Leak inspection device and workpiece inspection method

Abstract

Provided is a leak inspection device and a leak inspection method, the leak inspection device including: a storage part having a plurality of plate-shaped members capable of moving relative to each other along the plate thickness direction, the storage part being capable of storing a plurality of bag-shaped containers in which a gas is sealed in a gap formed between adjacent plate-shaped members among the plurality of plate-shaped members; a pressing part that presses each of the plurality of bag-shaped containers via the plate-shaped members by moving the plate-shaped members along the plate thickness direction; and a detection part that detects a state of leakage of the gas from the bag-shaped containers by measuring the distance in a direction along a plate thickness direction of the respective gaps in which the plurality of bag-shaped containers are stored when pressed by the pressing part.

Description

Leak inspection device and leak inspection method

[0001] The technology of the present disclosure relates to a leak inspection device and a leak inspection method.

[0002] Generally, to ensure the quality of bag-shaped containers, bag-shaped containers and their accessories are inspected for defects such as minute holes. If a bag-shaped container has a hole larger than the size specified by quality control standards, it may cause problems such as leakage of substances inside the bag-shaped container or intrusion of dirt from the outside. Therefore, in order to check for defects such as minute holes in bag-shaped containers, it has been proposed to perform a leak test, which is a method for inspecting for leakage of gas sealed in the bag-shaped container.

[0003] Utility Model Registration No. 3120603 describes an inspection device for packaging bags, which includes a pair of clamping means arranged on either side of an inflated bag-shaped object to be inspected, which is filled with food and a fluid; a drive means for the clamping means that presses one of the clamping means against the object to deform it; and a movement state detection means that detects at least the distance moved by the clamping means.When one of the clamping means presses against the bag-shaped object to be inspected, the movement state of that one of the clamping means is detected by the detection means, and the presence or absence of pinholes or poor welding in the object to be inspected is determined based on this detection.

[0004] Japanese Patent Application Laid-Open Publication No. 2016-118523 describes a leak inspection method for a packaged product in which a bag-shaped packaging film is filled with gas together with solid contents and sealed, characterized in that the package is held upright so that the contents are collected downward by gravity, and the top of the package where no contents are present is pressed to inspect the package for leaks.

[0005] Japanese Patent Laid-Open No. 07-159272 discloses a pinhole inspection device for sealed packaging bags, which has an inspection chamber in which a plurality of compartments capable of accommodating sealed packaging bags filled with inspection gas are arranged in series, adjacent compartments are separated by movable partition members, and compression springs are interposed between each partition member so that the distance between each partition member is changed by pressing the partition members on the end sides to press the sealed packaging bag, and the inspection gas leaked from the sealed packaging bag is supplied to a gas detector. The inspection chamber has a plurality of partition members slidably fitted inside a side wall portion surrounding the periphery to form the plurality of compartments, and The side walls are provided with detachable or openable lids for inserting and removing sealed packaging bags into each compartment, the wall surface near the end of the compartment on one end side is fixable, compression springs are provided between each partition member and stoppers are provided to prevent the distance between each partition member from becoming less than a predetermined distance, a pressing mechanism is provided to press the partition member on the other end side and change the distance between each partition member via the compression spring, and the inspection chamber is provided with suction piping to suck in test gas that has leaked into each compartment and supply it all to a gas detection device.This describes a pinhole inspection device for sealed packaging bags.

[0006] Japanese Utility Model Registration No. 3120603 describes a technique in which a detection means detects the movement of one of the clamping means when a bag-shaped test object sandwiched between a pair of clamping means is pressed and deformed by the other clamping means. Japanese Patent Application Laid-Open No. 2016-118523 also describes a technique in which pressure is applied to the top of an empty package to test for leaks. As described above, the techniques described in Japanese Utility Model Registration No. 3120603 and Japanese Patent Application Laid-Open No. 2016-118523 test objects one by one, which reduces the efficiency of the leak test process.

[0007] On the other hand, Japanese Patent Laid-Open Publication No. 07-159272 describes a pinhole inspection device for sealed packaging bags that supplies test gas leaking from the sealed packaging bag to a gas detection device. The technology described in Japanese Patent Laid-Open Publication No. 07-159272 detects test gas leaking from multiple test objects, so although multiple test objects can be inspected simultaneously, it is not possible to determine which of the multiple test objects the leak is from. Therefore, a separate task is required to identify which test object the leak is from, and there is room for improvement in the efficiency of leak inspection work.

[0008] Therefore, the technology disclosed herein provides a leak inspection device and a leak inspection method that can improve the efficiency of leak inspections of bag-shaped containers.

[0009] A first aspect of the technology disclosed herein is a leak testing device that includes: a storage section having a plurality of plate-like members that are movable relative to one another along the plate thickness direction, and that can store a plurality of bag-like containers with gas sealed inside in gaps formed between adjacent plate-like members among the plurality of plate-like members; a pressing section that presses each of the plurality of bag-like containers via the plate-like members by moving the plate-like members along the plate thickness direction; and a detection section that detects a gas leakage state from the bag-like containers by measuring the distance along the plate thickness direction of each of the gaps in which the plurality of bag-like containers are stored when pressed by the pressing section.

[0010] A second aspect of the technology disclosed herein is a leak testing device according to the first aspect, in which the pressing portion has a bag-shaped member stored in one of the gaps, and the plate-shaped member is moved by pressurizing the gas flowing into the bag-shaped member in the pressing portion.

[0011] A third aspect according to the technique of the present disclosure is the leak testing device according to the second aspect, in which the bag-like member includes a bag-like container for pressurization.

[0012] A fourth aspect of the technology disclosed herein is a leak testing device according to the first aspect, in which the plurality of plate-like members include a movable plate that is movable when subjected to a pressing force from a pressing portion, and a fixed plate that does not move even when subjected to a pressing force, and the fixed plate is provided in the storage portion at an end in the direction of movement of the movable plate.

[0013] A fifth aspect of the technology of the present disclosure is a leak testing device according to the fourth aspect, in which the fixed plates are provided at both ends of the storage section in the direction of movement of the movable plate, and the storage section further has a guide mechanism that guides the movement of the movable plate between the fixed plates.

[0014] A sixth aspect according to the technique of the present disclosure is the leak testing device according to the first aspect, wherein the plate-like member moves in the storage section in a horizontal direction.

[0015] A seventh aspect of the technology of the present disclosure is a leak testing device according to the first aspect, in which the plurality of bag-like containers include a plurality of container bodies stored in each of the gaps, and a hose portion extending from the container bodies and forming a flow path connecting each of the plurality of container bodies, and when gas is sealed in the bag-like container, no movement of gas occurs between the plurality of container bodies via the hose portion.

[0016] An eighth aspect according to the technique of the present disclosure is the leak testing device according to the first aspect, in which the detection unit includes a contact-type displacement sensor.

[0017] A ninth aspect of the technology of the present disclosure is a leak testing device according to the first aspect, in which the leak state includes the presence or absence of gas leakage from the bag-shaped container and / or the size of the hole through which the gas is leaking.

[0018] A tenth aspect of the technology of the present disclosure is a leak inspection method including: storing a plurality of bag-shaped containers with gas sealed inside in gaps formed between adjacent plate-shaped members among a plurality of plate-shaped members that are movable relative to each other along the plate thickness direction; moving the plate-shaped members along the plate thickness direction to press each of the plurality of bag-shaped containers via the plate-shaped members; and detecting a state of gas leakage from the bag-shaped containers by measuring the distance along the plate thickness direction of each of the gaps in which the plurality of bag-shaped containers are stored.

[0019] The technology disclosed herein provides a leak inspection device and a leak inspection method that can improve the efficiency of leak inspections of bag-shaped containers.

[0020] Fig. 1 is a schematic front view showing an example of the configuration of a leak test device according to an embodiment; Fig. 2 is a schematic perspective view showing an example of the configuration of a leak test device according to an embodiment; Fig. 3 is a flowchart showing an example of a leak test process according to an embodiment; Fig. 4 is a schematic perspective view showing an example of the configuration of a leak test device according to an embodiment;

[0021] An example of an embodiment of a leak test device 10 according to the technique of the present disclosure will be described with reference to the accompanying drawings.

[0022] In the following description, for convenience of explanation, the front-to-rear direction (also referred to as the depth direction), width direction, and height direction of the leak test device 10 are indicated by three arrows, X, Y, and Z. First, the height direction is indicated by arrow Z, and the direction indicated by arrow Z is the upward direction of the leak test device 10, and the opposite direction is the downward direction. The width direction is indicated by arrow X perpendicular to arrow Z, and the direction indicated by arrow X is the rightward direction of the leak test device 10, and the opposite direction is the leftward direction. The front-to-rear direction is indicated by arrow Y, which is perpendicular to arrows Z and X, and the direction indicated by arrow Y is the forward direction of the leak test device 10, and the opposite direction is the rearward direction. Furthermore, in the following description, expressions using sides, such as upper side, lower side, left side, right side, front side, and rear side, have the same meaning as expressions using directions.

[0023] As shown in FIGS. 1 and 2 as an example, a leak inspection device 10 is a device for inspecting a bag-shaped container B to be inspected for leakage. The leak inspection device 10 is an example of a "leak inspection device" according to the technology of the present disclosure. The bag-shaped container B is a bag-shaped container that is stored or transported while containing an object therein. Examples of the state of the object contained in the bag-shaped container B include gas, liquid, and solid. The bag-shaped container B is made of, for example, a resin, specifically, PP (polypropylene), PE (polyethylene), or EVA (ethylene vinyl acetate) resin. The size of the bag-shaped container B is, for example, 700 mm long x 500 mm wide.

[0024] More specifically, examples of the resin forming the bag-shaped container B include PE, such as low density polyethylene (LDPE), linear low density polyethylene (LLDPE), ultra low density polyethylene (ULDPE), and high density polyethylene (HDPE). Examples of PP include oriented polypropylene (OPP), cast polypropylene (CPP), and inflation polypropylene (IPP). Other examples of the resin forming the bag-shaped container B include ethylene vinyl alcohol copolymer (EVOH), nylon, polyester, polyolefin (PO), perfluoroalkoxy alkane (PFA), and polytetrafluoroethylene (PTFE). Examples of polyester include polyethylene terephthalate (PET) and polyethylene naphthalate (PEN).

[0025] Furthermore, the bag-shaped container B may have a laminated structure in which multiple materials are layered from the inside to the outside of the container. In this case, it may be configured by laminating multiple types of resin layers made of the resins described above. It goes without saying that the laminated structure of the bag-shaped container B may also be configured by including materials other than resin. For example, the bag-shaped container B may have a laminated structure having a metal layer or a paper layer. Specifically, the bag-shaped container B may have a laminated structure having at least a resin layer on the inside and a metal layer (e.g., an aluminum layer) on the outside. The bag-shaped container B may also have a laminated structure having a resin layer on the inside and a paper layer on the outside.

[0026] The leak testing device 10 includes a storage unit 11, a pressing unit 13, and a detection unit 15. The storage unit 11 is a portion capable of storing a plurality of bag-shaped containers B. The storage unit 11 has a plurality of plate-shaped members 12. In the storage unit 11, a bag-shaped container B is stored one by one in gaps K (see FIG. 2) formed between the plurality of plate-shaped members 12. In the example shown in FIG. 1, ten bag-shaped containers B1 to B10 are stored in the storage unit 11. The storage unit 11 is an example of a "storage unit" according to the technology of the present disclosure. In other words, the number of gaps K formed between the plurality of plate-shaped members 12 is not limited to ten.

[0027] The plurality of plate-like members 12 are movable relative to one another in a direction along the plate thickness direction. In the example shown in Fig. 1, the plurality of plate-like members 12 are movable in the left-right direction of the leak test device 10 (the direction along the X direction shown in Fig. 1).

[0028] Specifically, the multiple plate-like members 12 include fixed plates 14A and 14B and multiple movable plates 16. The fixed plates 14A and 14B are plate-like members that do not move even when subjected to a pressing force from the pressing unit 13, which will be described later. Specifically, the fixed plates 14A and 14B are plate-like members fixed to the main body of the leak testing device 10. The fixed plates 14A and 14B are arranged with their plate thickness direction in the left-right direction. The size, plate thickness, and material of the fixed plates 14A and 14B are appropriately set depending on the size of the bag-shaped container B and the pressing force applied to the fixed plates 14A and 14B. The fixed plates 14A and 14B are, for example, aluminum plate-like members measuring 900 mm long, 800 mm wide, and 20 mm thick. The fixed plates 14A and 14B are an example of a "fixed plate" according to the technology disclosed herein.

[0029] If the fixing plate 14 is made of aluminum, the surface may be anodized. The anodized surface provides the fixing plate 14 with anti-rust and scratch-resistant properties. The fixing plate 14 may also be made of a material other than aluminum. For example, the fixing plate 14 may be made of iron, stainless steel, copper, nickel, resin, wood, paper, glass, ceramic, or a combination of these materials. The fixing plate 14 may also be subjected to a surface treatment such as plating or painting.

[0030] The fixed plates 14A and 14B are provided at both ends of the storage section 11 in the left-right direction. Specifically, the fixed plate 14A is provided at the right end of the storage section 11, and the fixed plate 14B is provided at the left end of the storage section 11. For ease of explanation, the fixed plate 14A will be referred to as the right fixed plate 14A below, and the fixed plate 14B will be referred to as the left fixed plate 14B below.

[0031] A plurality of movable plates 16 are provided between the right fixed plate 14A and the left fixed plate 14B. The movable plates 16 are plate-shaped members that are movable when pressed by a pressing force from a pressing unit 13, which will be described later. Specifically, the plurality of movable plates 16 are arranged with their plate thickness direction aligned in the left-right direction, similar to the fixed plates 14A and 14B. The plurality of movable plates 16 are also arranged in the left-right direction in the storage unit 11. The movable plates 16 are an example of a "movable plate" according to the technology of the present disclosure.

[0032] In the example shown in FIG. 1 , ten movable plates 16A to 16J are provided between a right-side fixed plate 14A and a left-side fixed plate 14B. Hereinafter, when it is necessary to distinguish between the multiple movable plates 16, sub-reference numerals A to J are added to the reference numeral of the movable plate 16, and when it is not necessary to distinguish between them, they are simply referred to as movable plates 16. Among the multiple movable plates 16A to 16J, a gap K is formed between adjacent movable plates 16, and a bag-shaped container B is accommodated in each gap K. Specifically, as shown in FIG. 2 , a bag-shaped container B1 is accommodated between movable plates 16A and 16B. A bag-shaped container B2 is accommodated between movable plates 16B and 16C. A bag-shaped container B3 is accommodated between movable plates 16C and 16D. A bag-shaped container B4 is accommodated between movable plates 16D and 16E. Similarly, bag-shaped containers B5 to B10 are stored in gaps K formed between adjacent movable plates 16. As will be described in detail later, gas A is sealed in bag-shaped container B stored in gap K. Gas A is, for example, air.

[0033] Furthermore, the multiple movable plates 16 are movable relative to the main body of the leak test device 10. The leak test device 10 is installed with the left-right direction as the horizontal direction, and the multiple movable plates 16 are movable along the left-right direction. That is, the multiple movable plates 16 are movable along the horizontal direction. Here, the horizontal direction includes the completely horizontal direction and also includes the horizontal direction with a degree of tolerance acceptable in the technical field to which the technology of the present disclosure belongs. The size, thickness, and material of the multiple movable plates 16 are appropriately set depending on the size of the bag-shaped container B and the pressing force applied to the movable plates 16. The multiple movable plates 16 are, for example, aluminum plate-shaped members measuring 900 mm long, 800 mm wide, and 10 mm thick.

[0034] If the movable plate 16 is made of aluminum, the surface may be anodized. The anodized surface provides rust prevention and scratch prevention effects for the movable plate 16. Of course, the movable plate 16 may be made of a material other than aluminum. For example, the movable plate 16 may be made of iron, stainless steel, copper, nickel, resin, wood, paper, glass, ceramic, or a combination of these. The movable plate 16 may also be subjected to surface treatment such as plating or painting.

[0035] The storage unit 11 also has a guide mechanism 17 that guides the movement of the movable plate 16 between the right-side fixed plate 14A and the left-side fixed plate 14B. The guide mechanism 17 is an example of a "guide mechanism" according to the technology of the present disclosure. The guide mechanism 17 has shaft members 17A to 17D that span between the right-side fixed plate 14A and the left-side fixed plate 14B. One end of the shaft members 17A to 17D is attached to the right-side fixed plate 14A, and the other end is attached to the left-side fixed plate 14B. The shaft members 17A to 17D are rod-shaped members with a circular cross section. The shaft members 17A to 17D are, for example, stainless steel rod-shaped members with a diameter of 30 mm and a length of 700 mm.

[0036] It goes without saying that the cross-sectional shape of the shaft members 17A to 17D is not limited to a circle. For example, the cross-sectional shape of the shaft members 17A to 17D may be a polygon (for example, a triangle, a quadrangle (for example, a rectangle or a square), or a hexagon), an ellipse, or a partial circle. Furthermore, there are no particular limitations on the dimensions of the shaft members (for example, the size or length of the cross section), and there are no particular limitations on the number of shaft members.

[0037] The shaft members 17A to 17D are inserted through each of the plurality of movable plates 16. Each of the plurality of movable plates 16 is movable while being guided by the shaft members 17A to 17D. Here, an example has been shown in which the positions where each of the plurality of shaft members 17A to 17D is inserted are the four corners of the plurality of movable plates 16, but this is merely one example.

[0038] 2, shaft member 17A is provided on the upper front side of storage section 11, and shaft member 17B is provided on the lower front side. Shaft member 17C is provided on the upper rear side, and shaft member 17D is provided on the lower rear side of storage section 11. Shaft members 17A to 17D may be inserted into multiple movable plates 16 via linear bushings.

[0039] The leak test device 10 also includes a bag-shaped container holder 18. The bag-shaped container holder 18 is a member that supports a plurality of bag-shaped containers B stored in the storage section 11. The bag-shaped container holder 18 has clips C, and the clips C grip hose sections H extending from each of the plurality of bag-shaped containers B. This allows the bag-shaped containers B to be suspended from the bag-shaped container holder 18 via the hose sections H. In this manner, the bag-shaped containers B are supported in the leak test device 10.

[0040] Note that, although an example in which the bag-shaped container B is suspended via the hose portion H gripped by the clip C has been described here, this is merely one example. For example, instead of the clip C, a hook may be provided on the bag-shaped container holder 18, and the hose portion H may be hooked onto the hook to suspend the bag-shaped container B. Furthermore, instead of the hose portion H, a string-like member (e.g., a wire member with a clip attached to the tip) for suspending the bag-shaped container B may be provided on the bag-shaped container holder 18 together with the hose portion H.

[0041] The bag-shaped container holder 18 may be movable in the vertical direction, so that the bag-shaped containers B are stored in and removed from the storage section 11 in accordance with the vertical movement of the bag-shaped container holder 18. Furthermore, the bag-shaped container holder 18 may be movable in the horizontal direction, so that the bag-shaped containers B can be moved between a position above the storage section 11 and a container transfer position shifted from above the storage section 11. At the container transfer position, a cart (not shown) on which multiple bag-shaped containers B can be placed is positioned below the bag-shaped container holder 18, making it easy to transfer the bag-shaped containers B using the cart.

[0042] The pressing unit 13 moves the plurality of plate-like members 12 to press each of the plurality of bag-like containers B via the plate-like members 12. Specifically, the pressing unit 13 has a bag-like member PB for pressurization (hereinafter also simply referred to as "bag-like member PB"). As will be described in detail later, the bag-like member PB expands to press the bag-like containers B via the movable plate 16. The pressing unit 13 is an example of a "pressing unit" according to the technology of the present disclosure. The bag-like member PB is an example of a "bag-like member" according to the technology of the present disclosure.

[0043] The bag-shaped member PB is housed, for example, in the gap K between the left fixed plate 14B and the movable plate 16A. The bag-shaped member PB has, for example, the same material and the same size as the bag-shaped container B to be inspected. In other words, the bag-shaped member PB is a bag-shaped container B for pressurization. Here, "same" includes being completely the same, and also includes a tolerance within the range acceptable in the technical field to which the technology of the present disclosure pertains.

[0044] Note that, although an example in which the bag-shaped member PB is stored in the gap K between the left fixed plate 14B and the movable plate 16A has been described here, this is merely one example. The bag-shaped member PB may also be stored in the gap K between the right fixed plate 14A and the movable plate 16J. The bag-shaped member PB may also be stored between the movable plates 16. A plurality of bag-shaped members PB may also be provided. In this case, each of the plurality of bag-shaped members PB is stored in a respective one of the plurality of gaps K in which no bag-shaped container B is stored.

[0045] Detecting unit 15 detects the leakage state of gas A from bag-shaped container B by measuring the left-right distance of gap K in which bag-shaped container B is stored. Specifically, detecting unit 15 is a displacement sensor S that can measure the distance between adjacent plate-like members 12. For example, displacement sensor S is attached to the lower part of movable plate 16 and measures the distance to another movable plate 16 located to the left of that movable plate 16. Also, for example, displacement sensor S is attached to the lower part of right-side fixed plate 14A and measures the distance to movable plate 16J. Detecting unit 15 is an example of a "detecting unit" according to the technology disclosed herein.

[0046] The displacement sensor S is, for example, a contact-type displacement sensor. The displacement sensor S outputs the measurement result of the distance in the left-right direction of the gap K to the control device 30 described later. The displacement sensor S is an example of a "contact-type displacement sensor" according to the technology of the present disclosure.

[0047] The gas supply system 20 supplies a gas A (e.g., air) to the bag-shaped container B. The gas supply system 20 receives the gas A from an external gas supply source (e.g., a compressed air pipe or a compressed air cylinder used in a facility where the leak testing device 10 is installed).

[0048] The gas supply system 20 is configured to include piping, valves, pressure regulators (none of which are shown), etc. The pressure, flow rate, etc. of the gas A to be supplied are adjusted in the gas supply system 20. The gas A is supplied from the gas supply system 20 via piping 22. Downstream of the gas supply system 20 in the supply path, the piping 22 branches into a piping 24 for the bag-shaped container B and a piping 26 for the bag-shaped member PB for pressurization. A valve 28 is provided on the piping 24 for the bag-shaped container B. By closing the valve 28, the supply of the gas A to the bag-shaped container B is stopped.

[0049] The gas supply system 20 may be integrated with the leak inspection device 10. Alternatively, the gas supply system 20 may be separate from the leak inspection device 10. In other words, the gas supply system 20 may function as a supply system for gas A independent of the leak inspection device 10.

[0050] The leak test device 10 also includes a control device 30 and a display device 32. The control device 30 controls the detection of a leak state by the detection unit 15 and the display of the detection results in the leak test device 10. The control device 30 is realized by a computer including, for example, a CPU (Central Processing Unit), storage (for example, an EEPROM (Electrically Erasable and Programmable Read Only Memory) and / or an SSD (Solid State Drive)), and memory (for example, a RAM (Random Access Memory)).

[0051] The control device 30 may be realized by an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), and / or a programmable logic controller (PLC). Alternatively, the control device 30 may be realized by a combination of two or more of an ASIC, an FPGA, a PLC, and a computer. That is, the control device 30 may be realized by a combination of hardware and software.

[0052] The display device 32, under the control of the control device 30, displays information about the operating status of the leak test device 10 to the user of the leak test device 10. For example, the display device 32 displays the leak status of the gas A detected by the detection unit 15. The display device 32 is configured to include, for example, an LED (Light Emitting Diode) lamp that indicates the presence or absence of a leak status.

[0053] The display device 32 may be any device capable of presenting the leakage state in a manner that can be recognized by the user, and the display format is not particularly limited. For example, the display device 32 may be a liquid crystal display, in which case the detection results (for example, the measurement results of the distance of the gap K or the leakage state of each bag-shaped container B) may be displayed in real time on the display screen.

[0054] In the leak testing device 10 as described above, a plurality of bag-shaped containers B to be tested are stored in the storage section 11. Specifically, bag-shaped containers B1 to B9 are placed in the gaps K between adjacent movable plates 16 of the movable plates 16A to 16J. Also, bag-shaped container B10 is placed in the gap K between the movable plate 16J and the right-side fixed plate 14A. Furthermore, a bag-shaped member PB for pressurization is placed in the gap K between the left-side fixed plate 14B and the movable plate 16A.

[0055] Then, gas A flows from gas supply system 20 into bag-shaped container B and bag-shaped member PB. As gas A flows in, bag-shaped container B and bag-shaped member PB expand. The pressure of gas A flowing into bag-shaped container B and bag-shaped member PB is set to a predetermined pressure in gas supply system 20. Therefore, after pressurization, bag-shaped container B and bag-shaped member PB expand to a volume corresponding to the pressure. Here, the predetermined pressure is, for example, 10 kPa.

[0056] Bag-shaped container B, pressurized to a predetermined pressure, is in contact with the adjacent movable plate 16, or with movable plate 16J and right-side fixed plate 14A. Also, bag-shaped member PB is in contact with movable plate 16A and left-side fixed plate 14B. In this state, valve 28 provided on piping 24 is closed, thereby stopping the supply of gas A to bag-shaped container B. In this way, gas A is sealed inside bag-shaped container B.

[0057] After valve 28 is closed, gas A continues to be supplied to bag-shaped member PB to maintain a constant pressure inside. In other words, gas A flowing into bag-shaped member PB is pressurized. This maintains a constant pressure inside bag-shaped member PB, causing movable plate 16, which is in contact with bag-shaped member PB, to receive a pressing force from bag-shaped member PB. Then, bag-shaped container B is pressed via movable plate 16. Here, gas A at a predetermined pressure is sealed in bag-shaped container B. Therefore, although bag-shaped container B receives the pressing force, it deforms slightly, but transmits most of the pressing force to movable plate 16, which is located on the opposite side from the pressed side.

[0058] Bag-shaped container B1 is pressed by movable plate 16A. Bag-shaped container B then transmits the pressing force received from movable plate 16A to movable plate 16B. Movable plate 16B transmits the pressing force received from bag-shaped container B to bag-shaped container B2. In this way, the pressing force generated by pressing unit 13 is transmitted via movable plate 16 and bag-shaped container B sandwiched between movable plates 16. Furthermore, since storage unit 11 has fixed plates 14A and 14B, the pressing force from pressing unit 13 is received by fixed plates 14A and 14B. Specifically, left-side fixed plate 14B receives the pressing force from bag-shaped member PB and generates a reaction force against bag-shaped member PB. Furthermore, right-side fixed plate 14A receives the pressing force from bag-shaped container B10 and generates a reaction force against bag-shaped container B10.

[0059] The bag-shaped container B has a container body M and a hose portion H. The container body M is a bag-shaped portion capable of containing a liquid therein. The container body M of the bag-shaped container B is housed in the gap K. The hose portion H is a hose-shaped portion extending from the container body M. Liquid is transferred via the hose portion H. The hose portion H extends from the container body M and is further connected to other bag-shaped containers B. In this way, in the bag-shaped container B, the container bodies M are connected to each other via the hose portion H. In other words, internal fluid can move between the container bodies M. The container body M is an example of a "container body" according to the technology of the present disclosure, and the hose portion H is an example of a "hose portion" according to the technology of the present disclosure.

[0060] Therefore, in the leak testing device 10 according to this embodiment, when the gas A is sealed in the bag-shaped container B, the gas A does not move through the hose part H. Specifically, after the inflow of the gas A from the gas supply system 20 has finished, the hose part H is pinched from the outer periphery to block the flow path formed inside the hose part H. This prevents the gas A from moving between the container bodies M through the hose part H.

[0061] Here, consider a case where there is a defect in multiple bag-shaped containers B that causes leakage of gas A. Examples of defects include a tiny hole (i.e., a pinhole), poor welding of the peripheral edge M1 of the container body M, and poor bonding between the container body M and the hose portion H. In this case, as described above, gas A is sealed in the bag-shaped container B at a predetermined pressure. In addition, gas A does not move to another container body M via the hose portion H connecting the container bodies M to each other.

[0062] Therefore, if there is a defect, gas A will leak to the outside through the defect. Furthermore, by maintaining a constant pressing force from the pressing portion 13, the degree of leakage of the internal gas A to the outside can be maintained without weakening. For example, the leakage rate and amount of gas A can be maintained constant. Therefore, bag-shaped container B that continues to receive the pressing force will gradually shrink.

[0063] A defect exists in bag-shaped container B2. The pressing force from pressing unit 13 is transmitted to bag-shaped container B2 via movable plate 16B, and bag-shaped container B2 receives a reaction force from movable plate 16C. As a result, bag-shaped container B2 gradually contracts. Accordingly, the distance between movable plates 16B and 16C also decreases.

[0064] The detection unit 15 measures the distance between adjacent movable plates 16. The displacement sensor S attached to the lower part of the movable plate 16C comes into contact with the movable plate 16B to measure the distance between the movable plate 16B and the movable plate 16C. The displacement sensor S attached to the lower part of the movable plate 16C detects a change in the distance between the movable plate 16B and the movable plate 16C, which gradually decreases. This change in the distance between the movable plate 16B and the movable plate 16C, which gradually decreases, indicates that a leak has occurred. In other words, the displacement sensor S detects a leak state. The displacement sensor S outputs the measured distance between the movable plates 16 to the control device 30.

[0065] The control device 30 acquires the output results from the displacement sensors S. The processor of the control device 30 then controls the display of the leak state based on the output results from each of the multiple displacement sensors S. For example, if the distance between adjacent movable plates 16 after a predetermined time (e.g., 20 minutes) has elapsed since the start of the test has decreased by a threshold value (e.g., 1.5 mm) or more from the distance at the start of the measurement, it is determined that a leak has occurred in the bag-shaped container B corresponding to the displacement sensor S, and the processor causes the display device 32 to display an indication of the occurrence of a leak. For example, the processor causes the display device 32 to light up an LED lamp indicating the occurrence of a leak. Here, the LED lamps correspond to each of the multiple bag-shaped containers B, and by visually checking which lamp is lit, it is possible to identify which bag-shaped container B is leaking gas A.

[0066] The threshold value for determining whether or not there is a leak is set appropriately depending on the size and content of the bag-shaped container B. The threshold value can be determined in advance, for example, by conducting an experiment using the leak test device 10. That is, a bag-shaped container B with a hole of a reference size is prepared, and a leak test is carried out with the bag-shaped container B filled with gas A, and the distance between the movable plates 16 is measured over time, thereby obtaining the threshold value.

[0067] Although the leak state has been described above by way of example, the presence or absence of a leak is detected. For example, the size of the hole through which gas A is leaking may be detected in addition to or instead of the presence or absence of a leak.

[0068] In this case, a table showing the relationship between the amount of movement of the movable plates 16 after a predetermined time has elapsed (i.e., the amount of change in the distance between the movable plates 16) and the size of the hole is stored in the storage of the control device 30. The processor uses this table to derive the size of the hole. Specifically, the processor determines the amount of movement of the movable plates 16 based on the output result from the displacement sensor S, and derives the size of the hole corresponding to the amount of movement from the table. The processor then causes the display device 32 to display the size of the hole.

[0069] By checking the display on display device 32, the user can confirm the state of leakage of gas A from bag-shaped container B. Specifically, the user can confirm which bag-shaped container B among a plurality of bag-shaped containers B is leaking gas A. In this manner, leak testing is performed on bag-shaped containers B by leak testing device 10.

[0070] Next, a process for leak testing for the bag-shaped container B according to this embodiment (hereinafter also simply referred to as the testing process) will be described with reference to Figure 3. The flow of the testing process shown in Figure 3 is an example of a "leak testing method" according to the technology of the present disclosure.

[0071] As an example, as shown in Figure 3, in the inspection process, first, in step ST12, bag-shaped containers B are stored in gaps K of storage unit 11. Specifically, each of the plurality of bag-shaped containers B is stored in gaps K formed between movable plates 16 of storage unit 11. After step ST12 is performed, the inspection process proceeds to step ST14.

[0072] In step ST14, gas A is sealed into bag-shaped container B from gas supply system 20. After step ST14 is performed, the inspection process proceeds to step ST16.

[0073] In step ST16, pressing unit 13 presses bag-shaped container B via movable plate 16. Specifically, movable plate 16 receives a pressing force from bag-shaped member PB and presses each of the plurality of bag-shaped containers B. After step ST16 is performed, the inspection process proceeds to step ST18.

[0074] In step ST18, the detection unit 15 measures the distance of each gap K, thereby detecting the leakage state of the bag-shaped container B. Specifically, the displacement sensor S measures the distance between adjacent movable plates 16, and the leakage state (e.g., whether there is a leak) of the bag-shaped container B sandwiched between the movable plates 16 is detected. After step ST18 is performed, the inspection process proceeds to step ST20.

[0075] In step ST20, it is determined whether or not the end condition for the inspection process is satisfied. An example of the end condition for the inspection process is that a leak test has been conducted on the bag-shaped container B to be inspected. If the end condition for the inspection process is satisfied, the determination in step ST20 is affirmative, and the inspection process ends. If the end condition for the inspection process is not satisfied, the determination in step ST20 is negative, and the inspection process returns to step ST12 again.

[0076] As described above, in the leak testing device 10 according to this embodiment, a plurality of plate-like members 12 are provided in the storage unit 11, and bag-like containers B are stored in the gaps K formed between adjacent plate-like members 12. Gas A is sealed in each of the plurality of bag-like containers B. Then, the pressing unit 13 presses each of the bag-like containers B via the plate-like members 12. When pressed by the pressing unit 13, the detection unit 15 measures the distance of each gap K in which the bag-like container B is stored, thereby detecting the leakage state of gas A from the bag-like container B. This allows multiple bag-like containers B to be tested simultaneously, and also allows each bag-like container B to be tested for leakage one by one. As a result, the efficiency of leak testing of bag-like containers B is improved.

[0077] For example, when a detection gas (e.g., hydrogen gas) is sealed inside a plurality of bag-shaped containers B and a leak test is performed by pressing the bag-shaped containers B to detect the presence or absence of the detection gas, it is possible to check for the presence or absence of a leak, but to determine which bag-shaped container B is leaking from, it is necessary to separately check for defects in each container. With this configuration, multiple bag-shaped containers B can be inspected simultaneously, and it is also possible to inspect which bag-shaped container B is leaking from. As a result, the efficiency of leak testing is improved. Furthermore, because no detection gas is used, there is no need to prepare a dedicated detector or purchase the detection gas for testing, reducing the cost of testing.

[0078] Furthermore, in the leak test device 10 according to this embodiment, the pressing unit 13 has a bag-shaped member PB stored in one of the gaps K, and the plate-shaped member 12 is moved by pressurizing the gas A flowing into the bag-shaped member PB. This simplifies the structure of the pressing unit 13 compared to when a pressing mechanism such as an actuator is provided as the pressing unit 13. That is, the bag-shaped container B can be pressed by supplying gas A to the bag-shaped member PB from the gas supply system 20 that supplies gas A to the bag-shaped container B. Therefore, there is no need to provide a separate pressing mechanism, which contributes to simplifying the configuration of the leak test device 10.

[0079] Furthermore, in the leak test device 10 according to this embodiment, the bag-shaped member PB used in the pressing unit 13 is the bag-shaped container B for pressurization. Because the bag-shaped member PB used for pressing is the bag-shaped container B, it has the same shape as the bag-shaped container B. This allows the bag-shaped container B to be pressed more easily and appropriately than when a bag-shaped member PB having a different shape from the bag-shaped container B is used.

[0080] For example, if a bag-shaped member PB having smaller length and width than the bag-shaped container B is used, it will not be possible to press the entire bag-shaped container B, and only partial pressing will occur, resulting in uneven pressing. This may result in areas from which gas A has difficulty leaking, making it impossible to perform an appropriate leak test. On the other hand, if the bag-shaped member PB is larger than the bag-shaped container B, the pressure of the gas A to be introduced into the bag-shaped container PB when pressing it must be set higher than when using the bag-shaped container B, necessitating pressure control independent of the bag-shaped container B. In this configuration, the bag-shaped member PB is the bag-shaped container B for pressurization and has the same size as the bag-shaped container B, so the bag-shaped container B can be pressed easily and appropriately.

[0081] Furthermore, in the leak test device 10 according to this embodiment, the multiple plate-like members 12 include a movable plate 16 and a right-side fixed plate 14A and a left-side fixed plate 14B. The movable plate 16 is movable when pressed by the pressing unit 13, while the right-side fixed plate 14A and the left-side fixed plate 14B do not move even when pressed by the pressing unit 13. The right-side fixed plate 14A and the left-side fixed plate 14B are provided at both ends of the storage unit 11, respectively. This allows the right-side fixed plate 14A and the left-side fixed plate 14B to bear the pressing force from the pressing unit 13. This simplifies the configuration of the leak test device 10 compared to a configuration in which the movable plate 16 is pressed from both sides of the storage unit 11 using a pressing mechanism such as an actuator.

[0082] Furthermore, in the leak testing device 10 according to this embodiment, a right-side fixed plate 14A and a left-side fixed plate 14B are provided at both ends of the storage section 11 in the movement direction of the movable plate 16, and a guide mechanism 17 is provided between the right-side fixed plate 14A and the left-side fixed plate 14B. The guide mechanism 17 guides the movement of the movable plate 16. This stabilizes the movement of the movable plate 16 between the right-side fixed plate 14A and the left-side fixed plate 14B, and the pressing force from the pressing section 13 is stably transmitted to the bag-shaped container B. For example, if the movement of the movable plate 16 is unstable, the gap K between the movable plates 16 may not accurately reflect the deformation of the bag-shaped container B, which may reduce the accuracy of leak detection. In this configuration, the guide mechanism 17 stably moves the movable plate 16, allowing for accurate detection of the leak state of the bag-shaped container B.

[0083] Furthermore, in the leak testing device 10 according to this embodiment, the movement direction of the plurality of plate-like members 12 in the storage section 11 is horizontal (the direction along the X direction shown in FIG. 1 ). This reduces the effect of changes in the distance of the gap K due to the weight of the plurality of plate-like members 12 compared to when the movement direction of the plate-like members 12 is vertical, so that the distance of the gap K can be measured with high accuracy. As a result, this can contribute to improving the accuracy of detecting the leak state.

[0084] Furthermore, in the leak testing device 10 according to this embodiment, the bag-shaped container B includes a container body M and a hose portion H that extends from the container body M and forms a flow path connecting each of the multiple container bodies M. When gas A is sealed in the bag-shaped container B, movement of gas A does not occur via the hose portion H. As a result, even if the bag-shaped container B includes the hose portion H, movement of gas A via the hose portion H is restricted, and a leak state can be detected for each bag-shaped container B.

[0085] Furthermore, in the leak test device 10 according to this embodiment, the detection unit 15 is a contact-type displacement sensor S. The displacement sensor S measures the distance between adjacent movable plates 16 by contacting the movable plates 16. This provides better measurement accuracy for the distance of the gap K compared to distance measurement means using a laser sensor or distance measurement means using image processing, for example, and further contributes to reducing the cost of the leak test device 10.

[0086] Furthermore, in the leak test device 10 according to this embodiment, the leak state of the bag-shaped container B detected by the detection unit 15 includes the presence or absence of leakage of the gas A and / or the size of the hole through which the gas A is leaking. This allows detection of the leak state from multiple angles, thereby enabling accurate leak testing of the bag-shaped container B. For example, the leak test results can be used to determine whether the size of the hole through which the gas A is leaking meets quality standards.

[0087] In the above embodiment, an example was described in which pressing unit 13 has a bag-shaped member PB, and the bag-shaped member PB expands to apply a pressing force to plate-shaped member 12. However, the technology of the present disclosure is not limited to this. For example, pressing unit 13 may be a pressing mechanism such as a linear actuator (e.g., an air cylinder). In this case, a linear actuator serving as pressing unit 13 is provided on the left side of movable plate 16A, and the linear actuator moves movable plate 16A to press bag-shaped container B. Alternatively, linear actuators may be provided at both ends of storage unit 11, and movable plates 16A and 16J may be moved in opposite directions to press bag-shaped container B. However, as described above, using a bag-shaped member PB is preferable from the perspective of simplifying the device, etc.

[0088] Furthermore, in the above embodiment, an example was described in which shaft members 17A to 17D were used as the guide mechanism 17, but the technology of the present disclosure is not limited to this. A guide rail mechanism 40 may be used as the guide mechanism 17. As an example, as shown in FIG. 4 , the guide rail mechanism 40 includes linear guides 42A to 42D, a block 44, and a fixing bracket 46. The linear guides 42A to 42D are rail-shaped members that span between the right fixed plate 14A and the left fixed plate 14B. The linear guides 42A to 42D are attached to the side surfaces of the right fixed plate 14A and the left fixed plate 14B. The linear guides 42A to 42D support the movable plate 16 from the sides.

[0089] The following describes the configuration for supporting the movable plate 16, using the linear guide 42A as an example. A block 44 is slidably mounted on the linear guide 42A. The block 44 is movable along the longitudinal direction of the linear guide 42A. A fixing bracket 46 is mounted on the block 44. One end of the fixing bracket 46 is attached to the block 44, and the other end is attached to the movable plate 16 (here, the movable plate 16A). The fixing bracket 46 clamps the peripheral edge of the movable plate 16A.

[0090] When a pressing force is applied to the movable plate 16 by the pressing unit 13 (see FIG. 1, etc.), the movable plate 16 moves in the left-right direction (the direction along the X direction shown in FIG. 4) while being guided by the linear guide 42A. This allows the movable plate 16 to move stably.

[0091] Furthermore, in the above embodiment, an example in which a contact-type displacement sensor S is used as the detection unit 15 has been described, but the technology of the present disclosure is not limited to this. For example, a laser sensor may be used as the detection unit 15, or the distance of the gap K may be obtained by performing image processing on an image (e.g., a still image or a video) showing two adjacent movable plates 16. However, as described above, a contact-type displacement sensor S is preferable from the viewpoints of cost and measurement accuracy.

[0092] In the above embodiment, an example has been described in which the bag-shaped container B is stored in the gap K as is, but the technology of the present disclosure is not limited to this. For example, the bag-shaped container B may be stored in the gap K in a folded state so that its vertical length is halved.

[0093] Furthermore, in the above embodiment, an example was described in which ten bag-shaped containers B were grouped into one set and ten of them were inspected simultaneously, but the technology of the present disclosure is not limited to this. For example, five bag-shaped containers may be grouped into one set and two sets may be inspected simultaneously. That is, a plurality of sets may be inspected simultaneously. Furthermore, bag-shaped containers B do not have to be stored in all gaps K, and dummy bag-shaped containers B may be stored instead of the bag-shaped containers B to be inspected.

[0094] In addition, in the above embodiment, an example in which the bag-shaped containers B are connected to each other via the hose portion H has been described, but the technology of the present disclosure is not limited to this. For example, the bag-shaped containers B may be independent containers that are not connected by the hose portion H.

[0095] In the above embodiment, the control device 30 may send a control signal for opening or closing a valve to the gas supply system 20, and the valve may be opened or closed based on the control signal. For example, the control device 30 outputs a control signal to the gas supply system 20 to close the valve when the change in the distance of the gap K output from the detection unit 15 exceeds a predetermined value. The gas supply system 20 closes the valve based on the control signal and stops the supply of gas A to the leak detection device 10. This reduces the impact of excessively high pressure gas A on the leak detection device 10. As described above, the gas supply system 20 does not need to be completely independent from the control device 30, and the gas supply system 20 may operate under the control of the control device 30. On the other hand, the control device 30 may acquire an output from the gas supply system 20 and display the operating status of the gas supply system 20 on the display device 32. For example, the display device 32 displays the pressure of gas A in the gas supply system 20. In this case, the display device 32 may include, for example, a liquid crystal display that displays the pressure value.

[0096] The above-described description and illustrations are a detailed explanation of the parts related to the technology of the present disclosure and are merely an example of the technology of the present disclosure. For example, the above description of the configuration, functions, actions, and effects is an explanation of an example of the configuration, functions, actions, and effects of the parts related to the technology of the present disclosure. Therefore, it goes without saying that unnecessary parts may be deleted, new elements may be added, or replacements may be made to the above-described description and illustrations within the scope of the gist of the technology of the present disclosure. Furthermore, to avoid confusion and facilitate understanding of the parts related to the technology of the present disclosure, the above-described description and illustrations omit explanations of common technical knowledge that do not require particular explanation to enable the implementation of the technology of the present disclosure.

[0097] In this specification, "A and / or B" is synonymous with "at least one of A and B." In other words, "A and / or B" means that it may be only A, only B, or a combination of A and B. Furthermore, in this specification, the same concept as "A and / or B" is also applied when three or more things are expressed by connecting them with "and / or."

[0098] The disclosure of Japanese Patent Application No. 2023-168777, filed on September 28, 2023, is incorporated herein by reference in its entirety. All documents, patent applications, and technical standards described herein are incorporated herein by reference to the same extent as if each individual document, patent application, and technical standard were specifically and individually indicated to be incorporated by reference.

[0099] The following is further disclosed regarding the above embodiment. <Supplementary Note 1> A leak testing device comprising: a storage unit having a plurality of plate-like members that are relatively movable along a plate thickness direction and that can store a plurality of bag-like containers with gas sealed inside in gaps formed between adjacent plate-like members of the plurality of plate-like members; a pressing unit that moves the plate-like members along the plate thickness direction to press each of the plurality of bag-like containers via the plate-like members; and a detection unit that, when pressed by the pressing unit, detects a state of gas leakage from the bag-like containers by measuring a distance along the plate thickness direction between each of the gaps in which the plurality of bag-like containers are stored. <Supplementary Note 2> The leak testing device according to Supplementary Note 1, wherein the pressing unit has a bag-like member stored in one of the gaps, and the pressing unit pressurizes the gas flowing into the bag-like member, thereby moving the plate-like member. <Supplementary Note 3> The leak testing device according to Supplementary Note 2, wherein the bag-shaped member includes the bag-shaped container for pressurization. <Supplementary Note 4> The leak testing device according to any one of Supplementary Notes 1 to 3, wherein the plurality of plate-shaped members include a movable plate that is movable when subjected to a pressing force from the pressing section, and a fixed plate that does not move even when subjected to the pressing force, and the fixed plate is provided at an end in the storage section in the movement direction of the movable plate. <Supplementary Note 5> The leak testing device according to Supplementary Note 4, wherein the fixed plate is provided at both end in the storage section in the movement direction of the movable plate, and the storage section further has a guide mechanism that guides movement of the movable plate between the fixed plates. <Supplementary Note 6> The leak testing device according to any one of Supplementary Notes 1 to 5, wherein the movement direction of the plate-shaped member in the storage section is along the horizontal direction. <Supplementary Note 7> The plurality of bag-shaped containers include a plurality of container bodies stored in each of the gaps, and a hose portion extending from the container bodies and forming a flow path connecting each of the plurality of container bodies, and when the gas is sealed in the bag-shaped container, there is no movement of the gas between the plurality of container bodies via the hose portion. The leak testing device described in any one of Supplementary Note 1 to Supplementary Note 6.<Supplementary Note 8> The leak testing device according to any one of Supplementary Notes 1 to 7, wherein the detection unit includes a contact-type displacement sensor. <Supplementary Note 9> The leak testing device according to any one of Supplementary Notes 1 to 8, wherein the leakage state includes the presence or absence of leakage of the gas from the bag-shaped container and / or the size of a hole through which the gas is leaking.

Claims

1. A leak inspection device comprising: a storage section having a plurality of plate-like members that are relatively movable along a plate thickness direction, and capable of storing a plurality of bag-like containers with gas sealed inside in gaps formed between adjacent plate-like members of the plurality of plate-like members; a pressing section that presses each of the plurality of bag-like containers via the plate-like members by moving the plate-like members along the plate thickness direction; and a detection section that detects a leakage state of the gas from the bag-like containers by measuring the distance along the plate thickness direction of each of the gaps in which the plurality of bag-like containers are stored when pressed by the pressing section.

2. The leak inspection device according to claim 1, wherein the pressing section has a bag-shaped member stored in one of the gaps, and the plate-shaped member is moved by pressurizing the gas flowing into the bag-shaped member in the pressing section.

3. The leak inspection device according to claim 2, wherein the bag-shaped member includes a bag-shaped container for pressurization.

4. The leak inspection device according to claim 1, wherein the plurality of plate-like members include a movable plate that is movable when subjected to a pressing force from the pressing portion, and a fixed plate that does not move even when subjected to the pressing force, and the fixed plate is provided at an end of the storage portion in the direction of movement of the movable plate.

5. The leak inspection device according to claim 4, wherein the fixed plates are provided at both ends of the storage section in the direction of movement of the movable plate, and the storage section further has a guide mechanism for guiding the movement of the movable plate between the fixed plates.

6. The leak inspection device according to claim 1, wherein the movement direction of the plate-like member in the storage section is along the horizontal direction.

7. The leak inspection device as described in claim 1, wherein the plurality of bag-like containers include a plurality of container bodies stored in each of the gaps, and a hose portion extending from the container bodies and forming a flow path connecting each of the plurality of container bodies, and when the gas is sealed in the bag-like container, there is no movement of the gas between the plurality of container bodies via the hose portion.

8. The leak inspection device according to claim 1, wherein the detection unit includes a contact type displacement sensor.

9. The leak inspection device according to claim 1, wherein the leakage state includes the presence or absence of leakage of the gas from the bag-like container and / or the size of the hole through which the gas is leaking.

10. A leak inspection method comprising: storing a plurality of bag-shaped containers having gas sealed therein in gaps formed between adjacent plate-shaped members among a plurality of plate-shaped members that are movable relatively along a plate thickness direction; pressing each of the plurality of bag-shaped containers via the plate-shaped members by moving the plate-shaped members along the plate thickness direction; and detecting a leakage state of the gas from the bag-shaped containers by measuring the distance along the plate thickness direction of each of the gaps in which the plurality of bag-shaped containers are stored.