JP6273703B2 - Inspection method for inspection object and inspection apparatus therefor - Google Patents

Description

  BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inspection method and an inspection apparatus for an inspection object, and in particular, an inspection method for an inspection object capable of inspecting a defect related to leakage of the inspection object such as a container in a short time with high accuracy And an inspection device thereof.

Conventionally, foods, drugs, cosmetics, and the like that are required to prevent leakage of contents, prevent deterioration, and ensure safety have been sealed in containers. Further, defect inspection has been performed on the container in order to detect defects such as pinholes and cracks.
In the technical field of such defect inspection, various techniques have been proposed for the purpose of improving inspection accuracy and inspection efficiency.

  For example, Patent Document 1 discloses that a package to be inspected is placed in an airtight closed space forming member having a translucent window, the inside of the closed space forming member is sucked under reduced pressure, and an air current is ejected from the package to be inspected. There is disclosed a defect inspection method for a sealed container or the like, characterized in that the state is optically observed and inspected by a shadow graph method, a Schlieren method, or the like.

  Further, Patent Document 2 includes a container for covering a sealed body to be inspected, and a gas analysis unit for analyzing whether or not a specific gas is contained in the gas in the internal space of the container. An elastic body for compressing the inspection object is disposed inside the container, the elastic body has air permeability, and the gas pushed out from the detection object passes through the elastic body and passes through the elastic body. A leak inspection apparatus characterized by having a configuration that reaches a gas analysis unit is disclosed.

  Further, in Patent Document 3, in a method for inspecting leakage of a bag-shaped container, a nozzle is inserted into the opening of the bag-shaped container, and the opening edge of the bag-shaped container is paired with a pair of sealing members in the inserted state of the nozzle. To seal the gap between the nozzle and the bag-like container, and supply the compressed gas to the bag-like container through the nozzle from the compressed gas supply path connected to the nozzle in the sealed state. In addition, there is disclosed a bag inspection method for leaking a bag-like container characterized in that information on the presence or absence of leakage of the bag-like container is obtained by detecting the pressure or flow rate in the compressed gas supply path.

Further, Patent Document 4 discloses a leak inspection method for determining whether or not there is a leak in an inspection object that requires a predetermined sealing property, and the flow rate of gas flowing out from or flowing into the inspection object is determined. There is disclosed a leak inspection method characterized by measuring and determining the presence or absence of leakage of an inspection object.
In addition, the leak inspection method includes a reference container arranged so that gas can flow between the inspection object and the presence / absence and movement direction of the gas between the inspection object and the reference container. It is also characterized by measuring with a flow meter and inspecting the presence or absence of leakage of the inspection object.

JP-A 63-273031 JP 2004-257717 A JP 2013-2812 A JP-A-10-185749

However, according to the defect inspection method for the sealed container or the like of Patent Document 1 described above, there is a possibility that the defect cannot be detected when the defective portion is in a position behind the package to be inspected, and a reliable defect inspection cannot be performed. was there.
In addition, according to the leak inspection apparatus of Patent Document 2, there is a problem that it takes time for the specific gas leaking from the sealed body to reach the gas analyzer, and the inspection time cannot be shortened. In addition, since a specific gas such as helium gas is required, there is a problem that the running cost cannot be reduced.
Furthermore, according to the leak inspection method of the bag-like container of Patent Document 3 and the leak inspection method of Patent Document 4, the inspection is performed by detecting the flow rate and pressure. There was a problem that it was not possible to improve.
In recent years, products with low environmental impact and low cost have been demanded, and the materials used for the products are becoming thinner. On the other hand, in the inspection of defective products, high-precision inspection is required in a short time, and a sufficiently satisfactory inspection method has not yet been obtained.

  The present invention has been proposed in view of the above circumstances, and an object thereof is to provide an inspection method and an inspection apparatus for an inspection object that can be inspected in a short time and with high accuracy.

In order to achieve the above object, an inspection method for an inspected object according to the present invention is a method for inspecting the presence or absence of a defective portion of an inspected object in order to form a predetermined closed space for the inspection target portion of the inspected object. A step of covering with the closed space forming member and a step of determining the presence or absence of the defective portion with the gas detecting means, provided in communication between the closed space forming member and the gas detecting means , in the housing section detects a gas having a space for housing the gas, is accommodated detectable gas is air, the pressure is applied to the inside of the object to be inspected, the amount of leaked from defect of the inspection object In response, the gas in the closed space forming member that has flowed into the detection gas storage portion is heated and thermally expanded in the detection gas storage portion, and from the detection gas storage portion according to the thermally expanded volume. Extruding the detection gas to the gas detection means, The body detection means is a pressure gauge, a flow meter, or an optical detection means, and the optical detection means is heated and has a refractive index different from that of the atmosphere inside the optical detection means. This is a method of visualizing the refractive index distribution of the gas and detecting the extruded detection gas .

The inspection object inspection apparatus of the present invention is connected to the closed space forming member for forming a predetermined closed space that covers at least a part of the inspection object, and the closed space forming member, and the inside is air. comprising a detection for gas storage portion having a space for accommodating a certain detectable gas, and heating means for heating the detection gas in the detection gas storing section, and a gas detecting means for detecting said detectable gas, the Pressure is applied to the inside of the inspection object, and the gas in the closed space forming member that has flowed into the detection gas storage portion according to the amount leaked from the defective portion of the inspection object is stored in the detection gas. According to the thermally expanded volume, the detection gas is pushed out from the detection gas storage unit to the gas detection unit, and the gas detection unit is a pressure gauge, a flow meter, or an optical device. Detecting means, the optical detection Stage, the refractive index distribution of the detectable gas pushed out of the optical detection means internal atmosphere and the refractive index is heated is different visualized, configured to detect the extruded the detectable gas is there.

According to the inspection method and inspection apparatus for an inspection object of the present invention, even a slight leak from a defective portion of the inspection object can be inspected in a short time and with high accuracy.
Moreover, even if it is a case where a defective location is not specified by covering the test object part of a to-be-tested object with a closed space formation member, a to-be-inspected object can be test | inspected.
Moreover, since no special inspection gas is required, the degree of freedom in selecting a gas is great, and the capital investment cost can be reduced. Furthermore, even if harmful substances are included in the inspected object, the presence or absence of a defective portion can be detected before leaking out of the inspection apparatus, so that the inspection can be performed safely.
In addition, since the gas in the closed space forming member that has flowed into the detection gas storage portion is thermally expanded, a larger amount of detection gas is pushed out from the detection gas storage portion to the gas detection means by the amount of thermal expansion. Can be further improved.

FIG. 1 shows a schematic diagram of an inspection apparatus according to the first embodiment of the present invention. FIG. 2 shows a schematic diagram of an inspection apparatus according to the second embodiment of the present invention. FIG. 3 shows a schematic diagram of an inspection apparatus according to the third embodiment of the present invention. FIG. 4 shows a schematic diagram of an inspection apparatus according to the fourth embodiment of the present invention. FIG. 5 shows a schematic diagram of an inspection apparatus according to the fifth embodiment of the present invention.

The inspection method of the present invention is characterized in that gas flows out of a predetermined space in accordance with the volume of the fluid leaking from the defective portion and pushes out the detection gas provided outside the predetermined space. Enables high-precision inspection in a short time.
Further, the inspection object used in the inspection method of the present invention can correspond to various shapes. Although there is no restriction | limiting in particular in a shape, For example, there exist a film shape, a cup shape, a cup shape, a cylinder shape, a bag shape, etc. Applications include tanks, films, lids, containers and the like, and it is particularly preferable to use them for empty containers.
Specific embodiments are shown below, but the inspection method and inspection apparatus of the present invention are not limited to these.

[First embodiment of inspection method and inspection apparatus for inspection object]
In FIG. 1, an inspection apparatus 1 (to be appropriately abbreviated as an inspection apparatus 1) of an inspection object according to this embodiment includes a gas supply means 2, a closed space forming member 3, a detection gas storage section 4, and a gas detection means 5. And so on. The inspection apparatus 1 partially inspects the object to be inspected 10 to inspect defects that cause leakage such as pinholes.

(Gas supply means)
The gas supply means 2 is a means for supplying the inspection gas 11 to the object to be inspected 10. In this embodiment, clean air is used as the inspection gas 11. The inspection gas 11 is normally supplied from the gas supply means 2 to the inside of the inspection object 10 through a tube with a valve, a joint (not shown), or the like.
Note that clean air refers to air from which dust or the like has been removed by a filter or the like.
Moreover, as the gas supply means 2, an oilless compressor, a blower, compressed gas, etc. are mentioned normally.

(Closed space forming member)
The closed space forming member 3 has a shape that covers a part of the outside of the inspection object 10 (for example, a box shape without a bottom plate or a plate shape when the inspection object is cup-shaped). It is a member for forming a predetermined closed space between the object to be inspected 10. The closed space forming member 3 has a gas (referred to as a gas in the closed space forming member 3 as appropriate) in a predetermined closed space. Since this closed space forming member 3 is pressed against the inspection object 10 during inspection, the gas in the closed space forming member 3 is usually the air around the inspection object 10. Further, the closed space forming member 3 is normally connected to the detection gas storage portion 4 via a tube with a valve or the like. Here, the tube with valve is included in the closed space forming member 3.
Note that the closed space forming member 3 has an annular gasket (not shown) or the like at a portion in contact with the object to be inspected 10, and the gap between the object to be inspected 10 and the closed space forming member 3 is The trouble that the gas in the closed space forming member 3 communicates is prevented.
In addition, the shape of the closed space forming member 3 is appropriately set according to the shape of the inspection object 10 and the like.

(Detection gas storage)
The detection gas storage unit 4 stores detection gas therein, and is in direct communication with the gas detection means 5. The detection gas will be described later.
Here, if the inspection object 10 has a defect (not shown) such as a pinhole, the inspection gas 11 leaks from the defect. In the present embodiment, the inspection gas 11 leaks out, but depending on the inspected object 10, the contents of the inspected object 10 may leak out. The fluid 12 is called.
When the fluid (leaked fluid 12) leaks from the object to be inspected 10, the detection gas storage portion 4 communicates directly with the closed space forming member 3, so that it depends on the leaked amount. And immediately after leaking, the gas 13 in the closed space forming member (in this embodiment, the gas in the vicinity of the tip of the tube connecting the closed space forming member 3 and the detection gas storage portion 4) is detected. It flows into the gas storage part 4. Thereby, unlike the above-described leakage inspection apparatus of Patent Document 2, it does not require time until the specific gas leaked from the sealing body reaches the gas analysis unit, so that the inspection time can be shortened.

(Gas detection means)
The gas detection means 5 is a means for detecting a detection gas, and usually an optical detection means 5b described later is used. However, the gas detection means 5 is not limited to the optical detection means 5b, and for example, a pressure gauge, a flow meter, a gas detector, or the like may be used.
When the optical detection means 5b is used as the gas detection means 5, the detection gas is a gas having a refractive index different from that of the atmosphere inside the optical detection means 5b, as will be described later. Further, when a pressure gauge or a flow meter is used as the gas detection means 5, the detection gas is usually air, and when a gas detector is used, it is a gas that can be detected by the gas detector.

Here, when the fluid 12 (in this embodiment, the inspection gas 11) leaked from the inspection object 10 leaks, the gas 13 in the closed space forming member is stored in the detection gas as described above. It flows into the part 4. And since the gas detection means 5 is directly communicating with the detection gas storage part 4, according to the amount of the gas 13 in the closed space forming member 3 that has flowed into the detection gas storage part 4, and Immediately after flowing in, the gas in the detection gas storage unit 4 (in this embodiment, the detection gas near the tip of the tube connecting the detection gas storage unit 4 and the gas detection unit 5) is the gas detection unit 5. Flows in. In FIG. 1, the gas that has flowed into the gas detection means 5 is indicated by a detection gas 14.
Thereby, unlike the above-described leakage inspection apparatus of Patent Document 2, it does not require time until the specific gas leaked from the sealing body reaches the gas analysis unit, so that the inspection time can be shortened.
Since the inspection apparatus 1 is generally put into practical use as an automatic inspection apparatus, the gas detection means 5 inputs a signal indicating that the detection gas 14 flowing into the gas detection means 5 has been detected, Judgment means (not shown) comprising a computer or the like for judging the presence or absence of defects is provided.

Next, the operation of the inspection apparatus 1 having the above configuration, the inspection method for the inspection object according to the present embodiment, and the like will be described.
The inspection object inspection method according to the present embodiment is a method for inspecting the presence or absence of a defective portion (not shown) of the inspection object 10, and covers the inspection object portion of the inspection object 10 with the closed space forming member 3. And a step of applying pressure to the object to be inspected 10 and determining the presence or absence of a defective portion by the gas detection means 5, provided in communication between the closed space forming member 3 and the gas detection means 5. The detection gas 14 is stored in the detection gas storage 4.
That is, first, as shown in FIG. 1, in the inspection apparatus 1, the gas supply means 2 is communicated with the inspection object 10 through the tube with a valve, and the closed space forming member 3 is pressed against the inspection object 10 to be inspected. A part of the inspection object 10 is covered.

  Next, in the inspection apparatus 1, the valve is opened, and the inspection gas 11 is supplied into the inspection object 10. Thereby, the inside of the inspection object 10 becomes a positive pressure with respect to the outside air, and pressure is applied to the inspection object portion of the inspection object 10.

  If the inspection object 10 has a defective part such as a pinhole that causes leakage, fluid (gas) leaks from the defective part of the inspection object 10 into the space in the closed space forming member 3. The gas in the closed space forming member 3 is increased by the fluid 12 that has exited. Accordingly, the gas 13 in the closed space forming member flows into the detection gas storage portion 4 according to the volume of the leaked fluid 12 and immediately after the fluid leaks from the defective portion.

Next, according to the volume of the gas 13 in the closed space forming member that has flowed into the detection gas storage portion 4 and immediately after the gas 13 in the closed space formation member has flowed in, the gas from the detection gas storage portion 4 The detection gas 14 is pushed out to the detection means 5, and the gas detection means 5 detects the pushed detection gas 14.
Subsequently, in the inspection apparatus 1, the determination unit of the gas detection unit 5 inputs a signal from the gas detection unit 5 and determines whether there is a defect.

  Preferably, the presence or absence of a defect is determined while supplying the inspection gas 11 to the inspection object 10. If it does in this way, since the gas 14 for a detection will be continuously extruded by the gas detection means 5, the gas detection means 5 can detect the gas 14 for detection reliably, and will improve the reliability of determination of the presence or absence of a defect. Can do.

In the present embodiment, the valve of the tube with the valve that communicates the closed space forming member 3 and the detection gas storage portion 4 is normally open, so that depending on the volume of the fluid 12 that has leaked. The detection gas 14 flowing into the gas detection means 5 is continuously detected.
However, the present invention is not limited to this. For example, although not shown, the valve may be closed for a predetermined time and the valve may be opened after the predetermined time has elapsed. In this way, since the fluid 12 leaked during a predetermined time is stored, when the valve is opened, it flows into the gas detection means 5 according to the volume of the much stored fluid 12 leaked. The detection gas 14 to be detected can be detected, and even when the amount of leakage is very small, leakage can be detected and detection accuracy can be improved.

[Second Embodiment of Inspection Method and Inspection Device for Inspected Object]
In FIG. 2, the inspection apparatus 1a of the present embodiment has a closed space forming member 3 that is a chamber 3a for accommodating the object to be inspected in a sealed state, as compared with the inspection apparatus 1 of the first embodiment described above. Is different. Note that other configurations of the present embodiment are substantially the same as those of the inspection apparatus 1.
Therefore, in FIG. 2, the same components as those in FIG. 1 are denoted by the same reference numerals, and detailed description thereof is omitted.

  The chamber 3a has a structure for accommodating the object to be inspected 10 in a sealed state, and has a lid that can be opened and closed, a valve for adjusting the internal pressure, and the like, although not shown. Since the chamber 3a accommodates the inspection object 10, it is possible to inspect defects on the entire surface of the inspection object 10.

  As described above, according to the inspection apparatus 1a and the inspection method of the inspection object of the present embodiment, substantially the same effect as that of the first embodiment is obtained, and the inspection object 10 is accommodated in the chamber 3a. A defect on the entire surface of the inspection object 10 can be inspected, and the inspection object 10 can be inspected as a whole even when a defective portion is not specified.

[Third embodiment of inspection method and inspection apparatus for inspection object]
In FIG. 3, the inspection apparatus 1 b of this embodiment is different from the inspection apparatus 1 a of the second embodiment in that an optical detection means 5 b is provided as the gas detection means 5. In addition, the other structure of this embodiment is as substantially the same as the inspection apparatus 1a.
Therefore, in FIG. 3, the same components as those in FIG. 2 are denoted by the same reference numerals, and detailed description thereof is omitted.
Further, the detection gas of the present embodiment has a refractive index different from that of the atmosphere around the optical detection means 5b.

(Optical detection means)
The optical detection unit 5b includes a light source 51, a lens 52, a nozzle 53, a lens 54, a knife edge 55, an observation unit 56, and the like, and performs a schlieren method. That is, the optical detection means 5b is a means for visualizing the refractive index distribution, and can visualize the refractive index distribution of the detection gas 14 with respect to the atmosphere and accurately detect the extruded detection gas 14. it can.

Here, it is preferable that the detection gas has a refractive index different from that of the atmosphere inside the optical detection unit 5b by adjusting the temperature. In this way, the difference between the refractive index of the detection gas and the refractive index of the atmosphere inside the optical detection means 5b can be easily increased, and the detection performance can be improved.
Preferably, the inspection gas 11, the gas in the chamber 3 a, and the detection gas in the detection gas storage 4 are air. In this case, it is not necessary to use an expensive gas such as helium, so that the running cost can be reduced.

As described above, according to the inspection apparatus 1b and the inspection object inspection method of the present embodiment, the detection gas pushed out by the optical detection means 5b has the same effect as the second embodiment. 14 can be detected with high accuracy. That is, even if the leaked fluid 12 is very small, the optical detection means 5b reliably detects it, so that the inspection accuracy (also referred to as inspection performance) can be greatly improved.
In addition, since the optical detection means 5b can detect with sufficient precision, it can apply to 1st embodiment, 4th embodiment mentioned later, and 5th embodiment normally.

[Fourth embodiment of inspection method and inspection apparatus for inspection object]
In FIG. 4, the inspection apparatus 1 c of this embodiment uses liquefied nitrogen (also referred to as compressed gas as appropriate) as the gas supply means 2 and the detection gas for the inspection apparatus 1 of the first embodiment. The difference is that the storage unit 4 has a heater 41 as temperature control means. Note that other configurations of the present embodiment are substantially the same as those of the inspection apparatus 1.
Therefore, in FIG. 4, the same components as those in FIG. 1 are denoted by the same reference numerals, and detailed description thereof is omitted.

The heater 41 as the temperature adjusting means heats the detection gas in the detection gas storage unit 4. Accordingly, when the gas 13 in the closed space forming member flows into the detection gas storage portion 4, the gas 13 in the closed space formation member that has flowed in is heated and thermally expanded in the detection gas storage portion 4. Therefore, when the gas 13 in the closed space forming member flows into the detection gas storage portion 4, the detection gas having the same volume as the gas 13 in the closed space forming member and the inflow in the closed space forming member. The gas 13 is thermally expanded, and the detection gas having a volume corresponding to the thermal expansion is pushed out from the detection gas storage portion 4 to the gas detection means 5 as the detection gas 14c.
In this case, when the gas 13 in the closed space forming member flows into the detection gas storage portion 4, the gas 13 in the closed space formation member that has flowed in thermally expands. A larger amount of the detection gas is pushed out by the amount of expansion, thereby further improving the detection performance.
In addition, although a heating means is normally used as a temperature control means, it is not limited to this, For example, a cooling means may be sufficient.

Moreover, in this embodiment, the to-be-inspected object 10 is a retort pouch etc., and although not shown in figure instead of the said gas supply means 2, the means to drop liquefied nitrogen in the to-be-inspected object 10, and to-be-inspected object Closing means for closing 10 openings. If it does in this way, liquefied nitrogen will vaporize inside the sealed to-be-tested object 10, and the inside of the to-be-inspected object 10 can be made into a positive pressure.
Other configurations and methods are substantially the same as those in the first embodiment.

As described above, according to the inspection apparatus 1c and the inspection method of the object to be inspected according to the present embodiment, the heater 41 flows into the detection gas storage section 4 while having substantially the same effect as the first embodiment. Since the gas 13 in the closed space forming member is thermally expanded, more detection gas is pushed out from the detection gas storage portion 4 to the gas detection means 5 by the amount of thermal expansion, and the detection performance can be further improved. . In the third embodiment, liquid nitrogen is used, but pressure may be applied to the inspection object from the outside as a means for positively pressing the inside of the inspection object.
In addition, since the detection performance can be further improved according to the heater 41, it is normally applicable to the second embodiment, the third embodiment, and a fifth embodiment described later.

[Fifth embodiment of inspection method and inspection apparatus for inspection object]
In FIG. 5, the inspection apparatus 1 d of the present embodiment uses liquefied nitrogen as the gas supply means 2, as compared with the inspection apparatus 1 of the first embodiment, and the closed space forming member 3 and the detection gas storage section 4. Are different in volume communication through a partition member. Note that other configurations of the present embodiment are substantially the same as those of the inspection apparatus 1.
Therefore, in FIG. 5, the same components as those in FIG. 1 are denoted by the same reference numerals, and detailed description thereof is omitted.

In the present embodiment, a diaphragm 42 is provided in the detection gas storage 4 as a partition member. When the gas 13 in the closed space forming member flows into the upstream side, the diaphragm 42 is deformed to the downstream side according to substantially the same volume. In addition, although the diaphragm 42 is used as a partition member, it is not limited to this, For example, you may use a bellows-like sheet | seat (not shown).
In this case, for example, carbon dioxide is used as the detection gas, and even if the gas 13 in the closed space forming member is a gas different from carbon dioxide, it is partitioned by the diaphragm 42. The problem that the concentration of carbon dioxide in the storage unit 4 does not decrease and the refractive index fluctuates can be avoided.

Further, in the present embodiment, the object to be inspected 10 is a retort pouch or the like in substantially the same manner as the above-described fourth embodiment. Means for dropping liquefied nitrogen and closing means for closing the opening of the object to be inspected 10 are provided. If it does in this way, liquefied nitrogen will vaporize inside the sealed to-be-tested object 10, and the inside of the to-be-inspected object 10 can be made into a positive pressure.
Other configurations and methods are substantially the same as those in the first embodiment.

As described above, according to the inspection apparatus 1d and the inspection method of the object to be inspected according to the present embodiment, the gas 13 and the detection gas 14 in the closed space forming member can be obtained with substantially the same effect as the first embodiment. Even if they are different from each other, mixing can be prevented, so that the degree of freedom in selecting a gas can be increased, and usability and the like can be improved. In addition, when the refractive index of the gas 13 in the closed space forming member and the detection gas 14 are different from each other, they do not mix with each other, so that the problem that the refractive index of the detection gas 14 fluctuates can be avoided.
The diaphragm 42 can also be applied to the second to fourth embodiments.

As mentioned above, although the inspection method of the inspected object of the present invention and its inspection device were shown and explained, the inspection method of the inspected object and the inspection device concerning the present invention are limited only to the above-mentioned embodiment. It goes without saying that various modifications can be made within the scope of the present invention.
For example, the optical detection unit 5b is configured to perform the schlieren method, but is not limited thereto, and may be configured to perform, for example, the shadow graph method or the Mach-Zehnder method.

1, 1a, 1b, 1c, 1d Inspection device 2 Gas supply means
3 Closed Space Forming Member 3a Chamber 4 Detection Gas Storage
5 Gas detection means 5b Optical detection means 10 Inspected object 11 Inspection gas
12 Leaked fluid
13 Gas in the closed space forming member
14 Detection gas 41 Heater 42 Diaphragm 51 Light source
52 lenses
53 nozzles
54 lenses
55 Knife Edge
56 Observation means

Claims (6)

In a method of inspecting the presence or absence of a defective part of an inspection object,
Covering the inspection target portion of the inspection object with a closed space forming member for forming a predetermined closed space;
A step of determining the presence or absence of the defective portion by a gas detection means,
A detection gas that is air is stored in a detection gas storage portion that is provided in communication between the closed space forming member and the gas detection means, and has a space for storing gas therein .
Pressure is applied to the inside of the inspection object, and the gas in the closed space forming member that has flowed into the detection gas storage portion according to the amount leaked from the defective portion of the inspection object is used for the detection gas. According to the thermally expanded volume by heating in the storage unit, the detection gas is pushed out from the detection gas storage unit to the gas detection means,
The gas detection means is a pressure gauge, a flow meter, or an optical detection means,
The optical detection means visualizes the refractive index distribution of the extruded detection gas that is heated and has a refractive index different from the atmosphere inside the optical detection means, and the extruded detection gas is A method for inspecting an inspection object characterized by detecting . Wherein while supplying a gas for inspection to the inspection object, the inspection method of the object according to claim 1, characterized in that to determine the presence or absence of the defect. 3. The inspection object inspection method according to claim 1, wherein the closed space forming member is a chamber, and the inspection object is stored in the chamber. A closed space forming member for forming a predetermined closed space covering at least a part of the inspection object;
A detection gas storage portion connected to the closed space forming member and having a space for storing a detection gas that is air inside;
Heating means for heating the detection gas in the detection gas storage section;
Gas detection means for detecting the detection gas , and
Pressure is applied to the inside of the inspection object, and the gas in the closed space forming member that has flowed into the detection gas storage portion according to the amount leaked from the defective portion of the inspection object is used for the detection gas. According to the thermally expanded volume by heating in the storage unit, the detection gas is pushed out from the detection gas storage unit to the gas detection means,
The gas detection means is a pressure gauge, a flow meter, or an optical detection means,
The optical detection means visualizes the refractive index distribution of the extruded detection gas that is heated and has a refractive index different from the atmosphere inside the optical detection means, and the extruded detection gas is An inspection apparatus for inspecting an object to be detected . The inspection object inspection apparatus according to claim 4 , further comprising gas supply means for supplying an inspection gas to the inspection object. 6. The inspection object inspection apparatus according to claim 4, wherein the closed space forming member is a chamber.

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