JP6912715B2 - Vacuum heat insulating material - Google Patents

Description

The present invention relates to a panel type vacuum heat insulating material manufactured by a vacuum furnace method.

Vacuum heat insulating materials with excellent heat insulating performance are used in various fields in order to improve energy efficiency.

By the way, as a method of exhausting gas for forming a vacuum, a tip tube method and a vacuum furnace method are known. Of these, in the vacuum processing by the vacuum furnace method, the container in which the gas inside is exhausted is housed in the chamber and heated to a high temperature while keeping the inside of the chamber in a vacuum. As a result, in a state where the gas inside the container is discharged, the brazing material placed on the exhaust port of the container is melted and the exhaust port is closed. After that, the pressure in the chamber is returned to atmospheric pressure with cooling, but the inside of the container whose exhaust port is sealed with a brazing material remains in a vacuum state, and a vacuum heat insulating effect can be obtained.

The gas at the time of vacuum processing has a property as a fluid at a pressure of 0.1 Pa or more, which is a medium vacuum, and the gas is continuously discharged as a fluid by exhausting with a pump.

On the other hand, in a high vacuum of 0.1 Pa or less, which exhibits vacuum insulation performance, the gas has a remarkable molecular property, and the gas cannot be continuously discharged even if it is exhausted by a pump. In this case, the molecules that freely move in the space repeatedly collide with and reflect the wall, and the molecules accidentally exit from the exhaust port, so that the pressure gradually decreases.

The panel-type vacuum heat insulating material contains a plate-shaped core material for stabilizing the shape in a flat plate-shaped container. Therefore, this core material becomes an obstacle to exhaust. Specifically, the molecules in the space on the exhaust port side of the core material are easily discharged from the exhaust port, but the molecules in the space on the back side of the core material when viewed from the exhaust port side are not smoothly discharged. Even if the core material is a porous material, it is not easily discharged, and the molecules continue to collide and reflect against the wall while moving freely, and accidentally exit from the exhaust port in the container. The pressure inside decreases. This takes a lot of time. For this reason, it is also a cause of failure in vacuum processing.

Patent Document 1 describes a vacuum heat insulating material in which a through hole is formed in the thickness direction of the core material as one means for improving the exhaust efficiency in vacuum processing.

Japanese Unexamined Patent Publication No. 2009-156374

However, simply forming a through hole in the thickness direction of the core material merely improves the internal flow. In order to discharge gas efficiently, the flow of gas around the exhaust port must also be taken into consideration.

Therefore, an object of the present invention is to provide a vacuum heat insulating material capable of reducing the exhaust resistance around the exhaust port.

In order to achieve the above object, the vacuum heat insulating material of the present invention is arranged so as to face the first panel member in which the exhaust port for vacuum exhaust sealed by vacuum is formed and the first panel member. It includes a second panel member that forms a closed space with the first panel member, and a plate-shaped core material that is arranged in the closed space and has a gap formed in a region facing the exhaust port. It is characterized by that.

Further, in the vacuum heat insulating material of the present invention, in addition to the above configuration, the gap is a through hole formed so as to taper from the first panel member to the second panel member. A getter material capable of absorbing the gas in the closed space and larger than the opening on the second panel member side is arranged in the through hole.

Further, in the vacuum heat insulating material of the present invention, in addition to the above configuration, the second panel member has at least a through hole facing region facing the through hole when the internal pressure is lower than the atmospheric pressure. It is formed with a hardness that allows it to be deformed in a concave shape toward the through hole side, and is characterized in that an indicator indicating the position of the through hole is attached to the outer surface of the through hole facing region.

As described above, according to the present invention, since the gap is formed at the position facing the exhaust port, it is possible to reduce the resistance that the gas flow receives around the exhaust port.

Further, according to the present invention, in addition to the above effects, since the voids are formed as through holes extending in a tapered shape, the gas on the front and back surfaces of the core material can be directly guided to the exhaust port around the exhaust port. It is possible to shorten the exhaust time. In addition, since the getter material is set to a size that allows it to pass only on the exhaust port side, it can move in the gas flow direction from the second panel member side opposite to the exhaust port side, which hinders the exhaust flow. do not.

Further, according to the present invention, in addition to the above effects, a marker indicating the position of the through hole is attached to the outer surface of the through hole facing region which can be deformed concavely at a pressure lower than the atmospheric pressure, so that a vacuum is provided. Is maintained, it can be identified by the concave shape, and even if an abnormality occurs in the vacuum state and the concave shape disappears, it can be easily confirmed visually.

It is an overall perspective view of the heat insulating panel which concerns on 1st Embodiment of this invention. It is sectional drawing cut along the line AA of FIG. It is sectional drawing which shows the deformation example of the core material of FIG. FIG. 2 is a cross-sectional view showing another modified example of the core material. It is an enlarged view around the through hole of FIG. It is an overall perspective view of the heat insulating panel which concerns on 2nd Embodiment of this invention. It is an enlarged view which looked at the connecting area of the connected insulation panel of FIG. 6 from the side. It is a figure which shows the use state of the heat insulating panel of FIG. It is an overall perspective view of the heat insulating panel which concerns on 3rd Embodiment of this invention.

Hereinafter, the heat insulating panel according to the embodiment of the present invention will be described with reference to the drawings.

(First Embodiment)
FIG. 1 is an overall perspective view of the heat insulating panel 1 according to the first embodiment. The heat insulating panel 1 according to the present embodiment is a vacuum heat insulating material suitable for a vacuum furnace system in which a vacuuming process is performed in a chamber heated at a high temperature.

The heat insulating panel 1 has a flange portion 2b formed by folding back at a bent portion 2c on the peripheral edge of a container-shaped panel material 2 (first panel member) and a peripheral edge of a flat plate-shaped panel material 4 (second panel member). It is welded to form a closed space between the two. The portion of the structure of the panel material 2 excluding the flange portion 2b, that is, the portion forming the closed space is referred to as the container portion 2a. As the panel materials 2 and 4, aluminum material or stainless steel material processed to a thickness of about 0.05 mm is suitable. As shown in FIG. 1, the outer shape of the heat insulating panel 1 is substantially flat.

In the closed space formed by the panel materials 2 and 4, a core material 6 for maintaining the flat plate shape is internally provided. The core material 6 is represented by a dotted line in FIG.

The container-shaped panel material 2 is formed with an exhaust port 3 for exhausting air at the time of evacuation in the vicinity of one of the four corners. The exhaust port 3 is formed at the bottom of the recess 2d formed for stably placing the brazing material.

The core material 6 is formed with a through hole 6a at a position facing the recess 2d in which the exhaust port 3 is formed. The structure of the exhaust port 3 and its surroundings will be described with reference to FIG. 2, which is a cross-sectional view taken along the line AA of FIG.

In FIG. 2, the flow of gas during evacuation is indicated by an arrow. (A) shows the whole cross-sectional view, and (b) shows the enlarged view of the part surrounded by the alternate long and short dash line in (a). As shown in FIG. 2, in the configuration according to the present embodiment, the core material 6 is formed with the through hole 6a at a position facing the exhaust port 3 as described above, so that the panel materials 2 and 4 Of the closed space formed by, the gas from the space Rb on the side opposite to the exhaust port 3 with respect to the core material 6 is directly guided to the exhaust port 3. Therefore, regardless of whether or not the core material 6 has a porous structure, the flow to the exhaust port 3 is smoothly formed, so that the exhaust time can be shortened.

Further, the flow of gas from the space Rf on the same side as the exhaust port 3 with respect to the core material 6 is also directly guided to the exhaust port 3, so that exhaust is smoothly performed.

Next, two deformation examples with respect to the core material 6 of FIG. 2 will be described with reference to FIGS. 3 and 4.

FIG. 3 is a cross-sectional view showing a modified example of the core material 6 of FIG. Here, the same configurations as those in FIG. 1 will be described with the same reference numerals. The core material 12 of FIG. 3 is common to the core material 6 of FIG. 2 in that a gap is formed in the region facing the exhaust port 3. However, the core material 6 in FIG. 2 has a through hole 6a, whereas the core material 12 in FIG. 3 is different in that a gap is formed around the exhaust port 3 by the thin portion 12a. ing. In this way, the thickness of the portion facing the exhaust port 3 is formed to be thinner than the thickness of the other portion not facing the exhaust port 3, so that the periphery of the exhaust port 3 of the panel material 2 is concave (recessed 2d). ), It is possible to create an outward flow without obstructing the gas flow.

FIG. 4 is a cross-sectional view showing another modified example of the core material 6 of FIG. FIG. 4A shows a low vacuum or medium vacuum state which is an initial stage in vacuuming, and FIG. 4C shows a high vacuum state which is the final stage. Further, FIG. 4 (b) is a partially enlarged view of (a), and FIG. 4 (d) is a partially enlarged view of (c). Here, too, the same configurations as those in FIG. 1 will be described with the same reference numerals.

In the core material 6 of FIG. 2, the gap formed in the region facing the exhaust port 3 is a through hole 6a having an equal width extending to the side opposite to the exhaust port 3. On the other hand, the gap formed in the core material 14 of FIG. 4 is a tapered through hole 14a that becomes narrower as the distance from the exhaust port 3 increases.

Further, in the through hole 14a, a getter 8 capable of adsorbing the residual gas in the closed space formed by the panel materials 2 and 4 is provided. The getter 8 has a size that does not allow it to pass through the opening formed on the opposite side of the exhaust port 3. In this way, the getter 8 stays so as to be caught in the intermediate position of the tapered through hole 14a.

As shown in FIG. 4A, in a low vacuum or medium vacuum state of 0.1 Pa or more, the pressure difference from the inside of the chamber is relatively large. Some swelling occurs. In FIG. 4A, the expanded state is emphasized so that the action can be easily understood.

As described above, the through hole 14a has an opening on the side far from the exhaust port 3 having a size that the getter 8 cannot pass through. Therefore, in a low vacuum or medium vacuum state, the core material 14 is expanded by the expansion of the closed space. Even when the space between the getter and the panel material 4 is expanded, the getter 8 can be stably kept in the through hole 14a.

As a result, it is possible to prevent the getter 8 from moving and being sandwiched between the core material 14 and the panel material 4 during evacuation.

Further, in the process of evacuation, in the initial stage of being in a low vacuum or medium vacuum state, the air can be easily lifted by the exhaust air flow, so that the flow of exhaust gas from the space Rb on the opposite side of the exhaust port 3 is not obstructed. ..

Further, as described above, since the through hole 14a is formed so as to face the region where the exhaust port 3 is formed, the recess 2d formed around the exhaust port 3 covers the through hole 14a. It is approaching like. Therefore, even if the getter 8 is lifted by the exhaust flow generated in the initial stage, the recess 2d suppresses the getter 8 from being lifted more than necessary by the recess, so that the phenomenon that the getter 8 pops out from the through hole 14a can be prevented.

In the state of FIG. 4 (c) in which the difference between the pressure in the chamber and the pressure in the closed space of the heat insulating panel 1 becomes small after shifting to the high vacuum state, the expansion as shown in FIG. 4 (a) is suppressed and the exhaust is exhausted. The distance between the recess 2d around the mouth 3 and the opening of the through hole 14a is narrowed.

However, in the configuration according to the present embodiment, the through hole 14a is formed in a tapered shape so that the inner diameter is expanded toward the exhaust port 3 side.

That is, since the inclined inner wall of the through hole 14a is formed so as to align the inclined direction with the recess 2d of the exhaust port 3, the gas flow around the exhaust port 3 is not obstructed and the structure is less likely to be retained. ing.

In particular, it is remarkable at the stage of shifting to the high vacuum state of FIG. 4 (c) in which the influence of free movement of molecules becomes strong in the process of evacuation. Since the probability of collision / reflection of molecules with the wall is reduced, the exhaust efficiency is improved and the working time can be shortened. As a result, it is possible to prevent the failure of vacuum processing.

Subsequently, with respect to the heat insulating panel 1 having the configuration of FIG. 1, the structure of the panel material 4 in which the exhaust port 3 is not formed will be described with reference to FIG.

FIG. 5 is an enlarged view of the periphery of the through hole 6a of FIG. (A) indicates a state in which the internal pressure is lower than the atmospheric pressure (that is, a state in which the vacuum is well maintained), and (b) indicates a state in which the internal pressure is equal to the atmospheric pressure (a state in which the vacuum is deteriorated). The mark position 16 surrounded by the alternate long and short dash line in the figure indicates a region where the mark is attached to the outer surface of the panel material 4. Further, both FIGS. 5A and 5B show a state in which the exhaust port 3 is sealed with the brazing material 10.

As can be seen from FIG. 5A, in the configuration according to the present embodiment, the material of the region of the panel material 4 facing at least the through hole 6a is on the through hole 6a side when the internal pressure is lower than the atmospheric pressure. The hardness is set so that it can be deformed in a concave shape. As a result, when the vacuum state is well maintained, the dent in the region facing the through hole 6a can be visually confirmed as shown in FIG. 5A.

On the other hand, in FIG. 5B, the degree of vacuum is lowered, and the position facing the through hole 6a and the other positions are in an indistinguishable flat state.

However, since the mark is attached to the mark position 16 surrounded by the alternate long and short dash line, the position of the through hole 6a can be easily confirmed. Therefore, as shown in FIG. 5B, it is possible to easily visually detect the deteriorated state in which the degree of vacuum is lowered.

As a result, the vacuum state can be confirmed without using a dedicated vacuum check device, so that it is extremely easy to sort out non-defective products or defective products even at the site where the heat insulating panel 1 is handled, and the work efficiency is improved.

When the through holes 6a and 14a are formed at the positions where the exhaust port 3 is provided as in the configurations of FIGS. 2 and 4, in a vacuum state if the position of the exhaust port 3 can be confirmed. Confirmation is possible. However, even in a situation where the heat insulating panel 1 is arranged and the position of the exhaust port 3 cannot be confirmed, it can be reliably recognized by the mark. Specifically, this mark may be any of symbols, symbols and figures, and may be characters as long as it functions as a sign indicating a vacuum state.

(Second Embodiment)
FIG. 6 is an overall perspective view of the heat insulating panel 21 according to the second embodiment of the present invention. The same configuration as that of the example of FIG. 1 of the first embodiment will be described with the same reference numerals.

In the heat insulating panel 21, the container-shaped panel material 22 (first panel member) and the flat plate-shaped panel material 24 (second panel member) are welded to each other at the peripheral edges to form a closed space. It is common with the heat insulating panel 1 of FIG. Further, it is said that the container-shaped panel material 22 is provided with a core material 26 for maintaining the shape in the container portion 22a, and is welded to the flat plate-shaped panel material 24 by the flange portion 22b formed around the container portion 22a. The configuration is the same as that of the heat insulating panel 1 of FIG.

However, the configuration of FIG. 1 is different from the configuration of FIG. 1 in that concave notches 22d are formed at the four corners of the container portion 22a, and connecting holes 22e are formed at each of the four corners of the flange portion 22b on the peripheral edge. It's different.

In FIG. 6, in the structure of the panel material 22, the direction of the bending line 22c formed at the boundary between the container portion 22a and the flange portion 22b is represented by a chain line. In the configuration of the present embodiment, the connecting holes 22e are formed at the positions where the alternate long and short dash lines intersect, that is, at four locations where the extension lines of the respective bending lines 22c along the adjacent flange portions 22b intersect. .. Since it is configured in this way, by combining the front and back surfaces in a staggered manner, the container portions 22a having a heat insulating effect can be arranged so as to be in close contact with each other.

Welding is performed along the direction of the alternate long and short dash line on the bending line 22c. In addition, the cutout portion 22d and the connecting hole 22e are welded in the direction of the alternate long and short dash line L1 shown in the drawing. In this way, the connecting hole 22 is located at a position where the bending line 22c intersects in the extending direction.
Since e is formed, all can be welded linearly, which facilitates the work.

FIG. 7 is an enlarged view showing the periphery of the connection position of the heat insulating panel 21 of FIG. 6 from a side view. Here, one of the heat insulating panels 21 is shown with diagonal lines so that the connected structure can be easily identified. The above-mentioned connecting holes 22e are represented by dotted lines, and the direction through the center position of each connecting hole 22e is indicated by the alternate long and short dash line L2.

As shown in FIG. 7, when the heat insulating panels 21 are arranged so that the front and back sides are staggered and the connecting holes 22e are connected so as to coincide with each other, the respective container portions 22a are arranged without a gap. The three-dimensional structure of such a connected state is shown in FIG.

FIG. 8 is a perspective view showing a usage state of the heat insulating panel 21 of FIG. The adjacent heat insulating panels 21 are connected by arranging the front and back sides in a staggered manner. As a result, the container portions 22a having a heat insulating effect can be arranged without a gap, and the heat insulating effect can be enhanced.

(Third Embodiment)
FIG. 9 is an overall perspective view of the heat insulating panel 41 according to the third embodiment of the present invention. Here, the internal structure is represented by a partial break. Since the panel material 2 (first panel member) and the panel material 4 (second panel member) constituting the heat insulating panel 41 have the same configuration as that of FIG. 1, they are designated by the same reference numerals, and detailed description thereof will be omitted.

The configuration according to the present embodiment is different from the configuration of FIG. 1 in that grid-like grooves 46b and 46c are formed on the surface of the core material 46. With this configuration, the flow of exhaust gas in the space along the spreading direction of the core material 46 becomes smooth.

In particular, if the groove 46b on the panel material 2 side and the groove 46c on the panel material 4 side are formed so as to pass through the through hole 46a provided so as to face the exhaust port 3 (see FIG. 1), the air is exhausted more smoothly. A flow to the mouth 3 is formed. Here, a configuration in which the grooves 46b and 46c are formed in a grid pattern is shown as an example. However, the grooves 46b and 46c may be formed so as to extend in only one direction.

Further, the grooves 46b and 46c do not have to be formed in parallel, and may be formed so as to extend radially from the through hole 46a, for example.

Further, although the configuration in which the grooves 46b and 46c are formed on the front and back surfaces of the core material 46 is shown as an example, it may be formed on only one surface. For example, it is possible to form the groove 46c only on the surface of the core material 46 facing the space on the side far from the exhaust port 3.

Further, in the configuration according to the present embodiment, a configuration in which one core material 46 is arranged in the container is shown as an example. However, a plurality of core materials may be combined and installed internally in the container. In this case, if the grooves are formed only on the contact surface side with each other, it is not necessary to form the grooves on the side in contact with the panel materials 2 and 4, so that the mold is raised to the panel materials 2 and 4 in a vacuum. It is possible to prevent it.

The configuration shown in each of the above embodiments is an example of the present invention, and includes the following modifications.

In each of the above embodiments, the configuration in which the position of the exhaust port 3 is biased to one of the four corners of the rectangular flat plate-shaped heat insulating panel is shown as an example. However, the position of the exhaust port 3 may be closer to the center or may be formed at an intermediate position on the side.

Further, in each of the above-described embodiments, the configuration in which the exhaust port 3 is formed on the side of the panel members 2 and 22 having a container-like structure is shown as an example. However, as long as the relationship with the voids formed with the core material is the same, it may be formed on the flat plate-shaped panel materials 4 and 24.

Further, in the first embodiment described above, as an example of the through hole 6a formed in the core material 6, an equal width through hole 6a and a tapered through hole 14a are shown as an example, but other shapes are shown. It may be a through hole of. For example, a step may be formed on the inside, and a plurality of steps may be formed. Further, as a structure for holding the getter, a protrusion may be formed in a part in the inner peripheral direction. Further, the cross section does not have to be formed in a circular shape.

Further, in each of the above embodiments, the configuration in which the exhaust ports 3 of the heat insulating panels 1 and 41 are sealed by vacuum brazing is shown as an example. However, as a vacuum sealing method, in addition to brazing, soldering, welding, low melting point glass, or sealing with glass can be appropriately applied, and the same effect can be obtained.

Since the vacuum heat insulating material of the present invention can form the shape of the exhaust port in a thin shape by a vacuum furnace method, it is useful for heat shielding of a heating cooker, a partition wall of a refrigerator, a wall of a building material, and the like.

1 Insulation panel (vacuum heat insulating material)
2 panel material (1st panel member)
2a Container part 2b Flange part 2c Bending part 2d Recessed part 3 Exhaust port 4 Panel material (second panel member)
6 Core material 6a Through hole (void)
8 Getter 10 Row material 12 Core material 12a Thin-walled part 14 Core material 14a Through hole (void)
16 Mark position 21 Insulation panel (vacuum heat insulating material)
22 Panel material (1st panel member)
22a Container part 22b Flange part 22c Bending line 22d Notch part 22e Connecting hole 24 Panel material (second panel member)
26 Core material 41 Insulation panel (vacuum heat insulating material)
46 Core material 46a Through hole (void)
46b, 46c Groove L1 Dashed line L2 Dashed line Rf, Rb Space

Claims (2)

A first panel member having an exhaust port for vacuum exhaust sealed in a vacuum,
A second panel member, which is arranged to face the first panel member and forms a closed space with the first panel member,
It is provided with a plate-shaped core material arranged in the closed space and having a gap formed in a region facing the exhaust port.
The gap is a through hole formed so as to taper from the first panel member toward the second panel member, and the gas in the closed space can be absorbed in the through hole. , The vacuum heat insulating material, characterized in that a getter material larger than the opening on the second panel member side is arranged. The second panel member is formed with a hardness such that at least the through-hole facing region facing the through-hole is concavely deformable toward the through-hole side when the internal pressure is lower than the atmospheric pressure. the through-hole to the outer surface of the opposing region, the vacuum heat insulating material according to claim 1, characterized in that an indicator indicating the position of the through hole is attached.

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