JP2009097418A - Hermetically sealed scroll compressor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To exhibit cooling effect of coolant gas by the liquid injection at a maximum extent, by setting a positional relationship among liquid injection holes provided at an end plate of a fixed scroll or a turning scroll, a discharge bypass holes, and an intermediate pressure hole to an optimal relationship, so as to alleviate the problems such as performance deterioration and lap failures and damages of a sliding portion due to pressure increase in gas coolant in an operating compression chamber caused by the liquid injection. <P>SOLUTION: Liquid injection holes 85A, B through which liquid coolant is injected into compression chambers 37A, B formed by a fixed scroll blade 23 and a turning scroll blade 33 are provided on an end plate 19 of a fixed scroll 17, and discharge bypass holes 87A, B, located at a position closer to the center side of a spiral direction than the liquid injection holes 85A, B in the compression chambers 37A, B, for releasing the pressure in the compression chambers at equal to or greater than a fixed pressure, are provided on the end plate 19 of the fixed scroll 17. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a hermetic scroll compressor, and more particularly, to a liquid injection device that injects liquid refrigerant into a compression chamber in order to lower the temperature of discharged gas refrigerant from the compressor.

In a scroll compressor, when there is little heat load in the evaporator, it is not necessary to increase the refrigerant discharge amount from the compressor, so the gas that is being compressed is returned to the suction side to control the capacity. Missed technology is also known.
In addition, we know the technology that prevents the refrigerant gas pressure in the compression chamber from becoming higher than the target set value during high loads, thereby reducing the power used by the drive source and preventing damage to the sliding parts of the compressor. It has been.

  For example, Japanese Patent Laid-Open No. 2003-184775 (Patent Document 1) discloses a liquid refrigerant of ammonia in a scroll compressor used in a refrigeration apparatus using ammonia as a refrigerant so that the temperature of the discharged gas refrigerant does not exceed a set value. A liquid injection circuit for injecting the liquid into the compression chamber of the scroll compressor is shown.

Furthermore, in JP-A-6-26474 (Patent Document 2), as shown in FIG. 8, the liquid injection port 01 is interposed between spiral fixed scroll blades 04 formed on the end plate 03 of the fixed scroll 02. A configuration is disclosed that lowers the gas temperature by opening an electromagnetic valve on the liquid injection circuit and injecting liquid refrigerant into the compression chamber when the discharge gas temperature becomes higher than a set value.
FIG. 8 is a view of the fixed scroll 02 as viewed from the bottom side. Further, in this Patent Document 2, when the gas return port 05 is connected to the suction pipe of the compressor and the heat load in the evaporator is small, Alternatively, a configuration is shown in which when the high load operation cannot be performed due to the capacity of the power supply facility, the gas refrigerant during the compression stroke is returned to the suction side.

JP 2003-184775 A JP-A-6-26474

  As described above, Patent Document 1 and Patent Document 2 show a liquid injection circuit for injecting a liquid refrigerant of ammonia into a compression chamber of a scroll compressor, and Patent Document 2 further describes a liquid injection port. In addition to 01, a gas return port 05 is formed in the compression chamber.

  However, the arrangement relationship between the liquid injection port 01 and the gas return port 05 of Patent Document 2 is arranged at a symmetrical position with respect to the center portion of the scroll blade shape as shown in FIG. For this reason, in the compression chamber formed by meshing with the orbiting scroll, since the relationship is arranged in separate compression chambers, when the pressure in the working compression chamber is greatly increased by injection from the liquid injection port 01, However, there is a problem in that efficiency decreases due to increased power, lap breakage, or load increases. Moreover, even if the gas return port 05 is disposed in the same compression chamber as the liquid injection port 01, it is returned to the suction side, so that it is not effective for the problem that the pressure in the compression chamber increases greatly due to the liquid injection.

  Further, in both Patent Document 1 and Patent Document 2, an intermediate pressure port for guiding the intermediate pressure or high pressure in the compression chamber stroke to the back side of the end plate of the orbiting scroll in order to press the orbiting scroll to the fixed scroll side. The relationship between the gas injection port and the liquid injection port, and the relationship between the gas escape port for discharging the compressed gas into the sealed container and the liquid injection port are not shown.

  Therefore, the present invention has been made in view of such a background, and the optimal arrangement relationship among the liquid injection holes, the gas escape holes, and the intermediate pressure holes provided in the end plates of the fixed scroll or the orbiting scroll is optimal. Set the relationship to reduce problems such as efficiency drop, lap breakage and sliding part damage due to pressure increase of gas refrigerant in the working compression chamber due to liquid injection, and maximize the cooling effect of refrigerant gas of liquid injection It is an object of the present invention to provide a hermetic scroll compressor that can be exerted.

  In order to solve the above-mentioned problem, the present invention combines a fixed scroll having a spiral fixed scroll blade on an end plate and a orbiting scroll having a spiral orbiting scroll blade on an end plate. By rotating the fixed scroll through an anti-rotation mechanism, the volume of the compression chamber formed by the fixed scroll blade and the orbiting scroll blade is reduced to compress the gas, and the compressed gas is centered. In the hermetic scroll compressor configured to discharge from a portion, a liquid injection hole for injecting liquid refrigerant into a compression chamber formed by the fixed scroll blade and the orbiting scroll blade is provided in an end plate of the fixed scroll, In the compression chamber, located closer to the center in the spiral direction than the liquid injection hole, the pressure in the compression chamber is set above a certain level. The discharge bypass hole to release the discharge space have characterized by providing the end plate of the fixed scroll.

  According to this invention, in the compression chamber in which the liquid injection hole is installed, the discharge chamber is located closer to the center in the spiral direction than the liquid injection hole, and discharges compressed gas when the pressure in the compression chamber exceeds the discharge pressure. Since the bypass hole is provided in the end plate of the fixed scroll, even when the pressure in the working compression chamber is greatly increased by liquid injection, the compressed gas is discharged from the discharge bypass hole into the discharge space, and the working compression chamber by liquid injection is used. It is possible to prevent a decrease in efficiency due to an increase in pressure, a lap breakage due to an increase in load, damage to a sliding portion, and the like.

  Preferably, in the present invention, an intermediate pressure hole for taking out an intermediate pressure gas that leads to the back side of the end plate of the orbiting scroll and generates a pressing force that presses the orbiting scroll toward the fixed scroll side is provided in the liquid injection hole. It is desirable to provide the end plate of the orbiting scroll which forms another compression chamber outside the spiral direction with respect to the position.

According to this invention, since the intermediate pressure hole for taking out the intermediate pressure gas is provided on the end plate of the orbiting scroll that forms another compression chamber outside the spiral direction with respect to the position of the liquid injection hole, the liquid by the liquid injection is Inflow from the intermediate pressure hole into the intermediate pressure chamber is prevented.
For this reason, there is a problem that the lubricant flows into the intermediate pressure chamber to wash out the lubricating oil on the sliding surface, resulting in poor lubrication, or the intermediate pressure rises abnormally as the refrigerant liquid gasifies in the intermediate pressure chamber, and the orbiting scroll It is possible to prevent the pressing force that presses against the fixed scroll side from increasing, resulting in a decrease in efficiency and damage to the sliding portion.

  In the present invention, it is preferable that the intermediate pressure hole is installed outside the liquid injection hole by about 180 ° or more in the spiral direction in a state where the fixed scroll and the orbiting scroll are combined.

  According to this invention, since the intermediate pressure hole is installed outside the liquid injection hole by about 180 ° or more in the spiral direction, the position of the intermediate pressure hole is surely different from the working compression chamber in which the liquid injection is installed. Therefore, it is possible to reliably prevent the occurrence of poor lubrication, reduction in efficiency, and the like due to the liquid refrigerant caused by liquid injection flowing into the intermediate pressure chamber as described above.

In the present invention, it is preferable that a plurality of the liquid injection holes, discharge bypass holes, and intermediate pressure holes are provided, and the relationship is established in each of the plurality of compression chambers.
According to such a configuration, in each of the plurality of compression chambers, the discharge bypass hole is disposed on the center side in the spiral direction in the same compression chamber with respect to the position of the liquid injection hole, and the intermediate pressure hole is positioned at the position of the liquid injection hole. In contrast, it is installed in another compression chamber outside the spiral direction.
Therefore, it is possible to avoid a decrease in efficiency due to an increase in pressure in the working compression chamber that may occur due to liquid injection in each of the plurality of compression chambers in the compression stroke, and a lap breakage or a sliding portion damage due to an increase in load. In addition, the cooling effect of the refrigerant gas by liquid injection can be effectively obtained.

  According to the present invention, the arrangement relationship between the liquid injection hole provided in the end plate of the fixed scroll or the orbiting scroll, the discharge bypass hole, and the intermediate pressure hole is set to an optimal relationship, and the inside of the working compression chamber by the liquid injection is set. To obtain a hermetic scroll compressor capable of maximizing the cooling effect of liquid injection refrigerant gas by reducing problems such as reduced efficiency, lap breakage and sliding part damage associated with increased pressure of gas refrigerant Can do.

  Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the drawings. However, the dimensions, materials, shapes, relative arrangements, and the like of the components described in this embodiment are not intended to limit the scope of the present invention unless otherwise specified, and are merely illustrative examples. Only.

  FIG. 1 is an overall configuration cross-sectional view showing an embodiment of a hermetic scroll compressor according to the present invention, and FIG. 2 is an enlarged view of an upper portion of the overall cross-sectional view of FIG. FIG. 3 is a bottom view of the fixed scroll. 4A and 4B are drawings showing the orbiting scroll, wherein FIG. 4A is a plan view, and FIG. 4B is a cross-sectional view taken along line BB in FIG. 5 is a cross-sectional view taken along the line AA in FIG. FIG. 6 is a view corresponding to FIG. 5 showing another embodiment. FIG. 7 is an explanatory view of the operation state of the compression chamber.

The overall configuration of the hermetic scroll compressor will be described with reference to FIGS. 1 and 2. As shown in FIG. 1, a vertically long cylindrical sealed case 2 constituting the hermetic scroll compressor 1 is welded to a curved lower case 3, a curved upper case 5, and a cylindrical middle case 6. It is formed by bonding.
A frame member 7 is attached to the inside of the middle case 6 so as to partition the inside of the sealed case 2 up and down, close to the upper side in the sealed case 2.
A scroll compression mechanism unit 9 is disposed above the frame member 7, and a motor 13 is disposed below the orbiting scroll 11 that constitutes the scroll compression mechanism unit 9. Further, lubricating oil is accommodated in the bottom of the sealed case 2, and an oil supply pump 15 that pumps up the lubricating oil stored in the bottom is disposed below the motor 13.

  As shown in FIG. 2, the scroll compression mechanism unit 9 is composed of a fixed scroll 17 and a turning scroll 11 arranged below the fixed scroll 17. The fixed scroll 17 includes a disc-shaped end plate 19, an annular wall 21 protruding from the peripheral edge of one surface of the end plate 19, and the annular wall 21 at a portion surrounded by the annular wall 21. The fixed scroll blades 23 projecting at substantially the same height, the discharge port 25 provided in the substantially central portion of the end plate 19, and the suction port 27 provided in the peripheral portion of the end plate 19 are configured. . An extended portion of the annular wall 21 is fixed to the frame member 7 with a bolt 29.

  On the other hand, the orbiting scroll 11 has an outer diameter larger than the annular wall 21 and has an end plate 31 of the disc-shaped orbiting scroll 11 and a height equal to the fixed scroll blade 23 on one surface of the end plate 31. The orbiting scroll vane 33 projecting from the bearing boss 35 is projected from the center of the other surface.

  Further, the orbiting scroll vane 33 projecting spirally on the end plate 31 of the orbiting scroll 11 and facing upward, and the fixed scroll vane 23 projecting spirally on the end plate 19 of the fixed scroll 17 and facing downward. And a compression chamber 37 is formed between the respective walls.

  Then, in order to maintain the meshed state of the fixed scroll 17 and the orbiting scroll 11 and to make the orbiting scroll 11 orbit relative to the fixed scroll 17, between the end plate 31 of the orbiting scroll 11 and the frame member 7. Is provided with an Oldham mechanism 38.

  The frame member 7 is provided with a cylindrical space 39 that is eccentric with respect to the axial center line of the bearing boss portion 35 of the orbiting scroll 11 so as to penetrate in the vertical direction. A main bearing 43 that rotatably supports the 13 drive shafts 41 is provided.

A crank portion 45 is formed at an upper end portion of the drive shaft 41 at a position eccentric from the shaft center line of the drive shaft 41, and the crank portion 45 is fitted into the bearing boss portion 35 of the orbiting scroll 11. The bearing boss portion 35 forms a swing bearing for the crank portion 45.
Further, as shown in FIG. 1, an oil supply pump 15 is connected to the lower end portion of the drive shaft 41. The oil supply pump 15 pumps up lubricating oil by a pipe 47 and penetrates the shaft center portion of the drive shaft 41. Then, the oil is discharged from the upper end of the crank portion 45 into the bearing boss portion 35 through the through oil passage 49 provided.

  Note that the compressed gas used is ammonia refrigerant, and in order to suppress the rise in discharge gas temperature, the ammonia liquid refrigerant is fed into the compression chamber 37 from the liquid injection pipe 57 attached to the end plate 19 of the fixed scroll 17. It comes to inject. This liquid injection will be described later.

Further, as shown in FIG. 1, in order to cancel the unbalance caused by the rotation of the crank portion 45 eccentric with respect to the drive shaft 41, the drive shaft 41 includes an upper balancer 59, a middle balancer 61, a lower balancer in order from the top. 63 three balancers are attached.
Furthermore, a suction pipe 65 is provided through the upper case 5 at the suction port 27 of the fixed scroll 17, and a discharge pipe 67 for discharging high-pressure gas in the case is provided at the middle case 6.

Next, in the hermetic scroll compressor configured as described above, the refrigerant gas compression operation by the scroll compression mechanism unit 9 will be described.
First, when power is supplied to the motor 13, the drive shaft 41 starts to rotate. Then, the rotational force is transmitted to the orbiting scroll 11.
Since the bearing boss portion 35 of the orbiting scroll 11 is provided eccentrically with respect to the drive shaft 41 and is fitted to the crank portion 45 and supported by the Oldham mechanism 38, the orbiting scroll 11 does not rotate. Perform a swivel motion.
Accordingly, the orbiting scroll blade 33 implanted in the orbiting scroll 11 also performs orbiting motion, and the compression chamber 37 formed between the orbiting scroll blade 33 and the fixed scroll vane 23 is periodically provided along with the orbiting motion. A communication hole (not shown) formed around the frame member 7 after the gas is reduced and is sucked in through the suction pipe 65 is compressed and discharged from the discharge port 25 and discharged upward in the sealed case 2. The high-pressure gas is stored in the space below the frame member 7 in the sealed case 2 through the lower side, and discharged from the discharge pipe 67 to the outside.

Next, liquid injection will be described.
FIG. 3 is a view of the fixed scroll 17 as viewed from the lower surface side. The fixed scroll blade 23 is formed in a spiral shape, and the orbiting scroll blade 33 is fitted between the adjacent spiral-shaped fixed scroll blade 23. A spiral spiral groove 80 is formed in a concave shape. The inlet of the spiral groove 80 is connected to the suction port 27 and the outlet is connected to the discharge port 25.

Further, a through hole 83 of a bolt 29 for attaching the fixed scroll 17 to the frame member 7 is formed in the peripheral portion of the end plate 19 of the fixed scroll 17.
In the end plate 19 which is the bottom portion of the spiral groove 80, liquid injection holes 85 and 85 are formed at two positions at positions in contact with the vertical wall of the fixed scroll blade 23.

  A liquid injection pipe 57 is connected to the liquid injection hole 85. Then, a liquid injection valve or an electronically controlled expansion valve provided in a liquid injection circuit (not shown) is controlled in relation to the temperature of the compressed gas discharged from the discharge port 25, and the amount of liquid refrigerant supplied to the liquid injection pipe 57 Is to be controlled.

  By performing liquid injection in this way, the ammonia liquid as the liquid refrigerant is injected into the compressed gas in the compression stroke in the compression chamber and cooled, and compressed by the scroll compression mechanism unit 9 and discharged from the discharge port 25. It is possible to suppress the gas temperature from becoming high, and as a result, it is possible to suppress the temperature increase of the gas temperature in the sealed case 2 to exhibit the cooling effect of the motor 13 and to improve the efficiency of the motor 13.

As shown in FIG. 3, the liquid injection hole 85 and the discharge bypass hole 87 are formed side by side along the spiral direction of the fixed scroll blade 23, and the liquid injection hole 85 and the discharge bypass hole 87 are paired. Is arranged.
Further, as shown in FIG. 3, the discharge bypass hole 87 is provided inside the spiral from the liquid injection hole 85 and is installed in a range of 90 ° or less in the spiral angle.
By providing a relief hole inside the vortex, the compression in the compression chamber turns toward the center of the vortex and the volume is reduced and the pressure is increased. Thus, the function of the discharge bypass hole 87 is made reliable.
Further, the adjacent compression chambers 37 are installed so as to be positioned in the respective compression chambers 37 so that another pair of liquid injection holes 85 and discharge bypass holes 87 are provided.

  The discharge bypass hole 87 is controlled to be opened and closed based on the pressure in the compression chamber 37 by a discharge bypass control valve 89 installed in the upper part of the fixed scroll 17. When the temperature rises abnormally due to the load of the refrigeration system or the gas temperature, it automatically opens and is released from the scroll compression mechanism 9 into the discharge space in the sealed case 2 so that the pressure in the compression chamber 37 does not rise abnormally. So that it is controlled.

  Further, the contact between the tip surface of the scroll blade 23 of the fixed scroll 17 and the mirror surface of the end plate 31 of the other-side turning scroll 11, and the end surface of the scroll blade 33 of the turning scroll 11 and the end plate of the other-side fixed scroll 17. The orbiting scroll 11 is pressed against the fixed scroll 17 in order to make the contact with the mirror surface 19 slidably contact each other against the compression pressure in the compression chamber 37.

This pressing force causes a high pressure, which is the discharge pressure of the compressor, to act on the back side of the end plate 31 of the orbiting scroll 11 and supply an intermediate pressure in the middle of the compression stroke to the outer region. The orbiting scroll 11 is pressed in a well-balanced manner.
In order to guide this intermediate pressure to the back side of the end plate 31 of the orbiting scroll 11, an intermediate pressure hole 91 is formed in the end plate 31 of the orbiting scroll 11 as shown in FIG. .

  As shown in FIG. 4, the orbiting scroll blades 33 are formed in a spiral curve on the end plate 31 of the orbiting scroll 11, and a spiral passage 93 is formed between the spiral-shaped orbiting scroll blades 33. Two intermediate pressure holes 91 are drilled in the vicinity and the position on the center side of the circumference of the inlet, so as to sandwich the orbiting scroll blade 33.

The intermediate pressure hole 91 communicates with the side end surface of the end plate 31 through an intermediate pressure passage 95 extending radially inside the end plate 31 and is guided to the intermediate pressure chamber 97 of the frame member 7. The pressure during the compression stroke is applied to the back side of the end plate 31 of the orbiting scroll 11.
In addition, in the bearing boss portion 35 at the center portion of the end plate 31 of the orbiting scroll 11, the lubricating oil stored in the bottom of the sealed case 2 is pumped up and supplied by the oil pump 15, and simultaneously, the high-pressure gas in the sealed case 2 is also supplied. A high pressure chamber is formed by supply.

  Next, referring to FIG. 5 and FIG. 6, the positional relationship between the liquid injection hole 85, the discharge bypass hole 87, and the intermediate pressure hole 91 in a state where the orbiting scroll 11 and the fixed scroll 17 are combined. explain. FIG. 5 is a cross-sectional view taken along the line AA in FIG. 2. As shown in FIG. 5, the inner chamber compression chamber 37A formed inside the orbiting scroll 11 includes a liquid injection hole 85A, a discharge bypass hole 87A, And a liquid injection hole 85B and a discharge bypass hole 87B are installed in the outer chamber compression chamber 37B formed outside the orbiting scroll 11, respectively.

  Further, as shown in FIG. 5, the relative position between the liquid injection hole 85 and the intermediate pressure hole 91 is separated from the vortex outside by about 270 ° or more when the orbiting scroll 11 and the fixed scroll 17 are assembled. The liquid refrigerant is positioned in a completely different compression chamber 37 from the intermediate pressure hole 91.

  In each of the compression chambers 37A and 37B, an example has been described in which one discharge bypass hole 87A and 87B and one intermediate pressure hole 91 are provided for one of the liquid injection holes 85A and 85B. A plurality of holes 85 and a plurality of discharge bypass holes 87 and intermediate pressure holes 91 may be provided.

FIG. 6 shows a specification in which the position of the liquid injection hole is arranged close to the suction port 27. Thus, by installing it at a position close to the suction port 27, liquid injection into the compression chamber can be efficiently performed even for a compressor with a low compression ratio specification (high temperature specification).
In FIG. 6, the inner chamber compression chamber 97 </ b> A formed inside the orbiting scroll 11 is provided with a liquid injection hole 105 </ b> A and a discharge bypass hole 107 </ b> A, and an outer chamber compression chamber formed outside the orbiting scroll 11. 97B is provided with a liquid injection hole 105B and a discharge bypass hole 107B, respectively. Further, an intermediate pressure hole 91 is formed.

FIG. 7 shows the relationship between the operation state accompanying the rotation of the shaft of the compression chamber of the scroll compressor shown in FIG. 6 and the three types of holes.
FIG. 7A shows that the outer chamber compression chamber 97B formed between the spiral outer wall of the orbiting scroll blade 33 of the orbiting scroll 11 and the outer wall of the spiral groove 80 of the fixed scroll 17 forms the maximum sealed space, and the suction is completed. The compression stroke start state is shown. From this state, states in which the shaft rotates at a pitch of 90 ° and the compression operation proceeds are shown in order in (b), (c), and (d).
Further, (c) shows that the inner chamber compression chamber 97A formed between the spiral inner wall of the orbiting scroll blade 33 of the orbiting scroll 11 and the inner wall of the spiral groove 80 of the fixed scroll 17 forms a maximum sealed space. .

  The compression chamber is an outer chamber compression formed between the spiral outer wall of the orbiting scroll blade 33 of the orbiting scroll 11 and the outer wall of the spiral groove 80 of the fixed scroll 17 when the entire stroke from the suction to the discharge stroke is taken as one system. Two systems are formed: a compression system in the chamber 97B and a compression example in the inner chamber compression chamber 97A formed between the spiral inner wall of the orbiting scroll blade 33 of the orbiting scroll 11 and the inner wall of the spiral groove 80 of the fixed scroll 17. Therefore, looking at the positional relationship of the above three types of holes arranged in each, the intermediate pressure hole 91 on the outside in the spiral direction, the discharge bypass holes 107A and 107B on the inside, and the liquid injection holes 105A and 105B are arranged therebetween. ing. This positional relationship is the same for both systems.

The positional relationship of each hole will be specifically described with reference to FIG.
First, looking at the positional relationship between the intermediate pressure hole 91 and the liquid injection holes 105A and 105B, they are located on opposite sides of the spiral curve, so the period of opening to the same compression chamber during one rotation of the shaft is ( d) As seen in the figure, the distance is small and the mutual influence is small.
Next, looking at the positional relationship between the liquid injection holes 105A and 105B and the discharge bypass holes 107A and 107B, they are close to each other, so the period of opening to the same compression chamber during one rotation of the shaft is (a) to (c ) As shown in the figure, when the compression chamber pressure is abnormally increased due to liquid injection, the pressure can be released from the discharge bypass holes 107A and 107B.

According to the present embodiment as described above, in the arrangement relationship of the three types of holes shown in FIG. 5, the discharge bypass holes 87A and 87B have a spiral direction more than the liquid injection holes 85A and 85B in each of the compression chambers 37A and 37B. Is provided on the end plate 19 of the fixed scroll 17 so as to release the pressure in the compression chambers 37A and 37B at a predetermined pressure or higher, so that the pressure in the working compression chamber is greatly increased by liquid injection. Even in this case, the compressed gas is discharged from the discharge bypass holes 87A and 87B, and the efficiency is reduced due to an increase in pressure in the working compression chamber due to liquid injection, and further, the lap breakage and the sliding portion damage due to the load increase are prevented. Can do.
6 and 7, when the pressure in the working compression chambers 97A and 97B is greatly increased by liquid injection, the compressed gas is discharged from the discharge bypass holes 107A and 108B.

  Further, according to the present embodiment, the intermediate pressure hole 91 for taking out the intermediate pressure gas that leads to the back side of the end plate 31 of the orbiting scroll 11 and generates a pressing force that presses the orbiting scroll 11 to the fixed scroll 17 side, Since the liquid injection hole 85A, 85B, 105A, 105B is provided on the other compression chamber outside the spiral direction or on the end plate of the orbiting scroll at a position separated by nearly 180 ° even in the same compression chamber, the liquid by liquid injection Is prevented from flowing into the intermediate pressure chamber 97 from the intermediate pressure hole 91, and flows into the intermediate pressure chamber 97, and lubricates the sliding surface between the frame member 7 and the back surface of the end plate 31 of the orbiting scroll 11. The problem of poor lubrication due to washing, or the intermediate pressure abnormally increases as the liquid gasifies in the intermediate pressure chamber 97, and the orbiting scroll 1 The increasing force pressing the fixed scroll 17 side, it is possible to prevent the problem of damage to the reduced efficiency and the sliding portion.

  Furthermore, according to the relationship between the intermediate pressure hole 91, the liquid injection holes 85A and 85B, and the discharge bypass holes 87A and 87B shown in FIG. 5, the intermediate pressure hole 91 is in a state where the fixed scroll 17 and the orbiting scroll 11 are combined. Since it is installed outside of the spiral direction by about 270 ° or more from the injection hole 85B, the position of the intermediate pressure hole 91 is surely installed in a compression chamber different from the working compression chamber in which the liquid injection is installed, The liquid refrigerant of the liquid injection flows into the intermediate pressure chamber 97 as described above, and problems such as the occurrence of poor lubrication and a decrease in efficiency can be reliably prevented.

  Further, according to the relationship between the intermediate pressure hole 91, the liquid injection holes 105A and 105B, and the discharge bypass holes 107A and 107B shown in FIG. 6, the intermediate pressure hole 91 is in a state where the fixed scroll 17 and the orbiting scroll 11 are combined. Since it is installed on the outside of the spiral direction by about 180 ° or more from the injection hole 105B, the period during which the position of the intermediate pressure hole 91 is installed is a very short period, and the liquid refrigerant of the liquid injection is placed in the intermediate pressure chamber 97. The occurrence of poor lubrication and reduced efficiency can be suppressed as much as possible.

  In addition, each of the plurality of compression chambers 37A, 37B, 97A, and 97B in FIGS. 5 and 6 has the relationship of the liquid injection hole, the discharge bypass hole, and the intermediate pressure hole, that is, the discharge bypass hole is the liquid injection hole. In the same compression chamber, the intermediate pressure hole is located in the other compression chamber outside the spiral direction with respect to the position of the liquid injection hole, or in the same compression chamber. However, since they have a relationship of being separated by nearly 180 °, in each of the plurality of compression chambers 37A, 37B, 97A, and 97B in the compression stroke, the efficiency is reduced due to the pressure increase in the working compression chamber generated by liquid injection, and the load It is possible to effectively avoid lap breakage and sliding part damage due to increase, and liquid injection Deployment to improve the cooling effect of the refrigerant gas by, further, it is possible to suppress occurrence of poor lubrication flows into the intermediate pressure chamber 97 the liquid refrigerant in the liquid injection as much as possible.

  According to the present invention, the arrangement relationship between the liquid injection hole provided in the end plate of the fixed scroll or the orbiting scroll, the discharge bypass hole, and the intermediate pressure hole is set to an optimal relationship, and the inside of the working compression chamber by the liquid injection is set. To reduce the problems such as efficiency drop, lap breakage and sliding part damage due to increased pressure of gas refrigerant, and to maximize the cooling effect of liquid gas in liquid injection, to the hermetic scroll compressor It is useful when applying

1 is an overall configuration cross-sectional view showing an embodiment of a hermetic scroll compressor according to the present invention. It is an enlarged view of the upper part of the whole sectional view of FIG. It is a bottom view of a fixed scroll. It is drawing which shows a turning scroll, (a) is a top view, (b) is BB sectional drawing of (a). It is AA sectional drawing of FIG. It is a figure corresponding to FIG. 5 which shows other embodiment. It is operation | movement state explanatory drawing of a compression chamber. It is explanatory drawing of a prior art.

Explanation of symbols

1 Sealed scroll compressor 2 Sealed case 7 Frame member
DESCRIPTION OF SYMBOLS 9 Scroll compression mechanism part 11 Orbiting scroll 17 Fixed scroll 19, 31 End plate 23 Fixed scroll blade 33 Orbiting scroll blade
37 Compression chamber 80 Swirl groove 85 Liquid injection hole 85A, 85B, 105A, 105B Liquid injection hole 87 Discharge bypass hole 87A, 87B, 107A, 107B Discharge bypass hole 91 Intermediate pressure hole 93 Spiral path 95 Intermediate pressure path

Claims (4)

Combining a fixed scroll having a spiral fixed scroll blade on the end plate and a rotary scroll having a spiral turning scroll blade on the end plate, the orbiting scroll with respect to the fixed scroll via a rotation prevention mechanism A hermetic scroll configured to compress the gas by reducing the volume of the compression chamber formed by the fixed scroll blade and the orbiting scroll blade by discharging the compressed gas from the center. In the compressor,
A liquid injection hole for injecting liquid refrigerant into a compression chamber formed by the fixed scroll blade and the orbiting scroll blade is provided in an end plate of the fixed scroll, and is positioned closer to the center in the spiral direction than the liquid injection hole in the compression chamber. A hermetic scroll compressor characterized in that a discharge bypass hole for discharging the pressure in the compression chamber to a discharge space at a predetermined pressure or more is provided in an end plate of the fixed scroll.   An intermediate pressure hole for extracting an intermediate pressure gas that leads to the back side of the end plate of the orbiting scroll and generates a pressing force that presses the orbiting scroll toward the fixed scroll side is provided outside the spiral direction with respect to the position of the liquid injection hole. 2. The hermetic scroll compressor according to claim 1, wherein the scroll scroll compressor is provided on an end plate of the orbiting scroll forming another compression chamber.   3. The hermetic scroll compressor according to claim 2, wherein the intermediate pressure hole is installed outside the liquid injection hole by about 180 ° or more in a spiral direction in a state where the fixed scroll and the orbiting scroll are combined. .   3. The hermetic scroll compressor according to claim 1, wherein a plurality of the liquid injection holes, discharge bypass holes, and intermediate pressure holes are provided, and each of the plurality of compression chambers has the relationship.

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