JP2003240121A - Vacuum vessel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a means for easily and simply sealing a lid part in vacuum after a lid is mounted, in a vacuum vessel having a large opening. <P>SOLUTION: In this vacuum vessel 1 comprising a casing 2 having an opening and an opening part 5 at an upper part of a side wall 4 forming the opening, the lid 3 inserted into the opening part 5, and a metallic ring 7 having an inner periphery smaller than an outer periphery of the opening part 5 at a normal temperature, the ring 7 is fitted to the opening part 5 when the ring 7 is thermally expanded and the inner periphery of the ring 7 becomes larger than the outer periphery of the opening part 5, and the opening part 5 and the lid 3 are fastened and sealed in vacuum by contractile force generated in a process of contracting the ring 7 by cooling. The ring 7 is thermally expanded to eliminate the fastening force to open the lid 3. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vacuum container having a large opening, and more particularly to a technique for easily vacuum-sealing a lid that closes the opening.

[0002]

2. Description of the Related Art Conventionally, a metal housing is covered with a metal lid, and then a gasket is used between the lid and the housing to completely seal the lid and the housing, and many bolts, nuts, etc. are used. I used to work to maintain a high degree of vacuum by tightly tightening the lid and the housing.

[0003]

SUMMARY OF THE INVENTION By simplifying the above-mentioned work and removing the gap between the housing and the lid by a simple operation after covering the housing without using bolts, nuts, etc. An object of the present invention is to provide a sealing means capable of maintaining a vacuum and a means for reopening a lid by a simple operation.

[0004]

In order to solve the above-mentioned problems, the present invention has a housing having an opening and an opening at an upper portion of a side wall forming the opening, a lid inserted into the opening, and a room temperature ambient temperature. A metal ring having an inner circumference smaller than the outer circumference of the opening is provided, and the ring is heat-expanded and fitted into the outer circumference of the opening, and cooled to vacuum-seal the opening and the lid.

Therefore, the inner circumference of the opening provided in the upper portion of the vertical side wall of the housing formed in a container shape has substantially the same shape as the outer circumference of the lid inserted in this portion, with a very small gap. Make the lid accessible.

At room temperature, a metallic ring having an inner circumference slightly smaller than the outer circumference of the opening of the upper side wall of the housing facing the outer circumference of the lid, and a heating device for heating the ring are provided. When the ring is heated and expands and its inner circumference becomes slightly larger than the outer circumference of the opening of the housing, a device is provided to move this ring to the opening of the housing that faces the outer circumference of the lid, and the ring is placed in that part. Move and fit the ring into the opening. At this time, the heating device also moves together with the ring, but the heating operation is terminated after the movement.

In this state, the ring is naturally cooled or cooled by a cooling device to lower the temperature. The cooled ring tightens around the perimeter of the housing opening in an attempt to return to its original dimensions. The tightening force can be arbitrarily determined according to the linear expansion coefficient, Young's modulus, shape, etc. of the material of the ring, so that the required tightening force can be easily obtained according to the required degree of vacuum.

When the lid is opened, the heating device is activated to heat and expand the ring so that the inner circumference of the ring becomes larger than the outer circumference of the opening of the housing and the tightening force disappears before the lid is removed. In this case, heat conduction from the ring to the housing causes the housing and the lid to also thermally expand. However, since the heating is performed from the outside of the ring or the like, even if the temperature of the ring is sufficiently high, the temperature of the entire housing and lid is not high. Therefore, when the ring is heated, a gap is created between the ring and the housing so that the ring can be removed.

The heated and expanded ring is separated from the housing by the moving device and returned to its original position. At that position the ring cools and returns to its original size. If the linear expansion coefficient of the material of the lid and the material of the opening of the housing is selected to be smaller than the linear expansion coefficient of the material of the ring, it becomes easier to attach and detach the ring.

It is also possible to eliminate the moving device for moving the ring, place the ring fixed outside the opening at all times, and heat and expand the ring to open and close the lid only when opening and closing the lid. . Further, like the vacuum flat plate solar heat collector, the glass lid may be vacuum-sealed according to the present invention and then the lid may not be opened.

[0011]

1 is a sectional view showing a first embodiment of the present invention. 1 is a vacuum container, 2 is a housing, 3 is a lid,
4 is a vertical side wall of the housing 2, 5 is an opening formed by the upper part of the side wall 4, 6 is a vertical portion which is an end face of the lid 3 facing the opening 5, and 7 is fitted on the outer periphery of the opening 5. A ring made of metal, 8 is a heater that heats the ring 7, 9 is a cooler that cools the ring 7, 10 is a moving device that moves the ring 7 up and down in the drawing, 11 is a connection between the moving device 10 and the ring 7. Cable, 12 is a suction port for sucking air from the vacuum container 1, 1
Reference numeral 3 is a workpiece to be housed inside the vacuum container 1.

The housing 2 is formed by processing a single metal plate such as aluminum or stainless steel and is formed into a container shape in which the side wall 4 and the bottom plate are seamlessly integrated. With such a configuration, it is possible to obtain the housing 2 having an extremely high vacuum holding capacity. The housing 2 is formed in a circular shape or a polygonal shape such as a square with rounded corners when viewed from above. The upper portion of the side wall 4 of the housing 2 has an opening 5 that forms an opening of the housing 2.
And is formed thinner than the thickness of the main body portion including the side wall 4 of the housing 2.

The lid 3 has a shape corresponding to the shape of the housing 2 so as to close the opening of the housing 2, and is made of a material such as metal or glass. The lid 3 may have a flat plate shape, but the central portion may have a mountain shape as shown in the drawing.

The ring 7 has the same shape as the outer periphery of the opening 5,
It has an inner circumference slightly smaller than the outer circumference of the opening 5 at room temperature and is made of a metal such as stainless steel or carbon steel.

A case will be described with reference to FIG. 1 in which the lid 3 of the vacuum container 1 is opened and closed to insert and remove the workpiece 13. The work piece 13 that requires processing in a vacuum atmosphere has a lid 3
Is removed and is put into the inside of the housing 2 through the open opening. At this point, the atmospheric pressure inside the housing 2 is 1 atm.

After that, the lid 3 is inserted into the opening 5. The gap between the lid 3 and the inner periphery of the opening 5 is so small that it is called a fitting. Even if the gap is small, it is impossible to make the atmospheric pressure in the vacuum container 1 a vacuum because of the gap. Therefore, the ring 7 is used to eliminate this gap.

The inner circumference of the ring 7 is made slightly smaller than the outer circumference of the opening 5 at room temperature. The ring 7 is heated by the heater 8 to be expanded. When the ring 7 becomes hot and its inner circumference becomes larger than the outer circumference of the opening 5, the opening 5
The ring 7 is moved by the moving device 10 to the outside. At this time, the heating device 8 also moves together with the ring 7.

The heater 8 is generally provided near the ring 7, and electricity (electric heater, infrared lamp, etc.) is generally used as a heat source. Further, it is also a good method that the ring 7 and the heater 8 are integrated with each other by closely contacting the inside of the ring 7 or the outside thereof with the ring 7 through an insulator so that the ring 7 and the heater 8 are integrated. In the case of the inside of the ring 7, the heating wire will be embedded.

When the ring 7 reaches the outside of the opening 5 and fits into the outer periphery of the opening 5, the moving device 10 stops and holds the ring 7 in its place. Then, the ring 7 lowers the temperature by natural cooling. It is also a good method to cool the ring 7 with the cooler 9 to lower the temperature, without relying on natural cooling.

As the cooler 9, it is suitable to blow air with a suitable fan or to spray liquid such as water in a mist form. When the cooler 9 is used, it is important that the temperature drop of the ring 7 be uniformly reduced over the entire circumference of the ring 7. The ring 7 whose temperature has been lowered to near room temperature shrinks as the temperature decreases.

Since the inner circumference of the ring 7 is originally made smaller than the outer circumference of the opening 5, the ring 7 tightens the opening 5 during the contraction process. The tightening force is determined by the linear expansion coefficient of the material of the ring 7, the temperature at which the ring 7 is heated, the Young's modulus of both materials, the shape, etc.
Perimeter 1 mm ² of opening 5 from several kilograms to several tens
A compression force of kilograms is easily obtained. Due to this compressive force, the inner periphery of the opening 5 and the vertical portion 6 of the lid 3 come into close contact with each other to eliminate a gap, and a high degree of vacuum sealing is completed.

A metal having a high tensile strength is suitable for the ring 7. Among them, carbon steel and stainless steel are suitable because of their robustness. The linear expansion coefficient of these materials is 2
The average value between 0 ° C and 200 ° C is 12 × 10 for carbon steel.
^-6 , 16 × 10 ^{-6 for} stainless steel (SUS304)
Rank. For example, stainless steel (SUS304) is 20
When the temperature is raised by 0 ° C., it expands by 3.2 mm per 1 m. When expanded in this way, the ring 7 having an inner circumference smaller than the outer circumference of the opening 5 at room temperature can easily have an inner circumference larger than the outer circumference of the opening 5, and can be fitted into the outer circumference of the opening 5. .

Ring 7 made of stainless steel (SUS304)
Since the thermal conductivity thereof is about 1/3 of that of carbon steel, the temperature drop of the ring 7 during the movement by the moving device 10 is small and it is suitable for the device of the present invention. If both the vertical portion 6 of the lid 3 and the inner peripheral surface of the opening 5 corresponding thereto are mirror-finished and a soft metal material such as copper or tin is used as the material of the opening 5, Complete vacuum sealing can be completed only by the tightening force of the ring 7.

When the vacuum sealing is completed, the inside of the housing 2 is evacuated from the suction port 12 using a vacuum pump to create a vacuum. Therefore, in order to take out the work piece 13 after processing the work piece 13 in a vacuum such as sputtering,
When the ring 7 is heated and expanded by the heater 8 and the inner circumference of the ring 7 becomes larger than the outer circumference of the opening 5, the lid 3 is removed using a handle or the like (not shown), and the work piece 13 therein is taken out. good. At this time, the ring 7 and the heater 8 are attached to the housing 2
It can also be removed from and moved by the moving device 10.

The moving device 10 is for winding up the cable 11 and moving the ring 7 (and the heater 8) connected to the cable 11 to bring it to the opening 5.
The purpose is to use the ring 7 except when opening and closing the lid 3.
Is always kept away from the opening 5 of the housing 2. This ensures that the ring 7
To the outside of the opening 5, the heater 8 is energized to raise the temperature of the ring 7, the lid 3 is opened and closed, and at other times the energization can be cut off to save power.

Incidentally, in FIG. 1, the lid 3 is formed in a mountain shape having a raised central portion. When the lid 3 has such a shape, when the inside of the vacuum container 1 is evacuated, the atmospheric pressure applied to the lid 3 causes an outward force indicated by an arrow in the peripheral portion of the lid 3. This force causes the ring 7 to open
Opposite to the force for tightening, the advantage of increasing the tightening force between the lid 3 and the opening 5 is produced. Further, when the inside of the vacuum container 1 is returned to the atmospheric pressure, there is an advantage that the outer peripheral portion of the lid 3 is slightly shrunk in size so that the lid 3 can be easily removed.

FIG. 2 is a partially enlarged sectional view showing the structure of the outer peripheral portion of the lid 3 and the opening 5 at the place where the housing 2 and the lid 3 are joined,
(A) shows the case without a gasket, and (b) shows the case with a gasket. Reference numeral 21 is a gasket, and 22 is a groove for the gasket. Open the gasket 5 that is normally used.
It is also a good method to insert the gap between the lid 3 and the lid 3 to reduce the degree of surface finish required for both the opening 5 and the lid 3.
When inserting a gasket between the opening 5 and the lid 3,
Carbon steel or the like, which is harder than copper, may be used as the material of the opening 5.

When a rubber gasket is used as the gasket 21, the cross-sectional area of the groove 22 is made substantially the same as the cross-sectional area of the gasket 21. When a rubber gasket is used, it is necessary to cool the ring 7 rapidly by using the cooler 9 before the rubber gasket melts.

When the ring 7 is heated to a particularly high temperature, the rubber gasket cannot be used even if the cooler 9 is used depending on the temperature and the frequency of use. In such cases, hollow metal O
A hollow O-ring called a ring or trade name Heliostat is recommended as the gasket 21.

In FIG. 2, the thickness t1 at the opening 5 is the housing 2
The thickness is made smaller than the thickness t2 of the main body portion including the side wall 4 to reduce the thickness. When the inside of the housing 2 is evacuated, it receives a pressure due to a large atmospheric pressure. Therefore, in order to withstand the pressure, the thickness t2 is generally required to be considerably large.

However, since the lid 3 having a high mechanical strength is inserted inside the opening 5, the thickness is not required in this portion. Rather, in order to make close contact with the lid 3 when tightened with the ring 7, it is more effective to have a small thickness and flexibility. For this reason, the thickness of the opening 5 is smaller than the thickness of the main body 2 of the housing 2.

In FIG. 2, the ring 7 is installed near the upper end of the opening 5, and its lower end is positioned above the upper end of the thick main body portion of the housing 2 by a distance d as shown in the drawing. Has been done. When the heater 8 is always placed at the upper end of the opening 5 without moving the heater 8 and heating and cooling is performed there, the lid 3 is removed and there is no lid 3 at the opening 5. This is to prevent a large shear stress from being sandwiched between the ring 7 and the thick portion of the side wall 4 when the ring 7 cools and contracts.

As described above, according to the first embodiment, the metal ring 7 having an inner circumference smaller than the outer circumference of the opening 5 is heated and expanded at room temperature, fitted into the outer circumference of the opening 5, and cooled. Since the opening 5 and the lid 3 are vacuum-sealed,
A high vacuum can be maintained with a simple operation, and the lid can be easily opened by heating and expanding the ring 7.

FIG. 3 is a sectional view showing a second embodiment of the present invention. Reference numeral 31 is an inner housing, 32 is an outer housing, 33 is a bottom plate of the inner housing 31, and 34 is a side wall thereof. In the second embodiment, the housing is made of a single metal plate which is made by integrating a bottom plate and a side plate having the opening 5 into one body, and an outer housing 32 for holding a vacuum, and withstands atmospheric pressure. Therefore, it is divided into an inner casing 31 which is made to be sturdy and has a double structure. Others are the same as those in the first embodiment.

The bottom plate 33 and the side wall 3 which constitute the inner casing 31
Although 4 is usually formed integrally by pressing or die casting, it may be formed separately by using different materials. In either case, its strength is made strong by thickening the plate so that it can sufficiently withstand atmospheric pressure, but it does not necessarily have to be airtight. A metal is generally used as the material, but glass or the like can be used.

The outer housing 32 is for vacuum sealing provided along the outside of the inner housing 31, and is made of a relatively thin metal plate having a thickness of, for example, about 1 mm integrally by pressing or the like. An opening 5 is formed in the upper portion of the side wall. The role of the outer casing 32 is to seal the inside of the casing in a vacuum, and since it does not have the strength to withstand the atmospheric pressure, most of it is pressed against the inner casing 31 by the atmospheric pressure without a gap. The opening 5 at the upper portion of the side wall thereof ensures the airtightness of the housing when tightened by the ring 7 as in the first embodiment.

The opening 5 is sandwiched between the lid 3 and the ring 7, and tightly adheres to the lid 3 by the tightening force of the ring 7 for vacuum sealing. The role of the outer housing 32 is the ring 7
Because it is to complete the vacuum sealing by making use of the tightening force of, it is not made as sturdy as the inner casing 31,
It is made flexible so as to make full use of the tightening force of the ring 7. Since the outer casing 32 is composed of a single continuous metal plate such as aluminum, its vacuum holding capacity is perfect.

In order to effectively utilize the tightening force of the inner casing 31 and the ring 7 which are made to be sturdy so as to withstand atmospheric pressure by making the casing divided into two parts and thus having a double structure. The outer casing 32, which has a flexible opening 5 and serves as a vacuum holder as a whole, can be reasonably made according to the purpose, and a large vacuum container can be easily combined with the two. The advantage is that it can be made.

The inner casing 31 only has the strength to withstand the atmospheric pressure and may not have the ability to hold a vacuum. The requirement for the material is relaxed as compared with the case of the first embodiment, and a porous material or a flexible material is used. Since it can be used with non-functional materials, for example, pottery, porcelain, glass, etc. can also be used.

As described above, according to the second embodiment, in addition to the effects of the first embodiment, the inner casing 31 having a thicker plate and the outer casing 32 having a thinner plate are used as a casing. Therefore, a large vacuum container can be easily made, and in the case of the internal housing 31, the requirements for the material can be relaxed.

FIG. 4 is a sectional view showing the third embodiment.
Reference numeral 1 is an inner side plate, and 42 is an outer housing. The inner side plate 41 is used in place of the inner housing 31 of FIG. 3, and as shown in the figure, it is formed in a ring shape with a thick plate material and has only the side plate 34 without the bottom plate 33 of FIG. Equivalent to.
The inner side plate 41 is used so that the outer housing 42 made of a thin metal is not crushed by the atmospheric pressure, and has sufficient mechanical strength to withstand the atmospheric pressure. However, since it does not have the role of holding the vacuum, various materials can be used as the material of the inner casing 31 of FIG.

The outer casing 42 has substantially the same material and structure as the outer casing 32 of FIG. 3, and is intended for vacuum sealing like the outer casing 32. In the case of FIG. 4, the outer casing 42 is pressed into the interior of the casing by being pressed by the atmospheric pressure, but when the size of the casing, for example, the radius is not so large, the amount of depression is also small. It is not large and is useful in such a case because it saves material.

As described above, according to the third embodiment, in addition to the effects of the second embodiment, since the housing is constituted by the inner side plate 41 and the outer housing 42, the material can be saved. .

In the above-described embodiment, if the lid 3 is made of transparent glass, the vacuum container 1 is suitable as an inexpensive vacuum container for the vacuum flat plate type solar heat collecting device. When used as a vacuum container of a solar heat collector, the ring 7 is heated only once at the time of manufacturing and used for vacuum sealing, and thereafter is not heated again, and the opening 5 is not covered with the glass lid 3. Used to remain engaged in that position to maintain a vacuum seal for a long time.

[0045]

As described above, according to the present invention, the ring is heated and expanded to fit on the outer periphery of the opening, and is cooled to vacuum-seal the opening and the lid. Can be maintained. Also, the lid can be easily opened by heating and expanding the ring. Further, by forming the housing into a double structure, the constituent materials can be diversified, and a large vacuum container can be easily manufactured at low cost. Further, when the vacuum container is applied to the vacuum solar heat collecting apparatus, the vacuum flat plate solar heat collecting apparatus can be manufactured easily and inexpensively, and its economical effect is remarkable.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a first embodiment of the present invention.

FIG. 2 is a partially enlarged sectional view illustrating a lid and an opening.

FIG. 3 is a cross-sectional view showing a second embodiment of the present invention.

FIG. 4 is a cross-sectional view showing a third embodiment of the present invention.

[Explanation of symbols]

1 vacuum container 2 housing 3 lid 4 side walls 5 openings 6 Vertical part 7 ring 8 heater 9 cooler 10 Mobile devices 21 gasket 31 Internal housing 32,42 External housing 41 Internal side plate

Claims (11)

[Claims] 1. A housing having an opening, a housing having an opening above a side wall forming the opening, a lid inserted into the opening, and a metal having an inner circumference smaller than the outer circumference of the opening at room temperature. And a ring, the ring is heat-expanded to fit on the outer periphery of the opening, and the ring is cooled to vacuum-seal the opening and the lid. 2. The vacuum container according to claim 1, further comprising a heater for heating and expanding the ring. 3. The vacuum container according to claim 1, further comprising a cooler for forcibly cooling the heat-expanded ring in a state fitted in the outer periphery of the opening. 4. The vacuum container according to claim 1, wherein the thickness of the opening is smaller than the thickness of the main body portion of the housing. 5. The vacuum container according to claim 1, wherein the lid is formed in a mountain shape having a raised central portion. 6. The vacuum according to claim 1, wherein the heater is configured by closely adhering a heating wire to the inside or the outside of the ring through an insulator, and is integrated with the ring. container. 7. The vacuum container according to claim 1, wherein a gasket is provided between the opening and a vertical portion of the lid facing the opening. 8. The vacuum according to claim 1, wherein the housing is composed of an inner housing having a thicker plate thickness and an outer housing having a thinner plate thickness than the inner housing. container. 9. The housing according to claim 1, wherein the housing is composed of a ring-shaped inner side plate having a thicker plate thickness and an outer housing having a thinner plate thickness than the inner side plate. Vacuum container. 10. The opening is formed of a soft metal,
The vacuum container according to claim 1, wherein the ring is made of carbon steel or stainless steel. 11. A vacuum type solar heat collecting device, wherein the lid is made of transparent glass.
10. The vacuum container according to 10.