Scroll compressor

Abstract

To improve the reliability of a scroll-type compressor.SOLUTION: Each of grooves 41 is partially covered with a swirling spiral wall 26b which opposes a compression chamber 27 on the way of compression communicating with each of sub-discharge ports 40 so as to make the compression chamber 27 on the way of different compression and the compression chamber 27 communicating with a main discharge port 25h not communicate with each other. Then, each groove 41 constantly communicates with any of the compression chambers 27. By this constitution, an operation region in which each sub-discharge port 40 does not communicate with the inside of the compression chamber 27 is reduced compared with the case that each groove 41 is not formed at a fixed baseboard 25a on which each sub-discharge port 40 is formed. Therefore, a refrigerant gas is discharged from each sub-discharge port 40 in a further wider operation region. As a result, since an operation region in which a refrigerant gas cannot be discharged from each sub-discharge port 40 is reduced, an operation region in which pressure in the compression chamber 27 abnormally becomes high is reduced.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present invention relates to a scroll compressor.

Background Art

[0002] A scroll compressor has a fixed scroll and a orbiting scroll. The fixed scroll has a fixed substrate and a fixed spiral wall. The fixed spiral wall stands up from the fixed substrate. The orbiting scroll has an orbiting substrate and an orbiting spiral wall. The orbiting substrate faces the fixed substrate. The orbiting spiral wall stands up from the orbiting substrate toward the fixed substrate. The orbiting spiral wall meshes with the fixed spiral wall. A plurality of compression chambers are defined by the fixed scroll and the orbiting scroll. A main discharge port is formed at the center of the fixed substrate. The main discharge port discharges the compressed fluid.

[0003] In such a scroll compressor, for example, when liquid refrigerant is sucked into the compression chamber, liquid compression may occur in the compression chamber. When liquid compression occurs in the compression chamber in this way, there is a risk that the pressure in the compression chamber will become abnormally high. If such over-compression occurs in the compression chamber, problems such as deformation of the fixed spiral wall and the orbiting spiral wall may occur, deteriorating the reliability of the scroll compressor.

[0004] Therefore, for example, as in Patent Document 1, a scroll compressor provided with a sub-discharge port is known. In the scroll compressor of Patent Document 1, in at least one of the fixed scroll and the orbiting scroll, the sub-discharge port penetrates the spiral wall and the substrate. The sub-discharge port discharges the fluid in the compression chamber when the pressure in the compression chamber becomes equal to or higher than the set pressure. According to this, for example, even if liquid refrigerant is sucked into the compression chamber, the liquid refrigerant is discharged from the sub-discharge port before the pressure in the compression chamber becomes abnormally high. Therefore, it is possible to avoid the pressure in the compression chamber becoming abnormally high.

Prior Art Documents

Patent Documents

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 61-223288 [Summary of the Invention] [Problems to be Solved by the Invention]

[0006] However, in a configuration where the sub-discharge port penetrates the spiral wall as in Patent Document 1, in order to form the sub-discharge port in the spiral wall, it is necessary to design the width of the spiral wall wider. Therefore, the volume of the compression chamber decreases by the amount of the widened design of the spiral wall width. On the other hand, if the width of the spiral wall is designed wider without reducing the volume of the compression chamber, the size of the scroll compressor will inevitably increase.

[0007] Therefore, for example, it is conceivable to form the sub-discharge port on at least one of the fixed substrate and the orbiting substrate without penetrating the spiral wall. The sub-discharge port is arranged at a position different from the main discharge port. According to this, since there is no need to design the width of the spiral wall wider, the volume of the compression chamber does not decrease, and the size of the scroll compressor does not increase.

[0008] However, when the sub-discharge port is formed on at least one of the fixed substrate and the orbiting substrate in this way, depending on the arrangement position of the sub-discharge port, there is an operating region where the sub-discharge port does not communicate with the inside of the compression chamber. Therefore, there is an operating region where the fluid in the compression chamber cannot be discharged from the sub-discharge port. Then, in the operating region where the fluid cannot be discharged from the sub-discharge port, there is a risk that the pressure in the compression chamber becomes abnormally high. Therefore, it is desired to improve the reliability of the scroll compressor by enabling the fluid to be discharged from the sub-discharge port in a wider operating region. [Means for Solving the Problems]

[0009] The scroll compressor for solving the above problems includes a fixed substrate, a fixed scroll having a fixed spiral wall standing up from the fixed substrate, a turning substrate facing the fixed substrate, and a turning scroll having a turning spiral wall standing up from the turning substrate and meshing with the fixed spiral wall. A plurality of compression chambers are defined by the fixed scroll and the turning scroll. A main discharge port for discharging the compressed fluid is formed at the center of the fixed substrate. At least one of the fixed substrate and the turning substrate has a sub-discharge port disposed at a position different from the main discharge port and formed for discharging the fluid in the compression chamber when the pressure in the compression chamber becomes equal to or higher than a set pressure. In the substrate provided with the sub-discharge port, a groove communicating with the opening on the compression chamber side of the sub-discharge port is formed. The groove is partially covered by the opposing spiral walls so as not to communicate with another compression chamber during compression and the compression chamber communicating with the main discharge port with respect to the compression chamber during compression communicating with the sub-discharge port, and is always communicated with one of the compression chambers.

[0010] According to this, the groove is partially covered by the opposing spiral walls so as not to communicate with another compression chamber during compression and the compression chamber communicating with the main discharge port with respect to the compression chamber during compression communicating with the sub-discharge port. And the groove is always communicated with one of the compression chambers. Therefore, since the sub-discharge port is always communicated with one of the compression chambers through the groove, compared with the case where no groove is formed in the substrate provided with the sub-discharge port, the operation region where the sub-discharge port does not communicate with the inside of the compression chamber can be reduced. Thus, the fluid can be discharged from the sub-discharge port in a wider operation region. As a result, since the operation region where the fluid cannot be discharged from the sub-discharge port is reduced, the operation region where the pressure in the compression chamber becomes abnormally high can be reduced. As described above, the reliability of the scroll compressor can be improved.

[0011] In the scroll compressor described above, the width of the groove may be narrower than the width of the spiral wall of the fixed spiral wall and the orbiting spiral wall that overlaps with the sub-discharge port. According to this, with respect to the compression chamber during compression that communicates with the sub-discharge port, the compression chamber during compression and the compression chamber that communicates with the main discharge port are prevented by the spiral wall from communicating with each other through the groove. Therefore, since the compression of the fluid in each compression chamber is stably performed, the reliability of the scroll compressor can be further improved.

[0012] In the scroll compressor described above, either one of the groove and the sub-discharge port may communicate from a predetermined timing when the compression of the fluid starts in the compression chamber. According to this, for example, even if liquid refrigerant is inhaled into the compression chamber, the liquid refrigerant can be discharged from the sub-discharge port from a predetermined timing when the compression of the fluid starts in the compression chamber. Therefore, it is easy to avoid the occurrence of liquid compression in the compression chamber, so it is possible to avoid the pressure in the compression chamber from becoming abnormally high.

[0013] In the scroll compressor described above, the sub-discharge port and the groove are formed in the fixed substrate, and a reed valve for opening and closing the main discharge port and the sub-discharge port is provided on the surface of the fixed substrate opposite to the surface on which the fixed spiral wall is provided.

[0014] According to this, the reed valve can prevent the fluid discharged from the main discharge port and the sub-discharge port from flowing back to the main discharge port and the sub-discharge port. Thus, when the sub-discharge port is formed in the fixed substrate, a reed valve for opening and closing the main discharge port and the sub-discharge port needs to be provided on the surface of the fixed substrate opposite to the surface on which the fixed spiral wall is provided.

[0015] Here, for example, in order to reduce the operating region where the sub-discharge port does not communicate with the compression chamber, it is conceivable to increase the number of sub-discharge ports formed in the fixed substrate without forming a groove in the fixed substrate. However, as the number of sub-discharge ports formed in the fixed substrate increases, the number of reed valves for opening and closing the sub-discharge ports increases or the shape of the reed valves becomes complicated, which is not preferable. Therefore, a groove is formed in the fixed substrate. According to this, it is possible to reduce the operating region where the sub-discharge port does not communicate with the compression chamber while minimizing the number of sub-discharge ports formed in the fixed substrate. Therefore, since the number of reed valves does not increase and the shape of the reed valves does not become complicated, it is possible to improve the reliability of the scroll compressor while simplifying the configuration of the scroll compressor.

[0016] In the above scroll compressor, a pair of the sub-discharge ports are provided, and the pair of sub-discharge ports are respectively arranged so as to sandwich the main discharge port, and the groove may be formed in the substrate provided with the sub-discharge port so as to communicate with each sub-discharge port.

[0017] According to this, since the operating region where the fluid cannot be discharged from the sub-discharge port is further reduced, it is possible to further reduce the operating region where the pressure in the compression chamber becomes abnormally high. Therefore, the reliability of the scroll compressor can be further improved.

[0018] In the above scroll compressor, the groove may have a curved shape extending along a spiral wall rising from the substrate provided with the sub-discharge port. A groove having a curved shape extending along a spiral wall rising from a substrate provided with a sub-discharge port is suitable as a groove that is partially covered by an opposing spiral wall and is always communicated with one of the compression chambers.

Effect of the Invention

[0019] According to this invention, the reliability of the scroll compressor can be improved.

Brief Description of the Drawings

[0020]

Figure 1

Figure 2

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Figure 4

Figure 5

Figure 6

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Figure 8

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Figure 10

Figure 11

Figure 12

Figure 13

Figure 14

Figure 15

Figure 16

Figure 17

Embodiments for Carrying Out the Invention

[0021] Hereinafter, an embodiment in which a scroll compressor is embodied will be described with reference to FIGS. 1 to 17. The scroll compressor of this embodiment is used, for example, in a vehicle air conditioner. <Basic configuration of scroll compressor 10> As shown in FIG. 1, the scroll compressor 10 includes a cylindrical housing 11. The housing 11 has a motor housing 12, a shaft support housing 13, and a discharge housing 14. The motor housing 12, the shaft support housing 13, and the discharge housing 14 are made of a metal material. The motor housing 12, the shaft support housing 13, and the discharge housing 14 are made of, for example, aluminum. Further, the scroll compressor 10 includes a rotating shaft 15 housed in the housing 11.

[0022] The motor housing 12 has a plate-shaped end wall 12a and a cylindrical peripheral wall 12b. The peripheral wall 12b extends cylindrically from the outer peripheral portion of the end wall 12a. The axial direction of the peripheral wall 12b coincides with the axial direction of the rotating shaft 15. The motor housing 12 has a suction port 12h. The suction port 12h is formed in the peripheral wall 12b. The suction port 12h is formed in a portion of the peripheral wall 12b closer to the end wall 12a. The suction port 12h communicates the inside and outside of the motor housing 12. The suction port 12h sucks refrigerant gas as a fluid.

[0023] The motor housing 12 has a cylindrical boss portion 12d. The boss portion 12d protrudes from the inner surface of the end wall 12a. The first end, which is one end in the axial direction of the rotating shaft 15, is inserted into the boss portion 12d. The scroll compressor 10 includes a rolling bearing 16. The rolling bearing 16 is provided between the inner peripheral surface of the boss portion 12d and the outer peripheral surface of the first end of the rotating shaft 15. And the first end of the rotating shaft 15 is rotatably supported by the motor housing 12 via the rolling bearing 16.

[0024] The shaft support housing 13 has a disk-shaped end wall 17 and a cylindrical peripheral wall 18. The peripheral wall 18 extends cylindrically from the outer peripheral portion of the end wall 17. The axial direction of the peripheral wall 18 coincides with the axial direction of the rotary shaft 15. The shaft support housing 13 has an annular flange wall 19. The flange wall 19 extends radially outward of the rotary shaft 15 from the end portion on the side opposite to the end wall 17 on the outer peripheral surface of the peripheral wall 18. The outer peripheral portion of the flange wall 19 is in contact with the open end of the peripheral wall 12b of the motor housing 12.

[0025] The shaft support housing 13 has an insertion hole 17a. The insertion hole 17a is formed in the central portion of the end wall 17. The insertion hole 17a penetrates the end wall 17 in the thickness direction. The rotary shaft 15 is inserted into the insertion hole 17a. The end face 15e located on the second end side, which is the other end in the axial direction of the rotary shaft 15, is located inside the peripheral wall 18. The scroll type compressor 10 is provided with a rolling bearing 21. The rolling bearing 21 is provided between the inner peripheral surface of the peripheral wall 18 and the outer peripheral surface of the rotary shaft 15. And the rotary shaft 15 is rotatably supported by the shaft support housing 13 via the rolling bearing 21. Therefore, the rotary shaft 15 is rotatably supported by the housing 11.

[0026] The housing 11 has a motor chamber S1. The motor chamber S1 is partitioned by the motor housing 12 and the shaft support housing 13. The motor chamber S1 communicates with the suction port 12h. Refrigerant gas from the suction port 12h is inhaled into the motor chamber S1.

[0027] The scroll compressor 10 is provided with an electric motor 22. The electric motor 22 is housed in the motor chamber S1. The electric motor 22 has a cylindrical stator 23 and a cylindrical rotor 24. The rotor 24 is disposed inside the stator 23. The rotor 24 rotates integrally with the rotating shaft 15. The stator 23 surrounds the rotor 24. The rotor 24 has a rotor core 24a fixed to the rotating shaft 15 and a plurality of permanent magnets (not shown) provided on the rotor core 24a. The stator 23 has a cylindrical stator core 23a and a coil 23b. The stator core 23a is fixed to the inner peripheral surface of the peripheral wall 12b of the motor housing 12. The coil 23b is wound around the stator core 23a. Then, when electric power controlled by an inverter (not shown) is supplied to the coil 23b, the rotor 24 rotates. As a result, the rotating shaft 15 rotates integrally with the rotor 24.

[0028] The discharge housing 14 has a plate-shaped end wall 14a and a cylindrical peripheral wall 14b. The peripheral wall 14b extends cylindrically from the outer peripheral portion of the end wall 14a. The axial direction of the peripheral wall 14b coincides with the axial direction of the rotating shaft 15. The open end of the peripheral wall 14b is in contact with the outer peripheral portion of the flange wall 19.

[0029] The discharge housing 14, the bearing housing 13, and the motor housing 12 are fixed by bolts B1. The bolts B1 pass through the peripheral wall 14b of the discharge housing 14 and the outer peripheral portion of the flange wall 19 and are screwed into the peripheral wall 12b of the motor housing 12. Thereby, the bearing housing 13 is connected to the peripheral wall 12b of the motor housing 12, and the discharge housing 14 is connected to the flange wall 19 of the bearing housing 13. Therefore, the motor housing 12, the bearing housing 13, and the discharge housing 14 are arranged side by side in the axial direction of the rotating shaft 15 in this order.

[0030] The scroll compressor 10 is provided with a discharge chamber S2. The discharge chamber S2 is formed within a discharge housing 14. The discharge housing 14 has a discharge port 14h. The discharge port 14h is formed in an end wall 14a of the discharge housing 14. The discharge port 14h communicates with the discharge chamber S2. The discharge port 14h discharges the refrigerant gas within the discharge chamber S2.

[0031] The discharge port 14h and the suction port 12h are connected by an external refrigerant circuit 20. The external refrigerant circuit 20 has a condenser, an expansion valve, and an evaporator (not shown). The refrigerant gas discharged from the discharge port 14h flows through the external refrigerant circuit 20. The refrigerant gas flowing through the external refrigerant circuit 20 passes through the condenser, the expansion valve, and the evaporator, and then refluxes into the motor chamber S1 through the suction port 12h. The scroll compressor 10 and the external refrigerant circuit 20 constitute a vehicle air conditioner.

[0032] The scroll compressor 10 has a fixed scroll 25 and an orbiting scroll 26. The fixed scroll 25 and the orbiting scroll 26 are disposed inside a peripheral wall 14b of the discharge housing 14. The fixed scroll 25 is positioned closer to the end wall 14a than the orbiting scroll 26 in the axial direction of the rotating shaft 15.

[0033] As shown in FIGS. 1 and 2, the fixed scroll 25 has a fixed base plate 25a and a fixed spiral wall 25b. The fixed base plate 25a is disc-shaped. The fixed spiral wall 25b stands up from the fixed base plate 25a toward the side opposite to the end wall 14a. The fixed scroll 25 has a fixed outer peripheral wall 25c. The fixed outer peripheral wall 25c stands up cylindrically from the outer peripheral portion of the fixed base plate 25a. The fixed outer peripheral wall 25c surrounds the fixed spiral wall 25b. The open end face of the fixed outer peripheral wall 25c is located on the side opposite to the fixed base plate 25a with respect to the tip end face of the fixed spiral wall 25b.

[0034] As shown in FIG. 1, the orbiting scroll 26 has an orbiting base plate 26a and an orbiting spiral wall 26b. The orbiting base plate 26a is disc-shaped. The orbiting base plate 26a faces the fixed base plate 25a. The orbiting spiral wall 26b stands up from the orbiting base plate 26a toward the fixed base plate 25a. The orbiting spiral wall 26b meshes with the fixed spiral wall 25b. The orbiting spiral wall 26b is located inside the fixed outer peripheral wall 25c. The tip surface of the fixed spiral wall 25b contacts the orbiting base plate 26a. The tip surface of the orbiting spiral wall 26b contacts the fixed base plate 25a. And a plurality of compression chambers 27 are defined by the fixed base plate 25a, the fixed spiral wall 25b, the orbiting base plate 26a, and the orbiting spiral wall 26b. Therefore, a plurality of compression chambers 27 are defined by the fixed scroll 25 and the orbiting scroll 26. Each compression chamber 27 compresses the refrigerant gas.

[0035] The orbiting scroll 26 has a cylindrical boss portion 26c. The boss portion 26c protrudes from the end face 26e of the orbiting base plate 26a on the side opposite to the fixed base plate 25a. The axial direction of the boss portion 26c coincides with the axial direction of the rotating shaft 15.

[0036] The orbiting scroll 26 has a plurality of recesses 26d. The plurality of recesses 26d are formed around the boss portion 26c on the end face 26e of the orbiting base plate 26a. The plurality of recesses 26d are arranged at predetermined intervals in the circumferential direction of the rotating shaft 15. In FIG. 1, for the sake of explanation, only one recess 26d is shown. An annular ring member 28 is fitted into each recess 26d. The scroll compressor 10 includes a plurality of pins 29. Each pin 29 is provided on the shaft support housing 13. Each pin 29 protrudes from the end face 13e of the shaft support housing 13 on the side of the discharge housing 14. Each pin 29 is inserted into each ring member 28.

[0037] The scroll compressor 10 includes an eccentric shaft 31. The eccentric shaft 31 protrudes toward the orbiting scroll 26 from a portion eccentric with respect to the axis L1 of the rotating shaft 15 at the end face 15e of the rotating shaft 15. The eccentric shaft 31 is integrally formed with the rotating shaft 15. The axial direction of the eccentric shaft 31 coincides with the axial direction of the rotating shaft 15. The eccentric shaft 31 is inserted into the boss portion 26c.

[0038] The scroll compressor 10 includes a balance weight 32 and a bush 33. The balance weight 32 is integrated with the bush 33. The bush 33 is fitted onto the outer peripheral surface of the eccentric shaft 31. The balance weight 32 is integrally formed with the bush 33. The balance weight 32 is housed within the peripheral wall 18 of the bearing housing 13. The orbiting scroll 26 is supported by the eccentric shaft 31 so as to be relatively rotatable with respect to the eccentric shaft 31 via the bush 33 and the rolling bearing 34.

[0039] The rotation of the rotating shaft 15 is transmitted to the orbiting scroll 26 via the eccentric shaft 31, the bush 33, and the rolling bearing 34, and the orbiting scroll 26 rotates about its own axis. Then, when each pin 29 contacts the inner peripheral surface of each ring member 28, the rotation of the orbiting scroll 26 about its own axis is blocked, and only the revolution of the orbiting scroll 26 is permitted. As a result, the orbiting scroll 26 revolves while the orbiting spiral wall 26b contacts the fixed spiral wall 25b, and the refrigerant gas is compressed as the volume of the compression chamber 27 decreases. Therefore, the orbiting scroll 26 revolves as the rotating shaft 15 rotates. The balance weight 32 cancels out the centrifugal force acting on the orbiting scroll 26 when the orbiting scroll 26 revolves, and reduces the amount of imbalance of the orbiting scroll 26.

[0040] The scroll compressor 10 includes a first groove 35, a first hole 36, and a second groove 37. A plurality of the first grooves 35 are formed on the inner peripheral surface of the peripheral wall 12b of the motor housing 12. Each first groove 35 opens at the open end of the peripheral wall 12b. A plurality of the first holes 36 are formed on the outer peripheral portion of the flange wall 19 of the bearing housing 13. Each first hole 36 penetrates the flange wall 19 in the thickness direction. Each first hole 36 communicates with each first groove 35 respectively. A plurality of the second grooves 37 are formed on the inner peripheral surface of the peripheral wall 14b of the discharge housing 14. Each second groove 37 communicates with each first hole 36 respectively. In FIG. 1, for convenience of illustration, only one of the first groove 35, the first hole 36, and the second groove 37 is shown respectively.

[0041] As shown in FIGS. 1 and 2, the fixed scroll 25 has a pair of suction ports 38. Each suction port 38 is formed on the fixed outer peripheral wall 25c of the fixed scroll 25. Each suction port 38 penetrates the fixed outer peripheral wall 25c in the thickness direction. Each suction port 38 communicates with each second groove 37 respectively. The pair of suction ports 38 are arranged, for example, at positions that are 180 degrees apart in the circumferential direction of the fixed outer peripheral wall 25c.

[0042] As shown in FIG. 1, the scroll compressor 10 includes a suction chamber 39. The suction chamber 39 communicates with the pair of suction ports 38 respectively. The suction chamber 39 is formed inside the fixed outer peripheral wall 25c. The suction chamber 39 is a space inside the space of the fixed outer peripheral wall 25c that communicates with at least one of the pair of suction ports 38 as the orbiting scroll 26 orbits. Depending on the position of the orbiting scroll 26, the suction chamber 39 may communicate with one of the pair of suction ports 38 and not communicate with the other of the pair of suction ports 38. Furthermore, depending on the position of the orbiting scroll 26, the suction chamber 39 may communicate with both of the pair of suction ports 38 in some cases.

[0043] The refrigerant gas in the motor chamber S1 passes through each first groove 35, each first hole 36, each second groove 37, and each suction port 38 and is sucked into the suction chamber 39. The refrigerant gas sucked into the suction chamber 39 is compressed in the compression chamber 27 by the revolution of the orbiting scroll 26.

[0044] A back pressure chamber S3 is formed in the housing 11. The back pressure chamber S3 is located inside the peripheral wall 18 of the support housing 13. Therefore, the back pressure chamber S3 is formed at a position in the housing 11 on the side opposite to the fixed substrate 25a with respect to the orbiting substrate 26a. The support housing 13 partitions the back pressure chamber S3 and the motor chamber S1.

[0045] A back pressure introduction passage 26f is formed in the orbiting scroll 26. The back pressure introduction passage 26f penetrates the orbiting substrate 26a and the orbiting spiral wall 26b. The back pressure introduction passage 26f introduces a part of the refrigerant gas in the compression chamber 27 into the back pressure chamber S3. Since a part of the refrigerant gas in the compression chamber 27 is introduced into the back pressure chamber S3 through the back pressure introduction passage 26f, the back pressure chamber S3 has a higher pressure than the motor chamber S1. And as the pressure in the back pressure chamber S3 increases, the orbiting scroll 26 is biased toward the fixed scroll 25 so that the tip surface of the orbiting spiral wall 26b is pressed against the fixed substrate 25a.

[0046] <Main discharge port 25h> As shown in FIGS. 1 and 2, a main discharge port 25h is formed at the center of the fixed substrate 25a. The main discharge port 25h is in the shape of a circular hole. The main discharge port 25h penetrates the fixed substrate 25a in the thickness direction. The first end of the main discharge port 25h communicates with the compression chamber 27. The second end of the main discharge port 25h communicates with the discharge chamber S2. The main discharge port 25h discharges the refrigerant gas compressed in the compression chamber 27 to the discharge chamber S2.

[0047] The fixed substrate 25a is formed with sub-discharge ports 40. Therefore, the fixed substrate 25a is a substrate provided with the sub-discharge ports 40. And the fixed scroll wall 25b is a scroll wall that stands up from the substrate provided with the sub-discharge ports 40. As shown in FIG. 2, the scroll compressor 10 is provided with a pair of sub-discharge ports 40. The pair of sub-discharge ports 40 are respectively arranged so as to sandwich the main discharge port 25h. Therefore, each sub-discharge port 40 is arranged at a position different from that of the main discharge port 25h.

[0048] Each sub-discharge port 40 is in the shape of a circular hole. Each sub-discharge port 40 penetrates the fixed substrate 25a in the thickness direction. As shown in FIG. 1, the first end of each sub-discharge port 40 communicates with the compression chamber 27. The second end of each sub-discharge port 40 communicates with the discharge chamber S2. The hole diameter of each sub-discharge port 40 is smaller than the width of the orbiting scroll wall 26b. The orbiting scroll wall 26b is a scroll wall that overlaps each sub-discharge port 40 when the orbiting scroll 26 makes a revolution. Therefore, when the orbiting scroll 26 makes a revolution and the orbiting scroll wall 26b overlaps each sub-discharge port 40, the orbiting scroll wall 26b covers each sub-discharge port 40. Each sub-discharge port 40 discharges the refrigerant gas in the compression chamber 27 when the pressure in the compression chamber 27 becomes equal to or higher than the set pressure.

[0049] <groove 41> As shown in Fig. 2, a groove 41 is formed in the fixed substrate 25a. Therefore, in the present embodiment, the sub-discharge port 40 and the groove 41 are formed in the fixed substrate 25a. The groove 41 is formed in the fixed substrate 25a so as to communicate with each sub-discharge port 40 respectively. Each groove 41 communicates with the opening on the compression chamber 27 side of each sub-discharge port 40. Each groove 41 has a curved shape extending along the fixed scroll wall 25b. Each groove 41 extends from each sub-discharge port 40 along the fixed scroll wall 25b while curving in an arc shape. Thus, each sub-discharge port 40 communicates with the first end in the extending direction of each groove 41. The width of each groove 41 is the same as the aperture diameter of each sub-discharge port 40. Therefore, the width of each groove 41 is narrower than the width of the turning scroll wall 26b. Therefore, the width of each groove 41 is narrower than the width of the turning scroll wall 26b which is the scroll wall overlapping with the sub-discharge port 40.

[0050] Each groove 41 is located on the orbit of the turning scroll wall 26b when the turning scroll 26 is in a revolving motion. When the turning scroll 26 revolves and the turning scroll wall 26b overlaps each groove 41, the turning scroll wall 26b covers a part of each groove 41. Each groove 41 is covered in part by the turning scroll wall 26b which is the opposing scroll wall so as not to communicate the compression chamber 27 during compression that communicates with each sub-discharge port 40 with another compression chamber 27 during compression and the compression chamber 27 communicating with the main discharge port 25h, and is always communicated with one of the compression chambers 27. Each sub-discharge port 40 communicates from a predetermined timing when the compression of the refrigerant gas starts in the compression chamber 27.

[0051] <Reed valve 51> As shown in Fig. 3, the scroll compressor 10 includes a valve mechanism 50. The valve mechanism 50 is provided on the surface of the fixed substrate 25a opposite to the surface where the fixed scroll wall 25b is located. The valve mechanism 50 has a reed valve 51 and a retainer 52. Therefore, the reed valve 51 is provided on the surface of the fixed substrate 25a opposite to the surface where the fixed scroll wall 25b is provided.

[0052] The lead valve 51 is a thin plate that can be elastically deformed. The lead valve 51 is a metal plate. The lead valve 51 has an attachment portion 53, a main valve body 54, and two sub-valve bodies 55. The attachment portion 53, the main valve body 54, and the two sub-valve bodies 55 are integrally formed by a single metal plate.

[0053] The attachment portion 53 is in the shape of an elongated rectangular plate. The main valve body 54 and the two sub-valve bodies 55 are in the shape of elongated rectangular plates. The main valve body 54 and the two sub-valve bodies 55 extend from the attachment portion 53 with their respective longitudinal directions aligned. The longitudinal directions of the main valve body 54 and the two sub-valve bodies 55 are perpendicular to the longitudinal direction of the attachment portion 53.

[0054] The main valve body 54 extends from the attachment portion 53 toward the main discharge port 25h. And the tip of the main valve body 54 covers the main discharge port 25h. Each sub-valve body 55 extends from the attachment portion 53 toward each sub-discharge port 40. And the tip of each sub-valve body 55 covers each sub-discharge port 40.

[0055] The retainer 52 is a plate thicker than the lead valve 51. The retainer 52 and the lead valve 51 are attached to the fixed substrate 25a by screwing a bolt B2 passing through the attachment portion 53 of the retainer 52 and the lead valve 51 into the fixed substrate 25a. The retainer 52 is warped so as to gradually separate from the fixed substrate 25a as it goes from the attachment portion 53 toward the tips of the main valve body 54 and each sub-valve body 55. Thereby, the main valve body 54 and each sub-valve body 55 can swing in a direction of approaching and separating from the fixed substrate 25a with the end on the attachment portion 53 side as a pivot point.

[0056] The lead valve 51 opens the main discharge port 25h by swinging in a direction away from the fixed substrate 25a from the state where the main valve body 54 closes the main discharge port 25h. The lead valve 51 opens each sub-discharge port 40 by swinging in a direction away from the fixed substrate 25a from the state where each sub-valve body 55 closes each sub-discharge port 40. The retainer 52 adjusts the opening degrees of the main valve body 54 and the two sub-valve bodies 55. Thus, the lead valve 51 opens and closes the main discharge port 25h and each sub-discharge port 40.

[0057] The refrigerant gas compressed by the compression chamber 27 and discharged from the main discharge port 25h is discharged from the main discharge port 25h into the discharge chamber S2 by pushing back the main valve body 54. Further, the refrigerant gas discharged from each sub-discharge port 40 when the pressure in the compression chamber 27 becomes equal to or higher than the set pressure is discharged from the sub-discharge port 40 into the discharge chamber S2 by pushing back each sub-valve body 55.

[0058] [Operation of Embodiment] Next, the operation of this embodiment will be described. In FIGS. 4 to 16, the volume change of the compression chamber 27 accompanying the revolution of the orbiting scroll 26 is shown. FIG. 17 shows the relationship between the rotation angle and the compression ratio in the compression chamber 27 indicated by dot hatching in FIGS. 4 to 16, for example. In the description of [Operation of Embodiment], the compression chamber 27 indicated by dot hatching may be simply described as "compression chamber 27A". Also, in the description of [Operation of Embodiment], the compression chamber 27 shown in white may be simply described as "compression chamber 27B".

[0059] In FIG. 4, the timing T0 is shown where each suction chamber 39 into which refrigerant gas is sucked from each suction port 38 is partitioned into a pair of compression chambers 27A by the revolution of the orbiting scroll 26. Since each compression chamber 27A at timing T0 is just before the start of compression of the refrigerant gas, as shown in FIG. 17, the compression ratio of each compression chamber 27A is zero.

[0060] In Fig. 5, the timing T1 at which the compression of the refrigerant gas starts in each compression chamber 27A is shown. As shown in Fig. 5, at the timing T1, each sub-discharge port 40 communicates with each compression chamber 27. Therefore, each sub-discharge port 40 communicates from a predetermined timing at which the compression of the refrigerant gas starts in each compression chamber 27A. At this time, each groove 41 does not communicate with each compression chamber 27B. Therefore, each groove 41 is partially covered by the spiral scroll wall 26b so as not to communicate with another compression chamber 27B in the middle of compression and the compression chamber 27B communicating with the main discharge port 25h, which communicate with the compression chamber 27A in the middle of compression with which each sub-discharge port 40 communicates.

[0061] As shown in Figs. 6 to 8, the volume of each compression chamber 27A decreases as the revolving motion of the spiral scroll 26 progresses. As a result, as shown in Fig. 17, the compression ratio of each compression chamber 27A gradually increases. Also, as shown in Figs. 6 to 8, the area of each groove 41 that communicates with each compression chamber 27A gradually increases as the revolving motion of the spiral scroll 26 progresses.

[0062] As shown in Fig. 9, when the volume of each compression chamber 27A further decreases from the state shown in Fig. 8 as the revolving motion of the spiral scroll 26 progresses, each sub-discharge port 40 starts to overlap with the spiral scroll wall 26b. Then, as shown in Fig. 10, when the spiral scroll 26 further revolves from the state of Fig. 9, the spiral scroll wall 26b covers each sub-discharge port 40. At this time, the end portion of each groove 41 on the side opposite to the sub-discharge port 40 maintains communication with each compression chamber 27A. Therefore, each sub-discharge port 40 maintains communication with each compression chamber 27A via each groove 41. In the states of Figs. 4 to 10, each compression chamber 27A does not communicate with the main discharge port 25h, and each compression chamber 27B communicates with the main discharge port 25h.

[0063] As shown in Fig. 11, when the volume of each compression chamber 27A further decreases as the orbiting scroll 26 orbits, the end of each groove 41 on the side opposite to the sub-discharge port 40 is covered by the orbiting scroll wall 26b. As a result, the communication between each groove 41 and each compression chamber 27A is blocked. Therefore, the communication between each sub-discharge port 40 and each compression chamber 27A is blocked. And at the timing T2 when the communication between each sub-discharge port 40 and each compression chamber 27A is blocked, the communication between one of the pair of compression chambers 27A and the main discharge port 25h is started. On the other hand, at the timing T2, each sub-discharge port 40 communicates with each compression chamber 27B. Each sub-discharge port 40 communicates from a predetermined timing when the compression of the refrigerant gas starts in each compression chamber 27B.

[0064] As shown in Figs. 12 and 13, when the orbiting scroll 26 further orbits from the state of Fig. 11, the pair of compression chambers 27A communicate with the main discharge port 25h. And as shown in Fig. 13, the pair of compression chambers 27A communicate with each other. Further, as shown in Figs. 13 to 16, as the volume of the compression chamber 27A gradually decreases with the orbiting motion of the orbiting scroll 26, the refrigerant gas in the compression chamber 27A is discharged into the discharge chamber S2 through the main discharge port 25h. As shown in Fig. 17, from the timing T3 when the main valve body 54 of the reed valve 51 opens, the compression ratio of the compression chamber 27A becomes constant. And as shown in Fig. 16, at the timing T4 when the volume of the compression chamber 27A becomes the minimum and the main discharge port 25h is covered by the orbiting scroll wall 26b, the main valve body 54 of the reed valve 51 closes and the compression ratio of the compression chamber 27 becomes zero. In the states of Figs. 12 to 16, each groove 41 communicates with each compression chamber 27B. As shown in Fig. 17, in the operating region of the scroll compressor 10, each compression chamber 27 communicates with either each sub-discharge port 40 or the main discharge port 25h.

[0065] In this way, since each sub-discharge port 40 always communicates with one of the compression chambers 27 via each groove 41, compared with the case where the grooves 41 are not formed in the fixed substrate 25a, the operating region where each sub-discharge port 40 does not communicate with the inside of the compression chamber 27 is reduced. Therefore, it becomes possible to discharge the refrigerant gas from each sub-discharge port 40 in a wider operating region. As a result, since the operating region where the refrigerant gas cannot be discharged from each sub-discharge port 40 is reduced, the operating region where the pressure in the compression chamber 27 becomes abnormally high is reduced.

[0066] Each sub-discharge port 40 communicates from a predetermined timing when the compression of the refrigerant gas starts in the compression chamber 27. Therefore, for example, even if liquid refrigerant is sucked into the compression chamber 27, the liquid refrigerant is discharged from each sub-discharge port 40 from the predetermined timing when the compression of the refrigerant gas starts in the compression chamber 27. Therefore, it is easier to avoid the occurrence of liquid compression in the compression chamber 27.

[0067] [Effects of the Embodiment] In the above embodiment, the following effects can be obtained. (1) Each groove 41 is partially covered by the opposing swirling scroll wall 26b so as not to communicate with another compression chamber 27 in the process of compression and the compression chamber 27 communicating with the main discharge port 25h with respect to the compression chamber 27 in the process of compression with which each sub-discharge port 40 communicates. And each groove 41 is always communicated with one of the compression chambers 27. Therefore, compared with the case where the grooves 41 are not formed in the fixed substrate 25a provided with each sub-discharge port 40, the operating region where each sub-discharge port 40 does not communicate with the inside of the compression chamber 27 can be reduced. Therefore, the refrigerant gas can be discharged from each sub-discharge port 40 in a wider operating region. As a result, since the operating region where the refrigerant gas cannot be discharged from each sub-discharge port 40 is reduced, the operating region where the pressure in the compression chamber 27 becomes abnormally high can be reduced. As described above, the reliability of the scroll compressor 10 can be improved.

[0068] (2) The width of each groove 41 is narrower than the width of the spiral scroll wall 26b that overlaps with each sub-discharge port 40. According to this, for the compression chamber 27 during compression that communicates with each sub-discharge port 40, the compression chamber 27 during another compression and the compression chamber 27 that communicates with the main discharge port 25h are prevented from communicating with each other through each groove 41 by the spiral scroll wall 26b. Therefore, since the compression of the refrigerant gas in each compression chamber 27 is stably performed, the reliability of the scroll compressor 10 can be further improved.

[0069] (3) Each sub-discharge port 40 communicates from a predetermined timing when the compression of the refrigerant gas starts in the compression chamber 27. According to this, for example, even if liquid refrigerant is inhaled into the compression chamber 27, the liquid refrigerant can be discharged from each sub-discharge port 40 from a predetermined timing when the compression of the refrigerant gas starts in the compression chamber 27. Therefore, it is easy to avoid the occurrence of liquid compression in the compression chamber 27, and it is possible to avoid the pressure in the compression chamber 27 from becoming abnormally high.

[0070] (4) A reed valve 51 for opening and closing the main discharge port 25h and each sub-discharge port 40 is provided on the surface of the fixed base plate 25a opposite to the surface where the fixed scroll wall 25b is provided. According to this, the reed valve 51 can prevent the refrigerant gas discharged from the main discharge port 25h and each sub-discharge port 40 from flowing back to the main discharge port 25h and each sub-discharge port 40. In this way, when each sub-discharge port 40 is formed in the fixed base plate 25a, it is necessary to provide a reed valve 51 for opening and closing the main discharge port 25h and each sub-discharge port 40 on the surface of the fixed base plate 25a opposite to the surface where the fixed scroll wall 25b is provided.

[0071] Here, for example, in order to reduce the operating region where each sub-discharge port 40 does not communicate with the compression chamber 27, it is conceivable to increase the number of sub-discharge ports 40 formed in the fixed substrate 25a without forming the groove 41 in the fixed substrate 25a. However, as the number of sub-discharge ports 40 formed in the fixed substrate 25a increases, the number of reed valves 51 for opening and closing the sub-discharge ports 40 increases or the shape of the reed valve 51 becomes complicated, which is not preferable. Therefore, the groove 41 is formed in the fixed substrate 25a. According to this, it is possible to reduce the operating region where the sub-discharge port 40 does not communicate with the compression chamber 27 while minimizing the number of sub-discharge ports 40 formed in the fixed substrate 25a. Therefore, since the number of reed valves 51 does not increase and the shape of the reed valve 51 does not become complicated, the reliability of the scroll compressor 10 can be improved while the scroll compressor 10 has a simple configuration.

[0072] (5) The scroll compressor 10 is provided with a pair of sub-discharge ports 40. The pair of sub-discharge ports 40 are respectively arranged so as to sandwich the main discharge port 25h. And, in the fixed substrate 25a provided with the sub-discharge ports 40, grooves 41 are formed so as to communicate with the respective sub-discharge ports 40. According to this, since the operating region where the refrigerant gas cannot be discharged from the sub-discharge port 40 is further reduced, it is possible to further reduce the operating region where the pressure in the compression chamber 27 becomes abnormally high. Therefore, the reliability of the scroll compressor 10 can be further improved.

[0073] (6) The groove 41 having a curved shape extending along the fixed spiral wall 25b standing up from the fixed substrate 25a provided with the sub-discharge port 40 is preferably a groove 41 that is partially covered by the opposing turning spiral wall 26b and is always communicated with one of the compression chambers 27.

[0074] [Modification Example] Note that the above embodiment can be implemented with the following modifications. The above embodiment and the following modification examples can be implemented in combination with each other within a range where there is no technical contradiction.

[0075] ○ In the embodiment, the sub-discharge port 40 may be formed on the swivel substrate 26a instead of being formed on the fixed substrate 25a. And a groove 41 may be formed on the swivel substrate 26a. In this case, the fixed scroll wall 25b is a scroll wall that overlaps with each sub-discharge port 40 when the swivel scroll 26 performs a revolution motion. Therefore, when the swivel scroll 26 performs a revolution motion and the fixed scroll wall 25b overlaps with each sub-discharge port 40, the fixed scroll wall 25b covers each sub-discharge port 40. The width of each groove 41 is narrower than the width of the fixed scroll wall 25b which is a scroll wall overlapping with the sub-discharge port 40. Each groove 41 is partially covered by the fixed scroll wall 25b which is the opposing scroll wall so as not to communicate with another compression chamber 27 during compression and the compression chamber 27 communicating with the main discharge port 25h, and is always communicated with one of the compression chambers 27. Note that when the sub-discharge port 40 is formed on the swivel substrate 26a, the refrigerant gas discharged from the sub-discharge port 40 is discharged into the back pressure chamber S3, for example.

[0076] ○ In the embodiment, in addition to the fixed substrate 25a, the sub-discharge port 40 may also be formed on the swivel substrate 26a. In short, the sub-discharge port 40 may be formed on at least one of the fixed substrate 25a and the swivel substrate 26a. And the groove 41 may be formed on the substrate provided with the sub-discharge port 40.

[0077] ○ In the embodiment, each sub-discharge port 40 may communicate, for example, in the middle of the extending direction of each groove 41 instead of communicating with the first end in the extending direction of each groove 41. In this case, each sub-discharge port 40 does not communicate from a predetermined timing when the compression of the refrigerant gas starts in the compression chamber 27, but the first end in the extending direction of each groove 41 communicates from a predetermined timing when the compression of the refrigerant gas starts in the compression chamber 27. In short, either one of the groove 41 and the sub-discharge port 40 may communicate from a predetermined timing when the compression of the refrigerant gas starts in the compression chamber 27.

[0078] ○ In the embodiment, the groove 41 and the sub-discharge port 40 may not communicate from a predetermined timing at which the compression of the refrigerant gas starts in the compression chamber 27. ○ In the embodiment, each sub-discharge port 40 may not penetrate the fixed substrate 25a in the thickness direction. In this case, each groove 41 may communicate with the opening on the compression chamber 27 side of each sub-discharge port 40. Thus, when each sub-discharge port 40 does not penetrate the fixed substrate 25a, the hole diameter of each sub-discharge port 40 may be larger than the width of the swirling scroll wall 26b.

[0079] ○ In the embodiment, the reed valve for opening and closing the main discharge port 25h and the reed valve for opening and closing each sub-discharge port 40 may be provided as separate members on the surface of the fixed substrate 25a on the side opposite to the fixed scroll wall 25b.

[0080] ○ In the embodiment, the number of the sub-discharge ports 40 is not particularly limited, and for example, it may be one or three or more. The number of the grooves 41 is appropriately changed according to the number of the sub-discharge ports 40.

[0081] ○ In the embodiment, the shape of the groove 41 is not limited to a curved shape extending along the fixed scroll wall 25b. ○ In the embodiment, the number of the suction ports 38 formed in the fixed outer peripheral wall 25c of the fixed scroll 25 may be one or three or more. In short, the number of the suction ports 38 formed in the fixed outer peripheral wall 25c is not particularly limited.

[0082] ○ In the embodiment, there may be a timing when each groove 41 is entirely covered by the swirling scroll wall 26b. At this timing, the compression chambers 27 during compression do not communicate with each other via each groove 41. In such a case, each groove 41 is covered by the swirling scroll wall 26b only for a period during which the pressure in the compression chamber 27 does not become abnormally high even when each groove 41 is entirely covered by the swirling scroll wall 26b.

[0083] ○ In the embodiment, the scroll compressor 10 does not have to be of a type driven by the electric motor 22, and for example, it may be of a type driven by a vehicle engine.

[0084] ○ In the embodiment, the scroll compressor 10 has been used in a vehicle air conditioner, but is not limited thereto. For example, the scroll compressor 10 may be mounted on a fuel cell vehicle and may compress air as a fluid supplied to the fuel cell.

Description of Reference Numerals

[0085] 10... Scroll compressor, 25... Fixed scroll, 25a... Fixed substrate, 25b... Fixed spiral wall, 25h... Main discharge port, 26... Orbiting scroll, 26a... Orbiting substrate, 26b... Orbiting spiral wall, 27, 27A, 27B... Compression chamber, 40... Sub-discharge port, 41... Groove, 51... Reed valve.

Claims

1. A fixed scroll having a fixed substrate and a fixed spiral wall standing up from the fixed substrate, a swivel substrate facing the fixed substrate, and a swivel scroll having a swivel spiral wall standing up from the swivel substrate toward the fixed substrate and meshing with the fixed spiral wall, a plurality of compression chambers are defined by the fixed scroll and the swivel scroll, a main discharge port for discharging the compressed fluid is formed at the center of the fixed substrate, a scroll compressor, wherein at least one of the fixed substrate and the swivel substrate has a sub-discharge port disposed at a position different from the main discharge port and configured to discharge the fluid in the compression chamber when the pressure in the compression chamber becomes equal to or higher than a set pressure, a groove communicating with the opening on the compression chamber side of the sub-discharge port is formed in the substrate provided with the sub-discharge port, the groove is partially covered by the opposing spiral wall so as not to communicate with another compression chamber during compression and the compression chamber communicating with the main discharge port with respect to the compression chamber during compression communicating with the sub-discharge port, and is always communicated with one of the compression chambers in the standing direction of the opposing spiral wall. The scroll compressor is characterized by this.

2. The scroll compressor according to claim 1, wherein the width of the groove is narrower than the width of the spiral wall overlapping the sub-discharge port among the fixed spiral wall and the swivel spiral wall.

3. The scroll compressor according to claim 1 or claim 2, wherein either one of the groove and the sub-discharge port communicates from a predetermined timing at which compression of the fluid starts in the compression chamber.

4. The scroll compressor according to claim 3, wherein the sub-discharge port communicates with the compression chamber at the predetermined timing at which compression of the fluid starts in the compression chamber.

5. The sub-discharge port and the groove are formed in the fixed substrate, A reed valve for opening and closing the main discharge port and the sub-discharge port is provided on the surface of the fixed substrate opposite to the surface provided with the fixed spiral wall. The scroll compressor according to any one of claims 1 to 4 is characterized by this.

6. A pair of sub-discharge ports is provided, the pair of sub-discharge ports are respectively arranged so as to sandwich the main discharge port, The scroll compressor according to any one of claims 1 to 5, wherein the grooves are formed in the substrate provided with the sub-discharge ports so as to communicate with the respective sub-discharge ports. **Claim 7** The scroll compressor according to any one of claims 1 to 6, wherein the grooves are curved and extend along a spiral wall rising from the substrate provided with the sub-discharge ports.

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