Conducting leak tests using sealing devices

Abstract

Provides improved leak testing. [Solution] A method for performing a leak test on a specimen 12 includes the steps of placing the specimen 12 in a test chamber 14, testing the specimen 12 for leaks within the test chamber 14, and, if the leak test determines that there is no leak in the specimen 12, opening the test chamber 14 and removing the specimen 12, characterized in that, if the leak test determines that there is a leak in the specimen, the opening to the test chamber 14 is closed to prevent the specimen 12 from being removed.

Description

[Technical Field]

[0001] The present invention relates to performing a leak test on a test object. [Background Art]

[0002] For inspecting the presence or absence of leaks in a test object such as food packaging, it is known and common that a test object to be inspected is placed in a test chamber, and the test chamber is evacuated until the pressure therein becomes lower than the pressure inside the test object. Typically, the interior of the test object is at atmospheric pressure. The test chamber is evacuated by a vacuum pump.

[0003] After evacuation of the test chamber, gas leaking from the test object into the test chamber can be detected by a gas detector or a gas analyzer. If a predetermined amount of test gas is measured, it can be determined that the test object has a leak that caused the test gas to leak from inside the test object into the test chamber and reach the gas detector. Alternatively or additionally, the pressure inside the test chamber may be monitored; if the pressure inside the test chamber rises above a predetermined value or a predetermined amount, it can be determined that the test object has a leak that caused gas to leak from inside the test object into the test chamber and increase the pressure therein. [Summary of the Invention] [Problem to be Solved by the Invention]

[0004] Typically, a plurality of test objects undergo leak inspection one after another. An operator places a test object in the test chamber, closes the test chamber, starts and monitors the leak inspection, and takes out the test object after the leak inspection is completed. There is a concern that a test object detected as having a leak may be assigned to a group of test objects detected as having no leak and cannot be separated therefrom.

[0005] An object of the present invention is to enable improvement of leak inspection. [Means for Solving the Problem]

[0006] The method according to the present invention is defined by the configuration of claim 1. The leak inspection apparatus according to the present invention is defined by the configuration of claim 12.

[0007] In this invention, to prevent the removal of a sample from the testing chamber if the leak test results indicate a leak, the testing chamber is sealed according to the leak test results, and if there is no leak in the sample, the testing chamber is opened. This prevents the operator removing the sample from the testing chamber from treating a sample identified as having a leak as a sample without a leak, or from removing a sample from the testing chamber and mistakenly assigning it to a group of samples that have been tested for leaks. Since the testing chamber is sealed when a sample has a leak, the operator must first take additional action to remove the sample from the testing chamber. In other words, the procedure for a sample with a leak differs from that for a sample without a leak, reducing the risk of confusion by the operator.

[0008] The test chamber containing the subject can be evacuated to a vacuum pressure lower than the pressure inside the subject before leak testing. For this purpose, the test chamber may be connected to a vacuum pump. If there is a leak in the subject, gas will leak from inside the subject through the leak into the vacuum chamber.

[0009] Alternatively, the subject may be pressurized with at least a portion of a specific test gas until it becomes overpressurized. The subject is placed in a test chamber in the form of a storage chamber, and the concentration of the test gas in the storage chamber is measured. The increasing concentration of the test gas in the storage chamber over time serves as a measure of the subject's leakage.

[0010] Depending on the results of the leak test, the test chamber may be automatically sealed. The results of the leak test are the measurement results from a leak detector, which may be a gas detector and / or a gas analyzer and / or a gas measuring device.

[0011] Preferably, a key is required for a human operator to open or unlock the examination room. This key may be an electronic key in the form of a password or token, or a mechanical key.

[0012] The test chamber may be sealed off by a sealing device operated by a control device that receives information about the leak test from a leak detector. A leak detector is a measuring device that performs a leak test, such as a gas detector, a gas analyzer such as a mass spectrometer or an infrared absorption analyzer, or a gas measuring device.

[0013] In addition to or instead of the above configuration, the sealing of the examination chamber may be performed by applying or maintaining a vacuum inside the examination chamber. The sealing device in this exemplary embodiment can be understood as a control electronic unit that applies or maintains the vacuum, for example, by driving or maintaining the operation of a vacuum pump.

[0014] The examination chamber may be sealed by applying a mechanical force. This force may be a force that resists the force applied to open the examination chamber. This force may be a force applied by the vacuum inside the examination chamber, or a force applied by a mechanical closing element such as a lock or latch.

[0015] The measurement signal from the leak detector is sent as an electronic signal to a control unit electronically connected to the sealing device. If a leak is detected in the subject, the control unit may send a control signal to the sealing device that triggers the sealing device to seal the examination room.

[0016] In this case, subjects in which no leak was detected are described as having no leaks, and subjects in which a leak was detected are described as having a leak. For this purpose, the measurement signal of the leak testing device is typically compared to a reference value and / or a threshold. This makes it possible to automatically evaluate, based on the measurement signal, whether to classify the subject into the group of subjects with no leaks or the group of subjects with leaks. A human operator performing a leak test typically removes a subject confirmed to have no leaks from the testing chamber and assigns it to the group of subjects with no leaks by moving it to, for example, a container provided for this purpose, a conveyor belt provided for this purpose, or other spatially restricted area. The present invention is intended to reduce the risk that a human operator may mistakenly assign a subject identified as having a leak to the group of subjects with no leaks. By sealing the testing chamber, the operator's process differs from the process when the subject does not have a leak. By sealing the examination room when removing a sample, the worker has an additional opportunity to recognize that the sample has been found to have a leak and should not be assigned to a group of samples that do not have a leak.

[0017] An exemplary embodiment of the present invention will be described in detail with reference to the drawings. [Brief explanation of the drawing]

[0018] [Figure 1] This is a block diagram showing a leak inspection apparatus according to the present invention. [Modes for carrying out the invention]

[0019] The subject 12, which is to be tested for leaks, is placed inside the test chamber 14. The test chamber 14 is a typical vacuum chamber and is depicted in a closed state in the diagram. A vacuum pump 18 is connected to the test chamber 14 to evacuate it to a pressure lower than the pressure inside the subject 12. If there is a leak in the subject 12, the test gas will leak from inside the subject 12 into the outside of the subject 12 and into the inside of the test chamber 14.

[0020] A leak detector 16 is further connected to the inside of the test chamber 14 via a vacuum, allowing gas to pass through, to perform leak measurements. In the illustrated exemplary embodiment, the leak detector 16 is located on the gas line path connecting the test chamber 14 and the vacuum pump 18. Other configurations are also possible. The leak detector 16 may be a general gas detector, a gas analyzer, or a pressure measuring device that monitors the pressure inside the test chamber 14. Valves necessary for leak testing also exist, but are not shown in the drawing for simplification.

[0021] When the leak detector 16 measures the test gas leaking from the inside of the test object 12, or in the case of a pressure measuring device, when it measures a pressure increase indicating a leak in the test object 12, the leak detector 16 sends an electronic signal to a control device 22 electronically connected to the leak detector 16. The control device 22 is configured to automatically generate a control signal that drives the blocking device 20 to prevent the test chamber 14 from being opened when the measurement signal from the leak detector 16 indicates a leak in the test object 12. For this purpose, the control device 22 is electrically connected to the blocking device 20. The blocking device 20 may be a mechanical lock or a lock that locks the test chamber 14. Alternatively or additionally, the blocking device 20 may be a valve that connects the inside of the test chamber 14 to the outside air around the test chamber 14 and is opened to ventilate the test chamber 14 before the test chamber 14 is opened. To block the test chamber 14, the valve is kept closed to prevent the test chamber 14 from being ventilated. That is, the inside of the test chamber becomes a vacuum pressure so high that a human operator cannot open the test chamber 14. Therefore, the vacuum pressure generates a closing force for closing the test chamber. Alternatively or additionally, said closing force may be applied as a mechanical force by a closing device.

[0022] It is also conceivable that the control device 22 maintains or increases the vacuum pressure inside the test chamber 14 by driving the vacuum pump 18 or a further vacuum pump or maintaining the operation thereof. The blocking device 20 in this case can be understood as part of said vacuum pump or as a further vacuum pump.

[0023] This enables fully automatic, much faster and much more reliable leak detection for quality control and the manufacturing industry compared to conventional suction leak detection of heat exchangers performed manually by operators. Furthermore, the present invention includes the following embodiments. [Aspect 1] A method for performing a leak test on a subject (12), The process of placing the subject (12) inside the examination room (14), The process of checking for leaks in the subject (12) within the examination chamber (14), If the leak test determines that there is no leak in the subject (12), the process of opening the examination chamber (14) and removing the subject (12) is performed. In a method that provides, A method characterized in that, if the leak test determines that there is a leak in the subject, the opening of the examination chamber (14) is sealed to prevent the removal of the subject (12). [Aspect 2] A method according to Embodiment 1, characterized in that the test chamber (14) is automatically sealed in accordance with the result of the leak test. [Aspect 3] A method according to embodiment 1 or 2, characterized in that an electronic key or a mechanical key is required to release the seal. [Aspect 4] A method according to any one of embodiments 1 to 3, characterized in that the test chamber is sealed by a sealing device (20) operated by a control device (22) that receives information regarding the leak test from a measuring device (16) that performs the leak test. [Aspect 5] A method according to any one embodiment of embodiments 1 to 4, characterized in that the sealing of the test chamber (14) is performed by applying a vacuum inside the test chamber (14) or by maintaining a vacuum inside the test chamber (14). [Aspect 6] A method according to any one embodiment of embodiments 1 to 5, characterized in that the sealing of the examination chamber (14) is performed by applying mechanical force. [Aspect 7] A method according to embodiment 6, characterized in that the mechanical force is applied by the sealing device (20). [Aspect 8] A method according to the method of embodiment 7, characterized in that the sealing device (20) is a mechanical closing device. [Aspect 9] A method according to any one embodiment of embodiments 1 to 8, characterized in that, in order to check for leaks in the subject and to detect gas entering the test chamber from the leak in the subject, the test chamber (14) containing the subject (12) is evacuated until the pressure inside the test chamber is lower than the pressure inside the subject. [Aspect 10] A method according to any one embodiment of embodiments 1 to 8, characterized in that, in order to check for the presence or absence of a leak in the subject and to detect gas entering the test chamber from the leak in the subject according to the accumulation principle, the pressure inside the subject (12) is raised to a pressure higher than the pressure inside the test chamber. [Aspect 11] A method according to any one embodiment of embodiments 1 to 10, characterized in that the process of checking for leaks in the subject (12) is performed by a measuring device (16) in the form of a pressure measuring device, a gas detector, or a gas analyzer, and the measurement signal from the measuring device (16) is sent to the control device (22) that operates the sealing device (20). [Aspect 12] A leak test device for checking whether a subject (12) has a leak, A test room (14) for housing the subject (12), A leak detector (16) connected to the aforementioned test chamber (14), In a leak testing apparatus equipped with, A leak inspection apparatus characterized in that the sealing device (20) is configured to seal the test chamber (14) to prevent the removal of the test subject (12) when the measurement signal of the leak detector (16) corresponds to a test subject (12) with a leak, and to allow the test chamber (14) to be opened when the measurement signal corresponds to a test subject without a leak. [Aspect 13] In the leak inspection apparatus described in Embodiment 12, further, A vacuum pump (18) connected to the aforementioned examination chamber (14) for exhausting the examination chamber, A leak test apparatus characterized by comprising the following:

Claims

1. A method for performing a leak test on a subject (12), The process of placing the subject (12) inside the examination room (14), The process of checking for leaks in the subject (12) within the examination room (14), If the leak test determines that there is no leak in the subject (12), the process of opening the examination chamber (14) and removing the subject (12) is performed. In a method that provides, A method comprising: if the leak test determines that there is a leak in the subject, the opening of the examination chamber (14) is sealed to prevent the removal of the subject (12).

2. A method according to claim 1, wherein the test chamber (14) is automatically sealed in accordance with the result of the leak test.

3. A method according to claim 1 or 2, wherein an electronic key or a mechanical key is required to release the seal.

4. A method according to claim 1, wherein the test chamber is sealed by a sealing device (20) operated by a control device (22) that receives information regarding the leak test from a measuring device (16) that performs the leak test.

5. A method according to claim 1, wherein the sealing of the examination chamber (14) is performed by applying a vacuum inside the examination chamber (14) or by maintaining a vacuum inside the examination chamber (14).

6. A method according to claim 1, wherein the sealing of the examination chamber (14) is performed by applying mechanical force.

7. The method according to claim 6, wherein the mechanical force is applied by a sealing device (20) which is operated by a control device (22) that receives information regarding the leak inspection from a measuring device (16) that performs the leak inspection.

8. The method according to claim 7, wherein the sealing device (20) is a mechanical closing device.

9. A method according to claim 1, wherein the test chamber (14) containing the test subject (12) is evacuated until the internal pressure of the test chamber is lower than the internal pressure of the test subject, in order to check for leaks in the test subject and to detect gases entering the test chamber from leaks in the test subject.

10. A method according to claim 1, wherein the pressure inside the subject (12) is raised to a pressure higher than the pressure inside the examination chamber in order to check for leaks in the subject and to detect gas entering the examination chamber from the leaks in the subject according to the accumulation principle.

11. A method according to claim 1, wherein the process of checking for leaks in the subject (12) is performed by a measuring device (16) in the form of a pressure measuring device, a gas detector or a gas analyzer, and the measurement signal from the measuring device (16) is sent to a control device (22) that operates a sealing device (20).

12. A leak test device for checking for leaks in a subject (12), A test room (14) for housing the subject (12), A leak detector (16) connected to the aforementioned examination chamber (14), In a leak testing apparatus equipped with, A leak inspection device comprising a sealing device (20) configured to seal the test chamber (14) to prevent removal of a test subject (12) when the measurement signal from the leak detector (16) corresponds to a test subject (12) with a leak, and to allow the test chamber (14) to be opened when the measurement signal corresponds to a test subject without a leak.

13. In the leak inspection apparatus according to claim 12, further, A vacuum pump (18) connected to the examination chamber (14) for exhausting the examination chamber, A leak test device equipped with the following features.

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