JPH01227037A - Vessel for leak tester - Google Patents

Abstract

PURPOSE:To fix substantially the volume of a space formed between a vessel and a substance to be tested, and to make a time of inspection and the detecting sensitivity of a sensor invariable, by forming the vessel of a flexible material and by providing a standoff integrally on the inner surface of the vessel. CONSTITUTION:A substance 2 is set on the inside surface of a cover body 34 and inserted into a vessel 30, and the cover body 34 is fitted in an opening 32 of an outer case 31, so that the vessel 30 be sealed up. In this state, a trace gas G is supplied to the substance 2 to be tested and simultaneously the vessel 30 is exhausted to be vacuum. Then the vessel 30 formed of a flexible material shrinks and a standoff 6 comes into close contact with the outer surface of the substance 2. Accordingly, the volume of a space 7' formed between the vessel 30 and the substance 2 to be tested is fixed substantially even when the size of the substance 2 varies, the sensitivity of a sensor is kept invariable substantially, and also a time of inspection becomes unvaried substantially.

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention places a test object to which trace gas is supplied in an evacuated sealed container, and removes the trace gas leaking from the test object into the container. The present invention relates to a leak tester that detects a leak using a sensor, and particularly relates to improvements to its container.

[Conventional technology]

Various types of leak testing machines have been known that have been used to test the airtightness of pressure vessels and the like, examples of which include JP-A-49-4586 and JP-A-60. There are publications such as No. 178332. These systems evacuate the inside of a container and a test object placed in the container, and the trace gas supplied to the inside or outside of the test object passes through the test object to the outside of the test object. Alternatively, a leak detector is used to detect internal leakage.

Figure 3 shows a conventional example of such a leak testing machine.
Reference numeral 1 denotes a sealed container that stores the test object 2;
is evacuated by a roughing pump 3, and during scavenging, clean air is supplied from an air source 4 via a cleaner 5 and is evacuated by the pump 3. The test object 2 housed in the container 1 is held by standoffs 6, thereby forming a space 7 between it and the inner surface of the container. It is fed through the boat seal 9. In this state, the test object 2 may contain trace gas G.
If gas is leaking into the container 1, the leaked gas is guided by the detection pump 10 to the trace gas sensor 11 and detected, and the amount of leakage is recorded or displayed by the detector 12.

In addition, 13 to 18 are connection pipes, 19A to 19F are switching valves,
20 is a duct, 21 is a surge tank, and 22 is a boat seal.

When detecting a leak, first, the test object 2 is placed in a container, the container 1 is sealed, and the inner ends of the boat seals 9 and 22 are connected to the test object 2, respectively. Next, when the container 1 is evacuated to a predetermined pressure by the roughing pump 3, the pump 3 is stopped, and the trace gas G is supplied to the test object 2 from the trace gas supply source 8, and the container 1 is evacuated to a predetermined pressure.
is evacuated by the detection pump 10. As mentioned above, the trace gas G leaking from the test object 2 in this state is
The gas is guided to the trace gas sensor 11 via the connecting pipe 14 and detected there.

[Problem to be solved by the invention]

By the way, the conventional container 1 is made of a rigid body and has a constant volume. Further, since the container 1 is manufactured according to the test object 2, when the test object 2 changes, it is necessary to use a container that matches the size of the test object 2. In that case, it is possible to make the container 1 larger so that it can be conveniently used for both large and small test objects 2, and to standardize the container, but in this case, the detection There is a problem in that the time and detection sensitivity change, and in the case of small test objects, the detection time is long and the detection sensitivity is reduced.

That is, the test object 2 is small and the test object 2 and the container 1 are small.
When the space T formed between the test object 2 and
This is because the molecules of the trace gas G leaked into the container 1 are diffused over a wide range, resulting in a decrease in gas concentration, lowering the sensitivity of the sensor 11, and prolonging the time it takes for the leaked gas to reach the sensor 11.

Therefore, the present invention solves the above-mentioned problems, and with a simple configuration, the space between the container and the test object can be made to have a substantially constant volume regardless of the size of the test object.
It is an object of the present invention to provide a container for a leakage tester that can maintain test time and detection sensitivity substantially constant.

[Means to solve the problem]

In order to achieve the above object, the present invention stores a test object in a sealed and evacuated container, supplies trace gas to the test object, and removes the trace gas leaking from the test object into the υ container. In a leakage tester configured to detect leakage using a sensor, the container is formed of a flexible material, and the inner surface of the container contacts the outer surface of the test object during evacuation to form a certain space between the container and the outer surface. It is equipped with an integrated standoff.

[Effect]

In this invention, since the container is flexible, it contracts by evacuation, and the standoffs come into close contact with the outer surface of the test object. Therefore, the volume of the space formed between the container and the test object is approximately constant regardless of the size of the test object.

〔Example〕

Hereinafter, the present invention will be described in detail based on embodiments shown in the drawings.

FIG. 1 is a cross-sectional view of an embodiment of a container for a leak tester according to the present invention before evacuation, and FIG. 2 is a cross-sectional view of the same container after evacuation. Components and portions in the figure that are the same as those in FIG. 3 are designated by the same reference numerals, and their explanations will be omitted. In these figures, a container 30 containing the test object 2 is shown.
is formed of a flexible material such as rubber into a bag shape with one end open, and the open end 30m is connected to the opening 32 of the outer case 31.
It is bonded and fixed to the inner periphery of the The outer case 31
is a rigid body and has a communication hole 33 that communicates with the outside, and when a lid 34 is fitted into the opening 32 via an OIJ ring 35, the container 30 is hermetically sealed. The test object 2 to be housed in the container 30 is disposed on the inner surface of the lid 34, and the connecting tubes 13, .
15 is connected and the boat seal 9.22 is pierced. A standoff 6 that comes into contact with the outer surface of the test object 2 during evacuation is integrally provided on the inner surface of the container 30 in a protruding manner.

Note that the other configurations are the same as in FIG. 3.

In the leak tester container 30 having such a configuration, the test object 2 is set on the inner surface of the lid 34 and the container 30 is opened.
the lid 34 into the opening 32 of the outer case 31.
and seals the container 30. At this time, a large space 7 is formed between the container 30 and the test object 2, as shown in FIG. In this state, when the test object 2K) race gas G is supplied and the container 30 is evacuated at the same time, the container 30 contracts as shown in FIG. In close contact with the outer surface. In other words, the container 30 constitutes a variable volume container, so even if the size of the test object 2 changes,
There is no need to replace the container with a correspondingly sized container, and the space T' between the container 30 and the test object 2 in this state is significantly reduced and its volume remains unchanged regardless of the size of the test object 2. Therefore, even in the case of the small test object 2, the gas concentration of the trace gas G leaking into the space 7' does not decrease, and the sensitivity of the sensor is maintained approximately constant. The time it takes to reach the target does not take long and can be kept approximately constant.

Note that the cross-sectional shape of the standoff 6 of the container 30 is not limited to a rectangular shape, but can be changed to various shapes, and if a tip 38 made of a wear-resistant material is provided on the tip surface,
If the standoff 6 and MftL are replaced, the durability of the container 30 can be improved.

〔Effect of the invention〕

As explained above, the container for a leak tester according to the present invention is made of a flexible material and has standoffs integrally formed on its inner surface, and the test object is stored and sealed inside the container. Since the container is deflated by vacuum evacuation and the standoff is brought into contact with the outer surface of the test object, the space volume between the container and the test object is kept approximately constant regardless of the size of the test object. Therefore, even when detecting leaks from small test objects, detection sensitivity is good and detection can be made in a short time.Furthermore, since the volume is variable, there is no need to change the container, so handling of the test machine is easy. is simple and easy and allows rapid detection.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional view of an embodiment of the container for a leak tester according to the present invention before evacuation, Fig. 2 is a cross-sectional view of the same container after evacuation, and Fig. 3 is a conventional example of a leak tester. FIG. 1... Container, 2... Test object, 3... Roughing pump, 4... Air source, 6... No. standoff, 11... Trace gas sensor, 30 ... Container, 31 ... Outer case, 34 ...
・Lid body, 38... Chip made of wear-resistant material, G-shape・
trace gas. Patent applicant Yamaha Co., Ltd.

Claims (1)

[Claims] A leak test in which a test object is housed in a sealed and evacuated container, a trace gas is supplied to the test object, and a sensor detects the trace gas leaking from the test object into the container. In this machine, the container is made of a flexible material to have a variable volume, and the inner surface is in contact with the outer surface of the test object during evacuation to form a certain space between the container and the outer surface. A container for a leakage tester, characterized in that it is integrally provided with a standoff.