JP2009162134A - Control valve for variable displacement type compressor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a control valve for a variable displacement type compressor which is autonomously controllable so as to decrease the displacement by forcibly valve-opening an air supplying passage when the variable displacement type compressor is controlled to make displacement large and poor lubrication is generated, and preventing the temperature rise of the variable displacement type compressor. <P>SOLUTION: In a valve chamber 53 divided in a valve house 50 of a flow rate control valve CV1, a valve element 57 contacting and separating with/from a valve seat 58 provided in the valve chamber 53 to open and close the air supplying passage 38 is provided. Furthermore, in the flow rate control valve CV1, a valve element energizing plate 74 is arranged between a moving iron core 71 and a fixed iron core 69. When a temperature reaches a predetermined temperature, the valve element energizing plate 74 forcibly moves the valve element 57 in a direction separating from the valve seat 58 through the moving iron core 71 by its deformation. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a control valve that can change a discharge capacity by adjusting an opening degree of an air supply passage that connects a discharge pressure region of a variable displacement compressor and a crank chamber.

  In general, a variable capacity swash plate compressor (hereinafter referred to as a compressor) used in a refrigerant circulation circuit of a vehicle air conditioner adjusts the pressure of a crank chamber, which is a swash plate housing chamber, to thereby adjust the inclination angle of the swash plate. That is, the discharge capacity can be changed. The compressor is provided with a control valve for adjusting the pressure in the crank chamber (see, for example, Patent Document 1). The control valve of Patent Document 1 includes a movable wall and an operating rod that are sensitive to a pressure difference between two pressure monitoring points set in a refrigerant circulation circuit, and a differential pressure between two points determined by an electromagnetic force from a solenoid unit. The opening degree of the air supply passage is autonomously adjusted by the valve body portion of the operating rod so as to maintain the target value. Moreover, the control valve of patent document 1 is provided with the temperature detection means which detects the temperature which has correlation with the temperature of the room | chamber interior used as air conditioning object. Then, at the initial stage of cooling until the predetermined time elapses after the air conditioner switch is switched from OFF to ON, the set differential pressure is allowed to be changed according to the detected temperature information, and when necessary, the refrigerant circulation circuit is provided. A large flow rate of refrigerant can be passed.

The amount of high-pressure refrigerant gas introduced from the high-pressure region through the air supply passage into the crank chamber is controlled by adjusting the opening of the air supply passage by the control valve, and the pressure in the crank chamber is determined. As a result of changing the inclination angle of the swash plate in accordance with the change in the crank chamber pressure, the piston stroke, that is, the discharge capacity of the compressor is adjusted.
JP 2001-221164 A

  However, when a malfunction occurs in which the refrigerant flow rate in the refrigerant circulation circuit decreases due to refrigerant gas leakage in the refrigerant circulation circuit, the control valve is controlled to operate the compressor with a large discharge capacity. There is. That is, in the control valve, control is performed to block the air supply passage by the valve body portion and reduce the pressure in the crank chamber. Further, when the gas shortage occurs in the refrigerant circuit due to the refrigerant gas leakage, the return amount of the lubricating oil contained in the refrigerant gas to the compressor is reduced, and the lubrication is insufficient in the compressor. Then, in the compressor, there is a possibility that the temperature of the compressor rises due to sliding heat generation inside the compressor, causing a decrease in durability.

  The present invention has been made paying attention to such problems existing in the prior art. The purpose of the variable displacement compressor is to control the discharge capacity to be large, and when the lubrication is insufficient, the air supply passage is forcibly opened to reduce the discharge capacity autonomously. An object of the present invention is to provide a control valve for a variable displacement compressor that can control and prevent a temperature increase of the variable displacement compressor.

  In order to solve the above-mentioned problems, the invention according to claim 1 is a variable capacity that can constitute a refrigerant circulation circuit of an air conditioner and can change a discharge capacity by controlling a pressure of a crank chamber that houses a cam plate. A control valve that is used in a type compressor and that can change the discharge capacity by adjusting the opening of an air supply passage that connects a discharge pressure region of the variable displacement compressor and a crank chamber. A valve chamber defined in the valve housing to constitute a part of the air passage is provided with a valve body portion that opens and closes the air supply passage by contacting and separating from a valve seat provided in the valve chamber. A differential pressure-sensitive member that exerts a force based on a pressure difference between two pressure monitoring points set in the refrigerant circulation circuit on the valve body portion and participates in positioning of the valve body portion in the valve chamber, In addition, when it reaches a certain temperature, The valve body moving means for forcibly moved in a direction away the valve portion from the valve seat are those provided in the pressure region of the crank chamber.

  According to this, when a refrigerant gas leak or the like occurs in the refrigerant circuit and the refrigerant flow rate in the refrigerant circuit decreases, the pressure difference between the two pressure monitoring points becomes small. The valve body is seated on the valve seat, the air supply passage is shut off, and control is performed to increase the discharge capacity. Then, since the return amount of the lubricating oil contained in the refrigerant gas to the variable displacement compressor is also reduced, the variable displacement compressor becomes insufficiently lubricated and the operating situation becomes very severe. At this time, when the temperature of the capacity variable compressor reaches a predetermined temperature, the valve body moving means is deformed. Then, the air supply passage can be forcibly opened by moving the valve body in a direction away from the valve seat by the deformation of the valve body moving means. Then, high-pressure refrigerant gas is introduced into the crank chamber from the discharge pressure region, the crank chamber pressure increases, and the discharge capacity of the variable displacement compressor is reduced from the large capacity state. Therefore, the variable capacity compressor is in a low load state, sliding heat generation inside the variable capacity compressor is suppressed, and temperature rise is prevented. For example, other control valves are added by controlling the control valve autonomously by using information such as temperature that always occurs in the variable displacement compressor and the valve body moving means that deforms depending on the temperature. Thus, the configuration of the variable displacement compressor can be simplified and the size can be reduced as compared with the case where the valve is forcibly opened under the above conditions.

  The control valve has a movable iron core that is operatively connected to the valve body, and a fixed iron core to which the movable iron core can be contacted / separated, and an electromagnetic force that changes an electromagnetic urging force of the movable iron core by energization control from the outside. Provided with an actuator portion, and the valve body moving means is disposed between the movable iron core and the fixed iron core, and the valve body moving means moves the valve body portion via the movable iron core. May be. According to this, even if the position of the valve body portion is externally controlled by the electromagnetic actuator portion, the supply passage can be forcibly opened using the valve body portion moving means, and the discharge capacity can be reduced.

  The movable iron core has an insertion portion into which a lower end portion of a valve rod provided integrally with the valve body portion is inserted, and an insertion portion having a larger diameter than the insertion portion and the lower end side of the valve rod. A coil spring serving as a valve body moving means is disposed in a gap between the lower end side peripheral surface of the valve rod and the peripheral surface of the insertion portion facing the lower end side peripheral surface. The upper end portion is abutted and supported by the fixed iron core and the lower end portion is abutted and supported by the movable iron core, and the coil spring is made of a shape memory alloy that deforms when reaching a predetermined temperature. You may move the said valve body part via the movement of a rod.

According to this, by extension of the coil spring, the movable iron core can be moved in a direction away from the fixed iron core, that is, in a direction in which the valve body portion is separated from the valve seat.
An urging spring for urging the valve body in the direction separating the valve seat from the valve seat is disposed in the valve chamber, and one end of the urging spring is in contact with and supported by the inner surface of the valve chamber. And the other end portion is contacted and supported by a spring receiver attached to a valve rod including the valve body portion, and the valve body moving means is formed of a bimetal that is deformed when reaching a predetermined temperature. The valve body portion may be moved through movement of the urging spring by deformation of the spring receiver.

According to this, the valve body portion can be rapidly separated from the valve seat by utilizing the rapidly changing characteristic (jumping characteristic) of the bimetal.
The spring receiver made of the bimetal may be formed in an annular shape. According to this, the jumping characteristic with which a bimetal is provided can be exhibited reliably.

  An urging spring for urging the valve body in the direction separating the valve seat from the valve seat is disposed in the valve chamber, and one end of the urging spring is in contact with and supported by the inner surface of the valve chamber. The other end portion is abutted and supported by a spring receiver attached to the valve rod having the valve body portion, and the valve body moving means is made of the shape memory alloy that extends when reaching a predetermined temperature. It may be formed by a bias spring, and the valve body may be moved by extension of the bias spring.

  According to this, the urging spring is one component provided in the control valve in order to urge the valve body portion in the direction of separating the valve body portion from the valve seat. Then, by simply changing the material of this biasing spring to a shape memory alloy, when the temperature of the variable displacement compressor exceeds a predetermined temperature, the valve body is moved away from the valve seat by the extension of the biasing spring. The air supply passage can be forced to open, and the discharge capacity of the variable capacity compressor can be reduced as a result. Therefore, the problems of the present invention can be solved without greatly increasing the manufacturing cost.

  According to the present invention, the variable displacement compressor is controlled to increase the discharge capacity, and in a state where insufficient lubrication occurs, the air supply passage is forcibly opened to reduce the discharge capacity autonomously. Therefore, the temperature rise of the variable capacity compressor can be prevented.

  Hereinafter, an embodiment in which the control valve of the present invention is embodied as a flow rate control valve included in a variable capacity compressor used in a refrigerant circulation circuit of a vehicle air conditioner will be described with reference to FIGS. In the following description, “front” and “rear” of the variable capacity compressor are the front and rear directions in the direction of the arrow Y1 shown in FIG. 1, and “upper” and “lower” are the directions of the arrow Y2 shown in FIG. The direction is the vertical direction.

  As shown in FIG. 1, a variable displacement compressor (hereinafter simply referred to as a compressor 10) includes a cylinder block 11, a front housing 12 joined and fixed to a front end (one end) of the cylinder block 11, a cylinder The rear housing 14 is joined and fixed to the rear end (the other end) of the block 11 via a valve / port forming body 13. The cylinder block 11, the front housing 12, and the rear housing 14 constitute a housing of the compressor 10. A crank chamber 15 is defined in a region surrounded by the cylinder block 11 and the front housing 12 in the housing. A drive shaft 16 is rotatably supported by the housing, and the drive shaft 16 is rotatably disposed in the crank chamber 15. In the crank chamber 15, a lug plate 21 is fixed on the drive shaft 16 so as to be integrally rotatable. An engine (internal combustion engine) E, which is a travel drive source of the vehicle, is operatively connected to a front end portion of the drive shaft 16 outside the compressor 10 via a power transmission mechanism (not shown).

  A swash plate 22 as a cam plate is accommodated in the crank chamber 15. The swash plate 22 is supported by the drive shaft 16 so as to be slidable and tiltable. The hinge mechanism 23 is interposed between the lug plate 21 and the swash plate 22. Therefore, the swash plate 22 can be rotated synchronously with the lug plate 21 and the drive shaft 16 by the hinge connection with the lug plate 21 via the hinge mechanism 23 and the support of the drive shaft 16. It can be tilted with respect to the drive shaft 16 while being slid in the axial direction.

  A plurality of cylinder bores 11 a (only one is shown in the drawing) are formed through the cylinder block 11 so as to surround the drive shaft 16. The single-headed piston 20 is accommodated in each cylinder bore 11a so as to be able to reciprocate. The front and rear openings of the cylinder bore 11a are closed by the valve / port forming body 13 and the piston 20, and a compression chamber 28 whose volume is changed according to the reciprocation of the piston 20 is defined in the cylinder bore 11a. Each piston 20 is anchored to the outer peripheral portion of the swash plate 22 via a shoe 29. Therefore, the rotational motion of the swash plate 22 accompanying the rotation of the drive shaft 16 is converted into the reciprocating linear motion of the piston 20 via the shoe 29.

  A suction chamber 31 located in the central region and a discharge chamber 32 surrounding the suction chamber 31 are defined between the valve / port forming body 13 and the rear housing 14. Corresponding to each compression chamber 28, the valve / port forming body 13 includes a suction port 33, a suction valve 34 that opens and closes the suction port 33, a discharge port 35, and a discharge valve 36 that opens and closes the discharge port 35. Is formed. The refrigerant gas in the suction chamber 31 is sucked into the compression chamber 28 through the suction port 33 and the suction valve 34 by the movement from the top dead center position to the bottom dead center position side of each piston 20. The refrigerant gas sucked into the compression chamber 28 is compressed to a predetermined pressure by movement from the bottom dead center position of the piston 20 to the top dead center position side, and then is discharged through the discharge port 35 and the discharge valve 36. 32 is discharged.

  The refrigerant circulation circuit (refrigeration cycle) of the vehicle air conditioner includes the compressor 10 and the external refrigerant circuit 40 described above. The external refrigerant circuit 40 includes, for example, a gas cooler 41, an expansion valve 42, and an evaporator 43. In the downstream area of the external refrigerant circuit 40, a refrigerant flow pipe 45 that connects the outlet of the evaporator 43 and the suction passage 26 communicating with the suction chamber 31 is provided. In the upstream area of the external refrigerant circuit 40, a refrigerant flow pipe 46 that connects the discharge passage 27 communicating with the discharge chamber 32 and the inlet of the gas cooler 41 is provided. The compressor 10 sucks and compresses the refrigerant gas introduced from the downstream region of the external refrigerant circuit 40 into the suction chamber 31 through the suction passage 26, and discharges the compressed refrigerant gas to the discharge chamber 32. A throttle 27 a is provided in the middle of the external refrigerant circuit 40 downstream from the discharge passage 27 and upstream from the gas cooler 41.

  In the refrigerant circuit, the region from the outlet of the evaporator 43 to the suction chamber 31 of the compressor 10 can be grasped as the suction pressure region (suction pressure Ps) of the refrigerant circuit. A region from the discharge chamber 32 of the compressor 10 to the inlet of the gas cooler 41 in the refrigerant circulation circuit can be grasped as a discharge pressure region (discharge pressure Pd) of the refrigerant circulation circuit. In this discharge pressure region, in particular, the region upstream of the restrictor 27a (discharge chamber 32 side) is the high pressure side discharge pressure region P1 (PdH), and the region downstream of the restrictor 27a (gas cooler 41 side) is Each can be grasped as a low-pressure side discharge pressure region P2 (PdL).

  The inclination angle of the swash plate 22 (angle formed between the plane orthogonal to the axis of the drive shaft 16) is changed according to the change in the pressure in the crank chamber 15 (crank pressure Pc). The crank pressure Pc is controlled by a discharge passage 37, an air supply passage 38, and a flow rate control valve CV1 provided in the compressor 10. The discharge passage 37 communicates (connects) the crank chamber 15 and the suction pressure region (specifically, the suction chamber 31) of the refrigerant circulation circuit. The air supply passage 38 communicates (connects) the crank chamber 15 and the discharge pressure region (specifically, the discharge chamber 32) of the refrigerant circulation circuit. A flow control valve CV1 is disposed in the middle of the air supply passage 38, and the flow control valve CV1 can adjust the opening degree of the air supply passage 38.

  The amount of high-pressure refrigerant gas (discharge gas) introduced into the crank chamber 15 through the air supply passage 38 is adjusted by the flow control valve CV1, and the amount of gas discharged from the crank chamber 15 through the discharge passage 37 is adjusted. And the crank pressure Pc is determined. In response to the change in the crank pressure Pc, the difference between the crank pressure Pc via the piston 20 and the pressure in the compression chamber 28 is changed, and the inclination angle of the swash plate 22 is changed. The discharge capacity of the compressor 10 is adjusted. For example, when the crank pressure Pc decreases, the inclination angle of the swash plate 22 increases and the discharge capacity of the compressor 10 increases. Conversely, when the crank pressure Pc increases, the inclination angle of the swash plate 22 decreases and the discharge capacity of the compressor 10 decreases.

Next, the flow control valve CV1 will be described in detail.
As shown in FIG. 2, the valve housing 50 of the flow control valve CV1 includes an upper (one side) valve body 51 and a lower (other side) actuator housing 52. In the valve body 51, the valve chamber 53, the communication passage 54 communicating with the valve chamber 53, the insertion hole 59 communicating with the communication passage 54, and the insertion hole 59 are communicated in this order along the axial direction from the lower side. A pressure sensitive chamber 55 is defined. A valve rod 56 is disposed in the valve chamber 53 and the communication passage 54 so as to be movable in the axial direction (vertical direction) of the valve housing 50. The communication passage 54 and the pressure sensitive chamber 55 are blocked by the upper end portion (one end portion) of the valve rod 56 inserted into the insertion hole 59.

  The communication passage 54 communicates with the discharge chamber 32 of the compressor 10 via the upstream portion of the air supply passage 38, and the valve chamber 53 communicates with the crank chamber 15 of the compressor 10 via the downstream portion of the air supply passage 38. Has been. Therefore, the valve chamber 53 is a region having the same pressure as that of the crank chamber 15 (a pressure region of the crank chamber 15). The valve chamber 53 and the communication passage 54 constitute a part of the air supply passage 38. In the valve chamber 53, a valve body portion 57 formed at an intermediate portion of the valve rod 56 is disposed. In the valve body 51, a step located at the boundary between the valve chamber 53 and the communication passage 54 forms a valve seat 58 provided in the valve chamber 53. Therefore, in the present embodiment, the communication passage 54 forms a valve hole.

  When the valve rod 56 moves (upward) from the open state of the communication passage 54 (the air supply passage 38) to a position where the valve body portion 57 is seated on the valve seat 58, the valve body portion 57 is moved to the valve seat 58. The communication passage 54 (the air supply passage 38) is blocked (closed). On the contrary, when the valve rod 56 moves (moves downward) to a position where the valve body 57 is separated from the valve seat 58, the valve body 57 is separated from the valve seat 58 and the communication passage 54 (air supply passage 38). Is opened (opened). An urging spring 60 is disposed in the valve chamber 53. The urging spring 60 has an upper end portion (one end portion) as an inner surface of the valve chamber 53 that is in contact with and supported by a step surface 53 a (outer peripheral side of the valve seat 58) located at the boundary between the valve chamber 53 and the communication passage 54. The lower end portion (the other end portion) is in contact with and supported by a spring receiver 61 attached to the valve rod 56. The urging spring 60 urges the valve rod 56 in a direction (a valve opening direction) in which the valve body 57 is separated from the valve seat 58.

  In the pressure sensitive chamber 55, a bellows 62 as a differential pressure sensitive member is accommodated. The upper end (one end) of the bellows 62 is fixed to the upper end of the valve housing 50 (valve body 51). The upper end portion of the valve rod 56 is joined to the lower end portion (the other end portion) of the bellows 62. The valve rod 56 is operatively connected to the bellows 62 and moves up and down as the bellows 62 expands and contracts (up and down movement). It has become. The pressure sensitive chamber 55 is partitioned by a bellows 62 having a bottomed cylindrical shape into a first pressure chamber 63 that is an inner space of the bellows 62 and a second pressure chamber 64 that is an outer space.

  The first pressure chamber 63 is connected to the upstream side (the discharge chamber 32 side) of the throttle 27a via the first pressure detection passage 65. That is, the first pressure chamber 63 is connected to the high-pressure side discharge pressure region P1 as a pressure monitoring point of the refrigerant circulation circuit. The second pressure chamber 64 is connected to the downstream side of the throttle 27a via the second pressure detection passage 66. That is, the second pressure chamber 64 is connected to the low pressure side discharge pressure region P2 as a pressure monitoring point of the refrigerant circulation circuit.

  If a refrigerant flow is generated in the high-pressure side discharge pressure region P1 and the low-pressure side discharge pressure region P2, the pressure in the high-pressure side discharge pressure region P1 upstream from the restrictor 27a is the low-pressure side discharge pressure region downstream from the restrictor 27a. The pressure becomes larger than the pressure of P2, and a pressure difference is generated between the two pressure monitoring points. When the refrigerant flow rate in the external refrigerant circuit 40 increases, the pressure difference before and after the throttle 27a increases, and when the refrigerant flow rate in the external refrigerant circuit 40 decreases, the pressure difference before and after the throttle 27a decreases. When the pressure difference before and after the throttle 27a increases, the pressure difference between the first pressure chamber 63 and the second pressure chamber 64 increases, and when the pressure difference before and after the throttle 27a decreases, the first pressure chamber 63 and the second pressure chamber 63 increase. The pressure difference in the pressure chamber 64 is reduced. The pressure difference between the first pressure chamber 63 and the second pressure chamber 64 becomes a force that biases the valve rod 56 via the bellows 62.

  Accordingly, the bellows 62 is displaced at the lower end in accordance with the pressure difference before and after the throttle 27a, so that the fluctuation of the pressure difference is reflected in the positioning of the valve rod 56 (valve element portion 57). In addition, the bellows 62 operates the valve body 57 so that the discharge capacity of the compressor 10 is changed to the side that cancels the fluctuation of the pressure difference before and after the throttle 27a.

  The actuator housing 52 is provided with an electromagnetic actuator portion 67. The electromagnetic actuator portion 67 includes a bottomed cylindrical accommodating cylinder 68 at the center in the actuator housing 52. A cylindrical fixed iron core 69 is fitted and fixed in the upper opening of the housing cylinder 68. Due to the insertion of the fixed iron core 69, a plunger chamber 70 is defined at the lowermost part in the housing cylinder 68.

  A movable iron core 71 is accommodated in the plunger chamber 70 so as to be movable in the axial direction. A guide hole 69 a extending in the axial direction of the fixed iron core 69 is formed through the center of the fixed iron core 69, and the guide hole 69 a communicates the valve chamber 53 and the plunger chamber 70. Therefore, the pressure in the guide hole 69a and the plunger chamber 70 is the same as the pressure in the valve chamber 53, and the pressure in the guide hole 69a and the plunger chamber 70 is the same as the pressure in the crank chamber 15. Therefore, the guide hole 69 a and the plunger chamber 70 are the pressure region of the crank chamber 15. In the guide hole 69a, the lower end side of the valve rod 56 is disposed so as to be movable in the axial direction. The lower end portion of the valve rod 56 is fitted and fixed to the movable iron core 71 in the plunger chamber 70. Therefore, the movable iron core 71 and the valve rod 56 are always moved integrally (moved up and down).

  A coil 72 is wound around the outer peripheral side of the housing cylinder 68 so as to straddle the fixed iron core 69 and the movable iron core 71. Electric power is supplied to the coil 72 based on a command from an air conditioner ECU (not shown). Accordingly, an electromagnetic urging force (electromagnetic force) having a magnitude corresponding to the amount of power supplied to the coil 72 is generated between the movable iron core 71 and the fixed iron core 69, and this electromagnetic urging force is applied to the valve rod via the movable iron core 71. 56 (valve body portion 57), and urges the valve body portion 57 in the direction of seating on the valve seat 58.

  In the flow control valve CV1 configured as described above, the positioning of the valve body portion 57 by the bellows 62 is performed by changing the electromagnetic biasing force applied to the valve body portion 57 via the movable iron core 71 according to the amount of electric power supplied from the outside. It is possible to change the control target (set differential pressure) of the pressure difference before and after the throttle 27a, which is the reference for operation. That is, the flow control valve CV1 positions the valve rod 56 (valve element portion 57) autonomously in accordance with the fluctuation of the pressure difference so as to maintain the set differential pressure determined by the amount of power supplied to the coil 72. It is the composition to do. The set differential pressure can be changed from the outside by adjusting the amount of power supplied to the coil 72.

  In the plunger chamber 70, a valve body urging plate 74 as a valve body moving means is disposed in a gap between the upper end surface of the movable iron core 71 and the lower end surface of the fixed iron core 69. As described above, since the plunger chamber 70 has a pressure region having the same pressure as the crank chamber 15, the valve body biasing plate 74 disposed in the plunger chamber 70 has a pressure region having the same pressure as the crank chamber 15. It is arranged. In addition, the valve body urging plate 74 is made of bimetal, and is formed by bonding two metal plates having different thermal expansion coefficients, and has a property that the bending method changes according to a change in temperature. The valve body urging plate 74 of the present embodiment has a characteristic (jumping characteristic) that undergoes a sudden bending deformation at a predetermined temperature (for example, 150 ° C. ± 5 ° C.), and a temperature lower than the predetermined temperature (for example, 130 ° C. ± 5 ±). ℃)) and suddenly returns to the original shape. The predetermined temperature is a temperature that is slightly lower than the upper limit temperature at which the safety of the compressor 10 in heat is ensured, and is a temperature that is set to protect the compressor 10.

  The valve body urging plate 74 has an annular shape and is attached to the outer periphery on the lower end side of the valve rod 56. Further, the thickness of the valve body urging plate 74 is such that the movable iron core 71 moves toward the fixed iron core 69 so that the valve element 57 is seated on the valve seat 58 and the upper end surface of the movable iron core 71 and the fixed iron core 69. The thickness is substantially the same as the gap formed between the lower end surface of each other. Further, when the valve element urging plate 74 is bent and deformed, the outer peripheral edge side of the valve element urging plate 74 faces the movable iron core 71. Further, the bending deformation force of the valve body urging plate 74 is larger than the electromagnetic urging force (electromagnetic force) that moves the movable iron core 71 to the fixed iron core 69.

  Now, in the compressor 10 provided with the flow control valve CV1, leakage of the refrigerant gas from the refrigerant circulation circuit occurs, the return amount of the refrigerant gas from the refrigerant circulation circuit to the compressor 10 decreases, and the refrigerant gas It is assumed that there is a problem that the return amount of the contained lubricating oil to the compressor 10 is reduced. When the refrigerant flow rate in the external refrigerant circuit 40 decreases, the pressure difference between the pressure in the high-pressure side discharge pressure region P1 and the pressure in the low-pressure side discharge pressure region P2 decreases. Then, in the flow control valve CV1, the bellows 62 in the pressure sensing chamber 55 contracts, and the valve body 57 of the valve rod 56 seats on the valve seat 58 in response to the contraction of the bellows 62, thereby closing the communication passage 54. When the communication passage 54 is closed, the air supply passage 38 is shut off, and the flow control valve CV1 controls the discharge capacity of the compressor 10 to be large. And since the discharge capacity | capacitance of the compressor 10 is made large capacity | capacitance, the compressor 10 will be in a high load state, the temperature of the compressor 10 will rise, and the temperature of the flow control valve CV1 will also rise.

  As the temperature of the flow control valve CV1 rises and the temperature of the valve body urging plate 74 also rises, the valve body urging plate 74 is gradually bent and deformed. When the temperature of the valve body biasing plate 74 reaches a predetermined temperature, the valve body biasing plate 74 is suddenly bent and deformed due to the jumping characteristic. Then, as shown in FIG. 3, the upper end surface of the movable iron core 71 is pressed by the outer peripheral edge of the bent valve element biasing plate 74, and the movable iron core 71 moves (moves downward) away from the fixed iron core 69. . As a result, by the autonomous control of the flow control valve CV1, the valve rod 56 moves (downward) to a position where the valve body portion 57 is separated from the valve seat 58, and the valve body portion 57 is separated from the valve seat 58. Thus, the communication passage 54 (the air supply passage 38) is forcibly opened (opened). Then, high-pressure refrigerant gas is introduced from the discharge chamber 32 to the crank chamber 15 through the air supply passage 38, the crank pressure Pc increases, the inclination angle of the swash plate 22 decreases, and the discharge capacity of the compressor 10 decreases. Is done. Therefore, since the discharge capacity is reduced, the compressor 10 is in a low load state, and the temperature rise of the compressor 10 is suppressed.

According to the above embodiment, the following effects can be obtained.
(1) In the plunger chamber 70 (between the movable iron core 71 and the fixed iron core 69), which is a pressure region of the crank chamber 15, a valve body urging plate 74 that is bent and deformed when reaching a predetermined temperature is disposed. When the temperature of the valve body urging plate 74 reaches a predetermined temperature, the movable core 71 can be moved away from the fixed core 69 by bending deformation of the valve body urging plate 74. For this reason, the valve body 57 operatively connected to the movable iron core 71 can be separated from the valve seat 58 and the air supply passage 38 can be forcibly opened. Therefore, even if refrigerant gas leaks in the refrigerant circuit, the flow control valve CV1 is controlled so as to increase the discharge capacity, and insufficient lubrication occurs, the air is supplied based on the temperature of the compressor 10. The discharge control can be reduced by autonomously controlling the flow control valve CV1 so as to force the passage 38 to open. As a result, sliding heat generation inside the compressor 10 can be suppressed, the temperature of the compressor 10 can be prevented from rising, and a decrease in durability due to the temperature rise of the compressor 10 can be prevented.

  (2) The flow control valve CV1 operates the valve body 57 in accordance with the pressure difference between the high-pressure side discharge pressure region P1 and the low-pressure side discharge pressure region P2 before and after the throttle 27a. The flow rate control valve CV1 is controlled to increase the discharge capacity when refrigerant gas leakage occurs in the refrigerant circuit and the refrigerant flow rate in the external refrigerant circuit 40 decreases. When the refrigerant gas leaks in the refrigerant circuit, the return amount of the lubricating oil contained in the refrigerant gas to the compressor 10 also decreases, so that the operating state of the compressor 10 becomes very severe. Therefore, it is particularly preferable to adopt the measure for forcibly opening the flow control valve CV1 using the valve body urging plate 74 and reducing the discharge capacity of the compressor 10 for the flow control valve CV1.

  (3) The valve body urging plate 74 is formed in an annular shape, and is not formed with a notch for mounting on the outer periphery of the valve rod 56. Therefore, unlike the case where the notch is formed, the valve body urging plate 74 can reliably exhibit the jumping characteristics. As a result, the movable iron core 71 is rapidly moved away from the fixed iron core 69 by bending deformation of the valve body urging plate 74 that has reached a predetermined temperature, and the valve body portion 57 is rapidly separated from the valve seat 58. it can.

  (4) The time when the compressor 10 is controlled so as to increase the discharge capacity is when the refrigerant flow rate in the refrigerant circulation circuit is decreased, and the suction pressure Ps in the suction pressure region (suction chamber 31) is decreased. Is when Therefore, even if a control valve different from the flow rate control valve CV1 is added to the compressor 10 and the discharge capacity of the compressor 10 is controlled to be increased by the flow rate control valve CV1, the added control valve is sucked. It is also possible to detect a decrease in the pressure Ps and supply high-pressure refrigerant gas to the crank chamber 15 to reduce the discharge capacity. However, adding a control valve leads to an increase in the size of the compressor 10, which is not preferable. In the present embodiment, the discharge capacity of the compressor 10 can be reduced simply by disposing the valve body urging plate 74 between the movable iron core 71 and the fixed iron core 69 in the flow control valve CV1. Therefore, without adding a control valve, that is, without increasing the size of the compressor 10, it is possible to prevent an increase in the temperature of the compressor 10 due to the occurrence of insufficient refrigerant gas and insufficient lubrication.

  (5) The valve body urging plate 74 is disposed between the movable iron core 71 and the fixed iron core 69. By making the bending deformation force of the valve body urging plate 74 larger than the electromagnetic urging force (electromagnetic force) that moves the movable iron core 71 to the fixed iron core 69, the position of the movable iron core 71 (valve element portion 57) is changed to an electromagnetic actuator. Even if externally controlled by the portion 67, the movable core 71 can be separated from the fixed core 69 and the valve body 57 can be separated from the valve seat 58 by the valve body urging plate 74.

Each embodiment may be changed as follows.
As shown in FIG. 4A, in the flow control valve CV1 of the embodiment, the urging spring 60 provided in the valve chamber 53 as the pressure region of the crank chamber 15 may be made of a shape memory alloy. The urging spring 60 has a characteristic of rapidly expanding at a predetermined temperature (for example, 150 ° C. ± 5 ° C.) and returning to the original shape at a temperature lower than the predetermined temperature (for example, 130 ° C. ± 5 ° C.). The biasing spring 60 may be used as the valve body moving means. In this case, the valve body urging plate 74 is deleted. With this configuration, when the temperature of the flow control valve CV1 rises and the temperature of the urging spring 60 reaches a predetermined temperature, the urging spring 60 expands as shown in FIG. The valve rod 56 is moved (moved downward) in a direction in which the valve body 57 is separated from the valve seat 58 via the receiver 61. As a result, the communication passage 54 (air supply passage 38) is forcibly opened, and the discharge capacity of the compressor 10 can be reduced.

  The urging spring 60 is a component provided in the flow control valve CV1 in order to urge the valve body portion 57 in the direction of separating the valve body portion 57 from the valve seat 58. Then, only by reducing the cost of changing the material of the urging spring 60 to a shape memory alloy, the supply passage 38 is forcibly opened when the temperature of the compressor 10 exceeds a predetermined temperature, and the discharge capacity is increased. Can be reduced.

  As shown in FIG. 5 (a), in the flow control valve CV1 of the embodiment, it is provided in the valve chamber 53 as the pressure region of the crank chamber 15 and supports the lower end portion (the other end portion) of the urging spring 60. The spring receiver 61 may be formed of a bimetal in which the valve body urging plate 74 is formed in the embodiment. In this case, the inner periphery of the spring receiver 61 is supported by a step portion 56 a formed on the valve rod 56, and the inner periphery is attached to the valve rod 56. In addition, the spring receiver 61 comes into contact with the contact step 51 a formed on the inner peripheral surface of the valve housing 50 when the valve body 57 is seated on the valve seat 58. ing. When the temperature of the flow control valve CV1 rises and the temperature of the spring receiver 61 reaches a predetermined temperature, the spring receiver 61 is bent and deformed as shown in FIG. Then, since the inner peripheral portion of the spring receiver 61 is attached to the valve rod 56, the valve rod 56 is moved by the deformed spring receiver 61 in a direction in which the valve body portion 57 is separated from the valve seat 58 (downward movement). Let As a result, the communication passage 54 (air supply passage 38) is forcibly opened, and the discharge capacity of the compressor 10 can be reduced.

  As shown in FIG. 6, in the flow control valve CV <b> 1 of the embodiment, in the valve chamber 53 as the pressure region of the crank chamber 15, the valve body energizing as the valve body moving means is provided on the outer peripheral side of the energizing spring 60. A spring 98 may be added. The valve body biasing spring 98 is made of a shape memory alloy, has a characteristic of rapidly expanding at a predetermined temperature (for example, 150 ° C. ± 5 ° C.), and a temperature lower than the predetermined temperature (for example, 130 ° C. ± 5 ° C.). It will return to its original shape. In this case, the valve body urging plate 74 is deleted. With this configuration, when the temperature of the flow control valve CV1 rises and the temperature of the valve body biasing spring 98 reaches a predetermined temperature, the valve body biasing spring 98 expands and the valve via the spring receiver 61 extends. The rod 56 is moved (moved downward) in a direction in which the valve body 57 is separated from the valve seat 58. At this time, the urging force of the urging spring 60 is applied to the extension of the valve body urging spring 98, and the valve body portion 57 can be rapidly separated from the valve seat 58.

  As shown in Drawing 7, you may change flow control valve CV1 of an embodiment as follows. First, the valve body urging plate 74 in the flow control valve CV1 is deleted. Further, an insertion portion 71a having a diameter larger than the diameter of the valve rod 56 is formed in the movable iron core 71, and an insertion portion 71b having a smaller diameter than the insertion portion 71a is formed so as to communicate with the insertion portion 71a. That is, the movable iron core 71 is formed with an insertion portion 71 b into which the lower end portion of the valve rod 56 is inserted, and an insertion portion 71 a having a larger diameter than the insertion portion 71 b and the lower end side of the valve rod 56. Further, in the movable iron core 71, a step 71c is formed at the boundary between the insertion portion 71a and the insertion portion 71b.

  Then, the lower end portion of the valve rod 56 is fitted into the fitting portion 71b so that the valve rod 56 is integrated with the movable iron core 71, and the lower end side peripheral surface of the valve rod 56 and the insertion portion 71a facing the peripheral surface are provided. A coil spring 99 is disposed in an annular gap formed between the peripheral surface. The coil spring 99 is made of a shape memory alloy, and its upper end (one end) is in contact with and supported by the lower end surface of the fixed iron core 69 and its lower end (the other end) is in contact with and supported by the step 71c. That is, the coil spring 99 is disposed between the movable iron core 71 and the fixed iron core 69. The coil spring 99 urges the movable iron core 71 in a direction away from the fixed iron core 69, and separates the valve body 57 of the valve rod 56 integrated with the movable iron core 71 from the valve seat 58 (valve opening direction). ).

  The coil spring 99 that urges the movable iron core 71 is a shape memory alloy having a property of expanding when a predetermined temperature is reached, and functions as a valve body moving means. With this configuration, when the temperature of the flow control valve CV1 rises and the temperature of the coil spring 99 reaches a predetermined temperature, the coil spring 99 expands, that is, the direction in which the movable iron core 71 is separated from the fixed iron core 69, that is, the valve rod 56. Can be moved (moved downward) in a direction in which the valve body 57 separates from the valve seat 58. As a result, the communication passage 54 (air supply passage 38) is forcibly opened, and the discharge capacity of the compressor 10 can be reduced.

(Circle) the control valve of embodiment may be provided in the capacity | capacitance variable type compressor used for air conditioners other than for vehicles.
○ The variable capacity compressor may be a wobble type instead of a swash plate type.

The longitudinal cross-sectional view which shows the capacity | capacitance variable swash plate type compressor provided with the flow control valve. Sectional drawing which shows a flow control valve. Sectional drawing which shows the state which the valve body part separated from the valve seat by the deformation | transformation of the valve body energizing plate. (A) is a figure which shows the biasing spring made from a shape memory alloy as a valve body part moving means, (b) is a figure which shows the state which the biasing spring extended | stretched. (A) is a figure which shows the spring receiver made from a bimetal as a valve body part moving means, (b) is a figure which shows the state which the spring receiver bent and deformed. The figure which shows having provided the valve body biasing spring as a valve body part moving means in the outer peripheral side of the biasing spring. The figure which shows having provided the coil spring as a valve body part moving means between a movable iron core and a fixed iron core.

Explanation of symbols

  CV1 ... Flow control valve as a control valve, P1 ... High pressure side discharge pressure region as a pressure monitoring point, P2 ... Low pressure side discharge pressure region as a pressure monitoring point, 10 ... Variable capacity compressor, 15 ... Crank chamber, 22 Swash plate as cam plate, 32 ... discharge chamber as discharge pressure region, 38 ... air supply passage, 50 ... valve housing, 53 ... valve chamber, 53a ... step surface as inner surface of valve chamber, 56 ... valve rod, 57 ... Valve body part, 58 ... Valve seat, 60 ... Energizing spring as valve body part moving means, 61 ... Spring receiver as valve body part moving means, 62 ... Bellows as differential pressure sensitive member, 67 ... Electromagnetic actuator 69, fixed iron core, 71 ... movable iron core, 71a ... insertion part, 71b ... insertion part, 74 ... valve body urging plate as valve body part moving means, 99 ... coil spring as valve body part moving means.

Claims (6)

The refrigerant circulation circuit of the air conditioner is configured and used in a variable displacement compressor capable of changing the discharge capacity by controlling the pressure in the crank chamber that houses the cam plate. The discharge pressure area of the variable displacement compressor is A control valve capable of changing the discharge capacity by adjusting the opening of an air supply passage connecting the crank chamber;
The valve chamber defined in the valve housing to constitute a part of the air supply passage is provided with a valve body portion that opens and closes the air supply passage by contacting and separating from a valve seat provided in the valve chamber. And a differential pressure-sensitive member for exerting a force based on a pressure difference between two pressure monitoring points set on the refrigerant circulation circuit on the valve body portion to participate in positioning of the valve body portion in the valve chamber. Prepared,
Further, the variable capacity is characterized by comprising valve body moving means in the pressure region of the crank chamber for forcibly moving the valve body portion in a direction away from the valve seat by deformation of itself when a predetermined temperature is reached. Type compressor control valve.   A movable iron core operatively connected to the valve body, and a fixed iron core to which the movable iron core can be contacted / separated, and an electromagnetic actuator portion that changes an electromagnetic urging force of the movable iron core by energization control from the outside, 2. The variable capacity type of claim 1, wherein the valve body moving means is disposed between a movable iron core and the fixed iron core, and the valve body moving means moves the valve body through the movable iron core. Compressor control valve.   The movable iron core is formed with an insertion portion into which a lower end portion of the valve rod integrally provided with the valve body portion is inserted, and an insertion portion having a larger diameter than the insertion portion and the lower end side of the valve rod. A coil spring as a valve body moving means is disposed in a gap between a lower end side peripheral surface of the valve rod and a peripheral surface of the insertion portion facing the lower end side peripheral surface, and an upper end portion of the coil spring Is supported by the fixed iron core and its lower end is supported by the movable iron core, and the coil spring is made of a shape memory alloy that deforms when the temperature reaches a predetermined temperature. The control valve for a variable displacement compressor according to claim 2, wherein the valve body is moved through movement.   An urging spring for urging the valve body portion in a direction away from the valve seat is disposed in the valve chamber, and one end portion of the urging spring is abutted and supported on the inner surface of the valve chamber. In addition, the other end portion is abutted and supported by a spring receiver attached to a valve rod including the valve body portion, and the valve body portion moving means is formed by the spring receiver made of a bimetal that deforms when reaching a predetermined temperature. The control valve for a variable displacement compressor according to claim 1, wherein the valve body portion is moved through movement of the biasing spring by deformation of the spring receiver.   The control valve for a variable displacement compressor according to claim 4, wherein the spring receiver made of the bimetal is formed in an annular shape.   An urging spring for urging the valve body portion in a direction away from the valve seat is disposed in the valve chamber, and one end portion of the urging spring is abutted and supported on the inner surface of the valve chamber. The biasing spring is made of a shape memory alloy whose other end is in contact with and supported by a spring receiver attached to a valve rod having the valve body, and the valve body moving means expands when reaching a predetermined temperature. The control valve for a variable displacement compressor according to claim 1, wherein the valve body portion is moved by extension of the biasing spring.

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