JP2008190491A - Rotary compressor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent a clearance between a front end surface of a valve element in a state of closing a bypass passage and an inflow opening surface of the bypass passage from becoming a dead volume and lowering of the volumetric efficiency of a compression mechanism. <P>SOLUTION: At a position in which the valve element (64) closes a bypass hole (62) of the bypass passage (66), a clearance space (70) is formed between a front end surface of the valve element (64) and an open surface of the bypass hole (62). An oil infusion path (71) is formed in the valve element (64) to face the clearance space (70). When the valve element (64) is in a closing position of the bypass hole (62), oil is supplied to the clearance space (70) through an oil introduction path (29) and the oil infusion path (71), and the clearance space (70) is filled with the oil. <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.

  Conventionally, a rotary compressor is known in which a piston is eccentrically rotated in a cylinder chamber to compress a refrigerant in the compression chamber.

  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 includes a cylinder having a cylinder chamber and a piston accommodated in the 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.

As described above, in this rotary compressor, the capacity of the compression mechanism is made variable by changing the confining volume (substantial suction volume) of the refrigerant in accordance with the opening / closing operation of the valve body.
JP 59-12264 A

  In the rotary compressor as described in Patent Document 1, the tip surface of the valve body that closes the bypass passage is slightly recessed inside the bypass passage from the inflow opening surface of the bypass passage that opens in the inner wall of the compression chamber. It is necessary to. This is because if the tip surface protrudes into the compression chamber from the inflow opening surface, the tip of the valve body and the piston interfere with each other and a predetermined compression operation cannot be performed.

  On the other hand, when the front end surface of the valve body in the closed position is set to be recessed from the inflow opening surface of the bypass passage, a slight gap is formed between the front end surface of the valve body and the inflow opening surface of the bypass passage. End up. Therefore, when the compression operation as described above is performed in such a state, the gap becomes a dead volume of the compression chamber, and there arises a problem that the volume efficiency (compression efficiency) of the compression mechanism is lowered.

  The present invention has been made in view of such a point, and the object of the present invention is to create a dead volume in the gap between the front end surface of the valve body in a state in which the bypass passage is closed and the inflow opening surface of the bypass passage. It is to prevent the volumetric efficiency of the compression mechanism from being lowered.

  The first invention provides a drive shaft (33) while forming a compression chamber between the fixing member (41a, 41b, 44, 45, 46) and the fixing member (41a, 41b, 44, 45, 46). As a premise, the rotary compressor includes a compression mechanism (40a, 40b) having a movable member (47a, 47b) that rotates eccentrically with respect to the compressor, and compresses the refrigerant in the compression chamber. The rotary compressor has an inflow end that opens to the inner wall surface of the compression chamber and an outflow end that is connected to the suction side of the compression mechanism (40a, 40b), and the bypass passage (66 The inflow opening (62) is openable and closable, and in the closed state, the valve body (64) is located at the tip of the inflow opening surface of the bypass passage (66) recessed into the bypass passage (66). And an oil supply passage (72) for supplying oil to the distal end surface of the valve body (64) in the closed state.

  In the first invention, the movable member (47a, 47b) rotates eccentrically with respect to the fixed member (41a, 41b, 44, 45, 46), whereby the volume of the compression chamber is expanded and contracted, and the refrigerant is compressed. Here, when the compression operation is performed in a state where the valve body (64) closes the inflow opening (62) of 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 with the valve body (64) opening the inflow opening (62) of the bypass passage (66), a part of the refrigerant passes through the bypass passage (66) and the compression mechanism (40a, 40b). The remaining refrigerant is compressed in the compression chamber. As described above, in the compression mechanism (40a, 40b), 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, when the valve body (64) is in a state of closing the inflow opening (62) of the bypass passage (66), the tip surface of the valve body (64) is bypassed more than the opening surface of the inflow opening (62). It will be a position that is depressed inside the passage (66). Thereby, it is prevented that the front-end | tip part of the valve body (64) of a closed state interferes with a movable member (47a, 47b). On the other hand, when the valve body (64) is in this position, a slight gap is formed between the tip surface of the valve body (64) and the opening surface of the inflow opening (62), and this gap is the dead volume of the compression chamber. End up.

  Therefore, in the present invention, an oil supply passage (72) for supplying oil to the distal end surface of the valve body (64) in the closed state is provided. When oil is supplied from the oil supply passage (72) to the distal end surface of the valve body (64), the gap between the distal end surface of the valve body (64) and the opening surface of the inflow opening (62) is filled with oil. become. As a result, since this gap is closed by oil, it is avoided that this gap becomes a dead volume of the compression chamber during the compression operation.

  According to a second aspect of the present invention, in the rotary compressor of the first aspect, the oil supply passage (72) is formed in the valve body (64) so that oil flows, and the outflow end is a valve body (64 ) Has an oil injection path (71) that opens to the front end surface.

  In the second invention, an oil injection path (71) is formed in the valve body (64) in order to supply oil to the distal end surface of the closed valve body (64). When the valve body (64) closes the inflow opening (62) of the bypass passage (66), oil flows through the oil injection passage (71) into the valve body (64), and the valve body (64) It flows out to the tip surface. As a result, the gap formed in the tip surface of the valve body (64) is closed by this oil.

  According to a third aspect of the present invention, in the rotary compressor according to the second aspect, one end of the fixing member (41a, 41b, 44, 45, 46) is connected to the inflow opening (62) of the bypass passage (66). A valve body accommodating chamber (61) is formed in which the valve body (64) is fitted so that the inflow opening (62) can be freely opened and closed, and the oil supply passage (72) 64) the oil injection passage (71) formed penetrating from the front end surface to the back surface, and an oil introduction passage for introducing oil to the back surface side of the valve body (64) in the valve body storage chamber (61). (29) is provided.

  In 3rd invention, a valve body storage chamber (61) is formed so that the inflow opening part (62) of a bypass channel (66) may be faced. The valve body (64) is freely displaceable between a position where the inflow opening (62) of the bypass passage (66) is closed and a position where the valve body (61) is opened. When oil is introduced from the oil introduction path (29) to the back side of the valve body (64) with the valve body (64) in the closed position, this oil is injected into the valve body (64). It flows into the channel (71) and flows out to the tip surface of the valve body (64). As a result, the gap formed in the tip surface of the valve body (64) is closed by this oil.

  According to a fourth aspect of the present invention, in the rotary compressor according to any one of the first to third aspects, the oil supply passage (72) includes an oil separator (40) in the refrigerant discharged from the compression mechanism (40a, 40b). 30) It is characterized by being configured to introduce the oil separated by (30).

  In the fourth invention, the oil separated in the oil separator (30) flows into the oil supply passage (72). Here, since the pressure of the refrigerant discharged from the compression mechanism (40a, 40b) acts on the oil separator (30), this oil is pressed by the refrigerant discharged from the compression mechanism (40a, 40b) and the oil supply passage ( 72) and supplied to the front end face of the closed valve body (64). As a result, the gap formed in the tip surface of the valve body (64) is closed by this oil.

  According to a fifth invention, in the rotary compressor according to any one of the first to third inventions, the compression mechanism (40a, 40b) is housed, and the compression mechanism (40a, 40b) is accommodated in an internal space. The oil supply passage (72) is provided with a casing (21) formed with an oil reservoir (21a) in which oil discharged to fill the discharge refrigerant and lubricate the compression mechanism (40a, 40b) is stored. The oil reservoir (21a) is configured to be introduced with oil.

  In the fifth invention, the refrigerant discharged from the compression mechanism (40a, 40b) is filled in the casing (21). That is, the rotary compressor according to the present invention is a so-called high-pressure dome type compressor. An oil reservoir (21a) for lubricating oil of the compression mechanism (40a, 40b) is formed at the bottom of the casing (21). The oil accumulated in the oil reservoir (2) flows into the oil supply passage (72) so as to be pushed out by the high-pressure refrigerant in the casing (21), and is supplied to the front end face of the valve body (64) in the closed state. The As a result, the gap formed in the tip surface of the valve body (64) is closed by this oil.

  The sixth invention is characterized in that, in the rotary compressor of the fourth or fifth invention, a cooling means (32) for cooling the oil flowing through the oil supply passage (72) is provided. is there.

  In the sixth invention, when the oil flows through the oil supply passage (72), the oil is cooled by the cooling means (32). Here, the oil flowing into the oil supply passage (72) from the oil separator (30) of the fourth invention or the oil reservoir (21a) of the third invention is relatively hot, but this oil is cooled. It is cooled to a relatively low temperature by means (32). For this reason, even if this oil is supplied to the front end face of the valve body (64) in the closed state, the suction refrigerant in the compression chamber is suppressed from being heated by the oil.

  In a seventh aspect of the rotary compressor according to the first aspect of the present invention, when the valve element (64) closes the inflow opening (62) of the bypass passage (66), the oil supply passage (72) is opened. On the other hand, when the valve body (64) opens the inflow opening (62) of the bypass passage (66), the valve body (64) includes an opening / closing means (13, 63a) for closing the oil supply passage (72). To do.

  In the seventh invention, the oil supply passage (72) is opened and closed by the opening and closing means (13, 63a) so as to be interlocked with the opening and closing operation of the bypass passage (66) by the valve body (64). Specifically, when the valve body (64) closes the bypass passage (66), the oil supply passage (72) is opened. As a result, oil is supplied from the oil supply passage (72) to the distal end surface of the valve body (64), and the clearance on the distal end side of the closed valve body (64) is closed by the oil. On the other hand, when the valve body (64) opens the bypass passage (66), the oil supply passage (72) is closed. Therefore, when the valve body (64) is opened and the refrigerant in the compression chamber is sent to the suction side of the compression mechanism (40a, 40b) via the bypass passage (66), the front end surface of the valve body (64) Since no oil is supplied to the compressor, this oil is not sent to the suction side of the compression mechanism (40a, 40b). As a result, when the compression operation is performed with the bypass passage (66) opened, the refrigerant sucked in the compression mechanism (40a, 40b) is prevented from being heated by oil.

  The eighth invention is the rotary compressor according to the seventh invention, wherein one end of the fixing member (41a, 41b, 44, 45, 46) is connected to the inflow opening (62) of the bypass passage (66). A valve body accommodating chamber (61) is formed in which the valve body (64) is fitted so that the inflow opening (62) can be freely opened and closed, and the oil supply passage (72) The oil injection path (71) formed penetrating from the front end surface to the back surface of (64), and oil introduction for introducing oil to the back surface side of the valve body (64) in the valve body storage chamber (61) The opening / closing means (13, 63a) includes an oil injection path (71) and an oil introduction path (29) when the valve body (64) is displaced to the closed position of the bypass path (66). When the valve body (64) is displaced to the open position of the bypass passage (66), a shut-off portion (63a) that shuts off the oil injection passage (71) and the oil introduction passage (29) is provided. Special It is an.

  In the eighth invention, the valve body accommodating chamber (61) is formed so as to face the inflow opening (62) of the bypass passage (66). The valve body (64) is freely displaceable between a position where the inflow opening (62) of the bypass passage (66) is closed and a position where the valve body (61) is opened. Further, in the present invention, the blocking portion (63a) is provided as an opening / closing means for opening / closing the oil supply passage (72) according to the opening / closing position of the bypass passage (66) in the valve body (64).

  Specifically, when the valve body (64) is in a position to close the bypass passage (66), the blocking portion (63a) includes an oil injection path (71) formed in the valve body (64) and the valve body (64 ) Communicate with the oil introduction passage (29) on the back side. As a result, oil is introduced from the oil introduction path (29) to the oil injection path (71), and the oil is supplied to the distal end surface of the valve body (64). On the other hand, when the valve body (64) is in a position to open the bypass passage (66), the blocking portion (63a) blocks the oil injection passage (71) and the oil introduction passage (29). As a result, the introduction of oil from the oil introduction path (29) to the oil injection path (71) is prohibited, and no oil is supplied to the distal end surface of the valve body (64). As a result, when the compression operation is performed with the valve body (64) in the open position, the suction refrigerant of the compression mechanism (40a, 40b) is prevented from being heated by oil.

  According to a ninth aspect of the present invention, in the rotary compressor according to any one of the first to eighth aspects, the inflow end of the bypass passage (66) opens to the inner wall on the lower surface side of the compression chamber. It is what.

  In the ninth invention, the inflow opening (62) of the bypass passage (66) is formed in the lower inner wall of the compression chamber. From the oil supply passage (72), oil is supplied to the upper end of the closed valve body (64). For this reason, oil easily collects at the tip end side of the valve body (64), so that the clearance on the tip end side of the valve body (64) in the closed state can be reliably closed with oil.

  In the first invention, an oil supply passage (72) for supplying oil to a gap formed between the front end surface of the valve body (64) in a closed state and the inflow opening surface of the bypass passage (66) is provided. I am doing so. Therefore, according to the present invention, when the compression operation is performed with the valve body (64) in the closed state, the gap can be closed with oil, and the generation of dead volume in the compression chamber can be prevented. Therefore, it is possible to prevent a reduction in volumetric efficiency of the compression mechanism (40a, 40b) in this compression operation.

  In the second invention, the oil injection passage (71) for forming the oil supply passage (72) is formed in the valve body (64). For this reason, according to this invention, the clearance gap of the front end surface of the valve body (64) of a closed state can be block | closed with oil with a comparatively simple structure.

  In the third aspect of the invention, the oil injection passage (71) is formed so as to penetrate the valve body (64), and the oil introduction passage (29) is provided on the back side of the valve body (64) in the valve body housing chamber (61). Oil is introduced. For this reason, according to the present invention, the valve body (64) is displaced in the valve body housing chamber (61) to open and close the bypass passage (66), while the valve body (64) in the closed position is opened in the clearance on the tip side. Oil can be easily supplied. Further, by introducing oil to the back side of the oil introduction path (29) in this way, the valve body (64) can be displaced to the closed position of the bypass passage (66) using the pressure of this oil. .

  In the fourth invention, the oil separated by the oil separator (30) from the refrigerant discharged from the compression mechanism (40a, 40b) is caused to flow into the oil supply passage (72). In the fifth aspect of the invention, the oil in the oil reservoir (21a) in the casing (21) filled with the high-pressure refrigerant is caused to flow into the oil supply passage (72). For this reason, according to the 4th and 5th invention, without using the pump etc. for conveying oil, oil can be supplied to the front end side of a valve body (64), and the said clearance gap can be plugged up.

  In the sixth aspect of the invention, the oil flowing through the oil supply passage (72) is cooled by the cooling means (32). For this reason, in the present invention, even if oil enters the compression chamber from the distal end side of the valve body (64), it is possible to prevent the intake refrigerant from being heated. Therefore, it is possible to prevent the volumetric efficiency of the compression mechanism (40a, 40b) from being reduced due to the heating of the suction refrigerant in the compression mechanism (40a, 40b). In addition, when the oil is cooled in this way, the viscosity of the oil increases, so that the sealing performance of the gap on the tip side of the valve body (64) is improved, and the above-described generation of dead volume can be effectively prevented. .

  In the seventh and eighth inventions, the oil supply passage (72) is closed when the valve body (64) opens the bypass passage (66). For this reason, according to these inventions, it can be prohibited that oil from the oil supply passage (72) is sent to the suction side of the compression mechanism (40a, 40b) via the bypass passage (66). Therefore, it is possible to prevent the suction refrigerant of the compression mechanism (40a, 40b) from being heated by the oil, and it is possible to more reliably prevent the volumetric efficiency of the compression mechanism (40a, 40b) from being lowered.

  According to the ninth aspect, since the inflow opening (62) of the bypass passage (66) is formed in the inner wall on the lower side of the compression chamber, the front end surface of the valve body (64) and the inflow opening (62 ) Oil easily collects in the gap between the open surfaces. As a result, this gap can be more reliably closed with oil, and the generation of dead volume in the compression chamber can be effectively prevented.

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

  The rotary compressor (20) according to the embodiment 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 three-way switching valve (13), 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). 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 refrigerant circuit (11) is provided with a bypass pipe (28) and an oil separator (30). The bypass pipe (28) has one end connected to the rotary compressor (20) and the other end connected to the suction pipe (22). The oil separator (30) is connected to the discharge pipe (23) of the rotary compressor (20). The oil separator (30) is constituted by a sealed container, into which the refrigerant discharged from the rotary compressor (20) flows. In the oil separator (30), oil for lubricating each sliding portion of the rotary compressor (20) is separated from the discharged refrigerant. The separated oil is stored at the bottom of the oil separator (30).

  The refrigerant circuit (11) is provided with an oil return pipe (29a), a cooling heat exchanger (32), a three-way switching valve (13), and an introduction pipe (29b). The oil return pipe (29a) has an inflow end connected to the bottom of the oil separator (30) and an outflow end connected to the three-way switching valve (13). The cooling heat exchanger (32) is provided in the oil return pipe (29a). The cooling heat exchanger (32) constitutes a cooling means for cooling the oil flowing through the oil return pipe (29a). The inlet pipe (29b) has an inflow end connected to the three-way switching valve (13) and an outflow end connected to the rotary compressor (20). The remaining port of the three-way switching valve (13) is connected to the suction pipe (22) of the rotary compressor (20). The three-way switching valve (13) includes a state in which the oil return pipe (29a) and the introduction pipe (29b) communicate with each other (a state indicated by a solid line in FIG. 1), and an introduction pipe (29b) and a rotary compressor (20). It is configured to switch to a state (state indicated by a broken line in FIG. 1) in communication with the suction pipe (22). When the three-way switching valve (13) is in the state of the solid line in FIG. 1, an oil introduction path (29 for introducing oil into the rotary compressor (20) by the oil return pipe (29a) and the introduction pipe (29b). ) Is configured.

<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), the bypass pipe (28), and the introduction pipe (29b) 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.

  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). Moreover, the low pressure side discharge passage (49a) has an open end in an intermediate pressure space (50) formed in the middle plate (46) at the outflow end (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 space (50) is filled with refrigerant discharged from the low-stage compression mechanism (40a), and has an intermediate pressure atmosphere. The intermediate pressure space (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 space (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 chamber (61). ing.

  The bypass hole (62) constitutes an inflow opening 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 storage chamber (61) is formed from the lower end of the rear head (45) to the vicinity of the upper end. The valve body storage chamber (61) is formed in a cylindrical shape coaxial with the bypass hole (62). The upper end of the valve body storage chamber (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 storage chamber (61) so as to be displaceable in the vertical direction. The valve body (64) is formed in a columnar shape whose outer diameter increases in two stages from the upper side to the lower side of the valve body housing chamber (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 portion (64c) of the valve body (64) is substantially the same as the inner diameter of the valve body accommodating chamber (61). That is, the large diameter part (64c) of the valve body (64) is in sliding contact with the inner peripheral surface of the valve body storage chamber (61). And the valve body storage chamber (61) is divided into the upper space (61a) on the upper side and the lower space (61b) on the lower side by the large diameter part (64c) of the valve body (64).

  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). The height of the small diameter portion (64a) is shorter than the depth of the bypass hole (62). In other words, the valve body (64) is configured such that, at the position where the bypass hole (62) is closed, the upper end surface thereof is slightly recessed from the inflow opening surface of the bypass hole (62) ( (See FIG. 4A). Therefore, in the low-stage compression mechanism (40a), a slight gap space (70) is formed between the front end surface of the valve body (64) in the closed position and the inflow opening surface of the bypass hole (62). become. As a result, the lower end surface of the piston (47a) that rotates in a knitting manner in the low-stage side cylinder chamber (42a) is restricted from interfering with the distal end portion of the valve body (64).

  The outer diameter of the intermediate diameter portion (64b) of the valve body (64) is smaller than the inner diameter of the valve body storage chamber (61). That is, a cylindrical space is formed between the inner diameter portion (64b) of the valve body (64) and the inner peripheral surface of the valve body storage chamber (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 upper 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 storage chamber (61). In a state where the spring member (65) has a natural length, the valve body (64) is pushed down to a position where the small diameter portion (64a) opens the bypass hole (62).

  The valve body (64) has an oil injection path (71) extending from the upper tip surface to the lower back surface. That is, the upper end of the oil injection path (71) opens at the distal end surface of the valve body (64), and the lower end thereof opens at the back surface of the valve body (64). The oil injection path (71) substantially coincides with the axis of the valve body (64).

  In the valve body storage chamber (61), the bypass pipe (28) is connected to the upper space (61a). That is, the low-stage cylinder chamber (42a) communicates with the bypass pipe (28) via the bypass hole (62) and the upper space (61a). The bypass hole (62), the upper space (61a), and the bypass pipe (28) constitute a bypass passage (66). On the other hand, the oil introduction path (29) is connected to the inner peripheral surface of the lower space (61b). The oil injection passage (71), the lower space (61b), and the oil introduction passage (29) constitute an oil supply passage (72) for supplying oil to the distal end surface of the valve body (64). Low pressure refrigerant or high pressure oil is introduced into the lower space (61b) from the introduction pipe (29b) according to the setting of the three-way switching valve (13). That is, the lower space (61b) becomes either a low-pressure atmosphere or a high-pressure atmosphere according to the switching of the three-way switching valve (13).

  When the three-way switching valve (13) is set to the state shown by the solid line in FIG. 1, the high-pressure oil separated by the oil separator (30) is introduced into the lower space (61b) through the introduction pipe (29b). . Then, the high pressure oil displaces the valve body (64) upward against the biasing force of the spring member (65). As a result, as shown in FIG. 4A, the small diameter portion (64a) of the valve body (64) is engaged with the bypass hole (62), and the bypass passage (66) is closed. Further, when the three-way switching valve (13) is set in a state indicated by a broken line in FIG. 1, the low-pressure refrigerant flowing through the suction pipe (22) is introduced into the lower space (61b) through the introduction pipe (29b). Then, the valve body (64) is displaced downward by the biasing force of the spring member (65). As a result, as shown in FIG. 4B, the small diameter portion (64a) of the valve body (64) is pulled out from the bypass hole (62), and the bypass passage (66) is opened.

  By switching the three-way switching valve (13) as described above, in the low-stage compression mechanism (40a), the oil by the oil supply passage (72) is in a state where the valve body (64) is in the open position of the bypass hole (62). On the other hand, when the valve body (64) is in the closed position of the bypass hole (62), the oil supply through the oil supply passage (72) is stopped. That is, the three-way selector valve (13) of the present embodiment opens the oil supply passage (72) when the valve body (64) closes the bypass hole (62), while the valve body (64) When 62) is opened, an opening / closing means for closing the oil supply passage (72) is formed.

-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 oil separator (30) and the four-way switching valve (12), and is sent to the outdoor heat exchanger (14). Dissipates heat to 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 transferred to the intermediate pressure space of the rotary compressor (20) by the injection pipe (24). Introduced to (50). The refrigerant introduced into the intermediate pressure space (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 oil separator (30) and 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 in the open state, the intermediate-pressure gas refrigerant in the gas-liquid separator (18) is introduced into the intermediate-pressure space (50). The refrigerant introduced into the intermediate pressure space (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). As a result, each piston (47a, 47b) in which each eccentric shaft portion (35, 36) is fitted rotates eccentrically 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. In the rotary compressor (20), the following first compression operation and second compression operation can be switched according to the setting of the three-way switching valve (13), that is, the open / close state of the bypass passage (66) described above. It has become.

<First compression operation>
The first compression operation is to operate the rotary compressor (20) while closing the bypass passage (66). Specifically, in the first compression operation, the three-way switching valve (13) is set to the state shown by the solid line in FIG. As a result, the oil accumulated at the bottom of the oil separator (30) flows into the oil return pipe (29a) so as to be pushed out by the high-pressure refrigerant. The high-temperature oil flowing through the oil return pipe (29a) is cooled to a relatively low temperature when flowing through the cooling heat exchanger (32). The cooled oil passes through the three-way switching valve (13) and the introduction pipe (29b), and is introduced into the lower space (61b) on the back side of the valve body (64) in the valve body storage chamber (61). When high-pressure oil is introduced to the back side of the valve body (64), the valve body (64) is pushed upward in the valve body housing chamber (61) and displaced to a position where the bypass hole (62) is closed. (See FIG. 4A).

  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 space (50), the discharge valve is opened and the refrigerant passes from the low-stage discharge passage (49a) to the intermediate pressure space. Discharged to (50). The discharge of the refrigerant continues until the eccentric rotation angle of the low stage side piston (47a) reaches 360 degrees.

  In the first compression operation of the low-stage compression mechanism (40a) as described above, as described above, high-pressure oil is introduced into the back side of the valve body (64), and the valve body (64) is brought into the closed position. Is retained. Here, a slight gap space (70) is formed between the distal end surface of the valve body (64) in the closed position and the opening surface of the bypass hole (62). Therefore, in the conventional apparatus, when the compression operation is performed in this state, the gap space (70) becomes a dead volume of the compression chamber, and the volume efficiency of the compression mechanism is reduced. Therefore, in the present embodiment, during the first compression operation, oil is supplied to the distal end surface of the valve body (64) in order to close the gap space (70).

  Specifically, as shown in FIG. 4 (A), when the valve body (64) is in the closed position of the bypass hole (62), oil flows from the oil introduction path (29) toward the lower space (61b). Have been supplied. For this reason, the oil that has flowed out of the oil introduction path (29) flows into the oil injection path (71) through the lower space (61b). This oil flows upward in the oil injection path (71), and is supplied to the clearance space (70) from the tip surface of the valve body (64). As a result, the gap space (70) is closed by oil, so that the dead volume of the compression chamber during the first compression operation is reduced. The oil is cooled to a relatively low temperature by the cooling heat exchanger (32). For this reason, even if this oil enters the compression chamber, the suction refrigerant in the compression chamber is prevented from being heated. At the same time, the oil that has entered the compression chamber is used to lubricate the respective moving surfaces of the low-stage piston (47a).

  On the other hand, in the high-stage compression mechanism (40b), the refrigerant in the intermediate pressure space (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, in the valve body storage chamber (61) as described above, the valve body (64) is pushed downward by the spring member (65) (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, refrigerant compression 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 space (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 space (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.

  In the second compression operation of the low-stage compression mechanism (40a) as described above, when the valve body (64) is in the open position of the bypass hole (62) as shown in FIG. (72) is closed by a three-way selector valve (13). For this reason, in the second compression operation, unlike the first compression operation, oil is not supplied to the distal end surface of the valve body (64). As a result, it is avoided that oil flows out from the front end surface of the valve body (64) to the bypass passage (66), and the suction refrigerant of the low-stage compression mechanism (40a) is heated by this oil. Is prevented.

  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).

  Thus, in this rotary compressor (20), the closed volume (substantial suction volume) of the low-stage compression mechanism (40a) can be changed by opening and closing the bypass passage (66). . 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) 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, the suction volume of the low-stage compression mechanism (40a), and thus the suction, is switched by switching between the first compression operation and the second compression operation described above. The volume ratio (Vh / Vl) can be changed as appropriate. As a result, the rotary compressor (20) can be operated at an optimum suction volume ratio according to the operating conditions.

  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, the rotary compressor (20) of the present embodiment is operated from the first compression operation to the second compression operation when the pressure difference in the refrigerant circuit (11) is relatively small as described above. Can be switched. 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 the embodiment-
In the said embodiment, oil is supplied to the front end surface of the valve body (62) used as the closed position of a bypass hole (62) at the time of the said 1st compression operation | movement. For this reason, the clearance space (70) formed between the front end surface of the valve body (62) and the inflow opening surface of the bypass hole (62) can be closed with oil, and the compression chamber during the first compression operation can be closed. Dead volume can be minimized. Therefore, it is possible to prevent a decrease in volumetric efficiency of the low-stage compression mechanism (40a) during the first compression operation.

  In the above embodiment, the oil separated by the oil separator (30) from the refrigerant discharged from the rotary compressor (20) is supplied to the gap space (70). Therefore, the gap space (70) can be closed with oil without using a pump or the like for conveying the oil. At this time, the oil flowing through the oil supply passage (72) is cooled by the cooling heat exchanger (32). Therefore, even if oil enters the compression chamber from the distal end side of the valve body (64), it is possible to prevent the intake refrigerant from being heated. Therefore, it is possible to prevent the volume efficiency of the low-stage compression mechanism (40a) from being reduced due to the heating of the suction refrigerant in the low-stage compression mechanism (40a).

 Furthermore, in the above embodiment, the oil supply passage (72) is closed when the valve element (64) is in the closed position of the bypass hole (62) by switching the three-way switching valve (13). Therefore, in a state where the bypass passage (62) is opened by the valve body (64), oil is not supplied to the tip of the valve body (64), and therefore this oil is not sent to the bypass passage (62). . Therefore, it is possible to prevent the suction refrigerant of the low-stage compression mechanism (40a) from being heated by oil during the second compression operation, and the volumetric efficiency of the low-stage compression mechanism (40a) during the second compression operation. Decrease can be prevented.

  In the above embodiment, the bypass hole (62) is formed on the upper surface of the rear head (45). For this reason, oil easily collects in the gap space (70) between the distal end surface of the valve body (64) and the open surface of the bypass hole (62). As a result, the gap space (70) can be more reliably closed with oil, and the generation of dead volume in the compression chamber can be more effectively prevented.

-Modification of the embodiment-
You may comprise the oil introduction channel | path (29) of the said embodiment as follows.

<Modification 1>
As shown in FIGS. 6 and 7, in Modification 1, the inflow end of the oil supply passage (72) is connected to the oil reservoir (29) of the rotary compressor (20). Specifically, the oil return pipe (29a) of the oil introduction path (29) has an inflow end that passes through a portion of the rotary compressor (20) closer to the bottom side of the casing (21) and is an oil reservoir. It faces (21a). On the other hand, the outflow end of the oil return pipe (29a) is connected to the three-way switching valve (13) as in the above embodiment. Other configurations are the same as those in the above embodiment.

  When the three-way switching valve (13) is in the state shown by the solid line in FIG. 6 during the first compression operation of the first modification, the high-temperature oil in the oil sump (21a) is converted into the high-pressure refrigerant in the casing (21). So that it flows into the oil return pipe (29a). The high-temperature oil flowing through the oil return pipe (29a) is cooled to a relatively low temperature when flowing through the cooling heat exchanger (32). The cooled oil passes through the three-way switching valve (13) and the introduction pipe (29b), and is introduced into the lower space (61b) on the back side of the valve body (64) in the valve body storage chamber (61). When high-pressure oil is introduced to the back side of the valve body (64), the valve body (64) is pushed upward in the valve body housing chamber (61), and as shown in FIG. 7, the bypass hole (62) Is moved to the closing position. When the valve body (64) is in the closed position, the oil in the lower space (61b) flows through the oil injection passage (71) formed in the valve body (64), and the gap from the tip surface of the valve body (64). Outflow to space (70). As a result, the gap space (70) is closed with oil. On the other hand, during the second compression operation, the supply of oil through the oil supply passage (72) is prohibited by the three-way switching valve (13), so that the oil passes through the bypass passage (66) and the suction side of the low-stage compression mechanism (40a). Never be sent to.

  As described above, also in the first modification, the gap space (70) on the distal end side of the valve body (64) in the closed state is closed with oil, so that the dead volume of the compression chamber during the first compression operation is minimized. And volumetric efficiency can be prevented from decreasing. Moreover, in the modification 1, since the pressure of the high pressure refrigerant | coolant in a casing (21) is utilized as a conveyance source of oil, it is not necessary to provide a pump etc. separately. Also in this modified example 1, the oil in the oil sump (21a) becomes relatively high temperature, but this oil is cooled by the cooling heat exchanger (32) and then placed on the back side of the valve body (64). It has been introduced. For this reason, even if this oil enters the compression chamber from the distal end side of the valve body (64), it is possible to prevent the intake refrigerant from being heated.

<Modification 2>
As shown in FIG. 8, the oil introduction path (29) of Modification 2 directly connects the lower space (61b) of the valve body storage chamber (61) and the oil reservoir (21a) in the casing (21). Yes. In Modification 2, the three-way switching valve (13) and the cooling heat exchanger (32) of Embodiment 1 are omitted. Specifically, in the lid member (63) that seals the valve body housing chamber (61), a plurality of oil introduction passages (29) penetrates vertically around its axis. Each oil introduction path (29) has a lower end facing the oil reservoir (21a) and an upper end facing the lower space (61b). Therefore, in the second modification, the oil in the oil reservoir (21a) is always introduced into the lower space (61b) of the valve body storage chamber (61).

  The lid member (63) has a blocking portion (63a) formed on the upper surface thereof. The blocking portion (63a) is located on the axis of the lid member (63) and the valve body (64). That is, the blocking part (63a) is located on an extension line of the oil injection path (71) of the valve body (64). The blocking part (63a) is formed on a substantially semispherical sphere whose tip bulges upward. When the valve body (64) is displaced to the closed position, the blocking portion (63a) causes the oil injection passage (71) and the oil introduction passage (29) to communicate with each other, and when the valve body (64) is displaced to the open position, The injection path (71) and the oil introduction path (29) are shut off. That is, when the valve element (64) closes the bypass hole (62), the blocking part (63a) opens the oil supply passage (72), while the valve element (64) opens the bypass hole (62). Opening / closing means for closing the oil supply passage (72) is configured.

  In the second modification, the first compression operation and the second compression operation are automatically switched in accordance with the high / low differential pressure of the refrigerant circuit (11) accompanying the change in the operating condition of the air conditioner (10). Specifically, for example, under an operating condition where the differential pressure of the refrigerant circuit (11) is relatively large, the pressure of the high-pressure refrigerant in the casing (21) is also relatively large. In such a case, since the pressure of the oil acting on the back surface of the valve body (64) increases, the valve body (64) is displaced upward against the biasing force of the spring member (65), and the bypass hole (62) is closed (see FIG. 9A). As a result, the first compression operation described above is performed.

  In this first compression operation, the inflow end of the oil injection passage (71) is opened from the blocking portion (63a), and the oil injection passage (71) and each oil introduction passage (29) communicate with each other. For this reason, the oil flowing through the oil introduction path (29) flows upward through the oil injection path (71) via the lower space (61b), and is supplied to the gap space (70) from the tip surface of the valve body (64). The As a result, the gap space (70) is closed by oil, so that the dead volume of the compression chamber during the first compression operation is reduced.

  On the other hand, under operating conditions where the differential pressure of the refrigerant circuit (11) is relatively small, the pressure of the high-pressure refrigerant in the casing (21) is also relatively small. In such a case, since the pressure of the oil acting on the back surface of the valve body (64) also decreases, the valve body (64) is pressed downward by the spring member (65) to open the bypass hole (62). . As a result, the above-described second compression operation is performed. For this reason, under such operating conditions in which the high / low differential pressure is relatively small, the suction volume Vl of the low-stage compression mechanism (40a) decreases and the suction volume ratio (Vh / Vl) automatically increases. As a result, as described above, the fluctuation range of the compression torque of each compression mechanism (40a, 40b) is averaged to reduce vibration and noise, and from the injection pipe (24) to the high stage compression mechanism (40b ) Increases the amount of intermediate pressure refrigerant sent to the suction side, improving the economizer effect.

  In the second compression operation, the inflow end of the oil injection path (71) is closed by the blocking portion (63a), and the oil injection path (71) and each oil introduction path (29) are blocked (FIG. 9B )reference). For this reason, it is reliably prohibited to supply oil to the oil injection passage (71) of the valve body (71), and the inflow of oil to the bypass passage (66) is also prevented. Therefore, also in this modification 2, it can prevent reliably that the suction | inhalation refrigerant | coolant of the low stage compression mechanism (40a) will be heated with oil at the time of 2nd compression operation.

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

  As shown in FIG. 10, in the same manner as in the above embodiment, a bypass passage (66), a valve body storage chamber (61), and a valve body (64) are provided on the high-stage compression mechanism (40b) side. Also good. In this example, a bypass passage (66) is formed in the front head (44), while an outflow end of the bypass passage (66) is connected to the intermediate pressure space (50). In this example, when the bypass passage (66) is opened, a part of the refrigerant in the high-stage cylinder chamber (42b) is transferred to the intermediate pressure space (50), that is, the suction side of the high-stage compression mechanism (40b). It is configured to be returned to. Also in this example, by introducing oil from the oil supply passage (72) to the gap space (70) on the tip surface of the valve body (64), the gap space (70) can be closed with oil, and the compression chamber The dead volume of can be minimized.

  In the embodiment, a two-stage compressor having a low-stage side compression mechanism and a high-stage side compression mechanism is a target, but the present invention is not limited to this. For example, the present invention can be applied to a single-stage compressor having one compression mechanism. The compression mechanism 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 or a scroll compression mechanism may be employed as the compression mechanism. Further, the present invention may be adopted in a compression mechanism that simultaneously expands and contracts a plurality of compression chambers by relatively eccentrically rotating a cylinder having an annular cylinder chamber and an annular piston provided in the cylinder chamber. good.

  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 the embodiment of the present invention is carried. It is a longitudinal section of a rotary compressor concerning an embodiment. It is a cross-sectional view of the low stage side compression mechanism of the rotary compressor which concerns on embodiment. FIG. 4A is an enlarged longitudinal sectional view of the bypass passage of the rotary compressor according to the embodiment, FIG. 4A shows a state during the first compression operation, and FIG. 4B shows a state during the second compression operation. It is. It is a schematic explanatory drawing which shows operation | movement of the low stage compression mechanism of the rotary compressor which concerns on embodiment. It is a refrigerant circuit figure of the air conditioning apparatus by which the rotary compressor which concerns on the modification 1 of embodiment is mounted. It is a longitudinal cross-sectional view of the low stage side compression mechanism which concerns on the modification 1 of embodiment. It is a longitudinal cross-sectional view of the low stage side compression mechanism which concerns on the modification 2 of embodiment. It is the longitudinal cross-sectional view which expanded the bypass passage of the rotary compressor which concerns on the modification 2, FIG. 9 (A) shows the state at the time of 1st compression operation, FIG.9 (B) shows the state at the time of 2nd compression operation. Is. It is a longitudinal cross-sectional view of the rotary compressor which concerns on other embodiment.

Explanation of symbols

13 Three-way selector valve (open / close means)
20 Rotary compressor
21 Casing
21a Oil sump
29 Oil introduction path (oil supply path)
30 Oil separator
31 Cooling heat exchanger (cooling means)
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 chamber
63a Blocking part
64 Disc
66 Bypass passage
71 Oil injection path (oil supply path)
72 Oil supply passage

Claims (9)

It rotates eccentrically with respect to the drive shaft (33) while forming a compression chamber between the fixing member (41a, 41b, 44, 45, 46) and the fixing member (41a, 41b, 44, 45, 46). A rotary compressor including a compression mechanism (40a, 40b) having a movable member (47a, 47b) and compressing the refrigerant in the compression chamber;
A bypass passage (66) in which an inflow end opens in an inner wall surface of the compression chamber and an outflow end is connected to the suction side of the compression mechanism (40a, 40b);
The inflow opening (62) of the bypass passage (66) is configured to be openable and closable, and in the closed state, the tip of the inflow opening surface of the bypass passage (66) is recessed into the bypass passage (66). The disc (64),
A rotary compressor, comprising: an oil supply passage (72) for supplying oil to a distal end surface of the valve body (64) in a closed state. In claim 1,
The oil supply passage (72) has an oil injection passage (71) formed in the valve body (64) so that oil flows therethrough, and an outflow end opened to a front end surface of the valve body (64). Features a rotary compressor. In claim 2,
One end of the fixing member (41a, 41b, 44, 45, 46) faces the inflow opening (62) of the bypass passage (66), and the valve body (64) has the inflow opening (62). A valve body accommodating chamber (61) that is fitted so as to be freely opened and closed is formed,
The oil supply passage (72) includes the oil injection passage (71) formed penetrating from the front end surface to the back surface of the valve body (64), and the valve body (64 in the valve body housing chamber (61). And an oil introduction passage (29) for introducing oil to the back side of the rotary compressor. In any one of Claims 1 thru | or 3,
The oil supply passage (72) is configured to introduce oil separated by an oil separator (30) from refrigerant discharged from the compression mechanism (40a, 40b). Compressor. In any one of Claims 1 thru | or 3,
Oil in which the compression mechanism (40a, 40b) is accommodated, the internal space is filled with the refrigerant discharged from the compression mechanism (40a, 40b), and oil that lubricates the compression mechanism (40a, 40b) is stored at the bottom A casing (21) in which a reservoir (21a) is formed,
The rotary compressor characterized in that the oil supply passage (72) is configured to introduce oil from the oil reservoir (21a). In claim 4 or 5,
A rotary compressor comprising cooling means (32) for cooling oil flowing through the oil supply passage (72). In claim 1,
When the valve body (64) closes the inflow opening (62) of the bypass passage (66), the oil supply passage (72) is opened, while the valve body (64) opens the inflow opening of the bypass passage (66). Opening and closing means (13, 63a) for closing the oil supply passage (72) when the part (62) is opened is provided. In claim 7,
One end of the fixing member (41a, 41b, 44, 45, 46) faces the inflow opening (62) of the bypass passage (66), and the valve body (64) has the inflow opening (62). A valve body accommodating chamber (61) that is fitted so as to be freely opened and closed is formed,
The oil supply passage (72) includes the oil injection passage (71) formed penetrating from the front end surface to the back surface of the valve body (64), and the valve body (61) in the valve body storage chamber (61). 64) with an oil introduction path (29) for introducing oil on the back side,
When the valve element (64) is displaced to the closed position of the bypass passage (66), the opening / closing means (13, 63a) causes the oil injection passage (71) and the oil introduction passage (29) to communicate with each other. Rotary compression characterized by comprising a shut-off portion (63a) that shuts off the oil injection passage (71) and the oil introduction passage (29) when the (64) is displaced to the open position of the bypass passage (66) Machine. In any one of claims 1 to 8,
The inflow end of the bypass passage (66) opens to the inner wall on the lower side of the compression chamber.

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