JPH0447154B2 - - 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; The heating cycle starts 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 returns to the four-way valve 2 and the compressor 1. It is formed. this house,
The check valve 4 and the expansion valve 8, as well as the capillary tube 5 and the check valve 7, are 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. ,
It is equipped with a heat radiation control device that detects the temperature of low-pressure side members such as an accumulator and a suction pipe to bring the heat insulating material into close contact with the closed container or to separate it from the closed container.

Effect The present invention, with the above configuration, detects the temperature of the accumulator or suction pipe, controls the amount of heat radiation from the sealed container by bringing the heat insulating material into close contact with or separating it from the sealed container by using the heat radiation control device, and seals the sealed container. This is to maintain the appropriate temperature of the mold compressor. In other words, when the temperature of the accumulator or suction pipe exceeds a certain value, the heat radiation control device separates the heat insulating material from the sealed container to form a gap between the sealed container and the heat insulating material, and the natural convection that occurs between the two Increases heat dissipation and suppresses temperature rise in hermetic compressors. On the other hand, when the temperature of the accumulator or suction 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 the hermetic compressor from overcooling 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. 16 is an accumulator, which is connected to the hermetic compressor 11 via a suction pipe 17. The heat insulating material 18 is provided around the outer periphery of the closed container 12, and is partially overlapped at both ends in the circumferential direction.

Reference numeral 19 denotes a band-shaped heat radiation control device, which includes a bidirectional shape memory alloy portion 19a and an arm 19b having a constant radius of curvature. The shape memory alloy portion 19a is adhesively fixed to the heat insulating material 18 on the inner diameter side, and is in contact with the accumulator 16 on the outer diameter side. Further, when the temperature of the accumulator 16 exceeds a certain value, the radius of curvature of the shape memory alloy part 19a becomes larger than the sum of the radius of the closed container 12 and the thickness of the heat insulating material 18, and the temperature of the accumulator 16 becomes below a certain value. , the shape is memorized so that it is equal to or less than the radius of the closed container 12 and the thickness of the heat insulating material 18. The arm portion 19b is adhesively fixed to the heat insulating material 18, and is connected and fixed to the end of the shape memory alloy portion 19a. Note that 20 is a discharge pipe, which is connected to the closed container 12.

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 in through the suction pipe 17 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 20 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 the intake gas temperature rises and the accumulator 16
Since the temperature exceeds a certain value, the heat radiation control device 19 is activated. That is, in this case, the radius of curvature of the shape memory alloy part 19a of the band-shaped heat radiation control device 19 is larger than the sum of the radius of the closed container 12 and the thickness of the heat insulating material 18, and the heat insulating material 18 is It is separated from the closed container 12, and a gap is formed between the closed container 12 and the heat insulating material 18. 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, hermetic compressor 1
1 is sufficiently cooled to reach an appropriate temperature.

On the other hand, during low outside temperature or low load operation such as heating operation, the temperature of the accumulator 16 becomes lower than a certain value, so the heat radiation control device 19 works, and the radius of curvature of the shape memory alloy part 19a changes to the radius of the closed container 12. and the thickness of the heat insulating material 18 or less, and the heat insulating material 18 is brought into close contact with the closed container 12 by the arm portion 19b. 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, the band-shaped heat radiation control device 19 made of a bidirectional shape memory alloy whose radius of curvature changes depending on the temperature of the accumulator 16 is brought into contact with the accumulator 16, and the heat insulating material 18
By adhesively fixing it to the outside of the hermetic compressor 1, it is possible to
1 can be maintained at an appropriate temperature. the result,
The load range in which the hermetic compressor 11 can be operated can be expanded, and reliability can be improved. In addition, heating operation,
Especially at low outside temperatures, the temperature of the closed container 12 is below a certain value, and the heat radiation control device 19 brings the heat insulating material 18 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.

Further, the accumulator 16 is connected to the hermetic compressor 1.
The vibration propagated from the accumulator 16 causes large vibrations, which worsens the noise characteristics of the hermetic compressor 11.However, since shape memory alloy has the property of rapidly damping vibrations, it is possible to sufficiently dampen the vibrations of the accumulator 16. It is possible to attenuate the noise and improve the noise characteristics of the hermetic compressor 11.

The case where the temperature of the accumulator 16 is detected has been described above, but as shown in FIG. 3 as another embodiment of the present invention, the heat radiation control device 19 is brought into contact with the suction pipe 17. Temperature may also be detected. Alternatively, similar actions and effects can be obtained by detecting the temperature of the other suction side, that is, the low pressure member. Further, similar functions and effects can be obtained by using a bimetal instead of a shape memory alloy.

Effects of the Invention As described above, the present invention detects the temperature of a closed container containing a motor section and a compression mechanism section, a heat insulating material provided around the outer periphery of the closed container, and low-pressure side members such as an accumulator and a suction pipe. The compressor is equipped with a heat radiation control device that brings the insulation material 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. This has effects such as improving heating capacity and reducing power consumption, and since it is controlled by the temperature of the low-pressure side member, the defrosting time can be shortened due to the heat insulation effect during defrosting.

[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... Sealed container (low pressure side member), 13... Motor section, 14... Compression mechanism section, 16... Accumulator, 17... Suction pipe (low pressure side member), 18...
...Insulating material, 19...Heat radiation control device.

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 low-pressure side members such as an accumulator and suction pipe are detected and the heat insulating material is brought into close contact with the sealed container. What is claimed is: 1. A hermetic compressor characterized by comprising a heat radiation control device that separates the compressor from the hermetic container.