JPS63251639A - Device for absorbing vibration energy - Google Patents

Abstract

PURPOSE:To reduce vibration response of entire machinery, structure, etc. when a vibration energy absorbing device is used for protecting the machinery, structure, etc. against earthquake by making an outer and inner cylinders move vertically relative to each other while bringing the outer surface of the inner cylinder into frictional contact with the inner surface of the outer cylinder. CONSTITUTION:The outer surface of an inner cylinder 1 and the inner surface of an outer cylinder 2 are respectively applied with friction plates 3 and 4 which are in contact with each other with a certain contact pressure. Normally, an elastic contact pressure can be maintained by pess- or shrink-fitting the inner cylinder 1 into the outer cylinder 2. Installation to machinery or a structure is made of example by connecting an installation eye 5 to the machinery or structure and connecting the other installation eye 6 to a base. At the time of an earthquake, therefore, energy due to friction is absorbed between friction surface 3 and 4 by the relative axial movements of the installation eyes 5 and 6 of a vibration absorbing device as a relative displacement is produced between the machinery and the structure.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention relates to vibration energy absorption devices i and Z used for seismic support or seismic isolation of equipment, piping, and structures, and particularly , relates to a vibration energy absorbing device that absorbs vibration energy by utilizing friction between materials.

(Prior Art) Conventionally, in order to prevent equipment piping or structures from being destroyed by seismic force, various vibration energy absorption devices have been interposed between the foundation and equipment piping and the structure body. It is being done.

Such vibration energy absorption devices are classified based on their energy absorption mechanism: viscous type devices utilize the viscosity of a fluid or viscoelastic body, friction type devices utilize friction between materials, and vibration energy absorber devices utilize the plasticity of the materials. It is broadly divided into plastic method that utilizes deformation.

Among these, those that use friction have the advantage that they have a simpler structure and are less expensive than those of other types, and can be used even at high temperatures.

By the way, a conventional vibration energy absorbing device that utilizes the friction of materials is generally constructed as shown in FIG.

That is, an end plate 11 with a friction plate 12 is fixed to the lower surface of the device or structure 9, and an elastic support frame I5 is fixed at a position facing the end plate 11 of the foundation 10. A friction body 13 with an elastic body 16 and a friction plate 14 is inserted, and the elastic body 16 presses the friction body 13 against the end plate 11 with a predetermined force.

In such a vibration energy absorbing device, if a relative displacement occurs between the foundation lO and the structure 9 due to an earthquake, etc.,
Slip occurs on the N liquid surface, causing frictional energy loss. The relationship between the shearing force and the relative displacement X at that time is as shown in FIG. 7, and energy corresponding to the area surrounded by the arrow line is consumed per cycle. As a result, basic 1
The vibration energy between the device and the structure is absorbed, reducing the vibration response of the entire device or structure.

However, the conventional vibration energy absorbing device configured as described above has the following problems.

That is, when the equipment or structure 7 and the foundation 10 undergo relative displacement in the vertical direction y due to an earthquake or the like, it will not function as an energy absorbing device.

Note that oil dampers are the most common vibration energy absorbing device that is effective against vertical relative displacement between equipment or structure 9 and foundation 10, but oil dampers are expensive and cannot be used at high temperatures. It has the following drawbacks.

(Problems to be Solved by the Invention) As described above, conventional vibration energy absorbing devices using friction cannot be effective against vertical relative displacement between two points. Depending on the installation status or vibration status of equipment or structures, it may be more efficient to absorb energy for vertical relative displacement between two points.

Therefore, the present invention provides a friction-based vibration energy absorption device that is effective against vertical relative displacement between two points while maintaining the characteristics that the structure of the friction-based vibration energy absorption device is simple, inexpensive, and usable at high temperatures. is intended to provide.

[Structure of the invention]

(Means for Solving the Problems) According to the present invention, the outer shaft includes an inner shaft and an inner shaft, and is formed from an outer shaft coaxial with the inner shaft, and the outer surface of the inner shaft and the inner surface of the outer shaft are in frictional contact with each other. A vibration energy absorbing device is provided that is relatively movable in an axial direction.

(Operation) When a relative displacement occurs between the inner shaft and the outer shaft, slipping occurs on the frictional contact surfaces between the outer surface of the inner shaft and the inner surface of the outer shaft, thereby causing frictional energy loss. Therefore, by connecting the end of the inner shaft to either the structure (equipment) or the foundation and the end of the outer shaft to the other, the vibration energy of the structure (equipment) during an earthquake can be absorbed. , the vibration response of the entire structure (4!i device) can be reduced.

(Example) Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows a vibration energy absorbing device according to an embodiment of the present invention. A tubular outer shaft 2 coaxially encompasses a cylindrical inner shaft 1. Friction plates 3 and 4 are bonded to the outer surface of the inner shaft 1 and the inner surface of the outer shaft 2, respectively.
are in contact with each other with a certain contact pressure. Normally, for example, one end 5 of the vibration energy absorbing device is attached to a device or structure that can maintain elastic contact pressure by press-fitting or shrink-fitting the inner shaft 1 to the outer shaft 2.
It is installed by connecting it to a container or structure and the other end 6 to the foundation. Therefore, when equipment or structures vibrate during earthquakes, a relative displacement occurs between the equipment or structure and the foundation, and both ends 5 and 6 of the vibration energy absorbing device are relatively displaced in the axial direction, causing the friction surface 3,
4 absorbs energy due to sliding friction.

2 and 3 show another embodiment of the present invention. In FIG. 2, a circumferential groove 7 is cut on the inner surface of the outer shaft 2 to adjust the contact pressure and the contact state. It's uniform.

FIG. 3 shows a portion corresponding to the AA' cross section in FIG. 1, and is achieved by cutting a groove 8 on the inner surface of the outer shaft 2 along the axis.

As in FIG. 2, the contact pressure is adjusted and the contact condition is made uniform.

FIG. 4 shows yet another embodiment of the present invention. In this embodiment, the cross sections of the circular holes of the inner shaft 1 and the outer shaft 2 are tapered. According to such a configuration, when a relative displacement occurs in the direction in which the end points 5 and 6 approach each other,
As shown by the solid line in Figure 5, the frictional resistance force gradually increases as a function of displacement, and by installing two such vibration energy absorbers in opposite directions, the absorbed energy can be kept constant by the frictional force. It increases compared to the case where As a result, as the vibration displacement increases, the effect of absorbing vibration energy increases, which has the desirable property of reducing vibration response.

Note that the present invention is not limited to the above embodiments,
For example, the shape of the shaft is not limited to a cylindrical shape, but may also be a prismatic shape.
The optimal Taber shape shown in the figure can be determined depending on the equipment or structure to be installed.

〔Effect of the invention〕

As described above, according to the present invention, the structure of the vibration energy absorbing device using m-rubbing maintains the characteristics of being simple, inexpensive, and usable at high temperatures, while exhibiting an effect against vertical relative displacement between two points. A frictional vibration energy absorption device can be provided.

[Brief explanation of drawings]

FIG. 1 is a vertical cross-sectional view of a vibration energy absorbing device according to one embodiment of the present invention, FIGS. 2 to 4 are cross-sectional views of a vibration energy absorbing device according to another embodiment of the present invention, and FIG. A diagram for explaining the effect of one of the embodiments of the present invention, FIG. 6 is a longitudinal sectional view of a conventional vibration energy absorption device using friction, and FIG. 7 is a diagram for explaining the effect of the conventional device shown in FIG. It is a figure for explaining. 1...Inner shaft 2...Outer shaft 3.4...Friction plate 5,6-...Mounting with metal fittings 7.8...Groove
9...Equipment or structure 10...Foundation
11... End plate 12... Friction plate 1
3...Friction body 14...Friction plate 15...
Elastic body support frame 16...Elastic body Fig. 1 Fig. 2 Fig. 8 Fig. 4 Fig. 5

Claims (2)

[Claims] (1) It includes an inner shaft and an outer shaft coaxial with the inner shaft, and is characterized by being relatively movable in the axial direction while the outer surface of the inner shaft and the inner surface of the outer shaft are in frictional contact with each other. Vibration energy absorption device. (2) The vibration energy absorbing device according to claim 1, wherein at least one of the outer surface of the inner shaft and the inner surface of the outer shaft has a tapered cross-sectional shape including the shaft.