JP2008190492A - Rotary compressor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To propose a rotary compressor capable of opening and closing a bypass passage in accordance with an operation state of an air conditioner or the like with a simple construction. <P>SOLUTION: A valve element (64) is fitted in a valve element receiving part (61) to be displaced for opening and closing the bypass passage (66). A high pressure side space (61b) and a low pressure side space (61a) are formed in the valve receiving part (61) by the valve element (64). When a high-low differential pressure of a refrigerant circuit (11) varies, a differential pressure between the high pressure side space (61b) and the low pressure side space (61a) is varied and opening and closing positions of the bypass passage (66) by the valve element (64) are automatically changed. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a rotary compressor capable of returning a part of refrigerant in a compression chamber to a suction side of a compression mechanism through a bypass passage.

  2. Description of the Related Art Conventionally, a rotary compressor that compresses a refrigerant in a compression chamber by rotating a piston eccentrically in a cylinder chamber has been widely applied to an air conditioner that performs a refrigeration cycle in a refrigerant circuit.

  As a rotary compressor of this type, Patent Document 1 discloses a compressor provided with a bypass passage that communicates the inside of the compression chamber with the suction side of the compression mechanism in the compression mechanism. This compressor is provided with the cylinder which has a cylinder chamber, and the piston accommodated in a cylinder chamber. An eccentric shaft portion that is eccentric by a predetermined amount from the drive shaft is fitted into the piston. When the drive shaft rotates, the piston revolves in the cylinder chamber driven by the eccentric shaft portion. As a result, in the cylinder chamber, the volume of the compression chamber formed between the piston and the cylinder changes, and the refrigerant is compressed in the compression chamber.

  The bypass passage has an inflow end formed on the inner peripheral surface of the cylinder and opened to the compression chamber, and an outflow end connected to the suction pipe of the compression mechanism. The bypass passage can be opened and closed by a valve body. Specifically, a back pressure chamber connected to the discharge side of the compression mechanism is formed on the back side of the valve body through a refrigerant introduction pipe. The refrigerant introduction pipe is provided with a three-way valve that can be switched between a state in which the discharge side of the compression mechanism and the back pressure chamber are communicated with each other and a state in which the discharge side of the compression mechanism and the back pressure chamber are blocked. .

  When the discharge side of the compression mechanism and the back pressure chamber communicate with each other by switching the three-way valve, the valve body is displaced to a position where the bypass passage is closed by being pressed by the high-pressure refrigerant introduced into the back pressure chamber. When the piston revolves in the cylinder chamber in this state, the refrigerant sucked into the compression chamber from the suction port is compressed, and the entire amount of the refrigerant is discharged from the discharge port.

On the other hand, when the discharge side of the compression mechanism and the back pressure chamber are shut off by switching the three-way valve, the valve body is biased by the spring and displaced to a position where the bypass passage is opened. When the piston revolves in the cylinder chamber in this state, a part of the refrigerant sucked into the compression chamber from the suction port is returned to the suction side of the compression mechanism through the bypass passage, while only the remaining refrigerant is compressed and discharged. It is discharged from the outlet.
JP 59-12264 A

  As described above, in this rotary compressor, by appropriately changing the setting of the three-way valve in accordance with the operating conditions of the air conditioner, the open / closed state of the valve body is switched, and the confined volume of the refrigerant (substantial suction) (Volume) is changed. For this reason, this rotary compressor requires a three-way valve for opening and closing the valve body, piping connected to the three-way valve, and the like. In addition, in order to switch the three-way valve in accordance with the operating condition of the air conditioner, the state of the operating condition of the air conditioner is appropriately detected by a sensor or the like, and the three way is determined according to the detection result of the sensor. It is necessary to switch the valve setting. Therefore, in the rotary compressor of Patent Document 1, the structure of the apparatus becomes complicated, resulting in an increase in manufacturing cost or complicated maintenance.

  The present invention has been made in view of the above points, and its purpose is to propose a rotary compressor capable of opening and closing a bypass passage according to operating conditions of an air conditioner or the like with a simple structure. It is to be.

  The first invention is driven while forming a compression chamber between the fixing member (41a, 41b, 44, 45, 46, 81) and the fixing member (41a, 41b, 44, 45, 46, 81). A compression mechanism (40a, 40b, 80) having a movable member (47a, 47b, 82) that rotates eccentrically with respect to the shaft (33), and is connected to a refrigerant circuit (11) in which a refrigeration cycle is performed. A rotary compressor that compresses in the compression chamber is assumed. The rotary compressor has one end opened into the compression chamber and the other end opened and closed with a bypass passage (66) connected to the suction side of the compression mechanism (40a, 40b, 80) and the bypass passage (66). A valve body (64), and a valve body housing portion (61) in which one end faces the bypass passage (66) and the valve body (64) is fitted so that the bypass passage (66) can be freely opened and closed. And the valve body (64) in the valve body housing part (61) so that the open / close position of the valve body (64) is automatically switched in accordance with the change in the differential pressure of the refrigerant circuit (11). Further, the pressure on the discharge side of the compression mechanism (40a, 40b, 80) is acting.

  In the first invention, the movable member (47a, 47b, 82) rotates eccentrically with respect to the fixed member (41a, 41b, 44, 45, 46, 81), so that the volume of the compression chamber is expanded and contracted, and the refrigerant is Compressed. Here, when the compression operation is performed at the position where the valve body (64) closes the bypass passage (66), the entire amount of the refrigerant is compressed in the compression chamber. On the other hand, when the compression operation is performed at a position where the valve body (64) opens the bypass passage (66), a part of the refrigerant returns to the suction side of the compression mechanism (40a, 40b, 80) through the bypass passage (66). The remaining refrigerant is compressed in the compression chamber. As described above, in the compression mechanism (40a, 40b, 80), the suction volume of the compression chamber is variable according to the opening / closing operation of the bypass passage (66) by the valve body (64).

  In the present invention, the valve body (64) is fitted in the valve body housing part (61) so as to be displaceable. The pressure on the discharge side of the compression mechanism (40a, 40b, 80) is acting in the valve body housing part (61). When the pressure difference in the refrigerant circuit (11) changes according to the refrigeration cycle conditions of the refrigerant circuit (11), the pressure acting on the valve body (64) also changes accordingly. As a result, in the valve body housing part (61), the valve body (64) is displaced in accordance with the fluctuation of the pressure, and becomes a position where the bypass passage (66) is opened or closed. In other words, in the present invention, the open / close position of the valve body (64) is automatically switched so as to be interlocked with the change in the high / low differential pressure of the refrigerant circuit (11). Accordingly, the suction volume of the compression mechanism (40a, 40b, 80) is also automatically changed according to the high / low differential pressure of the refrigerant circuit (11).

  According to a second aspect of the invention, in the rotary compressor of the first aspect of the invention, one compression mechanism (80) is connected to the drive shaft (33), and the valve body (64) is connected to the refrigerant circuit (11). ), When the pressure difference in level is equal to or lower than a predetermined value, it is configured to be displaced to the open position of the bypass passage (66).

  The rotary compressor of the second invention is composed of a single-stage compressor that performs a compression stroke of a refrigeration cycle by one compression mechanism. On the other hand, the valve body (64) in the valve body housing part (61) is displaced to a position where the bypass passage (66) is opened when the height differential pressure of the refrigerant circuit (11) becomes a predetermined value or less. For this reason, under such operating conditions where the differential pressure of the refrigerant circuit (11) is relatively small, a part of the refrigerant in the compression chamber is returned to the suction side of the compression mechanism (80) via the bypass passage (66). It is. As a result, the suction volume of the compression mechanism (80) is reduced, and the refrigerant circulation amount of the rotary compressor is mechanically suppressed.

  According to a third aspect of the present invention, in the rotary compressor according to the second aspect of the present invention, a low-pressure side space (connected to the suction side of the compression mechanism (80) formed in one end side of the valve body housing part (61) ( 61a) and a high-pressure side space (61b) formed on the other end side and connected to the discharge side of the compression mechanism (80) are partitioned by the valve body (64), and the valve body (64) The differential pressure between the high-pressure side space (61b) and the low-pressure side space (61a) is acting toward the closed position of the bypass passage (66), and the high / low differential pressure of the refrigerant circuit (11) is below a predetermined value. The valve body (64) is provided with valve opening means (65) that acts on the valve body (64) so that the valve body (64) is displaced to the open position. is there.

  In 3rd invention, the inside of a valve body accommodating part (61) is partitioned off into the high voltage | pressure side space (61b) and the low voltage | pressure side space by the valve body (64). The high-pressure side space (61b) is connected to the discharge side of the compression mechanism (80) and has a high-pressure atmosphere. On the other hand, the low pressure side space (61a) is connected to the suction side of the compression mechanism (80) and has a low pressure atmosphere. Differential pressure between the high pressure side space (61b) and the low pressure side space (61a) acts on the valve body (64) toward the closed position of the bypass passage (66). Further, a reaction force directed to the opposite side of the differential pressure, that is, a force toward the opening position of the bypass passage (66) is applied to the valve body (64) by the valve opening means (65).

  When the pressure difference in the refrigerant circuit (11) exceeds a predetermined value, the pressure difference between the high pressure side space (61b) and the low pressure side space (61a) becomes relatively large. It is displaced to the closed position of the bypass passage (66). As a result, under an operating condition in which the differential pressure of the refrigerant circuit (11) is relatively large, the suction volume of the compression mechanism (80) increases, and the operating capacity of the rotary compressor automatically increases. On the other hand, when the differential pressure of the refrigerant circuit (11) is below a predetermined value, the differential pressure between the high pressure side space (61b) and the low pressure side space (61a) is relatively small. The opening means (65) is displaced to the open position of the bypass passage (66). As a result, under operating conditions in which the differential pressure of the refrigerant circuit (11) is relatively small, the suction volume of the compression mechanism (80) is reduced, and the refrigerant circulation rate of the rotary compressor is mechanically suppressed.

  According to a fourth aspect of the present invention, in the rotary compressor according to the first aspect, the compression mechanism includes a low-stage compression mechanism (40a) that compresses the refrigerant sucked from the refrigerant circuit (11), and the low-stage compression. The bypass passage includes the lower stage compression mechanism (40a) and the higher stage compression mechanism (40b) connected by the drive shaft (33) while sucking and compressing the refrigerant discharged by the mechanism (40a). (66) has one end opened to the compression chamber of the low-stage compression mechanism (40a) and the other end connected to the suction side of the low-stage compression mechanism (40a). The valve element (64) When the pressure difference of the refrigerant circuit (11) becomes a predetermined value or less, the refrigerant circuit (11) is configured to be displaced to the open position of the bypass passage (66).

  In the fourth invention, a compression mechanism is provided in which the low-stage compression mechanism (40a) and the high-stage compression mechanism (40b) are connected to each other by the drive shaft (33). The bypass passage (66) and the valve body accommodating portion (61) of the present invention are provided in the low-stage compression mechanism (40a), and the low-stage compression mechanism (40a) according to the opening / closing position of the valve body (64). ) Can be switched. Here, when the refrigerant is compressed in two stages by the both compression mechanisms (40a, 40b) under operating conditions where the differential pressure of the refrigerant circuit (11) is relatively small, the compression process of the refrigerant on the low-stage compression mechanism (40a) side. Is almost finished, and the high-stage compression mechanism (40b) may hardly compress the refrigerant. As a result, the fluctuation range of the refrigerant compression torque in the low stage compression mechanism (40a) is relatively larger than the fluctuation range of the refrigerant compression torque in the high stage compression mechanism (40b). As a result, there arises a problem that vibration and noise are generated with the rotation of the drive shaft (33) due to the unbalanced fluctuation range of the compression torque in both compression mechanisms (40a, 40b).

  Therefore, in the present invention, when the differential pressure of the refrigerant circuit (11) becomes a predetermined value or less, the valve body (64) of the low-stage compression mechanism (40a) is displaced to the closed position of the bypass passage (66). . For this reason, part of the refrigerant in the compression chamber of the low-stage compression mechanism (40a) is reduced through the bypass passage (66) under such operating conditions where the differential pressure of the refrigerant circuit (11) is relatively small. It is returned to the suction side of the stage side compression mechanism (40a). As a result, the suction volume of the low-stage compression mechanism (40a) is smaller than when the valve body (64) is in the closed position, and the fluctuation range of the compression torque of the low-stage compression mechanism (40a) is accordingly reduced. And the fluctuation range of the compression torque of both compression mechanisms (40a, 40b) is averaged. Therefore, the occurrence of vibration and noise accompanying the rotation of the drive shaft (33) due to the unbalance of the fluctuation range of the compression torque in both compression mechanisms (40a, 40b) is automatically eliminated.

  According to a fifth aspect of the present invention, in the rotary compressor according to the fourth aspect of the present invention, a low pressure formed in one end side of the valve body housing portion (61) and connected to the suction side of the low stage compression mechanism (40a). A side space (61a) and a high-pressure side space (61b) formed on the other end side and connected to the discharge side of the high-stage compression mechanism (40b) are partitioned by the valve body (64). The body (64) is subjected to a differential pressure between the high pressure side space (61b) and the low pressure side space (61a) toward the closed position of the bypass passage (66), and the difference in height of the refrigerant circuit (11). Valve opening means (65) for applying a reaction force against the differential pressure to the valve body (64) so that the valve body (64) is displaced to the open position when the pressure falls below a predetermined value. It is a feature.

  In 5th invention, the inside of a valve body accommodating part (61) is partitioned off into the high voltage | pressure side space (61b) and the low voltage | pressure side space by the valve body (64). The high-pressure side space (61b) is connected to the discharge side of the high-stage compression mechanism (40b) and has a high-pressure atmosphere. On the other hand, the low-pressure side space (61a) is connected to the suction side of the low-stage compression mechanism (40a) and has a low-pressure atmosphere. On the valve body (64), the differential pressure between the high pressure side space (61b) and the low pressure side space (61a) acts toward the closed position of the bypass passage (66). A reaction force that faces away from the pressure is also acting.

  When the pressure difference in the refrigerant circuit (11) exceeds a predetermined value, the pressure difference between the high pressure side space (61b) and the low pressure side space (61a) becomes relatively large. It is displaced to the closed position of the bypass passage (66). As a result, under operating conditions where the differential pressure of the refrigerant circuit (11) is relatively large, the suction volume of the low-stage compression mechanism (40a) is large, and the compression stroke is performed in a balanced manner by both compression mechanisms (40a, 40b). Is called. On the other hand, when the differential pressure of the refrigerant circuit (11) is below a predetermined value, the differential pressure between the high pressure side space (61b) and the low pressure side space (61a) is relatively small. The opening means (65) is displaced to the open position of the bypass passage (66). As a result, the suction volume of the low-stage compression mechanism (40a) is reduced under operating conditions where the pressure difference in the refrigerant circuit (11) is relatively small. For this reason, vibration and noise caused by the rotation of the drive shaft (33) due to the unbalance of the fluctuation range of the compression torque in both compression mechanisms (40a, 40b) are automatically eliminated.

  According to a sixth aspect of the present invention, in the rotary compressor according to the first aspect, the compression mechanism includes a low-stage compression mechanism (40a) that compresses the refrigerant sucked from the refrigerant circuit (11), and the low-stage compression. The bypass passage includes the lower stage compression mechanism (40a) and the higher stage compression mechanism (40b) connected by the drive shaft (33) while sucking and compressing the refrigerant discharged by the mechanism (40a). (66) has one end opened to the compression chamber of the high-stage compression mechanism (40b) and the other end connected to the suction side of the high-stage compression mechanism (40b). The valve element (64) When the pressure difference of the refrigerant circuit (11) becomes a predetermined value or less, the refrigerant circuit (11) is configured to be displaced to the closed position of the bypass passage (66).

  In the sixth invention, a compression mechanism is provided in which the low-stage compression mechanism (40a) and the high-stage compression mechanism (40b) are connected to each other by the drive shaft (33). The bypass passage (66) and the valve body accommodating portion (61) of the present invention are provided in the high stage side compression mechanism (40b), and the high stage side compression mechanism (40b) according to the opening / closing position of the valve body (64). ) Can be switched. Here, when the refrigerant is compressed in two stages by the both compression mechanisms (40a, 40b) under an operating condition where the differential pressure of the refrigerant circuit (11) is relatively small, as described above, in the low-stage compression mechanism (40a) The fluctuation width of the refrigerant compression torque is relatively larger than the fluctuation width of the refrigerant compression torque in the high-stage compression mechanism (40b), which causes vibration and noise.

  Therefore, in the present invention, when the differential pressure of the refrigerant circuit (11) becomes a predetermined value or less, the valve body (64) of the high-stage compression mechanism (40b) is displaced to the closed position of the bypass passage (66). . For this reason, under such operating conditions where the differential pressure of the refrigerant circuit (11) is relatively small, the entire amount of refrigerant is compressed in the compression chamber of the high-stage compression mechanism (40b). As a result, since the suction volume of the high-stage compression mechanism (40b) is larger than when the valve body (64) is in the open position, the fluctuation range of the compression torque of the high-stage compression mechanism (40b) is correspondingly increased. And the fluctuation range of the compression torque of both compression mechanisms (40a, 40b) is averaged. Therefore, the occurrence of vibration and noise accompanying the rotation of the drive shaft (33) due to the unbalance of the fluctuation range of the compression torque in both compression mechanisms (40a, 40b) is automatically eliminated.

  7th invention is the rotary compressor of 6th invention. WHEREIN: The said valve body accommodating part (61) is formed in the one end side, The high pressure side space connected with the discharge side of a high stage side compression mechanism (40b) (61b) and an intermediate pressure side space (61c) formed on the other end side and connected to the suction side of the high-stage compression mechanism (40b) are partitioned by the valve body (64). 64) is affected by the differential pressure between the high pressure side space (61b) and the intermediate pressure side space (61c) toward the open position of the bypass passage (66), and the high and low differential pressure of the refrigeration cycle is below a predetermined value. Then, the valve body (64) is provided with valve closing means (65) for acting on the valve body (64) with a reaction force against the differential pressure so that the valve body (64) is displaced to the closed position. is there.

  In 7th invention, the inside of a valve body accommodating part (61) is partitioned off into the high pressure side space (61b) and the intermediate pressure side space (61c) by the valve body (64). The high-pressure side space (61b) is connected to the discharge side of the high-stage compression mechanism (40b) and has a high-pressure atmosphere. On the other hand, the intermediate pressure side space (61c) is connected to the suction side of the high stage compression mechanism (40b), and has an intermediate pressure atmosphere. The valve body (64) has a differential pressure between the high pressure side space (61b) and the intermediate pressure side space (61c) acting toward the open position of the bypass passage (66). A reaction force that faces away from the pressure is also acting.

  In the state where the high and low differential pressure of the refrigerant circuit (11) exceeds a predetermined value, the differential pressure between the high pressure side space (61b) and the intermediate pressure side space (61c) becomes relatively large. It is displaced to the open position of the bypass passage (66). As a result, under operating conditions where the differential pressure of the refrigerant circuit (11) is relatively large, the suction volume of the high-stage compression mechanism (40b) is reduced, and the compression stroke is performed in a balanced manner by both compression mechanisms (40a, 40b). Is called. On the other hand, in the state where the differential pressure of the refrigerant circuit (11) is below a predetermined value, the differential pressure between the high pressure side space (61b) and the intermediate pressure side space (61c) is relatively small, so the valve body (64) The closing means (65) displaces the bypass passage (66) to the closed position. As a result, the suction volume of the high-stage compression mechanism (40b) increases under operating conditions in which the differential pressure difference of the refrigerant circuit (11) is relatively small. For this reason, vibration and noise caused by the rotation of the drive shaft (33) due to the unbalance of the fluctuation range of the compression torque in both compression mechanisms (40a, 40b) are automatically eliminated.

  The eighth invention is the rotary compressor of the third, fifth and seventh inventions, wherein the compression mechanism (40a, 40b, 80) is housed, and the high pressure of the refrigerant circuit (11) is stored in the internal space. A casing (21) filled with a refrigerant is provided, and the high-pressure side space (61b) of the valve body housing part (61) faces the internal space of the casing (21).

  The rotary compressor according to the eighth aspect of the invention is a so-called high-pressure dome type compressor in which the internal space of the casing (21) is filled with the high-pressure refrigerant in the refrigerant circuit (11). On the other hand, the high-pressure side space (61b) of the valve body housing part (61) faces the internal space of the casing (21), and the high-pressure refrigerant acts on the high-pressure side space (61b). As a result, the valve body (64) automatically switches the open / close position of the bypass passage (66) by this high pressure.

  A ninth aspect of the invention is the rotary compressor according to the eighth aspect of the invention, wherein an oil sump in which oil for lubricating the compression mechanism (40a, 40b, 80) is stored in the inner space of the casing (21). A portion (21a) is formed, and the high-pressure side space (61b) faces the oil sump portion (21a).

  In the ninth invention, the high pressure side space (61b) faces the oil sump (21a) of the casing (21), and oil that is pushed out by the high pressure refrigerant is introduced into the high pressure side space (61b). That is, high-pressure oil acts on the valve body (64) from the high-pressure side space (61b). As a result, the valve body (64) automatically switches the open / close position of the bypass passage (66) by the high pressure of the oil.

  In the first invention, the bypass passage (66) is opened and closed by displacing the valve body (64) provided in the valve body housing portion (61) in accordance with the change in the pressure difference of the refrigerant circuit (11). The pressure on the discharge side of the compression mechanism (40a, 40b, 80) is applied to the valve body (64). For this reason, according to the present invention, the open / close position of the valve body (64) can be changed in the height of the refrigerant circuit (11) without providing a three-way valve or the like as in the prior art or appropriately controlling the three-way valve. It can be switched automatically according to the pressure change. Therefore, this rotary compressor can be configured simply, and cost reduction or simplification of maintenance can be achieved.

  In the second invention, in the single-stage compression mechanism (80), the valve body (64) is displaced to the open position when the differential pressure of the refrigerant circuit (11) becomes a predetermined value or less. For this reason, under operating conditions where the differential pressure of the refrigerant circuit (11) is relatively small, the suction volume of the compression mechanism (80) is automatically reduced to mechanically suppress the refrigerant circulation rate of the rotary compressor. The Therefore, it is possible to operate at a frequency with high motor efficiency without significantly reducing the operating frequency of the rotary compressor.

  In the third invention, the refrigerant circuit (11) is obtained by utilizing the differential pressure between the high pressure side space (61b) and the low pressure side space (61a) and the reaction force of the valve opening means (65) against the differential pressure. When the pressure difference between the two becomes lower than a predetermined value, the valve body (64) is displaced to the open position of the bypass passage (66). Therefore, according to the present invention, the amount of refrigerant circulating in the rotary compressor can be mechanically suppressed with a relatively simple configuration under operating conditions where the pressure difference in the refrigerant circuit (11) is small.

  In the fourth aspect of the invention, when the pressure difference in the refrigerant circuit (11) becomes a predetermined value or less, the valve body (64) of the low-stage compression mechanism (40a) is automatically displaced to the open position of the bypass passage (66). I try to let them. In the sixth aspect of the invention, when the pressure difference in the refrigerant circuit (11) becomes a predetermined value or less, the valve body (64) of the high-stage compression mechanism (40b) is automatically set to the closed position of the bypass passage (66). To be displaced. Therefore, according to these inventions, in such operating conditions, the fluctuation range of the compression torque of the low stage compression mechanism (40a) and the fluctuation range of the compression torque of the high stage compression mechanism (40b) are quickly averaged. Therefore, vibration and noise can be prevented automatically.

  In the fifth invention, the refrigerant circuit (11) is obtained by utilizing the differential pressure between the high pressure side space (61b) and the low pressure side space (61a) and the reaction force of the valve opening means (65) against the differential pressure. When the pressure differential pressure is less than or equal to a predetermined value, the valve body (64) of the low-stage compression mechanism (40a) is displaced to the open position of the bypass passage (66). In the seventh invention, a refrigerant circuit (65) is used by utilizing the differential pressure between the high pressure side space (61b) and the intermediate pressure side space (61c) and the reaction force of the valve closing means (65) against the differential pressure. When the pressure difference between 11 and 11 falls below a predetermined value, the valve body (64) of the high-stage compression mechanism (40b) is displaced to the closed position of the bypass passage (66). Therefore, according to these inventions, with a relatively simple configuration, the fluctuation range of the compression torque of both compression mechanisms (40a, 40b) can be averaged, and the occurrence of vibration and noise can be prevented in advance. it can.

  In the eighth invention, the high pressure side space (61b) faces the internal space of the casing (21) filled with the high pressure refrigerant in the refrigerant circuit (11). For this reason, piping or the like for guiding the pressure on the discharge side of the compression mechanism (40b) to the high-pressure side space (61b) becomes unnecessary, and the structure of the rotary compressor can be further simplified.

  In the ninth aspect of the invention, the high pressure side space (61b) of the oil sump portion (21a) faces. For this reason, the open / close position of the valve body (64) can be switched using high-pressure oil. Further, when the valve body (64) is displaced with oil in this way, the gap between the outer peripheral surface of the valve body (64) in the closed position and the inner peripheral surface of the valve body housing portion (61) is oiled. Can be sealed. For this reason, it is possible to prevent relatively hot oil from entering the compression chamber of the compression mechanism (40a, 40b, 80) through the gap around the valve body (64), and the refrigerant in the compression chamber is heated by the oil. This can be avoided beforehand. Therefore, it is possible to prevent the volumetric efficiency of the compression mechanism (40a, 40b, 80) from being reduced by so-called refrigerant suction heating.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

Embodiment 1
The rotary compressor (20) according to Embodiment 1 of the present invention is applied to an air conditioner (10) that performs indoor cooling and heating.

<Overall configuration of air conditioner>
As shown in FIG. 1, the air conditioner (10) includes a refrigerant circuit (11) that performs a refrigeration cycle by circulating the refrigerant. The refrigerant circuit (11) includes the rotary compressor (20), outdoor heat exchanger (14), indoor heat exchanger (15), first expansion valve (16), second expansion valve (17), four-way A switching valve (12), a gas-liquid separator (18), and an accumulator (19) are connected.

  The discharge side of the rotary compressor (20) is connected to the first port (P1) of the four-way switching valve (12) through the discharge pipe (23). The suction side of the rotary compressor (20) is connected to the bottom of the accumulator (19) via the suction pipe (22). The top of the accumulator (19) is connected to the fourth port (P4) of the four-way switching valve (12). The outdoor heat exchanger (14) has one end connected to the second port (P2) of the four-way switching valve (12) and the other end connected to the gas-liquid separator (18) via the second expansion valve (17). Connected to the bottom. On the other hand, the indoor heat exchanger (15) has one end connected to the third port (P3) of the four-way switching valve (12) and the other end connected to the gas-liquid separator (18) via the first expansion valve (16). Connected to the bottom.

  The four-way selector valve (12) is in a state where the first port (P1) and the second port (P2) communicate with each other and the third port (P3) and the fourth port (P4) communicate with each other (indicated by a solid line in FIG. 1). State), the first port (P1) and the third port (P3) communicate with each other, and the second port (P2) and the fourth port (P4) communicate with each other (state indicated by a broken line in FIG. 1). It is comprised so that it may switch to.

  The refrigerant circuit (11) is provided with an injection pipe (24) and a bypass pipe (28). One end of the injection pipe (24) is connected to the top of the gas-liquid separator (18), and the other end is connected to the rotary compressor (20). The injection pipe (24) is provided with a solenoid valve (31) that can be freely opened and closed. When the electromagnetic valve (31) is opened, the intermediate pressure refrigerant in the gas-liquid separator (18) is introduced into the rotary compressor (20) by the injection pipe (24). The bypass pipe (28) has one end connected to the rotary compressor (20) and the other end connected to the suction pipe (22).

<Configuration of rotary compressor>
Next, the configuration of the rotary compressor according to the present invention will be described.

  As shown in FIG. 2, the rotary compressor (20) includes a casing (21) which is a vertically long and cylindrical sealed container. The discharge pipe (23) penetrates and is connected to the upper part of the casing (21). The suction pipe (22) and the bypass pipe (28) are connected through the body of the casing (21). Inside the casing (21), an electric motor (25) is disposed on the upper side thereof, and a compression mechanism (40) is disposed on the lower side thereof. The internal space of the casing (21) is filled with the refrigerant discharged from the compression mechanism (40). That is, the rotary compressor (20) is a so-called high-pressure dome type compressor in which the internal space of the casing (21) is filled with the high-pressure refrigerant in the refrigerant circuit (11).

  The electric motor (25) includes a stator (26) and a rotor (27). The stator (26) is fixed to the inner peripheral surface of the casing (21). The rotor (27) is disposed inside the stator (26). A main shaft portion (34) of a drive shaft (33) extending in the vertical direction is connected to the central portion of the rotor (27).

  The drive shaft (33) is driven to rotate about a predetermined rotation axis (X) when the electric motor (25) is energized. The drive shaft (33) is formed with a first eccentric shaft portion (35) and a second eccentric shaft portion (36) in order from the lower side. The first eccentric shaft portion (35) and the second eccentric shaft portion (36) have a larger diameter than the main shaft portion (34) and are formed eccentric to the rotation axis (X) of the main shaft portion (34). Yes. In the first eccentric shaft portion (35) and the second eccentric shaft portion (36), the eccentric directions with respect to the rotation axis (X) are reversed. Further, the height of the first eccentric shaft portion (35) is higher than that of the second eccentric shaft portion (36).

  An oil reservoir (21a) for lubricating oil is formed at the bottom of the casing (21). The lower end of the drive shaft (33) is immersed in the oil reservoir (21a). A centrifugal oil pump (33a) is provided at the lower end of the drive shaft (33). When the drive shaft (33) rotates, the lubricating oil in the oil reservoir (21a) is pumped upward by the oil pump (33a). This lubricating oil is supplied to each sliding portion of the compression mechanism (40), which will be described in detail later, via an oil passage (53) formed in the drive shaft (33).

  The compression mechanism (40) includes a low-stage compression mechanism (40a) and a high-stage compression mechanism (40b). In other words, this rotary compressor includes a so-called two-stage compression type compressor that includes two compression mechanisms and compresses the refrigerant in two stages.

  In the compression mechanism (40), a front head (44), a high-stage cylinder (41b), a middle plate (46), a low-stage cylinder (41a), and a rear head (45) are arranged in order from above. Constitutes a fixing member fixed to the casing (21). The drive shaft (33) passes through the front head (44), the middle plate (46), and the rear head (45). The front head (44) and the rear head (45) are fixed to the inner wall of the casing (21) and rotatably support the drive shaft (33). Further, the rear head (45) is immersed in the oil sump portion (21a) described above.

  The low stage side cylinder (41a) and the high stage side cylinder (41b) are formed in a cylindrical shape. A low-stage cylinder chamber (42a) is formed inside the low-stage cylinder (41a), and a high-stage cylinder chamber (42b) is formed inside the high-stage cylinder (41b). That is, the lower stage cylinder chamber (42a) has a lower open end closed by the rear head (45) and an upper open end closed by the middle plate (46). The low-stage cylinder chamber (42a) is formed between the rear head (45), the middle plate (46), and the low-stage cylinder (41a). On the other hand, the high-stage cylinder chamber (42b) has a lower open end closed by the middle plate (46) and an upper open face closed by the front head (44). The high-stage cylinder chamber (42b) is formed between the front head (44), the middle plate (46), and the high-stage cylinder (41b).

  The low-stage cylinder chamber (42a) is provided with a cylindrical low-stage piston (47a). The first eccentric shaft portion (35) is fitted in the low-stage piston (47a). On the other hand, a cylindrical high stage side piston (47b) is provided in the high stage side cylinder chamber (42b). The second eccentric shaft portion (36) is fitted into the high-stage piston (47b). The low stage side piston (47a) and the high stage side piston (47b) constitute a movable member. As described above, in this compression mechanism (40), the low-stage compression mechanism (40a) is provided from the rear head (45) to the middle plate (46), and from the middle plate (46) to the front head (44). A high-stage compression mechanism (40b) is provided over the entire area.

  The low-stage compression mechanism (40a) and the high-stage compression mechanism (40b) are so-called oscillating piston types in which each piston (47a, 47b) revolves so that each cylinder chamber (41a, 41b) oscillates. It is composed of a (swing type) rotary compression mechanism. The low-stage compression mechanism (40a) and the high-stage compression mechanism (40b) have the same basic configuration. On the other hand, the volume of the low-stage cylinder chamber (42a) of the low-stage compression mechanism (40a) is larger than the volume of the high-stage cylinder chamber (42b) of the high-stage compression mechanism (40b).

  As shown in FIG. 3, the lower stage compression mechanism (40a) is provided with a blade (38) and a pair of bushes (39, 39). The blade (38) is formed integrally with the low-stage piston (47a). The blade (38) extends radially outward from the outer peripheral surface of the low-stage piston (47a). The blade (38) partitions the low-stage side cylinder chamber (42a) into a low-pressure side low-pressure chamber (42a-Lp) and a high-pressure side high-pressure chamber (42a-Hp). The pair of bushes (39, 39) are fitted into bush holes (56) formed in the low-stage cylinder (41a). Each bush (39, 39) is formed in a substantially semi-cylindrical shape. Both bushes (39, 39) have their flat surfaces facing each other. Both the bushes (39, 39) hold the blade (38) between their flat surfaces so as to freely advance and retract. In addition, each bush (39, 39) has an arc-shaped outer peripheral surface in sliding contact with an inner peripheral surface of the bush hole (56). Each bush (39, 39) is swingably held in the bush hole (56) with the axis of the bush hole (56) as a fulcrum. The blade (38) and the bush (39) configured as described above constitute a rotation limiting mechanism for restricting the rotation of the low-stage piston (47a).

  The low stage side compression mechanism (40a) is formed with a low stage side suction passage (48a) and a low stage side discharge passage (49a). The low stage side suction passage (48a) is formed in the low stage side cylinder (41a). The suction pipe (22) is connected to the inflow end of the low stage side suction passage (48a). The outflow end of the low stage side suction passage (48a) opens to the low pressure chamber (42a-Lp) of the low stage side cylinder chamber (42a). That is, the outflow end of the lower stage side suction passage (48a) constitutes the suction port of the lower stage side cylinder chamber (42a). A low-pressure gas refrigerant is supplied from the low-stage suction passage (48a) to the low-stage cylinder chamber (42a). The low-stage discharge passage (49a) is formed in the middle plate (46). The inflow end of the low-stage discharge passage (49a) opens to the high-pressure chamber (42a-Hp) of the low-stage cylinder chamber (42a). That is, the inflow end of the low-stage discharge passage (49a) constitutes a discharge port of the low-stage cylinder chamber (42a). In addition, the outlet of the low-stage discharge passage (49a) opens to an intermediate pressure chamber (50) formed in the middle plate (46) (see FIG. 2). Furthermore, a discharge valve (not shown) is provided at the outflow opening of the low-stage discharge passage (49a). The intermediate pressure chamber (50) is filled with the refrigerant discharged from the low-stage compression mechanism (40a) and has an intermediate pressure atmosphere. The intermediate pressure chamber (50) communicates with the injection pipe (24).

  The high stage compression mechanism (40b) is provided with blades and bushes (not shown) in the same manner as the low stage compression mechanism (40a). The high stage side compression mechanism (40b) has a high stage side suction passage (48b) and a high stage side discharge passage (49b). The inflow end of the high-stage suction passage (48b) communicates with the intermediate pressure chamber (50). The outflow end of the high stage side suction passage (48b) opens to the low pressure chamber of the high stage side cylinder chamber (42b). The high stage discharge passage (49b) is formed in the front head (44). The inflow end of the high stage side discharge passage (49b) opens to the high pressure chamber of the high stage side cylinder chamber (42b). The outflow end of the high-stage discharge passage (49b) opens into the casing (21). A discharge valve (not shown) is provided at the outflow opening of the high-stage discharge passage (49b). Furthermore, a muffler (58) for reducing noise in the vicinity of the outflow opening of the high-stage discharge passage (49b) is provided on the upper portion of the front head (44) (see FIG. 2).

  As shown in FIGS. 4A and 4B, the rear head (45) of the low-stage compression mechanism (40a) described above is provided with a bypass hole (62) and a valve body accommodating portion (61). ing.

  The bypass hole (62) constitutes the inflow end of the bypass passage (66). The upper end of the bypass hole (62) opens to the lower inner wall surface of the low-stage cylinder chamber (42a). Further, as shown in FIG. 3, the bypass hole (62) is a reference line when a straight line connecting the rotation axis (X) of the drive shaft (33) and the axis of the bush hole (56) is used as a reference line. 3 is located on a straight line forming about 90 degrees in the clockwise direction in FIG. 3 around the rotation axis (X). The bypass hole (62) is disposed so that a part of the bypass hole (62) near the outer side in the radial direction straddles the rear head (45). Further, the bypass hole (62) is located radially outside the first eccentric shaft portion (35). That is, the bypass hole (62) is located radially outside the locus of the outer peripheral surface of the first eccentric shaft portion (35) that rotates eccentrically about the rotation axis (X). Therefore, in the low-stage compression mechanism (40a), the lubricating oil supplied to the outer peripheral surface of the first knitted core shaft portion (35) does not directly enter the bypass hole (62).

  The valve body accommodating part (61) is formed from the lower end of the rear head (45) to the vicinity of the upper end. A cylindrical space coaxial with the bypass hole (62) is formed in the valve body housing (61). The upper end of the valve body accommodating portion (61) faces the bypass hole (62), and the lower end thereof is sealed by the lid member (63).

  A valve body (64) is fitted in the valve body housing part (61) so as to be freely displaceable in the vertical direction. The valve body (64) is formed in a columnar shape whose outer diameter increases in two steps from the upper side to the lower side of the valve body housing part (61). That is, the valve body (64) has an upper-stage small-diameter portion (64a), an intermediate-stage-side intermediate-diameter portion (64b), and a lower-stage-side large-diameter portion (64c). The small diameter part (64a), the medium diameter part (64b), and the large diameter part (64c) are coaxial.

  The outer diameter of the large diameter part (64c) of the valve body (64) is substantially the same as the inner diameter of the valve body accommodating part (61). That is, the large diameter portion (64c) of the valve body (64) is in sliding contact with the inner peripheral surface of the valve body housing portion (61). And the valve body accommodating part (61) is divided by the large diameter part (64c) of the valve body (64) into the low voltage | pressure side space (61a) of the upper side, and the high voltage | pressure side space (61b) of the lower side. Yes.

  The outer diameter of the small diameter portion (64a) of the valve body (64) is substantially the same as the inner diameter of the bypass hole (62). That is, the small diameter portion (64a) of the valve body (64) is configured to be able to seal the bypass hole (62) by engaging with the bypass hole (62). The tip of the small diameter part (64a) is formed to be flat and parallel to the upper surface of the rear head (45). Further, the height of the small diameter portion (64a) coincides with the depth of the bypass hole (62) or is shorter than the depth of the bypass hole (62).

  The outer diameter of the intermediate diameter part (64b) of the valve body (64) is smaller than the inner diameter of the valve body accommodating part (61). That is, a cylindrical space is formed between the inner diameter part (64b) of the valve body (64) and the inner peripheral surface of the valve body accommodating part (61). In the cylindrical space, a spring member (65) is provided so as to cover the periphery of the medium diameter portion (64b). In the low pressure side space (61a), the spring member (65) is disposed so that one end thereof is in contact with the large diameter portion (64c) and the other end is in contact with the ceiling surface of the valve body housing portion (61).

  In the valve body housing part (61), the bypass pipe (28) is connected to the low pressure side space (61a). That is, the low stage side cylinder chamber (42a) communicates with the bypass pipe (28) through the bypass hole (62) and the low pressure side space (61a). The bypass hole (62), the low pressure side space (61a), and the bypass pipe (28) constitute a bypass passage (66). That is, the low pressure side space (61a) is connected to the suction side of the low stage side compression mechanism (40a). On the other hand, the high-pressure side space (61b) is connected to the discharge side of the high-stage compression mechanism (40b). Specifically, an introduction passage (29) is formed in the lid member (63). The lower end of the introduction passage (29) opens to the oil reservoir (21a) of the casing (21), and the upper end of the introduction passage (29) opens to the high-pressure side space (61b). As a result, high pressure oil is introduced into the high pressure side space (61b) through the introduction passage (29), and this high pressure oil acts on the back surface of the valve body (64).

  As described above, the pressure on the discharge side of the high-stage compression mechanism (40b) acts on the back surface side of the valve body (64), and the low pressure acts on the tip surface side thereof. Thereby, the differential pressure between the high pressure of the high pressure side space (61b) and the low pressure of the low pressure side space (61a) acts on the valve body (64) toward the closed position of the bypass passage (66). On the other hand, the spring member (65) described above constitutes a valve opening means that acts on the valve body (64) with a reaction force against the differential pressure toward the opening position of the bypass passage (66). The spring member (65) is arranged so that the valve body (64) is in an open position when the pressure difference of the refrigerant circuit (11) becomes a predetermined value or less as the operating condition of the air conditioner (10) changes. Energizing body (64). Details of the opening / closing operation of the valve body (64) will be described later.

-Operation of air conditioner-
The operation of the air conditioner (10) according to this embodiment will be described. The air conditioner (10) is configured to be capable of cooling operation and heating operation.

<Cooling operation>
During the cooling operation, the four-way switching valve (12) is set to the state shown by the solid line in FIG. When the electric motor (25) of the rotary compressor (20) is energized in this state, the operation of the rotary compressor (20) starts, and the refrigerant circulates in the refrigerant circuit (11) to perform a vapor compression refrigeration cycle. .

  The refrigerant compressed by the rotary compressor (20) is discharged from the discharge pipe (23), passes through the four-way switching valve (12), is sent to the outdoor heat exchanger (14), and radiates heat to the outdoor air. The high-pressure refrigerant radiated by the outdoor heat exchanger (14) is depressurized by the second expansion valve (17) to become an intermediate-pressure refrigerant and flows into the gas-liquid separator (18). The intermediate pressure refrigerant flowing into the gas-liquid separator (18) is separated into an intermediate pressure gas refrigerant and an intermediate pressure liquid refrigerant. Among them, the intermediate-pressure liquid refrigerant flowing out from the bottom of the gas-liquid separator (18) is decompressed by the first expansion valve (16) to become low-pressure liquid refrigerant and flows into the indoor heat exchanger (15). In the indoor heat exchanger (15), the refrigerant that has flowed in absorbs heat from the room air and evaporates, thereby cooling the room air. The low-pressure refrigerant that has flowed out of the indoor heat exchanger (15) sequentially passes through the four-way switching valve (12) and the accumulator (19) and is sucked into the rotary compressor (20). The refrigerant sucked into the rotary compressor (20) is compressed in the order of the low-stage compression mechanism (40a) and the high-stage compression mechanism (40b).

  In this cooling operation, when the solenoid valve (31) is set to the open state, the intermediate pressure gas refrigerant in the gas-liquid separator (18) is injected into the intermediate pressure chamber of the rotary compressor (20) by the injection pipe (24). Introduced to (50). The refrigerant introduced into the intermediate pressure chamber (50) is compressed by the high stage compression mechanism (40b) together with the refrigerant discharged from the low stage compression mechanism (40a). As described above, when the intermediate pressure refrigerant is sent from the injection pipe (24) to the suction side of the high-stage compression mechanism (40b), the enthalpy of the refrigerant sucked by the high-stage compression mechanism (40b) is reduced, so-called economizer. The effect improves the operating efficiency of the air conditioner (10).

<Heating operation>
During the heating operation, the four-way selector valve (12) is switched to the state indicated by the broken line in FIG. When the electric motor (25) of the rotary compressor (20) is energized in this state, the refrigerant circulates in the refrigerant circuit (11) to perform a vapor compression refrigeration cycle.

  The refrigerant compressed by the rotary compressor (20) is discharged from the discharge pipe (23), passes through the four-way switching valve (12), and flows into the indoor heat exchanger (15). In the indoor heat exchanger (15), the refrigerant that has flowed in dissipates heat to the room air, and the room air is heated. The refrigerant radiated by the indoor heat exchanger (15) is decompressed by the first expansion valve (16), becomes an intermediate pressure refrigerant, and flows into the gas-liquid separator (18). The intermediate pressure refrigerant flowing into the gas-liquid separator is separated into an intermediate pressure gas refrigerant and an intermediate pressure liquid refrigerant. Among them, the intermediate-pressure liquid refrigerant flowing out from the bottom of the gas-liquid separator (18) is decompressed by the second expansion valve (17) to become a low-pressure liquid refrigerant. The low-pressure liquid refrigerant decompressed by the second expansion valve (17) is sent to the outdoor heat exchanger (14) and absorbs heat from the outdoor air and evaporates. The low-pressure refrigerant that has flowed out of the outdoor heat exchanger (14) sequentially passes through the four-way switching valve (12) and the accumulator (19) and is sucked into the rotary compressor (20). The refrigerant sucked into the rotary compressor (20) is compressed in the order of the low-stage compression mechanism (40a) and the high-stage compression mechanism (40b).

  Also in this heating operation, when the solenoid valve (31) is set to the open state, the intermediate-pressure gas refrigerant in the gas-liquid separator (18) is introduced into the intermediate pressure chamber (50). The refrigerant introduced into the intermediate pressure chamber (50) is compressed by the high stage compression mechanism (40b) together with the refrigerant discharged from the low stage compression mechanism (40a). As described above, when the intermediate pressure refrigerant is sent from the injection pipe (24) to the suction side of the high-stage compression mechanism (40b), the enthalpy of the refrigerant sucked by the high-stage compression mechanism (40b) is reduced, so-called economizer. The effect improves the operating efficiency of the air conditioner (10).

-Operation of rotary compressor-
Next, the operation of the rotary compressor (20) will be described. In the rotary compressor (20), when the electric motor (25) is energized, the drive shaft (33) is rotated by the power generated by the electric motor (25). As a result, the first and second eccentric shaft portions (35, 36) rotate eccentrically with a predetermined amount of eccentricity with respect to the rotation shaft (X). Thereby, each piston (47a, 47b) in which each eccentric shaft part (35, 36) fits eccentrically rotates in each cylinder (41a, 41b). As a result, the following compression operation is performed in the low-stage compression mechanism (40a) and the high-stage compression mechanism (40b). Note that the compression operation of the low-stage compression mechanism (40a) is basically the same between the low-stage compression mechanism (40a) and the high-stage compression mechanism (40b). This will be described in detail.

<First compression operation>
The first compression operation is to operate the rotary compressor (20) while closing the bypass passage (66). The compression operation of the low-stage compression mechanism (40a) will be described with the eccentric rotation angle of the low-stage piston (47a) at the position shown in FIG. As the drive shaft (33) rotates, the low-stage piston (47a) at the position shown in FIG. 5A rotates eccentrically in the clockwise direction, and the low-stage piston (47a) and the low-stage cylinder (41a) come into contact with each other. The position is displaced clockwise. When this contact position passes through the opening of the low-stage suction passage (48a), a low-pressure chamber (42a-Lp) is formed in the low-stage cylinder chamber (42a) (see FIG. 5B). As the eccentric rotation angle of the low-stage piston (47a) increases, the refrigerant is sucked into the low-pressure chamber (42a-Lp) from the low-stage suction passage (48a) (FIGS. 5B to 5). (See (H)). The refrigerant is sucked into the low-pressure chamber (42a-Lp) until the eccentric rotation angle of the low-stage piston (47a) reaches 360 degrees (that is, 0 degrees).

  After that, when the low-stage piston (47a) slightly rotates from the state of FIG. 5 (A), the contact position between the low-stage piston (47a) and the low-stage cylinder (41a) changes to the low-stage intake passage ( 48a) through the opening. In the low-stage compression mechanism (40a), when the contact position passes through the opening of the low-stage suction passage (48a), the refrigerant is completely closed in the low-pressure chamber (42a-Lp). When the drive shaft (33) further revolves from this state, the low pressure chamber (42a-Lp) becomes a high pressure chamber (42a-Hp) and starts to compress the refrigerant. As the eccentric rotation angle of the low-stage piston (47a) increases, the volume of the high-pressure chamber (42a-Hp) decreases and the refrigerant is compressed. When the pressure of the refrigerant in the high pressure chamber (42a-Hp) exceeds the pressure of the refrigerant in the intermediate pressure chamber (50), the discharge valve is opened and the refrigerant flows from the low stage discharge passage (49a) to the intermediate pressure chamber. Discharged to (50). The discharge of the refrigerant continues until the eccentric rotation angle of the low stage side piston (47a) reaches 360 degrees.

  On the other hand, in the high-stage compression mechanism (40b), the refrigerant in the intermediate pressure chamber (50) flows through the high-stage discharge passage (49b) as the high-stage piston (47b) rotates eccentrically. It is sucked into the cylinder chamber (42b). When the pressure of the refrigerant in the high-stage side cylinder chamber (42b) exceeds the pressure of the refrigerant in the space in the casing (21), the discharge valve is opened, and the refrigerant flows from the high-stage side discharge passage (49b). It is discharged into the space in the casing (21). This refrigerant is discharged from the discharge pipe (23) to the refrigerant circuit (11) and used in the above-described refrigeration cycle.

<Second compression operation>
In the second compression operation, the rotary compressor (20) is operated while the bypass passage (66) is opened. Specifically, in the second compression operation, the three-way switching valve (13) is set to the state indicated by the broken line in FIG. As a result, the valve body (64) is pushed downward by the spring member (65) in the valve body housing part (61) as described above (see FIG. 4B). For this reason, in the second compression operation, the bypass hole (62) is opened. As described above, when the bypass passage (66) is opened, the low-stage cylinder chamber (42a) passes through the bypass passage (66) through the suction side (suction pipe (40) of the low-stage compression mechanism (40a). 22)).

  When the low-stage piston (47a) with the eccentric rotation angle of 0 degree is slightly rotated, the contact position between the low-stage piston (47a) and the low-stage cylinder (41a) is changed to the low-stage intake passage (48a). ) Pass through the opening. As a result, similarly to the first compression operation, a low pressure chamber (42a-Lp) is formed in the low stage side cylinder chamber (42a), and the low pressure chamber (42a-Lp) is formed from the low stage side suction passage (48a). The refrigerant is inhaled. Then, the eccentric rotation angle of the low-stage piston (47a) becomes 0 degree again, and further eccentrically rotates from this state, so that the contact position between the low-stage piston (47a) and the low-stage cylinder (41a) is low. When passing through the opening of the side suction passage (48a), the suction of the refrigerant in the low pressure chamber (42a-Lp) is completed at that time, and the low pressure chamber (42a-Lp) becomes the high pressure chamber (42a-Hp) .

  Here, in the second compression operation, the bypass passage (66) is in an open state. For this reason, even if the low-stage piston (47a) rotates further eccentrically, the refrigerant is not compressed in the high-pressure chamber (42a-Hp), and the refrigerant in the high-pressure chamber (42a-Hp) passes through the bypass hole (62). It is discharged to the suction pipe (22) through the bypass passage (66). This refrigerant discharge operation continues until the low-stage piston (47a) closes the bypass hole (62) (the eccentric rotation angle is about 90 degrees). Then, when the low-stage piston (47a) closes the bypass hole (62), the discharge of the refrigerant is completed, and at the same time, the confinement of the refrigerant in the high-pressure chamber (42a-Hp) is completed. When the drive shaft (33) further rotates from this state, compression of the refrigerant in the high pressure chamber (42a-Hp) is started, and the pressure of the refrigerant in the high pressure chamber (42a-Hp) is reduced to that of the refrigerant in the intermediate pressure chamber (50). When the pressure is exceeded, the discharge valve is opened and the refrigerant is discharged from the low-stage discharge passage (49a) to the intermediate pressure chamber (50). The discharge of the refrigerant continues until the eccentric rotation angle of the low stage side piston (47a) reaches 360 degrees. The refrigerant compression operation in the high-stage compression mechanism (40b) is the same as the first compression operation. As described above, in the above-described first compression operation, when the contact position between the low-stage piston (47a) and the low-stage cylinder (41a) passes through the opening of the low-stage suction passage (48a), the first compression operation is low. The closing of the refrigerant in the stage side compression mechanism (40a) is completed. On the other hand, in the second compression operation, the closing of the refrigerant in the low-stage compression mechanism (40a) is completed when the low-stage piston (47a) blocks the bypass hole (62).

<Automatic valve opening / closing operation>
In the rotary compressor (20), the first compression operation and the second compression operation are automatically switched according to a change in the operating condition of the air conditioner (10). That is, the open / close state of the valve body (64) is switched in accordance with the change in the pressure difference of the refrigerant circuit (11) that fluctuates with the change in the operating condition of the air conditioner (10).

  Specifically, for example, under operating conditions where the differential pressure of the refrigerant circuit (11) is relatively large, the pressure of the high-pressure refrigerant in the casing (21) increases. Under such conditions, the pressure acting on the valve body (64) by the high-pressure oil introduced from the oil reservoir (21a) into the high-pressure side space (61b) also increases. Then, the valve body (64) is pushed upward against the urging force of the spring member (65), and is displaced to a position where the bypass hole (62) is closed (see FIG. 4A). As a result, in the rotary compressor (20), the first compression operation described above is performed.

  On the other hand, under operating conditions in which the differential pressure of the refrigerant circuit (11) is relatively small, the pressure of the high-pressure refrigerant in the casing (21), and hence the pressure in the high-pressure side space (61b) of the valve body housing (61) is low. Become. When the pressure difference in the refrigerant circuit (11) becomes a predetermined value or less, the valve body (64) is pushed down by the spring member (65) and displaced to a position where the bypass hole (62) is opened (FIG. 4B )reference). As a result, in the rotary compressor (20), the second compression operation described above is performed.

  As described above, in the rotary compressor (20), the bypass passage (66) is automatically opened and closed in accordance with the change in the differential pressure of the refrigerant circuit (11), so that the low-stage compression mechanism (40a) The confinement volume (substantial suction volume) is changed. As a result, the ratio of the suction volume Vh of the high-stage compression mechanism (40b) to the suction volume Vl of the low-stage compression mechanism (40a) (suction volume ratio = Vh / Vl) automatically changes. That is, the low-stage piston (47a) of the low-stage compression mechanism (40a) and the high-stage piston (47b) of the high-stage compression mechanism (40b) are connected to the same drive shaft (33). Therefore, the suction volume ratio (Vh / Vl) of both compression mechanisms (40a, 40b) cannot be changed only by changing the rotational speed of the drive shaft (33). However, in the rotary compressor (20) of the present embodiment, by automatically switching between the first compression operation and the second compression operation described above, the suction volume Vl of the low-stage compression mechanism (40a), and thus the above-mentioned The suction volume ratio (Vh / Vl) is changed as appropriate. As a result, the rotary compressor (20) can be operated at an optimum suction volume ratio according to the operating conditions of the air conditioner (10).

  Specifically, for example, when the differential pressure of the refrigerant circuit (11) is relatively small, most of the refrigerant compression process is performed by the low-stage compression mechanism (40a). In such a case, since the refrigerant is hardly compressed by the high stage compression mechanism (40b), the fluctuation range of the compression torque of the low stage compression mechanism (40a) is the compression torque of the high stage compression mechanism (40b). It may become relatively large with respect to the fluctuation range, and vibration and noise may occur. In addition, under such operating conditions where the differential pressure of the refrigerant circuit (11) is relatively small, if most of the compression stroke is performed by the low-stage compression mechanism (40a), the discharge of the low-stage compression mechanism (40a) The pressure of the refrigerant (that is, the intermediate pressure) becomes relatively high. In such a case, the amount of intermediate pressure refrigerant sent from the injection pipe (24) to the suction side of the high-stage compression mechanism (40b) is reduced, and the economizer effect as described above cannot be sufficiently obtained. There is also.

  For this reason, in the rotary compressor (20) of the present embodiment, when the pressure difference in the refrigerant circuit (11) becomes a predetermined value or less in this way, the valve body (64) is automatically bypassed ( 66) is opened, and the second compression operation is performed. As a result, the suction volume Vl of the low-stage compression mechanism (40a) decreases and the suction volume ratio (Vh / Vl) increases, so that the refrigerant is compressed in a balanced manner by the compression mechanisms (40a, 40b). become. For this reason, the fluctuation range of the compression torque of each compression mechanism (40a, 40b) as described above is averaged, and vibration and noise can be reduced. In addition, since the pressure of the refrigerant discharged from the low-stage compression mechanism (40a) is lowered in this way, the intermediate pressure sent from the injection pipe (24) to the suction side of the high-stage compression mechanism (40b) by that amount. The amount of refrigerant increases. Therefore, a desired economizer effect can be obtained even under operating conditions where the differential pressure is relatively small, and the operating efficiency of the air conditioner (10) is improved.

-Effect of Embodiment 1-
In the first embodiment, the differential pressure between the low pressure side space (61a) and the high pressure side space (61b) is applied to the valve body (64) so as to be interlocked with the change in the high pressure difference of the refrigerant circuit (11). In addition, the opening / closing position of the bypass passage (66) by the valve body (64) is switched. For this reason, the open / close position of the valve body (64) is automatically changed without providing a three-way valve or the like for switching the opening / closing of the valve body (64) or controlling the three-way valve as appropriate. Can be switched. Therefore, this rotary compressor can be configured simply, and cost reduction or simplification of maintenance can be achieved.

  Further, in the above embodiment, when the differential pressure of the refrigerant circuit (11) becomes a predetermined value or less, the valve body (64) of the low-stage compression mechanism (40a) is automatically set to the open position of the bypass passage (66). It is made to displace. For this reason, the suction volume ratio (Vh / Vl) can be automatically increased by reducing the suction volume Vl of the low-stage compression mechanism (40a) under such an operating condition where the pressure difference is small. Therefore, the fluctuation range of the compression torque of the low stage side compression mechanism (40a) and the fluctuation range of the compression torque of the high stage side compression mechanism (40b) can be quickly averaged, thereby preventing vibration and noise. it can.

  Moreover, in the said embodiment, the introduction channel | path (29) is penetrated by the cover member (63), and the high voltage | pressure side space (61b) and the internal space of the casing (21) are connected. For this reason, high pressure can be applied to the high-pressure side space (61b) without providing piping or the like for introducing the refrigerant discharged from the high-stage compression mechanism (40b) into the high-pressure side space (61b). Furthermore, oil is introduced into the high-pressure side space (61b) from the introduction passage (29), and the valve body (64) is displaced using the high pressure of this oil. When the valve body (64) is displaced with oil in this way, the gap between the outer peripheral surface of the valve body (64) in the closed position and the inner peripheral surface of the valve body housing portion (61) is sealed with oil. be able to. For this reason, it is possible to prevent relatively high-temperature oil from entering the compression chamber of the low-stage compression mechanism (40a) through the gap around the valve body (64), and the refrigerant in the compression chamber is heated by the oil. This can be avoided beforehand. Therefore, it is possible to prevent the volumetric efficiency of the low-stage compression mechanism (40a) from being reduced by so-called refrigerant suction heating.

-Modification of Embodiment 1-
In the first embodiment, as shown in FIG. 6, the introduction passage (29) may be formed on the side of the high-pressure side space (61 b) of the valve body housing part (61). One end of the introduction passage (29) opens to the inner peripheral surface of the valve body housing portion (61), and the other end opens to the outer peripheral surface of the rear head (45). Also in this modified example, the high-pressure oil in the oil reservoir (21a) is introduced into the back surface side of the valve body (64) in the valve body housing part (61). Accordingly, as in the first embodiment, the valve body (64) can be automatically opened and closed in accordance with the change in the differential pressure level of the refrigerant circuit (11), and according to the operating conditions of the air conditioner (10). Thus, the first compression operation and the second compression operation can be switched.

<< Embodiment 2 >>
As shown in FIG. 7, in the rotary compressor (20) of the second embodiment, the bypass passage (66), the valve body housing part (61), and the valve body (64) are on the high-stage compression mechanism (40b) side. Is provided. Specifically, the bypass passage (66) of the second embodiment has one end connected to the high-stage cylinder chamber (42b) and the other end connected to the intermediate pressure chamber (50). The bypass hole (62) of the bypass passage (66) opens in the inner wall surface on the upper side of the compression chamber. On the other hand, the valve body accommodating portion (61) is formed in the front head (44) so as to face the bypass hole (62).

  A columnar valve body (64) is fitted into the valve body housing part (61) so as to be displaceable in the vertical direction. The valve body (64) has a small diameter portion (64a) formed in the lower portion thereof, and a large diameter portion (64c) formed in the upper portion thereof. The small diameter part (64a) of the valve body (64) is configured to engage with the bypass hole (62) and seal the bypass hole (62). The large diameter portion (64c) of the valve body (64) is in sliding contact with the inner peripheral surface of the valve body housing portion (61). The inside of the valve body housing portion (61) is partitioned by the valve body (64) into an intermediate pressure side space (61c) above and a high pressure side space (61b) below.

  A bypass branch pipe (28a) is connected to the intermediate pressure side space (61c). One end of the bypass branch pipe (28a) opens to the inner peripheral surface of the valve body housing part (61), and the other end is connected to the bypass passage (66). Accordingly, the intermediate pressure side space (61c) is connected to the suction side of the high stage compression mechanism (40b). The intermediate pressure side space (61c) is provided with a spring member (65) having one end connected to the upper back surface of the valve body (64) and the other end connected to the lid member (63). On the other hand, the high-pressure side space (61b) is formed between the outer peripheral surface of the small diameter portion (64a) of the valve body (64) and the inner peripheral surface of the valve body housing portion (61). The high-pressure side space (61b) is partitioned from the bypass hole (62) and is connected to the introduction passage (29). One end of the introduction passage (29) opens to the inner peripheral surface of the valve body housing part (61), and the other end opens to the outer peripheral surface of the front head (44). That is, the other end of the introduction passage (29) faces the internal space of the casing (21) filled with the high-pressure refrigerant. Thereby, the high pressure side space (61b) is connected to the discharge side of the high stage side compression mechanism (40b).

  As described above, in the valve body (64), a high pressure acts on the lower surface side of the large diameter portion (64c), and an intermediate pressure acts on the back surface side thereof. Thereby, in the valve body (64), a differential pressure between the high pressure in the high pressure side space (61b) and the intermediate pressure in the intermediate pressure side space (61c) acts toward the open position of the bypass passage (66). On the other hand, the above-described spring member (65) constitutes a valve closing means that acts on the valve body (64) with a reaction force against the differential pressure toward the closed position of the bypass passage (66). The spring member (65) is arranged so that the valve body (64) is in the closed position when the differential pressure of the refrigerant circuit (11) becomes a predetermined value or less as the operating condition of the air conditioner (10) changes. Energizing body (64).

  Also in the rotary compressor (20) of the second embodiment, the first compression operation and the second compression operation are automatically switched according to changes in the operating conditions of the air conditioner (10). That is, the open / close state of the valve body (64) is switched in accordance with the change in the pressure difference of the refrigerant circuit (11) that fluctuates with the change in the operating condition of the air conditioner (10).

  Specifically, for example, under operating conditions in which the differential pressure of the refrigerant circuit (11) is relatively large, the pressure of the high-pressure refrigerant in the casing (21), and thus in the high-pressure side space (61b) of the valve body housing part (61) The pressure increases. Under such conditions, the valve body (64) is pushed upward against the urging force of the spring member (65) and displaced to a position where the bypass hole (62) is opened (see FIG. 8A). As a result, in the rotary compressor (20), the second compression operation described above is performed.

  On the other hand, under operating conditions in which the differential pressure of the refrigerant circuit (11) is relatively small, the pressure of the high-pressure refrigerant in the casing (21), and hence the pressure in the high-pressure side space (61b) of the valve body housing (61) is low. Become. Then, when the differential pressure of the refrigerant circuit (11) becomes equal to or lower than a predetermined value, the valve body (64) is pushed down by the spring member (65) and displaced to a position where the bypass hole (62) is closed (FIG. 8B )reference). As a result, in the rotary compressor (20), the first compression operation described above is performed.

  As described above, in the second embodiment, the bypass hole (62) is automatically closed by the valve body (64) when the height differential pressure of the refrigerant circuit (11) becomes a predetermined value or less. As a result, the suction volume Vh of the high-stage compression mechanism (40b) is increased and the suction volume ratio (Vh / Vl) is automatically increased under operating conditions where the pressure difference is relatively small. As a result, as in the first embodiment, the fluctuation range of the compression torque of each compression mechanism (40a, 40b) is averaged to reduce vibrations and noise, and the high-stage compression mechanism from the injection pipe (24). The amount of intermediate pressure refrigerant sent to the suction side of (40b) increases, and the economizer effect is improved.

-Effect of Embodiment 2-
In the second embodiment, the differential pressure between the intermediate pressure side space (61c) and the high pressure side space (61b) is applied to the valve body (64) so as to interlock with the change in the high and low differential pressure of the refrigerant circuit (11). In addition, the opening / closing position of the bypass passage (66) by the valve body (64) is switched. For this reason, also in the present embodiment, a three-way valve or the like is provided for switching the opening and closing of the valve body (64) as in the conventional one, and the three-way valve is not appropriately controlled. The open / close position can be automatically switched. Therefore, this rotary compressor can be configured simply, and cost reduction or simplification of maintenance can be achieved.

  In the second embodiment, when the pressure difference in the refrigerant circuit (11) becomes a predetermined value or less, the valve body (64) of the high-stage compression mechanism (40b) is automatically set to the closed position of the bypass passage (66). To be displaced. For this reason, the suction volume ratio (Vh / Vl) can be automatically increased by increasing the suction volume Vh of the high-stage compression mechanism (40b) under such operating conditions where the pressure difference is small. Therefore, similarly to the first embodiment, the fluctuation range of the compression torque of the high stage side compression mechanism (40a) and the fluctuation range of the compression torque of the high stage side compression mechanism (40b) can be quickly averaged. In addition, vibration and noise can be prevented.

  In the second embodiment, the suction side pressure of the high-stage compression mechanism (40b) is applied to the back side of the valve body (64) in the valve body housing part (61). The suction-side pressure of the low-stage compression mechanism (40a) may be applied. In this case, the valve body (64) can be displaced by the differential pressure between the high pressure and the low pressure, and the open / close position of the valve body (64) can be switched automatically.

<< Embodiment 3 >>
As shown in FIG. 9, the rotary compressor (20) of Embodiment 3 includes a single-stage compression mechanism (80) in which one compression mechanism (80) is coupled to a drive shaft (33). is there. The compression mechanism (80) is a scroll-type compression mechanism.

  The rotary compressor (20) includes a sealed casing (21). A suction pipe (22) and a discharge pipe (23) are respectively connected through the casing (21). In the casing (21), the scroll compression mechanism (80) is provided on the upper side thereof, and an electric motor (not shown) for rotating the drive shaft (33) is provided in the lower part thereof. The scroll compression mechanism (80) includes a fixed scroll (81) constituting a fixed member and a movable scroll (82) constituting a movable member.

  The fixed scroll (81) is fixed to the upper inner wall of the casing (21). The fixed scroll (81) has a suction port (81a) to which the suction pipe (22) is connected on the outer peripheral side, and a discharge port (81b) on the axial center side. Further, a high-pressure introduction chamber (81d) filled with the refrigerant discharged from the scroll compression mechanism (80) is formed above the discharge port (81b). A spiral fixed side wrap (81c) is formed below the fixed scroll (81).

  The movable scroll (82) is configured such that the eccentric shaft portion (35) of the drive shaft (33) is fitted to the lower end side thereof and is rotated eccentrically with respect to the drive shaft (33). The movable scroll (82) is formed with an end plate (82a) facing the fixed scroll (81) and a spiral movable side wrap (82c) formed on the upper surface of the end plate (82a). In the scroll compression mechanism (80), the fixed side wrap (81c) of the fixed scroll (81) and the movable side wrap (82c) of the movable scroll (82) mesh with each other, so that the fixed scroll (81) and the movable scroll are engaged. (82), a compression chamber is formed. In the scroll compression mechanism (80), the refrigerant is sucked into the compression chamber from the outer peripheral side of the movable scroll (82) through the suction pipe (22) with the eccentric rotational motion of the movable scroll (82). This refrigerant is sent to the axial center side of the fixed scroll (81) while being compressed in the compression chamber, and is discharged from the discharge port (81b).

  In the third embodiment, a bypass hole (62) constituting a bypass passage is formed in the fixed scroll (81). Specifically, the bypass hole (62) is formed so as to face the tip of the outermost movable wrap (82d). The bypass hole (62) includes a space outside the outermost movable side wrap (82d) (that is, the suction side of the scroll compression mechanism (80)) and an innermost side of the outermost movable side wrap (82d). (That is, a space in the middle of compression of the compression chamber). Thus, in the scroll compression mechanism (80), a part of the refrigerant in the compression chamber is returned to the suction side through the bypass hole (62).

  Further, the fixed scroll (81) is provided with a valve body accommodating portion (61) and a valve body (64). The inside of the valve body accommodating part (61) has its lower end facing the bypass hole (62), and its upper end is connected to the high pressure introduction chamber (81d). A valve body (64) is fitted in the valve body housing part (61) so as to be freely displaceable in the vertical direction. And the inside of a valve body accommodating part (61) is divided by the valve body (64) into the low voltage | pressure side space (61a) of the lower side, and the high voltage | pressure side space (61b) of the upper side. The low pressure side space (61a) is provided with a spring member (65) so as to bias the valve body (64) upward.

  As described above, the valve body (64) has a high pressure acting on the back surface thereof and a low pressure acting on the tip surface thereof. Thereby, in the valve body (64), the differential pressure between the high pressure in the high pressure side space (61b) and the low pressure in the low pressure side space (61a) acts toward the closed position of the bypass passage (66). On the other hand, the spring member (65) described above constitutes a valve opening means that acts on the valve body (64) with a reaction force against the differential pressure toward the opening position of the bypass passage (66). The spring member (65) is arranged so that the valve body (64) is in an open position when the pressure difference of the refrigerant circuit (11) becomes a predetermined value or less as the operating condition of the air conditioner (10) changes. Energizing body (64).

  Also in the rotary compressor (20) of the third embodiment, the first compression operation and the second compression operation are automatically switched according to the change in the operating condition of the air conditioner (10). That is, the open / close state of the valve body (64) is switched in accordance with the change in the pressure difference of the refrigerant circuit (11) that fluctuates with the change in the operating condition of the air conditioner (10).

  Specifically, for example, under operating conditions in which the differential pressure of the refrigerant circuit (11) is relatively large, the discharge pressure of the scroll compression mechanism (80), and consequently the high pressure side space (61b) of the valve body housing (61) Pressure also increases. Under such conditions, the valve body (64) is pushed down against the urging force of the spring member (65) and displaced to a position where the bypass hole (62) is closed (see FIG. 9A). As a result, in the scroll compression mechanism (80), the entire amount of the refrigerant is compressed in the compression chamber in the same manner as the first compression operation described above.

  On the other hand, under operating conditions where the differential pressure of the refrigerant circuit (11) is relatively small, the discharge pressure of the scroll compression mechanism (80), and hence the pressure in the high-pressure side space (61b) of the valve body housing part (61) also decreases. . Then, when the differential pressure of the refrigerant circuit (11) becomes a predetermined value or less, the valve body (64) is pushed up by the spring member (65) and displaced to a position where the bypass hole (62) is opened (FIG. 9B )reference). As a result, in the scroll compression mechanism (80), a part of the refrigerant in the compression chamber is returned to the suction side in the same manner as the second compression operation described above. As a result, in this rotary compressor (20), the suction volume of the scroll compression mechanism (80) is automatically reduced under operating conditions where the high and low differential pressures are relatively small, and the refrigerant of this rotary compressor (20) Circulation amount is mechanically suppressed.

-Effect of Embodiment 3-
In Embodiment 3 described above, the differential pressure between the low pressure side space (61a) and the high pressure side space (61b) is applied to the valve body (64) so as to interlock with the change in the high and low differential pressure of the refrigerant circuit (11). In addition, the opening / closing position of the valve body (64) is switched. For this reason, also in the present embodiment, a three-way valve or the like is provided for switching the opening and closing of the valve body (64) as in the conventional one, and the three-way valve is not appropriately controlled. The open / close position can be automatically switched. Therefore, this rotary compressor can be configured simply, and cost reduction or simplification of maintenance can be achieved.

  In Embodiment 3 described above, in the single-stage rotary compressor (20), the valve body (64) is displaced to the open position when the differential pressure of the refrigerant circuit (11) becomes a predetermined value or less. ing. For this reason, when the differential pressure of the refrigerant circuit (11) is relatively operating, the suction volume of the compression mechanism (80) can be automatically reduced to mechanically suppress the refrigerant circulation rate of the rotary compressor. Therefore, it is possible to operate at a frequency with high motor efficiency without significantly reducing the operating frequency of the rotary compressor.

  In the third embodiment, the present invention is applied to the single-stage scroll compression mechanism (80). However, the present invention is similarly applied to other compression mechanisms such as a single-stage rotary compression mechanism. You may do it. In addition, by connecting the low-stage and high-stage scroll compression mechanisms to the drive shaft (33) and switching the open / close position of the valve body (64) in the same manner as in the first and second embodiments, The suction volume ratio of both compression mechanisms may be automatically changed.

<< Other Embodiments >>
The present invention may be configured as follows with respect to the above embodiment.

  The compression mechanism of the above embodiment may have any configuration as long as it includes a fixed member and a movable member that rotates eccentrically by forming a compression chamber between the fixed member. Specifically, a rolling piston type rotary compression mechanism may be adopted as this compression mechanism, and a cylinder having an annular cylinder chamber and an annular piston provided in the cylinder chamber rotate relatively eccentrically. Thus, a plurality of compression chambers may be employed in a compression mechanism that expands and contracts simultaneously.

  Further, the bypass hole (62) of the bypass passage (66) may be formed on any surface as long as it is an inner wall surface facing each cylinder chamber (42a, 42b). Specifically, the bypass hole (62) may be opened on the upper end surface and the lower end surface of the middle plate (46), or may be opened on the inner peripheral surface of each cylinder (41a, 41b).

  In addition, the above embodiment is an essentially preferable illustration, Comprising: It does not intend restrict | limiting the range of this invention, its application thing, or its use.

  As described above, the present invention is useful for a rotary compressor capable of returning a part of the refrigerant in the compression chamber to the suction side of the compression mechanism through the bypass passage.

It is a refrigerant circuit figure of the air harmony device with which the rotary compressor concerning Embodiment 1 of the present invention is carried. 1 is a longitudinal sectional view of a rotary compressor according to Embodiment 1. FIG. FIG. 3 is a cross-sectional view of the low-stage compression mechanism of the rotary compressor according to the first embodiment. FIG. 4A is an enlarged vertical sectional view of a bypass passage of the rotary compressor according to the first embodiment, FIG. 4A shows a state during a first compression operation, and FIG. 4B shows a state during a second compression operation. Is. FIG. 3 is a schematic explanatory diagram illustrating an operation of a low-stage compression mechanism of the rotary compressor according to the first embodiment. It is the longitudinal section which expanded the bypass passage of the rotary compressor concerning modification 1 of Embodiment 1. 6 is a longitudinal sectional view of a low-stage compression mechanism of a rotary compressor according to Embodiment 2. FIG. FIG. 8A is a longitudinal sectional view enlarging a bypass passage of the rotary compressor according to the second embodiment. FIG. 8A shows a state during the first compression operation, and FIG. 8B shows a state during the second compression operation. Is. It is a longitudinal cross-sectional view which shows the principal part of the rotary compressor which concerns on Embodiment 3, FIG. 8 (A) shows the state at the time of 1st compression operation, FIG.8 (B) shows the state at the time of 2nd compression operation. Is.

Explanation of symbols

11 Refrigerant circuit
20 Rotary compressor
21 Casing
21a Oil sump
33 Drive shaft
40a Low stage compression mechanism (compression mechanism)
40b High-stage compression mechanism (compression mechanism)
41a Low-stage cylinder (fixing member)
41b High-stage cylinder (fixing member)
44 Front head (fixing member)
45 Rear head (fixing member)
46 Middle plate (fixing member)
47a Low stage piston (movable member)
47b High piston (movable member)
61 Valve compartment
61a Low pressure side space
61b High pressure side space
61c Intermediate pressure side space
64 Disc
65 Spring member (valve opening means, valve closing means)
66 Bypass passage
80 Scroll compression mechanism (compression mechanism)
81 Fixed scroll (fixed member)
82 Movable scroll (movable member)

Claims (9)

A compression chamber is formed between the fixing member (41a, 41b, 44, 45, 46, 81) and the fixing member (41a, 41b, 44, 45, 46, 81), with respect to the drive shaft (33). And a compression mechanism (40a, 40b, 80) having a movable member (47a, 47b, 82) that rotates eccentrically and is connected to a refrigerant circuit (11) in which a refrigeration cycle is performed to compress the refrigerant in the compression chamber. A rotary compressor,
A bypass passage (66) having one end opened to the compression chamber and the other end connected to the suction side of the compression mechanism (40a, 40b, 80);
A valve body (64) for opening and closing the bypass passage (66);
One end faces the bypass passage (66), and the valve body (64) includes a valve body housing portion (61) fitted so as to displace the bypass passage (66) so as to be freely opened and closed.
In the valve body housing part (61), the valve body (64) is compressed into the valve body (64) so that the open / close position of the valve body (64) is automatically switched according to the change in the differential pressure of the refrigerant circuit (11). A rotary compressor characterized by the pressure on the discharge side of the mechanism (40a, 40b, 80) acting. In claim 1,
One compression mechanism (80) is connected to the drive shaft (33),
The valve body (64) is configured to be displaced to an open position of the bypass passage (66) when the differential pressure of the refrigerant circuit (11) becomes a predetermined value or less. Compressor. In claim 2,
In the valve body accommodating portion (61), a low pressure side space (61a) formed on one end side thereof and connected to the suction side of the compression mechanism (80), and formed on the other end side of the compression mechanism (80). The high pressure side space (61b) connected to the discharge side is partitioned by the valve body (64),
A differential pressure between the high pressure side space (61b) and the low pressure side space (61a) acts on the valve body (64) toward the closed position of the bypass passage (66),
Valve opening means for applying a reaction force against the differential pressure to the valve body (64) so that the valve body (64) is displaced to the open position when the differential pressure of the refrigerant circuit (11) becomes a predetermined value or less. (65) It is provided with the rotary compressor characterized by the above-mentioned. In claim 1,
The compression mechanism includes a low-stage compression mechanism (40a) that compresses the refrigerant sucked from the refrigerant circuit (11), and sucks and compresses the refrigerant discharged by the low-stage compression mechanism (40a). It is composed of a stage side compression mechanism (40a) and a high stage side compression mechanism (40b) connected by a drive shaft (33).
The bypass passage (66) has one end opened to the compression chamber of the low-stage compression mechanism (40a) and the other end connected to the suction side of the low-stage compression mechanism (40a).
The valve body (64) is configured to be displaced to an open position of the bypass passage (66) when the differential pressure of the refrigerant circuit (11) becomes a predetermined value or less. Compressor. In claim 4,
In the valve body accommodating part (61), a low pressure side space (61a) formed on one end side thereof and connected to the suction side of the low stage side compression mechanism (40a), and a high stage side formed on the other end side. The high pressure side space (61b) connected to the discharge side of the compression mechanism (40b) is partitioned by the valve body (64),
A differential pressure between the high pressure side space (61b) and the low pressure side space (61a) toward the closed position of the bypass passage (66) acts on the valve body (64),
Valve opening means for applying a reaction force against the differential pressure to the valve body (64) so that the valve body (64) is displaced to the open position when the differential pressure of the refrigerant circuit (11) becomes a predetermined value or less. (65) It is provided with the rotary compressor characterized by the above-mentioned. In claim 1,
The compression mechanism includes a low-stage compression mechanism (40a) that compresses the refrigerant sucked from the refrigerant circuit (11), and sucks and compresses the refrigerant discharged by the low-stage compression mechanism (40a). It is composed of a stage side compression mechanism (40a) and a high stage side compression mechanism (40b) connected by a drive shaft (33).
The bypass passage (66) has one end opened to the compression chamber of the high-stage compression mechanism (40b) and the other end connected to the suction side of the high-stage compression mechanism (40b).
The valve body (64) is configured to be displaced to a closed position of the bypass passage (66) when a differential pressure of the refrigerant circuit (11) becomes a predetermined value or less. Compressor. In claim 6,
The valve body accommodating portion (61) is formed at one end thereof and connected to the discharge side of the high-stage compression mechanism (40b), and the high-stage compression mechanism is formed at the other end. The intermediate pressure side space (61c) connected to the suction side of (40b) is partitioned by the valve body (64),
A differential pressure between the high pressure side space (61b) and the intermediate pressure side space (61c) toward the open position of the bypass passage (66) acts on the valve body (64),
A valve closing means (65) for applying a reaction force against the differential pressure to the valve body (64) so that the valve body (64) is displaced to the closed position when the differential pressure of the refrigeration cycle becomes a predetermined value or less. A rotary compressor characterized by comprising: In Claim 3, 5, and 7,
A casing (21) in which the compression mechanism (40a, 40b, 80) is housed and the internal space is filled with the high-pressure refrigerant of the refrigerant circuit (11);
The rotary compressor, wherein the high-pressure side space (61b) of the valve body housing part (61) faces the internal space of the casing (21). In claim 8,
In the internal space of the casing (21), an oil sump portion (21a) in which oil for lubricating the compression mechanism (40a, 40b, 80) is stored is formed at the bottom thereof,
The rotary compressor characterized in that the high-pressure side space (61b) faces the oil reservoir (21a).

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