JP5870056B2 - Scroll compressor - Google Patents

Description

  The present invention relates to a scroll compressor configured to provide a back pressure chamber on the back surface of a orbiting scroll and urge the orbiting scroll toward a fixed scroll, and more particularly to a back pressure for adjusting the pressure of the back pressure chamber. It is related with what has a control valve.

  As a conventional scroll compressor provided with a back pressure control valve for adjusting the pressure in the back pressure chamber, for example, there is one described in Patent Document 1 (Japanese Patent Laid-Open No. 2003-172276). The back pressure control valve is provided in a flow path that connects the compression chamber and the back pressure chamber after the working fluid is closed, and a constant value corresponding to the compression amount of the valve spring is added to the pressure of the compression chamber. The back pressure of the back pressure chamber is controlled to the pressure.

  Further, in this Patent Document 1, there is a bypass hole that connects a compression chamber after closing the working fluid and a discharge region (discharge chamber) where the working fluid is compressed and discharged in the compression chamber. A bypass valve provided on the fixed scroll and configured to flow from the compression chamber to the discharge region through the bypass hole but not in the opposite direction is illustrated. By the bypass valve flow path formed by the bypass hole and the bypass valve, the fluid in the compression chamber can be discharged to the discharge region when overcompression occurs in which the pressure in the compression chamber becomes higher than the pressure in the discharge region.

JP 2003-172276 A

  In the above-mentioned Patent Document 1, when the volumetric flow rate per unit time of the working fluid flowing through the bypass valve flow path (hereinafter also simply referred to as flow rate) is small, the working fluid flows smoothly. There is almost no pressure difference between both ends of the outlet and the outlet, and the pressure in the compression chamber with which the bypass valve flow path communicates can be reduced to almost the pressure in the discharge region.

  However, when the flow rate of the working fluid flowing through the bypass valve channel increases, the pressure difference between both ends of the bypass valve channel increases, and the pressure on the inlet side of the bypass valve channel, that is, the pressure in the compression chamber reaches the pressure in the discharge region. It cannot be reduced. Considering that the outlet side of the bypass valve channel is the discharge pressure, the effect of suppressing the pressure increase in the compression chamber is reduced, and the overcompression cannot be sufficiently eliminated.

  In particular, when the scroll compressor sucks a working fluid (a working fluid that is difficult to compress) having a liquid or a density close to the liquid (generated in a supercritical region or the like), the compression chamber is liquid-compressed and an abnormal increase in pressure occurs. The bypass valve opens quickly due to a sudden abnormal pressure increase in the compression chamber that occurs immediately after the occurrence of this liquid compression, so that the operation fluid that is difficult to compress is discharged to the discharge region. Thereby, even if liquid compression occurs in the compression chamber, the abnormal pressure rise is alleviated and damage to the scroll wrap is avoided.

  However, in the case of liquid compression, the density of the fluid that passes through the bypass valve flow path increases by an order of magnitude, so the pressure rise suppression effect in the compression chamber is extremely reduced compared to when gas is discharged from the bypass valve flow path. To do. For this reason, the conventional bypass valve flow path has a problem that an abnormal pressure increase in the compression chamber cannot be sufficiently avoided during liquid compression, and there is a risk of damaging the scroll wrap.

  An object of the present invention is to obtain a scroll compressor that can avoid an abnormal pressure increase in a compression chamber even during liquid compression.

  In order to achieve the above object, the present invention provides a fixed scroll having a fixed end plate and a fixed wrap standing on the fixed end plate, a turning scroll having a turning end plate and a turning lap standing on the rotating end plate, and sucking the working fluid before compression. And a suction region for guiding the compression chamber formed by the fixed scroll and the orbiting scroll, a discharge region for discharging the compressed working fluid compressed in the compression chamber, and a back surface of the orbiting scroll. A back pressure chamber that is held at a pressure between the suction pressure and the discharge pressure in order to press the orbiting scroll against the fixed scroll; A back pressure valve passage having a back pressure valve configured to be held constant, and a compression end plate formed on a fixed end plate of the fixed scroll communicates with the discharge region, and a bypass is provided in the middle. In a scroll compressor comprising a bypass valve flow path having a valve, the back pressure valve and the compression chamber in the back pressure valve flow path are communicated with a flow path portion connecting the bypass valve and the compression chamber in the bypass valve flow path. By connecting a back pressure communication passage for the purpose, the back pressure valve flow path is configured to communicate with the compression chamber via the bypass valve flow path, and liquid compression is generated in the compression chamber to generate a working fluid. Open the back pressure valve in the back pressure valve flow path by utilizing the pressure drop due to the flow through the bypass valve flow path, thereby reducing the pressure in the back pressure chamber, and the axial gap between the fixed scroll and the orbiting scroll It is characterized by being configured to increase.

  According to the present invention, it is possible to obtain an effect of obtaining a scroll compressor that can avoid an abnormal pressure increase in the compression chamber even during liquid compression.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a longitudinal sectional view showing a first embodiment of a scroll compressor according to the present invention. The S section enlarged view of FIG. The T section enlarged view of FIG. The top view of the turning scroll shown in FIG. The bottom view of the fixed scroll shown in FIG. 1, The figure which also displays the turning scroll with a dashed-dotted line. FIG. 4 is a diagram illustrating a scroll compressor according to a second embodiment of the present invention and corresponding to FIG. 2. The bottom view of the fixed scroll in Example 2 of this invention WHEREIN: A figure when a turning scroll is also displayed with a dashed-dotted line and the turning wrap outer line side compression chamber of the outermost circumference side starts to close. The bottom view of the fixed scroll in Example 2 of this invention WHEREIN: The figure when a turning scroll is also displayed with a dashed-dotted line and the rotation outer wrap extension side compression chamber of the outermost circumference side starts to close.

  Hereinafter, a scroll compressor according to a first embodiment of the present invention will be described with reference to the drawings. In each figure, the same reference numerals are given, and the parts indicate the same or corresponding parts.

  A first embodiment of the present invention will be described with reference to FIGS. 1 is a longitudinal sectional view showing a first embodiment of a scroll compressor of the present invention, FIG. 2 is an enlarged view of an S portion of FIG. 1, FIG. 3 is an enlarged view of a T portion of FIG. 1, and FIG. FIG. 5 is a bottom view of the fixed scroll shown in FIG. 1, and the orbiting scroll is also indicated by a one-dot chain line.

  First, the overall configuration of the scroll compressor according to the first embodiment will be described with reference to these drawings. As shown in FIG. 1, the scroll compressor 1 includes a fixed scroll 2, a turning scroll 3, a frame 4, an Oldham ring 5 (see FIG. 2), a crankshaft 6, a motor 10, a casing 8, and the like.

  As shown in FIG. 4, the orbiting scroll 3 has an orbiting wrap (scroll wrap) 3b erected on the upper surface of the orbiting end plate 3a. As shown by dotted lines, a key groove 3c that engages with a key of the Oldham ring 5 and a turning boss portion 3d are formed on the back surface of the turning end plate 3a. A swivel bearing 23 is provided on the swivel boss 3d, and a pin 6a, which is an eccentric part of the crankshaft 6 shown in FIG. The orbiting scroll 3 is configured to orbit by the eccentric movement of the pin portion 6a caused by the rotation of the crankshaft 6 that is rotatably supported by the main bearing 24.

  Further, as shown in FIG. 5, the fixed scroll 2 has a fixed wrap (scroll wrap) 2b erected on the lower surface side of the fixed end plate 2a. By engaging the fixed wrap 2b with the orbiting scroll 3b of the orbiting scroll 3, the compression chamber 100 (the compression chamber 100a on the outer side of the orbiting wrap 3b and the compression chamber 100b on the inner side of the orbiting wrap 3b) is interposed between the scroll wraps 2b and 3b. It is formed. The fixed scroll 2 in the present embodiment is configured so as not to form and use a compression chamber, ie, a symmetrical wrap, for 180 degrees at the end of the outer side winding of the orbiting wrap 3b. As a result, the two compression chambers 100 of the outer wrap side compression chamber 100a and the inner side compression chamber 100b of the swirl wrap 3b start to close at the same timing. FIG. 5 shows a state in which the compression chamber 100 (100a, 100b) has just started to close.

  As shown in FIGS. 1 and 5, the fixed scroll 2 is formed with a suction port 2 s, and a suction pipe 50 for introducing a working fluid from the outside of the scroll compressor 1 to the suction port 2 s, As shown in FIG. The suction pipe 50 passes through the upper casing 8b of the casing 8 and is press-fitted into the fixed scroll. A check valve 21 is provided at the suction port 2 s so as to face the lower portion of the suction pipe 50 in order to prevent a backflow of the working fluid immediately after the scroll compressor 1 is stopped. The fixed scroll 2 is formed with a suction region (suction portion) 95 (see FIG. 5) that communicates with the suction port 2s and serves as a suction pressure.

  2k shown in FIG. 5 is a suction groove that directly connects the side surface position of the swirling wrap 3b that the swirling outer line side compression chamber 100a finally closes to the suction port 2s, and the suction pressure loss of the outer line side compression chamber 100a of the swirling wrap 3b. It is for suppressing.

  Near the center of the fixed scroll 2, a discharge hole 2 d for discharging the compressed working fluid to the fixed back chamber (discharge chamber) 120 is formed. The working fluid discharged to the fixed back chamber 120 passes through a gap (groove) formed between the fixed scroll 2, the outer peripheral side of the frame 4 and the casing 8, and the motor in which the motor 10 is disposed. It flows to the chamber 121 side and is discharged to the outside from a discharge pipe 55 provided in the casing 8 of the motor chamber 121 portion. Thereby, the inside of the casing 8 (the fixed back chamber 120, the motor chamber 121, and the oil storage part 125) is a discharge area of discharge pressure.

  A plurality of bypass holes 2e are formed in the fixed end plate 2a as shown in FIG. 3 at a T portion (see FIG. 1) outside the discharge holes 2d of the fixed scroll 2, and an upper portion of each bypass hole 2e. In each, a bypass digging 2f is formed. These bypass excavations 2f are provided with bypass valves 9 (9a: valve plate, 9b: bypass valve seat, 9c: valve spring, 9d: spring retainer, 9e: spacer, 9f: retainer). A bypass valve flow path is formed by the bypass hole 2e, the bypass valve 9, and the bypass digging 2f.

  Next, the formation position of the bypass hole 2e shown in FIG. 3 will be described with reference to FIG. In this embodiment, the bypass hole 2e is provided in a total of four locations, two locations 2e1 and 2e2 along the inner surface of the fixed wrap 2b and two locations 2e1 and 2e2 along the outer surface of the fixed wrap 2b. ing. Each of the bypass holes 2e is disposed in the vicinity of the wall surface (inner line or outer line) of the fixed wrap 2b and within the width dimension of the orbiting wrap 3. Thus, the bypass hole 2e arranged in the vicinity of the inner line of the fixed wrap 2b faces only the outer line side compression chamber 100a formed on the outer line side of the swirl wrap 3b. Further, the bypass hole 2e arranged in the vicinity of the outer line of the fixed wrap 2b faces only the inner line side compression chamber 100b formed on the inner line side of the swirl wrap 3b. That is, the bypass hole 2e in the present embodiment is configured to face only one of the outer line side compression chamber 100a and the inner line side compression chamber 100b.

  In the present embodiment, there are two bypass holes 2e facing the outer line side compression chamber 100a. One of them 2e1 is arranged at a position facing the compression chamber on the low pressure side including the suction state, as already opened more than half in the low pressure side outer compression chamber 100a immediately after the start of closing. Another bypass hole 2e2 facing the outer line side compression chamber 100a faces the outer line side compression chamber 100a on the high pressure side closer to the center, and the bypass hole 2e2 is discharged from the outer line side compression chamber 100a on the high pressure side. Even if it comes to timing, it arrange | positions in the position which faces this outside line side compression chamber 100a.

  The bypass hole 2e facing the inner line side compression chamber 100b is configured similarly to the bypass hole facing the outer line side compression chamber 100a. That is, the bypass hole 2e1 is arranged at a position facing the compression chamber on the low pressure side including the suction state as already opened more than half in the low pressure side extension side compression chamber 100b immediately after the start of closing. The bypass hole 2e2 faces the extension side compression chamber 100b on the high pressure side closer to the center, and the bypass hole 2e2 does not reach the extension side compression chamber 100b even when the outer line compression chamber 100b on the high pressure side reaches the discharge timing. It is arranged at the position to face.

  The bypass hole 2e1 facing the low-pressure side compression chambers 100a and 100b is called an outermost bypass hole, and the bypass hole 2e2 facing the high-pressure side compression chambers 100a and 100b is called a non-outermost bypass hole.

  Next, the configuration of the bypass valve 9 will be described in detail with reference to FIG. A bypass valve seat 9b is provided at the bottom of the bypass digging 2f, and a bypass valve plate 9a is placed on the bypass valve seat 9b. The bypass valve plate 9a is pressed against the bypass valve seat 9b by a bypass valve spring 9c, and the pressing load is set to an appropriate value. This is to suppress vibration of the valve plate 9a when the bypass valve 9 is closed, and the pressing load is generally set to an extremely small value. The upper end of the bypass valve spring 9c is inserted into the protrusion of the spring retainer 9d, and the upper surface of the spring retainer 9d is positioned by the retainer 9f via the spacer 9e. Further, a small gap may be provided between the spacer 9e and the retainer 9f so that the pressing load may be the weight of the spring retainer 9d and the spacer 9e. In any case, the pressing load by the bypass valve spring 9c is substantially equal. Can be regarded as zero. The spring retainer 9d is provided with a hole (through hole) penetrating in the vertical direction. By configuring the bypass valve 9 in this way, when the pressure in the compression chamber 100 exceeds the pressure in the fixed back chamber 120, the valve plate 9a is opened, so that the working fluid in an overcompressed state in the compression chamber 100 is It flows out to the fixed back chamber 120 through the bypass hole 2e, the through hole formed in the spring retainer 9d, and the bypass digging. Thereby, it is comprised so that the overcompression and liquid compression which arise in the compression chamber 100 can be suppressed.

Thus, by providing the bypass valve 9 in the bypass valve flow path, the pressure in the compression chamber 100 facing the bypass hole 2e does not exceed the discharge pressure (pressure on the fixed back chamber 120 side). Can be made.
As described above, in the present embodiment, the outermost bypass hole 2e1 and the non-outermost bypass hole 2e2 communicate with the two compression chambers 100 of the outer wrap side compression chamber 100a and the inner line side compression chamber 100b of the swirl wrap 3b. Is configured to do. Among these, the bypass valve flow path (hereinafter referred to as the outermost bypass valve flow path) provided in the outermost bypass hole 2e1 is provided in order to avoid liquid compression that occurs depending on operating conditions. The fixed wrap 2b and the swivel wrap 3b are prevented from being damaged, and the reliability can be improved. That is, when an abnormal pressure rise in the compression chamber 100 occurs, the liquid or the like is discharged from the compression chamber 100 so that an extreme pressure rise due to the liquid compression does not occur when a working fluid having a density close to that of the liquid is sucked into the compression chamber 100. The working fluid can be discharged through the outermost bypass valve flow path.

  The bypass valve flow path (hereinafter referred to as the non-outermost bypass valve flow path) of the non-outermost bypass hole 2e2 is overcompressed so that the pressure in the compression chamber 100 on the high pressure side is higher than the pressure in the fixed back chamber 120. In this case, the working fluid in the compression chamber 100 is bypassed to the fixed back chamber 120. That is, it is provided to improve efficiency by preventing unnecessary compression when the compression chamber 100 is in an overcompression condition.

  Furthermore, in this embodiment, as shown in FIG. 2, the fixed scroll 2 is provided with a back pressure valve flow path. The back pressure valve flow path functions to let oil that has flowed into the back pressure chamber 110 through a back pressure chamber fluid introduction path, which will be described later, flow out to the compression chamber 100, and is provided in the middle of the back pressure valve flow path. The back pressure valve 7 controls the pressure (back pressure) in the back pressure chamber 110. The back pressure valve flow path includes a back pressure hole 2g that opens into the back pressure chamber 110 through a peripheral groove 2p formed on the outer periphery of the end plate surface of the fixed scroll, and a back pressure excavation 2h formed from the upper surface side of the fixed scroll 2. And the back pressure communication passage 2i, and finally join the outermost bypass hole 2e1, that is, the flow path portion connecting the bypass valve 9 and the compression chamber 100 in the outermost bypass valve flow path, then the compression It is configured to communicate with the chamber 100. In other words, the back pressure valve channel allows the back pressure chamber 110 and the compression chamber 100 to communicate with each other.

  Next, the configuration of the back pressure valve 7 will be described. A back pressure valve seat 7b is formed at the bottom of the back pressure excavation 2h, and a back pressure valve plate 7a is placed on the back pressure valve seat 7b. The back pressure valve plate 7a is pressed against the back pressure valve seat 7b by a back pressure valve spring 7c. This pressing load is set to a predetermined value. A value obtained by dividing this value (pressing load) by the area of the inner area of the seal portion in the back pressure valve seat 7 b is the differential pressure set by the back pressure valve 7. The optimum value of this differential pressure is derived from the force balance calculation even if the bypass valve flow path that suppresses overcompression is installed, even under a wide range of operating conditions. Set. In order to obtain the set differential pressure, it is determined by the compression amount of the back pressure valve spring 7c, and the adjustment of the compression amount is performed by the back pressure digging 2h of the back pressure valve cap 7d into which the upper end of the back pressure valve spring 7c is inserted. This can be done by adjusting the amount of insertion. Thereby, the back pressure excavation 2h becomes a space in the back pressure valve flow path.

  With this configuration, the back pressure valve channel is set by the back pressure valve 7 so that the pressure (back pressure) of the back pressure chamber 110 is higher than the average pressure of the compression chamber 100 through which the back pressure valve channel communicates. Control to increase only the differential pressure. Therefore, by providing the back pressure valve 7, the back pressure of the back pressure chamber 110 is higher than the suction pressure that is the pressure in the suction port 2s and the suction region 95 and is discharged from the discharge hole 2d. An intermediate pressure lower than the discharge pressure is maintained. As a result, as will be described later, the back pressure chamber 110 becomes one of the pressing force generating means for pressing the orbiting scroll 3 against the fixed scroll 2 together with the orbiting bearing chamber 115 (see FIG. 1) that is at the discharge pressure. Yes.

  As shown in FIGS. 1 and 2, the Oldham ring 5 and the crankshaft 6 are mounted on the frame 4, and the orbiting scroll 3 and the Oldham ring 5 are engaged with each other, and the pin portion 6a of the crankshaft 6 is turned on the orbiting scroll. 3 is inserted into the swivel boss 3d. Thereafter, the lower surface (fixed base plate surface 2 u) of the base plate portion 2 q which is the outer side portion of the fixed wrap 2 b in the fixed scroll 2 is fixed to the frame 4 with screws or bolts. As a result, the back pressure chamber 110 is formed on the back surface of the orbiting scroll 3 (between the orbiting scroll 3 and the frame 4). The Oldham ring 5 is engaged with a key groove 3 c formed on the back surface of the orbiting scroll 3 and a key groove (not shown) formed on the frame 4 to prevent the orbiting scroll 3 from rotating. .

  In the center of the crankshaft 6, an oil supply hole 6b penetrating in the axial direction is formed. An oil supply pipe 6x is press-fitted into the lower end of the crankshaft 6, and the oil accumulated in the oil storage part 125 formed in the bottom casing 8c of the casing 8 is supplied to the upper end of the oil supply hole 6b and the pin part 6a. It is configured to supply the back pressure chamber 110 with a differential pressure (a differential pressure between the pressure of the motor chamber 121 and the pressure of the back pressure chamber 110) via the slewing bearing chamber 115.

  A shaft balance 80 and a counterbalance 82 for rotational balance are fixed by shrink fitting or press fitting below the frame 4 of the crankshaft 6. The upper portion of the crankshaft 6 is supported by a main bearing 24 provided on the frame 4, and the lower portion of the crankshaft 6 is supported by a sub bearing 25 attached to the lower portion of the cylindrical casing 8a via a lower frame 35. It is supported.

  The auxiliary bearing 25 is composed of a ball 25a and a ball holder 25b, and is configured such that no one-side contact occurs even when the crankshaft 6 is bent. The ball holder 25b is fixed to the lower frame 35 by screwing or welding.

  The motor 10 includes a rotor 10a fixed to the crankshaft 6 and a stator 10b fixed by shrink fitting, press fitting, welding, or the like on the cylindrical casing 8a. Is connected to a hermetic terminal 220 to which is supplied.

  In the casing 8, the upper casing 8b is welded to the upper portion of the cylindrical casing 8a, and the bottom casing 8c is welded to the lower portion of the cylindrical casing 8a, whereby the casing 8 is configured as a sealed container. . The casing 8 accommodates the fixed scroll 2, the orbiting scroll 3, the frame 4, the crankshaft 6, and the motor 10. The fixed back chamber (discharge chamber) 120 is formed on the fixed scroll 2. Has been.

  The frame 4 is fixed to the cylindrical casing 8a by welding, and the discharge pipe 55 is fixed to the cylindrical casing 8a below the frame 4 by welding or brazing. The lower frame 35 is fixed to the lower portion of the cylindrical casing 8a by welding or brazing. A groove extending in the vertical direction is formed in the outer peripheral portion of the base plate portion 2q of the fixed scroll 2. Similarly, a groove extending in the vertical direction is formed in the outer peripheral portion of the frame 4, so that the fixed scroll 2 is When fixed to the frame 4 with screws or the like, the upper space inside the casing 8 (fixed rear chamber 120) and the upper space of the motor chamber 121 communicate with each other through the groove.

The suction pipe 50 press-fitted into the hermetic terminal 220 and the fixed scroll 2 is fixed to the upper casing 8b by welding or brazing.
The casing 8 is filled with oil at an appropriate stage of assembly, whereby the oil storage part 125 is formed between the lower frame 35 and the bottom casing 8c.

Next, the compression operation of the scroll compressor 1 will be described with reference to FIGS.
First, the working fluid that has flowed into the scroll compressor 1 from the suction pipe 50 will be described along the flow until it is discharged from the discharge pipe 55.

  In FIG. 1, when the crankshaft 6 is rotated by the motor 10, the orbiting scroll 3 performs an orbiting motion. As a result, the working fluid from the suction pipe 50 passes through the suction port 2 s and enters the suction region 95 shown in FIG. 5, and is taken into the compression chamber 100 formed by the fixed scroll 2 and the orbiting scroll 3 from here. This compression chamber 100 has two systems of an outer line side compression chamber 100a formed on the outer line side of the swirl wrap 3b and an inner line side compression chamber 100b formed on the inner line side, and these are formed simultaneously. The formed compression chamber 100 is reduced in volume as it moves to the center side (winding start side) of the scroll wrap as the orbiting scroll 3 turns. As a result, the working fluid inside the compression chamber 100 is compressed and discharged from the discharge hole 2d to the fixed back chamber 120. Thereby, the inside of the casing 8 becomes a discharge region of discharge pressure over the entire region (the fixed back chamber 120, the motor chamber 121, and the oil storage part 125). That is, the working fluid discharged to the fixed back chamber 120 then flows into the upper space of the motor 10 in the motor chamber 121 through the grooves formed in the outer periphery of the fixed scroll 2 and the frame 4, and thereafter It is discharged from the discharge pipe 55 to the outside. Thus, the scroll compressor of the present embodiment is a so-called high pressure chamber type scroll compressor.

  Note that, under an operating condition (overcompression condition) in which the compression in the compression chamber 100 is overcompressed, the pressure inside the compression chamber 100 tends to be higher than the pressure in the discharge region (fixed back chamber 120). However, in this embodiment, when the pressure in the compression chamber 100 becomes higher than the pressure in the fixed back chamber 120, the bypass valve 9 is opened, and the working fluid in the compression chamber 100 passes through the bypass valve channel. It flows out to the fixed back chamber 120. Thereby, overcompression can be avoided or reduced, and the performance of the scroll compressor 1 can be improved.

Next, the flow of oil will be described.
The oil in the oil storage part 125 is supplied from the oil storage part 125 shown in FIG. 1 to the oil supply pipe by the differential pressure between the discharge pressure inside the casing 8 and the pressure in the back pressure chamber 110 (pressure between the discharge pressure and the suction pressure). 6x passes through the oil supply hole 6b in the crankshaft 6 and enters the swivel bearing chamber 115 above the pin portion 6a. From here, the swivel bearing 23 is lubricated and then flows into the back pressure chamber 110. Similarly, the oil in the oil storage part 125 enters the radial oil supply hole in the middle of the oil supply hole 6 b in the crankshaft 6, lubricates the main bearing 24, and then flows into the back pressure chamber 110. Part of the oil rising in the oil supply hole 6b is supplied to the sub bearing 25 by centrifugal force through a radial oil supply hole formed in the sub bearing 25 portion. The oil supplied to the auxiliary bearing 25 returns to the oil storage part 125 after lubricating the auxiliary bearing.

  Thus, since the oil of the discharge pressure is supplied to the orbiting bearing chamber 115, the pressure becomes the discharge pressure and becomes one of the pressing force generating means for pressing the orbiting scroll 3 against the fixed scroll 2. Further, since the pressure of the oil flowing into the back pressure chamber 110 is a discharge pressure, the pressure of the back pressure chamber 110 is increased by the inflow of the oil. Since the working fluid (refrigerant) is dissolved in the oil (for example, the mass concentration is 10% or more), the working fluid is suddenly gasified (foamed) from the oil by the pressure reduction caused by flowing into the back pressure chamber 110. . When the working fluid is gasified, the volume increases by one digit or more. For this reason, the oil in the back pressure chamber 110 becomes a mist state in which fine oil droplets float in the gasified working fluid, and is dispersed throughout the back pressure chamber 110. Thereby, the Oldham ring 5 shown in FIG. 2 is lubricated. The oil supply path to the back pressure chamber 110 described above is the back pressure chamber fluid introduction path.

  Thereafter, the oil that has flowed into the back pressure chamber 110 passes through the back pressure valve passage in which the back pressure valve 7 is provided in the middle, and finally flows into the compression chamber 100 through the outermost bypass hole 2e1. The outermost bypass hole 2e1 is provided at a position communicating with the compression chamber 100 for a while from the start of closing. As a result, the sealing performance of the compression chamber 100 is improved and the leakage of the working fluid from the compression chamber during compression is suppressed, so that the compressor efficiency is improved. The back pressure valve 7 is configured to control the pressure in the back pressure chamber 110 to an intermediate pressure and press the orbiting scroll 3 against the fixed scroll 2 with an appropriate force. Thereby, since the thrust loss (sliding loss) between the end plate and the scroll wrap is reduced, the compressor efficiency can be improved also from this point.

  The oil supplied to the compression chamber 100 is discharged to the fixed back chamber 120 together with the working fluid through the discharge hole 2d and the bypass valve flow path when overcompression occurs. Thereafter, the oil is separated from the working fluid (gas refrigerant) by adhering to an inner wall of the casing 8 or a component member installed in the casing. The oil adhering to the inner wall of the casing and the constituent members is circulated through those members, and finally returns to the oil storage portion 125 at the bottom of the scroll compressor 1.

  As shown in FIG. 2, in the scroll compressor of the present embodiment, the outermost bypass hole 2e1 provided to avoid liquid compression (between the bypass valve 9 and the compression chamber 100 in the outermost bypass valve channel). A back pressure communication passage 2i (a passage closer to the compression chamber 100 than the back pressure valve 7) for communicating the back pressure valve 7 and the compression chamber 100 in the back pressure valve flow passage is connected to the flow passage portion). That is, the outermost bypass hole 2e1 is a combined flow path that combines the back pressure communication paths 2i of the back pressure valve flow path. Hereinafter, the compression chamber 100 side opening of the combined flow path is referred to as a confluence 70.

In the present embodiment, the following operations are performed by configuring in this way.
When liquid compression occurs in the compression chamber 100, the outermost bypass valve flow path performs a liquid compression avoidance operation, so that the bypass valve 9 is opened, and thereby the outermost bypass hole 2e1 enters the outermost bypass hole 2e1 from the compression chamber 100 to the fixed rear chamber 120. A high-speed liquid flow toward is generated. When a high-speed liquid flow is generated in the outermost bypass hole 2e1, the pressure in the outermost bypass hole 2e1 is significantly lower than the pressure in the compression chamber 100 by Bernoulli's theorem. For this reason, the pressure in the back pressure excavation 2h connected by the outermost bypass hole 2e1 and the back pressure communication path 2i is also significantly reduced. As a result, the back pressure valve 7 is opened, and the pressure in the back pressure chamber 110 is greatly reduced.

  That is, when the liquid flows through the outermost bypass hole 2e1, since the density is extremely higher than that of the gas, the generated pressure drop is extremely large. As described above, when the liquid compression occurs, the pressure in the back pressure digging 2h is significantly lower than the pressure in the compression chamber 100. Therefore, the pressure in the back pressure chamber 110 is also reduced by the same pressure drop. It is lower than during normal operation. As a result, the pressing force that presses the swivel end plate 3a toward the fixed end plate 2a is greatly reduced, so that the axial gap between both wraps (the gap between the wrap tooth tip and the tooth bottom) is enlarged, and the compression chamber 100 Sealing performance is reduced. In this embodiment, liquid compression can be avoided also by this operation.

  That is, at the same time as the liquid compression avoidance operation occurs in the outermost bypass valve flow path, the sealing performance of the compression chamber 100 is lowered, and another new liquid compression avoidance operation occurs. As a result, liquid compression can be avoided more reliably than before, and a highly reliable scroll compressor can be obtained.

  As described above, when the back pressure valve flow path joins the outermost bypass hole 2e1 of the outermost bypass valve flow path and the outermost bypass valve flow path causes the liquid compression avoiding operation, the back pressure chamber 110 is automatically set. This greatly reduces the pressure of the pressure chamber, thereby reducing the sealing performance of the compression chamber 100 and avoiding liquid compression.

  In the present embodiment, the outermost bypass hole 2e1 (the flow path portion connecting the bypass valve and the compression chamber in the bypass valve flow path) where the back pressure communication path 2i joins is straight and has a flow area. Are formed in a simple cylindrical shape configured to be constant. For this reason, there is less disturbance in the liquid flow in the outermost bypass hole 2e1, and the pressure drop when the liquid passes at high speed increases. Accordingly, the amount of pressure drop in the back pressure chamber 110 is also increased, and the pressing force of the orbiting scroll 3 against the fixed scroll 2 can be further reduced, so that the sealing performance of the compression chamber 100 is further reduced and the liquid pressure is more reliably increased. This has the effect of avoiding compression.

  In the above-described embodiment, the outermost bypass hole 2e1 facing only the outer line side compression chamber 100a among the two lines of the compression line on the outer line side and the inner line side of the swirl wrap 2b is shown by a hidden line (broken line) in FIG. An example in which the back pressure communication path 2i is connected to form a combined flow path has been described. However, the present invention is not limited to this, and the back pressure communication path 2i is connected to the outermost bypass hole 2e1 facing only the extension side compression chamber 100b at a position in the fixed end plate 2a as shown by a two-dot chain line in FIG. Also good.

  Further, both the back pressure communication passages 2i indicated by a broken line and a two-dot chain line in FIG. 5 may be installed at the same time to form a combined flow path. That is, since the scroll compressor of this embodiment uses a symmetrical wrap, the pressures of the outer line side compression chamber 100a and the inner line side compression chamber 100b facing the outermost bypass hole 2e1 are the same. It is possible to install the passage 2i at the same time.

  Thus, by providing two back pressure communication passages 2i, there are two flow paths for draining oil from the back pressure chamber 110, so that the pressure in the back pressure chamber 110 can be further reliably reduced to ensure liquid compression. Therefore, the reliability can be further improved. If the pressures of the outer side compression chamber 100a and the inner side compression chamber 100b facing the outermost bypass hole 2e1 are different, if the two back pressure communication passages 2i described above are installed, the two compression chambers pass through these back pressure communication passages. Internal leakage occurs, causing performance degradation.

  In addition, the said combined flow path is connected only to either the outer line side compression chamber 100a or the inner line side compression chamber 100b of the swirl wrap 3b, and does not communicate with both the outer line side compression chamber and the inner line side compression chamber at the same time. It is configured.

  A scroll compressor according to a second embodiment of the present invention will be described with reference to FIGS. FIG. 6 is a view showing a second embodiment of the scroll compressor of the present invention, and is a view corresponding to FIG. 2, FIG. 7 is a bottom view of the fixed scroll in the second embodiment of the present invention, and the orbiting scroll is also indicated by a one-dot chain line. FIG. 8 is a bottom view of the fixed scroll according to the second embodiment of the present invention, and the orbiting scroll is also indicated by a one-dot chain line. It is a figure when the turning lap extension side compression chamber starts to close. In these drawings, the portions denoted by the same reference numerals as those in FIGS. 1 to 5 described above indicate the same or corresponding portions, and the description of the same portions is omitted.

  In the second embodiment, the present invention is applied to a scroll compressor having an asymmetric tooth profile. The asymmetric tooth-shaped scroll compressor is used to form the compression chamber up to the end of the outer wrap side of the orbiting wrap 3b, and the end of the inner wrap side of the fixed wrap 2b is extended by 180 degrees or more. . For this reason, as shown in FIG. 7, every time the orbiting scroll 3 is turned 180 degrees, the two compression chambers 100 (the outer side compression chamber 100a and the inner side compression chamber 100b) alternately start the compression operation. Furthermore, the outermost bypass hole 2e1 ′ connected to the back pressure communication passage 2i alternately faces (communicates) with both the outer line side compression chamber 100a and the inner line side compression chamber 100b in accordance with the orbiting motion of the orbiting scroll 3. The fixed scroll 2 is provided at the center of the tooth bottom between the fixed wraps 2b. Since the outermost bypass hole 2e1 'in this embodiment communicates with both compression chambers, it is also referred to as both compression chamber communication outermost bypass holes 2e1'. The compression chamber communication outermost bypass holes 2e1 'form a flow path portion between the bypass valve 9 and the compression chamber 100 in the outermost bypass valve flow path.

  The compression chamber communication outermost bypass hole 2e1 'in the second embodiment differs from the outermost bypass hole 2e1 in the first embodiment described above in the position where the holes are formed. And the back pressure communication path 2i are changed as shown in FIG. 7, for example. Further, a joining port 70a, which is a compression chamber side opening of the combined flow path where the outermost bypass hole 2e1 and the back pressure communication passage 2i are joined, also opens at the center of the tooth bottom between the fixed wraps 2b. This junction 70a is also referred to as a compression chamber communication junction. In the present embodiment, both compression chamber communication junctions 70a are connected to the center of the tooth root from the end of winding of the fixed wrap 2b so that the compression chambers 100 of the two systems communicate immediately after the compression (closure) starts. It is provided at a position about 270 degrees along.

Further, in this embodiment, both the outer line side compression chamber 100a and the inner line side compression chamber 100b face the inner position further along the center of the tooth root than both the compression chamber communication outermost bypass holes 2e1 ′. A non-outermost bypass hole 2e2 'is provided. Since this bypass hole 2e2 'communicates with both compression chambers, it is also referred to as both compression chamber communication non-outermost bypass holes. By providing the both compression chamber communication non-outermost bypass holes 2e2 ', the compression chamber 100 is formed so that there is no section that does not communicate with the fixed back chamber (discharge chamber) 120 via the bypass valve flow path. Even if liquid compression occurs at any position of the throat, the liquid is discharged from the bypass valve channel so that an abnormal pressure increase in the compression chamber can be avoided.
Since the second embodiment is the same as the first embodiment except for the points described above, the description of the other parts will be omitted.

Next, the operation of this embodiment will be described.
The bypass valve flow paths of the compression chamber communication outermost bypass holes 2e1 ′ communicate with each other only in a section from when the compression chambers 100a and 100b start to close until the orbiting scroll 3 turns 180 degrees. The volume change of the compression chamber in the communicating section is small, and the volume ratio is “compression chamber volume at the start of closing / compression chamber volume at the position where the 180 degree rotation has advanced”. For this reason, the fluid flows through the compression chamber communication outermost bypass holes 2e1 ′ only when the liquid compression is substantially avoided, not when the over-compression of the gas refrigerant (gaseous working fluid) is suppressed. Accordingly, only when liquid compression occurs in the compression chamber 100, a high-speed liquid flow from the compression chamber 100 toward the fixed back chamber 120 is generated in both compression chamber communication outermost bypass holes 2e1 ′. Due to this high-speed liquid flow, as explained in the first embodiment, the pressure in the back pressure communication passage 2i connected to the compression chamber communication outermost bypass holes 2e1 ′ is greatly reduced by Bernoulli's theorem, Accordingly, the back pressure valve 7 is opened, and the pressure in the back pressure chamber 110 is significantly lower than the pressure during normal operation in which no liquid compression occurs only in the case of liquid compression.

  That is, the back pressure valve 7 usually reduces the pressure (back pressure) in the back pressure chamber by the same amount as the pressure drop in the compression chamber in communication. However, when liquid compression occurs, the normal operation is performed as described above. Back pressure is lower than time. As a result, only when liquid compression occurs, the pressing force for pressing the swivel end plate 3a against the fixed end plate 2a side is greatly reduced, and the gap between the tooth tip and the tooth bottom of the scroll wrap (gap in the axial direction) is reduced. It expands and the sealing performance of the compression chamber 100 decreases. Therefore, when liquid compression is occurring, leakage between the compression chambers can be increased, and an abnormal pressure increase in the compression chambers can be avoided. In addition, at the time of overcompression, which is not liquid compression, the back pressure does not decrease and can be maintained in a state in which leakage between the compression chambers is suppressed.

As described above, according to this embodiment, it is possible to reliably avoid the liquid compression, and at the time of overcompression of the gas refrigerant generated in the normal operation, the back pressure does not decrease and the performance of suppressing the leakage between the compression chambers. This enables a scroll compressor that achieves both high reliability and high performance.
In addition, according to the present embodiment, the single back pressure communication path 2i can realize a combined flow path corresponding to the two compression chambers 100, and the effect of avoiding liquid compression of the two compression chambers 100 at a lower processing cost. is there.

  The back pressure valve channel also serves to improve the sealing performance of the compression chamber 100 by supplying oil from the back pressure chamber 110 to the compression chamber 100. In this embodiment, one back pressure valve channel is connected to the two systems. Therefore, it is possible to distribute oil to the two compression chambers 100 evenly and supply approximately the same amount of oil. Therefore, since the sealing performance of all the compression chambers 100 to be formed can be improved, a high-performance scroll compressor can be realized.

  Further, the back pressure valve channel is opened from the time when the communicating compression chamber 100 starts to close until the turning scroll 3 turns 180 degrees. The pressure change is small. (In Example 1 above, the orbiting scroll 3 communicates until it rotates 360 degrees, so the pressure change in the compression chamber is greater than in Example 2.) The back pressure valve 7 opens the back pressure valve flow path. Since the control operation is performed so as to have a constant differential pressure with the pressure in the compression chamber 100, according to the second embodiment, the fluctuation of the back pressure is reduced. Thereby, the fluctuation | variation of the urging | biasing force which urges | biases the turning scroll 3 to the fixed scroll 2 becomes small, and an urging | biasing state can be stabilized. As a result, fluctuations in the axial gap between the wraps are reduced and the formed oil film is stabilized, so that the sealing performance can be improved, leakage during compression can be suppressed, and the performance can be improved.

  Further, the compression chamber communication junction 70a is provided at a position about 270 degrees along the center of the root from the end of winding of the fixed wrap 2b, so that the outer side compression immediately after the start of compression (closure) It faces the chamber 100a and the extension side compression chamber 100b. Thereby, since it can suppress that the hot oil heated in the compression chamber 100 flows into the suction area | region 95, the heating of suction gas is suppressed and a performance improvement can be aimed at also from this point.

The diameter of the bypass hole 2e is made smaller than the width of the swirl wrap 3b so that the two compression chambers 100 (100a, 100b) do not communicate with each other via the bypass hole 2e.
Thus, the combined flow path connecting the back pressure communication path 2i to the flow path section connecting the bypass valve 9 and the compression chamber 100 is the outer line side compression chamber 100a or the inner line side compression chamber of the swirl wrap 3b. It is configured to communicate with only one of 100b and not to communicate with both the compression chambers of the outer line side compression chamber and the inner line side compression chamber at the same time.

  Further, in the case of the both compression chamber communication non-outermost bypass holes 2e2 ′ provided at the center of the tooth bottom, the bypass hole is blocked by the tooth tip of the swirl wrap 3b as compared with the case where the bypass hole is provided at a position close to the fixed wrap in the tooth bottom. The period (the turning angle section of the orbiting scroll 3) can be shortened. This is because the direction in which the orbiting wrap 3b crosses the bypass hole 2e2 ′ is substantially perpendicular to the winding direction of the orbiting wrap 3b. The same applies to the compression chamber communication outermost bypass holes 2e1 ′.

  On the other hand, when the bypass hole 2e is provided near the lap of the tooth bottom, the bypass hole 2e is crossed in a direction near to the winding direction of the swivel wrap 3b. Therefore, according to the second embodiment, the period during which one bypass hole 2e faces the compression chamber can be lengthened. Therefore, the number of flow paths of the bypass valves 2e1 ′ and 2e2 ′ provided at the center of the tooth bottom is minimized. it can. Thereby, processing cost can be suppressed and the effect which a bypass valve flow path has, ie, the reliability improvement by liquid compression avoidance, and the performance improvement by overcompression suppression can be improved further.

  The compression chamber communication junction 70a is provided at a position slightly smaller than 270 degrees from the end of winding of the fixed wrap 2b along the center of the root, as indicated by a broken line 70a 'in FIGS. Even in this case, substantially the same effect can be obtained, and in this case, both the compression chamber communication junctions 70a can face the compression chamber immediately before the compression chamber 100 starts to close. Therefore, liquid compression can be prevented more effectively.

  As described above, according to each embodiment of the present invention, the flow path portion (outermost bypass holes 2e1, 2e1 ′) connecting the bypass valve 9 and the compression chamber 100 in the outermost bypass valve flow path is provided. Since the back pressure communication passage for communicating the back pressure valve 7 and the compression chamber 100 in the back pressure valve passage is connected, the back pressure valve passage is connected to the compression chamber 100 via the outermost bypass valve passage. It is comprised so that it may communicate with. As a result, when liquid compression occurs in the compression chamber 100 and a working fluid (liquid) flows through the outermost bypass valve flow path, a large pressure drop occurs. Therefore, the back pressure valve flow is utilized by utilizing this pressure drop. The back pressure valve 7 of the road can be opened to reduce the pressure in the back pressure chamber 110. As a result, the axial gap between the fixed scroll and the orbiting scroll increases, so that the sealing performance of the compression chamber 100 can be lowered. Therefore, according to the present embodiment, in addition to the liquid compression preventing effect by the outermost bypass valve flow path, the liquid compression preventing effect by reducing the sealing property of the compression chamber 100 can be obtained. It is possible to avoid it reliably. As a result, the risk of damaging the scroll wrap can be greatly reduced, and an extremely reliable scroll compressor can be realized.

  In the embodiment described above, a plurality of bypass valve passages communicating with the outer side compression chamber 100a or the inner side compression chamber 100b are provided, and the outermost bypass holes 2e1 and 2e1 ′ of the outermost bypass valve passages are provided in the outermost bypass holes 2e1 and 2e1 ′. The example which connected the back pressure communication path 2i of the said back pressure valve flow path was demonstrated. On the other hand, when there is only one bypass valve channel communicating with the outer line side compression chamber 100a or the inner line side compression chamber 100b, the bypass hole 2e of the bypass valve channel (bypass valve in the bypass valve channel) If the back pressure communication passage 2i of the back pressure valve flow path is connected to the flow path portion between 9 and the compression chamber 100), the same effect can be obtained.

In addition, this invention is not limited to an above-described Example, Various modifications are included. For example, in the second embodiment, the confluence port 70a that is the compression chamber side opening of both compression chamber communication passages (outermost bypass hole 2e1 ′) to which the back pressure communication passage 2i is connected is formed at the center of the bottom of the fixed end plate 2a. Although the example formed so as to face is described, the joining port 70a is separated from the fixed wrap 2b by the thickness of the swivel wrap 3b at the tooth bottom of the fixed end plate 2a, and the diameter is equal to or less than the thickness of the swivel wrap What is necessary is just to be sufficient, and it is not limited to what is formed in a tooth root center.
Further, the above-described embodiments have been described in detail for easy understanding of the present invention, and are not necessarily limited to those having all the configurations described.

1: scroll compressor,
2: fixed scroll, 2a: fixed end plate, 2b: fixed wrap (scroll wrap),
2d: discharge hole, 2e: bypass hole,
2e1, 2e1 ′: outermost bypass hole (flow path portion between bypass valve and compression chamber in outermost bypass valve flow path) (2e1 ′: outermost bypass hole communicating with both compression chambers),
2e2, 2e2 ': non-outermost bypass hole (2e2': both compression chamber communication non-outermost bypass holes),
2f: bypass excavation, 2g: back pressure hole, 2h: back pressure excavation, 2i: back pressure communication path,
2k: suction groove, 2p: peripheral groove, 2q: base plate part, 2r: suction digging, 2s: suction port,
2u: fixed base plate surface,
3: turning scroll, 3a: turning end plate, 3b: turning wrap (scroll wrap),
3c: keyway, 3d: boss part,
4: Frame, 5: Oldham ring,
6: Crankshaft, 6b: Oiling hole, 6x: Oiling pipe,
7: Back pressure valve, 7a: Valve plate, 7b: Valve seat, 7c: Valve spring, 7d: Valve cap,
7c: back pressure valve spring, 7d: back pressure valve cap 8: casing, 8a: cylinder casing, 8b: upper casing, 8c: bottom casing,
9: Bypass valve, 9a: Valve plate, 9b: Valve seat, 9c: Valve spring, 9d: Spring presser,
9e: spacer, 9f: retainer,
10: Motor, 10a: Rotor, 10b: Stator,
21: Check valve, 23: Slewing bearing, 24: Main bearing,
25: Sub bearing, 25a: Ball, 25b: Ball holder,
35: Lower frame,
50: suction pipe, 55: discharge pipe,
60: Compression oil supply passage,
70, 70a, 70a ': junction (70a, 70a': both compression chamber communication junction),
80: Shaft balance, 82: Counter balance,
95: Suction area,
100: compression chamber, 100a: outer side compression chamber, 100b: inner side compression chamber,
110: Back pressure chamber, 115: Slewing bearing chamber,
120: fixed back chamber (discharge chamber), 121: motor chamber, 125: oil storage section,
220: Hermetic terminal.

Claims (8)

A fixed scroll having a fixed end plate and a fixed wrap standing on the fixed end plate, a turning scroll having a swiveling end plate and a turning wrap standing on the fixed end plate, and the fixed scroll and the orbiting scroll that sucks the working fluid before compression. A suction region for leading to the compression chamber, a discharge region for discharging the compressed working fluid compressed in the compression chamber, and for pressing the orbiting scroll formed on the back surface of the orbiting scroll against the fixed scroll A back pressure chamber that is maintained at a pressure between the suction pressure and the discharge pressure, and a back pressure valve configured to communicate the back pressure chamber and the compression chamber and to maintain a constant differential pressure in the front and rear A back pressure valve flow path, and a bypass valve flow path formed in the fixed end plate of the fixed scroll and communicating with the compression chamber and the discharge region and having a bypass valve in the middle. In the scroll compressor,
By connecting a back pressure communication path for communicating the back pressure valve and the compression chamber in the back pressure valve flow path to a flow path portion connecting the bypass valve and the compression chamber in the bypass valve flow path, the back pressure valve The flow path is configured to communicate with the compression chamber via the bypass valve flow path, and utilizes a pressure drop caused by liquid compression occurring in the compression chamber and the working fluid flowing through the bypass valve flow path. Scroll compression, wherein the back pressure valve in the back pressure valve channel is opened, thereby reducing the pressure in the back pressure chamber and increasing the axial gap between the fixed scroll and the orbiting scroll. Machine.   2. The scroll compressor according to claim 1, wherein a flow path portion connecting the bypass valve and the compression chamber in the bypass valve flow path is configured to be linear and have a constant flow path area. A scroll compressor characterized by that.   3. The scroll compressor according to claim 2, wherein the combined flow path connecting the back pressure communication path to the flow path portion connecting the bypass valve and the compression chamber is an outer line side compression chamber or an extension line of the swirl wrap. A scroll compressor, wherein the scroll compressor is configured to communicate with only one of the side compression chambers and not to communicate with both of the outer compression chamber and the inner compression chamber at the same time.   4. The scroll compressor according to claim 3, wherein the joining port, which is the compression chamber side opening of the joining channel, is separated from the fixed wrap by a thickness of the swirl wrap at the tooth bottom of the fixed end plate, and the diameter of the joining port is A scroll compressor characterized by being configured to have a thickness equal to or less than the thickness of the orbiting wrap.   5. The scroll compressor according to claim 4, wherein the junction is provided at a center of a tooth bottom of the fixed end plate.   6. The scroll compressor according to claim 5, wherein the scroll compressor has an asymmetrical tooth profile configured to be used for forming a compression chamber up to the end of the outer winding of the orbiting wrap.   The scroll compressor according to claim 6, wherein the junction is provided at a position facing the compression chamber immediately after the start of closing. The scroll compressor as described in any one of Claims 1-7 WHEREIN: The said bypass valve flow path is provided with two or more , The bypass valve and compression chamber in the outermost bypass valve flow path are connected among them. A scroll compressor characterized in that a back pressure communication path for communicating a back pressure valve and a compression chamber in the back pressure valve flow path is connected to the flow path portion.

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