JP2013023229A - Vacuum sealing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vacuum sealing device capable of reducing pressure in a chamber container to a desired pressure and hermetically sealing a material to be sealed in the pressure-reduced condition.SOLUTION: The vacuum sealing device 10 includes: a chamber container 12 capable of reducing pressure therein by a vacuum pump 32; and a sealing device 14 for sealing the opening 24a of a vacuum heat insulating material 18 set in the chamber container 12. The sealing device 14 includes: bellows 16a to 16c elongated/contracted in the chamber container 12 and configured to partition the inner and outer spaces of the chamber container 12 in an airtight manner by communicating the inner space with the outside of the chamber container 12; a pressing base 44 installed at the leading end side in the elongation direction of the bellows 16a to 16c, and configured to press, when the bellows 16a to 16c are elongated, and hold the opening 24a between itself and a receiving base 54 installed in the chamber container 12; and heating units 56 and 58 and a heater 62 installed on the contact surfaces 44a and 54a between the pressing base 44 and the receiving base 54 and heating and joining the opening 24a.

Description

  The present invention relates to a vacuum sealing device that seals an opening of a material to be sealed in a chamber container whose inside is decompressed.

  In recent years, in order to improve the energy efficiency of refrigerators, vending machines, etc., a heat insulating material formed by sealing a core material such as a foaming resin or a fiber material under reduced pressure inside a sheath material such as an aluminum foil, a so-called vacuum heat insulating material has been used. Used (see, for example, Patent Document 1).

  Normally, when manufacturing vacuum insulation materials, a chamber container that can be depressurized inside, and the opening of the jacket material within the chamber container are sealed by thermal welding, as in the manufacture of vacuum packs for foods and the like. A vacuum sealing device having a sealing device for stopping is used. That is, a sealing material in which a core material is placed inside a bag-shaped outer covering material is set in the chamber container, the inside of the chamber container is decompressed, and the sealing device is driven in that state to seal the sealing material. By sealing the opening of the material, the core material can be sealed under reduced pressure inside the jacket material.

  In this type of vacuum sealing device, Patent Document 2 uses a cylinder mechanism having a rod that penetrates the wall surface of the chamber container from the outside and extends into the interior, and by moving the rod inside the chamber container, A vacuum sealing device that presses and holds an opening of a material to be sealed between a pressing stand at the tip of a rod and a cradle installed in a chamber container, and heats this to seal the opening by heat welding. It is disclosed. Further, in Patent Document 3, an air bag having a pressure table installed in a chamber container is disposed, and the pressure table is pushed up by supplying air from outside the chamber container to inflate the air bag. A vacuum sealing device is disclosed in which an opening of a material to be sealed is pressed between and heated.

JP 2006-118718 A Japanese Patent No. 3535954 Patent No. 3883451

  By the way, in the vacuum heat insulating material as described above, the degree of vacuum inside greatly affects the superiority or inferiority of the heat insulation performance, so it is necessary to seal the opening in a state where the pressure in the chamber container of the vacuum sealing device is reduced to a sufficient degree of vacuum. For example, it is desirable to reduce the pressure inside the container to about 1 Pa. Of course, reducing the pressure inside the chamber container, that is, the inside of the material to be sealed, to such a low pressure is effective in the field of foods and the like because it leads to a prolonged storage period.

  However, in the case of the device disclosed in Patent Document 2, an O-ring seals between the rod of the cylinder mechanism and the wall surface of the chamber container, thereby maintaining an airtight state inside and outside the chamber container. For this reason, in the vacuum state in which the inside of the chamber container is about 1 Pa as described above, the O-ring does not provide sufficient sealing performance, causing gas leakage, and reducing the inside of the chamber container to a desired pressure. It is difficult to maintain the state. Further, when the pressure in the chamber container is reduced to about 1 Pa in the apparatus of Patent Document 3 described above, for example, the air bag formed of rubber or the like cracks or the gas passes through fine pores on the wall surface of the air bag itself. There is a possibility of doing.

  The present invention has been made in consideration of the above-described problems of the prior art, and can be used to reduce the pressure inside the chamber container to a desired pressure and to seal the material to be sealed in the reduced pressure state. An object is to provide an apparatus.

  A vacuum sealing device according to the present invention includes a chamber container whose inside can be decompressed by a vacuum pump, and a sealing device that seals an opening of a material to be sealed set in the chamber container. The seal device is extendable within the chamber container, and the inner space communicates with the outside of the chamber container so that the inner and outer spaces of the chamber container are hermetically partitioned, and the bellows A pressing table that is provided on the distal end side in the extending direction and presses and sandwiches the opening of the material to be sealed with a receiving table installed in the chamber container when the bellows is extended; It is provided in the contact surface to the said to-be-sealed material among at least one of a receiving stand and the said press stand, The heating part which heats and joins the said opening part is provided, It is characterized by the above-mentioned.

  According to such a configuration, the bellows is used as an advancing / retracting mechanism that hermetically partitions the inner and outer spaces of the chamber container, and presses the pressing table against the opening of the material to be sealed to clamp the opening with the receiving table. By using this, gas leakage in the chamber container can be prevented and the pressure can be reduced to a desired vacuum state, and the opening can be sealed while maintaining this vacuum state. That is, by using a bellows as the advance / retreat mechanism, even when the chamber container is depressurized to a pressure of, for example, about 1 Pa, while the airtight state of the inner and outer spaces of the chamber container is reliably maintained by the bellows, The opening can be sealed.

  When the bellows is installed in a plurality along the longitudinal direction of the opening of the material to be sealed, and the pressing table is a rod-shaped member extending across the tip side of each bellows, for example, a sealing target Even if the opening of the material to be sealed is long, it is possible to stably press and hold the long opening using a bellows having a compact outer diameter, and downsize the device. can do.

  You may provide the guide member extended along the expansion-contraction direction of the said bellows, and arrange | positioned so that sliding contact is possible on the outer surface of this bellows. That is, in the vacuum sealing device, the bellows has a negative pressure in the outer space and a positive pressure in the inner space. By guiding the outer surface, the expansion and contraction operation can be further stabilized.

  The decompression pipe connected to the vacuum pump is branched into a first pipe and a second pipe, and the first pipe communicates with the internal space of the chamber container via the first on-off valve, while the second pipe A pipe communicates with the inner space of the bellows via a second on-off valve, and an air release pipe for opening the inner space of the bellows to the atmosphere is connected to the second pipe via an air release valve. A single vacuum pump can depressurize the chamber container and the bellows all at once. Furthermore, after evacuation, the first on-off valve and the second on-off valve are closed, and then the air release valve is opened to increase the pressure in the inner space of the bellows without using a mechanical drive mechanism such as a hydraulic cylinder. Thus, the bellows can be extended.

  When the plurality of bellows are installed side by side, the second pipe communicates with the inner space of each bellows through a plurality of branch pipes branched by the number of installed bellows. Because the inner space can be communicated at the branch point of the branch pipe, the pressure difference between the bellows can be reduced when decompressing with a vacuum pump or opening to the atmosphere with an open-air pipe, and the bellows can be expanded and contracted. be able to.

  Of the branch pipes communicating with the inner space of each bellows, at least each branch pipe to each bellows arranged at both ends in the longitudinal direction of the opening extends from the branch point to the inner space of each bellows. If the lengths of the bellows are set to be the same, among the bellows that raise the pressing table in cooperation with each other, at least the differential pressure when the atmosphere is introduced into the bellows on both ends in the longitudinal direction of the opening (pressing table) Since it can suppress, a press stand can be moved now stably.

  A buffer unit with an increased flow path volume may be connected to the second pipe or the atmosphere opening pipe. Then, after the atmosphere introduced from the open air pipe is once buffered by the buffer section, it can be flowed into each branch pipe, so that the expansion operation of each bellows can be synchronized more stably.

  The sealing material may be a vacuum heat insulating material formed by sealing under reduced pressure while including a core material with a covering material. That is, in the vacuum sealing device, as described above, the chamber container has an advance / retreat mechanism that hermetically partitions the inner and outer spaces of the chamber container and presses the pressing table against the opening of the material to be sealed and sandwiches it between the receiving table and the receiving table. Since the bellows is used, gas leakage in the chamber container can be prevented, and the opening can be smoothly sealed while maintaining a desired reduced pressure state. For this reason, an opening part can be sealed stably in the state decompressed to the vacuum state of about 1 Pa, for example, and a high quality vacuum heat insulating material can be manufactured.

  According to the present invention, the bellows is used as an advancing / retracting mechanism that hermetically partitions the inner and outer spaces of the chamber container, and presses the pressing table against the opening of the material to be sealed and clamps the opening with the receiving table. Thus, even when the inside of the chamber container is decompressed to a desired vacuum state, the opening can be sealed while maintaining this vacuum state.

FIG. 1 is an overall configuration diagram of a vacuum sealing device according to an embodiment of the present invention. FIG. 2 is a cross-sectional view taken along the line II-II in FIG. FIG. 3 is a cross-sectional view of the bellows contracted from the state shown in FIG. FIG. 4 is an enlarged side cross-sectional view of the vicinity of one end of the vacuum heat insulating material in a state of being set in the chamber container. FIG. 5 is a plan view of the bellows, the guide member, and the stopper member.

  DESCRIPTION OF EMBODIMENTS Hereinafter, preferred embodiments of a vacuum sealing apparatus according to the present invention will be described in detail with reference to the accompanying drawings.

  FIG. 1 is an overall configuration diagram of a vacuum sealing device 10 according to an embodiment of the present invention, and shows a state in which bellows 16a to 16c of a sealing device 14 are extended in a chamber container 12 shown in a side sectional view. ing. 2 is a cross-sectional view taken along line II-II in FIG. 1, and FIG. 3 is a cross-sectional view in a state in which bellows 16a to 16c are contracted from the state shown in FIG.

  As shown in FIGS. 1 to 3, the vacuum sealing apparatus 10 according to the present embodiment reduces the pressure in the chamber container 12 to a desired vacuum state, and then opens the sealing material set in the chamber container 12. By sealing the portion with a sealing device 14, the internal space of the material to be sealed can be sealed in a desired reduced pressure state. Hereinafter, a case where the vacuum heat insulating material 18 that is preferably used for heat insulation of a refrigerator or a vending machine is used as the material to be sealed to reduce the internal space under reduced pressure will be described as an example. Needless to say, the apparatus 10 can be applied to the reduced pressure sealing of a material to be sealed other than the vacuum heat insulating material.

  First, prior to the description of the vacuum sealing device 10, a specific configuration example of the vacuum heat insulating material 18 whose opening is sealed by the vacuum sealing device 10 will be mainly described with reference to FIG. FIG. 4 is an enlarged side cross-sectional view of the vicinity of one end of the vacuum heat insulating material 18 in a state set in the chamber container 12.

  As shown in FIG. 4, the vacuum heat insulating material 18 is a core material formed of a fiber material such as glass fiber or a foamed resin material between two outer cover materials 20a and 20b each formed of a plurality of layers. 22 and the outer edge 24 (see also FIG. 1 and FIG. 2) of the covering material 20a, 20b surrounding the core material 22 is heat-sealed in a vacuum so that the inside is hermetically sealed in a vacuum state. It is formed and has the same configuration as a known vacuum heat insulating material. For example, the vacuum heat insulating material 18 has a long side dimension (left and right direction in FIG. 1) of about 1800 mm, a short side dimension (left and right direction in FIG. 2) of about 800 mm, and a thickness (the thickness of the portion where the core material 22 is disposed). Is formed as a rectangular thin plate having a thickness of about 10 mm.

  The outer cover material 20a is a sheet (film) having a three-layer structure in which three sheet-like members are laminated and formed in close contact, and as shown in FIG. 4, an outermost protective layer 26a and an intermediate gas barrier layer 28a and the innermost layer heat-welded layer 30a. For the protective layer 26a, for example, a thin sheet in which polyethylene terephthalate (PET) or polyamide synthetic fiber (nylon) is formed to a thickness of about 20 μm to 100 μm is used. For the gas barrier layer 28a, for example, a thin sheet in which an aluminum foil is formed to a thickness of about 7 μm to 10 μm is used. For example, a thin sheet in which polyethylene is formed to a thickness of about 50 μm to 150 μm is used for the heat welding layer 30a.

  The jacket material 20b may have the same configuration as the jacket material 20a described above, and includes a protective layer 26b, a gas barrier layer 28b, and a thermal welding layer 30b similar to the protective layer 26a, the gas barrier layer 28a, and the thermal welding layer 30a. . Of course, the jacket materials 20a and 20b may have different structures.

  In the case of the present embodiment, the outer edge 24 of the vacuum heat insulating material 18 has three sides other than the opening 24a extending to one end (short side) shown on the left side in FIG. It is sealed. That is, the vacuum heat insulating material 18 is set in the vacuum sealing device 10 in a bag-like state in which the outer edge 24 on three sides other than the opening 24a is sealed, and the opening 24a on the remaining one side is in a vacuum. It is welded and sealed.

  Next, the configuration of the vacuum sealing device 10 will be described.

  As shown in FIGS. 1 to 3, the vacuum sealing device 10 includes a chamber container (vacuum chamber) 12 that is a sealed container capable of reducing the internal space to a predetermined degree of vacuum, and a vacuum heat insulating material 18 in the chamber container 12. Sealing device 14 for welding and sealing the opening 24a, vacuum pump 32 for evacuating and decompressing the internal space of the chamber container 12 and the inner spaces of the bellows 16a to 16c, and the vacuum piping connecting the vacuum pump 32 and each part (Vacuum piping) 34 and a control panel 36 for setting operation conditions and overall control of the vacuum sealing device 10.

  The chamber container 12 is formed in a rectangular flat box shape as a whole, and is provided with a projecting portion 12a projecting downward on one end side (sealing device 14 side), and a predetermined pressure (for example, 10 Pa or less, It is a sealed container that can be depressurized to preferably about 1 Pa). A mounting table 38 for positioning and mounting the vacuum heat insulating material 18 is installed in the chamber container 12 (see FIG. 1). The chamber container 12 can easily set the vacuum heat insulating material 18 on the mounting table 38 by configuring the lid 12b that forms the top surface so that it can be opened and closed, for example.

  The seal device 14 is erected from the bottom surface of the protruding portion 12a of the chamber container 12, and includes three bellows 16a, 16b, and 16c that can be expanded and contracted in the vertical direction in the chamber container 12 (see FIGS. 2 and 3), and each bellows. A columnar column 42 protruding from the center of the upper surface of the upper flange 40a of each of the 16a to 16c, and a pressing table (pressing bar) connected across the upper surface of each column 42 and extending in the arrangement direction of the bellows 16a to 16c. 44. The inner spaces of the bellows 16a to 16c are communicated with the vacuum pump 32 via branch pipes 46a to 46c, respectively.

  As shown in FIGS. 2 and 3, the bellows 16a to 16c have a lower flange 40b that is airtightly fixed to the bottom surface of the protruding portion 12a of the chamber container 12, and a bellows tubular shape whose lower end is airtightly fixed to the lower flange 40b. The expansion / contraction part 48 and the upper flange 40a which closes the upper opening of the expansion / contraction part 48 by being airtightly fixed to the upper end of the expansion / contraction part 48 are comprised. For example, the bellows 16a to 16c have an outer diameter of about 200 mm, an inner diameter of about 150 mm, a height of about 100 mm, and an expansion / contraction stroke of about 20 mm.

  In this embodiment, as the bellows 16a to 16c, a corrugated pressed thin ring-shaped (disk-shaped) metal plate is laminated on the stretchable portion 48, and the inner and outer edges of the adjacent metal plates are alternately welded. A so-called welded bellows is used. The welded bellows is advantageous in that a large amount of expansion and contraction can be obtained in a compact configuration and the pressure resistance against a pressure difference between the inside and outside is high. Of course, depending on the use conditions of the vacuum sealing device 10 and the like, a molded bellows in which a bellows tubular expansion / contraction part is formed by molding a metal material may be used instead of the welding bellows.

  The bottom surfaces of the bellows 16a to 16c are provided with suction ports 49a, 49b and 49c penetrating from the lower flange 40b to the bottom surface of the protruding portion 12a, and branch pipes 46a to 46c are airtightly connected to the suction ports 49a to 49c. By being connected, the inner space of bellows 16a-16c and branch piping 46a-46c are connected.

  Accordingly, the bellows 16a to 16c are installed as extendable partition members that hermetically partition the inner and outer spaces of the chamber container 12 by the inner and outer spaces, and only the lower flange 40b is the inner surface of the chamber container 12 (the bottom surface of the protruding portion 12a). It is fixed to. Therefore, the bellows 16a to 16c can move the upper flange 40a up and down by expanding and contracting the expansion / contraction part 48 in a free state in the chamber container 12 with the inner and outer spaces being hermetically partitioned. In the case of this embodiment, the expansion | extension operation | movement of bellows 16a-16c is performed by the pressure difference (differential pressure) in the inside and outside space. The contraction operation is performed by the weight of the bellows 16a to 16c itself, the weight of the pressing table 44, or the differential pressure in the inner and outer spaces.

  FIG. 5 is a plan view of the bellows 16b (16a, 16c), in which a part of the stopper member 52 disposed close to the top of the bellows 16b is omitted by a two-dot chain line.

  As shown in FIGS. 1, 2, and 5, a plurality of guide members 50 (four in this embodiment) are provided at regular intervals along the circumferential direction on the outer peripheral portions of the bellows 16 a to 16 c. ing. The guide member 50 is a pole that is slidably disposed adjacent to the outer surfaces (outer peripheral surfaces) of the bellows 16a to 16c and extends along the axial direction (stretching direction) of the bellows 16a to 16c, and the bellows 16a to 16c. This prevents the expansion and contraction of the expansion / contraction part 48 that occurs during expansion / contraction, and supports a smooth expansion / contraction operation.

  A thin plate ring-shaped stopper member 52 that connects the guide members 50 in the circumferential direction of the bellows 16a to 16c is fixed to the upper end of each guide member 50. In the plan view shown in FIG. 5, the stopper member 52 has an outer shape that overlaps with the vicinity of the outer peripheral edge of the upper surface of the upper flange 40 a of each bellows 16 a to 16 c. Each guide member 50 defines an upper limit position in the extension direction of the bellows 16a to 16c, and prevents the bellows 16a to 16c from being excessively extended and damaging the welded portion or the like in the stretchable portion 48. When the bellows 16a to 16c are extended for a predetermined length, the bellows 16a to 16c are installed so as to be able to contact the upper flange 40a (see also FIGS. 1 and 2).

  The pressing table 44 is a rectangular bar-like member installed on the top of each bellows 16a to 16c, that is, on the distal end side in the extending direction, and is provided on the top surface of the chamber container 12 (the inner surface of the lid 12b). Opposite the table 54. The pressing table 44 moves upward in accordance with the extending operation of the bellows 16a to 16c, and presses and holds the opening 24a of the vacuum heat insulating material 18 between the receiving table 54 and the opposing table 54.

  The pressing table 44 extends along the arrangement direction of the bellows 16a to 16c, that is, the extending direction of the opening 24a of the vacuum heat insulating material 18. For example, the long side dimension (left and right direction in FIG. 2) is 900 mm. The short side dimension (left-right direction in FIG. 1) is set to about 30 mm, and the thickness (height direction) is set to about 50 mm. In a similar manner, the receiving base 54 that holds the opening 24a together with the pressing base 44 has a long side dimension (left and right direction in FIG. 2) of about 900 mm and a short side dimension (left and right direction in FIG. 1) of about 30 mm. This is a stepped rod-shaped member.

  As shown in FIG. 4, the opening portions 24a sandwiched between the contact surfaces 44a and 54a are heated on the respective tip surfaces of the pressing table 44 and the receiving table 54, that is, the contact surfaces 44a and 54a to the opening 24a. Heating units 56 and 58 are provided respectively. In the case of this embodiment, both the heating parts 56 and 58 are made into the same structure, the cushion material 60 extended along the longitudinal direction of the press stand 44 (base 54), and the heater provided in the outer surface of the cushion material 60 62.

  As the heater 62, for example, an electric ribbon heater in which the length in the left-right direction in FIG. 2 is set to about 800 mm and the width in the left-right direction in FIG. 1 is set to about 20 mm is used. The cushion material 60 is a cushioning material for preventing the heater 62 from being damaged when the heater 62 is sandwiched between the pressing base 44 and the receiving base 54 together with the opening 24a. In order to ensure a sufficient cushioning property, it is preferable to use silicone rubber or the like whose thickness is set to about 2 mm, for example. Of course, the cushion material 60 can be omitted depending on the installation conditions of the heater 62 and the driving conditions of the pressing table 44.

  As shown in FIGS. 1 and 2, the decompression pipe 34 connects the internal space of the chamber container 12 and the vacuum pump 32, and further connects the inner space of the bellows 16 a to 16 c and the vacuum pump 32. Road.

  The decompression pipe 34 has a first pipe 34a that connects the chamber container 12 to the branch point (merging point) P1 before the vacuum pump 32, and a second pipe 34b that connects the bellows 16a to 16c to the branch point P1. Then, after the first pipe 34a and the second pipe 34b merge at the branch point P1, they are connected to the suction port of the vacuum pump 32. Accordingly, the pressure in the chamber container 12 and the bellows 16a to 16c can be simultaneously reduced by the single vacuum pump 32, so that the cost can be reduced and the control is facilitated, but the first pipe 34a and the second pipe Of course, 34b may be connected to a separate vacuum pump.

  As shown in FIG. 1, the first pipe 34 a is airtightly connected to a suction port 64 formed through the side wall 12 c of the chamber container 12, and an ON / OFF type electromagnetic on-off valve (first On-off valve) 66 is provided.

  Here, the side wall 12c provided with the suction port 64 is an end (sealed end) opposite to the opening 24a side (sealing side end) of the vacuum heat insulating material 18 set on the mounting table 38. ). By providing the suction port 64 in the side wall 12c in such a position, the chamber container 12 can be moved from the suction port 64 that is farthest from the opening 24a of the vacuum heat insulating material 18 and is directed in the direction opposite to the opening direction. The internal space can be evacuated. For this reason, it is possible to reduce as much as possible that the core material 22 encapsulated in the vacuum heat insulating material 18 in the form of powder or the like jumps out of the opening 24a during decompression. That is, if the suction port 64 is provided at a position facing the opening 24a, the powder or the like of the core material 22 is directly sucked from the opening 24a by the suction force from the vacuum pump 32, and the first pipe 34a. Although there is a possibility of being sucked in, the vacuum sealing device 10 can suppress the suction of the core material 22 into the first pipe 34a as much as possible. Of course, the installation position of the suction port 64 can be changed as appropriate. For example, when the core material 22 that does not easily pop out is used, the suction port 64 may be provided at a position facing the opening 24a.

  Connected between the electromagnetic opening / closing valve 66 and the suction port 64 of the first pipe 34 a is a chamber-side atmosphere opening pipe 72 that is opened to the atmosphere via a flow rate adjusting valve (needle valve) 68 and a stop valve 70. The chamber-side atmosphere opening pipe 72 is a pipe line that can open the internal space of the chamber container 12 to the atmosphere by opening the stop valve 70, and the opening speed can be adjusted as appropriate by the flow rate adjustment valve 68. The chamber-side atmosphere opening pipe 72 may be connected not through the first pipe 34 a but through a predetermined outer wall of the chamber container 12.

  The second pipe 34b passes from the vacuum pump 32 through an ON / OFF type electromagnetic on-off valve (second on-off valve) 74, and then branches to three branch pipes 46a, 46b, 46c at a branch point (junction point) P2. The branch pipes 46a to 46c are connected to suction ports 49a to 49c communicating with the inner spaces of the bellows 16a to 16c, respectively. At this time, as understood from FIG. 2, among the branch pipes 46 a to 46 c to the bellows 16 a to 16 c arranged in the longitudinal direction of the opening 24 a (pressing table 44) of the vacuum heat insulating material 18, The branch pipes 46a and 46c connected to the bellows 16a and 16c have a flow path length from the branch point P2 to the suction ports 49a and 49c, in other words, a flow from the branch point P2 to the inner space inlet of the bellows 16a and 16c. The road length is set to be the same (or substantially the same).

  Between the electromagnetic on-off valve 74 and the branch point P2 of the second pipe 34b, a bellows-side air release pipe (atmosphere) opened to the atmosphere via a flow rate adjusting valve (needle valve) 78 and a stop valve (atmosphere release valve) 80. Open piping) 82 is connected. The bellows-side atmosphere opening pipe 82 is a pipe line that can open the inner spaces of the bellows 16a to 16c to the atmosphere by opening the stop valve 80 in the same manner as the chamber-side atmosphere opening pipe 72 described above. Can be appropriately adjusted by the flow rate adjusting valve 78.

  The vacuum sealing device 10 further includes a pressure sensor 84 installed in the chamber container 12 for detecting the internal pressure of the chamber container 12, and a bellows side atmosphere for detecting the inner pressure of the bellows 16 a to 16 c. A pressure sensor 86 is provided between the flow rate adjustment valve 78 of the open pipe 82 and the branch point P2. Of course, the installation locations of the pressure sensors 84 and 86 can be appropriately changed as long as the pressures in the chamber container 12 and the bellows 16a to 16c can be detected.

  The control panel 36 is a control device provided with input means, display means, etc. (not shown) in order to set the operating conditions of the vacuum sealing device 10 and perform overall control, and is shown by a broken line in FIG. 1, for example. Thus, the vacuum pump 32, the electromagnetic on-off valves 66 and 74, and the pressure sensors 84 and 86 are connected by a signal line. The control panel 36 performs drive control of the vacuum pump 32 and ON / OFF control of the electromagnetic on-off valves 66 and 74 based on the pressure detected by the pressure sensors 84 and 86, for example. In the vacuum sealing device 10, the flow rate adjusting valves 68 and 78 and the stop valves 70 and 80 are manually operated, but the flow rate adjusting valves 68 and 78 and the stop valves 70 and 80 are also controlled. An electric type that can be driven and controlled by the panel 36 may be used.

  Next, an example of the vacuum sealing method of the vacuum heat insulating material 18 using the vacuum sealing apparatus 10 comprised as mentioned above is demonstrated.

  First, the lid 12b of the chamber container 12 is opened in the atmosphere, and the bag-like vacuum heat insulating material 18 in which only the opening 24a at one end of the outer edge 24 is not sealed is set on the mounting table 38, and the lid The body 12b is closed and the inside of the chamber container 12 is sealed. At this time, the opening 24a of the vacuum heat insulating material 18 is set at a position between the pressing table 44 and the receiving table 54 as shown in FIG.

  Subsequently, the stop valves 70 and 80 of the chamber side air release pipe 72 and the bellows side air release pipe 82 are closed, and an operation switch (not shown) of the control panel 38 is turned on to set the control panel 38 in advance. The operation of the vacuum sealing device 10 is started under operating conditions such as the set pressure. That is, under the control of the control panel 38, the electromagnetic on / off valve 66 of the first pipe 34a is opened and the electromagnetic on / off valve 74 of the second pipe 34b is also opened, and then the operation of the vacuum pump 32 is started.

  When the vacuum pump 32 is operated, the internal space of the chamber container 12 and the inner spaces of the bellows 16a to 16c are gradually decompressed. When it is confirmed that the pressure detected by the pressure sensors 84 and 86 has reached a preset pressure, the control panel 38 closes both the electromagnetic on-off valves 66 and 74 and the vacuum pump 32. Stop operation. Thereby, the internal space of the chamber container 12 and the inner spaces of the bellows 16a to 16c are in a vacuum state where the pressure is reduced to a desired pressure, and the inside of the vacuum heat insulating material 18 is also in the same vacuum state as in the chamber container 12.

  For example, when the vacuum heat insulating material 18 is vacuum-sealed as a material to be sealed as in the present embodiment, the interior of the chamber container 12 is 10 Pa or less, more preferably about 1 Pa in order to ensure sufficient heat insulation performance. The pressure should be reduced until

  Thus, in a state where the inside of the chamber container 12 and the inside of the bellows 16a to 16c are decompressed to a desired vacuum state, the inside and outside spaces of the bellows 16a to 16c, that is, the inside of the chamber container 12a that is the outside space of the bellows 16a to 16c. There is no pressure difference between the space and the inside of the expansion / contraction part 48 which is the inner space of the bellows 16a to 16c and the second pipe 34b (branch pipes 46a to 46c), for example, both are about 1 Pa. For this reason, the bellows 16a to 16c are in a contracted state to the initial position (natural length) due to their own weight and the weight of the pressing table 44 (see FIG. 3).

  Therefore, the inner space of the bellows 16a to 16c is opened to the atmosphere through the bellows-side atmosphere opening pipe 82 by opening the stop valve 80 under the flow rate adjustment by the flow rate adjusting valve 78. Thereby, the second pipe 34b (branch pipe 46a) on the inner side space of the bellows 16a to 16c in the negative pressure state and the downstream side of the electromagnetic on-off valve 74 (opposite side to the vacuum pump 32 side) from the bellows side atmosphere open pipe 82 External air is sucked into .about.46c).

  Then, as the pressure in the inner space gradually increases, the bellows 16a to 16c are gradually expanded by receiving pressure from the inside due to the internal / external differential pressure, and push up the pressing table 44. That is, the bellows 16a to 16c are in a vacuum state whose outer space is about 1 Pa, while the inner space gradually approaches an atmospheric pressure state of about 0.1 MPa, so that the lower part fixed to the bottom surface of the chamber container 12 The stretchable portion 48 gradually expands with the flange 40b as a reference, and pushes up the pressing table 44 held on the upper portion.

  Finally, when the inner space of the bellows 16a to 16c becomes equal to the atmospheric pressure and stabilizes, the bellows 16a to 16c press the lower surface side of the opening 24a of the vacuum heat insulating material 18 as shown in FIG. Then, the opening 24a is firmly sandwiched between the cradle 54 and its extension is restricted.

  The upper flange 40a of the bellows 16a to 16c is received by the stopper member 52 to restrict the expansion of the bellows 16a to 16c, and in this state, the pressing base 44 presses the opening 24a with a desired pressure. May be. Further, by providing such a stopper member 52, not only can the excessive pressing of the opening 24a be prevented, but the set position of the opening 24a is deviated and the elevation of the pressing table 44 cannot be restricted. Even in this case, since the upper limit extension length of the bellows 16a to 16c can be regulated by the stopper member 52, the bellows 16a to 16c can be prevented from being damaged due to excessive extension.

  When the opening 24a is firmly pressed and clamped by the pressing table 44 and the receiving table 54 from both sides, the heaters 62 of the heating units 56 and 58 are then turned on to open the opening 24a to the outer surface. Heating is performed from the side (the protective layers 26a and 26b), and the heat welding layers 30a and 30b that are in close contact with each other are welded by heat welding (high frequency welding). In this embodiment, since polyethylene is used as the heat welding layers 30a and 30b as described above, the heat welding layers 30a and 30b are reliably heated to a temperature equal to or higher than the melting point (for example, about 80 ° C. to 100 ° C.). For example, the surface temperature of the heater 62 is set to about 150 ° C., and the heating state is continued for a predetermined time.

  When the welding of the heat-welded layers 30a and 30b is completed, the sealing process for the opening 24a is completed by cooling the welded portion by leaving it for a while with the energization of the heater 62 stopped.

  Subsequently, by opening the stop valve 70 under the flow rate adjustment by the flow rate adjustment valve 68 to release the internal space of the chamber container 12 to the atmosphere via the chamber side air release pipe 72, the lid body 12b is then opened. It is possible to take out the vacuum heat insulating material 18 in which the core material 22 is vacuum-sealed at a desired pressure between the jacket materials 20a and 20b. This removal step is performed, for example, by closing the stop valve 80 and closing the bellows side air release pipe 82 before opening the internal space of the chamber container 12 to the atmosphere via the chamber side air release pipe 72 and then opening the electromagnetic release. After opening the valve 74 and driving the vacuum pump 32 to evacuate the inner space of the bellows 16a to 16c again to eliminate the differential pressure in the inner and outer spaces of the bellows 16a to 16c, the stop valves 70 and 80 are opened. The internal space of the chamber container 12 and the inner spaces of the bellows 16a to 16c may be simultaneously opened to the atmosphere.

  As described above, in the vacuum sealing device 10 according to the present embodiment, the chamber container 12 whose inside can be decompressed by the vacuum pump 32 and the sealing material (vacuum heat insulating material 18) set in the chamber container 12. And a seal device 14 for sealing the opening 24a. The seal device 14 can be expanded and contracted in the chamber container 12, and the inner space is outside the chamber container 12 by the second pipe 34b (branch pipes 46a to 46c). When the bellows 16a to 16c are extended and the bellows 16a to 16c are extended in the extending direction of the bellows 16a to 16c and the bellows 16a to 16c are extended, the chamber container 12, a pressing table 44 that presses and holds the opening 24 a between the receiving table 54 and the contact table 44 a of the pressing table 44 and the receiving table 54. Provided 4a, and a heating unit 56, 58 for sealing by heating and joining the opening 24a.

  As described above, in the vacuum sealing device 10, the bellows 16 a to 16 b are used as an advance / retreat mechanism that hermetically partitions the inner and outer spaces of the chamber container 12 and presses the pressing table 44 against the opening 24 a so as to be sandwiched between the receiving table 54. By using 16c, gas leakage in the chamber container 12 can be prevented, and after the pressure is reliably reduced to a desired vacuum state, the opening 24a can be sealed while the vacuum state is maintained. A product having a vacuum state (for example, the vacuum heat insulating material 18) can be manufactured. Moreover, since the vacuum sealing device 10 uses the bellows 16a to 16c as the advancing / retreating mechanism, even if the pressure in the chamber container 12 is reduced to a pressure of 10 Pa or less, and further about 1 Pa, the above-described conventional technology Thus, no gas leak occurs, and the higher-quality vacuum heat insulating material 18 can be manufactured.

  At this time, in the bellows 16a to 16c, the outer space has a negative pressure (for example, 1 Pa) and the inner space has a positive pressure (for example, atmospheric pressure). In the sealing device 14, the bellows 16 a to 16 c are prevented from being swayed or damaged by providing the guide member 50 that extends along the expansion / contraction direction of the bellows 16 a to 16 c and is slidable on the outer surface thereof. it can.

  By the way, when only one bellows formed in a circular shape in plan view is used, for example, when trying to drive a long pressing base 44 having a length of 800 mm or more and a width of about 30 mm, the bellows is The diameter of the chamber container 12 needs to be increased by excessively increasing the diameter. In contrast, in the vacuum sealing device 10, a plurality (three) of bellows 16 a to 16 c are arranged side by side along the longitudinal direction of the opening 24 a of the vacuum heat insulating material 18, and the front ends of the bellows 16 a to 16 c are arranged. Since the rod-shaped pressing base 44 extending across (upper part) is provided, a compact outer shape can be used for each bellows 16a to 16c. Can be miniaturized. If an elliptical or rectangular bellows is used in plan view, one or two bellows can sufficiently correspond to the long opening 24a instead of the bellows 16a to 16c. That is, the number of bellows can be appropriately changed depending on the structure of the bellows, the size of the opening 24a, the structure of the chamber container 12, and the like.

  Among the decompression pipes 34, the second pipes 34 b that drive the sealing device 14 are each of the bellows 16 a to 16 c by a plurality of (three in this embodiment) branch pipes 46 a to 46 c branched by the number of installed bellows 16 a to 16 c. Each communicates with the interior space. For this reason, since the inner space of each bellows 16a-16c can be communicated at the branch point P2, when the pressure is reduced by the vacuum pump 32 or the atmosphere is released by the bellows-side atmosphere opening pipe 82, the bellows 16a-16c are mutually connected. The pressure difference between the bellows 16a to 16c for supporting and driving one pressing table 44 in cooperation can be made uniform.

  At this time, as described above, among the branch pipes 46a to 46c, the branch pipes 46a and 46c to the bellows 16a and 16c arranged at both ends in the longitudinal direction of the opening 24a have the same flow path cross-sectional area. Furthermore, it is preferable that the length from the branch point P2 to the inner spaces of the bellows 16a and 16c is set to be the same or substantially the same. Then, among the bellows 46a to 46c that raise the pressing table 44 in cooperation with each other, the pressure difference when the atmosphere is introduced into the bellows 46a and 46c on both ends in the longitudinal direction of the pressing table 44 (opening 24a) is further increased. It becomes possible to suppress reliably, and it becomes possible to raise the press stand 44 stably. That is, in this embodiment, since the three bellows 16a to 16c are arranged in a line, if the expansion and contraction operations of the bellows 16a and 16c at both ends can be synchronized as much as possible, the expansion and contraction operation of the middle bellows 16b is possible. Even if there is a slight deviation, the vertical movement of the pressing table 44 can be sufficiently stabilized, and it is preferable that four or more bellows be used.

  As shown by a two-dot chain line in FIG. 2, for example, a buffer unit 90 that significantly increases the flow path volume may be connected to a position including the branch point P2 of the branch pipes 46a to 46c. By providing the buffer section 90, the air introduced from the bellows-side atmosphere opening pipe 82 is once buffered by the buffer section 90 and then flows into the branch pipes 46a to 46c. Can be synchronized more stably. Of course, the buffer unit 90 may be connected to a position other than the position including the branch point P2, for example, may be connected to the bellows-side atmosphere opening pipe 82.

  It should be noted that the present invention is not limited to the above-described embodiment, and it is needless to say that the present invention can be freely changed without departing from the gist of the present invention.

  For example, in the above embodiment, the opening 24a is formed only at one end portion of the vacuum heat insulating material 18 as the material to be sealed, and the configuration in which only the opening 24a is sealed is illustrated. Two or more units 14 may be installed, or the shape of the pressing table 44 may be changed, and two or more openings of the material to be sealed may be sealed simultaneously or continuously.

  Moreover, in the said embodiment, although the structure which each provided the heating parts 56 and 58 in both the press stand 44 and the receiving stand 54 was illustrated, since the opening part of a to-be-sealed material should just be welded as a heating part, You may provide only in one of the press stand 44 and the receiving stand 54. FIG.

DESCRIPTION OF SYMBOLS 10 Vacuum sealing apparatus 12 Chamber container 14 Sealing device 16a-16c Bellows 18 Vacuum heat insulating material 20a, 20b Outer covering material 22 Core material 24a Opening part 32 Vacuum pump 34 Decompression piping 34a 1st piping 34b 2nd piping 36 Control panel 44 Press Base 44a, 54a Contact surface 46a-46c Branch piping 48 Extendable part 50 Guide member 52 Stopper member 54 Receiving base 56, 58 Heating part 60 Cushion material 62 Heater 66, 74 Electromagnetic on-off valve 68, 78 Flow rate adjusting valve 70, 80 Stop valve 72 Chamber side open air piping 82 Bellows side open air piping 90 Buffer

Claims (8)

A vacuum sealing device comprising: a chamber container whose inside can be decompressed by a vacuum pump; and a sealing device for sealing an opening of a material to be sealed set in the chamber container,
The seal device is expandable and contractible in the chamber container, and a bellows for partitioning the inner and outer space of the chamber container in an airtight manner by communicating the inner space with the outside of the chamber container;
A pressing base provided on the front end side in the extension direction of the bellows and pressing and sandwiching the opening of the material to be sealed with a receiving base installed in the chamber container when the bellows is extended When,
A heating unit that is provided on a contact surface to at least one of the sealing materials among the receiving table and the pressing table, and heats and joins the opening.
A vacuum sealing device comprising: The vacuum sealing device according to claim 1, wherein
The bellows is installed side by side along the longitudinal direction of the opening of the material to be sealed,
The vacuum sealing device according to claim 1, wherein the pressing table is a rod-shaped member extending across the tip side of each bellows. The vacuum sealing device according to claim 1 or 2,
A vacuum sealing device, characterized in that a guide member is provided that extends along the expansion / contraction direction of the bellows and is arranged so as to be slidable on the outer surface of the bellows. The vacuum sealing device according to claim 1 or 2,
The decompression pipe connected to the vacuum pump is branched into a first pipe and a second pipe,
The first pipe communicates with the inner space of the chamber container via a first on-off valve, while the second pipe communicates with the inner space of the bellows via a second on-off valve,
An air release pipe for opening the inner space of the bellows to the atmosphere is connected to the second pipe via an air release valve. The vacuum sealing device according to claim 4, wherein
When the plurality of bellows are installed side by side, the second pipe communicates with the inner space of each bellows by a plurality of branch pipes branched by the number of installation of the bellows. Vacuum sealing device. The vacuum sealing device according to claim 5, wherein
Of the branch pipes communicating with the inner space of each bellows, at least each branch pipe to each bellows arranged at both ends in the longitudinal direction of the opening extends from the branch point to the inner space of each bellows. The vacuum sealing device is characterized in that the lengths are set to be the same. In the vacuum sealing device according to any one of claims 4 to 6,
A vacuum sealing device, wherein a buffer section having an increased flow volume is connected to the second pipe or the atmosphere opening pipe. In the vacuum sealing device according to any one of claims 1 to 7,
The said sealing material is a vacuum heat insulating material formed by carrying out pressure reduction sealing while including a core material with a jacket material.

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