JPH03244843A - Elasto-plastic damper - Google Patents

Abstract

PURPOSE:To keep off any reaction force to a pipeline from an elasto-plastic damper even if a low-speed displacement occurs, by installing a cylinder, where an elasto-plastic plate is connected, and an interconnecting mechanism having a piston and a viscoelastic material built-in this cylinder and allowing a movement of this viscoelastic material between two chambers in the cylinder, respectively. CONSTITUTION:A case 4 as a movable member of an elasto-plastic damper is connected to a pipeline 1, and a holddown member 11 is connected to a building wall 8 at the fixed side. The specified numbers of elasto-plastic plates 9 are locked to this holddown member 11, and it is provided with a cylinder 12 and a piston 13. A vicsoelastic material 14 such as high viscous oil or the like is sealed in this cylinder 12, and at time of displacement at low speed, it is moved between both chambers 12a and 12b via an interconnecting part 15, and at a time when both these chambers 12a, 12b come to the same pressure, the piston 13 is stopped, so that reaction is no longer added to the pipeline 1. As displacement at high speed, energy is absorbed by each elasto-plastic plate 9, thus vibration or the like in the pipeline is checked.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Field of Application) The present invention relates to an elastoplastic damper used as a vibration damping device for piping systems in nuclear power plants, and particularly for slow vibrations such as heat transfer in piping. This invention relates to an unconstrained elastoplastic damper that does not constrain displacement.

(Prior Art) FIG. 4 shows a conventional elastoplastic damper. In the figure, reference numeral 1 is a pipe, and a clamp 2 and a bottle 3 are connected to the case of the elastoplastic damper. 4 are connected, while the rod 5 of the elastic-plastic damper is connected to the building wall 8 via a support piece 6 and a pin 7.

As shown in FIGS. 4 and 5, the central part of a predetermined number of elastic-plastic plates 9 having a roughly rhombic shape is fixed to the rod 5, and both ends of each elastic-plastic plate 9 are fixed to the rod 5, as shown in FIGS. It is supported by case 4 via 10. and,
When the pipe 1 vibrates, the elastic-plastic plates 9 absorb energy through elastic-plastic deformation, thereby suppressing the vibration of the pipe 1.

(Problems to be Solved by the Invention) In the conventional elasto-plastic damper, the elasto-plastic plate 9, which is an energy absorber, exhibits elasto-plastic behavior against all deformations, so the piping 1 is free from low-speed movements such as heat transfer. Even when it deviates from the neutral position due to displacement, the elasto-plastic plate 9 exhibits elasto-plastic behavior, and there is a problem in that a reaction force from the elasto-plastic damper is applied to the plumber.

The present invention was developed with these points in mind, and it absorbs reaction forces caused by low-speed displacement such as heat transfer and reaction forces caused by installation errors, and also sufficiently absorbs high-speed vibration energy to suppress vibration. The purpose of this invention is to provide an elastoplastic damper that

[Structure of the invention]

(Means for Solving the Problem) As a means for achieving the above object, the present invention provides a movable member connected to a movable side, a fixed member connected to a fixed side,
Equipped with an elasto-plastic plate whose central part is connected to a fixed member and whose ends are supported by the movable member via rollers, the vibration energy on the movable side is absorbed by the elastic-plastic deformation of the elasto-plastic plate to suppress vibrations. In the elasto-plastic damper, the fixed members include a cylinder to which the elasto-plastic plate is connected, a piston disposed in the cylinder with one end connected to the fixed side, a viscoelastic substance sealed in the cylinder, and the piston. The present invention is characterized in that it is equipped with a communication mechanism that communicates two chambers formed in the intervening cylinder and allows movement of a viscoelastic substance between the two chambers in response to low-speed displacement.

(Function) In the elasto-plastic damper according to the present invention, when a low-speed displacement such as heat transfer occurs in the movable member, the viscoelastic substance sealed in the cylinder adjusts to the movement of the piston within the cylinder. , from one chamber to the other via a communication mechanism. Therefore, the neutral position is corrected so that the elastoplastic plate does not exhibit elastoplastic behavior, and therefore no reaction force is applied to the movable member. In addition, the reaction force due to installation error,
It is absorbed as well.

On the other hand, when high-speed displacement such as vibration occurs in the movable member, the viscoelastic substance sealed in the cylinder
The piston moves from one chamber to the other via a communication mechanism, but the displacement is much faster than the speed of movement, so the piston can be considered fixed within the cylinder. I can. Therefore, in this case,
As in the past, the elasto-plastic plate exhibits elasto-plastic behavior, and its elasto-plastic deformation absorbs energy and suppresses vibration.

(Example) Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

FIG. 1 shows an example of an elasto-plastic damper according to the present invention, and in the figure, reference numeral 1 is a pipe on the movable side. A case 4 as a movable member of the damper is also connected.

On the other hand, as shown in Fig. 1, on the building wall 8 which is the fixed side,
A fixing member 11 of the elastic-plastic damper is connected via the support piece 6 and the pin 7, and to this fixing member 11, the center portions of a predetermined number of elastic-plastic plates 9 are respectively fixed, as will be described in detail later. Both ends of each of these elastic-plastic plates 9 are supported by the case 4 via rollers 10.

As shown in FIG. 1, the fixed member 11 includes a cylinder 12 and a piston 13 disposed within the cylinder 12, and the tip of one rod 13H of the piston 13 is
It is connected to the support piece 6 via a pin 7. Each elastic-plastic plate 9 is fixed to the cylinder 12 at its center.

As shown in FIGS. 1 to 3, high viscosity oil or other viscoelastic substance 14 is sealed inside the cylinder 12, and between the inner circumferential surface of the cylinder 12 and the outer circumferential surface of the piston 13, Two chambers 12a are formed within the cylinder 12 via the piston 13.

A communication portion 15 having a small opening area is formed to communicate with each other. The communication portion 15 is designed to prevent the viscoelastic material 1 between the chambers 12a and 12b from moving at low speeds such as heat transfer.
4 to allow free movement.

Next, the operation of this embodiment will be explained.

When a low-speed displacement occurs in the pipe 1 due to heat transfer or the like, the displacement is transmitted to the case 4 via the clamp 2 and the pin 3, and further transmitted to the cylinder 12 via the roller 10 and the elastic-plastic plate 9.

On the other hand 1. Since one end of the rod 13a is connected to the building wall 8 via the pin 7 and the support piece 6, the piston 13 tries to maintain the neutral position before displacement occurs. Therefore, a relative displacement occurs between the cylinder 12 and the piston 13.

By the way, heat transfer is a slow displacement, so for example, when the piston 13 is displaced relative to the cylinder 12 in the direction of arrow A shown in FIG. 2, the volume of the chamber 12a on the left side in the figure becomes smaller. The viscoelastic substance 14 in the viscoelastic substance 12a smoothly moves to the chamber 12b on the right side in FIG. 2 as shown by the arrow B in FIG. The piston 13 stops.

That is, the displacement of the piping 1 causes the displacement of the piston 13 to
The position where the piston 13 stops is absorbed by the relative displacement with respect to the piston 13 and becomes the neutral position. For this reason, each elastic-plastic plate 9
does not exhibit elastoplastic behavior, and therefore no reaction force from the damper is applied to the pipe 1.

On the other hand, when a high-speed displacement such as vibration occurs in the piping 1, the displacement is transmitted to the case 4 via the clamp 2 and pin 3, and further to the roller 10 and the elastic-plastic plate 9. is transmitted to the cylinder 12 via.

On the other hand, since one end of the rod 13a of the piston 13 is connected to the building wall 8 and its position is fixed, the cylinder 1
A relative displacement occurs between 2 and the piston 13. Therefore, the viscoelastic substance 14 within the cylinder 12 is connected to both chambers 12a via the communication portion 15.

12b.

However, the substance 14 has viscoelasticity, and the communication portion 1
Since 5 has a small opening area, it is possible to follow a low-speed displacement but not a high-speed displacement, and the cylinder 12 is substantially fixed to the piston 13. Therefore, a relative displacement occurs between the case 4 and the cylinder 12, and each elastic-plastic plate 9 exhibits elastic-plastic behavior, and the elastic-plastic deformation absorbs energy and suppresses the vibration of the pipe 1.

As described above, according to this embodiment, low-speed displacement is not restricted, and restricted displacement such as vibration can be sufficiently suppressed.

Moreover, installation errors can also be absorbed, and reaction force can be prevented from being applied to the piping 1.

In addition, in the embodiment, as the viscoelastic substance 14,
Although the case where high viscosity oil is used has been described, other liquids or solids may be used as long as they have viscoelasticity.

Further, in the above embodiment, the outer diameter of the piston 13 is made smaller than the inner diameter of the cylinder 12, and the communication portion 1
5 has been described, however, an axial groove may be provided on the inner circumferential surface of the cylinder 12 or the outer circumferential surface of the piston 13, and this groove may be used as the communication portion 15.
An opening may be provided in the plate surface of No. 3, and this opening may be used as the communication portion 15.

Alternatively, both ends of the cylinder 12 in the axial direction may be connected with a vibrator, and the communication mechanism may be configured with this pipe.

Further, in the embodiment described above, the case of suppressing the vibration of the pipe 1 has been described, but the present invention can be similarly applied to suppressing the vibration of other members.

〔Effect of the invention〕

As explained above, in the present invention, the low-speed relative displacement between the cylinder and the piston can be absorbed by moving the viscoelastic material through the communication mechanism. It is possible to prevent reaction force from being applied to the movable side. Moreover, since the cylinder and piston are substantially fixed against high-speed displacement,
Due to the elastic-plastic deformation of the elastic-plastic plate, vibration energy can be sufficiently absorbed and vibrations on the movable side can be suppressed.

[Brief explanation of drawings]

FIG. 1 is a partial sectional view showing an elastoplastic damper according to an embodiment of the present invention, FIG. 2 is an enlarged view of the section ■ in FIG. 1, and FIG.
FIG. 4 is a partial sectional view showing a conventional elastic-plastic damper, and FIG. 5 is a sectional view taken along line V--V in FIG. 4. 1... Piping, 4... Case, 8... Building wall, 9...
...Elastic-plastic plate, 10...Roller, 11...Fixing member, 12...Cylinder, 12a, 12b...Chamber, 13
... Piston, 1, 3 a... Rod, 14...
Viscoelastic substance, 15... communicating part.

Claims (1)

[Claims] A movable member connected to a movable side, a fixed member connected to a fixed side, and an elastic-plastic plate whose central portion is connected to the fixed member and whose both ends are supported by the movable member via rollers, In an elasto-plastic damper that suppresses vibration by absorbing vibration energy on a movable side by elastic-plastic deformation of the elasto-plastic plate, the fixed member has one end connected to a cylinder to which the elasto-plastic plate is connected, and a fixed side. A piston arranged in a cylinder, a viscoelastic substance sealed in the cylinder, and two chambers formed in the cylinder through the piston are connected to each other, and the viscoelasticity between the two chambers against low-speed displacement is maintained. An elasto-plastic damper characterized by comprising a communication mechanism that allows the movement of substances.