JP4049619B2 - Vibration control device - Google Patents

Description

[0001]
【Technical field】
The present invention is attached to a relatively small vibration control object installed indoors / outdoors, and the object vibration (vibration) that can suppress vibration generated in the vibration control object over a relatively wide range of frequencies (frequency). The present invention relates to a novel vibration damping device that actively suppresses).
[0002]
[Background]
As a damping device, for example, for the purpose of providing a damping device for a pole that can control in the vertical (vertical) direction and the horizontal direction, can secure a damping performance in a wide frequency band, and has a simple structure. A vibration damping device as shown in FIG. 1 having the following configuration has been proposed by the same applicant as the present applicant (Japanese Patent Application No. 11-279816 / 338331).
[0003]
`` The support (12) has at least a peripheral wall (12a) and a bottom cover (12b), and the movable table (14) is movable in a substantially horizontal direction on the bottom cover (12b) of the support (12). The movable table (14) includes a substrate (14a) and a vertical guide body (14b), and the movable table (14) and the peripheral wall (12a) of the support (12) include a plurality of horizontal restoring springs ( 16), and the mass body (15) is supported on the upper side of the substrate of the movable table (14) so as to be movable in the vertical direction along the vertical guide body (14b) via the vertical restoring spring (19). A container (17) containing a viscous body (20) is provided on the upper side of the bottom cover (12b) of the support body (12), and integrally therewith on the lower side of the substrate (14a) of the moving base (14). A resistance plate (18) is provided, and the resistance plate (18) is arranged so as to adhere to the viscous body (20) in the container (17), and the substrate (14a) and the mass body ( 15), a hydraulic damper (22) is arranged vertically, and the cylinder (22a) of the hydraulic damper (22) is connected to the base plate (14a) or mass body (15) of the moving table, The rod (22c) of the piston (22b) of the damper (22) is connected to the mass body (15) or the substrate (14a) of the moving base (14), and the mass body (15), the hydraulic damper (22), and the vertical restoration The spring (19) constitutes a vertical damping part, the mass body (19) and the hydraulic damper (22) supported by the moving base (14), the container (17) containing the viscous body (20), and the resistance plate (16) and the horizontal restoring spring (16) form a horizontal damping part. ”
[0004]
DISCLOSURE OF THE INVENTION
The inventors of the present invention have come up with a vibration damping device having the following configuration as a result of diligent development for the purpose of simplifying the vibration damping device and facilitating the evaluation of vibration energy attenuation (modeling). .
[0005]
A support base that is horizontally fixed to the object to be controlled, a laterally-moving vibration control weight that is supported by a sliding part so as to be able to slide horizontally on the support base, and between the support base and the laterally-moving vibration control weight A viscoelastic element that is arranged, and a horizontal restoring spring body that restores the laterally movable body to a predetermined plane position, and one or more dashpots arranged via the laterally movable body, perpendicular to the laterally movable body And one or more longitudinally movable damping weights guided by the guide rod and vertically movable, the longitudinally movable damping weights being coupled to the piston rod of the dashpot, and the longitudinal compression elastic body in the dashpot cylinder In the vibration damping device configured to be supported via
The viscoelastic element is formed of a solid viscoelastic body, and the action axis of the horizontal restoring spring body is close to the sliding surface of the support base.
[0006]
As described above, when the viscoelastic element is a solid viscoelastic body, it is not necessary to have a complicated configuration in which a viscous body is placed in a container and a resistance plate is inserted as in the above-described prior art.
[0007]
Further, by bringing the action axis of the horizontal restoring spring body close to the sliding surface, the action line due to the movement of the sliding portion of the lateral moving body and the action line of the horizontal restoring spring body are substantially in the same plane, Compared to the above-described prior art in which the action lines are not close to each other, a smooth and stable movement of the lateral moving body is possible. As a result, the calculated value of the vibration energy attenuation ability becomes close to the actual measurement value, and vibration energy attenuation evaluation (modeling) becomes easier.
[0008]
In the above configuration, the coefficient of dynamic friction (μ ′) between the sliding portion of the laterally movable body and the sliding surface of the support base and between the vertical guide rod and the longitudinally moving damping weight is 1 for the former: Desirably, the relationship is / 100 or less and the latter: 1/500 or less.
[0009]
As described above, each dynamic friction coefficient (μ ′) between the sliding portion of the laterally movable body and the sliding surface of the support base and between the vertical guide rod and the longitudinally moving vibration damping weight is made as small as possible. By doing so, the amount of attenuation due to friction can be substantially ignored, and in this respect also, the vibration energy attenuation evaluation can be facilitated.
[0010]
In addition, although the damping device of each said structure aims at attenuation | damping of both horizontal vibration and vertical vibration, when only one of them is sufficient, it is set as the following structures, respectively.
[0011]
A support base that is horizontally fixed to an object to be controlled, a lateral moving body that also serves as a laterally-moving vibration control weight that is supported by a sliding portion so as to be capable of horizontal sliding on the support base, and the support base and the vibration control weight body A horizontal vibration damping device including a viscoelastic element disposed between and three or more horizontal restoring spring bodies arranged radially to restore the laterally movable body to a predetermined plane position,
The viscoelastic element is a solid viscoelastic body, and the horizontal restoring spring body is arranged along the sliding surface of the support base. The sliding portion of the lateral moving body (lateral movement damping weight) and the sliding surface of the support base The coefficient of dynamic friction (μ ′) is 1/100 or less.
[0012]
A support base that is horizontally fixed to the object to be controlled, one or more dashpots arranged vertically on the support base, and one or more movable vertically guided by a vertical guide bar on the support base A vertical movement damping weight, which is coupled to a dashpot piston rod and supported by a dashpot cylinder via a longitudinal compression elastic body for damping vertical vibration In
The fitting between the vertical guide rod and the longitudinal movement damping weight is characterized in that the coefficient of dynamic friction (μ ′) is 1/500 or less.
[0013]
In the vibration damping device having the above-described configuration, an acrylic rubber-based viscoelasticity is desirable as the solid viscoelastic body. The horizontal restoring spring body may be a leaf spring, an air spring or the like, but is usually a tension coil spring. The tension coil spring can easily reduce the outer diameter of the spring and save space, and can be easily mounted as compared with other spring bodies.
[0014]
In the above configuration, in order to obtain the dynamic friction coefficient (μ ′) between the sliding portion of the laterally movable body and the sliding surface of the support base, three or more sliding portions are arranged at equal intervals on the same circumference. It is desirable to use a special metal having hardness and slipperiness equivalent to that of SKD11 while forming with a rolling sphere.
[0015]
Further, the longitudinal compression elastic body may be a rubber elastic body or a leaf spring, but is usually a compression coil spring. In order to support the damping weight from below, a compressive force acts by gravity. For this reason, a compression spring makes sense.
[0016]
Further, in order to obtain the above dynamic friction coefficient (μ ′) in the fitting between the vertical guide rod and the vertical guide damping weight, the low friction bush is arranged on the upper and lower portions of the vertical guide hole. That's fine.
[0017]
Further, at this time, by connecting the upper ends of the guide rods with a horizontal connecting member, it is easy to ensure the verticality of each guide rod, and the vertical moving weight can be moved more smoothly. As a result, as a result, the calculated value of the vibration energy attenuation ability becomes close to the actual measurement value, and vibration energy attenuation evaluation (modeling) becomes easier.
[0018]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0019]
First, the vibration damping device for damping horizontal / vertical vibration shown in FIGS. 1 is a vertical sectional view, and FIG. 2 is a sectional view taken along line 2-2 of FIG.
[0020]
A support base 31 that is horizontally fixed to an object to be controlled (for example, a rack), a horizontal moving body 33 that is supported on the support base 31 so as to be able to move horizontally (laterally), and a support base 31 and a horizontal moving body ( Horizontal moving body) 33 and viscoelastic body elements 35, and three or more horizontal restoring spring bodies 35 arranged radially to restore the horizontal moving body 33 to a predetermined plane position. And one or more dashpots 39 arranged via the laterally movable body 33, and one or more longitudinally moving vibration damping weights 43 guided by the vertical guide rod 41 and movable vertically.
[0021]
The longitudinal movement damping weight 43 is coupled to the piston rod 39a of the dash pot 39 (screw coupled in the illustrated example) and supported by the cylinder 39b of the dash pot 39 via the longitudinal compression elastic body 45. Up to this point, it is basically the same as the above-described prior art vibration damping device.
[0022]
In the above configuration, in the present embodiment, the viscoelastic element 35 is a solid viscoelastic body, the action axis of the horizontal restoring spring body 37 is arranged along the sliding surface of the support base 31, and the lateral moving body 33. The friction coefficient (μ ′) between the sliding portion 47 and the sliding surface 31a of the support 31 and the vertical guide rod 41 and the longitudinal movement damping weight 43 is 1/100 or less, respectively. The latter: It is supposed to indicate 1/500 or less.
[0023]
More specifically, it is as follows.
[0024]
The support base 31 is disc-shaped and has three or more bolt holes 32 formed at equal intervals (six in the illustrated example) in order to attach the support base 31 to the object to be controlled.
[0025]
The distance S between the operating axis L of the horizontal restoring spring body 37 and the horizontal sliding surface 31a is such that when the horizontal restoring spring body 37 is a tension coil spring having a nominal outer diameter d, the tension coil spring 37 slips when vibration is generated. A distance that does not interfere with the surface 31a, for example, S = d / 2 + (0.5 to 3 mm).
[0026]
In addition, the sliding surface 31a of the coil spring support 31 is formed of a special metal having excellent sliding property and wear resistance in order to obtain a dynamic friction coefficient of a predetermined value or less between the sliding surface 31a and the sliding portion 47 of the lateral moving body 33. ing. Specifically, as a special metal, it is desirable that the sliding surface has hardness and slipperiness equivalent to “SKD11”. Here, “SKD11” means a die for alloy tool steel, and has a surface hardness of HRC58 or more.
[0027]
In the laterally moving body 33, a concentric middle protrusion 33b and a small circular protrusion 33c are formed stepwise on the lower surface of the disk body 33a.
[0028]
In the laterally movable body 33, the lower surface of the disc body 33a is positioned at the outer side of the middle circular protrusion 33b, and three or more (usually 6 to 10 in the example shown in FIG. 8) rolling spheres (normal steel balls) 51. The rolling sphere 51 is attached to the lower surface of the disc body 33a via a sphere holding member 49 that holds the sphere as a spherical pair. The spherical body holding member 49 is screwed to the lateral moving body 33.
[0029]
Moreover, the solid viscoelastic body which is a viscoelastic element is a cylinder or a prism. The solid viscoelastic body may be a rectangular column (a quadrangular column, a polygonal column) or an elliptical column, a rectangular column or the like when the generated vibration has directionality, but usually corresponds to lateral vibration in all directions. Therefore, it is a cylindrical body.
[0030]
The dimensions and material of the solid viscoelastic body 35 determine the natural frequency of the target structure by an internal damping constant . Specifically, an acrylic rubber type or a silicone rubber type can be preferably used. Other rubber-based viscoelastic materials are easily affected by viscoelastic properties (fluidity) by heat, whereas acrylic rubber and silicone rubber materials are less susceptible to heat by viscoelastic properties. Further, the acrylic rubber-based viscoelastic body itself has adhesiveness and does not require a fixing means such as an adhesive to be assembled. In the case of a silicone rubber system, it does not have adhesiveness.
[0031]
The solid viscoelastic body 35 is attached to the center of the support base 31 and the lower surface of the small circular protrusion 33c of the laterally movable body 33 using an adhesive or the like.
[0032]
Further, the horizontal restoring spring body 37 is formed of a tension coil spring, and the number thereof is three or more (usually 3 to 8, four in the illustrated example). If the number of coil springs is two, only lateral vibration in a specific direction can be handled. On the other hand, a larger number of coil springs is desirable, but the structure is complicated and the weight is increased.
[0033]
Each of the tension coil springs 37 is attached at the same intervals along the outer periphery of the sliding surface 31a of the support base 31 along the outer periphery of the lower surface of the small circular protrusion 33c of the laterally movable body. • Perform through the second Nibis. At this time, as shown in FIG. 2, both end fittings 37 a and 37 a of the coil spring 37 are engaged with the neck portions of the first and second screws 55 and 57 via the collar 59. The engagement metal fitting 37a can be smoothly rotated with respect to the screws 51 and 57. The first screw 55 on the support base side is provided with a locking nut 56 below the collar 59 so that it can cope with high frequency or strong vibration.
[0034]
Further, a cylinder 39a of a dash pot 39 is integrally formed at the center of the laterally movable body 33, and a viscous fluid 40 is enclosed in the cylinder 39a and a piston 39b is disposed. The piston 39b includes a conduction hole 39d or a conduction gap so that the viscous fluid 40 can partially conduct between the two chambers. And the piston rod 39c has penetrated the sealing body 42 which seals the upper end opening part of the cylinder 39a.
[0035]
A compression coil spring (longitudinal compression elastic body) 35 is fitted on the outer periphery of the cylinder 39a. The longitudinal movement damping weight 43 is ring-shaped and supported by the upper end of the compression coil spring via the upper closing portion. Further, the projecting tip of the piston 39b rod is screwed to the upper closing portion.
[0036]
On the other hand, the vertical guide rod 41 is screwed to the outer periphery of the laterally movable body 33. At this time, the number of the vertical guide bars 41 is 2 or more, usually 3 to 6, but is 4 in the illustrated example. At this time, the upper side of the screw coupling portion of the laterally movable body 33 is set as a fitting concave portion 33d in order to prevent the vertical guide rod 41 from being displaced due to the play of the screw.
[0037]
The vertical movement damping weight 43 is formed with vertical guide holes 43a corresponding to the vertical guide rods 41, and upper and lower portions of the vertical guide holes 43a are made of a low friction material (for example, fluorine resin, bearing alloy, etc.). The formed bush 44 is embedded. The fitting between the bush 44 and the vertical guide rod 41 is a slidable intermediate fit. For example, it is assumed that “+0.2 to −0” is fitted to the outer diameter D of the guide rod. The general diameter of the vertical guide hole 43a is “+1 to 2” so that the general part does not interfere with the guide rod.
[0038]
In the above description, the case where there is one dash pot 39 and one vertical movement damping weight 43 is taken as an example, but one or both may be plural. It becomes easy to respond to the vibration mode of the vibration suppression object.
[0039]
Next, usage modes of the present embodiment will be described.
[0040]
The apparatus model diagram of this embodiment is as shown in FIG. In other words, the vibration damping device includes the horizontal vibration damping means A and the vertical vibration damping means B. The horizontal vibration damping means A arranges the horizontal restoring spring body 37 in parallel with the Maxwell type damping model M in the horizontal direction. The vertical vibration damping means B has a configuration in which a vertical forked damping model F and a longitudinally moving damping weight 43 are coupled to each other. Naturally, the dynamic friction elements K1 and K2 generated by the horizontal movement and the vertical movement are also added in parallel.
[0041]
Screws are attached to the object to be controlled such as a rack so that the upper surface of the support base 31 is horizontal. When vibration is generated on the object to be controlled by an external force or an internal moving body, the horizontal vibration attenuating means A and the vertical seismic intensity attenuating means B respectively attenuate the vibration energy corresponding to the direction of the vibration, thereby suppressing the vibration. Achieve the goal.
[0042]
Next, an example of the numerical design of this embodiment will be described with reference to FIG.
[0043]
Here, the case where the natural frequency F is 4 to 12 Hz and the weight W of the vibration suppression object is 200 to 400 kg is taken as an example.
[0044]
At this time, the vibration damping device of the present invention is characterized in that the vertical movement damping weight 43 for the vertical direction is shared with the lateral movement damping weight. The weight of the laterally movable body (horizontal movable table) 33 and the spring / dashpot 39 is sufficiently small compared with the weight of the longitudinally-moving vibration damping weight 43 in FIG. 1, and W1 = 0. 03-0.10 W. Note that the longitudinally moving damping weight 43 is made of iron so that the laterally moving body 33, the dashpot 39, etc. are sufficiently smaller than the longitudinally moving damping weight 43 (within 10%). On the other hand, the laterally movable body, the dashpot, etc. are made of a light alloy such as aluminum. Further, in the design of the horizontal movement horizontal restoring spring body, the weight of the horizontal movement table is taken into consideration in addition to W1.
[0045]
Moreover, it sets according to the optimal natural frequency of an apparatus. Specifically, it is set in the range of f = 4 to 12 Hz.
[0046]
And each spring constant (k) of the horizontal restoring spring body (tensile coil spring) 37 and the longitudinal compression elastic body (compression coil spring) 45 that realizes the natural frequency is calculated based on the following calculation formula.
[0047]
k = 4π ² f ² · W1 (or W2) / g
From the above, the optimum damping constant in the vertical vibration damping means is set to h = 0.05 to 0.30. The storage shear modulus G1 and loss factor η of the viscoelastic element (rubber) in the horizontal vibration damping means are based on the set frequency (optimal frequency f) of the damping device and the operating temperature condition (10 to 40 ° C.) wp. The loss shear elastic modulus G2 is read from the chart shown by the material manufacturer, and is determined by η = G2 / G1. For example, in the case of a commercially available acrylic rubber-based viscoelastic body, G1 = 7 × 10 6 to 1.5 × 10 7 N / mm 2 and η = 0.04 to 1.2.
[0048]
The viscosity coefficient (c) of the dash pot 39 that realizes the above damping constant is given by c = 2h × √ (kW1 / g).
[0049]
The ratio (A / t) between the cross-sectional area (A) and the thickness (t) of the solid viscoelastic body is determined by k1 = G1 × A / t and C1 = G2 × A / (t × 2πf). An appropriate A / t is obtained by numerical analysis simulation using Maxwell type model constants. Specifically, A / t = 1.0 to 25.0 cm.
[0050]
In the above embodiment, when the vibration generated in the object to be controlled is only horizontal vibration or only vertical vibration, the vibration device for horizontal vibration attenuation or vertical vibration attenuation shown in FIGS. 4 to 5 may be used. . Basically, in the above embodiment, only the elements of the horizontal vibration damping means and only the elements of the vertical vibration damping means are assembled, and therefore, the corresponding reference numerals in the above embodiment are attached and their explanations are given. Is omitted. Since the lateral moving body is a lateral movement damping weight (horizontal movement damping weight), it is made of iron unlike the above embodiment.
[0051]
In FIG. 5, the upper end of the vertical guide bar 41 is connected by a horizontal connecting member 60 to make it easy to ensure the vertical degree of the vertical guide bar 41. In the illustrated example, the horizontal connecting member is a disc, but it may be a frame made by connecting a plurality of bar members.
[Brief description of the drawings]
FIG. 1 is a vertical sectional view showing an example of a vibration damping device for damping horizontal / vertical vibrations according to the present invention. FIG. 2 is a sectional view taken along line 2-2 of FIG. Fig. 5 is a vertical sectional view showing an example of a vibration damping device for horizontal vibration damping in the present invention. Fig. 5 is a vertical sectional view showing an example of a vibration damping device for vertical vibration damping. Fig. 6 is a schematic sectional view of a conventional vibration damping device. Figure [Explanation of symbols]
31 Support base 31a Sliding surface 33 of support base Horizontally moving body 35 Viscoelastic element (solid viscoelastic body)
37 Horizontal restoring spring body (Tension coil spring)
39 Dashpot 41 Vertical guide rod 43 Vertical movement damping weight 43a Vertical guide hole 44 Low friction bush 45 Vertical elastic compression body (compression coil spring)
47 Sliding part of laterally moving body

Claims (7)

A support base mounted horizontally on the object to be controlled, a horizontal moving body supported by a sliding portion so as to be able to move horizontally (laterally) on the support base, and between the support base and the horizontal moving body A viscoelastic element, and three or more tension coil springs arranged radially at equal intervals in order to restore the laterally movable body to a predetermined position on the plane, and further arranged via the laterally movable body One or more dashpots and one or more vertical movement damping weights that are guided by a vertical guide rod and can move vertically, and the vertical movement damping weights are coupled to the piston rods of the dashpots. In the vibration damping device supported by the cylinder of the dashpot via the compression coil spring ,
The viscoelastic element is formed of a columnar solid viscoelastic body having upper and lower surfaces fixed at the center position of the support base, and the tension coil spring has an inner end fixed to a lower surface of the laterally movable body, and an outer end. Is fixed to the upper surface of the support table, and
The friction coefficient (μ ′) between the sliding surface of the sliding portion of the laterally movable body and the guide rod and the longitudinally moving vibration damping weight is 1/100 or less, the latter: A vibration damping device characterized by exhibiting 1/500 or less . A support base that is horizontally fixed to the object to be controlled, a horizontal moving body that is supported by a sliding portion so as to be capable of horizontal sliding movement on the support base, and that also serves as a laterally moving vibration control weight ; In a vibration damping device for damping horizontal vibration, comprising a viscoelastic element arranged between and tension coil springs arranged radially in order to restore the laterally movable body to a predetermined plane position,
The viscoelastic element is formed of a columnar solid viscoelastic body having upper and lower surfaces fixed at the center position of the support base, and the tension coil spring has an inner end fixed to a lower surface of the laterally movable body, and an outer end. Is fixed to the upper surface of the support base, and the coefficient of dynamic friction (μ ′) between the sliding portion of the laterally movable body and the sliding surface of the support base is 1/100 or less. A vibration damping device characterized by that. A support base fixed horizontally to the object to be controlled; one or more dashpots arranged vertically on the support base; one or more movable vertically guided by a guide bar on the support base A vertical movement damping weight, which is coupled to a piston rod of the dashpot and supported by a cylinder of the dashpot via a compression coil spring. In
The tip outer peripheral part of the dashpot is a stepped small diameter part, and the stepped small diameter part is a spring seat of the compression coil spring,
The fitting between the guide rod and the longitudinally-moving vibration damping weight has a relationship in which a dynamic friction coefficient (μ ′) indicates 1/500 or less. The vibration damping device according to claim 1 or 2, wherein the solid viscoelastic body is an acrylic viscoelastic body. The sliding portion of the lateral moving body is formed of three or more rolling spheres arranged at equal intervals on the same circumference, and the sliding surface of the support base has a special hardness and slipperiness equivalent to SKD11. 3. The vibration damping device according to claim 1 , wherein the vibration damping device is made of metal. The vibration control system according to claim 1 or 3, wherein the vertical guide rod and the vertical guide hole of the longitudinally moving weight are fitted to each other by providing a low friction bush on the upper and lower portions of the vertical guide hole. apparatus. The vibration control device according to claim 1 or 3, wherein there are a plurality of the vertical guide bars, and upper ends of the guide bars are connected by a horizontal connecting member.

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