JP4779094B2 - Control valve for variable capacity compressor - Google Patents

Description

  The present invention relates to a control valve for a variable capacity compressor, and more particularly to a control valve for a variable capacity compressor that is suitable for controlling the discharge capacity of a variable capacity compressor that constitutes the refrigeration cycle of an automotive air conditioner.

  In general, an air conditioner for an automobile compresses the refrigerant flowing through the refrigeration cycle and discharges it as a high-temperature / high-pressure gas refrigerant, a condenser that condenses the gas refrigerant, and adiabatic expansion of the condensed liquid refrigerant. And an expansion device that converts the refrigerant into a low-temperature and low-pressure refrigerant, an evaporator that exchanges heat with the air in the vehicle interior by evaporating the refrigerant, and the like. The refrigerant evaporated in the evaporator is returned to the compressor and circulates in the refrigeration cycle.

  Since this compressor uses an engine whose rotational speed varies depending on the running state of the vehicle as a drive source, it cannot perform rotational speed control. Therefore, in order to obtain an appropriate cooling capacity regardless of the engine speed, a variable capacity compressor capable of varying the refrigerant discharge capacity is used.

  In such a variable capacity compressor, a compression piston is coupled to a swing plate attached to a shaft that is rotationally driven by an engine. The refrigerant discharge amount is adjusted by changing the stroke of the piston by changing the angle of the swing plate. The angle of the rocking 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 is controlled by a variable displacement compressor control valve provided between the discharge chamber and the crank chamber of the variable displacement compressor or between the crank chamber and the suction chamber.

  As such a control valve for a variable capacity compressor, for example, the amount of refrigerant introduced into the crank chamber is controlled in accordance with the pressure difference (Pd−Ps) between the discharge pressure Pd and the suction pressure Ps, and the pressure in the crank chamber (hereinafter referred to as “pressure”) Some control the Pc (referred to as “crank pressure”) (see, for example, Patent Document 1).

  This variable displacement compressor control valve communicates or closes the passage between the discharge chamber and the crank chamber so as to keep the differential pressure (Pd−Ps) between the discharge pressure Pd and the suction pressure Ps at the set differential pressure. The valve part is controlled to open and close and includes a solenoid that generates a driving force in the opening and closing direction with respect to the internal valve body. The set differential pressure can be changed by an external current supplied to the solenoid. When the refrigerant capacity increases and the differential pressure (Pd−Ps) becomes larger than the set differential pressure, the valve opening increases and the crank pressure Pc increases. As a result, the inclination angle of the swinging plate, and thus the stroke of the piston, becomes smaller, the discharge capacity becomes smaller, and the differential pressure (Pd−Ps) becomes smaller and changes so as to approach the set differential pressure. On the other hand, when the refrigerant capacity decreases and the differential pressure (Pd−Ps) becomes smaller than the set differential pressure, the valve opening becomes small and the crank pressure Pc decreases. As a result, the tilt angle of the swinging plate, and thus the stroke of the piston increases, the discharge capacity increases, and the differential pressure (Pd−Ps) increases and changes so as to approach the set differential pressure.

  Therefore, by adjusting this set differential pressure, the differential pressure (Pd−Ps) between the discharge pressure Pd and the suction pressure Ps can be controlled to a desired differential pressure, and the discharge capacity of the refrigerant from the variable capacity compressor Can be adjusted appropriately.

In addition, according to such a control valve for a variable capacity compressor, autonomous control is performed in which the valve opening changes so that the differential pressure (Pd−Ps) becomes the set differential pressure, and the discharge pressure Pd itself is controlled. Since the volume control based on the size is performed, there is also an advantage that the response is good for changing the discharge volume.
JP 2001-132650 A (FIG. 4)

  By the way, when the variable capacity compressor is started in the refrigeration cycle as described above, the differential pressure (Pd−Ps) between the discharge pressure Pd and the suction pressure Ps is set from almost zero by the variable capacity compressor control valve. A so-called soft start that gradually changes to the differential pressure is performed. FIG. 29 is an explanatory diagram showing changes in discharge pressure and suction pressure since the start of the conventional variable capacity compressor. In the figure, the horizontal axis represents the elapsed time t from the start, and the vertical axis represents the discharge pressure Pd and the suction pressure Ps. Also, the alternate long and short dash line in the figure represents the change in the discharge pressure Pd, and the solid line represents the change in the suction pressure Ps.

  That is, when the solenoid of the control valve for the variable capacity compressor is not energized, that is, in the minimum capacity operation where the function of the variable capacity compressor is substantially stopped, the pressure difference between the discharge pressure Pd and the suction pressure Ps ( Pd−Ps) is almost zero. At this time, as shown in the figure, the discharge pressure Pd and the suction pressure Ps are substantially the same pressure.

  When the solenoid is energized and the variable capacity compressor is started, the differential pressure (Pd−Ps) gradually increases and approaches the set differential pressure by adjusting the energization amount. The set differential pressure is adjusted by changing the amount of current supplied to the solenoid by a control device installed outside the control valve for the variable capacity compressor based on various external information.

  However, if the differential pressure (Pd−Ps) increases and the suction pressure Ps decreases excessively, for example, as shown by the broken line in the figure in order to increase the cooling capacity, the temperature of the evaporator proportional to this also decreases. In other words, the evaporator may freeze due to excessive cooling, and the cooling capacity may be significantly reduced. On the other hand, the autonomous control itself that makes the differential pressure (Pd−Ps) as described above does not hold the suction pressure Ps above a certain level. In other words, simply controlling the differential pressure (Pd−Ps) to the set differential pressure has no effect of setting the suction pressure Ps to a predetermined value or more, and the suction pressure Ps decreases while the differential pressure (Pd−Ps) remains constant. And overcooling may occur.

  Therefore, normally, the outlet temperature of the evaporator is detected and fed back to the control device. When the outlet temperature of the evaporator becomes lower than a predetermined reference value, the control device adjusts the suction pressure Ps so as not to decrease too much by controlling the energization amount to the solenoid to reduce the set differential pressure. . As a result, the discharge pressure Pd and the suction pressure Ps are changed so as to approach the set differential pressure as indicated by the one-dot chain line and the solid line in the figure, respectively, and the evaporator is prevented from freezing. Note that the two-dot chain line in the figure represents the pressure value Pmin corresponding to the reference value of the outlet temperature of the evaporator.

  However, when feedback control is performed by constantly monitoring the outlet temperature of the evaporator as described above, the suction pressure Ps repeatedly fluctuates relatively near a pressure value corresponding to the reference value of the outlet temperature. For this reason, from the viewpoint of control stability and responsiveness, it is preferable that the characteristic that the suction pressure Ps is maintained at or above the pressure value Pmin is obtained autonomously.

  It can be said that such a problem similarly exists in a control valve for a variable displacement compressor that employs a control system that maintains a differential pressure between two predetermined points of a refrigeration cycle at a set differential pressure. For example, the pressure difference between the discharge chamber outlet pressure (Pdh) of the variable capacity compressor and the variable capacity compressor outlet pressure (Pdl) becomes the set differential pressure, and the refrigerant discharged from the variable capacity compressor The control valve for a variable capacity compressor that controls the flow rate to be constant has the same problem.

  The present invention has been made in view of such problems, and has a simple configuration in a control valve for a variable capacity compressor that performs capacity control based on a differential pressure between two points of a refrigeration cycle of an automotive air conditioner. It aims at enabling freezing etc. of an evaporator to be prevented autonomously.

  In order to solve the above problems, a control valve for a variable capacity compressor according to an aspect of the present invention introduces a differential pressure between two predetermined points of a refrigeration cycle from a discharge chamber to a crank chamber so as to maintain a set differential pressure. The refrigerant flow rate is controlled to change the refrigerant discharge capacity from the variable capacity compressor. The control valve for the variable capacity compressor is arranged so as to be in contact with or separated from a body having a refrigerant passage formed therein, and a valve hole forming a refrigerant passage for communicating the discharge chamber and the crank chamber. The valve body to be operated, the shaft for transmitting the axial force to the valve body, and the solenoid force in the valve closing direction corresponding to the set differential pressure is applied to the shaft in the axial direction, and the valve body is moved in the opening / closing direction of the valve portion. A pressure chamber that is composed of a solenoid to be operated, an internal space surrounded by the body and the solenoid, and communicates with the suction chamber or the crank chamber to introduce any pressure, and is provided in the body or integrally with the body. A pressure sensing unit that senses the pressure in the chamber and generates a force in a direction to reduce the solenoid force when the pressure in the pressure chamber becomes lower than a set pressure.

  Here, the “differential pressure between two predetermined points” may be, for example, a differential pressure between the discharge pressure in the discharge chamber and the suction pressure in the suction chamber. In that case, the pressure chamber may be configured to communicate with the suction chamber and introduce suction pressure. Alternatively, the “differential pressure between two predetermined points” may be, for example, a differential pressure between the outlet pressure of the discharge chamber and the outlet pressure of the variable capacity compressor. In that case, the pressure chamber may communicate with the crank chamber and introduce the crank pressure.

  According to this aspect, the original capacity control for maintaining the differential pressure between the two points at the set differential pressure is performed, while the pressure in the pressure chamber is monitored, and when the pressure in the pressure chamber becomes lower than the set pressure, The pressure unit generates a force in a direction that reduces the solenoid force.

  That is, when the pressure chamber communicates with the suction chamber, the pressure sensing unit senses the suction pressure. Since the suction pressure is approximately proportional to the outlet temperature of the evaporator of the refrigeration cycle, the lower the suction pressure, the lower the outlet temperature of the evaporator. In this way, when the suction pressure is lower than the set pressure, by applying a force in the direction to reduce the solenoid force, the valve section can be easily opened, so that the discharge capacity of the variable capacity compressor is reduced and excessive. Cooling can be prevented.

  In addition, when the pressure chamber communicates with the crank chamber, the pressure sensing unit senses the crank pressure. In general, the crank pressure and the suction pressure do not change greatly. Therefore, if the crank pressure is low, the outlet temperature of the evaporator is low. In this way, when the crank pressure becomes lower than the set pressure, the solenoid force is reduced to make it easier to open the valve portion, thereby reducing the discharge capacity of the variable capacity compressor and preventing excessive cooling. .

  This capacity control is autonomously performed when the pressure sensing unit senses the pressure in the pressure chamber, so that the evaporator can be effectively prevented from freezing. In addition, since the pressure sensitive part is provided in the body or integrally provided in the body, the control valve for the variable capacity compressor having such control characteristics can be realized with a simple configuration.

  Another aspect of the present invention is also a control valve for a variable capacity compressor. The control valve for the variable capacity compressor controls the flow rate of the refrigerant introduced from the discharge chamber of the variable capacity compressor into the crank chamber, thereby changing the discharge capacity of the variable capacity compressor. The control valve for the variable capacity compressor is arranged so as to be in contact with or separated from a body having a refrigerant passage formed therein, and a valve hole forming a refrigerant passage for communicating the discharge chamber and the crank chamber. And a shaft for transmitting axial force to the valve body, a solenoid capable of applying a solenoid force in the valve closing direction of the valve portion to the shaft, and operating the valve body in the opening and closing direction of the valve portion; A pressure chamber that communicates with a suction chamber or a crank chamber of the variable capacity compressor and introduces any pressure, and is provided in the body or integrally with the body to sense the pressure of the pressure chamber, and the pressure chamber And a pressure-sensitive part that generates a force in a direction to reduce the solenoid force when the pressure of the pressure becomes lower than the set pressure.

  Also in this aspect, when the suction pressure or the crank pressure becomes lower than the set pressure, the valve portion can be easily opened by applying a force in a direction to reduce the solenoid force, so that the discharge capacity of the variable capacity compressor can be reduced. Is reduced and overcooling is prevented.

  According to the control valve for a variable capacity compressor of the present invention, it is possible to autonomously prevent the evaporator from being frozen and the like with a simple configuration.

  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.

[First Embodiment]
FIG. 1 is a cross-sectional view illustrating a configuration of a variable displacement compressor control valve according to a first embodiment.

  The variable displacement compressor control valve 1 is introduced from the discharge chamber into the crank chamber so as to maintain a differential pressure (Pd−Ps) between a discharge pressure Pd and a suction pressure Ps of a variable displacement compressor (not shown). It is configured as a so-called Pd-Ps valve that controls the refrigerant flow rate.

  The control valve 1 for the variable capacity compressor has a valve body 2 that opens and closes a refrigerant passage for introducing a part of the discharged refrigerant into the crank chamber, and adjusts the opening of the valve portion of the valve body 2 to the crank chamber. A solenoid 3 for controlling the flow rate of the refrigerant to be introduced is integrally assembled via a connecting member 4.

  The valve body 2 includes a stepped cylindrical body 5, a valve mechanism provided in the body 5, a pressure-sensitive member 6 described later that affects the operation of the valve mechanism, and the like.

  In the upper part of the body 5, a port 11 that communicates with the discharge chamber of the variable capacity compressor and receives the discharge pressure Pd is provided. The port 11 communicates internally with a port 13 provided on the side of the body 5. The port 13 communicates with a crank chamber of the variable capacity compressor and derives a controlled crank pressure Pc in the crank chamber.

  A cylindrical valve seat forming member 14 is press-fitted into a refrigerant passage communicating the port 11 and the port 13, and a valve hole 15 is formed by the internal passage. A valve seat 16 is formed by the end face of the valve seat forming member 14 on the crank chamber side.

  Further, a valve body 18 composed of one end portion of a long operating rod 17 is disposed so as to be able to contact and separate from the valve seat 16 from the crank chamber side. The valve body 18 is slidably supported by a guide hole 19 provided in the center of the body 5. The valve body 18 is disposed in the pressure chamber 21 communicating with the crank chamber on the downstream side of the valve hole 15, and opens and closes the valve hole 15 by attaching and detaching the outer peripheral edge of the distal end surface to the valve seat 16.

  A port 22 that communicates with the suction chamber of the variable capacity compressor and receives the suction pressure Ps is formed at a position spaced downward from the port 13 on the side of the body 5, and has a predetermined depth provided at the center of the lower end of the body 5. It communicates with the opening hole 24. An internal space in which the opening 24 surrounded by the body 5 and the solenoid 3 is located forms a pressure chamber 25 into which the suction pressure Ps is introduced. The suction pressure Ps is also introduced into the solenoid 3. In the pressure chamber 25, a pressure-sensitive member 6 is disposed as a pressure-sensitive part that operates by sensing the suction pressure Ps. A spring 26 that biases the pressure sensitive member 6 toward the solenoid 3 is interposed between the pressure sensitive member 6 and the body 5. Details of the pressure-sensitive member 6 will be described later.

  The body 5 is connected to the solenoid 3 via a stepped cylindrical connecting member 4. The upper end portion of the connection member 4 is press-fitted into the opening hole 24 of the body 5.

  On the other hand, the solenoid 3 generates a magnetic circuit by a case 31 that also functions as a yoke, a core 32 that is fixed in the case 31, a plunger 33 that is arranged to face the core 32 in the axial direction, and an externally supplied current. The electromagnetic coil 34 is provided. The case 31 is caulked and joined at its upper end to the lower end of the connecting member 4.

  The upper end portion of the core 32 is press-fitted into the inner peripheral surface of the connection member 4. The core 32 is provided with an insertion hole 35 penetrating the center in the axial direction, and the shaft 20 for transmitting the solenoid force to the valve body 18 is inserted therethrough. Since a predetermined clearance is provided between the upper end portion of the core 32 and the shaft 20, the suction pressure Ps in the pressure chamber 25 is also introduced into the solenoid 3 through this clearance. ing.

  Further, a bottomed sleeve 36 having a closed lower end is externally inserted into the core 32. In the bottomed sleeve 36, the plunger 33 is disposed below the core 32 so as to advance and retract in the axial direction. The bottomed sleeve 36 is press-fitted into the lower half of the connecting member 4 at the upper end. A bearing member 37 is fixedly disposed at the lower end of the bottomed sleeve 36, and the lower end of the shaft 20 is slidably supported.

  The shaft 20 is provided with a small-diameter portion 38 having a smaller diameter at the lower portion thereof, and a plunger 33 is externally inserted from the vicinity of the base end portion of the small-diameter portion 38. The tip of the small diameter portion 38 is slidably inserted into the bearing member 37.

  The plunger 33 has a stepped cylindrical shape, and the shaft 20 is inserted through a stepped circular hole 42 formed at the upper center thereof. A spring 46 is interposed between the core 32 and the plunger 33 to urge the plunger 33 in the direction of separating the plunger 33 from the core 32. A spring 47 is interposed between the plunger 33 and the bearing member 37 to urge the plunger 33 in the direction in which the plunger 33 approaches the core 32. The spring loads of the springs 46 and 47 can be adjusted by pressing the bottom surface of the bottomed sleeve 36 from the outside to deform it and displacing the bearing member 37.

  Next, the configuration and operation around the pressure-sensitive member will be described in detail. 2-5 is explanatory drawing showing operation | movement of the control valve for variable capacity compressors, and is equivalent to the partial expanded sectional view corresponding to the upper half part of FIG. FIG. 2 shows a state where the differential pressure (Pd−Ps) is smaller than the set differential pressure and the suction pressure Ps is larger than the set pressure. FIG. 3 shows a state where the differential pressure (Pd−Ps) is greater than the set differential pressure and the suction pressure Ps is greater than the set pressure. FIG. 4 shows a transitional state in which the suction pressure Ps is becoming smaller than the set pressure during the control of the differential pressure (Pd−Ps). Further, FIG. 5 shows a state when the suction pressure Ps is smaller than the set pressure during the control of the differential pressure (Pd−Ps).

  As shown in FIG. 2, the pressure-sensitive member 6 includes a hollow housing 51 interposed between the operating rod 17 and the shaft 20 and supported so as to be displaceable in the opening / closing direction of the valve portion, and a sealed space in the housing. A diaphragm 52 as a flexible member disposed so as to be divided into S1 and an open space S2, a spring 53 as an elastic member disposed in the sealed space S1, and a housing accommodated in the open space S2. And a reaction force transmission member 55 having three leg portions 54 penetrating through 51 and extending upward. The open space S2 communicates with the pressure chamber 25.

  The housing 51 is composed of a first housing 56 and a second housing 57 each having a lid shape made of stainless steel, and these openings are brought into contact with each other so that the outer edge portion of the diaphragm 52 made of a thin metal plate is sandwiched between the opening portions. The housing 51 is formed in a container shape by performing outer periphery welding along the joint portion with the diaphragm 52 sandwiched between the first housing 56 and the second housing 57. Since this welding is performed in a vacuum atmosphere, the sealed space S1 is in a vacuum state, but the sealed space S1 may be filled with air or the like.

  The center of the bottom of the first housing 56 opposite to the diaphragm 52 is formed flat, and supports the lower end of the operating rod 17 (that is, the end opposite to the valve body 18) from below. Further, in this flat portion, through holes 61 are formed at three places surrounding the actuating rod 17, and each of the three leg portions 54 of the reaction force transmission member 55 is inserted and protruded toward the valve body 18 side. ing. The inside of the first housing 56 communicates with the pressure chamber 25 through the through hole 61, and the suction pressure Ps is introduced. Therefore, the diaphragm 52 detects the suction pressure Ps and expands and contracts in the opening / closing direction of the valve portion.

  On the other hand, a concave shaft coupling portion 62 is formed by press molding at the bottom center of the second housing 57 opposite to the diaphragm 52, and the upper end portion of the shaft 20 is loosely fitted. In this way, the housing 51 is interposed so as to be sandwiched between the operating rod 17 and the shaft 20, and is supported so as to be displaceable in the opening / closing direction of the valve portion.

  A disk-shaped disc 63 made of stainless steel is welded to the surface of the diaphragm 52 on the second housing 57 side, and a spring 53 for adjusting a set load is interposed between the disc 63 and the bottom of the second housing 57. Has been. In each central portion of the diaphragm 52 and the disk 63, an uneven shape that fits to each other for centering the disk 63 is provided.

  A disc-shaped reaction force transmission member 55 made of stainless steel is welded to the center of the surface of the diaphragm 52 on the first housing 56 side. At three locations on the outer periphery of the reaction force transmission member 55, leg portions 54 are provided that extend upward (that is, on the side opposite to the diaphragm 52) and project from the through hole 61 of the first housing 56. These leg portions 54 can be attached to and detached from the surface of the body 5 facing the shaft 20, that is, the bottom surface 64 of the opening hole 24 by the operation of the pressure-sensitive member 6. A spring 26 that biases the pressure-sensitive member 6 in the valve opening direction is interposed between the first housing 56 and the body 5.

  Here, when the suction pressure Ps in the pressure chamber 25 becomes lower than a predetermined set pressure Pset, the diaphragm 52 is deformed to the valve body 18 side, and the leg portion 54 of the reaction force transmission member 55 presses the bottom surface 64. As a result, the reaction force acting on the reaction force transmission member 55 is transmitted to the shaft 20 via the diaphragm 52, the disk 63, the spring 53, and the second housing 57, so that a force in a direction to reduce the solenoid force Fs acts. It has become. This set pressure Pset is basically adjusted in advance by the spring load of the spring 53, and is set as a pressure value that can prevent freezing of the evaporator from the relationship between the temperature in the evaporator and the suction pressure Ps.

  In the above configuration, as shown in FIG. 1, the effective pressure receiving area (that is, the cross-sectional area of the valve hole 15) A of the valve body 18 and the effective pressure receiving area of the pressure sensitive member 6 (that is, the effective pressure receiving area of the diaphragm 52) B Assuming that the solenoid force Fs by the solenoid 3, the force F 1 by the spring 53 of the pressure-sensitive member 6, and the resultant force F 2 in the valve opening direction by the springs 26, 46, 47, the force of the following formulas (1) and (2) There is a balanced relationship.

1) When Ps> Pset A (Pd−Ps) = Fs−F2 (1)
2) When Ps <Pset A (Pd−Ps) + F2−Fs−B · Ps + F1 = 0
Here, since it is controlled so that Ps = Pset,
Pset = (A · Pd + F2 + F1-Fs) / (A + B) (2)
That is, 1) When the suction pressure Ps> the set pressure Pset, the leg portion 54 is separated from the bottom surface 64 of the body 5 as shown in FIGS. Therefore, as shown in the above equation (1), the variable displacement compressor control valve 1 is a so-called Pd-Ps valve that maintains the differential pressure (Pd-Ps) between the discharge pressure Pd and the suction pressure Ps at a set differential pressure. Works as. In the above formula (1), the resultant force F2 of the spring is constant, so that the set differential pressure can be changed by adjusting the solenoid force Fs by changing the value of the current supplied to the solenoid 3. FIG. 3 shows a state where the valve portion is slightly opened because the differential pressure (Pd−Ps) is larger than the set differential pressure.

  On the other hand, 2) When the suction pressure Ps <the set pressure Pset, the leg portion 54 contacts and presses the bottom surface 64 of the body 5 as shown in FIGS. FIG. 4 shows a transitional state where the suction pressure Ps drops below the set pressure Pset and reaches the state of FIG. As shown in FIG. 5, when the leg portion 54 pushes the body 5, the reaction force is transmitted to the shaft 20 through the diaphragm 52, the disk 63, the spring 53 and the second housing 57, and the solenoid force Fs is transmitted. The force of the direction to reduce acts. As a result, the valve body 18 moves in the valve opening direction as shown in the figure, the crank pressure Pc increases, the discharge capacity of the variable capacity compressor is reduced, and as a result, the suction pressure Ps increases. That is, the variable displacement compressor control valve 1 also operates as a so-called Ps valve that holds the suction pressure Ps at the set pressure Pset. As shown in the above equation (2), the variable displacement compressor control valve 1 can change the set pressure Pset by adjusting the solenoid force Fs by changing the value of the current supplied to the solenoid 3.

  FIG. 6 is an explanatory diagram showing changes in the discharge pressure and the suction pressure since the start of the variable capacity compressor. In the figure, the horizontal axis represents the elapsed time t from the start, and the vertical axis represents the discharge pressure Pd and the suction pressure Ps. Also, the alternate long and short dash line in the figure represents the change in the discharge pressure Pd, and the solid line represents the change in the suction pressure Ps.

  When the solenoid 3 of the control valve 1 for the variable capacity compressor is not energized, that is, in the minimum capacity operation where the function of the variable capacity compressor is substantially stopped, the pressure difference between the discharge pressure Pd and the suction pressure Ps ( Pd−Ps) is almost zero. At this time, as shown in the figure, the discharge pressure Pd and the suction pressure Ps are substantially the same pressure.

  When the solenoid 3 is energized and the variable capacity compressor is started, the differential pressure (Pd−Ps) is gradually increased to approach the set differential pressure. At this time, in order to increase the cooling capacity, if the differential pressure (Pd−Ps) increases and the suction pressure Ps tends to fall below the set pressure Pset, the force in a direction to reduce the solenoid force Fs by the operation of the pressure-sensitive member 6. Act. That is, the variable capacity compressor control valve 1 operates autonomously so as to maintain the suction pressure Ps at or above the set pressure Pset. For this reason, even if the suction pressure Ps decreases, the suction pressure Ps does not decrease greatly as represented by the dotted line in the figure, and is held near the set pressure Pset.

  As described above, the variable displacement compressor control valve 1 functions as a Pd-Ps valve that holds the differential pressure (Pd-Ps) at the set differential pressure during normal times when the suction pressure Ps is higher than the set pressure Pset. When the suction pressure Ps becomes lower than the set pressure Pset, it functions as a Ps sensing valve that holds the suction pressure Ps at the set pressure Pset. That is, the control valve 1 for the variable displacement compressor basically functions as a Pd-Ps valve for controlling the differential pressure (Pd-Ps), while it functions as a Ps sensing valve when the suction pressure Ps is too low, and excessive cooling is performed. Is preventing.

Next, the overall operation of the variable displacement compressor control valve will be described.
In the variable displacement compressor control valve 1 shown in FIG. 1, the spring load in the valve opening direction by the spring 26 and the spring 46 is set larger than the spring load in the valve closing direction by the spring 47. For this reason, when the solenoid 3 is not energized, the valve body 18 is separated from the valve seat 16 by the discharge pressure Pd, 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 of the variable capacity compressor to the port 11 passes through the valve portion in the fully open state and flows from the port 13 to the crank chamber. Therefore, since the crank pressure Pc becomes a pressure close to the discharge pressure Pd, the variable capacity compressor performs the minimum capacity operation.

  On the other hand, when the automotive air conditioner is started or when the cooling load is maximum, the current value supplied to the solenoid 3 is maximum, and the plunger 33 is attracted to the core 32 with the maximum suction force. At this time, the operating rod 17 including the valve body 18, the pressure-sensitive member 6, the shaft 20, and the plunger 33 integrally operate in the valve closing direction, and the valve body 18 is seated on the valve seat 16. Since the crank pressure Pc is reduced by this valve closing operation, the variable capacity compressor performs maximum capacity operation.

  Here, when the current value supplied to the solenoid 3 is set to a predetermined value, the operating rod 17 including the valve body 18, the pressure-sensitive member 6, the shaft 20 and the plunger 33 operate integrally. At this time, the valve body 18 includes a spring load of the spring 26 that urges the pressure-sensitive member 6 in the valve opening direction, a spring load of the spring 46 that urges the plunger 33 in the valve opening direction, and the plunger 33 in the valve closing direction. The spring load of the spring 47 that biases the valve 33, the load of the solenoid 3 that biases the plunger 33 in the valve closing direction, the force by the discharge pressure Pd that the valve body 18 receives in the valve opening direction, and the valve body 18 It stops at the valve lift position where the force by the suction pressure Ps received in the valve closing direction is balanced.

  In this balanced state, when the rotational speed of the variable capacity compressor increases with the engine speed and the discharge capacity increases, the discharge pressure Pd increases and the suction pressure Ps decreases. As a result, the differential pressure (Pd−Ps) increases and a force in the valve opening direction acts on the valve body 18, and the valve body 18 further lifts and increases the flow rate of the refrigerant flowing from the discharge chamber to the crank chamber. As a result, the crank pressure Pc increases, and the variable capacity compressor 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.

  When the suction pressure Ps becomes lower than the set pressure Pset during the operation of the refrigeration cycle by the operation of the variable capacity compressor as described above, the leg portion 54 of the reaction force transmission member 55 constituting the pressure-sensitive member 6 becomes the body. The reaction force acts on the shaft 20 in a direction to reduce the solenoid force. Thereby, the force in the valve closing direction on the valve body 18 is reduced, and the valve portion is opened. As a result, the crank pressure Pc increases and the discharge capacity is reduced. As a result, the suction pressure Ps is maintained at the set pressure Pset, and excessive cooling is prevented.

  As described above, according to the variable displacement compressor control valve 1 of the present embodiment, the original displacement control that maintains the differential pressure (Pd−Ps) between the discharge pressure Pd and the suction pressure Ps at the set differential pressure. On the other hand, the suction pressure Ps is monitored, and when the suction pressure Ps becomes lower than the set pressure Pset, the pressure-sensitive member 6 generates a force in a direction to reduce the solenoid force. Since the suction pressure Ps is substantially proportional to the outlet temperature of the evaporator of the refrigeration cycle, the lower the suction pressure Ps, the lower the outlet temperature of the evaporator. In this way, when the suction pressure Ps becomes lower than the set pressure Pset, the solenoid force is reduced to facilitate the opening of the valve portion, thereby reducing the discharge capacity of the variable capacity compressor and preventing excessive cooling. Can do.

  This capacity control is autonomously performed when the pressure-sensitive member 6 senses the suction pressure Ps of the pressure chamber 25, so that the evaporator can be effectively prevented from freezing. Further, since the pressure-sensitive member 6 is provided in the body 5, the variable displacement compressor control valve having both the control characteristics of the Pd-Ps valve and the Ps sensing valve can be realized with a simple configuration.

[Second Embodiment]
Next, a second embodiment of the present invention will be described. The control valve for a variable capacity compressor according to the present embodiment is characterized in that the valve body is constituted by a part of the housing of the pressure-sensitive member, the pressure-sensitive member operates by sensing the crank pressure Pc, and the like. Although different from the first embodiment, there are many parts in common with the configuration shown in the first embodiment. For this reason, about the component similar to the said 1st Embodiment, the same code | symbol is attached | subjected etc., and the description is abbreviate | omitted suitably. FIG. 7 is a cross-sectional view showing a configuration of a control valve for a variable capacity compressor according to a second embodiment. FIG. 8 is a partial enlarged cross-sectional view corresponding to the upper half of FIG.

  As shown in FIG. 7, the control valve 201 for the variable capacity compressor discharges so as to keep the differential pressure (Pd−Pc) between the discharge pressure Pd and the crank pressure Pc of a variable capacity compressor (not shown) at the set differential pressure. The Pd-Pc valve is configured to control the flow rate of the refrigerant introduced from the chamber into the crank chamber.

  The control valve 201 for the variable capacity compressor has a valve body 202 that opens and closes a refrigerant passage for introducing part of the discharged refrigerant into the crank chamber, and adjusts the opening of the valve portion of the valve body 202 to the crank chamber. A solenoid 3 for controlling the flow rate of the refrigerant to be introduced is integrally assembled via a connecting member 4.

  The body 205 of the valve body 202 is not provided with a port for introducing the suction pressure Ps, and is formed more compactly than the body 5 of the first embodiment. A port 11 that receives the discharge pressure Pd is provided in the upper portion of the body 205, and the port 11 communicates with a port 13 provided in a side portion of the body 205 inside. A valve hole 15 is formed by a refrigerant passage communicating between the port 11 and the port 13, and a valve seat 16 is formed by an end face on the crank chamber side. The port 13 communicates with an opening hole 24 having a predetermined depth provided in the center of the lower end of the body 205.

  An internal space surrounded by the body 205 and the solenoid 3 in which the opening 24 is located forms a pressure chamber 225 into which the crank pressure Pc is introduced. The crank pressure Pc is also introduced into the solenoid 3. In the pressure chamber 225, a pressure-sensitive member 206 is disposed as a pressure-sensitive portion that operates by sensing the crank pressure Pc. And the valve body 218 which contacts / separates from the crank chamber side by the valve seat 16 is comprised by the upper-end center part of this pressure-sensitive member 206. FIG. A spring 226 that urges the pressure sensitive member 206 in the valve opening direction is interposed between the pressure sensitive member 206 and the body 5.

  As shown in FIG. 8, the pressure-sensitive member 206 has substantially the same configuration as that of the pressure-sensitive member 6 of the first embodiment, but is a flat portion at the center of the upper end of the first housing 256 that constitutes the housing 251. However, the valve body 218 attached to and detached from the valve seat 16 is integrally configured.

  In the variable displacement compressor control valve 201, when the crank pressure Pc becomes lower than the set pressure as a result of the reduction of the suction pressure Ps, the three legs 54 of the reaction force transmission member 55 come into contact with the bottom surface 64 of the body 205. Press this. The reaction force by which the leg 54 pushes the body 205 is transmitted to the shaft 20 through the diaphragm 52, the disk 63, the spring 53, and the second housing 57, and a force in a direction to reduce the solenoid force Fs acts. As a result, the valve body 18 operates in the valve opening direction, the crank pressure Pc increases, the discharge capacity of the variable capacity compressor is reduced, and as a result, the suction pressure Ps increases. This set pressure is basically adjusted in advance by the spring load of the spring 53, and the evaporator is frozen from the relationship between the temperature in the evaporator and the suction pressure Ps, and the relationship between the suction pressure Ps and the crank pressure Pc. It is set as a pressure value that can prevent this.

  According to the control valve 201 for the variable displacement compressor of the present embodiment, the original displacement control for maintaining the differential pressure (Pd−Pc) between the discharge pressure Pd and the crank pressure Pc at the set differential pressure is performed. When the pressure Pc is monitored and the crank pressure Pc becomes lower than the set pressure, the pressure-sensitive member 206 generates a force in a direction that reduces the solenoid force. As described above, as a result of the reduction of the suction pressure Ps, when the crank pressure Pc becomes lower than the set pressure, the solenoid force is reduced to facilitate the opening of the valve portion, thereby reducing the discharge capacity of the variable capacity compressor. Overcooling can be prevented.

  This capacity control is autonomously performed when the pressure-sensitive member 206 senses the crank pressure Pc of the pressure chamber 225, so that the evaporator can be effectively prevented from freezing. Further, since the pressure-sensitive member 206 is provided in the body 205, a variable displacement compressor control valve having such control characteristics of the Pd-Pc valve and the Pc sensing valve can be realized with a simple configuration.

[Third Embodiment]
Next, a third embodiment of the present invention will be described. The control valve for a variable capacity compressor according to the present embodiment is largely different from that of the first embodiment in that the pressure-sensitive member is provided not at the inside of the body but at the end portion. There are also many parts in common with the configuration shown in the form. For this reason, about the component similar to the said 1st Embodiment, the same code | symbol is attached | subjected etc., and the description is abbreviate | omitted suitably. FIG. 9 is a cross-sectional view illustrating a configuration of a control valve for a variable displacement compressor according to a third embodiment. 10 is a partially enlarged cross-sectional view corresponding to the upper half of FIG.

  As shown in FIG. 9, the variable displacement compressor control valve 301 operates so as to keep the differential pressure (Pd−Ps) between the discharge pressure Pd and the suction pressure Ps of a variable displacement compressor (not shown) at the set differential pressure. It is configured as a Pd-Ps valve.

  In the variable displacement compressor control valve 301, a port 11 communicating with the discharge chamber from above, a port 13 communicating with the crank chamber, and a port 22 communicating with the suction chamber are provided on the side of the body 305 of the valve body 302. It has been. The port 22 communicates with an opening hole 24 having a predetermined depth provided in the center of the lower end of the body 305. An internal space in which the opening hole 24 surrounded by the body 305 and the solenoid 3 is located forms a pressure chamber 325 into which the suction pressure Ps is introduced.

  A cylindrical valve seat forming member 314 is press-fitted into the refrigerant passage communicating the port 11 and the port 13, and a valve hole 15 is formed by the lower half portion of the internal passage. A valve seat 16 is formed by the inner peripheral edge. The valve seat forming member 314 is provided with a guide hole 315 that passes through the valve seat forming member 314 in the axial direction, and a transmission rod 316 described in detail later is slidably inserted therethrough.

  The body 305 is provided with a pressure sensitive member 306 so as to seal the upper end opening. The pressure-sensitive member 306 is similar to the pressure-sensitive member 306 of the first embodiment, and is fixed to the body 305 with the similar configuration turned upside down. The body 305 is formed with a communication passage 317 that extends in the vertical direction at a position slightly away from the valve seat forming member 314 and communicates the upper end opening of the body 305 and the pressure chamber 325.

  As shown in FIG. 10, the pressure-sensitive member 306 is configured such that the inside of the first housing 356 constituting the housing 351 communicates with the pressure chamber 325 via the communication path 317 so that the suction pressure Ps is introduced. It has become. A disk 355 and a transmission rod 316 are sequentially welded to the lower surface of the diaphragm 52. In the present embodiment, the disk 355 and the transmission rod 316 constitute a reducing force transmission member.

  The transmission rod 316 is slidably inserted into the guide hole 315 and its lower end extends to the vicinity of the upper end of the shaft 20. In addition, a locking portion 321 that protrudes in the radial direction is provided at the central portion of the transmission rod 316 in the axial direction. When the transmission rod 316 is locked to the inner wall of the valve seat forming member 314, its top dead center. The movement in the axial direction is regulated. A communication hole 323 that connects the port 11 and the valve hole 15 is formed in a side portion of the valve seat forming member 314.

  On the other hand, the valve body 318 is integrally formed by the upper end portion of the shaft 20. The shaft 20 is slidably supported in a guide hole 324 formed between the port 13 and the port 22 of the body 305, and the valve body 318 is disposed so as to be able to contact and separate from the valve seat 16 from the crank chamber side. ing. When the valve body 318 is opened away from the valve seat 16, the high-pressure refrigerant introduced from the port 11 through the communication hole 323 to the valve hole 15 is formed between the valve hole 15 and the transmission rod 316. It is led out to the port 13 side through the refrigerant passage.

  In the variable capacity compressor control valve 301, when the suction pressure Ps becomes smaller than the set pressure, the diaphragm 52 is displaced downward by the urging force of the spring 53, and the force is applied to the shaft via the disk 355 and the transmission rod 316. 20 is transmitted. Thereby, a force in a direction to reduce the solenoid force Fs acts, and the valve body 318 operates in the valve opening direction. As a result, the crank pressure Pc increases, the discharge capacity of the variable capacity compressor is reduced, and the suction pressure Ps increases.

  According to the control valve 301 for the variable capacity compressor of the present embodiment, the original capacity control for maintaining the differential pressure (Pd−Ps) between the discharge pressure Pd and the suction pressure Ps at the set differential pressure is performed. When the pressure Ps is monitored and the suction pressure Ps becomes lower than the set pressure, the pressure-sensitive member 306 generates a force in a direction that reduces the solenoid force. As described above, when the suction pressure Ps becomes lower than the set pressure, a force that opposes the solenoid force is applied to facilitate the opening of the valve portion, so that the discharge capacity of the variable capacity compressor is reduced and excessive cooling is prevented. Can be prevented.

  This capacity control is autonomously performed when the pressure-sensitive member 306 senses the suction pressure Ps of the pressure chamber 325, so that the evaporator can be effectively prevented from freezing. In addition, since the pressure-sensitive member 306 is provided at one end of the body 305, the variable displacement compressor control valve having both the control characteristics of the Pd-Ps valve and the Ps sensing valve can be realized with a simple configuration.

[Fourth Embodiment]
Next, a fourth embodiment of the present invention will be described. The control valve for a variable capacity compressor according to the present embodiment is largely different from that of the first embodiment in that the valve seat is a movable valve seat, but the configuration shown in the first embodiment There are many common parts. For this reason, about the component similar to the said 1st Embodiment, the same code | symbol is attached | subjected etc., and the description is abbreviate | omitted suitably. FIG. 11 is a cross-sectional view showing a configuration of a control valve for a variable capacity compressor according to a fourth embodiment. 12 is a partially enlarged cross-sectional view corresponding to the upper half of FIG.

  As shown in FIG. 11, the variable displacement compressor control valve 401 operates to keep the differential pressure (Pd−Ps) between the discharge pressure Pd and the suction pressure Ps of a variable displacement compressor (not shown) at a set differential pressure. It is configured as a Pd-Ps valve.

  In the valve main body 402 of the variable displacement compressor control valve 401, the ports 11, 13, and 22 have the same arrangement configuration as in the first embodiment. A cylindrical movable valve seat forming member 414 is inserted into an axial through hole 411 communicating with the port 11 and the port 13 in the body 405, and a valve hole 15 is formed by an internal passage thereof. A valve seat 16 is formed by the inner peripheral edge of the side end face.

  On the other hand, the port 22 communicates with the opening hole 24 at the center of the lower end of the body 405, and a pressure chamber 25 into which the suction pressure Ps is introduced is formed. In the pressure chamber 25, a pressure-sensitive member 406 is disposed as a pressure-sensitive part that operates by sensing the suction pressure Ps. Further, an operating rod 417 is disposed between the pressure sensitive member 406 and the movable valve seat forming member 414. The operating rod 417 has an upper end surface slightly larger than the valve hole 15, and a valve body 418 is formed by the upper end portion. The valve body 418 operates in the axial direction together with the operating rod 417 and is attached to and detached from the valve seat 16 to open and close the valve hole 15.

  As shown in FIG. 12, the movable valve seat forming member 414 is provided with a flange portion 415 protruding outward in the radial direction at an upper end portion thereof. On the other hand, a ring-shaped spring receiving member 416 is press-fitted into the upper end opening of the body 405. A spring 419 for biasing the movable valve seat forming member 414 downward is interposed between the spring receiving member 416 and the flange portion 415. The flange portion 415 is in the vicinity of the upper end opening of the through hole 411. The bottom dead center of the movable valve seat forming member 414 is defined and the movement in the axial direction is restricted.

  The pressure-sensitive member 406 includes a disk 421 welded to the surface of the diaphragm 52 on the open space S2 side, and a reaction force transmission member 423 mounted on the disk 421. The reaction force transmission member 423 has three leg portions on the upper and lower sides of the cylindrical main body 424 (only one on each of the upper and lower sides is shown in the figure). The main body 424 is slidably inserted into an axial guide hole 425 that connects the port 13 and the port 22. Legs 426 extending downward from the main body 424 pass through the three through holes 61 provided in the first housing 56 and are supported by the disk 421 from below. On the other hand, the leg portion 427 extending upward from the main body 424 is disposed opposite to the lower surface of the movable valve seat forming member 414, and can be attached to and detached from the lower surface of the movable valve seat forming member 414 by the upward displacement of the reaction force transmission member 423. It has become.

  In this variable displacement compressor control valve 401, when the suction pressure Ps becomes smaller than the set pressure, the diaphragm 52 is displaced upward, and the upper leg portion 427 of the reaction force transmission member 423 is moved to the movable valve seat forming member 414. This is pressed against the lower surface. As a result, the movable valve seat forming member 414 is displaced slightly upward. On the other hand, the reaction force that the leg portion 427 pushes the body 405 is transmitted to the shaft 20 via the diaphragm 52, the disk 63, the spring 53, and the second housing 57, and a force in a direction that reduces the solenoid force Fs acts. Thereby, the valve body 418 operates relatively in the valve opening direction, the crank pressure Pc increases, and the discharge capacity of the variable capacity compressor is reduced. As a result, the suction pressure Ps increases.

  According to the control valve 401 for the variable capacity compressor of the present embodiment, the original capacity control for maintaining the differential pressure (Pd−Ps) between the discharge pressure Pd and the suction pressure Ps at the set differential pressure is performed. When the pressure Ps is monitored and the suction pressure Ps becomes lower than the set pressure, the pressure-sensitive member 406 generates a force in a direction that reduces the solenoid force. As described above, when the suction pressure Ps becomes lower than the set pressure, the solenoid force is reduced to make it easier to open the valve portion, thereby reducing the discharge capacity of the variable capacity compressor and preventing excessive cooling. it can.

  This capacity control is autonomously performed when the pressure-sensitive member 406 senses the suction pressure Ps of the pressure chamber 25, so that the evaporator can be effectively prevented from freezing. Further, since the pressure-sensitive member 406 is provided inside the body 405, a variable displacement compressor control valve having both the control characteristics of the Pd-Ps valve and the Ps sensing valve can be realized with a simple configuration.

[Fifth Embodiment]
Next, a fifth embodiment of the present invention will be described. The control valve for a variable capacity compressor according to the present embodiment is largely different from that of the first embodiment in that the body is simply configured by a member formed by press-molding stainless steel or the like. There is also a part in common with the configuration shown in the form. For this reason, about the component similar to the said 1st Embodiment, the same code | symbol is attached | subjected etc., and the description is abbreviate | omitted suitably. FIG. 13: is sectional drawing which shows the structure of the control valve for variable capacity compressors which concerns on 5th Embodiment.

  The variable displacement compressor control valve 501 is a refrigerant introduced from the discharge chamber into the crank chamber so as to keep the differential pressure (Pd−Ps) between the discharge pressure Pd and the suction pressure Ps of the variable displacement compressor 500 at the set differential pressure. It is configured as a Pd-Ps valve that controls the flow rate.

  The variable capacity compressor control valve 501 adjusts the valve body 502 that opens and closes the refrigerant passage for introducing a part of the discharged refrigerant into the crank chamber, and adjusts the opening of the valve portion of the valve body 502 to the crank chamber. A solenoid 503 for controlling the flow rate of refrigerant to be introduced is integrally assembled.

  The valve body 502 includes a bottomed cylindrical body 505 obtained by press molding, a valve mechanism provided in the body 505, a pressure-sensitive member 506 that affects the operation of the valve mechanism, and the like.

  A bottomed cylindrical stopper member 511 obtained by press molding is press-fitted into the lower half of the body 505 with the bottom facing up, and a cylindrical guide member 512 is press-fitted into the upper central part. Has been. Furthermore, a bottomed cylindrical valve seat forming member 513 obtained by press molding is press-fitted into the upper end opening of the body 505.

  A valve hole 507 is provided in the center of the bottom of the valve seat forming member 513 to connect the discharge chamber of the variable capacity compressor and the crank chamber. The valve seat 508 is formed by the inner peripheral edge of the end surface on the crank chamber side. ing. Further, a refrigerant passage is formed by a gap between the guide member 512 and the valve seat forming member 513 in the body 505, and the port 13 is provided on a side portion of the body 505 corresponding to the refrigerant passage. The discharge pressure Pd introduced from the port 11 is reduced by passing through the valve portion, and a controlled crank pressure Pc is generated. This crank pressure Pc is led out to the crank chamber side through the port 13.

  Further, a valve body 518 formed of one end portion of a long operation rod 517 is disposed so as to be able to contact and separate from the valve seat 508 from the crank chamber side. The operating rod 517 is slidably supported by a guide hole 519 provided in the center of the guide member 512.

  In addition, ports 22 that communicate with the suction chamber of the variable capacity compressor and receive the suction pressure Ps are formed at corresponding positions on each side of the body 505 and the stopper member 511. The port 22 communicates with an internal space composed of a region below the guide member 512 of the body 505. An opening 521 is provided at the center of the lower end of the body 505, and the internal space communicates with the inside of the solenoid 503. This internal space surrounded by the body 505 and the solenoid 503 forms a pressure chamber 525 into which the suction pressure Ps is introduced. The suction pressure Ps is also introduced into the solenoid 503. The pressure chamber 525 is provided with a pressure-sensitive member 506 as a pressure-sensitive portion that operates by sensing the suction pressure Ps, and details thereof will be described later.

  On the other hand, the solenoid 503 generates a magnetic circuit by a case 531 also functioning as a yoke, a core 532 fixed in the case 531, a plunger 533 arranged to face the core 532 in the axial direction, and a supply current from the outside. And an electromagnetic coil 534. The valve body 502 and the solenoid 503 are connected by abutting the lower end portion of the body 505 with the upper end portion of the case 531 and fixing the joint portion by crimping the upper end portion of the core 532.

  The core 532 is provided with an insertion hole 535 that passes through the center in the axial direction, and a shaft 520 for transmitting a solenoid force to the valve body 518 is inserted therethrough. Since a predetermined clearance is provided between the upper end portion of the core 532 and the shaft 520, the suction pressure Ps in the pressure chamber 525 is also introduced into the solenoid 503 through this clearance. ing.

  Further, a bottomed sleeve 536 having a closed lower end is externally inserted into the core 532. In the bottomed sleeve 536, a plunger 533 is disposed below the core 532 so as to be able to advance and retract in the axial direction. The bottomed sleeve 536 is contracted at its lower end, and the lower end of the shaft 520 is slidably supported by the contracted tube.

  The plunger 533 has a stepped cylindrical shape and is press-fitted into the lower half of the shaft 520. Between the core 532 and the plunger 533, a spring 537 that biases the plunger 533 in the direction of separating from the core 532 is interposed. In addition, a spring 538 that biases the plunger 533 in the direction to bring it close to the core 532 is interposed between the plunger 533 and the bottomed sleeve 536.

  A handle 540 is provided at the lower end opening of the case 531 so as to seal the inside of the solenoid 503 from below. The handle 540 also functions as a connector portion that exposes one end of a terminal connected to the electromagnetic coil 534.

  The variable capacity compressor control valve 501 configured as described above is fixed in a predetermined refrigerant passage of the variable capacity compressor 500 via the mounting washer 545.

  Next, the configuration and operation around the pressure sensitive member will be described. 14 and 15 are explanatory views showing the operation of the control valve for the variable capacity compressor, which corresponds to a partially enlarged sectional view corresponding to the upper half of FIG. FIG. 14 shows a state when the suction pressure Ps is larger than the set pressure during the control of the differential pressure (Pd−Ps). FIG. 15 shows a state when the suction pressure Ps is larger than the set pressure during the control of the differential pressure (Pd−Ps).

  As shown in FIG. 14, the pressure-sensitive member 506 has substantially the same configuration as the pressure-sensitive member 6 of the first embodiment, but the configuration of the first housing 556 that forms the housing 551 is slightly different. That is, a concave rod coupling portion 557 is formed by press molding at the bottom center of the first housing 556 opposite to the diaphragm 52, and the lower end portion of the operating rod 517 is loosely fitted. In the first housing 556, through holes 61 are formed at three positions surrounding the operating rod 517, and each of the three leg portions 54 of the reaction force transmission member 555 is inserted to protrude toward the valve body 518. .

  The reaction force transmission member 555 is formed to be approximately the same size as the disk 63. The leg 54 can be attached to and detached from the surface of the body 505 facing the shaft 520, that is, the bottom of the stopper member 511, by the operation of the pressure-sensitive member 506.

  On the other hand, a tapered spring 560 as a biasing member that biases the valve body 518 in the valve opening direction is provided between the lower end portion of the operating rod 517 and the guide member 512.

  In the above configuration, when the suction pressure Ps is larger than the set pressure, the leg portion 54 is separated from the stopper member 511 as shown in FIG. Therefore, the variable displacement compressor control valve 501 operates as a so-called Pd-Ps valve that holds the differential pressure (Pd−Ps) between the discharge pressure Pd and the suction pressure Ps at the set differential pressure. This figure shows a state in which the valve portion is slightly opened due to the differential pressure (Pd−Ps) being larger than the set differential pressure.

  On the other hand, when the suction pressure Ps is smaller than the set pressure, the leg portion 54 comes into contact with and presses the stopper member 511 as shown in FIG. A reaction force by which the leg portion 54 pushes the stopper member 511 is transmitted to the shaft 520 through the diaphragm 52, the disk 63, the spring 53, and the second housing 57, and a force in a direction to reduce the solenoid force Fs acts. As a result, the valve body 518 operates in the valve opening direction as shown in the figure, the crank pressure Pc increases, the discharge capacity of the variable capacity compressor is reduced, and as a result, the suction pressure Ps increases.

  According to the control valve 501 for the variable capacity compressor of the present embodiment, the original capacity control for maintaining the differential pressure (Pd−Ps) between the discharge pressure Pd and the suction pressure Ps at the set differential pressure is performed. When the pressure Ps is monitored and the suction pressure Ps becomes lower than the set pressure, the pressure-sensitive member 506 generates a force in a direction that reduces the solenoid force. As described above, when the suction pressure Ps becomes lower than the set pressure, the solenoid force is reduced to make it easier to open the valve portion, thereby reducing the discharge capacity of the variable capacity compressor and preventing excessive cooling. it can.

  This capacity control is autonomously performed when the pressure-sensitive member 506 detects the suction pressure Ps of the pressure chamber 525, so that the evaporator can be effectively prevented from freezing. In addition, since the pressure-sensitive member 506 is provided at one end of the body 505, a variable displacement compressor control valve having such control characteristics of the Pd-Ps valve and the Ps sensing valve can be realized with a simple configuration.

[Sixth Embodiment]
Next, a sixth embodiment of the present invention will be described. The control valve for a variable capacity compressor according to the present embodiment is greatly different from that of the first embodiment in that it is configured as a flow control type control valve that controls the flow rate of the discharged refrigerant at a constant level. However, there is also a part in common with the configuration shown in the first embodiment. For this reason, about the component similar to the said 1st Embodiment, the same code | symbol is attached | subjected etc., and the description is abbreviate | omitted suitably. FIG. 16: is sectional drawing which shows the structure of the control valve for variable displacement compressors based on 6th Embodiment. 17 is a partially enlarged cross-sectional view corresponding to the upper half of FIG.

  As shown in FIG. 16, the variable capacity compressor control valve 601 includes a valve main body 602 that opens and closes a refrigerant passage for introducing a part of the discharged refrigerant into the crank chamber, and an opening degree of the valve portion of the valve main body 602. A solenoid 3 for controlling the flow rate of the refrigerant to be adjusted and introduced into the crank chamber is integrally assembled.

  On the side of the body 605 of the valve body 602, from above, a port 611 that communicates with the outlet of the variable capacity compressor and receives the discharge pressure Pdl from above, and a port that communicates with the discharge chamber of the variable capacity compressor and receives the discharge pressure Pdh 612, a port 613 that communicates with the crank chamber of the variable capacity compressor and receives the crank pressure Pc is provided. Since a pressure reducing means such as an orifice is provided between the discharge chamber and the outlet of the variable capacity compressor, the discharge pressure Pdh is higher than the discharge pressure Pdl during normal control.

  Further, a bellows 620 is provided as a pressure-sensitive means that seals the upper end opening of the body 605 and expands and contracts in the axial direction. The bellows 620 is configured to be able to operate integrally with the shaft 20 via the transmission rod 630 and the pressure-sensitive member 640.

  The bellows 620 has a pressure chamber 622 inside a body 621 that can be expanded and contracted. The upper end of the main body 621 is fixed to a first stopper 623 that is press-fitted into the upper end opening of the body 605, and the lower end is closed by a second stopper 624 that faces the first stopper 623 in the axial direction. The first stopper 623 is provided with a refrigerant introduction path 625 communicating with the discharge chamber of the variable capacity compressor so that the discharge pressure Pdh can be introduced into the pressure chamber 622 inside the main body 621. On the other hand, the outside of the bellows 620 in the body 605 is a pressure chamber 626 that communicates with the port 611. Therefore, the bellows 620 expands and contracts in the axial direction by detecting a pressure difference (Pdh−Pdl) between the discharge pressure Pdh and the discharge pressure Pdl.

  In addition, a circular groove 627 having a predetermined depth along the axial direction is provided at the center of the lower surface of the second stopper 624 so that the upper end of the transmission rod 630 is inserted.

  As shown in FIG. 17, the transmission rod 630 is slidably inserted through a through hole 631 provided in the center of the body 605. An upper end portion of the transmission rod 630 is disposed in the pressure chamber 626 and connected to the bellows 620. On the other hand, the lower end portion of the transmission rod 630 is disposed in a refrigerant passage that has a reduced diameter and communicates the port 612 and the port 613 and is connected to the pressure-sensitive member 640. A valve hole 632 is formed by a refrigerant passage communicating between the port 612 and the port 613, and a valve seat 16 is formed by the inner peripheral edge of the end face on the crank chamber side (that is, the port 613 side).

  The pressure sensitive member 640 has substantially the same configuration as the pressure sensitive member 6 of the first embodiment, but the upper end surface of the first housing 642 constituting the housing 641 has a valve body 618 attached to and detached from the valve seat 16. It is composed. The lower end portion of the transmission rod 630 is loosely fitted in a recess 643 provided at the center of the upper end surface of the first housing 642.

  In the variable displacement compressor control valve 601, when the suction pressure Ps is high and the crank pressure Pc is higher than the set pressure, the leg portion 54 is separated from the bottom surface 564 of the body 605. For this reason, the control valve 601 for the variable capacity compressor functions as a flow control valve that controls the discharge flow rate of the refrigerant constant without the pressure-sensitive member 640 affecting the opening of the valve portion.

  That is, when the refrigerant discharge flow rate increases above the set flow rate, the differential pressure (Pdh-Pdl) between the discharge pressure Pdh and the discharge pressure Pdl increases, so that the bellows 620 expands and pushes down the pressure-sensitive member 640, and the valve 618 is operated in the valve opening direction. As a result, the crank pressure Pc rises and the capacity of the variable capacity compressor is lowered, so that the discharge capacity is reduced. On the other hand, when the refrigerant discharge flow rate decreases below the set flow rate, the pressure difference (Pdh−Pdl) between the discharge pressure Pdh and the discharge pressure Pdl decreases, and the bellows 620 decreases. As a result, the pressure sensitive member 640 is pushed up by a solenoid force or the like, and the valve body 618 is operated in the valve closing direction. As a result, the crank pressure Pc decreases, and the capacity of the variable capacity compressor is increased, so that the discharge capacity increases. In this way, the variable displacement compressor control valve 601 controls the refrigerant discharge flow rate to be constant so that the differential pressure (Pdh−Pdl) becomes the set differential pressure. Note that this set differential pressure can be adjusted by changing the value of the current supplied to the solenoid 3.

  As a result of the reduction in the suction pressure Ps, when the crank pressure Pc becomes smaller than the set pressure, the three leg portions 54 of the reaction force transmission member 55 come into contact with and press the bottom surface 564 of the body 605. The reaction force that the leg portion 54 presses the body 605 is transmitted to the shaft 20 through the diaphragm 52, the spring 53, and the second housing 57, and a force in a direction that reduces the solenoid force Fs acts. As a result, the valve body 618 operates in the valve opening direction, the crank pressure Pc increases, the discharge capacity of the variable capacity compressor is reduced, and as a result, the suction pressure Ps increases.

  According to the variable displacement compressor control valve 601 of the present embodiment, the original flow rate control is performed by maintaining the differential pressure (Pdh−Pdl) at the set differential pressure, while the crank pressure Pc is monitored, When the crank pressure Pc becomes lower than the set pressure, the pressure-sensitive member 606 generates a force in a direction that reduces the solenoid force. As described above, as a result of the reduction of the suction pressure Ps, when the crank pressure Pc becomes lower than the set pressure, the solenoid force is reduced to facilitate the opening of the valve portion, thereby reducing the discharge capacity of the variable capacity compressor. Overcooling can be prevented.

  This capacity control is autonomously performed when the pressure-sensitive member 640 senses the crank pressure Pc of the pressure chamber 25, so that the evaporator can be effectively prevented from freezing. In addition, since the pressure-sensitive member 640 is provided in the body 605, a variable displacement compressor control valve having both the flow rate control valve and the control characteristic of the Pc sensing valve can be realized with a simple configuration.

[Seventh Embodiment]
Next, a seventh embodiment of the present invention will be described. The control valve for a variable capacity compressor according to the present embodiment is substantially the same as that of the sixth embodiment except that a pressure sensitive member as a pressure sensitive portion is constituted by a bellows. For this reason, about the component similar to the said 6th Embodiment, the same code | symbol is attached | subjected etc., and the description is abbreviate | omitted suitably. FIG. 18 is a cross-sectional view showing a configuration of a control valve for a variable capacity compressor according to a seventh embodiment. FIG. 19 is a partially enlarged cross-sectional view corresponding to the upper half of FIG.

  In the control valve 701 for the variable capacity compressor, the pressure-sensitive member 706 of the valve main body 702 includes a bellows 711 as a flexible member and a case 712 that accommodates the bellows 711. The bellows 711 includes a reaction force transmission member 722 and a stopper member 723 that respectively close both ends of the main body 721 that can expand and contract in the axial direction. The inside of the main body 721 is a vacuum region, and a spring 724 that biases the main body 721 in the extending direction is interposed between the reaction force transmission member 722 and the stopper member 723. A circular groove 725 having a predetermined depth along the axial direction is provided in the center of the lower surface of the stopper member 723 so that the upper end portion of the shaft 20 is loosely fitted.

  As shown in FIG. 19, the case 712 has a covered cylindrical shape, and houses a bellows 711 so that a stopper member 723 is press-fitted into a lower end portion thereof. In the center of the upper end surface of the case 712, a recess 731 is provided for loosely fitting the lower end portion of the operating rod 730 interposed between the case 712 and the bellows 620. Further, through holes 61 are formed in three places surrounding the operating rod 730 on the peripheral edge of the upper end surface of the case 712, and each of the three leg portions 54 of the reaction force transmission member 722 is inserted and protrudes upward. I am letting. Note that the case 712 and the stopper member 723 may be combined to be regarded as a housing.

  The lower end portion of the operating rod 730 passes through the valve hole 632 and is connected to the pressure sensitive member 706. A valve body 718 facing the valve seat 16 from the crank chamber side is integrally formed at the lower end portion of the transmission rod 630.

  In the variable displacement compressor control valve 701, the leg 54 is separated from the bottom surface 64 of the body 705 when the suction pressure Ps is high and the crank pressure Pc is higher than the set pressure. For this reason, the control valve 701 for the variable capacity compressor functions as a control valve of a flow rate control type that controls the discharge flow rate of the refrigerant at a constant without the pressure sensitive member 706 affecting the opening degree of the valve portion.

  As a result of the reduction in the suction pressure Ps, when the crank pressure Pc becomes smaller than the set pressure, the three leg portions 54 of the reaction force transmission member 722 come into contact with and press the bottom surface 64 of the body 705. A reaction force by which the leg portion 54 pushes the body 705 is transmitted to the shaft 20 via the bellows 711, and a force in a direction to reduce the solenoid force Fs is applied. As a result, the valve body 718 operates in the valve opening direction, the crank pressure Pc increases, the discharge capacity of the variable capacity compressor is reduced, and as a result, the suction pressure Ps increases.

  According to the variable displacement compressor control valve 701 of the present embodiment, the original flow rate control is performed by keeping the differential pressure (Pdh-Pdl) at the set differential pressure, while the crank pressure Pc is monitored, When the crank pressure Pc becomes lower than the set pressure, the pressure-sensitive member 706 generates a force in a direction that reduces the solenoid force. As described above, as a result of the reduction of the suction pressure Ps, when the crank pressure Pc becomes lower than the set pressure, the solenoid force is reduced to facilitate the opening of the valve portion, thereby reducing the discharge capacity of the variable capacity compressor. Overcooling can be prevented.

  This capacity control is autonomously performed when the pressure-sensitive member 706 senses the crank pressure Pc of the pressure chamber 25, so that the evaporator can be effectively prevented from freezing. In addition, since the pressure-sensitive member 706 is provided in the body 705, a variable displacement compressor control valve having both the control characteristics of the flow rate control valve and the Pc sensing valve can be realized with a simple configuration.

[Eighth Embodiment]
Next, an eighth embodiment of the present invention will be described. The control valve for a variable capacity compressor according to the present embodiment is the same as the configuration shown in the fifth embodiment in that it has a body obtained by press-molding stainless steel or the like. The configuration of the pressure member is different. For this reason, about the component similar to the said 5th Embodiment, the same code | symbol is attached | subjected, and the description is abbreviate | omitted suitably. FIG. 20 is a cross-sectional view showing a configuration of a control valve for a variable displacement compressor according to an eighth embodiment. FIG. 21 is a partially enlarged cross-sectional view corresponding to the upper half of the control valve for the variable capacity compressor of FIG.

  As shown in FIG. 20, the variable displacement compressor control valve 801 is disposed from the discharge chamber so as to keep the differential pressure (Pd−Ps) between the discharge pressure Pd and the suction pressure Ps of the variable displacement compressor at the set differential pressure. The Pd-Ps valve is configured to control the flow rate of the refrigerant introduced into the crank chamber.

  The variable capacity compressor control valve 801 adjusts the opening of a valve body 802 for opening and closing a refrigerant passage for introducing a part of discharged refrigerant into the crank chamber, and adjusting the opening of the valve portion of the valve body 802 to the crank chamber. A solenoid 803 for controlling the flow rate of refrigerant to be introduced is integrally assembled.

  The valve body 802 includes a cylindrical first body 805 obtained by cutting, a bottomed cylindrical second body 806 obtained by press molding, a valve mechanism provided in the first body 805, and a second body 806. A pressure-sensitive member 807 that is provided inside and influences the operation of the valve mechanism is provided. A flange portion 808 extending radially outward is provided at the lower end portion of the first body 805, and the upper end portion of the second body 806 is caulked and joined to the flange portion 808. The lower end of the second body 806 is caulked and joined to the case 531 via the core 825 of the solenoid 803.

  A port 11 is provided on the side of the first body 805, and a port 13 is provided on the upper end opening. A stepped cylindrical valve seat forming member 810 is press-fitted into the upper half of the first body 805, and a valve seat 811 is formed by a lower end opening edge of the valve seat forming member 810. A valve hole 812 is formed inside the valve seat forming member 810, and a communication hole 813 is provided on the side of the valve seat forming member 810 to communicate the inside and the outside. On the other hand, an elongated operating rod 815 is disposed inside the first body 805. The upper end portion of the operating rod 815 is slidably supported by the valve seat forming member 810, and the lower end portion is connected to the pressure sensitive member 807. A valve body 816 is integrally formed at the center of the operating rod 815.

  A port 22 is provided on the side of the second body 806. A bottomed cylindrical stopper member 817 obtained by press molding is press-fitted into the upper half portion of the second body 806 with its bottom portion down. An opening is provided in the center of the bottom of the stopper member 817 and the pressure sensitive member 807 is inserted therethrough. The stopper member 817 is attached to and detached from three legs 819 of a reaction force transmission member 818, which will be described later, constituting the pressure-sensitive member 807.

  As shown in FIG. 21, the valve seat forming member 810 has a lower half portion press-fitted into the first body 805, and an outer diameter of the upper half portion is reduced. The operating rod 815 has an upper end portion slidably supported by the valve seat forming member 810, and a reduced diameter portion 820 is formed between the upper end portion and the valve body 816. The valve body 816 is located at the base end portion of the step portion formed by the reduced diameter portion 820 and is opposed to the valve seat 811 so as to be able to contact and separate from the discharge chamber side. For this reason, the refrigerant introduced from the port 11 is led out to the port 13 side through the refrigerant passage and the communication hole 813 formed between the reduced diameter portion 820 and the valve seat forming member 810. At this time, the discharge pressure Pd introduced from the port 11 side is depressurized when the refrigerant passes through the valve portion including the valve body 816 and the valve seat 811, and becomes a controlled crank pressure Pc via the port 13. Is introduced to the crank chamber side. On the other hand, the lower end portion of the operating rod 815 is connected to the pressure-sensitive member 807 via the diaphragm 823. A ring-shaped fixing member 824 is caulked and joined to the lower end opening of the first body 805, and the diaphragm 823 has an outer peripheral edge sandwiched between the first body 805 and the fixing member 824. It is fixed.

  A press-formed spring receiving member 821 is press-fitted into the upper end opening of the first body 805, and the valve body 816 is opened between the spring receiving member 821 and the upper end surface of the operating rod 815. A spring 822 biasing in the direction is interposed.

  The pressure-sensitive member 807 is interposed between the operating rod 815 and the shaft 20 and supported so as to be displaceable in the opening / closing direction of the valve portion, and the inside of the housing 830 includes a sealed space S1 and an open space S2. A diaphragm 831 as a flexible member disposed so as to be partitioned into two pieces, a disc spring 832 as an elastic member disposed in the sealed space S1, and a housing 830 that passes through the housing 830 while being accommodated in the open space S2. And a reaction force transmission member 818 having three legs 819 extending upward. The open space S <b> 2 is formed between the first body 805 and the second body 806 and communicates with the pressure chamber 25 connected to the port 22.

  The housing 830 is formed in a container shape by joining a first housing 833, a second housing 834, and a third housing 835, all obtained by press-molding stainless steel or the like. That is, the lid-shaped first housing 833 and the dish-shaped second housing 834 are assembled such that the opening is abutted and the outer edge of the diaphragm 831 made of a polyimide film is sandwiched between the outer edges. The joint between the first housing 833 and the second housing 834 is subjected to outer periphery welding with the diaphragm 831 sandwiched therebetween. A hole for evacuation is formed at the center of the lower end of the second housing 834. After the welding is performed in a vacuum atmosphere, the ball member 836 is welded and sealed to form a sealed space S1. Is done. In the sealed space S1, a convex disc spring 832 having a central portion slightly inflated upward along the diaphragm 831 is disposed. For this reason, the diaphragm 831 also has a convex shape along the disc spring 832 in a normal state. The sealed space S1 may be filled with air or the like.

  The first housing 833 has a cylindrical portion 837 extending opposite to the second housing 834, that is, upward, and a third housing 835 is externally inserted by press-fitting at an upper end portion thereof. The center portion of the third housing 835 is reduced in diameter and protrudes in a boss shape, and the lower end portion of the operating rod 815 is press-fitted. In other words, the lower end portion of the operating rod 815 has a small diameter, and the small diameter portion passes through the center of the diaphragm 823 and is press-fitted into the boss portion of the third housing 835. Since the diaphragm 823 is in close contact with both the operation rod 815 and the third housing 835 so that the refrigerant is prevented from leaking above and below the diaphragm 823, airtightness is maintained. For this reason, the discharge pressure Pd does not reach the pressure chamber 25.

Further, a disk-like reaction force transmission member 818 made of stainless steel is welded to the surface of the diaphragm 831 on the first housing 833 side. At three locations on the outer peripheral portion of the reaction force transmission member 818, leg portions 819 that extend upward (that is, on the side opposite to the diaphragm 831) and project from the through hole 838 of the first housing 833 are provided. These leg portions 819 can be attached to and detached from the bottom surface 839 of the stopper member 817 by the operation of the pressure-sensitive member 807. Also,
A bottomed cylindrical spring receiving member 841 is inserted into the cylindrical portion 837 of the first housing 833 by press-fitting. Between the spring receiving member 841 and the reaction force transmission member 818, a spring 843 that urges the reaction force transmission member 818 in a direction that opposes the load of the disc spring 832 is interposed. The spring 843 is for finely adjusting the load of the disc spring 832, and the load of the spring 843 is adjusted by the amount of press-fitting into the cylindrical portion 837 of the spring receiving member 841. The open space S2 formed between the first housing 833 and the third housing 835 communicates with the pressure chamber 25 through the through hole 838, and the suction pressure Ps is introduced. Therefore, the diaphragm 831 senses this suction pressure Ps and is deformed together with the disc spring 832 in the opening / closing direction of the valve portion. When the suction pressure Ps is increased, the disc spring 832 is deformed so as to be reversed with the peripheral edge portion as a fulcrum from the illustrated state (see FIG. 22), and substantially follows the inner wall of the second housing 834. In other words, the second housing 834 is compact because its inner wall is formed in a shape that substantially conforms to the shape when the disc spring 832 is inverted and deformed.

  Since the disc spring 832 has a shape in which the central portion protrudes toward the reaction force transmission member 818, the pressure receiving portion is biased toward the central portion with respect to the overall size, and the substantial pressure receiving area can be reduced. it can. For this reason, the solenoid force which opposes this can also be made small, and it can also contribute to the compactization of the solenoid 803. On the other hand, since the size of the diaphragm 831 is secured as it is, the stroke can be increased, and the flexible movement of the diaphragm 831 can be secured.

  On the other hand, a bearing member 851 for slidably supporting the upper end portion of the shaft 20 is press-fitted into the upper end opening portion of the core 825 constituting the solenoid 803. The inner diameter of the upper half portion of the bearing member 851 is increased, and the ball member 836 of the second housing 834 can be accommodated. The shaft 20 has an upper end connected to a pressure-sensitive member 807 via a ball member 836 so that a solenoid force can be transmitted from below.

  Here, when the suction pressure Ps in the pressure chamber 25 becomes lower than a predetermined set pressure Pset, the diaphragm 831 and the disc spring 832 are deformed to the valve body 816 side as shown in the figure, and the leg portion 819 of the reaction force transmission member 818. Presses the bottom surface 839. As a result, the reaction force acting on the reaction force transmission member 818 is transmitted to the shaft 20 via the diaphragm 831, the disc spring 832 and the second housing 834, and a force in a direction to reduce the solenoid force Fs acts. ing. This set pressure Pset is basically adjusted in advance by the spring load of the disc spring 832 and the spring 843, and is set as a pressure value that can prevent the evaporator from freezing based on the relationship between the temperature in the evaporator and the suction pressure Ps. ing.

  As shown in FIG. 20, in the solenoid 803 of this embodiment, the plunger 533 is press-fitted into the shaft 20, and is shown in the fifth embodiment between the plunger 533 and the bottomed sleeve 536. The spring 538 is not provided.

  Next, the operation around the pressure sensitive member will be described. 22-24 is explanatory drawing showing operation | movement of the control valve for variable displacement compressors, and respond | corresponds to FIG. FIG. 22 shows a state where the differential pressure (Pd−Ps) is slightly larger than the set differential pressure and the suction pressure Ps is larger than the set pressure. FIG. 23 shows a state where the differential pressure (Pd−Ps) is greater than the set differential pressure and the suction pressure Ps is greater than the set pressure. FIG. 24 shows a transitional state in which the suction pressure Ps is becoming smaller than the set pressure during the control of the differential pressure (Pd−Ps). Note that FIG. 21 described above shows a state where the suction pressure Ps is smaller than the set pressure during the control of the differential pressure (Pd−Ps).

  That is, when the suction pressure Ps is larger than the set pressure, the leg portion 819 is separated from the stopper member 817 as shown in FIG. Therefore, the variable displacement compressor control valve 801 operates as a so-called Pd-Ps valve that maintains the differential pressure (Pd−Ps) between the discharge pressure Pd and the suction pressure Ps at the set differential pressure. FIG. 23 shows a state in which the valve portion is opened when the differential pressure (Pd−Ps) is larger than the set differential pressure.

  On the other hand, when the suction pressure Ps becomes smaller than the set pressure, the leg portion 819 comes into contact with and presses the stopper member 817 as shown in FIGS. A reaction force by which the leg portion 819 pushes the stopper member 817 is transmitted to the shaft 20 via the diaphragm 831, the disc spring 832, and the second housing 834, and a force in a direction to reduce the solenoid force Fs acts. As a result, as shown in the figure, the valve body 816 operates in the valve opening direction, the crank pressure Pc increases, the discharge capacity of the variable capacity compressor is reduced, and as a result, the suction pressure Ps increases.

  According to the variable displacement compressor control valve 801 of the present embodiment, the original displacement control is performed to maintain the differential pressure (Pd−Ps) between the discharge pressure Pd and the suction pressure Ps at the set differential pressure. When the pressure Ps is monitored and the suction pressure Ps becomes lower than the set pressure, the pressure-sensitive member 807 generates a force in a direction that reduces the solenoid force. As described above, when the suction pressure Ps becomes lower than the set pressure, the solenoid force is reduced to make it easier to open the valve portion, thereby reducing the discharge capacity of the variable capacity compressor and preventing excessive cooling. it can.

  This capacity control is autonomously performed when the pressure-sensitive member 807 senses the suction pressure Ps of the pressure chamber 25, so that the evaporator can be effectively prevented from freezing. In addition, since the pressure sensitive member 807 is provided inside the second body 806, such a control valve for a variable capacity compressor having the control characteristics of the Pd-Ps valve and the Ps sensing valve can be realized with a simple configuration. The

[Ninth Embodiment]
Next, a ninth embodiment of the present invention will be described. The control valve for a variable capacity compressor according to the present embodiment has a configuration that simplifies the control valve for a variable capacity compressor of the eighth embodiment. For this reason, components that are substantially the same as those in the eighth embodiment are given the same reference numerals, and descriptions thereof are omitted as appropriate. FIG. 25 is a cross-sectional view showing a configuration of a control valve for a variable capacity compressor according to a ninth embodiment. FIG. 26 is a partially enlarged cross-sectional view corresponding to the upper half of the control valve for the variable capacity compressor of FIG.

  In the variable capacity compressor control valve 901, as shown in FIG. 25, the diaphragm 823 shown in FIG. 21 is not provided between the port 11 and the port 22. That is, the operating rod 915 is slidably inserted into the guide hole 921 that passes through the first body 905 in the axial direction. A valve body 916 is integrally formed with the operating rod 915. Since the clearance between the operating rod 915 and the guide hole 921 is small, the refrigerant is prevented from leaking from the port 11 to the port 22. Further, since the housing of the valve seat forming member 910 and the pressure-sensitive member 907 is configured to be small, the overall length of the variable displacement compressor control valve 901 is configured to be compact.

  That is, as shown in FIG. 26, the valve seat forming member 910 is formed into a bottomed cylindrical shape by press-molding stainless steel, and a valve hole 912 is formed by a circular hole provided at the center of the bottom. A valve seat 911 is formed by the lower peripheral edge of the valve hole 912. For this reason, the refrigerant passage in the valve hole 912 is shortened, and the length of the small diameter portion 920 of the operation rod 915 corresponding thereto is also shortened. As a result, the entire length of the operating rod 915 is shortened, and the first body 905 is compact as a whole.

  Further, the pressure-sensitive member 907 does not have the third housing 835 and the spring 843 as shown in FIG. That is, the housing 930 is configured by joining a cup-shaped first housing 933 and a second housing 834. A reaction force transmission member 918 having three legs 919 is provided inside the housing 930, but no spring for finely adjusting the load of the disc spring 832 is provided. For this reason, the housing 930 and thus the pressure-sensitive member 907 are configured to be compact as a whole. As a result, the second body 906 that accommodates the pressure-sensitive member 907 is compact as a whole.

  Each leg portion 919 of the reaction force transmission member 918 extends to the outside from the through hole 838 of the first housing 933 and is attached to and detached from the bottom surface 939 of the first body 905. A reaction force by which the leg portion 919 pushes the first body 905 is transmitted to the shaft 20 via the diaphragm 831, the disc spring 832, and the second housing 834, and a force in a direction to reduce the solenoid force Fs acts.

  According to the variable displacement compressor control valve 901 of the present embodiment, it is possible to obtain the same operational effects as the variable displacement compressor control valve 801 of the eighth embodiment, and to meet the demand for compactness. I can respond.

[Tenth embodiment]
Next, a tenth embodiment of the present invention will be described. Although the control valve for a variable capacity compressor according to the present embodiment differs from that of the eighth embodiment in that it is configured as a flow control valve that controls the flow rate of the discharged refrigerant at a constant level. In addition, the configuration of the solenoid or the like has a common part with the configuration shown in the eighth embodiment. For this reason, components that are substantially the same as those in the eighth embodiment are given the same reference numerals, and descriptions thereof are omitted as appropriate. FIG. 27 is a cross-sectional view showing a configuration of a variable displacement compressor control valve according to the tenth embodiment. 28 is a partially enlarged cross-sectional view corresponding to the upper half of FIG.

  As shown in FIG. 27, the variable displacement compressor control valve 1001 is configured by assembling a valve body 1002 and a solenoid 1003 integrally. The valve body 1002 is configured by joining a first body 1004 and a second body 1005 by press-fitting, and housing a first valve portion 1007 and a second valve portion 1008 therein. The first valve unit 1007 controls the flow rate of the refrigerant supplied from the discharge chamber to the crank chamber. On the other hand, the second valve unit 1008 variably controls the passage cross-sectional area of the refrigerant passage through which the high-pressure refrigerant flows from the discharge chamber of the variable capacity compressor to the refrigerant outlet. On the other hand, the connecting member 1009 and the case 531 are joined by crimping the upper end of the core 1018 of the solenoid 1003. The valve body 1002 and the solenoid 1003 are assembled by press-fitting the lower end portion of the second body 1005 into the connecting member 1009.

  A pressure-sensitive member 1010 that is substantially the same as the pressure-sensitive member 306 of the third embodiment shown in FIG. 9 and the like is press-fitted into the upper end opening of the first body 1004. Here, the same components as those of the pressure-sensitive member 306 are denoted by the same reference numerals, and description thereof is omitted. A port 1012 that communicates with the crank chamber and receives the crank pressure Pc is provided on the side of the first housing 1011 of the pressure-sensitive member 1010. A port 1013 that communicates with the discharge chamber and receives the discharge pressure Pdh2 is provided on the side of the first body 1004. A first valve portion 1007 is provided in the refrigerant passage communicating the port 1013 and the port 1012.

  On the other hand, on the side of the second body 1005, a port 1014 that communicates with the refrigerant outlet of the variable capacity compressor from above and receives the discharge pressure Pdl, and a port 1015 that communicates with the discharge chamber and receives the discharge pressure Pdh are provided. Yes. A second valve portion 1008 is provided in the refrigerant passage communicating the port 1015 and the port 1014.

  The variable displacement compressor control valve 1001 is applied to a variable displacement compressor configured such that a port 1015 for receiving the discharge pressure Pdh and a port 1013 for receiving the discharge pressure Pdh2 are both in direct communication with the discharge chamber. Can do. However, it is preferably applied to a variable capacity compressor configured such that the port 1015 communicates directly with the discharge chamber and the port 1013 communicates with the outlet of an oil separator provided on the downstream side of the discharge chamber. Thus, the lubricating oil for the variable capacity compressor contained in the refrigerant in a large amount can be returned to the crank chamber while the first valve portion 1007 controls the crank pressure Pc.

  A diaphragm 1016 is fixed between the first body 1004 and the second body 1005 so as to sandwich the peripheral edge thereof, and the two are kept airtight. An operating rod 1017 that passes through the center of the diaphragm 1016 is fixed to the diaphragm 1016, which will be described later.

  On the other hand, the core 1018 and the plunger 1019 of the solenoid 1003 have opposing surfaces in the axial direction formed in a complementary tapered shape so that the magnetic gap can be stably held even if they are separated from each other. A bearing member 1020 is press-fitted into the upper end opening of the core 1018 and supports the vicinity of the upper end of the shaft 20.

  As shown in FIG. 28, a valve hole 1021 is formed in the axially central portion of the first body 1004 by the inner peripheral surface of the flange portion extending inward, and the first valve seat 1022 is formed by the lower end opening edge thereof. Is formed. The operating rod 1017 passes through the valve hole 1021. The actuating rod 1017 has a stepped cylindrical shape, and penetrates the diaphragm 1016 slightly below the center in the axial direction. The diaphragm 1016 has an upper and lower surface sandwiched between a pair of disks 1023 that are extrapolated to the operating rod 1017, thereby defining an effective pressure receiving area. Both disks 1023 are fixed so as to be sandwiched between the step portion of the operating rod 1017 and the first valve body 1025 press-fitted into the operating rod 1017. In other words, the operating rod 1017 is supported by the diaphragm 1016 so as to be displaceable in the axial direction. The first valve body 1025 faces the first valve seat 1022 from the discharge chamber side and is freely contactable and separable. The first valve body 1025 constitutes the first valve portion 1007 together with the first valve seat 1022.

  A spring receiving member 1026 is press-fitted into the upper portion of the operating rod 1017. Between the spring receiving member 1026 and the first body 1004, a spring 1027 for biasing the actuating rod 1017 and thus the first valve body 1025 via the spring receiving member 1026 is interposed. The upper end of the operating rod 1017 can be attached to and detached from the disk 355 of the pressure sensitive member 1010. On the other hand, the lower end portion of the operating rod 1017 extends into the second body 1005, and a locking portion 1028 that protrudes slightly outward in the radial direction is formed at the tip thereof.

  On the other hand, a cylindrical guide member 1031 having an inner diameter substantially the same as the pressure receiving diameter of the diaphragm 1016 is press-fitted into the second body 1005. The upper opening edge of the guide member 1031 constitutes the second valve seat 1032. In addition, a stepped cylindrical second valve body 1033 and a bottomed stepped cylindrical guide 1034 press-fitted into the second body 1005 are disposed inside. The second valve body 1033 is attached to and detached from the second valve seat 1032 with a tapered surface near the upper end portion thereof. The upper end of the guide 1034 is joined to the lower end of the second valve body 1033, while the diameter of the guide 1034 is increased downward. The lower end of the guide 1034 is in sliding contact with the guide member 1031. The guide 1034 is supported on the shaft 20 from below. A communication hole 1036 is formed in the vicinity of the bottom portion with which the shaft 20 of the guide 1034 contacts. Further, in the space formed between the second valve body 1033 and the guide 1034, a locking portion 1028 of the operating rod 1017 is disposed so as to penetrate the bottom portion of the second valve body 1033. Therefore, the second valve body 1033 can be hooked on the locking portion 1028 by the movement of the operating rod 1017 and operate together with the operating rod 1017. Further, between the guide member 1031 and the guide 1034, a spring 1035 for biasing the guide 1034 and thus the second valve body 1033 in the valve closing direction is interposed.

  In the solenoid 1003 of this embodiment, the shaft 20 and thus the plunger 1019 are urged downward by the spring 1035, so that no spring is provided between the core 1018 and the plunger 1019.

  According to the control valve 1001 for the variable displacement compressor, when the solenoid 1003 is in a non-energized state, the spring 1035 pushes down the second valve body 1033 downward to fully close the second valve portion 1008, and the second valve body. 1033 pulls down the operating rod 1017 downward via the locking portion 1028 to fully open the first valve portion 1007. As a result, the variable capacity compressor shifts to the minimum capacity operation state. At this time, since the locking portion 1028 of the second valve body 1033 and the operating rod 1017 is locked, the refrigerant passage formed at the center of the second valve body 1033 and the guide 1034 is closed. Further, since the refrigerant having the discharge pressure Pdh leaks through the clearance between the guide 1034 and the guide member 1031, the inside of the solenoid 1003 is at a pressure close to the discharge pressure Pdh.

  When the solenoid 1003 is energized, the shaft 20 pushes the second valve body 1033 upward through the guide 1034 and opens the second valve portion 1008. At this time, the operating rod 1017 is also pushed up by the spring 1027 in conjunction with the pushing up of the second valve body 1033. When the first valve body 1025 is seated on the first valve seat 1022, the first valve portion 1007 is closed. As a result, the variable capacity compressor attempts to shift to the maximum capacity operation state. At this time, when the operating rod 1017 is separated from the second valve body 1033, the refrigerant passage formed at the center of the second valve body 1033 and the guide 1034 is opened, and the inside of the solenoid 1003 communicates with the port 1014, so the discharge pressure Pdl become.

  When the control current is maintained at a predetermined value during energization control of the solenoid 1003, the second valve body 1033 is held at a position where the solenoid force corresponding to the predetermined value and the biasing force by the spring 1035 are balanced. Thereby, the channel | path formed by the 2nd valve part 1008 is set to predetermined cross-sectional area. At this time, when the refrigerant flows through the second valve portion 1008, a predetermined differential pressure (ΔP = Pdh−Pdl) is generated before and after the refrigerant.

  Then, the diaphragm 1016 detects the differential pressure ΔP, and the first valve body 1025 is lifted from the first valve seat 1022 by a predetermined amount to open the first valve body 1025 in a predetermined valve open state. At this time, when the flow rate of the refrigerant passing through the second valve portion 1008 increases and the differential pressure ΔP increases, the diaphragm 1016 detects this and further opens the second valve portion 1008 to discharge the variable capacity compressor. Control in the direction of decreasing capacity. On the other hand, when the refrigerant flow rate decreases and the differential pressure ΔP decreases, the diaphragm 1016 senses this and shifts the second valve portion 1008 in the valve closing direction, and controls the variable displacement compressor in a direction in which the discharge capacity increases. To do. In this way, the variable capacity compressor is controlled to discharge the refrigerant at a flow rate corresponding to the control current supplied to the solenoid 1003.

  Further, in the variable displacement compressor control valve 1001, as a result of the suction pressure Ps being reduced, when the crank pressure Pc becomes smaller than the set pressure, the diaphragm 52 is displaced downward by the urging force of the spring 53, and the force is applied to the disc. 355, the operating rod 1017 and the guide 1034 are transmitted to the shaft 20. Thereby, a force in a direction to reduce the solenoid force Fs acts, and the first valve body 1025 operates in the valve opening direction. As a result, the crank pressure Pc increases, the discharge capacity of the variable capacity compressor is reduced, and the suction pressure Ps increases.

  According to the variable displacement compressor control valve 1001 of the present embodiment, while the original flow rate control is performed, the crank pressure Pc is monitored, and when the crank pressure Pc becomes lower than the set pressure, the pressure-sensitive member 1010. Generates a force in a direction to reduce the solenoid force. As described above, as a result of the reduction of the suction pressure Ps, when the crank pressure Pc becomes lower than the set pressure, the solenoid force is reduced to facilitate the opening of the valve portion, thereby reducing the discharge capacity of the variable capacity compressor. Overcooling can be prevented. The variable displacement compressor control valve 1001 is realized with a simple configuration because the pressure-sensitive member 1010 is provided at one end of the first body 1004.

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

  For example, in the above embodiment, the diaphragm 52 is made of a thin metal plate such as beryllium copper or stainless steel, but may be made of a resin material such as polyimide. In the latter case, for example, when a plurality of polyimide films are used, the damage resistance can be improved.

  In addition, although the control valve for variable capacity compressors of the above embodiment is suitably applied to a refrigeration cycle that uses alternative chlorofluorocarbon (HFC-134a) as a refrigerant, the control valve for variable capacity compressor of the present invention is It is also possible to apply to a refrigeration cycle using a refrigerant having a high operating pressure such as carbon dioxide. In that case, a heat exchanger such as a gas cooler is arranged in the refrigeration cycle instead of the condenser.

  Moreover, although the example which used the spring as an elastic member and an urging | biasing member was shown in the said embodiment, it can also be comprised with members which have other elastic force, such as rubber | gum.

It is sectional drawing which shows the structure of the control valve for variable capacity compressors which concerns on 1st Embodiment. It is explanatory drawing showing operation | movement of the control valve for variable displacement compressors. It is explanatory drawing showing operation | movement of the control valve for variable displacement compressors. It is explanatory drawing showing operation | movement of the control valve for variable displacement compressors. It is explanatory drawing showing operation | movement of the control valve for variable displacement compressors. It is explanatory drawing showing the mode of the change of the discharge pressure and the suction pressure from the time of starting of a variable capacity compressor. It is sectional drawing which shows the structure of the control valve for variable capacity compressors which concerns on 2nd Embodiment. It is a partial expanded sectional view corresponding to the upper half part of FIG. It is sectional drawing which shows the structure of the control valve for variable capacity compressors which concerns on 3rd Embodiment. It is a partial expanded sectional view corresponding to the upper half part of FIG. It is sectional drawing which shows the structure of the control valve for variable capacity compressors which concerns on 4th Embodiment. It is a partial expanded sectional view corresponding to the upper half part of FIG. It is sectional drawing which shows the structure of the control valve for variable capacity compressors which concerns on 5th Embodiment. It is explanatory drawing showing operation | movement of the control valve for variable displacement compressors. It is explanatory drawing showing operation | movement of the control valve for variable displacement compressors. It is sectional drawing which shows the structure of the control valve for variable capacity compressors concerning 6th Embodiment. It is a partial expanded sectional view corresponding to the upper half part of FIG. It is sectional drawing which shows the structure of the control valve for variable capacity compressors concerning 7th Embodiment. It is a partial expanded sectional view corresponding to the upper half part of FIG. It is sectional drawing which shows the structure of the control valve for variable capacity compressors which concerns on 8th Embodiment. It is a partial expanded sectional view corresponding to the upper half part of the control valve for variable displacement compressors of FIG. It is explanatory drawing showing operation | movement of the control valve for variable displacement compressors. It is explanatory drawing showing operation | movement of the control valve for variable displacement compressors. It is explanatory drawing showing operation | movement of the control valve for variable displacement compressors. It is sectional drawing which shows the structure of the control valve for variable capacity compressors concerning 9th Embodiment. It is a partial expanded sectional view corresponding to the upper half part of the control valve for variable displacement compressors of FIG. It is sectional drawing which shows the structure of the control valve for variable capacity compressors which concerns on 10th Embodiment. FIG. 28 is a partial enlarged cross-sectional view corresponding to the upper half of FIG. 27. It is explanatory drawing showing the mode of the change of the discharge pressure and the suction pressure after the starting of the conventional variable capacity compressor.

Explanation of symbols

1,201,301,401,501,601,701,801,901,1001 control valve for variable capacity compressor, 2,202,302,402,502,602,702,802,902,1002 valve body, 3 , 503, 803, 1003 Solenoid, 5,205, 305, 405, 505, 605, 705 Body, 6, 206, 306, 406, 506, 640, 807, 907 Pressure sensitive member, 14, 314, 513 Valve seat formation Member, 414 movable valve seat forming member, 15, 507, 632 valve hole, 16,508 valve seat, 17, 417, 517, 730 actuating rod, 18, 218, 318, 418, 518, 618, 718 valve body, 20 , 520 shaft, 21, 622, 626 pressure chamber, 25, 225, 325, 525 pressure Chamber, 51,251,351,551,641 housing, 52 diaphragm, 54,426,427,819,919 leg, 55,423,555,722,818,918 reaction force transmission member, 316,630 transmission rod, 511 stopper member, 512 guide member, 620,711 bellows, S1 sealed space, S2 open space, 805, 905, 1004 first body, 806, 906, 1005 second body, 1007 first valve portion, 1008 second valve portion .

Claims (17)

Variable capacity compression that changes the refrigerant discharge capacity from the variable capacity compressor by controlling the flow rate of refrigerant introduced from the discharge chamber to the crank chamber so that the differential pressure between two predetermined points in the refrigeration cycle is maintained at the set differential pressure. In machine control valves,
A body having a refrigerant passage formed therein;
A valve body that is disposed so as to be in contact with and separated from a valve hole that forms a refrigerant passage that communicates the discharge chamber and the crank chamber, and opens and closes the valve portion;
A shaft for transmitting axial force to the valve body;
A solenoid that applies a solenoid force in a valve closing direction corresponding to the set differential pressure to the shaft in an axial direction, and operates the valve body in an opening and closing direction of the valve portion;
A pressure chamber that is composed of an internal space surrounded by the body and the solenoid and introduces any pressure in communication with the suction chamber or the crank chamber;
Detects the pressure in the pressure chamber provided in the body or integrally with the body, and generates a force in a direction to reduce the solenoid force when the pressure in the pressure chamber becomes lower than a set pressure. A pressure sensitive part,
A control valve for a variable capacity compressor. The pressure sensitive part is
A housing supported by the shaft so as to be displaceable in the pressure chamber;
A flexible member provided so as to partition the inside of the housing into a sealed space and a space communicating with the pressure chamber, and deforms in a direction away from the shaft when the pressure in the pressure chamber becomes lower than the set pressure. When,
An elastic member disposed between the flexible member and the housing;
The flexible member has a leg portion connected to the opposite side of the shaft and extending to the outside of the housing, and the flexibility when the pressure in the pressure chamber becomes lower than the set pressure. Reaction force transmission in which the leg presses the body directly or indirectly by deformation of the member, and the reaction force applies a force in a direction to reduce the solenoid force to the shaft via the elastic member and the housing. Members,
The control valve for a variable capacity compressor according to claim 1, comprising: The valve body is composed of one end of an operating rod that is slidably inserted into a guide hole provided in the body and is pivotally supported.
3. The control valve for a variable capacity compressor according to claim 2, wherein a housing of the pressure-sensitive portion is disposed so as to be interposed between the other end portion of the operating rod and the shaft.   The control valve for a variable capacity compressor according to claim 3, further comprising an urging member for urging the operating rod in the valve opening direction in the pressure chamber. A bottomed cylindrical stopper member fixed in the body so as to be adjustable in position is provided,
The control valve for a variable capacity compressor according to claim 2, wherein a leg portion of the pressure-sensitive portion is configured to be detachable from a bottom portion of the stopper member.   The control valve for a variable capacity compressor according to claim 2, wherein the valve body is configured by a part of a housing of the pressure-sensitive portion. The valve body is integrally provided at one end of the shaft;
The pressure sensitive part is
A housing fixed to seal one end of the body;
Flexibility that is provided so as to partition the inside of the housing into a sealed space and a space communicating with the pressure chamber, and deforms in a direction close to the shaft when the pressure in the pressure chamber becomes lower than the set pressure. Members,
An elastic member disposed in the sealed space and biasing the flexible member toward the shaft;
A transmission rod provided on the shaft side of the flexible member and extending to the outside of the housing; and when the pressure in the pressure chamber becomes lower than the set pressure, A reduction force transmission member that applies a force in a direction in which the transmission rod reduces the solenoid force to the shaft by deformation;
The control valve for a variable capacity compressor according to claim 1, comprising: The valve hole is formed by an internal passage of a movable valve seat forming member provided in a refrigerant passage that allows the discharge chamber and the crank chamber to communicate with each other.
The valve body consists of one end of an operating rod that operates in the axial direction within the body,
The pressure sensitive part is
A housing supported by the shaft so as to be displaceable in the pressure chamber;
A flexible member provided so as to partition the inside of the housing into a sealed space and a space communicating with the pressure chamber, and deforms in a direction away from the shaft when the pressure in the pressure chamber becomes lower than the set pressure. When,
An elastic member disposed between the flexible member and the housing;
The flexible member has a leg portion connected to the opposite side of the shaft and extending to the outside of the housing, and the flexibility when the pressure in the pressure chamber becomes lower than the set pressure. A reaction force transmission member that applies a force in a direction to reduce the solenoid force to the shaft via the elastic member and the housing by the reaction force by the leg portion pressing the movable valve seat forming member by deformation of the member. When,
With
2. The control valve for a variable capacity compressor according to claim 1, wherein a housing of the pressure-sensitive portion is disposed so as to be interposed between the other end portion of the operating rod and the shaft. The differential pressure between the two points is a differential pressure between the discharge pressure of the discharge chamber and the suction pressure of the suction chamber,
The control valve for a variable capacity compressor according to claim 1, wherein the pressure chamber is configured to communicate with the suction chamber and introduce the suction pressure. The differential pressure between the two points is the differential pressure between the outlet pressure of the discharge chamber and the outlet pressure of the variable capacity compressor,
The control valve for a variable capacity compressor according to claim 1, wherein the pressure chamber is configured to communicate with the crank chamber and introduce a crank pressure.   The control valve for a variable capacity compressor according to claim 1, wherein the pressure-sensitive part includes a diaphragm.   The control valve for a variable capacity compressor according to claim 1, wherein the pressure sensitive part includes a bellows. In the control valve for the variable capacity compressor, which controls the flow rate of the refrigerant introduced from the discharge chamber of the variable capacity compressor into the crank chamber to change the discharge capacity of the variable capacity compressor,
A body having a refrigerant passage formed therein;
A valve body that is disposed so as to be in contact with and separated from a valve hole that forms a refrigerant passage that communicates the discharge chamber and the crank chamber, and opens and closes the valve portion;
A shaft for transmitting axial force to the valve body;
A solenoid force capable of applying a solenoid force in a valve closing direction of the valve portion to the shaft, and operating the valve body in an opening / closing direction of the valve portion;
A pressure chamber for introducing any pressure in communication with the suction chamber or the crank chamber of the variable capacity compressor;
Detects the pressure in the pressure chamber provided in the body or integrally with the body, and generates a force in a direction to reduce the solenoid force when the pressure in the pressure chamber becomes lower than a set pressure. A pressure sensitive part,
Bei to give a,
The pressure sensitive part is
A housing supported by the shaft so as to be displaceable in the pressure chamber;
A flexible member provided so as to partition the inside of the housing into a sealed space and a space communicating with the pressure chamber, and deforms in a direction away from the shaft when the pressure in the pressure chamber becomes lower than the set pressure. When,
An elastic member disposed between the flexible member and the housing;
The flexible member has a leg portion connected to the opposite side of the shaft and extending to the outside of the housing, and the flexibility when the pressure in the pressure chamber becomes lower than the set pressure. Reaction force transmission in which the leg presses the body directly or indirectly by deformation of the member, and the reaction force applies a force in a direction to reduce the solenoid force to the shaft via the elastic member and the housing. Members,
A control valve for a variable capacity compressor. In the control valve for the variable capacity compressor, which controls the flow rate of the refrigerant introduced from the discharge chamber of the variable capacity compressor into the crank chamber to change the discharge capacity of the variable capacity compressor,
  A body having a refrigerant passage formed therein;
  A valve body that is disposed so as to be in contact with and separated from a valve hole that forms a refrigerant passage that communicates the discharge chamber and the crank chamber, and opens and closes the valve portion;
  A shaft for transmitting axial force to the valve body;
  A solenoid force capable of applying a solenoid force in a valve closing direction of the valve portion to the shaft, and operating the valve body in an opening / closing direction of the valve portion;
  A pressure chamber for introducing any pressure in communication with the suction chamber or the crank chamber of the variable capacity compressor;
  Detects the pressure in the pressure chamber provided in the body or integrally with the body, and generates a force in a direction to reduce the solenoid force when the pressure in the pressure chamber becomes lower than a set pressure. A pressure sensitive part,
With
  In addition to the valve unit, the valve unit further includes another valve unit that controls the flow rate of refrigerant flowing from the discharge chamber to the refrigerant outlet of the variable capacity compressor,
  The valve section controls the flow rate of refrigerant flowing from the discharge chamber to the crank chamber of the variable capacity compressor based on the differential pressure across the other valve section, thereby changing the discharge capacity of the variable capacity compressor. , The flow rate of refrigerant flowing through the other valve unit is controlled to be constant,
  The solenoid operates the other valve unit so that a flow rate of refrigerant flowing through the other valve unit becomes a set flow rate;
  A control valve for a variable capacity compressor. The flexible member is made of a diaphragm,
The elastic member comprises a disc spring disposed along the diaphragm;
The control valve for a variable capacity compressor according to claim 13 . The disc spring has a shape in which the central portion protrudes toward the reaction force transmitting member, and the direction in which the central portion protrudes is reversed and deformable with the peripheral edge as a fulcrum. The control valve for a variable capacity compressor according to claim 15 , characterized in that: 17. The control valve for a variable capacity compressor according to claim 16 , wherein an inner wall of the housing is formed in a shape that substantially conforms to a shape when the disc spring is inverted and deformed.

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