JP2000230761A - Mounting structure of refrigerant leakage detecting means - Google Patents

Abstract

PROBLEM TO BE SOLVED: To permit the detection of leakage of combustible refrigerant from the connecting part of pipes before leaking out to the inside of a cabin or the like. SOLUTION: The mounting structure of a refrigerant leakage detecting means defines a sealed space 12 between a refrigerant flow passage space 10 and a space 11 outside of a pipe in the connecting part of the pipes 1, 5 by a method wherein the refrigerant flow passage space 10 is partitioned by an O-ring 4 while the space 11 outside of the pipe is partitioned by another O-ring 3. A gas sensor 8 is attached to the inside of the sealed space 12 to detect the refrigerant, leaked from the refrigerant flow passage space 10 into the sealed space 12.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a refrigeration cycle in which a flammable refrigerant flows, and a structure in which a detecting means for detecting refrigerant leaking from the junction is attached to a joint of pipes constituting the refrigeration cycle. It is about.

[0002]

2. Description of the Related Art In recent years, for the purpose of protecting the ozone layer and preventing global warming, HC has been used as an alternative refrigerant to Freon.
-134a and flammable refrigerants are being studied. Among these, natural refrigerants in which propane 100% or propane and isobutane are mixed at a weight ratio of 50% are considered to be promising as flammable refrigerants. In Europe and the United States, this refrigerant has already been tested experimentally in a refrigeration cycle. It is used as a flowing heat exchange medium. The present applicant has also conducted research and development on the structure of a refrigeration cycle using a flammable refrigerant.

[0003] On the other hand, when the flammable refrigerant leaks in the vehicle interior, the concentration of the flammable refrigerant in the vehicle interior easily increases because the vehicle interior basically assumes a closed space. It is easy to do so, and there may be some problems.

[0004] When pipes are joined together to form such a flow path of the flammable refrigerant, the joining portion of the pipes is conventionally welded or connected to one of the pipes as shown in FIG. The end of the pipe 100 is expanded beyond the outer diameter of the other pipe 101 to form an expanded section 102, and the pipe 1 to which the other O-ring 103 is attached by the expanded section 102.
01 is sealed by externally fitting the end of 01, so refrigerant leakage does not occur if there is not enough, but in the event of leakage, it is to prevent the occurrence of problems It is required to immediately detect the leakage of the refrigerant.

Therefore, as disclosed in Japanese Patent Application Laid-Open No. 10-103838, a refrigeration cycle provided with a sensor for detecting refrigerant leakage from a welded portion of a joint between a piping pipe and a piping pipe around an evaporator is disclosed. Are already known.

[0006]

However, although the above publication does not specifically disclose the location of the sensor, the leakage of the flammable refrigerant is detected when the flammable refrigerant leaks from the pipe to the outside, particularly to the vehicle interior. In the case of such an arrangement, after the refrigerant leaks into the passenger compartment, there is a possibility that it is not possible to ensure the safety of the occupant because the countermeasures are taken after the fact. Not enough.

[0007] Further, the gas vaporized by the flammable refrigerant is heavier than air and, if leaked into the vehicle interior, accumulates in the lower part of the vehicle interior. Therefore, even a small amount of leakage may cause discomfort to the occupant.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a mounting structure of a refrigerant leak detecting means capable of detecting a refrigerant leaking from a joint portion of a pipe before leaking to the outside such as a vehicle interior. I do.

[0009]

According to the present invention, there is provided a refrigerant leak detecting means mounting structure, wherein pipes for forming a refrigerant flow path are joined to each other to seal a joint portion between the pipes. It is characterized in that a further closed space is defined between the refrigerant flow passage space and the space outside the pipe, and a detecting means for detecting leakage of the refrigerant is mounted in the closed space. . Here, examples of the refrigerant include propane 100 or a combustible natural refrigerant obtained by mixing propane and isobutane at a weight ratio of 50%. Further, as the detecting means, a gas sensor for detecting a refrigerant gas in which the combustible natural refrigerant is vaporized may be used.

According to such a configuration, when the refrigerant leaks into the enclosed space, the leakage of the refrigerant can be detected by the detecting means mounted in the enclosed space.
The refrigerant leak can be detected before the refrigerant leaks into the space outside the pipe, particularly into the vehicle interior, and the pipe joint portion where the refrigerant has leaked can be repaired. Accordingly, even when a flammable refrigerant is used, leakage of the refrigerant to the outside of the pipe can be effectively suppressed, so that the vaporized gas of the refrigerant does not accumulate in the passenger compartment, which may cause discomfort to the occupant. Disappears.

In the closed space, an annular seal member is double-wrapped near the end of one of the pipes at intervals in the axial direction of the pipe, and this pipe is inserted into the other pipe. The seal member may be defined by closely contacting the inner peripheral surface of the other pipe (claim 2). Here, an O-ring is used as the annular seal member. Thus, the sealing member on the side of the end is separated from the refrigerant flow path space by the sealing member on the side of the end, and a sealed space separated from the space outside the pipe by the sealing member on the side opposite to the end is defined. Even if the refrigerant breaks and the refrigerant leaks from the refrigerant flow path space, it only exits into this sealed space, so that the refrigerant can be prevented from leaking out of the pipe as it is, and the leakage is detected by the detecting means. Can be detected.

In the closed space, an annular seal member is provided near an end of one of the pipes, and this pipe is inserted into the other pipe so that the seal member is attached to the inner peripheral surface of the other pipe. In addition to the above, the outside of the joint between the one pipe and the other pipe may be sealed by a case (claim 3). This forms a sealed space separated from the refrigerant flow passage space by the joint portion of the pipe and the space outside the pipe by a case, so that even if the refrigerant leaks from the joint portion of the pipe, the sealed space is closed. Since the refrigerant only exits inside, the refrigerant can be prevented from leaking out of the pipe as it is, and the leakage can be detected by the detecting means.

[0013]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows a joint portion between pipes 1 and 5, and the pipes 1 and 5 constitute a refrigeration cycle in which a flammable refrigerant is used by being appropriately piped. Is the main material.

The pipe 1 has a bead 2 extending in the radial direction of the pipe.
As seal members, annular O-rings 3 and 4 are doubly mounted on the outer periphery of the pipe 1 at predetermined intervals in the pipe axial direction.

The pipe 5 has a large-diameter portion 6a having an inner diameter larger than the outer diameter of the bead 2 of the pipe 1 and the outer diameter of the O-rings 3 and 4 of the pipe 1 at the tip portion thereof by taper processing or the like. And a small-diameter enlarged portion 6b having an inside diameter substantially the same as that of the tube-forming portion 6.

The lower peripheral surface of the small-diameter portion 6b of the pipe 5 is provided with a through-hole 7 in the radial direction of the pipe. A gas sensor 8 for detecting a gas concentration of the flammable refrigerant is disposed in the small-diameter portion 6b of the pipe 5, and a cord 9 extending from the gas sensor 8 is connected to the pipe 5 through the through-hole 7. It is designed to be pulled out.
Since the configuration of the gas sensor 8 is a known one, its description is omitted. However, since the vaporized gas of the flammable refrigerant is heavier than air, in order to accurately detect the gas concentration, in this embodiment, the gas sensor 8 is provided below the pipe 5. Located on the side.

By connecting the pipe 1 and the pipe 5 having the above-described structure, one of the pipes 5 is formed by the O-ring 4 in the small-diameter enlarged portion 6b of the pipe 5 so that the refrigerant flow path space 1 in the pipe 5 is formed.
The sealed space 12 is separated from the space 11 outside the pipe by the O-ring 3, and the gas sensor 8 is disposed in the sealed space 12.

2 and 3 show another embodiment of the present invention. Hereinafter, different portions will be mainly described, and the same portions appearing in the drawings will be denoted by the same reference numerals and the description thereof will be omitted. Omitted.

The pipes 1, 5 shown in FIGS.
The refrigeration cycle uses a flammable refrigerant by being appropriately piped similarly to the pipes 1 and 5 in FIG. 1, and is mainly made of, for example, aluminum or the like.

In this configuration, the pipe 5 is the same as the pipe 5 of FIG. 1 except that the pipe 5 has an expanded portion 6 having a large-diameter portion 6a and a small-diameter portion 6b at the tip. Since the gas sensor 8 is not disposed in the diameter portion 6b, the through hole 7 is not formed. The pipe 1 has only an O-ring 4 for sealing a joint portion with the pipe 5. Regarding other configurations, that is, the diameters of the bead 2 of the pipe 1, the large-diameter portion 6a and the small-diameter portion 6b of the pipe 5,
The description is omitted because it is the same as the pipes 1 and 5 in FIG.

On the other hand, the joint between the pipe 1 and the pipe 5 is covered by a case 13.
The case 13 is composed of an upper case 14 and a lower case 15, and the upper case member 14 and the lower case member 15 are joined by joining end surfaces 16, 17 extending in respective pipe axial directions. Thereby, the substantially cylindrical small-diameter portions 18 and 18 having substantially the same inner diameter as the portion other than the bead 2 of the pipe 1 and the portion other than the expanded portion 6 of the pipe 5, and the small-diameter portion of the pipe 5 positioned between the small-diameter portions 18. A substantially cylindrical large-diameter portion 19 having an inner diameter larger than the large-diameter portion 6a is formed.

At the opening end of the small-diameter portion 18, a sealing member 20 made of a synthetic resin or the like extending in the center direction is disposed, and the upper case member 14 and the lower case member 15 are arranged.
A sealing member 20 such as a rubber packing is also arranged on the joining end surfaces 16 and 17 of FIG. Although not shown, the upper case member 14 and the lower case member 15 are screwed together with the joining end surfaces 16 and 17 using, for example, a tapping screw.
The lower case 15 is fitted by engaging a locking portion formed near the joint end face 17 of the lower case 15 with a hole formed near the joint end face 16 of the upper case member 14.

A through hole 7 is provided in the lower peripheral surface of the lower case member 15 where the large-diameter portion 19 is formed, in the radial direction of the pipe, and the gas sensor 8 is provided in the large-diameter portion 19. The cord 9 which is arranged and extends from the gas sensor 8
Is drawn out of the case 13 through the through hole 7. This gas sensor 8 is a known sensor as in the case of FIG. 1, and in order to accurately detect a vaporized gas of a flammable refrigerant that is heavier than air, in this embodiment, the large-diameter portion 1
9 is arranged below.

The pipes 1 and 5 are joined by using the pipes 1 and 5 and the case 13 having such a configuration, and the upper case member 14 and the lower case member 15 are connected as shown in FIG.
The case 13 in a state where the gap between the joining end faces 16 and 17 is largely open covers the joints of the pipes 1 and 5 by, for example, moving in a radial direction with respect to the pipes 1 and 5, and then the joining end face 16 of the upper case member 14 And the joint end face 17 of the lower case member 15 are fitted. Thereby, the space 11 outside the pipe
Is separated by a seal member 20 provided on the opening of the small diameter portion 18 and the joint end faces 16 and 17, and a sealed space 12 is defined by the O-ring 4 from the refrigerant flow space 10 in the pipe. At the same time, the gas sensor 8 is arranged in the closed space 12.

However, according to both of these embodiments, since the gas sensor 8 is disposed in the closed space 12, it does not normally detect the flammable refrigerant, and When the flammable refrigerant or its vaporized gas leaks into the closed space 12, it detects the leakage and informs the occupant of the fact by a warning device or the like.

The location of the joint between the pipes 1 and 5 is not particularly limited. However, since the flammable refrigerant easily reaches a high concentration at which the flammable refrigerant causes a problem, Since it is highly necessary to suppress the leakage of the flammable refrigerant, it is optimal to use it for a pipe joint near an evaporator (not shown).

[0028]

As described above, according to the present invention, when the refrigerant leaks into the enclosed space, the leakage of the refrigerant can be detected by the detecting means mounted in the enclosed space. Before the refrigerant leaks to the outside, particularly to the vehicle interior, the pipe joint portion where the refrigerant has leaked can be repaired. Therefore, even when a flammable refrigerant is used, leakage of the refrigerant to the outside can be effectively prevented. Therefore, the gas in which the refrigerant is vaporized does not accumulate in the vehicle interior, and it is possible to prevent the passenger from feeling uncomfortable.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a configuration in which a gas sensor is disposed in a sealed space partitioned by an O-ring at a joint portion of a pipe.

FIG. 2 shows an embodiment different from that of FIG. 1, and is an explanatory view showing a joint portion of a pipe and a configuration of a case for sealing the joint portion.

FIG. 3 is a cross-sectional view showing a configuration in which a joint portion of the pipe shown in FIG. 2 is sealed with a case, and a gas sensor is disposed in a sealed space formed in the case in the case.

FIG. 4 is a cross-sectional view showing a configuration of a joint portion of a conventional pipe.

[Explanation of symbols]

 Reference Signs List 1 pipe 3 O-ring 4 O-ring 5 pipe 6 expanded part 6a large-diameter part 6b small-diameter part 8 gas sensor 10 refrigerant flow path space in pipe 11 space outside pipe 12 closed space 13 case

Claims (3)

[Claims] 1. A pipe for forming a refrigerant flow path is joined to each other to seal a joint portion between the pipes, and a space further sealed between a refrigerant flow path space in the pipe and a space outside the pipe is formed. A mounting structure for refrigerant leakage detecting means, wherein a detecting means for detecting leakage of the refrigerant is mounted in the enclosed space. 2. The closed space includes an annular seal member,
In the vicinity of the end of one of the pipes, the pipe is double-wrapped at an interval in the pipe axis direction, and this pipe is inserted into the other pipe to bring the sealing member into close contact with the inner peripheral surface of the other pipe. The mounting structure of the refrigerant leakage detecting means according to claim 1, wherein the mounting structure is defined by: 3. The closed space includes an annular seal member,
An exterior is provided near the end of one of the pipes, and this pipe is inserted into the other pipe so that the sealing member is in close contact with the inner peripheral surface of the other pipe, and a joining portion between the one pipe and the other pipe is provided. 2. The mounting structure of claim 1, wherein the outside is defined by sealing the outside with a case.