JP2020106423A - Pressure resistance inspection device and pressure resistance inspection method using search gas - Google Patents

Abstract

To provide a pressure resistance inspection device and a pressure resistance inspection method using a search gas with which it is possible to successively inspect test pieces for pressure resistance quickly in a short time and detect leakage accurately and simply.SOLUTION: The pressure resistance inspection device comprises: a closing plate 11 for opening/closing an inspection space S using a search gas such as hydrogen; a sensor 12 for detecting a search gas and attached to the closing plate 11; and approach retreat means 13 for bringing the sensor 12 closer to a test piece 2 arranged in the inspection space S or retreating the closing plate 11 from the inspection space S after inspection is finished. By letting the sensor 12 exposed to the outside air by this approach retreat means 13, it is made possible to reduce the influence of the search gas leaking out at the time the test piece 2 is unclamped.SELECTED DRAWING: Figure 1

Description

The present invention relates to a pressure resistance inspection device and a pressure resistance inspection method using a search gas.

For example, since piping components such as fittings are required to have high pressure resistance, a pressure resistance inspection using a search gas is performed before shipment to check the strength/presence of leakage.
In this case, when performing a pressure test on a work (test sample) such as a piping component, a test called a pressure change method may be performed. In the pressure resistance test by the pressure change method, prepare a leak-free standard product (master), pressurize the work and master simultaneously, and use the differential pressure sensor to measure the pressure change in the work due to leakage Leakage is detected by detecting the difference as a change.

On the other hand, as a pressure resistance test other than the pressure change method, a pressure resistance test may be performed by detecting a fluid leak from the inside of the work to the outside. In this case, it is known that air may be used as a search fluid in a pressure resistance test of a valve having a small nominal diameter (for example, a nominal diameter of 50 A or less). As a pressure resistance test by detecting such gas leakage, For example, a hydrogen leak test may be used. In this case, hydrogen/nitrogen mixed gas is applied to the work, and the leak is judged by detecting a gas leak to the outside with a gas sensor.
As a device for conducting a test by detecting this type of fluid leakage to the outside, for example, a submersion type pressure leak inspection device of Patent Document 1 is disclosed. This leak inspection device is designed to inspect a work for pressure leak by filling a work to be inspected with a fluid having a predetermined pressure and observing the presence or absence of bubbles in a state where the work is submerged in a water tank. ing.

Non-Patent Document 1, for example, discloses a submerged joint leak test as a technique for performing a pressure resistance test on a piping component with a submerged leak test apparatus. In this leak inspection, a joint, which is a piping component, is sunk into a water tank as a work, air pressure is applied, and the joint is visually inspected to confirm the leak location when a leak occurs.

JP 62-55538 A

Kojima Seisakusho Co., Ltd. (HP author name unknown), "100% inspection submersible joint leak inspection", [online], October 31, 2000, Kojima Seisakusho Co., Ltd. [Search on December 11, 2018], Internet <URL:http://kojima-core.co.jp/20001031report.html>

When performing a pressure test on a workpiece (test sample) by the pressure change method described above, if the volume of this workpiece is large or the inspection pressure is high, it is necessary to reduce the time at the stage of adjusting the pressure to the same as that of the reference product before starting leak measurement. In some cases, leakage may not be detected because the required pressure may become difficult to stabilize.

On the other hand, when detecting leakage of gas from a work submerged in water to the outside as in Patent Document 1 and Non-Patent Document 1, the operator visually observes whether bubbles are generated from the work. Therefore, it takes a lot of time for the confirmation work, and it is difficult to make the inspection time constant for each work, and the work time tends to be uneven. Since the visual inspection imposes a heavy burden on the operator, continuous inspection work leads to a further increase in time due to accumulated fatigue.
Further, it takes time to move up and down when the work is submerged in the water tank, and further time is required when the water drops of the work wet with water are wiped off or dried after the inspection. Since water is used for confirming gas leaks, there is a problem that equipment for wastewater treatment is required and post-treatment is time-consuming, and reduction of environmental load is also required.
For these reasons, it has been earnestly desired to develop a high-accuracy and simple withstand voltage inspection device that can shorten the withstand voltage inspection time and facilitate the detection work.

The present invention was developed in order to solve the conventional problems, and its purpose is to be able to quickly and continuously perform a withstand pressure test on a sample under a short time, and to detect a leak easily and accurately. To provide a withstand voltage inspection device and a withstand voltage inspection method using a special search gas.

In order to achieve the above object, the invention according to claim 1 is a pressure-proof inspection device using a search gas such as hydrogen, which comprises an opening/closing plate for opening and closing an inspection space and a search gas attached to the opening/closing plate to detect the search gas. And a proximity retreating means for retracting the opening/closing plate from the inspection space after the inspection is completed, or with the DUT placed in the inspection space, and the sensor is exposed to the outside air. As a result, the withstand voltage inspection device uses the search gas in which the influence of the search gas leaked when the sample is unclamped is reduced.

In the invention according to claim 2, the proximity retraction means is a rotation mechanism using a servomotor or the like, and is a pressure resistance inspection device using a search gas for retracting the opening/closing plate from the inspection space by the rotation mechanism.

According to a third aspect of the present invention, the proximity retraction means is a slide mechanism using a cylinder or the like, and is a pressure resistance inspection device using a search gas for retracting the opening/closing plate from the inspection space by the slide mechanism.

The invention according to claim 4 is a pressure resistance inspection method using a search gas such as hydrogen, wherein the opening/closing plate is used to open/close the inspection space, the sample is placed in the inspection space, and the sensor is attached to the opening/closing plate. By detecting the search gas in the state of being brought close to the sample by the proximity retreating means, and after the inspection by the search gas is completed, the proximity retreating means retracts the opening and closing plate from the inspection space and exposes the sensor to the outside air. This is a withstand voltage inspection method using a search gas that reduces the influence of the search gas leaked when the sample is unclamped.

In the invention according to claim 5, the sensor is kept in the measuring state even after the inspection is completed, and when hydrogen remains more than a predetermined amount, the gas diffusion means such as a fan is used to perform forced intake or forced exhaust near the sensor. As a result, it is a pressure resistance inspection method using a search gas that reduces the influence of the search gas leaked during the unclamping of the DUT and allows the next DUT to be inspected early.

According to the invention of claim 1, after the pressure resistance inspection is completed, the opening and closing plate is retracted from the inspection space by the proximity retraction means, and the sensor is exposed to the outside air to reduce the influence of the search gas leaked when the sample is unclamped. By doing so, the search gas around the sensor can be removed after the inspection is completed, and the influence of the search gas remaining in the inspection space can be suppressed early to shorten the processing time after the withstand voltage inspection. Therefore, it is possible to shorten the time required for the withstand voltage inspection of each sample, set the next sample to be ready for the withstand voltage test, and inspect the sample continuously and promptly. Moreover, with the DUT placed in the inspection space, the sensor is brought into proximity to the DUT by the proximity retracting means, so that the opening/closing plate can be easily used as the DUT by using this one proximity retracting means. The sensor can be brought close to or retracted, and a sensor attached to this opening/closing plate can be arranged at a predetermined position of the sample to accurately detect a leak.
There is little influence by the size of the sample and the high and low of the inspection pressure, the function described above is stably exhibited, and in addition to piping parts such as fittings, the sample can be quickly tested for pressure resistance in all aspects. Can be implemented.
Since the search gas is used as the inspection fluid, post-treatment is easy and the load on the environment is small.

According to the invention of claim 2, the proximity retracting means is a rotating mechanism using a servomotor or the like, and the opening/closing plate is retracted from the inspection space by this rotating mechanism. Therefore, the sensor can be swiftly moved when the opening/closing plate is retracted. The sensor is less affected by the search gas in the inspection space by contacting with the atmosphere to reduce the influence of the search gas early and rotating the opening/closing plate in the direction away from the inspection space to open the sensor.

According to the invention of claim 3, the proximity retracting means is a slide mechanism using a cylinder or the like, and the slide plate is used to retract the opening/closing plate from the inspection space. It is possible to reduce the influence of the search gas at an early stage by contacting with. The open/close plate slides away from the inspection space and becomes open, so that the sensor is less affected by the search gas in the inspection space. By increasing the distance, the influence of the search gas on the sensor can be further suppressed.

According to the invention of claim 4, after the inspection, the influence of the search gas remaining in the vicinity of the sensor can be reduced at an early stage, and the processing time after the breakdown voltage inspection can be shortened. Therefore, it is possible to shorten the time required for the withstand voltage inspection of each sample, and to quickly make the next sample ready for the withstand voltage inspection so that the sample can be continuously inspected in a short time. Moreover, the opening/closing plate can be easily brought close to or retracted from the DUT by one approaching and retracting means, and the sensor attached to the opening/closing plate can be arranged at a predetermined position of the DUT to accurately detect the leak.
There is little influence by the size of the sample and the high and low of the inspection pressure, the function described above is stably exhibited, and in addition to piping parts such as fittings, the sample can be quickly tested for pressure resistance in all aspects. Can be implemented.

According to the invention of claim 5, the search gas staying after the pressure resistance test can be quickly removed by forcibly inhaling or forcibly exhausting the vicinity of the sensor by the gas diffusion means such as a fan, and the influence of the search gas leaked at the time of unclamping. By performing the inspection of the next sample at an early stage by reducing the above, the withstand voltage test of the sample can be continuously performed in a short time.

It is a schematic diagram of one Embodiment of the pressure|voltage resistant inspection apparatus of this invention. It is a longitudinal cross-sectional view showing a sample. (A) is a longitudinal cross-sectional view of the cloth. (B) is a vertical cross-sectional view of the tee. (C) is a longitudinal sectional view of an elbow. It is a flowchart of a withstand voltage inspection method. It is a partially-omitted schematic diagram which shows the inspection process by the withstand voltage inspection apparatus of FIG. It is a partially-omitted schematic front view which shows the inspection process by the withstand voltage inspection apparatus of FIG. It is a graph showing the voltage transition of the sensor. It is the schematic diagram which showed other embodiment of the pressure|voltage resistant inspection apparatus of this invention.

Hereinafter, a breakdown voltage inspection apparatus using a search gas according to the present invention will be described in detail based on embodiments.
FIG. 1 shows an embodiment of a withstand voltage inspection apparatus of the present invention (hereinafter referred to as apparatus body 1), and FIG. 2 shows a sample (work) 2 to be inspected by this withstand voltage inspection apparatus. ing. FIG. 3 shows a flowchart of a withstand voltage inspection method using a search gas.

The sample 2 to be pressure-tested by the device body 1 is composed of, for example, pipe parts such as a pipe joint and a valve, and in this example, an integrally-molded screw-in type having a female screw on the flow path opening side as a pipe end connection part. Pipe fittings are used. The pipe joint (test sample) 2 includes the cloth shown in FIG. 2(a), the tee shown in FIG. 2(b), the elbow shown in FIG. 2(c), and the like. However, pipe fittings in which the central axes of all the branch flow paths 3 are arranged on substantially the same plane are suitable, which intersect at 90° intervals. Female screws 5 are formed on the inner peripheral sides of the open end faces 4 of the cloth, tee, and elbow, respectively. The pipe joint to be inspected has a nominal diameter of, for example, 1/8 inch to 4 inches, and although not shown, it is also possible to perform pressure resistance inspection of a straight pipe joint sample.

The apparatus main body 1 of FIG. 1 is a pressure resistance inspection apparatus using a search gas such as hydrogen, and includes a mounting jig 10, an opening/closing plate 11, a sensor 12, and a proximity retreat means 13.
The mounting jig 10 is provided in the apparatus main body 1 for clamping the DUT 2 so as to be capable of pressure resistance inspection, and has a frame body 20, a fixed side jig 21, a movable side jig 22, and a cylinder mechanism 23. ..

The frame body 20 has a rectangular parallelepiped shape, and the inside of the frame body 20 is hollowed out to provide a concave housing portion 20a. A fixed-side jig 21, a movable-side jig 22, and a cylinder mechanism 23 are housed in the housing portion 20a, and an inspection space S for the pressure resistance inspection of the sample 2 is provided.

The inspection space S has a volume capable of accommodating the DUT 1, and has a size capable of diffusing the search gas that is supplied to the DUT 1 and leaks, and is provided with a small volume in which this gas can be easily detected. To be The inspection space S is provided so as to be isolated from the outside by the opening/closing plate 11. In this case, if the leaked gas can be detected, it can be provided in a closed state or a semi-closed state.

The opening/closing plate 11 is provided by a transparent, semi-transparent or opaque acrylic plate, and one end side thereof is attached to a movable side jig 22 as a rotating shaft (not shown). It is rotatable. By rotating the opening/closing plate 11, the region of the inspection space S can be opened/closed. When the opening/closing plate 11 shown in FIGS. 4(a) and 4(e) is fully opened, the opening/closing plate 11 becomes substantially horizontal. On the other hand, when the opening/closing plate 11 shown in FIG. 4D is fully closed, the inspection space S can be closed to be isolated from the outside.

The sensor 12 is arranged in the vicinity of four clamp parts described later, and the four sensors 12 can detect the leak of the search gas corresponding to the four branch flow paths 3 when the sample 2 is a cross. In addition, even when the DUT 2 is a tee or an elbow, it is placed at an appropriate position. In FIG. 1, a through hole 24 is provided at a sensor mounting position on the opening/closing plate 11, and a gas detection unit 25 provided on the sensor 12 when the opening/closing plate 11 is fully closed is provided in the inspection space S with respect to the through hole 24. When facing, the sensor 11 is mounted so as to be flush with the surface of the opening/closing plate 11 on the inspection space S side. This makes it easier for the gas detection unit 25 to detect the leaked gas in the vicinity of the inspection space S, and when the opening/closing plate 11 opens, the gas detection unit 25 causes the inspection space to increase as the opening degree increases. It is designed to move away from S.

As the search gas detected by the sensor 12, for example, a mixed gas of nitrogen gas which is an inert gas and hydrogen gas having diffusivity is used, and the ratio of the nitrogen gas and the hydrogen gas is 95:5 and 5% hydrogen is used. Mixed gas is used.
Therefore, the sensor 12 is composed of a hydrogen gas sensor capable of detecting hydrogen gas, and the hydrogen gas sensor 12 detects hydrogen in a mixed gas of hydrogen and nitrogen, which is a diffusible gas leaked from the sample 2. It will be possible. The sensor 12 is attached to a position where hydrogen can be detected in the inspection space S by an arbitrary number of attachments.

The sensor 12 is composed of a module that outputs a voltage according to the concentration of leaked hydrogen when a predetermined voltage is applied. Before the breakdown voltage test, the output voltage may be changed by the resistance adjusting volume, and the sensitivity may be finely adjusted according to the warm-up state of the sensor 12 and the change of the hydrogen concentration in the atmosphere.

As the sensor 12, a commercially available semiconductor sensor that can output an analog signal (0-5V) is used, and for example, a hot wire semiconductor hydrogen sensor is used. The hydrogen sensor 12 is a sensor that utilizes a change in electrical conductivity due to adsorption of hydrogen gas on the surface of a metal oxide semiconductor such as stannic oxide (SnO ₂ ). In this case, the output voltage becomes logarithmic with respect to the gas concentration, and high-sensitivity output is possible even at low concentration.

The proximity retracting means 13 is a rotating mechanism using a servomotor 30, and is attached to the rotating shaft of the opening/closing plate 11 so that the opening/closing plate 11 can be opened/closed about the rotating shaft. From this fact, if the opening/closing plate 11 is operated in the closing direction by the proximity retreat means 13, the gas detection unit 25 of the sensor 12 attached to the opening/closing plate 11 is brought close to the sample 2 arranged in the inspection space S, or By operating the opening/closing plate 11 in the opening direction after the inspection, the opening/closing plate 11 can be retracted from the inspection space S.
At this time, the opening/closing plate 11 is retracted from the inspection space S by the rotating mechanism 13, and the gas detection unit 25 is brought into contact with the outside air while the sensor 12 is separated from the inspection space S, so that the sample 2 leaks during unclamping. The influence of the emitted search gas is reduced.

The fixed-side jig 21 is mounted in a fixed state in the frame body 20, and after the sample 2 is placed on the fixed-side jig 21 in a predetermined state, it is provided by the movable-side jig 22. The withstand voltage test can be performed with the prototype 22 clamped. The fixed-side jig 21 is provided with two cylindrical fixed clamp portions 31 and 31, and these fixed clamp portions 31 have a clamp surface 32 having a sealing property on the clamp side.

Each clamp surface 32 is provided in such a shape and at an interval that the open end surfaces 4, 4 of a pair of adjacent branch flow paths 3, 3 of the sample 2 can be clamped in a sealed state. It is provided at intervals of 90° according to the angle of the branch flow path 3. Although not shown, these fixed clamp portions 31 are provided with protrusions for supporting the sample 2 in a stable state.

Inside each fixed clamp part 31, a fluid flow path (not shown) for flowing a fluid such as a search gas is formed in communication with the connection side with the sample 2, and is connected to each of these fluid flow paths. Connection parts 33, 33 for external flow path connection are provided outside each fixed clamp part 31. In this example, the connection part 33 on the right side of FIG. 1 is the pressurizing side by the search gas, and the connection part 33 on the left side is the exhaust side, and the pressurizing side connecting part 33 and the exhaust side connecting part 33 respectively have external flow paths (not shown). By being connected, search gas and compressed air can be passed from the right side to the left side of the DUT 2.

On the other hand, the movable jig 22 is attached to a piston 34 provided in the cylinder mechanism 23, and is provided by the piston 34 so as to be capable of reciprocating in the vertical direction in FIG. The movable-side jig 22 is provided with two columnar movable clamp portions 35, 35, and these movable clamp portions 35 have sealing plug-like clamp surfaces 36, 36 having a sealing property on the clamp side. Both or one of these clamping surfaces 36 is brought into contact with the sample 2, and the cylinder mechanism 23 presses the sample 2 in the direction of the fixed-side jig 21 for clamping.

As described above, the movable clamp portion 35 can be provided in various structures as long as it can press the sample 2 in the direction of the fixed-side jig 21, but it is symmetrical to the fixed clamp portion 31 as in this example. By providing the sample 2 in a shape, the non-inspection side of the sample 2 is pressed while being positioned by the movable clamp parts 35 at 90° intervals, so that the sample 2 can be fixed to the fixed clamp part 31. Become. As a result, in addition to the case where the DUT 2 is the cloth shown in FIGS. 1 and 2A, the fixed jig 21 is used even when the tee shown in FIG. 2B and the elbow shown in FIG. And the movable side jig 22 are firmly held, and the two open end surfaces 4 of the sample 2 and the clamp surface 32 of the fixed clamp portion 31 can be fixed while ensuring the sealing performance. In this case, it is possible to replace the movable clamp portion 35 with a different shape depending on the shape and size of the tee or elbow, and this makes it possible to handle tees and elbows of various shapes and sizes.

A search gas supply source and an exhaust flow path (not shown) are connected to the connection part 33, respectively, and the search gas is supplied from one connection part 33 side in the clamped state of the sample 2 to apply a predetermined pressure to the inside of the cloth 2. A pressure resistance test is performed by pressurizing and leaking gas into the inspection space S with the sensor 12, and then exhausting from the other connecting portion 33 side.

Although not shown, for example, if the fixed clamp portion 31 and the movable clamp portion 35 are formed into a square shape and the volume thereof is larger than the inspection space S, the inspection space S increases as the volume of the clamp portions 31 and 35 increases. Volume becomes relatively small. By narrowing the inspection space S in this way, the inspection time can be shortened.

The apparatus main body 1 may have a clamp structure different from the one described above, or an attachment structure other than the clamp structure may be used to fix and hold the sample 2 in the inspection space S. As long as it can be withdrawn from the inspection space S, it can be provided in any form depending on the shape and structure of the sample 2.

The search gas can be used in various forms as long as it is a mixture of a diffusible gas and an inert gas. For example, helium gas or methane gas can be used as the diffusible gas, or an inert gas can be used. Alternatively, argon gas may be used.

The sample 2 is not limited to a screw-in type pipe joint, but may be a pipe joint formed by integral molding of other structures. Further, the pipe joint is not limited to an integrally molded product, and may be a pipe joint in which a plurality of parts are combined. For example, a cap nut-shaped pipe end connecting portion is provided via a sealing member such as an O-ring, screw connection or caulking. The pipe end connecting portion may be integrated with the joint main body. Further, not only the pipe joint but also a piping device such as a valve may be the DUT 2. When the valve is the DUT 2, various valves such as a ball valve and a gate valve can be pressure tested.

The DUT 2 may be a straight pipe joint, and in this case, a mounting jig having a straight gas flow path at the clamp portion may be used. Even if the flow passages 3 are provided at an angle other than 90°, by using a mounting jig provided with a clamp portion corresponding to the angle, a joint of any shape or a pipe of various structures can be obtained. Can handle parts.

The opening/closing plate may be made of various materials other than the acrylic plate, and may be set to open at an angle larger than the horizontal direction when fully opened.

Next, a pressure resistance inspection method using the search gas by the apparatus body and the operation will be described. FIG. 3 shows a flow chart of the withstand voltage inspection method, and FIGS. 4 and 5 show schematic diagrams of the inspection process by the apparatus main body of FIG. In this example, a cloth having a nominal diameter of 3/8 inch was used as the sample.

First, in the state of FIG. 4A and FIG. 5A, the rotating mechanism 13 is operated to rotate the opening/closing plate 11 to the open state (fully open state), and the inspection space S is opened. At this time, the movable jig 22 is moved upward by the cylinder mechanism 23.

In this state, as shown in FIG. 4B and FIG. 5B, the cloth (test sample) 2 is placed on the fixed clamp portion 31 of the fixed-side jig 21 so that the predetermined position of the inspection space S is reached. To place. At this time, the opening end surfaces 4 and 4 of the arbitrary two branch flow paths 3 and 3 of the cross 2 are placed so as to abut against the two clamp surfaces 32 and 32 of the fixed clamp portion 31, respectively, and the protrusions are supported by the protrusions. Make Cross 2 stable.

4(c) and 5(c), the cylinder mechanism 23 is operated to lower the movable side jig 22, and the two clamp surfaces 36 of the movable clamp portion 35 are connected to the two branch flow paths above the cross 2. The opening end faces 4 and 4 of 3 and 3 are contacted and clamped. As a result, the two opening end surfaces 4 and 4 on the upper part of the cloth 2 are closed in a sealed state by the clamp surfaces 36 and 36, and the two opening end surfaces 4 and 4 on the lower part of the cloth 2 are connected to the gas flow path in a communicating state. It is possible to supply the search gas into the cross 2 from the pressure side connection portion 33 and exhaust the search gas from the exhaust side connection portion 33.

FIGS. 4D and 5D show a state in which the inspection mechanism S is isolated from the outside by operating the rotating mechanism 13 to rotate the opening/closing plate 11 to the fully closed state. At this time, the inspection space S is in a semi-sealed state, and the gas detection portion 25 of the sensor 12 attached to the opening/closing plate 11 is in a state of being close to the cross 2.

A search gas having a pressure of 1.4 MPa is supplied from the pressurizing side connection portion 33 into the cloth 2, and a pressure resistance test of the cloth 2 is performed. In this case, when the cloth 2 has a porosity due to cracks or cavities, gas leakage occurs outside, and the leaked search gas diffuses into the inspection space S. By detecting this search gas with the sensor 12, the quality of the cloth 2 as a product is determined.

After the completion of the pressure resistance inspection with the search gas, compressed air is supplied from the pressurizing side connecting portion 33, and the compressed air is used to air purge the internal flow path from the pressurizing side connecting portion 33 toward the exhaust side connecting portion 33. The residual hydrogen inside is discharged to the outside.

Subsequently, in FIG. 5E, the rotating mechanism 13 is operated to rotate the opening/closing plate 11 to the fully opened state, the opening/closing plate 11 is retracted from the inspection space S, and the gas detection unit 25 of the sensor 12 is positively activated. Try to expose it to the open air. As a result, as shown in the figure, when the cross 2 is unclamped, there is no risk that the search gas leaked from the inspection space S will come into contact with the gas detection unit 25, and the influence of this search gas on the sensor 12 can be reduced. Then, the inspection of the next cloth (test sample) 2 can be carried out at an early stage.

In this case, if the opening/closing plate 11 when fully opened is opened at an angle larger than the horizontal direction, the sensor 12 is further separated from the search gas (inspection space S), and the gas detection unit 25 faces the inspection space S. Therefore, the influence of the residual search gas released from the inspection space S to the outside can be further suppressed. Further, if the gas is lighter than air, such as hydrogen gas, it becomes easy to diffuse above the inspection device.
Then, the cloth (sample) 2 is unclamped with the opening/closing plate 11 fully opened, and the cloth 2 is taken out from the inspection space S.

As described above, after the inspection with the search gas is completed, the opening/closing plate 11 is retracted from the inspection space S by the rotating mechanism 13 which is the proximity retraction means, so that the sensor 12 is exposed to the outside air and leaks when the cross 2 is unclamped. Since the influence of the search gas is reduced, the search gas can be quickly removed from the vicinity of the gas detection unit 25 of the sensor 12, and the time until the next withstand voltage test can be shortened.

The opening/closing plate 11 is provided with a through hole 24, and when the sensor 12 is mounted in the through hole 24, the gas detection unit 25 faces the inspection space S and is flush with the surface of the opening/closing plate 11 on the inspection space S side. Since the gas is leaked into the inspection space S during the pressure resistance test, the gas detection unit 25 contacts the outside air when the opening/closing plate 11 is rotated in the opening direction. A large contact area can be secured. Therefore, it is possible to effectively remove the residual gas in the vicinity of the gas detection unit 25 and quickly return the sensor 12 to a gas detectable state.

Since the cloth 2 is arranged in the inspection space S and the search gas leaking from the cloth 2 is electrically detected by the sensor 12, the leaking search gas can be accurately detected in a short time regardless of the volume of the cloth 2. Can be detected. As a result, automation can be achieved, an error in the detection result for each worker is prevented, and the inspection time becomes substantially constant. Since there is no need for the operator to check for leaks, the burden on the operator is small, and there is no need to perform post-processing such as drying on each cloth 2 after the pressure resistance test.

4(e) and 4(f) show a state in which the exhaust fan 40 is arranged as a gas diffusion means in the apparatus main body 1 in a direction intersecting with the opening/closing direction of the opening/closing plate 11. With the fan 40 thus provided and the sensor 12 is maintained in the measurement state even after the inspection is completed, when the residual gas (hydrogen) remains above a predetermined level, the fan 40 is used to forcibly inhale the vicinity of the sensor 12. Alternatively, forced exhaust may be performed. As a result, the influence of the search gas leaked during the unclamping of the cloth 2 can be reduced more quickly, and the next cloth (test sample) 2 can be inspected earlier. As the gas diffusion means 40, something other than a fan may be used.

As described above, the sensor 12 not only detects the gas leaking from the cloth (test sample) 2 into the inspection space S, but also detects the search gas remaining in the atmosphere around the apparatus body 1, It may be operated at a time other than during the withstand voltage inspection. As a result, as described above, the measurement by the sensor 12 is continued even after the inspection is finished, and while the ambient atmosphere is measured by the sensor 12, the gas diffusion means 40 performs the forced intake or the forced exhaust to perform the search gas reduction control. Thus, the search gas can be removed in a short time while grasping the residual degree.

Here, in FIG. 6, an example of voltage transition when the search gas (mixed gas of 5% hydrogen and 95% nitrogen in this embodiment) is measured by the sensor 12 when the gas diffusion means 40 is provided. It is shown schematically. In the graph, the horizontal axis represents the passage of time and the vertical axis represents the change in the voltage of the sensor 12 with the passage of time.

The sensor 12 was adjusted by a digital potentiometer (not shown), and the reference voltage when the search gas was not detected was 2.0V. Assuming that the sample 2 without leakage is inspected, the change in voltage from before clamping to after measuring the pressure of the sample 2 is shown as a change in the graph. In this graph, when the voltage rises to 2.1 V after the sample 2 is unclamped, it is determined that there is a large amount of residual search gas, the fan 40 is activated, and air purge is performed. If the voltage does not drop below 2.05 V, it is determined that there is residual gas, and the next withstand voltage test of the sample 2 is not performed.

(1) to (9) in the graph show the main points at the time of withstand voltage inspection.
(1) shows the initial voltage of the sensor 12, which is the voltage immediately after the power of the apparatus body 1 is turned on. In (2), the sample 2 is clamped by the mounting jig 10, the opening/closing plate 11 is fully closed to make the inspection space S semi-closed, and the sensor 12 is zero-adjusted toward the start of the pressure inspection. The reference voltage is set to 2.0V. (3) shows the change in voltage when the DUT 2 is pressurized with the search gas, and the inspection time is set to 30 seconds to check for gas leakage from the change in voltage. In this example, since the sample 2 has no leakage, the voltage at this time is almost unchanged and is maintained at about 2.0V.

In (4), the voltage is shown when the opening/closing plate 11 is fully opened after the pressure resistance test, and then the sample 2 is unclamped and removed. After this unclamping, the residual gas in the sample 2 diffuses around the apparatus main body 1 and the voltage of the sensor 12 rises.

In the vicinity of (5), when the measured voltage rises above a preset value (for example, 2.1V) set as a criterion for determining the presence or absence of residual gas, a fan 40 or an air purge is used to remove residual gas. Let it start. As a result, the residual gas is diffused from the apparatus main body 1 and the voltage starts to decrease. By forcibly removing the residual gas after the unclamping of the sample 2 in this manner, it becomes possible to prepare for the withstand voltage inspection of the next sample 2.

In (6), when the voltage drops near the voltage of the set value (for example, 2.1 V), the fan 40 and the air purge are stopped. At this time, the residual gas is almost diffused from the apparatus main body 1.

In (7), the following DUT 2 is clamped by the mounting jig 10 and the opening/closing plate 11 is fully closed to make the inspection space S semi-closed. At this time, the voltage slightly increases due to a slight amount of gas that has not completely escaped from the apparatus main body 1.

At that time, as shown in the state (8), when the sensor 12 rises to a reference voltage or higher (for example, 2.05 V or higher), it is determined that the gas that interferes with the withstand voltage test remains, and the residual gas remains. The fan 40 and the air purge are activated to remove the gas. In this way, by forcibly removing the residual gas after the second and subsequent clamping of the sample 2, it is possible to continuously perform the withstand voltage inspection.

In (9), the fan 40 and the air purge are stopped when the voltage falls below a set value (for example, 2.05 V or less), and the next sample 2 is subjected to a withstand voltage test.

As described above, by performing the forced exhaust of the residual gas twice by starting the fan 40 and the air purge during the pressure resistance inspection, the time required for the pressure resistance inspection of the sample 2 can be significantly reduced. In the case of FIG. The time from the power-on of the main body 1 to the start of the inspection of the first DUT 2 can be carried out in about 75 seconds, which enables a quick withstand voltage inspection.

FIG. 7 shows a partially cutaway side view of another embodiment of the withstand voltage inspection apparatus of the present invention. In this embodiment, the same parts as those in the above embodiment are designated by the same reference numerals, and the description thereof will be omitted.

In this device main body 50, the proximity retracting means 51 is composed of a slide mechanism using a cylinder 52, and an opening/closing plate 53 made of an acrylic plate is changed from the closed state shown in FIG. 7A to a frame as shown in FIG. 7B. By sliding in parallel with the length direction of the body 54 and opening the body 54, the region of the inspection space S inside the frame 54 can be opened and closed.

Also in this case, similarly to the rotating mechanism 13 described above, when the opening/closing plate 53 is in the open state shown in FIG. 7B, the gas detection unit 25 of the sensor 12 is in contact with the outside air, so that the gas is not in contact with the outside air. It is possible to effectively remove the residual search gas in the vicinity of the gas detection unit 25 while ensuring a large contact area.

In this device body 50, when the sample is clamped, the opening/closing plate 11 slides in the same direction as the cylinder 52, so that space saving can be achieved. The opening/closing plate 11 slides in the length direction of the frame body 54, but may be configured to slide in a direction orthogonal to the length direction of the frame body 54. The slide mechanism 51 may be a drive mechanism other than the cylinder 52.

Although the embodiments of the present invention have been described above in detail, the present invention is not limited to the description of the embodiments, and does not depart from the spirit of the invention described in the claims of the present invention. Therefore, various changes can be made.

1 Device body 2 Cross (sample)
11 Open/close plate 12 Sensor 13 Rotation mechanism (proximity withdrawal means)
30 servo motor 40 fan (gas diffusion means)
51 Slide mechanism (proximity withdrawal means)
52 cylinder S inspection space

Claims (5)

A pressure resistance inspection device using a search gas such as hydrogen, comprising an opening/closing plate for opening/closing the inspection space, a sensor attached to the opening/closing plate to detect the search gas, and a test device in which the sensor is arranged in the inspection space. A proximity retracting means for retracting the opening and closing plate from the inspection space after the inspection is completed or when the inspection is completed. A withstand voltage inspection device using a search gas, which is characterized in that the influence of the search gas leaked at that time is reduced. The pressure withstanding inspection apparatus using a search gas according to claim 1, wherein the proximity retraction means is a rotating mechanism using a servo motor or the like, and the rotating mechanism is used to retract the opening/closing plate from the inspection space. 2. The pressure resistance inspection device using a search gas according to claim 1, wherein the proximity retraction means is a slide mechanism using a cylinder or the like, and the slide mechanism retracts the opening/closing plate from the inspection space. A pressure resistance test method using a search gas such as hydrogen, in which an opening/closing plate is used to open/close the inspection space, a sample is placed in the inspection space, and a sensor attached to the opening/closing plate is used to perform the above-mentioned operation by the proximity retracting means. After the search gas is detected in the state of being brought close to the sample, and after the inspection by the search gas is completed, the proximity retracting means retracts the opening/closing plate from the inspection space and exposes the sensor to the outside air, thereby A withstand voltage inspection method using a search gas, characterized in that the influence of the search gas leaked during unclamping of the sample is reduced. Even after the inspection is completed, the sensor is kept in the measurement state, and if hydrogen remains above a certain level, the sample is tested by performing forced intake or exhaust near the sensor using a gas diffusion means such as a fan. The withstand voltage inspection method using a search gas according to claim 4, wherein the influence of the search gas leaked during unclamping of the product is reduced so that the next test product is inspected early.

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