JP2007051618A - Variable displacement compressor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent generation of a torsional load between a rotating shaft and a fixed capacity control valve by preventing leakage of lubricating oil existing between a rotary shaft and the shaft. <P>SOLUTION: A spring expanding in response to driving torque is interposed between a pulley 18 of transmitting driving force from an engine and a bracket 17 fixed to the rotary shaft 6, and is constituted so as to directly transmit rotation of the pulley 18 to the shaft 20 via a disc 21. A male screw formed on a fixed iron core 23 of the capacity control valve 22 is threadedly engaged with a female screw formed on the tip of the rotary shaft 6, and the shaft 20 rotates its fixed iron core 23. When the driving torque for driving this variable displacement compressor increases, the rotary shaft 6 and the shaft 20 relatively rotate, and increase a magnetic gap between the fixed iron core 23 and a movable iron core. Thus, the driving torque is reduced by controlling so as to increase a valve lift of a valve part and to reduce delivery capacity. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a variable capacity compressor, and more particularly, to a variable capacity compressor capable of varying a discharge capacity in accordance with a torque used in an air conditioner for an automobile and driven by an engine.

  In a variable capacity compressor, a piston that reciprocates in parallel with a rotating shaft is connected to a swash plate attached to a rotating shaft driven by an engine, and the pressure in the crank chamber that the piston receives and the pressure in all the cylinders that the piston receives. The discharge capacity is made variable by controlling the inclination angle of the swash plate based on the difference from the average value. Since the inclination angle of the swash plate and the discharge capacity have a corresponding relationship, if the inclination angle of the swash plate or the stroke of the piston connected to the swash plate can be detected, the discharge capacity of the variable capacity compressor can be accurately known. it can. However, even if the discharge capacity is the same, the power required to drive the variable capacity compressor is known to vary greatly depending on the suction pressure and discharge pressure. Depending on the usage conditions, the required load of the variable capacity compressor Torque may increase. When the load torque increases, the engine power may become insufficient, and the engine may stop.

  Therefore, the driving torque transmitted from the pulley that receives the driving force of the engine to the rotating shaft is measured by a torque detector and converted into an electric signal, and the crank torque of the discharge pressure Pd is used as a load torque when driving the variable capacity compressor. It has been proposed to feed back to a control device for a capacity control valve that controls the amount of refrigerant introduced into the chamber, and to control the capacity control valve so that the target value is reached when the load torque increases (for example, (See Patent Document 1).

  In this variable capacity compressor, since the drive torque is detected by a torque detector and the load torque is predicted and controlled by this, there is a control error and a response delay, and the mechanism for detecting the drive torque is complicated. It was expensive.

  On the other hand, by inserting an elastic body between a pulley that receives the driving force of the engine and a bracket fixed to the rotation shaft of the swash plate, the driving force of the engine is transmitted from the pulley to the bracket via the elastic body. There is also known a variable displacement compressor that controls the discharge capacity based on the change in the relative rotation angle between the generated pulley and the bracket (for example, see Patent Document 2).

In this variable capacity compressor, the fluctuation of the drive torque of the variable capacity compressor is detected by the change in the relative rotation angle between the pulley and the bracket, and this is mechanically transmitted directly to the capacity control unit by the shaft. . As a result, if there is a change in drive torque due to engine load fluctuation, it is immediately transmitted to the capacity control unit to control the discharge capacity, enabling control with good accuracy and responsiveness, and engine efficiency and responsiveness. Can be improved. In addition, since the detected torque is mechanically transmitted to the capacity control unit, it can be configured at low cost.
JP 2001-132634 A (paragraph numbers [0028] to [0031], FIG. 3) JP 2004-124867 A (paragraph numbers [0017] to [0021], FIGS. 2 to 4)

  However, in the variable capacity compressor described in Patent Document 2, the change in the relative rotation angle is converted into the change in the axial direction of the rotation shaft, and the change is provided on the side opposite to the side where the pulley is provided. Because it is configured to transmit directly to the shaft through a shaft that is rotatably supported by the rotating shaft and can be moved back and forth in the axial direction, the axial movement of the shaft relative to the rotating shaft causes the lubricating oil between them to flow out. There was a problem that it would act. Further, since the capacity control unit to which the rotating shaft is fixed is driven, a torsional load is generated in the meantime, and a change in drive torque cannot be accurately transmitted to the capacity control unit. there were.

  The present invention has been made in view of such points, and makes it difficult for the lubricating oil between the rotating shaft and the shaft to leak, and without causing a torsional load between the shaft and the capacity control unit. An object of the present invention is to provide a variable capacity compressor capable of driving the compressor.

  In the present invention, in order to solve the above-described problem, a relative rotation angle between the pulley and the bracket generated by transmitting the driving force of the engine to a bracket fixed to the rotation shaft of the swash plate via the elastic body. In a variable displacement compressor that detects a change in the rotation as a torque for driving the rotating shaft and varies a discharge capacity in accordance with the detected torque, and a rotation of the pulley that is rotatably held by the rotating shaft. A shaft that transmits to a fixed iron core of a solenoid unit that sets a discharge capacity at a magnetic field, and a magnetic resistance of a magnetic passage that passes through the fixed iron core in accordance with a change in relative rotation angle between the fixed iron core and the rotating shaft There is provided a variable capacity compressor characterized by comprising a magnetoresistive variable means for changing the above.

  According to such a variable capacity compressor, the change in the relative rotation angle between the pulley and the bracket is converted into the change in the magnetic resistance of the magnetic path passing through the fixed iron core, and the change in the relative rotation angle, that is, the rotation axis is changed. As the driving torque increases, the capacity control unit can control the capacity so that the discharge capacity decreases. As a result, the torque for driving the rotating shaft is transmitted to the capacity control unit in a non-contact manner, so that no torsional load is generated between the rotating shaft and the fixed capacity control unit. Since it is only rotating within the rotating shaft without moving in the axial direction, leakage of the lubricating oil existing between the rotating shaft and the shaft can be prevented.

  The variable capacity compressor of the present invention is configured such that the torque for driving the rotating shaft is transmitted to the capacity control unit in a non-contact manner, so that the shaft between the rotating shaft and the fixed capacity control unit is interposed. Since no torsional load is generated, there is an advantage that the control accuracy can be improved.

  In addition, the shaft only rotates within the rotation axis with a change in the relative rotation angle, and does not move in the axial direction, so that it is possible to prevent leakage of lubricating oil existing between the rotation axis and the shaft. There is.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a central sectional view showing the configuration of the variable capacity compressor according to the first embodiment.
The variable capacity compressor has a cylinder block 1 in the center thereof, and a front housing 2 is joined to a front end portion thereof (the left side in the figure is the front). A rear housing 4 is joined to the rear end of the cylinder block 1 via a valve plate 3.

  An internal space formed by the cylinder block 1 and the front housing 2 constitutes a crank chamber 5. A rotation shaft 6 is disposed so as to penetrate the center of the crank chamber 5, and the rotation shaft 6 is rotatably supported by bearings 7 and 8 provided in the cylinder block 1 and the front housing 2. A lug plate 9 is fixed to the rotary shaft 6, and a swash plate 12 is supported to be tiltable with respect to the axis of the rotary shaft 6 via a support arm 10 and a guide pin 11 protruding from the lug plate 9. Has been. The swash plate 12 is connected via a shoe 15 to the head of a piston 14 slidably disposed in a plurality of cylinder bores 13 formed in the cylinder block 1.

  The rotary shaft 6 has a front end portion protruding through the front housing 2 and protruding to the outside, and a lip seal 16 is provided to seal a gap between the rotary shaft 6 and the front housing 2 from the outside. The rotating shaft 6 has a bracket 17 fixed to the tip portion thereof so as to rotate integrally with the rotating shaft 6.

  A pulley 18 to which driving force from the engine is transmitted is rotatably supported by a bearing 19 at the front end portion of the front housing 2. Although not shown, for example, a plurality of springs (elastic bodies) are interposed between the pulley 18 and the bracket 17, and the driving force of the engine received by the pulley 18 is transmitted to the bracket 17 via the spring. (This spring can be, for example, the compression coil spring shown in FIGS. 2 and 7 of Patent Document 2). At this time, the spring expands and contracts according to the torque with which the pulley 18 drives the bracket 17, whereby the relative rotation angle of the bracket 17 with respect to the pulley 18 changes. That is, when the torque for driving the bracket 17 is small, the amount of contraction of the spring is small, so the change in the relative rotation angle between the pulley 18 and the bracket 17 is small, and the torque for driving the bracket 17 is large. Since the amount of contraction of the spring is large, the amount of change in the relative rotation angle between the pulley 18 and the bracket 17 is large, so that the torque that drives the bracket 17 is between the pulley 18 and the bracket 17. It is detected as a change in relative rotation angle.

  A shaft 20 is disposed at the axial position of the rotary shaft 6 so as to penetrate the rotary shaft 6, and a disk 21 is fixed to the front end portion thereof. The outer periphery of the disk 21 is fixed to the pulley 18, and the shaft 20 is rotated simultaneously with the pulley 18. Further, a seal member is provided near the front end of the rotating shaft 6 so as to prevent the lubricating oil from leaking through the clearance between the rotating shaft 6 and the shaft 20. In the illustrated example, this seal member has a double seal structure with two O-rings. Here, since the shaft 20 only rotates in the rotating shaft and does not move in the axial direction, leakage of lubricating oil between the rotating shaft and the shaft can be sufficiently prevented by the O-ring.

  The rear end portion of the shaft 20 extends to the rear end portion of the rotary shaft 6 and is processed into a hexagonal cross section, for example. The rotary shaft 6 has a screw provided at the rear end portion thereof, and a fixed iron core 23 of the capacity control valve 22 provided with the screw is screwed thereto, and the rear end portion of the shaft 20 is engaged with the fixed iron core 23. It is loosely fitted. Accordingly, when the torque for driving the bracket 17 is very small and the change in the relative rotation angle between the pulley 18 and the bracket 17 is small, the fixed iron core 23 protrudes most from the rear end portion of the rotating shaft 6. When the relative rotational angle between the pulley 18 and the bracket 17 increases as the torque for driving the bracket 17 increases, the fixed iron core 23 moves to the rear end portion of the rotary shaft 6. It will be screwed in. That is, the threaded portion that is screwed together with the rotating shaft 6 and the fixed iron core 23 rotated by the shaft 20 can change the amount of change in the relative rotation angle between the pulley 18 and the bracket 17. It has a function of converting into 23 axial movements.

  The rear housing 4 communicates with the cylinder bore 13 via a suction chamber 25 communicated with the cylinder bore 13 via a suction relief valve 24 provided on the valve plate 3 and a discharge relief valve 26 provided on the valve plate 3. The discharge chamber 27 and the capacity control valve 22 are provided. In this embodiment, it is assumed that the cylinder block 1 and the rear housing 4 are made of a non-magnetic material such as aluminum, and the valve plate 3 is made of a magnetic material such as iron. Although not shown, the discharge chamber 27 is connected to the condenser of the refrigeration cycle of the air conditioner, and the suction chamber 25 is connected to the evaporator or accumulator of the refrigeration cycle.

  The capacity control valve 22 is disposed in a refrigerant passage formed in the rear housing 4 so as to communicate between the discharge chamber 27 and the crank chamber 5, and a part of the high-pressure refrigerant discharged into the discharge chamber 27 is supplied to the crank chamber 5. In this way, the pressure in the crank chamber 5 is controlled, and thereby the discharge capacity of the variable capacity compressor is controlled. Although not shown, the crank chamber 5 communicates with the suction chamber 25 via a fixed orifice so that the refrigerant introduced into the crank chamber 5 by the capacity control valve 22 always leaks into the suction chamber 25 slightly. Yes.

FIG. 2 is a central sectional view showing the configuration of the capacity control valve of the variable capacity compressor according to the first embodiment.
The capacity control valve 22 is arranged on the same axis as the rotary shaft 6, and has a valve part for controlling the flow rate of the refrigerant introduced from the discharge chamber 27 into the crank chamber 5, and the refrigerant discharged from the variable capacity compressor by an external signal. And a solenoid unit for setting the discharge capacity.

  The valve portion of the capacity control valve 22 has a body 31, and the body 31 is controlled to communicate with the discharge chamber 27 of the rear housing 4 and receive the discharge pressure Pd, and to communicate with the crank chamber 5. And a port 33 for outputting the pressure Pc. A valve seat 34 formed integrally with the body 31 is disposed in the refrigerant passage between the port 32 and the port 33, and the valve body 35 is disposed on the side of the space communicating with the port 32 so as to face the valve seat 34. The valve seat 34 is disposed so as to be able to contact and separate. The valve body 35 is urged in the valve closing direction by a spring 37 disposed between the valve body 35 and a spring receiving member 36 press-fitted into the port 33.

  The valve body 35 is integrally formed with a shaft 38 extending through a valve hole. The shaft 38 is supported by the body 31 such that a portion having substantially the same diameter as the valve hole is movable forward and backward in the axial direction, and an end surface opposite to the side where the valve body 35 is provided is connected via a port 39. It is exposed to the space where the crank chamber pressure Pc is introduced.

  The solenoid portion has a yoke 40 that is press-fitted and fixed to the body 31 of the valve portion, a coil 41 is disposed inside thereof, and a movable iron core 42 is disposed at the center portion thereof so as to be movable back and forth in the axial direction. ing. The movable iron core 42 is biased toward the valve portion by a spring 43 so that the bottom surface of the recess formed at the center of the end surface on the valve portion side contacts the end surface of the shaft 38 integrated with the valve body 35. It has become. The spring 43 that urges the movable iron core 42 in the direction of the valve portion and urges the shaft 38 in the valve opening direction is larger than the spring 37 that urges the valve body 35 in the valve closing direction. Therefore, when the solenoid portion is not energized, the valve portion is maintained in a fully open state.

  The solenoid unit also forms a magnetic circuit by the fixed iron core 23 that rotates together with the rotating shaft 6 and the shaft 20 and the magnetic valve plate 3 in which the opening end of the yoke 40 is disposed in close proximity.

  On the outer periphery of the body 31, O-rings 44 and 45 are provided around the axial direction across the port 32 so as to seal the port 32 into which the discharge pressure Pd is introduced from the pressure Pc of the crank chamber. . Moreover, since the capacity control valve 22 is installed in the rear housing 4, it is necessary to draw out two electric wires for the solenoid part to the outside. The number of wires to be drawn can be reduced to one.

Next, the operation of the variable capacity compressor having the above configuration will be described.
First, when the coil 41 is not energized, the valve element 35 is energized by a spring 43 having a larger spring load than the spring 37 energizing the movable iron core 42, and the capacity control valve 22 is fully opened. ing.

  At this time, when the pulley 18 receives a driving force from the engine, the driving force is transmitted to the bracket 17 via a spring (not shown), so that the rotating shaft 6 fixed to the bracket 17 is driven to rotate. The lug plate 9 fixed to 6 rotates, the swash plate 12 swings, and the piston 14 reciprocates. As a result, the refrigerant having the suction pressure Ps is sucked into the cylinder bore 13 from the suction chamber 25 via the suction relief valve 24, and then the compressed refrigerant having the discharge pressure Pd is discharged to the discharge chamber 27 via the discharge relief valve 26. Is done.

  Since the refrigerant in the discharge chamber 27 is introduced into the crank chamber 5 via the capacity control valve 22 that is fully open, the pressure Pc in the crank chamber 5 is maximized, and the swash plate 12 moves relative to the rotating shaft 6. Tilts at right angles. This minimizes the stroke of the piston 14, and the variable capacity compressor operates at the minimum capacity.

  Next, when the maximum current is supplied to the coil 41, the movable iron core 42 is attracted by the fixed iron core 23 against the biasing force of the spring 43, and the valve body 35 is pulled by the biasing force of the spring 37. The valve portion is fully closed. As a result, the pressure Pc in the crank chamber 5 is minimized, the stroke of the piston 14 is maximized, and the variable capacity compressor operates at the maximum capacity.

  Further, when a predetermined value of current is supplied to the coil 41, the valve body 35 of the valve portion balances the attractive force between the movable iron core 42 and the fixed iron core 23 and the urging force of the springs 37 and 43. Set to valve lift. As a result, the variable capacity compressor is controlled to a discharge capacity corresponding to the value of the energization current to the coil 41.

  Here, when the vehicle enters a high load state such as an uphill traveling state or a sudden acceleration traveling state, the driving force of the engine increases and the variable capacity compressor is driven with an unnecessarily large driving force. For this reason, a spring (not shown) provided in the middle of transmission of the driving force is compressed, and the pulley 18 and the bracket 17 are twisted and relatively rotated. The change in the relative rotation angle due to the twist corresponds to the torque applied to drive the variable capacity compressor. The change in the relative rotation angle rotates the bracket 17 with respect to the disk 21 fixed to the pulley 18. When the bracket 17 is rotated with respect to the disk 21, a screw portion interposed between the rotary shaft 6 fixed to the bracket 17 and the fixed iron core 23 rotating integrally with the disk 21 via the shaft 20 is formed. The rotational movement is converted into the movement of the fixed iron core 23 in the axial direction, and the fixed iron core 23 is moved away from the movable iron core 42. As a result, the magnetic force between the fixed iron core 23 and the movable iron core 42 is increased, so that the attractive force is reduced. Therefore, the load of the spring 43 is increased and the valve body 35 is urged in the valve opening direction. As a result, the flow rate of the refrigerant introduced into the crank chamber 5 increases, and the variable capacity compressor is controlled in a direction in which the discharge capacity decreases. This means that the load torque of the variable capacity compressor is reduced. Since the load of the engine is reduced, the efficiency and responsiveness of the engine can be improved.

  In this way, the variable capacity compressor senses an increase in driving torque due to engine load fluctuations with the spring interposed between the pulley 18 and the bracket 17, and directly detects it with the fixed iron core 23 of the capacity control valve 22. And the displacement control valve 22 is controlled in the direction with a small discharge capacity, thereby simplifying the configuration and enabling control with good responsiveness. In addition, transmission of the detected drive torque for driving the variable capacity compressor to the capacity control valve 22 is performed in a non-contact manner, and therefore, between the rotating shaft 20 and the fixed capacity control valve 22. Since no torsional load is generated, the control accuracy can be improved.

FIG. 3 is a diagram illustrating an example of a suction force characteristic of the capacity control valve.
In this attractive force characteristic, the vertical axis indicates the attractive force generated between the fixed iron core 23 and the movable iron core 42, and the horizontal axis indicates the magnetic gap between the fixed iron core 23 and the movable iron core 42. Yes. According to this characteristic, if the magnetic gap is the same, the attractive force increases almost in proportion to the value of the current supplied to the solenoid unit. That is, when the load torque of the variable capacity compressor does not fluctuate, the suction force by which the fixed iron core 23 sucks the movable iron core 42 increases as the value of the current supplied to the solenoid unit increases. As a result, the valve body 35 moves in the direction in which the valve lift becomes smaller, so that the variable capacity compressor is controlled in the direction in which the discharge capacity becomes larger.

  When a certain amount of current is supplied to the solenoid unit, that is, when the magnetic gap is at a predetermined value, if the load torque of the variable capacity compressor increases, the fixed iron core 23 moves in the direction in which the magnetic gap increases. As a result, the suction force decreases accordingly. Decreasing the suction force means that the load of the spring 43 is increased, whereby the movable iron core 42 urges the shaft in the valve opening direction and acts in the direction of increasing the valve lift. As a result, the variable capacity compressor is controlled in a direction in which the discharge capacity decreases, so that the required torque for driving the variable capacity compressor is reduced, and the engine load can be reduced.

  In the illustrated example, when the same attractive force is to be obtained, the magnetic gap interval tends to gradually increase when the current value is increased at equal intervals. However, from the relationship of controllability, it is preferable to make the change intervals of the magnetic gap equal to the increase of the current value at the same attractive force so that the relationship between the current value and the magnetic gap is proportional.

  FIG. 4 is a central sectional view showing the configuration of the capacity control valve of the variable capacity compressor according to the second embodiment. In FIG. 3, the same components as those shown in FIGS. 1 and 2 are denoted by the same reference numerals, and detailed description thereof is omitted.

  Compared with the variable capacity compressor according to the first embodiment, the variable capacity compressor according to the second embodiment moves the fixed iron core 23 of the solenoid portion in the axial direction according to the detected torque. The difference is that the configuration of the screw part to be converted into motion and the configuration of the magnetic circuit of the fixed iron core 23 are changed.

  That is, the rotary shaft 6 is configured such that a screw is externally provided at a rear end portion thereof, and a fixed iron core 23 of the capacity control valve 22 in which the screw is provided is screwed. Further, the fixed iron core 23 is integrally formed with a flange portion 46 protruding outward in the radial direction at a position opposite to the yoke 40 with the valve plate 3 interposed therebetween.

  With the above-described configuration, the rotation shaft 6 and the fixed iron core 23 are screwed together with respect to a change in the relative rotation angle between the rotation shaft 6 and the shaft 20 that occurs in response to a change in torque that drives the variable capacity compressor. The fixed iron core 23 is moved in the axial direction by the threaded portion, and acts to reduce the required torque for driving the variable capacity compressor as the torque increases.

  The flange portion 46 formed integrally with the fixed iron core 23 is a magnetic resistance between the valve plate 3 and the fixed iron core 23 in a magnetic path formed by the yoke 40, the valve plate 3 and the fixed iron core 23. Therefore, the attractive force of the magnetic circuit is increased.

  FIG. 5 is a central sectional view showing the configuration of the variable displacement compressor according to the third embodiment, and FIG. 6 is a central sectional view showing the configuration of the displacement control valve of the variable displacement compressor according to the third embodiment. is there. 5 and 6, the same components as those shown in FIGS. 1 and 2 are denoted by the same reference numerals, and detailed description thereof is omitted.

  The variable capacity compressor according to the third embodiment is different from the variable capacity compressor according to the first embodiment in that the valve plate 3 is made of a nonmagnetic material. Since the non-magnetic valve plate 3 cannot be used as a part of the magnetic circuit of the solenoid unit, the variable capacity compressor has a capacity control valve 22 having a magnetic path between the yoke 40 and the fixed iron core 23. Is configured to penetrate through the valve plate 3.

  In the capacity control valve 22, a magnetic annular plate 47 is disposed in the yoke 40 so as to be adjacent to the bobbin of the coil 41, and a magnetic passage is formed between the yoke 40 and the rotating fixed iron core 23. I am doing so.

  FIG. 7 is a central sectional view showing the configuration of the capacity control valve of the variable capacity compressor according to the fourth embodiment. In FIG. 7, the same components as those shown in FIG. 6 are denoted by the same reference numerals, and detailed description thereof is omitted.

  The variable capacity compressor according to the fourth embodiment has a magnetic path formed between the yoke 40 and the fixed iron core 23 as compared with the variable capacity compressor according to the third embodiment. It differs in that it is provided on the fixed iron core 23 side instead of the side. That is, in the capacity control valve 22, a flange portion 48 protruding radially outward from the fixed iron core 23 is formed integrally with the fixed iron core 23, and this is fixed iron core 23 rotating with the yoke 40. A magnetic path is formed between the two.

  FIG. 8 is a central sectional view showing the configuration of the variable capacity compressor according to the fifth embodiment, and FIG. 9 is a central sectional view showing the configuration of the capacity control valve of the variable capacity compressor according to the fifth embodiment. is there. 8 and 9, the same components as those shown in FIGS. 5 and 6 are denoted by the same reference numerals, and detailed description thereof is omitted.

  The variable capacity compressor according to the fifth embodiment is different from the variable capacity compressor according to the third embodiment in that the configuration of the valve portion of the capacity control valve 22 is changed, and the capacity control valve 22 is changed. Is different in that the length of the rear housing 4 and the total length of the variable capacity compressor are shortened.

  That is, the capacity control valve 22 has a cylindrical body 51 extending in the axial direction fixed to the tip of the body 31. This cylindrical body 51 constitutes a port 32 into which a refrigerant having a discharge pressure Pd is introduced, and constitutes a guide for moving the movable iron core 42 forward and backward in the axial direction. A valve body 35 is integrally formed at the inner end of the cylindrical body 51, and a valve seat 34 for the valve body 35 is provided on the movable iron core 42. Therefore, in the capacity control valve 22, the valve body 35 is fixed with respect to the body 31, and the valve seat 34 constitutes a valve portion that is movable with respect to the body 31.

The movable iron core 42 is urged in the valve opening direction by a spring 52, and an O-ring 53 is provided around the tip of the body 31.
In the configuration example of the capacity control valve 22, a port for allowing the controlled refrigerant to flow out to the crank chamber 5 is not particularly provided. However, a solenoid portion is disposed in the cylinder block 1 through the valve plate 3. Since the space of the cylinder block 1 in which the solenoid part is arranged communicates with the front housing 2 constituting the crank chamber 5, it flows out into the solenoid part via the valve part comprising the valve body 35 and the valve seat 34. The refrigerant pressure Pc is to be introduced into the crank chamber 5.

  The operation of the variable capacity compressor according to the fifth embodiment including the capacity control valves 22 having different configurations is the same as that of the variable capacity compressor according to the first to fourth embodiments. That is, when the solenoid part is not energized, the movable iron core 42 is urged by the spring 52 in a direction away from the fixed iron core 23, so that the valve seat 34 is separated from the valve body 35 and the valve part is fully open. The variable capacity compressor operates at the minimum capacity. When the maximum current is supplied to the coil 41, the valve portion is fully closed, and the variable capacity compressor operates at the maximum capacity. When a predetermined value of current is supplied to the coil 41, the variable capacity compressor is controlled to a discharge capacity corresponding to the value of the energization current to the coil 41. Here, when the torque for driving the variable capacity compressor increases due to engine load fluctuations, the fixed iron core 23 moves away from the movable iron core 42, so the load of the spring 52 increases and the valve portion The valve lift is increased, and the variable capacity compressor is controlled in a direction in which the discharge capacity decreases, thereby reducing the required torque for driving the variable capacity compressor.

  FIG. 10 is a central sectional view showing the configuration of the capacity control valve of the variable capacity compressor according to the sixth embodiment, and FIG. 11 is a sectional view taken along the line aa in FIG. ) Shows the state transition when the driving torque shifts from the minimum to the maximum. 10 and 11, the same components as those shown in FIGS. 1 to 9 are denoted by the same reference numerals, and detailed description thereof is omitted.

  In the variable capacity compressor according to the sixth embodiment, the variable capacity compressor according to the first to fifth embodiments has a fixed iron core 23 according to fluctuations in driving torque that drives the variable capacity compressor. The difference is that the magnetic resistance of the magnetic path is changed while the magnetic gap between the magnetic core 42 and the movable iron core 42 is changed.

  The valve portion of the capacity control valve 22 has the same configuration as that shown in FIGS. 2, 4, 6 and 7, but the configuration of the solenoid portion is changed. That is, the fixed iron core 23 is fixed to the shaft 20 by press-fitting the shaft 20 therein, and a plurality of claws 61 projecting radially outward adjacent to the bobbin of the coil 41 are integrally formed. . In the example shown in the figure, four claws 61 are arranged at equal intervals in the circumferential direction, but the number is not limited to this number. Therefore, the magnetic gap between the fixed iron core 23 and the movable iron core 42 does not change and is constant. On the other hand, an annular magnetic member 63 is also fixed to the tip of the rotating shaft 6 via a joint 62. On the inner side of the magnetic member 63, four claws 64 project from the claws 61 of the fixed iron core 23.

  In the variable capacity compressor having the above configuration, when the driving torque when driving the variable capacity compressor is small and the twist of the rotary shaft 6 with respect to the shaft 20 is small, as shown in FIG. The claw 61 of the fixed iron core 23 and the claw 64 of the magnetic member 63 are in a positional relationship so that their centers coincide. Thereby, in the magnetic circuit of the solenoid unit, the magnetic resistance of the magnetic path formed by the yoke 40, the magnetic member 63, the claw 64, the claw 61, and the fixed iron core 23 is minimized. This corresponds to the state when the magnetic gap between the fixed iron core 23 and the movable iron core 42 is the smallest in the variable capacity compressors of the first to fifth embodiments.

  Here, when the driving torque when driving the variable capacity compressor is increased, the torsion of the rotating shaft 6 with respect to the shaft 20 is increased, and the relative rotation angle between the shaft 20 and the rotating shaft 6 is increased, as shown in FIG. (B) Further, as shown in (C), the centers of the claws 61 of the fixed iron core 23 and the claws 64 of the magnetic member 63 are gradually shifted, and accordingly, the magnetic resistance of the magnetic path gradually increases. Go.

  At the point where the drive torque when driving the variable capacity compressor is maximum, the center of the claw 61 of the fixed iron core 23 is the claw adjacent to the magnetic member 63 as shown in FIG. Coincides with the center of the valley between 64, at which time the reluctance of the magnetic path is maximized. This corresponds to the state when the magnetic gap between the fixed iron core 23 and the movable iron core 42 is the largest in the variable capacity compressor of the first to fifth embodiments.

Therefore, the variable capacity compressor according to the sixth embodiment also performs the same operation as the variable capacity compressor according to the first to fifth embodiments.
In the variable capacity compressor according to the first to sixth embodiments described above, the fixed iron core 23 of the solenoid portion needs to be adjusted after assembling the position in the axial direction or the relative angle with the rotary shaft 6. However, the adjustment can be easily performed by changing the relative angle between the pulley 18 and the disk 21 fixed thereto.

It is a central sectional view showing the composition of the variable capacity compressor concerning a 1st embodiment. It is a center sectional view showing composition of a capacity control valve of a variable capacity compressor concerning a 1st embodiment. It is a figure which shows an example of the attraction | suction force characteristic of a capacity | capacitance control valve. It is a center sectional view showing the composition of the capacity control valve of the variable capacity compressor concerning a 2nd embodiment. It is a center sectional view showing the composition of the variable capacity compressor concerning a 3rd embodiment. It is a center sectional view showing the composition of the capacity control valve of the variable capacity compressor concerning a 3rd embodiment. It is a center sectional view showing the composition of the capacity control valve of the variable capacity compressor concerning a 4th embodiment. It is a center sectional view showing the composition of the variable capacity compressor concerning a 5th embodiment. It is a center sectional view showing the composition of the capacity control valve of the variable capacity compressor concerning a 5th embodiment. It is a center sectional view showing the composition of the capacity control valve of the variable capacity compressor concerning a 6th embodiment. FIG. 11 is a cross-sectional view taken along the line aa in FIG. 10, and (A) to (D) show state transitions when the drive torque shifts from the minimum to the maximum.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Cylinder block 2 Front housing 3 Valve plate 4 Rear housing 5 Crank chamber 6 Rotating shaft 7, 8 Bearing 9 Lug plate 10 Support arm 11 Guide pin 12 Swash plate 13 Cylinder bore 14 Piston 15 Shoe 16 Lip seal 17 Bracket 18 Pulley 19 Bearing 20 Shaft 21 Disc 22 Capacity control valve 23 Fixed iron core 24 Suction relief valve 25 Suction chamber 26 Discharge relief valve 27 Discharge chamber 31 Body 32, 33 Port 34 Valve seat 35 Valve body 36 Spring receiving member 37 Spring 38 Shaft 39 Port 40 Yoke 41 Coil 42 Movable iron core 43 Spring 44, 45 O-ring 46 Flange part 47 Annular plate 48 Flange part 51 Tubular body 52 Spring 53 O-ring 61 Claw 62 Joint 63 Magnetic member 64 Claw

Claims (9)

A change in the relative rotation angle between the pulley and the bracket, which is generated when the driving force of the engine is transmitted to a bracket fixed to the rotating shaft of the swash plate via an elastic body, is used as a torque for driving the rotating shaft. In a variable capacity compressor that detects and varies the discharge capacity according to the detected torque,
A shaft that is rotatably held by the rotary shaft and transmits the rotation of the pulley to a fixed iron core of a solenoid unit that sets a discharge capacity in a capacity control unit;
Magnetoresistive variable means for changing the magnetic resistance of the magnetic path passing through the fixed iron core according to the change in the relative rotation angle between the fixed iron core and the rotating shaft,
A variable capacity compressor characterized by comprising:   The magnetoresistive variable means is interposed between the fixed iron core and the rotating shaft, and moves the fixed iron core in the axial direction in accordance with a change in the relative rotation angle, thereby moving the fixed iron core and the rotating iron core. The variable capacity compressor according to claim 1, wherein the variable capacity compressor is a screw portion that changes a magnetic gap with the iron core.   The variable capacity compressor according to claim 2, wherein the screw portion is configured to move the fixed iron core in a direction away from the movable iron core as the relative rotation angle increases.   The said screw part has the external thread provided in the outer periphery of the said fixed iron core, and the internal thread provided in the said rotating shaft so that it might screw-engage with the said external thread. Variable capacity compressor.   The said screw part has the external thread provided in the outer periphery of the said rotating shaft, and the internal thread provided inside the said fixed iron core so that it may screw-engage with the said external thread. Variable capacity compressor.   The variable magnetic resistance means includes a plurality of first claws that are arranged in a circumferential direction on the outer periphery of the fixed iron core, and a protrusion that is disposed on the outer circumference of the first claw and rotates together with the rotating shaft. An annular magnetic member; and a second claw projecting on the inner side of the magnetic member so as to oppose the first claw, wherein the first claw and the first claw according to a change in the relative rotation angle The variable capacity compressor according to claim 1, wherein the center of the second claw is shifted.   When the relative rotation angle is small, the centers of the first claw and the second claw substantially coincide with each other, and as the relative rotation angle increases, the first claw and the second claw become larger. 7. The variable capacity compressor according to claim 6, wherein the center deviation is increased.   The capacity control unit is a capacity control valve that is disposed in a passage formed between the discharge chamber and the crank chamber and controls the flow rate of the refrigerant flowing from the discharge chamber to the crank chamber, and the relative rotation angle is The required torque for driving the rotating shaft is reduced by controlling to increase the flow rate of the refrigerant when the magnetoresistive variable means is changed to increase the magnetic resistance as it increases. Item 2. The variable capacity compressor according to Item 1. A magnetic valve plate sandwiched between the cylinder block and the rear housing is disposed so as to be positioned in the vicinity of the outer periphery of the rotating shaft or the fixed iron core, so that the magnet between the yoke of the solenoid unit and the fixed iron core is arranged. The variable capacity compressor according to claim 1, wherein the variable capacity compressor is configured as a passage.

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