JPH0445673B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a hermetic compressor used in an air conditioner.

BACKGROUND TECHNOLOGY Conventional hermetic compressors of this type have been designed to prevent abnormal temperature rises that would lead to reductions in motor windings and poor lubrication of sliding parts, as disclosed in, for example, Japanese Utility Model Publication No. 52-26291. A liquid injection cooling system was used.

FIG. 4 shows the configuration of a conventional hermetic compressor. That is, the cooling cycle from the compressor 1 through the four-way valve 2, the outdoor heat exchanger 3, the check valve 4, the capillary tube 5, and the indoor heat exchanger 6, and then returning to the four-way valve 2 and the compressor 1; A heating cycle is formed from the compressor 1 through the four-way valve 2, the indoor heat exchanger 6, the check valve 7, the heating expansion valve 8, the outdoor heat exchanger 3, and then back to the four-way valve 2 and the compressor 1. has been done. Of these, the check valve 4 and the expansion valve 8 or the capillary tube 5 and the check valve 7 are each arranged in parallel. The compressor 1 is cooled by branching an injection extension pipe 10 from the intermediate point 9 between the check valves 4 and 7 and supplying the injection flow rate to the compressor 1 via the injection extension pipe 10. That's what I do.

Problems to be Solved by the Invention However, in the conventional configuration as described above, the pressure at the inlet of the injection pipe 10 is approximately equal to the discharge pressure of the compressor 1 during both cooling and heating. As a result, more injection flow is required during cooling to cool the compressor 1 to a suitable temperature. For this reason, although a small injection flow rate is sufficient during heating, the inject flow rate is not reduced during heating, resulting in the problem of overcooling the compressor 1.

In view of the above-mentioned problems, the present invention provides a hermetic compressor that controls the temperature according to the air-conditioning load.

Means for Solving the Problems In order to solve the above problems, the hermetic compressor of the present invention includes a hermetic container containing a motor section and a compression mechanism section, a heat insulating material provided around the outer periphery of the hermetic container. ,
The airtight container is equipped with a heat radiation control device that detects the temperature of a high-pressure side member such as a discharge pipe and brings the heat insulating material into close contact with the airtight container or separates it from the airtight container.

Effects The present invention has the above configuration, detects the temperature of the closed container or the discharge pipe, and controls the amount of heat radiated from the closed container by bringing the heat insulating material into close contact with or separating it from the closed container using the heat radiation control device, It maintains the temperature of the hermetic compressor appropriately. In other words, when the temperature of the sealed container or discharge pipe exceeds a certain value, the heat radiation control device separates the insulating material from the sealed container to form a gap between the sealed container and the insulating material, and the natural convection that occurs in that gap is released. Increases the amount of heat and suppresses the temperature rise of the hermetic compressor. On the other hand, when the temperature of the hermetic container or the discharge pipe falls below a certain value, the heat radiation control device brings the heat insulating material into close contact with the hermetic container to prevent overcooling of the hermetic compressor due to heat radiation.

Embodiment Hereinafter, a hermetic compressor according to an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 shows a longitudinal cross-sectional view of a hermetic compressor according to an embodiment of the present invention, and FIG. 2 is a cross-sectional view taken along line AA of the hermetic compressor shown in FIG. In FIGS. 1 and 2, reference numeral 11 denotes a hermetic compressor, which is composed of a hermetic container 12, a motor section 13, and a compression mechanism section 14. Motor part 1
The stator 15 and compression mechanism section 14 of No. 3 are connected to the airtight container 1.
It is fixed at 2.

A heat insulating material 16 is provided so as to be wrapped around the outer periphery of the closed container 12, and the heat insulating material 16 is partially overlapped at both ends in the circumferential direction. Reference numeral 17 denotes a band-shaped heat radiation control device made of a bidirectional shape memory alloy, which is adhesively fixed to the inside of the heat insulating material 16 and is in contact with the closed container 12 . The heat radiation control device 17 is
When the temperature of the closed container 12 exceeds a certain value, the radius of curvature becomes larger than the radius of the closed container 12, and when the temperature of the closed container 12 falls below a certain value, the radius of curvature becomes equal to the radius of the closed container 12. is stored in shape memory. Note that the suction pipe 18 is connected to the compression mechanism section 14, and the discharge pipe 19 is connected to the closed container 1.
Connected to 2.

The operation based on the above configuration will be explained below.

The compression mechanism section 14 is driven by the motor section 13,
Gas refrigerant is sucked through the suction pipe 18 and compressed, and the high temperature and high pressure gas refrigerant is discharged into the closed container 12 . Thereafter, the high temperature gas refrigerant is transferred to the motor section 13.
The liquid passes through a passage formed by the stator 15 and the closed container 12, reaches the discharge pipe 19 at the upper part of the closed container 12, and flows out from the closed container 12. Here, the stator 15 generates heat and has a higher temperature than the gas refrigerant. Therefore, since the closed container 12 is in direct contact with the high temperature gas refrigerant and the stator 15, the temperature is high.

During cooling operation, especially when the load is large at high outside temperatures, the hermetic compressor 11 tends to reach an abnormally high temperature, but when the temperature of the hermetic container 12 exceeds a certain value, the heat radiation control device 17 is activated. That is, in this case, the radius of curvature of the band-shaped heat radiation control device 17 is equal to that of the closed container 12.
, the heat insulating material 16 is separated from the closed container 12 by the heat radiation control device 17, and a gap is formed between the closed container 12 and the heat insulating material 16. There, natural convection occurs, and air whose temperature is sufficiently low compared to the temperature of the hermetic compressor 11 flows in, thereby promoting heat radiation from the hermetic container 12. As a result, the hermetic compressor 11 is sufficiently cooled and reaches an appropriate temperature.

On the other hand, during low outside temperature or low load operation such as heating operation, the temperature of the closed container 12 becomes lower than a certain value, so the heat radiation control device 17 operates, and its radius of curvature becomes equal to the radius of the closed container 12. Insulation material 1
6 is tightly attached to the closed container 12. As a result, the hermetic compressor 11 is cooled with low-temperature air and does not become overcooled, and the hermetic compressor 11 reaches an appropriate temperature.

As described above, according to this embodiment, by providing the band-shaped heat radiation control device 17 made of a bidirectional shape memory alloy whose radius of curvature changes depending on the temperature of the closed container 12 inside the heat insulating material 16, cooling and heating can be performed. Or hermetic compressor 11 regardless of low load or high load.
temperature can be maintained appropriately. As a result, the operable load range of the hermetic compressor 11 can be expanded, and reliability can be improved. In addition, heating operation,
Particularly at low outside temperatures, the temperature of the closed container 12 is below a certain value, and the heat radiation control device 17 brings the heat insulating material 16 into close contact with the closed container 12, so that the heat radiation loss from the closed container 12 can be reduced and the heating capacity can be improved. Furthermore, when the hermetic compressor 11 is turned off during on-off operation under high load, the hermetic container 1
When the temperature of 2 drops, the heat radiation control device 17 operates,
The insulation material 16 that had been separated from the closed container 12 until then
Since it is in close contact with the closed container 12, energy loss due to heat radiation from the closed container 12 during off-time can be reduced, and power consumption can be reduced.

Although the case where the temperature of the closed container 12 is detected has been described above, the same operation and effect can be obtained by detecting the temperature of the discharge pipe 19. That is, FIGS. 3a and 3b show another embodiment of the present invention, and in this example, the heat radiation control device 17 similar to that in FIGS. The temperature of the discharge pipe 19 is detected. Further, in this example, the heat radiation control device 17 is adhesively fixed to the outside of the heat insulating material 16. 20 is an accumulator.

Effects of the Invention As described above, the present invention provides an airtight container with a built-in motor section and a compression mechanism section, a heat insulating material provided around the outer periphery of the airtight container, and temperature control of high-pressure side members such as the airtight container and a discharge pipe. Equipped with a heat radiation control device that detects heat insulation and brings it into close contact with or separates it from the hermetic container, it not only maintains the temperature of the hermetic compressor appropriately, but also expands the load range and improves reliability. In addition, since it is controlled by the temperature of the high-pressure side member, it is possible to speed up cold start and hot restart.

[Brief explanation of drawings]

FIG. 1 is a longitudinal cross-sectional view of a hermetic compressor according to an embodiment of the present invention, FIG. 2 is a cross-sectional view of the hermetic compressor shown in FIG. 1, and FIGS. FIG. 4 is a refrigeration cycle diagram showing a conventional method for cooling a hermetic compressor. 12... Airtight container (high pressure side member), 13... Motor section, 14... Compression mechanism section, 16... Heat insulating material, 17... Heat radiation control device, 19... Discharge pipe (high pressure side member).

Claims (1)

[Claims] 1 A sealed container containing a motor part and a compression mechanism part, a heat insulating material provided around the outer periphery of the sealed container, and the temperature of high-pressure side members such as the sealed container and discharge pipe are detected and the heat insulating material is tightly attached to the sealed container. What is claimed is: 1. A hermetic compressor, characterized in that it is equipped with a heat radiation control device that controls the temperature of the compressor and separates it from the hermetic device.