JP2003207410A - Leak inspection apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a leak inspection apparatus for surely inspecting leakage of the closed piping with reduced consumption of an inspection gas and better working efficiency. <P>SOLUTION: A freezing circuit 8 is guided into a chamber 2 through an opening which is formed at the lower side of the chamber 2 having a space filled with helium. The freezing circuit 8 is transported by a lift 9 to the upper part within the chamber 2 while the freezing circuit 8 is evacuate by a vacuum pump 5 connected to the freezing circuit 8. A detector 4 which is disposed outside the freezing circuit 8 to detect presence of helium, determines leakage of the freezing circuit 8 by detecting presence of the helium. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a leak inspection device for inspecting a leak in a pipe of a closing device such as a refrigeration circuit.

[0002]

2. Description of the Related Art A refrigeration circuit is an example of a closing device. The refrigeration circuit has a compressor, a condenser, a drier,
A heat exchanger and the like are connected by piping to form a circuit, and a connecting portion with this piping is connected by welding or the like.

Refrigerant is sealed in the refrigerating circuit having such a circuit configuration, and the problem at that time is refrigerant leakage. Leakage mainly occurs at a joint portion such as a welded portion, and if a leak occurs, there is a problem that the refrigerating capacity does not come out, and when an HC refrigerant is used, there is a risk of explosion.

As a leak inspection method, a refrigerant is sealed in a refrigeration circuit and then a leak detector is used to inspect the piping of the refrigeration circuit. However, it is difficult to perform a reliable leak inspection because there are parts that are difficult to trace on the pipe and parts that are difficult to see.

Therefore, a leak inspection method using an inspection gas such as nitrogen or helium is implemented. A refrigeration circuit whose inside is in a vacuum state is introduced into a leak test container called a capsule. The capsule is equipped with an inlet for introducing a refrigeration circuit and a vacuum pump for evacuating the inside of the capsule. Whether the refrigeration circuit has passed the first leak test and the second leak test To judge.

[0006] In the first leak inspection, the inside of the capsule is evacuated and at the same time, for example, 3 kg of nitrogen is put in the refrigeration circuit.
/ Cm ² G is sealed, the pressure in the refrigeration circuit is checked, and it is judged whether the pressure in the refrigeration circuit is lower than 3 Kg / cm ² G. The refrigeration circuit that passed the test is evacuated, and the second leak inspection is performed.

In the second leak inspection, He / N2 is applied to the refrigeration circuit which passed the first leak inspection, for example, 8K.
At the same time as g / cm ² G was enclosed, the inside of the capsule was evacuated to about 0.1 Torr. After that, the pressure in the refrigeration circuit and the vacuum residual pressure in the capsule are checked to determine whether or not the product is an acceptable product.

[0008]

When the inspection is carried out by the above-mentioned method using the inspection gas, after the inspection is completed, the inspection gas must be exhausted and then the enclosure must be sealed in a closing device such as a refrigeration circuit. However, there is a problem that the inspection gas is wasted and the work process is complicated.

The present invention is intended to solve the above problems, and it is an object of the present invention to suppress the consumption of inspection gas, simplify the work process, and reduce the time loss.

[0010]

The invention according to claim 1 is
A chamber that forms a space filled with helium, an opening is provided below the chamber, and a closing device such as a piping-connected refrigeration circuit that is housed in the chamber, and the closing device is provided through the opening. A moving device that is introduced into the chamber and that can move the closing device upward in the chamber; a vacuum pump that is connected to the closing device and that makes the inside of the pipe a high vacuum; and a vacuum pump that is provided outside the closing device. A detector for detecting the presence of helium in the pipe of the closing device, the inside of the chamber is evacuated in the pipe by the vacuum pump, and the detector detects the presence or absence of helium. By doing so, the presence or absence of a leak in the closing device is determined.

According to a second aspect of the present invention, a chamber for forming a space filled with helium and an opening portion provided under the chamber are provided to close a refrigeration circuit connected to the pipe and accommodated in the chamber. A device and a moving device for introducing the closing device into the chamber through the opening and enabling the closing device to move upward in the chamber;
A vacuum pump that is connected to the closing device and that makes a high vacuum inside the pipe, and a detector that is arranged outside the closing device and detects the presence of helium in the pipe of the closing device,
The closure device is introduced into the chamber while vacuuming the inside of the pipe by the vacuum pump, and the presence or absence of a leak in the closure device is determined by detecting the presence or absence of helium by the detector. To do.

According to a third aspect of the present invention, the moving device comprises:
The closing device is mounted on an elevator that moves up and down from the opening of the chamber so that it can be moved into the chamber.

According to a fourth aspect of the present invention, the closing device comprises:
It is characterized in that the presence or absence of a leak is determined in the upper part of the chamber.

The above invention has the following effects.

According to the first to fourth aspects of the present invention, since helium is lighter than air, a high-concentration helium layer is formed in the upper part of the chamber, and the closed circuit to be inspected is evacuated by a vacuum pump while the upper part of the chamber is evacuated. It is possible to carry out a leak inspection by transporting to a container and detecting the presence or absence of helium in the pipe by the detector. Therefore, it is not necessary to recover the helium in the pipe of the closing device after the inspection is completed, and thus the consumption of the inspection gas can be suppressed. In addition, since the inside of the piping of the closing device can be evacuated during the leak inspection, the products that have passed the leak inspection can be filled with the inclusions immediately after the inspection is completed, which has the effect of simplifying the work process. , Has the effect of reducing the working time.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described below with reference to the drawings. 1 is a vertical sectional view of a leak inspection apparatus showing a first embodiment, FIG. 2 is a vertical sectional view of a leak inspection apparatus showing a second embodiment, and FIG. 3 is a leak inspection apparatus showing a third embodiment. FIG. 1, 2, and 3, the same reference numerals indicate the same parts.

The leak inspection apparatus 1 comprises a chamber 2 which is filled with helium and has a lower opening, a helium cylinder 3 for supplying helium, a helium detector 4 for detecting the presence of helium, a vacuum pump 5, and an inspection product. Refrigeration circuit 8
And a concentration controller 7 for detecting the helium concentration in the lower part of the chamber 2 and opening and closing the valve 6 connected to the helium cylinder 3.

The refrigeration circuit 8 for inspecting for leaks is composed of a compressor, a condenser, a drier, a heat exchanger, etc., which are not shown. The decompression tubes 10 formed of thick rubber or the like on the high pressure side and the low pressure side of the compressor are connected to the high pressure side and the low pressure side of the compressor, respectively, and the decompression tubes 10 are merged into one before the vacuum pump 5. Then, it is connected to the vacuum pump 5. An exhaust tube 11 is pulled out from the vacuum pump 5.

If the helium detector 4 has a property capable of withstanding a vacuum, the helium detector 4 is placed inside the decompression tube 10 as shown in FIG. 1, and if it cannot withstand a vacuum, the exhaust tube 1 as shown in FIG.
It is installed in 1.

A leak inspection method will be described using the leak inspection apparatus configured as described above.

In FIGS. 1 and 2, an elevator 9 such as a belt conveyor is used and is moved in the directions of arrows A to B. The refrigeration circuit 8 in which the compressor, the condenser, the drier, the heat exchanger and the like are assembled is evacuated by the vacuum pump 5 before the chamber 2 and the air in the refrigeration circuit 8 is sufficiently evacuated. Then, it is carried to the chamber 2 by a belt conveyor or the like. The chamber 2 is filled with helium in advance, and the valve 6 is opened and closed by the concentration controller 7 so that the amount of helium in the chamber 2 becomes constant.

The refrigeration circuit 8 that has been sufficiently evacuated is conveyed into the chamber 2 filled with helium while being evacuated by the vacuum pump 5, and is sent to the upper part of the chamber 2 by the elevator 9 in the form of a belt conveyor. Since helium is lighter than air, the helium concentration is higher in the upper part of the chamber 2 than in the lower part of the chamber 2. The open end of the exhaust tube 11 is exposed outside the chamber 2 or a portion with a low helium concentration.

The refrigeration circuit 8 is inspected for a leak condition by the helium detector 4 while being transported in the chamber 2. The refrigeration circuit 8 is conveyed in the chamber 2 in a vacuum state, and if it is an acceptable product, the helium detector 4 does not detect helium. But,
If there is a leak point in the refrigeration circuit 8, helium which is the external atmosphere will be sucked in from that point,
The presence of helium is confirmed by the helium detector 4. The refrigeration circuit 8 in which the presence of helium has been confirmed is rejected and removed from the production line. When helium is confirmed by the helium detector, it may be notified by a buzzer or the like, or may be notified by a lamp or the like.

The refrigerating circuit 8 that has passed the inspection is carried out of the chamber 2 and then filled with the refrigerant.

FIG. 3 shows an example in which a jack is used as the elevator 9 for feeding to the upper part of the chamber 2. Although the helium detector 4 is provided on the side of the decompression tube 10 in this drawing, the helium detector 4 may be provided on the side of the exhaust tube 11 as shown in FIG.

A predetermined number of refrigeration circuits 8 that have been sufficiently evacuated are placed on the elevator 9. After that, while vacuuming the refrigeration circuit 8, the state of (a) is jacked up from the state of (b) and sent above the chamber 2, and the helium detector 4 inspects the leak status. The refrigeration circuit 8 is conveyed in the chamber 2 in a vacuum state, and if it is an acceptable product, the helium detector 4 does not detect helium. However, if there is a leak point in the refrigeration circuit 8, helium, which is the external atmosphere, is sucked in from that point, and the presence of helium is confirmed by the helium detector 4. The refrigeration circuit 8 in which the presence of helium has been confirmed is rejected and removed from the production line. When helium is detected by the helium detector, it may be notified by a buzzer or the like, or may be notified by a lamp.

After a certain period of time, the jack is lowered and the refrigeration circuit 8 that has passed the leak inspection is filled with the refrigerant.

[0028]

The above invention has the following effects.

According to the first to fourth aspects of the present invention, since helium is lighter than air, a high-concentration helium layer is formed on the upper part of the chamber, and the closing device to be inspected is transferred to the upper part of the chamber while performing vacuuming with a vacuum pump. Then, the leak inspection can be performed by detecting the presence or absence of helium in the pipe with the detector. Therefore, it is not necessary to recover the helium in the pipe of the closing device after the inspection is completed, so that the consumption of the inspection gas can be suppressed. In addition, since the inside of the piping of the closure device can be evacuated during the leak inspection, the products that have passed the leak inspection can be filled with the inclusions immediately after the inspection is completed, which has the effect of simplifying the work process. The working time can be shortened.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view of a leak inspection device showing a first embodiment.

FIG. 2 is a vertical cross-sectional view of a leak inspection device showing a second embodiment.

FIG. 3 is a vertical cross-sectional view of a leak inspection device showing a third embodiment.

[Explanation of symbols]

1 Leak inspection device 2 chambers 3 helium cylinder 4 Helium detector 5 vacuum pump 6 valves 7 Concentration controller 8 Refrigeration circuit 9 elevator 10 Decompression tube 11 Exhaust tube

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Katsumi Fukui             2-5-3 Keihan Hondori, Moriguchi City, Osaka Prefecture             Within Yo Denki Co., Ltd. (72) Inventor Minoru Okajima             2-5-3 Keihan Hondori, Moriguchi City, Osaka Prefecture             Within Yo Denki Co., Ltd. (72) Inventor Makoto Toki             2-5-3 Keihan Hondori, Moriguchi City, Osaka Prefecture             Within Yo Denki Co., Ltd. F term (reference) 2G067 AA12 AA34 BB02 BB03 BB04                       BB12 BB25 BB30 CC13 DD17                       DD18

Claims (4)

[Claims] 1. A chamber that forms a space filled with helium, and an opening is provided below the chamber,
A closing device such as a piping-connected refrigeration circuit housed in the chamber, and a moving device for introducing the closing device into the chamber through the opening and enabling the closing device to move upward in the chamber. In the chamber, a vacuum pump connected to the closing device to make a high vacuum inside the pipe, and a detector arranged outside the closing device to detect the presence of helium in the pipe of the closing device, 2. The leak inspection apparatus, wherein the presence or absence of a leak in the closure device is determined by evacuating the inside of the pipe of the closure device by the vacuum pump and detecting the presence or absence of helium by the detector. 2. A chamber that forms a space filled with helium, and an opening is provided below the chamber,
A closing device such as a piping-connected refrigeration circuit housed in the chamber, and a moving device for introducing the closing device into the chamber through the opening and enabling the closing device to move upward in the chamber. A vacuum pump connected to the closing device to make a high vacuum inside the pipe, and a detector arranged outside the closing device for detecting the presence of helium in the pipe of the closing device. Is introduced into the chamber while vacuuming the inside of the pipe by the vacuum pump, and the presence or absence of helium is detected by the detector to determine the presence or absence of a leak in the closing device. apparatus. 3. The leak inspection apparatus according to claim 1, wherein the moving device is configured to mount the closing device on an elevator that moves up and down from an opening of the chamber so as to be movable into the chamber. . 4. The closure device determines whether or not there is a leak in the upper part of the chamber.
The leak inspection device described.