Leak testing apparatus, method for leak testing, and program

Abstract

To perform inspection in consideration of environmental changes of a sealed body.SOLUTION: The leak testing apparatus includes: a pressure maintaining unit (2) configured to maintain an inspection unit (1) at a predetermined pressure, on which a sealed body (200) containing a predetermined gas is placed; a pressure adjustment unit (3) configured to decompress the inspection unit (1) after the inspection unit (1) has been returned to atmospheric pressure following a predetermined period of time; and a control unit (5) configured to execute a process for determining the sealed body (200) having a defect on the basis of the pressure difference between the inside and outside of the sealed body (200) generated by the decompression of the pressure adjustment unit (3).SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a leak inspection device, a leak inspection method, and a program. [Background technology]

[0002] Known tests include a container burst strength test, in which an inlet is opened in a sealed body and gas is injected through a pipe to increase the internal pressure, thereby checking the strength of the container and the seal strength, a deadweight test, in which a heavy object such as a weight is placed on the container to check that no damage or peeling occurs, and a drop impact test, in which the container is dropped from a certain height to check that no damage or peeling occurs due to the impact. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-42948 Summary of the Invention [Problem to be solved by the invention]

[0004] Changes in atmospheric pressure due to weather create a pressure difference with the internal pressure of the sealed body, placing stress on the sealed body.

[0005] Furthermore, if the sealed body is transported at a different altitude (above sea level), a pressure difference occurs between the internal and external air pressures of the sealed body, placing a load on the sealed body. It would be convenient if such a load could be predicted in advance. In one aspect, the present invention aims to perform an inspection of a sealed body taking into account environmental changes. [Means for solving the problem]

[0006] To achieve the above object, the disclosed leak test device includes an air pressure maintaining unit that maintains an inspection chamber in which a sealed body filled with a predetermined gas is placed at a predetermined air pressure, a pressure reducing unit that reduces the pressure in the inspection chamber that has been returned to atmospheric pressure after a predetermined time has passed, and a control unit that executes a process to determine whether the sealed body has a defect based on the pressure difference between the inside and outside of the sealed body generated by the pressure reduction in the pressure reducing unit. [Effects of the Invention]

[0007] In one embodiment, inspection can be performed taking into account environmental changes of the sealed body. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a diagram illustrating a leak test device according to a first embodiment. [Figure 2] FIG. 2 is a diagram illustrating a hardware configuration for realizing a control function of a control unit according to an embodiment. [Figure 3] FIG. 10 is a diagram illustrating a leak test device according to a second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, a leak test device according to an embodiment will be described in detail with reference to the drawings.

[0010] In order to facilitate understanding of the invention, the position, size, shape, range, etc. of each component shown in the following drawings may not represent the actual position, size, shape, range, etc. Therefore, the present invention is not necessarily limited to the position, size, shape, range, etc. disclosed in the drawings, etc. In the embodiments, elements expressed in the singular include the plural unless otherwise clearly indicated in the context. First Embodiment FIG. 1 is a diagram showing a leak test device according to the first embodiment.

[0011] The leak test device 10 of the first embodiment is a device that tests for the presence or absence of gas leakage from a sealed body 200 that is the test object. Examples of the sealed body 200 include a sealed package in which a product such as a snack is sealed in a package, an automobile airbag detonator, a tank, a small sealed part, and the like, which are products that themselves have a sealed structure, or products that become sealed by closing a partial opening. The leak test device 10 includes a test section 1, an air pressure maintaining section 2, a pressure increasing / depressurizing section 3, a leak test section 4, a control section 5, a pipe 6, and a pressure sensor 7.

[0012] The inspection unit 1 has a seal plate 11 and a lid-shaped container 12. A sealed object 200 to be inspected is placed on the seal plate 11. Although one sealed object 200 is placed in Fig. 1, a plurality of sealed objects 200 may be inspected.

[0013] An O-ring 12a is placed on the edge of the container 12, and by placing the container 12 over the seal plate 11, the space surrounded by the seal plate 11 and the container 12 is kept airtight. In the following explanation, the space inside the testing unit 1 that is kept airtight is referred to as the "testing space." The inspection space is connected to an air pressure maintaining section 2, a pressurizing / depressurizing section 3, and a leak inspection section 4 by pipes 6, respectively.

[0014] The piping 6 serves as a gas flow path when the testing space is maintained at a desired atmospheric pressure or when the gas in the testing space is sucked out to reduce the pressure in the testing space. The inner diameter of the piping 6 is, for example, about 6 mm to 8 mm.

[0015] A valve 61 is arranged at the outlet of the pressurizing / depressurizing unit 3 in the piping 6. A valve 62 is also arranged on the inspection unit 1 side of the valve 61. The valve 61 opens or closes the gas flow path of the piping 5 arranged between the pressurizing / depressurizing unit 3 and the inspection unit 1. The valve 62 is used to release the air pressure inside the piping 6. In other words, the valve 62 is an example of a release unit that returns the air pressure inside the inspection unit 1 to atmospheric pressure.

[0016] The control unit 5 is realized by the CPU 101, which will be described later, etc. The control unit 5 controls the entire leak test device 10, such as starting and stopping the operations of the air pressure maintaining unit 2, the pressurizing / depressurizing unit 3, and the leak test unit 4, and opening and closing the valves 61 and 62. The control unit 5 also receives the test results from the leak test unit 4 and determines that the tested sealed body 200 has a leak.

[0017] The air pressure maintaining unit 2 can maintain the air pressure in the testing space set by the pressure sensor 7 through the piping 6 at any air pressure for a certain period of time (for example, in minutes). In addition, the air pressure maintaining unit 2 can also perform an operation to return the air pressure in the testing space to the predetermined air pressure if the air pressure in the testing space changes due to deformation of the sealed body 200 or a temperature change.

[0018] The pressurizing / depressurizing unit 3 includes a vacuum pump and a compressor. When gas is to be sucked from the testing space, the control unit 5 opens the valve 61. The pressurizing / depressurizing unit 3 then operates the vacuum pump to suck gas from the testing space through the piping 6, thereby reducing the pressure in the testing space. Thereafter, the valve 61 is closed, thereby maintaining a vacuum in the testing space. In other words, the pressurizing / depressurizing unit 3 of this embodiment itself does not have the function of maintaining the air pressure in the testing space at a constant pressure, as does the air pressure maintaining unit 2.

[0019] The leak inspection unit 4 of the embodiment performs a direct pressure leak inspection. Specifically, the leak inspection unit 4 sucks in the gas inside the inspection space. When sucking, the control unit 5 opens the valve 62. The leak inspection unit 4 then sucks in the gas inside the inspection space via the piping 6. Based on the detection by the pressure sensor 7, the leak inspection unit 4 detects a pressure change in the inspection space that occurs when a small amount of gas leaks from the sealed body 200 in Pascal units (hereinafter, also simply referred to as the detection process). The detection unit of the leak inspection unit 4 of the embodiment is, for example, approximately 1 / 100,000 atmosphere units. This inspection can be performed, for example, by using the PLT-3000 series manufactured and sold by Takachiho Seiki Co., Ltd. The pressure sensor 7 detects the pressure inside the pipe 6 . FIG. 2 is a diagram illustrating a hardware configuration for realizing the control function of the control unit according to the embodiment.

[0020] The control unit 5 is controlled as a whole by a CPU (Central Processing Unit) 101. A RAM (Random Access Memory) 102 and a plurality of peripheral devices are connected to the CPU 101 via a bus 106.

[0021] The RAM 102 is used as a main storage device for the control unit 5. The RAM 102 temporarily stores at least a part of the OS (Operating System) programs and application programs executed by the CPU 101. The RAM 102 also stores various data used in processing by the CPU 101. A ROM (Read Only Memory) 103, a graphics processing unit 104, and an input interface 105 are connected to the bus 106.

[0022] The ROM 103 magnetically writes and reads data. The ROM 103 is used as a secondary storage device for the leak test device 1. The ROM 103 stores the OS program, application programs, and various data.

[0023] The touch panel 3a is connected to the graphics processing unit 104. The graphics processing unit 104 displays an image on the screen of the touch panel 3a in accordance with an instruction from the CPU 101.

[0024] The touch panel 3a and signal lines for each button and switch are connected to the input interface 105. The input interface 105 transmits signals sent from the touch panel 3a and buttons to the CPU 101. Note that the touch panel 3a is an example of a pointing device, and other pointing devices can also be used. Examples of other pointing devices include a tablet, a touchpad, and a trackball. The control functions of this embodiment can be realized by the hardware configuration described above.

[0025] Next, the operation of the leak test device 10 will be described. The operation will be described in order below, but the operation is an example and other operations can be added. Furthermore, some steps may be automated or performed manually. <Step S1>

[0026] The sealed body 200 to be inspected is placed on the seal plate 11. The container 12 with the O-ring 12a is placed over the seal plate 11 to define an inspection space. This operation may be performed by a machine or a human (tester). <Step S2>

[0027] The control unit 5 sets the air pressure maintaining unit 2 to a predetermined air pressure. For example, if the sealed body is a product, the air pressure is set to the altitude of the area where the sealed body is sold. The air pressure to be set can be determined in advance by the tester. <Step S3>

[0028] The control unit 5 inputs pressure to the pressurizing / depressurizing unit 3 to operate the pressurizing / depressurizing unit 3. At this time, the control unit 5 opens the valve 61 and closes the valve 62. Thereafter, when the control unit 5 determines, based on the detection of the air pressure in the pipe 6 by the pressure sensor 7, that the air pressure in the pipe 6 has reached the air pressure set in step S2, the control unit 5 closes the valve 61. <Step S4> After a given time has elapsed, the control unit 5 opens the valve 62. As a result, the pressure inside the pipe 6 returns to atmospheric pressure. <Step S5>

[0029] The control unit 5 performs a detection process. During the detection process, the control unit 5 opens the valve 61. Then, the control unit 5 operates the pressurizing / depressurizing unit 3. The pressurizing / depressurizing unit 3 sucks in the gas inside the test space through the piping 6. When the pressure sensor 7 detects the air pressure inside the piping 6 and determines that the piping 6 has reached an arbitrarily set pressure (test pressure), the control unit 5 closes the valve 61. At this time, the valve 62 remains closed. The control unit 5 then drives the leak detection unit 4. The leak detection unit 4 sucks in the gas inside the test space through the piping 6 and detects the pressure change inside the test space in Pascals. Specifically, as described above, if there is a leak in the sealed body, the test pressure will change, and therefore, whether or not a leak has occurred is determined based on the output of the pressure sensor 7, and a judgment of pass (no leak) or fail (leak has occurred) is made.

[0030] As described above, the leak test device 10 includes an air pressure maintaining unit 2 that maintains the test unit 1, on which the sealed body 200 containing a predetermined gas is placed, at a predetermined air pressure, a pressurizing / depressurizing unit 3 that depressurizes the test unit 1 that has been returned to atmospheric pressure after a predetermined time has passed, and a control unit 5 that executes processing to determine whether the sealed body 200 has a defect based on the pressure difference between the inside and outside of the sealed body 200 generated by the depressurization by the pressurizing / depressurizing unit 3. Therefore, it is possible to perform tests that take into account environmental changes to the sealed body, such as changes in weather and air pressure.

[0031] Note that the leak test device 10 can also perform tests assuming that sealed bodies are placed at multiple locations. For example, assume that point A, where the sealed bodies 200 are manufactured, is at an altitude of 0 m, point B, where the manufactured sealed bodies are stored in a warehouse, is at an altitude of 1,000 m, and point C, where the sealed bodies are sold, is at an altitude of 2,000 m. In this case, the control unit 5 operates the pressurizing / depressurizing unit 3 in step S5. When the pressure sensor 7 detects that the pressure inside the pipe 6 has reached the pressure assumed for point B, the control unit 5 closes the valve 61 and causes the leak test unit 4 to execute the detection process. Thereafter, the control unit 5 opens the valve 61 again and operates the pressurizing / depressurizing unit 3. When the pressure sensor 7 detects that the pressure inside the pipe 6 has reached the pressure assumed for point C, the control unit 5 closes the valve 61 and causes the leak test unit 4 to execute the detection process. <Second embodiment> Next, a leak test device according to a second embodiment will be described. The following description of the leak test device of the second embodiment will focus on the differences from the first embodiment described above, and a description of the same points will be omitted. FIG. 3 is a diagram illustrating a leak test device according to the second embodiment. A leak test device 10a according to the second embodiment shown in FIG. 3 has a test section 1a configured differently from the test section 1 according to the first embodiment.

[0032] Inspection unit 1a has vibration unit 13 that vibrates at a predetermined frequency and flexible tube 14 that transmits the vibration of vibration unit 13 to seal plate 11. Each sealed body 201 is an example of a product that is, for example, stacked and packed and transported by transportation means such as a truck or train. Each sealed body 201 may be placed in inspection unit 1a in a packed state using packaging means such as cardboard.

[0033] Next, the operation of the leak test device 10a will be described. The operation will be described in order below, but the operation is an example, and other operations can be added. Furthermore, some steps may be automated or performed manually. <Step S1a>

[0034] Each sealed body 201 to be inspected is stacked on the seal plate 11 in a similar manner to the packaged state. A container 12 with an O-ring 12a is placed over the seal plate 11 to define an inspection space. This operation may be performed by a machine or a human (tester). <Step S2a>

[0035] The same process as in step S2 is executed. That is, the control unit 5 sets the air pressure maintaining unit 2 to a predetermined air pressure. For example, if the sealed object is a product, the air pressure is set to the air pressure at the altitude of the area where the sealed object is sold. The air pressure to be set can be determined in advance by the tester. <Step S3a>

[0036] The control unit 5 vibrates the vibration unit 13 at a predetermined frequency. The vibration frequency can be determined in advance by the tester, assuming, for example, the frequency of vibrations exerted on the loading platform when a truck travels on a road at a constant speed, or the frequency of vibrations exerted on the loading platform when a train departs from a station and arrives at its destination. This allows for a simulation similar to that during transportation. The test pressure is not affected by the vibration unit 13 because the connection is via flexible tube 14. <Step S4a> The same process as in step S3 is executed. <Step S5a> The same process as in step S4 is executed. <Step S6a> The same process as in step S5 is executed. According to the leak test device 10a of the second embodiment, the same effects as those of the leak test device 10 of the first embodiment can be obtained.

[0037] Furthermore, the leak test device 10a of the second embodiment can perform a test that takes into account environmental changes caused by transportation of the sealed body 201. This makes it possible to perform a realistic simulation of transportation.

[0038] Although the processes performed by the leak test devices 10 and 10a are distributed among multiple parts, several functions may be combined into one part, or all functions may be integrated into one part. For example, in the present embodiment, the air pressure maintaining unit 2 and the pressure increasing / depressurizing unit 3 are described as separate parts, but this is not limiting, and the air pressure maintaining unit 2 and the pressure increasing / depressurizing unit 3 may be integrated.

[0039] Furthermore, the leak test method is not limited to that of the embodiment, and a gas may be sealed in the sealed body. In this case, the type of gas to be sealed is not particularly limited, but may be, for example, helium gas. The leak test device may analyze whether or not the gas sucked from the pipe 6 contains gas (e.g., helium gas) inside the sealed body. This leak test method may be a conventionally known method (e.g., the method described in JP 2015-42948 A).

[0040] Although the leak test device, leak test method, and program of the present invention have been described above based on the illustrated embodiments, the present invention is not limited to these, and the configuration of each part can be replaced with any configuration having a similar function. In addition, any other components or processes may be added to the present invention. Furthermore, in this embodiment, all processing is started and stopped by the control unit 5, but some of the processing may be started and stopped manually by a human being using a manual switch.

[0041] The types of loads that can be simulated on the sealed bodies 200, 201 by the air pressure maintaining unit 2 alone, the vibration unit 13 alone, and the combination of the air pressure maintaining unit 2 and the vibration unit 13 are not particularly limited, but include the effects of internal loads (loads applied to the sealed body from the inside) due to the altitude of the place of use or the altitude during transportation, and the effects of external impact loads (loads applied to the sealed body from the outside) such as impacts during transportation by truck or stacking loads in a warehouse, etc. In this embodiment, the test is performed by reducing the pressure in the test space, but the test may be performed by pressurizing the test space. Furthermore, the present invention may be a combination of any two or more configurations (features) of the above-described embodiments.

[0042] The above processing functions can be realized by a computer. In this case, a program is provided that describes the processing contents of the functions possessed by the control unit 5. The above processing functions are realized on the computer by executing the program on the computer. The program describing the processing contents can be recorded on a computer-readable recording medium. Examples of computer-readable recording media include magnetic storage devices, optical disks, magneto-optical recording media, and semiconductor memories. Examples of magnetic storage devices include hard disk drives, flexible disks (FDs), and magnetic tapes. Examples of optical disks include DVDs, DVD-RAMs, and CD-ROM / RWs. Examples of magneto-optical recording media include MOs (Magneto-Optical disks).

[0043] When distributing a program, for example, the program is recorded on a portable recording medium such as a DVD or CD-ROM and sold. Alternatively, the program can be stored in a storage device of a server computer and transferred from the server computer to other computers via a network.

[0044] A computer that executes a program stores, for example, a program recorded on a portable recording medium or a program transferred from a server computer in its own storage device. The computer then reads the program from its own storage device and executes processing in accordance with the program. Note that the computer can also read the program directly from a portable recording medium and execute processing in accordance with that program. The computer can also execute processing in accordance with the program received each time a program is transferred from a server computer connected via a network.

[0045] At least a part of the above processing functions can also be realized by electronic circuits such as a DSP (Digital Signal Processor), an ASIC (Application Specific Integrated Circuit), or a PLD (Programmable Logic Device). [Explanation of symbols]

[0046] 1, 1a Inspection Department 11 Seal plate 12 containers 12a O-ring 13 Vibration unit 14 Flexible tube 2. Pressure maintaining unit 3 Pressure adjustment section 4. Leak inspection section 5. Control section 6 Piping 61, 62 valves 7 Pressure Sensor 10, 10a Leak testing device 200, 201 Sealed body

Claims

1. an air pressure maintaining unit that maintains an inspection chamber in which a sealed body containing a predetermined gas is placed at a predetermined air pressure; a pressure reducing unit that reduces the pressure in the inspection chamber that has been returned to atmospheric pressure after a predetermined time has elapsed; a control unit that executes a process of determining whether the sealed body has a defect based on a pressure difference between the inside and outside of the sealed body generated by the decompression of the decompression unit; A leak inspection device comprising:

2. The leak test device according to claim 1 , further comprising a vibration unit that vibrates the test chamber, which is set at a predetermined air pressure, for a predetermined period of time.

3. 3. The leak test apparatus according to claim 2, wherein the sealed bodies are stacked and installed in the test chamber.

4. The computer maintaining an inspection chamber in which a sealed body containing a predetermined gas is placed at a predetermined atmospheric pressure; After a predetermined time has elapsed, the pressure inside the inspection chamber is returned to atmospheric pressure, Decompressing the inspection chamber to generate a pressure difference between the inside and outside of the seal to determine whether the seal has a defect. A control method comprising: executing a process.

5. On the computer, maintaining an inspection chamber in which a sealed body containing a predetermined gas is placed at a predetermined atmospheric pressure; After a predetermined time has elapsed, the pressure inside the inspection chamber is returned to atmospheric pressure, Decompressing the inspection chamber to generate a pressure difference between the inside and outside of the seal to determine whether the seal has a defect. A program characterized by executing a process.

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