JP2005307882A - Capacity control mechanism in variable displacement compressor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a capacity control mechanism capable of shortening a time taken until a discharge capacity is increased after the start of a variable displacement compressor and improving operation efficiency when operating by a minimum capacity. <P>SOLUTION: A first control valve 32, a second control valve 46, and a third control valve 47 are assembled into a rear housing 13. A valve element 49 of the second control valve 46 partitions a back pressure chamber 52 in a valve housing 48. When the first control valve 32 is in an opened state, the pressure of a discharge chamber 132 spreads to the back pressure chamber 52, and the second control valve 46 is closed. When the first control valve 32 is closed, the second control valve 46 is opened. The third control valve 47 is shifted to an opened state in a process in which a difference between the pressure of a control pressure chamber 121 and the pressure of a suction chamber 131 is increased from the closed state. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention supplies the refrigerant in the discharge pressure region to the control pressure chamber, discharges the refrigerant in the control pressure chamber to the suction pressure region, regulates the pressure in the control pressure chamber, and adjusts the pressure in the control pressure chamber. The present invention relates to a capacity control mechanism in a variable capacity compressor that controls the discharge capacity.

  In a variable capacity compressor having a control pressure chamber that accommodates a swash plate with a variable tilt angle, the tilt angle of the swash plate decreases as the pressure in the control pressure chamber increases, and the tilt angle of the swash plate decreases as the pressure in the control pressure chamber decreases. Becomes larger. When the inclination angle of the swash plate decreases, the stroke of the piston decreases and the discharge capacity decreases. When the inclination angle of the swash plate increases, the stroke of the piston increases and the discharge capacity increases.

  Since the refrigerant supplied to the control pressure chamber is a compressed high-pressure refrigerant, the operation efficiency of the variable capacity compressor becomes worse as the discharge flow rate of the refrigerant discharged from the control pressure chamber to the suction pressure region increases. . Therefore, from the viewpoint of operating efficiency in the variable capacity compressor, the passage cross-sectional area of the discharge passage for discharging the refrigerant from the control pressure chamber to the suction pressure region is preferably as small as possible.

  If the variable capacity compressor is stopped for a long time, the refrigerant liquefies and accumulates in the control pressure chamber. Assuming that the variable capacity compressor is started with liquid refrigerant accumulated in the control pressure chamber, the liquid refrigerant in the control pressure chamber is sucked when the passage cross-sectional area of the discharge passage is fixed and small. The pressure in the control pressure chamber becomes excessive due to vaporization of the liquid refrigerant in the control pressure chamber without being quickly discharged to the pressure region. Therefore, it takes too much time for the discharge capacity to increase after the variable capacity compressor is started.

Patent Document 1 discloses a capacity control mechanism of a variable capacity compressor for solving such a problem.
The capacity control mechanism disclosed in Patent Document 1 includes a first control valve for changing a cross-sectional area of a supply passage for supplying refrigerant from a discharge pressure region to a crank chamber (control pressure chamber), and a suction pressure region from the crank chamber. And a second control valve for changing the passage sectional area of the discharge passage for discharging the refrigerant. The first control valve is a variable valve opening control valve that can change the valve opening continuously by changing the electromagnetic force. In a state where the first control valve is not energized, the valve opening degree of the first control valve is maximized, and the variable displacement compressor has the minimum inclination of the swash plate. This state is a minimum capacity operation state in which the discharge capacity is fixed to the minimum capacity. In a state where the first control valve is energized, the valve opening degree of the first control valve becomes smaller than the maximum, and the variable displacement compressor has the inclination angle of the swash plate exceeding the minimum. This state is an intermediate capacity operation state in which the discharge capacity is not fixed to the minimum capacity.

The spool of the second control valve (the valve body for changing the passage cross-sectional area of the discharge passage) defines a back pressure chamber, and the back pressure chamber communicates with a pressure region downstream from the first control valve. Yes. A communication groove is formed in the spool. The communication groove is for securing a minute minimum passage cross-sectional area in the discharge passage. When the variable displacement compressor is started, the first control valve is closed and the spool is moved in a direction to increase the passage cross-sectional area of the discharge passage. As a result, the liquid refrigerant in the control pressure chamber is quickly discharged to the suction pressure region, and the time taken for the discharge capacity to increase after the start of the variable displacement compressor is shortened.
JP 2002-21721 A

  If the passage cross-sectional area of the communication groove is too large, the refrigerant discharge flow rate from the control pressure chamber to the suction pressure region increases during the minimum capacity operation, and the operation efficiency during the minimum capacity operation is reduced. Deteriorate.

  Conversely, when the first control valve is open due to energization, the second control valve is closed (the spool is seated on the valve seat), and the refrigerant is discharged from the crank chamber to the suction pressure region. This is done via the groove only. At this time, intermediate capacity control (intermediate capacity control) equal to or greater than the minimum capacity is performed. If the cross-sectional area of the communication groove is too small, it is difficult to ensure a refrigerant discharge flow rate suitable for intermediate capacity control.

  The present invention provides a refrigerant from the control pressure chamber to the suction pressure region so that the time required for the discharge capacity to increase immediately after the start of the variable capacity compressor is shortened and the operation efficiency at the time of minimum capacity operation is improved. It aims at providing the capacity | capacitance control mechanism which can adjust discharge | emission flow volume.

  For this purpose, the present invention supplies the refrigerant in the discharge pressure region to the control pressure chamber via the supply passage, and discharges the refrigerant in the control pressure chamber to the suction pressure region via the discharge passage. The first aspect of the present invention is a first control that adjusts the cross-sectional area of the supply passage. In the first aspect of the invention, the first aspect of the invention is directed to a displacement control mechanism in a variable displacement compressor that controls the discharge capacity by regulating the pressure in the control pressure chamber. A valve, a second control valve that adjusts the cross-sectional area of the discharge passage, and the second control valve in parallel, and based on a differential pressure between the pressure in the control pressure chamber and the pressure in the suction pressure region A third control valve that adjusts a cross-sectional area of the discharge passage, a normally open passage that always communicates the control pressure chamber and the suction pressure region, and has a minimum passage cross-sectional area in the discharge passage; And when the first control valve is in the closed state, When the control valve is in the open state and the first control valve is in the open state, the third control valve is changed from the closed state to the open state in the process of increasing the differential pressure between the control pressure chamber and the suction pressure region. A capacity control mechanism that can be migrated was configured.

  The passage sectional area of the supply passage is a passage sectional area in the first control valve defined by the valve opening of the first control valve. The passage sectional area of the discharge passage is defined by the passage sectional area of the normally open passage, the passage sectional area of the second control valve defined by the valve opening of the second control valve, and the valve opening of the third control valve. It is the sum with the passage sectional area in the 3rd control valve.

  If the first control valve is closed and the second control valve is opened by increasing the valve opening of the second control valve when the second control valve is open, the control pressure chamber The liquid refrigerant in is immediately discharged to the suction pressure region. That is, it is possible to adjust the refrigerant discharge flow rate from the control pressure chamber to the suction pressure region so that the time required until the discharge capacity increases immediately after the start of the variable displacement compressor is shortened.

  When the first control valve is in the open state and the second control valve is in the closed state, the passage sectional area of the discharge passage when the third control valve is in the closed state matches the passage sectional area of the normally open passage. . If the variable displacement compressor is in the minimum capacity operation state (operation state in which the discharge capacity is fixed at the minimum capacity) when the second control valve is in the closed state and the third control valve is in the closed state, The refrigerant outflow rate from the control pressure chamber to the suction pressure region at that time can be reduced by reducing the passage cross-sectional area of the normally open passage. That is, the refrigerant discharge flow rate from the control pressure chamber to the suction pressure region can be adjusted so that the operation efficiency during the minimum capacity operation is improved. In the present specification, the minimum capacity operation refers to the operation of a variable capacity compressor in which the discharge capacity is fixed to the minimum capacity.

  When the third control valve shifts from the closed state to the open state in the process in which the differential pressure between the control pressure chamber and the suction pressure region increases, the refrigerant discharge flow rate discharged from the control pressure chamber to the suction pressure region increases. That is, when the second control valve is in the closed state and the third control valve is in the open state, it is possible to ensure a refrigerant discharge flow rate suitable for capacity operation (intermediate capacity operation) of the minimum capacity or more. In other words, the refrigerant discharge flow rate from the control pressure chamber to the suction pressure region can be adjusted so as to provide good intermediate capacity control. In the present specification, the intermediate capacity operation refers to an operation of a variable capacity compressor whose discharge capacity is not fixed to the minimum capacity.

  According to a second aspect of the present invention, in the first aspect, the first control valve is a variable valve opening type control valve capable of continuously adjusting a cross-sectional area of the supply passage, and the capacity control mechanism includes the The first control valve is in the open state with the maximum valve opening, the second control valve is in the closed state, the first control state in which the third control valve is in the closed state, and the first control valve is in the intermediate valve opening Open state, the second control valve is closed, the third control valve is open, the first control valve is closed, the second control valve is open, the third control valve is open, A third control state in which the control valve is in a closed state can be taken, and when the differential pressure between the control pressure chamber and the suction pressure region increases from the first control state, the second control state is entered. The configuration is such that migration is possible.

  If the capacity control mechanism is set to the third control state when starting the variable capacity compressor, the liquid refrigerant in the control pressure chamber is discharged to the suction pressure region via the second control valve. When the second control valve is open, the passage cross-sectional area of the discharge passage is made large so that the liquid refrigerant in the control pressure chamber is quickly discharged to the suction pressure region. That is, it is possible to adjust the refrigerant discharge flow rate from the control pressure chamber to the suction pressure region so that the time required until the discharge capacity increases immediately after the start of the variable displacement compressor is shortened.

  In the first control state, the refrigerant in the discharge pressure region is supplied to the control pressure chamber, and the refrigerant in the control pressure chamber is discharged to the suction pressure region only through the normally open passage. By reducing the passage cross-sectional area of the normally open passage as much as possible, the refrigerant outflow rate from the control pressure chamber to the suction pressure region can be reduced. That is, the refrigerant discharge flow rate from the control pressure chamber to the suction pressure region can be adjusted so that the operation efficiency during the minimum capacity operation is improved.

  When the third control valve shifts from the closed state to the open state in the process of increasing the differential pressure between the control pressure chamber and the suction pressure region from the first control state (that is, from the first control state to the second control state) The refrigerant discharge flow rate discharged from the control pressure chamber to the suction pressure region increases. In the second control state, the refrigerant in the discharge pressure region is supplied to the control pressure chamber, and the refrigerant in the control pressure chamber is discharged to the suction pressure region via the third control valve and the normally open passage. The passage cross-sectional area of the discharge passage when the third control valve is in the open state is larger than the passage cross-sectional area of the normally open passage. In other words, the refrigerant discharge flow rate from the control pressure chamber to the suction pressure region can be adjusted so as to provide good intermediate capacity control.

  As the first control valve, for example, a variable valve opening control valve that reduces the valve opening when the electromagnetic force is increased is suitable. Furthermore, it has a pressure-sensitive means for picking up a pressure difference between two points in the discharge pressure region or between two points in the suction pressure region, and when the refrigerant flow rate in the discharge pressure region increases, the valve opening increases. It is preferable to use as the first control valve a variable valve opening type control valve that reduces the valve opening when the refrigerant flow rate in the region decreases. In addition, the first control valve has, for example, a pressure-sensitive means that is sensitive to the pressure in the suction pressure region. When the pressure in the suction pressure region increases, the valve opening decreases, and when the pressure in the suction pressure region decreases, the valve opens. Control valves that increase the degree can also be used.

  According to a third aspect of the present invention, in any one of the first and second aspects, the second control valve includes a valve hole that is a part of the discharge passage, a valve body that opens and closes the valve hole, A spring that urges the valve body in a direction to open the valve hole, and the valve body defines a back pressure chamber on the opposite side of the valve hole, downstream of the first control valve, and the The back pressure chamber is communicated with a pressure region upstream of the control pressure chamber.

  When the first control valve is in the open state, the pressure of the refrigerant that has passed through the first control valve is applied to the back pressure chamber, and the valve body of the second control valve is closed. Since the refrigerant in the discharge pressure region does not pass through the first control valve when the first control valve is in the closed state, the valve body of the second control valve is in the open state. The second control valve that is opened and closed according to the pressure state in the back pressure chamber brought about by the opened and closed state of the first control valve is suitable as a control valve that quickly discharges the liquid refrigerant in the control pressure chamber.

  According to a fourth aspect of the present invention, in any one of the first to third aspects, the third control valve includes a valve hole that is a part of the discharge passage, a valve body that opens and closes the valve hole, A spring for urging the valve body toward the closed position for closing the valve hole, and the third control valve when the valve body of the third control valve closes the valve hole of the third control valve The pressure in the control pressure chamber is received through the valve hole.

  The third control valve that opens and closes by pressure control through the valve body between the pressure in the control pressure chamber and the pressure in the suction pressure region is suitable as a control valve that adjusts the cross-sectional area of the discharge passage.

  The present invention provides a refrigerant from the control pressure chamber to the suction pressure region so that the time required for the discharge capacity to increase immediately after the start of the variable capacity compressor is shortened and the operation efficiency at the time of minimum capacity operation is improved. There is an excellent effect that the discharge flow rate can be adjusted.

A first embodiment in which the present invention is embodied in a clutchless variable displacement compressor will be described below with reference to FIGS.
As shown in FIG. 1, a front housing 12 is joined to the front end of the cylinder block 11. A rear housing 13 is joined and fixed to the rear end of the cylinder block 11 via a valve plate 14, valve forming plates 15 and 16, and a retainer forming plate 17. The cylinder block 11, the front housing 12, and the rear housing 13 constitute an overall housing of the clutchless variable displacement compressor 10.

  A rotary shaft 18 is rotatably supported via radial bearings 19 and 20 on the front housing 12 and the cylinder block 11 forming the control pressure chamber 121. The rotating shaft 18 that protrudes outside from the control pressure chamber 121 obtains driving force from the vehicle engine E that is an external driving source via a pulley (not shown) and a belt (not shown).

  A rotary support 21 is fixed to the rotary shaft 18, and a swash plate 22 is supported so as to be slidable and tiltable in the axial direction of the rotary shaft 18. A guide pin 23 provided on the swash plate 22 is slidably fitted in a guide hole 211 formed in the rotary support 21. The swash plate 22 can be tilted in the axial direction of the rotary shaft 18 by the linkage of the guide hole 211 and the guide pin 23 and can rotate integrally with the rotary shaft 18. The tilt of the swash plate 22 is guided by the slide guide relationship between the guide hole 211 and the guide pin 23 and the slide support action of the rotary shaft 18.

  If the radius center part of the swash plate 22 moves to the rotation support body 21 side, the inclination angle of the swash plate 22 increases. The maximum inclination angle of the swash plate 22 is regulated by the contact between the rotary support 21 and the swash plate 22. The swash plate 22 shown by a solid line in FIG. 1 is in a minimum tilt state, and the swash plate 22 shown by a chain line is in a maximum tilt state. The minimum inclination angle of the swash plate 22 is slightly larger than 0 °.

  Pistons 24 are accommodated in a plurality of cylinder bores 111 penetrating the cylinder block 11. The rotational movement of the swash plate 22 is converted into the back-and-forth reciprocating movement of the piston 24 via the shoe 25, and the piston 24 reciprocates in the cylinder bore 111.

  A suction chamber 131 and a discharge chamber 132 are defined in the rear housing 13. A suction port 141 and a discharge port 142 are formed in the valve plate 14 and the valve forming plates 15 and 16. A suction valve 151 is formed on the valve forming plate 15, and a discharge valve 161 is formed on the valve forming plate 16. The refrigerant in the suction chamber 131 that is the suction pressure region flows into the cylinder bore 111 by pushing the suction valve 151 away from the suction port 141 by the backward movement of the piston 24. The gaseous refrigerant that has flowed into the cylinder bore 111 is discharged from the discharge port 142 to the discharge chamber 132 which is a discharge pressure region by pushing the discharge valve 161 away from the discharge port 142 by the forward movement of the piston 24. The discharge valve 161 abuts on the retainer 171 on the retainer forming plate 17 and the opening degree is regulated.

  The suction passage 26 for introducing the refrigerant into the suction chamber 131 and the discharge passage 27 for discharging the refrigerant from the discharge chamber 132 are connected by an external refrigerant circuit 28. On the external refrigerant circuit 28, a heat exchanger 29 for removing heat from the refrigerant, an expansion valve 30, and a heat exchanger 31 for transferring ambient heat to the refrigerant are interposed. The expansion valve 30 is a temperature type automatic expansion valve that controls the flow rate of the refrigerant according to the change in the gas temperature on the outlet side of the heat exchanger 31. A throttle 281 is provided in the middle of an external refrigerant circuit (hereinafter referred to as an external refrigerant circuit 28A) downstream from the discharge passage 27 and upstream from the heat exchanger 31.

As shown in FIG. 2, a first control valve 32, a second control valve 46 and a third control valve 47 are assembled in the rear housing 13.
The pressure sensing body 36 that divides the pressure sensing chambers 34 and 35 in the first control valve 32 is urged from the pressure sensing chamber 34 side to the pressure sensing chamber 35 side by a pressure sensing spring 37. The pressure sensitive chamber 34 is in communication with the discharge chamber 132, and the pressure sensitive chamber 35 is in communication with the external refrigerant circuit 28 </ b> A downstream of the throttle 281. That is, the pressure sensitive chamber 34 is at the pressure in the discharge chamber 132, and the pressure sensitive chamber 35 is at the pressure of the external refrigerant circuit 28 </ b> A downstream of the throttle 281 and upstream of the heat exchanger 29. ing. The pressure in the pressure sensitive chamber 34 and the pressure in the pressure sensitive chamber 35 are opposed to each other via the pressure sensitive body 36.

  The pressure-sensitive chambers 34 and 35, the pressure-sensitive body 36, and the pressure-sensitive spring 37 are differential pressures between the pressure in the discharge chamber 132 and the pressure in the external refrigerant circuit 28 downstream from the throttle 281 and upstream from the heat exchanger 31. The pressure-sensitive means 33 is configured to respond to the above. When the refrigerant flow rate in the external refrigerant circuit 28A (discharge pressure region) increases, the pressure difference before and after the throttle 281 increases, and when the refrigerant flow rate in the external refrigerant circuit 28 (discharge pressure region) decreases, the pressure before and after the throttle 281 increases. The difference between is reduced. The pressure sensing means 33 moves the valve body 38 away from the valve seat 39 by increasing the pressure difference before and after the restrictor 281, and the valve element 38 is moved to the valve seat 39 by decreasing the pressure difference before and after the restrictor 281. Move closer. That is, the pressure sensing means 33 increases the valve opening according to the increase in the refrigerant flow rate in the discharge pressure region (external refrigerant circuit 28A), and the valve according to the decrease in the refrigerant flow rate in the discharge pressure region (external refrigerant circuit 28A). Decrease the opening.

  A valve body 38 is connected to the pressure sensitive body 36, and the valve body 38 opens and closes the valve hole 40. The pressure in the pressure-sensitive chamber 34 and the spring force of the pressure-sensitive spring 37 urge the valve body 38 in a direction away from the seating position where the valve body 38 contacts the valve seat 39. When the valve body 38 is separated from the seating position, the valve hole 40 communicates with the discharge chamber 132 through the passage 57.

  The fixed iron core 42 constituting the solenoid 41 of the first control valve 32 attracts the movable iron core 44 based on excitation by supplying current to the coil 43. That is, the electromagnetic force of the solenoid 41 biases the valve body 38 toward the seating position in contact with the valve seat 39 against the spring force of the opening biasing spring 45. The solenoid 41 receives current supply control (duty ratio control in this embodiment) of the control computer C.

  The second control valve 46 includes a valve housing 48, a valve body 49 accommodated in the valve housing 48, and a spring 50 that biases the valve body 49. The valve body 49 partitions the inside of the valve housing 48 into an AC chamber 51 and a back pressure chamber 52. The AC chamber 51 and the back pressure chamber 52 communicate with each other through a clearance around the valve body 49. A valve hole 53 is formed in the valve housing 48 so as to face the AC chamber 51 and communicate with the suction chamber 131, and the spring 50 is accommodated in the AC chamber 51. The valve body 49 opens and closes the valve hole 53, and the spring 50 biases the valve body 49 in a direction away from the position where the valve body 49 is seated on the valve seat 54.

  An AC port 55 and an introduction port 56 are formed in the valve housing 48. The AC port 55 faces the AC chamber 51, and the introduction port 56 faces the back pressure chamber 52. The AC chamber 51 communicates with the control pressure chamber 121 via the AC port 55 and the passage 58, and the back pressure chamber 52 communicates with the valve hole 40 of the first control valve 32 via the introduction port 56 and the passage 59. doing. The passage 58, the AC port 55, the AC chamber 51, the back pressure chamber 52, the introduction port 56, the passage 59, the valve hole 40 and the passage 57 constitute a supply passage for supplying refrigerant from the discharge chamber 132 to the control pressure chamber 121. To do.

  The passage sectional area of the supply passage from the discharge chamber 132 to the control pressure chamber 121 is the passage sectional area of the first control valve 32 defined by the valve opening degree of the first control valve 32. When the first control valve 32 is in the closed state, the cross-sectional area of the supply passage from the discharge chamber 132 to the control pressure chamber 121 is zero.

  When the valve body 49 is separated from the seating position (when the second control valve 46 is in the open state), the control pressure chamber 121 and the suction chamber 131 include the passage 58, the AC port 55, the AC chamber 51, and It communicates via the valve hole 53. The passage 58, the AC port 55, the AC chamber 51, and the valve hole 53 constitute a first discharge passage for discharging the refrigerant from the control pressure chamber 121 to the suction chamber 131, and the valve hole 53 is the first discharge passage. Part of

  The third control valve 47 includes a valve housing 60, a valve body 61 accommodated in the valve housing 60, and a spring 62 that biases the valve body 61. A valve hole 63 is formed in the valve housing 60, and the valve body 61 opens and closes the valve hole 63. The spring 62 urges the valve body 61 toward a seating position where the valve body 61 contacts the valve seat 64. The valve hole 63 communicates with the control pressure chamber 121 through the passage 65.

  A discharge port 602 is formed in the valve housing 60 so as to communicate with the suction chamber 131, and the spring accommodation chamber 601 that accommodates the spring 62 communicates with the suction chamber 131 via the discharge port 602. When the valve body 61 is separated from the seating position, the discharge port 602 communicates with the valve hole 63 via the spring accommodating chamber 601. The pressure in the control pressure chamber 121 is transmitted to the valve body 61 through the passage 65 and the valve hole 63, and the pressure in the suction chamber 131 is transmitted to the valve body 61 through the discharge port 602 and the spring accommodating chamber 601. In other words, the pressure in the control pressure chamber 121 and the pressure in the suction chamber 131 are opposed via the valve body 61.

  A normally open passage 66 is formed in the valve body 61. The normally open passage 66 communicates the valve hole 63 and the spring accommodating chamber 601. When the valve body 61 is separated from the seating position (when the third control valve 47 is in the open state), the control pressure chamber 121 and the suction chamber 131 are connected to the passage 65, the valve hole 63, the spring accommodating chamber 601, and It communicates via the discharge port 602. The passage 65, the valve hole 63, the spring accommodating chamber 601 and the discharge port 602 constitute a second discharge passage for discharging the refrigerant from the control pressure chamber 121 to the suction chamber 131, and the valve hole 63 is a second discharge passage. Become part of the passage. The third control valve 47 adjusts the cross-sectional area of the second discharge passage based on the differential pressure between the pressure in the control pressure chamber 121 and the pressure in the suction chamber 131.

  When the valve body 61 is in the seating position (when the third control valve 47 is in the closed state), the control pressure chamber 121 and the suction chamber 131 are connected to the passage 65, the valve hole 63, the normally open passage 66, and the spring accommodating chamber. Communicating via the 601 and the discharge port 602. The passage 65, the valve hole 63, the normally open passage 66, the spring accommodating chamber 601 and the discharge port 602 constitute a third discharge passage for discharging the refrigerant from the control pressure chamber 121 to the suction chamber 131. Is part of a third discharge passage that always connects the control pressure chamber 121 and the suction chamber 131.

  The discharge passage for discharging the refrigerant from the control pressure chamber 121 to the suction chamber 131 is constituted by first to third discharge passages. The first control valve 32, the second control valve 46, the third control valve 47, and the normally open passage 66 constitute a capacity control mechanism together with the supply passage and the first and second discharge passages. The first discharge passage and the second discharge passage are in parallel with each other, and the second control valve 46 and the third control valve 47 are in parallel with each other.

  When the second control valve 46 is in the open state, the passage sectional area of the second control valve 46 is φ1, and the passage sectional area of the normally open passage 66 is φ3. When the passage sectional area of the third control valve 47 when the third control valve 47 is in the open state is φ2, the sum of the passage sectional area φ3 of the normally open passage 66 and the passage sectional area φ2 of the third control valve 47 ( φ2 + φ3) is smaller than the passage cross-sectional area φ1 of the second control valve 46 when the second control valve 46 is in the open state. The first discharge passage has a passage cross-sectional area φ1 determined when the second control valve 46 is in the open state, and the third discharge passage is when the third control valve 47 is in the closed state. It has a defined passage cross-sectional area φ3. When the second control valve 46 is in the closed state and the third control valve 47 is in the open state, the passage cross-sectional area of the discharge passage from the control pressure chamber 121 to the suction chamber 131 is (φ2 + φ3). A relationship of φ3 <(φ2 + φ3) <φ1 is set between the passage cross-sectional areas φ1, φ2, and φ3. The passage sectional area φ1 is made as large as possible, and the passage sectional area φ3 is made as small as possible.

  The passage cross-sectional area of the discharge passage from the control pressure chamber 121 to the suction chamber 131 is the passage cut-off in the second control valve 46 defined by the passage cross-sectional area of the normally open passage 66 and the valve opening degree of the second control valve 46. This is the sum of the area and the passage cross-sectional area of the third control valve 47 defined by the valve opening of the third control valve 47. For example, when both the second control valve 46 and the third control valve 47 are closed, the passage sectional area of the discharge passage from the control pressure chamber 121 to the suction chamber 131 is φ3. When the second control valve 46 is in the closed state and the third control valve 47 is in the open state, the passage sectional area of the discharge passage from the control pressure chamber 121 to the suction chamber 131 is (φ2 + φ3). When the second control valve 46 is in the open state and the third control valve 47 is in the closed state, the passage cross-sectional area of the discharge passage from the control pressure chamber 121 to the suction chamber 131 is (φ1 + φ3).

  As shown in FIGS. 1 and 2, the control computer C that performs current supply control (duty ratio control) on the solenoid 41 of the first control valve 32 supplies current to the solenoid 41 by turning on the air conditioner operation switch 67. The current supply is stopped when the air conditioner operation switch 67 is turned OFF. A room temperature setter 68 and a room temperature detector 69 are signal-connected to the control computer C. When the air conditioner operation switch 67 is in the ON state, the control computer C controls the solenoid 41 based on the temperature difference between the target room temperature set by the room temperature setter 68 and the detected room temperature detected by the room temperature detector 69. Control the current supply.

  The degree of opening and closing in the valve hole 40, that is, the valve opening degree in the first control valve 32 is determined by the balance of the electromagnetic force generated by the solenoid 41, the spring force of the open biasing spring 45, and the biasing force of the pressure sensing means 33. The first control valve 32 can continuously adjust the interval (valve opening) between the valve body 38 and the valve seat 39 by changing the electromagnetic force (changing the duty ratio). That is, the first control valve 32 can continuously adjust the passage cross-sectional area of the first control valve 32 by changing the duty ratio, and when the refrigerant flow rate in the external refrigerant circuit 28A increases, the valve opening increases, This is a variable valve opening control valve that reduces the valve opening when the refrigerant flow rate in the refrigerant circuit 28A decreases. That is, the first control valve 32 can continuously adjust the passage cross-sectional area of the first control valve 32 by changing the electromagnetic force, and when the refrigerant flow rate in the discharge pressure region increases, the valve opening increases and the discharge pressure increases. This is a variable valve opening control valve that reduces the valve opening when the refrigerant flow rate in the region decreases. The air conditioner operation switch 67, the room temperature setting device 68, the room temperature detector 69, and the control computer C constitute electromagnetic force changing means for changing the electromagnetic force in the first control valve 32.

  FIG. 1 shows a state where the duty ratio is zero as current supply control for the solenoid 41. In this state, the valve opening degree of the first control valve 32 is maximized. When the vehicle engine E is stopped for a long time, the refrigerant pressure in the variable capacity compressor 10 becomes uniform, and the pressure in the control pressure chamber 121 (control pressure) and the pressure in the suction chamber 131 (suction) Pressure) is zero. When the differential pressure is zero, the valve body 49 in the second control valve 46 is held at a position farthest from the valve hole 53 by the spring force of the spring 50, and the valve body 61 in the third control valve 47 is spring-loaded. The valve hole 63 is held at a position where the valve hole 63 is closed by the spring force of 62.

  The control computer C performs a control for setting the duty ratio to zero as a current supply control to the solenoid 41 for a predetermined time t1 (for example, about several seconds) when the engine is started. This control is for avoiding engine stall by minimizing the load torque due to the operation of the variable displacement compressor 10.

  FIG. 2 shows a state in which the engine is started and the variable displacement compressor 10 is in an operating state and the duty ratio is zero as current supply control for the solenoid 41. The first control valve 32 is in the open state with the maximum valve opening due to de-energization. When the variable displacement compressor 10 starts operation, the refrigerant in the cylinder bore 111 is discharged to the discharge chamber 132, and the refrigerant pressure in the discharge chamber 132 is spread to the back pressure chamber 52 of the second control valve 46. Thereby, the valve body 49 in the second control valve 46 is disposed at a position where the valve hole 53 is closed against the spring force of the spring 50 as shown in FIG.

  In the state of FIG. 2, the pressure (control pressure) in the control pressure chamber 121 is slightly higher than the pressure (suction pressure) in the suction chamber 131, and the pressure (control pressure) in the control pressure chamber 121 and the suction chamber 131 are The differential pressure from the internal pressure (suction pressure) is small. Therefore, the valve body 61 in the third control valve 47 closes the valve hole 63 by the spring force of the spring 62. Therefore, in the state of FIG. 2, the refrigerant in the control pressure chamber 121 flows out to the suction chamber 131 via the passage 65 and the normally open passage 66. In this state, that is, in the first control state in which the first control valve 32 is in the open state with the maximum valve opening, the second control valve 46 is in the closed state, and the third control valve 47 is in the closed state, the inclination angle of the swash plate 22 Is the minimum, and the variable capacity compressor 10 performs the minimum capacity operation.

  The minimum inclination angle of the swash plate 22 is slightly larger than 0 °, and the discharge from the cylinder bore 111 to the discharge chamber 132 is performed even in the minimum capacity operation. In the present embodiment, the refrigerant circulation in the external refrigerant circuit 28 is stopped in a state where the variable displacement compressor 10 performs a minimum capacity operation (that is, a state where the inclination angle of the swash plate 22 is minimum). The refrigerant discharged from the cylinder bore 111 into the discharge chamber 132 flows into the control pressure chamber 121 through the supply passage, and the refrigerant in the control pressure chamber 121 flows out into the suction chamber 131 through the discharge passage. Then, the refrigerant in the suction chamber 131 is sucked into the cylinder bore 111 and discharged into the discharge chamber 132. That is, in the minimum capacity operation, the refrigerant circulates through the discharge chamber 132, the control pressure chamber 121, the suction chamber 131, and the cylinder bore 111, and the lubricating oil that flows together with the refrigerant lubricates the inside of the compressor.

  When the predetermined time t1 elapses after the engine is started, the control computer C energizes the first control valve 32 with a duty ratio of 100% over the predetermined time t2 regardless of whether the air conditioner operation switch 67 is ON or OFF. With this energization, the valve body 38 of the first control valve 32 is disposed at the closed position where the valve hole 40 is closed, and the valve hole 40 is closed. Since the valve hole 40 is closed, the refrigerant in the discharge chamber 132 does not flow into the control pressure chamber 121, and the discharge pressure in the discharge chamber 132 does not reach the back pressure chamber 52 of the second control valve 46. Absent. Therefore, as shown in FIG. 3, the valve body 49 of the second control valve 46 is disposed at a position where the valve hole 53 is opened.

  When the engine is stopped for a long time, the liquid refrigerant is accumulated in the control pressure chamber 121, but the valve hole 53 of the second control valve 46 is opened after a predetermined time t1 after the engine is started. Since the passage sectional area φ1 of the first discharge passage extending from the control pressure chamber 121 to the suction chamber 131 via the passage 58 and the valve hole 53 is increased, the liquid refrigerant in the control pressure chamber 121 passes through the passage 58 and It quickly flows out to the suction chamber 131 via the valve hole 53 of the second control valve 46. That is, there is no refrigerant inflow from the discharge chamber 132 to the control pressure chamber 121, and an increase in pressure in the control pressure chamber 121 due to vaporization of the liquid refrigerant is suppressed, so that the pressure (control pressure) and suction in the control pressure chamber 121 are suppressed. The pressure difference from the pressure in the chamber 131 (suction pressure) is the smallest, and the inclination angle of the swash plate 22 is maximized. Since the differential pressure between the pressure in the control pressure chamber 121 (control pressure) and the pressure in the suction chamber 131 (suction pressure) is the smallest, the valve body 61 in the third control valve 47 is valved by the spring force of the spring 62. 63 is closed. Accordingly, the refrigerant in the control pressure chamber 121 flows out to the suction chamber 131 via the passage 58 and the valve hole 53 of the second control valve 46 and to the suction chamber 131 via the passage 65 and the normally open passage 66. leak. In this state, that is, as shown in FIG. 3, in the third control state in which the first control valve 32 is closed, the second control valve 46 is open, and the third control valve 47 is closed, the swash plate 22 The inclination angle is maximum, and the variable capacity compressor 10 performs maximum capacity operation. In this specification, the maximum capacity operation refers to the operation of a variable capacity compressor whose discharge capacity is fixed to the maximum capacity.

  FIG. 4 shows an energization control according to the temperature difference between the target room temperature set by operating the room temperature setter 68 and the detected room temperature detected by the room temperature setter 68 when the air conditioner operation switch 67 is ON. This shows a state where the duty ratio control is being performed. In the state of FIG. 4, the first control valve 32 is energized and opened in an intermediate valve opening (an intermediate valve opening that is not zero and not maximum), and the refrigerant in the discharge chamber 132 is in the open state. Is supplied to the control pressure chamber 121, and the second control valve 46 is closed. The pressure difference between the pressure in the control pressure chamber 121 and the pressure in the suction chamber 131 is the largest, and the valve body 61 of the third control valve 47 is arranged at the open position where the valve hole 63 is opened by this pressure difference. Is done. The refrigerant in the control pressure chamber 121 flows out to the suction chamber 131 through the passage 65, the valve hole 63, and the second discharge passage passing through the periphery of the valve body 61, and the passage 65, the valve body 61, and the normally open passage. It flows out to the suction chamber 131 through the third discharge passage via 66. In this state, that is, in the second control state in which the first control valve 32 is in the open state, the second control valve 46 is in the closed state, and the third control valve 47 is in the open state, the inclination angle of the swash plate 22 is not less than the minimum inclination angle. Thus, the variable capacity compressor 10 performs an intermediate capacity operation.

  In the second control state of FIG. 4, when the duty ratio is increased, the opening degree of the first control valve 32 decreases, and the amount of refrigerant supplied from the discharge chamber 132 to the control pressure chamber 121 decreases. Since the refrigerant in the control pressure chamber 121 flows out to the suction chamber 131 through the second discharge passage and the third discharge passage, the pressure in the control pressure chamber 121 decreases. Accordingly, the inclination angle of the swash plate 22 increases and the discharge capacity increases. Conversely, when the duty ratio is lowered, the valve opening in the first control valve 32 increases, and the amount of refrigerant supplied from the discharge chamber 132 to the control pressure chamber 121 increases. Therefore, the pressure in the control pressure chamber 121 increases, the inclination angle of the swash plate 22 decreases, and the discharge capacity decreases.

  In the second control state of FIG. 4, when the rotational speed of the variable capacity compressor 10 increases, the refrigerant flow rate in the external refrigerant circuit 28A increases, the refrigerant pressure in the discharge chamber 132, and the external refrigerant circuit downstream from the throttle 281. The differential pressure from the refrigerant pressure in 28A increases. The pressure sensing means 33 moves the valve body 38 of the first control valve 32 away from the valve seat 39 according to the increase in the differential pressure, and the valve opening degree of the first control valve 32 increases. Increasing the valve opening in the first control valve 32 increases the amount of refrigerant supplied from the discharge chamber 132 to the control pressure chamber 121. Therefore, the pressure in the control pressure chamber 121 increases, the inclination angle of the swash plate 22 decreases, and the discharge capacity decreases. Conversely, when the rotational speed of the variable capacity compressor 10 decreases, the refrigerant flow rate in the external refrigerant circuit 28A decreases, and the refrigerant pressure in the discharge chamber 132 and the refrigerant pressure in the external refrigerant circuit 28A downstream from the throttle 281 become smaller. The differential pressure of becomes smaller. The pressure sensing means 33 brings the valve body 38 of the first control valve 32 closer to the valve seat 39 in accordance with the decrease in the differential pressure, and the valve opening degree of the first control valve 32 decreases. Decreasing the valve opening in the first control valve 32 reduces the amount of refrigerant supplied from the discharge chamber 132 to the control pressure chamber 121. Accordingly, the pressure in the control pressure chamber 121 decreases, the inclination angle of the swash plate 22 increases, and the discharge capacity increases.

  In the present embodiment, the capacity control mechanism has a first control state that provides the minimum capacity operation shown in FIG. 2, a second control state that provides the intermediate capacity operation shown in FIG. 4, and a first control state that provides the maximum capacity operation shown in FIG. Three control states can be taken. That is, the capacity control mechanism can take the first control state, the second control state, and the third control state by combining the first control valve 32, the second control valve 46, and the third control valve 47. It is configured. The capacity control mechanism is configured such that when the first control valve 32 is in the closed state, the second control valve 46 is in the open state, and when the first control valve 32 is in the open state, the control pressure chamber 121 and the suction chamber 131 (suction pressure region). The third control valve 47 can shift from the closed state to the open state in the process in which the differential pressure with respect to) increases. That is, in the capacity control mechanism, when the first control valve 32 is in the open state, the third control valve 47 is closed in the process in which the differential pressure between the control pressure chamber 121 and the suction chamber 131 (suction pressure region) increases. It is comprised so that it can transfer to an open state from.

  In the second control state of FIG. 4, the inclination angle of the swash plate 22 depends on the energization control (duty ratio control) for the first control valve 32 and the rotational speed of the variable displacement compressor 10, but the external refrigerant circuit The refrigerant flow rate at 28A mainly depends on energization control (duty ratio control).

In the first embodiment in which the present invention is applied to the clutchless variable displacement compressor 10 that performs the variable displacement operation as described above, the following effects can be obtained.
(1-1) When the capacity control mechanism is set to the third control state when starting the variable capacity compressor 10, the liquid refrigerant in the control pressure chamber 121 passes through the valve hole 53 of the second control valve 46. And discharged to the suction chamber 131. Since the passage cross-sectional area φ1 of the second control valve 46 in the open state is increased, the liquid refrigerant in the control pressure chamber 121 is quickly discharged to the suction chamber 131. In addition, when the capacity control mechanism is in the third control state, the refrigerant in the discharge chamber 132 is not supplied to the control pressure chamber 121, and thus the pressure increase in the control pressure chamber 121 is suppressed. That is, the disadvantage that it takes time until the discharge capacity increases after the variable displacement compressor 10 is started due to the vaporization of the liquid refrigerant in the control pressure chamber 121 is avoided.

  As shown in FIG. 2, when the capacity control mechanism is in the first control state, the refrigerant in the discharge chamber 132 is supplied to the control pressure chamber 121, and the refrigerant in the control pressure chamber 121 passes through the normally open passage 66 (third discharge passage). ) Only to the suction chamber 131. That is, when the capacity control mechanism is in the first control state, the inclination angle of the swash plate 22 becomes the minimum inclination angle, and the variable displacement compressor 10 is operated with the minimum capacity. Since the passage cross-sectional area φ3 of the normally open passage 66 is reduced, the refrigerant outflow rate from the control pressure chamber 121 to the suction chamber 131 can be reduced, and the operation efficiency during the minimum capacity operation is improved.

  As shown in FIG. 4, when the capacity control mechanism is in the second control state, the refrigerant in the discharge chamber 132 is supplied to the control pressure chamber 121, and the refrigerant in the control pressure chamber 121 passes through the valve hole 63 of the third control valve 47 and the normal pressure. It is discharged to the suction chamber 131 via the open passage 66. When the capacity control mechanism is in the second control state, the passage cross-sectional area of the discharge passage from the control pressure chamber 121 to the suction chamber 131 is larger than the passage cross-sectional area φ3 of the normally open passage 66 (φ2 + φ3), and a good intermediate capacity A refrigerant discharge flow rate suitable for control can be secured.

  (1-2) When the first control valve 32 is in the open state, the pressure of the refrigerant that has passed through the valve hole 40 of the first control valve 32 spreads to the back pressure chamber 52 of the second control valve 46, and the second control valve 46 is closed. Since the refrigerant in the discharge chamber 132 does not flow through the first control valve 32 when the first control valve 32 is in the closed state, the second control valve 46 is in the open state. The second control valve 46 is quickly opened and closed according to the pressure state in the back pressure chamber 52 caused by the opening and closing state of the first control valve 32. The second control valve 46 opened and closed according to the pressure state in the back pressure chamber 52 caused by the opening and closing state of the first control valve 32 is a control valve for quickly discharging the liquid refrigerant in the control pressure chamber 121. Is preferred.

  (1-3) When the differential pressure between the pressure in the control pressure chamber 121 and the pressure in the suction chamber 131 increases from when the capacity control mechanism is in the second control state, the valve body 61 of the third control valve 47 is The valve 62 is moved to the open position where the valve hole 63 is opened against the spring force of the spring 62. The third control valve 47 that opens and closes by pressure control via the valve body 61 between the pressure in the control pressure chamber 121 and the pressure in the suction chamber 131 is a simple mechanism. Such a third control valve 47 is suitable as a control valve for adjusting the passage sectional area of the discharge passage for discharging the refrigerant from the control pressure chamber 121 to the suction chamber 131.

  (1-4) The configuration in which the first to third control valves are assembled to the rear housing 13 is to simplify the passage connection between the first to third control valves and the suction chamber 131 and the discharge chamber 132. Is preferred. That is, the rear housing 13 is suitable as a place where the first to third control valves are assembled.

  (1-5) The normally open passage 66 for always connecting the control pressure chamber 121 and the suction chamber 131 is provided in the valve body 61 of the third control valve 47. The valve body 61 of the third control valve 47 is large enough to open and close the valve hole 63 (that is, the diameter of the end surface of the valve body 61 that closes the valve hole 63 is larger than the diameter of the valve hole 63). It is necessary to make the hole diameter larger than the diameter of the normally open passage 66. If the normally open passage 66 is provided in the valve body 61 so as to open the normally open passage 66 in the center of the end face of the valve body 61 that closes the valve hole 63, the valve body 61 can be closed even when the valve hole 61 is closed. The normally open passage 66 always allows the control pressure chamber 121 and the suction chamber 131 to communicate with each other. That is, even when the normally open passage 66 is provided in the valve body 61, it is not necessary to increase the size of the valve body 61, and the valve body 61 is suitable as a place where the normally open passage 66 is provided.

In the present invention, the following embodiments are also possible.
(1) As shown in FIG. 5, the valve hole 40 of the first control valve 32 and the control pressure chamber 121 communicate with each other through the supply passage 70, and the branch passage 71 connected in the middle of the supply passage 70 is connected to the second control valve. 46 back pressure chambers 52A may be connected. The same reference numerals are used for the same components as those in the first embodiment.

  The back pressure chamber 52A is cut off from the storage chamber 72 that stores the spring 50 by the valve body 49A. When the first control valve 32 is in the open state, the pressure in the discharge chamber 132 is applied to the back pressure chamber 52, and the second control valve 46A is closed. When the first control valve 32 is in the closed state, the second control valve 46A is opened, and the refrigerant in the control pressure chamber 121 can be discharged to the suction chamber 131 via the passage 58, the storage chamber 72, and the valve hole 53. It is.

  (2) As shown in FIG. 6, when the valve hole 53B passes directly through the passage 58 and the valve body 49A closes the valve hole 53B, the pressure in the control pressure chamber 121 moves the valve body 49A away from the valve hole 53B. A second control valve 46B adapted to urge the valve body 49A may be used. In a state where the valve body 49A opens the valve hole 53B, the refrigerant in the control pressure chamber 121 is discharged to the suction chamber 131 via the passage 58, the valve hole 53B, the storage chamber 72, and the discharge port 481. The same reference numerals are used for the same components as in the embodiment of FIG.

  (3) As shown in FIG. 7, a third control valve 47 </ b> C provided with a normally open passage 66 </ b> C in the valve housing 60 may be used so as to always communicate with the passage 65 and always communicate with the spring accommodating chamber 601. . The same reference numerals are used for the same components as in the embodiment of FIG.

  (4) In the embodiment of FIG. 5 or FIG. 6, an electromagnetic on-off valve may be used as the second control valve. In this case, when the first control valve 32 is energized and the first control valve 32 is opened, the discharge passage via the passage 58 is closed, and the first control valve 32 is energized to energize the first control valve 32. When the valve 32 is in the closed state, the electromagnetic on-off valve may be controlled to open and close so that the discharge passage via the passage 58 is opened.

(5) In the embodiment of FIG. 5, the second control valve 46A may be provided with a normally open passage, and in the embodiment of FIG. 6, the second control valve 46B may be provided with a normally open passage.
(6) Instead of the pressure-sensitive means 33 in the first control valve 32, a control valve provided with a pressure-sensitive means sensitive to suction pressure may be used as the first control valve. The pressure sensing means sensitive to the suction pressure biases the valve body in a direction away from the valve hole. That is, the pressure-sensitive means that is sensitive to the suction pressure urges the valve opening of the first control valve 32 to increase.

  As the rotational speed of the variable capacity compressor increases, the refrigerant flow rate in the external refrigerant circuit increases and the cooling capacity increases, so the suction pressure decreases. When the suction pressure is reduced, the urging force of the pressure sensing means for urging the valve body of the first control valve away from the valve hole is increased, and the valve opening degree of the first control valve is increased. When the rotational speed of the variable capacity compressor is reduced, the refrigerant flow rate in the external refrigerant circuit is reduced and the cooling capacity is reduced, so that the suction pressure is increased. When the suction pressure increases, the urging force of the pressure sensing means for urging the valve body away from the valve hole becomes weak, and the valve opening degree of the first control valve becomes small.

  The valve opening degree in the first control valve provided with the pressure sensing means sensitive to the suction pressure is the electromagnetic force generated by the solenoid 41 (see FIG. 2), the spring force of the open biasing spring 45 (see FIG. 2), the pressure sensing means. It is determined by the balance of 33 urging forces. When such a control valve is used as the first control valve, the suction pressure is defined as the suction set pressure corresponding to the energization control (duty ratio control).

  (7) A variable electromagnetic force type control valve provided with pressure-sensitive means for increasing or decreasing the valve opening according to the differential pressure between two points in the suction pressure region may be used as the first control valve. That is, a control valve that increases the valve opening when the refrigerant flow rate in the suction pressure region increases and decreases the valve opening when the refrigerant flow rate in the suction pressure region decreases may be used as the first control valve.

  (8) The first control valve may be configured by providing in parallel a pair of electromagnetic on-off valves that have a constant valve opening in the open state. When the passage cross-sectional area in the open state of one electromagnetic on-off valve is different from the passage cross-sectional area in the open state of the other electromagnetic on-off valve, the passage cross-sectional area of the supply passage is determined by the combination of opening and closing of the pair of electromagnetic on-off valves. Three types of zero, small, and large, or four types of zero, small, medium, and large can be set. When the cross-sectional area of the supply passage is set to zero, small, and large, the minimum capacity operation is performed when the cross-sectional area of the supply passage is large, and the maximum when the cross-sectional area of the supply passage is zero. Capacity operation can be performed. When the passage cross-sectional area of the supply passage is small, an intermediate capacity operation that is larger than the minimum capacity and smaller than the maximum capacity can be performed. When the cross-sectional area of the supply passage is set to four types of zero, small, medium, and large, the minimum capacity operation is performed when the cross-sectional area of the supply passage is large, and the cross-sectional area of the supply passage is small or small. When the vehicle is in the middle, it is possible to operate two intermediate capacities that are larger than the minimum capacity and smaller than the maximum capacity.

  (9) The first control valve, the second control valve, and the third control valve are separated from the housing of the variable displacement compressor, and the control valve and the suction chamber or discharge chamber in the variable displacement compressor are connected by piping. You may comprise.

  (10) The present invention may be applied to a variable displacement compressor that obtains driving force from an external driving source via a clutch. In such a variable capacity compressor, when the clutch is in the connected state, the refrigerant circulates through the external refrigerant circuit even when the inclination angle of the swash plate is minimum. It is possible not to circulate through the external refrigerant circuit.

The technical idea that can be grasped from the embodiment described above will be described below.
[1] The first control valve is a variable valve opening control valve capable of continuously adjusting a cross-sectional area of the supply passage, and the capacity control mechanism is configured such that the first control valve is the largest valve. An open state of the opening, a first control state in which the second control valve is in a closed state, a third control valve is in a closed state and brings about a minimum capacity operation, and the first control valve is in an intermediate valve opening degree. A second control state in which the second control valve is in a closed state, the third control valve is in an open state to provide an intermediate capacity operation, the first control valve is in a closed state, and the second control valve is in an open state The third control valve is in a closed state and can take a third control state that provides maximum capacity operation, and the differential pressure between the control pressure chamber and the suction pressure region from the first control state is 2. The variable displacement compressor according to claim 1, wherein the second control state can be shifted in the process of increasing. Capacity control mechanism.

  [2] The first control valve is a variable valve opening control valve capable of continuously adjusting a passage cross-sectional area of the supply passage by changing electromagnetic force, and the valve opening of the first control valve is The capacity control mechanism in the variable capacity compressor according to any one of claims 2 and 1, which is controlled by current supply control of electromagnetic force changing means.

  [3] The discharge passage includes a first discharge passage and a second discharge passage provided in parallel, and the valve hole of the second control valve is a part of the first discharge passage, The variable displacement compression according to any one of claims 1 to 4, and [1] and [2], wherein the valve hole of the third control valve is a part of the second discharge passage. Capacity control mechanism in the machine.

  [4] The variable displacement type according to any one of [1] to [4] and [1] to [3], wherein the normally open passage is provided in a valve body of the third control valve. Capacity control mechanism in the compressor.

  [5] The first control valve, the second control valve, and the three control valve are assembled in a housing of a variable displacement compressor, and the items [1] to [4]. A capacity control mechanism in the variable capacity compressor according to any one of the above.

The side sectional view of the whole compressor which shows a 1st embodiment. The principal part expanded side sectional view which shows a 1st control state. The principal part expansion side sectional view showing the 3rd control state. The principal part expansion side sectional view showing the 2nd control state. The principal part expanded sectional side view which shows another embodiment. The principal part expanded sectional side view which shows another embodiment. The principal part expanded sectional side view which shows another embodiment.

Explanation of symbols

  10: Variable capacity compressor. 121: Control pressure chamber. 131: A suction chamber as a suction pressure region. 132: A discharge chamber as a discharge pressure region. 32 ... A first control valve constituting a capacity control mechanism. 40: A valve hole of the first control valve that becomes a part of the supply passage. 46, 46A, 46B ... second control valves constituting a capacity control mechanism. 47, 47C: a third control valve constituting a capacity control mechanism. 49, 49A ... Valve body of the second control valve. 50: Spring of the second control valve. 52, 52A ... Back pressure chamber. 53, 53B ... Valve holes of the second control valve that are part of the first discharge passage. 61: A valve body of the third control valve. 62 ... Third control valve spring. 63 ... A valve hole of the third control valve that becomes a part of the second discharge passage. 66 ... Normally open passage. 70: Supply passage. φ1, φ2, φ3 ... passage cross-sectional area.

Claims (4)

The refrigerant in the discharge pressure region is supplied to the control pressure chamber through the supply passage, and the refrigerant in the control pressure chamber is discharged to the suction pressure region through the discharge passage to adjust the pressure in the control pressure chamber. In the capacity control mechanism in the variable capacity compressor that controls the discharge capacity by regulating the pressure in the pressure chamber,
A first control valve for adjusting a cross-sectional area of the supply passage;
A second control valve for adjusting a cross-sectional area of the discharge passage;
A third control valve that is in parallel with the second control valve, and that adjusts a passage cross-sectional area of the discharge passage based on a differential pressure between the pressure of the control pressure chamber and the pressure of the suction pressure region;
A normally open passage that always communicates the control pressure chamber and the suction pressure region and has a minimum passage cross-sectional area in the discharge passage;
When the first control valve is closed, the second control valve is opened. When the first control valve is opened, the differential pressure between the control pressure chamber and the suction pressure region is increased. A capacity control mechanism in a variable capacity compressor in which the third control valve can be shifted from a closed state to an open state.   The first control valve is a variable valve opening control valve capable of continuously adjusting a cross-sectional area of the supply passage, and the capacity control mechanism is configured such that the first control valve has a maximum valve opening. An open state, a first control state in which the second control valve is in a closed state, a third control valve in a closed state, an open state in which the first control valve is at an intermediate valve opening degree, and the second control valve is in a closed state A second control state in which the third control valve is in an open state; a third control state in which the first control valve is in a closed state; the second control valve is in an open state; and the third control valve is in a closed state. 2. The first control state can be shifted to the second control state in the process in which the differential pressure between the control pressure chamber and the suction pressure region increases. A capacity control mechanism in the described variable capacity compressor.   The second control valve includes a valve hole that is a part of the discharge passage, a valve body that opens and closes the valve hole, and a spring that biases the valve body in a direction to open the valve hole, and The valve body has a configuration in which a back pressure chamber is defined on the side opposite to the valve hole, and the back pressure chamber communicates with a pressure region downstream of the first control valve and upstream of the control pressure chamber. The capacity | capacitance control mechanism in the variable capacity type compressor of any one of Claim 1 and Claim 2.   The third control valve includes a valve hole that is a part of the discharge passage, a valve body that opens and closes the valve hole, and a spring that biases the valve body toward a closed position that closes the valve hole. And when the valve body of the said 3rd control valve has closed the valve hole of the said 3rd control valve, it was set as the structure which receives the pressure of the said control pressure chamber via the valve hole of the said 3rd control valve. The capacity control mechanism in the variable capacity compressor according to claim 3.

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