JP2014070588A - Scroll compressor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a scroll compressor which enables the cost thereof to be further reduced and besides, can reduce pressure loss of a discharged refrigerant and suppress generation of noise.SOLUTION: The scroll compressor includes: a compressing mechanism 15 in which a discharge port 41 for discharging a compressed refrigerant is formed; a discharged refrigerant passage in which the refrigerant discharged from the discharge port 41 flows; a valve element 71 positioned in the discharged refrigerant passage 47, and switching an opening state to open the discharge port 41 of the compressing mechanism 15 and a closing state to close the discharge port 41 of the compressing mechanism 15; and a back pressure chamber 72 formed at a side opposite to the discharge port 41 while the valve element 71 is interposed between them. In the discharged refrigerant passage 47, a passage reduced portion where a cross-sectional area orthogonal to the flowing direction of the refrigerant is reduced is formed on the way of the discharged refrigerant passage. Further the discharged refrigerant passage 47 is connected with a back pressure chamber communication passage 81 for communicating between the neighborhood of the passage reduced portion 49 and the back pressure chamber 72.

Description

  The present invention relates to a scroll compressor.

  Conventionally, as a scroll compressor, as disclosed in Patent Document 1 (Japanese Patent Laid-Open No. 4-241702) and Patent Document 2 (Japanese Patent Laid-Open No. 2004-353565), compression is performed from a discharge space through which discharged refrigerant flows when operation is stopped. In order to prevent the refrigerant from flowing back into the chamber, a device having a discharge check valve (discharge valve) has been proposed. In these compressors, a plate-like discharge check valve is provided so that the discharge port can be opened and closed.

  In the compressors disclosed in Patent Documents 1 and 2, the discharge check valve is basically in an open state in which the discharge port is opened with the pressure of the discharged refrigerant during the operation of the compressor. The discharge port is closed. In this compressor, the discharge check valve is preferably in a full lift state in order to ensure the flow path of the discharged refrigerant during operation of the compressor, and when stopped, the discharge port is completely closed and the discharged refrigerant is discharged. Is preferably prevented from flowing back.

  However, the discharge check valve during operation fluctuates up and down during one cycle, and its behavior is greatly influenced by the operating conditions, the diameter of the discharge port, and the weight of the discharge check valve. The condition where the operating condition is smaller than the compressor's set inherent compression ratio, that is, the condition where the overcompression amount becomes large (low compression ratio side), the discharge check valve is more likely to float from the valve seat, and conversely, the amount of undercompression The larger the condition is (the higher compression ratio side), the longer the sitting time becomes, and the more difficult it becomes to fly. And as the diameter of the discharge port increases, the influence of the pressure action on the discharge check valve increases, so that the amount of vertical fluctuation of the discharge check valve increases. As the weight of the discharge check valve increases, the amount of vertical fluctuation of the discharge check valve decreases.

  Therefore, in order to increase the compressor efficiency, it is preferable to make the discharge check valve easier to float by reducing the weight of the discharge check valve or increasing the diameter of the discharge port, When looking only at the compressor efficiency, the amount of vertical fluctuation of the discharge check valve increases, and the discharge check valve collides with the valve seat surface or the opposite surface between the valve seat surface and the discharge check valve. Since the speed to perform the chattering increases, it is recognized as an abnormal sound when chattering. Furthermore, in this case, since the discharge check valve is likely to be in a full lift state, due to the viscosity of the lubricating oil mixed in the discharged refrigerant, the discharge check valve is placed on the opposite surface between the valve seat surface and the discharge check valve. The phenomenon of adhesion is likely to occur. For this reason, when the compressor is stopped, there is a concern that it takes some time to reach the closed state, that is, the compressor reverse phenomenon occurs due to the reverse flow of the discharged refrigerant at the time of stop.

  Therefore, in the compressor disclosed in Patent Document 2, a back pressure chamber formed on the back side of the valve body, a spring member disposed in the back pressure chamber, and a plurality (first to first) connected to the back pressure chamber. 3) a passage portion and a cylinder chamber, and a switching mechanism (piston and spring member) provided in the communication passage for switching the contact point of the back pressure chamber. In this compressor, the first passage portion communicating with the back pressure chamber by the switching mechanism communicates with either the second passage portion communicating with the crank chamber or the third passage portion communicating with the Oldham chamber. . In this compressor, during operation, the piston moves by receiving the oil film pressure generated in the bearing portion of the drive shaft, and the first passage portion communicates with the third passage portion. As a result, the back pressure chamber becomes a low pressure space, and the valve body is adsorbed by the back pressure chamber and kept in an open state, so that the generation of abnormal noise due to chattering is suppressed. On the other hand, since the oil film pressure disappears as soon as it stops, the piston moves by the biasing force of the spring, and the first passage portion communicates with the second passage portion. Accordingly, the back pressure chamber becomes a high pressure space, and there is almost no differential pressure between the pressures acting on the upper surface and the lower surface of the valve body, and the valve body moves downward due to gravity to close the discharge port.

  However, in this compressor, there is a concern that the increase in the number of parts and the formation of passages and the like will be complicated and costly.

  Therefore, an object of the present invention is to provide a scroll compressor that can reduce the pressure loss of discharged refrigerant and suppress the generation of abnormal noise while further reducing the cost.

  A scroll compressor according to a first aspect of the present invention includes a compression mechanism, a discharged refrigerant path, a valve body, and a back pressure chamber. The compression mechanism is formed with a discharge port for discharging the compressed refrigerant. The discharge refrigerant path is a path through which the refrigerant discharged from the discharge port flows. The valve body is located in the discharge refrigerant path and switches between an open state in which the discharge port of the compression mechanism is opened and a closed state in which the discharge port of the compression mechanism is closed. The back pressure chamber is formed on the opposite side of the discharge port with the valve body interposed therebetween. In the middle of the discharge refrigerant path, there is formed a path reduction portion in which the cross-sectional area perpendicular to the refrigerant flow direction is reduced. The discharge refrigerant path is connected to a back pressure chamber communication path that connects the vicinity of the path reduction portion and the back pressure chamber.

  In the present invention, during the operation of the scroll compressor, it is possible to produce an ejector effect in which the refrigerant pressure is reduced and the refrigerant in the back pressure chamber communication path is drawn into the discharge refrigerant path in the path reduction section. As a result, the refrigerant pressure in the back pressure chamber communicating with the back pressure chamber communication path can be reduced, and the valve body located in the discharge refrigerant path can be easily attracted to the back pressure chamber side. That is, for example, when the valve body moves in the vertical direction, the valve body can be in a full lift state (fully open state) in the discharge refrigerant path during operation of the scroll compressor. Thereby, the pressure loss of the refrigerant discharged from the discharge port can be reduced. On the other hand, when stopping, in addition to the gravity acting on the valve body, the refrigerant in the discharge refrigerant path and the back pressure chamber communication path flows back and forth in the back pressure chamber communication path to some extent. It can act as a force that moves the body to the discharge port side. As described above, in the present invention, by causing the ejector effect, the valve body can be prevented from being positioned at a halfway position in the discharge refrigerant path, so that chattering can be suppressed and the generation of abnormal noise can be suppressed. Moreover, since such an effect can be produced only by providing the path reducing portion and the back pressure chamber communication passage communicating with the back pressure chamber, the cost can be suppressed.

  A scroll compressor according to a second aspect of the present invention is the scroll compressor according to the first aspect of the present invention, and further includes a lid member and a housing. The compression mechanism includes a movable scroll and a fixed scroll that engages with the movable scroll and forms a compression chamber that compresses the refrigerant together with the movable scroll. The fixed scroll has a recessed space on the upper surface. The lid member is attached to the upper surface of the fixed scroll so as to cover the recessed space of the fixed scroll from above. The housing mounts the compression mechanism. The housing has a through space penetrating in the vertical direction. The discharge refrigerant path is formed by a recessed space, a through space, and an intermediate space formed in the fixed scroll so as to communicate the recessed space and the through space. The discharge port is formed in the fixed scroll so as to open into the recessed space. The back pressure chamber is recessed in the lower surface of the lid member so as to communicate with the recessed space. The back pressure chamber communication path includes a first back pressure chamber communication path and a second back pressure chamber communication path. The first back pressure chamber communication passage is formed in the lid member and communicates with the back pressure chamber. The second back pressure chamber communication path is formed in the fixed scroll and connects the vicinity of the path contracting portion in the discharge refrigerant path and the first back pressure chamber communication path. When the valve body is fully open in the recessed space, the upper surface of the valve body contacts the lower surface of the lid member to close the back pressure chamber. On the other hand, when the valve body is in the closed state, the lower surface thereof contacts the fixed scroll to open the back pressure chamber. The path reduction part is formed in the intermediate part.

  In the present invention, the refrigerant in the back pressure chamber and the back pressure chamber communicating with the back pressure chamber are caused to flow into the discharge refrigerant path by the path reducing portion in the discharge refrigerant path, thereby reducing the refrigerant pressure in the back pressure chamber. A difference can be provided in the refrigerant pressure in the vicinity of the discharge port. Thus, in the present invention, since the refrigerant pressure in the back pressure chamber can be kept low, the valve body can be maintained in a fully open state in contact with the lower surface of the lid member during operation of the scroll compressor. Therefore, since the flow path of the refrigerant discharged from the discharge port can be sufficiently secured, the pressure loss of the refrigerant can be reduced. Furthermore, since chattering can be suppressed, the occurrence of abnormal noise can also be suppressed.

  The scroll compressor which concerns on the 3rd viewpoint of this invention is a scroll compressor which concerns on the 1st viewpoint of this invention, Comprising: A 1st attachment member, a 2nd attachment member, a covering member, a discharge pipe, and a back pressure A chamber communication path forming member. The compression mechanism includes a movable scroll and a fixed scroll that forms a compression chamber that meshes with the movable scroll and compresses the refrigerant together with the movable scroll. The discharge port is formed on the upper surface of the fixed scroll. The first attachment member is formed with a vertical penetration space that penetrates in the vertical direction and communicates with the discharge port, and is attached to the upper surface of the fixed scroll. The second attachment member is attached to the upper surface of the first attachment member, and forms a gap space between the second attachment member and the first attachment member. The cover member surrounds the first mounting member and the second mounting member from above, and the inner surface thereof is in close contact with the first mounting member. The discharge pipe discharges the refrigerant discharged from the discharge port to the outside and penetrates the covering member. The back pressure chamber communication path forming member forms a back pressure chamber communication path. The discharge refrigerant path is formed by a vertically penetrating space, a gap space, a discharge refrigerant space between the first mounting member, the second mounting member, and the cover member, and an internal space of the discharge pipe. The back pressure chamber is formed in the second mounting member so as to communicate with the gap space. When the valve body is fully open in the gap space, the upper surface of the valve body comes into contact with the inner surface of the second mounting member to close the back pressure chamber, while opening the upper and lower through space together with the discharge port. On the other hand, when the valve body is in the closed state, the lower surface thereof contacts the upper surface of the first mounting member to open the back pressure chamber, while closing the vertical through space together with the discharge port. The path reduction part is formed in the discharge pipe. The back pressure chamber communication path forming member is located in the discharge refrigerant space. In addition, the path reducing portion has one end connected to the second mounting member and opened to the back pressure chamber, and the other end connected to the discharge pipe and opened near the path reducing portion.

  In the present invention, the refrigerant in the back pressure chamber and the back pressure chamber communicating with the back pressure chamber are caused to flow into the discharge refrigerant path by the path reducing portion in the discharge refrigerant path, thereby reducing the refrigerant pressure in the back pressure chamber. A difference can be provided in the refrigerant pressure in the vicinity of the discharge port. Thus, in the present invention, since the refrigerant pressure in the back pressure chamber can be kept low, the valve body can be maintained in a fully open state in contact with the inner surface of the second mounting member during operation of the scroll compressor. Therefore, since the flow path of the refrigerant discharged from the discharge port can be sufficiently secured, the pressure loss of the refrigerant can be reduced. Furthermore, since chattering can be suppressed, the occurrence of abnormal noise can also be suppressed.

  In the scroll compressor according to the present invention, it is possible to reduce the pressure loss of the discharged refrigerant and suppress the generation of abnormal noise while reducing the cost.

The longitudinal cross-sectional view of the scroll compressor which concerns on one Embodiment of this invention. The schematic perspective view of the fixed scroll which comprises a compression mechanism. The longitudinal cross-sectional view of a part of scroll compressor for showing the open state of a valve body. The longitudinal cross-sectional view of a part of scroll compressor for showing the closed state of a valve body. The longitudinal cross-sectional view of the scroll compressor which concerns on the modification A. The schematic exploded perspective view of the 1st attachment member, a valve element, and the 2nd attachment member concerning modification A. The longitudinal cross-sectional view of a part of scroll compressor which shows the open state of the valve body which concerns on the modification A. The longitudinal cross-sectional view of a part of the scroll compressor showing the closed state of the valve body according to Modification A.

  Hereinafter, a scroll compressor 1 as an embodiment of the present invention will be described with reference to the drawings.

(1) Configuration of Scroll Compressor FIG. 1 is a longitudinal sectional view of a scroll compressor 1 according to an embodiment of the present invention. In the following description, the direction along the central axis OO of the drive motor 16 shown in FIG. 1 is defined as the axial direction or the vertical (vertical) direction. A direction orthogonal to the central axis OO is a radial direction or a horizontal (horizontal) direction.

  The scroll compressor 1 is used for compressing a refrigerant in a refrigerant circuit that performs a refrigeration cycle by circulating the refrigerant. The scroll compressor 1 is a high-low pressure dome type compressor, and compresses refrigerant by revolving at least one scroll of two scrolls meshing with each other without rotating. As shown in FIG. 1, the scroll compressor 1 mainly includes a casing 10, a suction pipe 18, a discharge pipe 19, a compression mechanism 15, a housing 23, a valve body 71, a back pressure chamber 72, The Oldham coupling 39, the drive motor 16, the lower bearing 60, the oil separation plate 65, the shaft 17, and the gas guide 58 are provided. The scroll compressor 1 includes a compression mechanism 15, a housing 23, a valve body 71, a back pressure chamber 72, an Oldham joint 39, a drive motor 16, a lower bearing 60, an oil separation plate 65, a shaft 17, and a casing 10. It has a sealed structure in which the gas guide 58 is accommodated. The scroll compressor 1 is configured such that a suction pipe 18 and a discharge pipe 19 are attached to the casing 10 so as to pass therethrough. Hereinafter, the components of the scroll compressor 1 will be described.

(1-1) Casing, Suction Pipe, and Discharge Pipe The casing 10 is a vertical cylindrical container that extends in the axial direction, and is mainly hermetically sealed with a substantially cylindrical tubular portion 11 and an upper end of the tubular portion 11. It is comprised from the bowl-shaped upper wall part 12 welded in the shape, and the bowl-shaped bottom wall part 13 welded to the lower end of the cylindrical part 11 airtightly.

  The internal space of the casing 10 is partitioned into a high-pressure space S1 that is a space below the compression mechanism 15 and a low-pressure space S2 that is a space above the compression mechanism 15. An oil storage space P that is a space for storing lubricating oil is formed at the bottom of the internal space of the casing 10. Lubricating oil is used to keep the lubricity of sliding parts such as the compression mechanism 15 good during the operation of the scroll compressor 1.

  In addition, a suction pipe 18 and a discharge pipe 19 are connected to the casing 10. The suction pipe 18 is a tubular member that is attached so as to penetrate the upper wall portion 12, and is used for sucking the refrigerant circulating in the refrigerant circuit from the outside of the casing 10 to the compression chamber 40 (described later) in the compression mechanism 15. It is a member. In addition, the suction pipe 18 is a tubular member that is fitted into a main suction hole (not shown) of the fixed scroll 24 (not shown) and is attached to penetrate the cylindrical portion 11, and from the high-pressure space S1. It is a member for discharging the compressed refrigerant to the outside of the casing 10.

(1-2) Compression Mechanism FIG. 2 is a schematic perspective view of the fixed scroll 24 constituting the compression mechanism 15.

  The compression mechanism 15 sucks low-temperature and low-pressure refrigerant, and discharges the compressed low-temperature and low-pressure refrigerant after compressing the refrigerant into a high-temperature and high-pressure refrigerant. As shown in FIG. 1, the compression mechanism 15 is connected to the upper end portion of the shaft 17. The compression mechanism 15 mainly has a fixed scroll 24 and a movable scroll 26.

(1-2-1) Fixed Scroll The fixed scroll 24 has a disc-shaped first end plate 24a and a spiral shape that is integrally connected to the lower surface of the first end plate 24a and orthogonal to the lower surface of the first end plate 24a ( Involute-shaped) first wrap 24b.

  The fixed scroll 24 is formed with a main suction hole and an auxiliary suction hole (not shown) adjacent to the main suction hole. The main suction hole communicates the internal space of the suction pipe 18 with the compression chamber 40. The low pressure space S2 and the compression chamber 40 are communicated with each other through the auxiliary suction hole.

  A discharge port 41 is formed at the center of the first end plate 24a. The discharge port 41 is a hole for discharging the refrigerant compressed in the compression chamber 40.

  A concave space S3 (see FIGS. 1 and 2) is formed on the upper surface of the first end plate 24a. The recessed space S3 is a space that is recessed in the upper surface of the first end plate 24a and extends in the horizontal direction. The discharge port 41 is formed so as to open into the recess space S3. A lid member 44 is attached to the upper surface of the fixed scroll 24 with bolts (not shown) so as to cover the recessed space S3 from above. And this recessed part space S3 functions as a muffler space which consists of an expansion chamber which silences the driving | running | working sound of the compression mechanism 15 when the cover member 44 is covered. The fixed scroll 24 and the lid member 44 are sealed by being brought into close contact with each other via a gasket (not shown).

  Further, the fixed scroll 24 is formed with an intermediate space S4 (see FIGS. 1 and 2) that allows the recess space S3 and a through space S5 (described later) of the housing 23 to communicate with each other. As shown in FIG. 1, the intermediate space S <b> 4 communicates the recessed space S <b> 3 and the penetration space S <b> 5 and penetrates the lower surface of the fixed scroll 24. The intermediate space S4 is composed of a first intermediate space S4a in which the refrigerant flows so as to be inclined with respect to the central axis O from the upper side to the lower side, and a second intermediate space S4b in which the refrigerant flows in the axial direction. Is formed.

(1-2-2) Movable Scroll The movable scroll 26 is mainly composed of a second end plate 26a and a spiral shape (involute that is integrally connected to the upper surface of the second end plate 26a and orthogonal to the upper surface of the second end plate 26a. Shaped) second wrap 26b, an upper end bearing 26c formed on the lower surface of the second end plate 26a, and groove portions 26d formed at both ends of the second end plate 26a. Oil supply pores 63 are formed in the second end plate 26a. The oil supply pore 63 communicates the outer peripheral portion of the upper surface of the second end plate 26a and the space inside the upper end bearing 26c. The upper end bearing 26c pivotally supports an eccentric portion 17b (described later) of the shaft 17 through a bearing metal 26e. A key portion (not shown) of the Oldham coupling 39 is fitted into the groove portion 26d.

  In the compression mechanism 15 having the above configuration, the first end plate 24a, the first end plate 24b, the second end plate 26a, and the second end plate 26a of the movable scroll 26 mesh with the first end plate 24b of the fixed scroll 24 and the second end plate 26a. A compression chamber 40, which is a space surrounded by the second wrap 26b, is formed. That is, the fixed scroll 24 and the movable scroll 26 together form a compression chamber 40. In the compression chamber 40, the refrigerant is compressed by reducing the volume by the revolving motion of the movable scroll 26.

(1-3) Housing The housing 23 is press-fitted into the inner peripheral surface of the cylindrical portion 11 of the casing 10, and the outer peripheral surface thereof is in close contact with the inner peripheral surface of the cylindrical portion 11 of the casing 10 in an airtight manner. As described above, the outer peripheral surface of the housing 23 and the inner peripheral surface of the cylindrical portion 11 of the casing 10 are in close contact with each other, thereby partitioning the high-pressure space S1 and the low-pressure space S2 described above.

  The housing 23 is formed with a housing recess 31 that is recessed in the center of the upper surface, and a bearing 32 that extends downward from the center in the axial direction. An upper end bearing 26 c of the movable scroll 26 is located in the inner space of the housing recess 31. A bearing hole 33 is formed in the housing 23 so as to penetrate the lower end surface of the bearing portion 32 and the bottom surface of the housing recess 31. The shaft 17 is inserted into the bearing hole 33 through the bearing metal 34 so as to be rotatable.

  The housing 23 is fixed with bolts or the like so that the fixed scroll 24 is placed on the upper surface thereof, and the movable scroll 26 is held together with the fixed scroll 24 via the Oldham joint 39. Further, a through space S5 penetrating in the vertical direction is formed in the outer peripheral portion of the housing 23. The through space S5 connects the intermediate space S4 and the high-pressure space S1. Further, the cross-sectional area perpendicular to the refrigerant flow direction of the through space S5 is formed to be the same as the cross-sectional area perpendicular to the refrigerant flow direction of the second intermediate space S4b. The refrigerant flow direction is the direction indicated by the thick and dotted arrows in FIG.

  In the present embodiment, the refrigerant discharged from the discharge port 41 is, as shown by the arrows in FIG. 1, the recessed space S3, the intermediate space S4 (the first intermediate space S4a and the second intermediate space S4b), and the through space S5. Are sequentially discharged and discharged into the high-pressure space S1. That is, the recessed space S3 and the intermediate space S4 formed in the fixed scroll 24 and the through space S5 formed in the housing 23 form a discharge refrigerant path 47 through which the refrigerant discharged from the discharge port 41 flows.

(1-4) Valve body The valve body 71 is a circular flat plate member provided to prevent the backflow of the refrigerant discharged from the discharge port 41 (see FIG. 2). As shown in FIG. 1, the valve body 71 is positioned such that the lower surface thereof faces the discharge port 41 in the recessed space S <b> 3 constituting the discharge refrigerant path 47. Further, the valve body 71 is configured such that its cross-sectional area is larger than the cross-sectional area of the discharge port 41. The valve body 71 switches between an open state (see FIGS. 1 and 3) in which the discharge port 41 is opened and a closed state (see FIG. 4) in which the discharge port 41 is closed. Specifically, the valve body 71 switches between the open state and the closed state by a differential pressure generated between the refrigerant pressure near the discharge port 41 and the refrigerant pressure in the back pressure chamber 72 described later. Here, FIG. 3 is a longitudinal sectional view of a part of the scroll compressor 1 for showing the opened state of the valve body 71, and FIG. 4 is a view of the scroll compressor 1 for showing the closed state of the valve body 71. It is a partial longitudinal cross-sectional view. As shown in FIG. 3, the valve body 71 is in contact with the lower surface 44a of the lid member 44 in the fully opened state, and forms a recessed space S3 in the fixed scroll 24 in the closed state as shown in FIG. This is a forming surface that is in contact with the discharge surface 42a where the discharge port 41 opens. In the scroll compressor 1, a plurality of (three in the present embodiment) guide portions 73 (FIG. 2) extending upward from the surface of the discharge surface 42a and around the discharge port 41 in the recess space S3. Reference) is provided. The guide part 73 is arrange | positioned so that the valve body 71 may be surrounded, and guides the valve body 71 to an up-down direction.

(1-5) Back Pressure Chamber The back pressure chamber 72 is a space that is recessed on the lower surface of the lid member 44 so as to be positioned on the opposite side of the discharge port 41 in the axial direction with the valve body 71 interposed therebetween. The back pressure chamber 72 communicates with the recessed space S3.

  When the valve body 71 is in the fully opened state, the discharge port 41 is opened as described above, and the upper surface of the valve body 71 contacts the lower surface of the lid member 44 to close the back pressure chamber 72 (see FIGS. 1 and 3). reference). On the other hand, when the valve body 71 is in the closed state, the discharge port 41 is closed and the lower surface thereof contacts the discharge surface 42a of the fixed scroll 24 to open the back pressure chamber 72 (see FIG. 4).

(1-6) Oldham Joint The Oldham Joint 39 is an annular member for preventing the rotation of the movable scroll 26. The Oldham coupling 39 has a key portion fitted in the groove portion 26 d of the movable scroll 26. As a result, the movable scroll 26 is supported by the housing 23 via the Oldham joint 39.

(1-7) Drive Motor As shown in FIG. 1, the drive motor 16 is a brushless DC motor that is connected to a shaft 17 that is connected to the compression mechanism 15 and drives the compression mechanism 15 via the shaft 17. . The drive motor 16 is disposed below the compression mechanism 15. The drive motor 16 mainly includes a stator 51 that is fixed to the inner wall of the cylindrical portion 11 of the casing 10 and a rotor 52 that is rotatably disposed inside the stator 51 in the radial direction. An air gap, which is a slight gap, is formed between the inner peripheral surface of the stator 51 and the outer peripheral surface of the rotor 52.

  The stator 51 has a coil part (not shown) around which a conducting wire is wound, and a coil end 53 formed above and below the coil part. In addition, a plurality of core cut portions (not shown) are formed on the outer peripheral surface of the stator 51 so as to extend from the upper end surface to the lower end surface of the stator 51 and at predetermined intervals in the circumferential direction. ing. The core cut portion forms a motor cooling passage 55 extending in the axial direction between the tubular portion 11 and the stator 51. A shaft 17 (a main shaft portion 17a (described later) of the shaft 17) is fitted in the central portion of the rotor 52.

(1-8) Lower Bearing The lower bearing 60 is a bearing that is disposed below the drive motor 16 and supports the lower portion of the shaft 17 (the main shaft portion 17a of the shaft 17). The outer surface of the lower bearing 60 is joined to the inner wall of the cylindrical portion 11 of the casing 10 in an airtight manner.

(1-9) Oil Separation Plate The oil separation plate 65 is a flat plate member that separates the lubricating oil from the descending refrigerant. The oil separation plate 65 is fixed to the upper end surface of the lower bearing 60.

(1-10) Shaft The shaft 17 has a hollow shape in which an oil supply hole 61 extending in the axial direction is formed. The lower end of the shaft 17 is immersed in the lubricating oil stored in the oil storage space P, and the oil supply hole 61 communicates with the oil storage space P. The oil supply hole 61 communicates with the oil chamber 89. The oil chamber 89 is a space formed by the upper end surface of the shaft 17 and the lower surface of the second end plate 26a. The oil chamber 89 communicates with a sliding portion between the fixed scroll 24 and the movable scroll 26 (referred to as a sliding portion of the compression mechanism 15 in this embodiment as appropriate) through the oil supply hole 63 of the second end plate 26a. ing. The oil chamber 89 communicates with the compression chamber 40 and the low-pressure space S <b> 2 via the sliding portion of the compression mechanism 15.

  Further, the shaft 17 is formed therein with a first oil supply horizontal hole 61a, a second oil supply horizontal hole 61b, and a third oil supply horizontal hole 61c branched in the horizontal direction from an oil supply hole 61 extending in the axial direction. The first oil supply lateral hole 61a is formed so that the lubricating oil can be supplied to the sliding portion between the bearing metal 26e and the shaft 17. The second oil supply lateral hole 61 b is formed so as to supply lubricating oil to the sliding portion between the bearing metal 34 and the shaft 17. The third oil supply lateral hole 61c is formed so that lubricating oil can be supplied to the sliding portion between the lower bearing 60 and the shaft 17.

  A more specific configuration will be described. The shaft 17 has a main shaft portion 17a whose axis coincides with the rotation center of the rotor 52, an eccentric portion 17b constituting the upper end portion of the shaft 17, and a rotating system (movable scroll 26, An Oldham joint 39, a shaft 17 and a balance weight portion 17c for balancing the mass of the rotor 52).

  The main shaft portion 17a has a cylindrical shape and is a portion that rotates around the central axis OO. The upper portion of the main shaft portion 17 a is pivotally supported by the bearing portion 32 of the housing 23 via the bearing metal 34, and the lower portion thereof is pivotally supported by the lower bearing 60.

  The eccentric portion 17b has a cylindrical shape and is provided at the upper end of the main shaft portion 17a so as to be eccentric with respect to the axis of the main shaft portion 17a. The upper end of the eccentric part 17b is fitted in the space inside the upper end bearing 26c of the movable scroll 26, and is pivotally supported by the upper end bearing 26c via a bearing metal 26e. That is, the shaft 17 is connected to the movable scroll 26 by fitting the eccentric portion 17 b of the shaft 17 into the upper end bearing 26 c of the movable scroll 26.

  The balance weight portion 17c is a portion that is fixed in close contact with the outer peripheral surface of the main shaft portion 17a.

  As described above, the shaft 17 is driven by the drive motor 16 by connecting the compression mechanism 15 (specifically, the movable scroll 26) and the drive motor 16 (specifically, the rotor 52). The force is transmitted to the compression mechanism 15. Specifically, when a current flows through the drive motor 16, first, the rotor 52 rotates counterclockwise as viewed from above about the central axis OO, and this rotational driving force is transmitted to the shaft 17. The shaft 17 rotates counterclockwise as viewed from above. As the shaft 17 rotates, the rotational driving force of the rotor 52 (drive motor 16) is transmitted to the movable scroll 26 (compression mechanism 15) connected to the shaft 17, and the movable scroll 26 is driven. At this time, since the rotation of the movable scroll 26 is prohibited by the Oldham joint 39, the movable scroll 26 performs a revolving motion with an eccentric radius around the central axis OO without rotating.

(1-11) Gas Guide The gas guide 58 is a member for guiding the compressed refrigerant flowing through the through space S5 to the high pressure space S1. The gas guide 58 is fixed to the cylindrical portion 11 of the casing 10, and forms a space for guiding the refrigerant to the high-pressure space S <b> 1 together with the inner peripheral surface of the cylindrical portion 11.

(2) Configuration of the path reduction portion and the back pressure chamber communication path, and the operation of the valve body In the scroll compressor as described above, the valve body is basically opened during the operation of the scroll compressor, and the scroll compression is performed. It closes when the machine stops. In such a scroll compressor, the valve body is preferably in contact with the lower surface of the lid member in order to ensure the flow path of the discharged refrigerant during the operation of the scroll compressor. It is preferable to completely close the discharge port so that the discharged refrigerant does not flow backward.

  However, the valve body during operation fluctuates up and down during one cycle, and its behavior is greatly influenced by the operating conditions, the diameter of the discharge port, and the weight of the valve body. The valve body is more likely to float as the operating condition is on the low compression ratio side, and conversely, the valve body is less likely to float as the operating condition is higher. The larger the discharge port, the greater the influence of the pressure action on the valve body, so the vertical fluctuation range of the valve body increases, and the weight of the valve body increases as the weight increases. Make it smaller. Therefore, in order to increase the compressor efficiency, it is preferable to make the valve body in operation easy to float by reducing the weight of the valve body or increasing the diameter of the discharge port. If you look straight ahead, the amount of vertical fluctuation of the valve body will increase, and the speed at which the valve body will collide with the valve seat surface that functions as the valve seat, or the opposite surface that sandwiches the valve check surface and the discharge check valve. Since it becomes large, it will be recognized as an abnormal sound during chattering. Further, in this case, since the valve body is likely to be in a full lift state, the phenomenon that the valve body adheres to the opposite surface of the valve seat surface and the valve body due to the viscosity of the lubricating oil mixed in the discharged refrigerant is likely to occur. Become. For this reason, when the compressor is stopped, there is a concern that it takes some time to reach the closed state, that is, the compressor reverse phenomenon occurs due to the reverse flow of the discharged refrigerant at the time of stop. Therefore, in the compressor disclosed in Patent Document 2, a back pressure chamber formed on the back side of the valve body, a spring member disposed in the back pressure chamber, and a plurality (first to first) connected to the back pressure chamber. 3) By providing the passage portion and cylinder chamber, and a switching mechanism (piston and spring member) provided in the communication passage for switching the contact point of the back pressure chamber, the pressure loss of the discharged refrigerant can be reduced and the noise can be reduced. Is suppressed. However, in this compressor, there is a concern that the increase in the number of parts and the formation of passages and the like will be complicated and costly.

  Therefore, in the present embodiment, a path reduction portion 49 in which a cross-sectional area perpendicular to the refrigerant flow direction is reduced is formed in the middle of the discharge refrigerant path 47, and the path between the back pressure chamber 72 and the discharge refrigerant path 47 is formed. A back pressure chamber communication passage 81 is provided for communicating with the vicinity of the reduction portion 49. Hereinafter, these specific configurations will be described, and then the operation of the valve body 71 will be described.

(2-1) Path Reduction Unit In this embodiment, as shown in FIG. 1 and the like, a cross-sectional area perpendicular to the refrigerant flow direction of the second intermediate space S4b (here, referred to as a flow path cross-sectional area as appropriate) It is made smaller than the cross-sectional area orthogonal to the refrigerant | coolant flow direction of 1 intermediate | middle space S4a. In the fixed scroll 24, a portion that reduces the flow path cross-sectional area of the first intermediate space S4a to the flow path cross-sectional area of the second intermediate space S4b is a path reduction portion 49.

  Here, the flow passage cross-sectional area of the refrigerant in the second intermediate space S4b (cross-sectional area orthogonal to the refrigerant flow direction) is made smaller than the flow passage cross-sectional area of the refrigerant flowing through the first intermediate space S4a by the path reduction unit 49. Thus, the flow rate of the refrigerant is increased in the second intermediate space S4b. That is, the path reduction unit 49 functions as a throttle unit that increases the flow rate of the refrigerant discharged from the discharge port 41. Thus, in the present embodiment, the discharge refrigerant path 47 has a portion that increases the refrigerant flow rate until the refrigerant discharged from the discharge port 41 flows into the high-pressure space S1. In the present embodiment, as described above, the flow passage cross-sectional area of the second intermediate space S4b and the flow passage cross-sectional area of the through space S5 are formed to be the same. The road cross-sectional area may be larger than the flow path cross-sectional area of the second intermediate space S4b.

(2-2) Back Pressure Chamber Communication Channel The back pressure chamber communication channel 81 is a channel connected to the discharge refrigerant channel 47, and includes a first back pressure chamber communication channel 82, a second back pressure chamber communication channel 83, have.

  The first back pressure chamber communication passage 82 is formed inside the lid member 44 and communicates with the back pressure chamber 72. The first back pressure chamber communication passage 82 includes a horizontal passage 82 a that communicates with the back pressure chamber 72 and extends in the horizontal direction, and an upper and lower passage 82 b that branches downward from the horizontal passage 82 a and penetrates the lower surface of the lid member 44. It is configured.

  The second back pressure chamber communication passage 83 is formed in the fixed scroll 24. The second back pressure chamber communication path 83 communicates the first back pressure chamber communication path 82 and a portion in the vicinity of the path contracting portion 49 in the discharge refrigerant path 47 (specifically, the second intermediate space S4b). Yes. Specifically, the second back pressure chamber communication passage 83 communicates with the upper and lower passages 82b of the first back pressure chamber communication passage 82 and extends into the inclination passage 83a and the inclination passage 83a. The upper and lower passages 83b communicate with each other in the vertical direction, and the horizontal passages 83c communicate with the upper and lower passages 83b and extend in the horizontal direction. The inclined passage 83 a passes through the upper surface of the fixed scroll 24. The horizontal passage 83c communicates with a portion (second intermediate space S4b) in the vicinity of the path reducing portion 49 in the discharged refrigerant path 47.

  As described above, in the present embodiment, the discharge refrigerant path 47 is formed with the path reducing portion 49 that reduces the cross-sectional area perpendicular to the refrigerant flow direction. Therefore, the refrigerant discharged from the discharge port 41 and flowing through the discharge refrigerant path 47 (specifically, the recessed space S3 and the first intermediate space S4a) increases its flow rate when passing through the path reduction portion 49. Become. Thereby, the pressure of the refrigerant in the second intermediate space S4b decreases. Here, the back pressure chamber communication path 81 communicates the back pressure chamber 72 and the second intermediate space S4b, which is the vicinity of the path reducing portion 49 in the discharge refrigerant path 47. Therefore, when the pressure of the refrigerant in the second intermediate space S4b decreases, the refrigerant located in the back pressure chamber communication path 81 connected to the second intermediate space S4b is discharged to the discharge refrigerant path 47 (specifically, the second refrigerant space 47). The phenomenon of flowing into the intermediate space S4b) occurs (see the thick and solid arrows in FIG. 3). That is, the opening portion facing the discharge refrigerant path 47 of the horizontal passage 83 c of the second back pressure chamber communication path 83 functions as an inlet that guides the refrigerant located in the back pressure chamber communication path 81 to the discharge refrigerant path 47. . Thus, in the present embodiment, during the operation of the scroll compressor 1, the refrigerant pressure is decreased in the second intermediate space S4b of the discharge refrigerant path 47, and the refrigerant in the back pressure chamber communication path 81 is discharged to the discharge refrigerant path 47 (first 2 The ejector effect that is drawn into the intermediate space S4b) can be produced.

  Then, the refrigerant drawn into the discharge refrigerant path 47 (second intermediate space S4b) from the back pressure chamber communication path 81 is merged with the refrigerant flowing from the first intermediate space S4a in the discharge refrigerant path 47, and the through space S5. Will flow into the high-pressure space S1.

  Here, it is desirable that the discharge port 41 has a large cross-sectional area as much as possible. This is because the valve body 71 can easily float and can be easily fully opened (full lift state). As a result, since the refrigerant continues to be drawn from the horizontal passage 83c to the second intermediate space S4b, the back pressure chamber 72 is a negative pressure space compared to the recessed space S3 and the intermediate space S4.

(2-3) Operation of the valve body When the scroll compressor 1 is stopped, the refrigerant pressure in the back pressure chamber 72 and the refrigerant pressure in the vicinity of the discharge port 41 are equal to each other. The closed state is caused by the action of gravity (see FIG. 4). Then, when the operation of the scroll compressor 1 is started, the valve element 71 moves upward and immediately reaches the lower surface 44a of the lid member 44, and finally is fully opened while repeatedly colliding with the lower surface 44a ( Full lift state) (see FIG. 3). Here, in the present embodiment, the back pressure chamber communication passage 81 is provided that forms the path reduction portion 49 in the discharge refrigerant passage 47 and communicates the back pressure chamber 72 and the vicinity of the path reduction portion 49 in the discharge refrigerant passage 47. Therefore, the refrigerant in the back pressure chamber communication path 81 and the back pressure chamber 72 can flow into the discharge refrigerant path 47 (see the thick and solid arrows in FIG. 3). As a result, the refrigerant in the back pressure chamber communication path 81 and the back pressure chamber 72 is continuously drawn to the discharge refrigerant path 47 via the horizontal path 83c, so that the refrigerant pressure in the back pressure chamber 72 is reduced in the recess space S3. It is possible to maintain a lower state than the intermediate space S4. And the valve body 71 can also maintain a fully open state.

  When the scroll compressor 1 is stopped, the refrigerant pressure in the back pressure chamber 72 and the refrigerant pressure in the vicinity of the discharge port 41 become equal to each other, and the valve body 71 moves downward due to the action of gravity. The discharge port 41 is closed (see FIG. 4). On the other hand, when the scroll compressor 1 is stopped, at the same time, the refrigerant in the high-pressure space S2 flows backward toward the compression chamber 40. Here, in the present embodiment, after the scroll compressor 1 is stopped, the refrigerant also flows into the back pressure chamber 72 via the back pressure chamber communication passage 81 (see the bold arrow in FIG. 4). And since a refrigerant | coolant flows in into the back pressure chamber 72, the refrigerant | coolant flow (dynamic pressure) will act as a force which pushes the valve body 71 below not a little. Therefore, the refrigerant that flows backward from the high-pressure space S2 can be quickly avoided from entering the compression chamber 40.

(3) Operation of Scroll Compressor Hereinafter, basic refrigerant and lubricating oil flows in the scroll compressor 1 will be described.

(3-1) Flow of refrigerant When the drive motor 16 is driven, the rotor 52 rotates. As a result, the shaft 17 fixed to the rotor 52 performs axial rotation. The rotational driving force of the shaft 17 is transmitted to the movable scroll 26 through the upper end bearing 26c. The eccentric portion 17b connected to the movable scroll 26 of the shaft 17 is eccentric with respect to the central axis OO. The movable scroll 26 is prevented from rotating by the Oldham joint 39. Thereby, the movable scroll 26 performs a revolving motion without rotation.

  The low-temperature and low-pressure refrigerant before compression fills the low-pressure space S2 through the suction pipe 18 and is sucked into the compression chamber 40 of the compression mechanism 15 through the main suction hole and the auxiliary suction hole of the fixed scroll 24. By the revolving motion of the movable scroll 26, the volume of the compression chamber 40 is gradually reduced while moving from the outer peripheral portion of the fixed scroll 24 toward the center portion. As a result, the refrigerant in the compression chamber 40 is compressed into a compressed refrigerant. After the compressed refrigerant is discharged from the discharge port 41 to the recessed space S3, the compressed refrigerant passes through the intermediate space S4 and the through space S5, and then the high-pressure space S1 (specifically, in the axial direction between the compression mechanism 15 and the drive motor 16). It is discharged to the space between. A part of the compressed refrigerant flows downward in the space between the gas guide 58 and the cylindrical portion 11 of the casing 10. The compressed refrigerant further descends through the motor cooling passage 55 and reaches the space below the drive motor 16. Thereafter, the compressed refrigerant reverses the flow direction, moves up the motor cooling passage 55 and the air gap, and flows again into the space between the compression mechanism 15 and the drive motor 16 in the axial direction. Finally, the compressed refrigerant is discharged from the discharge pipe 19 to the outside of the casing 10.

(3-2) Flow of lubricating oil First, when the drive motor 16 is driven, the rotor 52 rotates. As a result, the shaft 17 fixed to the rotor 52 performs axial rotation. When the compression mechanism 15 is driven by the rotation of the shaft 17 and the compressed refrigerant is discharged into the high-pressure space S1, the pressure in the high-pressure space S1 increases. Here, the oil supply hole 61 formed in the shaft 17 communicates with the low pressure space S <b> 2 via the oil chamber 89 and the oil supply hole 63. As a result, a pressure difference is generated between the upper end portion and the lower end portion of the oil supply hole 61. As a result, the oil supply hole 61 itself acts as a differential pressure pump, and the lubricating oil stored in the oil storage space P is sucked into the oil supply hole 61 and ascends the oil supply hole 61.

  The lubricating oil that has risen up to the oil chamber 61 and reaches the oil chamber 89 is supplied to the sliding portion of the compression mechanism 15 via the oil supply hole 63. The lubricating oil that has lubricated the sliding portion of the compression mechanism 15 is discharged from the compression chamber 40 to the high-pressure space S1 through the same path as the compressed refrigerant. Thereafter, the lubricant oil collides with the oil separation plate 65 after descending the motor cooling passage 55 together with the compressed refrigerant. At this time, the lubricating oil adhering to the oil separation plate 65 falls in the high pressure space S1 and is stored in the oil storage space P.

  On the other hand, most of the lubricating oil that is sucked from the oil storage space P and rises through the oil supply hole 61 is divided into the first oil supply horizontal hole 61a, the second oil supply horizontal hole 61b, and the third oil supply horizontal hole 61c. A portion of the lubricating oil split into the first oil supply lateral hole 61a and the lubricating oil in the oil chamber 89 flows into the high-pressure space S1 after lubricating the sliding portion between the shaft 17 (eccentric portion 17b) and the bearing metal 26e. And returned to the oil storage space P. Lubricating oil branched into the second oil supply lateral hole 61b is supplied to the sliding portion between the upper portion of the shaft 17 (main shaft portion 17a) and the bearing metal 34. Then, it flows into the high-pressure space S1 and is returned to the oil storage space P. Further, the lubricating oil divided into the third oil supply lateral hole 61b lubricates the sliding portion between the lower portion of the shaft 17 (main shaft portion 17a) and the lower bearing 60 and leaks into the high pressure space S1, and then the high pressure space S1. To the oil storage space P.

(4) Features As described above, in the present embodiment, the refrigerant in the back pressure chamber communication path 81 and the back pressure chamber 72 communicating with the back pressure chamber communication path 81 is discharged by the path reducing portion 49 in the discharge refrigerant path 47. By flowing into the passage 47 (second intermediate space S4b), a difference can be provided between the refrigerant pressure in the back pressure chamber 72 and the refrigerant pressure in the vicinity of the discharge port 41.

  As described above, in the present embodiment, the refrigerant pressure in the back pressure chamber 72 can be lowered by the back pressure chamber communication path 81 and the path contracting portion 49 in the discharge refrigerant path 47. Therefore, during operation of the scroll compressor 1, the valve body 71 can be easily maintained in contact with the lower surface 44 a of the lid member 44. In the present embodiment, the valve body 71 can be positioned at a position that does not obstruct the flow of the refrigerant discharged from the discharge port 41 most in the recessed space S3 of the discharge refrigerant path 47. The pressure loss of the refrigerant can be reduced. Therefore, the efficiency of the scroll compressor 1 can be improved.

  Further, since the refrigerant pressure in the back pressure chamber 72 can be reduced, the valve body 71 can be easily maintained in contact with the lower surface 44 a of the lid member 44 during operation of the scroll compressor 1. Therefore, the occurrence of chattering in which the valve body 71 repeats the open state and the closed state can be suppressed, and the valve body 71, the fixed scroll 24 (specifically, the discharge surface 42a of the fixed scroll 24), and the lower surface 44a of the lid member 44 It is also possible to suppress the generation of abnormal noise due to the contact.

  In addition, after the scroll compressor 1 is stopped, the refrigerant that has flowed back through the back pressure chamber communication passage 81 flows into the back pressure chamber 72, so that the flow of the refrigerant pushes the valve element 71 downward. Acts as Therefore, the valve body 71 can be switched to the closed state as soon as possible after the scroll compressor 1 is stopped.

(5) Modification (5-1) Modification A
In the above embodiment, the scroll compressor 1 according to the present invention has been described by taking the high and low pressure dome type scroll compressor 1 as an example, but the present invention is not limited to this. For example, instead of the high and low pressure dome type scroll compressor 1, a low pressure dome type scroll compressor 101 may be adopted as the compressor according to the present invention. Hereinafter, the scroll compressor 101 will be described with reference to FIGS. FIG. 5 is a longitudinal sectional view of the scroll compressor 101. FIG. 6 is a schematic exploded perspective view of the first mounting member 161, the valve body 171, and the second mounting member 162. FIG. 7 is a longitudinal sectional view of a part of the scroll compressor 101 showing the opened state of the valve body 171. FIG. 8 is a vertical sectional view of a part of the scroll compressor 101 showing the closed state of the valve body 171. In the following description, the direction along the central axis OO of the drive motor 116 shown in FIG. 5 is defined as the axial direction or the vertical (vertical) direction. In addition, a direction orthogonal to the central axis OO is defined as a radial direction and a lateral (horizontal) direction.

<Scroll compressor>
The scroll compressor 101 is used to compress a refrigerant in a refrigerant circuit that performs a refrigeration cycle by circulating the refrigerant. The scroll compressor 101 is a low-pressure dome type compressor, and compresses the refrigerant by revolving the other scroll without revolving at least one of the two scrolls engaged with each other. As shown in FIG. 5, the scroll compressor 101 mainly includes a casing 110, a suction pipe 118, a discharge pipe 119, a compression mechanism 115, a housing 123, a first mounting member 161, and a second mounting member. 162, a valve body 171, a back pressure chamber 172, a drive motor 116, a lower bearing 160, a shaft 117, and a back pressure chamber communication path forming member 180. The scroll compressor 101 includes a compression mechanism 115, a housing 123, a first mounting member 161, a second mounting member 162, a valve body 171, a back pressure chamber 172, a drive motor 116, a lower bearing 160, and a shaft 17 inside the casing 110. And, it has a sealed structure in which the back pressure chamber communication path forming member 180 is accommodated. The scroll compressor 101 is configured such that the suction pipe 118 and the discharge pipe 119 are attached to the casing 110 so as to penetrate therethrough. Hereinafter, components of the scroll compressor 101 will be described.

(A) Casing, Intake Pipe, and Discharge Pipe The casing 110 is a vertical cylindrical container that extends in the axial direction, and is mainly hermetically sealed with a substantially cylindrical tubular portion 111 and an upper end of the tubular portion 111. It is comprised from the bowl-shaped upper wall part 112 (equivalent to a covering member) to be welded, and the bowl-shaped bottom wall part 113 welded to the lower end of the cylindrical part 111 airtightly.

  The internal space of the casing 10 is partitioned into a high pressure space S11 that is an upper space of a first mounting member 161 (described later) attached to the upper surface of the compression mechanism 115 and a low pressure space S12 that is a lower space of the first mounting member 161. Has been. That is, all the members including the compression mechanism 115 and below the compression mechanism 115 are present in the low pressure space S12. An oil storage space P <b> 1 that is a space for storing lubricating oil is formed at the bottom of the internal space of the casing 110. Lubricating oil is used to keep the lubricity of sliding parts such as the compression mechanism 115 good during the operation of the scroll compressor 101.

  In addition, a suction pipe 118 and a discharge pipe 119 are connected to the casing 110. The suction pipe 18 is a tubular member attached through the tubular portion 111 and is a member for sucking the refrigerant circulating in the refrigerant circuit from the outside of the casing 110 to the compression mechanism 115. The discharge pipe 119 is a tubular member that penetrates and is attached to the upper wall portion 112, and the refrigerant compressed in the compression chamber 140 (described later) and discharged from the discharge port 141 (described later) to the outside of the casing 110. It is a member for discharging. The discharge pipe 119 will be described later.

(B) Compression mechanism The compression mechanism 115 sucks low-temperature and low-pressure refrigerant, and discharges the compressed low-pressure refrigerant after compressing it into a high-temperature and high-pressure refrigerant. The compression mechanism 115 is connected to the upper end of the shaft 117 as shown in FIG. The compression mechanism 115 mainly has a fixed scroll 124 and a movable scroll 126.

(B-1) Fixed Scroll The fixed scroll 124 is a disc-shaped first end plate 124a and a spiral shape (involute shape) integrally connected to the lower surface of the first end plate 124a and orthogonal to the lower surface of the first end plate 124a. ) First wrap 124b. The fixed scroll 124 is formed with a suction hole (not shown). The suction hole is a hole that communicates the low pressure space S <b> 12 and the compression chamber 140, and guides the refrigerant flowing from the suction pipe 118 to the compression chamber 140.

  In addition, a discharge port 141 is formed at the center of the upper surface of the first end plate 124a. The discharge port 141 is open to the compression chamber 140 and discharges the refrigerant compressed in the compression chamber 140.

(B-2) Movable Scroll The movable scroll 126 is mainly connected to the upper surface of the second end plate 126a and the second end plate 126a, and is a spiral shape (involute shape) orthogonal to the upper surface of the second end plate 126a. The second wrap 126b, an upper end bearing 126c formed on the lower surface of the second end plate 126a, and grooves (not shown) formed at both ends of the second end plate 126a. The upper end bearing 126c pivotally supports an eccentric part 117b (described later) of the shaft 117 via a bearing metal (not shown). A part (not shown) of a plurality of key parts of an Oldham coupling (not shown) is fitted in the groove. Here, the Oldham coupling is an annular member for preventing the movable scroll 126 from rotating. In the Oldham coupling, the remaining portions of the plurality of key portions are also fitted into the groove portion (not shown) of the housing 123. And thereby, the movable scroll 126 is supported by the housing 123 via the Oldham coupling. The second end plate 126a is formed with a hole for oiling (not shown).

  In the compression mechanism 115 having the above-described configuration, the first end plate 124a, the first end plate 124b, the second end plate 126a, and the second end plate 126a of the fixed scroll 124 and the second end 126b of the movable scroll 126 are engaged with each other. A compression chamber 140 that is a space surrounded by the second wrap 126b is formed. That is, the fixed scroll 124 and the movable scroll 126 together form a compression chamber 140. In the compression chamber 140, the refrigerant is compressed by reducing the volume by the revolving motion of the movable scroll 126.

(C) Housing The housing 123 is press-fitted into the inner peripheral surface of the cylindrical portion 111 of the casing 110, and the outer peripheral surface thereof is attached to the inner peripheral surface of the cylindrical portion 111 of the casing 110.

  The housing 123 is formed with a housing recess 131 that is recessed in the center portion of the upper surface, and a bearing portion 132 that extends downward from the center portion in the axial direction. An upper end bearing 126 c of the movable scroll 126 is located in the inner space of the housing recess 131. The housing 123 is formed with a bearing hole 133 that penetrates the lower end surface of the bearing portion 132 and the bottom surface of the housing recess 131. A shaft 117 is rotatably inserted into the bearing hole 133 via a bearing metal (not shown).

  The housing 123 is fixed with bolts or the like so that the fixed scroll 124 is placed on the upper surface thereof, and the movable scroll 126 is held together with the fixed scroll 124 via the Oldham joint.

(D) 1st attachment member The 1st attachment member 161 is a disk-shaped member, as shown in FIG.5 and FIG.6, and is attached to the upper surface of the fixed scroll 124. FIG. The outer peripheral surface of the first mounting member 161 is in close contact with the inner peripheral surface of the upper wall portion 112 of the casing 110. Thereby, the above-described high-pressure space S11 and low-pressure space S12 are partitioned. The internal space of the casing 110 is partitioned in the vertical direction. The first mounting member 161 is formed with an upper and lower through space S13 penetrating in the vertical direction and communicating with the discharge port 141 at the center thereof. In the case of this modification, the vertical through space S13 also functions as a discharge port that defines the behavior of the valve body 171.

(E) Second attachment member The second attachment member 162 is a member attached to the upper surface of the first attachment member 161 by a bolt 163 (see FIG. 6). As shown in FIG. The valve pressing portion 162a and a plurality of (two in the present embodiment) valve guide portions 162b extending downward from the lower surface of the valve pressing portion 162a and contacting the upper surface of the first mounting member 161 are integrated. It is configured by molding. The valve pressing part 162a is horizontally arranged. The lower surface of the valve pressing portion 162a has a function of restricting the upward movement of the valve body 171. As shown in FIG. 1, a back pressure chamber 172 is recessed in the lower surface of the valve pressing portion 162a. The cross-sectional area of the back pressure chamber 172 is smaller than the cross-sectional area of the valve body 171. The back pressure chamber 172 will be described in detail later. In addition, a through hole 173 that penetrates the upper surface of the valve pressing portion 162 a is formed in the valve pressing portion 162 a so as to communicate with the back pressure chamber 172. The through hole 173 is a hole for allowing the back pressure chamber communication path forming member 180 to penetrate the back pressure chamber 172. The valve guide portion 162b is a member that guides the valve body 171 in the vertical direction, and extends downward from a substantially central portion in the short side direction at one end portion in the longitudinal direction on the lower surface of the valve pressing portion 162a. The two valve guide portions 162b are arranged so as to surround the valve body 171. The length of the valve guide portion 162b in the direction corresponding to the longitudinal direction of the valve pressing portion 162a is shorter than the length of the valve pressing portion 162a in the longitudinal direction. Moreover, the length of the valve guide part 162b in the direction corresponding to the short direction of the valve pressing part 162a is shorter than the length of the valve pressing part 162a in the short direction. Therefore, a gap space S14 communicating with the back pressure chamber 172 is formed between the lower surface of the valve pressing portion 162a of the second mounting member 162 and the upper surface of the first mounting member 161. Then, the high-pressure refrigerant discharged from the discharge port 141 flows out into the discharge refrigerant space S15 through the gap space S14. Here, the discharge refrigerant space S15 refers to the upper surfaces of the first mounting member 161 and the second mounting member 162 inside the casing 110 and the first mounting member 161 and the second mounting member 162 from the upper side in the high pressure space S11. It is a space formed by the inner surface of the upper wall portion 112 as a surrounding covering member.

  Thus, in the present embodiment, the refrigerant discharged from the discharge port 141 is the gap space S14 formed by the upper and lower through spaces S13 of the first mounting member 161, the first mounting member 161 and the second mounting member 162, And flows into the internal space S16 of the discharge pipe 119 via the discharge refrigerant space S15 (see the thick line arrow in FIG. 5). That is, the upper and lower through space S13, the gap space S14, the discharge refrigerant space S15, and the internal space S16 of the discharge pipe 119 form a discharge refrigerant path 147 through which the refrigerant discharged from the discharge port 141 flows.

(F) Valve body The valve body 171 is a flat plate member provided to prevent the backflow of the refrigerant discharged from the discharge port 141 (see FIG. 6). As shown in FIG. 6, the valve body 171 has recesses 171 a that are recessed inward from both ends in the longitudinal direction. The concave portion 171a is configured such that the valve guide portion 162b of the second mounting member 162 fits into a space formed by the formation surface. In this way, by forming the recess 171a that fits in the valve guide portion 162b in the valve body 171, the valve guide portion 162b can be easily moved in the vertical direction while suppressing the displacement. It can be done. In this modified example, the concave portion 171a is formed in the valve body 171. However, the present invention is not limited to this. Even if the concave portion 171a is not formed, the valve guide portion 162b is arranged in the lateral direction of the valve body 171. Since the movement can be restricted, the valve body 171 can move in the vertical direction.

  As shown in FIG. 5, the valve body 171 is positioned such that its lower surface faces the discharge port 141 in the gap space S <b> 14 that constitutes the discharge refrigerant path 147. Further, the valve body 171 is configured such that the cross-sectional area thereof is larger than the cross-sectional area of the vertical through space S13. And the valve body 171 has the open state (refer FIG.5 and FIG.7) which opens the up-and-down penetration space S13 with the discharge port 141, and the closed state (refer FIG. 8) which closes the up-and-down penetration space S13 with the discharge port 141. Switch. Specifically, the valve body 171 switches between the open state and the closed state by a differential pressure generated between the refrigerant pressure in the vicinity of the discharge port 141 and the refrigerant pressure in the back pressure chamber 172. As shown in FIGS. 5 and 7, the valve body 171 is in contact with the inner surface of the second mounting member 162 (specifically, the lower surface of the valve pressing portion 162a) in the fully opened state, as shown in FIG. In the closed state, the upper surface of the first mounting member 161 is in contact.

(G) Back pressure chamber As described above, the back pressure chamber 172 is a space recessed in the lower surface of the second mounting member 162 so as to be positioned on the opposite side in the axial direction from the discharge port 141 with the valve body 171 interposed therebetween. It is. The back pressure chamber 172 communicates with the gap space S14.

  When the valve body 171 is in the fully open state, as described above, the discharge port 141 and the upper and lower through space S13 are opened, and the upper surface thereof is in contact with the inner surface of the second mounting member 162 (the lower surface of the valve pressing portion 162a). The back pressure chamber 172 is closed (see FIGS. 5 and 7). On the other hand, when the valve body 171 is in the closed state, the discharge port 141 and the vertical through space S13 are closed, and the lower surface thereof is in contact with the upper surface of the first mounting member 161 to open the back pressure chamber 72 (FIG. 8). See).

(H) Drive Motor The drive motor 116 is a brushless DC motor that is connected to a shaft 117 that is connected to the compression mechanism 115 and drives the compression mechanism 115 via the shaft 117. The drive motor 16 is disposed below the compression mechanism 115. The drive motor 116 mainly includes a stator 151 that is fixed to the inner wall of the cylindrical portion 111 of the casing 110 and a rotor 152 that is rotatably disposed radially inward of the stator 151. An air gap, which is a slight gap, is formed between the inner peripheral surface of the stator 151 and the outer peripheral surface of the rotor 152.

  The stator 151 has a coil part (not shown) around which a conducting wire is wound, and a coil end 153 formed above and below the coil part. A plurality of core cut portions (not shown) are formed on the outer peripheral surface of the stator 151 from the upper end surface to the lower end surface of the stator 151 and at predetermined intervals in the circumferential direction. ing. The core cut portion forms a motor cooling passage 155 extending in the axial direction between the tubular portion 111 and the stator 151. A shaft 117 (a main shaft portion 17a (described later) of the shaft 17) is fitted in the central portion of the rotor 152.

(I) Lower Bearing The lower bearing 160 is a bearing that is disposed below the drive motor 116 and pivotally supports the lower portion of the shaft 117 (the main shaft portion 117a of the shaft 117). The outer surface of the lower bearing 160 is joined to the inner wall of the cylindrical portion 111 of the casing 110 in an airtight manner.

(J) Shaft The shaft 117 has a hollow shape in which an oil supply hole (not shown) extending in the axial direction or the radial direction is formed. The lower end of the shaft 117 is immersed in the lubricating oil stored in the oil storage space P1, and the oil supply hole communicates with the oil storage space P1.

  The shaft 117 has a main shaft portion 117a whose axis coincides with the rotation center of the rotor 152, an eccentric portion 117b constituting the upper end portion of the shaft 117, and a rotating system (movable scroll 126, Oldham coupling, shaft 117, and rotor 152). In order to balance the mass, a balance weight portion 117c fixed in close contact with the outer peripheral surface of the main shaft portion 117a is provided.

  The main shaft portion 117a has a cylindrical shape and is a portion that rotates around the central axis OO. The upper portion of the main shaft portion 117 a is pivotally supported by the bearing portion 132 of the housing 123, and the lower portion thereof is pivotally supported by the lower bearing 160.

  The eccentric part 117b has a cylindrical shape and is provided at the upper end of the main shaft part 117a so as to be eccentric with respect to the axis of the main shaft part 117a. The upper end of the eccentric part 117b is fitted in the space inside the upper end bearing 126c of the movable scroll 126 and is pivotally supported by the upper end bearing 26c. That is, the shaft 117 is connected to the movable scroll 126 by fitting the eccentric portion 117 b of the shaft 117 into the upper end bearing 126 c of the movable scroll 126.

  As described above, the shaft 117 is driven by the drive motor 116 by connecting the compression mechanism 115 (specifically, the movable scroll 126) and the drive motor 116 (specifically, the rotor 152). The force is transmitted to the compression mechanism 115. Specifically, when a current flows through the drive motor 116, first, the rotor 152 rotates counterclockwise as viewed from above about the central axis OO, and this rotational driving force is transmitted to the shaft 117. The shaft 117 rotates counterclockwise as viewed from above. When the shaft 117 rotates, the rotational driving force of the rotor 152 (drive motor 116) is transmitted to the movable scroll 126 (compression mechanism 115) connected to the shaft 117, and the movable scroll 126 is driven. At this time, since the rotation of the movable scroll 126 is prohibited by the Oldham joint, the movable scroll 126 performs a revolving motion with an eccentric radius around the central axis OO without rotating.

  Next, the detailed configuration of the discharge pipe 119 and the back pressure chamber communication path forming member 180 will be described, and then the operation of the valve body 171 will be described.

<Configuration of discharge pipe and back pressure chamber communication passage forming member>
(A) Configuration of Discharge Pipe The discharge pipe 119 is mainly composed of a tubular first discharge part 191 and a tubular second discharge part 192 whose inner diameter is larger than the inner diameter of the first discharge part 191. . One end of the first discharge part 191 penetrates the cylindrical part 111 of the casing 110 in the horizontal direction, and the other end is directly connected to a device (not shown) constituting the refrigerant circuit. The second discharge part 192 penetrates the cylindrical part 111 of the casing 110 in the horizontal direction. The inner diameter of the second discharge part 192 is the same as the outer diameter of the first discharge part 191, and the inner peripheral surface thereof is in close contact with the outer peripheral surface of one end of the first discharge part 191 by welding or the like. The second discharge part 192 includes a refrigerant introduction part 193, a path reduction part 194, and a cylindrical part 195, and these are integrally formed.

  The refrigerant introduction portion 193 is a cylindrical introduction portion that guides the refrigerant in the discharge refrigerant space S15 to the internal space S16 of the discharge pipe 119. The path contraction part 194 is a cylindrical part connected to the downstream side in the refrigerant flow direction of the refrigerant introduction part 193, and the longitudinal cross-sectional area of the internal space in the second discharge part 192 (from the upstream side to the downstream side in the refrigerant flow direction) The cross-sectional area perpendicular to the refrigerant flow direction is reduced. The path reducing portion 194 is configured such that the longitudinal sectional area of the inner space at the downstream end 194a in the refrigerant flow direction is the smallest in the longitudinal sectional area of the internal space S16 of the entire discharge pipe 119. In other words, the path reduction unit 194 functions as a throttle unit that increases the flow rate of the refrigerant discharged from the discharge port 141. Here, the inner space of the path reduction unit 194 in the internal space S16 of the discharge pipe 119, that is, the space in which the cross-sectional area perpendicular to the refrigerant flow direction is reduced is referred to as a path reduction space S16a. The cylindrical portion 195 is connected to the downstream side of the path reducing portion 194 in the refrigerant flow direction. The cylindrical part 195 has the first discharge part 191 in close contact with the inner peripheral surface thereof. The cylindrical portion 195 is formed with a through-hole 195 a that allows one end portion of the back pressure chamber communication path forming member 180 to pass through on the outer peripheral surface thereof. The through-hole 195a is formed in the vicinity of the path reduction part 194 in the internal space S16 of the discharge pipe 119 constituting the discharge refrigerant path 147, that is, in the vicinity of the path reduction space S16a.

(B) Configuration of Back Pressure Chamber Communication Channel Forming Member The back pressure chamber communication channel forming member 180 is a tubular member, and one end of the back pressure chamber communication channel forming member 180 is connected to the second mounting member 162 via the through-hole 173 so that one end is The back pressure chamber 172 opens. Further, the back pressure chamber communication path forming member 180 has the other end connected to the cylindrical portion 195 of the discharge pipe 119 via the through-hole 195a, so that the other end is connected to the internal space S16 of the discharge pipe 119. It is open. Here, since the through hole 195a is formed near the path reduction space S16a in the internal space S16 of the discharge pipe 119, the other end of the back pressure chamber communication path forming member 180 is the internal space S16 of the discharge pipe 119. Is opened in the vicinity of the path reduction space S16a. As described above, the back pressure chamber communication path forming member 180 has an inner space S16 (specifically, the inner space S16 of the discharge pipe 119 constituting the discharge refrigerant path 147 (specifically, the path reduced space S16a). Back pressure chamber communication passage 181 is formed.

  As described above, in the present modification, the path reducing space S16a is provided in the discharge refrigerant path 147 (specifically, the internal space S16 of the discharge pipe 119) by the path reducing unit 194 that reduces the cross-sectional area orthogonal to the refrigerant flow direction. Is formed. Therefore, the refrigerant discharged from the discharge port 141 and flowing through the discharge refrigerant path 147 (specifically, the vertical through space S13, the gap space S14, and the discharge refrigerant space S15) and flowing into the internal space S16 of the discharge pipe 119 passes through the path. When passing through the reduced space S16a, the flow velocity increases. Then, when the flow rate of the refrigerant is increased by the path reduction space S16a, the pressure of the refrigerant at the portion is decreased. Here, the back pressure chamber communication path 181 allows the back pressure chamber 172 to communicate with the vicinity of the path reduced space S16a in the discharge refrigerant path 147. Therefore, the refrigerant located in the back pressure chamber communication path 181 connected in the vicinity of the pressure of the refrigerant in the path reduction space S16a is reduced to the discharge refrigerant path 147 (specifically, the tubular shape of the discharge pipe 119). The phenomenon of flowing into the inner space of the portion 195 occurs (see the dotted arrow in FIG. 7). That is, the through hole 195 a formed in the discharge pipe 119 functions as an introduction port that guides the refrigerant located in the back pressure chamber communication path 181 to the discharge refrigerant path 147. As described above, in the present modification, during the operation of the scroll compressor 101, the refrigerant pressure is reduced in the path reduction unit 194 of the discharge refrigerant path 147, and the refrigerant in the back pressure chamber communication path 181 is drawn into the discharge refrigerant path 147. The ejector effect can be produced.

  The refrigerant drawn from the back pressure chamber communication path 181 into the discharge refrigerant path 147 (the inner space of the tubular portion 195 of the discharge pipe 119) is merged with the refrigerant passing through the path reduction space S16a in the discharge refrigerant path 147. Then, it is discharged to the outside of the casing 110.

  Here, it is desirable to increase the cross-sectional area of the discharge port 141 and the through space 13 as much as possible. This is because the valve body 171 can be easily lifted and can be easily fully opened (full lift state). As a result, the refrigerant continues to be drawn into the inner space of the tubular portion 195 of the discharge pipe 119 via the through hole 195a, so that the back pressure chamber 172 has a negative pressure space compared to the pressure of the gap space S14. Become.

<Operation of valve body>
In the stopped state of the scroll compressor 101, the refrigerant pressure in the back pressure chamber 172 and the refrigerant pressure in the vicinity of the vertical through space S13 are equal to each other, so that the valve element 171 is closed by the action of gravity. (See FIG. 8). When the operation of the scroll compressor 101 is started, the valve body 171 rises, immediately contacts the lower surface of the valve presser 162a, and finally becomes fully opened (full lift state) while repeating the collision (see FIG. 1 and FIG. 1). (See FIG. 7). Here, in the present modification, a back pressure chamber communication path 181 is provided that forms a path reduction space S16a in the discharge refrigerant path 147 and communicates the back pressure chamber 172 and a portion of the discharge refrigerant path 147 near the path reduction space S16a. Therefore, the refrigerant in the back pressure chamber communication path 181 and the back pressure chamber 172 can flow into the discharge refrigerant path 147 (refer to the bold and solid arrows in FIG. 7). As a result, the refrigerant in the back pressure chamber 172 continues to be drawn into the inner space of the tubular portion 195 of the discharge pipe 119 via the through hole 195a, so that the pressure in the back pressure chamber 172 is lower than that in the gap space S14. The pressure can be maintained. And the valve body 171 can also maintain a fully open state.

  When the scroll compressor 101 is stopped, the refrigerant pressure in the back pressure chamber 172 and the refrigerant pressure in the vicinity of the upper and lower through space S13 become equal to each other, and the valve body 171 moves downward by the action of gravity. Then, the discharge port 141 and the upper and lower through space S13 are shifted to a closed state (see FIG. 8). On the other hand, when the scroll compressor 101 is stopped, at the same time, the refrigerant in the high-pressure space S11 flows backward toward the compression chamber 140. Here, in this modified example, after the scroll compressor 101 is stopped, the refrigerant flows into the back pressure chamber 172 via the back pressure chamber communication path 181 (see the thick arrow in FIG. 8). Then, when the refrigerant flows into the back pressure chamber 172, the refrigerant flow (dynamic pressure) acts as a force that pushes the valve body 171 downward. Therefore, the refrigerant that flows backward from the high-pressure space S11 can be quickly avoided from entering the compression chamber 140.

<Operation of scroll compressor>
(A) Flow of refrigerant When the drive motor 116 is driven, the rotor 152 rotates. As a result, the shaft 117 fixed to the rotor 152 performs an axial rotation motion. The rotational driving force of the shaft 117 is transmitted to the movable scroll 126 through the upper end bearing 126c. The eccentric portion 117b connected to the movable scroll 126 of the shaft 117 is eccentric with respect to the central axis OO. The movable scroll 126 is prevented from rotating by an Oldham joint. As a result, the movable scroll 126 performs a revolving motion without rotation.

  The low-temperature and low-pressure refrigerant before compression fills the low-pressure space S12 through the suction pipe 118 and is then sucked into the compression chamber 140 through the suction hole. By the revolving motion of the movable scroll 126, the volume of the compression chamber 140 is gradually reduced while moving from the outer peripheral portion of the fixed scroll 124 toward the center portion. As a result, the refrigerant in the compression chamber 140 is compressed into a high-temperature and high-pressure compressed refrigerant. The compressed refrigerant is discharged upward from the discharge port 141 and flows into the internal space S16 of the discharge pipe 119 via the upper and lower through spaces S13, the gap space S14, and the discharge refrigerant space S15. And it discharges outside the casing 110 by the internal space S16 of the discharge pipe 119.

  Part of the refrigerant that has flowed into the casing 110 via the suction pipe 118 descends through the motor cooling passage 55 and reaches the space below the drive motor 16. Thereafter, the direction of flow of the refrigerant is reversed, the motor cooling passage 155 and the air gap are raised, and again flow into the space between the compression mechanism 115 and the drive motor 116 in the axial direction.

(B) Flow of lubricating oil When the compression mechanism 115 is driven by the axial rotation of the shaft 117, the lubricating oil stored in the oil storage space P1 rises in the axial direction through the oil supply hole extending in the axial direction.

  The lubricating oil rising in the axial direction through the oil supply hole is supplied to the sliding portion of the compression mechanism 115 via the oil supply hole formed in the movable scroll 126. Further, the lubricating oil that rises in the axial direction through the oil supply hole is also branched into a part of the oil supply hole that extends in the radial direction to lubricate the sliding portion between the shaft 117 (eccentric portion 117b) and the upper end bearing 126c, The sliding part between the upper part of 117 (main shaft part 117a) and the bearing part 132 of the housing 123 is lubricated, and the sliding part between the lower part of the shaft 117 (main shaft part 117a) and the lower bearing 160 is lubricated. And the lubricating oil which lubricated each sliding part falls in the oil storage space P1.

<Features>
As described above, in the present modification, the refrigerant in the back pressure chamber communication path 181 and the back pressure chamber 172 communicating with the back pressure chamber communication path 181 is transferred to the discharge refrigerant path 147 by the path contraction unit 194 in the discharge refrigerant path 147. By making it flow in, a difference can be provided between the refrigerant pressure in the back pressure chamber 172 and the refrigerant pressure in the vicinity of the discharge port 141.

  As described above, in the present embodiment, the refrigerant pressure in the back pressure chamber 172 can be lowered by the back pressure chamber communication path 181 and the path contraction unit 194 in the discharge refrigerant path 147. Therefore, it becomes easy to maintain the valve body 171 in contact with the inner surface of the second mounting member 162 during operation of the scroll compressor 101. In the present modification, the valve body 171 can be positioned in the gap space S14 of the discharge refrigerant path 147 so as not to disturb the flow of the refrigerant discharged from the discharge port 141, so that the valve body 171 is discharged from the discharge port 141. The pressure loss of the refrigerant can be reduced. Therefore, the efficiency of the scroll compressor 101 can be improved.

  Further, since the refrigerant pressure in the back pressure chamber 172 can be reduced, the valve body 171 can be easily maintained in contact with the inner surface of the second mounting member 162 during operation of the scroll compressor 101. Therefore, it is possible to suppress the occurrence of chattering in which the valve body 171 repeats the open state and the closed state, and abnormal noise is generated due to contact between the valve body 171 and the upper surface of the first mounting member 161 and the inner surface of the second mounting member 162. Can also be suppressed.

  In addition, after the scroll compressor 101 is stopped, the refrigerant that has flowed back through the back pressure chamber communication passage 181 flows into the back pressure chamber 172, so that the flow of the refrigerant pushes the valve element 171 downward at least. Acts as Therefore, the valve body 171 can be switched to the closed state as soon as possible after the scroll compressor 101 is stopped.

(5-2) Modification B
In the above-described embodiment, it has been described that the path reduction unit 49 is formed in the intermediate space S4 of the fixed scroll 24. However, the present invention is not limited to this. For example, the cross-sectional area perpendicular to the refrigerant flow direction of the through space S5 of the housing 23 is changed to the cross-sectional area perpendicular to the refrigerant flow direction of the intermediate space S4 without changing the cross-sectional area perpendicular to the refrigerant flow direction in the entire intermediate space S4. You may reduce rather than. That is, the path reducing portion 49 may be formed in the through space S5 of the housing 23. In this case, the back pressure chamber communication path is formed with a third back pressure chamber communication path (not shown) in addition to the first back pressure chamber communication path 82 and the second back pressure chamber communication path 83. . The third back pressure chamber communication path is formed in the housing 23 so as to communicate with the second back pressure chamber communication path 83. Specifically, the third back pressure chamber communication passage is constituted by an upper and lower passage communicating with the second back pressure chamber communication passage 83 and extending in the vertical direction, and a horizontal passage communicating with the upper and lower passage and extending in the horizontal direction. . The horizontal passage communicates with a through space S5 as a path reduction space in the discharged refrigerant path 47.

  Even in this case, it is possible to obtain the same effect as the above embodiment.

    The present invention can be variously applied to a scroll compressor provided with a valve body that opens and closes a discharge port that discharges a compressed refrigerant.

DESCRIPTION OF SYMBOLS 1,101 Scroll compressor 15,115 Compression mechanism 23,123 Housing 24,124 Fixed scroll 26,126 Movable scroll 40,140 Compression chamber 41,141 Discharge port 44 Lid member 47,147 Discharge refrigerant path 49,194 Path contraction part 71,171 Valve body 72,172 Back pressure chamber 81,181 Back pressure chamber communication path 82 First back pressure chamber communication path 83,84 Second back pressure chamber communication path 161 First mounting member 162 Second mounting member 180 Back pressure Chamber communication passage forming member 181 Back pressure chamber communication passage S3 Recessed space S4 Intermediate space S5 Through space S13 Vertical through space S14 Gap space S15 Discharge refrigerant space S16 Internal space of discharge pipe

JP-A-4-241702 JP 2004-353565 A

Claims (3)

A compression mechanism (15, 115) in which discharge ports (41, 141) for discharging the compressed refrigerant are formed;
A discharge refrigerant path (47, 147) through which the refrigerant discharged from the discharge port flows;
A valve body (71, 171) located in the discharge refrigerant path and switching between an open state in which the discharge port of the compression mechanism is opened and a closed state in which the discharge port of the compression mechanism is closed;
Back pressure chambers (72, 172) formed on the opposite side of the discharge port across the valve body;
With
In the middle of the discharge refrigerant path, a path reduction part (49, 194) whose cross-sectional area perpendicular to the refrigerant flow direction is reduced is formed, and the vicinity of the path reduction part and the back pressure chamber are connected to each other. Back pressure chamber communication passages (81, 181) for communication are connected,
Scroll compressor (1, 101). The compression mechanism (15) includes a movable scroll (26), a compression scroll (40) that meshes with the movable scroll and compresses the refrigerant together with the movable scroll, and a fixed scroll (S3) formed on the upper surface (S3). 24)
A lid member (44) attached to the upper surface of the fixed scroll so as to cover the recessed space of the fixed scroll from above; and a housing (23) for placing the compression mechanism;
The housing is formed with a through space (S5) penetrating vertically.
The discharge refrigerant path is formed by the concave space, the through space, and an intermediate space (S4) formed in the fixed scroll so as to communicate the concave space and the through space.
The discharge port is formed in the fixed scroll so as to open into the recessed space,
The back pressure chamber is recessed in the lower surface of the lid member so as to communicate with the recessed space,
The back pressure chamber communication path includes a first back pressure chamber communication path (82) that is formed in the lid member and communicates with the back pressure chamber, and is formed in the fixed scroll and in the vicinity of the path contracting portion in the discharge refrigerant path. And a second back pressure chamber communication path (83, 84) for communicating with the first back pressure chamber communication path,
When the valve body is in a fully open state, the upper surface of the valve body contacts the lower surface of the lid member to close the back pressure chamber, and when the valve body is in the closed state, the lower surface contacts the fixed scroll. Open the back pressure chamber,
The path reduction part (49) is formed in the intermediate space.
The scroll compressor (1) according to claim 1. The compression mechanism (115) includes a movable scroll (126), and a fixed scroll (124) that meshes with the movable scroll and forms a compression chamber (140) that compresses the refrigerant together with the movable scroll.
The discharge port (141) is formed on the upper surface of the fixed scroll,
A vertical attachment space (S13) that penetrates in the vertical direction and communicates with the discharge port is formed, and a first attachment member (161) attached to the upper surface of the fixed scroll, attached to the upper surface of the first attachment member, A second mounting member (162) that forms a gap space (S14) between the first mounting member and the first mounting member, and the first mounting member and the second mounting member are enclosed from above, and the inner surface of the first mounting member is in close contact with the first mounting member A cover member (112), a discharge pipe (119) that discharges the refrigerant discharged from the discharge port to the outside and penetrates the cover member, and a back pressure chamber that forms the back pressure chamber communication path (181) A communication path forming member (180),
The discharge refrigerant path includes an upper and lower through space, a gap space, a discharge refrigerant space (S15) between the first mounting member, the second mounting member, and the cover member, and an internal space of the discharge pipe. (S16) and
The back pressure chamber (172) is formed in the second mounting member so as to communicate with the gap space,
When the valve body (171) is in the fully open state in the gap space, the upper surface of the valve body (171) contacts the inner surface of the second mounting member to close the back pressure chamber. Open and close the upper and lower penetrating spaces together with the discharge port while opening the back pressure chamber with its lower surface contacting the upper surface of the first mounting member when in the closed state,
The path reduction part (194) is formed in the discharge pipe,
The back pressure chamber communication path forming member is located in the discharge refrigerant space, and one end is connected to the second mounting member and opens to the back pressure chamber, and the other end is connected to the discharge pipe and the path is reduced. Opening in the vicinity of the part,
The scroll compressor (101) according to claim 1.

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