WO2007066463A1

WO2007066463A1 - Scroll compressor

Info

Publication number: WO2007066463A1
Application number: PCT/JP2006/322120
Authority: WO
Inventors: Hiroyuki Yamaji; Kazuhiko Matsukawa; Takeshi Imanishi
Original assignee: Daikin Industries, Ltd.
Priority date: 2005-12-05
Filing date: 2006-11-06
Publication date: 2007-06-14
Also published as: JP2007154761A

Abstract

A scroll compressor has a first compression chamber (25a) formed between the inner peripheral surface of a stationary wrap (21b) and the outer peripheral surface of a moving wrap (22b) and also has a second compression chamber (25b) formed between the outer peripheral surface of the stationary wrap (21b) and the inner peripheral surface of the moving wrap (22b). A suction volume regulation mechanism (30) is provided at at least one position within a range of one spiral turn on the outer part of the spiral, and the mechanism (30) is capable of regulating a suction volume by adjusting a suction close position of the compression chambers (25a, 25b) in a suction process of the compression mechanism (20). When operation of a refrigerant circuit is in a low-compression-ratio operating condition that is outside a design point of the scroll compressor, over-compression is prevented independent of control of a motor, a reduction in efficiency of the compressor is prevented, and in addition an occurrence of a failure caused by overturn of a movable scroll (22) is prevented.

Description

Specification

scroll compressor

Technical field

[0001] The present invention relates to a scroll compressor in which at least one of two scroll members that squeeze each other performs an eccentric rotational movement, and particularly relates to an overcompression prevention structure.

Background technology

[0002] Scroll compressors have conventionally been used, for example, as a compression mechanism for compressing refrigerant gas in a refrigeration cycle (see, for example, Patent Document 1). A scroll compressor is equipped within a casing with a fixed scroll (first scroll member) and a movable scroll (second scroll member), both of which have spiral wraps on an end plate that engage each other. The fixed scroll is fixed to a nozzle that is press-fitted or welded into the casing, and the movable scroll is rotatably fitted to the eccentric part of the drive shaft (crankshaft). In this scroll compressor, the movable scroll only revolves around the fixed scroll without rotating, thereby contracting the compression chamber formed between the wraps of both scrolls and compressing gas such as refrigerant. The operation of discharging from the discharge port of the compression mechanism is performed. When gas is inhaled, the ends of the wraps of both scrolls are open, and when these are closed, a compression chamber is formed and compression begins.

[0003] Incidentally, a scroll compressor has a structure that compresses the sucked gas by changing the volume up to a certain volume, and has a "fixed volume ratio (fixed compression ratio)" determined by the shape of the compression mechanism. are doing. To explain the operation of the compression mechanism of this scroll compressor in detail, the compression chamber is not connected to the discharge port of the compression mechanism during gas compression, but is connected to the spiral teeth (wrap) of the fixed scroll and movable scroll. After the gas reaches a certain pressure by reducing the volume of the compression chamber between the two, the compression chamber communicates with the discharge port and high-pressure gas is discharged.

[0004] Therefore, for example, the internal pressure (discharge pressure) of the compression chamber under operating conditions of a low compression ratio (low pressure ratio) that deviates from the design point of the refrigerant circuit operating condition of a power scroll compressor is determined by the refrigerant under that operating condition. The pressure will rise to a level higher than the circuit high pressure (overcompression). Overcompression During production, power is consumed to perform extra compression, reducing the efficiency of the compressor.

[0005] On the other hand, the scroll compressor of Patent Document 1 is a variable capacity compressor equipped with an inverter-controlled electric motor, and has thinner teeth at the end of the spiral wrap. It has a configuration with larger gaps on the sides. In this scroll compressor, during high-speed operation, the amount of suction refrigerant trapped at the end of the wrap is relatively large due to the sealing effect of the lubricating oil, whereas during low-speed operation, the sealing effect of the lubricating oil weakens. As a result, gas leaks occur where the gap is set large, and the amount of trapped refrigerant is relatively small. Therefore, during low-speed operation, the refrigerant is compressed with a reduced amount of suction refrigerant, so overcompression can be suppressed.

Patent document 1: Japanese Patent Application Laid-open No. 11 82331

Disclosure of invention

Problems that the invention seeks to solve

[0006] The compressor of Patent Document 1 can prevent overcompression when the operating conditions of the refrigerant circuit are at a low compression ratio when the compressor is operating at low speed, but when the operating conditions of the refrigerant circuit are at a low compression ratio when the compressor is operating at high speed. When the compression ratio is low, the amount of refrigerant sucked is large, so there is a problem that overcompression cannot be prevented. In other words, the scroll compressor of Patent Document 1 has a restriction that slowing down the rotational speed of the electric motor is a necessary condition for preventing overcompression.

[0007] In addition, in the above compressor, when the operating conditions of the refrigerant circuit become operating conditions of a low compression ratio, the motor is operated at a low rotation speed by inverter control. Generally speaking, efficiency is lower when rotating at low speeds than when rotating at high speeds, so there was a problem in that the efficiency of the compressor also decreased.

[0008] Furthermore, scroll compressors generally have a structure in which the movable scroll is pushed against the fixed scroll in the axial direction using high gas pressure, or a structure in which the movable scroll is supported by a thrust bearing. The force that prevents the scroll from overturning (tilting) When operating at a low compression ratio, the high pressure generally decreases and the axial pressing force on the movable scroll decreases (in other words, the ratio of radial load to axial load) (increases), so in the former case, overturning is more likely to occur due to overturning moment. stop If the movable scroll overturns, problems such as poor compression, reduced operating capacity, and reduced compressor efficiency will occur.

[0009] The present invention was made in view of the above-mentioned problems, and its purpose is to solve the problem when the operating condition of the refrigerant circuit becomes a low compression ratio operating condition where the design point of the S-scroll compressor deviates from the operating condition. The second objective is to prevent overcompression from occurring regardless of the control of the electric motor, prevent the efficiency of the compressor from decreasing, and prevent malfunctions due to overturning of the scroll member. Means to solve problems

[0010] The first invention is such that at least one of the two scroll members (21, 22), which has spiral wraps (21b, 22b) that bite into each other on the end plate (21a, 22a), performs eccentric rotational movement. Assuming a scroll compressor with a compression mechanism (20) inside the casing (10)! /, Ru.

[0011] This scroll compressor is configured between the inner circumferential surface of the wrap (21b) of the first scroll member (21) and the outer circumferential surface of the wrap (22b) of the second scroll member (22). The compressor is configured between the first compression chamber (25a), the outer circumferential surface of the wrap (21b) of the first scroll member (21), and the inner circumferential surface of the wrap (22b) of the second scroll member (22). The suction volume can be adjusted by adjusting the suction closed position of the compression chambers (25a, 25b) during the suction stroke of the compression mechanism (20). It is characterized in that a volume adjustment mechanism (30) is provided at at least one location within the range of one turn on the outer circumferential side of the spiral.

[0012] In the first invention, by providing the suction volume adjustment mechanism (30) within one turn on the outer circumferential side of the spiral, at least one of the first compression chamber (25a) and the second compression chamber (25b) It is possible to operate with a smaller suction volume. For example, if the suction volumes of both the first compression chamber (25a) and the second compression chamber (25b) are reduced, the "fixed compression ratio" of the scroll compressor becomes smaller. This allows operation in which the discharge pressure is lower than during normal operation (hereinafter referred to as adjustment operation). Therefore, when the operating conditions of the refrigerant circuit are at a low compression ratio that deviates from the design point during normal operation of the scroll compressor, the internal pressure of the compression chambers (25a, 25b) This prevents the pressure from becoming too high compared to the high pressure in the refrigerant circuit under the conditions of rotation. By providing suction volume adjustment mechanisms (30) in multiple locations, the discharge pressure can be adjusted in multiple stages.

[0013]Furthermore, by providing the suction volume adjustment mechanism (30), operation that controls the capacity of the compression mechanism (20) becomes possible. For example, suction in both the first compression chamber (25a) and the second compression chamber (25b) By operating the suction volume adjustment mechanism (30) to reduce the volume, the actual number of turns of the vortex can be reduced to control the volume even during operation.

[0014] Furthermore, in the present invention, it is also possible to change the suction volume of only one of the first compression chamber (25a) and the second compression chamber (25b). In this regard, in an asymmetric spiral structure in which the number of turns (length of the spiral) of the spirals (wraps (21b, 22b)) of the two scroll members (21, 22) are different, the first compression chamber (25a) Since the compression ratio of the first compression chamber (25b) and the second compression chamber (25b) are adjusted at the center of the vortex to match the discharge pressure, during the compression of the vortex, the pressure between the first compression chamber (25a) and the second compression chamber (25b) There is a pressure difference between the two, causing an imbalance in the gas load acting on the vortex. Specifically, when the suction volume of the first compression chamber (25a) is large and the suction volume of the second compression chamber (25b) is small, the pressure in the first compression chamber (25a) is higher during compression. Therefore, vibrations are likely to occur due to fluctuations in the rotational torque of the volute (the torque that acts in the direction of the vortex's rotation due to the gas load). On the other hand, if only the suction volume of the first compression chamber (25a) is reduced, the pressure difference between the gases between the first compression chamber (25a) and the second compression chamber (25b) can be reduced. This makes it possible to reduce the effects of vibrations caused by unbalanced gas loads and fluctuations in the rotational torque of the vortex.

[0015] Furthermore, since the gas load balance is a relative relationship between the first compression chamber (25a) and the second compression chamber (25b), the suction volume of the second compression chamber (25b) changes in the direction of increasing it. You may let them. Specifically, the configuration is such that the suction volume of both the first compression chamber (25a) and the second compression chamber (25b) can be adjusted, and the suction volume adjustment position of the first compression chamber (25a) is Move the suction volume adjustment position of the second compression chamber (25b) to the outer circumference of the spiral (toward the end of the spiral).

[0016] Furthermore, in this invention, by operating the suction volume adjustment mechanism (30), it is possible to reduce the area on which the axial load due to the internal pressure of the compression chambers (25a, 25b) acts, and also to prevent swirling. Since the point of application of the gas load can be moved to a position closer to the drive center, the overturning moment is reduced and overturning is less likely to occur.

[0017] A second invention is the first invention, wherein the suction volume adjustment mechanism (30) is capable of adjusting the suction closed position in both the first compression chamber (25a) and the second compression chamber (25b). It is characterized by being a mechanism.

[0018] In this second invention, as described in the first invention, the first compression chamber (25a) and the second Capacity control is performed by simultaneously reducing the suction volumes of both compression chambers (25b), and the fixed compression ratio of the scroll compressor is reduced, making it possible to lower the discharge pressure than during normal operation. Therefore, when the operating conditions of the refrigerant circuit are at a low compression ratio that deviates from the design point during normal operation of the scroll compressor, the internal pressure of the compression chambers (25a, 25b) will be lower than that of the operating conditions. The high pressure of the refrigerant circuit can be prevented from rising too high.

[0019] A third invention is the second invention, wherein the suction volume adjustment mechanism (30) is capable of switching the first compression chamber (25a) and the second compression chamber (25b) between a communication state and a disconnection state. It is characterized by being configured with an opening/closing mechanism (31).

[0020] In this third invention, in the normal operating state when the opening/closing mechanism (31) is closed, the inner periphery of the wrap (21b) of the first scroll member (21) that is separated at the winding end side of the spiral When the surface and the outer circumferential surface of the wrap (22b) of the second scroll member (22) substantially contact each other (there is a gap on the order of microns, but an oil film is formed between them and refrigerant leakage does not become a problem). The contact position (seal point) at the end of the first compression chamber (25a) becomes the suction closed position, and the compression stroke in the first compression chamber (25a) begins. Further, the outer circumferential surface of the wrap (21b) of the first scroll member (21), which was also separated at the end of the spiral, and the inner circumferential surface of the wrap (22b) of the second scroll member (22) are substantially The contact position (seal point) at the time of contact becomes the suction closing position, and the compression stroke in the second compression chamber (25b) begins.

[0021] On the other hand, when the opening/closing mechanism (31) is opened, the above-mentioned contact position touches the position of the opening/closing mechanism (31) in both the first compression chamber (25a) and the second compression chamber (25b). The compression chambers (25a, 25b) will not be completely closed until it passes. In other words, until a seal point is formed past the opening/closing mechanism (31), the first compression chamber (25a) is connected to the suction side of the compression mechanism (20) via the second compression chamber (25b). The second compression chamber (25b) is in communication with the suction side of the compression mechanism (20) via the first compression chamber (25a), and the contact positions of both wraps (21b, 22b) are open and closed. Immediately after passing the mechanism (31), the position where the seal point is formed becomes the suction closing position, and the first compression chamber (25a) and second compression chamber (25b) are formed to enter the compression stroke. (See Figures 11 to 16). Therefore, the size of the suction volume can be adjusted depending on the position where the opening/closing mechanism (31) is provided. By adjusting the suction volume in this way, the operating conditions of the refrigerant circuit can be adjusted to the design point during normal operation of the power scroll compressor. This prevents the internal pressure of the compression chambers (25a, 25b) from becoming too high than the high pressure of the refrigerant circuit when operating conditions are such that the compression ratio is extremely low.

[0022] A fourth invention is the first or second invention, wherein the suction volume adjustment mechanism (30) connects at least one of the first compression chamber (25a) and the second compression chamber (25b) to the casing ( 10) is characterized by being comprised of an opening/closing mechanism (31) that can be switched between a communicating state and a blocking state with respect to the low pressure space (17) provided in the low pressure space (17). Note that the above-mentioned "low pressure space (17)" may be a space inside the casing (10) of a type of compressor in which the inside of the casing (10) has a low pressure, or the inside of the casing (10) may be a high pressure space. It may be the low pressure space (17) in a type of compressor that is divided into (16) and low pressure space (17), or it may be the suction space that communicates with the suction side of the compression mechanism (20). .

[0023] In the fourth invention, in the normal operating state when the opening/closing mechanism (31) is closed, the wraps (21b, 22b) separated at the winding end side of the spiral are separated from each other, as in the third invention. The position where the two substantially come into contact and a seal point is formed becomes the suction closed position, and a first compression chamber (25a) and a second compression chamber (25b) are formed.

[0024] On the other hand, when the opening/closing mechanism (31) is opened, the contact position of both wraps (21b, 22b) is the opening/closing mechanism in both the first compression chamber (25a) and the second compression chamber (25b). The compression chambers (25a, 25b) are not completely closed until they pass a certain position (31). In other words, until a seal point is formed past the opening/closing mechanism (31), at least one of the first compression chamber (25a) and the second compression chamber (25b) is kept under low pressure inside the casing (10). It is in communication with the space (17), and the position where the seal point is formed immediately after the contact position of both wraps (21b, 22b) passes the position of the opening/closing mechanism (31) is the suction closed position. , compression chambers (2 5a, 25b) are formed that enter the compression stroke. Therefore, the size of the suction volume can be adjusted depending on the position where the opening/closing mechanism (31) is provided. By adjusting the suction volume in this way, when the refrigerant circuit operating conditions are at a low compression ratio that deviates from the design point during normal operation of the power scroll compressor, This prevents the internal pressure of the compression chambers (25a, 25b) from becoming too high than the high pressure of the refrigerant circuit.

[0025] In a fifth invention, in the first or second invention, the suction volume adjustment mechanism (30) has a structure in which the suction volume adjustment mechanism (30) has a structure in which the wrap (21b) of the first scroll member (21) and the wrap of the second scroll member (22) (22b) is substantial For at least one of the first compression chamber (25a) and the second compression chamber (25b) formed in contact with the first compression chamber (25a) and the second compression chamber (25b), the inner circumference side and the outer circumference side of the contact position can be switched between a communicating state and a blocking state. It is characterized by being comprised of an opening/closing mechanism (31).

[0026] In the fifth invention, in the normal operating state when the opening/closing mechanism (31) is closed, the wraps (21b, 22b) that are separated at the end of the spiral, as in the third and fourth inventions, ) substantially come into contact with each other and the position where the seal point is formed becomes the suction closed position, forming a first compression chamber (25a) and a second compression chamber (25b) that enter the compression stroke.

[0027] On the other hand, when the opening/closing mechanism (31) is opened, the contact position of both wraps (21b, 22b) is the opening/closing mechanism in both the first compression chamber (25a) and the second compression chamber (25b). The compression chambers (25a, 25b) are not completely closed until they pass a certain position (31). In other words, until a seal point is formed past the position of the opening/closing mechanism (31), at least one of the first compression chamber (25a) and the second compression chamber (25b) is connected to the inner periphery of the contact position. The side part is in communication with the suction side of the compression mechanism (20) via the outer peripheral part, and immediately after the contact position of both wraps (21b, 22b) passes the opening/closing mechanism (31). The position where the seal point is formed becomes the suction closing position, and compression chambers (25a, 25b) are formed where the compression stroke begins. Therefore, the size of the suction volume can be adjusted depending on the position where the opening/closing mechanism (31) is provided. By adjusting the suction volume in this way, when the operating conditions of the refrigerant circuit are at a low compression ratio that deviates from the design point for normal operation of the scroll compressor, the compression This prevents the internal pressure of the chambers (25a, 25b) from becoming too high than the high pressure of the refrigerant circuit.

[0028] A sixth invention is one of the third to fifth inventions, wherein the opening/closing mechanism (31) includes a communication path ( 32, 37), a closing member (33) movable between an open position for opening and a closed position for closing the communicating path (32, 37), and a closing member (33) positioned in the open position and the closed position. It is characterized by being equipped with an opening/closing drive mechanism (34) that changes the opening/closing drive mechanism! /, Ru.

[0029] In the sixth invention, when the closing member (33) is set to the closed position by the opening/closing drive mechanism (34), the opening/closing mechanism (31) can be switched to the cutoff state, and thereby the compression The mechanism (20) can be operated in normal operation at the design compression ratio. In addition, the opening/closing mechanism (3 When the closing member (33) is set to the open position according to 1), the opening/closing mechanism (31) can be switched to the open state, thereby allowing operation with the suction volume of the compression mechanism (20) changed. Therefore, it can be used when the refrigerant circuit operating conditions are at a low compression ratio that deviates from the design point for normal operation of the scroll compressor.

[0030] A seventh invention is based on the sixth invention, wherein the opening/closing drive mechanism (34) includes a biasing member (35) that biases the closing member (33) toward the open position, and a biasing member (35) that biases the closing member (33) toward the open position. ) and a switching member (36) for switching between applying high pressure against the urging force of the urging member (35) and applying low pressure to the closing member (33)!/ヽAs a feature! / ヽru.

[0031] In the seventh invention, when high pressure is applied to the closing member (33), the closing member (33) may be switched to the blocking state against the biasing force of the biasing member (35). When low pressure is applied to the closing member (33), the closing member (33) can be switched to the open state by the biasing force of the biasing member (35). By switching the closing member (33) between the closed state and the open state in this way, the compression mechanism (20) can be operated in normal operation at the design compression ratio, and in operation at a low compression ratio that deviates from the design point during normal operation. It can be made to correspond to the conditions.

[0032] In an eighth invention, in the sixth or seventh invention, the communication passage (32, 37) is formed in the hole (32) or the end plate (21a, 22a) of the first scroll or the second scroll. It is characterized by being composed of grooves (37)! /, Ru.

[0033] In the eighth invention, when the opening/closing mechanism (31) is switched to the communicating state, before the seal point is formed past the position of the opening/closing mechanism (31), the compression chamber (25a, The gas in 25b) flows through the communication passages (32, 37) to keep the compression chambers (25a, 25b) in an unclosed state. Immediately after the contact position of both wraps (21b, 22b) passes the opening/closing mechanism (31), the position where the seal point is formed becomes the suction closed position, and gas compression begins.

[0034] A ninth invention is characterized in that, in the first or second invention, the first scroll member (21) and the second scroll member (22) have an asymmetric spiral structure in which the number of spiral turns is different. It is characterized by

[0035] In the ninth invention, in the compression mechanism (20) having an asymmetric spiral structure, it is possible to adjust the suction closing position of at least one of the first compression chamber (25 a) and the second compression chamber (25b). in Wear. By making it possible to adjust the suction closed position in both the first compression chamber (25a) and the second compression chamber (25b), as explained in the first invention, the suction volume of the compression chambers (25a, 25b) can be adjusted. By reducing the fixed compression ratio, the fixed compression ratio can be reduced by reducing the fixed compression ratio. 25a, 25b) from becoming too high than the high pressure of the refrigerant circuit under the operating conditions.

[0036] Furthermore, if the suction volume is configured to be changed in only one of the first compression chamber (25a) and the second compression chamber (25b), as explained in the first invention, for example, the first compression chamber ( By reducing only the suction volume of 25a), it is possible to reduce the pressure difference between the gas in the first compression chamber (25a) and the second compression chamber (25b), which prevents unbalanced gas loads and rotation of the vortex. This makes it possible to reduce the effects of vibration caused by torque fluctuations.

[0037] A tenth invention is based on the ninth invention, characterized in that the suction volume adjustment mechanism (30) is provided at only one location within one turn on the outer peripheral side of the spiral.

[0038] In the tenth invention, since the suction volume adjustment mechanism (30) is provided at only one location, the suction volume adjustment mechanism (30) is provided in at least one of the first compression chamber (25a) and the second compression chamber (25b). Inhalation volume can be adjusted in two stages.

[0039] The eleventh invention is the second invention, wherein the first scroll member (21) and the second scroll member (22) are configured to have a symmetrical spiral structure with an equal number of spiral turns, and the suction volume adjustment mechanism ( 30) are provided at symmetrical positions with respect to the center of the spiral.

[0040] In the eleventh invention, in the compression mechanism (20) having a symmetrical spiral structure, suction is performed in the first compression chamber (25a) and the second compression chamber (25b) that are symmetrical with respect to the spiral center. The closed position can be adjusted. Therefore, as explained in the first invention, the fixed compression ratio can be reduced by reducing the suction volume of the compression chambers (25a, 25b), so that the operating conditions of the refrigerant circuit can be adjusted to suit the scroll compressor. When operating conditions are at a low compression ratio that deviates from the design point during normal operation, the internal pressure in the compression chambers (25a, 25b) becomes too high than the high pressure in the refrigerant circuit under those operating conditions. can be suppressed.

[0041] A twelfth invention provides the compression mechanism (20) in any one of the first to eleventh inventions. A fixed scroll (21), which is a first scroll member (21) held by one single thing (10), and a movable, which is a second scroll member (22), which performs an eccentric rotational movement relative to the fixed scroll (21). A scroll (22) is provided, and an electric motor (45), which is a drive source for the movable scroll (22) and whose rotational speed can be variably adjusted, is housed in the casing (10). It is said that Note that the fixed scroll (21) is generally fixed with bolts or the like to a housing (23) that is held in the casing (10) by press-fitting or welding.

[0042] In the twelfth invention, the movable scroll (22) performs an eccentric rotational movement relative to the fixed scroll (21), and the scroll is configured such that the operating capacity is variable by controlling the rotational speed of the electric motor (45). In the scroll compressor, it is possible to perform control to reduce the fixed compression ratio of the scroll compressor, so the operating conditions of the refrigerant circuit can be changed to low compression ratio operating conditions that are outside the design point during normal operation of the scroll compressor. The internal pressure of the compression chambers (25a, 25b) can be prevented from becoming too high than the high pressure of the refrigerant circuit under the operating conditions. Furthermore, in this invention, the suction volume can be adjusted regardless of the rotation speed of the electric motor (45), and the suction volume adjustment mechanism (30), which is also a mechanical capacity control mechanism, is incorporated in the rotation speed control of the electric motor (45). By combining them, it is also possible to widen the range of capacity control.

[0043] A thirteenth invention is the twelfth invention, in which the electric motor (45) is in an operating state in which the suction volume adjustment mechanism (30) makes the suction volume of the compression mechanism (20) smaller than during normal operation, It is characterized by being configured to make the rotation speed faster than during normal operation.

[0044] In the thirteenth invention, when the suction volume adjustment mechanism (30) makes the suction volume of the compression mechanism (20) smaller than that during normal operation, control is performed to increase the rotational speed of the electric motor (45). Therefore, the electric motor (45) can be operated without reducing its efficiency. Furthermore, by controlling the rotational speed of the electric motor (45) to be faster, it is possible to prevent the operating capacity from decreasing even if the suction volume decreases.

Effect of the invention

[0045] According to the present invention, reducing the suction volumes of both the first compression chamber (25a) and the second compression chamber (25b) is substantially the same as reducing the number of spiral turns (compression ratio). The compression ratio can be set according to the operating conditions. Then, the fixed compression ratio of the scroll compressor becomes smaller, and the discharge pressure (internal pressure in the compression chambers (25a, 25b)) becomes lower than during normal operation. Even when the refrigerant circuit operating conditions are at a low compression ratio that is outside the design point of the scroll compressor during normal operation, the internal pressure in the compression chambers (25a, 25b) remains This prevents the pressure from becoming too high than the high pressure in the refrigerant circuit under those operating conditions. Therefore, it is possible to prevent overcompression from occurring.

[0046] Furthermore, by providing suction volume adjustment mechanisms (30) at multiple locations, it becomes possible to perform control to prevent overcompression in a step-by-step manner in response to changes in the operating conditions of the refrigerant circuit. The accuracy of is improved.

[0047] In addition, since the suction volume adjustment mechanism (30) is provided within the range of one turn on the outer circumference of the spiral, the operating capacity of the compressor can be adjusted by changing the suction closed position during operation and reducing the suction volume. It is also possible to control to reduce .

[0048] Furthermore, in this invention, the fixed compression ratio can be changed by adjusting the suction volume, so if the electric motor (45) is an inverter-controlled variable rotation speed type, it is possible to change the fixed compression ratio by adjusting the suction volume. Overcompression can be prevented regardless of low speed rotation, and the rotational speed of the electric motor (45) is not a constraint on overcompression prevention. Unlike the compressor of Patent Document 1, which can prevent overcompression only at low speeds, overcompression can be prevented even at high speeds, and in that case, the electric motor (45) can be operated with high efficiency, so the compressor Efficiency reduction can be prevented.

[0049] Furthermore, if the suction volume of only one of the first compression chamber (25a) and the second compression chamber (25b) is changed, the first compression in the middle of compression in the asymmetric spiral structure compression mechanism (20) Since the pressure difference between the gas in the chamber (25a) and the second compression chamber (25b) can be reduced, it is possible to reduce the effects of vibration caused by unbalanced gas loads and fluctuations in the rotational torque of the vortex. .

[0050] Furthermore, in this invention, by operating the suction volume adjustment mechanism (30), it is possible to reduce the area on which the axial load due to the internal pressure of the compression chambers (25a, 25b) acts, and also to prevent swirling. Since the point of action of the gas load can be moved to a position closer to the center, the overturning moment becomes smaller and overturning becomes less likely. Therefore, problems such as poor compression, reduction in operating capacity, and reduction in compressor efficiency can be prevented.

[0051] Conventional methods for controlling the capacity of scroll compressors include compressor ON-OFF control, rotational speed control using an inverter, and an unloading mechanism that bypasses intermediate-pressure refrigerant to the low-pressure side. control, etc., and each can be used alone or in combination. It is. In either case, when operating at a capacity smaller than the rated capacity of the compressor, control is performed that emphasizes capacity adjustment rather than efficiency. On the other hand, in the present invention, the electric motor (45) can be rotated at high speed in addition to adjusting the capacity, so that a decrease in efficiency can be prevented.

[0052] According to the second invention, by reducing the suction volumes of both the first compression chamber (25a) and the second compression chamber (25b), the operation of the refrigerant circuit is improved as in the first invention. Even when operating conditions are at a low compression ratio that deviates from the design point for normal operation of the scroll compressor, it is possible to prevent overcompression from occurring. In addition, overcompression can be prevented whether the electric motor (45) rotates at high speed or low speed, and a decrease in operating efficiency of the compressor can be suppressed when the motor (45) rotates at high speed. Capacity control can also be performed by changing the suction closed position and reducing the suction volume.

[0053] According to the third invention, the suction volume adjustment mechanism (30) includes an opening/closing mechanism capable of switching the first compression chamber (25a) and the second compression chamber (25b) between a communicating state and a blocking state. By simply providing (31), the suction closed position of the first compression chamber (25a) and the second compression chamber (25b) can be adjusted to change the suction volume. By adjusting the size of the suction volume, it is possible to prevent overcompression from occurring even when the refrigerant circuit operating conditions are at a low compression ratio that deviates from the swirl design point, and the capacity can be increased. The control amount can also be adjusted.

[0054] According to the fourth invention, at least one of the first compression chamber (25a) and the second compression chamber (25b) is connected to the low pressure space (17) provided in the casing (10). By simply providing an opening/closing mechanism (31) that can be switched between a communication state and a cutoff state, the suction closed position of at least one of the first compression chamber (25a) and the second compression chamber (25b) can be adjusted, and the suction volume can be increased. can be changed. By adjusting the size of the suction volume, it is possible to prevent overcompression from occurring even when the operating conditions of the refrigerant circuit are at a low compression ratio far from the swirl design point, and the capacity can be increased. The control amount can also be adjusted.

[0055] According to the fifth invention, the wrap (21b) of the first scroll member (21) and the wrap (22b) of the second scroll member (22) are formed in a state where the wrap (22b) is substantially in contact with each other. For at least one of the first compression chamber (25a) and the second compression chamber (25b), an opening/closing mechanism (31) that can switch the inner circumferential side and the outer circumferential side of the contact position between a communicating state and a blocking state is simply provided. and the first compression chamber (25 The suction volume can be changed by adjusting the suction closed position of at least one of a) and the second compression chamber (25b). By adjusting the suction volume, overcompression can occur even when the operating conditions of the refrigerant circuit are at a low compression ratio, which is far from the design point during normal operation of the scroll compressor. It is possible to prevent this from occurring, and also to adjust the amount of capacity control.

[0056] According to the sixth invention, the opening/closing mechanism (31) includes the communicating passage (32, 37) that allows gas to flow in the communicating state of the opening/closing mechanism (31), and the communicating passage (32, 37). 37), a closing member (33) movable between an open position for opening and a closed position for closing, and an opening/closing drive mechanism (34) for changing the position of the closing member (33) between the open position and the closed position. The operation of the suction volume adjustment mechanism (30) can be controlled simply by configuring the suction volume adjustment mechanism (30). The compression mechanism (20) can be operated in response to fluctuations in the compression ratio (pressure ratio) of the refrigerant circuit, and overcompression can also be prevented.

[0057] According to the seventh invention, the opening/closing drive mechanism (34) is attached to the urging member (35) that urges the closing member (33) toward the open position and the closing member (33). All that is required is a configuration including a switching member (36) that switches between a state in which high pressure is applied by applying the biasing force of the closing member (35) and a state in which low pressure is applied to the closing member (33). , the reliable operation of the opening/closing mechanism (31) can be guaranteed. Then, by controlling the operation of the suction volume adjustment mechanism (30) by the opening/closing mechanism (31), the compression mechanism (20) can be operated at the design compression ratio in normal operation and at the design point during normal operation. It can be adapted to operating conditions with low compression ratios, and capacity control is also possible.

[0058] According to the eighth invention, the communication passage (32, 37) is the hole (32) or groove (37) formed in the end plate (21a, 22a) of the first scroll or the second scroll. This alone can guarantee the open/close operation of the opening/closing mechanism (31). By controlling the operation of the suction volume adjustment mechanism (30) by the opening/closing mechanism (31), the compression mechanism (20) can be operated at a normal operation at the design compression ratio and at a low compression rate that deviates from the design point during normal operation. It can be adapted to different operating conditions.

, capacity control is also possible.

[0059] According to the ninth invention, in a scroll compressor with an asymmetric spiral structure, when the suction volumes of both the first compression chamber (25a) and the second compression chamber (25b) are reduced, the scroll compressor's Since the fixed compression ratio is small, overcompression can be prevented even when the operating conditions of the refrigerant circuit are at a low compression ratio that deviates from the design point for normal operation of the scroll compressor. It becomes possible to prevent this. In addition, if the suction volume of only one of the first compression chamber (25a) or the second compression chamber (25b) is changed, the pressure difference between the gas in the first compression chamber (25a) and the second compression chamber (25b) during compression will change. This makes it possible to reduce the effects of vibrations caused by unbalanced gas loads and fluctuations in the rotational torque of the vortex. In addition, capacity control can be performed to reduce the suction volume by changing the suction closed position during operation.

[0060] According to the tenth invention, since the suction volume adjustment mechanism (30) is provided only at one location within the range of one turn on the outer circumferential side of the spiral, the first compression chamber (25a) and the second compression chamber Regarding at least one of (25b), the inhalation volume can be adjusted in two stages. In addition, the structure can be simplified compared to providing the suction volume adjustment mechanism (30) at multiple locations.

[0061] According to the eleventh invention, in the scroll compressor having a symmetrical spiral structure, since the suction volume adjustment mechanism (30) is provided at a symmetrical position with respect to the center of the spiral, each compression chamber (25a , 25b), the fixed compression ratio can be reduced by reducing the suction volume. Therefore, when the operating condition of the refrigerant circuit is a low compression ratio that deviates from the design point of the normal operation of the force scroll compressor, the internal pressure of the compression chambers (25a, 25b) will be lower than that of the operating condition. This prevents the pressure from becoming too high compared to the high pressure in the refrigerant circuit. In addition, capacity control can be performed to reduce the suction volume by changing the suction closed position during operation.

[0062] According to the twelfth invention, the movable scroll (22) rotates eccentrically relative to the fixed scroll (21), and the operating capacity is configured to be variable by controlling the rotational speed of the electric motor (45). In a scroll compressor, it is possible to perform control to reduce the fixed compression ratio of the scroll compressor, so that the operating conditions of the refrigerant circuit become lower than the design point of the normal operation of the scroll compressor. This prevents the internal pressure of the compression chambers (25a, 25b) from becoming too high than the high pressure of the refrigerant circuit under the operating conditions. In addition, the suction volume can be adjusted regardless of the rotation speed of the electric motor (45), and the suction volume can be controlled to be reduced by changing the suction closing position during operation.

[0063] According to the thirteenth invention, when the suction volume adjustment mechanism (30) makes the suction volume of the compression mechanism (20) smaller than that during normal operation, the rotational speed of the electric motor (45) is increased. Since the control is performed, the electric motor (45) can be operated with high efficiency, and the capacity can be maintained at the same level as before capacity control. ability can be maintained. In this way, by combining the rotational speed control of the electric motor (45) and the mechanical capacity control of the suction volume adjustment mechanism (30), in addition to reducing overcompression, the efficiency of the electric motor (45) is improved and the compressor is improved. Improved efficiency can be achieved. Further, by controlling the rotational speed of the electric motor (45) to be faster, a decrease in operating capacity can be suppressed. In other words, while maintaining the operating capacity, the suction volume adjustment mechanism (30) can be used not for capacity adjustment but for efficiency improvement. Furthermore, by controlling the rotational speed of the electric motor (45) to be faster when the suction volume of the compression mechanism (20) is made smaller than during normal operation, the leakage of refrigerant inside the spiral is reduced. It also has the effect of improving compression efficiency.

Brief description of the drawing

[FIG. 1] FIG. 1 is a longitudinal cross-sectional view of a scroll compressor according to a first embodiment.

[Figure 2] Figure 2 is a cross-sectional view taken along line II II in Figure 1, showing the cross-sectional structure of the compression mechanism.

[Figure 3] Figure 3 is a cross-sectional structural diagram of the opening/closing mechanism (suction volume adjustment mechanism).

[Figure 4] Figure 4 is a bottom view of the fixed scroll screw.

[FIG. 5] FIG. 5 is a sectional view showing a subassembly of the fixed scroll.

[Fig. 6] Fig. 6 is a sectional view of a compression coil panel that constitutes the opening/closing mechanism.

[Fig. 7] Fig. 7 is a front view of a piston that constitutes the opening/closing mechanism.

[FIG. 8] FIG. 8 is a cross-sectional view of a seal member attached to a piston.

[Fig. 9] Fig. 9 is a sectional view showing the opening/closing mechanism in a communicating state.

[Fig. 10] Fig. 10 is a sectional view showing the opening/closing mechanism in a blocked state.

FIG. 11 is a sectional view showing the first operating state of the compression mechanism.

FIG. 12 is a sectional view showing the second operating state of the compression mechanism.

[FIG. 13] FIG. 13 is a cross-sectional view showing a third operating state of the compression mechanism.

[Fig. 14] Fig. 14 is a sectional view showing a fourth operating state of the compression mechanism.

[Fig. 15] Fig. 15 is a sectional view showing a fifth operating state of the compression mechanism.

[FIG. 16] FIG. 16 is a sectional view showing a sixth operating state of the compression mechanism.

[Fig. 17] Fig. 17 is a cross-sectional view of a compression mechanism according to a modification of the first embodiment.

[Fig. 18] Fig. 18 is a cross-sectional structural diagram of the opening/closing mechanism according to the second embodiment.

[Fig. 19] Fig. 19 is a cross-sectional view showing the first operating state of the compression mechanism according to the third embodiment. [Figure 20] Figure 20 is a cross-sectional view showing a second operating state of the compression mechanism according to Embodiment 3.

1 scroll compressor

10 Casing

17 Low pressure space

20 Compression mechanism

21 Fixed scroll (1st scroll member)

21a Fixed side mirror plate

21b Fixed side wrap

22 Movable scroll (2nd scroll member)

22a Movable end plate

22b Movable side wrap

25a 1st compression chamber

25b 2nd compression chamber

30 Suction volume adjustment mechanism

31 Opening/closing mechanism

32 holes (communication path)

33 Piston (closing member)

34 Opening/closing drive mechanism

35 Compression coil panel (biasing member)

36 Switching valve (switching member)

37 groove (communication path)

45 Electric motor

BEST MODE FOR CARRYING OUT THE INVENTION

[0066] Hereinafter, embodiments of the present invention will be described in detail based on the drawings.

[0067] 《Embodiment 1 of the invention》 Embodiment 1 of the present invention will be described.

[0068] The scroll compressor of this embodiment is installed, for example, in a refrigerant circuit of an air conditioner that performs a vapor compression refrigeration cycle, and compresses low-pressure refrigerant sucked in from an evaporator and discharges it to a condenser. be.

[0069] As shown in FIG. 1, the scroll compressor (1) is configured as a so-called completely hermetic type. This scroll compressor (1) includes a casing (10) formed in the shape of a vertically elongated cylindrical closed container. The casing (10) includes a body (11) that is a vertically elongated cylindrical member, an upper body (12) fixed to the upper end of the body (11), and a lower body fixed to the lower end of the body (11). It consists of a body (13).

[0070] The casing (10) houses a compression mechanism (20) that compresses refrigerant and an electric motor (45) that drives the compression mechanism (20). This electric motor (45) is disposed below the compression mechanism (20) and is connected to the compression mechanism (20) via a drive shaft (40) that is a rotating shaft. This electric motor (45) uses a brushless DC motor whose rotational speed can be variably adjusted by inverter control.

[0071] A suction pipe (14) is attached to pass through the upper body (12), which is the top of the casing (10). This suction pipe (14) is connected at its terminal end (lower end in the figure) to the compression mechanism (20). A discharge pipe (15) is attached to the body (11) of the casing (10) so as to penetrate therethrough. The discharge pipe (15) has a terminal end (right end in the figure) opened between the compression mechanism (20) and the electric motor (45) in the casing (10).

[0072] The drive shaft (40) is arranged on the vertical center line of the casing (10). The drive shaft (40) includes a main shaft portion (41) and an eccentric portion (42), and constitutes a crankshaft. The eccentric portion (42) is formed to have a smaller diameter than the main shaft portion (41), and is formed on the upper end surface of the main shaft portion (41). The eccentric portion (42) is eccentric by a predetermined dimension with respect to the axis of the main shaft portion (41), and forms an eccentric pin.

[0073] A lower bearing member (48) is fixed within the body (11) of the casing (10) near its lower end. The lower bearing member (48) rotatably supports the lower end of the main shaft (41) of the drive shaft (40) via the sliding bearing (48a).

[0074] Although not shown, inside the drive shaft (40), there is an oil supply passage extending in the vertical direction. A road is formed. Furthermore, an oil supply pump (43) is provided at the lower end of the main shaft (41). Refrigerating machine oil is sucked up from the bottom of the casing (10) by this oil supply pump (43), and the refrigerating machine oil passes through the oil supply passage of the drive shaft (40) to the sliding parts of the compression mechanism (20) and the drive shaft. (40) is supplied to the bearing section.

[0075] The electric motor (45) is composed of a stator (46) and a rotor (47). stator

(46) is fixed to the body (11) of the casing (10). The rotor (47) is connected to the main shaft portion (41) of the drive shaft (40) and rotationally drives the drive shaft (40).

[0076] The compression mechanism (20) includes a fixed scroll (21) as a first scroll member, a movable scroll (22) as a second scroll member, and a fixed support for the fixed scroll (21). Equipped with a housing (23) that holds!/ヽru. As described later, the fixed scroll (21) and the movable scroll (22) are provided with spiral wraps (21b, 22b) on end plates (21a, 22a) that squeeze into each other. The compression mechanism (20) is configured such that the movable scroll (22) performs an eccentric rotational movement relative to the fixed scroll (21).

[0077] The housing (23) is composed of a flange portion (23a), a main body portion (23b), and a bearing portion (23c). These flange portion (23a), main body portion (23b), and bearing portion (23c) are formed continuously from top to bottom, and the main body portion (23b) is fitted into the body portion (11) of the casing (10). It's joined!/,ru. The flange portion (23a) is located at the upper end of the main body portion (23b) and projects radially outward from the main body portion (23b). The bearing portion (23c) is formed to have a smaller diameter than the main body portion (23b), and protrudes downward from the lower surface of the main body portion (23b). This bearing portion (23c) rotatably supports the main shaft portion (41) of the drive shaft (40) via a sliding bearing (23d).

[0078] The fixed scroll (21) includes a fixed end plate (21a), a fixed wrap (21b), and an edge (21c). The fixed side end plate (21a) is formed into a substantially disk shape. The fixed-side wrap (21b) is erected on the lower surface of the fixed-side end plate (21a), and is integrally formed with the fixed-side end plate (21a). This fixed side wrap (21b) is formed in the shape of a spiral wall with a constant height. The edge portion (21c) includes a wall-shaped portion that extends downward from the outer peripheral edge of the fixed end plate (21a), a lower end portion of the portion on the wall, and a lower end portion of the wall portion that protrudes outward in the radial direction. 23) and a flange-shaped part fixed to the upper surface of the flange part (23a).

[0079] The movable scroll (22) includes a movable end plate (22a), a movable wrap (22b), and a boss portion (2 2c). The movable end plate (22a) is formed into a substantially disk shape. The movable side wrap (22b) is erected on the upper surface of the movable end plate (22a) and is integrally formed with the movable end plate (22a). This movable side wrap (22b) is formed in the shape of a spiral wall with a constant height, and is configured to fit into the fixed side wrap (21b) of the fixed scroll (21). The boss portion (22c) extends downward from the lower surface of the movable end plate (22a) and is integrally formed with the movable end plate (22a).

[0080] The eccentric portion (42) of the drive shaft (40) is inserted into the boss portion (22c) via a sliding bearing (22d). Therefore, when the drive shaft (40) rotates, the movable scroll (22) revolves around the axis of the main shaft (41). The orbital radius of the movable scroll (22) is the same as the eccentricity of the eccentric portion (42), that is, the dimension from the axis of the main shaft portion (41) to the axis of the eccentric portion (42).

[0081] The movable end plate (22a) is located in the first recess (23e) provided on the upper end surface of the housing (23), and the boss portion (22c) is located in the main body (23b) of the housing (23). The second recess (23f) is located within the second recess (23f). Note that an Oldham joint (24) that prevents rotation of the movable scroll (22) is disposed between the movable end plate (22a) and the housing (23). The first recess (23e) is formed in a size that allows eccentric rotational movement of the movable end plate (22a), and the second recess (23f) is formed in a size that allows eccentric rotational movement of the boss part (22c). is formed in

[0082] FIG. 2 is a sectional view taken along line II II in FIG. 1, and shows the cross-sectional shape of the compression mechanism (20). As shown in Fig. 2, the scroll compressor (1) of this embodiment employs a so-called asymmetric spiral structure, and the fixed side wrap (21b) and the movable side wrap (22b) have a different number of turns (the number of spirals). length) are different. Specifically, the fixed side wrap (21b) has a spiral number longer than that of the movable side wrap (22b) by approximately 1Z2 turns. However, no outer peripheral surface is formed on the outermost turn of the fixed side wrap (21 b), and within that range the fixed side wrap (2 lb) is attached to the edge (21c) of the fixed scroll (21). linked. The end of the fixed wrap (21b) ends in such a way that the outer end and the inner end, which is located one turn longer than the outer end, face each other. The outer circumferential end (end of winding) of the movable wrap (22b) is located near the movable wrap (22b). [0083] The compression mechanism (20) has a plurality of compartments formed by interlocking a fixed side wrap (21b) and a movable side wrap (22b) between a fixed side end plate (21a) and a movable side end plate (22a). Equipped with compression chambers (25a, 25b). These multiple compression chambers (25a, 25b) are comprised of a first compression chamber (25a) formed between the inner circumferential surface of the fixed side wrap (21b) and the outer circumferential surface of the movable side wrap (22b); It consists of a second compression chamber (25b) constructed between the outer peripheral surface of the wrap (21b) and the inner peripheral surface of the movable wrap (22b), and the first compression chamber (25a) and the second compression chamber. A plurality of each of (25b) is formed. In this example, the number of turns on the fixed side wrap (21b) is greater than the number of turns on the movable side wrap (22b)! , so the maximum volume of the first compression chamber (25a) is larger than the maximum volume of the second compression chamber (25b)!/.

[0084] As shown in FIG. 1, a suction port (29) to which the terminal end of the suction pipe (14) is connected is formed on the outer peripheral side of the fixed scroll (21). Although not shown, this suction port (29) is equipped with a check valve that only allows refrigerant to be sucked into the compression chambers (25a, 25b) and prohibits the flow of refrigerant in the opposite direction. . This suction port (29) intermittently communicates with each of the first compression chamber (25a) and the second compression chamber (25b) as the movable scroll (22) revolves.

[0085] A recess (21g) is formed at the upper end of the fixed end plate (21a), and a discharge cover (27) is provided on the upper surface of the fixed end plate (21a) to cover the recess (21g). installed. A space in which this concave portion (21g) is covered with a discharge cover (27) is configured as a discharge chamber (28). A discharge port (26) that opens into the discharge chamber (28) is formed in the center of the fixed end plate (21a). The discharge port (26) intermittently communicates with each of the first compression chamber (25a) and the second compression chamber (25b) as the movable scroll (22) revolves. The gas refrigerant discharged into the discharge chamber (28) passes through a gas passage (not shown) formed in the fixed scroll (21) and the housing (23) to the space (high pressure space) (16) below the housing (23). The force of the discharge pipe (15) is also discharged to the outside of the casing (10). Inside the casing (10), the space below the housing (23) is a high-pressure space (16), while the space above the housing (the space around the compression mechanism (20)) is a low-pressure space (17). ) is configured to be

[0086] In this embodiment, a suction volume adjustment device is provided that can adjust the suction volume by adjusting the suction closed position of the compression chambers (25a, 25b) during the suction stroke of the compression mechanism (20). A structure (30) is provided. This suction volume adjustment mechanism (30) adjusts the suction closed position (the position where the suction stroke is completed and the compression stroke begins) in both the first compression chamber (25a) and the second compression chamber (25b). As shown in Figure 2, it is provided at only one location within one turn on the outer circumference of the spiral. The suction volume adjustment mechanism (30) includes an opening/closing mechanism (31) that can switch the first compression chamber (25a) and the second compression chamber (25b) between a communication state and a cutoff state.

[0087] Specifically, the opening/closing mechanism (31) has a first compression chamber (25a) and a second compression chamber (25b) in communication with each other, as shown in FIG. 3 showing its cross-sectional structure. A communication passage (32) that sometimes allows refrigerant to flow between the compression chambers (25a, 25b), an open position where the communication passage (32) is opened, and a closed position where the communication passage (32) is closed. It is equipped with a piston (closing member) (33) that is movable between the piston (33) and an opening/closing drive mechanism (34) that changes the position of the piston (33) between an open position and a closed position.

[0088] The communication path (32) is constituted by a stepped hole (32) formed in the fixed end plate (21a). As shown in Figure 4, which is a bottom view of the fixed scroll (21), this stepped hole (32) is formed within one turn on the outer circumference of the spiral, at a position diagonally below and to the left of the center of the spiral in the figure. There is. As shown in Figure 5, which is a cross-sectional view of the subassembly of the fixed scroll (21), this stepped hole (32) has a large diameter part (32a) opened on the upper surface of the fixed end plate (21a), and and a small diameter portion (32b) having a smaller diameter than the above-mentioned communication path (32). This stepped hole (32) is formed such that the small diameter portion (32b) is located between the teeth of the fixed side wrap (21b). This small diameter portion (32b) is a circular hole with a diameter larger than the thickness of the teeth of the movable side wrap (22b).

[0089] Inside the stepped hole (32) are the compression coil panel (biasing member) (35) shown in Figure 6, and the piston (33) that opens and closes the small diameter part (32b) at its tip (Fig. 7) is loaded. As shown in Figure 7, this piston (33) has a plug part (33a) sized to fit with the small diameter part (32b), and a compression coil panel (35) with a larger diameter than this plug part (33a). The panel receiving part (33b) to which the panel is attached and the seal mounting part (33c), which has a larger diameter than this panel receiving part (33b), are integrally formed so that the force on the tip (lower end in the figure) is also continuous. It is something that A seal mounting groove (33d) is formed along the circumferential direction in the seal mounting portion (33c), and this seal mounting groove (33d) is formed along the circumferential direction. A ring-shaped seal member (33e) shown in FIG. 8 is attached to the groove (33d).

[0090] As shown in Figure 5, the opening/closing drive mechanism (34) applies low pressure to the compression coil panel (35) that urges the piston (33) toward the open position and to the piston (33). It is comprised of a switching valve (switching member) (36) that switches between the state and the state where high pressure is applied to the piston (33) against the biasing force of the compression coil panel (35). When low pressure is applied to the rear end surface (upper end surface) of the piston (33) by the switching valve (36), the compression coil panel (35) pushes up the piston (33) more than the force trying to push down the piston (33). When the force prevails, the communication passage (32) opens as shown in Figure 9, and the first compression chamber (25a) and the second compression chamber (25b) become in communication (see Figure 3). On the other hand, when high pressure is applied to the rear end surface of the piston (33) by the switching valve (36), the force pushing down the piston (33) tries to push the piston (33) up by the compression coil panel (35). As shown in FIG. 10, the communication passage (32) is closed, and the first compression chamber (25a) and the second compression chamber (25b) are cut off.

[0091] Details of the operation of the suction volume adjustment mechanism (30) (opening/closing mechanism (31)) will be described later, but when operating with the piston (33) in the closed position, the first compression chamber (25a) and Since the second compression chamber (25b) is cut off, the refrigerant is compressed with the designed suction volume, resulting in normal operation. On the other hand, when operating with the piston (33) in the open position, the first compression chamber (25a) and the second compression chamber (25b) are in communication, resulting in less suction than the design value. This is an adjustment operation that compresses the refrigerant by volume. When performing this adjustment operation, in this embodiment, the rotational speed of the electric motor (45) is made faster than during normal operation.

[0092] Driving behavior

Next, the operation of the scroll compressor (1) described above will be explained.

[0093] First, when the electric motor (45) is driven, the drive shaft (40) rotates, and the movable scroll (22) (22) performs a revolution movement relative to the fixed scroll (21). At this time, the fixed scroll (21) is prevented from rotating by the Oldham joint (24).

[0094] With the orbital movement of the movable scroll (22), the volume of the compression chambers (25a, 25b) repeatedly increases and decreases periodically. In the compression chambers (25a, 25b), when the volume of the portion communicating with the suction port (29) increases, the refrigerant in the refrigerant circuit passes from the suction pipe (14) through the suction port (29) and enters the compression chamber (25a). , 25b), and the volume of the part where the suction side is completely closed decreases. After the refrigerant is compressed, it is discharged from the discharge port (26) into the discharge chamber (28). The refrigerant in the discharge chamber (28) flows into the high pressure space (16) below the housing (23) through a gas passage (not shown), and is supplied to the condenser of the refrigerant circuit through the discharge pipe (15).

[0095] (Operation of compression mechanism during normal operation)

Here, the refrigerant suction operation and refrigerant compression operation of the compression mechanism (20) when the suction volume adjustment mechanism (30) is activated (during normal operation) will be explained with reference to FIGS. 11 to 16. do . During this normal operation, the piston (33) of the opening/closing mechanism (31) is in the closed position and closes the communication passage (32), and the first compression chamber (25a) and the second compression chamber (25b) are closed. It is in a blocked state. 11 to 16 are cross-sectional views showing the operating states of the compression mechanism (20) in six stages, in which the movable scroll (22) revolves clockwise in the figure at predetermined angular intervals. It shows the state of being.

[0096] First, in the first operating state shown in Fig. 11, the winding end of the movable wrap (22b) is located between the teeth of the fixed wrap (21b), and the outermost With both the first compression chamber (25a-0) and the second compression chamber (25b-0) open to the low pressure side, both compression chambers (25a-0, 25b-0) are connected to the suction port (29 ). Regarding the first compression chamber (25a), the outer peripheral surface of the movable wrap (22b) and the inner peripheral surface of the fixed wrap (21b) substantially contact each other at point P1 on the center line Y in the figure. (“Contact” here refers to a state in which there is a gap on the order of microns, but an oil film is formed so that refrigerant leakage is not a problem), and the contact point (seal point) is located inside P1. The peripheral side (starting side of the spiral) (25a-l) has already entered the compression stroke.

[0097] From here, the movable scroll (22) revolves clockwise in the figure, and when it enters the second operating state shown in Fig. 12, the inner circumferential surface of the winding end of the movable side wrap (22b) touches the fixed side wrap. (21b), and its contact position (seal point) P2 becomes the suction closing position of the second compression chamber (25b-l). At this time, the first compression chamber (25a-0) at the outermost periphery is in the middle of the suction stroke where the volume expands, and the seal point at the winding end side has not yet been formed.

[0098] When the movable scroll (22) revolves from there and enters the third operating state shown in Figure 13, the volume in the second compression chamber (25b-1) decreases and the refrigerant compression stroke begins, causing the outermost In the first compression chamber (25a -0), the volume is further expanded and the refrigerant suction stroke progresses. In the fourth operating state of Figure 14 , the compression stroke in the second compression chamber (25b-1) and the suction stroke in the outermost first compression chamber (25a-0) are further advanced. Regarding the second compression chamber (25b), a new second compression chamber (25b-0) is formed on the end side of the spiral compared to the second compression chamber (25b-l), which is already in the middle of compression. The inhalation stroke begins at .

[0099] When the fifth operating state shown in Fig. 15 is reached, the suction stroke force S in the second compression chamber (25b-0) at the outermost periphery continues, while the outer circumferential surface of the winding end of the movable wrap (22b) contacts the inner peripheral surface of the fixed side wrap (21b), and the contact position (seal point) P1 becomes the suction closed position of the first compression chamber (25a-l). When the sixth operating state shown in Fig. 16 is reached, the compression stroke in the first compression chamber (25a-l) formed in the state shown in Fig. 15 progresses, and the second compression chamber (25b-0) at the outermost periphery progresses. The inhalation process progresses. Then, returning to the first operating state shown in Fig. 11, a new first compression chamber (25a-0) is created on the outer circumferential side (end side of the spiral) of the first compression chamber (25a-l), which is in the middle of compression. It is formed.

[0100] After that, the operations shown in Figures 11 to 16 are repeated, and the first compression chamber (25a-l) and second compression chamber (25b-l), which are in the middle of compression, reduce their volume while filling the inner periphery of the spiral. They move to the side and change to the first compression chamber (25a-2) and the second compression chamber (25b-2), respectively, just before discharge. The first compression chamber (25a-2) and the second compression chamber (25b-2) communicate with the discharge port (26) when they move to the innermost side and the volume becomes the minimum, and the refrigerant flows through the first compression chamber (25a-2) and the second compression chamber (25b-2). Compression mechanism (20) Force Discharged.

[0101] (Operation of compression mechanism during adjustment operation)

Next, regarding the refrigerant suction operation and refrigerant compression operation of the compression mechanism (20) when the suction volume adjustment mechanism (30) is in operation (during adjustment operation), refer to FIGS. 11 to 16 as well. I will explain. During this adjustment operation, the piston (3 3) of the opening/closing mechanism (31), which is the suction volume adjustment mechanism (30), is in the open position, opening the small diameter portion (32b), which is the communication passage (32). The first compression chamber (25a) and the second compression chamber (25b) are in communication state (state where communication is possible)!/,.

[0102] First, in the first operating state shown in Figure 11, both the outermost first compression chamber (25a-0) and second compression chamber (25b_0) are open to the low pressure side, and The point that the compression chambers (25a_0, 25b_0) communicate with the suction port (29) is the same as during normal operation. On the other hand, during normal operation, the outer circumferential surface of the movable side wrap (22b) and the inner circumferential surface of the fixed side wrap (21b) come into contact at point P1 on the center line Y in the figure, and the inner circumferential surface of this point (seal point) is Peripheral side (beginning of spiral) While the first compression chamber (25a_l) on the side) was already completely closed, this first compression chamber (25a-1) was It communicates with the second compression chamber (25b-0). Therefore, this first compression chamber (25a-l) is still in a state before the suction closed position, and is in the middle of the suction stroke like the second compression chamber (25b).

[0103] When the second operating state shown in Figure 12 is reached, the contact point PI between the inner circumferential surface of the fixed side wrap (21b) and the outer circumferential surface of the movable side wrap (22b) connects to the communication path (32) of the opening/closing mechanism (31). ) is displaced to the position immediately after passing through. Therefore, the contact position (seal point) P1 at this time becomes the suction closed position of the first compression chamber (25a-1). On the other hand, in this state, the outermost second compression chamber (25b-l), which was closed during normal operation, is formed on the spiral outer circumferential side of the first compression chamber (25a-l), which has entered the compression stroke. It communicates with the outermost first compression chamber (25a-0) through the communication passage (32). Since the first compression chamber (25a-0) at the outermost periphery is in the middle of the suction stroke, the second compression chamber (25b) is not yet fully closed for suction.

[0104] This state is the same in the third operating state shown in FIG. 13 and the fourth operating state shown in FIG. No seal point is formed at the end of the winding. At this time, the outermost first compression chamber (25a-0) is also in the middle of the suction stroke. In addition, in the fourth operating state shown in FIG. 14, a new second compression chamber (25b-0) is beginning to be formed on the spiral outer peripheral side of the second compression chamber (25b-l).

[0105] When the fifth operating state shown in Fig. 15 is reached, the outer peripheral surface of the fixed side wrap (21b) and the movable side wrap

The contact point P2 with the inner peripheral surface of (22b) passes through the communication passage (32) of the opening/closing mechanism (31). Therefore, the contact point P2 at this time becomes the sealing point of the second compression chamber (25b-1), and the compression stroke in the second compression chamber (25b-l) is started. In this state, during normal operation, the outermost first compression chamber (25a-l) is closed, but during adjustment operation, the outermost first compression chamber (25a_l) is closed to the outermost second compression chamber. It is still in the middle of the suction stroke because it communicates with the low pressure side through the compression chamber (25b_0). This is the same in the sixth operating state in FIG. 16, and also in returning to the first operating state in FIG.

[0106] As described above, by keeping the communication passage (32) of the opening/closing mechanism (31) open, the suction volumes of both the first compression chamber (25 a) and the second compression chamber (25b) are maintained in normal operation. smaller than time. As a result, the compression ratio becomes smaller than during normal operation, assuming the suction pressure is the same as during normal operation. The discharge pressure will decrease.

[0107] When performing this adjustment operation, in this embodiment, the rotational speed of the electric motor (45) is made faster than during normal operation, so the capacity of the scroll compressor (1) is increased to the same level as during normal operation. can be kept equal to

[0108] Effects of Embodiment 1

As described above, this embodiment is equipped with a suction volume adjustment mechanism (30) that changes the suction volume by performing volume control within one turn on the outer circumference of the spiral, unlike the case where the volume is controlled during compression. By doing so, the compression ratio of the scroll compressor (1) can be reduced. Therefore, an adjustment operation can be performed in which the discharge pressure is lowered than during normal operation. Therefore, even when the operating conditions of the refrigerant circuit are at a low compression ratio that deviates from the design point during normal operation of the scroll compressor (1), the internal pressure of the compression chambers (25a, 25b) is lower than the operating condition. This prevents the pressure from rising too much compared to the high pressure in the refrigerant circuit under these conditions. Therefore, it is possible to prevent overcompression from occurring.

[0109] Furthermore, in this embodiment, even when high-speed operation is performed with a low differential pressure, overcompression can be prevented, and the rotational speed of the electric motor (45) does not become a constraint on preventing overcompression. And, unlike the compressor (1) of Patent Document 1, which can prevent overcompression only at low speeds, overcompression can be prevented even at high speeds, and in that case, the electric motor (45) can be operated with high efficiency. Since the compressor (1) can be operated, a decrease in efficiency of the compressor (1) can be prevented.

[0110] Furthermore, in this embodiment, by providing the suction volume adjustment mechanism (30), the first compression chamber

The suction volumes of both (25a) and the second compression chamber (25b) can be adjusted to be smaller than during normal operation. After adjusting the suction volume of the compression chambers (25a, 25b) using the suction volume adjustment mechanism (30), the electric motor ( By increasing the rotational speed of motor (45), it is possible to simultaneously improve the efficiency of motor (45) and reduce internal leakage from the vortex. That is, in this embodiment, the suction volume adjustment mechanism (30) can be used not for capacity adjustment but for efficiency improvement while maintaining the operating capacity. Note that when the suction volume adjustment mechanism (30) makes the suction volume of the compression mechanism (20) smaller than that during normal operation, it is not always necessary to control the rotation speed of the electric motor (45) to increase. The rotation speed of (45) may not be changed. . In this case, the variable range of capacity can be expanded to the constant capacity side.

[0111] Furthermore, in this embodiment, when the suction volume adjustment mechanism (30) is activated, the area on which the axial load due to the internal pressure of the compression chambers (25a, 25b) acts can be reduced, and the movable side Since the point of action of the gas load on the wrap (22b) can be moved to a position closer to the center of the eccentric portion (42) of the drive shaft (40), the overturning moment is reduced and overturning is less likely to occur. Become. Therefore, problems such as poor compression, reduced operating capacity, and reduced efficiency of the compressor (1) can be prevented.

[0112] Furthermore, in this embodiment, since the suction volume adjustment mechanism (30) is provided at only one location within the range of one turn on the outer circumferential side of the spiral, the suction volume can be adjusted in two stages. Furthermore, if the suction volume adjustment mechanism (30) is provided at only one location, the structure can be most simplified as opposed to providing it at multiple locations.

[0113] Furthermore, in the present embodiment, the suction volume adjustment mechanism (30) includes an opening/closing mechanism ( 31), the suction closed positions of the first compression chamber (25a) and the second compression chamber (25b) can be adjusted and the suction volume can be changed, which also reduces the complexity of the structure. can be prevented.

[0114] In particular, the opening/closing mechanism (31) has a small diameter portion (32b) of the stepped hole (32), which is a communication path that allows gas to flow when the opening/closing mechanism (31) is in communication, and a small diameter portion (32b) of the stepped hole (32). 32b), which is a closing member movable between an open position for opening and a closed position for closing, and an opening/closing drive mechanism (34) for changing the position of the piston (33) between the open position and the closed position. The structure is extremely simple because the communication passage (32) is formed by a stepped hole (32) formed in the end plate of the fixed scroll (21). The opening/closing drive mechanism (34) also includes a compression coil panel (35) that is a biasing member that biases the piston (33) toward the open position, and a state that applies low pressure to the piston (33). Reliable operation of the opening/closing mechanism (31) can be guaranteed simply by providing a configuration including a switching valve (36), which is a switching member that switches between the state of applying high pressure and the state of applying high pressure.

[0115] Modification of Embodiment 1

A modification of Embodiment 1 is shown in FIG. 17.

[0116] FIG. 17 is a cross-sectional view showing the structure of the compression mechanism (20). In this modification, the fixed scroll (21) and the movable scroll (22) have a symmetrical spiral structure with an equal number of spiral turns. has been completed. The suction volume adjustment mechanism (30) is provided at a position symmetrical to the center of the spiral. The structure of the suction volume adjustment mechanism (30) is the same as the examples shown in FIGS. 1 to 16.

[0117] In this modification, in the compression mechanism (20) with a symmetrical spiral structure, suction is performed in each of the first compression chamber (25a) and the second compression chamber (25b), which are symmetrical with respect to the spiral center. Closed position can be adjusted. Therefore, as in the examples shown in Figures 1 to 16, the fixed compression ratio can be lowered by reducing the suction volume of the compression chambers (25a, 25b), so the operating conditions of the refrigerant circuit are lower than those of the scroll compressor. When the operating condition is a low compression ratio that deviates from the design point for normal operation in (1), the internal pressure in the compression chambers (25a, 25b) is higher than the high pressure in the refrigerant circuit under that operating condition. You can prevent it from becoming too much. Therefore, overcompression can be prevented. Furthermore, while maintaining the operating capacity, the suction volume adjustment mechanism (30) can be used not for capacity adjustment but for efficiency improvement.

[0118] The other effects described in the examples of FIGS. 1 to 16 can also be achieved in this modification as similar effects.

[0119] 《Embodiment 2 of the invention》

Embodiment 2 of the present invention is an example in which the structure of the opening/closing mechanism (31) (suction volume adjustment mechanism (30)) is different from that of Embodiment 1. Specifically, the opening/closing mechanism (31) communicates the first compression chamber (25a) and the second compression chamber (25b) with the low pressure space (17) provided in the casing (10). and a cutoff state. The opening/closing mechanism (31) has the same configuration as Embodiment 1 except for the communication path (32). A portion of the communication passage (32) corresponding to the small diameter portion (32b) of Embodiment 1 communicates the first compression chamber (25a) and the second compression chamber (25b) with each other, and also communicates with the inside of the movable scroll (21). It is a through hole (32c) that penetrates radially outward to the outer periphery and communicates with the surrounding low pressure space (17). The communication passage (32) should be connected to the piping on the suction side of the compression mechanism (20), and if a suction space is provided, it should be connected to the suction space. It's okay ヽ.

[0120] Also in this embodiment, in the normal operating state when the opening/closing mechanism (31) is closed, the wraps (21b, 22b) that were separated at the winding end side of the spiral are substantially separated from each other, as in the first embodiment. The position where a seal point is formed by contacting the target becomes the suction closing position, and at that time, the A compression stroke is started in the first compression chamber (25a) and the second compression chamber (25b).

[0121] On the other hand, when the opening/closing mechanism (31) is opened, even if the first compression chamber (25a) and the second compression chamber (25b) are misaligned, the movable side wrap (22b) and the fixed side The compression chambers (25a, 25b) are not completely closed until the contact position of the wrap (21b) passes through the position of the opening/closing mechanism (31). This point is also the same as the first embodiment. In other words, until the above contact point passes the opening/closing mechanism (31), the first compression chamber (25a) and the second compression chamber (25b) are in communication with the low pressure space (17) in the casing (10). The position immediately after the contact position passes the opening/closing mechanism (31) is the suction closed position, and the compression chambers (25a, 25b) are formed to enter the compression stroke. Therefore, the size of the suction volume can be adjusted depending on the position where the opening/closing mechanism (31) is provided.

[0122] By adjusting the size of the suction volume in this way, as in Embodiment 1, the operating conditions of the refrigerant circuit can be adjusted to a low compression ratio that deviates from the design point during normal operation of the scroll compressor (1). Since the internal pressure of the compression chambers (25a, 25b) can be prevented from becoming too high than the high pressure of the refrigerant circuit when the operating conditions are as follows, overcompression can be prevented from occurring. It is also possible to use the suction volume adjustment mechanism (30) to improve efficiency rather than adjust capacity while maintaining the operating capacity.

[0123] Modification of Embodiment 2

In the second embodiment, the suction volume adjustment mechanism (30) (opening/closing mechanism (31)) communicates one of the first compression chamber (25a) and the second compression chamber (25b) with the low pressure space (17). It may be a device that can be switched between a state and a cutoff state. For example, only the first compression chamber (25a) may be switched between a communicating state and a blocking state with respect to the low pressure space (17).

[0124] In this regard, in an asymmetric spiral structure in which the fixed scroll (21) and the movable scroll (22) have different numbers of turns (wraps (21b, 22 b)), the first compression chamber (25a) and the The compression ratio of the two compression chambers (25b) is adjusted at the center of the vortex to match the discharge pressure, so during the compression of the vortex, the pressure changes between the first compression chamber (25a) and the second compression chamber (25b). There is a difference, and an imbalance occurs in the gas load acting on the vortex. Specifically, since the suction volume of the first compression chamber (25a) is large and the suction volume of the second compression chamber (25b) is small, the pressure in the first compression chamber (25a) is higher during compression. Therefore, the rotational torque of the vortex (the vortex due to the gas load) Vibration is also likely to occur due to fluctuations in the torque (acting in the direction that causes the roll to rotate). On the other hand, by reducing only the suction volume of the first compression chamber (25a), the pressure difference between the gases between the first compression chamber (25a) and the second compression chamber (25b) can be reduced. Therefore, it is possible to reduce the effects of vibrations caused by unbalanced gas loads and fluctuations in the rotational torque of the vortex.

[0125] Furthermore, since the gas load balance is a relative relationship between the first compression chamber (25a) and the second compression chamber (25b), the suction volume of the second compression chamber (25b) changes in the direction of increasing it. You may let them. In that case, the configuration is such that the suction volume of both the first compression chamber (25a) and the second compression chamber (25b) can be adjusted, and the position for adjusting the suction volume of the first compression chamber (25a) is adjusted. Shift the suction volume adjustment position of compression chamber 2 (25b) to the outer circumference of the spiral (toward the end of the spiral).

[0126] 《Embodiment 3 of the invention》

Embodiment 3 of the present invention is an example in which the structure of the opening/closing mechanism (31) (suction volume adjustment mechanism (30)) is different from that of Embodiment 1. Specifically, the opening/closing mechanism (31) has a first compression chamber (25a) and a second compression chamber ( Both of 25b) are constituted by an opening/closing mechanism (31) that can switch the inner circumferential side and the outer circumferential side of the contact position between a communication state and a cutoff state.

[0127] This opening/closing mechanism (31) differs in the shape of the communication path from that of Embodiment 1, and is formed by grooves (37a, 37b) curved along the wraps (21b, 22b). Further, the communication passages (37a, 37b) are divided into a passage (37a) for the first compression chamber (25a) and a passage (37b) for the second compression chamber (25b). A communication passage (37a) for the first compression chamber (25a) is formed along the inner circumferential surface of the stationary side wrap (21b), and a communication passage (37b) for the second compression chamber (25b) is formed on the stationary side. It is formed along the outer circumferential surface of the wrap (21b). Although the opening/closing structure of the communication passages (37a, 37b) is not shown, the structure is similar to that described in Embodiment 1, and the shape of the piston (33) is adapted to fit each communication passage (37a, 37b). All you have to do is adopt what is prescribed.

[0128] Also in this embodiment 3, in the normal operating state when the opening/closing mechanism (31) is closed, the wraps (21b, 22b) separated at the winding end side of the spiral are separated from each other as in each of the above embodiments. The position where the seal points are formed by substantially contacting each other becomes the suction closed position, and a first compression chamber (25a) and a second compression chamber (25b) are formed.

[0129] On the other hand, when the opening/closing mechanism (31) is opened, the first compression chamber (25a) and the second compression chamber (25b) In either case, the compression chambers (25a, 25b) are not completely closed until the contact point of both wraps (21b, 22b) passes through the location of the opening/closing mechanism (31). In other words, until the above-mentioned contact point passes the opening/closing mechanism (31), one of the first compression chamber (25a) and the second compression chamber (25b) has a part on the inner circumference side of the above-mentioned contact point on the outer circumference side. The contact position immediately after the opening/closing mechanism (31) is the suction closed position, and the compression stroke begins. Compression chambers (25a, 25b) are formed. Specifically, in the state shown in Figure 19, the second compression chamber (25b-1), which is closed during normal operation, is not closed, and in the state shown in Figure 20, the first compression chamber (25a-l) is also closed. ) is not completely closed.

[0130] Therefore, in this third embodiment as well, the size of the suction volume can be adjusted depending on the position where the opening/closing mechanism (31) is provided. By adjusting the suction volume in this way, the operating conditions of the refrigerant circuit can be adjusted when the operating conditions of the refrigerant circuit are at a low compression ratio that is outside the design point of the normal operation of the scroll compressor (1). Furthermore, since the internal pressure of the compression chambers (25a, 25b) can be prevented from becoming too high than the high pressure of the refrigerant circuit, overcompression can be prevented from occurring.

[0131] Also in this third embodiment, if the communication passage (37a) is provided only on the first compression chamber (25a) side so that only the suction volume of the first compression chamber (25a) can be reduced, Since the pressure difference between the gas in the compression chamber (25a) and the second compression chamber (25b) can be reduced, it is possible to reduce the effects of vibrations caused by unbalanced gas loads and fluctuations in the rotational torque of the vortex. becomes. In addition, since the balance of gas load is the relative relationship between the first compression chamber (25a) and the second compression chamber (25b), both the first compression chamber (25a) and the second compression chamber (25b) The structure is such that the suction volume can be adjusted, and the suction volume adjustment position of the second compression chamber (25b) is set closer to the outer circumference of the spiral (the winding end side) than the suction volume adjustment position of the first compression chamber (25a). ).

[0132] 《Other embodiments》

The above embodiment may have the following configuration.

[0133] In each of the above embodiments, the suction volume adjustment mechanism (30) is installed in the first compression chamber (25a) and the second compression chamber (25b) by one turn on the outer circumferential side of the spiral (wrap (21b, 22b)). Although it is installed at only one location within the range, it may be installed at multiple locations. Then, the suction volume of the compression mechanism (20) will be increased in stages. Since it can be adjusted, it is possible to perform more detailed control according to the operating conditions of the refrigerant circuit.

[0134] The present invention is also applicable to a double-tooth type scroll compressor or a scroll compressor in which both scroll members rotate.

[0135] Further, the shape of the communication passage (32) described in Embodiment 1 is not limited to the circular stepped hole, but may be changed to any shape set as appropriate.

[0136] The above embodiments are essentially preferable examples, and are not intended to limit the scope of the present invention, its applications, or its uses.

Industrial applicability

[0137] As explained above, the present invention is useful for an overcompression prevention structure of a scroll compressor in which at least one of two scroll members that squeeze each other performs an eccentric rotational motion.

Claims

The scope of the claims

[1] A compression mechanism (20 ) in a casing (10),

A first compression chamber (25a) configured between the inner circumferential surface of the wrap (21b) of the first scroll member (21) and the outer circumferential surface of the wrap (22b) of the second scroll member (22); At least one side of the second compression chamber (25b) configured between the outer peripheral surface of the wrap (21b) of the scroll member (21) and the inner peripheral surface of the wrap (22b) of the second scroll member (22). Regarding the suction volume adjustment mechanism (30), the suction volume can be adjusted by adjusting the suction closed position of the compression chambers (25a, 25b) during the suction stroke of the compression mechanism (20). A scroll compressor characterized in that the scroll compressor is provided at at least one location within one winding range.

[2] In claim 1,

A scroll compressor characterized in that the suction volume adjustment mechanism (30) is a mechanism that can adjust the suction closed position in both the first compression chamber (25a) and the second compression chamber (25b).

[3] In claim 2,

The suction volume adjustment mechanism (30) is configured with an opening/closing mechanism (31) that can switch the first compression chamber (25a) and the second compression chamber (25b) between a communicating state and a blocking state. Scroll compressor.

[4] In claim 1,

The suction volume adjustment mechanism (30) brings at least one of the first compression chamber (25a) and the second compression chamber (25b) into communication with the low pressure space (17) provided in the casing (10). A scroll compressor comprising an opening/closing mechanism (31) that can be switched between a cutoff state and a cutoff state.

[5] In claim 1,

The suction volume adjustment mechanism (30) has a first compression chamber formed when the wrap (21b) of the first scroll member (21) and the wrap (22b) of the second scroll member (22) are substantially in contact with each other. At least one of (25a) and the second compression chamber (25b) shall be constructed with an opening/closing mechanism (31) that can switch the inner and outer circumferential sides of the contact position between a communicating state and a blocking state. Features Scroll compressor.

[6] In claim 3,

The opening/closing mechanism (31) includes communication passages (32, 37) that allow gas to flow when the opening/closing mechanism (31) is in communication, and an open position where the communication passages (32, 37) are opened and a closed position where the communication passages (32, 37) are closed. A scroll characterized in that it is equipped with a closing member (33) that is movable and an opening/closing drive mechanism (34) that changes the position of the closing member (33) between an open position and a closed position. compressor.

[7] In claim 6,

The opening/closing drive mechanism (34) includes a biasing member (35) that biases the closing member (33) toward the open position, and a biasing force of the biasing member (35) attached to the closing member (33). A scroll compressor comprising: a switching member (36) for switching between applying high pressure to the closing member (33) and applying low pressure to the closing member (33).

[8] In claim 6,

The communication path (32, 37) is constituted by a hole (32) or groove (37) formed in the end plate (21a, 22a) of the first scroll member (21) or the second scroll member (22). A scroll compressor featuring:

[9] In claim 1,

A scroll compressor characterized in that the first scroll member (21) and the second scroll member (22) have an asymmetric spiral structure in which the number of spiral turns is different.

[10] In claim 9,

A scroll compressor characterized in that a suction volume adjustment mechanism (30) is provided at only one location within one turn on the outer circumferential side of a spiral.

[11] In claim 2,

The first scroll member (21) and the second scroll member (22) have a symmetrical spiral structure with an equal number of spiral turns,

A scroll compressor characterized in that the suction volume adjustment mechanism (30) is provided at a symmetrical position with respect to the center of the spiral.

[12] In claim 1,

The compression mechanism (20) is a fixed member, which is a first scroll member (21) held in the casing (10). It comprises a scroll (21), and a movable scroll (22) that is a second scroll member (22) that rotates eccentrically relative to the fixed scroll (21),

A scroll compressor characterized in that a casing (10) houses an electric motor (45) which is a driving source for a movable scroll (22) and whose rotational speed can be variably adjusted.

In claim 12,

The electric motor (45) is configured to make the rotational speed faster than during normal operation in an operating state in which the suction volume adjustment mechanism (30) makes the suction volume of the compression mechanism (20) smaller than during normal operation. A scroll compressor characterized by: