JP2022178881A - Attenuation addition device - Google Patents

Abstract

To provide an attenuation addition device which can attenuate the vibration of a vibration control object with respect to wide-range input acceleration.SOLUTION: An attenuation addition device 1 comprises: a restoration force generation part 6 arranged between a bottom part of a vibration control object B and a placing part C on which the vibration control object B is placed, and generating a restoration force for restoring a relative position to a default position P1 when the relative position of a lower face B1 of the vibration control object B with respect to an upper face C1 of the placing part C is changed to a second position P2 from the default position P1; a pressing force generation part 7 for generating a pressing force for pressing the lower face B1 of the vibration control object B to the upper face C1 of the placing part C; and a friction force adjusting part 8 for changing a friction force which the vibration control object B directly or indirectly receives from the upper face C1 of the placing part C depending on a length of a distance from the default position P1 up to the second position P2.SELECTED DRAWING: Figure 4

Description

An embodiment of the present invention relates to a damping application device, and more particularly to a vibration damping technique for suppressing response displacement to vibration input such as seismic waves and shock waves.

Various devices installed in nuclear power plants and the like are desirably constructed so as to maintain their functions against various external forces such as seismic loads and impact loads of flying objects. In recent years, the design basis seismic ground motion has been revised, and the assumed seismic load has been overestimated. In some cases, it is difficult to ensure earthquake resistance only by rigidly reinforcing measures to withstand the tremors of conventional earthquakes. For this reason, countermeasures have been proposed that incorporate the concept of seismic isolation to prevent direct transmission of seismic input from the building to the equipment. As a method of incorporating seismic isolation, there is a method of installing seismic isolation devices such as laminated rubber and sliding bearings between various equipment and the floor of the building. As for the spent nuclear fuel storage rack, there is a self-supporting installation method in which the spent nuclear fuel storage rack is placed on the bottom of the fuel pool without being fixed with anchor bolts. In a general seismic isolation device, since the natural frequency is set to be lower than the frequency range including the main component of the seismic motion, the response displacement to the vibration input increases. Therefore, the support member that supports the lower end of the equipment is provided with a mechanism that adjusts the restoring force and the frictional force. There have been proposed techniques for suppressing the vibration input of the

FIG. 5 of Patent Literature 2 shows that large damping can be applied to a damping object.

Japanese Patent No. 6591310 JP 2020-85158 A

A conventional damping addition device has a problem that when an acceleration exceeding the input acceleration to which the optimum damping is added is input, the damping to be added gradually decreases.
SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a damping addition device capable of attenuating the vibration of an object to be damped against a wide range of input acceleration.

In order to solve the above problems, an attenuation applying device in an embodiment is arranged between a bottom portion of an object to be damped and a mounting portion on which the object to be damped is placed, and the object to be damped Restoration generating a restoring force for restoring the relative position to the default position when the relative position of the lower surface of the vibration damping object with respect to the upper surface of the mounting portion changes from a default position to a second position due to vibration. a force generating portion, a pressing force generating portion for generating a pressing force for pressing the lower surface of the object to be damped against the upper surface of the mounting portion, and the object to be damped directly from the upper surface of the mounting portion. Alternatively, the frictional force adjustment unit changes the frictional force indirectly received depending on the size of the distance from the default position to the second position.

According to the embodiments of the present invention, it is possible to provide a damping addition device capable of damping the vibration of a damping object against a wide range of input acceleration.

FIG. 1 is a schematic front view schematically showing how the damping applying device according to the first embodiment or the second embodiment is attached to an object to be damped. FIG. 2 is a schematic cross-sectional view schematically showing an example of a restoring force generating portion. FIG. 3 is a schematic cross-sectional view schematically showing an example of the pressing force generating portion. FIG. 4 is a schematic cross-sectional view schematically showing an example of the frictional force adjusting section. FIG. 5 is a schematic cross-sectional view schematically showing an example of the frictional force adjusting section. FIG. 6 is a schematic cross-sectional view schematically showing a first modified example of the frictional force adjusting section. FIG. 7 is a schematic cross-sectional view schematically showing a second modification of the frictional force adjusting section. FIG. 8 is a schematic diagram showing a vibration model of an object to be damped to which a conventional damping adding device is attached. FIG. 9 is a schematic diagram showing a vibration model of an object to be damped to which the damping applying device according to the first embodiment is attached. FIG. 10 is a graph showing the relationship between input acceleration and damping ratio. FIG. 11 is a graph showing the relationship between the natural frequency ratio and the damping ratio. FIG. 12 is a schematic cross-sectional view schematically showing an example of a frictional force adjusting section of a damping adding device according to the second embodiment.

An attenuation applying device 1 according to an embodiment will be described below with reference to the accompanying drawings. In the following description, members and portions having the same functions are denoted by the same reference numerals, and repeated descriptions of members and portions denoted by the same reference numerals are omitted.

(First embodiment)
An attenuation adding device 1A according to the first embodiment will be described with reference to FIGS. 1 to 11. FIG. FIG. 1 is a schematic front view schematically showing how an attenuation applying device 1A according to the first embodiment is attached to a damping object B. FIG. In FIG. 1, in order to make it easier to understand the arrangement of the attenuation applying device 1A, the parts other than the device 2 are shown in cross-sectional views instead of front views. FIG. 2 is a schematic cross-sectional view schematically showing an example of the restoring force generator 6. As shown in FIG. FIG. 3 is a schematic cross-sectional view schematically showing an example of the pressing force generating portion 7. As shown in FIG. 4 and 5 are schematic cross-sectional views schematically showing an example of the frictional force adjusting portion 8. FIG. FIG. 6 is a schematic cross-sectional view schematically showing a first modified example of the frictional force adjusting section 8. As shown in FIG. FIG. 7 is a schematic cross-sectional view schematically showing a second modification of the frictional force adjusting section 8. As shown in FIG. FIG. 8 is a schematic diagram showing a vibration model of a damping object B to which a conventional damping applying device 100 is attached. FIG. 9 is a schematic diagram showing a vibration model of a damping object B to which the damping applying device 1A according to the first embodiment is attached. FIG. 10 is a graph showing the relationship between input acceleration and damping ratio. FIG. 11 is a graph showing the relationship between the natural frequency ratio and the damping ratio.

(Structure/action)
The damping applying device 1A in the first embodiment is arranged between the damping object B and the mounting portion C such as the sliding disk 4. As shown in FIG. The attenuation applying device 1A is used to attenuate the vibration generated in the damping object B when an external force such as an earthquake load or an impact load acts on the mounting portion C. FIG. Spent nuclear fuel storage racks, electric panels, pumps, heat exchangers, transformers, and the like used in nuclear power plants are examples of damping objects B. FIG.

In the example shown in FIG. 1, a sliding plate 4 is placed on the floor surface 3 of the building. The sliding plate 4 is fixed to the floor surface 3 by fixing members 91 such as bolts. In the example shown in FIG. 1, the mounting portion C on which the vibration damping object B is mounted is the sliding plate 4, but the mounting portion C may be the floor surface 3 itself.

In the example shown in FIG. 1, the damping object B is equipment 2 (for example, storage equipment such as spent nuclear fuel storage racks, electrical equipment such as electrical panels and transformers, thermal equipment such as heat exchangers, or a fluid device such as a pump) and a base member 5. The base member 5 is fixed to the lower surface of the device 2 by welding, bolts, or the like. Alternatively, the device 2 may be placed directly on the placement portion C and the base member 5 may be omitted.

In the example shown in FIG. 1, the base member 5 is provided with a restoring force generating portion 6, a pressing force generating portion 7, and a frictional force adjusting portion 8, which will be described later. The base member 5 may have a housing structure capable of accommodating at least part of the restoring force generating section 6 , the pressing force generating section 7 , and the frictional force adjusting section 8 . In the example shown in FIG. 1, the base member 5 has a plurality of side plates 5A, a lower plate 5B and an upper plate 5C. The lower portions of the side plates 5A are fixed to the lower plate 5B by welding or the like, and the upper portions of the side plates 5A are fixed to the upper plate 5C by welding or the like.

A damping applying device 1A in the first embodiment includes a restoring force generating section 6, a pressing force generating section 7, and a frictional force adjusting section 8. As shown in FIG.

The restoring force generator 6 is arranged between the bottom of the object B to be damped (for example, the base member 5) and the mounting portion C (for example, the sliding plate 4) on which the object B to be damped is placed. be done. In the example shown in FIG. 2A, the vibration of the damping object B due to the external force acting on the mounting part C causes the bottom surface B1 of the damping object B with respect to the top surface C1 of the mounting part C. In the example shown in FIG. changes from the default position P1 (in other words, first position) to a second position P2 (see FIG. 2B) different from the default position P1.

When the vibration of the vibration damping object B causes the relative position of the bottom surface B1 of the vibration damping object B with respect to the top surface C1 of the mounting portion C to change from the default position P1 to the second position P2, the restoring force generating unit 6 , generates a restoring force that restores the relative position to the default position P1 (see FIG. 2(a)).

In the example shown in FIG. 3A, the pressing force generator 7 generates a pressing force that presses the lower surface B1 of the damping object B against the upper surface C1 of the mounting portion C. In the example shown in FIG. The pressing force generates a frictional force between the lower surface B1 and the upper surface C1 when the lower surface B1 of the damping object B slides on the upper surface C1 of the mounting portion C. As shown in FIG. For example, the pressing force generator 7 changes the relative position of the bottom surface B1 of the damping object B with respect to the top surface C1 of the mounting part C from the default position P1 to the second position P2 when the damping object B vibrates. , a frictional force F1 is applied to the lower surface B1 of the damping object B in the direction from the second position P2 toward the default position P1. The frictional force F1 absorbs the vibration energy of the damping object B, and the vibration of the damping object B is attenuated.

In the example shown in FIGS. 4 and 5, the frictional force adjusting section 8 adjusts the frictional force directly or indirectly received by the damping object B from the upper surface C1 of the placing section C from the default position P1 to the second position. It changes depending on the magnitude of the distance to P2.

4 and 5, the relative position of the lower surface B1 of the damping object B with respect to the upper surface C1 of the placement section C is the default position P1 (see FIG. 4(a) or FIG. 5(a)). to the second position P2 (see FIG. 4(b) or FIG. 5(b)). In the example shown in FIG. 4B, the distance from the default position P1 to the second position P2 is relatively small. In this case, the frictional force adjusting unit 8 adjusts the magnitude (F1) of the frictional force directly or indirectly applied to the vibration damping object B from the upper surface C1 of the mounting unit C to a relatively small value. do. In the example shown in FIG. 5B, the distance from the default position P1 to the second position P2 is relatively large. In this case, the frictional force adjusting unit 8 adjusts the magnitude of the frictional force (F1+F2) that the damping object B directly or indirectly receives from the upper surface C1 of the mounting unit C to a relatively large value. do.

(effect)
In the first embodiment, the damping applying device 1A reduces the frictional force directly or indirectly received by the vibration damping object B from the upper surface C1 of the mounting portion C to the distance from the default position P1 to the second position P2. It has a frictional force adjuster 8 that changes depending on the size. Depending on the magnitude of the distance from the default position P1 to the second position P2, in other words, the magnitude of change in the relative position of the lower surface B1 of the object to be damped B with respect to the upper surface C1 of the mounting portion C, the vibration damping By changing the magnitude of the frictional force that functions as the braking force acting on the object B, the vibration of the damping object B can be effectively damped against a wide range of input acceleration. For example, when the input acceleration input to the damping object B is large and the amplitude of the damping object B is large, a larger braking force acts. As a result, the vibration of the damping object B can be effectively damped.

(optional additional configuration)
Next, with reference to FIGS. 1 to 7, an optional additional configuration that can be employed in the attenuation adding device 1A according to the first embodiment will be described.

(Friction force adjustment unit 8)
In the examples shown in FIGS. 4 and 5, the frictional force adjusting section 8 slides on the upper surface C1 of the mounting section C depending on the distance from the default position P1 to the second position P2. Change the total area of the sliding surface.

In the example shown in FIG. 4B, the distance from the default position P1 to the second position P2 is relatively small. In the example shown in FIG. 4B, the sliding surface that slides against the upper surface C1 of the mounting portion C is the lower surface B1 of the vibration damping object B (more specifically, the lower surface B1 of the base member 5). ).

In the example shown in FIG. 5B, the distance from the default position P1 to the second position P2 is relatively large, and the damping object B is in contact with the sliding block 17. In the example shown in FIG. In the example shown in FIG. 5B, the damping object B and the sliding block 17 slide with respect to the mounting portion C. In the example shown in FIG. In this case, the sliding surfaces that slide against the upper surface C1 of the mounting portion C are the lower surface B1 of the vibration damping object B (more specifically, the lower surface B1 of the base member 5) and the sliding block 17. It is both the lower surface 17w. Therefore, in the example shown in FIG. 5(b), the total area of the sliding surface that slides on the upper surface C1 of the mounting portion C is larger than that in the example shown in FIG. 4(b). Since the total area of the sliding surfaces is large, the magnitude of the frictional force directly or indirectly applied to the damping object B from the upper surface C1 of the mounting portion C becomes a relatively large value. In the example shown in FIG. 5B, the vibration damping object B directly receives the frictional force F1 from the upper surface C1 of the mounting portion C, and the vibration damping object B receives the frictional force F1 from the upper surface C1 of the mounting portion C via the sliding block 17. Frictional force F2 is received indirectly.

(sliding block 17)
In the example shown in FIG. 4( a ), the frictional force adjuster 8 has a sliding block 17 provided independently of the base member 5 forming the bottom of the damping object B. In the example shown in FIG. The sliding block 17 is mounted on the sliding plate 4 forming the mounting portion C so that a gap 16 is formed between the sliding block 17 and the base member 5 .

It is assumed that the input acceleration input to the mounting portion C is small and the vibration response of the damping object B is small. When the vibration response of the vibration damping object B is small, as illustrated in FIG. ) is smaller than the magnitude e. In this case, the base member 5 does not come into contact with the sliding block 17, and only the base member 5 slides on the mounting portion C. As shown in FIG. Therefore, the presence of the sliding block 17 does not contribute to an increase in the frictional force that the damping object B receives from the upper surface C1 of the mounting portion C. As shown in FIG.

Next, it is assumed that the input acceleration input to the mounting portion C is large, and the vibration response of the damping object B is increased. When the vibration response of the damping object B is large, as illustrated in FIG. ) becomes larger than the magnitude e. In this case, the contact of the base member 5 with the sliding block 17 increases the frictional force directly or indirectly applied to the damping object B from the upper surface C1 of the mounting portion C. As shown in FIG. More specifically, both the base member 5 and the sliding block 17 slide with respect to the mounting portion C by the contact of the base member 5 with the sliding block 17 . As a result, the vibration-damping object B is moved from the top surface of the mounting part C by the additional frictional force F2 indirectly received by the vibration-damping object B from the top surface C1 of the mounting part C via the sliding block 17 . The frictional force received from C1 increases.

In the example shown in FIG. 5B, the relative displacement between the base member 5 and the sliding disk 4 is the threshold value e (more specifically, the gap 16 between the sliding block 17 and the base member 5). When the magnitude e) is exceeded, an additional frictional force F2 is generated in the sliding block 17 of the frictional force adjusting unit 8, and the frictional force F1 between the base member 5 and the upper surface C1 of the sliding disk 4 and the additional frictional force F1 Vibrational energy of the damping object B is absorbed by the frictional force F2. In the example shown in FIG. 5, by setting the size of the gap 16 between the sliding block 17 and the base member 5 according to the size of the assumed relative displacement, the threshold value e can be easily set. It is possible to adjust.

In the example shown in FIG. 4A, a first through-hole portion 511h is formed in the base member 5 (more specifically, the lower plate 5B of the base member 5), and the sliding block 17 is provided with the first through-hole portion 511h. It is arranged inside one through-hole portion 511h. A gap 16 is formed between the outer surface 17t of the sliding block 17 and the inner surface of the first through hole portion 511h. In a state where the relative position of the lower surface B1 of the damping object B with respect to the upper surface C1 of the mounting portion C is the default position P1, the distance between the outer surface 17t of the sliding block 17 and the inner surface of the first through hole portion 511h ( e) corresponds to the size of the gap 16 .

The sliding block 17 may have a ring shape in plan view, or may have another shape. The outer surface 17t of the sliding block 17 may have a circular shape in plan view, and the inner surface of the first through hole portion 511h may have a circular shape in plan view. In the example shown in FIG. 4A, in a state where the relative position of the lower surface B1 of the vibration damping object B with respect to the upper surface C1 of the mounting portion C is the default position P1, the center of the sliding block 17 in plan view, It coincides with the center of the first through-hole portion 511h in plan view. Alternatively, in a state where the relative position of the lower surface B1 of the damping object B is the default position P1, the center of the sliding block 17 in plan view is displaced from the center of the first through hole portion 511h in plan view. good too.

For example, in a state in which the relative position of the lower surface B1 of the damping object B with respect to the upper surface C1 of the mounting portion C has returned from the second position P2 to the default position P1, the center of the sliding block 17 in plan view is It may be shifted from the center of the first through hole portion 511h. When the vibration damping object B has returned to the default position P1 and the center of the sliding block 17 in plan view is deviated from the center of the first through hole portion 511h in plan view, the size of the gap 16 is means the minimum distance between the outer surface 17t of the sliding block 17 and the inner surface of the first through hole portion 511h.

(Other Configurations of Frictional Force Adjusting Unit 8)
In the example shown in FIG. 4A , the frictional force adjusting section 8 has a first shaft 18 , a first biasing force adjusting member 19 and a first elastic member 21 . The friction force adjuster 8 may have washers 20 such as a first washer 20a and a second washer 20b.

In the example shown in FIG. 4A, the first shaft 18 is fixed to the mounting portion C (more specifically, the sliding platen 4). The first shaft 18 is fixed to the mounting portion C by screwing or the like. In the example shown in FIG. 4A, a through hole portion 17h is formed in the slide block 17, and the first shaft 18 is inserted into the through hole portion 17h. A lower end portion 18b of the first shaft 18 is fixed to the slide plate 4 by screwing or the like.

The first biasing force adjusting member 19 can change its position along the longitudinal axis AX<b>1 of the first shaft 18 . The first biasing force of the first elastic member 21 is adjusted by changing the position of the first biasing force adjusting member 19 along the longitudinal axis AX1 of the first shaft 18 . The first biasing force adjusting member 19 may be any member as long as the position thereof can be changed along the longitudinal axis AX1 of the first shaft 18 . The first biasing force adjusting member 19 may be a first nut 190 screwed onto the first shaft 18, or may be a cam member that moves along a cam groove formed in the first shaft 18. . Further, when the first shaft 18 is a bolt, the first biasing force adjusting member 19 may be the head of the bolt.

In the example shown in FIG. 4A , the first biasing force adjusting member 19 is a first nut 190 that screws onto the first shaft 18 . In the example shown in FIG. 4A, a male threaded portion is formed on the upper end portion 18a of the first shaft 18, and the first nut 190 is screwed onto the male threaded portion. In this case, by rotating the first nut 190 relative to the first shaft 18 around the longitudinal axis AX1 of the first shaft 18, the first nut 190 rotates along the longitudinal axis AX1 of the first shaft. repositioned along The first nut 190 is rotated by, for example, a known rotating jig (not shown).

The first elastic member 21 is arranged between the first biasing force adjusting member 19 (more specifically, the first nut 190 ) and the sliding block 17 . The first elastic member 21 applies a first biasing force to the sliding block 17 in the direction toward the sliding disk 4 (more specifically, vertically downward direction). By changing the position of the first biasing force adjusting member 19 along the longitudinal axis AX<b>1 of the first shaft 18 , the amount of elastic deformation of the first elastic member 21 is changed to change the amount of elastic deformation applied to the sliding block 17 . The magnitude of the first biasing force is changed (in other words, the first biasing force is adjusted).

In the example shown in FIG. 4A, the first elastic member 21 includes a plurality of disc springs stacked along the longitudinal direction of the first shaft 18. In the example shown in FIG. Alternatively, the first elastic member 21 may be a spring other than a disc spring, or rubber. In the example shown in FIG. 4( a ), the first elastic member 21 is arranged around the first shaft 18 .

In the example shown in FIG. 4( a ), the first washer 20 a is arranged between the first elastic member 21 and the sliding block 17 . The first washer 20a smoothly guides the movement of the sliding block 17 when the sliding block 17 slides on the upper surface C1 of the mounting portion C. As shown in FIG. The coefficient of static friction between the lower surface of the first washer 20a and the upper surface of the sliding block 17 is preferably smaller than the coefficient of static friction between the lower surface 17w of the sliding block 17 and the upper surface C1 of the mounting portion C. . In this case, when the sliding block 17 is pressed by the base member 5, the sliding block 17 is smoothly guided by both the first washer 20a and the mounting portion C, and the first washer 20a and the mounting portion C slide against both.

In the example shown in FIG. 4( a ), the first washer 20 a functions as a lower spring retainer that contacts the lower end of the first elastic member 21 .

In the example shown in FIG. 4A , the second washer 20 b is arranged between the first biasing force adjusting member 19 (more specifically, the first nut 190 ) and the first elastic member 21 . The second washer 20 b functions as an upper spring retainer that contacts the upper end of the first elastic member 21 . In the example shown in FIG. 4A, the second washer 20b smoothly guides the rotation of the first nut 190 when the first nut 190 is rotated.

In the example shown in FIG. 5A, when an external force such as an earthquake load or an impact load acts on the mounting portion C, the base member 5 slides on the upper surface C1 of the sliding disk 4, causing the upper surface C1 of the sliding disk 4 to slide. The relative position of the lower surface B1 of the base member 5 with respect to C1 changes from the default position P1 to the second position P2. When the distance from the default position P1 to the second position P2 (in other words, the relative displacement of the base member 5 with respect to the sliding plate 4) exceeds the size e of the gap 16, the base member 5 and the sliding block 17 come into contact with each other. Then, the base member 5 and the sliding block 17 slide against the sliding disk 4 (see FIG. 5(b)). When the base member 5 and the sliding block 17 slide against the sliding disk 4, a frictional force F1 is generated from the sliding disk 4 to the base member 5 in the direction from the second position P2 to the default position P1. An additional frictional force F2 is generated from the moving platen 4 to the sliding block 17 in the direction from the second position P2 toward the default position P1. Vibrational energy of the damping object B is absorbed by the frictional force F1 and the additional frictional force F2.

In the example shown in FIG. 5B (in other words, when the input acceleration input to the mounting portion C is relatively large), the frictional force F1 acting between the sliding plate 4 and the base member 5 , and the additional frictional force F2 acting between the sliding disk 4 and the sliding block 17 contribute to damping the vibration of the object B to be damped. On the other hand, in the example shown in FIG. 4B (in other words, when the input acceleration input to the mounting portion C is relatively small), the friction acting between the sliding plate 4 and the base member 5 is The force F1 contributes to damping the vibration of the damping object B, and the sliding block 17 does not contribute to damping the vibration of the damping object B. In this way, the vibration of the damping object B can be damped more effectively with respect to a wide range of input acceleration.

When the frictional force adjusting section 8 has the sliding block 17 and the first biasing force adjusting member 19, the ratio of the magnitude of the additional frictional force F2 to the magnitude of the frictional force F1 can be easily changed or can be adjusted. Therefore, it is possible to easily add optimum damping according to the vibration characteristics of the object B to be damped.

In the example shown in FIG. 5A, the first elastic member 21 is provided in the first space SP1 inside the base member 5 (more specifically, by the upper plate 5C, the lower plate 5B, and the plurality of side plates 5A). enclosed space). In this case, the first elastic member 21 is protected by the base member 5 . As illustrated in FIG. 5( a ), the first nut 190 and/or the upper end portion 18 a of the first shaft 18 may be arranged in the first space SP<b>1 inside the base member 5 .

In the example shown in FIG. 5A, the upper plate 5C of the base member 5 is formed with a first access hole portion 511d. The first access hole portion 511d is preferably formed at a position facing the first biasing force adjusting member 19 (or the first shaft 18). When the upper plate 5C is formed with the first access hole portion 511d, the user can operate the first biasing force adjusting member 19 (or the first shaft 18) through the first access hole portion 511d. can.

In the example shown in FIG. 1, the damping applying device 1A includes at least two frictional force adjusters 8. In the example shown in FIG. The number of frictional force adjusting units 8 provided in the damping applying device 1A is determined according to the size of the object B to be damped.

(First modification)
FIG. 6 shows the frictional force adjusting portion 8 in the first modified example. In the example shown in FIG. 6, the frictional force adjuster 8 has an elastic member 22 arranged in the gap 16 between the base member 5 and the sliding block 17 . The elastic member 22 reduces the impact when the base member 5 (more specifically, the lower plate 5B) contacts the sliding block 17. As shown in FIG. The elastic member 22 is, for example, a leaf spring.

(Second modification)
FIG. 7 shows the frictional force adjusting portion 8 in the second modified example. In the example shown in FIG. 7(a), the sliding block 17 has a plurality of blocks including a first block 17a and a second block 17b.

The first block 17a is mounted on the sliding plate 4 so that a first gap 16a is formed between the first block 17a and the base member 5 (more specifically, the lower plate 5B). . Further, the second block 17b is slidable so that a second gap 16b larger than the first gap 16a is formed between the second block 17b and the base member 5 (more specifically, the lower plate 5B). It is placed on the moving platen 4 .

As illustrated in FIG. 7(b), the distance from the default position P1 to the second position P2 is larger than the size e1 of the first gap 16a (see FIG. 7(a)), When the size e2 (see FIG. 7A) of the second gap 16b is smaller than the size e2 (see FIG. 7A), the base member 5 comes into contact with the first block 17a. The frictional force directly or indirectly received from C1 is increased.

Further, as illustrated in FIG. 7C, the size of the distance from the default position P1 to the second position P2 is larger than the size e2 of the second gap 16b (see FIG. 7A). When the base member 5 contacts both the first block 17a and the second block 17b, the frictional force directly or indirectly applied to the damping object B from the upper surface C1 of the mounting portion C further increases. be done.

In the example shown in FIG. 7, the number of sliding blocks 17 that contribute to damping the vibration of the damping object B is changed according to the magnitude of the input acceleration input to the mounting portion C. In the example shown in FIG. For example, when the magnitude of the input acceleration input to the mounting portion C is small, the number of sliding blocks 17 contributing to damping the vibration of the damping object B is zero, and the acceleration input to the mounting portion C is zero. As the magnitude of the input acceleration increases, the number of sliding blocks 17 that contribute to damping the vibration of the damping object B increases. The number of sliding blocks 17 that contribute to damping the vibration of the vibration object B is further increased. In this way, in the example shown in FIG. 7, the vibration of the damping object B can be damped more effectively with respect to a wider range of input acceleration.

(Restoring force generator 6)
In the example shown in FIG. 2( a ), the restoring force generator 6 has a bar spring 9 arranged between the base member 5 and the sliding plate 4 . A bar spring 9 is supported by each of the base member 5 and the sliding disk 4 .

When the relative position of the lower surface B1 of the vibration damping object B with respect to the upper surface C1 of the mounting portion C changes from the default position P1 to the second position P2, the bar spring 9 utilizes the bending rigidity of the bar spring 9 to Restore the relative position to the default position P1. More specifically, when the base member 5 slides against the upper surface C1 of the slide plate 4 due to an external force such as an earthquake load or an impact load acting on the mounting portion C, the bar spring 9 The bending rigidity restores the relative position of the base member 5 to the slide plate 4 to the original position (in other words, the default position P1).

In the example shown in FIG. 2A, the lower end portion 9b of the bar spring 9 is fitted into a first fitting portion 10 (more specifically, a first concave portion) formed in the sliding disc 4. there is In this case, the horizontal relative movement of the lower end portion 9b of the bar spring 9 with respect to the slide plate 4 is restrained by the first fitting portion 10 . In the example shown in FIG. 2A, the upper end portion 9a of the bar spring 9 is fitted into a second fitting portion 11 (more specifically, a through hole portion) formed in the upper plate 5C of the base member 5. are combined. In this case, the horizontal relative movement of the upper end portion 9 a of the bar spring 9 with respect to the base member 5 is restrained by the second fitting portion 11 .

In the example shown in FIG. 2A, a second through hole portion 512h is formed in the base member 5 (more specifically, the lower plate 5B of the base member 5), and the bar spring 9 is provided with the second through hole portion 512h. It is inserted into the through hole portion 512h. A third gap G3 is formed between the outer surface 9t of the bar spring 9 and the inner surface of the second through hole portion 512h. The distance between the outer surface 9t of the bar spring 9 and the inner surface of the second through hole portion 512h corresponds to the size of the third gap G3. The size of the third gap G3 is preferably larger than the size e of the gap 16 between the sliding block 17 and the base member 5 illustrated in FIG. 4(a). Since the third gap G3 is sufficiently large, interference between the base member 5 and the lower end portion 9b of the bar spring 9 is prevented when the base member 5 vibrates in the horizontal direction.

In the example illustrated in FIG. 1 , the damping applying device 1A has at least two restoring force generators 6 . The number of restoring force generators 6 included in the damping applying device 1A is determined according to the size of the object B to be damped.

(Pressing force generator 7)
In the example shown in FIG. 3A , the pressing force generating section 7 has a second shaft 12 , a second biasing force adjusting member 13 and a second elastic member 15 . The pressing force generator 7 may have washers 14 such as a third washer 14a and a fourth washer 14b.

In the example shown in FIG. 3(a), the second shaft 12 is fixed to the mounting portion C (more specifically, the sliding platen 4). The second shaft 12 is fixed to the mounting portion C by screwing or the like. In the example shown in FIG. 3A, the base member 5 (more specifically, the lower plate 5B of the base member 5) is formed with a third through-hole portion 513h, and the second shaft 12 is provided with the third through-hole portion 513h. 3 is inserted into the through-hole portion 513h. A lower end portion 12b of the second shaft 12 is fixed to the sliding disk 4 by screwing or the like.

A fourth gap G4 is formed between the outer surface 12t of the second shaft 12 and the inner surface of the third through hole portion 513h. The distance between the outer surface 12t of the second shaft 12 and the inner surface of the third through hole portion 513h corresponds to the size of the fourth gap G4. The size of the fourth gap G4 is preferably larger than the size e of the gap 16 between the sliding block 17 and the base member 5 illustrated in FIG. 4(a). The sufficiently large fourth gap G4 prevents interference between the base member 5 and the second shaft 12 when the base member 5 vibrates in the horizontal direction.

The second biasing force adjusting member 13 can change its position along the longitudinal axis AX2 of the second shaft 12 . The second biasing force of the second elastic member 15 is adjusted by changing the position of the second biasing force adjusting member 13 along the longitudinal axis AX2 of the second shaft 12 . The second biasing force adjusting member 13 may be any member as long as the position thereof can be changed along the longitudinal direction axis AX2 of the second shaft 12 . The second biasing force adjusting member 13 may be a second nut 130 screwed onto the second shaft 12 or may be a cam member that moves along a cam groove formed in the second shaft 12. . Further, when the second shaft 12 is a bolt, the second biasing force adjusting member 13 may be the head of the bolt.

In the example shown in FIG. 3A , the second biasing force adjusting member 13 is a second nut 130 screwed onto the second shaft 12 . In the example shown in FIG. 3A, a male threaded portion is formed on the upper end portion 12a of the second shaft 12, and the second nut 130 is screwed onto the male threaded portion. By rotating the second nut 130 relative to the second shaft 12 around the longitudinal axis AX2 of the second shaft 12, the second nut 130 is positioned along the longitudinal axis AX2 of the second shaft. Be changed. The second nut 130 is rotated by, for example, a known rotating jig (not shown).

The second elastic member 15 is arranged between the second biasing force adjusting member 13 (more specifically, the second nut 130) and the base member 5 (more specifically, the lower plate 5B of the base member 5). be done. The second elastic member 15 applies a second biasing force to the base member 5 in a direction toward the sliding plate 4 (more specifically, vertically downward). The base member 5 is pressed against the sliding board 4 by the second biasing force. By changing the position of the second biasing force adjusting member 13 along the longitudinal axis AX2 of the second shaft 12 , the amount of elastic deformation of the second elastic member 15 is changed and the second applied to the base member 5 is changed. The magnitude of the biasing force is changed (in other words, the second biasing force is adjusted).

In the example shown in FIG. 3A, the second elastic member 15 includes a plurality of disc springs laminated along the longitudinal direction of the second shaft 12. In the example shown in FIG. Alternatively, the second elastic member 15 may be a spring other than a disc spring, or rubber. In the example shown in FIG. 3( a ), the second elastic member 15 is arranged around the second shaft 12 .

In the example shown in FIG. 3( a ), the third washer 14 a is arranged between the second elastic member 15 and the base member 5 . The third washer 14a smoothly guides the movement of the base member 5 when the base member 5 slides on the upper surface C1 of the mounting portion C (more specifically, the upper surface of the sliding plate 4). . The coefficient of static friction between the lower surface of the third washer 14a and the base member 5 is preferably smaller than the coefficient of static friction between the lower surface B1 of the base member 5 and the upper surface C1 of the mounting portion C. In this case, when the base member 5 vibrates in the horizontal direction, the base member 5 is smoothly guided by both the third washer 14a and the mounting portion C, and is slide.

In the example shown in FIG. 3( a ), the third washer 14 a functions as a lower spring retainer that contacts the lower end of the second elastic member 15 .

In the example shown in FIG. 3A, the fourth washer 14b is arranged between the second biasing force adjusting member 13 (more specifically, the second nut 130) and the second elastic member 15. As shown in FIG. The fourth washer 14 b functions as an upper spring receiver that contacts the upper end of the second elastic member 15 . In the example shown in FIG. 3A, the fourth washer 14b smoothly guides the rotation of the second nut 130 when the second nut 130 is rotated.

In the example shown in FIG. 3A, when an external force such as an earthquake load or an impact load acts on the mounting portion C, the base member 5 slides on the upper surface C1 of the sliding disk 4, causing the upper surface C1 of the sliding disk 4 to slide. The relative position of the lower surface B1 of the base member 5 with respect to C1 changes from the default position P1 to the second position P2 (see FIG. 3(b)). When the base member 5 slides against the slide plate 4, a frictional force F1 is generated from the slide plate 4 to the base member 5 in the direction from the second position P2 to the default position P1. The frictional force F1 absorbs the vibration energy of the damping object B, and the vibration of the damping object B is attenuated.

In the example shown in FIG. 3A, when the second biasing force adjusting member 13 is changed in position along the longitudinal axis AX2 of the second shaft 12, the second biasing force applied to the base member 5 is size is changed. Further, by changing the magnitude of the second biasing force, the magnitude of the above-described frictional force F1 is changed (in other words, adjusted).

In the example shown in FIG. 3A, the second elastic member 15 is provided in the second space SP2 inside the base member 5 (more specifically, by the upper plate 5C, the lower plate 5B, and the plurality of side plates 5A). enclosed space). In this case, the second elastic member 15 is protected by the base member 5 . The second nut 130 and/or the upper end portion 12a of the second shaft 12 may be arranged in the second space SP2 inside the base member 5, as illustrated in FIG. 3(a).

In the example shown in FIG. 3A, the upper plate 5C of the base member 5 is formed with a second access hole portion 513d. The second access hole portion 513d is preferably formed at a position facing the second biasing force adjusting member 13 (or the second shaft 12). When the second access hole portion 513d is formed in the upper plate 5C, the user can operate the second biasing force adjusting member 13 (or the second shaft 12) through the second access hole portion 513d. can.

In the example shown in FIG. 1, the damping applying device 1A includes at least two pressing force generators 7. In the example shown in FIG. The number of pressing force generators 7 included in the damping applying device 1A is determined according to the size of the object B to be damped.

(Combined action by the restoring force generator 6, the pressing force generator 7, and the friction force adjuster 8)
In the example shown in FIG. 1, the base member 5 slides on the upper surface C1 of the sliding plate 4 when an external force such as an earthquake load is applied horizontally to the mounting portion C. As shown in FIG.

When the base member 5 slides on the upper surface C1 of the sliding plate 4, the restoring force generator 6 illustrated in FIG. Suppressed. By preparing bar springs 9 having different cross-sectional shapes and/or cross-sectional dimensions, the bending stiffness of the bar springs 9 can be changed to adjust the support stiffness (natural frequency) of the damping object B.

When the base member 5 slides on the upper surface C1 of the sliding disk 4, the pressing force generator 7 illustrated in FIG. Vibrational energy of the damping object B is absorbed by the frictional force. The amount of deformation of the second elastic member 15 can be adjusted using the second biasing force adjusting member 13 to change the pressing force for pressing the base member 5 against the sliding disk 4 . Thus, the magnitude of the frictional force F1 between the base member 5 and the sliding disc 4 generated when the base member 5 slides on the upper surface C1 of the sliding disc 4 can be adjusted.

It is assumed that the input acceleration input to the mounting portion C is large and the vibration response of the damping object B is increased. As illustrated in FIG. 5(b), the relative displacement between the base member 5 and the sliding disk 4 reaches the threshold value e (more specifically, the gap 16 between the sliding block 17 and the base member 5). When the magnitude e) is exceeded, an additional frictional force F2 is generated in the frictional force adjusting portion 8, the frictional force F1 between the base member 5 and the upper surface C1 of the sliding disk 4, and the additional frictional force F2 Vibrational energy of the damping object B is absorbed by . By setting the size of the gap 16 between the sliding block 17 and the base member 5 according to the size of the assumed relative displacement, the threshold e can be easily adjusted. Further, the amount of deformation of the first elastic member 21 can be adjusted using the first biasing force adjusting member 19 to change the pressing force for pressing the sliding block 17 against the sliding disk 4 . Thus, it is possible to freely adjust the magnitude of the additional frictional force F2 with respect to the magnitude of the frictional force F1 between the base member 5 and the upper surface C1 of the sliding disk 4. FIG.

(effect)
Next, with reference to FIGS. 8 to 11, an example of the effect produced by the damping applying device 1A will be described using a vibration model of the damping object B to which the damping applying device 1A is attached.

FIG. 8 shows a vibration model of a damping object B to which a conventional damping applying device 100 is attached. “W1” indicates the weight of the vibration damping object B, “k1” indicates the stiffness (spring constant) of the vibration damping object B, and “c1” indicates the damping coefficient of the vibration damping object B. "W2" indicates the weight of the damping applying device 100, "k2" indicates the rigidity (spring constant) of the damping applying device 100, and "Fr2" indicates the frictional force generated by the pressing force generating section 7. . FIG. 9 shows an example of a vibration model of a damping object B to which the damping applying device 1A according to the first embodiment is attached. "W1" indicates the weight of the damping object B, "k1" indicates the stiffness (spring constant) of the damping object B, "c1" indicates the damping coefficient of the damping object B, and "W2 ' indicates the weight of the damping applying device 1A, 'k2' indicates the stiffness (spring constant) of the damping applying device 1A, 'Fr2' indicates the frictional force generated by the pressing force generating section 7, and 'Fr2' ” indicates the additional frictional force generated by the frictional force adjuster 8 .

FIG. 10 is a graph showing the relationship between the input acceleration input to the mounting portion C and the damping ratio. The damping ratio means the ratio of the damping coefficient to the critical damping coefficient. FIG. 10 shows how much the damping ratio increases (in other words, how much the damping performance is improved) by attaching the damping applying device 100 or the damping applying device 1A to the damping object B. It is shown.

In addition, in FIG. 10, the damping ratio of the damping object B itself to which the damping addition device is not attached is 4%, and the resonance frequency range of the damping object B is sufficiently covered. An example is shown in which a sine sweep wave is input in the frequency range of . The horizontal axis of FIG. 10 indicates the magnitude of the horizontal input acceleration input to the mounting portion C, and the vertical axis of FIG. 10 indicates the damping ratio. In FIG. 10, black circles, black triangles, black squares, white circles, white triangles, and white squares indicate the damping device 100 attached to the damping object B (the ratio of the stiffness ratio k2/k1 and the frictional force Fr2 to the weight W1 is shown in the graph) is attached, the change in the damping ratio with respect to the input acceleration is shown. In FIG. 10, the thick solid line indicates the change in the damping ratio with respect to the input acceleration when the damping applying device 1A is attached to the damping object B. FIG.

From FIG. 10, it can be understood that the damping ratio has remarkable amplitude dependence (in other words, a characteristic that greatly fluctuates according to the magnitude of input acceleration). In the example shown in FIG. 10, the damping ratio increases as the input acceleration increases from 10 Gal. In addition, the damping ratio becomes maximum when the input acceleration exceeds 100 Gal, and the damping ratio gradually decreases as the input acceleration further increases. In the example of FIG. 10, a damping ratio substantially higher than the damping ratio of 4% before the damping addition device 1 is attached is obtained regardless of the input acceleration.

In the example of FIG. 10, the maximum value of the damping ratio is not affected by the magnitude of the frictional force Fr2 of the damping addition device 100, and tends to increase as the stiffness k2 of the damping addition device 100 decreases. In addition, when the frictional force Fr2 of the damping applying device 100 increases, the peak of the damping ratio (damping characteristic curve) tends to shift to the high acceleration side.

In the first embodiment, as the response amplitude of the damping object B increases (in other words, the relative displacement of the damping object B with respect to the mounting portion C increases), the frictional force adjustment unit 8 adds additional Frictional force Fr2' is generated. Therefore, in the first embodiment, when the magnitude of the input acceleration increases, the peak of the damping ratio (damping characteristic curve) is shifted to It is possible to shift to the high acceleration side during vibration. In this way, damping reduction on the high acceleration side is suppressed. As a result, in the first embodiment, the vibration of the damping object B can be effectively damped against a wide range of input acceleration.

As illustrated in FIG. 7, the damping applying device 1A may have a plurality of frictional force adjusters 8 with different gap 16 sizes (e1; e2). In this case, the frictional force can be increased in multiple steps according to the relative displacement between the base member 5 and the sliding disk 4 . Therefore, it is possible to effectively attenuate the vibration of the damping object B against a wider range of input acceleration.

FIG. 11 shows a graph obtained by rearranging the graph shown in FIG. 10 using the natural frequency ratio as a parameter. The natural frequency ratio is the ratio of the natural frequency of the damping object B after the damping adding device 1A is installed to the natural frequency of the damping object B before the damping adding device 1A is installed. means.

In the example shown in FIG. 9, when the stiffness k2 of the damping applying device 1A decreases, the natural frequency of the damping object B decreases. FIG. 11 shows that the maximum value of the damping ratio tends to increase when the stiffness k2 of the damping application device 1A decreases and the natural frequency of the damping object B decreases (shifted leftward on the horizontal axis in FIG. 11). showing. FIG. 11 shows the result that the damping ratio (4%) before the damping addition device 1A is attached increases up to about 27% at maximum.

For example, by attaching the damping applying device 1A in the first embodiment to the damping object B, the natural frequency of the damping object B is increased by 0.5 to 0.9 times the original natural frequency. It is assumed that the settings are as follows. In this case, in the example shown in FIG. 11, the damping ratio (4%) of the damping object B before the damping addition device 1A is attached is reduced by about 3% by attaching the damping addition device 1A. ~23% can be added to give a damping ratio of approximately 7-27%. Considering that the damping ratio when the damping object B is fixed by a normal welded structure is about 1%, the damping adding device 1A in the first embodiment provides a very large damping to the damping object B. is found to be added.

Vibration suppression technology using a conventional sliding-type seismic isolation mechanism avoids the frequency range of the main component of seismic motion, ) is set to a very low frequency, for example of the order of 0.3 Hz. In this case, there is a possibility that the displacement of the damping object B will become large due to the long period seismic motion.

On the other hand, in the first embodiment, the natural frequency of the damping object B after the damping applying device 1A is attached to the damping object B is determined by the damping applying device 1A attached to the damping object B. It is possible to set to be 0.5 times or more and 0.9 times or less of the natural frequency of the damping object B before being damped. For example, when the damping object B includes a structure such as a spent nuclear fuel storage rack or an electrical panel, the natural frequency of the damping object B is 10 Hz before the damping addition device 1A is attached. ~30 Hz. In this case, the natural frequency of the vibration damping object B can be set to 5 Hz or more in the state after the damping applying device 1 is attached to the vibration damping object B. FIG. In this case, the natural frequency of the damping object B to which the damping applying device 1A in the first embodiment is attached is changed to the natural frequency of the damping object B to which a general seismic isolation mechanism is attached (0. 3 Hz) can be about 16 times or more. Assuming that both have the same response acceleration, the ratio of the response displacement between the two is the square of the ratio of the frequencies of the two. It can be seen that the response displacement of the vibration object B is one several hundredth of the response displacement of the vibration damping object B to which a general seismic isolation mechanism is attached, and is extremely small.

When adopting a general seismic isolation mechanism, the response displacement of the damping object B becomes large. Therefore, it is necessary to increase the layout area for the damping object B. On the other hand, the damping object B to which the damping applying device 1A in the first embodiment is attached has a very small response displacement compared to a general seismic isolation mechanism, so the layout design of the damping object B is easy.

Furthermore, in the damping applying device 1A in the first embodiment, the stiffness k2 and/or the frictional force of the damping applying device 1A are determined according to the vibration characteristics of the damping object B and/or the vibration input conditions to the mounting portion C. When Fr2 is adjustable, the damping applying device 1A can apply optimum damping to the object B to be damped.

Furthermore, in the damping application device 1A of the first embodiment, if the magnitude of the additional frictional force Fr2′ and/or the magnitude e of the gap 16 are adjustable, these parameters can be adjusted. Therefore, it is possible to obtain a high damping effect for a wide range of input acceleration. For example, a high damping effect can be obtained for various vibration inputs such as earthquake input and shock wave input accompanying a projectile colliding with a building. In addition, various equipment such as spent nuclear fuel storage racks, electrical panels, pumps, heat exchangers, and transformers used in nuclear power plants are adjusted according to their respective vibration characteristics, making it possible to control vibration. An optimum damping force can be applied to the object B.

(Second embodiment)
An attenuation adding device 1B according to a second embodiment will be described with reference to FIGS. 1 to 3 and 12. FIG. FIG. 1 is a schematic front view schematically showing how a damping applying device 1B according to the second embodiment is attached to a damping object B. FIG. In FIG. 1, in order to make it easier to understand the arrangement of the attenuation applying device 1B, the parts other than the device 2 are shown in cross-sectional views instead of front views. FIG. 2 is a schematic cross-sectional view schematically showing an example of the restoring force generator 6. As shown in FIG. FIG. 3 is a schematic cross-sectional view schematically showing an example of the pressing force generating portion 7. As shown in FIG. FIG. 12 is a schematic cross-sectional view schematically showing an example of the frictional force adjusting section 8 of the damping applying device 1B in the second embodiment.

In the first embodiment, the frictional force adjusting section 8 has a sliding surface that slides on the upper surface C1 of the mounting section C depending on the distance from the default position P1 to the second position P2. An example in which the total area is changed, more specifically, an example in which the sliding block 17 is additionally slid has been described. On the other hand, in the second embodiment, the frictional force adjuster 8 generates additional frictional force without changing the total area of the sliding surface that slides on the upper surface C1 of the mounting portion C. is different from the first embodiment.

In the second embodiment, the points different from the first embodiment will be mainly described. On the other hand, in the second embodiment, repetitive explanations of matters already explained in the first embodiment will be omitted. Therefore, it goes without saying that the matters already explained in the first embodiment can be applied to the second embodiment even if they are not explicitly explained in the second embodiment.

(Structure/action)
As exemplified in FIGS. 1 to 3, the damping applying device 1B in the second embodiment includes (1) a bottom portion (more specifically, the base member 5) of the vibration damping object B, a vibration damping object It is arranged between the mounting portion C (more specifically, the sliding plate 4) on which the object B is mounted, and vibration of the vibration damping target object B causes vibration of the upper surface C1 of the mounting portion C. (2) a restoring force generating unit 6 that generates a restoring force that restores the relative position to the default position P1 when the relative position of the lower surface B1 of the object B changes from the default position P1 to the second position P2; and a pressing force generation unit 7 for generating a pressing force for pressing the lower surface B1 of the object to be shaken B against the upper surface C1 of the placement unit C. Further, as illustrated in FIG. 12, the damping applying device 1B in the second embodiment (3) reduces the frictional force that the damping object B receives from the upper surface C1 of the mounting portion C from the default position P1 to the third A frictional force adjuster 8 that changes depending on the magnitude of the distance to the second position P2 is provided.

In the example shown in FIG. 12, the dynamic friction coefficient between the first area AR1 of the upper surface C1 of the mounting part C and the vibration damping object B is the same as that of the second area AR2 of the upper surface C1 of the mounting part C and the vibration damping object. larger than the coefficient of dynamic friction with object B. Further, in the example shown in FIG. 12, when the distance from the default position P1 to the second position P2 is smaller than the threshold e, the lower surface B1 of the damping object B contacts the first area AR1. If the distance from the default position P1 to the second position P2 is equal to or greater than the threshold value e, the lower surface B1 of the damping object B comes into contact with the first area AR1. When the lower surface B1 of the damping object B comes into contact with the above-described first area AR1, additional frictional force is generated.

In the second embodiment, the magnitude of the distance from the default position P1 to the second position P2, in other words, the magnitude of change in the relative position of the lower surface B1 of the damping object B with respect to the upper surface C1 of the mounting section C , the magnitude of the frictional force acting as the braking force acting on the damping object B is changed. In this way, the vibration of the damping object B can be effectively damped against a wide range of input acceleration. For example, when the input acceleration input to the damping object B is large and the amplitude of the damping object B is large, a larger braking force acts. As a result, the vibration of the damping object B can be effectively damped.

Although several embodiments of the invention have been described above, these embodiments are presented by way of example and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and modifications can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the scope of the invention described in the claims and equivalents thereof.

DESCRIPTION OF SYMBOLS 1, 1A, 1B... Attenuation addition apparatus, 2... Equipment, 3... Floor surface, 4... Sliding board, 5... Base member, 5A... Side plate, 5B... Lower plate, 5C... Upper plate, 6... Restoring force generation part , 7... Pressing force generating part, 8... Frictional force adjusting part, 9... Bar spring, 9a... Upper end part, 9b... Lower end part, 9t... Outer surface, 10... First fitting part, 11... Second fitting part, Reference Signs List 12 second shaft 12a upper end 12b lower end 12t outer surface 13 second biasing force adjusting member 14 washer 14a third washer 14b fourth washer 15 second elasticity Member 16 Gap 16a First gap 16b Second gap 17 Sliding block 17a First block 17b Second block 17h Through hole 17t Outer surface 17w Lower surface 18 First shaft 18a Upper end 18b Lower end 19 First biasing force adjusting member 20 Washer 20a First washer 20b Second washer 21 First elastic member 22 Elastic member 91 Fixed member 100 Attenuation addition device 130 Second nut 190 First nut 511d First access hole 511h First through hole 512h Second through hole 513d... second access hole portion, 513h... third through hole portion, AR1... first area, AR2... second area, B... damping object, B1... lower surface, C... placement section, C1... upper surface, G3 ... third gap, G4 ... fourth gap, SP1 ... first space, SP2 ... second space

Claims (7)

The vibration damping object is arranged between the bottom portion of the vibration damping object and a mounting portion on which the vibration damping object is placed, and the vibration of the vibration damping object causes the vibration damping object to move toward the top surface of the mounting portion. a restoring force generating unit that generates a restoring force that restores the relative position to the default position when the relative position of the lower surface of the lower surface changes from the default position to the second position;
a pressing force generation unit that generates a pressing force that presses the lower surface of the damping object against the upper surface of the mounting unit;
a frictional force adjusting unit that changes the frictional force directly or indirectly applied to the damping object from the upper surface of the mounting unit depending on the size of the distance from the default position to the second position; An attenuation addition device. The frictional force adjusting section changes a total area of a sliding surface that slides on the upper surface of the mounting section, depending on a distance from the default position to the second position. 2. The attenuation adding device according to 1. The frictional force adjustment unit has a sliding block provided independently of a base member that constitutes the bottom of the vibration damping object,
The sliding block is mounted on a sliding disk that constitutes the mounting portion such that a gap is formed between the sliding block and the base member,
When the size of the distance from the default position to the second position is greater than the size of the gap, the frictional force is increased by the contact of the base member with the sliding block. The attenuation adding device according to claim 1 or 2. The frictional force adjustment unit is
a first shaft fixed to the sliding disk;
a first biasing force adjustment member positionable along the longitudinal axis of the first shaft;
and a first elastic member disposed between the first biasing force adjusting member and the sliding block, and applying a first biasing force to the sliding block in a direction toward the sliding disk. Attenuation addition device as described. The damping addition device according to claim 3 or 4, wherein the frictional force adjusting section has an elastic member arranged in the gap between the base member and the sliding block. The sliding block has a plurality of blocks including a first block and a second block,
The first block is mounted on the sliding plate so that a first gap is formed between the first block and the base member,
The second block is mounted on the sliding plate so that a second gap larger than the first gap is formed between the second block and the base member,
When the size of the distance from the default position to the second position is larger than the size of the first gap and smaller than the size of the second gap, the base member contacts the first block. configured to increase the frictional force by
When the size of the distance from the default position to the second position is greater than the size of the second gap, the base member contacts both the first block and the second block, causing the frictional force 6. The damping addition device according to any one of claims 3 to 5, wherein is further increased. The restoring force generating unit has a bar spring disposed between the base member and the sliding disc and supported by the base member and the sliding disc, respectively;
The pressing force generating unit is
a second shaft fixed to the sliding disk;
a second biasing force adjustment member positionable along the longitudinal axis of the second shaft;
and a second elastic member disposed between the second biasing force adjusting member and the base member and applying a second biasing force to the base member in a direction toward the sliding disk. An attenuation adding device according to any one of the preceding claims.

Images