JPS6230310B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION a. Field of Industrial Application The present invention relates to a method for creating a vacuum. Specifically, the present invention relates to a method of ejecting fluid in an annular manner and causing the annular jet to collide with a seal member to create a vacuum in a space surrounded by the jet and the seal member.

b. Prior Art Vacuum is generally defined as "a state of a specific space at a pressure lower than atmospheric pressure."

Such a vacuum state is widely used not only in engineering, physical, and chemical research fields, but also in various industrial fields. For example, in the field of metal industry, when performing brazing, welding, casting, etc., the work is carried out under vacuum conditions to prevent metal oxidation and promote gas escape in the metal to obtain high quality products. The method is being implemented. Furthermore, heat treatment of metals, high-temperature tensile tests, etc. are carried out under vacuum conditions in order to prevent oxidation.

Conventionally, a common method for creating a vacuum state is to remove air in a sufficiently airtight container using a vacuum pump.

c Problems to be Solved by the Invention However, the above method is complicated and requires a special airtight container and a vacuum pump, so it is easy to evacuate a predetermined spatial range. It's hard to call it a method.

The present invention has been made in view of the above problems, and its purpose is to provide a new method that can easily bring a predetermined spatial range into a vacuum state.

d Means for Solving the Problems The gist of the present invention for achieving the above object is to eject fluid from an annular nozzle to form an annular jet, and collide the jet with a sealing member, thereby connecting the nozzle and the jet. and a seal member, and the jet flow collides with the seal member so that the jet flow flows toward the outside of the space.

That is, in the method of forming a vacuum according to the present invention, first, fluid is ejected from an annular nozzle to form an annular jet.

This annular jet itself is used as a sealing member to form a predetermined space together with any other sealing member.

In this way, a sealed predetermined space is formed, and the jet stream is made to collide with the collision surface provided at the end of the other sealing member.

In this case, the collision surface is formed in such a way that most of the jet flows immediately after the collision toward the outside of the predetermined space.

This method consists of four points.

E-Function With this configuration, the predetermined space can be brought into a vacuum state by the flow until the jets collide and the outward flow of the predetermined space at the time of collision. Note that air, hot air, inert gas, other gases, or fluids such as water and oil can be used as the jet fluid.

f Embodiments Hereinafter, preferred embodiments of the present invention will be described in detail by way of example based on the drawings.

FIG. 1 is a diagram conceptually explaining an apparatus for illustrating an embodiment of the method according to the present invention. In the figure, 1 is an annular nozzle, 2 is an annular jet ejected from the annular nozzle 1 by an air compressor or the like (not shown), and 3 is a seal member with which the annular jet 2 collides. The annular nozzle 1 is a straight nozzle, and the upper surface of the sealing member 3, that is, the surface 3a with which the annular jet 2 collides, is a straight nozzle.
It is inclined downward toward the outside so that the flow mainly flows toward the outside (outside the predetermined space 4 formed by the nozzle 1, the annular jet 2, and the sealing member 3). The angle of inclination β is preferably greater than or equal to 0°, but it can also be set to 0°. The annular jet 2 creates a vacuum inside the annular jet 2, that is, the predetermined space 4, by the flow until it collides with the collision surface 3a and the outward flow after the collision. Note that the annular jet 2 itself functions as a sealing member.

In this case, as shown in FIG. 2, without inclining the collision surface 3a of the pedestal 3, the fluid passage 1a of the annular nozzle 1 is directed downward and outwardly so that it is widened at the end, and the annular jet 2 flows outward. You can do it like this. The angle θ of the jet flow at this time is less than 0° and greater than that.

FIG. 3 shows a case where the annular nozzle 1 is a divergent nozzle with an aperture inserted in the middle. In this case, the fluid flowing inside the nozzle is throttled midway, and the nozzle outlet ejects the fluid at a speed exceeding the speed of sound.

FIG. 4 shows a case where a recess 1b is provided at the lower end of the annular nozzle 1 in order to widen the space 4 that becomes vacuum. In addition, in the figure, a recessed portion may be provided on the upper surface of the sealing member 3.

FIG. 5 shows a case where an annular jet 2' is used as the sealing member 3. That is, two annular nozzles 1, 1' are arranged facing each other, and both annular nozzles 1,
An annular jet 2, 2' is ejected from 1' in a spreading shape,
One annular jet 2 collides with the other annular jet 2', and both collided annular jets 2, 2' flow toward the outside of the space 4.

FIG. 6 shows a case where an annular jig 5 (also used as a work table) is used. This jig 5 also does not act as a collision surface for the annular jets, and the annular jets 2, 2' collide with both sides of the jig 5 from the two annular nozzles 1, 1', and the collided jets 2, 2' are It is designed to flow outward. A workpiece (not shown) or the like can be installed in the hollow portion 5a of the jig 5.

FIG. 7 shows a case where a telescopic jig 6 is used.
This jig 6 acts as a sealing member, and
Circular annular side plate 6 on which the two annular jets 2, 2' collide
a, 6b and a bellows pipe 6c connecting the side plates 6a, 6b. If such a telescopic jig 6 is used, the size of the vacuum space 4 can be changed while maintaining the vacuum state. 7 drawn with a two-dot chain line is a workbench. 8 is a fluid passage for a vacuum pump provided in the workbench 7;
If a higher vacuum condition is desired, a vacuum pump can also be used. Note that a vacuum pump can be used in combination not only in the case of Fig. 7, but also in the jig 5 in the case of Fig. 6, and in the center of the annular nozzle 1 in the cases of Figs. 1 to 5. This is possible by providing a fluid passage.

FIG. 8 shows a case where elongated objects such as metal rods 9, 9' are brazed, welded, pressure welded, etc. in this case,
The two annular nozzles 1, 1' are provided with hollow parts 1c, 1'c in their centers for inserting metal rods 9, 9', and the metal rods 9, 9' and the nozzles 1, 1' are 1
The parts d and 1'd are in close contact and sealed. By doing so, only the parts where the long object is required can be placed under a local vacuum condition.

9 and 10, the inside of the container 10 is evacuated,
In addition, the case where the opening 10a of the container 10 is sealed, that is, the case where it is used as an air packing is shown. The vacuum condition within the container 10 is maintained by sealing with an annular jet 2. Alternatively, sealing may be performed by lowering the packing 11 provided at the lower end of the nozzle 1 and bringing it into close contact with the opening 10a.

FIG. 11a shows an annular nozzle 1 with a special shape. This annular nozzle 1 has a nozzle inner member 1e.
A spiral linear protrusion 1f is provided on the surface. FIG. 11b is a conceptual diagram showing the nozzle inner member 1e and the spiral linear protrusion 1f viewed from above. Since the spiral linear protrusion 1f is provided as shown in the figure, the fluid passing through the nozzle 1 is ejected while rotating in the direction shown by the arrow 12. Therefore, the sealing effect of the annular jet is further strengthened. Note that it is also possible to eject the fluid while rotating the annular nozzle itself.

FIG. 12a shows yet another annular nozzle 1 having a special shape. This nozzle 1 has a constricted end portion of a fluid passage 1a. By constricting the passage 1a at the tip in this way, the speed of the jet flow can be made extremely high. Figure 12b shows this aperture part 1.
It is a figure which expands and shows g.

FIG. 13 is a diagram showing the state of the tip of the annular nozzle 1. FIG. 13a shows that when the distal end surface of the inner member 1e is retracted from the distal end surface of the outer member 1h, the
Figure b shows the case when it is protruded, and Figure 13c shows the case when it is flush.

14 and 15 show the case where the seal member 3 has a special shape. Figure 14 shows the annular jet 2.
A seal member 3 suitable for the case where the angle α between the contact surface 3a of the seal member and the impact surface 3a of the seal member is large is shown. If this angle α is large, a backflow as indicated by a broken line arrow 13 occurs. Therefore, this sealing member 3 is provided with a concave backflow prevention portion 14 to prevent the backflow 13 from entering the vacuum space 4. FIG. 15 shows a sealing member 3 suitable for the case where the angle α is small. If this angle α is small, the space 4 will only have a low degree of vacuum, so in order to obtain a large angle α, the lower part of the collision surface 3a is formed in the shape of a circular arc.

(Experimental Example) As an experimental device, the device shown in FIG. 16 was used. In this case, diameter l ₁ = 20 mm, diameter l ₂ = 16 mm, H′ =
It is 100mm. Using this device, an experiment was conducted with the pressure at the nozzle outlet set to P ₁ =120 mmHg, and as a result, the pressure in the predetermined space became negative by P ₂ =-4.8 mmHg.

Although various embodiments of the method according to the present invention have been described above, the degree of vacuum that can be obtained by this method varies depending on the flow velocity V of the jet (generally, the higher the flow velocity V, the higher the degree of vacuum can be obtained. ), the distance H between the nozzle and the seal member, the ejection angle θ of the jet, the angle β of the collision surface, etc., so it is necessary to appropriately select these factors.

The method according to the present invention can be used in the following cases.

1 Vacuum brazing, vacuum welding (performed using the equipment shown in Figures 6, 7, and 8) 2 Vacuum casting 3 Electron beam welding, electron beam processing (see Figure 17, 15 is a filament, 16 is an electron beam, 17 is a welded product.) 4 Vacuum scouring, vacuum melting 5 Vacuum heat treatment 6 Vacuum deposition, vacuum plating 7 Vacuum high temperature tensile test (See Figure 18. In the figure, 18 is a high temperature bath and 19 is a test piece. ) 8 Other work in vacuum such as vacuum discharge, vacuum drying, vacuum impregnation, vacuum distillation, etc. 9 Treatment of stiff shoulders (improving blood circulation by impinging annular fluid on the affected area to create a vacuum) g Effect of the invention As explained above, according to the method for creating a vacuum state according to the present invention, a vacuum state can be created very simply and easily anywhere. Therefore, the method according to the present invention can be used in a wide variety of fields and will greatly contribute to industry.

[Brief explanation of the drawing]

FIGS. 1 to 8 and FIGS. 14 and 15 are diagrams each explaining an embodiment of the method according to the present invention and conceptually showing an apparatus for implementing the method, and FIGS. 9 and 10. The figure shows the case where the method according to the present invention is used as a sealing means. Figures 11 and 12 are diagrams showing a special annular nozzle used in the present invention. Figure 13 is the shape of the tip of the annular nozzle. FIG. 16 is a conceptual diagram showing the apparatus used in the experiment, and FIGS. 17 and 18 are diagrams showing application examples of the method according to the present invention. DESCRIPTION OF SYMBOLS 1... Annular nozzle, 2... Annular jet, 3... Seal member, 3a... Collision surface, 4... Vacuum space, 5... Jig, 6... Telescopic jig, 10...
Container, 11... Packing, 14... Backflow inflow prevention part.

Claims (1)

[Claims] 1. Fluid is ejected from an annular nozzle to form an annular jet, and this jet collides with a sealing member to form a space between the nozzle, the jet, and the sealing member, and the jet A method for forming a vacuum state, characterized in that the jet stream impinges on the sealing member so as to flow outward in a space. 2. The method for creating a vacuum state according to claim 1, wherein the surface of the sealing member with which the annular jet collides is formed so that the jet flows toward the outside of the space after collision. 3. A method for creating a vacuum state according to claim 1, wherein the sealing member is formed by an annular jet jet ejected from another annular nozzle.