JPH0727162A - Damper for microamplitude - Google Patents

Abstract

PURPOSE:To provide a damper for microamplitude which is constituted to effectively suppress microvibration generated at the cooling water circulation pump of an atomic power plant and the piping system thereof. CONSTITUTION:In a damper for microamplitude to suppress the generation of microvibration between a fixed flange 1 and a moving flange 2, double inner and outer expandable bellows cylinder bodies 3 and 5 are arranged between the fixed flange l and the moving flange 2. An outer working fluid chamber 9 is formed between the inner and outer bellows cylinder bodies 3 and 5. A partition is located in the inner bellows cylinder body 5, the interior thereof is partitioned into an air chamber 8 and an inner working fluid chamber 7. The inner and outer working fluid chambers 7 and 9 are respectively filled with working fluid S, and an orifice means 4 through which the working fluid S in the inner and outer working fluid chambers 7 and 9 is caused to flow is provided in the inner bellows cylinder body 5.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention suppresses minute vibrations generated in cooling water circulation pumps and piping systems installed in chemical plants, thermal power plants and nuclear power generation facilities, and vibrations in piping systems such as marine engines. The present invention relates to a damper for small amplitude, which can be used for suppression, an engine body, and the like.

[0002]

2. Description of the Related Art Generally, a cooling water circulation pump installed in a chemical plant, a thermal power plant, and a nuclear power plant and its piping system are supported by a fixed system such as a building by a plurality of supporting devices such as a pedestal and a straddle and a mechanical snap. Vibration generated by a vibration damping device such as a bar is effectively damped, and safety against vibration is ensured. As is well known, this mechanical snubber receives and damps dynamic displacements that occur during earthquakes, pump driving, etc. to prevent damage to supported objects such as cooling water circulation pumps and piping systems. In addition to preventing it, it also allows static displacement such as thermal expansion that occurs due to high heat due to rise of cooling water.

[0003]

By the way, this mechanical snubber works effectively against large vibrations such as earthquakes and pump vibrations, but it has mechanical backlash and friction inside the connecting portion and inside. It was impossible to stop a minute vibration of about 0.1 to 0.2 mm. In particular, in a cooling water circulation pump for a nuclear power plant, which requires extremely high safety, such a series of minute vibrations may have a great influence.

Therefore, the present invention has been devised in order to effectively solve the above-mentioned problems, and the purpose thereof is to effectively prevent minute vibrations generated in a cooling water circulation pump of a nuclear power plant and its piping system. A damper for a minute amplitude that can be suppressed is provided.

[0005]

In order to achieve the above object, the present invention is a damper for minute amplitude for suppressing minute vibration between a fixed flange and a movable flange. A heavy bellows cylinder is provided, an outer working fluid chamber is formed between the inner and outer bellows cylinders, and a closing plate is provided in the inner bellows cylinder, and an air chamber communicating the inside with the outside through intake and exhaust ports. An inner working fluid chamber is partitioned and formed, and each of the inner and outer working fluid chambers is filled with a working fluid, and an orifice means for circulating a working fluid in the inner and outer working fluid chambers is provided. As the fluid, an electrorheological fluid whose viscosity continuously changes depending on the strength of the applied electric field is used.

[0006]

According to the present invention, when the compressive and tensile loads, that is, the movable flange moves toward and away from the fixed flange due to vibration, the air in the air chamber in the inner bellows cylinder expands and contracts, so that the inner and outer bellows cylinders. The pressure in the outer working fluid chamber between and the pressure in the inner working fluid chamber in the inner bellows cylinder alternate. When the working fluid having viscosity in both working fluid chambers passes through the orifice means and alternately reciprocates in both working fluid chambers due to this pressure change, the orifice means becomes a flow resistance of the working fluid and the movable flange. The approaching / separating movement of, that is, the vibration is attenuated and suppressed. Further, by using an electrorheological fluid as the working fluid instead of the ordinary viscous fluid, the flow resistance of the working fluid changes according to the applied voltage, so that the vibration damping performance can be continuously varied. You can also

[0007]

An embodiment of the present invention will be described in detail below with reference to the accompanying drawings.

1 to 3 show an embodiment of a damper A for minute amplitude according to the present invention. As shown in the figure, this minute amplitude damper A is expanded and contracted between a fixed flange 1 fixed to a wall surface B of a building and a movable flange 2 connected to a support object C such as a cooling water circulation pump or a piping system. A free outer bellows cylinder 3 is provided so that the movable flange 2 can move toward and away from the fixed flange 1. Further, in the outer bellows cylinder 3, a disk-shaped orifice means 4 for partitioning the inside thereof and an inner bellows cylinder 5 for connecting the orifice means 4 and the fixed flange 1 are provided. Due to the orifice means 4 and the inner bellows cylinder 5, the inside thereof is the outer fluid working chamber 9
And the movable flange side fluid working chamber 10 are partitioned and formed. Further, a closing body 6 is provided at a substantially central portion in the inner bellows tubular body 5, and the orifice means 4 side is partitioned into an internal working fluid chamber 7 and the fixed flange 1 side is partitioned into an air chamber 8. The outer fluid working chamber 9, the movable flange side fluid working chamber 10, and the inner working fluid chamber 7 are filled with a highly viscous working fluid S.

Further, as shown in FIG. 2, a plurality of orifices 11a, 11b, 11b ... Are formed in the central portion and the peripheral portion of the disk-shaped orifice means 4, and the outer fluid working chamber 9 and The working fluid S flows between the movable flange side fluid working chambers 10 and between the movable flange side fluid working chamber 10 and the internal working fluid chamber 7.

Further, the fixed flange 1 is formed with an intake / exhaust hole 12 communicating with the air chamber, and the air chamber 8 is open to the atmosphere. The intake / exhaust holes 12 are fixed flanges 1.
It does not need to be formed into a tube-like pipe (not shown)
Or the like, the outer fluid working chamber 9 and the outer bellows cylinder 3 may be formed directly through the air chamber 8, or the air chamber 8 may be hermetically sealed in some cases. The outer bellows tubular body 3 and the inner bellows tubular body 5 are well-known metal bellows and can be expanded and contracted in the length direction thereof, but have a very rigid property for expansion and contraction in the radial direction. .

Next, the operation of this embodiment will be described.

First, as shown in FIG. 4, when the fluid flow or the vibration due to the driving of a motor (not shown) or the like, tensile stress, that is, the movable flange 2 is attracted in the direction opposite to the fixed flange 1, When the outer bellows tubular body 3 extends, the inside of the outer fluid working chamber 9 and the movable flange side fluid working chamber 10 become negative pressure state, and at the same time, the movable flange side fluid working chamber 10
The inside working fluid chamber 7 and the inside of the air chamber 8 communicating with are also in a negative pressure state. Then, outside air flows into the air chamber 8 from the intake / exhaust holes 12, and as the air chamber 8 expands and its volume increases, the working fluid S in the inner working fluid chamber 7 becomes the center of the orifice means 4. From the orifice 11a of the portion through the movable flange side fluid working chamber 10 side and the orifice 11 again.
It flows through b, 11b ... into the outer fluid working chamber 9. Then, the working fluid S becomes the orifice 11a.
, 11b, 11b ... As flow resistance, the movable flange 2 is prevented from moving away from the fixed flange 1 in the opposite direction, and the tensile stress is attenuated.

On the contrary, when the compressive stress, that is, when the movable flange 2 is pulled toward the fixed flange 1 side, FIG.
As shown in, the pressure inside the outer fluid working chamber 9, the movable flange-side fluid working chamber 10, and the movable flange-side fluid working chamber 10 rises, and the air in the air chamber 8 is exhausted and contracts, thereby operating. The fluid S flows in the opposite direction to the above case,
This serves as flow resistance, and the close movement of the movable flange 2 to the fixed flange 1 side is suppressed, and the compressive stress is attenuated.

By alternately performing these actions in a short time, the minute vibration of the movable flange 2, that is, the vibrating portion C as shown in FIG. 3, is effectively damped and suppressed. In the present embodiment, the operation in the case of vibration generated on the movable flange 2 side has been described, but the same operation is also performed when vibration occurs on the fixed flange 1 side provided on the building B side due to an earthquake or the like. Of course, the vibration is damped and suppressed by. It is also possible to obtain desired damping performance by arbitrarily setting the viscosity of the working fluid used and the size of the orifice.

When the pipe is thermally deformed due to temperature stress or the like, its movement is extremely slow and flow resistance at the orifice hardly occurs. Therefore, the resistance to deformation is only the spring force of the bellows. This spring force is sufficiently small compared to that due to the rigidity of the pipe, so that it does not adversely affect the pipe. Further, by appropriately selecting the number of peaks, diameter, and plate thickness of the bellows, it is possible to realize a damper that attenuates a minute vibration displacement while allowing a large slow deformation such as thermal deformation.

Next, FIG. 6 shows a second embodiment of the present invention.

As shown, in this embodiment, the working fluid S
Electrodes 13 and 13 are provided on the orifice means 4 which comes into contact with, and an electrorheological fluid (ER fluid) is used as the working fluid S. As is well known, this electrorheological fluid has a property that the apparent viscosity continuously changes depending on the strength of an applied electric field. Usually, starch, cellulose, alumina, an ion exchange resin are contained in an insulating dispersion medium. And the like fixed particles are dispersed.

Therefore, in this embodiment, the apparent viscosity of the working fluid S is continuously changed by controlling the voltage applied from the controller 14 to the electrodes 13 and 13, so that an arbitrary damping coefficient can be obtained. A variable damper that can be configured.

[0019]

In summary, according to the present invention, the microvibration generated in the cooling water circulation pump of the nuclear power plant and its piping system is effectively suppressed, and the damping performance is arbitrarily changed as necessary. It has an excellent effect such as being able to.

Further, from the operational characteristics of the present invention, it is apparent that the present invention can be applied not only to the piping system of plants but also to the vibration control of a marine engine or the like, the engine vibration proof mount and the like.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention.

FIG. 2 is a view taken along the line AA in FIG.

FIG. 3 is an explanatory view showing an example of a mounting state of the device of the present invention.

FIG. 4 is an explanatory diagram showing an action when a tensile stress is applied.

FIG. 5 is an explanatory diagram showing an operation when a compressive stress is applied.

FIG. 6 is a sectional view showing another embodiment of the present invention.

[Explanation of symbols]

 1 Fixed Flange 2 Movable Flange 3 Inner Bellows Cylindrical Body 4 Orifice Means 5 Outer Bellows Cylindrical Body 6 Closing Plate 7 Inner Working Fluid Chamber 8 Air Chamber 9 Outer Working Fluid Chamber S Working Fluid

Continuation of the front page (51) Int.Cl. ⁶ Identification number Office reference number FI technical display area F16F 9/53 F16L 3/20 3/215

Claims (2)

[Claims] 1. A damper for small amplitude for suppressing minute vibration between a fixed flange and a movable flange, wherein an expandable inner and outer double bellows cylinder is provided between the fixed flange and the movable flange, and between the inner and outer bellows cylinders. An inner working fluid chamber and an outer working fluid chamber, a closing plate is provided in the inner bellows cylinder, and an inner working fluid chamber and an air chamber communicating with the outside through an intake / exhaust port are formed to define the inner and outer working chambers. A minute amplitude damper characterized in that the fluid chamber is filled with a working fluid, and an orifice means is provided to allow the working fluid inside and outside the working fluid chamber to flow therethrough. 2. The damper for micro-amplitude according to claim 1, wherein the working fluid is an electrorheological fluid whose viscosity continuously changes depending on the strength of an applied electric field.