JP2002267564A - Leakage inspection device for work - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a leakage inspection device for a work having good work efficiency. SOLUTION: This leakage inspection device is provided with a container 10 in which a hollow work M is stored to be put in and out and sealed, a tracer gas supplier 21 capable of supplying tracer gas into the work M, a pump 31 capable of discharging gas in the container 10, a sniffer probe 41 disposed close to an exhaust part 31b of the pump 31 to suck some of gas passing the exhaust part 31b, and a sniffer leak detector 43 for detecting the tracer gas quantity in gas sucked by the sniffer probe 41.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the use of a tracer gas (a gas for leak inspection such as helium) to detect the presence or absence of a leak in an entire hollow work (used for storing a gas or liquid therein). The present invention relates to a work leak inspection device for inspecting a workpiece.

[0002]

2. Description of the Related Art Conventionally, a container (bell jar) 1 as one of the work leak inspection devices, as shown in FIG.
02 and a vacuum pump 10 for evacuating the inside of the work 101
3, a tracer gas filling device 104 capable of supplying a tracer gas into the work 101, a vacuum pump 105 for evacuating the vessel 102, and a leak detector 106 for detecting the amount of the tracer gas in the vessel 102 It has been known.

[0003] In the above-described device for inspecting leakage of a work, the work 101 is arranged at a predetermined position in a container 102,
After the inside of the work 101 is evacuated to a predetermined pressure by the vacuum pump 103 and the inside of the container 102 is evacuated to the predetermined pressure by the vacuum pump 105, a tracer gas is supplied into the work 101 by the tracer gas supply device 104, and The leak detector 106 detects the amount of tracer gas leaking from the container 101 into the container 102, and inspects the entire work 101 for the presence or absence of leakage (generally referred to as a bell jar method).

[0004] As one of the work leak inspection devices, as shown in FIG. 2, a tracer gas supply 204 capable of supplying a tracer gas into the work 201, and a gas around an inspection point of the work 201 are sucked. There is also known a sniffer probe 206a which includes a sniffer probe 206a for performing the detection and a sniffer leak detector 206b for detecting a tracer gas amount in the gas sucked by the sniffer probe 206a.

[0005] In the work leak inspection apparatus described above, the work 201 is operated by the tracer gas supply device 204.
The operator operates the sniffer probe 206a to bring the tip of the sniffer probe 206a close to each inspection point of the work 201, and aspirates gas around each inspection point with the sniffer probe 206a. The leak detector 206b detects the amount of tracer gas in the sucked gas to check whether or not there is a leak at each inspection point (generally referred to as a sniffer method).

[0006]

By the way, in the work leak inspection apparatus used in the above-mentioned bell jar method, generally, the pressure in the container 102 (the inlet pressure of the leak detector 106) is reduced to about 5 by the vacuum pump 105.
It is necessary to perform the inspection by evacuating to Torr or less. For this reason, it is necessary to use expensive stainless steel as the container 102 and to perform special vacuum welding or the like, which is disadvantageous in cost. In addition, the inside of the container 102 is about 5 T
Since it takes a long time to evacuate to orr or less, the inspection time for each work becomes long, and the work efficiency is poor.

On the other hand, the work leak inspection apparatus used in the above-described sniffer method can check whether or not the work 201 leaks under the atmospheric pressure. And the vacuum pump 103 is not required. Further, the sniffer leak detector 206b is inexpensive as compared with the leak detector 106 in the bell jar method. By moving the probe 206a to various places,
In order to inspect the presence or absence of leakage of the work 201 as a whole, there is a case where the presence or absence of leakage cannot be confirmed unless the sniffer probe 206a is brought close to all parts of the work 201. Yes, work efficiency is poor. In addition, the sniffer probe 206a is
There is a problem that the inspection cannot be performed unless the workpiece 201 is approached to a distance of about several mm, and there is a problem that an untestable portion may be generated when a workpiece 201 having a complicated shape is to be inspected, resulting in poor work efficiency.

[0008]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a work leak inspection apparatus with high work efficiency. A container capable of accommodating and removably sealing, a tracer gas supply device capable of supplying a tracer gas into the work, a pump capable of discharging gas in the container, and a pump in close proximity to an exhaust portion of the pump. A sniffer probe that is arranged and sucks a part of the gas passing through the exhaust unit, and a sniffer leak detector that detects a tracer gas amount in the gas sucked by the sniffer probe is characterized by having a configuration including: There is.

In this case, it is possible that the tracer gas supply device is attached to the container so that the tracer gas can be supplied to the work accommodated in the container.

[0010]

In the work leak inspection apparatus according to the present invention, the gas in the container discharged by the pump passes through the exhaust part of the pump, and a part of the sniffer is disposed close to the pump. Aspirated by the probe. By the way, when the tracer gas leaks from the work accommodated in the container and supplied with the tracer gas, a part of the tracer gas is sucked by the sniffer probe together with the gas in the container, and the sniffer leak detector detects the tracer gas. The amount of the tracer gas in the sucked gas is detected, whereby it is possible to inspect whether or not the work as a whole has leaked.

As described above, in the work leak inspection apparatus according to the present invention, the gas in the container containing the tracer gas leaking from the whole work is not sucked by the sniffer probe but in the vicinity of each work. Is discharged by a pump, a part of which is sucked by a sniffer probe, and the amount of tracer gas in the gas is detected by a sniffer leak detector. The leak inspection device can efficiently perform the inspection for the presence / absence of a leak as a whole work, which has a poor working efficiency.

Further, in the work leak inspection apparatus according to the present invention, since the tracer gas leaked from the work is discharged by the pump together with the gas in the container, it is necessary to evacuate the inside of the container to 5 Torr or less. In addition, the working time can be shortened, and the leak test can be performed more efficiently than the test device used for the bell jar method.

Further, in the work leak inspection apparatus according to the present invention, it is not necessary to evacuate the inside of the container to 5 Torr or less as described above, so that it is not necessary to use an expensive stainless steel container. Since there is no need to perform special vacuum welding or the like on the container, and it is possible to use an inexpensive sniffer leak detector,
It can be carried out at a lower cost than a work leak inspection device used in the bell jar method.

In practicing the present invention, when the tracer gas supply device is attached to the container so that the tracer gas can be supplied to the work contained in the container, the tracer gas is supplied to the work. After that, the inspection can be started immediately (the operation of the pump is started), so that a tracer gas is supplied into the work from the tracer gas supply device in advance, and the work is stored in a container and the inspection is performed. Then, the tracer gas amount (remaining amount of the work) in each work at the start of the test (at the start of the operation of the pump) can be made substantially constant, and a stable leak test can be performed.

[0015]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 3 shows a work leak inspection device according to the present invention. The inspection device includes a container 10 capable of receiving and sealing a hollow work M so that it can be taken in and out, and
Tracer gas (helium gas for inspection) in work M
, A discharger 30 for discharging air from the container 10, a detector 40 for detecting the amount of tracer gas leaked from the work M, and the like.

The container 10 is made of a rolled steel material for general structure (JIS).
It is formed by a standard (for example, SS400 or the like) and has a rectangular parallelepiped shape capable of housing the work M inside by opening a door (not shown) provided on the front surface. The two connection ports 11 and 12 respectively have a tracer gas supply means 20 and an exhaust means 3.
0 is connected.

The tracer gas supply means 20 includes a container 10
A tracer gas is supplied to the work M accommodated therein, and is connected to the tracer gas supply cylinder 21 attached to the container 10 and the connection port 11 of the container 10 while being connected to the cylinder 21. An introduction pipe 22 and an on-off valve V1 interposed in the introduction pipe 22 are provided. A connection pipe 23 is connected to the inside of the container 10 at the connection port 11 of the container 10. The connection pipe 23 connects the introduction pipe 22 and the work M. One end of the connection pipe 23 is airtightly connected to the connection port 11 of the container 10 via a connector (not shown) in the container 10. The end is detachably and hermetically connected to the connection port m of the work M via a connection tool (not shown).

Further, a tracer gas recovery means 50 and a decompression means 60 for the work M are connected to the introduction pipe 22 at a position closer to the container 10 than the open / close valve V1.

The tracer gas collecting means 50 collects the tracer gas from the work M for which the leak inspection has been completed, and includes a tracer gas collecting cylinder 51 and a pipe 52 connected to the cylinder 51 and connected to the introduction pipe 22.
And an opening / closing valve V2 interposed in the pipe 52.

The pressure reducing means 60 of the work M is for evacuating the inside of the work M to a predetermined pressure at the time of a leak test. The first vacuum pump 61 is connected to the pump 61 and connected to the introduction pipe 22. Pipe 62 and the same pipe 6
2 is provided with an on-off valve V3 interposed.

The evacuation means 30 includes a second vacuum pump 31 for evacuating the inside of the container 10 and an intake unit 3 of the vacuum pump 31.
1a and a pipe 32 connected to the connection port 12 of the container 10, and a switching valve V4 interposed in the pipe 32.
And an exhaust silencer 34 connected to the exhaust part 31b of the second vacuum pump 31 via a pipe 33, and a pipe 3 connected to the switching valve V4.
The air suction silencer 36 is connected through a connection 5, and a detection unit 40 is connected to an intermediate portion of the pipe 33.

The switching valve V4 is an electromagnetic valve for selectively switching communication between the container 10 and the second vacuum pump 31 and communication between the container 10 and the intake silencer 36. 10 is in a communication state with the second vacuum pump 31 and is in a cutoff state with the intake muffler 36. In the energized state, the container 10 is in a communication state with the suction muffler 36 and is in a cutoff state with the second vacuum pump 31. It has become.

The detecting means 40 includes a known sniffer probe 41 and a known sniffer leak detector 43 connected to the sniffer probe 41 via a tube 42. The sniffer probe 41 is an inexpensive sniffer probe similar to the sniffer probe used in the conventional sniffer method. The tip of the sniffer probe faces the inside of the pipe 33, and the tracer in the air exhausted by the second vacuum pump 31 is used. It is designed to contain gas. The sniffer leak detector 43 detects the amount of leakage of the work M from the tracer gas accommodated by the sniffer probe 41.

The work inspection apparatus according to the present embodiment configured as described above is used by repeating the following procedure. Initial state (opening / closing valves V1, V2, V3 closed, switching valve V
4 is de-energized, the first vacuum pump 61 and the second vacuum pump 31 are stopped, and the sniffer probe 41 and the sniffer leak detector 43 are stopped).
Then, the work M is accommodated in the container 10 by opening the door 0, and the connection tool assembled at the tip of the connection pipe 23 is connected to the connection port m of the work M, and then the door of the container 10 is closed. Activating the first vacuum pump 61 and opening / closing valve V3
Is opened and the inside of the work M is evacuated to a predetermined pressure.
The first vacuum pump 61 is stopped, and the on-off valve V3 is closed. After the on-off valve V1 is opened and the tracer gas is supplied from the tracer gas supply cylinder 21 into the work M, the on-off valve V1 is opened.
Close 1. The second vacuum pump 31 is operated to discharge the gas in the container 10 and the sniffer probe 41 and the sniffer leak detector 43 are operated. Detection value (leak rate value) detected by the sniffer leak detector 43 within a predetermined time
Is compared with a predetermined allowable value to determine a pass / fail. While stopping the second vacuum pump 31, the sniffer probe 41 and the sniffer leak detector 4
Stop 3 The on / off valve V2 is opened to collect the tracer gas in the work M into the tracer gas collection cylinder 51, and the switching valve V4 is turned on to open the container 10 to the atmosphere. The on-off valve V2 is closed, and the switching valve V4 is turned off. The door of the container 10 is opened, the connection tool assembled at the tip of the connection pipe 23 is removed from the connection port m of the work M, and the work M is taken out.

As is apparent from the above description, in the work leak inspection apparatus of this embodiment, the gas in the container 10 discharged by the second vacuum pump 31
One part of the gas passes through one exhaust part 31 b, and a part thereof is sucked by the sniffer probe 41 arranged close to the pump 31. By the way, when the tracer gas leaks from the work M housed in the container 10 and supplied with the tracer gas, a part of the tracer gas is sucked by the sniffer probe 41 together with the gas in the container 10 to be used for the sniffer. The leak detector 43 detects the tracer gas amount in the sucked gas,
This makes it possible to inspect the work M as a whole for leakage.

As described above, in the present embodiment, the gas in the container 10 including the tracer gas leaking from the whole work M is not sucked by the sniffer probe 41 but the gas around each inspection point of the work M. It is discharged by the second vacuum pump 31, a part of which is sucked by the sniffer probe 41, and the tracer gas amount in the gas is detected by the sniffer leak detector 43, so that the work used in the conventional sniffer method is used. With the leak inspection device of the above, it is possible to efficiently inspect whether or not there is a leak as a whole work, which has a poor working efficiency.

In this embodiment, the tracer gas leaked from the work M is discharged together with the gas in the container 10 by the second vacuum pump 31.
There is no need to evacuate the inside of the container 10 to 5 Torr or less, so that the working time can be reduced, and a leak test can be performed more efficiently than a test device used for the bell jar method.

Further, in the present embodiment, since it is not necessary to evacuate the inside of the container 10 to 5 Torr or less as described above, it is not necessary to use an expensive stainless steel as the container 10 (stainless steel). It is possible to use a material made of rolled steel for general structural use, which is cheaper than a steel plate), does not need to perform special vacuum welding or the like on the container 10, and is a sniffer which is less expensive than a leak detector used in the bell jar method. Since the leak detector 43 can be used, it can be implemented at a lower cost than an inspection device used for the bell jar method.

In the work leak inspection apparatus of the present embodiment, the tracer gas supply cylinder 21 is
The inspection is started immediately after the tracer gas is supplied to the work M because the tracer gas can be supplied to the work M accommodated in the container 10 (second vacuum pump 3
1 can be started), the tracer gas is supplied into the work from the tracer gas supply cylinder in advance, and the work is started at the start of the inspection (vacuum pump (At the start of operation), the amount of tracer gas (remaining amount of work) in each work can be made substantially constant, and a stable leak test can be performed.

In the above embodiment, the tracer gas supply cylinder 21 is attached to the container 10,
The tracer gas was supplied to the work M accommodated therein through the introduction pipe 22 and the connection pipe 23. However, the tracer gas supply cylinder 21 was not attached to the container 10, and the introduction pipe 22 and the Without providing the connection pipe 23, the work M may be supplied and filled in advance from the tracer gas supply cylinder 21 to the work M, and the work M filled with the tracer gas may be accommodated in the container 10. It is possible.

[Brief description of the drawings]

FIG. 1 is a schematic view of a conventional work leak inspection apparatus used for a bell jar method.

FIG. 2 is a schematic view of a conventional work leak inspection apparatus used for a sniffer method.

FIG. 3 is a schematic diagram of a work leak inspection device according to the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 ... Container, 21 ... Tracer gas supply cylinder (tracer gas supply), 31 ... 2nd vacuum pump, 31b ... Exhaust part, 41 ... Sniffer probe, 43 ... Sniffer leak detector, M ... Work.

Claims (2)

[Claims] 1. A container capable of accommodating and sealing a hollow work so that it can be taken in and out, a tracer gas supply device capable of supplying a tracer gas into the work, and a pump capable of discharging gas in the container. A sniffer probe that is disposed close to the exhaust part of the pump and sucks a part of the gas passing through the exhaust part, and a sniffer leak detector that detects a tracer gas amount in the gas sucked by the sniffer probe And a work leak inspection device. 2. The leak inspection apparatus according to claim 1, wherein the tracer gas supply device is attached to the container so that tracer gas can be supplied to the work accommodated in the container.