JPH08219603A - Refrigerating cycle device and refrigerant shortage detecting device for the device - Google Patents

Abstract

PURPOSE: To provide a pressure-detecting device wherein a refrigerant shortage- detecting device is integrated, which can accurately detect the shortage of a refrigerant. CONSTITUTION: A pressure switch 1 is arranged between a refrigerant condenser wherein a liquid receiving unit is integrated, and an expansion valve in a refrigerating cycle device. The pressure switch 1 is equipped with a refrigerant quantity shortage-detecting means 16 and pressure-detecting means. The refrigerant quantity shortage-detecting means 16 consists of a float 23, permanent magnet 24 which is provided around the float 23, and a magnetism-detecting tape 25 which is stuck on the outside of a housing 12. When a refrigerant in the refrigerating cycle device reduces, the liquid level of the refrigerant in a pressure cell 14 decreases. Accompanying this, the position of the float 23 decreases as well. Since the permanent magnet 24 is provided on the float 23, when the position of the float 23 decreases, the magnetism-detecting tape 25 detects the magnetism of the permanent magnet 24 and discolors, and the shortage of the refrigerant quantity can be detected.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a refrigerating cycle device equipped with a refrigerant shortage detection means and a pressure detection device integrated with the refrigerant shortage detection device.

[0002]

2. Description of the Related Art Refrigeration cycle devices used for automobile air conditioners include refrigerant compressors, refrigerant condensers, liquid receivers,
Some include an expansion valve, which is a pressure reducing means, and a refrigerant evaporator. Conventionally, as a means for detecting such a shortage of the amount of refrigerant in the refrigeration cycle apparatus, there is a liquid receiver or a sight glass provided in a pipe between the liquid receiver and the expansion valve. Whether or not the amount of refrigerant is insufficient is determined by the operator visually observing the sight glass.

[0003]

By the way, in the case of a refrigeration cycle apparatus having a subcooler in addition to the above refrigeration cycle apparatus, the number of parts is reduced as disclosed in Japanese Utility Model Publication No. 5-48032. In order to secure a mounting space, there is proposed a refrigeration cycle device including a liquid receiver integrated refrigerant condenser in which a condenser, a liquid receiver, and a subcooler are integrated.

In the case of a refrigeration cycle apparatus having a refrigerant condenser having a structure as disclosed in Japanese Utility Model Publication No. 5-48032, the sight glass, which is means for detecting a shortage of the amount of refrigerant, is an outlet of the refrigerant condenser. It is provided in. However, when the sight glass is provided in a part of the refrigerant condenser in this way, there is a problem that it is difficult for the operator to visually observe because the refrigerant condenser is mainly provided at the tip of the vehicle. . Further, when a sight glass is provided as a separate body in the pipe between the refrigerant condenser integrated with the liquid receiving section and the expansion valve, there is a problem that the number of parts increases and the manufacturing cost increases.

The present invention has been made in view of the above points, and in a refrigeration cycle apparatus including a refrigerant condenser having a structure in which a condenser, a receiver and a subcooler are integrated, an inexpensive refrigerant shortage An object of the present invention is to provide a detection device.

[0006]

In order to solve the above-mentioned problems, a first aspect of the present invention is a structure in which a pressure reducing means, an evaporator, a compressor, a condenser part and a liquid receiving part and a supercooling part are integrated. And a space part communicating with the inside of the pipe provided in a pipe connecting the refrigerant condenser and the pressure reducing means, and a refrigerant sealed in the space part. The technical means of including the refrigerant amount shortage detecting means including the float located on the liquid surface of the above and the displacement detecting means for detecting the displacement of the float is adopted.

According to a second aspect of the present invention, in the first aspect, the displacement detecting means for detecting the displacement of the float detects the magnetism of the permanent magnet provided on the float and displaced integrally with the float. It employs a technical means consisting of a magnetic detection means for detecting. Further, in claim 3, the pressure reducing means, the evaporator, the compressor,
Applied to a refrigeration cycle apparatus having a liquid receiving unit-integrated refrigerant condenser having a structure in which a liquid receiving unit and a supercooling unit are integrated in a condensing unit, the refrigerant condenser and the decompression unit are connected. A space having a space communicating with the inside of the pipe, a pressure detecting means for detecting the pressure of the refrigerant in the pipe, a float positioned on the liquid surface of the refrigerant sealed in the space of the pressure detecting means; The technical means of including a refrigerant amount shortage detection means including a displacement detection means for detecting the displacement of the float is adopted.

Further, claim 4 is the same as claim 3
The pressure detecting means includes a diaphragm having a peripheral portion sandwiched above the space portion, and a pressure detecting portion that detects the pressure of the refrigerant by deformation of the diaphragm, and the displacement detecting means is provided on the float. The present invention employs a technical means that includes a permanent magnet and a magnetism detecting means for detecting the magnetism of the permanent magnet.

Further, a fifth aspect of the present invention is that, in the third or fourth aspect, the pressure detecting portion is provided on a side of the diaphragm opposite to the space portion, and the operating rod is displaced along with the deformation of the diaphragm. The technical means is provided with a contact switch having a pair of opposed contacts that are operated according to the displacement of the actuation rod. Further, a sixth aspect of the present invention is the method according to any one of the third to fifth aspects, wherein the pressure detection means and the refrigerant amount shortage detection means are contained inside a housing having the space portion, and the magnetic detection means. Is a magnetic tape provided at a predetermined position outside the housing.

[0010]

As described in claim 1, since the space portion communicates with the inside of the pipe connecting the refrigerant condenser and the pressure reducing means, the space portion is changed due to the fluctuation of the refrigerant amount of the refrigeration cycle apparatus. The height of the liquid surface of the refrigerant enclosed in the fluctuates. Along with that, the position of the float located on the liquid surface of the refrigerant sealed in the space is displaced. Therefore, by detecting the displacement of the float, the refrigerant amount shortage detection means can detect the shortage of the refrigerant amount.

By the way, in a normal refrigeration cycle apparatus having no subcooling section, the refrigerant which has passed through the condenser and is condensed into a liquid state is separated into gas and liquid in the liquid receiver and sent to the pressure reducing means. However, although the refrigerant that has passed through the liquid receiver is in a liquid state, it is in a saturated state, so that bubbles are likely to be generated due to a slight change in the environment. Therefore, the float may be displaced irrespective of the fluctuation of the refrigerant amount enclosed in the refrigeration cycle apparatus, and it is difficult to accurately detect the shortage of the refrigerant amount due to the displacement of the float.
However, in the refrigeration cycle apparatus including the subcooling unit as described in claim 1, the refrigerant that has passed through the liquid receiving unit and is gas-liquid separated is sent to the subcooling unit in a saturated state, and further, the subcooling unit. By being supercooled by, it is sent to the pressure reducing means in a completely liquid state. That is, the refrigerant in a completely liquid state flows into the space portion communicating with the inside of the pipe connecting the refrigerant condenser and the pressure reducing means. Therefore, it is possible to prevent the displacement of the float due to the generation of bubbles due to a slight change in the environment, and it is possible to provide a refrigeration cycle apparatus including a refrigerant amount shortage detection means with few malfunctions.

In the second aspect, the same operation and effect as the first aspect can be obtained. Further, in claim 3, claim 1
In addition to the same operation and effect as described above, since the refrigerant amount shortage detection means is provided in the space of the pressure detection means, the refrigerant amount shortage detection means can be incorporated in the pressure detection device. Therefore, it is possible to integrate the pressure detection unit and the refrigerant shortage detection unit, and it is not necessary to newly provide the refrigerant shortage detection device as a separate body, and the manufacturing cost can be suppressed.

Further, in claims 4, 5 and 6, the same operation and effect as in claim 3 can be obtained.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment in which the present invention is applied to a vehicle air conditioner will be described below with reference to the drawings. FIG. 2 is a system diagram showing a refrigeration cycle device 11 to which the pressure switch 1 is applied, which is a pressure detection device integrated with the refrigerant shortage detection device according to the present invention. As shown in FIG. 2, the refrigeration cycle apparatus 11 includes a compressor 2, which is driven by a running engine of a vehicle through an electromagnetic clutch (not shown), a refrigerant condenser 6 integrated with a liquid receiving section, and an expansion which is a pressure reducing means. The valve 7 and the evaporator 8 are functional components. Each functional component is connected by a pipe 9. The refrigerant condenser 6 integrated with the liquid receiving portion is
This is a refrigerant condenser in which the condensing unit 3, the liquid receiving unit 4, and the supercooling unit 5 are integrated. As shown in FIGS. 2 and 3, the pipe 9 that connects the subcooling unit 5 and the expansion valve 7 is connected to the inside of the pipe 9 through a communication hole 13 provided in the lower portion of the housing 12. The pressure switch 1 having the pressure receiving chamber 14 which is the above space is provided. That is, the pressure switch 1 is arranged between the refrigerant condenser 6 and the expansion valve 7.

FIG. 3 is a perspective view of the refrigerant condenser 6 integrated with the liquid receiving portion. The refrigerant condenser 6 is mainly divided into a condenser section 3, a supercooling section 5, and a liquid receiving section 4. In the condenser 3, a large number of finned tubes are vertically arranged in parallel. Similarly, a large number of finned tubes are vertically arranged in parallel in the supercooling section 5 arranged below the condenser section 3.

Two header pipes 26a and 26b are arranged opposite to each other with a space provided between the condenser section 3 and the supercooling section 5 arranged vertically. The header pipe 26a is arranged on the inlet side of the condenser 3, and the header pipe 26b is arranged on the outlet side of the condenser 3. When these header pipes 26a and 26b are assembled to the condenser 3 and the supercooling unit 5, the header pipes 26a and 26b are placed at the height of the boundary between the condenser 3 and the supercooling unit 5. Is the separator 27
(Indicated by a dotted line in FIG. 3) is provided. Therefore, the header pipes 26a and 26b are spatially divided into two by the separator 27. Note that the header pipe 26a is provided with a refrigerant inlet 10a at the upper portion and a refrigerant outlet 10b at the lower portion. On the other hand, although not shown, pores communicating with the liquid receiving portion 4 are provided at positions above and below the header pipe 26b with the separator 27 interposed therebetween.

The liquid receiving portion 4 is in the shape of a pipe, its length is shorter than that of the header pipe 26b, and it communicates with the header pipe 26b through the two pores (not shown) described above. The high-temperature, high-pressure gaseous refrigerant that has been adiabatically compressed by the compressor 2 is supplied to the refrigerant condenser 6 via the refrigerant inlet 10a. The supplied refrigerant flows through each finned tube of the condenser 3 in the direction of arrow A in FIG. 2, heat-exchanges with the outside air to be condensed and liquefied, and is a space above the separator 27 of the header pipe 26b. Flow into. At this time, the refrigerant is in a gas-liquid two phase. Further, the gas-liquid two-phase refrigerant is passed through the pores along the arrow B in FIG.
It flows into the liquid receiving part 4 communicating with b. The gas-liquid two-phase refrigerant is gas-liquid separated in the liquid receiving section 4, the gas refrigerant having a small specific gravity is accumulated in the upper portion of the liquid receiving section 4, and the liquid refrigerant having a large specific gravity is accumulated in the lower portion of the liquid receiving section 4. The liquid refrigerant flows into the space below the separator 27 of the header pipe 26b through the pores provided in the lower portion of the liquid receiving section 4, and then flows into the supercooling section 5. The refrigerant introduced into the supercooling section 5 flows through each finned tube in the direction of arrow C in FIG. 2 and is further cooled by the outside air to be in a supercooled state. The refrigerant that has been completely liquefied by being supercooled further reaches the refrigerant outlet port 10b through the space below the separator 27 of the header pipe 26a. The liquid refrigerant that has passed through the refrigerant outlet port 10b is sent to the expansion valve 7 through the pipe 9.

FIG. 1 is a sectional view of a pressure switch 1 which is a pressure detection device integrated with a refrigerant shortage detection device according to the present invention. The pressure switch 1 includes a pressure detection unit and a refrigerant amount shortage detection unit 16 which will be described later. The pressure detection means is
The structure is almost the same as that of a known pressure switch that detects a change in pressure due to deformation of the diaphragm, and the housing 1
A diaphragm 17 and a pressure detector 18 are provided inside the unit 2. The pressure detector 18 is mainly composed of the diaphragm 1.
The operating rod 19 is movable up and down according to the amount of deformation of 7, and the contact rod 20 that is activated when the operating rod 19 is displaced by the increase of the pressure of the refrigerant. The periphery of the diaphragm 17 is hermetically sandwiched by the packing 21, and the lower part of the diaphragm 17 is a pressure receiving chamber 14 which is a space communicating with the pipe 9 via the communication hole 13. The contact switch 20 is provided above the diaphragm 17. On the other hand, the operating rod 19 is the diaphragm 1
It is provided almost vertically from 7 to the contact switch 20. The electrical signal of the contact switch 20 is the terminal 2
It is sent via 2 to a control device (not shown). When the pressure detecting means detects an abnormal increase in the pressure of the refrigerant, this control device controls the electromagnetic clutch to be de-energized so that the operation of the compressor 2 is stopped. Here, in order to provide the refrigerant amount shortage detection means 16 described later in the pressure receiving chamber 14, the pressure receiving chamber 14 of this embodiment is larger than the conventional pressure switch.

The refrigerant shortage detecting means 16 is a float 23.
And a permanent magnet 24, which is a displacement detecting means for the float 23, and a magnetic detection tape 25. The magnetic detection tape 25 is a magnetic detection means for the permanent magnet 24. Float 2
3 is made of resin such as polypropylene and floats on the liquid surface of the refrigerant enclosed in the pressure receiving chamber 14. The permanent magnet 24 is arranged so that the float 2 is parallel to the liquid surface of the refrigerant.
It is fixed to the periphery of 3 with an adhesive or the like.

On the outer periphery of the housing 12, for example,
A magnetic detection tape 25 using sand iron or the like is attached. The magnetic detection tape 25 is attached to the outside of the housing 12 at the same position as the liquid level of the refrigerant in the pressure receiving chamber 14 when it is determined that the amount of the refrigerant is insufficient. The magnetic detection tape 25 has a property of discoloring when a magnet approaches and magnetism is detected.

Next, the operation of this embodiment will be described. First, the operation of the pressure detecting means will be described. When the pressure of the refrigerant rises abnormally, the pressure of the refrigerant sealed in the pressure receiving chamber 14 through the communication hole 13 rises, and the diaphragm 17 is pressed upward. Along with this, the operating rod 19 is displaced upward, and the contact switch 20 operates. When the pressure of the refrigerant rises abnormally, the pressure detecting means thus detects the abnormal rise of the pressure of the refrigerant and sends a signal to the controller to stop the operation of the compressor 2.

Next, the operation of the refrigerant shortage detection means 16 will be described. When the amount of the refrigerant filled in the refrigeration cycle device 11 is appropriate, the pressure receiving chamber 14 in the housing 12 of the refrigerant shortage detection device 1 communicating with the pipe 9 is filled with the refrigerant. Therefore, the float 23 is the uppermost portion of the pressure receiving chamber 14 (the float 23 shown by the solid line in FIG. 1).
Position). However, when the amount of the refrigerant is insufficient, the liquid level of the refrigerant in the pressure receiving chamber 14 drops, and the float 23 moves to the position where the magnetic detection tape 25 is attached (the position of the float 23 shown by the chain double-dashed line in FIG. 1). To do. At this time, when the permanent magnet 24 provided around the float 23 approaches the magnetic detection tape 25, the magnetic detection tape 25 is discolored, and the worker can recognize the shortage of the refrigerant amount.

By the way, in a normal refrigeration cycle apparatus having no subcooling section, the refrigerant that has passed through the condenser and condensed into a liquid state is separated into gas and liquid in the receiver and sent to the expansion valve. . However, although the refrigerant that has passed through the liquid receiver is in a liquid state, it is in a saturated state, so that bubbles are likely to be generated due to a slight change in the environment. Therefore, even in such a refrigeration cycle apparatus, even if a refrigerant shortage detection device that detects a shortage of the refrigerant amount due to the displacement of the float according to the present invention is used, the float is generated due to the generation of bubbles caused by a slight change in the environment. It may be displaced and malfunction may occur, and it is not possible to accurately detect the shortage of the refrigerant amount. However, in the refrigeration cycle apparatus 11 including the subcooling unit 5, the liquid refrigerant that has passed through the liquid receiving unit 4 and is gas-liquid separated is sent to the subcooling unit 5 in a saturated state, and is further cooled in the subcooling unit 5. By being cooled, it is sent to the expansion valve 7 in a completely liquid state. That is, the refrigerant in the completely liquid state flows into the pressure switch 1 arranged between the refrigerant condenser 6 and the expansion valve 7. Therefore, by disposing the float type pressure switch 1 as in the present invention between the refrigerant condenser 6 and the expansion valve 7, there is provided a refrigerant amount shortage detection means that is less likely to malfunction due to a slight change in the environment.
A pressure detection device integrated with a refrigerant shortage detection device can be provided.

Further, the conventional pressure switch can incorporate the refrigerant shortage detecting means 16 and the pressure detecting means and the refrigerant amount shortage detecting means can be integrated.
The manufacturing cost of the pressure switch 1 integrated with the refrigerant shortage detection device can be kept low. In the above embodiments, the magnetic detection tape was used as the magnetic detection means, but it is sufficient if the magnetism of the magnet provided on the float can be detected. For example, the same effect can be obtained by using a reed switch as the magnetic detection means. .

In the above embodiments, the magnetic detecting means is used as the float displacement detecting means. However, the float displacement detecting means is limited to the magnetic detecting means as long as the displacement of the float due to the variation of the refrigerant amount can be detected. It is not something that will be done. Further, in the above embodiment, the float is provided in the pressure receiving chamber of the pressure switch that detects the abnormal increase in the pressure of the refrigerant due to the deformation of the diaphragm, and the pressure detection device is integrated with the refrigerant shortage detection device, but the refrigerant amount is insufficient. A pressure detecting means having a space communicating with the inside of a pipe connecting the refrigerant condenser and the pressure reducing means, which can be provided with a float as the detecting means, may be used, and the pressure detecting means is not limited to this. . Further, similarly, it is possible to provide a float that is a refrigerant amount shortage detection means, having a space portion that communicates with the inside of the pipe that connects the refrigerant condenser and the pressure reducing means, as long as it is any component, insufficient refrigerant amount The portion provided with the detection means is not limited to the pressure detection means.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a pressure switch 1 according to the present invention.

FIG. 2 is a refrigeration cycle apparatus 1 for a refrigeration apparatus using the present invention.
It is a system diagram showing 1.

FIG. 3 is a pressure switch 1 and a refrigerant condenser 6 according to the present invention.
It is a perspective view of.

[Explanation of symbols]

1 Pressure switch which is a pressure detection device integrated with a refrigerant shortage detection device 14 Pressure receiving chamber which is a space 16 Refrigerant amount shortage detection means 23 Float 24 Permanent magnet 25 which is displacement detection means 25 Magnetic detection tape which is magnetic detection means

Claims (6)

[Claims] 1. A refrigerant condenser integrated with a liquid receiver having a structure in which a liquid receiver and a supercooler are integrated in a condenser, the pressure condenser, the evaporator, the compressor, and the refrigerant condenser. Space that is provided in a pipe that connects the container and the decompression means, communicates with the inside of the pipe, a float that is located on the liquid surface of the refrigerant that is enclosed in the space, and displacement that detects displacement of the float A refrigeration cycle device comprising: a refrigerant amount shortage detection means including a detection means. 2. The displacement detecting means for detecting the displacement of the float comprises a permanent magnet provided on the float and displaced integrally with the float, and a magnetic detecting means for detecting the magnetism of the permanent magnet. The refrigeration cycle apparatus according to claim 1, which is characterized in that. 3. A refrigeration cycle apparatus comprising a decompression means, an evaporator, a compressor, and a liquid receiver integrated refrigerant condenser having a structure in which a liquid receiver and a supercooler are integrated in a condenser. Which has a space portion communicating with the inside of a pipe connecting the refrigerant condenser and the pressure reducing means, a pressure detecting means for detecting the pressure of the refrigerant in the pipe, and the space of the pressure detecting means. A refrigerant shortage detection device integrated type pressure, comprising: a float positioned on the liquid surface of the refrigerant enclosed in a portion; and a refrigerant amount shortage detection means having a displacement detection means for detecting the displacement of the float. Detection device. 4. The pressure detecting means includes a diaphragm having a peripheral portion sandwiched in an upper portion of the space portion, and a pressure detecting portion for detecting the pressure of the refrigerant by deformation of the diaphragm, and the displacement detecting means is provided. 4. The pressure detection device integrated with a refrigerant shortage detection device according to claim 3, further comprising: a permanent magnet provided on the float, and a magnetic detection means for detecting magnetism of the permanent magnet. 5. The pressure detecting portion is provided on a side of the diaphragm opposite to the space portion, and an operating rod that is displaced according to the deformation of the diaphragm, and a pair of opposing rods that are activated according to the displacement of the operating rod. 5. A pressure detection device integrated with a refrigerant shortage detection device according to claim 3 or 4, further comprising: a contact switch having a contact. 6. The magnetic detection means, wherein the pressure detection means and the refrigerant shortage detection means are contained inside a housing having the space, and the magnetic detection means is provided at a predetermined position outside the housing. The pressure detection device integrated with the refrigerant shortage detection device according to any one of claims 3 to 5, wherein the pressure detection device is a tape.