JP2006170140A - Displacement control valve for variable displacement type compressor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a displacement control valve contributing improvement of controllability of displacement in a variable displacement type compressor. <P>SOLUTION: A valve element 44 is formed on a transmission rod 38 driven by a solenoid 34 as one unit. The valve element 44 consists of a cylinder part 441 and a tapered part 442. The tapered part 442 has a shape of which diameter is reduced as it goes from a chamber 42 side toward a valve hole 41 side. The maximum diameter part 443 of the tapered part 442 exists on a boundary of the taper parted 442 and the cylinder part 441, and the minimum diameter part 444 of the tapered part 442 exists on a boundary of the tapered part 442 and a cylinder shape small diameter part 381 of a transmission rod 38. The tapered part 442 as a section area change part includes the minimum diameter part 444 as the minimum section area part and the maximum diameter part 443 as the maximum section area part, and has a shape of which section area increases as it goes from the minimum diameter part 444 toward the maximum diameter part 443. <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 valve in a variable capacity compressor that controls a 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 control pressure chamber pressure increases, and the swash plate tilt angle decreases as the control pressure chamber pressure 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.

Patent Document 1 discloses a capacity control valve including a valve body for opening and closing a supply passage for supplying a refrigerant from a discharge pressure region to a crank chamber (control pressure chamber). The valve body has a tapered portion, and when the tapered portion contacts the valve seat, the valve hole is closed. When the valve body is displaced in the direction of opening the valve hole, the amount of refrigerant flowing from the discharge pressure region into the crank chamber increases, the pressure in the crank chamber increases, and the discharge capacity decreases. Conversely, when the valve body is displaced in the direction of closing the valve hole, the amount of refrigerant flowing into the crank chamber from the discharge pressure region decreases, the pressure in the crank chamber decreases, and the discharge capacity increases.
JP 2001-349278 A

  The tapered portion of the valve body enters the valve hole from the smallest diameter side, and an intermediate portion between the smallest diameter portion and the largest diameter portion of the tapered portion is in contact with the valve seat which is the opening edge of the valve hole. That is, the maximum diameter of the tapered portion is larger than the diameter of the valve hole, and the portion of the tapered portion having a diameter larger than the diameter of the valve hole cannot enter the valve hole. When the valve hole is opened, the refrigerant in the discharge pressure region flows from the smallest diameter portion side of the tapered portion to the largest diameter portion side, and a pressure close to the discharge pressure is applied to the tapered portion. The pressure applied to the tapered portion urges the valve body in the direction of increasing the valve opening. Further, the pressure (control pressure) in the crank chamber is applied to the valve body, and the pressure applied to the tapered portion and the pressure applied to the valve body from the crank chamber are opposed to each other through the valve body.

  When viewed in the moving direction of the valve body, the pressure hole is open in the vicinity of the taper portion (the portion larger than the diameter of the valve hole) that protrudes from the peripheral wall surface of the valve hole in the radial direction of the valve hole. Sometimes it depends on the size of the valve opening. That is, when viewed in the moving direction of the valve body, the pressure applied to the tapered portion protruding from the peripheral wall surface of the valve hole in the radial direction of the valve hole varies depending on the magnitude of the valve opening. The fluctuation of the pressure according to the valve opening degree fluctuates the difference between the pressure applied to the tapered portion and the pressure spreading from the crank chamber to the valve body. Such fluctuation of the differential pressure deteriorates the capacity controllability.

  An object of the present invention is to provide a capacity control valve that contributes to an improvement in capacity controllability in a variable capacity compressor.

  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 to regulate the pressure in the control pressure chamber. The invention of claim 1 is directed to a capacity control mechanism in a variable capacity compressor that controls the discharge capacity by regulating the pressure in the control pressure chamber, and the invention of claim 1 comprises a valve hole that is a part of the supply passage or the discharge passage. And a valve body having a cross-sectional area changing portion that enters and exits the valve hole, and the cross-sectional area changing portion has a minimum cross-sectional area portion and a maximum cross-sectional area portion, and the maximum cross-sectional area portion from the maximum cross-sectional area portion side. The shape is such that the cross-sectional area increases toward the cross-sectional area part side, the cross-sectional area changing part enters the valve hole from the minimum cross-sectional area part side, and the maximum cross-sectional area part enters the valve hole. The maximum cross-sectional area portion is possible In a state that has entered into the valve hole, wherein the valve hole is closed.

  When the maximum cross-sectional area portion of the cross-sectional area changing portion is pulled out from the valve hole, the valve hole is opened, and the cross-sectional area changing portion protrudes from the valve hole in the radial direction of the valve hole when viewed in the moving direction of the valve body. Absent. Such a configuration without protrusion prevents the pressure difference between the pressure applied to the tapered portion and the pressure applied to the valve body from the opposite side from greatly fluctuating due to the difference in valve opening.

In a preferred example, the peripheral surface of the cross-sectional area changing portion is a conical surface.
The conical surface is suitable as the peripheral surface of the cross-sectional area changing portion.
In a preferred example, there is a small clearance between the maximum cross-sectional area part and the peripheral wall surface of the valve hole in which the refrigerant can flow through the valve hole in a state where the maximum cross-sectional area part enters the valve hole.

  The existence of such a small clearance reduces fluctuations in the differential pressure (the differential pressure between the pressure applied to the taper portion and the pressure applied to the valve body from the opposite side) when the maximum cross-sectional area portion has escaped from the valve hole. .

In a preferred example, the valve hole is a part of the supply passage, and the capacity control valve is a normally open type in which the valve hole is always open at the minimum capacity of the variable capacity compressor.
When the compressor is not operating, or when the compressor is operating in the minimum capacity state, the maximum cross-sectional area portion of the cross-sectional area changing portion has escaped from the valve hole and is a part of the supply passage. The hole is open.

In a preferred example, the valve hole is a part of the discharge passage, and the capacity control valve is a normally closed type in which the valve hole is always closed when the variable capacity compressor has a minimum capacity.
When the compressor is not operating or when the compressor is operating at the minimum capacity, the maximum cross-sectional area portion of the cross-sectional area changing portion enters the valve hole and is a part of the discharge passage. The hole is closed.

  The present invention has an excellent effect of providing a capacity control valve that contributes to an improvement in capacity controllability in a variable capacity compressor.

Hereinafter, a first embodiment of the present invention will be described with reference to FIGS.
As shown in FIG. 1A, a front housing 12 is connected to the front end of the cylinder block 11. A rear housing 13 is connected 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 entire housing of the 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 an electromagnetic clutch (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.
As shown in FIG. 1B, a pair of arms 212 and 213 project from the rotary support 21 toward the swash plate 22, and a pair of protrusions 221 and 222 are provided on the rotary support 21. It protrudes toward 21. The protrusions 221 and 222 are inserted into a recess 214 formed between the pair of arms 212 and 213. The protrusions 221 and 222 can move in the recess 214 while being sandwiched between the pair of arms 212 and 213. The bottom of the recess 214 is formed on the cam surface 211, and the tip portions of the protrusions 221 and 222 can slidably contact the cam surface 211. The swash plate 22 can be tilted in the axial direction of the rotary shaft 18 and can rotate integrally with the rotary shaft 18 by linking the projections 221 and 222 sandwiched between the pair of arms 212 and 213 and the cam surface 211. Tilt of the swash plate 22 is guided by the slide guide relationship between the cam surface 211 and the protrusions 221 and 222 and the slide support action of the rotating shaft 18. The pair of arms 212, 213 and the protrusions 221, 222 are provided between the swash plate 22 and the rotary support 21, can tilt the swash plate 22 with respect to the rotary support 21, and swash plate 22 from the rotary shaft 18. The hinge mechanism 23 is connected so as to be able to transmit torque.

  If the diameter 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 the solid line in FIG. 1A is in the maximum tilt state, and the swash plate 22 shown by the chain line is in the minimum tilt state.

  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 is formed in the valve plate 14, the valve forming plate 16 and the retainer forming plate 17. A discharge port 142 is formed in the valve plate 14 and the valve forming plate 15. 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 which 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 (movement from the right side to the left side in FIG. 1A). . The gaseous refrigerant flowing into the cylinder bore 111 pushes the discharge valve 161 away from the discharge port 142 by the forward movement of the piston 24 (movement from the left side to the right side in FIG. 1A), and is a discharge chamber that is a discharge pressure region. It is discharged to 132. 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 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 external refrigerant circuits 28A and 28B) downstream of the discharge passage 27 and upstream of the heat exchanger 29. The external refrigerant circuit 28A is upstream of the throttle 281 and the external refrigerant circuit 28B is downstream of the throttle 281.

An electromagnetic capacity control valve 32 is assembled in the rear housing 13.
As shown in FIG. 2A, the fixed iron core 35 constituting the solenoid 34 of the capacity control valve 32 attracts the movable iron core 37 based on excitation by supplying current to the coil 36. The solenoid 34 receives current supply control (duty ratio control in the present embodiment) of the control computer C (shown in FIG. 1A). A transmission rod 38 is fixed to the movable iron core 37.

  The valve housing 39 constituting the capacity control valve 32 is provided with a valve hole forming wall 40, and the valve hole forming wall 40 is formed with a valve hole 41. The peripheral wall surface 411 of the valve hole 41 is a circumferential surface with no diameter change. A chamber 42 is formed between the valve hole forming wall 40 and the fixed iron core 35. The valve hole 41 is connected to the chamber 42, and the chamber 42 communicates with the control pressure chamber 121 through the passage 43.

  The chamber 42 communicates with a gap 59 between the movable iron core 37 and the fixed iron core 35 through a passage 351. Further, the chamber 42 communicates with the back pressure space 60 on the back surface of the movable iron core 37 via the passage 351 and the passage 371. That is, the pressure (control pressure) in the control pressure chamber 121 is spread to the back pressure space 60 via the chamber 42 and the passages 351 and 371.

  As shown in FIG. 2B, a valve body 44 is formed integrally with the transmission rod 38. As shown in FIG. The valve body 44 includes a cylindrical portion 441 and a tapered portion 442. The tapered portion 442 has a shape that decreases in diameter from the chamber 42 side toward the valve hole 41 side. The maximum diameter portion 443 of the taper portion 442 is a boundary between the taper portion 442 and the cylindrical portion 441, and the minimum diameter portion 444 of the taper portion 442 is a boundary between the taper portion 442 and the cylindrical small diameter portion 381 of the transmission rod 38. It is. The tapered portion 442 as the cross-sectional area changing portion has a minimum diameter portion 444 as a minimum cross-sectional area portion and a maximum diameter portion 443 as a maximum cross-sectional area portion, and from the minimum diameter portion 444 side to the maximum diameter portion 443 side. The cross-sectional area increases as it goes.

  The cylindrical portion 441 of the valve body 44 can slide within the valve hole 41, and the valve hole 41 is closed when the cylindrical portion 441 (maximum diameter portion 443) enters the valve hole 41. Even in a state where the cylindrical portion 441 enters the valve hole 41, a minute clearance exists between the peripheral wall surface 411 of the valve hole 41 and the cylindrical portion 441. The cylindrical portion 441 is slidable within the valve hole 41 due to the presence of a minute clearance between the peripheral wall surface 411 and the cylindrical portion 441. The presence of this minute clearance allows a slight circulation of the refrigerant in the valve hole 41 when the cylindrical portion 441 (maximum diameter portion 443) enters the valve hole 41. That is, in a state where the cylindrical portion 441 (maximum diameter portion 443) enters the valve hole 41, the valve hole 41 is not completely closed but is in a loosely closed state that allows a slight flow. .

  As shown in FIG. 2A, a spring receiver 52 is provided at a portion of the transmission rod 38 in the chamber 42, and a biasing spring 53 is interposed between the spring receiver 52 and the valve hole forming wall 40. Has been. The transmission rod 38 is biased in a direction to move the movable iron core 37 away from the fixed iron core 35 by the spring force of the biasing spring 53.

  A first pressure sensing chamber 45 and a second pressure sensing chamber 46 are partitioned in the capacity control valve 32. The stationary end of the bellows 47 that partitions the first pressure sensing chamber 45 and the second pressure sensing chamber 46 is connected to an end wall 48 that constitutes the valve housing 39, and the movable end of the bellows 47 is connected to the transmission rod 38. The small diameter portion 381 is joined. The transmission rod 38 is interlocked with the bellows 47.

  The first pressure sensing chamber 45 is communicated with the external refrigerant circuit 28A upstream of the throttle 281 via the pressure introduction passage 49, and the second pressure sensing chamber 46 is located more than the throttle 281 via the pressure introduction passage 50. It communicates with the downstream external refrigerant circuit 28B. That is, the inside of the first pressure sensing chamber 45 is a region that becomes the pressure of the external refrigerant circuit 28A upstream from the throttle 281, and the inside of the second pressure sensing chamber 46 is downstream from the throttle 281 and from the heat exchanger 29. Is also a region that becomes the pressure of the upstream external refrigerant circuit 28B. The pressure in the first pressure sensing chamber 45 and the pressure in the second pressure sensing chamber 46 are opposed via a bellows 47.

  If refrigerant flows are generated in the external refrigerant circuits 28A and 28B, the pressure of the external refrigerant circuit 28A upstream of the throttle 281 is lower than the pressure of the external refrigerant circuit 28B downstream of the throttle 281 and upstream of the heat exchanger 29. Also grows. When the refrigerant flow rate in the external refrigerant circuits 28A and 28B (discharge pressure region) increases, the difference in pressure before and after the throttle 281 increases, and when the refrigerant flow rate in the external refrigerant circuits 28A and 28B (discharge pressure region) decreases, the throttle 281. The difference in pressure before and after is reduced. When the pressure difference before and after the restriction 281 increases, the pressure difference between the pressure sensitive chambers 45 and 46 increases, and when the pressure difference before and after the restriction 281 decreases, the pressure difference between the pressure sensitive chambers 45 and 46 decreases. The differential pressure between the pressure sensitive chambers 45 and 46 becomes a force for urging the transmission rod 38 from the valve hole 41 side toward the chamber 42 side.

  The pressure sensitive chambers 45 and 46 and the bellows 47 have a differential pressure between the pressure of the external refrigerant circuit 28A upstream of the throttle 281 and the pressure of the external refrigerant circuit 28B downstream of the throttle 281 and upstream of the heat exchanger 29. A sensitive pressure sensing means 51 is configured. The opening and closing of the valve hole 41 includes the electromagnetic force generated by the solenoid 34, the biasing force that biases the transmission rod 38 in the direction in which the pressure (control pressure) in the back pressure space 60 closes the valve hole 41, and the spring of the biasing spring 53. It depends on the balance between the force and the urging force of the pressure sensing means 51.

  The pressure sensing means 51 picks up the pressure at the first point (external refrigerant circuit 28A) and the pressure at the second point (external refrigerant circuit 28B) in the discharge pressure region (external refrigerant circuit 28A, 28B), and the first point. The position of the transmission rod 38, that is, the position of the valve body 44 is regulated according to the pressure difference between the pressure at the second point and the pressure at the second point.

  As shown in FIG. 1A, the control computer C that performs current supply control (duty ratio control) on the solenoid 34 of the capacity control valve 32 supplies current to the solenoid 34 when the air conditioner operation switch 54 is turned on. The current supply is stopped by turning off the air conditioner operation switch 54. A room temperature setter 55 and a room temperature detector 56 are signal-connected to the control computer C. When the air conditioner operation switch 54 is in the ON state, the control computer C controls the solenoid 34 based on the temperature difference between the target room temperature set by the room temperature setter 55 and the detected room temperature detected by the room temperature detector 56. Control the current supply. When the duty ratio is increased, the transmission rod 38 (valve element 44) is displaced from the chamber 42 side to the valve hole 41 side.

  As shown in FIGS. 3 and 4, when the maximum diameter portion 443 of the valve body 44 is pulled out from the valve hole 41 and the valve hole 41 is in the open state, the refrigerant in the external refrigerant circuit 28B flows into the pressure introduction passage 50, the first 2 is sent to the control pressure chamber 121 through a supply passage 57 called a pressure sensing chamber 46, a valve hole 41, a chamber 42 and a passage 43. As shown in FIG. 2B, when the maximum diameter portion 443 of the valve body 44 enters the valve hole 41 and the valve hole 41 is in the closed state, the refrigerant in the external refrigerant circuit 28B passes through the supply passage 57. It is blocked from being sent to the control pressure chamber 121.

  As shown in FIG. 1A, the control pressure chamber 121 and the suction chamber 131 communicate with each other via the discharge passage 58. The refrigerant in the control pressure chamber 121 can flow out to the suction chamber 131 via the discharge passage 58. The pressure in the control pressure chamber 121 is determined by the refrigerant supply from the external refrigerant circuit 28B to the control pressure chamber 121 via the supply passage 57 and the refrigerant discharge from the control pressure chamber 121 to the suction chamber 131 via the discharge passage 58. It is regulated.

  In FIG. 2A, the maximum current is supplied to the solenoid 34, and the valve hole 41 is in a closed state. In this state, the amount of refrigerant supplied from the external refrigerant circuit 28B to the control pressure chamber 121 via the supply passage 57 is substantially zero, and the refrigerant in the control pressure chamber 121 passes through the discharge passage 58. It flows out to the suction chamber 131. Therefore, the pressure in the control pressure chamber 121 is low, and the inclination angle of the swash plate 22 is the maximum inclination angle. In this state, the stroke of the piston 24 is maximized and the discharge capacity is maximized.

  In FIG. 3, less than the maximum current is supplied to the solenoid 34, and the valve hole 41 is in an open state. In this state, the refrigerant is supplied from the external refrigerant circuit 28B to the control pressure chamber 121 via the supply passage 57, and the inclination angle of the swash plate 22 is smaller than the maximum inclination angle.

  In the state of FIG. 4, the current supply to the solenoid 34 is stopped, and the valve hole 41 is fully open. In this state, a large amount of refrigerant is supplied from the external refrigerant circuit 28B to the control pressure chamber 121 via the supply passage 57, and the inclination angle of the swash plate 22 becomes the minimum inclination angle. The capacity control valve 32 is a normally open capacity control valve in which the valve hole 41 is open when the current supply to the solenoid 34 is stopped.

In the first embodiment, the following effects can be obtained.
(1-1) In a state where the maximum diameter portion 443 of the tapered portion 442 is pulled out from the valve hole 41, the valve hole 41 is opened, and the tapered portion 442 has a diameter of the valve hole 41 when viewed in the moving direction of the valve body 44. It does not protrude from the valve hole 41 in the direction.

  If the valve body 44 is viewed in the moving direction, the tapered portion 442 protrudes from the peripheral wall surface 411 of the valve hole 41 in the radial direction of the valve hole 41 (that is, the diameter of the maximum diameter portion 443 is the diameter of the valve hole 41). Larger). Since the pressure state in the vicinity of the protruding taper portion 442 (the portion larger than the diameter of the valve hole) changes depending on the valve opening when the valve hole 41 is open, the radial direction of the valve hole 41 The pressure applied to the protruding taper portion 442 varies depending on the valve opening. Such pressure fluctuation according to the valve opening degree fluctuates the difference between the pressure applied to the tapered portion 442 (equivalent to the discharge pressure) and the pressure (control pressure) spreading from the back pressure space 60 to the valve body 44. Such a variation in the differential pressure makes the behavior of the valve body 44 (transmission rod 38) unstable and makes the capacity controllability worse. Further, when the valve hole 41 is switched from the closed state to the open state, the pressure of the refrigerant that flows out from the inside of the valve hole 41 to the chamber 42 is suddenly applied to the protruding portion of the tapered portion 442. There is a risk of moving. That is, the pressure receiving area in the tapered portion 442 that receives the pressure of the refrigerant that is about to flow out of the valve hole 41 into the chamber 42 increases abruptly, so that the valve body 44 may move excessively. This also deteriorates the capacity controllability in the capacity control valve 32.

  The configuration in which the tapered portion 442 does not protrude from the valve hole 41 in the radial direction of the valve hole 41 when viewed in the moving direction of the valve body 44 is the pressure applied to the tapered portion 442 (equivalent to the discharge pressure) and the valve body from the opposite side. It is suppressed that the differential pressure with respect to the pressure (control pressure) applied to 44 greatly fluctuates due to the difference in valve opening. As a result, the capacity controllability in the variable capacity compressor 10 (see FIG. 1A) is improved.

  (1-2) If the passage cross-sectional area in the valve hole 41 which is a part of the supply passage 57 is finely changed, fine capacity control can be performed. The tapered portion 442 having a conical circumferential surface is a suitable configuration for finely changing the passage cross-sectional area in the valve hole 41 in accordance with the position of the valve body 44 that has entered the valve hole 41.

  (1-3) Even when the cylindrical portion 441 (maximum diameter portion 443) enters the valve hole 41, a minute clearance exists between the peripheral wall surface 411 of the valve hole 41 and the cylindrical portion 441. Due to the presence of this minute clearance, the refrigerant in the second pressure sensing chamber 46 flows little by little through the valve hole 41 to the chamber 42. Therefore, the pressure in the vicinity of the valve hole 41 in the chamber 42 is compared with a case where the valve hole is completely closed by the valve body disclosed in Patent Document 1 (a state where a small amount of refrigerant cannot be circulated), Get higher. In other words, since there is a minute clearance between the peripheral wall surface 411 of the valve hole 41 and the cylindrical portion 441, the differential pressure when the maximum diameter portion 443 comes out of the valve hole 41 (opposite to the pressure applied to the tapered portion 442). Fluctuation in pressure difference from the pressure applied to the valve body 44 from the side is reduced.

Next, a second embodiment of FIG. 5 will be described. The same reference numerals are used for the same components as those in the first embodiment.
A discharge pressure introducing chamber 61 is formed in the valve housing 39 constituting the capacity control valve 32A. The discharge pressure introduction chamber 61 communicates with an external refrigerant circuit 28 </ b> C between the discharge chamber 132 and the heat exchanger 29 via a passage 62. A spring receiver 63 and an urging spring 64 are accommodated in the discharge pressure introducing chamber 61. A biasing spring 64 is interposed between the spring receiver 63 and the end wall 48, and a small diameter portion 381 of the transmission rod 38 is joined to the spring receiver 63. The urging spring 64 urges the transmission rod 38 from the valve hole 41 side to the chamber 42 side. The transmission rod 38 is urged from the valve hole 41 side to the chamber 42 side by the urging spring 53.

  The pressure in the discharge pressure introduction chamber 61 is equivalent to the pressure (discharge pressure) in the external refrigerant circuit 28C which is a discharge pressure region, and the pressure in the chamber 42 and the back pressure space 60 is in the control pressure chamber 121. It corresponds to pressure (control pressure). One end side (small diameter portion 381 side) of the transmission rod 38 receives the pressure of the discharge pressure introduction chamber 61, and the other end side of the transmission rod 38 receives the pressure (control pressure) of the back pressure space 60. The transmission rod 38 receives a load F1 of the product of the cross-sectional area of the cylindrical portion 441 of the valve body 44 and the control pressure by the control pressure in the back pressure space 60 from the chamber 42 side to the valve hole 41 side. Further, the transmission rod 38 receives the load F2 of the product of the cross-sectional area of the cylindrical portion 441 and the discharge pressure from the valve hole 41 side to the chamber 42 side by the discharge pressure in the discharge pressure introduction chamber 61. That is, the load F1 and the load F2 are opposed via the transmission rod 38. Accordingly, the transmission rod 38 is urged from the valve hole 41 side to the chamber 42 side by the load difference (F2-F1). That is, the load difference (F2-F1) opposes the electromagnetic force of the solenoid 34.

  The degree of opening and closing in the valve hole 41 is determined by the balance of the electromagnetic force generated by the solenoid 34, the spring force of the biasing springs 53 and 64, and the biasing force due to the load difference (F2-F1). When the differential pressure between the discharge pressure and the control pressure increases, the load difference (F2-F1) increases. When the differential pressure between the discharge pressure and the control pressure decreases, the load difference (F2-F1) decreases. When the load difference (F2-F1) increases, the transmission rod 38 is displaced from the valve hole 41 side to the chamber 42 side, and when the load difference (F2-F1) decreases, the transmission rod 38 moves from the chamber 42 side to the valve hole 41 side. Displace to

In the second embodiment, the same effects as in the first embodiment can be obtained, and the following effects can be obtained.
(2-1) The capacity control valve 32A having a configuration in which the pressure in the discharge pressure introduction chamber 61 and the pressure (control pressure) in the back pressure space 60 are opposed to each other via the transmission rod 38 is Only differential pressure is controlled. That is, the capacity control valve 32 </ b> A is controlled so that the differential pressure between the discharge pressure and the control pressure is balanced with the electromagnetic force in the solenoid 34. Since the capacity control valve 32A does not use the pressure-sensitive means 51 using the bellows 47 as in the first embodiment, the normally-open capacity control valve 32A of the present embodiment has a capacity incorporating the pressure-sensitive means 51. Compared to the control valve 32, the mechanism is simplified.

Next, a third embodiment of FIG. 6 will be described. The same reference numerals are used for the same components as those in the second embodiment.
A suction pressure introduction chamber 651 is formed in the chamber forming housing 65 constituting the capacity control valve 32B. The urging spring 53 accommodated in the suction pressure introducing chamber 651 urges the transmission rod 38 from the valve hole 41 side to the chamber 42 side. The suction pressure introduction chamber 651 communicates with the suction chamber 131 through the passage 66. The suction pressure introduction chamber 651 communicates with the back pressure space 60 through passages 351 and 371. The pressure (suction pressure) in the suction chamber 131 is transmitted to the back pressure space 60 via the passage 66, the suction pressure introduction chamber 651, and the passages 351 and 371. That is, the back pressure space 60 becomes a suction pressure region.

  The transmission rod 38 receives the load F3 of the product of the cross-sectional area of the cylindrical portion 441 of the valve body 44 and the suction pressure from the chamber 42 side to the valve hole 41 side by the suction pressure in the back pressure space 60. Further, the transmission rod 38 receives the load F2 of the product of the cross-sectional area of the cylindrical portion 441 and the discharge pressure from the valve hole 41 side to the chamber 42 side by the discharge pressure in the discharge pressure introduction chamber 61. That is, the load F3 and the load F2 are opposed via the transmission rod 38. Therefore, the transmission rod 38 is urged from the valve hole 41 side to the chamber 42 side by the load difference (F2-F3). That is, the load difference (F2-F3) opposes the electromagnetic force of the solenoid 34.

  The degree of opening and closing in the valve hole 41 is determined by the balance of the electromagnetic force generated by the solenoid 34, the spring force of the biasing springs 53 and 64, and the biasing force due to the load difference (F2-F3). When the differential pressure between the discharge pressure and the suction pressure increases, the load difference (F2-F3) increases. When the differential pressure between the discharge pressure and the suction pressure decreases, the load difference (F2-F3) decreases. When the load difference (F2-F3) increases, the transmission rod 38 is displaced from the valve hole 41 side to the chamber 42 side, and when the load difference (F2-F3) decreases, the transmission rod 38 moves from the chamber 42 side to the valve hole 41 side. Displace to

In the third embodiment, the same effects as in the first embodiment can be obtained, and the following effects can be obtained.
(3-1) The capacity control valve 32B having a configuration in which the pressure of the discharge pressure introduction chamber 61 and the pressure (suction pressure) of the back pressure space 60 are opposed to each other via the transmission rod 38 is configured to reduce the discharge pressure and the suction pressure. Only differential pressure is controlled. That is, the capacity control valve 32B is controlled so that the differential pressure between the discharge pressure and the suction pressure is balanced with the electromagnetic force in the solenoid 34. Since the capacity control valve 32B does not use the pressure sensitive means 51 using the bellows 47 as in the first embodiment, the normally open capacity control valve 32B of the present embodiment has a capacity incorporating the pressure sensitive means 51. Compared to the control valve 32, the mechanism is simplified.

Next, a fourth embodiment of FIG. 7 will be described. The same reference numerals are used for the same components as those in the first embodiment.
A control pressure introduction chamber 671, a suction pressure introduction chamber 672, and a valve hole 673 are formed in the chamber forming housing 67 constituting the capacity control valve 32C. The control pressure introduction chamber 671 and the suction pressure introduction chamber 672 are connected via a valve hole 673.

  An auxiliary rod 68 is connected to the bellows 47 accommodated in the housing 69. The auxiliary rod 68 passes through the partition wall 691 of the housing 69 and protrudes into the suction pressure introduction chamber 672, and the cylindrical small diameter portion 681 of the auxiliary rod 68 protrudes through the valve hole 673 into the control pressure introduction chamber 671. . The small diameter portion 681 is joined to the transmission rod 38, and the auxiliary rod 68 is interlocked with the transmission rod 38.

  A valve body 70 is integrally formed with the auxiliary rod 68. The valve body 70 includes a cylindrical portion 701 and a tapered portion 702. The tapered portion 702 has a shape that decreases in diameter from the suction pressure introduction chamber 672 side toward the valve hole 673 side. The maximum diameter portion 703 of the taper portion 702 is a boundary between the taper portion 702 and the cylindrical portion 701, and the minimum diameter portion 704 of the taper portion 702 is a boundary between the taper portion 702 and the small diameter portion 681 of the auxiliary rod 68. The tapered portion 702 as the cross-sectional area changing portion has a minimum diameter portion 704 as the minimum cross-sectional area portion and a maximum diameter portion 703 as the maximum cross-sectional area portion, and from the minimum diameter portion 704 side to the maximum diameter portion 703 side. The cross-sectional area increases as it goes.

  The cylindrical portion 701 of the valve body 70 can slide in the valve hole 673, and the valve hole 673 is closed in a state where the cylindrical portion 701 (maximum diameter portion 703) enters the valve hole 673. Even in a state in which the cylindrical portion 701 enters the valve hole 673, a minute clearance exists between the peripheral wall surface of the valve hole 673 and the cylindrical portion 701. The cylindrical part 701 is slidable in the valve hole 673 due to the presence of a minute clearance between the peripheral wall surface of the valve hole 673 and the cylindrical part 701. The presence of this minute clearance allows a slight circulation of the refrigerant in the valve hole 673 when the cylindrical portion 701 (maximum diameter portion 703) enters the valve hole 673. That is, in a state where the cylindrical portion 701 (maximum diameter portion 703) enters the valve hole 673, the valve hole 673 is not completely closed but is in a loosely closed state that allows a slight flow. .

  The control pressure introduction chamber 671 communicates with the control pressure chamber 121 via the passage 71, and the suction pressure introduction chamber 672 communicates with the suction chamber 131 via the passage 72. The passage 71, the control pressure introduction chamber 671, the valve hole 673, the suction pressure introduction chamber 672, and the passage 72 constitute a discharge passage 73 that discharges the refrigerant in the control pressure chamber 121 to the suction chamber 131. The discharge chamber 132 and the control pressure chamber 121 communicate with each other via the supply passage 74.

  The control pressure introduction chamber 671 communicates with the back pressure space 60 via the passages 351 and 371, and the back pressure space 60 becomes a control pressure region. The valve hole 673 is opened / closed by the electromagnetic force generated by the solenoid 34, the urging force that urges the transmission rod 38 in the direction in which the pressure (control pressure) in the back pressure space 60 closes the valve hole 41, and the inside of the control pressure introduction chamber 671. This is determined by the balance between the spring force of the biasing spring 53 and the biasing force of the pressure-sensitive means 51.

  The control computer C controls current supply to the solenoid 34 (duty ratio control) based on the temperature difference between the target room temperature set by the room temperature setter 55 and the detected room temperature detected by the room temperature detector 56. When the duty ratio is increased, the transmission rod 38 and the auxiliary rod 68 (valve element 70) are displaced from the control pressure introduction chamber 671 side to the valve hole 673 side.

  In the state of FIG. 7, the valve hole 673 of the capacity control valve 32 </ b> C is opened to the maximum (the minimum diameter portion 704 has escaped from the valve hole 673), and the refrigerant in the control pressure chamber 121 passes through the discharge passage 73. It flows out to the suction chamber 131. The refrigerant in the discharge chamber 132 is sent to the control pressure chamber 121 via the supply passage 74, but the pressure in the control pressure chamber 121 is low when the valve hole 673 is opened to the maximum, and the swash plate 22. The tilt angle shown in FIG. 1A is the maximum tilt angle. In this state, the stroke of the piston 24 (see FIG. 1A) is maximized and the discharge capacity is maximized.

  When the current supply to the solenoid 34 is stopped, the maximum diameter portion 703 enters the valve hole 673 and the valve hole 673 is closed. In a state where the valve hole 673 is closed, the refrigerant in the control pressure chamber 121 does not flow out to the suction chamber 131 via the discharge passage 73. Since the refrigerant in the discharge chamber 132 is sent to the control pressure chamber 121 through the supply passage 74, the pressure in the control pressure chamber 121 is high when the valve hole 673 is closed, and the swash plate 22 [FIG. The tilt angle (see (a)) is the minimum tilt angle. The capacity control valve 32C is a normally closed capacity control valve in which the valve hole 673 is closed when the current supply to the solenoid 34 is stopped.

In the fourth embodiment, the same effects as the items (1-2) and (1-3) in the first embodiment are obtained, and the following effects are obtained.
(4-1) The configuration in which the tapered portion 702 does not protrude from the valve hole 673 in the radial direction of the valve hole 673 when viewed in the moving direction of the valve body 70 is the pressure applied to the tapered portion 702 (equivalent to control pressure), The pressure difference from the pressure applied to the valve body 70 from the opposite side (the urging force of the pressure-sensitive means 51) is prevented from greatly fluctuating due to the difference in valve opening. As a result, the capacity controllability in the variable capacity compressor 10 (see FIG. 1A) is improved.

In the present invention, the following embodiments are also possible.
(1) In the configuration in which the circumferential surface of the cross-sectional area changing portion is tapered, the diameter of the taper portion changes linearly from the maximum diameter portion of the taper portion toward the minimum diameter portion. It is good also as a structure which changes nonlinearly as it goes to the minimum diameter part.

(2) The peripheral wall surface of the valve hole may be tapered. In this case, the valve body having the cross-sectional area changing portion enters and exits on the minimum diameter portion side of the tapered valve hole.
(3) In the first and fourth embodiments, a pressure sensitive means using a diaphragm or a piston may be used instead of the bellows.

1 shows a first embodiment, (a) is a side sectional view of the whole compressor. (B) is sectional drawing of a hinge mechanism. (A) is sectional drawing of a capacity control valve. (B) is a fragmentary sectional view of a capacity control valve. The fragmentary sectional view of a capacity control valve. The fragmentary sectional view of a capacity control valve. Sectional drawing of the capacity | capacitance control valve which shows 2nd Embodiment. Sectional drawing of the capacity | capacitance control valve which shows 3rd Embodiment. Sectional drawing of the capacity | capacitance control valve which shows 4th 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. 28A, 28B, 28C ... External refrigerant circuit as a discharge pressure region. 32, 32A, 32B, 32C ... capacity control valves. 44, 70 ... Valve body. 41,673 ... Valve holes. 411 ... A peripheral wall surface. 442, 702... Tapered portion as a cross-sectional area changing portion. 443, 703 ... The maximum diameter portion as the maximum cross-sectional area portion. 444, 704 ... Minimum diameter portion as a minimum cross-sectional area portion. 57, 74 ... supply passage. 58, 73 ... discharge passage.

Claims (5)

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 valve in the variable capacity compressor that controls the discharge capacity by regulating the pressure in the pressure chamber,
A valve hole serving as a part of the supply passage or the discharge passage;
A valve body having a cross-sectional area changing portion that enters and exits the valve hole,
The cross-sectional area changing part has a minimum cross-sectional area part and a maximum cross-sectional area part, and the cross-sectional area increases from the minimum cross-sectional area part side toward the maximum cross-sectional area part side, The cross-sectional area changing part enters the valve hole from the minimum cross-sectional area part side, the maximum cross-sectional area part can enter the valve hole, and the maximum cross-sectional area part enters the valve hole in the state described above. A capacity control valve in a variable capacity compressor in which the valve hole is closed.   The capacity control valve in the variable capacity compressor according to claim 1, wherein a circumferential surface of the cross-sectional area changing portion is a conical surface.   The micro clearance which a refrigerant | coolant can distribute | circulate through the said valve hole in the state which the said largest cross-sectional area part entered into the said valve hole exists between the said maximum cross-sectional area part and the surrounding wall surface of the said valve hole. 3. A displacement control valve in the variable displacement compressor according to any one of 2 above.   The valve hole is a part of the supply passage, and the capacity control valve is a normally open type in which the valve hole is always open at the minimum capacity of the variable capacity compressor. 4. A capacity control valve in the variable capacity compressor according to any one of 3 above.   The valve hole is a part of the discharge passage, and the capacity control valve is a normally closed type in which the valve hole is always closed when the variable capacity compressor has a minimum capacity. 4. A capacity control valve in the variable capacity compressor according to any one of 3 above.

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