JPH02180323A - Change method of proper vibration number of sub vibration system attached to main vibration system and vibration-proof device therefor - Google Patents

Abstract

PURPOSE:To make the vibration amplitude of a main vibration system the minimum value, by arranging between the main mass of the main vibration system and the sub mass of a sub vibration system 2 regulation springs mutually opposed in a direction which is at a right angle to the movement direction of these systems. CONSTITUTION:A main vibration system consists of a main mass M1 and a main spring having a spring constant K1. A sub vibration system consists of a sub mass M2 and a sub spring K2 having a spring constant K2. Between the main mass M1 and the sub mass M2, at least 2 regulation springs (spring constants K3) are arranged in mutual opposition and in a direction which is at a right angle to the movement direction V of these systems. The regulation of the proper vibration number of the sub vibration system is conducted by changing the pre-load of the regulation spring (spring constants K3). Thus, the vibration amplitude of the main vibration system can be made minimum.

Description

[Detailed Description of the Invention] L1 Vol. 2 and Month 11 The present invention is a vibration system consisting of a main vibration system and a sub-vibration system (also called a "dynamic damper"), in which the natural frequency of the sub-vibration system is made variable. The present invention relates to a method and a vibration isolator implementing this method.

In general, one vibration system is constructed by adding a sub-vibration system to the main vibration system, and the natural frequency of the sub-vibration system is selected appropriately relative to the natural frequency of the main vibration system. By doing this, the amplitude of the main vibration system of this vibration system can be made extremely small.
It is a known place. For example, this is stated in the rlB
, 2 constant speed type dynamic damper. It is also known that various vibration isolating devices that utilize the principles of such a vibration system have been developed.

By the way, in such a vibration system, in order to make the amplitude of the system zero when there is a change in the natural frequency of the main vibration system, the characteristic frequency of the secondary vibration system (dynamic damper) must be changed accordingly. It is also necessary to change the vibration frequency. To do this, it is necessary to change the spring constant of the springs and masses that make up the sub-vibration system, or increase or decrease the mass, or both. There is.

However, in order to change the spring constant, it is necessary to replace the springs or increase or decrease the number of springs, which requires large-scale construction work. On the other hand, when the mass increases or decreases, in addition to the same problem, there is also the problem that the level must be readjusted because the total weight changes.

In addition, even in a vibration isolator that uses such a vibration system, if there is a change in the natural frequency of the main vibration system that makes up the device, it may be difficult to adjust the attached sub-vibration system. The problem was that there was no.

Therefore, in the above-mentioned vibration system, the present invention uses a conventional method to adjust the natural frequency of the sub-vibration system when there is a change in the natural frequency of the main vibration system. The object of the present invention is to find a new method that can easily do this without replacing the spring or increasing or decreasing the mass.

Further, it is an object of the present invention to obtain a novel vibration isolating device that implements this method.

In the present invention, in order to solve this problem, the method includes a main vibration system (soil type ff1M1 and spring constant
A secondary vibration system (consisting of a main spring with a rigidity of 1i M
2 and a secondary spring with a spring constant of 2), there is a at least two adjusting springs (
The spring constants K3) are arranged opposite to each other, and the sub-vibration system (
Deputy MN, M7. This is characterized in that the natural frequency of the secondary spring (2) is adjusted by changing the preload of the adjustment spring (spring constant K3).

In addition, in the device, the flat main vibration system mass receiver whose planar outline is approximately rectangular is placed on a lower frame having approximately the same dimensions and whose planar outline is also flat. At each corner, the main vibration system's main spring (spring constant K3) is placed between them, and the main vibration system's mass receiver is installed horizontally at the bottom of the frame. The sub-vibration system mass receiver, which is almost rectangular in shape but smaller in size, has a frame on which the sub-vibration system is constructed. The total mass 82) of the sub-mass is arranged horizontally so that it can be placed freely, and this sub-vibration system mass receiver has four sub-vibration system mass suspension rods connected to each lower end at the four corners of the frame. , the main vibration system mass receiver extends upward so as to loosely penetrate the frame, and there is a connection between the two ends of each sub-vibration system mass suspension rod and the top surface of the main vibration system soil mass frame. Arrange the secondary springs (spring constant K3) of the system,
Furthermore, the auxiliary vibration system support has at least one adjustment spring support rod connected to each end of the pair of opposing side walls of the frame and horizontally perpendicular to each side wall. In addition, the upper main vibration system mass receiver is rearranged so that it extends beyond the corresponding side wall of the frame, and in this case, the main vibration system mass receiver is separated from the side wall of the frame by a bracket at the location of each adjustment spring support rod. are respectively suspended so that each adjustment spring support rod loosely passes through them, and between these brackets and the outer end of the adjustment spring support rod, an adjustment spring (with a spring constant of 3 ), respectively.

Hereinafter, the present invention will be explained in detail based on FIGS. 1 to 5 of the attached one-dimensional drawings showing the principle of the method and an embodiment of the apparatus.

First, FIG. 1 is a schematic diagram showing the principle of the present invention, and in the figure, each reference numeral represents the following element, respectively. That is, Ml...main vibration system main mass (quality 1M), K1...main vibration system main spring (spring constant KI), C1...vibration vibration system damper, M2...sub-vibration system quality n< quality Hk M2),
K2...Sub-vibration system sub-spring (spring constant 2), C2...
- Sub-vibration system damper, K, - Adjustment spring for sub-vibration system adjustment (spring constant K3).

Further, from this figure, the relationship between each element is clear without any special explanation.

Then, such a secondary vibration system (rigidity 1 and secondary spring 2)
The main vibration system (consisting of soil ffl old and main spring K3) is configured to vibrate in the direction indicated by arrow V.

In the present invention, the main mass M having such an arrangement is
+ and a main vibration system (M,, K3) consisting of the main spring,
In a vibration system consisting of a rigid mass and a secondary spring, and a secondary vibration system (dynamic damper) (M2. to 2), the rigid mass that constitutes the secondary vibration system (M2. to 2) is composed of a rigid mass and a secondary spring. I
M2 and the soil J that makes up the main vibration system (M,, K1)
! LM, and are connected by 3 (in the case of this figure, 2 sets) to two or more sets of adjustment springs having a spring constant arranged perpendicular to the direction of motion V of this vibration system. It is characterized by:

In the vibration system according to the present invention having such a configuration, the natural frequency of the main vibration system (I in M5.) is changed by 1.
In order to make the amplitude zero when the vibration occurs, conventionally this is a sub-vibration system (dynamic damper) (M2. to 2).
What was previously done by changing the natural frequency of 2 to the rigid N M 2 and/or the secondary spring can be done by changing the preload of 2 to the adjustment spring.

That is, as shown in FIG. 2, there are five preloads ffi.
The length of the adjustment spring under (F,) is 1.
° closing, and 1. the main vibration system in the direction of the movement direction V of the vibration system 11. If the relative displacement between the and the sub mass M2 of the sub vibration system is X, the restoring force F in the movement direction V of the sub 11□ of the sub vibration system due to the adjustment spring 3 is X/l
, 41 then PL, (F,/10)-X =
- (1) allows approximation. In addition, preload F. If δ is the deflection of 1 inch, then F, = ・δ. ) Therefore, the spring constant of the sub-vibration system is '-' when two sets of adjustment springs are used as in this example.
2-1-2 (F, /lo) -(2)
By changing the installation deflection δ, the preload F can be calculated as follows. increases or decreases, and therefore the secondary vibration system (M2.
) can be changed.

The method of the present invention utilizes this principle, and the main vibration system (MK,)
In a vibration system consisting of a sub-vibration system (M2., 2), when there is a change in the natural frequency of the main vibration system (M,, K3), in order to minimize the amplitude, An adjustment spring is placed between each ft1M and M2 of the main and sub-vibration system in a direction transverse to the motion direction V of this vibration system.
Planned load F. This is done by changing the .

Next, one embodiment of the vibration isolating device according to the present invention, which includes a vibration system made according to this principle, will be explained based on FIGS. 3 to 5. However, this device uses a compression spring as the adjustment spring.

As can be seen from these figures, in the device of the present invention, the flat main vibration system mass receiver whose planar outline is approximately rectangular has the same dimensions as Frenim 1, and whose flat plate outline is also flat. on the lower frame 2 of, arranged vertically between them at each corner, with a spring constant of 1,
The main vibration system mass receiver is installed horizontally via the main vibration system spring 3 configured as a compression spring, and the main vibration system mass receiver is located at the bottom of the frame 1 between it and the lower frame 2, although it has an approximately rectangular shape. The main vibration system mass receiver carries the mass that constitutes the sub-vibration system, which is smaller than the dimensions of the frame 1.The sub-vibration system mass receiver has the frame 4 placed horizontally; 4, the four sub-vibration system masses i15 are connected at their lower ends at their four corners, and the main vibration system mass receiver extends vertically upward so as to loosely pass through the frame 1. A spring constant of 2
A sub-vibration system spring 6 configured as a compression spring having a Two spring support rods 7 for I11 spaced apart from each other are rotatably connected via pins 8 at each end, and are connected to each side wall. The main vibration system mass receivers on the top and at right angles to the frame 1 are arranged horizontally so as to extend beyond the corresponding side walls of the frame 1. At the spring support rods 7, plate-shaped brackets 9 having rectangular outlines with their upper ends fixed are suspended so that each adjustment spring support rod 7 loosely passes through them. A compression spring 10 as an adjustment spring having a spring constant of is disposed between each of these brackets 9 and the outer end of each adjustment spring support rod 7. The adjustment spring 10 has a preload of P1 by means of an adjustment nut 11 screwed into the free end of the adjustment spring support rod 7.
In addition, a spherical bearing 11 is attached outwardly to the penetrating portion of the adjustment spring support rod 7 of each bracket 9, and the adjustment spring 10 is mounted on the adjustment spring support rod 7. By adjusting the adjusting nut 11, the preload F0 can be adjusted between the adjusting nut 11 screwed into the vicinity of its free end and the spherical bearing 12 attached to the plate nod 9.
The spherical bearing 12 is used to prevent the adjustment spring support rod 7 from interfering with the free vertical movement of the frame 4, and the auxiliary vibration system mass receiver.

One embodiment of the device of the present invention has the above configuration, and the main vibration system mass receiver is mounted on the frame 1, for example, the vibration generating machine 20 (its mass and main vibration system mass receiver are mounted on the frame 1). 1, the total mass of which corresponds to the main mass H2 of the main vibration system in FIG. When the mass receiver is mounted with a frame 4 whose total mass corresponds to the sub-mass H2 of the sub-vibration system, the vibration of the vibration-generating machine 20 is supported via the lower frame 2. It is used to prevent the vibration from being transmitted to the floor of the building where the vibration is generated.
If the natural frequency of 0 differs from the design value on which the device is based, the preload of the adjustment spring 10 can be adjusted by adjusting the
1, the natural frequency of the auxiliary vibration system consisting of the compression spring 6 having a stiffness tL and a spring constant of 2 is changed according to the principle explained above, and the vibration of the vibration generating machine 20 is reduced. , can be prevented from being transmitted to the support frame 2.

Since the present invention has the above-described configuration and operation, when the natural frequency of the main vibration system changes in a vibration system consisting of a main vibration system and a sub-vibration system, To provide a method for adjusting a sub-vibration system, which makes it easy to change the natural frequency of the sub-vibration system, thereby making it easy to minimize the amplitude of the main vibration system, and to provide a vibration isolator implementing this method. It is.

[Brief explanation of the drawing]

Fig. 1 is a schematic diagram of the overall arrangement for explaining the principle of the method of the present invention, Fig. 2 is a schematic diagram illustrating the action of the adjustment spring, and Fig. 3 shows one embodiment of the device of the present invention. A plan view, FIG. 4 is a sectional view taken along the 1C IV line in FIG. 3, and FIG. 5 is a cross-sectional view taken along the v-vt! ; It is a sectional view according to A. ■...Main vibration system mass receiver is frame, 2...Lower frame, 3...Main vibration system spring, 4...Sub-vibration system 'n quantity receiver is frame, 5...Sub-vibration system a quantity Hanging cup, 6... Secondary vibration system spring, 7... Spring support rod for adjustment, 8... Pin,
9... Bracket, IO/adjustment spring, 11... Adjustment nut, 12... Spherical bearing, 20... Vibration generation n
Machine, 21... Sub-vibration system mass is sub-mass on the frame. Special JT applicant: Mitsubishi Steel Corporation

Claims (1)

[Claims] 1. A sub-vibration system (consisting of a sub-mass M_2H and a sub-spring K_2 having a spring constant K_2) is attached to the main vibration system (consisting of a main mass M_1 and a main spring having a spring constant K_1). In the vibration system, the main mass (M_1) of the main vibration system,
Between the secondary mass (M_2) of the secondary vibration system, at least two adjustment springs (
By arranging the spring constants K_3) to face each other, and changing the preload of the adjustment spring (spring constant K_3), the natural frequency of the sub-vibration system (sub-mass M_2, sub-spring K_2) can be adjusted. A method for changing the natural frequency of a sub-oscillation system in a vibration system, characterized in that: 2. A flat main vibration system mass receiving frame having a substantially rectangular planar outline is placed on top of a lower frame having approximately the same dimensions and also having a flat planar outline at each corner,
It is installed horizontally via the main spring (spring constant K_1) of the main vibration system placed between them, and at the bottom of the main vibration system mass receiving frame, between it and the lower frame.
A sub-vibration system mass receiving frame, which is almost rectangular in shape but smaller in size, is placed on top of the sub-vibration system mass receiving frame (total mass M_2 of the sub-vibration system mass receiving frame and the sub-mass). The sub-vibration system mass receiving frame is arranged horizontally so that it can be freely placed, and from this sub-vibration system mass receiving frame, four sub-vibrating system mass suspension rods, each of which is connected at its lower end, are connected at its four corners, and the main vibration system mass receiving frame is loosely connected. A sub-spring (spring constant K_2) of the sub-vibration system is installed between the upper end of each sub-vibration system mass suspension rod and the top surface of the main vibration-receiving frame, extending upward to penetrate. Further, from a pair of opposing side walls of the sub-vibration system mass receiving frame, at least one adjustment spring support rod is connected at each end, and each is perpendicular to each side wall. It is arranged horizontally and extends beyond the corresponding side wall of the upper main vibration system mass receiving frame, and in this case, a bracket is attached from the side wall of the main vibration system mass receiving frame at the location of each adjustment spring support rod. , respectively, so that each adjustment spring support rod loosely passes through the brackets, and between these brackets and the outer end of the adjustment spring support rod,
A vibration isolator characterized in that adjustment springs (spring constant K_3) are arranged respectively.