JP2004278511A - Control valve for variable displacement compressor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a control valve for a variable displacement compressor capable of controlling the variable displacement compressor to the minimum capacity without using an electromagnetic clutch, and being constructed without accommodating a solenoid in a pressure chamber. <P>SOLUTION: A plunger of the solenoid is formed by a first plunger 21 and a second plunger 32, and a diaphragm 26 sensing suction pressure Ps is disposed between them, such that the first plunger 21 controls a valve element 16 via a shaft, with component elements of the solenoid except for the first plunger 21 being disposed on a side of the diaphragm 26 where the atmospheric pressure is received. Further, when the solenoid is not energized, the high suction pressure Ps urges the second plunger 32 toward the core 31 side via the diaphragm 26, and a spring 24 causes the first plunger 21 to urge the valve element 16 to the fully open position, which enables the variable displacement compressor to be controlled to the minimum capacity. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a control valve for a variable displacement compressor, and more particularly to a control valve for a variable displacement compressor that controls the discharge capacity of a refrigerant in a variable displacement compressor of an air conditioner for an automobile.

  A compressor used in a refrigeration cycle of an automotive air conditioner uses an engine whose rotation speed changes according to a running state as a driving source, and thus cannot perform rotation speed control. Therefore, in general, a variable displacement compressor capable of changing the discharge capacity of the refrigerant is used in order to obtain an appropriate cooling capacity without being restricted by the engine speed.

  In general, a variable displacement compressor is configured such that a swinging plate provided with a variable inclination angle is driven by a rotating motion of a rotating shaft in an airtight crank chamber to perform a swinging motion, and the swinging motion of the swinging plate is performed. As a result, the piston reciprocating in the direction parallel to the rotation axis draws the refrigerant in the suction chamber into the cylinder and compresses it, and then discharges it to the discharge chamber. At this time, by changing the pressure in the crank chamber, the inclination angle of the swing plate is changed, thereby changing the refrigerant discharge amount. The control valve for the variable displacement compressor controls so as to change the pressure in the crank chamber.

  Such a variable displacement compressor control valve for variably controlling the capacity of a compressor generally introduces a part of the refrigerant having a discharge pressure Pd discharged from a discharge chamber into a hermetically formed crank chamber. The pressure Pc in the crank chamber is controlled by controlling the amount of introduction, and the amount of introduction is controlled according to the suction pressure Ps of the suction chamber. That is, the control valve for the variable displacement compressor senses the suction pressure Ps and controls the flow rate of the refrigerant having the discharge pressure Pd introduced from the discharge chamber into the crank chamber so that the suction pressure Ps is kept constant. I have.

  For this reason, the control valve for a variable displacement compressor is provided with a pressure sensing portion for sensing the suction pressure Ps, and a valve portion for opening and closing the passage from the discharge chamber to the crank chamber in accordance with the suction pressure Ps sensed by the pressure sensing portion. And Further, in the control valve for a variable displacement compressor in which the value of the suction pressure Ps at the time of entering the variable displacement operation can be freely set from the outside, a solenoid capable of changing the set value of the pressure sensing section by an external current is used. Have.

  By the way, among the conventional control valves for a variable displacement compressor that can be controlled externally, there is an electromagnetic clutch that transmits or cuts off a driving force to an engine between an engine and a rotating shaft provided with a rocking plate. There is a control valve for controlling a variable displacement compressor having a configuration in which an engine and a rotating shaft are directly connected without using a compressor (for example, see Patent Document 1).

This control valve has a valve section that controls opening and closing of a passage from the discharge chamber to the crank chamber, a solenoid that generates an electromagnetic force that causes the valve section to act in the closing direction, and a suction pressure Ps that is lower than the atmospheric pressure. It has a configuration in which a pressure-sensitive portion that causes the valve portion to act in the opening direction as it becomes lower is arranged in this order. For this reason, when the solenoid is not energized, the valve portion is in the fully opened state, and the pressure Pc in the crank chamber can be maintained at a pressure close to the discharge pressure Pd, whereby the swing plate is moved with respect to the rotating shaft. Thus, the variable capacity compressor can be operated at the minimum capacity. This means that even if the engine and the rotating shaft are directly connected, the discharge capacity can be made substantially close to zero, so that the electromagnetic clutch can be eliminated.
JP-A-2000-110731 (paragraph numbers [0010], [0044], FIG. 1)

  However, in a conventional control valve for controlling a variable displacement compressor that does not require an electromagnetic clutch, a pressure sensing portion and a valve portion are arranged with a solenoid interposed therebetween, and a sense for comparing the suction pressure Ps with the atmospheric pressure. Since the pressure section is configured to guide the suction pressure Ps via the solenoid, the entire solenoid must be housed in the pressure chamber, and the solenoid must be designed in consideration of the pressure resistance. There was a problem that it did not become.

  The present invention has been made in view of such a point, and it is possible to control a variable displacement compressor to a minimum capacity without using an electromagnetic clutch, and it is possible to configure the solenoid without accommodating the solenoid in a pressure chamber. An object of the present invention is to provide a control valve for a variable displacement compressor.

  In order to solve the above-mentioned problem, the present invention provides a control valve for a variable displacement compressor in which a discharge capacity of a refrigerant is changed by controlling a pressure in an airtightly formed crank chamber. A control valve for a variable displacement compressor, wherein the control valve is divided into a plunger and a second plunger, and a pressure sensing element for sensing a suction pressure of a suction chamber is arranged between the first plunger and the second plunger. Is provided.

  According to such a variable displacement compressor control valve, a pressure sensitive body is disposed between the first plunger and a solenoid other than the first plunger, and the pressure sensitive body has a large pressure relative to the pressure in the variable displacement compressor. Since the partition between the pressure and the atmospheric pressure is provided, the solenoid can be configured without being housed in the pressure chamber. When the solenoid is not energized, the first plunger urges the valve portion to the fully open position, and the suction pressure urges the second plunger away from the first plunger via the pressure-sensitive body. As a result, the variable displacement compressor can be controlled to the minimum displacement, and thus can be applied to a variable displacement compressor that does not use an electromagnetic clutch.

  As described above, according to the present invention, the plunger of the solenoid is divided into two, the pressure sensing element for sensing the suction pressure is disposed between them, and the pressure of the crank chamber is controlled by one of the divided plungers. The valve opening is controlled. Thus, the portion from the valve portion to the portion where the pressure-sensitive element is disposed, including the plunger on the side for controlling the opening of the valve portion, is configured as a portion to which pressure is applied, and the portion for controlling the opening of the valve portion is configured. Solenoids other than the plunger can be configured to be open to the atmosphere without being housed in the pressure chamber.

  Also, when the solenoid is not energized, the pressure-sensitive element separates from the plunger on the side that controls the opening of the valve section, and the displacement of the pressure-sensitive element is not transmitted to the valve section, and the valve section is maintained in the fully open state. Therefore, the variable displacement compressor can be controlled to the minimum displacement without using the electromagnetic clutch.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a central longitudinal sectional view showing the configuration of the control valve for a variable displacement compressor according to the first embodiment.

  The control valve for a variable displacement compressor has a valve section in the upper part of the figure. The valve portion forms a port 12 in which an upper opening of the body 11 communicates with a discharge chamber of the variable displacement compressor and receives a discharge pressure Pd, and a strainer 13 is mounted on the port 12. The port 12 receiving the discharge pressure Pd communicates with the crank chamber of the variable displacement compressor, and internally communicates with a port 14 formed in the body 11 to derive a controlled pressure Pc from the crank chamber. A valve seat 15 is formed integrally with the body 11 in a refrigerant passage communicating the port 12 and the port 14. A valve body 16 is disposed so as to be able to advance and retreat in the axial direction so as to face the discharge seat Pd receiving side of the valve seat 15. The valve body 16 is urged in a valve closing direction by a spring 17, and the load of the spring 17 is adjusted by an adjusting screw 18 screwed to the port 12. A port 19 that communicates with a suction chamber of the variable displacement compressor and receives a suction pressure Ps is formed below the body 11 in the drawing.

  A cylindrical body 20 is arranged on the lower end surface of the body 11, and a first plunger 21 is arranged in the cylindrical body 20 so as to be able to advance and retreat in the axial direction. The first plunger 21 is provided with a guide 22 made of, for example, polytetrafluoroethylene and having a low sliding resistance at a lower position in the figure, and its outer peripheral surface is slidably contacted with the inner wall of the cylindrical body 20. When the first plunger 21 advances and retreats in the axial direction, the first plunger 21 has a function of guiding the inner plunger 21 at a predetermined distance from the inner wall surface. Note that the guide 22 is not provided on the entire circumference, but is partially cut, so that the suction pressure Ps can be introduced into a space formed on the lower end surface side of the first plunger 21. I have.

  The first plunger 21 has a flange portion 23 fixed at the upper end position in the figure by press-fitting, and a spring 24 is inserted between the flange portion 23 and the upper end surface of the tubular body 20. At the upper axis position of the first plunger 21, a lower end portion of a shaft 25 which is disposed so as to be able to advance and retreat in the axial direction with little clearance from the body 11 at the axis position of the body 11 is press-fitted and fixed. Thus, the first plunger 21 is positioned at the axial position of the body 11 by the shaft 25 and the guide 22. The upper end of the shaft 25 extends through the valve hole and is in contact with the valve body 16.

  The spring 24 for urging the first plunger 21 upward in the drawing has a larger spring force than the spring 17 for urging the valve body 16 in the valve closing direction. Therefore, when the solenoid is not energized, the first plunger 21 is in contact with the ceiling of the room communicating with the port 19 and the valve body 16 in contact with the shaft 25 is in its fully open state, as shown in the figure. positioned.

  Below the drawing of the first plunger 21, a diaphragm 26 constituting a pressure-sensitive portion is arranged. The outer peripheral edge of the diaphragm 26 is sandwiched between the cylindrical body 20 and a solenoid case 27 and sealed by a packing 28. The diaphragm 26 is clamped between the cylindrical body 20 and the solenoid case 27 by fixing the upper edge of the case 27 to the lower end of the body 11 with the cylindrical body 20 interposed therebetween by caulking. Is Thus, the portion constituting the pressure chamber of the control valve for the variable displacement compressor is the portion partitioned by the diaphragm 26, and the lower portion of the drawing is a portion to which the atmospheric pressure is applied. The diaphragm 26 is made of a single sheet of, for example, a polyimide film. However, if a plurality of the sheets are used as needed, damage resistance due to repeated collision of the first plunger 21 can be increased.

  An electromagnetic coil 29 is disposed in the case 27, and a sleeve 30 is disposed inside the electromagnetic coil 29. A core 31 is inserted and fixed to the lower part of the sleeve 30 in the drawing. A second plunger 32 is arranged between the core 31 and the diaphragm 26 so as to be able to advance and retreat in the axial direction within the sleeve 30. In the second plunger 32, the upper end of the shaft 33 disposed at the axial position in the figure is press-fitted and fixed, and the lower end of the shaft 33 is inserted into a handle 34 that closes the open end of the case 27. It is supported by a bearing 35 arranged. A spring 36 is disposed between the second plunger 32 and the core 31 to urge the second plunger 32 toward the diaphragm 26.

  An O-ring 37 is provided around the body 11 between the port 12 where the discharge pressure Pd is introduced and the port 14 where the pressure Pc is led to the crank chamber, and guides the port 14 where the pressure Pc is led and the suction pressure Ps. An O-ring 38 is provided around the body 11 between the port 19 and an O-ring 39 for shutting off the suction pressure Ps from atmospheric pressure is provided around the lower end of the case 27 in the drawing. Then, a control current is supplied to the electromagnetic coil 29 via a harness 40.

  In the above-described configuration, the cylindrical body 20, the case 27, and the handle 34 are formed of a magnetic material, and perform the function of a yoke in a magnetic circuit of the solenoid. 20, the first plunger 21, the second plunger 32, the core 31, and the handle 34.

  The illustrated state of the control valve for a variable displacement compressor shows a state where the solenoid is not energized and the suction pressure Ps is high, that is, a state where the air conditioner is not operating. Since the suction pressure Ps is high, the diaphragm 26 is displaced downward in the drawing against the load of the spring 36, and the second plunger 32 is in contact with the core 31. On the other hand, since the first plunger 21 is urged upward in the figure by the spring 24, it is separated from the diaphragm 26 and is not affected by the diaphragm 26 that is displaced by a change in the suction pressure Ps. Further, the first plunger 21 urges the valve body 16 to its fully opened position via the shaft 25. Therefore, in this state, even if the rotary shaft of the variable displacement compressor is rotationally driven by the engine, the variable displacement compressor is operated with the minimum displacement.

  FIG. 2 is a central longitudinal sectional view of the control valve for the variable capacity compressor showing a state when the variable capacity compressor is started, and FIG. 3 is a view showing a state of the control valve for the variable capacity compressor showing a state when the variable capacity compressor is in a steady operation. It is a center longitudinal cross-sectional view.

  When the maximum control current is supplied to the solenoid coil 29 of the solenoid, such as when the variable displacement compressor is started, as shown in FIG. 2, the second plunger 32 is driven by a high suction pressure Ps. Is pressed downward and is in contact with the core 31, so that the core 31 remains at the same position even when the core 31 is sucked. Therefore, at this time, the second plunger 32 and the core 31 behave like a fixed iron core, the second plunger 32 sucks the first plunger 21, and the first plunger 21 is moved through the diaphragm 26 into the second plunger 32. Is adsorbed. Since the first plunger 21 is attracted to the second plunger 32, the shaft 25 is pulled down, so that the valve body 16 is seated on the valve seat by the spring 17, and the valve portion is fully closed. As a result, the passage from the discharge chamber to the crank chamber is blocked, so that the variable displacement compressor immediately shifts to the operation of the maximum displacement.

  When the variable displacement compressor continues to operate at the maximum displacement and the suction pressure Ps in the suction chamber becomes sufficiently low, the diaphragm 26 senses the suction pressure Ps and tries to displace upward in the figure. At this time, if the control current supplied to the electromagnetic coil 29 of the solenoid is reduced according to the set temperature of the air conditioning, as shown in FIG. 3, the first plunger 21, the diaphragm 26 and the second plunger 32 remain in the adsorption state. Together, they move upward in the drawing to a position where the suction pressure Ps, the load of the springs 17, 24, and 36, and the suction force of the solenoid are balanced. As a result, the valve body 16 is pushed up by the shaft 25 and separated from the valve seat 15 to be set to a predetermined opening. Therefore, the refrigerant at the discharge pressure Pd is introduced into the crankcase while being controlled at a flow rate corresponding to the opening degree, and the variable displacement compressor shifts to the operation of the capacity corresponding to the control current.

  When the control current supplied to the solenoid coil 29 of the solenoid is constant, the diaphragm 26 senses the suction pressure Ps and controls the opening of the valve. For example, when the refrigeration load increases and the suction pressure Ps increases, the diaphragm 26 is displaced downward in the drawing, so that the valve body 16 also moves downward, the opening degree of the valve section decreases, and the variable displacement compression is performed. The machine operates to increase the displacement. Conversely, when the refrigeration load decreases and the suction pressure Ps decreases, the diaphragm 26 is displaced upward in the figure and the opening of the valve section increases, so that the variable displacement compressor reduces the displacement. It operates to control the suction pressure Ps to be constant.

  FIG. 4 is a central longitudinal sectional view showing the configuration of the control valve for a variable displacement compressor according to the second embodiment. 4, the same reference numerals are given to the same or equivalent components as those shown in FIG. 1, and the detailed description thereof will be omitted.

  The control valve for a variable displacement compressor according to the second embodiment is different from the control valve for a variable displacement compressor according to the first embodiment in that the port 12 for receiving the discharge pressure Pd from the discharge chamber and the crank The position with respect to the port 14 for deriving the controlled pressure Pc into the chamber is reversed.

  In this control valve for a variable displacement compressor, the valve element 16 and the pressure-sensitive piston 41 are formed integrally, and the discharge pressure Pd from the discharge chamber is introduced into the small diameter portion connecting these. The outer diameter of the pressure-sensitive piston 41 is the same as the inner diameter of the valve hole forming the valve seat 15, and the pressure receiving area of the valve body 16 and the pressure receiving area of the pressure-sensitive piston 41 are the same. As a result, the discharge pressure Pd cancels the force acting on the valve element 16 upward in the figure by the force acting on the pressure-sensitive piston 41 downward in the figure, and the control of the valve element 16 by the solenoid and the diaphragm 26 increases the high discharge pressure. It is not affected by Pd.

  The pressure-sensitive piston 41 has a function for canceling the influence of the discharge pressure Pd and, similarly to the control valve for the variable displacement compressor according to the first embodiment, controls the movement of the solenoid and the diaphragm 26 to the valve body 16. It also has the function of a shaft for transmitting to the shaft.

  Other than that, the configuration in which the plunger is divided into two and the diaphragm 26 is disposed therebetween and the configuration of the solenoid are the same as those of the control valve for the variable displacement compressor according to the first embodiment. Therefore, the operation of the control valve for a variable displacement compressor is the same as that of the control valve for a variable displacement compressor according to the first embodiment, and the description of the operation is omitted.

  FIG. 5 is a central longitudinal sectional view showing the configuration of the control valve for a variable displacement compressor according to the third embodiment. In FIG. 5, the same or equivalent components as those shown in FIG. 1 are denoted by the same reference numerals, and detailed description thereof will be omitted.

  The control valve for a variable displacement compressor according to the third embodiment controls the flow rate of the refrigerant at the discharge pressure Pd introduced into the crank chamber by the control valve for a variable displacement compressor according to the first and second embodiments. In addition to the control, the flow rate of the refrigerant having the pressure Pc released from the crank chamber to the suction chamber is also controlled.

  In this control valve for a variable displacement compressor, a passage communicating with the crank chamber is provided in two parts. That is, the body 11 has a port 14a for introducing the controlled pressure Pc1 to the crank chamber and a port 14b for introducing the pressure Pc2 in the crank chamber. This is to form a passage through which the refrigerant introduced from the discharge chamber and controlled by the valve section once enters the crank chamber and then escapes to the suction chamber, and lubricates the compressor mixed in the refrigerant. This ensures that oil can pass through the crankcase.

  The port 14b from which the refrigerant returns from the crank chamber is opened to a space communicating with the port 19 to the suction chamber via the communication passage 42. This open portion is configured to be opened and closed by the first plunger 21. Therefore, when the valve portion is fully closed, the passage between the crank chamber and the suction chamber is opened, and the transition to the maximum capacity operation is performed by maximizing the flow rate of the refrigerant escaping from the crank chamber to the suction chamber. When the valve section is fully opened, the passage between the crank chamber and the suction chamber is closed, and the flow rate of the refrigerant introduced from the discharge chamber to the crank chamber is maximized to shift to the minimum capacity operation. Can be expedited.

  Other than that, regarding the configuration in which the plunger is divided into the first plunger 21 and the second plunger 32 and the diaphragm 26 is disposed between them, and the configuration of the solenoid, the variable displacement compressor according to the first embodiment is described. Control valve. Therefore, the operation of the control valve for a variable displacement compressor is the same as that of the control valve for a variable displacement compressor according to the first embodiment, and the description of the operation is omitted.

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

  In the control valve for a variable displacement compressor according to the fourth embodiment, when the first plunger 21 collides with the diaphragm 26 when the first plunger 21 is attracted by the second plunger 32 when the solenoid is energized. Buffer means for alleviating the impact. That is, the disk 43 is inserted between the first plunger 21 and the diaphragm 26, the spring 44 is inserted between the first plunger 21 and the disk 43, and the disk 43 is always brought into contact with the diaphragm 26. In addition to the function described above, the variable displacement compressor control valve according to the first to third embodiments has the same function as the spring 24 that biases the first plunger 21 toward the valve section. The disk 43 is held by a guide 22 which is provided around the first plunger 21 and extends below the lower end thereof.

  Thus, since the disk 43 is urged by the spring 44, the second plunger 32, the diaphragm 26, and the disk 43 are always in contact with each other, and always move together. When the solenoid is not energized, the first plunger 21 and the disk 43 are separated by a spring 44 as shown. When the solenoid is energized, the first plunger 21 is sucked by the integrated disk 43, collides with the disk 43 and is sucked. The impact force at that time is buffered and absorbed by the disk 43 and transmitted to the diaphragm 26, so that the impact on the diaphragm 26 is reduced.

  Other than that, regarding the configuration in which the plunger is divided into the first plunger 21 and the second plunger 32 and the diaphragm 26 is disposed between them, and the configuration of the solenoid, the variable displacement compressor according to the first embodiment is described. Control valve. Therefore, the operation of the control valve for a variable displacement compressor is the same as that of the control valve for a variable displacement compressor according to the first embodiment, and the description of the operation is omitted.

  FIG. 7 is a central longitudinal sectional view showing the configuration of the control valve for a variable displacement compressor according to the fifth embodiment. 7, the same reference numerals are given to the same or equivalent elements as the constituent elements shown in FIG. 4, and the detailed description thereof will be omitted.

  The control valve for a variable displacement compressor according to the fifth embodiment includes a mechanism for adjusting the load of the spring 36 in the control valve for a variable displacement compressor according to the second embodiment shown in FIG. I have. That is, an adjusting screw 45 is screwed to the handle 34 at the lower end in the figure, and the adjusting screw 45 is formed in a shape that supports the lower end of the shaft 33 so as to be movable in the axial direction. I have. In the middle of the shaft 33, a retaining ring 46 is fitted, and a spring receiver 47 is provided so that the upward movement of the drawing is restricted by the retaining ring 46. The spring receiver 47, the adjusting screw 45 A spring 36 is disposed between the two. Thus, by adjusting the screw-in amount of the adjusting screw 45 into the handle 34, the load of the spring 36 can be adjusted, and the set value of the control valve for the variable displacement compressor can be adjusted.

  FIG. 8 is a central longitudinal sectional view showing the configuration of the control valve for a variable displacement compressor according to the sixth embodiment. In FIG. 8, the same or equivalent elements as those shown in FIGS. 6 and 7 are denoted by the same reference numerals, and detailed description thereof will be omitted.

  The control valve for a variable displacement compressor according to the sixth embodiment is configured such that the first plunger 21 and the disk 43 are guided by a sleeve 48 fixed to the cylindrical body 20 by press fitting so as to be able to advance and retreat in the axial direction. And the first plunger 21 is in contact with a pressure-sensitive piston 41 formed integrally with the valve body 16. The cylindrical body 20 has a circular space between the cylindrical body 20 and the sleeve 48 whose diameter is enlarged in the lower part of the figure, and a communication hole 49 is provided in a step portion thereof, and a port through which the suction pressure Ps is introduced. 19 and the space on the upper surface of the diaphragm 26 are communicated with each other. Further, a connector 50 to which a connector of a harness is connected is provided at a lower end portion in the figure of the solenoid. The connector 50 has an adjusting screw 45 for adjusting the load of the spring 36, and a communication hole 51 for communicating the inside of the solenoid with the atmosphere. Other configurations are the same as the configuration of the variable displacement compressor control valve according to the fourth embodiment shown in FIG. 6 except that the valve element 16 has a tapered shape. The description of the operation is omitted.

  FIG. 9 is a central longitudinal sectional view showing the configuration of the control valve for a variable displacement compressor according to the seventh embodiment. In FIG. 9, the same or equivalent components as those shown in FIG. 8 are denoted by the same reference numerals, and detailed description thereof will be omitted.

  The control valve for a variable displacement compressor according to the seventh embodiment is different from the control valve for a variable displacement compressor according to the sixth embodiment shown in FIG. 8 in that the first plunger 21 and the disk 43 are centered. While this is performed by the sleeve 48 fixed to the cylindrical body 20, it is performed by another method. That is, the first plunger 21 is centered by being fitted into a pressure-sensitive piston 41 integral with the valve body 16, and the disk 43 has a diaphragm protruding from the center of the end face on the side of the diaphragm 26. The centering is performed by fitting into a concave portion provided in the center of the second plunger 26 and the second plunger 32. The same effect can be obtained by providing a concave portion on the disk 43 and providing convex portions on the diaphragm 26 and the second plunger 32. The other configuration is the same as the configuration of the control valve for a variable displacement compressor according to the fifth embodiment shown in FIG. 7, and therefore the description of the operation is omitted.

  FIG. 10 is a central longitudinal sectional view showing the configuration of the control valve for a variable displacement compressor according to the eighth embodiment. 10, the same or equivalent components as those shown in FIGS. 7 and 8 are denoted by the same reference numerals, and detailed description thereof will be omitted.

  The control valve for a variable displacement compressor according to the eighth embodiment differs from the control valve for a variable displacement compressor according to the fifth embodiment shown in FIG. 7 in that the shape of the first plunger 21 is changed. The structure is such that it abuts 26 quickly.

  That is, the first plunger 21 is held slidably in contact with the inner wall of the cylindrical body 20 by a C-shaped guide 22 provided around the first plunger 21 so as to be able to advance and retreat in the axial direction at a predetermined distance from the inner wall surface. ing. Therefore, the first plunger 21 is held by the tubular body 20 with a relatively large clearance from the tubular body 20. The first plunger 21 is formed such that the end face facing the diaphragm 26 is not a plane but a plane near the center and a gently tapered shape around the center, or a circular cross section with a large radius.

  When the guide 22 is made of, for example, polytetrafluoroethylene having a characteristic of expanding and contracting depending on the type of heat or refrigerant, the first plunger 21 and the second plunger 32 draw when the first plunger 21 and the second plunger 32 are sucked by supplying power to the solenoid. There is a case where the diaphragm 21 comes into contact with the diaphragm 26 after being inclined. At this time, the end face of the first plunger 21 facing the diaphragm 26 comes into contact with the tapered portion, so that the valve body 16 can be quickly closed. Thus, a two-stage operation that occurs when the end face of the first plunger 21 facing the diaphragm 26 is flat, that is, the outer peripheral surface of the first plunger 21 comes into contact with the diaphragm 26 due to the suction force. Since the two-stage operation in which the plane of the abutment 21 contacts the diaphragm 26 does not take place, the valve body 16 can be quickly closed, and the phenomenon that the first plunger 21 stops in the first-stage operation does not occur. The body 16 can be closed with high accuracy.

  The control valve for a variable displacement compressor has a tapered end face of the first plunger 21 with the diaphragm 26, and the first plunger 21 is held by two guides 22 as shown in FIG. Since the configuration is the same as that of the control valve for a variable displacement compressor according to the fifth embodiment shown in FIG.

  FIG. 11 is a central longitudinal sectional view showing the configuration of the control valve for a variable displacement compressor according to the ninth embodiment. 11, the same reference numerals are given to the same or equivalent components as those shown in FIG. 10, and the detailed description is omitted.

  The control valve for a variable displacement compressor according to the ninth embodiment is different from the control valve for a variable displacement compressor according to the eighth embodiment shown in FIG. 10 in that the control valve senses the suction pressure Ps. The difference is that bellows is used for the pressure body.

  That is, the bellows 52 is disposed between the first plunger 21 and the second plunger 32. The bellows 52 has a flange portion extending in the radial direction at the upper end face in the figure, clamped by the cylindrical body 20 and the solenoid case 27, and sealed by the packing 28. The lower end surface of the bellows 52 in the figure is closed and is in contact with the second plunger 32. The first plunger 21 is formed integrally with a cylindrical body 53 below the figure, and the cylindrical body 53 is located in a hollow portion of the bellows 52. When the solenoid is in a non-energized state and the first plunger 21 is urged upward in the drawing by the spring 24, the cylindrical body 53 of the first plunger 21 is separated from the bellows 52.

  The control valve for a variable displacement compressor is the same as the control valve for a variable displacement compressor according to the eighth embodiment shown in FIG. 10 except that a bellows 52 is used as a pressure-sensitive body. Therefore, the operation is the same as that of the control valve for a variable displacement compressor according to the eighth embodiment, and the description of the operation is omitted.

  FIG. 12 is a partially enlarged central longitudinal sectional view illustrating a configuration of a valve section of a control valve for a variable displacement compressor according to a tenth embodiment. 12, elements that are the same as or equivalent to the elements shown in FIG. 11 are given the same reference numerals, and detailed descriptions thereof will be omitted.

  The control valve for a variable displacement compressor according to the tenth embodiment is configured such that the pressure receiving balance of the discharge pressure Pd in the valve portion is broken and the full-open state can be quickly established regardless of the state of the suction pressure Ps. It is.

  That is, in the control valve for a variable displacement compressor shown in FIGS. 4 and 7 to 11, the port arrangement of the valve portion is in the order of the suction pressure Ps, the discharge pressure Pd, and the pressure Pc into the crank chamber from the solenoid side. Thus, the highest discharge pressure Pd does not affect the control of the valve element 16. This is because the inner diameter A of the valve hole is made equal to the outer diameter B of the pressure-sensitive piston 41 so that the pressure-receiving area of the valve element 16 and the pressure-receiving area of the pressure-sensitive piston 41 are the same. This is achieved by canceling the force acting on the body 16 upward in the figure by the force acting on the pressure-sensitive piston 41 downward in the figure. In the configuration in which the discharge pressure Pd is canceled, the valve portion of the valve body 16 is controlled by the pressure difference (Pc-Ps) between the pressure Pc into the crank chamber and the suction pressure Ps.

  However, the differential pressure (Pc−Ps) between the pressure Pc applied to the valve element 16 and the suction pressure Ps applied to the pressure-sensitive piston 41 is higher than the suction pressure Ps because the pressure Pc is higher than the suction pressure Ps. This means that a load is applied to the self-closing side. For this reason, for example, when the power supply to the solenoid is turned off to open the valve portion fully, the spring 24 urging the first plunger 21 in the valve opening direction pushes the pressure-sensitive piston 41 to open the valve element 16. Although the valve is separated from the seat 15, the load applied to the self-closing side increases as the differential pressure (Pc-Ps) increases, so that the valve portion gradually becomes difficult to open, and in some cases, a phenomenon that the valve portion does not open occurs. In particular, in a variable displacement compressor that does not require an electromagnetic clutch, the control valve is forcibly opened to control the discharge capacity to a minimum when the power supply to the solenoid is turned off, regardless of the suction pressure Ps. There is a need to.

  Therefore, in this variable displacement compressor control valve, the inner diameter A of the valve hole is set to be, for example, about 3% larger than the outer diameter B of the pressure-sensitive piston 41, and the pressure receiving area of the valve element 16 is larger than the pressure receiving area of the pressure-sensitive piston 41. By increasing the pressure, the receiving pressure balance of the discharge pressure Pd is broken toward the valve opening direction. As a result, even if the differential pressure (Pc-Ps) increases, the load applied to the self-closing side is reduced, so that when the power supply to the solenoid is turned off, the valve portion is reliably fully opened by the urging force of the spring 24. Will be able to do that.

  FIG. 13 is a central longitudinal sectional view showing the configuration of the control valve for a variable displacement compressor according to the eleventh embodiment. In FIG. 13, the same or equivalent components as those shown in FIGS. 5 and 10 are denoted by the same reference numerals, and detailed description thereof will be omitted.

  The control valve for a variable displacement compressor according to the eleventh embodiment controls the discharge pressure Pd of the refrigerant introduced into the crank chamber by the control valve for a variable displacement compressor according to the eighth embodiment shown in FIG. In addition to controlling the flow rate of the refrigerant introduced into the crank chamber while canceling, the flow rate of the refrigerant having the pressure Pc released from the crank chamber to the suction chamber is also controlled.

  That is, the body 11 is provided with a port 14a for leading the refrigerant to the crank chamber and a port 14b for introducing the refrigerant from the crank chamber. The port 14b is connected to the first plunger 21 by the refrigerant passage 54 coaxial with the pressure-sensitive piston 41. Communicates with the space in which is accommodated. A valve body 55 is formed integrally with an end of the pressure-sensitive piston 41 on the solenoid side, and an end surface thereof is in contact with the first plunger 21. The valve body 55 has a valve body structure of a spool valve, and when the valve body 16 is lifted from the valve seat 15, closes the refrigerant passage 54 to block the flow of the refrigerant from the crank chamber to the suction chamber. When the valve body 16 is seated on the valve seat 15, the refrigerant passage 54 is opened to allow the refrigerant in the crank chamber to escape to the suction chamber via the port 19. As a result, the pressure Pc in the crank chamber can be quickly increased and decreased, and the variable displacement compressor can be promptly shifted to the minimum displacement operation or the maximum displacement operation.

1 is a central longitudinal sectional view showing a configuration of a control valve for a variable displacement compressor according to a first embodiment. FIG. 3 is a central longitudinal sectional view of the control valve for the variable displacement compressor, showing a state when the variable displacement compressor is started. It is a center longitudinal cross-sectional view of the control valve for variable capacity compressors which shows the state at the time of the variable capacity compressor at the time of steady operation. It is a center longitudinal section showing the composition of the control valve for variable displacement compressors concerning a 2nd embodiment. It is a center longitudinal section showing the composition of the control valve for variable displacement compressors concerning a 3rd embodiment. It is a center longitudinal section showing the composition of the control valve for variable displacement compressors concerning a 4th embodiment. It is a center longitudinal section showing the composition of the control valve for variable displacement compressors concerning a 5th embodiment. It is a center longitudinal section showing the composition of the control valve for variable displacement compressors concerning a 6th embodiment. It is a center longitudinal section showing the composition of the control valve for variable displacement compressors concerning a 7th embodiment. It is a center longitudinal section showing the composition of the control valve for variable displacement compressors concerning an 8th embodiment. It is a center longitudinal section showing the composition of the control valve for variable displacement compressors concerning a 9th embodiment. It is a partial expansion central longitudinal section explaining the composition of the valve part of the control valve for variable displacement compressors concerning a 10th embodiment. It is a center longitudinal section showing the composition of the control valve for variable displacement compressors concerning an eleventh embodiment.

Explanation of reference numerals

11 Body 12 Port 13 Strainer 14, 14a, 14b Port 15 Valve Seat 16 Valve Body 17 Spring 18 Adjust Screw 19 Port 20 Cylindrical Body 21 First Plunger 22 Guide 23 Flange 24 Spring 25 Shaft 26 Diaphragm 27 Case 28 Packing 29 Electromagnetic Coil 30 Sleeve 31 Core 32 Second plunger 33 Shaft 34 Handle 35 Bearing 36 Spring 37, 38, 39 O-ring 40 Harness 41 Pressure sensitive piston 42 Communication path 43 Disk 44 Spring 45 Adjust screw 46 Retaining ring 47 Spring receiver 48 Sleeve 49 Communication Hole 50 Connector 51 Communication hole 52 Bellows 53 Cylindrical body 54 Refrigerant passage 55 Valve body Pc Pressure in crank chamber Pd Discharge pressure Ps Suction pressure

Claims (20)

In a control valve for a variable displacement compressor, which controls the pressure in the airtightly formed crank chamber to change the discharge capacity of the refrigerant,
A variable plunger, wherein a plunger of a solenoid is divided into a first plunger and a second plunger, and a pressure sensing element for sensing a suction pressure of a suction chamber is arranged between the first plunger and the second plunger. Control valve for displacement compressor.   The first plunger is disposed between the valve unit that controls the pressure in the crank chamber and the pressure-sensitive element so as to open the valve unit, and the second plunger is energized by the solenoid. At the time, the first plunger is attracted to the first plunger via the pressure sensing element to be integrated with the first plunger, and is urged in a direction away from the first plunger by the suction pressure received by the pressure sensing element when the power is not supplied. The control valve for a variable displacement compressor according to claim 1.   The control valve for a variable displacement compressor according to claim 2, wherein the pressure-sensitive body is a diaphragm.   4. The control valve for a variable displacement compressor according to claim 3, wherein the diaphragm is made of a polyimide film.   The control valve for a variable displacement compressor according to claim 4, wherein the polyimide film is configured by stacking a plurality of the polyimide films.   The control valve for a variable displacement compressor according to claim 2, wherein the pressure-sensitive body is a bellows.   3. The variable displacement compressor according to claim 2, wherein the valve portion is disposed between first and second ports respectively communicating with a discharge chamber of the variable displacement compressor and the crank chamber. 4. Control valve.   The valve portion is configured such that a valve seat formed in a passage between the first port communicating with the discharge chamber of the variable displacement compressor and the second port communicating with the crank chamber has A valve body disposed so as to be able to freely contact and separate from the side of the first port, and a shaft arranged between the valve body and the first plunger for transmitting the movement of the first plunger to the valve body. The control valve for a variable displacement compressor according to claim 7, wherein   The valve portion is configured such that a valve seat formed in a passage between the first port communicating with the discharge chamber of the variable displacement compressor and the second port communicating with the crank chamber has A valve element disposed so as to be able to freely contact and separate from the side of the second port, an outer diameter substantially equal to an inner diameter of a valve hole forming the valve seat, the same pressure receiving area as the valve element, and the valve element An end face on the solenoid side is formed integrally with the valve body to receive the suction pressure and transmit the movement of the first plunger to the valve body while receiving the discharge pressure from the discharge chamber in the opposite direction. The control valve for a variable displacement compressor according to claim 7, further comprising: a pressure-sensitive piston.   2. The control valve for a variable displacement compressor according to claim 1, wherein a buffering means is arranged between the pressure sensing element and the first plunger.   The buffering means has a disk disposed between the pressure-sensitive body and the first plunger, and a spring that constantly urges the disk to contact the pressure-sensitive body. The control valve for a variable displacement compressor according to claim 10, wherein:   The control valve for a variable displacement compressor according to claim 11, wherein the first plunger and the disk are centered by a sleeve.   The first plunger is centered by being fixed to a pressure-sensitive piston that is formed integrally with a valve body of a valve unit that controls the pressure in the crank chamber and that is held movably in the axial direction. The centering is performed by fitting the concave / convex portion formed at the center of the end face facing the pressure sensitive body with the concave / convex portion formed at the center of the pressure sensitive body and the second plunger. The control valve for a variable displacement compressor according to claim 11, wherein   The first plunger is fixed to a pressure-sensitive piston whose side for controlling a pressure in the crank chamber is formed integrally with a valve body of the valve portion and is held movably in the axial direction. 2. The control valve for a variable displacement compressor according to claim 1, wherein the side of the control valve is held by a C-shaped guide provided around the outside.   2. The variable displacement compression according to claim 1, wherein the first plunger is held movably in the axial direction by two C-shaped guides provided around the outer periphery of the first plunger while being spaced apart in the axial direction. Control valve for machine.   16. The control valve for a variable displacement compressor according to claim 15, wherein the first plunger has a tapered surface in contact with the pressure-sensitive body to reduce the area of a plane facing the pressure-sensitive body. .   The valve portion is configured such that a valve seat formed in a passage between the first port communicating with the discharge chamber of the variable displacement compressor and the second port communicating with the crank chamber has A valve element disposed so as to be able to freely contact and separate from the side of the second port, an outer diameter smaller than an inner diameter of a valve hole forming the valve seat, a pressure receiving area smaller than the valve element, and the valve element. An end face on the solenoid side is formed integrally with the valve body to receive the suction pressure and transmit the movement of the first plunger to the valve body while receiving the discharge pressure from the discharge chamber in the opposite direction. The control valve for a variable displacement compressor according to claim 7, further comprising: a pressure-sensitive piston.   The valve portion is provided between first and second ports communicating with the discharge chamber and the crank chamber of the variable displacement compressor, respectively, and third and fourth ports communicating with the crank chamber and the suction chamber, respectively. Disposed between the first port and the second port, the valve being disposed to be able to freely contact and separate from the first port side with respect to a valve seat formed in a first passage between the first port and the second port. A body disposed between the valve body and the first plunger for transmitting the movement of the first plunger to the valve body; and a shaft connected to the third port and the fourth port. 3. The control valve for a variable displacement compressor according to claim 2, wherein the first plunger opens and closes a second passage therebetween.   The valve portion is provided between first and second ports communicating with the discharge chamber and the crank chamber of the variable displacement compressor, respectively, and third and fourth ports communicating with the crank chamber and the suction chamber, respectively. Between the first port and the second port, and a valve seat formed in a first passage between the first port and the second port is disposed so as to be able to freely contact and separate from a side of the second port. A first valve body, an outer diameter substantially equal to an inner diameter of a valve hole formed integrally with the first valve body and forming the valve seat, the same pressure receiving area as the valve body, and the valve body A pressure-sensitive piston that receives a discharge pressure from the discharge chamber in a reverse direction, and opens and closes a second passage between the third port and the fourth port. Receiving the pressure to transmit the movement of the first plunger to the valve body; The control valve according to claim 2, characterized in that it comprises a piston and the second valve body formed integrally. The solenoid includes a spring that urges the second plunger toward the first plunger against the suction pressure received by the pressure sensing element, and an adjusting screw that adjusts a load of the spring. The control valve for a variable displacement compressor according to claim 1, wherein:

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