JP3028054B2 - Scroll gas compressor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a bypass valve for a scroll gas compressor.

[0002]

2. Description of the Related Art In a scroll gas compressor having low vibration and low noise characteristics, a suction chamber is provided at an outer peripheral portion of a spiral forming a compression space, a discharge port is provided at a central portion of the spiral, and a suction volume and a final volume are reduced. The volume ratio determined by the compression chamber volume is constant.

[0003] In particular, when the fluctuation of the compression ratio determined by the suction pressure and the discharge pressure is small, the volume ratio is set in accordance therewith to compress a fluid such as a reciprocating compressor or a rotary compressor. High-efficiency compression can be performed without the need for a discharge valve device.

When this scroll gas compressor is used as a refrigerant compressor for air conditioning, the suction pressure and discharge pressure of the refrigerant change due to variable speed operation and fluctuations in air conditioning load. The difference between the actual compression ratio and the set compression ratio causes under-compression or over-compression operation. During insufficient compression, the high-pressure refrigerant gas in the discharge chamber intermittently flows back from the discharge port to the compression chamber,
This leads to an increase in compression input.

[0005] It also compresses a liquid refrigerant and a large amount of lubricating oil.
When a so-called liquid compression phenomenon occurs, an excessive compression state occurs, which may lead to an abnormal increase in compression input, excessive vibration and noise, and damage to the compressor.

As a measure to prevent the backflow of the compressed fluid due to the insufficient compression, a check valve device may be provided at the outlet side of the discharge port.

As a measure for reducing over-compression, as described in Japanese Patent Publication No. 5-49830, a bypass hole is provided at a symmetrical position from a pair of compression chambers in the middle of compression to a discharge chamber. Means for providing a bypass valve on the outlet side of a bypass hole to allow only fluid to flow out to a discharge chamber are known.

[0008]

However, in the above-mentioned conventional structure, a check valve is provided at the discharge port, and a bypass valve is also provided at the compression chamber near the discharge port. When a large number of bypass holes are provided, the check valve device and the bypass valve interfere with each other, so that the bypass hole cannot be arranged at a required position near the discharge port,
As a result of opening the bypass hole at a position distant from the discharge port, there has been a problem that over-compression cannot be effectively prevented depending on the operation compression ratio.

[0009] As an even more important problem, the installation of the bypass hole has a problem that the gas during compression remains in the bypass hole, and as a result, the compression efficiency tends to be reduced.

In addition, since the check valve device is opened with a delay after the final compression chamber is opened to the discharge chamber, over-compression occurs in the discharge port, and the effect is reduced in the discharge stroke after the bypass valve is opened. There is a problem that it is not possible to achieve a substantial reduction in the compression input.

Further, there is a problem that the arrangement of a plurality of bypass valves for individually bypassing the plurality of bypass holes is complicated, space saving is difficult, and the opening and closing noise of the plurality of bypass valves is large. Was.

SUMMARY OF THE INVENTION The present invention solves such a conventional problem. A bypass valve for opening a check valve device for opening and closing a discharge port in advance in accordance with the opening operation of the bypass valve, and a bypass hole. An object of the present invention is to provide a bypass valve having excellent opening response.

[0013]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a valve of a check valve device in which a bypass valve of a bypass discharge chamber provided on a head plate closer to a compression chamber than a check valve device is opened. The body is pushed up to open the discharge port. By the arrangement of the bypass valve, it is possible to prevent a delay in opening the check valve device after the compression completion compression chamber is opened to the discharge port.

[0014]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a first embodiment of the present invention; The bypass valve is located at the bottom of the bypass discharge chamber and the bypass valve is arranged at the bottom of the bypass discharge chamber to allow fluid discharge only from the compression chamber to the bypass discharge chamber. When the bypass valve opens, the valve element of the check valve device is pushed up A bypass valve is configured to open the discharge port.

According to this configuration, when the operating compression ratio is smaller than the set compression ratio, the gas during compression is partially discharged into the discharge chamber through the bypass hole and the bypass discharge chamber, and overcompression is reduced, and Since the valve body of the check valve device is pushed up and the discharge port is opened beforehand, the discharge of the compressed gas to the discharge chamber side starts immediately after the compression chamber is opened to the discharge port, and overcompression at the discharge port. Can be prevented.

According to a second aspect of the present invention, a bypass discharge chamber having a bypass hole opened in the bottom surface and the other end communicating with the discharge chamber is provided on the end plate closer to the compression chamber than the check valve device, and is provided at the bottom of the bypass discharge chamber. A reed valve type bypass valve is arranged to allow fluid discharge only from the compression chamber to the bypass discharge chamber, and the head of the reed valve body of the bypass valve so that the bypass valve simultaneously opens and closes at least one or more bypass holes. Are arranged so as to surround the discharge port.

According to this configuration, a plurality of bypass holes are simultaneously opened and closed, and a passage necessary for discharging the gas during compression can be secured without delay. In addition, they can be arranged in a low-cost and space-saving configuration.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A horizontal scroll gas compressor according to an embodiment of the present invention will be described below with reference to the drawings.

(Embodiment 1) In FIG. 1, reference numeral 1 denotes an iron hermetically sealed container, the entire interior of which is a high-pressure atmosphere communicating with a discharge pipe (not shown), and a motor 3 is provided at the center and a compression section is provided at the right. A main body frame 5 of a compression unit that is arranged and supports one end of a drive shaft 4 to which a rotor 3a of the motor 3 is fixed is fixed to the closed casing 1, and a 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 a refueling pump device (not shown), and the other end finally communicating with the main bearing 8. Fixed scroll 7
Scroll 13 which forms compression chamber 2 by meshing with
Is a spiral orbiting scroll wrap 13a and the orbiting shaft 1
3c and a lap support disk 13b which is upright.
It is arranged between the fixed scroll 7 and the main body frame 5.

The fixed scroll 7 comprises a head plate 7a and a spiral fixed scroll wrap 7b. The fixed scroll wrap 7b has a discharge port 30 at the center and a suction 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 penetrating the end wall of the closed casing 1. The orbiting bearing 14 eccentrically arranged from the main shaft of the drive shaft 4 and disposed in the right end hole of the drive shaft 4 is configured to engage and slide with the orbital shaft 13 c of the orbiting scroll 13. Wrap support disk 13 for orbiting scroll 13
A small gap is formed between b and the thrust bearing 19 provided on the main body frame 5 so that an oil film can be formed.

An annular seal member 18 which is substantially concentric with the pivot shaft 13c is mounted on the lap support disk 13b in a loose state, and the annular seal member 18 is attached to the inner rear chamber A2.
It separates 0 from the outside. The upstream side and the downstream side of the rear chamber A20 communicate with the oil sump 11 via the sliding surface of the swing bearing 14, the oil hole 12 of the drive shaft 4, and the main bearing 8.

The space between the oil chamber 15 at the bottom of the slewing bearing 14 and the rear chamber C16 in the outer peripheral space of the lap support disk 13b is
It communicates through an oil passage 21 provided in the lap support disk 13b. The oil passage 21 has a narrowed portion A22 and a narrowed portion B23 at both ends thereof, and a bypass oil hole 24 in the middle.

The bypass oil hole 24 is provided in the orbiting scroll 13
Are arranged so as to intermittently communicate with an annular oil groove 25 provided on the thrust bearing 19 surface with the turning motion of the thrust bearing 19.
The annular oil groove 25 and the rear chamber C16 communicate with each other via a drain oil passage 26 provided as a part of the annular oil groove 25.

The annular oil groove 25 of the thrust bearing 19 is arranged to intermittently communicate with a locking groove (not shown) of the orbiting scroll 13 which engages with the rotation preventing member 27.
Between the rear chamber C16 and the suction chamber 31, the lap support disc 1
Oil groove 43 provided on the surface of the end plate 7a that is in sliding contact with the end plate 3b
(See FIG. 2).

A check valve device 35 for opening and closing the outlet side of the discharge port 30 is mounted on the plane of the end plate 7a of the fixed scroll 7, and the check valve device 35 includes a reed valve 35a made of a thin steel plate and a valve retainer. 35b. A bypass discharge chamber 36 surrounding the discharge port 30 is adjacent to the check valve device 35 and has a head plate 7a.
Is recessed.

In the center of the end plate 7a, a bypass hole 39 opening to the second compression chamber 2b intermittently communicating with the discharge port 30 and the bypass discharge chamber 36 is provided in the vicinity of the discharge port 30. Valve 40 that opens and closes the outlet side of the
Are arranged at the bottom of the bypass discharge chamber 36.

The bypass hole 39 is formed in such a manner that a pair of second bypass holes 39b, third bypass holes 39c, and fourth bypass holes 39d arranged symmetrically with respect to the discharge port 30 follow the progress of compression. Are sequentially arranged symmetrically. The bypass valve 40 includes a reed valve body 40a made of a thin steel plate and a valve retainer 40b.

The head 40a1 of the reed valve body 40a is configured to surround the discharge port 30 and close the second bypass hole 39b, the third bypass hole 39c, and the fourth bypass hole 39d.

As shown in FIG. 5, when the reed valve body 40a for closing the bypass hole 39 is opened to the maximum, the reed valve 35a of the check valve device 35 is pushed up, and the position of the discharge port 30 can be released. The bypass valve 40 and the check valve device 35 are arranged.

In the head plate 7a, a pair of first bypass holes 39a opened to the first compression chamber 2a and the discharge chamber 32 intermittently communicating with the suction chamber 31 are symmetrically arranged, and the first bypass hole 39a is opened. An auxiliary bypass valve device 42 for opening and closing the outlet side of the hole 39a is attached.

FIG. 6 shows the compressor operating speed on the horizontal axis and the pressure and compression ratio on the vertical axis, and shows the relationship between the compressor operating speed and the suction pressure, discharge pressure and compression ratio when the air conditioner is operating. It is a characteristic diagram.

FIG. 7 is a PV diagram (acupressure diagram) of a conventional scroll gas 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.

The operation of the scroll gas compressor configured as described above will be described.

In FIGS. 1 to 7, when the drive shaft 4 is rotationally driven by the motor 3, the orbiting scroll 13 supported by the thrust bearing 19 of the main frame 5 orbits.
From the refrigerating cycle connected to the compressor, the suction refrigerant gas containing the lubricating oil flows into the suction chamber 31 via the suction pipe 33 and flows into the compression chamber 2 formed between the orbiting scroll 13 and the fixed scroll 7. Compressed and transferred to the central outlet 3
0, and is discharged to the outside of the compressor from a discharge pipe (not shown) while cooling the motor 3 through the discharge chamber 32.

The discharge refrigerant gas containing the lubricating oil is supplied to the discharge chamber 3
2 is separated in the middle of the passage from the discharge pipe (not shown),
Collect in oil sump 11.

The lubricating oil in the oil reservoir 11 to which the discharge pressure acts is
The oil is supplied to an oil chamber 15 through an oil hole 12 of the drive shaft 4 by an oil supply pump device (not shown) connected to one end of the drive shaft 4, and most of the oil is sent to an oil reservoir 11 through a main bearing 8. Return to. Part of the lubricating oil that has passed through the slewing bearing 14 fills the inner rear chamber A <b> 20 partitioned by the annular seal member 18.

A part of the lubricating oil in the oil chamber 15 is supplied to the cut portion and the sliding portion of the annular seal member 18 and the orbiting scroll 13.
Finally via the oil passage 21 provided in the rear chamber C1
Flow into 6.

The lubricating oil flowing through the oil passage 21 is firstly depressurized by the throttle portion A22 at the inlet, and a part of the lubricating oil flows into the annular oil groove 25 provided in the thrust bearing 19 through the bypass oil hole 24. Then, the remaining lubricating oil is
After the secondary decompression in the lubricating oil passing through both paths,
Flows into the rear room C16 which leads to.

The lubricating oil in the oil passage 21 is supplied to the orbiting scroll 1
3, the bypass oil hole 24 is formed into an annular oil groove 2
5 intermittently communicates with the passage resistance.

That is, when the turning speed is low, the oil passage 2
A large amount of lubricating oil flows into the annular oil groove 25 and is adjusted so that a small amount of lubricating oil in the oil passage 21 flows into the annular oil groove 25 when the turning speed is high.

The refrigerant gas pressure in the compression chamber 2 acts to move the orbiting scroll 13 away from the fixed scroll 7 in the main axis direction of the drive shaft 4. On the other hand, the wrap support disk 13b of the orbiting scroll 13 has the rear chamber A20 where the discharge pressure acts.
(The inner part surrounded by the annular seal member 18).

Therefore, the force for moving the orbiting scroll 13 away from the fixed scroll 7 and the back pressure are complicated.

As a result, when the back pressure is larger than the repulsive force of the orbiting scroll 13, the lap support disk 13b is supported by the end plate 7a of the fixed scroll 7, and in the opposite case, the lap support disk 13b is supported by the thrust bearing 19. .

In any of the above cases, the lap support disk 1
A minute gap is maintained between the sliding surface 3b and the sliding surface, and an oil film is formed by the lubricating oil supplied to the sliding surface,
The sliding resistance is reduced.

Wrap support disk 13 of orbiting scroll 13
b is the end plate 7a of the fixed scroll 7 or the thrust bearing 1
9, the gap between the compression chambers 2 is very small and is sealed by an oil film of the lubricating oil that has flowed into the compression chamber 2 through the rear chamber C16 and the suction chamber 31 in this order. Bypass hole 3
The lubricating oil that has flowed into the compression chamber 2 is retained in 9, and a small amount of refrigerant gas enters and exits the bypass hole 39 during compression.

On the other hand, in the scroll gas compressor, since the ratio of the suction volume to the final compression chamber volume, that is, the compression ratio determined by the volume ratio and the characteristics of the refrigerant is constant, a large amount of refrigerant is generated at the beginning of the cold start of the compressor. When the liquid flows into the compression chamber 2 and the liquid is compressed, the pressure in the compression chamber 2 rises abnormally and the discharge chamber 3
2 pressure.

As shown in FIG. 2, when the first compression chamber 2a intermittently communicating with the suction chamber 31 is compressed immediately before and immediately after the discharge port 30 is opened, as shown in FIGS. , End plate 7a
The auxiliary bypass valve device 42 and the second bypass hole 39b for closing the outlet side of the first bypass hole 39a provided in the
The bypass valves 40 closing the outlet sides of the bypass hole 39c and the fourth bypass hole 39d are sequentially opened to allow the refrigerant to flow out to the discharge chamber 32, thereby lowering the compression chamber pressure.

Further, a second intermittent communication with the discharge port 30 is provided.
If liquid compression occurs in the compression chamber 2b, the second bypass hole 39b, the third bypass hole 39c, and the fourth
The reed valve body 40a of the bypass valve 40 closing the outlet side of the bypass hole 39d is opened as shown in FIG.
The reed valve 35a of No. 5 is pushed open like a two-dot chain line to release the end of the discharge port 30.

From the state immediately after the second compression chamber 2b is opened to the discharge port 30 shown in FIG. 2 to the state where the second compression chamber 2b is advanced by 90 degrees as shown in FIG. Instead, the compressed refrigerant gas is smoothly discharged from the discharge port 30 and the bypass hole 39.

Therefore, the compressed refrigerant gas is supplied to the second compression chamber 2
b continuously flows into the discharge chamber before opening to the discharge port 30,
Excessive over-compression does not occur in the second compression chamber 2b and the discharge port 30.

Further, since the compressed refrigerant gas continuously flows from the second compression chamber 2b to the discharge port 30 and the discharge chamber 32 before the discharge port is opened, the outflow noise of the refrigerant gas and the pressure pulsation in the discharge chamber 32 are reduced. Smaller, reducing compressor noise and vibration.

The second to fourth bypass holes (39b, 3b)
9c, 39d) are arranged so as not to be simultaneously closed by the end faces of the orbiting scroll wrap 13a. Thereby, the second to fourth bypass holes (39b, 39c, 3
The bypass valve 40 that opens and closes at the same time as 9d) is continuously opened.

The opening operation of the auxiliary bypass valve device 42 and the bypass valve 40 is not limited to the case where 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 or the like is smaller than the compression ratio set in the rated load operation state, as indicated by the hatched portion in FIG. It becomes overcompressed.

In such a case, similarly to the above, the reed valve element 40a of the bypass valve 40 that closes the outlet side of the second bypass hole 39b, the third bypass hole 39c, and the fourth bypass hole 39d opens to allow the refrigerant to flow. The gas is discharged into the discharge chamber 32, and the pressure in the compression chamber drops on the way, as shown by the two-dot chain line 99, so that the compression load is reduced.

Generally, the pressures of the compression chambers 2 (compression chambers A and B) arranged at symmetric positions are different from each other due to the difference in the degree of sealing of the compression chamber gap.

The pressure difference in the compression chamber 2 is
The rotation force is applied to the rotation preventing member 27 by applying the rotation force to the rotation prevention member 3. However, when the auxiliary bypass valve device 42 and the bypass valve 40 are opened to reduce the compression load, the pressure of the compression chamber 2 (compression chamber A, compression chamber B) is instantaneously generated during the compression stroke via the discharge chamber 32. And the compression chamber pressure difference is reduced.

On the other hand, during high-speed operation of the compressor, the pressure in the suction chamber 31 is decreased and the pressure in the discharge chamber 32 is increased. As a result, the actual compression ratio of the refrigeration cycle operation is larger than the set compression ratio of the scroll gas compressor. In this state, the bypass valve 40 does not open.

In this state, the refrigerant gas in the discharge chamber 32 is discharged from the discharge port 30 during the process of increasing the volume of the second compression chamber 2b and before the check valve device 35 closes the discharge port 30.
And intermittently flows back into the second compression chamber 2b. This backflow refrigerant gas is recompressed in the second compression chamber 2b, resulting in a compression loss.

However, since the gap between the compression chambers is sealed by the oil film when the lubricating oil supplied to the suction chamber 31 passes through the compression chamber together with the suction refrigerant gas, the refrigerant gas discharged to the compression chamber that is not opened to the discharge chamber 30 Backflow is prevented.

Further, the lubricating oil supplied to the compression chamber fills the bypass hole 39, and the amount of the refrigerant gas retained in the bypass hole 39 is small. As a result, the compression loss due to the re-expansion and re-compression of the refrigerant gas remaining in the bypass hole 39 is extremely small.

Further, since the bypass discharge chamber 36 is recessed in the end plate 7a, the passages of the second bypass hole 39b, the third bypass hole 39c, and the fourth bypass hole 39d are shortened. The compression loss due to the re-expansion and re-compression of the refrigerant gas is reduced to a negligible level.

[0066]

As is apparent from the above description, claim 1
According to the invention described above, a check valve device that permits fluid flow only from the discharge port to the discharge chamber and opens and closes the outlet side of the discharge port is arranged, and is opened to the compression chamber in the middle of compression closest to the discharge port and At least one pair of bypass holes each having an end finally communicating with the discharge chamber are provided symmetrically on the end plate of the fixed scroll, and the bypass discharge chamber having an opening at the bottom surface and the other end communicating with the discharge chamber is a check valve device. Than on the end plate on the compression chamber side,
With a configuration in which a bypass valve is arranged at the bottom of the bypass discharge chamber to allow fluid discharge only from the compression chamber to the bypass discharge chamber,
By opening the bypass valve, the valve body of the check valve device is pushed up to open the discharge port, thereby forming a bypass valve.

According to this configuration, when the pressure in the compression chamber becomes higher than the pressure in the discharge chamber, the bypass valve is opened and a part of the gas during compression is discharged to the discharge chamber via the bypass discharge chamber. , The pressure increase in the compressor can be suppressed, and an increase in compression input can be prevented.

Also, before the compression chamber opens to the discharge port, the bypass valve opens the non-return valve device closing the discharge port. The discharge section starts to be discharged into the discharge chamber through the compression chamber gap and the discharge port.Furthermore, immediately after the compression chamber and the discharge port are opened, it can be discharged to the discharge chamber with a low gas passage resistance. Over-compression can be suppressed. Thereby, the compression input can be reduced in addition to the above-described bypass effect.

According to a second aspect of the present invention, there is provided a check valve device which permits a fluid flow only from the discharge port to the discharge chamber and opens and closes the outlet side of the discharge port, and the compression valve in the middle of compression closest to the discharge port. At least one pair or more bypass holes that open to the chamber and the other end finally communicates with the discharge chamber are provided symmetrically in the end plate,
A bypass discharge chamber with a bypass hole opened at the bottom and the other end communicating with the discharge chamber is provided on the end plate of the fixed scroll closer to the compression chamber than the check valve device, and a reed valve type bypass valve is arranged at the bottom of the bypass discharge chamber. Thus, the fluid discharge from the compression chamber to only the bypass discharge chamber is allowed.

The head of the reed valve body of the bypass valve is arranged so as to surround the discharge port so that the bypass valve opens and closes at least one or more bypass holes at the same time. A simple bypass valve can be provided.

Further, a plurality of bypass holes can be appropriately arranged in the vicinity of the discharge port as appropriate, and an effective bypass action for reducing the compression input can be obtained by appropriately securing the bypass passage.

Further, since a continuous bypass operation can be performed and the frequency of opening and closing the bypass valve is reduced, it is possible to reduce the compressor noise and vibration.

[Brief description of the drawings]

FIG. 1 is a partial longitudinal sectional view of one embodiment of a scroll gas compressor of the present invention.

FIG. 2 is an enlarged vertical sectional view of the main part of the same.

FIG. 3 is an enlarged vertical sectional view of the main part of the same.

FIG. 4 is a sectional view taken along line AA in FIG. 1;

FIG. 5 is an external view of a bypass valve.

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

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

[Explanation of symbols]

 Reference Signs List 2 compression chamber 2b second compression chamber 4 drive shaft 5 main frame 7 fixed scroll 7a end plate 7b fixed scroll wrap 13 orbiting scroll 13a orbiting scroll wrap 13b lap support disk 30 discharge port 31 suction chamber 32 discharge chamber 35 check valve device 35a Reed valve 35b Valve retainer 36 Bypass discharge chamber 39 Bypass hole 39a First bypass hole 39b Second bypass hole 39c Third bypass hole 39d Fourth bypass hole 40 Bypass valve 40a Reed valve element 40a1 Head 42 Auxiliary bypass valve device

Claims (2)

(57) [Claims] 1. A fixed scroll wrap, which is formed upright on one surface of a mirror plate forming a part of a fixed scroll, stands upright on a wrap supporting disk forming a part of a revolving scroll and is fixed. Orbiting scroll wraps similar in shape to the scroll wraps are meshed with each other to form a pair of spiral compression spaces between the two scrolls, and a discharge port communicating with a discharge chamber is provided in the center of the fixed scroll wrap, and the fixed scroll wrap is provided. A suction chamber is provided outside the scroll wrap to prevent rotation of the orbiting scroll, which engages with the wrap support disk engaged with the drive shaft and the main frame that fastens the fixed scroll and supports the drive shaft. The orbiting scroll makes a revolving motion with respect to the fixed scroll via a member, whereby each compression space is directed from the suction side to the discharge side. A scroll compression mechanism that is divided into a plurality of compression chambers that continuously move and that changes volume to compress fluid, and an oil supply passage to at least one of the compression chamber and the suction chamber is formed. The disk has at least one of a form in which the anti-compression space side of the disc is supported by a thrust bearing provided in the main body frame and a form in which the orbiting scroll is urged against the fixed scroll by back pressure. A check valve device that allows fluid flow only from the outlet to the discharge chamber and opens and closes the outlet side of the discharge port is disposed, and is open to the compression chamber in the middle of compression closest to the discharge port, and the other end is final. At least one pair of bypass holes communicating with the discharge chamber are provided in the end plate symmetrically with respect to the discharge port, the bypass having an opening at the bottom surface and the other end communicating with the discharge chamber. An outlet is provided on the end plate closer to the compression chamber than the check valve device, and a bypass valve is arranged at the bottom of the bypass discharge chamber to allow fluid discharge only from the compression chamber to the bypass discharge chamber. ,
A scroll gas compressor, wherein the bypass valve is configured to push up a valve element of the check valve device to open the discharge port by opening the bypass valve. 2. A fixed scroll wrap, which is formed upright on one surface of a mirror plate forming a part of a fixed scroll, and is fixed upright on a wrap supporting disk forming a part of an orbiting scroll. The orbiting scroll wraps having a shape similar to the scroll wrap are engaged with each other to form a pair of spiral compression spaces between the two scrolls, and a discharge port communicating with a discharge chamber is provided at a center portion of the fixed scroll wrap, and the fixed scroll wrap is provided. A suction chamber is provided outside the scroll wrap to prevent rotation of the orbiting scroll, which engages with the wrap support disk engaged with the drive shaft and the main frame that fastens the fixed scroll and supports the drive shaft. The orbiting scroll makes a revolving motion with respect to the fixed scroll via a member, whereby each compression space is directed from the suction side to the discharge side. A scroll compression mechanism that is divided into a plurality of compression chambers that continuously move and that changes volume to compress fluid, and an oil supply passage to at least one of the compression chamber and the suction chamber is formed. The disk has at least one of a form in which the counter compression space side of the disc is supported by a thrust bearing provided in the main body frame and a form in which the orbiting scroll is urged against the fixed scroll by back pressure. A check valve device that allows fluid flow only from the outlet to the discharge chamber and opens and closes the outlet side of the discharge port is disposed, and is open to the compression chamber in the middle of compression closest to the discharge port, and the other end is final. At least one pair of bypass holes communicating with the discharge chamber are provided in the end plate symmetrically with respect to the discharge port, the bypass having an opening at the bottom surface and the other end communicating with the discharge chamber. An outlet chamber is provided on the end plate closer to the compression chamber than the check valve device, and a reed valve type bypass valve is arranged at the bottom of the bypass discharge chamber to discharge fluid only from the compression chamber to the bypass discharge chamber. A scroll gas compressor having a permissible configuration, wherein a head of a reed valve body of the bypass valve is arranged so as to surround the discharge port so that the bypass valve simultaneously opens and closes at least one or more of the bypass holes.