.In addition, since the rack is directly provided on the upper surface of the weight, and the fixed position shaft having the pinion that meshes with the rack is arranged above the weight. In addition, the position of the weights can be lowered to reduce the overall height of the device.

(Iv) By selecting the stroke and mass of the weight,
The damping effect can be further enhanced.

(V) Since a weight having a high specific gravity (solid: lead, liquid: mercury, etc.) can be used for the weight, the weight can be made compact, and thus the installation area of the entire apparatus can be small.

(Vi) Since the structure is simple, maintenance is easy.

[Brief description of the drawings]

FIG. 1 is a front view showing an outline of an embodiment of a structure vibration damping device of the present invention, FIG. 2 is a plan view of FIG. 1, FIG. 3 is a side view of FIG. 1, and FIG. FIG. 5 is a diagram showing a model of the principle of the present invention, FIG. 6 and FIG.
The figures are schematic diagrams each showing an example of a conventional apparatus. 1 ... structure, 3 ... weight, 4 ... support roller, 8 ...
Rack, 9 ... Shaft, 11 ... Pinion, 13 ... Reducer, 15
…… oil damper (damper), 16 …… flywheel.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-62-31736 (JP, A) JP-A-58-174740 (JP, A) JP-A-61-256036 (JP, A) JP-A-61-256036 70243 (JP, A) JP 47-50072 (JP, B1) (58) Fields investigated (Int. Cl. ⁶ , DB name) F16F 15/02 E04H 9/02 E01D 1/00

Claims (2)

(57) [Claims] 1. A weight having upper and lower surfaces curved in an arc shape so as to perform single-string vibration is swingably arranged via a support roller on an upper portion of a structure, and is provided on an upper surface of the weight. An arc-shaped rack extending in the vibration direction is directly provided, and an input shaft of the speed reducer is connected to a fixed position shaft having a pinion that meshes with the rack, and an attenuator is connected to an output shaft of the speed reducer. A structure vibration damping device further comprising a flywheel provided on the shaft. 2. A weight having upper and lower surfaces curved in an arc shape so as to perform single-string vibration is swingably arranged via a supporting roller on an upper portion of the structure, and is provided on an upper surface of the weight. Directly providing an arc-shaped rack extending in the vibration direction, and connecting a variable drive type rotating device to a fixed position shaft having a pinion engaged with the rack, connecting an attenuator to the variable drive type rotating device, And a structure having a flywheel provided on the shaft.