JP3652271B2 - Inspection method for internal pressure of package - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for internal pressure of a package that is decompressed by storing a filler such as a vacuum heat insulating plate or food in a non-breathable film.
[0002]
[Prior art]
In recent years, energy conservation has been strongly desired from the viewpoint of preventing global warming, and energy conservation of household appliances and the like has become an urgent issue. In particular, heat insulation and cooling equipment such as refrigerators, freezers, jar rice cookers, water heaters, etc. require heat insulating materials with excellent heat insulating performance from the viewpoint of efficiently using heat. Vacuum insulation plates are known.
[0003]
FIG. 5 shows an example of a structural diagram of a vacuum heat insulating plate as a package. Reference numeral 1 denotes a vacuum heat insulating plate (packaging body), which is obtained by covering the filling 2 in a non-breathable film 3 and reducing the inside to seal the periphery.
[0004]
Here, the filler 2 is an inorganic powder such as silica or pearlite, an inorganic fiber such as glass wool, an organic continuous foam such as a continuous urethane foam, or a powder obtained by crushing a rigid urethane foam recovered from a used refrigerator. It's okay.
[0005]
Further, the air-impermeable film 3 includes at least a heat-welded layer made of polyethylene, polypropylene, or the like, a metal foil such as aluminum, a metal vapor-deposited film such as aluminum or copper, or an inorganic material subjected to vapor-deposition such as ceramic. A laminate film containing a high gas barrier layer such as a vapor deposition film is generally used.
[0006]
Since the vacuum heat insulating plate 1 improves the heat insulating performance by reducing the pressure inside, the internal pressure inspection of the manufactured vacuum heat insulating plate is indispensable.
[0007]
As a method for inspecting the internal pressure of the vacuum heat insulating plate, for example, as described in Japanese Patent Publication No. 6-78958 and Japanese Patent Publication No. 7-99349, the package is stored in a container, and the inside of the container is decompressed with a pump. A method for inspecting the internal pressure of a package by measuring the amount of swelling of the package is known.
[0008]
[Problems to be solved by the invention]
However, according to Japanese Examined Patent Publication No. 6-78958, it is necessary to provide a concave portion on the surface portion of the filling (described as a filled body in Japanese Examined Patent Publication No. 6-78958), so that the number of steps for producing a vacuum heat insulating plate increases. The surface of the vacuum heat insulating plate after fabrication is not flat due to the recess, and when used in combination with a foam heat insulating material such as urethane, for example, there is a possibility that voids may be generated by inhibiting urethane fluidity.
[0009]
Moreover, when a fiber, powder, etc. are applied as a filler, it was difficult to provide a recessed part beforehand.
[0010]
Japanese Patent Publication No. 7-99349 discloses a method capable of inspecting without providing a recess. For example, when a fiber is applied as a filler, a process of installing a vacuum heat insulating plate in the chamber and reducing the pressure in the chamber In this case, the pressure difference between the inside and outside of the vacuum heat insulating plate is reduced, and the restoration of the fibers compressed by the atmospheric pressure may occur.At this time, in the measurement by the displacement sensor, this restoration is read as the amount of swelling, Depending on the material of the packing, there are cases where accurate determination cannot be made.
[0011]
In view of the above problems, the present invention provides a method for inspecting a vacuum heat insulating plate with no deterioration in productivity due to an increase in the number of processes, and when any material such as fiber or powder is applied as a filling material. It is an object of the present invention to accurately determine the internal pressure inspection of a package including a vacuum heat insulating plate without being affected by the restoration of the filler that occurs during decompression.
[0012]
[Means for Solving the Problems]
In order to solve the above-described problems, in the method for inspecting the internal pressure of a package according to the present invention, after the package is installed in a vacuum chamber, the pressure in the chamber is reduced to a predetermined pressure lower than the required internal pressure of the package at least. At this time, the displacement sensor measures the amount of swelling of the package, and uses the amount of swelling to inspect the internal pressure of the package, at least from atmospheric pressure to a predetermined amount in the chamber. The amount of swelling of the package body up to the pressure and the swelling of the package body from a pressure in the chamber that is at least a pressure lower than atmospheric pressure and greater than the required internal pressure of the package body to a predetermined pressure in the chamber The quality of the package is determined by measuring the amount.
[0014]
Further, the internal pressure inspection method for a packaging body according to the present invention is an internal pressure inspection device for a packaging body, wherein after the packaging body is placed in a vacuum chamber, at least the inside pressure of the packaging body required in the chamber is set. The pressure is reduced to a predetermined pressure, which is a low pressure, and at this time, the amount of swelling of the package is measured by a displacement sensor, and the amount of swelling is used to inspect the internal pressure of the package. The amount of swelling of the package from atmospheric pressure to a predetermined pressure in the chamber, and a predetermined pressure in the chamber from the pressure in the chamber that is at a pressure lower than atmospheric pressure and at least greater than the required internal pressure of the package. The amount of swelling of the package up to the pressure of the product is measured, and the ratio of the amount of swelling of the package in the degree of decompression in the chamber (ΔH / ΔP) is measured to determine the quality of the package. It is characterized by that.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
In the method for inspecting the internal pressure of a package according to claim 1 of the present invention, after the package is placed in a vacuum chamber, the pressure in the chamber is reduced to a predetermined pressure lower than the required internal pressure of the package at least. At this time, the amount of swelling of the package is measured by a displacement sensor, and the amount of swelling is used to determine the quality of the package. When the pressure in the chamber is reduced, Since the differential pressure is small, restoration of the packing occurs. This restoration is read as a swollen amount by the displacement sensor. In addition, the swell amount reading value of the displacement sensor due to the restoration of the filling shows a proportional relationship with the degree of decompression of the chamber pressure, so that the influence of the restoration of the filling becomes large only by measuring the swell amount from the atmospheric pressure, In some cases, the correct amount of swelling cannot be read and cannot be determined.
[0017]
However, by measuring the amount of swelling from the pressure in the chamber that is at a pressure lower than the atmospheric pressure and at least larger than the required internal pressure of the package to reduce the influence, It becomes possible to measure the amount of swelling of the package.
[0018]
Therefore, even when any material such as fiber or powder is applied as the filling, it is possible to accurately determine the internal pressure inspection of the package including the vacuum heat insulating plate without being affected by the restoration of the filling generated when the pressure in the chamber is reduced.
[0019]
In the method for inspecting the internal pressure of the package according to claim 2 of the present invention, after the package is installed in the vacuum chamber, the inside of the chamber is reduced to a predetermined pressure lower than the required internal pressure of the package at least. At this time, the displacement sensor is used to measure the amount of swelling of the package, and the amount of swelling is used to inspect the internal pressure of the package, and at least a predetermined pressure in the chamber from atmospheric pressure. And the amount of swelling of the package from a pressure in the chamber that is depressurized from atmospheric pressure and greater than the required internal pressure of the package to a predetermined pressure in the chamber. Further, the quality of the package is determined by measuring the ratio (ΔH / ΔP) of the swelling amount of the package in the degree of decompression in the chamber.
[0020]
Note that ΔH / ΔP described above indicates the amount of swelling of the package that occurs during a slight pressure decrease in the chamber, and indicates that it is differentiated.
[0021]
Here, when the pressure in the chamber is reduced, the differential pressure with respect to the inside of the package is reduced, so that restoration of the filling occurs. This restoration is read as a swollen amount by the displacement sensor. Here, the swell amount reading value of the displacement sensor due to the restoration of the filling shows a proportional relationship with the degree of decompression of the chamber pressure, so the ratio of the swell amount generated by the restoration of the filling at the degree of decompression in the chamber (ΔH / ΔP) is a substantially constant value.
[0022]
On the other hand, when the internal pressure of the package becomes higher than the pressure in the chamber, it suddenly bulges. Therefore, the ratio of expansion amount (ΔH / ΔP) in the degree of decompression in the chamber is determined by the pressure in the chamber When the pressure becomes lower than the internal pressure, a rapid increase is shown, and a tendency that is clearly different from the ratio of the swelling amount (ΔH / ΔP) generated by the restoration of the filling at the degree of decompression in the chamber is shown.
[0025]
Therefore, it is possible to accurately determine the internal pressure inspection of the package including the vacuum heat insulating plate without being affected by the restoration of the filling material generated when the pressure in the chamber is reduced.
[0030]
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0031]
(Embodiment 1)
FIG. 1 is a cross-sectional view of a method for inspecting the internal pressure of a package according to an embodiment of the present invention, and the structure thereof includes a chamber 5 having a space and a container 4 that can be opened and closed. Exhaust pump 6 for reducing pressure, leak valve 7, pressure gauge 8 for measuring the pressure in the chamber, control panel 9 for controlling the exhaust pattern and measurement end by the value of the pressure gauge 8, measuring the swelling amount of the package The displacement sensor 10 and the pass / fail judgment machine 11 that analyzes and determines the measurement value from the displacement sensor.
[0032]
Here, the vacuum heat insulating plate 1 is set as a measurement object, set in the chamber 5, the inside of the chamber 4 is closed, the chamber 5 is sealed, and the exhaust pump 6 is started. The swelling of the vacuum heat insulating plate 1 at this time can be read by the displacement sensor 10 and the measured value can be analyzed and judged by the pass / fail judgment machine 11.
[0033]
Here, the displacement sensor 10 is provided with a mechanism for laser irradiation and light reception, and the irradiated laser hits the surface of the vacuum heat insulating plate 1 and is reflected and received again.
[0034]
The amount of swelling of the vacuum heat insulating plate 1 can be measured by converting the change in the received light into a distance from the irradiation position by the pass / fail judgment machine 11.
[0035]
The pass / fail judgment machine 11 requires at least a mechanism capable of controlling the measurement origin in the measurement of the swelling amount of the vacuum heat insulating plate 1 by laser irradiation and light reception of the displacement sensor 10 in conjunction with the pressure gauge 8 and the chamber. Provided with a mechanism to notify when a certain amount of swelling is detected before the pressure is reduced to a predetermined pressure that is lower than the internal pressure of the package, such as a buzzer or a lamp to turn on ing.
[0036]
(Embodiment 2)
In FIG. 2, the typical pattern of the change of the amount of swelling from atmospheric pressure in the pressure in the chamber of the vacuum heat insulation board 1 is shown.
[0037]
In FIG. 2, the pressure in the chamber showing a sudden amount of swelling is the internal pressure of each sample. In Nos. 1-4, no. Nos. 1 and 2 are non-defective products lower than the required internal pressure. 3 and 4 are defective products higher than the required internal pressure.
[0038]
In FIG. 1 and No. Although 2 is a non-defective product that is lower than the required internal pressure, the amount of swelling from atmospheric pressure is greatly different. This is no. This is because 2 is greatly affected by the restoration of the packing. Due to the effect of restoration of the filling, the defective product No. No. 3 Since the swelling amount of 2 is greatly detected at the time of measurement, accurate measurement cannot be performed only by measuring the swelling amount from the atmospheric pressure.
[0039]
Here, when the amount of swelling from the pressure A in the chamber, which is lower than the atmospheric pressure shown by the broken line in FIG. 2 and at least larger than the required internal pressure, to a predetermined pressure in the chamber, is measured, FIG. 5 shows the change in the amount of swelling with the pressure of the pressure, and the influence of restoration of the filling can be reduced.
[0040]
Therefore, the internal pressure of the vacuum heat insulating plate 1 can be accurately determined regardless of the packing.
[0041]
For example, in FIG. 3, the quality of the vacuum insulation board 1 that has detected a bulging amount amm or more before reaching a predetermined pressure is determined to be a defective product, and a pass / fail judgment unit 11 sounds a buzzer or turns on a lamp. It becomes possible.
[0042]
(Embodiment 3)
FIG. 4 shows the relationship between the ratio of the swelling amount (ΔH / ΔP) of the vacuum heat insulating plate 1 and the pressure in the chamber at the degree of pressure reduction in the chamber in the same sample shown in FIG.
[0043]
The amount of swelling generated due to the effect of restoration of the filling has a correlation with the degree of decompression in the chamber, and the ratio (ΔH / ΔP) is a substantially constant value.
[0044]
On the other hand, when the internal pressure of the vacuum heat insulating plate 1 becomes higher than the pressure in the chamber, it suddenly bulges. Therefore, the ratio of expansion amount (ΔH / ΔP) in the degree of decompression in the chamber is When the pressure becomes lower than the internal pressure of the vacuum heat insulating plate 1, it shows a rapid increase, and shows a significantly larger value than the amount of swelling generated due to the effect of restoration of the packing in the degree of decompression in the chamber.
[0045]
Therefore, by using the ratio (ΔH / ΔP) of the swelling amount of the vacuum heat insulating plate 1 in the degree of decompression in the chamber for the quality determination, the internal pressure of the vacuum heat insulating plate 1 can be accurately determined without being affected by the packing. .
[0046]
For example, in FIG. 4, the vacuum heat insulating plate 1 in which the value of ΔH / ΔP is detected to be not less than b before reaching a predetermined pressure is regarded as a defective product, and a buzzer is sounded or a lamp is turned on by the pass / fail judgment machine 11. Judgment is possible.
[0047]
Further, as described above, the amount of swelling generated due to the effect of restoration of the packing has a correlation with the degree of decompression in the chamber, and the ratio (ΔH / ΔP) is a substantially constant value. On the other hand, it is also possible to accurately determine the internal pressure of the vacuum heat insulating plate 1 by performing differentiation twice (Δ ² H / ΔP ² ) and obtaining an inflection point.
[0048]
(Embodiment 4)
By adjusting the exhaust pump 6 and the leak valve 7 with the control panel 9 shown in FIG. 1, the exhaust speed can be reduced in the vicinity of the required predetermined pressure. Since it is possible to prevent undetection of the amount of swelling due to a delay until the occurrence of swelling due to slight tension generated between the film and the film, it is possible to accurately check the internal pressure of the package.
[0049]
In addition, it is also possible to change the exhaust pattern by using two or more exhaust pumps 6 and stopping the operation of some exhaust pumps at the control panel 9 near the required predetermined pressure. is there.
[0050]
(Embodiment 5)
The control panel 9 shown in FIG. 1 controls the exhaust pump 6 and the leak valve 7 so as to maintain the pressure in the chamber near a predetermined pressure. In this case, it is possible to prevent undetection of the amount of swelling due to a delay until the occurrence of swelling due to a slight tension generated between the two, and it is possible to accurately check the internal pressure of the package.
[0051]
【The invention's effect】
As described above, in the internal pressure inspection apparatus for a package according to the present invention, it is not affected by the restoration of the filling generated when the chamber pressure is reduced, and between the filling and the non-breathable film covering the filling. The internal pressure of the package can be inspected with high accuracy in a short time by using the amount of swelling measured using a displacement sensor without being affected by the delay until the occurrence of swelling due to slight tension generated in the case.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of an internal pressure inspection device for a package according to an embodiment of the present invention. FIG. 2 is a diagram showing the relationship between the pressure in a chamber and the amount of swelling of the package (from atmospheric pressure).
[Fig. 3] Relationship between the pressure in the chamber and the amount of expansion of the package [Fig. 4] Relationship between the pressure in the chamber and the ratio of the amount of expansion of the package in the degree of decompression in the chamber [Fig. 5] Conventional vacuum insulation Sectional view of plate [Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Vacuum insulation board 2 Filling material 3 Air-impermeable film 4 Container 5 Chamber 6 Exhaust pump 7 Leak valve 8 Pressure gauge 9 Control panel 10 Displacement sensor 11 Pass / fail judgment machine

Claims (2)

  After installing the package in a vacuum chamber, the chamber is depressurized to a predetermined pressure lower than the required internal pressure of the package at least, and at this time, the amount of swelling of the package is measured by a displacement sensor. And a method of inspecting the internal pressure of the package using the amount of swelling, wherein the amount of swelling of the package is at least from atmospheric pressure to a predetermined pressure in the chamber, and the pressure is lower than atmospheric pressure. The internal pressure of the package that determines the quality of the package by measuring the amount of swelling of the package from the pressure in the chamber greater than the required internal pressure of the package to a predetermined pressure in the chamber Inspection method.   After installing the package in a vacuum chamber, the chamber is depressurized to a predetermined pressure lower than the required internal pressure of the package at least, and at this time, the amount of swelling of the package is measured by a displacement sensor. Performing a method of inspecting the internal pressure of the package using the amount of expansion, wherein the amount of expansion of the package is at least from atmospheric pressure to a predetermined pressure in the chamber, and is at least depressurized from atmospheric pressure. Measure the amount of swelling of the package from a pressure in the chamber that is greater than the required internal pressure of the package to a predetermined pressure in the chamber, and also swell the package at a reduced pressure in the chamber A method for inspecting the internal pressure of a packaging body by determining the quality of the packaging body by measuring a ratio (ΔH / ΔP) of the quantity.

Images