JP2006090288A - Two-stage compressor and refrigerator using it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a two-stage compressor in which amount of refrigerant circulation is restrained from reducing by inhibiting refrigerating machine oil from mixing with the refrigerant, and provide further a refrigerator using the compressor. <P>SOLUTION: The two-stage compressor comprises a tightly closed vessel 36 storing the refrigerating machine oil 31 in the bottom, an electric motor 38, a low-stage compression part 32 and a high-stage compression part 34 provided respectively with pistons 40a, 40b, which are reciprocated by the electric motor 38, and cylinders 42a, 42b. The refrigerant is discharged within the tightly closed vessel 36 from a low-stage discharge pipe 62 connected on the discharge side of the low-stage compression part 32, and sucked into a high-stage suction pipe 64 connected on the suction side of the high-stage compression part 34. A radially projected flange 65 is provided around an opening 64a of the high-stage suction pipe 64. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a two-stage compressor having two compression elements and a refrigerator using a refrigeration cycle having the compressor.

  The refrigeration cycle of refrigeration refrigerators currently on the market consists of a compressor, a condenser, a refrigeration cooler, a refrigeration cooler, etc. connected to a storage room in different temperature zones such as a refrigeration room and a freezing room. Are each cooled to a predetermined temperature. Since the compressor used in such a refrigeration cycle is a so-called single-stage compression system, the suction pressure to the compressor is limited to the pressure of a low-temperature refrigeration cooler, which increases the efficiency of the refrigeration cycle. There are limits.

  Therefore, as shown in FIG. 7, a two-stage compressor 100 including a low-stage compression unit 104 and a high-stage compression unit 106 is provided inside the sealed container 102, and a high-stage connected to the discharge side of the high-stage compression unit 106. The outlet side of the condenser connected to the stage discharge pipe 108 is connected to the intermediate pressure suction pipe 110 communicating with the inside of the sealed container 102 via the intermediate pressure decompression device and the intermediate pressure cooler, and the low pressure decompression device and A refrigerator using a refrigeration cycle connected to a low-stage suction pipe 112 connected to the suction side of the low-stage compressor 104 via a low-pressure cooler has been proposed (for example, Patent Document 1).

  The above-described two-stage compressor 100 includes an electric motor 114, pistons 116 and 117 and cylinders 118 and 119 driven reciprocally by the electric motor 114 inside a sealed container 102 that stores the refrigerating machine oil 101 in the inner and lower portions, respectively. The low-stage compression unit 104 and the high-stage compression unit 106 provided are accommodated, and the low-stage discharge pipe 120 connected to the discharge side of the low-stage compression unit 104 and the high-stage connected to the suction side of the high-stage compression unit 106 The stage suction pipe 122 is connected to the inside of the sealed container 102.

In such a refrigeration cycle, the suction pressure into the two-stage compressor 100 is made to correspond to the cooling capacity required for both coolers, and each storage is cooled with cold air at an appropriate temperature, thereby reducing power consumption. Can be planned. Further, since the low-stage discharge pipe 120 and the high-stage suction pipe 122 are connected via the sealed container 102, the inside of the sealed container 102 becomes an intermediate pressure, and the low-stage compression unit 104 and the high-stage compression unit 106 Provide a small pressure difference between the cylinders 118 and 119 and the sealed container 102 to reduce the amount of refrigerant gas leaked between the compression units 104 and 106 and the sealed container 102 to improve the refrigerating capacity. Thus, low power consumption can be achieved.
JP 2001-74325 A

  However, in the above-described two-stage compressor 100, the refrigeration oil 101 is scattered inside the sealed container 102 by the rotation of the electric motor 102, adheres to the high-stage suction pipe 122, and is sucked in a large amount from the opening of the pipe 122. Since the sucked refrigerating machine oil 101 circulates in the refrigeration cycle together with the refrigerant gas, there is a problem that the circulation amount of the refrigerant gas is reduced and the refrigeration capacity is lowered.

  The present invention has been made in consideration of the above circumstances, and prevents refrigerating machine oil adhering to the high-stage suction pipe 122 from being sucked from the opening through the high-stage suction pipe 122. It aims at providing the two-stage compressor which can suppress the fall of the cooling capacity of a refrigerating cycle, and a refrigerator using the same.

  A two-stage compressor according to the present invention is a compressor that compresses a refrigerant in two stages, stores refrigerating machine oil at the inner bottom of a sealed container, and includes a motor, a piston that is reciprocated by the motor, and a cylinder. A high-stage compression section and a high-stage compression section are arranged, and the refrigerant discharged from the low-stage discharge pipe connected to the discharge side of the low-stage compression section to the inside of the sealed container is introduced to the suction side of the high-stage compression section. The high-stage suction pipe is sucked from the connected high-stage suction pipe, and a flange projecting radially outward is provided in the vicinity of the opening of the high-stage suction pipe.

  In the two-stage compressor of the present invention, a flange projecting radially outward is provided in the vicinity of the opening of the high-stage suction pipe that sucks the refrigerant gas inside the hermetic container into the high-stage compression section. Refrigerating machine oil adhering to the suction pipe can be prevented from reaching the opening through the pipe and suppressed from being sucked into the high-stage compression section.

  According to the present invention, it is possible to suppress the reduction of the refrigerant gas discharged from the two-stage compressor by suppressing the intake of the refrigeration oil to the high-stage compressor, and thus improve the driving efficiency of the two-stage compressor. The power consumption of the refrigerator can be reduced.

(First embodiment)
Hereinafter, a first embodiment of the present invention will be described with reference to the drawings.

  1 is a longitudinal sectional view of a two-stage compressor 30 according to a first embodiment of the present invention, FIG. 2 is a plan sectional view of the two-stage compressor 30, and FIG. 3 is a portion of the two-stage compressor 30. 4 is a configuration diagram of a refrigeration cycle 10 using the two-stage compressor 30, and FIG. 5 is a schematic longitudinal sectional view of a refrigerator 1 equipped with the refrigeration cycle 10.

  As shown in FIG. 5, the refrigerator 1 according to the present embodiment forms a storage space inside a heat insulating box, and a partition wall defines a freezing space 2 in a freezing room or ice making room, and a refrigerating space 3 in a refrigerating room or vegetable room. In addition, the storage space is divided into a plurality of temperature zones. The refrigeration space 2 and the refrigeration space 3 are cooled and held at a predetermined temperature by a refrigeration cooler 4, a refrigeration cooler 5, and cold air circulation fans 6, 7 provided respectively. It is cooled by the refrigerant supplied from the two-stage compressor 30 installed in the machine room 8 at the lower back of the main body of the refrigerator 1.

  As shown in FIG. 4, the refrigeration cycle 10 used in the refrigerator 1 includes a compressor 30, a condenser 12, a refrigerant flow switching valve 14, a refrigeration cooler 4 connected in parallel, and a refrigeration cooler 5. Are connected in a ring. The refrigerant vaporized in the condenser 12 is divided by the switching valve 14 and supplied to the refrigeration cooler 4 or the refrigeration cooler 5 via the capillaries 16 and 18 which are decompression devices, respectively, and is evaporated to evaporate each cooling. The coolers 4 and 5 are cooled, and the cool air is circulated by the cool air fans 6 and 7 to cool the respective storage chambers to a predetermined temperature. The evaporated vaporized refrigerant returns to the compressor 30 via the accumulator 20 again. It is configured as follows.

  As shown in FIGS. 1 and 2, the compressor 30 is a reciprocating two-stage compressor in which a compression element is constituted by a low-stage compression section 32 and a high-stage compression section 34. An electric motor 38 supported in an anti-vibration state by an elastic support member 37 is disposed on the inner bottom surface of the sealed container 36 to be stored, and a pair of pistons 40a and 40b driven reciprocally by the electric motor 38 are slidably accommodated above the electric motor 38. A low-stage compression section 32 and a high-stage compression section 34 including cylinders 42a and 42b are disposed.

  More specifically, an eccentric shaft 41 is integrally provided at the upper end portion of the rotating shaft 39 of the electric motor 38 so as to be eccentric from the central axis by a predetermined amount. The rotating shaft 39 rotates to rotate eccentrically. The pair of connecting rods 44a and 44b are reciprocated by the eccentric shaft 41. Pistons 40a and 40b are fitted and fixed to the tips of the connecting rods 44a and 44b by ball joints 46a and 46b, respectively, so that the pistons 40a and 40b in the cylinders 42a and 42b reciprocate.

  The open ends of the cylinders 42a and 42b are closed by valve plates 48a and 48b to form compression chambers 50a and 50b, and the valve covers 52a and 52b are provided between the valve plates 48a and 48b on the outside thereof. Cover to form. Suction ports 54a and 54b and discharge ports 56a and 56b are provided at portions of the valve plates 48a and 48b facing the compression chambers 50a and 50b, and are opened and closed by a valve (not shown). The internal space of the valve covers 52a and 52b is divided into two parts, one of the spaces forms suction chambers 58a and 58b facing the suction ports 54a and 54b, and the other space discharges facing the discharge ports 56a and 56b. Chambers 60a and 60b are provided.

  A low-stage suction pipe 68 extending from the side surface of the hermetic container 36 to the outside is connected to the suction chamber 58a of the low-stage compression section 32, that is, the suction side, and cooling for freezing is performed through the accumulator 20 at the opening. The end of the suction pipe 22 connected to the container 4 is connected.

  A through-hole 61a is provided in the cylinder 42a and the valve plate 48a in the low-stage compression section 32 so as to open to the inside of the sealed container 36 and the discharge chamber 60a. The low-stage discharge pipe 62 is connected to the discharge side of the low-stage compression section 32 by inserting the terminating low-stage discharge pipe 62 into the terminal. On the other hand, the cylinder 42b and the valve plate 48b in the high-stage compression section 34 are provided with a through hole 61b so as to open to the inside of the sealed container 36 and the suction chamber 58b, and the container 36 is provided at the opening on the sealed container 36 side. The high-stage suction pipe 64 is connected to the suction side of the high-stage compression section 34 by inserting the high-stage suction pipe 64 that terminates in the inside. In this way, the refrigerant gas discharged from the low-stage discharge pipe 62 into the sealed container 36 is sucked from the high-stage suction pipe 64.

  As shown in FIGS. 1 and 3, the low-stage discharge pipe 62 and the high-stage suction pipe 64 are arranged so as to be substantially horizontal or inclined upward toward the tip. A flange 65 is provided in the vicinity of the opening 64a. More specifically, the flange 65 projects radially outward from the outer peripheral surface near the opening 64a, and is made of an insulator such as a vulcanized fiber, preferably an insulator having an appropriate flexibility such as a fluororesin.

  A high-stage discharge pipe 70 extending from the side surface of the hermetic container 36 is connected to the discharge chamber 60b of the high-stage compression section 34, that is, the discharge side, and connected to the inlet side of the condenser 12 at the opening. The ends of the discharge pipes 24 are connected.

  The suction pipe 26 connected to the outlet side of the refrigeration cooler 5 is vaporized by the refrigeration cooler 5 by being connected to an intermediate pressure suction pipe 66 that penetrates the side surface of the hermetic container 36 and terminates therein. The refrigerant gas thus introduced is introduced into the internal space of the sealed container 36.

  Next, the operation of the refrigeration cycle 10 will be described.

  When the rotating shaft 39 of the electric motor 38 of the compressor 30 is rotated by turning on the power, the pistons 40a and 40b reciprocate in the cylinders 42a and 42b by the connecting rods 44a and 44b, respectively. The low-stage compression unit 32 sucks the refrigerant gas into the compression chamber 50a from the refrigeration cooler 4 through the accumulator 20, the suction pipe 22, the low-pressure suction pipe 68, and the suction chamber 58a, and then compresses the refrigerant gas to the intermediate pressure. Then, the liquid is discharged into the sealed container 36 through the discharge chamber 60a and the low-stage discharge pipe 62.

  The refrigerant gas discharged from the low-stage discharge pipe 62 is mixed with the refrigerant gas flowing into the sealed container 36 from the intermediate-pressure suction pipe 66 and is compressed from the high-stage suction pipe 64 through the suction chamber 58b. The air is sucked into the compression chamber 50b of the section 34 and compressed to a high pressure. The refrigerant gas compressed by the high stage compression unit 34 is sent to the condenser 12 through the discharge chamber 60b, the high stage discharge pipe 70, and the discharge pipe 24.

The refrigerant that has been radiated in the condenser 12 and condensed and turned into a liquid state is divided into two by the switching valve 14, and one of the refrigerants has an evaporation temperature (for example, −25 ° C.) corresponding to the cooling temperature in the refrigeration space 2. The refrigerant flows into the refrigeration capillary 16 set in the above and is depressurized, flows into the refrigeration cooler 4 and evaporates, and then returns to the compressor 30 via the accumulator 20, the suction pipe 22, and the low-stage suction pipe 68, and is again low. Sucked into the stage compression unit 32. The other liquid refrigerant from the condenser 12 flows into the refrigeration capillary 18 set to have an evaporation temperature (for example, −5 ° C.) corresponding to the cooling temperature in the refrigeration space 3, is reduced in pressure, and is supplied to the refrigeration cooler 5. After flowing in and evaporating, it returns to the compressor 30 through the suction pipe 26 and the intermediate pressure suction pipe 66.

  The refrigerating machine oil 31 is sucked up by the centrifugal force from the lower end portion of the rotating shaft 39 and scattered from the upper end portion of the eccentric shaft 41 by the centrifugal force, and the sliding portions of the pistons 40a and 40b and the cylinders 42a and 42b and the connecting rods 44a, Lubricate the sliding portion 44b. At that time, the refrigerating machine oil 31 adheres to the high-stage suction pipe 64 and flows toward the opening 64a along the outer peripheral surface of the pipe 64, but the flange 65 disposed in the vicinity of the opening 64a The flow is blocked and the refrigerating machine oil 31 can be prevented from flowing in from the opening 64a.

  Thus, according to the above-described embodiment, the flange 65 projecting radially outward is provided in the vicinity of the opening 64 a of the high stage suction pipe 64, so that the refrigeration oil 31 attached to the high stage suction pipe 64 is provided. Can be prevented from being sucked from the opening 64a through the pipe 64, and therefore, the reduction in the circulation amount of the refrigerant gas circulating in the refrigeration cycle 10 can be suppressed, and the efficiency of the refrigeration cycle 10 can be improved. Can do. Further, since the high-stage suction pipe 64 is arranged so as to be inclined substantially horizontally or toward the tip, the refrigerating machine oil 31 flows toward the opening 64a through the high-stage suction pipe 64 by gravity. Can be prevented, and the suction of the refrigerating machine oil 31 from the opening 64a can be more effectively prevented.

  In addition, since the flange 65 is made of an insulator having an appropriate flexibility such as a fluororesin, the hitting sound generated when the flange 65 comes into contact with peripheral components due to vibration when the two-stage compressor 30 is driven is prevented. At the same time, even if it contacts the stator winding or the lead wire of the electric motor 38, it will not leak.

(Second Embodiment)
FIG. 6 shows a second embodiment of the high-stage suction pipe 64 in the above embodiment. In this embodiment, the diameter of the opening 64a of the high-stage suction pipe 64, which is arranged so as to be inclined upward as it goes to the tip, is expanded so that it is larger than the inner diameter of the other part, and the expanded opening 64a is closed by a fine net-like demister 67 knitted with a thin metal wire. Thus, by covering the opening 64a with the demister 67, the refrigerating machine oil 31 can be prevented from being captured by the demister 67 and flowing into the high-stage compression section 34. In addition, by expanding the opening 64 a of the high-stage suction pipe 64, the flow rate of the refrigerant gas to be sucked in is improved to improve the capture capability of the refrigeration oil 31 in the demister 67, and the opening 64 a is covered with the demister 67. Therefore, it is possible to prevent a decrease in the refrigerant gas suction amount.

  INDUSTRIAL APPLICATION This invention can be utilized for the refrigerator which improved cycle efficiency by the two-stage compression refrigerating cycle structure which suppressed the fall of the refrigerant | coolant circulation amount.

It is a longitudinal section of the two-stage compressor concerning one embodiment of the present invention. It is a plane sectional view of the same two-stage compressor. It is a fragmentary sectional view of the same two-stage compressor. It is a block diagram of the refrigerating cycle using the same two-stage compressor. It is a schematic longitudinal cross-sectional view of the refrigerator carrying the same refrigeration cycle. It is a fragmentary sectional view which shows the example of a change of a two-stage compressor. It is a longitudinal cross-sectional view of the conventional two-stage compressor.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Refrigerator 4 ... Refrigeration cooler 5 ... Refrigeration cooler 10 ... Refrigeration cycle 12 ... Condenser 14 ... Switching valve 16, 18 ... Capillary tube (pressure reduction device) 30 ... Two-stage compressor 31 ... Refrigerator oil 32 ... Low stage Compression section 34 ... High stage compression section 36 ... Sealed container 38 ... Electric motors 40a and 40b ... Pistons 42a and 42b ... Cylinder 62 ... Low stage discharge pipe 64 ... High stage suction pipe 64a ... Opening section 65 ... Flange 66 ... For intermediate pressure Suction pipe 67 ... Demister 68 ... Low stage suction pipe 70 ... High stage discharge pipe

Claims (6)

In the compressor that compresses the refrigerant in two stages,
Refrigerating machine oil is stored in the inner bottom portion of the sealed container, an electric motor, and a low-stage compression section and a high-stage compression section each provided with a piston and a cylinder that are reciprocally driven by the electric motor,
The refrigerant discharged into the sealed container from the low-stage discharge pipe connected to the discharge side of the low-stage compression section is sucked from the high-stage suction pipe connected to the suction side of the high-stage compression section. ,
A two-stage compressor characterized in that a flange projecting radially outward is provided in the vicinity of the opening of the high-stage suction pipe.   2. The two-stage compressor according to claim 1, wherein the high-stage suction pipe is disposed so as to be inclined substantially horizontally or toward the tip. 3.   The two-stage compressor according to claim 1 or 2, wherein the flange is made of vulcanized fiber or fluororesin. In the compressor that compresses the refrigerant in two stages,
Refrigerating machine oil is stored in the inner bottom portion of the sealed container, an electric motor, and a low-stage compression section and a high-stage compression section each provided with a piston and a cylinder that are reciprocally driven by the electric motor,
The refrigerant discharged into the sealed container from the low-stage discharge pipe connected to the discharge side of the low-stage compression section is sucked from the high-stage suction pipe connected to the suction side of the high-stage compression section. ,
The high-stage suction pipe has a demister that has a demister that is expanded so that the diameter of the opening is larger than the inner diameter of the other part and closes the opening.   5. The two-stage compressor according to claim 1, further comprising a suction pipe for intermediate pressure that penetrates the sealed container and communicates with the inside. The two-stage compressor according to any one of claims 1 to 5, a condenser connected to a high-stage discharge pipe connected to a discharge side of the high-stage compression unit, and an outlet side of the condenser. A refrigeration cooler and a refrigeration cooler connected from the switching valve via a pressure reducing device,
The outlet side of the refrigeration cooler is connected to a lower stage suction pipe connected to the suction side of the lower stage compression section, and the refrigerant gas flowing out of the refrigeration cooler is sucked into the lower stage suction pipe. The outlet side of the refrigeration cooler is connected to a suction pipe for intermediate pressure communicating with the inside of the sealed container, and the refrigerant gas flowing out of the refrigeration cooler is combined with the refrigerant gas discharged from the low-stage discharge pipe A refrigerator that is sucked into a high-stage suction pipe, compressed, and discharged from the high-stage discharge pipe.

Images