JP2010285898A - Variable capacity compressor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a variable capacity compressor wherein the minimum inclination angle of a swash plate when an air conditioner is turned off can be set to a relatively small value, the valve opening degree of a flow rate adjusting mechanism can be maximized rapidly when an air conditioner is turned on, although there is an oil returning passage provided with a variable orifice, and the structure of the flow rate adjusting mechanism is simple. <P>SOLUTION: The variable capacity compressor 1 is provided with a first valve device 59 which has an opening/closing means for opening/closing an oil returning passage 45 on a route of the oil returning passage 45; a second valve device 62 having a variable portion 61 which has a throttle passage 60 and can change the length of the portion of the throttle passage 60, which is along the flow direction of oil; and a flow rate adjusting mechanism 50 which contains the first valve device 59 and the second valve device 62, and is comprised of a storage chamber 57 having an inlet port 52 for communicating with a separation portion 39 side to separate oil and an outlet port 54 for communicating with a crank chamber 8 side. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a variable displacement compressor having a structure capable of separating oil mixed in a working fluid flowing in a working fluid path of the compressor.

  This type of compressor has a lubricating oil separation device that separates the working fluid and lubricating oil in the discharge chamber, and an oil return passage that returns the lubricating oil separated by the lubricating oil separation device to the crank chamber. A reciprocating fluid machine having a configuration in which a variable orifice-shaped flow control valve that is opened and closed according to a pressure difference between a chamber and a crank chamber is disposed in the oil return passage has already been disclosed in, for example, Patent Document 1 It is publicly known.

  And the oil separated by the lubricating oil separator returns to the crankcase by the force of the differential pressure, so when the degree of opening of the flow control valve is fixed, proper oil return is achieved under all operating conditions However, in the reciprocating fluid machine shown in Patent Document 1, the variable orifice flow control valve is large when the differential pressure value between the high pressure side and the low pressure side is small. The valve opening degree is set so as to decrease when the value of the differential pressure between the valve and the low pressure side is large. For example, when the oil is difficult to return, the opening degree of the valve can be relatively increased. The amount is optimized.

  Further, for example, in the case of a clutchless variable displacement compressor as shown in Patent Document 2, when the air conditioner is OFF, the degree of opening of the electromagnetic control valve is fully opened by eliminating the supply current to the electromagnetic control valve. Since the pressure in the crank chamber becomes relatively high, the inclination angle of the swash plate of the compressor becomes a minimum state. On the other hand, when the operation of the air conditioner is turned on again, current is supplied to the electromagnetic control valve, the degree of opening of the electromagnetic control valve is reduced, the pressure in the crank chamber is relatively lowered, and the compressor The inclination angle of the swash plate is increased and a return state is established.

  In the clutchless variable displacement compressor as shown in Patent Document 2, since the compressor is always rotating, in order to reduce power consumption when the air conditioner is turned off, The minimum inclination angle is set to be small within the range up to the limit position where it can be restored.

  Furthermore, in a compressor having an oil separation mechanism in the discharge passage, the oil separation mechanism is constituted by a separation cylinder and an oil separation chamber, and a valve constituted by a valve chamber, a spool and a spring in the oil supply passage. The valve chamber is divided into a first pressure-sensitive chamber and a second pressure-sensitive chamber by a spool, and the respective pressure differences received from the first pressure-sensitive chamber and the second pressure-sensitive chamber increase. Furthermore, the amount of lubricating oil supplied to the suction chamber is controlled by the spool sliding in the valve chamber, and the opening of the oil supply passage is enlarged and then reduced after the valve is fully opened. When the operation is stopped, the oil supply passage is blocked by a spring. For example, Patent Document 3 discloses a structure having such a structure.

  That is, in the compressor shown in Patent Document 3, when the valve means has a variable orifice shape, the opening area where the lateral hole opened in the spool communicates with the lateral hole opened in the wall surface of the housing depends on the amount of movement of the spool. It has a structure that uses change.

JP 2007-192154 A JP 2009-114901 A JP 2008-133810 A

  However, in a reciprocating fluid machine as disclosed in Patent Document 1, when the operation of the air conditioner is turned on to return to a return state in which the inclination angle of the swash plate of the compressor is relatively large, the flow control valve Since the degree of valve opening is fully open, the amount of high-pressure gas flowing from the high-pressure side to the crank chamber through the flow control valve becomes relatively large, and it takes a long time to return the inclination angle of the swash plate of the compressor to the return state. In order to avoid this, the minimum inclination angle of the swash plate has to be set relatively larger than when a fixed orifice type flow control valve is used. It was. Accordingly, in the variable orifice flow control valve shown in Patent Document 1, the power consumption when the air conditioner operation is OFF is relatively large, and the power saving effect of the compressor other than when the air conditioner operation is OFF is achieved. There was also the inconvenience of killing.

  Further, in the structure of the variable orifice valve means of the compressor shown in Patent Document 3, when the differential pressure between the high pressure side and the low pressure side gradually increases, the spool moves in the direction of pushing the spring, and the horizontal hole opened in the spool When the differential pressure increases further, the opening area gradually decreases after becoming the maximum, and becomes the minimum when the spring is most contracted. There was a problem that the opening area did not become maximum immediately.

  Further, in the structure of the variable orifice valve means of the compressor shown in Patent Document 3, the opening area is determined by the relative positional relationship between the lateral hole opened in the spool and the lateral hole opened in the wall surface of the housing. The positioning of the spool and its opening must be determined with high precision by the positioning means, and the structure of the valve means is complicated, and there is a possibility that the refrigerant and oil on the high pressure side leak to the low pressure side through the positioning means.

  Further, in the structure of the variable orifice valve means of the compressor shown in Patent Document 3, according to the investigation results of the applicant of the present application, the lateral hole opened in the spool of the compressor shown in Patent Document 3 and the wall surface of the housing are opened. It is considered that the opening area with the lateral hole is preferably such that the diameter dimension (hereinafter referred to as equivalent diameter) when the opening shape is replaced with a circular shape can be varied in the range of 0.15 mm to 0.35 mm. However, when the shape of the opening is replaced with a circular shape, it is necessary to relatively reduce the size of each side hole in order to set the size of such a small equivalent diameter. When the size of the horizontal hole is relatively small, the amount of movement of the spool needs to be reduced. The amount of movement of the spool is determined by the spring, but FIG. 2 and FIG. 3 is difficult to design to obtain a spring force that draws out the appropriate change in the opening area. The relationship between the size of the spring shown in FIG. There was a question of feasibility.

  Therefore, the present invention maintains the function of the flow rate adjusting mechanism disposed on the oil return passage connecting the high pressure side and the crank chamber when the air conditioner is not operating, and closes the valve when the air conditioner is OFF. Improves the returnability of the inclination angle of the swash plate of the compressor, can set the minimum inclination angle of the swash plate of the compressor to a relatively small value, and the valve opening degree of the flow rate adjusting mechanism also operates the air conditioner. It is an object of the present invention to provide a variable displacement compressor, particularly a clutchless variable displacement compressor, which can be maximized immediately when it is turned on and has a simple flow rate adjusting mechanism.

  A variable displacement compressor according to the present invention includes a housing, a crank chamber formed inside the housing, a drive shaft that is rotatably supported by the housing and rotates with an external driving force, and the crank chamber A swash plate that rotates in synchronization with the rotation of the drive shaft, a piston that reciprocates in the cylinder bore as the swash plate rotates, and a suction chamber that selectively communicates with the cylinder bore by the reciprocation of the piston And a discharge chamber, in which the discharge capacity is controlled by changing the inclination angle of the swash plate, a discharge region including the discharge chamber is provided to separate oil mixed in the working fluid An oil separation mechanism is provided in the discharge region and an oil return passage for returning the oil separated by the oil separation mechanism to the crank chamber is provided on the oil return passage. And a first valve device having an opening / closing means for opening and closing the oil return passage, and a variable throttle means having a throttle passage and capable of changing a length along the oil flow direction in the throttle passage. The second valve device, the first valve device and the second valve device are housed, and the inlet for communicating with the oil separation mechanism side and the outlet for communicating with the crank chamber side are opened. A flow rate adjustment mechanism comprising a chamber is provided (claim 1).

  Thereby, in the second valve device, when the differential pressure between the high pressure side such as the discharge region and the low pressure side such as the crank chamber is small, the dimension along the oil flow direction in the throttle passage becomes relatively short, When the differential pressure between the high pressure side such as the discharge area and the low pressure side such as the crank chamber is large, the dimension along the oil flow direction in the throttle passage is set to be relatively long. In addition to optimizing the return amount of oil to the crank chamber, the first valve device is set so that the valve body closes the inlet of the storage chamber when the operation of the air conditioner is OFF, so that the high pressure gas flows. It avoids flowing to the crank chamber via the adjusting mechanism, improves the returnability of increasing the inclination angle of the swash plate, and relatively reduces the minimum inclination angle of the swash plate when the air conditioner is off. It is possible.

  The opening / closing means of the first valve device includes a valve body urged by an elastic mechanism toward the inflow port side, and a peripheral edge of the opening on the storage chamber side of the inflow port. And a close valve seat (claim 2).

  As a result, when the operation of the air conditioner is turned off, the differential pressure between the high pressure side and the low pressure side disappears or becomes very small, so the biasing force by the elastic mechanism is different from the valve body of the first valve device. Since the pressure is greater than the pressing force generated by the pressure, the valve body of the first valve device is in close contact with the valve seat formed on the opening periphery of the inlet and closes the inlet. On the other hand, when the operation of the air conditioner is not OFF, the differential pressure between the high pressure side and the low pressure side is relatively large, so that the biasing force by the elastic mechanism is not applied to the valve body of the first valve device. Since the pressing force generated by the differential pressure becomes larger, the valve body of the first valve device is separated from the valve seat formed at the opening peripheral edge of the inlet and the inlet is opened.

  The throttling means of the second valve device includes a shaft having a predetermined gap between a through hole that opens to the inlet side and the other opens to the outlet side and the inner surface of the through hole. A variable portion that is inserted into the through-hole so as to be movable along a direction and is urged by an elastic mechanism toward the inlet side, and along the axial direction of the through-hole of the variable portion. A throttle passage is formed between the surface and the inner surface of the through hole, and the length of the throttle passage along the oil flow direction can be varied by changing the amount of insertion of the variable portion into the through hole. (Claim 3).

  Thus, when the differential pressure between the high pressure side such as the discharge region and the low pressure side such as the crank chamber is small, the biasing force by the elastic mechanism is larger than the pressing force generated by the differential pressure, so that the variable portion of the second valve device Moves to the inlet side, so that the dimension along the oil flow direction in the throttle passage is relatively short, and when the differential pressure between the high pressure side such as the discharge area and the low pressure side such as the crank chamber is large, there is a difference. Since the pressing force generated by the pressure is greater than the urging force of the elastic mechanism, the variable portion of the second valve device moves to the outlet side, so that the dimension along the oil flow direction in the throttle passage is relatively Since it becomes longer, it is possible to optimize the return amount of oil to the crankcase during operation of the air conditioner.

  The valve body of the first valve device and the variable portion of the second valve device are more fluid in the valve body of the first valve device than the variable portion of the second valve device. It is located upstream of the direction and is formed so as to move integrally.

  As a result, the elastic mechanism for urging the valve body of the first valve device and the elastic mechanism for urging the variable portion of the second valve device can be made common, and the oil return passage is also provided. There is no need to form one for the first valve device and one for the second valve device.

  As described above, according to these inventions, in the second valve device, when the differential pressure between the high-pressure side such as the discharge region and the low-pressure side such as the crank chamber is small, along the oil flow direction in the throttle passage. When the differential pressure between the high pressure side such as the discharge area and the low pressure side such as the crank chamber is large, the dimension along the oil flow direction in the throttle passage is relatively long. By doing so, it is possible to maintain the effect of optimizing the return amount of oil to the crank chamber during operation of the air conditioner. In the first valve device, when the operation of the air conditioner is OFF, the valve body is set so as to close the inlet of the storage chamber, thereby improving the returnability of increasing the inclination angle of the swash plate. Since it is possible to relatively reduce the minimum inclination angle of the swash plate when the operation is OFF, it is possible to meet the demand for power saving of the compressor even when the air conditioner is OFF.

  In particular, according to the second aspect of the present invention, when the operation of the air conditioner is turned off, the differential pressure between the high pressure side and the low pressure side disappears or becomes very small. On the other hand, since the urging force by the elastic mechanism is larger than the pressing force generated by the differential pressure, the valve body of the first valve device is in close contact with the valve seat formed at the opening periphery of the inlet and closes the inlet. Therefore, it is possible to avoid the high-pressure gas from flowing into the crank chamber from the discharge region including the discharge chamber to the crank chamber through the flow rate adjustment mechanism even when the operation of the air conditioner is OFF. On the other hand, when the operation of the air conditioner is other than OFF, the differential pressure between the high pressure side and the low pressure side becomes larger, so the difference between the biasing force by the elastic mechanism with respect to the valve body of the first valve device. Since the pressing force generated by the pressure becomes larger, the valve body of the first valve device is separated from the valve seat formed at the opening peripheral edge of the inflow port, and the inflow port is opened. The function as can be ensured.

  Particularly, when the differential pressure between the high pressure side such as the discharge area and the low pressure side such as the crank chamber is small, the urging force by the elastic mechanism is larger than the pressing force generated by the differential pressure. Therefore, since the variable part of the second valve device moves to the inlet side, the size of the throttle passage along the flow direction of the oil can be relatively shortened, and the high pressure side such as the discharge region and the crank chamber, etc. When the differential pressure from the low pressure side is large, the pressing force generated by the differential pressure is greater than the biasing force of the elastic mechanism, so the variable portion of the second valve device moves to the outlet side. Since the dimension along the oil flow direction can be made relatively long, it is possible to optimize the return amount of the oil to the crank chamber when the operation of the air conditioner is not on or off.

  In particular, according to the invention described in claim 4, the elastic mechanism for urging the valve body of the first valve device and the elastic mechanism for urging the variable portion of the second valve device are also made common. It is not necessary to form the oil return passage for the first valve device and the second valve device, so that the structure of the compressor can be simplified, and the manufacturing cost can be relatively reduced. Reduction can be achieved.

FIG. 1 is a cross-sectional view showing an example of the configuration of a variable capacity compressor in which a flow rate adjusting mechanism according to the present invention is used. FIG. 2 is an explanatory diagram showing the configuration of the flow rate adjusting mechanism and the state in which the first valve device of the flow rate adjusting mechanism is opened because the differential pressure between the crank chamber pressure and the storage chamber pressure is relatively large. is there. FIG. 3 shows the configuration of the flow rate adjusting mechanism described above, and the first valve device of the flow rate adjusting mechanism is eliminated because the differential pressure between the crank chamber pressure and the storage chamber pressure disappears or becomes very small when the operation of the air conditioner is OFF. It is explanatory drawing which shows the closed state. FIG. 4 is an explanatory diagram showing the configuration of the flow rate adjusting mechanism and the state in which the relief valve is operated because the value of the differential pressure between the crank chamber pressure and the storage chamber pressure shows an abnormal value. FIG. 5 is a characteristic diagram showing a change in the valve opening degree of the flow rate adjusting mechanism as a whole from the state where the operation of the air flow rate adjusting mechanism, particularly the air conditioner, is turned on and started. FIG. 6 shows a configuration of a flow rate adjusting mechanism according to an embodiment different from the flow rate adjusting mechanism shown in FIGS. 2 to 4, and the flow rate adjustment is performed because the differential pressure between the crank chamber pressure and the storage chamber pressure is relatively large. It is explanatory drawing which shows the state which the 1st valve apparatus of the mechanism opened. FIG. 7 shows the configuration of the flow rate adjusting mechanism described above, and the first valve device of the flow rate adjusting mechanism is eliminated because the differential pressure between the crank chamber pressure and the storage chamber pressure disappears or becomes very small when the operation of the air conditioner is OFF. It is explanatory drawing which shows the closed state.

  Embodiments of the present invention will be described below with reference to the accompanying drawings.

  FIG. 1 shows an example of a variable capacity compressor 1 according to the present invention. The variable capacity compressor 1 is a clutchless that forms part of a refrigeration cycle that uses carbon dioxide as a refrigerant as a working fluid. A substantially cylindrical cylinder housing 2, a cylinder block 3 fixed in the cylinder housing 2, a front head 4 located on the front side (left side in FIG. 1) of the cylinder housing 2, and a cylinder A rear head 5 is mounted on the rear side (right side in FIG. 1) of the housing 2 via a valve plate 6. These cylinder housing 2, front head 4, and rear head 5 are in the axial direction of a cylinder bore 17 to be described later. The fastening bolts 58a and 58b are appropriately inserted along and joined together and fixed to form the housing 7.

  In the variable capacity compressor 1, a crank chamber 8 is defined in the housing 7 by the front head 4, the cylinder housing 2, and the cylinder block 3. In the crank chamber 8, a drive shaft 9 is housed. One end in the longitudinal direction protrudes from the front head 4 and a power transmission member (not shown) such as a pulley is fixed and is rotated by external power. And the one side end mentioned above of the drive shaft 9 is provided so that the boss | hub part 4a which protrudes outside the center part of the front head 4 may be penetrated.

  Further, the one end of the drive shaft 9 is sealed between the front head 4 and the front head 4 through a shaft sealing device 10 such as a mechanical seal provided between the front head 4 and the boss 4a of the front head 4. In addition, a thrust flange 11 provided on the outer peripheral surface, a radial bearing 12 provided on the inner surface of the front head 4 inside the base end of the boss 4a, and a thrust bearing provided on the inner surface of the front head 4 13 is rotatably supported by the housing 7 via the 13. The other end of the drive shaft 9 opposite to the boss 4 a is rotatably supported by the housing 7 via a radial bearing 15 housed in the support recess 14 of the cylinder block 3.

  Furthermore, the cylinder block 3 is formed with cylinder bores 17 arranged at equal intervals on the circumference centering on the support recess 14 for supporting the drive shaft 9, and a single-headed piston 18 in the cylinder bore 17. Is inserted in the axial direction of the cylinder bore 17 so as to be able to reciprocate. The single-head piston 18 is provided with a piston ring 22 in this embodiment.

  The swash plate 19 is formed in a substantially cylindrical shape having a predetermined thickness. The swash plate 19 is housed in the crank chamber 8 and is swingably held on the drive shaft 9 via a pin 24 and a sleeve 44. A rotational force is transmitted from the drive shaft 9 via a rod 20 fixed to the drive shaft 9. Further, a tail portion 18 a of a single-head piston 18 protruding into the crank chamber 8 is moored at a peripheral portion of the swash plate 19 via a pair of shoes 21, 21, and the rod 20 extends along the radial direction of the swash plate 19. It is slidably mounted via an interposition member 87 in a longitudinal hole 31 that extends and opens outward.

  An annular sleeve 44 is externally mounted on the drive shaft 9, and the sleeve 44 is swash plate by an elastic mechanism 47 such as a spring, one of which contacts the thrust flange 11 and the other contacts the projection of the sleeve 44. The swash plate 19 is biased along the axial direction of the drive shaft 9 so that the inclination angle of the 19 is relatively small.

  As a result, when the drive shaft 9 rotates, the swash plate 19 rotates in synchronism with this, and this rotational motion is converted into the reciprocating motion of the single-headed piston 18 via the shoes 21, 21. The volume of the compression chamber 23 formed between the single-headed piston 18 and the valve plate 6 in the cylinder bore 17 is changed by the movement.

  The rear head 5 is joined to the cylinder block 3 via the valve plate 6 to define a suction chamber 25 and a discharge chamber 26 continuously formed around the suction chamber 25. The discharge chamber 26 communicates with the discharge port 16 opened on the outer surface of the rear head 5. Further, the valve plate 6 has a suction hole 27 that communicates the suction chamber 25 and the compression chamber 23 via a suction valve 28, and a discharge hole 29 that communicates the discharge chamber 26 and the compression chamber 23 via a discharge valve 30. And are formed. The rear head 5 is provided with a pressure control valve (not shown) in an air supply passage (not shown) communicating the discharge chamber 26 and the crank chamber 8.

  Thus, when the drive shaft 9 rotates, the rotational force is transmitted to the swash plate 19 through the rod 20 and the swash plate 19 rotates, and the single-head piston 18 reciprocates in the cylinder bore 17 as described above. In the downward stroke of the single-headed piston 18, the working fluid in the suction chamber 25 is sucked into the compression chamber 23 through the suction hole 27, and in the upward stroke of the single-headed piston 18, the working fluid in the compression chamber 23 is compressed and discharged. Then, the ink is discharged into the discharge chamber 26 through 29.

  When the pressure in the crank chamber 8 (hereinafter referred to as crank chamber pressure) is reduced by the pressure control valve, the differential pressure between the crank chamber pressure and the pressure in the compression chamber 23 of the single-headed piston 18 (hereinafter referred to as compression chamber pressure). The moment in the direction of increasing the stroke of the single-headed piston 18 caused by this increases, the swash plate 19 moves toward the front head 4 against the spring force of the elastic mechanism 47, and the swash plate 19 swings around the pin 24. Thus, the inclination angle of the swash plate 19 with respect to the surface along the radial direction of the drive shaft 9 is increased, the stroke amount of the one-head piston 18 is increased, and the discharge capacity is increased. On the other hand, when the pressure in the crank chamber 8 (hereinafter referred to as crank chamber pressure) is increased by the pressure control valve, the stroke of the single-head piston 18 caused by the differential pressure between the crank chamber pressure and the compression chamber pressure is decreased. The moment increases, the swash plate 19 moves to the rear head 5 side by the spring force of the elastic mechanism 47, the swash plate 19 swings about the pin 24, and the diameter of the drive shaft 9 of the swash plate 19 is increased. The inclination angle with respect to the surface along the direction becomes small, the stroke amount of the single-head piston 18 becomes small, and the discharge capacity decreases.

  In the variable displacement compressor 1 described above, in this embodiment, the drive shaft 9 is formed with the introduction hole 32 penetrating the drive shaft 9 along the radial direction thereof, and the drive is driven out of the introduction holes 32. A first discharge hole 33 extending along the axial direction of the drive shaft 9 is formed from a substantially central portion on the side along the radial direction of the shaft 9. The first discharge hole 33 has a uniform diameter portion 34a extending along the axial direction of the drive shaft 9 with the substantially same inner diameter, and the diameter of the first discharge hole 33 temporarily increases toward the rear head 5 in the axial direction of the drive shaft 9. The enlarged-diameter portion 34b is formed of a projecting portion 35 projecting along the axial direction of the drive shaft 9 from the rear head 5 side. It has become.

  Then, one side extends in the projecting direction of the projecting portion 35, and opens to the enlarged diameter portion 34 b of the first discharge hole 33 at the approximate center of the projecting portion 35, and the other opens to the suction chamber 25. A second discharge hole 36 that communicates the discharge hole 33 and the suction chamber 25 is formed. Accordingly, the introduction passage 32, the first discharge hole 33, and the second discharge hole 36 constitute an extraction passage and a first oil separation mechanism (extraction OS). . In the first oil separation mechanism (bleeding OS), oil separation (first extraction OS) from the working fluid flowing in from the introduction hole 32 is performed by the centrifugal force generated by the rotation of the drive shaft 9, and further, Even when the working fluid flows from the first discharge hole 33 into the second discharge hole 36, the oil is separated from the working fluid (second extraction OS). Moreover, since the introduction hole 32 is formed by penetrating along the radial direction of the drive shaft 9, the flow rate of the working fluid is reduced, and the oil separation performance as the execution of the first extraction OS is improved. Yes.

  Further, the rear head 5 extends from the discharge chamber 26 in a direction perpendicular to the first discharge passage 37 extending in the same direction as the reciprocating direction of the single-headed piston 18, and A second discharge passage 38 communicating with the outlet 16 and relatively communicating with the first discharge passage 37 in the vicinity of the discharge port 16 is formed. In the second discharge passage 38, a separation portion 39 is mounted and fixed at a position facing the portion connected to the first discharge passage 37. The separation portion 39 includes a small-diameter portion 40 extending along the direction in which the second discharge passage 38 extends, and the small-diameter portion 40 extends from the discharge hole side end to the discharge port 16 side in the extending direction. It is composed of a diameter-expanded portion 41 that increases in diameter so as to contact the inner surface of the second discharge passage 38 as it goes. Accordingly, the first oil discharge mechanism 37 (discharge OS) is configured by the first discharge passage 37, the second discharge passage 38, and the separation portion 39.

  Further, in this embodiment, the rear head 5 is provided with a filter 42 below the separation portion 39 of the second discharge passage 38, and a first dust collecting pot 43 is formed below the filter 42. Has been. The oil separated by the second oil separation mechanism (discharge OS) communicates with the second discharge passage 38 below the filter 42 through the oil return passage 45 that communicates with the crank chamber 8. Then, the oil is returned to the crank chamber 8, and a second dust collection pot 46 is formed in the middle of the oil return passage 45.

  With such a configuration of the second oil separation mechanism (discharge OS), the working fluid discharged from the first discharge passage 37 to the second discharge passage 38 is allowed to flow outside the small diameter portion 40 of the separation portion 39. After turning in a spiral shape downward, the inside of the small diameter portion 40 is lifted from the lower opening of the small diameter portion 40 and discharged from the discharge port 16. The oil contained in the working fluid can be reliably separated by causing the working fluid to flow while descending while turning around the outer periphery of the small diameter portion 40 at a high speed. Further, the oil separated through the oil return passage 45 can be returned to the crank chamber 8. A check valve (not shown) is arranged between the second oil separation mechanism and the discharge port 16 so that the working fluid is not discharged from the compressor when the operation of the air conditioner is OFF.

  By the way, in the variable capacity compressor 1, the flow rate adjusting mechanism 50 is disposed on the path of the oil return passage 45. In this embodiment, the flow rate adjusting mechanism 50 is disposed in the vicinity of the boundary portion between the rear head 5 and the valve plate 6 as shown in FIG. 1, and as shown in FIGS. 2 to 4, the valve plate 6. A recess 51 opened to the side is formed, and the cartridge is accommodated in the recess 51 like a cartridge.

  As shown in FIGS. 2 to 4, the flow rate adjusting mechanism 50 is connected to the upstream component member 53 having the inlet 52 connected to the upstream side of the oil return passage 45 and the downstream side of the oil return passage 45. A downstream component member 55 having an outlet 54 to be formed, and a cylindrical component member 56 opened to the upstream component member 53 side and the downstream component member 55 side, and these component members 53, By assembling 55 and 56, a storage chamber 57 is defined inside. The downstream member 55 is formed with a passage 90 whose one end communicates with the outlet 54 and whose other end communicates with an escape passage described below.

  The storage chamber 57 includes a first valve device 59 that opens and closes the oil return passage 45 and a throttle passage 60 and a variable portion 61 that changes the length of the throttle passage 60 along the oil flow direction. The second valve device 62 is accommodated.

  The first valve device 59 includes a valve body 65, a valve seat 66, a spring receiving member 67, and a spring 68. The valve body 65 has a closed portion 63 having an outer shape having an outer diameter larger than the inner diameter of the inlet 52 of the upstream side component 53, and has a larger dimension along the radial direction of the inlet 52 than the closed portion 63. It consists of a spring receiving portion 64 which is an outer shape. The valve seat 66 is formed by flattening the opening peripheral portion inside the storage chamber 57 of the inflow port 52 of the upstream side component member 53 so that the closing portion 63 of the valve body 65 can be brought into close contact therewith. The spring receiving member 67 is located on the downstream side of the storage chamber with respect to the valve body 65, and the dimension along the radial direction of the inflow port 52 is the spring receiving portion when compared with the spring receiving portion 64 of the valve body 65. The outer shape is the same as or larger than 64 and is basically fixed in the storage chamber 57. One side of the spring 68 is in contact with the spring receiving member 67 and the other side is in contact with the spring receiving portion 64 of the valve body 65. The spring 68 presses the valve body 65 toward the upstream component member 53 side by the spring force. Thus, when the pressure difference between the crank chamber pressure and the storage chamber pressure disappears or is close to the spring force, the closing portion 63 of the valve body 65 can be in close contact with the valve seat 66 on the periphery of the inflow port 52. It is a size. In this embodiment, the spring receiving member 67 has an extending portion 69 that extends toward the inflow port 52, and the spring 68 is packaged on the extending portion 69.

  The second valve device 62 includes a passage 70 that extends from the top in the extending direction of the extending portion 69 of the spring receiving member 67 to the outlet 54 side and is open on both sides thereof, and the spring receiving portion 64 of the valve body 65 is closed. A variable portion 61 that extends from the opposite side of the section side and whose axis in the extending direction coincides with the axis of the passage 70, and the depth at which the variable portion 61 is inserted into the passage 70 is variable. Thus, the length of the throttle passage 60 can be varied. The inner diameter dimension of the passage 70 and the opening diameter of the inflow port 52 are substantially the same. The depth at which the variable portion 61 is inserted into the passage 70 is adjusted using the spring force of the spring 68, and the valve body 65 is close to the spring receiving member 67 against the spring force of the spring 68. In this case, the depth at which the variable portion 61 is inserted into the passage 70 is increased, and the length of the throttle passage 60 is also increased as indicated by the dimension value L1 in FIG. On the other hand, when the valve body 65 is farthest from the spring receiving member 67 due to the spring force of the spring 68, the depth at which the variable portion 61 is inserted into the passage 70 becomes shallow, and the length of the throttle passage 60 is also shown in FIG. 3, the value becomes smaller as indicated by the dimension value L2.

  Further, in this embodiment, the flow rate adjusting mechanism 50 includes a spring 72 called a disc spring or the like in the storage chamber 57. The spring 72 is interposed between the spring receiving member 67 and the surface of the downstream side component member 55 having the outlet 54. Normally, as shown in FIGS. 2 and 3, the spring receiving member The spring receiving member 67 is supported in a form having a predetermined space between the surface 67 and the surface of the downstream component member 55 having the outlet 54. A relief valve is constituted by the outer surface of the spring receiving member 67 and the cylindrical component member 56. That is, the outer surface of the spring receiving member 67 and the cylindrical component member 56 are in close contact with each other by the spring 72 as shown in FIGS. 2 and 3 at normal times, but the differential pressure between the crank chamber pressure and the storage chamber pressure. Is abnormally large, the spring receiving member 67 is displaced to the outlet 54 side against the spring force of the spring 72, and as shown in FIG. 4, the cylindrical component member 56 and the outer surface of the spring receiving member 67 In the meantime, a high-pressure gas escape passage communicating with the passage 90 and the outlet 54 formed in the downstream side component 55 is temporarily formed. When the spring receiving member 67 is displaced to the outlet 54 side, the depth at which the variable portion 61 is inserted into the passage 70 is the deepest, and the length of the throttle passage 60 is also shown as a dimension value L3 in FIG. To be bigger.

  When the operation of the air conditioner is OFF, when the differential pressure between the crank chamber pressure and the pressure at the inlet 52 of the storage chamber becomes 0 MPa or a value close thereto, the valve body 65 of the first valve device 59 is blocked. The part 63 is in close contact with the valve seat 66 of the inflow port 52 to close the inflow port 52, and the high-pressure gas of the working fluid flows into the crank chamber 8 through the return passage 45 from the discharge port 16 and the surrounding discharge region. It is avoided.

  Further, at the start of the operation of the air conditioner, the closing portion 63 of the valve body 65 of the first valve device 59 starts to be pressed from the inlet 52 side by a slightly generated differential pressure, and is separated from the valve seat 66 of the inlet 52. However, the proportion of the second valve device 62 inserted into the passage 70 of the variable portion 61 is relatively small, and the length of the throttle passage 60 is relatively short accordingly. As a result, the valve opening degree becomes maximum when the air conditioner is started.

  After the air conditioner is started, when the air conditioner is in an ON state, the differential pressure between the crank chamber pressure and the storage chamber pressure is increased and the ratio of being inserted into the passage 70 of the variable portion 61 of the second valve device 62 is temporarily. Since it becomes larger and the length of the throttle passage 60 becomes longer, the ratio of the valve opening degree as a whole of the flow rate adjusting mechanism 50 becomes smaller. Then, when the differential pressure between the crank chamber pressure and the storage chamber pressure reaches a predetermined pressure (for example, 8.5 MPa), the second valve device 62 regulates the insertion of the variable portion 61 further deeper. As a result, the outlet 54 side of the valve body 65 is in contact with the inlet 52 side of the extending portion 69, whereby the length of the throttle passage 60 can be kept constant. Here, the degree of opening of the flow rate adjusting mechanism 50 as a whole is simply that the closing portion 63 of the valve body 65 of the first valve device 59 opens when the closing portion 63 approaches or closes to the valve seat 66 of the inlet 52. In addition to the degree, the rate at which the variable portion 61 of the second valve device 62 is inserted into the passage 70 changes, and the length of the throttle passage 60 changes accordingly. The flow resistance is also taken into account. Furthermore, when the predetermined gap of the throttle passage 60 is changed in accordance with the insertion depth of the variable portion 61 by, for example, tapering the variable portion 61 as will be described later, the change of the gap is taken into account.

  On the other hand, when the differential pressure between the crank chamber pressure and the storage chamber pressure rises and shows an abnormal value, the relief valve constituted by the outer surface of the spring receiving member 67 and the cylindrical component member 56 functions. Since the high-pressure gas escapes to the crank chamber 8 side from the escape passage between the outer surface of the spring receiving member 67 and the cylindrical component member 56 and the passage 90, the difference between the crank chamber pressure and the storage chamber pressure that opens to the discharge chamber 26. In addition to reducing the pressure, the crank chamber pressure is increased and the inclination angle of the swash plate 19 is reduced.

  The characteristic line diagram of FIG. 5 shows the valve opening degree and the relief valve of the flow rate adjusting mechanism 50 as a characteristic line. Describing this special chart, it is desirable that the point A indicating the differential pressure until the first valve device 59 is opened is less than 1 MPa. As soon as the first valve device 59 is opened, the first valve device 59 is opened to the maximum valve opening degree indicated as point B. Thereafter, the valve opening degree gradually decreases to the point C of the predetermined differential pressure, and finally becomes constant. Furthermore, when the pressure reaches a point D of a predetermined differential pressure, the relief valve is activated.

  According to the above, when the operation of the air conditioner is OFF, the valve opening degree of the flow rate adjusting mechanism 50 is 0, so that the high pressure gas of the working fluid passes through the return passage 45 from the discharge port 16 and the discharge region around it. Therefore, the inclination angle of the swash plate 19 when the operation of the air conditioner is OFF can be made smaller than when the fixed orifice is used, and power saving when the operation of the air conditioner is OFF can be achieved. .

  Further, it is preferable that the valve opening degree of the entire flow rate adjusting mechanism 50 is maximized when the operation of the air conditioner is restored. By adopting the structure of this flow rate adjusting mechanism 50, as shown in the characteristic diagram of FIG. When the operation of the air conditioner is restored, the valve opening degree of the flow rate adjusting mechanism 50 as a whole is maximized. Of the characteristic lines shown in FIG. 5, the line from point B to point C is linear as shown in FIG. 5 as (1), but is also shown as (2) in FIG. For example, by slightly tapering the variable portion 61, the predetermined gap of the throttle passage 60 is changed according to the insertion depth of the variable portion 61 in order to obtain desired characteristics. May be.

  Although the flow rate adjusting mechanism 50 has been described as being provided at the boundary portion of the rear head 5 with the valve plate 6, the flow adjusting mechanism 50 is not necessarily limited to this and may be on the oil return passage 45. However, the oil return passage 45 may be provided above the portion where the second dust collecting pot 46 branches, or provided so as to straddle the cylinder block 3 or between the cylinder block 3 and the rear head 5. Also good.

  6 and 7, another configuration of the flow rate adjusting mechanism 50 is shown. Hereinafter, the flow rate adjusting mechanism 50 will be described. However, the same components as those of the flow rate adjusting mechanism 50 described above are denoted by the same reference numerals, and the description thereof is omitted.

  The flow rate adjusting mechanism 50 is the same as the flow rate adjusting mechanism 50 shown in FIG. 1 in that it is disposed on the oil return passage 45, but the flow rate adjusting mechanism 50 shown in FIG. Differently, it is arranged across the rear head 5 and the cylinder block 3.

  That is, as shown in FIGS. 6 and 7, the flow rate adjusting mechanism 50 forms a recess 51 that opens to the valve plate 6 with respect to the rear head 5, forms a through hole 6 a in the valve plate 6, and By forming the recess 71 opened to the valve plate 6 side with respect to the block 3, the rear head 5, the valve plate 6 and the cylinder block 3 are appropriately combined while aligning the recess 51, the through hole 6a and the recess 71, A storage chamber 57 is directly defined inside the variable capacity compressor, a first valve device 59 for opening and closing the inlet 52 in the storage chamber 57, and a second passage having a throttle passage 60 having a variable length. The valve device 62 is housed.

  The storage chamber 57 has relatively small compartments 74 and 76 on the upstream and downstream sides of the oil return passage 45 and communicates with the compartments 74 and 76 between the compartments 74 and 76. A large compartment 75 is provided. The compartment 74 contains a filter 77 for collecting dust, and a block body 78 having an inlet 52 to the compartment 75 is disposed on the upstream side of the compartment 75 so as to be in contact with the side of the compartment 74 of the compartment 75. . The block body 78 is provided with an O-ring 79 on the outer peripheral surface, and the space between the block body 78 and the inner surface of the compartment 75 is hermetically sealed.

  The first valve device 59 includes a valve body 80 including a closing portion 81 and a spring receiving portion 82 that are larger than the inner diameter of the inlet 52 formed in the block body 78, and a storage chamber of the inlet 52 of the block body 78. The valve seat 66 is formed at the peripheral edge of the opening on the 57 side and can be in close contact with the closing portion 81, and the wall surface extends in the direction intersecting the axial direction of the oil return passage 45 on the boundary side of the compartment 75 with the compartment 76. A spring receiving portion 84 and a spring 68 are included. The spring 68 is in contact with the spring receiving portion 82 of the valve body 80 on one side and is in contact with the spring receiving portion 84 on the other side, and presses the valve body 80 toward the block body 78 by the spring force. The spring force is set to a size that allows the closing portion 81 of the valve body 80 to be in close contact with the valve seat 83 when the differential pressure between the crank chamber pressure and the pressure at the inlet 52 of the storage chamber is eliminated or close to it. Has been. In this embodiment, a gap is formed between the outer peripheral surface of the valve body 80 and the inner surface of the compartment 75, and a notch 85 is formed on the outer peripheral surface of the valve body 80, thereby facilitating the flow of oil. I am trying. The gap between the outer peripheral surface of the valve body 80 and the inner surface of the compartment 75 is set to be smaller than the gap of the throttle passage 60.

  The second valve device 62 includes a compartment 76 and a variable portion 86 extending from the opposite side of the valve body 80 to the closing portion 81 side toward the compartment 76, and the variable portion 86 is provided in the compartment 76. The length of the throttle passage 60 can be varied by varying the depth at which the lens is inserted. The depth at which the variable portion 86 is inserted into the compartment 76 is also adjusted using the spring force of the spring 68 and linked to the distance from the inlet 52 of the closing portion 81 of the valve body 80. ing.

  That is, when the valve body 80 is close to the spring receiving portion 84 against the spring force of the spring 68, the depth at which the variable portion 86 is inserted into the chamber 76 becomes relatively deep, and the throttle passage The length of 60 also increases as shown by the dimension value L4 in FIG. On the other hand, when the valve body 80 is farthest from the spring receiving portion 84 due to the spring force of the spring 68, the depth at which the variable portion 86 is inserted into the chamber 76 becomes relatively shallow, The length is also reduced as shown by the dimension value L5 in FIG.

  The inner diameter L6 of the compartment 76 shown in FIGS. 6 and 7 and the inner diameter L7 of the inlet 52 are the same.

  With the configuration of the flow rate adjusting mechanism 50 as described above, when the operation of the air conditioner is OFF, the differential pressure between the crank chamber pressure and the pressure in the storage chamber or the inlet 52 is 0 MPa or a value close to this. The closing portion 81 of the valve body 80 of the first valve device 59 is in close contact with the valve seat 66 of the inflow port 52 to close the inflow port 52, and the working fluid high-pressure gas from the discharge port 16 and its surrounding discharge region. Is prevented from flowing into the crank chamber 8 through the return passage 45.

When the air conditioner is activated, the closing portion 81 of the valve body 80 of the first valve device 59 starts to be pressed from the inlet 52 side by a slightly generated differential pressure, and is separated from the valve seat 66 of the inlet 52. However, since the ratio of the variable portion 86 of the second valve device 62 inserted into the compartment 76 is relatively small, and the length of the throttle passage 60 is relatively short along with this, the entire flow rate adjusting mechanism 50 is reduced. As a result, the valve opening degree becomes the maximum at the start of the air conditioner operation.

  When the operation of the air conditioner is on after the air conditioner is activated, the differential pressure between the crank chamber pressure and the storage chamber pressure increases, and the ratio of being inserted into the compartment 76 of the variable portion 86 of the second valve device 62 is high. Since the length of the throttle passage 60 becomes longer for a while and the length of the throttle passage 60 becomes longer, the ratio of the degree of opening of the flow rate adjusting mechanism 50 as a whole also decreases. Then, when the differential pressure between the crank chamber pressure and the storage chamber pressure reaches a predetermined pressure (for example, 8.5 MPa), the second valve device 62 restricts insertion of the variable portion 86 further deeper. Thus, the length of the throttle passage 60 can be kept constant.

  For this reason, also in this embodiment, the valve opening degree as a whole of the flow rate adjusting mechanism 50 appears as a solid characteristic line shown in the characteristic diagram of FIG. 5, so that the same effect as the previous embodiment can be obtained. Can do.

  In the variable capacity compressor 1, as shown in FIG. 1, a heat insulating material 85 is disposed on the discharge chamber 26, the first discharge passage 37, the second discharge passage 38, and the peripheral wall of the suction chamber 25. It has become a thing. Thereby, it is possible to cut off heat conduction between the high-pressure and high-temperature working fluid flowing on the high-pressure side of the variable displacement compressor 1 and the low-pressure and low-temperature working fluid flowing on the low-pressure side of the variable displacement compressor 1. Thus, overheating of the working fluid in the suction region including a suction port (not shown) can be prevented.

DESCRIPTION OF SYMBOLS 1 Variable capacity type compressor 7 Housing 8 Crank chamber 9 Drive shaft 17 Cylinder bore 18 Single-head piston 19 Swash plate 23 Compression chamber 25 Suction chamber 26 Discharge chamber 39 Separation part 45 Oil return passage 50 Flow rate adjustment mechanism 52 Inlet 54 Outlet 57 Storage Chamber 59 First valve device 60 Throttle passage 61 Variable portion 62 Second valve device 65 Valve body 66 Valve seat 68 Spring 70 Passage 76 Room 80 Valve body 86 Variable portion

Claims (4)

A housing, a crank chamber formed inside the housing, a drive shaft rotatably supported by the housing and rotated by an external driving force, and disposed in the crank chamber and synchronized with the rotation of the drive shaft A swash plate that rotates, a piston that reciprocates in the cylinder bore as the swash plate rotates, and a suction chamber and a discharge chamber that selectively communicate with the cylinder bore by the reciprocating motion of the piston. In a variable capacity compressor that controls the discharge capacity by changing the inclination angle of
There is an oil return passage that includes a discharge region including the discharge chamber, an oil separation mechanism that separates oil mixed in the working fluid, and an oil return passage that returns the oil separated by the oil separation mechanism to the crank chamber. ,
On the oil return passage, there is provided a first valve device having an opening / closing means for opening and closing the oil return passage, and a throttle passage and the length of the throttle passage along the oil flow direction can be changed. A second valve device having possible variable throttle means, an inlet for accommodating these first and second valve devices and communicating with the oil separation mechanism side, and for communicating with the crank chamber side A capacity type compressor provided with a flow rate adjusting mechanism comprising a storage chamber having an outlet opening.   The opening / closing means of the first valve device includes a valve body urged by an elastic mechanism toward the inflow port side, and a peripheral edge of the opening on the storage chamber side of the inflow port. The variable capacity compressor according to claim 1, wherein the variable capacity compressor is constituted by a close valve seat.   The throttling means of the second valve device includes a shaft having a predetermined gap between a through hole that opens to the inlet side and the other opens to the outlet side and the inner surface of the through hole. A variable portion that is inserted into the through-hole so as to be movable along a direction and is urged by an elastic mechanism toward the inlet side, and along the axial direction of the through-hole of the variable portion. A throttle passage is formed between the surface and the inner surface of the through hole, and the length of the throttle passage along the oil flow direction can be varied by changing the amount of insertion of the variable portion into the through hole. The variable capacity compressor according to claim 1, wherein   The valve body of the first valve device and the variable portion of the second valve device are such that the valve body of the first valve device is more in the direction of oil flow than the variable portion of the second valve device. The variable capacity compressor according to any one of claims 1 to 3, wherein the compressor is formed so as to be located upstream and to move integrally.

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