JP2006112417A - Control valve for variable displacement compressor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a control valve for a variable displacement compressor of constant flow control type compactly formed without requiring a pressure sensor for detecting a pressure difference. <P>SOLUTION: This control valve comprises a first valve 11 formed of a check valve opening/closing by a pressure difference between a discharge pressure Pdh from a discharge chamber and a discharge pressure Pdl at the outlet of the variable displacement compressor, a second valve 12 opening and closing by detecting a pressure difference between the discharge pressure Pdh and a pressure Pc in a crankcase, and a solenoid 14 setting a pressure difference for the first valve 11. The movement of the valve element 20 of the first valve 11 is transmitted to the valve element 27 of the second valve 12 through a shaft 29. Thus, the second valve 12 controls the pressure Pc of the crankcase so that a pressure difference between areas across the first valve 11 is equal to a specified pressure difference set by the solenoid 14 to control constant the flow of a refrigerant discharged from the outlet of the variable displacement compressor. <P>COPYRIGHT: (C)2006,JPO&NCIPI

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 mounted on a variable capacity compressor that constitutes a refrigeration cycle of an automotive air conditioner and that controls the flow rate of refrigerant discharged therefrom. About.

  Since the compressor used for compressing the refrigerant in the refrigeration cycle of the air conditioner for automobiles uses the engine as a drive source, the rotational speed control cannot be performed. Therefore, in order to obtain an appropriate cooling capacity without being restricted by the engine speed, a variable capacity compressor capable of changing the compression capacity of the refrigerant is used.

  In such a variable capacity compressor, a compression piston is connected to a swing plate attached to a shaft that is rotationally driven by an engine, and the stroke of the compression piston is changed by changing the angle of the swing plate. The amount of refrigerant discharged is changed.

  The angle of the swing plate is continuously increased by introducing a part of the compressed refrigerant into the sealed crank chamber, changing the pressure of the introduced refrigerant, and changing the balance of pressure applied to both sides of the compression piston. Is changing.

  The pressure in the crank chamber is changed 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. This variable capacity compressor control valve is, for example, controlled so as to be communicated or closed so as to keep the differential pressure across the valve that controls the flow rate of the refrigerant flowing from the discharge chamber to the crank chamber at a predetermined pressure value. Specifically, the differential pressure can be set to a predetermined pressure value by changing the control current value of the control valve for the variable capacity compressor from the outside. As a result, when the engine speed increases and the discharge pressure increases, the pressure introduced into the crank chamber increases and the capacity of the refrigerant that can be compressed is changed to be small, and when the engine speed decreases, The capacity of the refrigerant that can be compressed by reducing the pressure introduced is greatly varied so that the compression capacity of the variable capacity compressor is kept constant regardless of the engine speed.

  As one method for controlling the compression capacity of such a variable capacity compressor, a control valve for a variable capacity compressor that controls the flow rate of refrigerant discharged from the variable capacity compressor to be constant is known. (For example, refer to Patent Document 1).

According to this control valve for a variable capacity compressor, two pressure sensors are provided at positions separated in the flow direction of the refrigerant passage toward the suction chamber, and suction is performed by detecting a differential pressure between the two pressure monitoring points. The flow rate of the refrigerant to be indirectly monitored, and the control valve for the variable capacity compressor controls the flow rate of the refrigerant introduced from the discharge chamber to the crank chamber so that the suction flow rate becomes constant, thereby the variable capacity compressor The flow rate of the refrigerant discharged from is controlled so as to be constant.
JP 2001-107854 A (paragraph numbers [0034] to [0036], FIGS. 2 and 3)

  However, the conventional variable displacement compressor control valve that controls the variable displacement compressor so that the refrigerant discharge flow rate is constant detects the differential pressure in the refrigerant circulation passage to control the variable displacement compressor control valve. Therefore, an expensive pressure sensor and a control device are required to increase the cost of the air conditioner for automobiles.

  The present invention has been made in view of these points, and is used in a variable capacity compressor in which the discharge flow rate of refrigerant is controlled to be constant, and a pressure sensor for detecting a differential pressure is provided. An object of the present invention is to provide a control valve for a variable capacity compressor that can be configured compactly without being required.

  In the present invention, in order to solve the above problem, in a control valve for a variable capacity compressor that controls the refrigerant discharged from the variable capacity compressor to a constant flow rate, the variable valve is introduced from the discharge chamber of the variable capacity compressor and is variable. A first valve in which a passage area is set according to the flow rate of refrigerant flowing out to the outlet of the capacity compressor, and the variable capacity compressor so as to keep a differential pressure before and after the first valve at a predetermined differential pressure A second valve that controls the pressure of the crank chamber in conjunction with the first valve, and a flow rate of the refrigerant that is to be controlled for a differential pressure before and after the passage area set by the first valve. And a solenoid for setting the predetermined differential pressure. A control valve for a variable capacity compressor is provided.

  According to such a control valve for a variable capacity compressor, the first valve detects the differential pressure between the discharge pressure on the discharge chamber side and the discharge pressure on the outlet side of the variable capacity compressor, and the second valve discharges The differential pressure between the discharge pressure on the chamber side and the pressure in the crank chamber is detected, and the second valve is cranked so that the differential pressure before and after the first valve is maintained at a predetermined differential pressure set by a solenoid. Operates to control chamber pressure. As a result, the first valve indirectly measures the discharge flow rate of the refrigerant, so that a pressure sensor for that purpose becomes unnecessary, and the cost of the automotive air conditioner can be reduced.

  The control valve for a variable capacity compressor according to the present invention is configured to indirectly measure the refrigerant discharge flow rate with the first valve and control the crank valve pressure by controlling the second valve based on the value. This eliminates the need for an expensive pressure sensor for measuring the discharge flow rate, and has the advantage that the cost of the automotive air conditioner can be reduced.

  Further, since the first valve is structured to open according to the flow rate of the refrigerant flowing from the discharge chamber of the variable capacity compressor toward the outlet, the variable capacity compressor shifts to the operation of the minimum capacity and the refrigerant The valve is closed when the flow rate reaches the minimum flow rate, and when the relationship between the pressure at the discharge chamber and outlet of the variable capacity compressor is reversed, just after shifting to the minimum capacity operation, the valve is maintained closed. Since the pressure at the outlet is maintained at the pressure before the transition to the minimum capacity operation, the check valve provided at the outlet of the variable capacity compressor can be eliminated for this purpose. There is an advantage that can be reduced.

  Furthermore, since the first valve has a larger pressure receiving area for receiving the discharge pressure on the discharge chamber side than the second valve, when the rotational speed of the variable capacity compressor changes abruptly, the capacity caused thereby It is possible to react quickly in a direction to suppress the change, and it is possible to configure a variable capacity compressor with good responsiveness.

Embodiments of the present invention will be described below in detail with reference to the drawings, taking as an example a control valve that is applied to a flow rate control type variable displacement compressor that controls the flow rate of discharged refrigerant at a constant level.
FIG. 1 is a central longitudinal sectional view showing a detailed structure of a control valve for a variable capacity compressor according to a first embodiment.

  The variable displacement compressor control valve 10 according to the first embodiment includes a first valve 11 that operates according to the flow rate of refrigerant discharged from the variable displacement compressor, and a crank chamber of the variable displacement compressor. The second valve 12 that controls the pressure Pc, the third valve 13 that controls the amount of refrigerant leakage, and a solenoid 14 that can set the flow rate of refrigerant discharged from the variable capacity compressor from the outside. ing.

  The first valve 11 is formed in a first body 15 disposed at the upper end of the drawing. When the variable capacity compressor control valve 10 is mounted on the variable capacity compressor, the first body 15 has a port 16 that communicates with a discharge chamber of the variable capacity compressor and into which a refrigerant having a discharge pressure Pdh is introduced. And a port 17 through which the refrigerant having the discharge pressure Pdl is led out in communication with the outlet of the variable capacity compressor, and a refrigerant passage 18 connecting these ports 16 and 17 is provided inside. A valve seat 19 is formed in the refrigerant passage 18 in the middle, and a valve body 20 is disposed on the side of the port 17 with respect to the valve seat 19 so as to be able to contact with and separate from the valve seat 19. The body 20 is biased in a direction to close the refrigerant passage 18 by a spring 21 having a weak spring force. Here, the valve seat 19 and the valve body 20 constitute the first valve 11 and open when the discharge pressure Pdh at the port 16 is higher than the urging force of the spring 21 than the discharge pressure Pdl at the port 17, Other than that, it has the structure of the non-return valve which closes.

  The second valve 12 is formed in a second body 22 having a first body 15 fixed thereto by press-fitting. The second body 22 has a refrigerant introduction space formed between the first body 15 and the first body 15 by fitting, and the refrigerant introduction space is formed in the refrigerant passage formed in the first body 15. The refrigerant having the discharge pressure Pdh is introduced from the discharge chamber of the variable capacity compressor through the valve 23. A strainer 24 is provided on the refrigerant inlet side of the refrigerant passage 23 formed in the first body 15. In the second body 22, when the variable capacity compressor control valve 10 is mounted on the variable capacity compressor, the refrigerant of the pressure Pc controlled in communication with the crank chamber of the variable capacity compressor is transferred to the crank chamber. It has a port 25 which is led out toward A valve hole is provided in the upper center of the second body 22 between the refrigerant introduction space and the internal space communicating with the port 25, and is in contact with the valve seat 26 formed on the lower end surface of the valve hole. A separable valve body 27 is held by the second body 22. The valve body 27 is urged in a direction away from the valve seat 26 by a spring 28. Here, the valve seat 26 and the valve body 27 constitute a second valve 12 that controls the flow rate of the refrigerant having the discharge pressure Pdh and supplies the refrigerant having the pressure Pc to the crank chamber, that is, a so-called Pd-Pc valve.

  The first body 15 is further formed with a through hole in its axial direction, and a shaft 29 is disposed so as to be able to advance and retract in the axial direction through the through hole and the valve hole of the second valve 12. . The upper part of the shaft 29 in the figure is loosely fitted to the valve body 20 of the first valve 11, and the lower part of the figure is loosely fitted to the valve body 27 of the second valve 12. The upper portion of the shaft 29 has an outer diameter larger than the inner diameter of the through hole of the first body 15. As a result, when the shaft 29 moves downward in the figure, the taper stepped portion at the boundary between the upper part and the lower part comes into contact with the upper end surface of the through hole, and the clearance between the shaft 29 and the through hole is closed. Thus, this valve mechanism constitutes the third valve 13.

  A hole is formed in the lower center of the second body 22 in the figure, and the opening edge of the bottomed sleeve 30 is tightly coupled to the hole. In the bottomed sleeve 30, a core 31 and a plunger 32 of the solenoid 14 are provided. The core 31 is fixed by press-fitting to the hole in the lower center of the first body 15 and the bottomed sleeve 30. The plunger 32 is disposed in the bottomed sleeve 30 so as to be slidable in the axial direction, and is fixed to one end of a shaft 33 disposed through the core 31 in the axial direction. The plunger 32 is also urged in the direction of the core 31 by a spring 34 so that the other end of the shaft 33 abuts the lower end surface of the valve body 27 of the second valve 12 in the figure. A coil 35 is disposed on the outer periphery of the bottomed sleeve 30, and a harness 36 for supplying power to the coil 35 is led out to the outside. The middle portion of the bottomed sleeve 30 communicates with an internal space communicating with the port 25 through a pressure equalizing hole 37 formed in the second body 22.

  In the variable displacement compressor control valve 10 having the above configuration, when the solenoid 14 is in a non-energized state, the spring 28 of the second valve 12 is applied to the biasing force of the spring 34 of the solenoid 14 as shown in FIG. Accordingly, the valve body 27 is urged away from the valve seat 26, and the second valve 12 is fully opened. Further, the first valve 11 is fully closed because the valve body 20 is seated on the valve seat 19 by the urging force of the spring 21.

  FIG. 1 also shows the state of the variable displacement compressor control valve 10 immediately after the automotive air conditioner stops operating. This is a case where the automobile air conditioner has been operated so far and the solenoid 14 is in a non-energized state. In this case, since the solenoid 14 has no force to attract the plunger 32 to the core 31, the second valve 12 opens the valve body 27 against the urging force of the spring 34 of the solenoid 14. By being urged in the direction, it is fully opened. Therefore, the introduced refrigerant having the discharge pressure Pdh is supplied from the port 25 to the crank chamber via the strainer 24, the refrigerant passage 23 and the second valve 12, and the variable capacity compressor is shifted to its minimum capacity operation. . As a result, the variable capacity compressor hardly performs work, so the discharge pressure Pdh introduced into the variable capacity compressor control valve 10 becomes lower than the discharge pressure Pdl at the outlet of the variable capacity compressor. The first valve 11 is fully closed by the pressure.

  Further, when the variable capacity compressor is operating at a predetermined capacity, the valve body 20 of the first valve 11 moves away from the valve seat 19, and at that time, the shaft 29 is moved downward in the figure. And the third valve 13 is closed. In this state, when the solenoid 14 is deenergized, the valve body 20 of the first valve 11 moves upward in the figure, and the valve body 27 of the second valve 12 moves downward in the figure, the shaft 29 A high discharge pressure Pdl is applied to the upper portion and a lower discharge pressure Pdh is applied to the lower portion, thereby maintaining the valve closed state. As a result, the clearance between the shaft 29 and the through hole is closed, and the discharge pressure Pdl maintained at a high pressure leaks to the upstream side of the second valve 12 that is lower than this via the clearance. Nothing will happen.

  As a result, the outlet pressure of the variable capacity compressor can maintain the discharge pressure Pdl before the automobile air conditioner is stopped. This is advantageous in that the efficiency of the variable capacity compressor is improved since it is not necessary to compress from the beginning to the discharge pressure Pdl when the automotive air conditioner resumes operation. Usually, a check valve for this purpose is provided at the outlet of the variable capacity compressor, but the function is provided by the first valve 11 of the control valve 10 for the variable capacity compressor. Accordingly, there is an effect that a check valve is not required and the cost of the variable capacity compressor can be reduced.

Next, the operation of the variable displacement compressor control valve 10 will be described in detail with reference to FIGS.
FIG. 2 is an enlarged cross-sectional view of a main part showing a state immediately after energization of the variable displacement compressor control valve according to the first embodiment, and FIG. 3 is a diagram of the variable displacement compressor control valve according to the first embodiment. FIG. 4 is an enlarged cross-sectional view of a main part showing a transition state after energization, FIG. 4 is an enlarged cross-sectional view of the main part showing a balance state of the control valve for a variable capacity compressor according to the first embodiment, and FIG. It is a principal part expanded sectional view which shows the transient state at the time of the discharge pressure rapid increase of the control valve for variable capacity compressors which concerns on a form.

  First, assuming that the solenoid 14 shown in FIG. 1 has passed a predetermined current from the non-energized state, immediately after that, the second valve 12 is attached to the solenoid 14 as shown in FIG. It is fully closed instantaneously by power. As a result, the variable capacity compressor starts operating at the maximum capacity, but immediately after this energization, the discharge pressure Pdh is still lower than the discharge pressure Pdl at the outlet of the variable capacity compressor, so the first valve 11 Is in a fully closed state. At this time, the shaft 29 is pushed upward by the valve element 27 of the second valve 12 and the third valve 13 is opened, but through the clearance between the shaft 29 and the through hole. Although the discharge pressure Pdl leaks to the discharge pressure Pdh, this leakage is very small, and the discharge pressure Pdh is about to increase immediately, so that there is no particular problem.

  The variable capacity compressor starts operation at the maximum capacity, and when the discharge pressure Pdh is sufficiently higher than the discharge pressure Pdl, as shown in FIG. 3, the valve body 20 is separated from the valve seat 19 by the differential pressure. Move to. As a result, the first valve 11 is opened, and the refrigerant having the discharge pressure Pdh introduced into the port 16 becomes the discharge pressure Pdl and flows from the port 17 to the outlet of the variable capacity compressor. At this time, the refrigerant flow rate having a value obtained by multiplying the passage area formed by opening the first valve 11 by the differential pressure across the first valve 11 flows through the first valve 11.

  The valve body 20 of the first valve 11 comes in contact with the upper end of the shaft 29 lifted upward by the valve body 27 of the second valve 12 by moving in the valve opening direction. . As a result, the first valve 11 and the second valve 12 are interlocked with each other via the shaft 29, and the second valve 12 is connected to the discharge pressure Pdh and the discharge pressure Pdl of the first valve 11. And the differential pressure between the discharge pressure Pdh and the pressure Pc are detected.

  When the differential pressure between the discharge pressure Pdh of the first valve 11 and the discharge pressure Pdl further increases, the pressure receiving area of the valve body 20 of the first valve 11 is larger than the pressure receiving area of the valve body 27 of the second valve 12. Therefore, the valve body 20 of the first valve 11 urges the valve body 27 of the second valve 12 in the valve opening direction by the differential pressure before and after that, and the differential pressure between the discharge pressure Pdh and the discharge pressure Pdl. 4 reaches a predetermined value, as shown in FIG. 4, the pressure applied before and after the first valve 11 and the second valve 12, the load of the springs 21 and 28, and the current value of the solenoid 14 are adjusted. The second valve 12 is slightly opened at a place where the power is balanced, and the controlled pressure Pc is supplied to the crank chamber, so that the capacity of the variable capacity compressor is controlled.

  In other words, the control valve 10 for the variable capacity compressor has the second pressure so that the pressure difference between the front and the back of the passage area formed by the refrigerant flowing out of the discharge chamber flowing through the first valve 11 is kept at the pressure difference set by the solenoid 14. The valve 12 controls the crank chamber pressure to control the discharge flow rate of the variable capacity compressor at a constant level. That is, for example, if the engine speed is increased and the discharge pressure Pdh is increased, the valve body 20 of the first valve 11 is increased in the valve body 27 of the second valve 12 by the amount of the differential pressure before and after that. Energize in the direction to open more. As a result, the crank chamber pressure Pc increases, so that the variable capacity compressor is controlled so as to reduce the capacity so that a predetermined discharge flow rate is obtained. Conversely, when the discharge pressure Pdh decreases and the differential pressure across the first valve 11 decreases, the valve body 20 urges the valve body 27 of the second valve 12 in a more closing direction. As a result, the crank chamber pressure Pc decreases, so that the variable capacity compressor operates in a direction to increase the capacity and is controlled to have a predetermined discharge flow rate.

  By the way, the discharge pressure Pdh of the refrigerant discharged from the discharge chamber changes sensitively in response to changes in the rotational speed of the variable capacity compressor. Therefore, when the engine speed increases rapidly and the variable capacity compressor speed increases rapidly, the discharge pressure Pdh also increases rapidly. In such a case, since the pressure receiving area of the valve body 20 of the first valve 11 is set larger than the pressure receiving area of the valve body 27 of the second valve 12 in the control valve 10 for the variable displacement compressor, the first The force that the valve body 20 of the first valve 11 further urges the valve body 27 of the second valve 12 in the valve opening direction due to the change in the differential pressure before and after that instantaneously increases, as shown in FIG. In addition, the second valve 12 opens for a moment larger than the normal valve opening operation, and the variable capacity compressor is quickly controlled to reduce the capacity. On the other hand, when the engine speed rapidly decreases and the discharge pressure Pdh decreases rapidly, the valve body 20 of the first valve 11 operates greatly in the direction to close instantaneously. Therefore, the variable capacity compressor is quickly controlled to increase the capacity. Thus, after reacting with a rapid response to the sudden change in the discharge pressure Pdh, the variable capacity compressor control valve 10 can quickly restore the variable capacity compressor to a predetermined discharge capacity.

  FIG. 6 is a central longitudinal sectional view showing the detailed configuration of the control valve for a variable capacity compressor according to the second embodiment. In FIG. 6, the same or equivalent components as those shown in FIG. 1 are denoted by the same reference numerals, and detailed description thereof is omitted.

  The variable displacement compressor control valve 10a according to the second embodiment operates as detected by the second valve 12 compared to the variable displacement compressor control valve 10 according to the first embodiment. The pressure to change is changed. That is, the second valve 12 of the variable displacement compressor control valve 10 according to the first embodiment senses the differential pressure between the discharge pressure Pdh on the discharge side and the pressure Pc of the crank chamber. The second valve 12 of the variable displacement compressor control valve 10a according to the second embodiment senses a differential pressure between the discharge pressure Pdh on the discharge side and the suction pressure Ps of the suction chamber.

  In the variable capacity compressor control valve 10a, the second body 22 is provided with a port 38 through which the suction pressure Ps is introduced in communication with the suction chamber of the variable capacity compressor when the control valve 10a is attached to the variable capacity compressor. It has been. The second body 22 also holds a shaft 39 formed integrally with the valve body 27 of the second valve 12 between the port 25 of the pressure Pc and the port 38 of the suction pressure Ps so as to be movable forward and backward in the axial direction. is doing. The shaft 39 has an outer diameter substantially equal to the effective diameter at which the second valve 12 receives the discharge pressure Pdh, and the valve body 27 receives the discharge pressure Pdh on the discharge side. Is configured such that the lower end surface thereof receives the suction pressure Ps of the suction chamber and senses the differential pressure therebetween. In order to accurately sense the differential pressure between the discharge pressure Pdh and the suction pressure Ps, the outer diameter of the shaft 39 may be made equal to the inner diameter of the valve hole of the second valve 12, but this second embodiment. Then, in order to simplify the configuration of the portion that supports the shaft 39, the outer diameter of the shaft 39 is made larger than the inner diameter of the valve hole of the second valve 12 so that the operation of the second valve 12 is not substantially affected. It is. A spring 28 that urges the valve element 27 of the second valve 12 in the valve opening direction is provided at the lower end of the shaft 39. In the variable displacement compressor control valve 10a, the bottomed sleeve 30 of the solenoid 14 communicates with the port 38, and the suction pressure Ps is introduced therein.

  In the variable capacity compressor control valve 10a configured as described above, the variable valve according to the first embodiment is operated except that the second valve 12 operates by sensing the differential pressure between the discharge pressure Pdh and the suction pressure Ps. Since the operation is the same as that of the compressor control valve 10, detailed description thereof is omitted.

  FIG. 7 is a central longitudinal sectional view showing a detailed configuration of a control valve for a variable capacity compressor according to a third embodiment, and FIG. 8 is an enlarged view of the cross section taken along the line AA in FIG. 9 is an enlarged cross-sectional view showing a main part of the variable displacement compressor control valve according to the third embodiment in a non-energized state, and FIG. 10 is an energization of the variable displacement compressor control valve according to the third embodiment. The principal part expanded sectional view which shows the state immediately after is shown, FIG. 11 is the principal part expanded sectional view which shows the state at the time of control of the control valve for variable displacement compressors concerning 3rd Embodiment. 7 to 11, the same or equivalent components as those shown in FIG. 1 are denoted by the same reference numerals, and detailed description thereof is omitted.

  The variable displacement compressor control valve 10b according to the third embodiment differs greatly from the variable displacement compressor control valves 10 and 10a according to the first and second embodiments in that 1 valve 11 configuration. In other words, the first valve 11 of the variable displacement compressor control valves 10 and 10a according to the first and second embodiments has a passage area corresponding to the refrigerant flow rate, whereas the third embodiment has The first valve 11 of the variable displacement compressor control valve 10b is configured such that the passage area does not change according to the refrigerant flow rate in the normal control range.

  The first valve 11 has a valve body 20 that is disposed so that a refrigerant passage 18 formed in the first body 15 can advance and retreat in the axial direction. As shown in FIG. 8, the valve body 20 has a plurality of guides 40 integrally formed on the outer periphery thereof, and guides the valve body 20 along the refrigerant passage 18 in the axial direction, and the refrigerant flow rate changes. Thus, a refrigerant passage 41 is formed between the inner wall of the refrigerant passage 18 and the passage area does not change even if the valve lift changes.

  In the first valve 11, a tubular valve seat forming member 42 is disposed on the upstream side facing the valve body 20. The valve seat forming member 42 is press-fitted into the port 16 into which the refrigerant having the discharge pressure Pdh is introduced, and constitutes the first valve 11 together with the valve body 20.

  Further, in the valve body 20 of the first valve 11, a shaft 29 constituting the valve body of the third valve 13 is disposed so as to be movable forward and backward in the axial direction of the valve body 20. A spring 21 is inserted between the valve body 20 and the shaft 29 to urge the valve body 20 and the shaft 29 away from each other, and when the solenoid 14 is in a non-energized state, the first valve 11 The third valve 13 is maintained in the closed state.

  In the second valve 12, the valve body 27 is formed integrally with the shaft 33 of the solenoid 14, and the spring 28 urging the valve body 27 in the valve opening direction includes the core 31 and the plunger 32 of the solenoid 14. It is inserted between. The shaft 14 of the solenoid 14 is also terminated by a transmission shaft 43 extending through the valve hole of the second valve 12, and the transmission shaft 43 is connected to the refrigerant passage 23 and the outlet of the variable capacity compressor. A hole formed between the port 17 and the port 17 is slidable in the axial direction of the shaft 33.

  In the variable displacement compressor control valve 10b having the above-described configuration, when the solenoid 14 is in a non-energized state, the first valve 11 and the third valve 13 are moved by the spring 21 as shown in FIG. 20 and the shaft 29 are urged away from each other, the valve body 20 is seated on the end surface of the valve seat forming member 42, and the shaft 29 is seated on the opening end of the hole supporting the transmission shaft 43. Both are fully closed. Further, the spring 28 of the solenoid 14 urges the plunger 32 in the direction away from the core 31 against the urging force of the spring 34, and thereby, a second shaft formed integrally with the shaft 33 fixed to the plunger 32. The valve body 27 of the valve 12 is moved downward in the figure, and the second valve 12 is fully opened.

  Accordingly, the variable capacity compressor is rotationally driven by the engine, and thereby the refrigerant having the discharge pressure Pdh introduced from the discharge chamber of the variable capacity compressor passes through the strainer 24, the refrigerant passage 23, and the second valve 12 to the port 25. Therefore, the variable capacity compressor is operated at its minimum capacity. When the non-energized state of the solenoid 14 is a state after the variable capacity compressor is operated at a predetermined capacity, the discharge pressure Pdh of the port 16 connected to the discharge chamber is the port 17 connected to the outlet of the variable capacity compressor. Therefore, the first valve 11 having the check valve structure is maintained in the fully closed state by the differential pressure.

  Next, assuming that the solenoid 14 shown in FIG. 9 has passed a predetermined current from the non-energized state, immediately after that, as shown in FIG. It is fully closed instantaneously by the biasing force. As a result, the variable capacity compressor shifts to the maximum capacity operation. Immediately after this energization, the discharge pressure Pdh is still lower than the discharge pressure Pdl at the outlet of the variable capacity compressor. Is in a fully closed state. At this time, the shaft 29 of the third valve 13 is pushed upward in the figure by the transmission shaft 43 integral with the valve body 27 of the second valve 12.

  When the variable capacity compressor continues to operate at its maximum capacity and the discharge pressure Pdh is higher than the discharge pressure Pdl by a predetermined value or more, the valve body 20 is pushed open by these differential pressures as shown in FIG. Thereby, in the first valve 11, the refrigerant having the discharge pressure Pdh introduced into the port 16 passes through the refrigerant passage 41 formed between the valve body 20 and the inner wall of the refrigerant passage 18 and becomes the discharge pressure Pdl. Then, it flows from the port 17 to the outlet of the variable capacity compressor.

  When the first valve 11 is opened, the valve body 20 abuts on the upper end surface of the shaft 29 in the figure, and the lower end surface of the shaft 29 in the figure abuts on the upper end surface of the transmission shaft 43 in the figure. After the opening of the first valve 11, the valve body 20 of the first valve 11, the valve body 27 of the second valve 12, and the shaft 29 of the third valve 13 operate integrally. . For this reason, the first valve 11 and the second valve 12 are interlocked with each other via the shaft 29, and the second valve 12 has a discharge pressure Pdh between the first valve 11 and the discharge pressure Pdl. The operation is performed by detecting the differential pressure and the differential pressure between the discharge pressure Pdh and the pressure Pc.

  Here, it is assumed that the variable capacity compressor control valve 10b receives a predetermined energization current to control the variable capacity compressor to a predetermined capacity and is balanced in the state shown in FIG. Here, for example, if the engine speed increases and the discharge pressure Pdh increases, the valve body 20 of the first valve 11 is lifted by the increase in the differential pressure before and after that, and the first valve 11 is lifted via the shaft 29. The valve body 27 of the second valve 12 is urged in a direction to open more. As a result, the crank chamber pressure Pc increases, so that the variable capacity compressor is controlled so as to reduce the capacity so that a predetermined discharge flow rate is obtained. Conversely, when the discharge pressure Pdh decreases and the differential pressure across the first valve 11 decreases, the valve body 20 urges the valve body 27 of the second valve 12 in a more closing direction. As a result, the crank chamber pressure Pc decreases, so that the variable capacity compressor operates in a direction to increase the capacity and is controlled to have a predetermined discharge flow rate.

  FIG. 12 is a central longitudinal sectional view showing a detailed configuration of a control valve for a variable capacity compressor according to a fourth embodiment. In FIG. 12, components that are the same as or equivalent to those shown in FIG. 7 are given the same reference numerals, and detailed descriptions thereof are omitted.

  The variable displacement compressor control valve 10c according to the fourth embodiment introduces refrigerant into the second valve 12 as compared with the variable displacement compressor control valve 10b according to the third embodiment. The difference is that the port 44 is formed independently of the port 16 for introducing the refrigerant into the first valve 11. The port 44 is provided on the side surface of the second body 22, and O-rings are provided on both sides in the axial direction of the valve body 27 with the port 44 interposed therebetween.

  A part of the refrigerant having the discharge pressure Pdh introduced from the discharge chamber of the variable capacity compressor to the port 16 of the first valve 11 can be introduced into the port 44 of the second valve 12. However, preferably, the variable capacity compressor control valve 10c is applied to a variable capacity compressor having an oil separator downstream of the discharge chamber, and the refrigerant having the discharge pressure Pdh2 at the outlet of the oil separator is supplied to the port 44. It is good to introduce to.

  FIG. 13 is a central longitudinal sectional view showing a detailed configuration of a control valve for a variable capacity compressor according to a fifth embodiment. In FIG. 13, the same or equivalent components as those shown in FIG. 12 are denoted by the same reference numerals, and detailed description thereof is omitted.

  The variable displacement compressor control valve 10d according to the fifth embodiment has the same internal structure as the variable displacement compressor control valve 10c according to the fourth embodiment. The difference is that the positions of the port 44 for introducing the refrigerant and the port 25 for deriving the refrigerant are interchanged with respect to the second valve 12.

  With this port arrangement, the refrigerant having the pressure Pc controlled from between the valve body 27 of the second valve 12 and the transmission shaft 43 formed integrally with the shaft 33 of the solenoid 14 passes through the port 25. Is derived. Since the pressure Pc is applied in the axial direction opposite to the valve body 27 and the transmission shaft 43 and canceled, the influence of the pressure Pc on the control operation of the variable displacement compressor control valve 10d can be eliminated. Therefore, the variable capacity compressor control valve 10d is not affected by the pressure Pc, and the passage area of the refrigerant passage 41 between the valve body 20 of the first valve 11 and the inner wall of the refrigerant passage 18 is reduced. A flow rate determined by the differential pressure between the discharge pressure Pdh before and after the refrigerant passage 41 and the discharge pressure Pdl can flow. The differential pressure between the discharge pressure Pdh and the discharge pressure Pdl is set by the solenoid 14, and the set differential pressure controls the crank chamber pressure Pc in conjunction with the first valve 11 and the second valve 12. As a result, the predetermined value is maintained, so that the flow rate of the refrigerant passing through the first valve 11 toward the outlet of the variable capacity compressor is maintained constant.

  FIG. 14 is a central longitudinal sectional view showing a detailed configuration of a control valve for a variable capacity compressor according to a sixth embodiment. In FIG. 14, the same or equivalent components as those shown in FIG. 12 are denoted by the same reference numerals, and detailed description thereof is omitted.

  Compared with the variable displacement compressor control valve 10d according to the fifth embodiment, the variable displacement compressor control valve 10e according to the sixth embodiment is caused by internal refrigerant leakage during variable displacement control. It has a structure with improved impact.

  That is, the variable displacement compressor control valve 10e is connected to the suction chamber between the port 17 of the discharge pressure Pdl and the port 25 of the crank chamber pressure Pc with respect to the port arrangement of the variable displacement compressor control valve 10d. A port 45 of the suction pressure Ps that communicates is formed. As a result, the distance between the port 17 of the discharge pressure Pdl and the port 25 of the pressure Pc is increased, and the transmission shaft 43 of the shaft 33 is also lengthened. Therefore, the distance between the transmission shaft 43 and the third valve 13 is different. A component shaft 46 is inserted so that one end of the movable portion of the solenoid 14 is supported only by the transmission shaft 43.

  With such a configuration, when the variable displacement compressor control valve 10e is performing variable displacement control of the variable displacement compressor, the third valve 13 is open, and thus supports the shaft 46 and the shaft 46. Even if the refrigerant having the discharge pressure Pdl leaks through the clearance with the first body 15, the leaked refrigerant flows out to the suction chamber via the port 45 and does not flow to the port 25 leading to the crank chamber. . Therefore, no refrigerant leakage occurs in the crank chamber that directly determines the discharge capacity of the variable capacity compressor, so that the pressure Pc in the crank chamber does not change and the capacity control of the variable capacity compressor is accurately performed. Can do. Note that refrigerant leaks between the port 25 for deriving the controlled pressure Pc and the port 45 for the suction pressure Ps even through the clearance between the transmission shaft 43 and the first body 15 supporting the shaft. Occurs. However, since this clearance has a smaller passage area than the orifice provided between the crank chamber and the suction chamber in the variable capacity compressor and flowing the refrigerant from the crank chamber to the suction chamber, the capacity of the variable capacity compressor If the passage area of the orifice is set in consideration of the clearance without affecting the control, the influence of the clearance due to the refrigerant leakage can be substantially eliminated.

  In the above embodiment, it is assumed that the present invention is applied to a system using HFC-134a as an alternative chlorofluorocarbon as a refrigerant in a refrigeration cycle. On the other hand, when applied to a system using a refrigerant having a very high operating pressure such as carbon dioxide, since the high pressure must be controlled, particularly in the second valve 12, the pressure receiving area is reduced. In order to reduce this, it is necessary to design the valve diameter to be small, and it is necessary to change the sealing method with the outside when the variable displacement compressor control valve is mounted on the variable displacement compressor. In the following, an embodiment in consideration of application to a system using carbon dioxide as a refrigerant will be described.

  FIG. 15 is a central longitudinal sectional view showing a detailed configuration of a control valve for a variable capacity compressor according to a seventh embodiment. In FIG. 15, the same or equivalent components as those shown in FIG. 13 are denoted by the same reference numerals, and detailed description thereof is omitted.

  The variable displacement compressor control valve 10f according to the seventh embodiment is formed integrally with the shaft 33 of the solenoid 14 in the variable displacement compressor control valve 10d according to the fifth embodiment. The valve body 27 and the transmission shaft 43 of the second valve 12 are configured separately, and are biased by the spring 28 in the valve opening direction of the second valve 12. Thereby, the valve element 27 of the second valve 12 can be formed of a thin but strong material, and the degree of freedom in design can be increased. In the variable displacement compressor control valve 10f, the second body 22 and the core 31 of the solenoid 14 are integrally formed, and the core 31 is press-fitted into a bottomed sleeve 30 having a flange at the open end. Yes. A packing 47 is disposed on the outer peripheral edge of the flange. The packing 47 is formed of a material that does not permeate the refrigerant and cause external leakage. Furthermore, a screw thread 49 for attaching to the variable capacity compressor is engraved on the outer periphery of the case 48 constituting the solenoid yoke near the flange.

FIG. 16 is a diagram illustrating an example in which the control valve for a variable capacity compressor according to the seventh embodiment is applied to a variable capacity compressor of a carbon dioxide system.
The variable capacity compressor has a crank chamber 51 formed in an airtight manner, and has a rotating shaft 52 that is rotatably supported therein. One end of the rotary shaft 52 extends to the outside of the crank chamber 51 via a shaft seal device (not shown), and a pulley 53 to which driving force is transmitted from the vehicle engine is fixed. The rotating shaft 52 is provided with a swinging plate 54 with a variable inclination angle. A plurality (one in the illustrated example) of cylinders 55 are arranged around the axis of the rotation shaft 52. Each cylinder 55 is provided with a piston 56 that converts the rotational movement of the swing plate 54 into a reciprocating movement. Each cylinder 55 is connected to a suction chamber 59 and a discharge chamber 60 via a suction relief valve 57 and a discharge relief valve 58, respectively. A variable displacement compressor control valve 10f is disposed between the discharge chamber 60 and an outlet port 61 formed so as to communicate with the discharge chamber 60 and between the discharge chamber 60 and the crank chamber 51. An orifice 62 is provided between the suction chamber 59 and the suction chamber 59. The variable capacity compressor further has a passage indicated by a broken line in the drawing that communicates from the discharge chamber 60 to the control valve 10f for the variable capacity compressor. The variable capacity compressor control valve 10f is inserted into the mounting hole of the variable capacity compressor and screwed into the variable capacity compressor.

  The variable capacity compressor has an outlet port 61 connected to a gas cooler 63, an internal heat exchanger 64, and an expansion valve 65 through a high-pressure refrigerant line. From the expansion valve 65, an evaporator 66 and an accumulator 67 are connected through a low-pressure refrigerant line. And it connects to the inlet port formed so that it may connect with the suction chamber 59 via the internal heat exchanger 64 again, and the closed circuit refrigeration cycle is comprised.

  In the variable capacity compressor configured as described above, when the driving force is transmitted from the engine and the rotating shaft 52 rotates, the swing plate 54 provided on the rotating shaft 52 swings while rotating. Then, the piston 56 connected to the outer peripheral portion of the swing plate 54 reciprocates in a direction parallel to the axial direction of the rotary shaft 52, whereby the refrigerant having the suction pressure Ps in the suction chamber 59 is sucked into the cylinder 55. The refrigerant having the compressed discharge pressure Pdh is compressed into the discharge chamber 60 and discharged into the discharge chamber 60. At this time, the high-pressure refrigerant in the discharge chamber 60 is depressurized to the discharge pressure Pdl when passing through the variable displacement compressor control valve 10f, and is sent from the outlet port 61 to the gas cooler 63. The refrigerant is introduced into the crank chamber 51 through the variable displacement compressor control valve 10f. As a result, the pressure Pc in the crank chamber 51 rises, and the inclination angle of the swing plate 54 is determined so that the bottom dead center of the piston 56 is at a position where the pressure in the cylinder 55 and the pressure Pc in the crank chamber 51 are balanced. It is done. Thereafter, the refrigerant introduced into the crank chamber 51 is returned to the suction chamber 59 through the orifice 62.

  In the variable capacity compressor control valve 10f, the first valve 11 detects the flow rate of the refrigerant sent from the discharge chamber 60 to the gas cooler 63, and the second valve 12 supplies the flow rate of the refrigerant according to the detected flow rate to the crank chamber. The refrigerant is introduced into 51 and controlled so that the flow rate of the refrigerant sent from the discharge chamber 60 to the gas cooler 63 is constant. For example, when the engine speed increases, the discharge pressure Pdh increases. As a result, the flow rate of the refrigerant sent from the discharge chamber 60 to the gas cooler 63 via the variable capacity compressor control valve 10f increases, and the differential pressure across the first valve 11 increases. As the differential pressure increases, the second valve 12 opens, and the refrigerant flow rate at the discharge pressure Pdh2 introduced into the crank chamber 51 also increases, so the pressure Pc in the crank chamber 51 increases. Accordingly, the variable displacement compressor tilts in the direction in which the swing plate 54 is perpendicular to the rotation shaft 52 and reduces the stroke of the piston 56, so that the compression capacity of the cylinder 55 is reduced, and the refrigerant capacity is reduced. Reduce the discharge flow rate. As described above, even if the engine speed increases and the flow rate of the discharged refrigerant increases, the variable capacity compressor control valve 10f increases the flow rate of the refrigerant introduced into the crank chamber 51 as the refrigerant flow rate increases. Since the control is performed to increase the pressure Pc of the crank chamber 51 and decrease the discharge capacity, the flow rate of the refrigerant discharged from the variable capacity compressor is controlled to be constant. Similarly, when the engine speed decreases, the flow rate of the refrigerant at the discharge pressure Pdl sent from the discharge chamber 60 to the gas cooler 63 via the variable displacement compressor control valve 10f decreases, so that the refrigerant is introduced into the crank chamber 51. Since the flow rate of the refrigerant having the discharge pressure Pdh2 also decreases and the pressure Pc in the crank chamber 51 decreases, the variable capacity compressor is controlled so that the discharge capacity of the refrigerant increases, and the flow rate of the discharged refrigerant Is controlled to be constant.

It is a center longitudinal cross-sectional view which shows the detailed structure of the control valve for variable capacity compressors which concerns on 1st Embodiment. It is a principal part expanded sectional view which shows the state immediately after electricity supply of the control valve for variable displacement compressors which concerns on 1st Embodiment. It is a principal part expanded sectional view which shows the transition state after electricity supply of the control valve for variable capacity compressors which concerns on 1st Embodiment. It is a principal part expanded sectional view which shows the balance state of the control valve for variable capacity compressors which concerns on 1st Embodiment. It is a principal part expanded sectional view which shows the transient state at the time of the discharge pressure rapid increase of the control valve for variable capacity compressors which concerns on 1st Embodiment. It is a center longitudinal cross-sectional view which shows the detailed structure of the control valve for variable capacity compressors which concerns on 2nd Embodiment. It is a center longitudinal cross-sectional view which shows the detailed structure of the control valve for variable capacity compressors concerning 3rd Embodiment. It is the figure which expanded and showed the AA arrow cross section of FIG. It is a principal part expanded sectional view which shows the control valve for variable capacity compressors which concerns on 3rd Embodiment in the state which is not energized. It is a principal part expanded sectional view which shows the state immediately after electricity supply of the control valve for variable displacement compressors concerning 3rd Embodiment. It is a principal part expanded sectional view which shows the state at the time of control of the control valve for variable displacement compressors concerning 3rd Embodiment. It is a center longitudinal cross-sectional view which shows the detailed structure of the control valve for variable capacity compressors which concerns on 4th Embodiment. It is a center longitudinal cross-sectional view which shows the detailed structure of the control valve for variable capacity compressors which concerns on 5th Embodiment. It is a center longitudinal cross-sectional view which shows the detailed structure of the control valve for variable capacity compressors concerning 6th Embodiment. It is a center longitudinal cross-sectional view which shows the detailed structure of the control valve for variable capacity compressors concerning 7th Embodiment. It is a figure which shows an example which applied the control valve for variable displacement compressors concerning 7th Embodiment to the variable displacement compressor of a carbon dioxide system.

Explanation of symbols

10, 10a to 10f Variable displacement compressor control valve 11 First valve 12 Second valve 13 Third valve 14 Solenoid 15 First body 16, 17 Port 18 Refrigerant passage 19 Valve seat 20 Valve body 21 Spring 22 Second 2 Body 23 Refrigerant passage 24 Strainer 25 Port 26 Valve seat 27 Valve body 28 Spring 29 Shaft 30 Bottomed sleeve 31 Core 32 Plunger 33 Shaft 34 Spring 35 Coil 36 Harness 37 Equal pressure hole 38 Port 39 Shaft 40 Guide 41 Refrigerant passage 42 Valve Seat forming member 43 Transmission shaft 44, 45 Port 46 Shaft 47 Packing 48 Case 49 Thread 51 Crank chamber 52 Rotating shaft 53 Pulley 54 Swing plate 55 Cylinder 56 Piston 57 Relief valve for suction 58 Relief valve for discharge 59 Suction 60 the discharge chamber 61 outlet port 62 orifice 63 gas cooler 64 internal heat exchanger 65 expansion valve 66 evaporator 67 accumulator

Claims (15)

In a control valve for a variable capacity compressor that controls the refrigerant discharged from the variable capacity compressor to a constant flow rate,
A first valve in which a passage area is set according to a flow rate of a refrigerant introduced from a discharge chamber of the variable capacity compressor and flowing out to an outlet of the variable capacity compressor;
A second valve for controlling the pressure in the crank chamber of the variable capacity compressor in conjunction with the first valve so as to keep the differential pressure before and after the first valve at a predetermined differential pressure;
A solenoid for setting the predetermined differential pressure according to the flow rate of the refrigerant to be controlled, the differential pressure before and after the passage area set by the first valve;
A control valve for a variable capacity compressor. The first valve has a first valve seat formed in a first refrigerant passage that introduces refrigerant from the discharge chamber and flows out to the outlet, and from the downstream side facing the first valve seat. A first valve element disposed in an energized state in the valve closing direction,
The second valve has a second valve seat formed in a second refrigerant passage for introducing a refrigerant from the discharge chamber and flowing it out to the crank chamber, and a downstream side facing the second valve seat. A second valve body having a pressure receiving area smaller than that of the first valve body, and a spring for biasing the second valve body in a valve opening direction against a biasing force of the solenoid. Have
Further, the passage area is disposed between the first valve body and the second valve body to transmit the urging force of the solenoid to the first valve body and receive the first valve body. 2. The control valve for a variable capacity compressor according to claim 1, further comprising a shaft for transmitting a change in differential pressure between the front and rear to the second valve body.   The shaft is held in a through-hole formed in the body of the first valve so that the first valve body and the second valve body can be opened and closed in the valve closing direction. When the body side has an outer diameter larger than the inner diameter of the through hole and the second valve is fully opened by the biasing force of the spring when the solenoid is not energized, the clearance between the body and the through hole The control valve for a variable capacity compressor according to claim 2, wherein a third valve for closing the valve is configured.   3. The second valve according to claim 2, wherein the second valve is configured to operate by detecting a differential pressure between a discharge pressure of the refrigerant introduced from the discharge chamber and a pressure of the refrigerant flowing out to the crank chamber. 3. The control valve for a variable capacity compressor according to 3.   The second valve is configured to operate by detecting a differential pressure between a discharge pressure of the refrigerant introduced from the discharge chamber and a suction pressure in the suction chamber of the variable capacity compressor. A control valve for a variable capacity compressor according to 2 or 3.   The second valve includes the second valve body and another shaft having an outer diameter substantially equal to an effective diameter for receiving a discharge pressure of the refrigerant introduced from the discharge chamber and receiving the suction pressure on an end surface thereof. 6. The control valve for a variable capacity compressor according to claim 5, wherein the control valve is integrally formed. In a control valve for a variable capacity compressor that controls the refrigerant discharged from the variable capacity compressor to a constant flow rate,
A first valve having a check valve configuration disposed in a first refrigerant passage introduced from a discharge chamber of the variable capacity compressor and flowing out to an outlet of the variable capacity compressor;
A second valve disposed in a second refrigerant passage introduced from the discharge chamber and flowing into the crank chamber of the variable capacity compressor;
A shaft that is disposed between the first valve and the second valve and transmits a change in the differential pressure before and after the first valve to the second valve to interlock with each other in the same opening and closing direction;
A predetermined differential pressure corresponding to the flow rate of the refrigerant that applies a biasing force in the valve closing direction to the second valve according to the current value and controls the differential pressure before and after the first valve via the shaft. Solenoid set to
A control valve for a variable capacity compressor. In a control valve for a variable capacity compressor that controls the refrigerant discharged from the variable capacity compressor to a constant flow rate,
The lift is made according to the flow rate of the refrigerant introduced from the discharge chamber of the variable capacity compressor and flowing out to the outlet of the variable capacity compressor, and after opening, the passage area of the refrigerant passage does not change regardless of the lift amount. And the valve
A second valve for controlling the pressure in the crank chamber of the variable capacity compressor in conjunction with the first valve so as to keep the differential pressure before and after the first valve at a predetermined differential pressure;
A solenoid that sets the differential pressure before and after the refrigerant passage when the first valve is opened to the predetermined differential pressure according to the flow rate of the refrigerant to be controlled;
A control valve for a variable capacity compressor. The first valve has a first valve seat formed in a first refrigerant passage that introduces refrigerant from the discharge chamber and flows out to the outlet, and an outer peripheral surface on the downstream side of the first valve seat. The first valve body is disposed so as to be able to advance and retract in the axial direction facing the first valve seat in a state of being spaced from the inner wall of the first refrigerant passage, and the first valve A spring for urging the body in the valve closing direction,
The second valve includes a second valve seat formed in a second refrigerant passage for introducing the refrigerant from the discharge chamber and allowing the refrigerant to flow out to the crank chamber, and the solenoid facing the second valve seat. A second valve body which is disposed in a biased state in the valve opening direction so as to be movable back and forth in the axial direction on the side of the first valve body and has a smaller pressure receiving area than the first valve body, and the first valve via the valve hole. A transmission shaft disposed in a through hole communicating with the refrigerant passage and operating integrally with the second valve body,
Further, the urging force of the solenoid applied to the second valve body is transmitted to the first valve body via the transmission shaft, and the differential pressure before and after the refrigerant passage received by the first valve body is reduced. 9. The control valve for a variable capacity compressor according to claim 8, further comprising a shaft for transmitting the change to the second valve body.   The shaft is disposed on the first valve body so as to be able to advance and retreat in the axial direction and is biased toward the second valve with respect to the first valve body by the spring, and the solenoid is energized. The first valve body and the second valve body operate in contact with the transmission shaft biased to advance from the through hole to the first refrigerant passage. When the solenoid is de-energized, the second valve body is urged in the valve opening direction to form a third valve that closes the through hole with which the transmission shaft is retracted. The control valve for a variable displacement compressor according to claim 9, wherein   The control valve for a variable capacity compressor according to claim 9, wherein the second valve body and the transmission shaft of the second valve are formed integrally with the shaft of the solenoid.   The refrigerant inlets of the first refrigerant passage and the second refrigerant passage for introducing the refrigerant from the discharge chamber are communicated with first and second ports formed independently. Item 10. The control valve for a variable displacement compressor according to Item 9.   The second port which is a refrigerant inlet of the second refrigerant passage is disposed closer to the first valve than the second valve seat, and closer to the solenoid than the second valve seat. 13. The control valve for a variable capacity compressor according to claim 12, wherein a third port communicating with the refrigerant outlet of the second refrigerant passage is disposed.   The second port, which is a refrigerant inlet of the second refrigerant passage, is disposed closer to the solenoid than the second valve seat, and closer to the first valve than the second valve seat. 13. The control valve for a variable capacity compressor according to claim 12, wherein a third port communicating with the refrigerant outlet of the second refrigerant passage is disposed. A fifth port communicating with the suction chamber of the variable capacity compressor is disposed between the third port and a fourth port communicating with the refrigerant outlet of the first refrigerant passage; The control valve for a variable capacity compressor according to claim 14, wherein a refrigerant leaking through a clearance between the transmission shaft and the transmission shaft is caused to flow to the fifth port.

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