JP6340501B2 - Control valve for variable capacity compressor - Google Patents

Description

  The present invention relates to a control valve that controls the discharge capacity of a variable capacity compressor.

  An automotive air conditioner is generally configured by arranging a compressor, a condenser, an expansion device, an evaporator, and the like in a refrigeration cycle. As the compressor, a variable capacity compressor (also simply referred to as “compressor”) capable of varying the refrigerant discharge capacity is used so that a constant cooling capacity is maintained regardless of the engine speed. In this compressor, a piston for compression is connected to a swing plate attached to a rotary shaft that is driven to rotate by an engine, and the discharge amount of the refrigerant is changed by changing the stroke of the piston by changing the angle of the swing plate. adjust. The angle of the swing plate can be continuously changed by introducing a part of the discharged refrigerant into the sealed crank chamber and changing the balance of pressure applied to both surfaces of the piston. The pressure in the crank chamber (hereinafter referred to as “crank pressure”) Pc is controlled by a variable displacement compressor control valve (also simply referred to as “control valve”) provided between the discharge chamber and the crank chamber of the compressor. The

  As such a control valve, there is one that controls the crank pressure Pc by controlling the amount of refrigerant introduced into the crank chamber in accordance with the differential pressure (Pd−Ps) between the discharge pressure Pd and the suction pressure Ps of the compressor. (For example, refer to Patent Document 1). Such a control valve is configured as an electromagnetic valve and has a valve hole in the body for communicating the discharge chamber and the crank chamber. A valve seat is formed at the opening end of the valve hole, and the valve body arranged in the body is attached to and detached from the valve seat to open and close the valve part, or the valve body is brought into contact with and separated from the valve seat. The refrigerant flow rate introduced into the crank chamber is controlled by adjusting the opening degree. At that time, the valve element operates autonomously so that the differential pressure (Pd−Ps) is maintained at the set differential pressure set by the amount of current supplied to the solenoid. According to such a control valve, by adjusting the set differential pressure, the differential pressure (Pd−Ps) can be controlled to a desired value, and the refrigerant discharge capacity from the compressor can be adjusted appropriately. it can. Further, since the capacity control based on the magnitude of the discharge pressure Pd itself is performed, there is also an advantage that the response is good for changing the discharge capacity.

JP 2001-132650 A

  By the way, such control valves often have a ball shape or a taper shape as the shape of the valve body in order to ensure the sealing performance of the valve portion when the valve is closed. The seating performance of the valve body on the valve seat is improved. However, the inventors have verified that control hunting tends to occur when such a valve body is used. In such a control valve, the effective pressure receiving diameter of the valve body is reduced when the solenoid valve is opened from the closed state, and as a result, the valve body is easily opened. When this control valve is mounted on the compressor, the sensitivity of the valve opening operation is increased, so that it is considered that control hunting of the compressor is likely to be caused.

  In recent years, in particular, there has been a problem of global warming, and proposals have been made to shift the refrigerant used in the refrigeration cycle from carbon dioxide to carbon dioxide or the like instead of the conventional alternative fluorocarbon. In this refrigeration cycle using carbon dioxide, the pressure of the refrigerant is increased to a supercritical region exceeding the critical temperature, and thus the discharge pressure of the refrigerant becomes very high. For this reason, we are anxious about the influence of the control hunting mentioned above becoming larger.

  An object of the present invention is to maintain stable control characteristics in a control valve that performs capacity control based on a differential pressure between a discharge pressure and a suction pressure of a compressor.

  In one embodiment of the present invention, the discharge capacity of a variable capacity compressor that compresses the refrigerant introduced into the suction chamber and discharges it from the discharge chamber is changed by adjusting the flow rate of the refrigerant introduced from the discharge chamber into the crank chamber. This is a control valve for a variable capacity compressor. The control valve connects a discharge chamber communication port communicating with the discharge chamber, a crank chamber communication port communicating with the crank chamber, a suction chamber communication port communicating with the suction chamber, a discharge chamber communication port, and a crank chamber communication port. A body having a valve hole provided in the passage; a valve body that opens and closes a valve seat provided at an opening end of the valve hole; and a valve body that opens and closes the valve part; A solenoid that generates a solenoid force for driving the valve body in the valve closing direction, and a spring that can apply an urging force in the valve opening direction against the solenoid force to the valve body.

  A discharge chamber communication port, a crank chamber communication port, and a suction chamber communication port are provided in this order from one end side of the body, and a solenoid is provided on the other end side of the body. The valve body is configured to operate autonomously so that the differential pressure between the discharge pressure in the discharge chamber and the suction pressure in the suction chamber is maintained at a set differential pressure corresponding to the supply current value to the solenoid. The valve seat is constituted by a plane perpendicular to the axis of the valve hole. On the other hand, the valve body has a flat surface perpendicular to the axis, and comprises a flat valve attached to and detached from the valve seat on the flat surface. When the solenoid is energized, when the valve is opened from the closed state, the force due to the pressure of the crank chamber acting on the valve body becomes larger in the valve closing direction than when the valve is closed.

  According to this aspect, since the valve body is a flat valve, when the valve body is opened from the closed state, the influence of the pressure in the crank chamber greatly acts in the valve closing direction of the valve body. That is, the ease of opening of the valve triggered by the valve opening operation (that is, the increase in sensitivity of the valve opening operation) is suppressed. As a result, control hunting can be prevented or suppressed, and stable control characteristics of the control valve can be maintained.

  According to the present invention, a stable control characteristic can be maintained in a control valve that performs capacity control based on a differential pressure between a discharge pressure and a suction pressure of a compressor.

It is a system diagram showing the refrigerating cycle of the air-conditioner for vehicles concerning an embodiment. It is sectional drawing which shows the structure of the control valve which concerns on embodiment. It is a partial expanded sectional view corresponding to the upper half part of FIG. It is the elements on larger scale of a control valve. It is the elements on larger scale of a control valve. It is a figure which shows the control characteristic of a solenoid. It is a figure which represents typically the structure of the valve part periphery which concerns on embodiment and its modification. It is a figure which represents typically the structure of the valve part periphery which concerns on a comparative example. It is a figure showing the differential pressure control characteristic which concerns on embodiment and its modification. It is a figure showing the structure of the control valve which concerns on a modification.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the following description, for the sake of convenience, the positional relationship between the structures may be expressed as upper and lower with reference to the illustrated state.
FIG. 1 is a system diagram illustrating a refrigeration cycle of a vehicle air conditioner according to an embodiment.

  The air conditioner of this embodiment includes a so-called supercritical refrigeration cycle using carbon dioxide that operates at high pressure as a refrigerant. This air conditioner includes a variable capacity compressor (simply referred to as “compressor”) 101 that compresses a refrigerant in a gas phase that circulates in a refrigeration cycle, and an external heat exchanger that cools the compressed high-temperature and high-pressure gas-phase refrigerant. A gas cooler 102, an expansion device 103 that adiabatically expands the cooled refrigerant and depressurizes it, an evaporator 104 that evaporates the expanded refrigerant to remove latent heat of vaporization and cools the air in the passenger compartment, and removes the evaporated refrigerant A liquid receiver 105 is provided that separates the liquid and returns the separated carbon dioxide in a gas phase state to the compressor 101.

  The compressor 101 has a rotation shaft (not shown) that is rotatably supported in the crank chamber 116. The rotating shaft is provided with a swing plate with a variable inclination angle, and one end of the rotating shaft extends outside the crank chamber 116 and is connected to the output shaft of the engine via a pulley. A plurality of cylinders 112 are disposed around the rotation shaft, and pistons that reciprocate by the rotational movement of the swing plate are disposed in each cylinder 112. Each cylinder 112 is connected to the suction chamber 110 via a suction valve, and is connected to the discharge chamber 114 via a discharge valve. The compressor 101 compresses the refrigerant introduced into the cylinder 112 through the suction chamber 110 and discharges it through the discharge chamber 114.

  The angle of the oscillating plate of the compressor 101 is maintained at a position where the load of the spring that urges the oscillating plate in the crank chamber 116 and the load due to the pressure applied to both surfaces of the piston connected to the oscillating plate are balanced. . The angle of the swing plate is continuously changed by introducing a part of the refrigerant discharged into the crank chamber 116 to change the crank pressure Pc and changing the balance of pressure applied to both surfaces of the piston. The refrigerant discharge capacity is adjusted by changing the stroke of the piston by changing the angle of the swing plate. The crank pressure Pc is controlled by the control valve 1 provided between the discharge chamber 114 and the crank chamber 116 of the compressor 101.

  That is, a part of the refrigerant discharged from the compressor 101 is introduced into the crank chamber 116 via the control valve 1 and used for capacity control of the compressor 101. The control valve 1 is configured as a solenoid-driven electromagnetic valve and is energized and controlled by the control unit 120. In the present embodiment, the control unit 120 outputs a pulse signal set to a predetermined duty ratio to the drive circuit 122 and outputs a current pulse corresponding to the duty ratio from the drive circuit 122 to drive the solenoid. The control valve 1 is a refrigerant flow rate introduced into the crank chamber 116 from the discharge chamber 114 so that the differential pressure (Pd−Ps) between the discharge pressure Pd and the suction pressure Ps of the compressor 101 approaches a set differential pressure that is a control target value. Adjust. As a result, the discharge capacity of the compressor 101 changes. That is, the control valve 1 functions as a so-called Pd-Ps differential pressure valve.

  The refrigerant passage 118 that connects the crank chamber 116 and the suction chamber 110 is provided with an orifice 119 so that the refrigerant in the crank chamber 116 leaks to the suction chamber 110 side, and the crank pressure Pc is not excessively increased. . A check valve 130 is provided in the refrigerant passage between the discharge chamber 114 and the refrigerant outlet in the compressor 101.

  The control unit 120 includes a CPU that executes various arithmetic processes, a ROM that stores various control programs, a RAM that is used as a work area for data storage and program execution, an input / output interface, and the like. The control unit 120 includes a PWM output unit that outputs a pulse signal having a designated duty ratio. However, since the configuration itself is a known one, a detailed description thereof is omitted. The control unit 120 determines the set differential pressure based on predetermined external information detected by various sensors such as the engine speed, the temperature inside and outside the vehicle, and the temperature of air blown from the evaporator 104, and the set differential pressure The energization of the control valve 1 is controlled so that a solenoid force for maintaining the above is obtained. When there is an acceleration cut request for reducing the load torque of the compressor 101 in a high engine load state such as when the vehicle is accelerated or when traveling on an uphill, the control unit 120 cuts off the current or suppresses the energization to a predetermined lower limit value. Then, the variable capacity compressor is shifted to the minimum capacity operation.

  The expansion device 103 is configured as a so-called temperature-type expansion valve, feeds back the refrigerant temperature on the outlet side of the evaporator 104, adjusts the valve opening, and supplies liquid refrigerant according to the heat load to the evaporator 104. To do. The refrigerant that has passed through the evaporator 104 is returned to the compressor 101 via the liquid receiver 105 and compressed again.

  The check valve 130 is opened as long as the discharge capacity of the compressor 101 is large to some extent and the differential pressure (Pd−Pdl) between the discharge pressure Pd of the discharge chamber 114 and the outlet pressure Pdl of the refrigerant outlet exceeds the valve opening differential pressure. Maintain valve status. This valve opening differential pressure is set by the load of the spring built in the check valve 130. On the other hand, when the discharge capacity of the compressor 101 is reduced and the discharge pressure Pd is not sufficiently increased, for example, during the minimum capacity operation, the check valve 130 is closed by the biasing force of the spring, and the gas cooler 102 is closed. The reverse flow of the refrigerant from the side to the discharge chamber 114 is prevented. Note that the check valve 130 closes during the minimum capacity operation of the compressor 101, but the refrigerant discharged from the discharge chamber 114 is returned to the suction chamber 110 via the control valve 1 and the crank chamber 116. The internal circulation of the refrigerant gas is ensured.

  FIG. 2 is a cross-sectional view showing the configuration of the control valve 1 according to the embodiment.

  The control valve 1 is configured by integrally assembling a valve body 2 and a solenoid 3. The valve body 2 has a stepped cylindrical body 5. The body 5 is made of brass in the present embodiment, but may be made of an aluminum alloy. The body 5 is provided with ports 10, 12, and 14 from the upper end side. Among these, the port 10 is provided at the upper end of the body 5, and the ports 12 and 14 are provided at the side of the body 5. The port 10 functions as a “discharge chamber communication port” that communicates with the discharge chamber 114, the port 12 functions as a “crank chamber communication port” that communicates with the crank chamber 116, and the port 14 communicates with the suction chamber 110. It functions as a “communication port”.

  In the body 5, a stepped cylindrical valve seat forming member 16 is disposed in a passage communicating the port 10 and the port 12. The valve seat forming member 16 is formed by quenching stainless steel (for example, SUS420), and has a hardness higher than that of the body 5. The valve seat forming member 16 is coaxially inserted into the upper portion of the body 5 and is fixed by caulking the upper portion of the body 5 inward. The valve seat forming member 16 is provided with a through hole along the axis, and a valve hole 18 is formed by the lower half thereof. A valve chamber 20 communicating with the port 12 is formed below the valve seat forming member 16 in the body 5. The lower half of the valve seat forming member 16 has a tapered shape with an outer diameter that decreases downward, and extends into the valve chamber 20. A valve seat 22 is formed on the lower end surface of the valve seat forming member 16. A valve body 24 is disposed in the valve chamber 20 so as to face the valve seat 22 from below. The opening degree of the valve portion is adjusted by the valve body 24 coming into contact with and separating from the valve seat 22.

  In the present embodiment, as described above, by adopting a soft material as the material of the body 5, the workability is maintained high, while the member on which the valve seat 22 is formed (the valve seat forming member 16) has high hardness. This prevents or suppresses the wear and deformation of the valve seat 22. Thereby, good seating performance of the valve body 24 can be maintained. That is, in this embodiment, since the control valve 1 is applied to a supercritical refrigeration cycle using carbon dioxide as a refrigerant, the discharge pressure Pd of the compressor 101 is very high. For this reason, there is a possibility that cavitation occurs when the high-pressure refrigerant passes through the valve portion when the valve is opened, or foreign matter contained in the refrigerant collides with the valve seat 22 at high speed. For this reason, when the valve seat 22 is made of a soft material like the body 5, the valve seat 22 is easily worn and deformed (erosion), and the sealing performance of the valve portion is deteriorated and the control set value (set value) changes. May be incurred. On the other hand, in this embodiment, they can be prevented or suppressed by increasing the material strength (hardness) of the valve seat 22 and its periphery. In the present embodiment, the valve seat forming member 16 has a Vickers hardness of 500 or more (preferably 700 or more).

  A partition wall 26 is provided so as to partition the internal space of the body 5 vertically. A valve chamber 20 is formed above the partition wall 26, and a working chamber 28 is formed below the partition wall 26. The valve chamber 20 communicates with the crank chamber 116 via the port 12. The working chamber 28 communicates with the suction chamber 110 through the port 14. A guide portion 30 extending in the axial direction is provided at the center of the partition wall 26. A guide hole 32 is formed so as to penetrate the guide portion 30 along the axis, and a long operating rod 34 is inserted into the guide hole 32 so as to be slidable in the axial direction. The valve body 24 is provided coaxially at the upper end of the operating rod 34. The valve body 24 and the operating rod 34 are integrally formed by cutting stainless steel.

  The guide part 30 protrudes small on the upper surface side of the partition wall 26 and protrudes largely on the lower surface side. The guide portion has a tapered shape with an outer diameter that decreases downward, and extends into the working chamber 28. Thereby, the length of the guide hole 32 is sufficiently secured, and the operation rod 34 is stably supported. The valve body 24 operates integrally with the operating rod 34, and attaches and detaches to the valve seat 22 at its upper end surface to open and close the valve portion. Since the hardness of the valve seat forming member 16 is sufficiently high, the valve seat 22 is not easily deformed even when the valve body 24 is repeatedly seated, and the durability of the valve portion is ensured.

  A retaining ring 36 (E-ring) is fitted to the lower portion of the operating rod 34, and a disk-shaped spring receiver 38 is provided so that the downward movement is restricted by the retaining ring 36. Between the spring receiver 38 and the partition wall 26, a spring 40 (functioning as a “first spring”) that biases the operating rod 34 downward (in the valve closing direction) is interposed. The spring 40 is a tapered spring whose diameter decreases from the lower surface of the partition wall 26 toward the lower spring receiver 38. Since the guide portion 30 is tapered as described above, such a tapered spring 40 can be arranged. A lower portion of the body 5 is a small diameter portion 42 and constitutes a connecting portion with the solenoid 3.

  A filter member 44 that suppresses entry of foreign matter into the port 10 is provided at the upper end opening of the body 5. Since the refrigerant discharged from the compressor 101 may contain foreign matters such as metal powder, the filter member 44 prevents or suppresses the foreign matters from entering the control valve 1. The filter member 44 is configured by stacking two metal meshes vertically.

  On the other hand, the solenoid 3 includes a cylindrical core 50, a bottomed cylindrical sleeve 52 that is externally attached to the core 50, a plunger 54 that is accommodated in the sleeve 52 and is disposed so as to face the core 50 in the axial direction, and a sleeve A cylindrical bobbin 56 extrapolated to 52, an electromagnetic coil 58 wound around the bobbin 56, a cylindrical case 60 provided so as to cover the electromagnetic coil 58 from the outside, and above the bobbin 56 A stepped cylindrical connecting member 62 assembled between the core 50 and the case 60, and an end member 64 provided so as to seal the lower end opening of the case 60.

  The sleeve 52 and the plunger 54 are made of electromagnetic soft iron (SUY) having excellent magnetic properties. Electromagnetic soft iron is a material that has few impurities and that can provide high magnetic flux density, high magnetic permeability, and a small coercive force. More specifically, SUY-1 is used which has moderate hardness, good workability, and a small coercive force (60 to 80 A / m). Thereby, even if the supply current to the solenoid 3 is relatively low, the necessary solenoid force can be ensured. For this reason, it is possible to reduce the size of the electromagnetic coil 58 and thus the control valve 1.

  The sleeve 52 is made of a non-magnetic material and accommodates a plunger 54 in the lower half thereof. An annular collar 66 is embedded in the end member 64. The collar 66 is interposed between the sleeve 52 and the case 60 below the bobbin 56. The case 60, the connecting member 62 and the collar 66 are made of a magnetic material and form a yoke of the solenoid 3. The valve main body 2 and the solenoid 3 are fixed by press-fitting the small diameter portion 42 (lower end portion) of the body 5 into the upper end opening of the connection member 62. In the present embodiment, the body 5, the valve seat forming member 16, the connection member 62, the case 60, and the end member 64 form the body of the entire control valve 1.

  An insertion hole 67 is formed so as to penetrate the center of the core 50 in the axial direction, and a shaft 68 is inserted so as to penetrate the insertion hole 67. The shaft 68 is provided coaxially with the operating rod 34 and supports the operating rod 34 from below. The diameter of the shaft 68 is larger than that of the operating rod 34. A plunger 54 is assembled to the lower half of the shaft 68. In the present embodiment, the shaft 68 and the operating rod 34 constitute a “transmission rod” that transmits the solenoid force to the valve body 24.

  The plunger 54 is coaxially supported on the shaft 68 at the upper portion thereof. A retaining ring 70 (E-ring) is fitted at a predetermined position in the axial direction intermediate portion of the shaft 68, and the upward movement of the plunger 54 is restricted by the retaining ring 70. A communication groove 71 parallel to the axis is provided on the side surface of the plunger 54, and a communication path through which the refrigerant passes is formed between the plunger 54 and the sleeve 52.

  A ring-shaped shaft support member 72 is press-fitted into the upper end portion of the core 50, and the upper end portion of the shaft 68 is supported by the shaft support member 72 so as to be slidable in the axial direction. A part of the outer periphery of the shaft support member 72 is cut away, so that a communication path is formed between the core 50 and the shaft support member 72. The suction pressure Ps of the working chamber 28 is also guided into the solenoid 3 through this communication path.

  The lower end portion of the sleeve 52 is slightly reduced in diameter, and a ring-shaped shaft support member 76 (functioning as a “support member”) is press-fitted into the reduced diameter portion 74. The shaft support member 76 slidably supports the lower end portion of the shaft 68. That is, since the shaft 68 is supported at two points by the upper support member 72 and the lower support member 76, the plunger 54 can be stably operated in the axial direction. A part of the outer periphery of the shaft support member 76 is cut away, so that a communication path is formed between the sleeve 52 and the shaft support member 76. The suction pressure Ps introduced into the solenoid 3 is via a communication path between the core 50 and the shaft 68, a communication path between the plunger 54 and the sleeve 52, and a communication path between the shaft support member 76 and the sleeve 52. The sleeve 52 is filled.

  A spring 78 (functioning as a “second spring”) that biases the plunger 54 upward, that is, in the valve closing direction is interposed between the shaft support member 76 and the plunger 54. That is, the valve body 24 receives a resultant force of the force in the valve opening direction by the spring 40 and the force in the valve closing direction by the spring 78 as a spring load. However, since the load of the spring 40 is larger than that of the spring 78, the spring load by the springs 40, 78 acts in the valve opening direction. This spring load can be set by adjusting the press-fitting position of the shaft support member 76 in the sleeve 52. The press-fitting position can be finely adjusted by temporarily pressing the shaft support member 76 into the sleeve 52 and then deforming the center of the bottom of the sleeve 52 in the axial direction using a predetermined tool.

  A pair of connection terminals 80 connected to the electromagnetic coil 58 extend from the bobbin 56, and extend through the end members 64 to the outside. For convenience of explanation, only one of the pair is displayed in the figure. The end member 64 is attached so as to seal the entire structure in the solenoid 3 included in the case 60 from below. The end portion of the connection terminal 80 is drawn out from the end member 64 and is connected to an external power source (not shown). The end member 64 also functions as a connector part that exposes the connection terminal 80.

  The control valve 1 configured as described above is fixed to a mounting hole (not shown) provided in the compressor 101 via a washer. A plurality of O-rings interposed between the mounting holes and exhibiting a sealing function are fitted to the outer peripheral surface of the control valve 1. That is, annular grooves are respectively provided above and below the port 12 in the body 5, and O-rings 82 and 84 are fitted. An annular groove is also provided below the port 14 in the connecting member 62, and an O-ring 86 is fitted. Further, an O-ring 88 is also fitted to the connecting portion between the case 60 and the end member 64.

3 is a partially enlarged cross-sectional view corresponding to the upper half of FIG.
The filter member 44 is configured by overlapping two metal meshes 46 and 48 in the thickness direction. That is, the mesh 46 is disposed so as to face the outside of the body 5, and the mesh 48 is disposed so as to face the inside of the body 5. The reason why the meshes 46 and 48 are made of metal is that the pressure resistance is insufficient for the resin mesh because the filter member 44 is placed on the high pressure side of the supercritical refrigeration cycle.

  The meshes 46 and 48 are both formed in a circular sheet shape, but have different mesh sizes and rigidity. That is, the mesh 46 is finer than the mesh 48 (the aperture ratio is small). On the other hand, the mesh 48 has a larger wire diameter and higher rigidity than the mesh 46. This is to ensure a high filter function by the mesh 46 and to secure (reinforce) the strength of the entire filter member 44 by the mesh 48.

  After the filter member 44 is placed so as to be inserted into the upper end opening of the body 5, the filter member 44 is fixed by caulking the upper end of the body 5 inward. Thus, since the filter member 44 has a simple configuration in which two meshes are directly stacked and directly fixed to the body 5, the component cost and the manufacturing cost can be suppressed. The filter member 44 is disposed inside the body 5 as shown in the figure, so that deformation or breakage due to contact with an external structure is prevented or suppressed.

  A through hole 90 provided in the center of the valve seat forming member 16 has a lower half thereof reduced in diameter to form a valve hole 18. That is, the upper half portion of the through hole 90 is a large diameter portion 92 and the lower half portion is a small diameter portion 94, and the small diameter portion 94 forms the valve hole 18. The connecting portion between the large diameter portion 92 and the small diameter portion 94 is a tapered surface whose inner diameter is reduced downward. The through-hole 90 is reduced in diameter from the upstream side toward the downstream side.

  In addition, a bleed hole 96 parallel to the through hole 90 is provided outside the through hole 90 in the valve seat forming member 16 in the radial direction. The bleed hole 96 is for ensuring oil circulation in the compressor 101 by allowing a minimum amount of refrigerant to flow into the crank chamber 116 even when the valve is closed. In order to ensure stable operation of the compressor 101, the refrigerant contains lubricating oil, and the bleed hole 96 ensures oil circulation inside and outside the crank chamber 116.

  The bleed hole 96 is configured by connecting an upper leakage passage 98 and a communication passage 99 below the leakage passage 98. The inner diameter of the leak passage 98 is set to a size that allows the refrigerant to leak, and is considerably smaller than the inner diameter of the valve hole 18. The inner diameter of the communication path 99 is smaller than the large diameter portion 92 of the through hole 90 and larger than the small diameter portion 94. In the modification, the inner diameter of the communication path 99 may be equal to or larger than the inner diameter of the large diameter portion 92 of the through hole 90 or may be equal to or smaller than the inner diameter of the small diameter portion 94.

  A connecting portion between the leak passage 98 and the communication passage 99 is a tapered surface whose inner diameter increases downward. The bleed hole 96 is enlarged in steps from the upstream side toward the downstream side. An annular protrusion 150 is provided on the upper surface of the valve seat forming member 16 so as to surround the through-hole 90, and has a step shape in which the radially inner side and the outer side of the protrusion 150 are lowered by one step. The width of the protrusion 150 is sufficiently small, and in this embodiment, the width is equal to or smaller than the width of the valve hole 18. The leak passage 98 opens upward at the position of the protrusion 150.

  As described above, the bleed hole 96 has a small inlet for the refrigerant, and the inlet is opened on the upper surface of the step shape, thereby preventing or suppressing entry of foreign matter through the bleed hole 96. That is, even if a foreign object smaller than the mesh (opening hole width) of the filter member 44 enters the port 10, the width of the projection 150 is sufficiently small and the inlet of the bleed hole 96 is further small. The possibility of entering through the hole 96 is very low. Even if a foreign object hits the protrusion 150, there is a high possibility that the foreign object falls to a low position inside and outside the protrusion 150. In particular, when the valve is closed, the refrigerant can flow through the bleed hole 96, but the possibility that foreign matter contained in the refrigerant is guided to the bleed hole 96 is low. When the valve is opened, even if foreign matter enters the port 10, most of it passes through the valve hole 18 and is discharged from the port 12.

  Further, in the valve chamber 20, an annular groove 152 is formed around the guide portion 30 protruding from the center of the upper surface of the partition wall 26. Further, the outer diameter of the valve body 24 is slightly larger than that of the operation rod 34 directly below. For this reason, even if foreign matter enters the valve chamber 20 through the valve hole 18, the possibility that the foreign matter enters the sliding portion between the operating rod 34 and the guide hole 32 is extremely low. Even if most of the foreign matter that has passed through the valve hole 18 is discharged from the port 12 or remains in the valve chamber 20, it accumulates in the annular groove 152 and enters the gap between the operating rod 34 and the guide hole 32. Unlikely. That is, the annular groove 152 can function as a foreign matter trap. For this reason, the operation | movement lock of the valve body 24 by a foreign material biting into the sliding part of the action | operation rod 34 and the guide hole 32 is prevented.

  In this embodiment, the seal portion diameter a (inner diameter of the valve hole 18) in the valve portion of the valve body 24 is made slightly larger than the sliding portion diameter b of the operating rod 34 (a> b), and the valve body. The pressure sensitivity of 24 is set optimally. That is, by making such a setting increase the contribution to the valve closing direction of the crank pressure Pc at the time of valve opening, it is difficult to open the valve part a little. As a result, the differential pressure (Pd−Ps) starts to rise gradually, and the influence of the crank pressure Pc is increased compared with the case where both diameters are the same, and the operation responsiveness of the swash plate of the compressor 101 is lowered and opened. Control hunting at the time of valve is prevented or suppressed. For adjusting the pressure sensitivity, for example, a technique described in JP-A-2006-57506 can be used.

  Further, in the present embodiment, as described above, the guide portion 30 protrudes largely toward the working chamber 28 than the valve chamber 20, whereby the lower end portion of the operating rod 34 is positioned at the lower end position of the body 5 (that is, the small diameter portion). 42 (lower end opening part). This facilitates the mounting of the retaining ring 36 to the operating rod 34. That is, in order to fit the retaining ring 36 to the operating rod 34, first, the operating rod 34 must be inserted from the valve chamber 20 side. This is because the outer diameter of the valve body 24 is larger than the guide hole 32. On the other hand, in order to fit the retaining ring 36 to the operating rod 34, in consideration of workability, the fitting portion formed on the operating rod 34 is exposed from the opening end portion of the body 5, or at least the opening end thereof. It is necessary to locate in the vicinity of the part. For this reason, if the guide portion 30 extends evenly above and below the partition wall 26, the operating rod 34 needs to be unnecessarily long, which is not preferable. Therefore, in this embodiment, by moving the guide portion 30 downward, a stable guide function by the guide portion 30 is ensured, and good workability when the retaining ring 36 is attached is also maintained. Further, the operating rod 34 is not unnecessarily lengthened, so that the body 5 and thus the control valve 1 can be made compact.

  Furthermore, in the present embodiment, as described above, the guide portion 30 and the spring 40 are tapered so that the outer diameter is reduced downward. Thereby, the lower half part of the spring 40 is accommodated in the upper end opening part of the core 50, and the outer diameter of the small diameter part 42 is made as small as possible. As a result, the outer diameter of the connecting member 62 is reduced, and it is possible to select an O-ring 86 having a smaller outer diameter. Thereby, when the control valve 1 is attached to the attachment hole of the compressor 101, the influence of the refrigerant pressure acting in the direction opposite to the attachment direction is reduced. That is, since the lower part than the O-ring 86 is atmospheric pressure, if the O-ring 86 is large, a fixing structure with high pressure resistance is required to prevent the control valve 1 from falling off. In this respect, since the O-ring 86 can be made small in this embodiment, a simple fixing structure such as a washer is sufficient.

  4 and 5 are partially enlarged views of the control valve 1. 4A is an enlarged view of a portion A in FIG. 2, and FIG. 4B is an enlarged view of a portion B in FIG. 5A is a cross-sectional view taken along the line CC in FIG. 3, FIG. 5B is a cross-sectional view taken along the line EE in FIG. 4A, and FIG. It is FF arrow sectional drawing of B).

  As shown in FIG. 4A, the opposing surfaces of the core 50 and the plunger 54 are generally complementary, and the outer peripheral edge of each opposing surface is tapered. That is, the lower end surface of the core 50 has a flat surface 160 at the center and a tapered surface 162 at the outer peripheral edge. The flat surface 160 forms a right angle with respect to the axis L1 of the core 50, and the tapered surface 162 increases its inner diameter downward, and forms an angle θ1 with respect to the axis L1 of the core 50. On the other hand, the upper end surface of the plunger 54 has a flat surface 164 at the center and a tapered surface 166 at the outer peripheral edge. The flat surface 164 is perpendicular to the axis L2 of the plunger 54, the tapered surface 166 has an outer diameter that decreases upward, and forms an angle θ2 with respect to the axis L2 of the plunger 54. In the present embodiment, θ1 = θ2 = 45 degrees. The characteristics of the solenoid 3 are adjusted by the setting of the tapered surface, details of which will be described later.

  A concave portion 168 having a predetermined depth is formed in the center of the flat surface 164 of the plunger 54 and the retaining ring 70 is accommodated. That is, interference between the retaining ring 70 and the core 50 is prevented.

  As shown in FIG. 4B, a concave press adjusting portion 170 is formed at the center of the lower surface of the reduced diameter portion 74 of the sleeve 52. By pressing the tip of the tool against the pressing adjusting portion 170, the press-fitting position of the shaft support member 76 can be shifted while the bottom surface of the sleeve 52 is deformed upward in the axial direction (inward of the sleeve 52). The set load by the springs 40 and 78 can be finely adjusted.

  In addition, since the shaft support member 76 is press-fitted into the sleeve 52 in this way, even if the bottom portion of the sleeve 52 is deformed after the set load is adjusted, the set load can be maintained without being changed. . That is, in the present embodiment, as described above, carbon dioxide that operates at a high pressure is used as the refrigerant, so that a high pressure acts even at the suction pressure Ps. For this reason, there is a possibility that the bottom portion of the sleeve 52 deformed by the press adjusting unit 170 may be deformed in the direction of returning to the original by the suction pressure Ps. Even if such a case occurs, the shaft support member 76 is firmly press-fitted into the inner wall of the sleeve 52, so that it is not affected by the deformation of the bottom thereof. That is, according to the present embodiment, by adopting a structure that adjusts the press-fitting position of the shaft support member 76, the set load by the spring can be stably maintained even in a high-pressure environment.

  As illustrated, a space is formed between the end member 64 and the sleeve 52. A communication hole 172 is provided at the bottom of the end member 64 to communicate the space with the outside. The communication hole 172 is an air hole for releasing the air in the space to the outside when the sleeve 52 and the end member 64 are assembled, and functions as a pressure relief passage for releasing the pressure generated in the space during the assembly. .

  As shown in FIG. 5A, the shaft support member 72 has a so-called D-cut on the outer periphery of a disc-shaped main body, and a pair of flat surfaces 180 are formed. A communication path 182 is formed between the flat surface 180 and the inner peripheral surface of the core 50. Further, as shown in FIG. 5B, a so-called D cut is made on one side surface of the plunger 54, and a flat surface 77 is formed. A communication path 183 is formed between the flat surface 77 and the sleeve 52. A communication groove 71 having a predetermined width parallel to the axis is provided on the opposite side surface 79 of the plunger 54. A communication path 185 is formed between the communication groove 71 and the sleeve 52. Further, as shown in FIG. 5C, the shaft support member 76 has a so-called D-cut on the outer periphery of the disc-shaped main body, and a pair of flat surfaces 184 are formed. A communication path 186 is formed between the flat surface 184 and the sleeve 52. The suction pressure Ps of the working chamber 28 is filled into the sleeve 52 through these communication paths 182 to 186.

  The plunger 54 is D-cut as described above, and has a non-circular cross section (not point-symmetric with respect to the axis center). Thus, the radial magnetic gap between the flat surface 77 on the D cut side and the opposite side surface 79 is made different. With such a configuration, when the solenoid 3 is energized, the plunger 54 is attracted more strongly in the radial direction by the opposite side surface 79, which is the side having the smaller magnetic gap with the sleeve 52. That is, the plunger 54 can be displaced in the radial direction. Thereby, it is possible to prevent the plunger 54 from rattling in the radial direction when the plunger 54 operates in the sleeve 52 when the valve is opened. Further, due to the appropriate sliding resistance between the plunger 54 and the sleeve 52, fine vibration of the valve body 24 by PWM control can be suppressed. As a result, the operation sound of the plunger 54 and the collision sound when the valve body 24 is seated can be reduced.

  Returning to FIG. 2, in the above configuration, although the diameter of the operating rod 34 is slightly smaller than the inner diameter of the valve hole 18, it has almost the same size, so the influence of the crank pressure Pc acting on the valve body 24 in the valve chamber 20 is Almost canceled (offset). Therefore, the differential pressure (Pd−Ps) between the discharge pressure Pd and the suction pressure Ps substantially acts on the valve body 24 with respect to the pressure receiving area approximately the size of the valve hole 18. The valve body 24 operates so that the differential pressure (Pd−Ps) is maintained at the set differential pressure set by the control current supplied to the solenoid 3.

Next, the basic operation of the variable displacement compressor control valve will be described.
In the control valve 1, when the solenoid 3 is not energized, the valve body 24 is separated from the valve seat 22 by the load in the valve opening direction due to the resultant force of the springs 40 and 78, and the valve portion is held in the fully opened state. At this time, the high-pressure refrigerant having the discharge pressure Pd introduced from the discharge chamber 114 of the compressor 101 to the port 10 passes through the valve portion in the fully open state and flows from the port 12 to the crank chamber 116. As a result, the crank pressure Pc is increased, and the compressor 101 performs the minimum capacity operation at which the discharge capacity is minimized.

  On the other hand, when the automotive air conditioner is activated or when the cooling load is maximum, the supply current value to the solenoid 3 is maximum, and the plunger 54 is attracted to the core 50 with the maximum suction force. At this time, the operating rod 34 including the valve body 24, the shaft 68, and the plunger 54 are integrally operated in the valve closing direction, and the valve body 24 is seated on the valve seat 22. Since the crank pressure Pc is reduced by the valve closing operation, the compressor 101 performs the maximum capacity operation at which the discharge capacity is maximized.

  Here, when the current value supplied to the solenoid 3 during the capacity control is set to a predetermined value, the operating rod 34 including the valve body 24, the shaft 68, and the plunger 54 operate integrally. At this time, the valve body 24 includes a spring load of the spring 40 that biases the operating rod 34 in the valve opening direction, a spring load of the spring 78 that biases the plunger 54 in the valve opening direction, and the plunger 54 in the valve closing direction. A valve lift position in which the load of the energizing solenoid 3, the force due to the discharge pressure Pd received by the valve body 24 in the valve opening direction, and the force due to the suction pressure Ps received by the valve body 24 in the valve closing direction are balanced. Stop at.

  In this balanced state, when the rotational speed of the compressor 101 increases with the rotational speed of the engine and the discharge capacity increases, the differential pressure (Pd−Ps) increases and the force in the valve opening direction acts on the valve body 24. The valve body 24 is further lifted to increase the flow rate of the refrigerant flowing from the discharge chamber 114 to the crank chamber 116. As a result, the crank pressure Pc increases, and the compressor 101 operates in a direction to decrease the discharge capacity, and is controlled so that the differential pressure (Pd−Ps) becomes the set differential pressure. When the engine speed decreases, the reverse operation is performed and the differential pressure (Pd−Ps) is controlled to be the set differential pressure.

  FIG. 6 is a diagram showing the control characteristics of the solenoid 3. In the figure, the horizontal axis indicates the supply current value Isol (A) to the solenoid 3, and the vertical axis indicates the set differential pressure (Pd-Ps) (Mpa) as the control target value. In the present embodiment, as described above, the opposing surface between the core 50 and the plunger 54 is tapered, thereby improving the resolution on the high current side in the control current range (also referred to as “control current value range”). ing.

  That is, as described above, the angle of the tapered surfaces on the core 50 side and the plunger 54 side is set to 45 degrees (θ1 = θ2 = 45 degrees in FIG. 4A), so that the control is performed as shown by the solid line in the figure. The characteristic after the intermediate value of the current value range is changed. That is, the control characteristic of the solenoid 3 is such that the slope (change amount) of the set differential pressure (Pd−Ps) with respect to the supply current value Isol is smaller on the higher current side than the intermediate value. Specifically, the control current value range is 0.2A to 0.68A, and the control characteristic is changed with 0.45A, which is an intermediate value thereof, as a boundary. This improves the resolution on the high current side. This means that when the set differential pressure (Pd−Ps) is increased, the set differential pressure can be finely adjusted. In other words, it means that the amount of change in the electromagnetic force of the solenoid 3 can be reduced as the current is higher. In this embodiment, carbon dioxide that operates at a high pressure is used as a refrigerant. Therefore, it is very convenient to improve the control accuracy in such a range that the differential pressure increases.

  In the figure, the alternate long and short dash line indicates the case where the angle of the tapered surface is 30 degrees (θ1 = θ2 = 30 degrees), and the broken line indicates the case where the angle of the tapered surface is 20 degrees (θ1 = θ2 = 20 degrees). Show. Thus, the characteristic change before and after the intermediate value can be increased by increasing the taper angle, and conversely, the characteristic change before and after the intermediate value can be reduced by decreasing the taper angle. For this reason, an optimal control characteristic can be acquired by changing a taper angle according to a specification.

  Next, the valve opening characteristic of the valve part in this embodiment is demonstrated. FIG. 7 is a diagram schematically illustrating the configuration around the valve unit according to the embodiment and its modification. 7A and 7B show the configuration of the present embodiment, and FIG. 7C shows the configuration of a modification. FIG. 8 is a diagram schematically illustrating the configuration around the valve portion according to the comparative example. 8A shows the configuration of the first comparative example, and FIGS. 8B and 8C show the configuration of the second comparative example. In each figure, the black arrow indicates the discharge pressure Pd, the gray arrow indicates the crank pressure Pc, and the white arrow indicates the suction pressure Ps.

  As shown in FIG. 7A, in this embodiment, a so-called flat valve is adopted as the valve body 24. That is, the front end surface of the valve body 24 is a flat surface perpendicular to the axis, and the valve body 24 is seated in surface contact with the valve seat 22 when the valve is closed. Further, as described above, the seal portion diameter a (inner diameter of the valve hole 18) in the valve portion of the valve body 24 is larger than the sliding portion diameter b of the operating rod 34 (a> b). In the illustrated valve closing state, the pressure receiving diameter (referred to as “effective pressure receiving diameter d”) by which the valve body 24 receives the discharge pressure Pd is equal to the seal portion diameter a of the valve portion (the inner diameter of the valve hole 18) (d). = A). Crank pressure Pc acts on the contact portion between the valve body 24 and the valve seat 22 in the valve opening direction. For this reason, the crank pressure Pc acting on the region surrounded by the alternate long and short dash line in the figure in the valve body 24 is cancelled. In this manner, the balance of the force acting on the valve body 24 is maintained.

  On the other hand, when the valve is opened as shown in FIG. 7B, the effective pressure receiving diameter d of the valve body 24 is larger than the seal portion diameter a (d> a). This is a characteristic unique to flat valves. For this reason, the area | region where the crank pressure Pc is canceled in the valve body 24 becomes small compared with the time of valve closing. As a result, the area in which the crank pressure Pc acts in the valve closing direction (see the annular region indicated by the two-dot chain line) is relatively large, and the influence of the force in the valve closing direction due to the crank pressure Pc is large. At this time, the force in the valve opening direction due to the discharge pressure Pd also increases, but this is absorbed by the solenoid force. This is because, as a control characteristic of the control valve 1, the valve body 24 operates so that the differential pressure (Pd−Ps) is maintained at the set differential pressure. That is, as the crank pressure Pc increases after the valve portion opens, the force in the valve closing direction acting on the valve body 24 increases. In other words, the ease of opening the valve portion (increase in sensitivity) is suppressed, leading to prevention or suppression of hunting.

  In addition, the stabilization effect of control by adoption of such a flat valve can be acquired by the modification shown in FIG. That is, in this modification, the seal part diameter a (inner diameter of the valve hole 18) in the valve part and the sliding part diameter b of the operating rod 134 are made equal (a = b). In such a configuration, the influence of the crank pressure Pc is almost completely canceled when the valve is closed. However, when the valve is opened, the effective pressure receiving diameter d is increased as shown in the figure, so that the valve closing direction due to the crank pressure Pc is increased. The power of will come to act. However, since the area over which the crank pressure Pc acts in the valve closing direction is small compared to the present embodiment, the effect is also relatively small.

  On the other hand, in the first comparative example shown in FIG. 8A, such an effect cannot be obtained. That is, in the first comparative example, the sliding portion diameter b of the operating rod 234 is made larger than the seal portion diameter a (inner diameter of the valve hole 18) in the valve portion (a <b). In such a configuration, as shown in the figure, the force due to the crank pressure Pc acts in the valve opening direction. As a result, the valve part is easily opened and hunting is likely to occur.

  The same applies to the second comparative example shown in FIG. That is, in this second comparative example, the seal portion diameter a (inner diameter of the valve hole 18) in the valve portion and the sliding portion diameter b of the operating rod 134 are made equal (a = b). On the other hand, the valve body 224 is not a flat valve but a tapered valve having a tapered surface whose outer diameter gradually increases in the valve opening direction. When the valve body 224 is closed, the valve body 224 is in line contact with the valve seat 22. Sit in. That is, the valve seat 22 is formed by the opening edge of the valve hole 18. In such a configuration, the influence of the crank pressure Pc is almost completely canceled when the valve is closed, but when the valve is opened, the effective pressure receiving diameter d becomes smaller as shown in FIG. 8C. As a result, the force due to the crank pressure Pc acts in the valve opening direction by opening the valve. As a result, the valve part is easily opened and hunting is likely to occur.

  That is, as in the present embodiment and the modification, the valve body is a flat valve, and the seal portion diameter a of the valve body is set to be larger than the sliding portion diameter b of the operating rod (a ≧ b), thereby hunting. Can be prevented or suppressed.

  FIG. 9 is a diagram illustrating the differential pressure control characteristics according to the embodiment and its modification. The figure shows the relationship between the differential pressure (Pd−Ps), which is the object to be controlled, and the valve opening, for each supply current value to the solenoid 3. In the figure, the horizontal axis indicates the differential pressure (Pd-Ps), and the vertical axis indicates the differential pressure (Pc-Ps). Since the differential pressure (Pc−Ps) on the vertical axis increases as the valve opening increases, the difference in valve opening is substantially shown. Regarding the supply current value to the solenoid 3, the solid line is 250 mA, the wavy line is 390 mA, the one-dot chain line is 530 mA, and the two-dot chain line is 680 mA. The thick line shows the case where the sliding part diameter b of the working rod is 1.2 mm, and the thin line shows the case where the sliding part diameter b of the working rod is 1.0 mm. The seal part diameter a (inner diameter of the valve hole 18) in the valve part is set to 1.2 mm.

  The following can be seen from the figure. That is, when the sliding portion diameter b is 1.0 mm, that is, when the seal portion diameter a in the valve portion is larger than the sliding portion diameter b of the operating rod as in this embodiment, the differential pressure (Pd− The amount of change in the differential pressure (Pc−Ps) with respect to the change in Ps) is alleviated. This means that by making the sliding part diameter b relatively small, the change in the opening of the valve part with respect to the change in the differential pressure (Pd−Ps) can be made small. In other words, when the control valve is mounted on the compressor, it means that the sensitivity of the valve opening according to the rotation speed of the compressor can be suppressed and the control can be stabilized.

  As described above, in the present embodiment, since the valve body 24 is a flat valve, the influence of the crank pressure Pc greatly acts in the valve closing direction of the valve body 24 when the valve body 24 is opened from the closed state. It becomes like this. That is, the ease of opening of the valve triggered by the valve opening operation (that is, the increase in sensitivity of the valve opening operation) is suppressed. As a result, control hunting can be prevented or suppressed, and stable control characteristics of the control valve 1 can be maintained. Further, since the valve body 24 is a flat valve, a relatively large flow rate can be obtained with respect to the valve opening degree (the lift amount of the valve body 24 from the valve seat 22). On the other hand, since electromagnetic soft iron is used as the material of the sleeve 52 and the plunger 54, high magnetic permeability can be obtained and coercive force can be kept small. As a result, the valve opening at the time of valve opening can be made relatively large, and a sufficient flow rate can be secured without enlarging the electromagnetic coil 58. In addition, when the current is turned off, it is possible to quickly shift to the fully open state, and it is possible to quickly shift the compressor to the minimum capacity operation.

  Further, when the control valve 1 is applied to a so-called supercritical cycle and a high-pressure refrigerant is introduced into the port 10, the pressure resistance strength can be ensured because the filter member 44 is formed of a metal mesh instead of a resin mesh. Further, the filter member 44 is realized by a simple configuration in which the disk-shaped meshes 46 and 48 are stacked as they are, and is simply fixed by caulking the distal end portion of the body 5. For this reason, it is not necessary to provide a metal frame having a high pressure resistance as the filter structure, and the number of parts and the manufacturing cost can be reduced. As a result, the filter structure can be realized easily and at low cost.

  The preferred embodiments of the present invention have been described above. However, the present invention is not limited to specific embodiments, and various modifications can be made within the scope of the technical idea of the present invention. Absent.

  FIG. 10 is a diagram illustrating a configuration of a control valve according to a modification. 10A is a partially enlarged cross-sectional view of the lower half of the control valve, and FIG. 10B is a cross-sectional view taken along the line GG in FIG. 10A. In the said embodiment, the structure which suppresses rattling by putting the plunger 54 in the radial direction by giving D cut to the plunger 54 was shown. In this modification, as illustrated, the plunger 254 has a symmetrical structure with respect to the axis. On the other hand, a concave notch 268 is provided at a specific location on the inner peripheral surface of the collar 266. With such a configuration, when the solenoid is energized, the suction force can be biased to one side. Thereby, it is possible to prevent the plunger 254 from rattling in the radial direction when the plunger 254 operates in the sleeve 52 when the valve is opened. Further, due to the appropriate sliding resistance between the plunger 254 and the sleeve 52, fine vibration of the valve body 24 due to PWM control can be suppressed.

  In the above embodiment, the filter member 44 is configured by stacking two metal meshes, but may be configured by stacking three or more metal meshes. In other words, at least one of a fine mesh and a coarse mesh may be superposed on each other.

  In the above embodiment, the example in which the entire valve seat forming member 16 is made of a material having high hardness has been shown, but only the valve seat 22 and its peripheral part may be made of a material having high hardness. For example, the valve seat forming member may be made of a material having the same or equivalent softness as that of the body 5, and a fitting hole may be provided in the center of the end portion to press-fit a high hardness valve seat member. The end face of the valve seat member may be the valve seat 22.

  In the above embodiment, the example in which the shaft support member 76 functions as a spring bearing that supports the spring 78 and also functions as a bearing that supports the shaft 68 has been described. In the modified example, a spring bearing that supports the spring 78 and a bearing that supports the shaft 68 may be provided separately, and the above press-fitting adjustment structure may be applied to the spring bearing.

  In the above-described embodiment, the actuating rod 34 and the shaft 68 are manufactured separately, and then connected to each other so as to abut on each other coaxially in the axial direction so that the solenoid force is transmitted to the valve body 24. An example to do. In a modification, the actuating rod 34 and the shaft 68 may be integrally formed by a single member.

  In the said embodiment, the valve seat formation member 16 showed the structure which made the refrigerant inlet of the bleed hole 96 small diameter, and opened the inlet to the upper surface of a step shape (refer FIG. 3). This configuration remarkably exhibits the foreign substance intrusion suppression function in the refrigeration cycle in which the refrigerant pressure becomes high as in the above embodiment. That is, there is a problem that the higher the discharge pressure Pd is, the easier it is for foreign matter to pass through the filter member 44 and enter the port 10, and at least the foreign matter enters the valve chamber through the bleed hole 96 by the foreign matter intrusion suppression function. The possibility of reaching 20 can be reduced. As a result, the control characteristics of the control valve 1 under a high pressure environment are favorably maintained.

  In the above embodiment, the example in which the protrusion 150 is formed in an annular shape on the upper surface of the valve seat forming member 16 has been shown, but it is needless to say that other shapes may be adopted. For example, only the vicinity of the refrigerant inlet of the bleed hole 96 may be a protrusion. Moreover, although the example which provides only one bleed hole 96 was shown in the said embodiment, you may provide in multiple places. Even in that case, the refrigerant inlet of each bleed hole 96 may be provided on the upper surface of the projection (step shape).

  In the above-described embodiment, an example in which the annular groove 152 is formed by lowering the peripheral edge of the partition wall 26 by one step has been shown (see FIG. 3). This configuration also remarkably exhibits the foreign substance trap function in the refrigeration cycle in which the refrigerant pressure becomes high as in the above embodiment. That is, the higher the discharge pressure Pd, the more likely that foreign matter will pass through the filter member 44 and enter the port 10 and thus the valve chamber 20. At least, the foreign matter trap function causes the foreign matter and the guide rod 34 to guide the foreign matter. The possibility of reaching the gap with the hole 32 can be reduced. As a result, the control characteristics of the control valve 1 under a high pressure environment are favorably maintained.

  In the above embodiment, an example in which one annular groove is formed as the foreign matter trapping structure is shown, but other structures may be adopted. For example, a plurality of annular grooves may be formed concentrically. Alternatively, only a small region at the center of the upper surface of the guide portion 30 may be convex and the guide hole 32 may be opened on the upper surface of the convex portion. For example, the diameter of the convex portion may be made sufficiently small, for example, to be 1/3 or less of the inner diameter of the valve chamber 20. The diameter of the convex portion may be the same as that of the valve body 24. That is, rather than providing a groove in the outer peripheral edge of the partition wall 26, the upper end position of the guide portion 30 may be configured to be higher than the periphery thereof.

  Although not described in the above embodiment, the communication hole 172 shown in FIG. 4B may be positioned directly below the pressing adjustment unit 170 so as to function as a tool insertion hole.

  In the said embodiment, the example which comprises the control valve 1 as what is called a Pd-Ps differential pressure valve was shown. In the modified example, for example, a so-called Pc-Ps differential pressure valve that makes the differential pressure (Pc-Ps) between the crank pressure Pc and the suction pressure Ps close to the set differential pressure that is a control target value may be used. That is, for the control valve that changes the discharge capacity of the variable capacity compressor that compresses the refrigerant introduced into the suction chamber and discharges it from the discharge chamber by adjusting the flow rate of the refrigerant led from the crank chamber to the suction chamber, You may apply each structure, such as a valve part of the said embodiment, a filter, and a solenoid. Alternatively, it may be applied to a so-called Ps control valve that brings the suction pressure Ps close to a set pressure that is a control target value. In particular, when these control valves are applied to a supercritical refrigeration cycle using carbon dioxide or the like as a refrigerant, the functions of the above structures are effectively exhibited.

  In the said embodiment, the example which applies the control valve which has said each structure to the supercritical refrigerating cycle which uses a carbon dioxide as a refrigerant | coolant was shown. In a modification, the same control valve may be applied to a supercritical refrigeration cycle using a refrigerant other than carbon dioxide. Or you may apply to the refrigerating cycle from which the pressure of a refrigerant | coolant becomes high although it does not operate | move in a supercritical region. For example, you may apply to the refrigerating cycle which uses HFC-134a, HFO-1234yf, etc. as a refrigerant | coolant.

  In the said embodiment, the example which applies the said structure to the control valve for variable displacement compressors was shown. In the modified example, the above-described configuration may be applied to other use electromagnetic valves such as a hot water control valve.

  In the embodiment and the modification, in order to suppress the slight vibration of the valve body 24 by the PWM control, an example of performing D cut that cuts out the entire axial direction of one side surface of the plunger 54 and the inner peripheral surface of the collar 266 is performed. (See FIG. 5B and FIG. 10). In another modification, a notch may be provided only in a part in the axial direction (for example, an intermediate portion in the axial direction), and the suction force of the solenoid may be biased to one side.

  In addition, this invention is not limited to the said embodiment and modification, A component can be deform | transformed and embodied in the range which does not deviate from a summary. Various inventions may be formed by appropriately combining a plurality of constituent elements disclosed in the above embodiments and modifications. Moreover, you may delete some components from all the components shown by the said embodiment and modification.

  DESCRIPTION OF SYMBOLS 1 Control valve, 2 Valve body, 3 Solenoid, 5 Body, 10, 12, 14 port, 16 Valve seat formation member, 18 Valve hole, 20 Valve chamber, 22 Valve seat, 24 Valve body, 28 Actuation chamber, 34 Actuation rod , 44 filter member, 46, 48 mesh, 50 core, 54 plunger, 68 shaft, 101 compressor, 110 suction chamber, 114 discharge chamber, 116 crank chamber, 224 valve body, 234 actuating rod, 254 plunger, 266 collar.

Claims (3)

Control for variable capacity compressor that changes the discharge capacity of the variable capacity compressor that compresses the refrigerant introduced into the suction chamber and discharges it from the discharge chamber by adjusting the flow rate of the refrigerant introduced from the discharge chamber into the crank chamber In the valve
A discharge chamber communication port communicating with the discharge chamber, a crank chamber communication port communicating with the crank chamber, a suction chamber communication port communicating with the suction chamber, and the discharge chamber communication port and the crank chamber communication port are connected. A body having a valve hole provided in the passage;
A valve body that opens and closes the valve portion by attaching to and detaching from a valve seat provided at an opening end of the valve hole;
A solenoid that is provided in the body and generates a solenoid force for driving the valve body in a valve closing direction in accordance with a supplied current amount;
A spring capable of applying a biasing force in the valve opening direction against the solenoid force to the valve body;
A transmission rod that is slidably supported in the axial direction in the body and transmits the solenoid force to the valve body;
With
The discharge chamber communication port, the crank chamber communication port, and the suction chamber communication port are provided in order from one end side of the body, and the solenoid is provided on the other end side of the body,
The valve body is configured to operate autonomously so that the differential pressure between the discharge pressure of the discharge chamber and the suction pressure of the suction chamber is maintained at a set differential pressure corresponding to a supply current value to the solenoid. ,
While the valve seat is constituted by a surface perpendicular to the axis of the valve hole, the valve body comprises a flat valve attached to and detached from the valve seat on a flat surface perpendicular to the axis,
Upon opening from the closed state in energized state to the solenoid, the pressure force of the crank chamber acting on the valve body, Ri Na largely in the closing direction than when the valve is closed,
The solenoid is
A non-magnetic sleeve fixed to the body;
A core fixed coaxially to the sleeve;
A plunger accommodated in the sleeve and disposed opposite to the core in the axial direction and capable of being integrally displaced in the axial direction with the transmission rod;
Including
The body includes a valve chamber formed between the valve hole and the crank chamber communication port, a working chamber that communicates the inside of the sleeve and the suction chamber communication port, and the valve chamber and the working chamber. A partition wall and a guide hole provided in the partition wall;
The valve body is disposed in the valve chamber;
The transmission rod is slidably supported in the guide hole, one end side is connected to the valve body in the valve chamber, and the other end side is connected to the solenoid.
A control valve for a variable capacity compressor , wherein a seal part diameter in the valve hole of the valve body is larger than a sliding part diameter in the guide hole of the transmission rod .   2. The control valve for a variable capacity compressor according to claim 1, which is applied to a refrigeration cycle in which a refrigeration action is performed in a supercritical region exceeding a critical temperature of the refrigerant. The control valve for a variable capacity compressor according to claim 1 , wherein the core and the plunger are made of electromagnetic soft iron.

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