JPH0799349B2 - Decompression inspection device for packages - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to inspection of a vacuum break and an insufficient decompression of a package in which a filling material such as food or a heat insulating material is enclosed and decompressed.

Configuration of Conventional Example and Its Problems In recent years, in order to improve the heat insulating performance of a heat insulating box without increasing the wall thickness, a package in which a filling material such as pearlite is vacuum-sealed and a conventional foamed heat insulating material are provided. It is proposed to use them together.

The structure of this package will be described with reference to FIG. 1. Reference numeral 1 is a package, and a flexible container 2 made of a plastic-metal laminate film or the like is filled with a filling 3 made of pearlite, and the inside is The container 2 was closed after the pressure was reduced to 1 Torr.

However, since such package 1 has improved heat insulation performance by being decompressed, if the container 2 is not tightly sealed, a predetermined degree of decompression is not maintained and the heat insulation performance deteriorates.

Therefore, referring to FIG. 2, a conventional apparatus for inspecting the heat insulation performance of such a package 1 will be described. Reference numeral 4 is a thermal conductivity measuring apparatus, which is an upper surface heating plate 5 for keeping a constant temperature of 40 ° C. and a constant temperature of 10 ° C. Lower heat plate 6 to keep and heat flow sensor 7 to measure heat flow
Made of.

Then, the packaging body 1 is arranged in the upper heating plate 5 and the lower heating plate 6, and when the packaging body 1 reaches equilibrium with respect to the heat transfer, the heat flow sensor 7 measures the heat flow rate which flows through the packaging body 1 to package the heat flow rate. The thermal conductivity of the package 1 was determined by multiplying by the thickness of 1 and dividing by the temperature difference between the upper and lower plates 5, 6.

Next, the operation of the above conventional example will be described. The thermal conductivity of the package 1 can be obtained by the thermal conductivity measuring device 4 as described above, and the quality of the performance can be determined. However, since the heat flow rate changes depending on the temperature gradient of the package 1, heat transfer must be in an equilibrium state. I can't measure. That is, it is essential that the package 1 be maintained at a constant temperature gradient by the heat flow supplied from the upper surface hot plate 5 to the lower surface hot plate 6.

As a result, one measurement usually requires an inspection time of 1 to 2 hours. It is also possible to obtain the thermal conductivity from the characteristics by capturing the heat flow rate in the non-equilibrium state, but this effect is affected because the package 1 is covered by the container 2 having a thermal conductivity of about 0.2 kcal / mh ° C. It is difficult to receive and detect the thermal conductivity of 0.005 kcal / mh ° C. of the filler 3 in the package 1. As a result, there is a problem in that it is difficult to inspect all of the packages 1 in mass production, which requires a very large number of inspection devices and enormous investment.

If the container 2 is visually visibly perforated, the container 2 and the filler 3 have a poor adhesion to the filler, so that there is a gap between the container 2 and the filler 3 and the container surface is Become softer. Therefore, it can be rejected as a defective product until such inspection.

The object of the present invention is to eliminate the drawbacks of the above-mentioned conventional examples, and enables the inspection of the vacuum break and the reduced pressure of the package in a short time, and by removing the defective products due to the vacuum break and the insufficient reduced pressure by 100% inspection. This helps ensure quality.

In order to achieve the above object, the present invention provides a chamber for accommodating a package whose inside is decompressed by placing a filling in a flexible container, and a chamber for a short time and less than the internal decompression of the package. A decompression device for decompressing to a low predetermined pressure,
A detection device that optically detects the swelling change amount of the container of the package provided in the chamber, and a pass / fail judgment means that determines the product as a defective product when the amount of the swelling change amount is equal to or more than a certain value by the detection device. The irradiation lens and the light receiving lens of the detection device are attached to a container forming the chamber.

Description of Embodiments The structure of one embodiment of the present invention will be described below with reference to FIGS. 3 to 5, but the same structures as in the related art will be denoted by the same reference numerals and detailed description thereof will be omitted.

In the figure, reference numeral 8 is an apparatus for inspecting the degree of reduced pressure of the package 1, which is divided into upper and lower containers 9 and 10 and is provided with a chamber 11 for opening and closing by moving the upper container 9 up and down.

A pressure switch 12 is provided in the chamber 11, and decompression of the decompression device 13 is stopped when a predetermined pressure is reached. Reference numeral 14 is a detection device for detecting the amount of change in the bulging of the container 2 of the package 1 provided in the chamber 11.

Further, 15 is interlocked with the operation of the pressure switch 12, and displays a swelling change amount when a predetermined pressure is reached, and includes a display unit 15 that lights a lamp when the amount of the swelling change amount is 4 mm or more. There is.

The detection device 14 includes a laser beam generator 16, an irradiation lens 17, a light receiving lens 18, and a displacement calculator 19.
The surface of the package 1 is irradiated with a laser beam from the irradiation lens 17, and the light receiving lens 18 receives the light flux reflected on the surface of the package 1, and when the thickness of the package 1 changes, the light receiving lens 18
The displacement calculator 19 uses the displacement of the light receiving position of to convert the displacement change amount.

The detection device 14 is arranged on the outer surface of the upper container 9, and a transparent window 20 is arranged in the upper container 9 so as to be perpendicular to the optical axes of the irradiation lens 13 and the light receiving lens 14. Further, when the package 1 is left standing in the lower container 10 in the chamber 11 and the chamber 11 is sealed, the light receiving position at this position is input to the displacement calculator 19 as an initial position.

Next, the operation of the above embodiment will be described.

In the figure, when the package 1 is left standing in the chamber 11 and the inside of the chamber 11 is decompressed by the decompression device 13, the inside decompression degree of the packaging 1 is maintained, so that the inside pressure of the chamber 11 is lower than the decompression degree. Container 2 of package 1 at the moment
Is bulging like a balloon and its thickness is displaced. This bulging displacement is detected by the detection device 14.

That is, as the container 2 swells, the laser beam emitted from the irradiation lens 17 is reflected on the container 2 to receive light.
Although it is incident on 18, the light receiving position at the light receiving lens 18 is displaced,
Corresponding to this shift, the displacement calculator 19 again converts the amount of movement.

Then, when the pressure in the chamber 11 reaches a predetermined degree of pressure reduction, the pressure switch 12 operates to stop the pressure reducing device 13.

At this time, the bulge change amount measured by the detection device 14 is simultaneously input to the display unit 15. Therefore, the lamp of the display unit 15 is turned on when the bulge changes by 4 mm or more.
Therefore, if the internal pressure of the package 1 is higher than the predetermined pressure, the container 2 is expanded to a certain size or more, and the lamp of the display unit 15 is turned on. On the contrary, if the internal pressure of the package 1 is lower than the pressure in the chamber 11, the container does not swell, or even if it swells, it is less than 4 mm, so the lamp of the display unit 15 of the detection device does not light.

Therefore, it is possible to determine whether the internal pressure of the package 1 is higher or lower than a predetermined pressure by reading the lamp of the display unit 15, and it is possible to make a pass / fail judgment for a defective product that has a vacuum break or insufficient decompression, and to judge whether the heat insulation performance is good or bad. Can be done.

That is, there is a density relationship between the internal vacuum degree of the package 1 and the thermal conductivity, and if the internal vacuum degree is at a predetermined pressure when the type of the filling 3 such as foamed perlite is constant, it is possible to obtain a predetermined heat. It is possible to judge whether or not the conductivity is obtained.

Further, these actions will be described.

If there is a hole in the container 2 of the package 1 and it can be visually judged to be defective, it is not necessary to perform this inspection.
On the contrary, when such a package 1 is inspected, the chamber 11
Even if the inside is depressurized, the air in the package 1 is easily discharged from the hole of the container 2, so that the pressure difference between the package 1 and the chamber 11 is unlikely to occur, and the bulge of the container 2 does not change. Or, the bulge is small and the inspection device malfunctions.

Next, when the container 2 of the package 1 has a hole and cannot be visually checked, this inspection is performed. In this case, by reducing the pressure in the chamber 11, the air in the package 1 tends to move from the hole of the container 2, but it is difficult to pass because it moves through the hole, so that the inside of the chamber 11 is short-timed. A pressure difference is generated between the inside of the package 1 and the inside of the chamber 11 by depressurizing the container 1. When the pressure inside the chamber 11 becomes lower than the regular inside pressure of the package 1, the container 2 expands and changes. As described above, when the bulge is 4 mm or more, the lamp lights up and it can be determined that the product is defective.

Further, a case will be described in which the container 2 of the package 1 has no holes, but the degree of reduced pressure is not high when the package 1 is formed.

As an example, 0.007kcal / mh ℃ (Internal pressure 1.0Torr), and 0.0
The swelling displacement of the thickness of the package 1 under reduced pressure at 080 kcal / mh ° C (internal pressure 2.0 Torr) will be explained. When the pressure in the chamber is reduced by about 5% lower than the internal pressure, it suddenly swells (Fig. 4). Shown in). Correlation between the degree of pressure reduction in the chamber 11 and the thermal conductivity of the package 1 at this time (shown in FIG. 5)
Therefore, the heat insulating performance of the package 1 can be easily assumed.

Therefore, the inside of the chamber 11 is depressurized to a predetermined pressure corresponding to this thermal conductivity which makes the package 1 having a predetermined thermal conductivity or higher a defective product, and the detection device 14 detects that the bulge of the package 1 is 4 mm or more. As a result, the display unit 15 turns on the lamp, so that it can be determined that the product is defective. Therefore, it is possible to easily inspect all defective products such as vacuum break and insufficient decompression, which can contribute to ensuring process quality.

Since the amount of displacement change is detected by the optical detection device 14, the bulging of the container 2 of the package 1 does not have a mechanical influence such as a load, so that the amount of displacement change does not vary and accuracy and reproducibility are improved. There is no problem with. Further, since the irradiation lens and the light receiving lens are attached to the container, the irradiation lens and the light receiving lens do not operate due to the flow of the air flow generated when the pressure in the chamber is reduced, so that the inspection can be reliably performed.

Even if the thickness of the package pair 1 is not constant, the time point when the chamber 11 is closed is input as the initial position, so that the package bodies 1 having different thicknesses can be continuously used without any problem.

In addition, although the heat insulating pack has been described as an example in the embodiments, it can also be used for inspection of decompression of a retort food or the like in which food or the like is enclosed and decompressed.

EFFECTS OF THE INVENTION The present invention is configured as described above, and the package is left standing in the chamber, and the chamber is depressurized to a predetermined pressure lower than the internal depressurization of the package in a short time and the swelling change of the container of the package is changed. When the amount of swelling change is greater than a certain amount by detecting the amount by the detection device, it is judged as a defective product by the quality judgment means, so the internal decompression degree of the package can be easily inspected and a vacuum break or insufficient decompression can be judged. can do. Further, since the detection device is of an optical type, it is excellent in accuracy and reproducibility that a mechanical influence such as a load exerts on a bulging change of the container of the package. Further, even if the thickness of the package is not constant, the time when the chamber is closed is input as the initial position, so that packages having different thicknesses can be continuously used without any problem.

[Brief description of drawings]

FIG. 1 is a sectional view of a package, FIG. 2 is a front view of a conventional inspection apparatus, FIG. 3 is a sectional view of an inspection apparatus according to an embodiment of the present invention, and FIG. A change diagram of the amount of change in thickness, FIG. 5 shows a relationship diagram between the thermal conductivity of the package and the degree of pressure reduction in the chamber. 1 ... Package, 2 ... Container, 3 ... Package, 11 ... Chamber, 13 ... Decompression device, 14 ... Detection device.

Claims (1)

[Claims] 1. A chamber for accommodating a package whose inside is decompressed by placing a filler in a flexible container, and decompression for decompressing the inside of the chamber to a predetermined pressure lower than the internal decompression of the package. A device, a detection device for optically detecting a swelling change amount of a container of a package provided in the chamber, and a pass / fail judgment means for determining a defective product when the swelling change amount is equal to or larger than a certain amount by the detection device. And a decompression degree inspection device for a package, in which an irradiation lens and a light receiving lens of the detection device are attached to a container forming the chamber.