JP4547332B2 - Control valve for variable capacity compressor - Google Patents

Description

  The present invention relates to a control valve for a variable capacity compressor, and more particularly to a control valve for a variable capacity compressor used in a refrigeration cycle of an automotive air conditioner.

  In an automotive air conditioner, since the rotational speed of the engine that is the power source is not constant, it is necessary to perform control such that the refrigeration capacity is maintained constant regardless of the rotational speed of the engine. In response to this requirement, a swash plate type variable capacity compressor that makes the discharge capacity of the refrigerant variable is generally used. In this variable capacity compressor, a swash plate provided with a variable inclination angle in a crank chamber performs a swinging motion by rotation of a rotating shaft, and a plurality of pistons reciprocate in a direction parallel to the rotating shaft by the swinging motion. Thus, the refrigerant is sucked, compressed, and discharged. At this time, by changing the pressure in the crank chamber with the control valve, the inclination angle of the swash plate is changed, and the stroke of the piston is changed to vary the refrigerant discharge capacity.

  Such a control valve is generally disposed in a refrigerant passage that connects the discharge chamber and the crank chamber, and controls the pressure Pc in the crank chamber by controlling the flow rate of the refrigerant at the discharge pressure Pd introduced from the discharge chamber into the crank chamber. Is controlling. The refrigerant introduced into the crank chamber is drawn into the suction chamber through a fixed orifice. This control valve senses the suction pressure Ps in the suction chamber with a pressure-sensitive member such as a diaphragm, for example, and controls the flow rate of the refrigerant introduced into the crank chamber so that the suction pressure Ps becomes constant.

  In addition, a control valve is disposed in a refrigerant passage that allows communication between the crank chamber and the suction chamber, and a fixed orifice is provided between the discharge chamber and the crank chamber to control the flow rate of the refrigerant extracted from the crank chamber. ing.

  In both variable displacement compressors using both types of control valves, a fixed orifice that does not change the flow path area is inserted in series in the passage from the discharge chamber to the crank chamber or from the crank chamber to the suction chamber. Therefore, in a variable capacity compressor using such a control valve, the amount of refrigerant circulating inside the compressor is increased, so that the compression efficiency is inevitably poor.

  In addition, two valves that operate in conjunction with each other are disposed in the refrigerant passage that communicates the discharge chamber and the crank chamber and the refrigerant passage that communicates the crank chamber and the suction chamber, respectively, and the flow rate of refrigerant entering the crank chamber And a control valve for simultaneously controlling the flow rate of the refrigerant extracted from the crank chamber (for example, Japanese Patent Laid-Open No. 58-158382, FIG. 3). Thus, when the control valve controls to increase the refrigerant flow rate, either the refrigerant passage that communicates the discharge chamber and the crank chamber or the refrigerant passage that communicates the crank chamber and the suction chamber, the other controls the flow rate. Since the control is performed so as to reduce, the flow rate of the refrigerant circulating inside the variable capacity compressor can be reduced, and a variable capacity compressor having better compression efficiency than the control valve having the above-described configuration can be configured.

  Further, two valves that are operated in conjunction with each other are arranged in a refrigerant passage that communicates the discharge chamber and the crank chamber and a refrigerant passage that communicates the crank chamber and the suction chamber, and one of the refrigerant passages is opened. There has also been proposed a control valve configured to close the other refrigerant passage when in the control state (for example, JP-A-64-41680, FIG. 2). Thereby, since the other refrigerant path is closed when one refrigerant path is controlling the refrigerant flow rate, the control valve can further reduce the refrigerant circulating in the variable capacity compressor.

  However, in the control valve described in Japanese Patent Laid-Open No. 58-158382 in which valves are arranged on the inlet side and the outlet side with respect to the former crank chamber, one of the two valves operating in conjunction with each other is closed. Since the other side is opening, there is always an open area, and the flow rate of the refrigerant circulating inside can be reduced only to a certain extent, and a sufficient improvement in compression efficiency has been obtained. There was no problem.

Further, in the control valve described in Japanese Patent Application Laid-Open No. 64-41680 in which the other valve is closed when the latter one valve is open, when the suction pressure is lowered to a first set pressure or lower, Since the refrigerant passage (extraction side) between the suction chamber and the suction chamber is completely closed, the pressure in the crank chamber is reduced against slight changes in the valve of the refrigerant passage (insertion side) between the discharge chamber and the crank chamber. Reacts sensitively. Thus, if the pressure in the crank chamber is increased to over time, be changed placed side opening can not be reduced accumulated gas refrigerant in the crank chamber, naturally sucked with decreasing discharge capacity The pressure rises to the second set pressure or higher, and the outlet side refrigerant passage opens, and the pressure in the crank chamber finally decreases. A so-called hunting phenomenon occurs in which the discharge capacity increases as the pressure in the crank chamber decreases, the suction pressure decreases below the first set pressure, and the above cycle is repeated again. As described above, the latter control valve has a problem in that stable controllability cannot be obtained.

  The present invention has been made in view of the above points, and controls a variable capacity compressor that can improve the compression efficiency by reducing the refrigerant circulation amount inside the variable capacity compressor while obtaining stable controllability. The purpose is to provide a valve.

In the present invention, in order to solve the above problem, in a control valve of a variable capacity compressor capable of varying a refrigerant discharge capacity by controlling a pressure in the crank chamber, the discharge chamber of the variable capacity compressor and the crank A first valve for controlling the flow rate of the refrigerant flowing from the discharge chamber to the crank chamber, and the first valve disposed between the crank chamber and the suction chamber of the variable capacity compressor. When the first valve controls the flow rate of the refrigerant flowing from the discharge chamber to the crank chamber, the flow rate of the refrigerant flowing from the crank chamber to the suction chamber is controlled to a minimum predetermined amount, and the first valve A second valve that controls the flow rate of the refrigerant flowing from the crank chamber to the suction chamber when it is in a fully closed state or in the vicinity of the fully closed state, and the first valve and the second valve that sense the suction pressure in the suction chamber. Valve Comprising a pressure sensitive portion for displacing the lift, and the second valve, the flow rate of refrigerant wherein the diameter of the valve hole of the second valve the first valve flows from the discharge chamber to the crank chamber When the control is performed, the flow rate of the refrigerant flowing from the crank chamber to the suction chamber is reduced to a clearance set between the valve body diameter of the second valve inserted into the valve hole of the second valve. There is provided a control valve for a variable displacement compressor characterized by having a fixed orifice function of a predetermined amount .

  According to such a control valve of the variable capacity compressor, the second valve that controls the flow rate of the refrigerant flowing from the crank chamber to the suction chamber of the variable capacity compressor is such that the first valve is fully closed or near the fully closed state. Since the first valve is configured to start the flow control after the second valve is at or near the minimum opening, the discharge chamber is changed to the crank chamber, Furthermore, the flow rate of the refrigerant flowing from the crank chamber to the suction chamber, that is, the flow rate of the refrigerant that does not contribute to the refrigeration by circulating through the variable capacity compressor can be minimized, and the pressure in the crank chamber can be reduced. Increased sensitivity is suppressed. As a result, compression efficiency can be improved while obtaining stable controllability.

  These and other objects, features and advantages of the present invention will become apparent from the following description taken in conjunction with the accompanying drawings which illustrate preferred embodiments by way of example of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a conceptual diagram showing the configuration of a control valve of a variable capacity compressor according to the present invention.
The control valve of the variable capacity compressor according to the present invention includes a ball valve 11 constituting a first valve, a spool valve 12 constituting a second valve, a diaphragm 13 constituting a pressure sensitive part, and a pressure setting part. The constituting solenoids 14 are arranged in this order.

  The ball valve 11 introduces the refrigerant having the discharge pressure Pd from the discharge chamber of the variable capacity compressor, and supplies the refrigerant having the pressure Pc1 whose flow rate is controlled to the crank chamber of the variable capacity compressor. The spool valve 12 introduces a refrigerant having a pressure Pc2 from the crank chamber, and controls the flow rate of the refrigerant supplied to the suction chamber of the variable capacity compressor in conjunction with the operation of the ball valve 11. The diaphragm 13 receives the suction pressure Ps in the suction chamber and displaces the ball valve 11 and the spool valve 12 so as to increase the pressure in the crank chamber when the pressure falls below a predetermined suction pressure set point. As the pressure in the crank chamber increases, the discharge capacity of the compressor decreases, and as a result, the suction pressure of the air conditioner is controlled in the vicinity of a predetermined suction pressure set point. The solenoid 14 applies an urging load to the diaphragm 13 to set a suction pressure set point, and the urging load is set according to a current value supplied from the outside.

The spool valve 12 includes a valve seat 15 and a valve body 16 that can be inserted into and removed from the valve hole, and a predetermined clearance 17 is provided between the valve seat 15 and the valve body 16. This clearance 17, when the valve body 16 is inserted into the valve hole, constitutes a fixed orifice flow area does not change between the crank chamber and the suction chamber, the size of the variable displacement compressor Determined by the stability of the machine's swashplate. The valve body 16 is formed integrally with a shaft 18 that drives the ball valve 11, and the valve body 16 and the shaft 18 are joined by a frustoconical joining portion 19 having a tapered cross section. ing.

  The spool valve 12 can be freely changed so as to have an opening / closing timing different from the opening / closing timing of the interlocking ball valve 11 according to characteristics such as hunting, controllability, and stability of the variable capacity compressor. . This change in the opening / closing timing is achieved by changing the distance between the tip of the valve body 16 that is the boundary with the joint portion 19 and the tip of the shaft 18 that contacts the valve body 20 of the ball valve 11, so that the ball valve 11 is fully closed. This can be done easily by shifting the tip of the valve body 16 in the axial direction.

  In the ball valve 11, the valve body 20 moves in the valve opening direction when the shaft 18 moves in the right direction in the figure. The maximum opening degree of the ball valve 11 is that a step portion 21 provided on the shaft 18 is formed in the body. It is regulated by contacting the stepped portion 22.

FIG. 2 is a partially enlarged explanatory view showing the control valve set at the first opening / closing timing, and FIG. 3 is a diagram showing the characteristics of the control valve set at the first opening / closing timing.
The first opening / closing timing is the same as the opening / closing timing of the ball valve 11 and the opening / closing timing of the spool valve 12. When the ball valve 11 is fully closed, the tip of the valve body 16 of the spool valve 12 is It is made to correspond to the opening end surface of the seat 15 on the solenoid side.

  Thus, the characteristics of the control valve when the valve body 16 of the spool valve 12 moves in the axial direction are as shown in FIG. In FIG. 3, the horizontal axis indicates the stroke of the shaft 18, and the origin is the position where the step portion 21 of the shaft 18 is brought into contact with the step portion 22 of the body so that the shaft 18 is positioned closest to the ball valve 11. (Or when the solenoid is not energized). The vertical axis in FIG. 3 indicates the opening areas of the ball valve 11 and the spool valve 12. A line represented by Pd-Pc represents a change in the opening area of the ball valve 11, and a line represented by Pc-Ps represents a change in the opening area of the spool valve 12.

  At this first opening / closing timing, while the ball valve 11 is open, the spool valve 12 has an opening area corresponding to the clearance 17 and is a fixed orifice. When the shaft 18 moves toward the solenoid 14 and reaches the position s1, the ball valve 11 is fully closed when the valve body 20 is seated. When the shaft 18 further moves toward the solenoid 14, the tip of the shaft 18 moves away from the valve body 20 of the ball valve 11, the ball valve 11 remains fully closed, and the spool valve 12 starts to open from the fixed orifice state. The opening area increases according to the stroke. When the ball valve 11 is fully closed, the refrigerant compressed through the control valve does not flow into the crank chamber, but a piston that sucks and compresses the refrigerant and a cylinder that slidably accommodates the piston The blow-by gas slightly leaks into the crank chamber through the gap between the pressure and the pressure Pc (= Pc1 = Pc2) in the crank chamber.

FIG. 4 is a partially enlarged explanatory view showing the control valve set at the second opening / closing timing, and FIG. 5 is a diagram showing the characteristics of the control valve set at the second opening / closing timing.
This second opening / closing timing is a timing in which the timing at which the spool valve 12 opens is delayed from the timing at which the ball valve 11 closes. When the ball valve 11 is fully closed, the spool valve 12 is still in the closed state (fixed orifice state). )It is in. For this purpose, the distance between the tip of the valve body 16 on the ball valve 11 side and the tip of the shaft that contacts the valve body 20 of the ball valve 11 is reduced by a distance a as compared with the case of the first opening / closing timing. When the ball valve 11 is closed, the tip of the valve body 16 of the spool valve 12 on the ball valve 11 side is in the valve hole.

  Thus, at this second opening / closing timing, as shown in FIG. 5, when the shaft 18 moves toward the solenoid 14, the ball valve 11 is first fully closed at the position s1. At this time, the spool valve 12 has an opening area corresponding to the clearance 17. When the shaft 18 further moves toward the solenoid 14 and reaches the position s2, the spool valve 12 starts to open for the first time.

FIG. 6 is a partially enlarged explanatory view showing a control valve set at the third opening / closing timing, and FIG. 7 is a diagram showing characteristics of the control valve set at the third opening / closing timing.
The third opening / closing timing is a timing at which the spool valve 12 is opened earlier than the timing at which the ball valve 11 is closed. For this purpose, the distance between the tip of the valve body 16 on the ball valve 11 side and the tip of the shaft that contacts the valve body 20 of the ball valve 11 is increased by b as compared with the case of the first opening / closing timing. When the ball valve 11 is closed, the tip of the valve body 16 of the spool valve 12 on the ball valve 11 side is located closer to the solenoid 14 than the valve seat 15.

  Thus, at the third opening / closing timing, as shown in FIG. 7, when the shaft 18 moves toward the solenoid 14, first, at the position s1, the spool valve 12 starts to open first, and then At the position s2, the ball valve 11 is fully closed.

  FIG. 8 is a partially enlarged explanatory view showing a control valve in which fixed orifices are formed on the inlet side and the outlet side, and FIG. 9 is a diagram showing the characteristics of the control valve set at the fourth opening / closing timing. In FIG. 8, the same components as those shown in FIG.

  In this control valve, fixed orifices are formed on both the inlet side and the outlet side with respect to the crank chamber. In the ball valve 11, the tip portion of the shaft 18 on the side where the valve element 20 abuts has a spool shape. In addition, the contact end portion 23 with the valve body 20 has a clearance 24 between the outer periphery thereof and the inner wall of the valve hole. This clearance 24 is located in the valve hole when the ball valve 11 is in the vicinity of the fully closed, and constitutes a fixed orifice that does not change the flow path area between the compression chamber and the crank chamber. This fixed orifice stabilizes the flow rate of refrigerant introduced from the discharge chamber to the crank chamber in the region where the refrigerant is introduced into the crank chamber by blow-by gas and the flow rate of the refrigerant discharged from the crank chamber is controlled by the spool valve 12. It is for securing. There is a distance c between the rear end (diameter reduction start position) of the contact end portion 23 and the seating position of the valve body 20. In this example, when the ball valve 11 is fully closed and the valve body 20 is in contact with the contact end portion 23, the tip of the valve body 16 of the spool valve 12 and the valve closing start position of the spool valve 12 are The distance d between is set to the same value as the distance c.

  As shown in FIG. 9, the characteristics of the control valve at this time are as follows. First, when the solenoid is not energized, the stepped portion 21 of the shaft 18 is in contact with the stepped portion 22 of the body. State, spool valve 12 is in a fixed orifice state.

  As the energization current increases, the ball valve 11 changes from the fully open state to the direction of decreasing the opening area, and the spool valve 12 maintains the fixed orifice state. When the shaft 18 moves to the position s1, the rear end of the abutting end 23 reaches the seating position of the valve body 20, and the spool valve 12 reaches the valve opening start position where the valve body 16 exits from the fixed orifice state. When the shaft 18 further moves from the position s1, the rear end of the contact end portion 23 enters the valve hole to be in the fixed orifice state, and the spool valve 12 is changed from the fixed orifice state to the direction in which the opening area is increased.

  Thereafter, the fixed orifice state of the ball valve 11 is maintained until the opening area of the ball valve 11 becomes smaller than the opening area of the fixed orifice. Finally, the ball valve 11 is seated and fully closed.

  Here, the distance c and the distance d are set to the same value, but the opening / closing timing of the spool valve 12 can be easily changed by increasing or decreasing the distance d according to the characteristics of the variable capacity compressor. .

  FIG. 10 is a conceptual diagram showing a control valve in which fixed orifices are formed on the inlet side and the outlet side, and FIG. 11 is a diagram showing the characteristics of the control valve set at the fifth opening / closing timing. In FIG. 10, the same components as those shown in FIG. 1 are denoted by the same reference numerals.

  In this control valve, spool valves 11a and 12 each comprise a valve disposed between the compressor and the crank chamber and a valve disposed between the crank chamber and the suction chamber. The valve body 16 of the spool valve 12, the shaft 18 and the valve body 20a of the spool valve 11a are integrally formed. The valve body 20a has a smaller diameter than the shaft 18 supported by the body and has a valve hole. A clearance 24 is provided between the inner wall and the inner wall. And between this valve body 20a and the shaft 18, it is diameter-reduced and has a spool shape. Further, when the spool valve 12 is in the valve closing start position, a distance e is provided between the rear end (diameter reduction starting position) of the valve body 20a and the valve closing start position where the valve body 20a enters the valve hole. .

  As shown in FIG. 11, the characteristic of the control valve at this time is that, when the solenoid is not energized, the step portion 21 of the shaft 18 is in contact with the step portion 22 of the body, so that the spool valve 11a is fully opened. State, the spool valve 12 is fully closed and is in a fixed orifice state.

  As the energization current increases, the spool valve 11a changes from the fully open state to the direction in which the opening area is reduced because the rear end of the valve body 20a approaches the valve hole, and the spool valve 12 maintains the fixed orifice state. ing. When the shaft 18 moves to the position s1, the spool valve 11a reaches the valve closing start position, and the spool valve 12 reaches the valve opening starting position where the valve body 16 comes out of the fixed orifice state. When the shaft 18 further moves from the position s1, the valve body 20a enters the valve hole, the spool valve 11a enters the fixed orifice state and maintains the state, and the spool valve 12 increases the opening area from the fixed orifice state. It will change.

  In the above embodiment, an electric control valve using a solenoid that can freely set the set value (pressure control point) by an external control current as means for setting the suction pressure Ps of the suction chamber has been described. Next, a mechanical control valve in which the pressure setting of the suction pressure Ps is fixed will be described.

  FIG. 12 is a conceptual diagram showing a configuration of a mechanical control valve of the variable capacity compressor. In FIG. 12, the same components as those shown in FIG. 1 are denoted by the same reference numerals, and detailed description thereof is omitted.

  This control valve includes a ball valve 11 constituting a first valve, a spool valve 12 constituting a second valve, a diaphragm 13 constituting a pressure sensing part, and a spring 25 constituting a pressure setting part. Arranged in order.

  Also in this control valve, the spool valve 12 functions as a fixed orifice while the ball valve 11 variably controls its opening area, and variably controls the opening area when the ball valve 11 is in a fully closed state. It has become. Of course, the opening / closing timing of the spool valve 12 is set to one of the first to third opening / closing timings described above according to the characteristics of the variable capacity compressor.

  The diaphragm 13 has a disk 26 disposed on the surface on the spring 25 side, and is biased toward the spool valve 12 by the spring 25 via the disk 26. The spring 25 is adjusted to a spring load corresponding to a predetermined suction pressure control point. Therefore, the control valve receives the suction pressure Ps of the suction chamber and the diaphragm 13 urges the ball valve 11 and the spool valve 12 so as to increase the pressure in the crank chamber when it falls below a predetermined suction pressure control point. Then, by controlling the discharge capacity of the variable capacity compressor, the suction pressure of the air conditioner is controlled in the vicinity of a predetermined suction pressure control point.

  Of course, also in this control valve, the fixed orifice is formed on both the refrigerant inlet side and the outlet side of the crank chamber by providing the contact end portion 23 constituting the fixed orifice shown in FIG. And it can be set as the control valve set to the 4th opening-and-closing timing.

  FIG. 13 is a conceptual diagram showing a configuration of a mechanical control valve of the variable capacity compressor. In FIG. 13, the same components as those shown in FIGS. 1 and 10 are denoted by the same reference numerals, and detailed description thereof is omitted.

  This control valve includes a spool valve 11a constituting a first valve, a spool valve 12 constituting a second valve, a diaphragm 13 constituting a pressure sensing portion, and a spring 25 constituting a pressure setting portion. Arranged in order.

The spool valve 11a has the same configuration as that shown in FIG. 10. Therefore, the control valve has the fifth opening / closing timing characteristic shown in FIG.
Also in this control valve, the suction pressure Ps in the suction chamber is received and the lift amount of the spool valves 11a and 12 is displaced, and as a result, the pressure in the crank chamber is controlled so that the suction pressure Ps becomes constant.

  FIG. 14 is a conceptual diagram showing the configuration of the control valve of the variable displacement compressor in which the fixed orifice function of the second valve is made independent. In FIG. 14, the same components as those shown in FIG. 1 are denoted by the same reference numerals, and detailed description thereof is omitted.

  The control valve shown in FIG. 1 has the function of a fixed orifice with a clearance 17 provided between the valve body 16 of the spool valve 12 and the inner wall of the valve hole. The fixed orifice 27 having an opening area equivalent to the opening area formed by the No. 17 is formed in the body. In this case, the clearance 17 provided between the valve body 16 and the inner wall of the valve hole is made as small as possible. As a result, when the spool valve 12 throttles the refrigerant passage between the crank chamber and the suction chamber, the refrigerant is caused to flow toward the fixed orifice 27 having a large diameter and not to the clearance 17 having a small gap. I have to. As a result, there is an effect that the change in the flow rate of the refrigerant due to the sludge contained in the refrigerant can be reduced.

  That is, the clearance 17 between the valve body 16 of the spool valve 12 and the inner wall of the valve hole is, for example, 0.1 mm, and the fixed orifice 27 having an opening area corresponding to the clearance 17 is a hole with a diameter of 1 mm. If sludge adheres to the inner wall of the body 16 or the valve hole or the inner wall of the fixed orifice 27 and grows to a thickness of, for example, 0.1 mm, the clearance 17 is almost closed by the thickness of the sludge. On the other hand, in the case of the fixed orifice 27, the diameter is reduced only to 0.8 mm, and the change in the flow rate of the refrigerant due to the adhering sludge is small. Moreover, since the refrigerant mainly flows through the fixed orifice 27 which is easy to flow, there is an advantage that the flow of the refrigerant is small in the narrow clearance 17 and sludge is difficult to adhere.

  The configuration in which the fixed orifice 27 is provided in parallel with the spool valve 12 constituting the second valve has been described by taking as an example the case where it is applied to a control valve of the type having the solenoid 14 shown in FIG. The same applies to the mechanical control valve shown in FIG.

  As described above, in the present invention, the first valve that controls the flow rate of the refrigerant flowing from the discharge chamber to the crank chamber, the second valve that controls the flow rate of the refrigerant flowing from the crank chamber to the suction chamber, and the suction pressure And a pressure setting unit for setting the suction pressure Ps. The second valve starts flow rate control after the first valve is fully closed or close to the fully closed state. The valve was configured such that the flow rate control was started after the second valve reached the minimum opening or near the minimum opening. As a result, when the control of the first valve and the second valve is switched, there is no region where the first valve and the second valve are in the open state at the same time, so that from the discharge chamber to the crank chamber, The flow rate of the refrigerant flowing from the crank chamber to the suction chamber, that is, the flow rate of the refrigerant that does not contribute to refrigeration by circulating inside the variable displacement compressor can be minimized, and the efficiency of the variable displacement compressor Can be improved. Furthermore, since the second valve has a fixed orifice function for setting the flow rate of the refrigerant flowing from the crank chamber to the suction chamber to the minimum predetermined flow rate, the pressure in the crank chamber can be stably adjusted, which is excellent. Controllability can be obtained.

  The above merely illustrates the principle of the present invention. In addition, many modifications and changes can be made by those skilled in the art, and the present invention is not limited to the precise configuration and application shown and described above, and all corresponding modifications and equivalents may be And the equivalents thereof are considered to be within the scope of the invention.

It is a conceptual diagram which shows the structure of the control valve of the variable capacity compressor by this invention. It is a partial expanded explanatory view which shows the control valve set to the 1st opening / closing timing. It is a figure which shows the characteristic of the control valve set to the 1st opening / closing timing. It is a partial expanded explanatory view which shows the control valve set to the 2nd opening / closing timing. It is a figure which shows the characteristic of the control valve set to the 2nd opening / closing timing. It is a partial expanded explanatory view which shows the control valve set to the 3rd opening / closing timing. It is a figure which shows the characteristic of the control valve set to the 3rd opening / closing timing. It is a partial expanded explanatory view which shows the control valve in which a fixed orifice is formed in the inlet side and the outlet side. It is a figure which shows the characteristic of the control valve set to the 4th opening / closing timing. It is a conceptual diagram which shows the control valve in which a fixed orifice is formed in the inlet side and the outlet side. It is a figure which shows the characteristic of the control valve set to the 5th opening / closing timing. It is a conceptual diagram which shows the structure of the mechanical control valve of a variable capacity compressor. It is a conceptual diagram which shows the structure of the mechanical control valve of a variable capacity compressor. It is a conceptual diagram which shows the structure of the control valve of the variable capacity compressor which made the fixed orifice function of the 2nd valve independent.

DESCRIPTION OF SYMBOLS 11 Ball valve 11a, 12 Spool valve 13 Diaphragm 14 Solenoid 15 Valve seat 16 Valve body 17 Clearance 18 Shaft 19 Joint part 20, 20a Valve body 21 Step part 22 Step part 23 Contact end part 24 Clearance 25 Spring 26 Disc 27 Fixed orifice

Claims (10)

In the control valve of the variable capacity compressor that can vary the discharge capacity of the refrigerant by controlling the pressure in the crank chamber,
A first valve disposed between a discharge chamber of the variable capacity compressor and the crank chamber to control a flow rate of refrigerant flowing from the discharge chamber to the crank chamber;
The suction from the crank chamber when the first valve is disposed between the crank chamber and the suction chamber of the variable capacity compressor and controls the flow rate of the refrigerant flowing from the discharge chamber to the crank chamber. A second valve for controlling the flow rate of the refrigerant flowing into the chamber to the minimum predetermined amount and controlling the flow rate of the refrigerant flowing from the crank chamber to the suction chamber when the first valve is fully closed or in the vicinity of the fully closed state. When,
A pressure sensing unit that senses a suction pressure in the suction chamber and displaces lift amounts of the first valve and the second valve;
Equipped with a,
The second valve is provided in the valve hole of the second valve when the diameter of the valve hole of the second valve and the flow rate of the refrigerant flowing from the discharge chamber to the crank chamber are controlled by the first valve. A fixed orifice function is provided in the clearance set between the valve body diameter of the second valve to be inserted so that the flow rate of the refrigerant flowing from the crank chamber to the suction chamber is a minimum predetermined amount . A control valve for a variable capacity compressor. A shaft extending through the valve hole of the second valve and extending along the same axis as the valve hole of the second valve to transmit the opening / closing operation of the second valve to the first valve; The control valve for a variable capacity compressor according to claim 1, wherein 3. The control valve for a variable displacement compressor according to claim 2, wherein the shaft has a frustoconical shape at a joint portion with the valve body of the second valve. 3. The control valve for a variable displacement compressor according to claim 2, wherein the shaft has a spool shape at a tip portion of the shaft that contacts the valve body of the first valve. The control valve for a variable capacity compressor according to claim 2, wherein the shaft is capable of contacting and separating from the valve body of the first valve. The flow rate of the refrigerant flowing from the discharge chamber to the crank chamber in a clearance set between the diameter of the tip portion of the shaft contacting the valve body of the first valve and the diameter of the valve hole of the first valve 3. The control valve for a variable capacity compressor according to claim 2, wherein a fixed orifice function is provided to make the minimum predetermined amount. The control valve for a variable displacement compressor according to claim 1, wherein the first valve is a spool valve. The variable capacity compressor according to any one of claims 1 to 7, further comprising a pressure setting unit that applies a biasing load to the pressure sensing unit to set a pressure control point of a control valve. Control valve. 9. The control valve for a variable displacement compressor according to claim 8, wherein the pressure setting unit is a solenoid that sets the pressure control point by applying an urging load by an external signal. 9. The control valve for a variable capacity compressor according to claim 8, wherein the pressure setting unit is a spring that sets the pressure control point by a spring force.

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