JPH0972371A - Microvibration absorbing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To stabilize vibration absorption characteristics even when the temperature of internal fluid is changed by providing a plurality of thermal actuating parts to steppedly set the opening area of an orifice according to different working temperatures. SOLUTION: When the temperature of internal fluid R is increased, thermal actuating parts 36 reach a high temperature transformation point in order of a working temperature set to a low value and a shape is changed, and the opening area of an orifice 35 is gradually decreased. However, since viscosity of internal fluid R is decreased, resistance occurring when the internal fluid R flows through the orifice 35 is not widely fluctuated. When the increasing temperature of the internal fluid R is decreased, the thermal actuating parts 36 reach a low temperature transformation point in order of a working temperature set to a low value and are restored to an original shape. Since, though the opening area of the orifice 35 is gradually increased, viscosity of the internal fluid R is increased, resistance occurring when the internal fluid R flows through is not widely fluctuated. Thus, even when the temperature of the internal fluid R is changed, a damping force against vibration of a substance B to be vibrated is hardly changed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a microvibration absorbing device, and more particularly to reducing variations in vibration absorbing characteristics when temperature changes.

[0002]

2. Description of the Related Art As a device for absorbing vibrations of pipes and various devices connected to the pipes, that is, a vibration suppressing device, an oil damper is applied, and Japanese Utility Model Publication No. 1-63843 and Japanese Utility Model Publication No. 1-1141939. Japanese Patent Publication No. 3-65
No. 095 and Japanese Utility Model Laid-Open No. 4-119291 are proposed.

These techniques utilize a flow path resistance generated when an internal fluid contained in a deformable container is caused to flow through an orifice provided in the same container as a damping force.

[0004]

However, in these techniques, since the viscosity of the internal fluid changes with the temperature change, when the opening area of the orifice is constant, when the internal fluid flows through the orifice. It is insufficient in that the flow path resistance fluctuates, and as a result, the vibration absorption characteristics change.

The present invention has been made in view of the above circumstances, and an object thereof is to stabilize the vibration absorption characteristics even when the temperature of the internal fluid changes.

[0006]

A device for absorbing vibration of an object to be vibrated which is arranged in a connected state between the object to be vibrated and a support structure. An expanding / contracting container that changes, an accumulator that is connected to the expanding / contracting container and absorbs fluctuations in the internal fluid, and a control unit that is interposed between the expanding / contracting container and the accumulator to exert insertion resistance on the internal fluid. The control means includes an orifice which is provided in a communication state between the expansion container and the accumulator and through which the internal fluid is inserted, and a thermal operation unit which is arranged in the orifice and reduces the opening area of the orifice when the temperature of the internal fluid rises. The configuration provided is adopted. Control means,
A configuration is employed in which a plurality of thermal actuation units are provided to set the opening area of the orifice stepwise by different operating temperatures.
When the temperature of the internal fluid rises and reaches the high temperature transformation point, the thermal working part changes its shape to reduce the opening area of the orifice, and when the temperature of the internal fluid falls and reaches the low temperature transformation point, it returns to its original shape. A configuration of a shape memory alloy that recovers and increases the opening area of the orifice is adopted.

Due to the expansion and contraction of the expandable container based on the vibration of the object to be vibrated, the internal fluid of the expandable container enters and leaves the accumulator via the control means, and absorbs the fluctuation of the internal fluid. In the control means portion, the internal fluid receives resistance when passing through the orifice to prevent the expansion and contraction movement of the expansion and contraction container, thereby absorbing the vibration. As the temperature of the internal fluid rises, the heat-actuated part reaches the high temperature transformation point in the order in which the operating temperature is set low, the shape changes, and the opening area of the orifice gradually decreases. Is low, the resistance that occurs when the internal fluid passes through the orifice does not fluctuate significantly. As the temperature of the increased internal fluid decreases, the thermal operating part reaches the low temperature transformation point in the order in which the operating temperature is set higher and recovers the original shape, and the opening area of the orifice gradually increases, Since the viscosity of the internal fluid becomes high, the resistance generated when the internal fluid passes through the orifice does not fluctuate significantly. Therefore, even if the temperature of the internal fluid changes, the damping force for the vibration of the object to be vibrated hardly changes.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of a minute vibration absorbing device according to the present invention will be described with reference to FIGS. In the figure, reference numeral A is a minute vibration absorber, B is a vibrating object,
C is a support structure, 1 is a telescopic container, 2 is an accumulator,
3 is a control means, 4 is a fixed frame, and R is an internal fluid.

The microvibration absorber A is interposed between the object to be vibrated B and the support structure C in a connected state, and the connection direction of these is a vibration absorbing direction to absorb the vibration of the object to be vibrated B. As shown in FIG. 1, the expandable container 1, the accumulator 2, the control means 3, and the fixed frame 4 are combined. In this case, the object B to be vibrated is, for example, a pipe, and the supporting structure C is a structure such as a building having a capability of supporting the object B to be vibrated or a heavy object.

The expandable container 1 is a bellows 1 made of metal or the like.
1 and an object B to be vibrated which is integrally arranged at the tip of the bellows 11.
And a fastener 13 such as a bolt or a nut for attaching the mounting plate 12 to the vibrating object B so that the vibrating object B and the control means 3 can be connected. Will be distributed. The control means 3 is arranged at the base of the bellows 11 so as to cover it.

The inside of the accumulator 2 is connected to the telescopic container 1 via the control means 3, and the telescopic container 1
For absorbing the fluctuation of the internal fluid R in the expansion container 1 and having a bellows 21 made of metal or the like similar to the bellows 11 of the expansion container 1 and arranged in series with the expansion container 1 and the control means 3 and controlled. It is attached to the means 3 so as to be extendable.

The control means 3 is arranged between the expandable container 1 and the accumulator 2 to change the insertion resistance of the internal fluid R, and is a partition plate 31 made of metal or the like.
A mounting plate 32 for connecting the bellows 11 to the upper surface of the partition plate 31, and the bellows 21 to the lower surface of the partition plate 31.
And a fastener 34 such as a bolt / nut for fixing the partition plate 31 by sandwiching the partition plate 31 between the mounting plates 32, 33.

The fixed frame 4 is attached to the support structure C by fasteners 41 such as bolts and nuts, and the upper part to which the telescopic container 1, the control means 3 and the accumulator 2 are connected is attached by fasteners 34. To be

The internal fluid R is, for example, a non-compressible viscous fluid and is filled in the expandable container 1 and the accumulator 2 in a filled state.

The partition plate 31 is made of a shape memory alloy, which is formed in a long hole shape as shown in FIG. 2 and a plurality of shape memory alloys which are arranged in parallel at the openings of the orifice 35 at equal intervals as shown in FIG. And a heat actuating portion 36.

When the temperature of the internal fluid R rises and reaches the high temperature transformation point, the heat actuating portion 36 changes its shape to reduce the opening area of the orifice 35, and the temperature of the internal fluid R decreases to undergo the low temperature transformation. When the point is reached, the shape is restored to the original shape and the opening area of the orifice 35 is increased, so that it has a bidirectional operating characteristic. In the state before the shape is changed, as shown in FIG. The portion 36b has a shape twisted substantially at right angles to the end portion 36a, and in a state after the shape is changed, the portion 36b has a flat rectangular shape as shown in FIG.

In the microvibration absorbing device A constructed as described above, when the object B to be vibrated such as the pipe is vibrated, the viscosity of the internal fluid R and the orifice 35 are increased.
Vibrations such as minute amplitudes are absorbed based on the size of the opening area of the.

In FIG. 1, a vibrating object B is a supporting structure C.
When moving toward, the telescopic container 1 is wholly compressed. When the expandable container 1 is compressed, the volume of the expandable container 1 decreases, so that the internal fluid R filled therein flows into the accumulator 2 via the orifice 35 in the control means 3. At this time, the accumulator 2 displaces the bellows 21 and absorbs the fluctuation of the internal fluid R as the volume of the internal fluid R moves in and out. Therefore, the internal fluid R is
It receives a resistance based on the viscosity when it is inserted through 5, and acts to absorb the vibration of the vibrating object B.

By the way, the viscosity of the internal fluid R changes according to its temperature, and when the temperature of the internal fluid R rises, the viscosity decreases, and when the temperature of the internal fluid R decreases, the viscosity increases. As the temperature of the internal fluid R rises, the thermal actuation part 36
Indicates that the operating temperature reaches the high temperature transformation point and the shape changes, and the opening area of the orifice 35 gradually decreases, but since the viscosity of the internal fluid R decreases, The resistance generated during insertion does not change significantly. As the temperature of the increased internal fluid R decreases, the thermal operating part 36 reaches the low temperature transformation point in the order in which the operating temperature is set low and recovers the original shape, and the opening area of the orifice 35 gradually increases. However, since the viscosity of the internal fluid R becomes high, the resistance generated when the internal fluid R passes through the orifice 35 does not change significantly. Therefore, even if the temperature of the internal fluid R changes, the damping force for the vibration of the vibrating object B hardly changes.

FIG. 6 shows the relationship between the damping force I of the microvibration absorber A for the new animal B and the temperature T of the internal fluid R.
When the internal fluid R is at the lowest temperature T ₀ in the operating temperature range of the control means 3, the shape of each of the thermal operating parts 36 is twisted as shown in FIG.
Has the largest open area.

When the temperature of the internal fluid R rises, the viscosity of the internal fluid R correspondingly decreases, and the damping force I gradually decreases. When the temperature of the internal fluid R reaches the high temperature transformation temperature point T ₁ of the heat actuating portion 36 where the operating temperature is set to the lowest, the shape of the heat actuating portion 36 changes to a rectangular shape as shown in FIG. Since the opening area of the orifice 35 is increased, the damping force is once increased. When the temperature of the internal fluid R further rises, the damping force becomes small again. Then, when the temperature of the internal fluid R reaches the high temperature transformation point T ₂ of the heat actuating portion 36 in which the transformation temperature is set to be the second lowest, the shape of the heat actuating portion 36 changes to a rectangular shape and the orifice 35.
Since the opening area of is further expanded, the damping force becomes large again.

In the microvibration absorbing device A, the temperature of the internal fluid R rises from T ₀ , and the thermal operating parts 36 are set in stages.
Every time the high temperature transformation points T ₁ , T ₂ , T ₃ and T ₄ of the above are reached, the same operation as described above is repeated. As a result, when the temperature T of the internal fluid R rises within the operating temperature range (T _{0 to} T ₅ ) of the control means 3, the damping force I falls within the range (I _{min to} I _max ) in FIG.
Keep on.

When the internal fluid R reaches the highest temperature T ₅ in the operating temperature range of the control means 3, the shape of each thermal operating portion 36 is rectangular as shown in FIG. The open area of 35 is minimal.

When the temperature of the internal fluid R decreases from T ₅ , the viscosity of the internal fluid R increases accordingly, and the damping force I gradually increases. And the temperature of the internal fluid R is
When the operating temperature reaches the low temperature transformation point t ₄ of the heat-actuated portion 36 set to be the highest, the heat-actuated portion 36 recovers its original shape and becomes a twisted shape as shown in FIG. Becomes smaller, the damping force becomes smaller once. When the temperature of the internal fluid R further decreases, the damping force increases again. Then, when the temperature of the internal fluid R reaches the low temperature transformation point t ₃ of the heat actuating portion 36 where the transformation temperature is set to the second highest value, the heat actuating portion 36 recovers its original shape and becomes a twisted shape. The opening area of the orifice 35 is further narrowed and the damping force is reduced again.

In the microvibration absorbing device A, the temperature of the internal fluid R decreases from T ₅ , and the heat actuating parts 36 are set in stages.
Every time the low temperature transformation points t ₄ , t ₃ , t ₂ and t ₁ of the above are reached, the same operation as described above is repeated. As a result, when the temperature T of the internal fluid R decreases within the operating temperature range (T _{0 to} T ₅ ) of the control means 3, the damping force I is set to the range (i _{min to} i _max ) in FIG.
Keep on.

Since the operating temperature of the thermal actuating portion 36 is lower at the low temperature transformation point than at the high temperature transformation point, it is lower than the damping force range (I _{min to} I _max ) when the temperature of the internal fluid R rises. Range of damping force when temperature drops due to temperature (i _{min to} i _max )
Is set higher. Therefore, in the microvibration absorber A, when the temperature T of the internal fluid R changes within the operating temperature range (T _{0 to} T ₅ ) of the control means 3, the damping force I is as shown in FIG.
Is maintained within a predetermined range (I _{min to} i _max ) shown in FIG. 3, and as a result, the vibration absorption characteristics are stably maintained regardless of the temperature of the internal fluid.

It is desirable that the operating temperature range of the control means 3 is set to an optimum range in consideration of the surrounding environment in which the minute vibration absorber A is installed.

[Other Embodiments] In the microvibration absorbing device of the present invention, the following technique can be applied instead of the above embodiment. a) In the expandable container 1, the side wall is formed of a metal cylinder or the like, and the bellows 11 is arranged in a part thereof. b) Connection pipes are connected to the plurality of expandable containers 1, and the accumulator 2 is arranged at a position separated from the expandable container 1. c) The orifice 35 is set to an arbitrary number. d) The number of heat actuating parts 36 is set to an arbitrary number. e) The heat actuating part 36 is made of bimetal or shape memory plastic.

[0029]

The microvibration absorbing device according to the present invention has the following excellent effects. (1) The thermal operation unit provided in the control means reduces the opening area of the orifice when the temperature of the internal fluid rises and increases the opening area of the orifice when the temperature of the internal fluid decreases, so that the temperature of the internal fluid changes. The vibration absorption characteristics can be stably maintained. (2) Since the plurality of thermal actuating parts provided in the control means change the shape and recover the shape at different operating temperatures and gradually set the opening area of the orifice, the magnitude of the damping force should be kept stable. It is possible to widen the operating temperature range of the control means. (3) When the temperature of the internal fluid rises and the temperature of the internal fluid reaches the high temperature transformation point, the shape changes and the opening area of the orifice decreases, and when the temperature of the internal fluid falls and reaches the low temperature transformation point. Since it is composed of a shape memory alloy that has the operating characteristic of recovering the shape of the orifice and increasing the opening area of the orifice, the opening area of the orifice is quickly changed with respect to the temperature change of the internal fluid, that is, the change of the viscosity. The structure of the control means is simplified.

[Brief description of drawings]

FIG. 1 is a front sectional view showing an embodiment of a microvibration absorbing device according to the present invention.

FIG. 2 is a cross-sectional view taken along line X-X of the microvibration absorber of FIG.

FIG. 3 is a plan sectional view showing an arrangement of an orifice and a thermal operation unit in the microvibration absorbing device of FIG.

FIG. 4 is a trihedral view showing a shape of a heat actuating portion before deformation.

FIG. 5 is a plan view showing the deformed shape of the heat actuating portion.

FIG. 6 is a graph showing the relationship between the internal fluid temperature and the damping force in the microvibration absorbing device of FIG.

[Explanation of symbols]

 A Micro vibration absorbing device B Vibrating object C Support structure R Internal fluid 1 Expansion container 2 Accumulator 3 Control means 4 Fixed frame 11 Bellows 12 Mounting plate 13 Fastener 21 Bellows 31 Partition plate 32, 33 Mounting plate 34 Fastener 35 Orifice 36 Thermally Operating Part 36a End Part 36b Central Part 41 Fastener

Claims (3)

[Claims] 1. A device for absorbing vibration of an object to be vibrated by being connected between the object to be vibrated (B) and a support structure (C), wherein the device is connected to the object to be vibrated and fluid Flexible container (1) with variable amount, and accumulator (2) connected to the flexible container to absorb fluctuation of internal fluid (R)
And a control means (3) disposed between the telescopic container and the accumulator to exert insertion resistance on the internal fluid, the control means being provided in a communication state between the telescopic container and the accumulator. An orifice (35) through which a fluid is inserted, and a thermal actuating portion (3) arranged in the orifice to reduce the opening area of the orifice when the temperature of the internal fluid rises.
6) A microvibration absorbing device comprising: 2. The control means (3) is provided with a plurality of thermal actuating parts (36) for gradually setting the opening area of the orifice (35) according to different operating temperatures. Micro vibration absorption device. 3. The thermal actuating portion (36) changes its shape when the temperature of the internal fluid (R) rises and reaches a high temperature transformation point to reduce the opening area of the orifice (35), thereby increasing the temperature of the internal fluid (R). 3. The microvibration absorbing device according to claim 1 or 2, characterized in that when the temperature decreases and reaches a low temperature transformation point, the shape is restored to the original shape and the opening area of the orifice is increased.