JP2017166366A - Scroll compressor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a scroll compressor capable of reducing friction force between both scrolls, without causing a compression failure.SOLUTION: A scroll compressor is equipped with a compression mechanism 4 composed of a fixed scroll 21 and a moving scroll 22, and compresses a coolant in a compression chamber 34 formed between laps 24 and 32 of both scrolls by revolving and slewing the moving scroll. The scroll compressor is equipped with a back pressure chamber 39 formed on a back surface of the moving scroll; and a communication hole 48 which is opened/closed by the moving scroll and communicates the back pressure chamber and a sucking portion 37. The communication hole communicates the back pressure chamber and the sucking portion at an angle delayed from a design discharge completion step of the compression mechanism only by a predetermined swiveling angle.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a scroll compressor that compresses a working fluid in a compression chamber formed between laps of both scrolls by orbiting a movable scroll with respect to a fixed scroll.

  Conventionally, this type of scroll compressor has a compression mechanism composed of a fixed scroll having a spiral wrap on the surface of the end plate and a movable scroll having a spiral wrap on the surface of the end plate, and each scroll wrap is opposed to each other. The compression chamber is formed between the wraps, and the movable fluid is revolved with respect to the fixed scroll by a motor, and the working fluid (refrigerant) is compressed in the compression chamber (for example, Patent Documents). 1).

  In this case, a back pressure chamber for pressing the movable scroll against the fixed scroll is formed on the back surface of the end plate of the movable scroll so as to oppose the compression reaction force from the compression chamber. Conventionally, a constant back pressure load that overcomes the compression reaction force is applied to the movable scroll by supplying the back pressure chamber after adjusting the discharge pressure and maintaining the pressure in the back pressure chamber constant. Moreover, in patent document 1, the balance hole which connects a suction side and a back pressure chamber in the vicinity of the compression final process (design discharge end process) was formed, and it was set as the structure which forcibly lubricates each sliding part by this balance hole.

Japanese Patent Laid-Open No. 61-178589

  Here, the compression reaction force largely fluctuates during one revolution of the orbiting scroll. Conventionally, the back pressure load is set to be larger than a value at which the fluctuating compression reaction force becomes maximum. Therefore, at the turning angle at which the compression reaction force becomes small, the force pressing the movable scroll against the fixed scroll becomes excessive, and the frictional force between each lap and the end plate against which the lap is pressed increases, resulting in a problem that the power consumption increases.

  The compression reaction force is theoretically minimized in the above-described discharge end process. Therefore, for example, it is conceivable to connect the suction side and the back pressure chamber through a balance hole in the vicinity of the designed discharge end process (compression final process) as in Patent Document 1.

  However, even after the design discharge end process, the lap is sealed with oil, so that the compression reaction force falls later than the design discharge end process. Therefore, if the suction side communicates with the back pressure chamber in the design discharge end process as in the conventional case, the pressing force is insufficient, and in the worst case, the back pressure load becomes smaller than the compression reaction force, and both scrolls are There was a problem that it was separated and caused a compression failure.

  The present invention has been made to solve the conventional technical problem, and an object of the present invention is to provide a scroll compressor capable of reducing the frictional force between both scrolls without causing a compression failure. And

  In order to solve the above problems, a scroll compressor according to the present invention includes a compression mechanism including a fixed scroll and a movable scroll each having a spiral wrap formed on each surface of each end plate so as to face each other, and the movable scroll is fixed. By rotating orbiting the scroll, the working fluid is compressed in the compression chamber formed between the laps of both scrolls, and the back pressure chamber formed on the back surface of the end plate of the movable scroll and the revolution It is opened and closed by an orbiting scroll that has a turning motion, and has a communication part for communicating the back pressure chamber and the suction pressure region. This communication part has a back at an angle delayed by a predetermined turning angle from the design discharge end process of the compression mechanism. The pressure chamber communicates with the suction pressure region.

  In the scroll compressor according to a second aspect of the present invention, in the above invention, the communication portion is connected to the back pressure chamber and the suction at an angle that is delayed from the turning angle in the design discharge end process of the compression mechanism by a range in which each lap is oil sealed. It is characterized by communicating with the pressure region.

  According to a third aspect of the present invention, there is provided the scroll compressor according to the above invention, wherein the communicating portion has a predetermined centered on an angle delayed by a range in which each lap is oil-sealed from the turning angle in the design discharge end process of the compression mechanism. A plurality of swivel angles are formed.

  According to a fourth aspect of the present invention, there is provided a scroll compressor comprising a thrust plate that contacts the back surface of the end plate of the movable scroll in each of the above inventions to partition the back pressure chamber and the suction pressure region, and the communication portion is formed on the thrust plate. It is characterized by.

  A scroll compressor according to a fifth aspect of the present invention is characterized in that, in each of the above-described inventions, the communicating portion is configured by a hole opened to the back pressure chamber and the suction pressure region.

  A scroll compressor according to a sixth aspect of the invention is characterized in that, in the first to fourth aspects of the invention, the communicating portion is formed by a groove extending from the back pressure chamber to the suction pressure region.

  According to the present invention, a compression mechanism including a fixed scroll and a movable scroll each having a spiral wrap formed on each surface of each end plate is opposed to each other, and the movable scroll is revolved with respect to the fixed scroll. In the scroll compressor that compresses the working fluid in the compression chamber formed between the laps of both scrolls, the back pressure chamber formed on the back surface of the end plate of the movable scroll and the movable scroll that revolves and revolves. A communication portion for communicating the pressure chamber and the suction pressure region is provided, and this communication portion connects the back pressure chamber and the suction pressure region at an angle delayed by a predetermined turning angle from the design discharge end process of the compression mechanism. Because it is in communication, the back pressure from the back pressure chamber is at an appropriate angle at which the compression reaction force, which fluctuates greatly during one revolution of the orbiting scroll, is reduced. So heavy can be reduced.

  As a result, the frictional force between the scrolls can be reduced and the increase in power consumption can be eliminated without causing a compression failure in the compression mechanism.

  In particular, as in the second aspect of the present invention, the communicating portion communicates the back pressure chamber and the suction pressure region at an angle that is delayed from the swivel angle in the design discharge end process of the compression mechanism by a range in which each lap is oil-sealed. By doing so, it is possible to accurately reduce the back pressure load in accordance with the delay in the reduction of the compression reaction force due to the sealing between the laps with oil even after the design discharge end process.

  Further, as in the third aspect of the present invention, the communication portion is set within a predetermined swivel angle range centered on an angle that is delayed by a range in which each lap is oil-sealed from the swivel angle in the design discharge end process of the compression mechanism. If a plurality of them are formed, the back pressure load can be reduced along with the reduction of the compression reaction force, and the frictional force between the two scrolls can be more suitably reduced.

  In this case, when a thrust plate that contacts the rear surface of the end plate of the movable scroll and separates the back pressure chamber and the suction pressure region is provided as in the invention of claim 4, a communication portion is formed in the thrust plate. The productivity is extremely good as compared with the case where it is directly formed on the housing or the like constituting the compressor.

  Further, if the communicating portion is constituted by a hole opened in the back pressure chamber and the suction pressure region as in the invention of claim 5, the workability is improved. The same applies to the case where the communicating portion is constituted by a groove extending from the back pressure chamber to the suction pressure region as in the sixth aspect of the invention.

It is sectional drawing of the scroll compressor of one Embodiment to which this invention is applied. It is a top view of the fixed scroll of the compression mechanism of the scroll compressor of FIG. (Example 1) which is sectional drawing of the compression mechanism part except the fixed scroll of the scroll compressor of FIG. It is a top view of the movable scroll of the compression mechanism of FIG. It is another sectional drawing of the compression mechanism part except the fixed scroll of the scroll compressor of FIG. It is a top view of the movable scroll of the compression mechanism of FIG. It is a figure which shows the relationship between the clearance gap between the laps of both scrolls of the scroll compressor of FIG. 1, and a turning angle (crank angle). It is a figure which shows the relationship between the pressure of the compression chamber in the compression mechanism of the scroll compressor of FIG. 1, and a turning angle. It is a figure which shows the relationship between the compression reaction force and turning angle of the scroll compressor of FIG. It is a figure which shows the relationship between the compression reaction force of the scroll compressor of FIG. 1, a back pressure load, and a turning angle. It is sectional drawing of the compression mechanism part except the fixed scroll of the scroll compressor of the other Example of this invention (Example 2). It is a top view of the movable scroll of the compression mechanism of FIG. It is another top view of the movable scroll of the compression mechanism of FIG. It is sectional drawing of the compression mechanism part except the fixed scroll of the scroll compressor of another another Example of this invention (Example 3). It is a top view of the movable scroll of the compression mechanism of FIG. It is another top view of the movable scroll of the compression mechanism of FIG. (Example 4) which is a top view of the movable scroll of the scroll compressor of another another Example of this invention. It is a figure which shows the relationship between the compression reaction force of the scroll compressor of FIG. 17, a back pressure load, and a turning angle.

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

  FIG. 1 is a cross-sectional view of a scroll compressor 1 according to an embodiment to which the present invention is applied. The scroll compressor 1 according to the embodiment is used in, for example, a refrigerant circuit of a vehicle air conditioner, and sucks, compresses and discharges a refrigerant as a working fluid of the vehicle air conditioner. A so-called inverter-integrated scroll compressor including an inverter 3 for operating the electric motor 2 and a compression mechanism 4 driven by the electric motor 2.

  The scroll compressor 1 according to the embodiment includes a main housing 6 that houses the electric motor 2 and the inverter 3 inside, a compression mechanism housing 7 that houses the compression mechanism 4 inside, an inverter cover 8, and a compression mechanism cover 9. It has. The main housing 6, the compression mechanism housing 7, the inverter cover 8, and the compression mechanism cover 9 are all made of metal (made of aluminum in the embodiment), and they are integrally joined to form a housing of the scroll compressor 1. 11 is configured.

  The main housing 6 includes a cylindrical peripheral wall portion 6A and a partition wall portion 6B. The partition wall portion 6 </ b> B is a partition wall that partitions the main housing 6 into a motor housing portion 12 that houses the electric motor 2 and an inverter housing portion 13 that houses the inverter 3. One end surface of the inverter accommodating portion 13 is opened, and the opening is closed by the inverter cover 8 after the inverter 3 is accommodated. The motor housing 12 also has an opening at the other end, and this opening is closed by the compression mechanism housing 7 after the electric motor 2 is housed. A support portion 16 for supporting one end portion of the rotating shaft 14 of the electric motor 2 protrudes from the partition wall portion 6B.

  The compression mechanism housing 7 is open on the opposite side to the main housing 6, and this opening is closed by the compression mechanism cover 9 after the compression mechanism 4 is accommodated. The compression mechanism housing 7 includes a cylindrical peripheral wall portion 7A and a frame portion 7B on one end thereof, and the compression mechanism 4 is accommodated in a space defined by the peripheral wall portion 7A and the frame portion 7B. The frame portion 7 </ b> B forms a partition that partitions the main housing 6 and the compression mechanism housing 7. The frame portion 7B has a through hole 17 through which the other end portion of the rotating shaft 14 of the electric motor 2 is inserted. The other end portion of the rotating shaft 14 is connected to the compression mechanism 4 side of the through hole 17. A supporting bearing 18 is fitted. Reference numeral 19 denotes a sealing material that seals the outer peripheral surface of the rotary shaft 14 and the inside of the compression mechanism housing 7 at the through-hole 17 portion.

  The electric motor 2 includes a stator 22 around which a coil 21 is wound, and a rotor 23. For example, a direct current from a vehicle battery (not shown) is converted into a three-phase alternating current by the inverter 3 and supplied to the coil 21 of the electric motor 2 so that the rotor 23 is rotationally driven. ing.

  The main housing 6 is formed with a suction port (not shown), and the refrigerant sucked from the suction port passes through the main housing 6 and is described later outside the compression mechanism 4 in the compression mechanism housing 7. Inhaled into the inhaler 37. Thereby, the electric motor 2 is cooled by the suction refrigerant. The refrigerant compressed by the compression mechanism 4 is discharged from a discharge port (not shown) formed in the compression mechanism cover 9 from a discharge space 27 described later.

  The compression mechanism 4 includes a fixed scroll 21 and a movable scroll 22. The fixed scroll 21 is integrally provided with a disc-shaped end plate 23 and a spiral wrap 24 having an involute shape standing on the surface (one surface) of the end plate 23 or a curve similar to this. The surface of the end plate 23 on which the wrap 24 is erected is fixed to the compression mechanism housing 7 with the frame portion 7B side. A discharge hole 26 is formed in the center of the end plate 23 of the fixed scroll 21, and this discharge hole 26 communicates with a discharge space 27 in the compression mechanism cover 9. Reference numeral 28 denotes a discharge valve provided in the opening of the discharge hole 26 on the back surface (the other surface) side of the end plate 23.

  The movable scroll 22 is a scroll that revolves around the fixed scroll 21. The movable scroll 22 is a disc-shaped end plate 31 and an involute that is erected on the surface (one surface) of the end plate 31, or approximated thereto. A spiral wrap 32 made of a curve and a boss 33 formed so as to protrude from the center of the back surface (the other surface) of the end plate 31 are integrally provided. The movable scroll 22 is disposed so that the wrap 32 faces the fixed scroll 21 and the wrap 32 faces the wrap 24 of the fixed scroll 21 and is engaged with each other. The compression chamber 34 is interposed between the wraps 24 and 32. Form.

  That is, the wrap 32 of the movable scroll 22 is opposed to the wrap 24 of the fixed scroll 21, meshes so that the tip of the wrap 32 is in contact with the surface of the end plate 23, and the tip of the wrap 24 is in contact with the surface of the end plate 31. The boss 33 of the scroll 22 is fitted with an eccentric portion 36 that is eccentric from the axis at the other end of the rotary shaft 14. When the rotary shaft 14 is rotated together with the rotor 23 of the electric motor 2, the movable scroll 22 is configured to revolve with respect to the fixed scroll 21 without rotating.

  Since the movable scroll 22 revolves eccentrically with respect to the fixed scroll 21, the eccentric direction and contact position of each lap 24, 32 move while rotating, and the compression chamber 34 in which refrigerant is sucked from the above-described suction portion 37 on the outside. Gradually shrinks while moving inward. As a result, the refrigerant is compressed and finally discharged from the central discharge hole 26 to the discharge space 27 through the discharge valve 28.

  In FIG. 1, reference numeral 38 denotes an annular thrust plate. This thrust plate 38 partitions a back pressure chamber 39 formed on the back side of the end plate 31 of the movable scroll 22 and a suction portion 37 as a suction pressure region outside the compression mechanism 4 in the compression mechanism housing 7. It is located outside the boss 33 and is interposed between the frame portion 7 </ b> B and the movable scroll 22. A sealing material 41 is attached to the back surface of the end plate 31 of the movable scroll 22 and abuts against the thrust plate 38. The back pressure chamber 39 and the suction portion 37 are partitioned by the sealing material 41 and the thrust plate 38.

  The thrust plate 38 is provided with a communication hole 48 that constitutes a communication portion of the present invention. Reference numeral 42 denotes a sealing material that is attached to the surface of the frame portion 7B on the thrust plate 38 side, abuts against the outer peripheral portion of the thrust plate 38, and seals between the frame portion 7B and the thrust plate 38.

  Reference numeral 43 denotes a back pressure passage formed from the compression mechanism cover 9 to the compression mechanism housing 7, and an orifice 44 is attached in the back pressure passage 43. The back pressure passage 43 communicates the inside of the discharge space 27 in the compression mechanism cover 9 and the back pressure chamber 39, whereby the discharge pressure adjusted by the orifice 44 is supplied to the back pressure chamber 39. It is configured as follows. Due to the pressure in the back pressure chamber 39 (back pressure), a back pressure load that presses the movable scroll 22 against the fixed scroll 21 is generated. By this back pressure load, the movable scroll 22 is pressed against the fixed scroll 21 against the compression reaction force from the compression chamber 34 of the compression mechanism 4, and the contact between the wraps 24, 32 and the end plates 31, 23 is maintained, and the compression is performed. The refrigerant can be compressed in the chamber 34.

  In the embodiment of FIG. 1, an oil passage 46 is formed in the rotary shaft 14, and a pressure adjusting valve 47 is provided in the oil passage 46. The oil passage 46 communicates the back pressure chamber 39 with the main housing 6 (suction pressure region), but the pressure regulating valve 47 is used when the pressure (back pressure) in the back pressure chamber 39 reaches the maximum value. Open and function so that the back pressure does not increase any more.

  Next, FIG. 3 shows an enlarged cross section of the compression mechanism 4 portion excluding the fixed scroll 21. In the case of FIG. 3, the pressure adjusting valve 47 is shown as being attached to the frame portion 7B. In the embodiment, as described above, the thrust plate 38 is provided with a communication hole 48 as a communication portion. The communication hole 48 is a passage for communicating the back pressure chamber 39 and the suction portion 37 as a suction pressure region, and is opened and closed by the revolving orbiting motion of the movable scroll 22.

  3 and 4, when the center X2 of the movable scroll 22 moves to the communication hole 48 side from the turning center X1 of the movable scroll 22, the seal material 41 of the movable scroll 22 moves outside the communication hole 48. Therefore, the communication hole 48 is located in the back pressure chamber 39. That is, in this state, the communication hole 48 is closed by the end plate 31 of the movable scroll 22 and the suction portion 37 and the back pressure chamber 39 are not communicated.

  On the other hand, when the center X2 of the movable scroll 22 moves to the opposite side of the communication hole 48 with respect to the turning center X1 as shown in FIGS. 5 and 6, the communication hole 48 is positioned outside the seal material 41 of the movable scroll 22. In this state, the communication hole 48 opens to the back pressure chamber 39 and the suction portion 37, and communicates the back pressure chamber 39 and the suction portion 37. As a result, the pressure in the back pressure chamber 39 (back pressure) escapes to the suction portion 37, so that the back pressure load is reduced.

  Next, the position where the communication hole 48 is formed will be described. 7 shows the relationship between the gap between the wrap 24 of the fixed scroll 21 and the wrap 32 of the movable scroll 22 and the turning angle of the movable scroll 22, FIG. 8 shows the relationship between the pressure of the compression chamber 34 in the compression mechanism 4 and the turning angle, and FIG. The relationship between the compression reaction force applied to the movable scroll 22 and the turning angle is shown.

  The ends on the center side of both wraps 24 and 32 start to be separated from each other at the turning angle A1 in the design discharge end process from the state of contact as shown in FIG. However, between the wraps 24 and 32, even if the swivel angle A1 in the design discharge end process is passed, in the range R1 up to a predetermined swivel angle A2, the oil for sliding portion lubrication enclosed with the refrigerant is used. The wraps 24 and 32 are substantially sealed (FIG. 7). Therefore, it is considered that the pressure in the compression chamber 34 of the compression mechanism 4 theoretically changes from the suction pressure to the discharge pressure as shown by the broken line L1 in FIG. As indicated by the solid line L2, the discharge pressure is maintained up to the turning angle A2 which is delayed by this range R1 from the turning angle A1 in the design discharge end process.

  Therefore, the compression reaction force applied to the movable scroll 22 in the direction in which the movable scroll 22 is pulled away from the fixed scroll 21 is theoretically the minimum change at the turning angle A1 in the design discharge end process as shown by the broken line L3 in FIG. However, in actuality, as shown by the solid line L4, the minimum change is shown at the turning angle A2 delayed by a predetermined angle from the turning angle A1.

  Therefore, for example, when the turning angle of the movable scroll 22 in which the communication hole 48 is opened is set to the turning angle A1 in the design discharge end process, the back pressure load from the back pressure chamber 39 is indicated by a broken line L5 in FIG. In this way, the rotation angle A1 is reduced to a minimum, and therefore, the speed is lowered faster than the actual reduction of the compression reaction force indicated by the solid line L4, and the rotation is reversed. When the back pressure load is reduced with respect to the compression reaction force, the movable scroll 22 moves away from the fixed scroll 21, resulting in poor compression.

  Therefore, in the present invention, the movable scroll 22 is the above-described turning angle A2 (actual compression reaction indicated by L4 in FIGS. 9 and 10) delayed by a predetermined turning angle corresponding to the range R1 from the turning angle A1 in the design discharge ending process. The communication hole 48 is formed at a position where the opening is opened as shown in FIGS. As a result, as shown by the solid line L6 in FIG. 10, the turning angle at which the compression reaction force is actually minimized and the turning angle at which the back pressure load is minimized are exactly matched.

  Thus, in the present invention, the communication hole 48 for communicating the back pressure chamber 39 and the suction portion 37 (suction pressure region) is formed, and this communication hole 48 is a turning angle in the design discharge end process of the compression mechanism 4. Since the back pressure chamber 39 and the suction portion 37 communicate with each other at the turning angle A2 that is delayed by a predetermined angle from A1, the compression reaction force that varies greatly during one revolution of the revolution turning motion of the movable scroll 22 decreases. The back pressure load from the back pressure chamber 39 can be reduced at an appropriate angle. As a result, the frictional force between the scrolls 21 and 22 can be reduced without causing a compression failure in the compression mechanism 4 and the increase in power consumption can be eliminated.

  In particular, the back pressure chamber 39 and the suction portion 37 have a communication hole 48 at a turning angle A2 delayed by a range R1 in which the space between the laps 21 and 22 is oil-sealed from the turning angle A1 in the design discharge end process of the compression mechanism 4. Therefore, even after the design discharge end process, the back pressure load is accurately reduced in accordance with the delay in the reduction of the compression reaction force due to the sealing between the laps 21 and 22 with oil. Will be able to.

  Further, in the embodiment, since the communication hole 48 is formed in the thrust plate 38 that contacts the back surface of the end plate 31 of the movable scroll 22 and divides the back pressure chamber 39 and the suction portion 37, it is directly formed in the compression mechanism housing 7. Compared with the case, productivity becomes very good. In the embodiment, the communication hole 48 that opens to the back pressure chamber 39 and the suction portion 37 constitutes a communication portion that communicates the back pressure chamber 39 and the suction portion 37, so that the workability is also improved.

  In the above embodiment, the communication portion of the present invention is configured by the communication hole 48. However, the present invention is not limited to this, and the communication portion may be configured by a groove (referred to as a communication groove 51) as shown in FIGS. . In that case, a long communication groove 51 in the radial direction of the movable scroll 22 is formed on the surface of the thrust plate 38 on the movable scroll 22 side.

  The communication groove 51 is also opened and closed by the revolving orbiting motion of the movable scroll 22 so that the back pressure chamber 39 and the suction portion 37 communicate with each other in the opened state, and the position where the communication groove 51 is formed is the same as described above. The movable scroll 22 is set to a position that is opened when the turning angle A2 is delayed by a predetermined turning angle corresponding to the range R1 from the turning angle A1 in the design discharge end process.

  That is, as shown in FIG. 13, when the center X2 of the movable scroll 22 moves to the communication groove 51 side from the turning center X1 of the movable scroll 22, the seal material 41 of the movable scroll 22 is outside the outer end of the communication groove 51. To be located. In this state, since the communication groove 51 is located in the back pressure chamber 39, the entire communication groove 51 is closed by the end plate 31 of the movable scroll 22, and the suction portion 37 and the back pressure chamber 39 are not communicated.

  On the other hand, as shown in FIGS. 11 and 12, when the center X2 of the movable scroll 22 moves to the opposite side to the communication groove 51 with respect to the turning center X1 and reaches the turning angle A2 described above, A part of the movable scroll 22 is positioned outside the sealing material 41. In this state, the communication groove 51 extends from the back pressure chamber 39 to the suction portion 37, and the inside opens to the back pressure chamber 39 and the outside opens to the suction portion 37. And communicated with each other. As a result, the pressure in the back pressure chamber 39 (back pressure) escapes to the suction portion 37, and the back pressure load is reduced as in the above embodiment.

  As described above, when the communication portion is formed by the communication groove 51 extending from the back pressure chamber 39 to the suction portion 37 (the suction pressure region 9) in the thrust plate 38, the workability is similarly improved.

  In the above embodiments, the present invention has been described with the scroll compressor 1 provided with the thrust plate 38. However, in the case of a scroll compressor having no thrust plate, as shown in FIG. A communication groove 52 (communication portion) having the same shape as that of the above embodiment may be formed at a position that opens at the same turning angle A2 on the surface of the frame portion 7B on the movable scroll 22 side. However, in this case, the sealing material 41 directly contacts the frame portion 7B, and the back pressure chamber 39 and the suction portion 37 are sealed and partitioned.

  That is, in this case, as shown in FIG. 16, when the center X2 of the movable scroll 22 moves to the communication groove 52 side from the turning center X1 of the movable scroll 22, the seal material 41 of the movable scroll 22 moves outside the communication groove 52. Be positioned outside the edge. In this state, since the communication groove 52 is located in the back pressure chamber 39, the entire communication groove 52 is closed by the end plate 31 of the movable scroll 22, and the suction portion 37 and the back pressure chamber 39 are not communicated.

  On the other hand, as shown in FIGS. 14 and 15, when the center X2 of the movable scroll 22 moves to the side opposite to the communication groove 52 with respect to the turning center X1 and reaches the turning angle A2 described above, A part of the movable scroll 22 is positioned outside the sealing material 41. In this state, the communication groove 52 extends from the back pressure chamber 39 to the suction portion 37, and the inside opens to the back pressure chamber 39 and the outside opens to the suction portion 37. And communicated with each other. As a result, the pressure in the back pressure chamber 39 (back pressure) escapes to the suction portion 37, so that the back pressure load decreases as in the above embodiments.

  Even when the thrust plate is not provided, the communication portion may be formed by forming the communication hole as described above in the frame portion 7B. The workability is better when the communication groove 52 is formed as in this embodiment. It becomes good.

  Next, FIG. 17 shows an example in which a plurality of communication holes (communication portions) as in the embodiment described above are formed. The communication holes 53, 54, and 56 in this case are also formed in the thrust plate 38 in the same manner as described above. However, in the case of the embodiment, first, the passage area is the largest at the position opened at the turning angle A2 of the movable scroll 22 described above. A large first communication hole 53 (large hole) is formed. Then, the second communication hole 54 (medium hole) having the next largest passage area and the third communication hole 56 (small size) having the smallest passage area are within a predetermined turning angle range centered on the turning angle A2. Two holes are formed.

  In this case, the second communication holes 54 are formed on both sides at the turning angle of the first communication hole 53, and the third communication holes 56 are opposite to the first communication holes 53 of the second communication holes 54. Each is formed on the side. With this configuration, when the third communication hole 56 is opened, the back pressure load is slightly reduced, and when the second communication hole 54 is opened, the back pressure load is further reduced, so that the first communication hole 53 is formed. Since the pressure decreases most when it is opened, the back pressure substantially follows the decrease in the actual compression reaction force (solid line L4 in FIG. 19) as shown in FIG. The load can be reduced. Thereby, the frictional force between the scrolls 21 and 22 can be more suitably reduced.

  In the embodiment, the present invention is applied to the scroll compressor used in the refrigerant circuit of the vehicle air conditioner. However, the present invention is not limited to this, and the present invention is effective for the scroll compressor used in the refrigerant circuit of various refrigeration apparatuses. It is. In the embodiments, the present invention is applied to a so-called inverter-integrated scroll compressor. However, the present invention is not limited to this, and the present invention can also be applied to a normal scroll compressor not integrally provided with an inverter.

DESCRIPTION OF SYMBOLS 1 Scroll compressor 2 Electric motor 3 Inverter 4 Compression mechanism 6 Main housing 7 Compression mechanism housing 8 Inverter cover 9 Compression mechanism cover 21 Fixed scroll 22 Movable scroll 24, 32 Lap 23, 31 End plate 34 Compression chamber 37 Suction part (Suction pressure area) )
38 Thrust plate 39 Back pressure chamber 41 Sealing material 48, 53, 54, 56 Communication hole (Communication part 51, 52 Communication groove (Communication part)

Claims (6)

A compression mechanism composed of a fixed scroll and a movable scroll each having a spiral wrap formed on each surface of each end plate so as to face each other, and by rotating the movable scroll with respect to the fixed scroll, In a scroll compressor that compresses a working fluid in a compression chamber formed between the wraps,
A back pressure chamber formed on the back of the end plate of the movable scroll;
Opened and closed by the orbiting scroll that revolves and revolves, and includes a communicating portion for communicating the back pressure chamber and the suction pressure region;
The communication portion communicates the back pressure chamber and the suction pressure region at an angle delayed by a predetermined turning angle from the design discharge end step of the compression mechanism.   The communicating portion communicates the back pressure chamber and the suction pressure region at an angle that is delayed by a range in which each lap is oil-sealed from the turning angle of the design discharge end process of the compression mechanism. The scroll compressor according to claim 1.   A plurality of the communication portions are formed in a predetermined swivel angle range centering on an angle delayed by a range in which the laps are oil-sealed from the swivel angle in the design discharge end process of the compression mechanism. The scroll compressor according to claim 2. A thrust plate for contacting the back surface of the end plate of the movable scroll and partitioning the back pressure chamber and the suction pressure region;
The scroll compressor according to any one of claims 1 to 3, wherein the communication portion is formed in the thrust plate.   The scroll compressor according to any one of claims 1 to 4, wherein the communication portion is configured by a hole opened in the back pressure chamber and the suction pressure region.   The scroll compressor according to any one of claims 1 to 4, wherein the communication part is configured by a groove extending from the back pressure chamber to the suction pressure region.

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