JP2016169698A - Variable capacity type swash plate compressor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve discharge capacity controllability.SOLUTION: A differential pressure adjustment valve 80 is disposed in a pressure sensing chamber 55. A valve element 70 is provided with an energization spring 74 for energizing the differential pressure adjustment valve 80 toward a valve seat 71e. When a load acting on the differential pressure adjustment valve 80 based on two-point differential pressure is over the energization force applied to the differential pressure adjustment valve 80 from the energization spring 74, the differential pressure adjustment valve 80 is separated from the valve seat 71e, and a first pressure chamber 55a and a second pressure chamber 55b are communicated. Thus rise of the two-point differential pressure in a region of a large flow rate of a refrigerant gas is suppressed. As a result, reduction of a discharge capacity of a variable capacity type swash plate compressor caused by reduction of an inclination angle of the swash plate at a time when the load acting on the valve element 70 based on the two-point differential pressure is over the energization force applied to the valve element 70 from a solenoid portion 60 when electric power supplied to the solenoid portion 60 is maximum, can be suppressed.SELECTED DRAWING: Figure 5

Description

  The present invention relates to a variable capacity swash plate compressor that forms a refrigerant circulation circuit of a vehicle air conditioner, for example, and can change the discharge capacity by changing the inclination angle of the swash plate by changing the pressure of a control pressure chamber.

  In this type of variable displacement swash plate compressor, a rotating shaft is rotatably supported in a housing. The swash plate rotates by obtaining a driving force from the rotating shaft. The variable capacity swash plate compressor has an extraction passage from the control pressure chamber to the suction pressure region and an air supply passage from the discharge pressure region to the control pressure chamber. The control valve controls the pressure (Pc) of the control pressure chamber, thereby changing the inclination angle of the swash plate with respect to the direction perpendicular to the rotation axis of the rotation shaft. Thereby, the piston moored to the swash plate reciprocates with a stroke corresponding to the inclination angle of the swash plate, and the discharge capacity is changed.

  By the way, in a vehicle, in order to suitably perform engine output control, estimation of a compressor driving torque necessary for driving a variable displacement swash plate compressor using the engine as a drive source is performed. . Generally, the discharge capacity is used as a parameter for estimating the compressor driving torque. Therefore, the pressure (PdH) at the first pressure monitoring point of the refrigerant circulation circuit and the pressure (PdL) at the second pressure monitoring point downstream from the first pressure monitoring point in the flow direction of the refrigerant gas circulating in the refrigerant circulation circuit. ) (Hereinafter referred to as “the differential pressure between two points”). A control valve having a valve body that moves in the direction of the load so as to reduce the inclination angle of the swash plate by applying a load based on the differential pressure between the two points is disclosed in Patent Document 1. Yes.

  The control valve controls the valve opening degree of the valve body by supplying an urging force that opposes the load applied to the valve body based on the differential pressure between the two points, for example, by supplying power to the valve body. It has a solenoid part. The solenoid unit controls power supply based on a temperature difference between the set target room temperature and the detected actual room temperature. Then, by controlling the supply of electric power to the solenoid part, the load applied to the valve body based on the differential pressure between the two points is balanced with the urging force applied to the valve body from the solenoid part. The valve opening of the valve body is controlled.

  When the flow rate of the refrigerant gas flowing through the refrigerant circulation circuit increases, the differential pressure between the two points increases, and when the flow rate of the refrigerant gas flowing through the refrigerant circulation circuit decreases, the differential pressure between the two points decreases. Therefore, there is a correlation between the differential pressure between the two points and the flow rate of the refrigerant gas flowing through the refrigerant circuit. Since the flow rate of the refrigerant gas flowing through the refrigerant circulation circuit is equal to the discharge capacity discharged from the variable capacity swash plate compressor, the discharge capacity can be determined by directly measuring the amount of power supplied to the solenoid unit having a correlation with the discharge capacity. Can be grasped. Therefore, for example, it is possible to estimate the compressor driving torque using the discharge capacity without providing a flow rate sensor for detecting the flow rate of the refrigerant gas.

  In a variable capacity swash plate compressor having a single-head piston, the swash plate chamber functions as a control pressure chamber in order to change the tilt angle of the swash plate. For example, in a state where the supply of electric power to the solenoid unit is stopped, the load based on the differential pressure between the two points acts on the valve body, so that the valve opening degree of the air supply passage by the valve body becomes maximum. Therefore, the supply amount of the refrigerant gas from the discharge pressure region through the air supply passage to the swash plate chamber is maximized, and the inclination angle of the swash plate is minimized to minimize the discharge capacity of the variable displacement swash plate compressor. . On the other hand, when electric power is supplied to the solenoid unit, the urging force applied from the solenoid unit to the valve body acts on the valve body, and the valve opening degree of the air supply passage by the valve body becomes smaller than the maximum. Accordingly, the supply amount of the refrigerant gas from the discharge pressure region through the air supply passage to the swash plate chamber decreases, and the inclination angle of the swash plate increases to increase the discharge capacity of the variable displacement swash plate compressor.

JP 2001-221158 A

  Here, the solid line in the graph of FIG. 7 is a characteristic line L10 indicating the relationship between the differential pressure between two points and the flow rate of the refrigerant gas. As shown in FIG. 7, in the region where the flow rate of the refrigerant gas is small, it is difficult for a differential pressure to be generated between the first pressure monitoring point and the second pressure monitoring point. The fluctuation of the differential pressure between points is small. Therefore, in the region where the flow rate of the refrigerant gas is small, when the valve opening degree of the valve body is controlled by the solenoid unit, the urging force applied to the valve body from the solenoid unit must be changed slightly. It is difficult to control the discharge capacity of the variable capacity swash plate compressor.

  In addition, the differential pressure between the two points increases with an increase in the flow rate of the refrigerant gas, and the load acting on the valve body based on the differential pressure between the two points is a solenoid when the power supplied to the solenoid unit is maximum. If it exceeds the urging force applied to the valve body from the part, the inclination angle of the swash plate will decrease, and the discharge capacity of the variable displacement swash plate compressor will decrease.

  Therefore, for example, it is conceivable to increase the flow passage cross-sectional area of the throttle between the first pressure monitoring point and the second pressure monitoring point. According to this, even when the flow rate of the refrigerant gas increases as shown by a characteristic line L11 indicated by a two-dot chain line in the graph of FIG. 7 compared to before increasing the flow passage cross-sectional area (characteristic line L10). The increase in the differential pressure between the two points is reduced. Therefore, the load acting on the valve body based on the differential pressure between the two points is less likely to exceed the urging force applied to the valve body from the solenoid portion when the power supplied to the solenoid portion is maximum. It is possible to easily secure the discharge capacity of the plate compressor. However, when the flow passage cross-sectional area of the restrictor is increased in this way, in the region where the flow rate of the refrigerant gas is small, it becomes more difficult to apply a differential pressure between the first pressure monitoring point and the second pressure monitoring point. The controllability of the discharge capacity of the variable capacity swash plate compressor is further deteriorated.

  The present invention has been made to solve the above problems, and an object of the present invention is to provide a variable displacement swash plate compressor capable of improving the controllability of the discharge capacity.

  A variable capacity swash plate compressor that solves the above problems includes a housing having a cylinder block in which a discharge pressure region, a suction pressure region, and a plurality of cylinder bores are formed, and a rotating shaft that is rotatably supported by the housing; A swash plate that is rotated by obtaining a driving force from the rotary shaft and can be tilted with respect to a direction perpendicular to the rotational axis of the rotary shaft; a piston that is reciprocally stored in the cylinder bore; A control pressure chamber for changing the tilt angle; and a control valve for controlling the pressure of the control pressure chamber. The control valve controls the pressure of the control pressure chamber to change the tilt angle of the swash plate. The piston is reciprocated at a stroke corresponding to the inclination angle of the swash plate to constitute a refrigerant circulation circuit, and the refrigerant circulation circuit is configured to be a first in the discharge pressure region. pressure A first pressure point in the discharge pressure region that is downstream of the first pressure monitoring point and lower in pressure than the first pressure monitoring point in the flow direction of the refrigerant circulating in the refrigerant circulation circuit. And a pressure sensing chamber partitioned into a first pressure chamber communicating with the first pressure monitoring point and a second pressure chamber communicating with the second pressure monitoring point. A communication chamber communicating with the control pressure chamber, a valve hole communicating the communication chamber and the pressure sensing chamber, and a pressure difference between the pressure at the first pressure monitoring point and the pressure at the second pressure monitoring point A load based on the differential pressure between the two points is applied, and a valve body that moves in the direction of the load so as to reduce the inclination angle of the swash plate, and power supply is performed. An urging force that opposes the load applied to the valve body based on pressure is applied to the valve body to provide a valve for the valve body. A solenoid portion that controls the degree of pressure, and the valve body includes a valve seat disposed in the first pressure chamber, and the pressure sensitive chamber is disposed in the pressure sensitive chamber with the first pressure chamber. A differential pressure regulating valve that is partitioned into the second pressure chamber and is movable in unison with the valve body in contact with the valve seat is disposed, and the control valve controls the differential pressure regulating valve to A biasing member that biases toward the valve seat is further provided, and a load acting on the differential pressure adjustment valve based on the differential pressure between the two points is applied to the differential pressure adjustment valve from the biasing member. When the pressure exceeds the value, the differential pressure adjusting valve is separated from the valve seat, and the first pressure chamber and the second pressure chamber communicate with each other.

  According to this, as the refrigerant gas flow rate increases, the differential pressure between the two points increases, and the load acting on the differential pressure adjustment valve based on the differential pressure between the two points is applied from the biasing member to the differential pressure adjustment valve. When the pressure force exceeds the urging force applied to the valve, the differential pressure regulating valve is separated from the valve seat, and the first pressure chamber and the second pressure chamber communicate with each other, so that an increase in the differential pressure between the two points is suppressed. Therefore, an increase in the differential pressure between the two points when the flow rate of the refrigerant gas is in a large flow rate region is suppressed. As a result, the load acting on the valve body based on the differential pressure between the two points exceeds the urging force applied to the valve body from the solenoid portion when the power supplied to the solenoid portion is maximum, and the inclination angle of the swash plate Can be suppressed, and the discharge capacity of the variable capacity swash plate compressor can be suppressed from decreasing, and the controllability of the discharge capacity can be improved.

In the variable displacement swash plate compressor, it is preferable that a throttle is provided in a communication path connecting the first pressure monitoring point and the first pressure chamber.
According to this, in the flow direction of the refrigerant gas flowing through the communication passage, the pressure on the first pressure chamber side is lowered than the throttle. Therefore, when the differential pressure regulating valve is separated from the valve seat and the first pressure chamber and the second pressure chamber communicate with each other, the increase in the differential pressure between the two points can be further suppressed, and the discharge capacity can be reduced. Controllability can be further improved.

  According to the present invention, the controllability of the discharge capacity can be improved.

A side sectional view showing a variable capacity type swash plate type compressor in an embodiment. Sectional drawing of a control valve when the inclination angle of a swash plate is a maximum inclination angle. Sectional drawing of a control valve when the inclination angle of a swash plate is the minimum inclination angle. The side sectional view of a variable capacity type swash plate compressor when the inclination angle of the swash plate is the minimum inclination angle. Sectional drawing of a control valve which shows the state which the differential pressure regulation valve spaced apart from the valve seat. The graph which shows the relationship between the differential pressure | voltage between two points | pieces, and the flow volume of refrigerant gas. The graph which shows the relationship between the differential pressure | voltage between two points in the prior art example, and the flow volume of refrigerant gas.

  Hereinafter, an embodiment embodying a variable displacement swash plate compressor will be described with reference to FIGS. The variable capacity swash plate compressor of the present embodiment is mounted on a vehicle and used for a vehicle air conditioner.

  As shown in FIG. 1, a housing 11 of a variable capacity swash plate compressor 10 is connected to a first cylinder block 12 and a first cylinder block 12 and a second cylinder block 13 as cylinder blocks connected to each other. A front housing 14 and a rear housing 15 connected to the second cylinder block 13 are provided. A first valve / port forming body 16 is interposed between the front housing 14 and the first cylinder block 12. A second valve / port forming body 17 is interposed between the rear housing 15 and the second cylinder block 13.

  A suction chamber 14 a and a discharge chamber 14 b are defined between the front housing 14 and the first valve / port forming body 16. The discharge chamber 14b is disposed on the outer peripheral side of the suction chamber 14a. A suction chamber 15 a and a discharge chamber 15 b are defined between the rear housing 15 and the second valve / port forming body 17. Further, the rear housing 15 is formed with a pressure adjusting chamber 15c. The pressure adjustment chamber 15c is located at the center of the rear housing 15, and the suction chamber 15a is disposed on the outer peripheral side of the pressure adjustment chamber 15c. Further, the discharge chamber 15b is disposed on the outer peripheral side of the suction chamber 15a. The discharge chambers 14b and 15b are connected to each other through a discharge passage 18. Each discharge chamber 14b, 15b is a discharge pressure area.

  The first valve / port forming body 16 is formed with a suction port 16a communicating with the suction chamber 14a and a discharge port 16b communicating with the discharge chamber 14b. The second valve / port forming body 17 is formed with a suction port 17a communicating with the suction chamber 15a and a discharge port 17b communicating with the discharge chamber 15b.

  A rotating shaft 20 is rotatably supported in the housing 11. A cylindrical first support member 21 is press-fitted into the outer peripheral surface of one end of the rotating shaft 20. A cylindrical second support member 22 is press-fitted into the outer peripheral surface of the other end of the rotating shaft 20. Therefore, the first support member 21 and the second support member 22 constitute a part of the rotating shaft 20. The first support member 21 (one end of the rotating shaft 20) is inserted through a shaft hole 12 h formed in the first cylinder block 12. Further, the second support member 22 (the other end portion of the rotating shaft 20) is inserted through a shaft hole 13 h formed in the second cylinder block 13. And the edge part (the other end part of the rotating shaft 20) of the 2nd support member 22 is located in the pressure regulation chamber 15c.

  A first sliding bearing 21a is disposed between the first support member 21 and the shaft hole 12h. A second sliding bearing 22a is disposed between the second support member 22 and the shaft hole 13h. The first support member 21 is rotatably supported by the first cylinder block 12 via the first slide bearing 21a, and the second support member 22 is supported by the second cylinder block via the second slide bearing 22a. 13 is rotatably supported.

  A lip seal type shaft seal device 20 s is interposed between the front housing 14 and the rotary shaft 20. A vehicle engine as an external drive source is operatively connected to one end of the rotating shaft 20 via a power transmission mechanism (not shown). In the present embodiment, the power transmission mechanism is a constant transmission type clutchless mechanism (for example, a combination of a belt and a pulley).

  A swash plate chamber 24 defined by the first cylinder block 12 and the second cylinder block 13 is formed in the housing 11. The swash plate chamber 24 accommodates a swash plate 23 that rotates by obtaining a driving force from the rotary shaft 20 and can be tilted with respect to a direction orthogonal to the rotation axis L of the rotary shaft 20. The swash plate 23 is formed with an insertion hole 23a through which the rotary shaft 20 is inserted. The swash plate 23 is attached to the rotating shaft 20 by inserting the rotating shaft 20 into the insertion hole 23a.

  In the first cylinder block 12, a plurality of first cylinder bores 12a as cylinder bores penetrating in the axial direction of the first cylinder block 12 are arranged around the rotating shaft 20 (only one first cylinder bore 12a is shown in FIG. 1). Has been. Each first cylinder bore 12a communicates with the suction chamber 14a via the suction port 16a and also communicates with the discharge chamber 14b via the discharge port 16b. In the second cylinder block 13, a plurality of second cylinder bores 13a as cylinder bores penetrating in the axial direction of the second cylinder block 13 are arranged around the rotating shaft 20 (only one second cylinder bore 13a is shown in FIG. 1). Has been. Each second cylinder bore 13a communicates with the suction chamber 15a via the suction port 17a and also communicates with the discharge chamber 15b via the discharge port 17b. The 1st cylinder bore 12a and the 2nd cylinder bore 13a are arranged so that it may become a pair in front and back. In the first cylinder bore 12a and the second cylinder bore 13a as a pair, a double-headed piston 25 as a piston is accommodated so as to be reciprocable in the front-rear direction. The variable capacity swash plate compressor 10 of this embodiment is a double-headed piston swash plate compressor.

  Each double-headed piston 25 is anchored to the outer peripheral portion of the swash plate 23 via a pair of shoes 26. Then, the rotational motion of the swash plate 23 accompanying the rotation of the rotary shaft 20 is converted into the reciprocating linear motion of the double-headed piston 25 via the shoe 26. Therefore, the pair of shoes 26 is a conversion mechanism that causes the double-headed piston 25 to reciprocate within the paired first cylinder bore 12a and second cylinder bore 13a by the rotation of the swash plate 23. In each first cylinder bore 12a, a first compression chamber 19a is defined by a double-headed piston 25 and a first valve / port forming body 16. In each second cylinder bore 13a, a second compression chamber 19b is defined by a double-headed piston 25 and a second valve / port forming body 17.

  The first cylinder block 12 is formed with a first large-diameter hole 12b that is continuous with the shaft hole 12h and has a larger diameter than the shaft hole 12h. The first large-diameter hole 12 b communicates with the swash plate chamber 24 and forms a part of the swash plate chamber 24. The swash plate chamber 24 and the suction chamber 14 a communicate with each other through a suction passage 12 c that penetrates the first cylinder block 12 and the first valve / port forming body 16.

  The second cylinder block 13 is formed with a second large-diameter hole 13b that is continuous with the shaft hole 13h and has a larger diameter than the shaft hole 13h. The second large-diameter hole 13 b communicates with the swash plate chamber 24 and forms a part of the swash plate chamber 24. The swash plate chamber 24 and the suction chamber 15a communicate with each other through a suction passage 13c that passes through the second cylinder block 13 and the second valve / port forming body 17.

  The first support member 21 is provided with an annular first flange 21f disposed in the first large-diameter hole 12b. A first thrust bearing 27 a is disposed between the first flange 21 f and the first cylinder block 12 in the axial direction of the rotary shaft 20. The second support member 22 is provided with an annular second flange 22f disposed in the second large-diameter hole 13b. A second thrust bearing 27 b is disposed between the second flange 22 f and the second cylinder block 13 in the axial direction of the rotary shaft 20.

  A suction port 13 s is formed in the peripheral wall of the second cylinder block 13. The suction port 13s and the discharge passage 18 are connected by an external refrigerant circuit 45. The external refrigerant circuit 45 includes a condenser 46 connected to the discharge passage 18, an expansion valve 47 connected to the condenser 46, and an evaporator 48 connected to the expansion valve 47. 13s is connected. The variable capacity swash plate compressor 10 constitutes a refrigerant circulation circuit (cooling circuit) of the vehicle air conditioner.

  The refrigerant gas sucked into the swash plate chamber 24 through the suction port 13s is sucked into the suction chambers 14a and 15a through the suction passages 12c and 13c. Therefore, the suction chambers 14a and 15a and the swash plate chamber 24 are in the suction pressure region, and the pressures are almost equal.

  A throttle 49 for reducing the discharge pulsation of the refrigerant gas is provided between the discharge passage 18 and the condenser 46 in the discharge pressure region of the refrigerant circulation circuit. Then, the refrigerant circulation circuit has a first pressure monitoring point P1 upstream of the throttle 49 and a second pressure monitoring point P2 downstream of the throttle 49 in the flow direction of the refrigerant gas circulating in the refrigerant circulation circuit. And have. The pressure (PdH) at the first pressure monitoring point P1 is higher than the pressure (PdL) at the second pressure monitoring point P2.

  In the swash plate chamber 24, there is provided an actuator 30 capable of changing the inclination angle of the swash plate 23 with respect to a first direction (vertical direction in FIG. 1) perpendicular to the rotation axis L of the rotary shaft 20 in the swash plate 23. The actuator 30 is provided between the second flange 22 f and the swash plate 23. The actuator 30 includes an annular partition body 31 that can rotate integrally with the rotary shaft 20. The partition body 31 is formed with an insertion hole 31h through which the rotary shaft 20 is inserted. The rotating shaft 20 is inserted into the insertion hole 31 h and press-fitted and fixed, so that the partition body 31 is integrated with the rotating shaft 20.

  The actuator 30 includes a bottomed cylindrical moving body 32 that is disposed between the second flange 22 f and the partition body 31 and is movable in the axial direction of the rotary shaft 20 in the swash plate chamber 24. The moving body 32 is disposed so as to be able to enter inside the second large-diameter hole 13b. The moving body 32 includes an annular bottom portion 32a having an insertion hole 32e through which the rotary shaft 20 is inserted, and a cylindrical portion 32b extending along the axial direction of the rotary shaft 20 from the outer peripheral edge of the bottom portion 32a. The moving body 32 can rotate integrally with the rotary shaft 20. The space between the inner peripheral surface of the cylindrical portion 32 b and the outer peripheral surface of the partition body 31 is sealed with a seal member 33, and the space between the through hole 32 e and the rotary shaft 20 is sealed with a seal member 34. The actuator 30 has a control pressure chamber 35 partitioned by the partition body 31 and the moving body 32.

  A return spring 28 a is fixed to the first support member 21. The return spring 28 a extends from the first support member 21 toward the swash plate chamber 24. Further, an inclination angle reducing spring 28 b is interposed between the partition body 31 and the swash plate 23. One end of the inclination reduction spring 28 b is fixed to the partition body 31, and the other end is fixed to the swash plate 23. The inclination-decreasing spring 28b biases the swash plate 23 in a direction in which the inclination angle of the swash plate 23 decreases.

  The rotary shaft 20 is formed with an in-shaft passage 29 that communicates the control pressure chamber 35 and the pressure adjustment chamber 15c. The in-axis passage 29 includes a first in-axis passage 29 a extending along the axial direction of the rotating shaft 20 and a second in-axis passage 29 b communicating with the first in-axis passage 29 a and extending along the radial direction of the rotating shaft 20. And is formed from. The rear end of the first in-axis passage 29a communicates with the pressure adjustment chamber 15c. One end of the second in-axis passage 29 b communicates with the tip of the first in-axis passage 29 a, and the other end opens into the control pressure chamber 35. Therefore, the control pressure chamber 35 and the pressure adjusting chamber 15c communicate with each other via the first in-axis passage 29a and the second in-axis passage 29b.

  In the swash plate chamber 24, a lug arm 40 is disposed between the swash plate 23 and the first flange 21f. The lug arm 40 is formed in a substantially L shape from one end to the other end. A weight portion 40 w is provided at one end of the lug arm 40. The weight portion 40 w passes through the groove portion 23 b of the swash plate 23 and is located on the rear end side of the swash plate 23.

  On one end side of the lug arm 40, an insertion hole 40h is formed through which the columnar first pin 41 that passes through the groove 23b is inserted. The first pin 41 is inserted into the insertion hole 40h, whereby one end side of the lug arm 40 is connected to the upper end side (upper side in FIG. 1) of the swash plate 23. Thus, one end side of the lug arm 40 is supported so as to be swingable around the first swing center M1 with respect to the swash plate 23 with the axis of the first pin 41 as the first swing center M1. The other end side of the lug arm 40 is connected to a connecting portion (not shown) of the first support member 21 by a cylindrical second pin 42. Thereby, the other end side of the lug arm 40 is supported so as to be swingable around the second swing center M2 with respect to the first support member 21 with the axis of the second pin 42 as the second swing center M2. Yes. In the present embodiment, the lug arm 40, the first pin 41, and the second pin 42 constitute a link mechanism that allows the inclination angle of the swash plate 23 to be changed.

  A connecting portion 32 c that protrudes toward the swash plate 23 is provided at the tip of the cylindrical portion 32 b of the moving body 32. A cylindrical connecting pin 43 is press-fitted and fixed to the connecting portion 32c. Further, an insertion hole 23h through which the connecting pin 43 is inserted is formed on the lower end side (lower side in FIG. 1) which is the outer peripheral side of the insertion hole 23a of the swash plate 23. The connecting portion 32 c is connected to the lower end side of the swash plate 23 via the connecting pin 43.

  An electromagnetic control valve 50 that controls the pressure in the control pressure chamber 35 is assembled to the rear housing 15. The control valve 50 is electrically connected to a control computer (not shown). An air conditioner switch (not shown) is signal-connected to the control computer.

  As shown in FIG. 2, the valve housing 50 h of the control valve 50 includes a cylindrical first housing 51 in which the solenoid unit 60 is accommodated, and a cylindrical second housing 52 in which the columnar valve body 70 is accommodated. Have. The solenoid unit 60 includes a cylindrical fixed iron core 61, a movable iron core 62 that is attracted to the fixed iron core 61 when power is supplied to the coil 60 a of the solenoid unit 60, and a direction in which the movable iron core 62 is separated from the fixed iron core 61. And an urging spring 63 for urging the The electromagnetic force of the solenoid unit 60 attracts the movable iron core 62 toward the fixed iron core 61. The solenoid unit 60 receives energization control (duty ratio control) of the control computer.

  The fixed iron core 61 is disposed closer to the valve body 70 than the movable iron core 62. A driving force transmission rod 64 is attached to the movable iron core 62. The driving force transmission rod 64 can move integrally with the movable iron core 62. The fixed iron core 61 includes a small-diameter portion 61a located inside the coil 60a, and a large-diameter portion 61b that protrudes from the opening of the first housing 51 opposite to the movable iron core 62 and has a larger diameter than the small-diameter portion 61a. Have. A recess 61c is formed on the end surface of the large diameter portion 61b opposite to the small diameter portion 61a. The second housing 52 is fitted into the recess 61c. The opening of the second housing 52 opposite to the first housing 51 is closed by a cylindrical lid member 53.

  A communication chamber 54 and a pressure sensing chamber 55 are formed in the second housing 52. The communication chamber 54 is disposed closer to the solenoid unit 60 than the pressure sensing chamber 55. The driving force transmission rod 64 protrudes into the communication chamber 54. The communication chamber 54 has a smaller diameter than the pressure sensing chamber 55. Between the communication chamber 54 and the pressure sensing chamber 55 in the second housing 52, a press-fit recess 56 having a diameter larger than that of the communication chamber 54 and smaller than that of the pressure sensing chamber 55 is formed. An annular valve seat member 57 is press-fitted into the press-fit recess 56. A valve hole 57 h is formed in the central portion of the valve seat member 57. The valve hole 57 h communicates the communication chamber 54 and the pressure sensitive chamber 55.

  The valve body 70 includes a valve portion 71 that opens and closes the valve hole 57h. The valve portion 71 is disposed in the pressure sensitive chamber 55. The valve portion 71 has an end surface seal portion 71 s that comes into contact with the periphery of the valve hole 57 h on the end surface on the pressure sensitive chamber 55 side of the valve seat member 57 from the pressure sensitive chamber 55. Further, the valve body 70 includes a columnar protrusion 72 that is continuous with the valve 71 and passes through the valve hole 57 h and protrudes into the communication chamber 54. The tip of the projecting portion 72 is in contact with the driving force transmission rod 64. A restriction ring 73 is attached to the outer peripheral surface of the valve portion 71.

  In the pressure sensitive chamber 55, a bottomed cylindrical differential pressure regulating valve 80 is disposed. By this differential pressure regulating valve 80, the pressure sensitive chamber 55 is partitioned into a first pressure chamber 55a on the opposite side to the solenoid unit 60 and a second pressure chamber 55b on the solenoid unit 60 side. The differential pressure regulating valve 80 includes a disc-shaped bottom portion 80a and a cylindrical portion 80b extending from the outer peripheral edge of the bottom portion 80a toward the lid member 53 in a direction orthogonal to the bottom portion 80a. An insertion hole 80h is formed at the center of the bottom 80a, through which the end of the valve portion 71 opposite to the protruding portion 72 is inserted. And the edge part on the opposite side to the protrusion part 72 in the valve part 71 passes the insertion hole 80h from the 2nd pressure chamber 55b, and protrudes inside the cylindrical part 80b. A valve seat 71e, which is an annular flange, is provided at the end of the valve portion 71 opposite to the protruding portion 72. And the circumference | surroundings of the insertion hole 80h of the inner surface by the side of the 1st pressure chamber 55a in the bottom part 80a can contact | abut to the end surface by the side of the solenoid part 60 in the valve seat 71e. Therefore, the valve seat 71e is disposed in the first pressure chamber 55a.

  An urging spring 74 as an urging member is disposed between the regulating ring 73 around the valve portion 71 and the bottom portion 80a of the differential pressure regulating valve 80. The biasing spring 74 biases the differential pressure adjusting valve 80 toward the valve seat 71e. In the state where the periphery of the insertion hole 80h in the bottom 80a is in contact with the valve seat 71e, the insertion hole 80h is closed. A spring 75 is disposed between the lid member 53 and the valve seat 71e.

  A first port 521 that communicates with the communication chamber 54 is formed in the second housing 52. The communication chamber 54 communicates with the pressure adjustment chamber 15 c via the first port 521 and the first passage 91. The second housing 52 is formed with a second port 522 communicating with the second pressure chamber 55b. The second pressure chamber 55b communicates with the second pressure monitoring point P2 via the second port 522 and the second passage 92. The second passage 92, the second port 522, the second pressure chamber 55b, the valve hole 57h, the communication chamber 54, the first port 521 and the first passage 91, the pressure adjusting chamber 15c and the in-shaft passage 29 An air supply passage 95 extending from the monitoring point P2 to the control pressure chamber 35 is formed.

  The lid member 53 is formed with a third port 523 communicating with the first pressure chamber 55a. The first pressure chamber 55a communicates with the first pressure monitoring point P1 through the third port 523 and the third passage 93. Therefore, the third port 523 and the third passage 93 form a communication passage 94 that connects the first pressure monitoring point P1 and the first pressure chamber 55a. The flow path cross-sectional area of the third port 523 is smaller than the flow path cross-sectional area of the third passage 93. Therefore, the third port 523 functions as a throttle provided in the communication path 94. The channel cross-sectional area of the third port 523 is smaller than the channel cross-sectional area in the insertion hole 80h.

  The valve body 70 is a load based on a differential pressure between two points, which is a differential pressure between the pressure in the first pressure chamber 55a (first pressure monitoring point P1) and the pressure in the second pressure chamber 55b (second pressure monitoring point P2). Is applied to move in the direction of closing the valve hole 57h. The valve body 70 closes the air supply passage 95 by closing the valve hole 57h by the end face seal portion 71s coming into contact with the periphery of the valve hole 57h on the end face of the valve seat member 57 on the pressure sensing chamber 55 side. The valve is closed. Further, the valve body 70 is configured such that the end face seal portion 71 s is separated from the periphery of the valve hole 57 h on the end face of the valve seat member 57 on the pressure sensing chamber 55 side, and the valve hole 57 h is opened, so that the air supply passage 95 is opened. The valve is opened. The differential pressure regulating valve 80 is movable integrally with the valve body 70 in a state where the periphery of the insertion hole 80h in the bottom portion 80a is in contact with the valve seat 71e.

  As shown in FIG. 3, in the variable displacement swash plate compressor 10 having the above-described configuration, the movable iron core 62 is biased by a spring when the air conditioner switch is turned off and the supply of power to the solenoid unit 60 is stopped. The fixed iron core 61 is separated by the urging force of 63. Then, a load based on the differential pressure between the two points is applied to the valve body 70, and the valve body 70 moves toward the solenoid unit 60. As a result, the end surface seal portion 71s contacts the periphery of the valve hole 57h on the end surface of the valve seat member 57 on the pressure sensing chamber 55 side, and the valve hole 57h is closed. When the valve hole 57h is closed by the end face seal portion 71s, the second passage 92, the second port 522, the second pressure chamber 55b, the valve hole 57h, the communication chamber 54, the first port 521, from the second pressure monitoring point P2. The supply of the refrigerant gas to the control pressure chamber 35 through the first passage 91, the pressure adjustment chamber 15c, and the in-shaft passage 29 is shut off. Then, the refrigerant gas is discharged from the control pressure chamber 35 to the suction chamber 15a through a bleed passage (not shown), whereby the pressure in the control pressure chamber 35 approaches the pressure in the suction chamber 15a.

  As shown in FIG. 4, the pressure in the control pressure chamber 35 approaches the pressure in the suction chamber 15 a, and the pressure difference between the control pressure chamber 35 and the swash plate chamber 24 decreases, so that the double-headed piston 25 acting on the swash plate 23. The swash plate 23 pulls the moving body 32 through the connecting pin 43 by the compression reaction force from the moving body 32, and the moving body 32 moves so that the bottom 32 a of the moving body 32 approaches the partition body 31. When the moving body 32 moves so that the bottom 32a of the moving body 32 approaches the partition body 31, the swash plate 23 swings around the first swing center M1. As the swash plate 23 swings around the first swing center M1, the lug arm 40 swings around the second swing center M2, and the lug arm 40 approaches the first flange 21f. As a result, the inclination angle of the swash plate 23 is reduced, and the swash plate 23 contacts the return spring 28a. When the inclination angle of the swash plate 23 is reduced, the stroke of the double-headed piston 25 is reduced and the discharge capacity is reduced.

  As shown in FIG. 2, when the air conditioner switch is turned on and power is supplied to the solenoid unit 60, the electromagnetic force of the solenoid unit 60 resists the biasing force of the biasing spring 63 and the movable iron core 62. Is attracted toward the fixed iron core 61. The control computer controls power supply to the solenoid unit 60 based on the temperature difference between the set target room temperature and the detected actual room temperature.

  The valve portion 71 is opened by a balance between the degree of attraction of the movable iron core 62 to the fixed iron core 61 (the urging force of the urging spring 63) and the load applied to the valve body 70 based on the differential pressure between the two points. The degree is adjusted. When the power supply to the solenoid unit 60 is increased (duty ratio control is increased), the degree of attraction of the movable iron core 62 to the fixed iron core 61 increases. Then, an urging force that opposes the load applied to the valve body 70 based on the differential pressure between the two points is applied to the valve body 70, and the end surface seal portion 71 s is formed on the end surface of the valve seat member 57 on the pressure sensitive chamber 55 side. The valve opening degree of the valve portion 71 is increased away from the periphery of the valve hole 57h.

  When the valve opening of the valve portion 71 increases, the second passage 92, the second port 522, the second pressure chamber 55b, the valve hole 57h, the communication chamber 54, the first port 521, the first passage from the second pressure monitoring point P2. 91, the flow rate of the refrigerant gas supplied to the control pressure chamber 35 through the pressure adjustment chamber 15c and the in-shaft passage 29 increases, and the pressure in the control pressure chamber 35 approaches the pressure at the second pressure monitoring point P2.

  As shown in FIG. 1, when the pressure in the control pressure chamber 35 approaches the pressure at the second pressure monitoring point P2, and the pressure difference between the control pressure chamber 35 and the swash plate chamber 24 increases, the moving body 32 is connected to the connecting pin. While pulling the swash plate 23 through 43, the bottom 32 a of the moving body 32 moves so as to be separated from the partition body 31. When the moving body 32 moves so that the bottom 32a of the moving body 32 is separated from the partition body 31, the swash plate 23 is in the direction opposite to the swing direction when the tilt angle of the swash plate 23 is decreased around the first swing center M1. Rocks. As the swash plate 23 swings in the direction opposite to the swing direction when the tilt angle of the swash plate 23 decreases, the lug arm 40 moves around the second swing center M2 around the first swing center M1. The swinging motion of the lug arm 40 is away from the first flange 21f. Thereby, the inclination angle of the swash plate 23 is increased, the stroke of the double-headed piston 25 is increased, and the discharge capacity is increased.

  Therefore, in the present embodiment, the control valve 50 is disposed on the air supply passage 95, the valve opening degree of the control valve 50 is adjusted, and the control pressure chamber 35 is supplied from the discharge pressure region via the air supply passage 95. By controlling the amount of refrigerant gas supplied, so-called “entry-side control” is performed in which the pressure in the control pressure chamber 35 is controlled.

Next, the operation of this embodiment will be described.
As shown in FIG. 5, as the flow rate of the refrigerant gas flowing through the refrigerant circuit increases, the differential pressure between the two points increases, and the load acting on the differential pressure adjustment valve 80 based on the differential pressure between the two points is When the urging force applied to the differential pressure regulating valve 80 from the urging spring 74 is exceeded, the differential pressure regulating valve 80 is separated from the valve seat 71e, and the first pressure chamber 55a and the second pressure chamber 55b are inserted into the insertion hole. It communicates via 80h. As a result, an increase in the differential pressure between the two points is suppressed.

  The solid line in the graph of FIG. 6 is the characteristic line L1 which shows the relationship between the differential pressure between two points of this embodiment, and the flow volume of refrigerant gas. A broken line in the graph of FIG. 6 is a characteristic line L2 indicating the relationship between the differential pressure between two points of the control valve not provided with the differential pressure adjusting valve 80 and the flow rate of the refrigerant gas, and is a comparative example with respect to the present embodiment. It is. The characteristic line L1 suppresses an increase in the differential pressure between two points when the flow rate of the refrigerant gas is in a large flow rate region as compared with the characteristic line L2.

  At this time, since the pressure on the first pressure chamber 55a side is lower than the third port 523 in the flow direction of the refrigerant gas flowing through the communication path 94 by the third port 523 functioning as a throttle, the differential pressure regulating valve 80 However, when the first pressure chamber 55a and the second pressure chamber 55b communicate with each other, the increase in the differential pressure between the two points can be further suppressed. As a result, the load acting on the valve body 70 based on the differential pressure between the two points exceeds the urging force applied to the valve body 70 from the solenoid section 60 when the power supplied to the solenoid section 60 is maximum, It is suppressed that the inclination angle of the swash plate 23 becomes small and the discharge capacity of the variable displacement swash plate compressor 10 decreases.

In the above embodiment, the following effects can be obtained.
(1) A differential pressure adjusting valve 80 is disposed in the pressure sensitive chamber 55. The valve body 70 is provided with a biasing spring 74 that biases the differential pressure adjusting valve 80 toward the valve seat 71e. When the load acting on the differential pressure adjusting valve 80 based on the differential pressure between the two points exceeds the urging force applied from the urging spring 74 to the differential pressure adjusting valve 80, the differential pressure adjusting valve 80 The first pressure chamber 55a and the second pressure chamber 55b communicate with each other apart from the seat 71e. According to this, since the first pressure chamber 55a and the second pressure chamber 55b communicate with each other and an increase in the differential pressure between the two points is suppressed, the difference between the two points when the flow rate of the refrigerant gas is in the high flow rate region. Increase in pressure is suppressed. Therefore, the load acting on the valve body 70 based on the differential pressure between the two points exceeds the urging force applied to the valve body 70 from the solenoid section 60 when the power supplied to the solenoid section 60 is maximum, and the load It can be suppressed that the inclination angle of the plate 23 becomes small and the discharge capacity of the variable displacement swash plate compressor 10 decreases. As a result, the controllability of the discharge capacity can be improved.

  (2) The communication path 94 is provided with a third port 523 that functions as a throttle. According to this, the pressure on the first pressure chamber 55a side is lower than the third port 523 in the flow direction of the refrigerant gas flowing through the communication passage 94. Therefore, the increase in the differential pressure between the two points when the differential pressure regulating valve 80 is separated from the valve seat 71e and the first pressure chamber 55a and the second pressure chamber 55b communicate with each other can be further suppressed. Further, the controllability of the discharge capacity can be further improved.

In addition, you may change the said embodiment as follows.
In the embodiment, in the communication passage 94, the third passage 93 may be provided with a throttle.

In the embodiment, the third port 523 may not function as a diaphragm.
In the embodiment, the urging spring 74 may be disposed between the valve seat member 57 and the differential pressure regulating valve 80, for example. In this case, the restriction ring 73 may not be provided on the outer peripheral surface of the valve portion 71.

  In the embodiment, the variable displacement swash plate compressor 10 is provided with a control valve on the extraction passage, and the valve opening of the control valve is adjusted to move from the control pressure chamber to the suction pressure region through the extraction passage. It may be configured to perform so-called “extraction-side control” in which the pressure of the control pressure chamber 35 is controlled by controlling the amount of refrigerant gas discharged.

In the embodiment, the variable capacity swash plate compressor 10 may be configured to include a three-way valve type control valve that achieves both “insertion side control” and “extraction side control”.
In the embodiment, the actuator 30 moves the moving body 32 so that the inclination angle of the swash plate 23 increases as the pressure of the control pressure chamber 35 decreases, and the pressure of the control pressure chamber 35 becomes the pressure of the suction chamber 15a. , The inclination angle of the swash plate 23 is maximized, and when the pressure in the control pressure chamber 35 increases, the moving body 32 moves so that the inclination angle of the swash plate 23 becomes small. The configuration may be such that the inclination angle of the swash plate 23 is minimized by making the pressure substantially equal to the pressure in the discharge chamber 15b. That is, the actuator 30 may be configured such that the pressure in the control pressure chamber 35 decreases in order to increase the discharge capacity.

  In the embodiment, the variable capacity swash plate compressor 10 is a double-headed piston swash plate compressor that employs a double-headed piston 25, but may be a single-headed piston swash plate compressor that employs a single-headed piston. . The variable capacity swash plate compressor 10 may be configured to control the pressure in the swash plate chamber 24 by the control valve 50 in order to change the inclination angle of the swash plate 23. In this case, the swash plate chamber 24 functions as a control pressure chamber that changes the inclination angle of the swash plate 23.

  In the embodiment, one end of the rotating shaft 20 may be connected to an engine of a vehicle as an external drive source via a clutch mechanism that can select transmission and interruption of power by electric control from the outside.

  In the embodiment, the variable capacity swash plate compressor 10 may not be used for a vehicle air conditioner, and may be used for other air conditioners.

  P1 ... first pressure monitoring point, P2 ... second pressure monitoring point, 10 ... variable displacement swash plate compressor, 11 ... housing, 12 ... first cylinder block as cylinder block, 12a ... first cylinder bore as cylinder bore, DESCRIPTION OF SYMBOLS 13 ... 2nd cylinder block as a cylinder block, 13a ... 2nd cylinder bore as a cylinder bore, 14a, 15a ... Suction chamber which is a suction pressure area | region, 14b, 15b ... Discharge chamber which is a discharge pressure area | region, 20 ... Rotating shaft, 23 ... Swash plate, 25 ... Double-headed piston as piston, 35 ... Control pressure chamber, 50 ... Control valve, 54 ... Communication chamber, 55 ... Pressure sensitive chamber, 55a ... First pressure chamber, 55b ... Second pressure chamber, 57h ... Valve hole, 60 ... solenoid part, 70 ... valve body, 71e ... valve seat, 74 ... urging spring as urging member, 80 ... differential pressure regulating valve, 94 ... communication path, 523 ... throttle The third port to function Te.

Claims (2)

A housing having a cylinder block in which a discharge pressure region, a suction pressure region, and a plurality of cylinder bores are formed;
A rotating shaft rotatably supported by the housing;
A swash plate capable of obtaining a driving force from the rotating shaft and rotating to tilt in a direction perpendicular to the rotating axis of the rotating shaft;
A piston housed in the cylinder bore so as to be capable of reciprocating;
A control pressure chamber for changing an inclination angle of the swash plate;
A control valve for controlling the pressure of the control pressure chamber,
By controlling the pressure of the control pressure chamber by the control valve, the inclination angle of the swash plate is changed, and the piston reciprocates with a stroke corresponding to the inclination angle of the swash plate, thereby constituting a refrigerant circulation circuit. A variable capacity swash plate compressor,
The refrigerant circuit is
A first pressure monitoring point in the discharge pressure region;
A second pressure monitor in the discharge pressure region that is downstream of the first pressure monitoring point and lower in pressure than the first pressure monitoring point in the flow direction of the refrigerant circulating in the refrigerant circulation circuit. And
The control valve is
A pressure sensing chamber partitioned into a first pressure chamber communicating with the first pressure monitoring point and a second pressure chamber communicating with the second pressure monitoring point;
A communication chamber communicating with the control pressure chamber;
A valve hole communicating the communication chamber and the pressure sensing chamber;
A load based on a differential pressure between two points, which is a differential pressure between the pressure at the first pressure monitoring point and the pressure at the second pressure monitoring point, is applied, and the direction of the load so as to reduce the tilt angle of the swash plate A valve body that moves to
A solenoid that controls the valve opening degree of the valve body by applying an urging force that opposes the load applied to the valve body based on the differential pressure between the two points by supplying power to the valve body. And
The valve body has a valve seat disposed in the first pressure chamber,
In the pressure-sensitive chamber, the pressure-sensitive chamber is divided into the first pressure chamber and the second pressure chamber, and is capable of moving integrally with the valve body in contact with the valve seat. Is placed,
The control valve further includes a biasing member that biases the differential pressure regulating valve toward the valve seat,
When the load acting on the differential pressure regulating valve based on the differential pressure between the two points exceeds the biasing force applied from the biasing member to the differential pressure regulating valve, the differential pressure regulating valve is A variable displacement swash plate compressor, wherein the first pressure chamber and the second pressure chamber communicate with each other apart from a seat.   The variable capacity swash plate compressor according to claim 1, wherein a throttle is provided in a communication path connecting the first pressure monitoring point and the first pressure chamber.