JPS6023672A - Fluid seal - Google Patents

Abstract

PURPOSE:To automate the opening/closing of a seal with a simple structure by providing a driving body made of a shape memory alloy in a non-metallic elastic body. CONSTITUTION:The circumference of a metallic inner ring 14 is uniformly divided at three positions, for example, and individual inner rings 14 are connected to each other with clamps 11 made of a shape memory alloy. The elastic force of a cover 12 made of a non-metallic elastic body such as rubber is stronger than the force of the clamps 11 at a low temperature, and the clamps 11 are elliptically deformed. Next, when the temperature of the clamps 11 is increased, the clamps 11 become circular in shape, the inner diameter of a fluid seal is shrinked, and the seal is set to a closed state.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a fluid seal, and particularly to a fluid seal suitable for automating a machine that repeatedly seals high-pressure fluid.

BACKGROUND OF THE INVENTION Conventionally, as shown in FIG. 1, a seal 4 is required to seal the gap between a hole leading into a chamber 2 containing a fluid 3 and a cylindrical body l fitted through the hole. In this apparatus, Fukagawa developed a method in which an umbrella-shaped seal as shown in FIG. 2 is used as the seal 4, and a suppressor 5 is provided as a means for bringing the seal 4 into close contact with the cylindrical body l.

The problem with the conventional example of setting θ to 2 for the body seal is that the seal 4 is greatly deformed using particularly high-pressure fluid in order to improve its compactness, so if this is repeated, the life of the seal will be shortened due to material deterioration. In addition, in order to generate the pressure to press the seal 4, a complicated mechanism is required to press the pressing pad 5 with nitrogen pressure or the like.

[Purpose of the invention]

An object of the present invention is to provide a fluid seal that can seal high-pressure fluid and that can automate the opening and closing of the seal with a simple mechanism.

[Summary of the invention]

Conventional fluid seals require large deformations to create a tight layer, and require complex mechanisms to automate opening and closing operations. For this reason, we investigated a fluid seal that does not cause major deformation of the seal and can be opened and closed using a simple mechanism. As a result of our research, we devised a fluid seal in which a driving body made of a shape memory base is built into a ring-shaped non-metallic elastic body made of the same materials as rubber and plastic used in Takumi's fluid seals. did.

Shape-memory base metal has the property of suddenly exhibiting a large change in shape and the generation of force at certain warm stitches when the temperature rises. The fact that shape-memory alloys have such properties is illustrated in the miscellaneous reading ``Machine Design'', Volume 24, No. 10 (August 1981 issue), 6.
On pages 7 to 73, there is a detailed explanation of ``Shape 1C memory alloy and its application to mechanical parts''. When the shape change and force generation of shape memory alloys are used for fluid seals,
It is possible to seal the fluid without using a complicated mechanism as in the past, and the amount of deformation applied to the non-metallic elastic body of the seal can be extremely small.

The shape memory alloy used in the fluid seal of the present invention is driven by subjecting the shape memory alloy to a thermal cycle in a temperature range from room temperature to about 100C.

In the fluid seal of the present invention, among the opening and closing operations of the seal, the closing operation is performed by the force of the shape memory alloy itself, while the closing operation is performed using the force of a nonmetallic elastic body or a metallic elastic body.

[Embodiments of the invention]

Hereinafter, one embodiment of the present invention will be explained with reference to FIG. Fig. 3 Beam/Gang Shape This is a type of fluid seal that opens and closes by contracting or expanding the inner diameter of the purple fluid seal.

In FIG. 3, the metal inner ring 14 is divided into three equal parts of the circumference. The number of divisions is arbitrary, and the greater the number, the better the adhesion as a fluid seal. The clamp 11 is made of shape memory alloy and the clamp 14 is made of shape memory alloy.
Comrades ke connect. The appearance of the clap 11 is as shown in FIG. Clap 11 is multi/site mode T
It is made of shape memory alloy such as TI alloy or Cu alloy with M degree of around 50C. The cross-sectional shape of the clap 11 changes depending on the temperature, as shown in FIG. Low temperature analogy is 20
In C, the elastic force of the cover 12 made of a non-metallic elastic body such as rubber is stronger than the force of the clamp 11, so the clamp 11 is deformed into an elliptical shape. If the elastic force of the cover 12 alone is insufficient to change the shape of the clap 11, as shown in FIG. The body is inserted, and the reaction force is used to make the clap 11 into an elliptical shape. When the shape of the clasp 7 becomes elliptical, the inner shape of the fluid pool expands and the seal becomes open.

Next, if the temperature of Clap 11 is ^warm, then l-1: 80C.
At this temperature, the clamp 11 itself has a circular shape memorized, so at this temperature the cover 12. f) Or, a force for restoring the shape stronger than that of an elastic body such as the spring 16 acts, and the shape of the comb 7 becomes circular. At this time, the inner diameter of the single flow sol contracts by one section, and the seal becomes open.

In order to heat the clap 11 to a high surface, a resistance wire 17 is attached to the surface of the clap 11 as shown in FIG. A method is used in which a wet and warm fluid such as vortex water is introduced to fill the inside of the fluid seal.

As a method of cooling Clap ll' to a low temperature, it is possible to cut off the current, or to cool it naturally after discharging the high temperature fluid.
Pipe 15 of Figure Ii Ratio 3 is placed inside the cryogenic fluid sound fluid seal of Reisui Temple.

By applying reversible shape memory treatment to the shape memory alloy used for Naoriji/Zo 11, it is possible to memorize the shape at low temperatures as shown in FIG. 5. In order to perform reversible shape memory treatment (for example, as shown in FIG. 8, the processing jig 21
By giving a strong summer deformation, it becomes an elliptical shape. This amount of deformation is 39 or more in surface strain of the shape memory alloy.

When the above processing is applied, the circular high temperature shape shown in FIG. 8(C) and the triangular low temperature shape shown in FIG. It is reproduced repeatedly according to the clustering. When using the clamp 11 which has been subjected to the above-described shape memory treatment, the reaction force required for the spring 16 shown in FIG. 6 is reduced. Therefore, the spring 16 can be omitted or downsized.

In addition, in FIG. 3, the outer ring 13 is fitted with the ring of the cap fitting, and is provided to facilitate the outer curve of the cover 12 of the fluid seal to tightly wrap and contact the inner surface of the hole of the fluid chamber. ing.

According to this embodiment, when the fluid seal is closed, the amount of deformation that the cover 12, which is made of a non-metallic elastic body, undergoes is much smaller than the amount of deformation that a fluid seal such as a conventional umbrella-shaped seal undergoes. . Therefore, the life of the non-metallic elastic body due to material deterioration is significantly improved compared to conventional fluid seals. Further, according to this embodiment, since the g-motion mechanism is built inside the fluid seal, the size can be reduced. In addition, since only thermal summerization is used as a driving means, the mechanism used to automate the opening and closing operations of the fluid seal is simpler than in the past.

FIG. 9 shows a second embodiment of the invention. In FIG. 9, coil 18 is made of a shape memory alloy. coil 1
The number 8 does not necessarily have to be two; the same effect can be obtained with just one. The tightness of the fluid seal improves as the number of coils 18 increases. The coil 18 is also equipped with a shape memory treatment so that it contracts under high temperature conditions.

An inner ring 14 made of metal is fitted inside the coil 18 and forms an inner groove of the coil 18. The inner ring 14 is divided into three parts, but the number of divisions is arbitrary, and the greater the number of divisions, the better the tightness of the fluid seal. A gap is provided between the inner rings 14, but this gap +=J is narrowed because the coil does not generate strong contractile force when the coil 8 becomes hot. When the gap between the inner rings 14 is narrowed, the cup (-12) made of a non-metallic elastic material such as rubber inside the ring is tightened. Therefore, the fluid seal is closed. As a means of heating the coil 18 to a high temperature, the coil 18 can be heated through the vibrator 15 tray.
A method is used in which high-temperature fluid such as hot water is introduced into the interior of the system. A metal outer ring 13 having a guide groove for the coil 18 is provided on the outside of the coil 18 . The role of the outer jJi 13 is to facilitate the close contact of the outer diameter side surface of the fluid seal with force/<-12 to the inner surface of the hole of the fluid chaff.

fzJ=-Carp A/18 is subjected to shape memory treatment so that it contracts at a high temperature, for example 80C, and becomes tightly wound.

Assemble the fluid seal as follows.

That is, the outer ring 13 to which the inner ring 14 and the vibrator 15 are connected is placed in a predetermined position with the coil pitch of the coil 18 subjected to shape memory treatment fully stretched at room temperature. Finally, the whole is stored inside the cover 12.

According to this embodiment, the amount of drive body for the shape memory alloy sheath can be increased compared to the case of the first embodiment.
Even if the fluid seal has the same dimensions, the tightness and pressure resistance of the fluid seal can be significantly increased.

〔Effect of the invention〕

According to the present invention, when the pressure of the fluid in the fluid seal is several atmospheres or more,
It is possible to maintain airtightness even in a range of tens of atmospheres.

Furthermore, since the opening and closing operations of the fluid seal can be performed by a very simple mechanism, the cost required for automation is reduced compared to conventional systems.

[Brief explanation of the drawing]

Figure 1 is a diagram showing a conventional fluid seal mechanism, and Figure 2 is a diagram showing a conventional fluid seal mechanism.
Cross-sectional view of the umbrella-type fluid seal, FIG. 3(a)lq, cross-sectional view of the fluid seal of the first embodiment of the present invention, 3rd! ! 4j(b
) is an A-A sectional view, Figure 4 is an external view of the shape memory alloy clamp, and Figure 5 is the low temperature (a) and high temperature (b) of the clamp.
Figure 6 is a sectional view of the clamp to which a spring tray is applied, Figure 7 is an external view showing how a resistance wire is attached to the clamp, and Figure 8 is a clamp subjected to reversible shape memory treatment. Cross-sectional views at high and low temperatures after the process and treatment, No. 9
FIG. 9(a) is a sectional view of a fluid seal according to a second practical example of the present invention, and FIG. 9(b) is a sectional view taken along line A-A. 11... Clamp, 14... Inner ring, 12... Cup (-113... Outer ring, 15... Pipe, 16...
Gooseberry/G, 17...Resistance wire, 18...Coil. Agent Patent Attorney Naohashi Akitei 1 Figure 2 Figure 1 Old (1 噌'1 Figure 8M (b) (C) (d) No. q (σ) Figure (e)

Claims (1)

[Claims] (1) A fluid seal characterized in that a driving body made of a shape memory alloy is provided inside a non-metallic elastic body, and the movement of this driving body seals the fluid. 2. A fluid seal according to claim 1, characterized in that a resistance heating element or a high-temperature fluid is used as a heat source for the drive body made of a shape memory alloy. 3. A fluid seal according to claim 1, characterized in that an elastic metal body is used as an auxiliary means for moving the shape memory alloy drive body. 4. A fluid seal according to claim 1, characterized in that the shape memory alloy is previously subjected to a "J-common shape memory treatment" as a means for facilitating the operation of the drive body made of the shape memory alloy.