JPH09170574A - Scroll gas compressor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize effective piping constitution of a by-pass hole for improvement of compression efficiency of a scroll gas compressor furnished with a capacity ratio constantly without a closed compressed space. SOLUTION: By-pass holes 39a, 39b to communicate a second compression chamber 2b and a discharge chamber 32 to each other at a position where a part of the by-pass holes 39a, 39b is not blocked by a revolving scroll lap 13a in a state immediately before the second compression chamber 2b nearest to a discharge port is communicated to the discharge port 30 and in a state where the second compression chamber 2b advances by 150 degrees from the former state. In this constitution, in the case when a driving compression ratio is smaller than a set compression ratio, it is possible to reduce compression input and to prevent damage of a compressor by preventing overcompression by discharging a part of gas in the middle of compression to a discharge chamber 32.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bypass valve device for a scroll gas compressor.

[0002]

2. Description of the Related Art A scroll compressor having low vibration and low noise characteristics has a suction chamber located at the outer periphery of a spiral forming a compression space, a discharge port provided at the center of the spiral, and a suction volume and final compression. The volume ratio determined by the chamber volume is constant. In particular, when there is little fluctuation in the compression ratio determined by the suction pressure and the discharge pressure, a discharge valve for compressing fluid such as a reciprocating compressor or a rotary compressor is set by setting a volume ratio that matches it. Highly efficient compression is possible without requiring a device.

When this scroll compressor is used as a refrigerant compressor for air conditioning, the suction pressure and the discharge pressure of the refrigerant change due to variable speed operation and air conditioning load fluctuations. Then, due to the difference between the actual compression ratio and the set compression ratio, insufficient compression or overcompression operation occurs. At the time of insufficient compression, the high-pressure refrigerant gas in the discharge chamber intermittently flows backward from the discharge port into the compression chamber, resulting in an increase in compression input. Further, when a so-called liquid compression phenomenon occurs in which a liquid refrigerant or a large amount of lubricating oil is compressed, an excessive compression state occurs, which may cause abnormal increase in compression input, excessive vibration and noise, and compressor damage.

A check valve device may be provided on the outlet side of the discharge port as a measure for preventing the backflow of the compressed fluid due to such insufficient compression. Further, as a measure for reducing liquid compression, as described in Japanese Patent Publication No. 5-49830, in particular, a compression chamber having a compression chamber which is not always connected to the suction chamber or the discharge chamber and which is a constantly closed space is provided. In the case of space, bypass holes are provided at symmetrical positions leading from the compression chamber to the discharge chamber, which is a normally closed space with a high frequency of excessive compression.
There is known a means for preventing a compressor from being damaged due to liquid compression or overcompression by providing a bypass valve device on the outlet side of the bypass hole that allows only the fluid to flow into the discharge chamber.

[0005]

However, in the above-mentioned conventional structure, the liquid compression which is the over-compression and the normal over-compression may occur not only in the above-mentioned always closed space but also in any compression chamber during the compression. is there. Further, depending on the configuration of the scroll compressor, there may be a case where the volume ratio is such that there is no compression chamber that is always a closed space. Therefore, installing a bypass hole causes gas to remain in the compression chamber during compression,
As a result, since the compression efficiency is likely to be lowered, there is a problem that there are few guidelines for setting the bypass hole position, particularly in the case of the scroll gas compressor having the volume ratio in which the compression chamber that is always the closed space does not exist. It was Further, the position of the bypass hole provided to prevent damage to the compressor is often determined by the arrangement configuration of the bypass valve device in relation to the check valve device that opens and closes the discharge port. As a matter of course, there is little idea of actively introducing a bypass hole and a bypass valve device to improve the compression efficiency in a wide compression ratio operation region of the scroll gas compressor, and an effective bypass function for improving the compression efficiency. It has been desired to realize a scroll gas compressor equipped with.

The present invention is intended to solve such a conventional problem, and it is an object of the present invention to improve the performance in an operating condition with a compression ratio of medium or lower without impairing the performance in an operating condition with a large compression ratio. And

[0007]

In order to solve the above-mentioned problems, the present invention provides a bypass hole in a specific range of the compression chamber closest to the discharge port. By opening the bypass hole, it is possible to improve the overall compression efficiency through the entire operation compression ratio region including the case where the operation compression ratio is larger than the set compression ratio and the case where the operation compression ratio is smaller than the set compression ratio.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION In order to solve the above-mentioned problems, the invention according to claim 1 does not have a space which does not intermittently communicate with the discharge chamber or the suction chamber in the spiral compression space, A position immediately before the compression chamber closest to the outlet communicates with the discharge port and a state in which the compression chamber closest to the discharge port is advanced by 150 degrees from that state are positioned so that the orbiting scroll wrap does not block part of the bypass hole. A bypass hole that connects the compression chamber and the discharge chamber is provided. Further, according to this configuration, even when the operating compression ratio is larger than the set compression ratio,
It is possible to promote partial discharge of gas in the compression chamber immediately before opening to the discharge port to the discharge port, and suppress overcompression when discharging gas from the discharge port. Further, when the operating compression ratio is smaller than the set compression ratio, it is possible to prevent the overcompression by partially discharging the gas during the compression to the discharge chamber.

According to the second aspect of the present invention, the single bypass valve device arranges the bypass holes close to each other so as to simultaneously open and close the plurality of bypass holes, and the bypass holes are dispersed to continuously maintain the gas during compression. It is possible to secure the passage of the bypass hole while discharging the gas to the discharge chamber.

According to the third aspect of the present invention, the check valve device for opening and closing the discharge port also serves as the bypass valve device, so that the degree of freedom of the bypass hole opening position can be increased and the bypass valve device can be omitted.

According to a fourth aspect of the present invention, another auxiliary bypass hole and an auxiliary bypass hole are opened and closed at a position retracted within 360 degrees from the bypass hole closest to the discharge port and within 360 degrees from the start of compression. By disposing the bypass valve device on the end plate, the area of the closed compression space can be reduced and the area of overcompression can be reduced.

According to a fifth aspect of the present invention, the compression chamber between the bypass hole and the auxiliary bypass hole is opened in a state where it is fully opened and closed by the orbiting scroll wrap, and the other end communicates with the decompression device of the refrigeration cycle. In addition, the injection holes are provided in the end plate, and when the compressor operating compression ratio is higher than the set compression ratio (undercompression state), part of the unevaporated refrigerant (refrigerant mixture of liquid and gas) is compressed during compression. It is possible to flow into the chamber to cool the compression portion, increase the compression completion pressure to eliminate the insufficient compression state, and increase the discharge pressure.

According to a sixth aspect of the present invention, an opening / closing valve is provided in the middle of the refrigerant injection pipe between the pressure reducing device of the refrigeration cycle and the injection hole, and the opening / closing valve is provided when the compressor operating compression ratio is larger than the set compression ratio. Is connected to a refrigeration cycle in which the on-off valve is controlled so as to be shut off when the compressor is in operation other than that. It is possible to prevent the refrigerant liquid compression immediately after the compressor is started and reduce the starting load.

[0014]

Embodiments of the present invention will be described below with reference to the drawings.

(Embodiment 1) In FIG. 1, an iron-made hermetically sealed container 1 showing a partial vertical sectional view of a horizontal scroll refrigerant compressor.
Has a high-pressure atmosphere that communicates with a discharge pipe (not shown). The motor 3 is arranged in the central part and the compression part is arranged in the right part, and one end of the drive shaft 4 fixed to the rotor 3a of the motor 3 is supported. The main body frame 5 of the compression unit is fixed to the closed container 1, and the fixed scroll 7 is attached to the main body frame 5. The main shaft direction oil hole 12 provided in the drive shaft 4 has one end communicating with an oil supply pump device (not shown) and the other end finally communicating with the main bearing 8. The orbiting scroll 13 that meshes with the fixed scroll 7 to form the compression chamber 2 includes a spiral orbiting scroll wrap 13a and a wrap support disk 13b in which an orbiting shaft 13c is upright. It is located in between. The fixed scroll 7 includes an end plate 7a and a spiral fixed scroll wrap 7b. The fixed scroll wrap 7a has a discharge port 30 at the center and an intake chamber 3 at the outer periphery.
1 is arranged. The discharge port 30 is connected to the adjacent discharge chamber 3
2 leads to a high-pressure space in which the motor 3 is arranged. The suction chamber 31 communicates with a suction pipe 33 that penetrates the end wall of the closed container 1. The orbiting bearing 14 arranged in the right end hole of the drive shaft 4 eccentrically from the main shaft of the drive shaft 4 is configured to engage and slide with the orbiting shaft 13c of the orbiting scroll 13. Between the lap support disk 13b of the orbiting scroll 13 and the thrust bearing 19 provided on the main body frame 5, there is provided a minute gap capable of forming an oil film. An annular seal member 18 which is substantially concentric with the swivel shaft 13c is mounted on the lap support disk 13b in a loosely fitted state, and the annular seal member 18 separates the inner rear chamber A20 from the outer side. The back chamber A20 communicates with the adjacent main bearing 8 while
It also communicates with the oil hole 12 of the drive shaft 4 via the sliding surface of the slewing bearing 14. Between the oil chamber 15 at the bottom of the slewing bearing 14 and the back chamber C16 in the outer peripheral space of the lap support disk 13b,
It communicates via an oil passage 21 provided in the lap support disk 13b. The oil passage 21 has a throttle portion A22 and a throttle portion B23 at both ends thereof, and a bypass oil hole 24 in the middle thereof. The bypass oil hole 24 is arranged so as to intermittently communicate with an annular oil groove 25 provided on the surface of the thrust bearing 19 as the orbiting scroll 13 orbits. The annular oil groove 25 and the back chamber C16 communicate with each other through an exhaust oil passage 26 provided in a part of the annular oil groove 25. The annular groove 25 of the thrust bearing 19 is a rotation preventing member (not shown).
It is also arranged so as to intermittently communicate with a locking groove (not shown) of the orbiting scroll 13 that engages with. The back chamber C16 and the suction chamber 31 are communicated with each other via an oil groove 50 (see FIGS. 2 and 3) provided on the surface of the end plate 7a that is in sliding contact with the lap support disk 13b. A check valve device 35 that opens and closes the outlet side of the discharge port 30 is mounted on the plane of the end plate 7a of the fixed scroll 7. The check valve device 35 includes a thin steel plate reed valve 35a and a valve retainer 35b. Become. A second portion that intermittently communicates with the discharge port 30 is provided at the center of the end plate 7a.
Two pairs of the first bypass hole 30a and the second bypass hole 39b, which are open to the compression chamber 2b and the discharge chamber 32 and have an opening to the second compression chamber 2b smaller than the width of the orbiting scroll wrap 13a, are orbiting scrolls. Along the wall surface of the wrap 13a, they are sequentially symmetrically arranged so as to follow the compression progress direction,
A bypass valve device 40 for opening and closing the outlet side of the first bypass hole 39a and the second bypass hole 39b is arranged on the end plate 7a. In addition, a pair of auxiliary bypass holes 49 that open to the first compression chamber 2a and the discharge chamber 32 that are intermittently in communication with the suction chamber 31 and the opening to the first compression chamber 2a is smaller than the width of the orbiting scroll wrap 13a. Orbiting scroll wrap 13
An auxiliary bypass valve device 42 that is symmetrically arranged near the wall surface of a and opens and closes the outlet side of the auxiliary bypass hole 49 is arranged on the end plate 7a.

FIG. 2 is a view showing a cross section taken along the line AA in FIG. 1. The state of the compression space immediately before the second compression chamber 2b which is intermittently communicated with the discharge port 30 and the discharge port 32 is opened. Indicates. The first bypass hole 39a and the second bypass hole 39b are arranged at positions that are not partially blocked by the orbiting scroll wrap 13a.

FIG. 3 shows the state of the compression space when the orbiting scroll wrap 13a in FIG. 2 is advanced by 150 degrees.
In this state, the first bypass hole 39a and the second bypass hole 39b are arranged at positions that are not partially blocked by the orbiting scroll wrap 13a, and the first bypass hole 39a and the second bypass hole 39b are The passage is secured.

FIG. 4 is a view showing a state in which the first bypass hole 39a, the second bypass hole 39b and the auxiliary bypass hole 49 shown in FIGS. 2 and 3 are sequentially opened and closed as the orbiting scroll wrap 13a orbits. Particularly, (a) shows an intermediate state between FIG. 2 and FIG. (B)-(d)
Shows the other positional relationship among the orbiting scroll wrap 13a, the first bypass hole 39a, the second bypass hole 39b, and the auxiliary bypass hole 49.

FIG. 5 is a view showing an arrangement in which the check valve device 35, the bypass valve device 40, and the auxiliary bypass valve device 42 shown in FIG. 1 are mounted on the end plate 7a.

In FIG. 6, the horizontal axis represents the compressor operating speed and the vertical axis represents the pressure and the compression ratio, and the actual load showing the relationship between the compressor operating speed and the suction pressure, the discharge pressure, and the compression ratio when the air conditioner is operating. It is a figure which shows a characteristic.

FIG. 7 is a P-V diagram of a conventional scroll refrigerant compressor in which the horizontal axis represents the volume change of the compression chamber and the vertical axis represents the pressure change of the compression chamber.

In the structure of the scroll refrigerant compressor described above, when the drive shaft 4 is rotationally driven by the motor 3, the orbiting scroll 13 supported by the thrust bearing 19 of the body frame 5 orbits, and the refrigeration cycle connected to the compressor. The suction refrigerant gas containing the lubricating oil flows into the suction chamber 31 via the suction pipe 33, is compressed and transferred to the compression chamber 2 formed between the orbiting scroll 13 and the fixed scroll 7, and the central portion Is discharged from the discharge pipe (not shown) to the outside of the compressor while cooling the motor 3 through the discharge port 30 and the discharge chamber 32. The discharge refrigerant gas containing the lubricating oil is separated in the middle of the passage from the discharge chamber 32 to the discharge pipe (not shown) and is collected in the oil sump 11. Lubricating oil acting on the discharge pressure is sent to the oil chamber 15 via the oil hole 12 of the drive shaft 4 by the oil supply pump device (not shown) connected to one end of the drive shaft 4.
Most of the oil returns to the oil sump 11 via the sliding surfaces of the orbiting bearing 14 and the main bearing 8, while the remaining lubricating oil passes through an oil passage 21 provided in the orbiting scroll 13 and finally to the rear surface. It flows into the chamber C16. The lubricating oil flowing through the oil passage 21 is
A primary pressure reduction is performed at the throttle portion A22 at the inlet portion, a part of the lubricating oil flows into the annular oil groove 25 provided in the thrust bearing 19 through the bypass hole 24, and the remaining lubricating oil is subjected to the secondary pressure reduction at the throttle portion B23. After being lubricated, the lubricating oils that have passed through both paths merge in the back chamber C16 communicating with the suction chamber 31. Oil passage 2
The first lubricating oil is affected by the passage resistance when the bypass hole 24 intermittently communicates with the annular oil groove 25 in accordance with the orbiting motion of the orbiting scroll 13. That is, when the turning speed is slow, a large amount of lubricating oil in the oil passage 21 flows into the annular oil groove 25,
When the swirling speed is high, the lubricating oil in the oil passage 21 is in the annular oil groove 2
It is adjusted so that it flows into 5 less. The pressure of the refrigerant gas in the compression chamber 2 is the orbiting scroll 13 in the main axis direction of the drive shaft 4.
Acts to separate the fixed scroll 7 from the fixed scroll 7. On the other hand, the wrap support disk 13b of the orbiting scroll 13 receives a back pressure from the back chamber A20 (the inner part surrounded by the annular seal member 18) where the discharge pressure acts. Therefore, the force for separating the orbiting scroll 13 from the fixed scroll 7 and the back pressure cancel each other out. As a result, when the back pressure is larger than the separating force of the orbiting scroll 13, the lap support disk 13 b is fixed to the end plate 7 of the fixed scroll 7.
It is supported by a and, in the opposite case, by a thrust bearing 19. In any of the above cases, the lap support disk 13b
A small gap is maintained between the sliding surface and the sliding surface, and an oil film is formed by the lubricating oil supplied to the sliding surface to reduce the sliding resistance. Regardless of whether the lap support disk 13b of the orbiting scroll 13 is supported by the end plate 7a of the fixed scroll 7 or the thrust bearing 19, the gap between the compression chambers 2 is very small, and the compression chambers are sequentially passed through the back chamber C16 and the suction chamber 31. It is sealed with an oil film of the lubricating oil flowing into No. 2. On the other hand, since the scroll compressor has a constant compression ratio, a large amount of the refrigerant liquid is sucked into the suction pipe 33 in the initial stage of the cold start of the compressor.
There is a case where the liquid returns from the refrigeration cycle via the flow path and flows into the compression chamber 2 to cause liquid compression, and the compression chamber 2 has an abnormally increased pressure and becomes higher than the pressure in the discharge chamber 32. When liquid compression occurs in the first compression chamber 2a (see FIGS. 2 and 3) that intermittently communicates with the suction chamber 31, as shown in FIG. 5, the outlet of the auxiliary bypass hole 49 provided in the end plate 7a. The auxiliary bypass valve device 42 for closing the side and the bypass valve 40 for closing the outlet side of the first bypass hole 39a and the second bypass hole 39b are sequentially opened to allow the refrigerant to flow out to the discharge chamber 32, thereby lowering the pressure of the compression chamber. In addition, the second compression chamber 2 that communicates intermittently with the discharge port 30.
When liquid compression occurs in b (see FIGS. 2 and 3), the first bypass hole 39a and the second bypass hole 3 provided in the end plate 7a are provided.
The bypass valve 40 that closes the outlet side of 9b opens to allow the refrigerant to flow into the discharge chamber 32, thereby reducing the pressure in the compression chamber. In addition,
The first bypass hole 39a, the second bypass hole 39b, and the auxiliary bypass hole 49 are the same among the first bypass hole 39a, the second bypass hole 39b, and the auxiliary bypass hole 49, regardless of which compression chamber 2 the liquid compression occurs. Since each bypass hole is arranged so as to open with either of them, at least one of the auxiliary bypass valve device 42 and the bypass valve device 40 always opens. Further, the auxiliary bypass valve device 42 and the bypass valve 40 are opened not only when liquid compression occurs in the compression chamber 2. That is, as shown in FIG. 6, the suction pressure in the normal refrigeration cycle operation decreases as the compressor changes from low speed to high speed operation.
On the other hand, the discharge pressure generally rises, and the compression ratio generally rises. Therefore, when the auxiliary bypass valve device 42 and the bypass valve 40 are not installed, the compression ratio at the time of low speed operation of the compressor is smaller than the compression ratio set in the rated load operation state, as shown by the shaded portion in FIG. It becomes over-compressed. In such a case, as described above, the reed portion 40b of the bypass valve 40 that closes the outlet sides of the first bypass hole 39a and the second bypass hole 39b opens to let the refrigerant flow into the discharge chamber 32, and the two-dot chain line As indicated by 99, the compression chamber pressure drops midway and the compression load is reduced. In general, the respective pressures of the compression chambers 2 (compression chamber A, compression chamber B) arranged at symmetrical positions are different from each other due to the difference in sealing degree of the compression chamber. This pressure difference in the compression chamber 2 gives a rotation force to the orbiting scroll 13 to give a rotation force to a rotation preventing member (not shown) of the orbiting scroll 13. However, when the auxiliary bypass valve device 42 and the bypass valve 40 are opened to reduce the compression load, the compression chamber 2 (compression chamber A, compression chamber B)
Is instantaneously equalized via the discharge chamber 32 during the compression stroke, and the pressure difference in the compression chamber is reduced. On the other hand, during high-speed operation of the compressor, the pressure in the suction chamber 31 decreases and the pressure in the discharge chamber 32 increases. As a result, the actual refrigeration cycle operation compression ratio is larger than the scroll compressor set compression ratio (compression state). Thus, the refrigerant gas in the discharge chamber 32 undergoes the second compression via the discharge port 30 in the process of expanding the volume of the second compression chamber 2b and before the check valve device 35 closes the discharge port 30. The gas flows back into the chamber 2b intermittently. This backflow refrigerant gas is recompressed in the second compression chamber 2b and becomes an overcompressed state. Also in this case, similarly to the above, the bypass valve device 40 is opened through the first bypass hole 39a and the second bypass hole 39b,
The over-compressed refrigerant gas is partially discharged into the discharge chamber 32 to reduce the pressure in the compression chamber. By opening the bypass valve device 40 through the first bypass hole 39a, the timing of discharging the refrigerant gas from the second bypass hole 39b to the discharge chamber 32 is accelerated, the compression chamber pressure drop is accelerated, and the overcompression loss is reduced. . Since the first bypass hole 39a and the second bypass hole 39b are not opened at the position closest to the discharge port 30, the second compression chamber 2b is closed by the orbiting scroll wrap 13a even immediately before the discharge port 32 is opened. Instead, it functions as a bypass action to the discharge chamber 32. Also, the first
Since the bypass hole 39a and the second bypass hole 39b are opened at a position where they are not blocked by the orbiting scroll wrap 13a even when the second compression chamber 2b has advanced by 150 degrees from the state immediately before opening to the discharge port 32, the orbiting scroll 39a is opened. The second compression chamber 2b is not partially blocked after the wrap 13a passes through the first bypass hole 39a and the second bypass hole 39b, and the bypass that is always effective against the overcompression phenomenon occurring in the compression chamber 2 is generated. It can exert its effect. Further, since the first bypass hole 39a and the second bypass hole 39b are arranged with an appropriate interval, the time when the first bypass hole 39a and the second bypass hole 39b are simultaneously closed by the orbiting scroll wrap 13a. It can be shortened and the effectiveness of bypass action is lengthened. That is, by continuing the bypass action from the first bypass hole 39a and the second bypass hole 39b, the second compression chamber 2
The change in pressure of the second compression chamber 2b when b is opened to the discharge port 32 becomes small, and the sound flowing out to the discharge chamber 32 and the check valve device 3 are generated.
The generated sound and discharge pulsation from 2 are reduced.

Due to the residual differential pressure immediately after the compressor is stopped, the lubricating oil in the oil sump 11 is forced into the oil hole 12, the oil passage 21, the rear chamber C16,
It flows into the first compression chamber 2a through the suction chamber 31 in sequence. Oil compression occurs in the first compression chamber 2a when the compressor is restarted. Naturally, this lubricating oil is discharged to the discharge chamber 32 through the auxiliary bypass hole 49, and thereafter, the smooth compressor operation continues. The pressure of the back chamber C16 communicating with the suction chamber 31 can be set to a suction pressure equivalent to the suction pressure or an intermediate pressure between the suction pressure and the discharge pressure depending on the passage resistance between the suction chamber 31 and the back chamber C16. it can.

In the above embodiment, one auxiliary bypass hole is symmetrically arranged, but a plurality of auxiliary bypass holes may be symmetrically arranged.
A single auxiliary bypass valve device may open and close a plurality of auxiliary bypass holes.

(Embodiment 2) FIG. 8 is a view showing the shape of a check valve device 35a in which the check valve device 35 and the bypass valve device 40 in FIG. 5 are integrated.

In the above structure, the check valve device for closing the discharge port 32 by partially discharging the refrigerant gas in the middle of the compression of the second compression chamber 2b to the discharge chamber 32 through the first bypass hole 39a and the second bypass hole 39b. 40a has begun to open, and the compression completion refrigerant gas is discharged to the discharge chamber 32 through the discharge port 32 immediately after the second compression chamber 2b is opened to the discharge port 32 without delay. Therefore, the pressure of the discharge port 32 after the completion of compression does not rise excessively, and the compression input is reduced. Although the check valve device 35a and the auxiliary bypass valve device 42 have different configurations in FIG. 8, the above-described operation is the same even if all of them are connected.

Further, although the refrigerant compressor has been described in the above embodiment, other gas compressors such as nitrogen, oxygen, and helium have the same operation.

(Embodiment 3) FIG. 9 shows a scroll refrigerant compressor 101 in the middle of a decompression device 103 of a refrigeration cycle piping system.
Is connected to the compression chamber of the refrigerant injection pipe 105, and an opening / closing valve 106 is provided in the middle thereof to open the opening / closing valve 106 when the compressor operating compression ratio is larger than the set compression ratio (compression insufficiency state). It is a figure which shows the refrigerating cycle which carries out the refrigerant injection of the unevaporated refrigerant (mixed refrigerant of liquid and gas) which decompressed the refrigerant liquefied in the condenser 102 to the intermediate pressure between discharge pressure and suction pressure in the compression chamber. The refrigerant injection pipe 105 is opened symmetrically with respect to the second compression chamber 2b shown in (3) of FIG. 4 (opened between the first bypass hole 39a and the auxiliary bypass hole 49) and provided on the end plate 7a. Through the injection hole 98, the second compression chamber 2
It leads to b. The injection hole 98 is opened along the wall surface of the orbiting scroll wrap 13a, and the size of the opening is set so as to be opened and closed by the orbiting scroll wrap 13a.

In the above construction, when the compressor operating compression ratio is larger than the set compression ratio (compression insufficiency state), part of the non-evaporated refrigerant (refrigerant mixture of liquid and gas) flows into the second compression chamber 2b. Then, it merges with the refrigerant gas in the middle of compression via the suction chamber 31 to cool the compression section, increase the compression completion pressure to eliminate the insufficient compression state, and increase the pressure in the discharge chamber 32. The refrigerant gas passing through the discharge chamber 32 can lower the temperature of the motor 3 and increase the efficiency of the motor 3. When this refrigeration cycle is used for the heating operation of the air conditioner, it is possible to raise the temperature of the air blown into the room and improve the heating capacity.
When the pressure of the refrigerant gas during compression becomes higher than the pressure of the discharge chamber 32, the refrigerant gas during compression passes through the first bypass hole 39a and the second bypass hole 39b in the same manner as described above.
It can be partially discharged to prevent overcompression. When the compressor operating compression ratio is less than or equal to the set compression ratio, the on-off valve 106 is shut off and the refrigerant injection action is stopped. As a matter of course, immediately after the compressor is started and after the compressor is stopped, the on-off valve 106 is shut off to prevent the refrigerant liquid compression immediately after the compressor is started and reduce the starting load.

[0030]

As is apparent from the above-described embodiments, the invention according to claim 1 has a discharge port in the form of a spiral compression space in which there is no space that does not communicate with the discharge chamber or the suction chamber intermittently. The state immediately before the compression chamber that is closest to the discharge port communicates with the discharge port, and the compression chamber that is closest to the discharge port is 150
In the state in which the bypass scroll hole is partially closed by the orbiting scroll wrap in the state of being moved forward, a bypass hole communicating between the compression chamber and the discharge chamber is provided. If it is larger than the set compression ratio,
It is possible to promote partial discharge of gas in the compression chamber immediately before opening to the discharge port to the discharge chamber and suppress overcompression when discharging gas from the discharge port to reduce compression input. When the operating compression ratio is smaller than the set compression ratio, it is possible to partially discharge the gas in the middle of the compression to the discharge chamber to prevent overcompression, thereby reducing the compression input and preventing the compressor from being damaged.

According to the second aspect of the present invention, the single bypass valve device arranges the bypass holes close to each other so as to simultaneously open and close the plurality of bypass holes. According to this configuration, the bypass holes are dispersed and compressed. The gas can be continuously discharged to the discharge chamber during the process to reduce the discharge noise. Further, the passage of the bypass hole can be secured to further enhance the effect of the bypass action.

According to the third aspect of the present invention, the check valve device for opening and closing the discharge port also serves as the bypass valve device. According to this configuration, the degree of freedom of the bypass hole opening position is widened and the operation compression in a wide range is performed. A bypass effect can be exerted on the specific area. Further, the cost can be reduced by omitting the bypass valve device.

According to a fourth aspect of the present invention, another auxiliary bypass hole and an auxiliary bypass hole which is opened and closed at a position retracted within 360 degrees from the bypass hole closest to the discharge port and within 360 degrees from the start of compression. By arranging the bypass valve device on the end plate, this configuration can reduce the area of the closed compression space, reduce the frequency of overcompression, and reduce the compressor starting input. As a result, the durability of the compressor can be improved and the size of the compressor can be reduced.

According to a fifth aspect of the present invention, the compression chamber between the bypass hole and the auxiliary bypass hole is opened with the orbiting scroll wrap fully closed and the other end is connected to the middle of the decompression device of the refrigeration cycle. With this configuration, the injection hole is provided in the end plate. According to this configuration, when the compressor operating compression ratio is higher than the set compression ratio (insufficient compression), part of the unevaporated refrigerant (mixed refrigerant of liquid and gas) It can flow into the compression chamber during compression to cool the compression section, raise the compression completion pressure to eliminate the insufficient compression state, and raise the discharge pressure, so this refrigeration cycle can be used for heating operation of the air conditioner. When used, the temperature of air blown indoors can be increased to improve heating capacity. In addition, even when the refrigerant is slightly excessively flowing into the compression chamber through the refrigerant injection hole, excessive overcompression does not occur due to the bypass action to the discharge chamber via the bypass valve device, so that the refrigerant injection effect is effectively exhibited. It is not necessary to adjust the injection amount of the refrigerant. As a result, the refrigerant injection effect can be exhibited in a wide range of the operation compression ratio.

According to a sixth aspect of the present invention, an opening / closing valve is provided in the middle of the refrigerant injection pipe between the pressure reducing device of the refrigeration cycle and the injection hole, and the opening / closing valve is provided when the compressor operating compression ratio is larger than the set compression ratio. Is connected to a refrigeration cycle that controls to shut off the on-off valve during compressor operation other than that.With this configuration, refrigerant liquid compression is prevented immediately after the compressor is started and the durability of the compressor is improved. With this, it is possible to reduce the starting load.

[Brief description of the drawings]

FIG. 1 is a partial vertical cross-sectional view of a scroll refrigerant compressor showing an embodiment of the present invention.

FIG. 2 is a sectional view taken along the line AA in FIG.

FIG. 3 is a state diagram when the compression space in FIG. 2 is advanced by 150 degrees.

4A is a state diagram showing a sequential change of the compression space in FIG. 2, FIG. 4B is the same state diagram, FIG. 4C is the same state diagram, and FIG.

FIG. 5 is a layout diagram of a check valve device, a bypass valve device, and an auxiliary bypass valve device.

FIG. 6 is a characteristic diagram showing the relationship between compressor operating speed and pressure.

FIG. 7 is a characteristic diagram showing a volume change and a pressure change state of the compression chamber.

FIG. 8 is a layout view of a check valve device and an auxiliary bypass valve device according to another embodiment of the present invention.

FIG. 9 is a piping system diagram in which the scroll gas compressor of the present invention is connected to a refrigeration cycle.

[Explanation of symbols]

 4 Drive Shaft 5 Body Frame 7 Fixed Scroll 7a End Plate 7b Fixed Scroll Wrap 13 Orbiting Scroll 13a Orbiting Scroll Wrap 13b Lap Support Disc / Lap Support Disc 19 Thrust Bearing 30 Discharge Port 31 Suction Chamber 32 Discharge Chamber 35 Check Valve Device 39a No. 1 Bypass hole 39b Second bypass hole 40 Bypass valve device 42 Auxiliary bypass valve device 49 Auxiliary bypass hole 98 Injection hole 103 Pressure reducing device 105 Refrigerant injection pipe 106 Open / close valve

Claims (6)

[Claims] 1. A spiral fixed scroll wrap which is formed upright on one surface of a mirror plate which is a part of a fixed scroll, and which is upright and fixed on a lap support disk which is a part of an orbiting scroll. Orbiting scroll wraps similar in shape to scroll wraps are meshed with each other to form a pair of spiral compression spaces between the scrolls, and a discharge port communicating with a discharge chamber is provided in the center of the fixed scroll wrap, and the fixed scroll is fixed. A suction chamber is provided outside the scroll wrap to prevent rotation of the orbiting scroll that engages with the wrap support disc that engages with the drive shaft and the body frame that fastens the fixed scroll and supports the drive shaft. When the orbiting scroll revolves with respect to the fixed scroll through the member, the compression spaces are directed from the suction side to the discharge side. Forming a scroll compression mechanism that is divided into a plurality of compression chambers that continuously move to change the volume so as to compress the fluid, and the anti-compression space side of the lap support disk is supported by a thrust bearing provided in the main body frame. Or a configuration in which the orbiting scroll is biased to the fixed scroll side by back pressure, and a check valve device is disposed on the end plate to allow a fluid flow only from the discharge port to the discharge chamber adjacent to the end plate. Then, at least one pair of bypass holes, which are opened in the compression chamber in the middle of compression in a state where they are fully opened and fully closed by the orbiting scroll wrap and whose other end communicates with the discharge chamber, are symmetrically arranged on the end plate, and the bypass hole is provided. With a configuration in which the end plate is provided with a bypass valve device that allows the discharge of fluid only from the compression chamber to the discharge chamber via
The compression space does not have a space that does not intermittently communicate with either the discharge chamber or the suction chamber, and the bypass hole is in a state immediately before the compression chamber closest to the discharge port communicates with the discharge port, A scroll gas compressor provided at a position where a part of the bypass hole is not closed by the orbiting scroll wrap when the closest compression chamber is advanced by 150 degrees from that state. 2. The scroll gas compressor according to claim 1, wherein a single bypass valve device arranges the bypass holes close to each other so as to simultaneously open and close the plurality of bypass holes. 3. The scroll gas compressor according to claim 1, wherein the check valve device also serves as a bypass valve device. 4. A pair of auxiliary bypass holes at a position retracted within 360 degrees from the bypass hole closest to the discharge port and within 360 degrees from the start of compression, and a bypass valve device for opening and closing the auxiliary bypass hole. The scroll gas compressor according to claim 1, wherein the scroll gas compressor is arranged on an end plate. 5. An injection hole, which is opened in a compression chamber between the bypass hole and the auxiliary bypass hole in a state where it is fully opened and closed by an orbiting scroll wrap and the other end of which is communicated with the decompression device of the refrigeration cycle, is used as an end plate. The scroll gas compressor according to claim 1, wherein the scroll gas compressor is provided. 6. An on-off valve is provided in the middle of the refrigerant injection pipe between the decompression device of the refrigeration cycle and the injection hole, and the on-off valve is opened when the compressor operating compression ratio is larger than the set compression ratio. The scroll gas compressor according to claim 5, wherein the scroll gas compressor is connected to a refrigerating cycle that controls to shut off the on-off valve during operation of the compressor other than.