JPH0816497B2 - Dual type dynamic vibration absorber - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dual type dynamic vibration reducer using a pair of lever levers on the left and right.

[Prior art]

[0002] In recent years, a dynamic vibration absorber has begun to attract attention as a vibration control device for structures, and has been applied to actual structures both in Japan and overseas. The dynamic vibration reducer adjusts its natural period in the vicinity of the natural period of the structure to be dampened, thereby interposing damping to the relative displacement between the structure and the dynamic vibration reducer at the resonance point, and The absorption response reduces the displacement response of the structure. The smaller the mass of the dynamic vibration absorber, the more preferable, but if it is made too small, the displacement amplitude becomes extremely large at the resonance point. In addition, there is a problem that the amplitude of the spring of the dynamic vibration absorber becomes very large even when the dynamic vibration absorber is used to suppress the vibration of a structure having a long natural period, particularly a skyscraper or a bridge.

As a result, there is a problem in that the spring member is difficult to design because the spring member follows the large displacement and excessive stress is generated in the spring member.

Therefore, in order to reduce the amplitude of the spring (4), a weight (7) is attached to the tip of the lever (9) for lever that penetrates the damping mass (3), and the damping mass (3) is A "lever type dynamic vibration absorber (B)" that is operated by "lever action" was proposed. However, with this method, although the amplitude of the spring (4) could be reduced with respect to the above-mentioned problem, on the contrary, the moment due to the reaction of the "leverage action" was applied to the fulcrum (6) of the lever (9) for leverage. However, there is a problem in that it causes coupling to generate complex vibrations in the vibration system.

[0005]

The problem to be solved by the present invention is to reduce the amplitude of the spring by utilizing the "lever action", and at the same time eliminate the "moment" generated by using the lever for lever. The point is to try to achieve an effective dynamic vibration absorber for structures.

[0006]

A dual type dynamic vibration absorber of the present invention
The basic type of (A) is, as shown in claim 1, "a support structure (2) attached to a vibration system (1) and a damping spring (4) attached to the vibration system (1)". A damper (5) arranged in parallel with the damping spring (4), and a damping mass (3) supported by the damping spring (4) and connected to the damper (5), Support structure (2) with its fulcrum (6)
The levers (9) are pivotally attached to each other, extend in opposite directions, have a weight (7) attached to the tip, and the point of action (8) is restrained by the damping mass (3). It is composed of and ''.

As a first modification thereof, a dual type dynamic vibration reducer according to claim 2 is a "support structure attached to a vibration system (1)".
(2), a damping spring (4) attached to the vibration system (1), a damping mass (3) supported by the damping spring (4), and the damping spring
A lower air spring (13a) installed on the bottom (12) of the support structure (2) parallel to (4) and connected to the damping mass (3), and the ceiling of the support structure (2). The upper air spring (13b), which is installed in the part (11) and faces the lower air spring (13a) and is connected to the damping mass (3), connects the upper and lower air springs (13a, 13b). An orifice (1) having a damper (5) function provided in the passage
4) and its supporting point (6) are pivotally attached to the support structure (2),
It extends in opposite directions, and a weight (7) is attached to the tip,
The point of action (8) is composed of a pair of levers for levers (9) which are restrained by the damping mass (3) '.

As a second modified example thereof, the dual type dynamic vibration absorber according to claim 3 is a "support structure attached to a vibration system (1)".
(2) and the lower air spring (13a) attached to the vibration system (1),
The damping mass (3) supported by the lower air spring (13a) and the ceiling part (11) of the support structure (2) are installed, and the lower air spring (13)
the upper air spring (13) connected to the damping mass (3) facing the a)
b) and partition walls (26) (26) that divide the inside of the pressure vessels (18a) (18b) of the upper and lower air springs (13a) (13b) into a bellows side and a non-bellows side.
And an orifice (14a) (1) having a damper (5) function provided in a communication passage that connects the bellows side chamber and the non-bellows side chamber.
4b) and its fulcrum (6) are pivotally attached to the support structure (2), extend in opposite directions, a weight (7) is attached to the tip, and the action point (8) is the damping mass. It is composed of a pair of levers for levers (9) constrained to (3) '.

As a result, when the lever (9) for leverage is vibrated, the levers (9) extend in opposite directions, so that the fulcrum (6) pivotally attached to the support structure (2). As a result, the moments generated by the two are canceled out, and as a result, the amplitude of the spring (4) can be reduced by using the "leverage action", and the "moment" generated by using the lever for the lever (9) is also eliminated. I was able to do things and achieved an effective dynamic vibration absorber (A).

[0010]

The present invention will be described below with reference to the illustrated embodiments. FIG. 1 is a schematic view of a dual type dynamic vibration absorber (A) according to the present invention, FIGS. 2 to 4 are a plan sectional view, a front view and a vertical sectional view of the first embodiment, and FIG. It is a longitudinal cross-sectional view of a second embodiment.

In FIG. 4, the vibration system (1) is used for structures having a long natural period, particularly skyscrapers and bridges.
Disturbances are constantly input from the ground surface (10), and they are vibrating in a complicated manner due to vibrations generated by the wind.

The support structure (2) in FIG. 4 is a vibration system.
(1) is a gate-shaped block fixed to the building, and the ceiling plate (11) and the bottom plate (12) are provided with air springs (13a) and (13b) facing each other. The damping mass (3) is mounted on the opposing mounting surfaces of the springs (13a) (13b). Upper and lower air springs (13
a) and (13b) are connected to each other via a variable orifice (14) and to a pneumatic source (16) via a regulator (15). As a result, the air springs (13a) (13b) connected via the variable orifice (14) act as the damper (5), and the coil spring (1
7) acts as a damping spring (4).

Next, the structures of the upper and lower air springs (13a) and (13b) will be described in detail. The lower air spring (13a) is fixed to the lower pressure vessel (18a) provided upright on the bottom plate (12) and the upper end opening of the lower pressure vessel (18a), and the outer circumference of the outer end of the rubber bellows (19a) is fixed. A sandwiched ring seat (20a) and a bellows slide seat (21a) fixed to the lower surface of the lower block part (3a) of the damping mass (3) and sandwiching the inner circumference of the inner end of the rubber bellows (19a). , A lift seat (23) housed inside the pressure vessel (18a) and screwed to an adjusting screw (22) attached to the bottom plate (12), a lift seat (23) and a bellows holding seat (2).
It is composed of a coil spring (17) arranged between the coil spring (1) and the coil spring (17). Rotating the adjusting screw (22) raises and lowers the lift seat (23) so that the lever lever (9) can be adjusted horizontally via the coil spring (17) and the damping mass (3). Has become. The upper air spring (13b) is the same as the lower air spring except that the coil spring is not installed inside. As for the alphabetical suffix, the lower one is (a) and the upper one is (b).

The damping mass (3) consists of upper and lower block parts (3a) (3
b) and the plate part (3c) mounted between the block parts (3a) and (3b), and the upper and lower air springs (13a) (13)
Above the bellows holding seats (21a) (21b) between the opposing mounting surfaces of b),
Both lower blocks (3a) (3b) are fixed, and the damping mass
(3) is coupled and supported by the vibration system (1). Although the upper and lower block portions (3a) and (3b) in the figure are solid bodies, they may be cylindrical bodies if necessary.

The levers (9) and (9) for levers are arranged so as to extend in mutually opposite directions, and weights (7) and (7) are attached to their tips. The fulcrums (6) and (6) of the levers (9) and (9) are pivotally attached to the support structure (2), respectively, and their action points (8)
(8) is in contact with the plate portion (3c) of the damping mass (3). In this embodiment, the fulcrum bearing (6a) is fitted into the through hole (24) formed in the side surface of the support structure (2), and the fulcrum bearing (6a) is attached to the fixed end of the lever (9) for leverage. , Point of action
Attach the action point bearing (8a) to (8), and
I try to contact (3c).

The weight (7) is composed of upper and lower split blocks, and is fixed to an arbitrary position of the free end of the lever for lever (9) by a bolt (25). As a result, the distance from the fulcrum (6) to the action point (8) and the distance from the action point (8) to the weight (7)
The distance ratio (L ₁ / L ₂ ) to the position of the center of gravity is variable, and the optimum position is adjusted according to the natural period of the structure (1) to be damped.

However, when the support structure (2) of the dual type dynamic vibration absorber (A) is attached to the vibration system (1) such as a high-rise building or a bridge, the disturbance or vibration system ( The vibration system (1) vibrates due to the vibration generated from the structure itself which is 1). The support structure (2) of the dual type dynamic vibration absorber (A) also vibrates in accordance with this vibration. Then, the weight (7) fixed to the free end of the lever (9) vibrates at a frequency that cancels the vibration of the structure (1) to be damped. At this time, the weight (7)
Since the vibration of is amplified by the lever (9) for leverage,
The amplitude of the coil spring (4) is smaller than that of (7). Further, since the lever for lever (9) extends to the opposite side, the lever for lever (9) swings symmetrically, and the "moment applied to the coil spring (4) through the action point bearing (6a). And a supporting structure as a reaction of the above "leverage"
"Moment" from fulcrum bearing (6a) added to (2)
Can reverse each other and cancel each other out, thereby canceling the generation of the "moment" which is a drawback when the "leverage action" is used.

FIG. 6 (a) shows the vibration cycle of the structure (1) when the dynamic vibration absorber (A) is not used, and FIG. 6 (b) uses the dynamic vibration absorber (A) for this. This is the vibration period of the structure (1) in the case of. According to FIG. 6 (b), it can be seen that the vibration of the structure (1) is rapidly attenuated.

In FIG. 7, the opening of the orifice (14) is
This shows the effect of (1) on damping, and damping can be easily adjusted by adjusting the opening of the orifice (14).

FIG. 5 shows a second embodiment of the present invention, in which the pressure vessels (18a) and (18b) are separated from each other by the partition wall (2) instead of using the coil spring (17).
6) Divide each by (26) and change both by variable orifice (14a)
This is an example of communication in (14b). Piping system is lower pressure vessel
(18a) is connected to the pneumatic source (16) via the lower regulator (15a), and the upper pressure vessel (18b) is connected to the pneumatic source (16b) via the upper regulator (15b). ), And the pressure (P ₁ ) (P ₂ ) can be set individually between the upper and lower air springs (13a) (13b). In this case, rubber bellows (19a) (19
The part with b) acts as a damping spring (4) (4), and the orifices (14a) (14b) provided in the communication passage that connects the bellows side chamber and the non-bellows side chamber are dampers (5) (5). Play a role.
The pressures (P ₁ ) and (P ₂ ) may be the same or different values. Also, by changing this pressure (P ₁ ) (P ₂ ), the natural frequency of the dual type dynamic vibration absorber (A) can be changed as appropriate, and the dual type dynamic vibration absorber (A) was installed. It is possible to select the optimum natural frequency for the vibration system (1).

In the case of the embodiment of FIG. 5, the pressure vessel (1
Although an example in which 8a) and (18b) are divided by the partition walls (26) and (26) is shown, of course, the present invention is not limited to this, and a pressure vessel that functions as a non-bellows side chamber is separately prepared, and both are variable orifices (14a). (14
You may communicate in b).

In addition, although only schematically shown in FIG. 1, the damping spring (4) and the damper (5) are connected in parallel to each other and connected to the damping mass (3). Point of action of lever (9)
The dual type dynamic vibration reducer (A) may be configured such that (8) is not separated from the vibration damping mass (3).

The dual type dynamic vibration absorber (A) shown in FIGS.
Although it is used for absorbing vertical vibrations, when absorbing horizontal vibrations, although not shown, the action point of the lever for leverage is restrained by the plate part of the damping mass and the air springs on both sides are also restrained. The coil spring is housed in, and the structure of the left and right air springs will be targeted.

[0024]

As described above, in the dual type dynamic vibration reducer according to the present invention, since the levers for levers having the weights attached to their tips are arranged so as to extend in mutually opposite directions, "leverage" It was possible to reduce the amplitude of the vibration damping spring by using, and at the same time, to eliminate the "moment" generated by using the lever for the lever, and it was possible to achieve a dynamic vibration absorber effective for the structure.

Also, since the ratio of the distance from the fulcrum of the lever for lever to the action point and the distance from the action point to the center of gravity of the weight can be made variable, it is optimal for the natural period of the vibration system. Since the position of the deadweight can be determined and the diameter of the orifice can be varied, the optimum damping of the vibration system can be easily obtained by selecting an appropriate orifice diameter.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing the concept of the present invention.

FIG. 2 is a plan view in which a part of a dual type dynamic vibration reducer according to the present invention is shown in section.

FIG. 3 is a front view of a first embodiment of a dual type dynamic vibration reducer according to the present invention.

FIG. 4 is a vertical cross-sectional view of a first embodiment of a dual type dynamic vibration reducer according to the present invention.

FIG. 5 is a vertical cross-sectional view of a second embodiment of the dual type dynamic vibration reducer according to the present invention.

FIG. 6 is a graph comparing the damping states of the vibration system when the dynamic vibration absorber is not used and when it is used.

FIG. 7 is a graph showing changes in the damping state of the vibration system when the orifice diameter is changed in the present invention.

FIG. 8 is a perspective view of a conventional example.

[Explanation of symbols]

(A) ... Dual-type dynamic vibration absorber of the present invention (1) ... Vibration system (2) ... Support structure (3) ... Damping mass (4) ... Damping spring (5) ... Damper (6) ... Support point ( 7)… Weight (8)… Point of action (9)… Lever for leverage

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Naruo Yamamoto No. 112, Fukakusa, Fukakusa Nishidate-cho, Fushimi-ku, Kyoto-shi, Kyoto Prefecture

Claims (5)

[Claims] 1. A support structure attached to a vibration system, a vibration damping spring attached to the vibration system, a damper arranged in parallel with the vibration damping spring, and a support by a vibration damping spring. And the damping mass to which the damper is connected and the fulcrum of which is pivotally attached to the support structure, extend in opposite directions, a weight is attached to the tip, and the action point is restrained by the damping mass. A dual type dynamic vibration absorber, which is characterized by comprising a pair of levers for leverage. 2. A support structure attached to a vibration system, a damping spring attached to the vibration system, a damping mass supported by the damping spring, and a parallel to the damping spring. A lower air spring installed on the bottom of the support structure and connected to the damping mass, and an upper air installed on the ceiling of the support structure and facing the lower air spring and connected to the damping mass. A spring, an orifice having a damper function provided in a communication path connecting the upper and lower air springs, and a fulcrum of which is pivotally attached to the support structure, extend in opposite directions, and a weight is attached to the tip, A dual-type dynamic vibration absorber, characterized in that the action point is composed of a pair of levers for leverage that are restrained by a damping mass. 3. A support structure attached to a vibrating system, a lower air spring attached to the vibrating system, a damping mass supported by the lower air spring, and a ceiling part of the supporting structure. And an upper air spring facing the lower air spring and connected to the damping mass, a partition wall that divides the pressure vessel of the upper and lower air springs into a bellows side and a non-bellows side, and a bellows side chamber and a non-bellows side chamber. An orifice having a damper function, which is provided in a connecting passage to be connected, and a fulcrum of which is pivotally attached to a support structure, extend in opposite directions, a weight is attached to the tip, and a point of action is a damping mass. A dual-type dynamic vibration reducer, which is composed of a pair of levers for restraining the lever. 4. The dual type according to claim 1, 2 or 3, wherein the ratio of the distance from the fulcrum to the point of action and the distance from the point of action to the center of gravity of the weight can be made variable. Dynamic vibration absorber. 5. The dual type dynamic vibration reducer according to claim 2, 3 or 4, wherein the diameter of the orifice can be made variable.