JPH0989043A - Dynamic damping device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To adjust a natural vibration frequency over a wide range so that a change of the center of gravity due to change of a weight can be decreased, by supporting a plurality of sheets of shims inserted between an upper end of each non-linear characteristic spring and a weight load supporting base plate. SOLUTION: A dynamic damping device for horizontal vibration, constituted by a helical coil spring 3 as a spring element, steel block as a large weight 11 and a plurality of steel plates, T shape steel 5, etc., as a small weight 12, is mounted on a vibration damped structure 7. Right/left parts of a horizontal rectangular weight support base plate 1a are support mounted on total eight pairs of ball bearing springs, and a weight 1 is supported along a lengthwise center line of the weight support base plate 1a. The weight 1 comprises the small weight 12 formed of a plurality of the same rectangular steel plates secured to an upper surface on the weight support base plate 1a and the large weight 11 formed of a rectangular cubic steel block secured to a lower surface of the weight support base plate. Accordingly, in the dynamic damping device, by adjusting a height of a spring, rigidity can be adjusted, so that a natural vibration frequency of the dynamic damping device can be set.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dynamic vibration absorbing device for damping the vibration of a large structure, a high-rise structure or the like.

[0002]

2. Description of the Related Art As shown in the side view of FIG. 7, the basic construction of a dynamic vibration absorber is a weight 01, a spring element 03, and a ball bearing 02.
In particular, the weight 01 includes a large weight 011 and a small weight 012 for adjustment. This type of dynamic vibration absorber can reduce the vibration amplitude, the vibration acceleration, etc. of the structure to be controlled by matching its natural frequency ω with the natural frequency ω ₀ of the structure to be controlled. Here, the natural frequency ω of the dynamic vibration absorber is given by the equation (1) by the mass M of the weight 01 and the rigidity K of the spring element 03. ω = √ (K / M) (1) Therefore, in order to adjust ω to ω ₀ , it is necessary to change M or K. Further, the damping of the dynamic vibration absorber for best reducing the vibration of the structure is given by the equation (2). ξ = √ [3μ / [8 (1 + μ) ³ ] (2) where μ = mass M of dynamic vibration absorber / amount of structural material M ₀ ξ = damping ratio

[0003]

However, in this type of dynamic vibration absorber, in order to match its natural frequency with that of the target structure in a wide range and accurately, as shown in FIG. It is necessary to adjust the small weight 012 on the weight 011 so that the adjustment takes time. Further, the center of gravity of the weight 01 changes with the increase of the small weight 012, which may impair the reliability of the dynamic vibration reducer.

The present invention has been proposed in view of the above circumstances and has a simple structure capable of adjusting the natural frequency over a wide range and reducing the change of the center of gravity due to the increase or decrease of the weight. It is an object of the present invention to provide a dynamic vibration damping device that is low in cost and highly reliable.

[0005]

In order to achieve this object, the present invention provides a left and right side plate 1 having the same cross section and the same length, which are projected parallel to each other along the left and right sides of a vertically long horizontal rectangular bottom plate. It consists of a pair of model steel rails, a ball bearing arranged on each of the above model steel rails, supported rotatably in the longitudinal direction, and a non-linear characteristic spring whose reaction force increases non-linearly as the height increases. A plurality of pairs of supporting members of the same size, a horizontal rectangular weight load support base plate having left and right portions supported on the plurality of support members and movable in the front-rear direction, and a vertical direction of the weight load support base plate. A large weight fixed on the lower surface of the base plate on the centerline of the direction and a small weight fixed on the upper surface of the base plate and made of rectangular steel plate of the same size, the upper ends of the springs and the weight load support. A shim with a plurality of plates inserted and supported between the base plate and Characterized in that was.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described with reference to the drawings. FIG. 1 is an overall cross sectional view thereof, and FIG.
-II is a vertical cross-sectional view as seen from the arrow, FIG. 3 is an enlarged view showing a part III in FIG.
FIG. 4 is a plan view and a side view showing the helical coil spring of FIG. FIG. 5 is a process diagram showing an assembling procedure of the helical coil spring shown in FIG. 4, and FIG. 6 is a characteristic diagram of the helical coil spring shown in FIG. 4 and a diagram showing its arrangement.

First, referring to FIGS. 1 and 2, the overall structure will be described. A helical coil spring (hereinafter referred to as a spring) 3 as a spring element on a vibration-damped structure 7, a large ingot 11 as a steel ingot and a small ingot. A horizontal vibration dynamic vibration absorber made up of a plurality of steel plates as the weight 12 and a T-shaped steel 5 is mounted. Here, the ball bearings 2 and the springs 3 are opposed to each other, and in this embodiment, four pairs of the ball bearings 2 and the springs 3 are arranged in two rows in the front-rear direction to form the left and right parallel I-shaped steels 5, 5. A total of 8 pairs are arranged above. A total of 8 pairs of ball bearings-on the spring, the left and right parts of a horizontal rectangular weight support base plate 1a are mounted and supported, and the weight 1 is supported along the longitudinal center line of the weight support base plate 1a. ,
The weight 1 is composed of a small weight 12 made of a plurality of identical rectangular steel plates fixed to the upper surface of the weight support base plate 1a, and a rectangular cubic steel ingot fixed to the lower surface of the weight support base plate. Large weight 1
It consists of 1.

Next, referring to FIGS. 3 to 4, the structure of the spring will be described. As shown in FIG. 4, the spring 3 has a horizontal rectangular upper bar 3a of the same size and a lower portion extending in the front-rear direction at appropriate vertical intervals. A plurality of bars 3b, and a plurality of bars of the same diameter (here, five front and rear parts, respectively) are formed on the left side surfaces and the right side surfaces of both bars 3a and 3b at a constant pitch.
c, the lower mounting holes 3d are five on each side of the front part, and the upper and lower bars are mounted on each of the upper and lower bars so that each of the five mounting holes is on the rear side so as to form an inverted V shape, as shown in FIG. The holes are formed so that both the upper and lower bars are V-shaped toward the center O. Here, the upper and lower ends of the semicircular spring element 3e made of a stranded wire are inserted into the pair of upper and lower mounting holes 3c and 3d, respectively, and fixed by a coagulating agent or the like. Therefore, in each spring element 3e, as shown in the plan view of FIG. 5A, the five front elements are oriented in the direction of expanding to the front, and the five rear elements are oriented in the direction of expanding to the rear. The total length of the coil spring element is L, the lateral width is B, and the total height is H. Here, an example of the procedure for assembling the helical coil spring will be described. In the side view of FIG. 1B, first, as shown in (1), 20 helical thin wires are bundled to form an appropriate length unit shown in (2). A spring is formed, and seven unit springs are bundled and curved as shown in (3) to manufacture a plurality of arc-shaped unit springs. Next, as shown in (4), each of the pair of upper and lower rectangular support base plates 1a, 1b is provided with five inclined insertion holes on each of the left and right sides at equal intervals, and then each arcuate unit. Insert the upper and lower ends of the spring into the insertion holes 3c and 3d of the upper and lower bars 3a and 3b, respectively,
Each is fixed with a coagulant or the like.

With such a structure, the dynamic vibration absorber can adjust the rigidity K by adjusting the height of the spring.
The natural frequency of the dynamic vibration absorber can be set to a required value without increasing or decreasing the weight of the weight.

The structure of the ball bearing portion will be described with reference to FIG.
2a is a plurality of equal-diameter steel balls inserted in the groove of the longitudinal groove member 2b vertically provided on the upper surface of the I-shaped steel 5, and 2c is attached along the left and right parts of the lower surface of the weight support base plate 1a. It is a plurality of shim plates of the same size that are worn and extend in the front-rear direction. Thus, the ball bearing 2 is formed by the equal-diameter steel ball 2a, the groove member 2b, and the shim plate 2c. In addition, when adjusting the thickness of the shim, the weight and the entire mounting base plate are lifted and the bolts and nuts are removed. Since the shim plate 2c is fixed to the support base plate 1a with bolts and nuts, it can be easily removed.

In the dynamic vibration absorbing device having such a structure, when the mass of the steel plate is M and the spring rigidity is K, the natural frequency of this dynamic vibration absorber can be obtained by the equation (3). Here, the rigidity K of the helical coil spring 3 has amplitude dependence (see FIG. 8) as shown in FIG. 6, and the static deflection x of the spring x
Is a function of. Usually, as shown in the figure, the relationship between the static deflection x and the rigidity K is expressed by the equation (3). K = A (1 / ^xr ) (3) A: constant r:> 1 Therefore, by adjusting the plate thickness of the shim 4 of the ball bearing, the natural frequency can be adjusted to the required value. Can be set.

In the above embodiment, the weight has the center of gravity of the entire apparatus located near the spring mounting position due to the weights of the large weight 11 and the small weight 12, and the weight adjustment is performed with the small weight. It is performed by increasing or decreasing only the steel plate forming the weight 12.

[0013]

In such a dynamic vibration reducer, the natural frequency can be adjusted by changing the static deflection amount of the spring and changing the rigidity without using a large number of small weights. Furthermore, since only the ball bearings bear the weight and the spring is not subjected to weight load, fatigue of the spring is small. Therefore, the performance and reliability of the dynamic vibration reducer can be improved.

In short, according to the present invention, a pair of left and right shaped steel rails having the same cross section and the same length are provided so as to project parallel to each other along the left and right sides of the bottom plate of the vertically long horizontal rectangle.
A plurality of pairs of the same size consisting of ball bearings respectively arranged on the above-mentioned type steel rails and rotatably supported in the longitudinal direction, and a non-linear characteristic spring whose reaction force increases non-linearly with an increase in height. A pair of support members, a horizontal rectangular weight load support base plate whose left and right portions are supported on the plurality of support members and movable in the front-rear direction, and a vertical centerline of the weight load support base plates, Between a large weight fixed to the lower surface of the base plate and a small weight fixed to the upper surface of the base plate and made of a rectangular steel plate of the same size, between the upper ends of the springs and the weight load support base plate. Equipped with a plurality of shims that are inserted and supported, the natural frequency can be adjusted over a wide range, and the change of the center of gravity due to the increase or decrease of the weight can be reduced. Simple structure, low cost and reliable To obtain a dynamic vibration absorber The present invention is extremely useful industrially.

[Brief description of drawings]

FIG. 1 is an overall cross-sectional view showing a dynamic vibration damping device of an embodiment of the present invention.

FIG. 2 is an overall vertical sectional view taken along line II-II of FIG.

FIG. 3 is an enlarged view showing a part III in FIG.

FIG. 4 shows the helical coil spring of FIG. 3, and FIGS. 4A and 4B are a plan view and a side view, respectively.

5A to 5C are process diagrams showing an assembling procedure of the helical coil spring shown in FIG.

FIG. 6 is a characteristic diagram of the helical coil spring of FIG. 4 and a diagram showing an arrangement procedure.

FIG. 7 is a basic configuration diagram showing a conventional dynamic vibration absorbing device.

8 is a diagram showing a relationship between static deflection and rigidity of the dynamic vibration absorbing device of FIG. 7, and showing that rigidity has amplitude dependency.

[Explanation of symbols]

 1 Weight 1a Support base plate (upper part) 1b Support base plate (lower part) 2 Ball bearing 2a Equal diameter steel ball 2b Groove member 2c Shim plate 3 Helical coil spring (spring) 3a Upper bar 3b Lower bar 3c Upper through hole 3d Lower part Through hole 3e Spring element 5 I-type steel 6 Cover 7 Damped structure 11 Large weight 12 Small weight

Claims (1)

[Claims] 1. A pair of left and right shaped steel rails having the same cross section and the same length, which are provided in parallel with each other so as to project along the left and right sides of a vertically long horizontal rectangular bottom plate, and are respectively arranged on the respective shaped steel rails. A plurality of pairs of support members of the same size, which include a ball bearing supported rotatably in the longitudinal direction and a non-linear characteristic spring whose reaction force increases non-linearly with an increase in height, and the plurality of support members. A horizontal rectangular weight load support base plate with left and right parts supported above and movable in the front-rear direction, and a large size fixed to the lower surface of the weight load support base plate on the vertical centerline of the weight load support base plate. A small weight that is fixed to the upper surfaces of the weight and the base plate and is made of a rectangular steel plate of the same size, and a plurality of shims that are inserted and supported between the upper ends of the springs and the weight load support base plate. A dynamic vibration absorbing device characterized by being provided.