JP4118413B2 - Variable displacement swash plate compressor - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a variable displacement swash plate compressor that includes an external control type control valve, adjusts the pressure in the crank chamber by operating the control valve, and controls the discharge capacity of the medium by changing the inclination angle of the drive swash plate. Regarding improvement.
[0002]
[Prior art]
Compressors used in automobile air conditioners include electronically controlled variable displacement swash plate compressors equipped with externally controlled control valves.
[0003]
The control valve includes a low pressure side valve body that opens and closes a low pressure side communication path between the suction side pressure chamber and the crank chamber, a high pressure side valve body that opens and closes a high pressure side communication path between the discharge side pressure chamber and the crank chamber, and The plunger provided with the valve body and the solenoid coil which generate | occur | produces the magnetic force which moves the said plunger are provided. The amount of current supplied to the solenoid coil of the control valve is controlled by a signal from an autoamplifier that calculates the required amount of cooling capacity based on the outside air temperature, the passenger compartment temperature, the amount of solar radiation, and the like.
[0004]
In the variable capacity swash plate compressor, the control valve is operated to adjust the pressure in the crank chamber, thereby changing the inclination angle of the drive swash plate, and the refrigerant discharge capacity according to the required cooling capacity. The capacity is controlled.
[0005]
[Problems to be solved by the invention]
Since the solenoid coil of the external control type control valve requires a large force in a small installation space, the power consumption is relatively large, and the amount of heat generated by Joule heat in the solenoid coil is relatively large.
[0006]
However, when the amount of heat generated by the solenoid coil increases, the resistance value of the coil increases, the flowing current decreases, and the generated magnetic force decreases. For this reason, in order to ensure a sufficient magnetic force even when the amount of heat generated by the solenoid coil increases, the solenoid coil design expects a relatively large safety factor. As a result, an increase in the size of the solenoid coil and, in turn, a reduction in the size of the variable displacement swash plate compressor provided with an external control type control valve has been hindered.
[0007]
Conventionally, when designing the casing or rear head of the compressor, the actual situation is that the cooling of the solenoid coil of the control valve has not been designed.
[0008]
Therefore, the present invention provides a variable capacity swash plate compressor that can design a rear head so as to promote cooling of a solenoid coil of an externally controlled control valve, thereby reducing the size of the solenoid coil and reducing power consumption. With the goal.
[0009]
[Means for Solving the Problems]
In order to achieve the above object, the invention according to claim 1 includes a cylinder block in which a plurality of cylinder bores are formed,
A first head attached to one side surface of the cylinder block and forming a suction side pressure chamber and a discharge side pressure chamber;
A second head attached to the other side of the cylinder block and forming a crank chamber;
A drive swash plate having an inclination angle variably connected to the drive shaft;
An external control type control valve that opens and closes the communication path between the suction side pressure chamber and the crank chamber by moving a valve element in response to energization to a solenoid coil;
Wherein actuation of the control valve to adjust the pressure of the crank chamber, a variable capacity swash plate type compressor which is adapted to control the discharge displacement of the inclination angle by changing the medium of the drive swash plate, wherein the control valve In the variable capacity swash plate type compressor in which the communication path is configured so that the medium flows around the solenoid coil ,
The solenoid coil of the control valve is arranged to face the suction side pressure chamber of the first head through a partition wall,
Forming a hole in the partition wall facing the solenoid coil to form the communication path;
And a partition wall provided in the suction side pressure chamber so that the medium flowing into the suction side pressure chamber of the first head flows toward the hole. is there.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a partial cross-sectional view showing an electronically controlled variable displacement swash plate compressor having an externally controlled control valve according to an embodiment of the present invention, and FIG. 2 is a front view showing a rear head shown in FIG. FIG. 3 is a cross-sectional view showing the control valve.
[0013]
The capacity variable swash plate compressor 10 of this embodiment comprises the cooling cycle of the air conditioning apparatus for motor vehicles with the capacitor | condenser, the expansion valve, and the evaporator. The high-pressure gaseous refrigerant (corresponding to the medium) discharged from the compressor 10 is condensed by the condenser, is adiabatically expanded by the expansion valve, and flows into the evaporator as a low-temperature low-pressure gas-liquid mixed refrigerant. This refrigerant exchanges heat with the air blown into the passenger compartment in the evaporator, becomes a gaseous refrigerant, and returns to the compressor 10.
[0014]
The variable displacement swash plate compressor 10 includes a cylinder block 12 in which a plurality of cylinder bores 11 are formed, and a rear head 15 that is attached to one side surface of the cylinder block 12 and that forms a suction side pressure chamber 13 and a discharge side pressure chamber 14. (Corresponding to the first head) and a front head 17 (corresponding to the second head) which is attached to the other side surface of the cylinder block 12 and forms the crank chamber 16. A drive shaft 18 is rotatably provided in the crank chamber 16 via a bearing. The drive shaft 18 is rotationally driven by the rotational movement of the engine transmitted through a belt, a pulley 19 and a magnet clutch 20. The
[0015]
A drive rod 21 that rotates together with the drive shaft 18 is provided on the drive shaft 18 so as to protrude in a direction perpendicular to the drive shaft 18. A drive swash plate 23 is connected to the drive rod 21 so as to be able to tilt and swing with respect to the drive shaft 18 with a pin 22 as a fulcrum. As a result, the rotational force of the drive shaft 18 is transmitted to the drive swash plate 23 via the drive rod 21 and the pin 22. A non-rotating socket plate 26 is slidably attached to the drive swash plate 23 via a thrust bearing 24 and a radial bearing 25.
[0016]
The socket plate 26 is slidably connected to a guide plate 27 fixed to the crank chamber 16, thereby preventing rotation and allowing reciprocation in the axial direction. A plurality of piston rods 29 are attached to the socket plate 26 via spherical bearings 28 at equal intervals in the circumferential direction. A piston 31 is coupled to the other end of the piston rod 29 via a spherical bearing 30. Yes.
[0017]
Then, the rotation of the drive swash plate 23 causes the socket plate 26 to reciprocate in the axial direction by a so-called razor-like operation, thereby causing the piston 31 to reciprocate via the piston rod 29. A front side portion of the piston 31 of the cylinder bore 11 into which the piston 31 is inserted is a compression chamber, and a rear side portion communicates with the crank chamber 16.
[0018]
As shown in FIG. 2, the rear head 15 is provided with a suction port 36 that communicates with the suction-side pressure chamber 13 via a passage 35, and a discharge port 38 that communicates with the discharge-side pressure chamber 14 via a passage 37. It has been. A low pressure side conduit 39 communicating with the evaporator 33 is connected to the suction port 36, and a high pressure side conduit 40 communicating with the condenser 34 is connected to the discharge port 38. Through the low-pressure side conduit 39, the suction port 36, and the passage 35, the return refrigerant from the evaporator 33 is guided to the suction-side pressure chamber 13, and this refrigerant is sucked into the valve plate 41 as shown in FIG. It flows into the compression chamber in the cylinder bore 11 against the closing resilience of the suction valve that closes the opening 42. On the other hand, the compressed refrigerant discharged into the discharge side pressure chamber 14 against the closing elastic force of the discharge valve 44 that closes the discharge port 43 provided in the valve plate 41 passes through the passage 37, the discharge port 38, and the high pressure side. It is fed into the capacitor 34 via the conduit 40.
[0019]
As shown in FIG. 1, an external control type control valve Cv that is operated by a signal from an autoamplifier is provided in the rear head 15.
[0020]
As shown in FIG. 3, the control valve Cv of the present embodiment opens and closes a low-pressure side valve port 51 (which constitutes a part of the low-pressure side communication passage 70) that communicates the suction-side pressure chamber 13 and the crank chamber 16. A low pressure side valve body 52 that opens, and a high pressure side valve body 54 that opens and closes a high pressure side valve port 53 (constituting a part of the high pressure side communication passage) that connects the discharge side pressure chamber 14 and the crank chamber 16, and A needle 55 provided with two valve bodies 52, 54, a plunger 56 that can move forward and backward (up and down in the illustrated example), and a solenoid coil 57 that generates a magnetic force for moving the plunger 56 are provided.
[0021]
The high pressure side valve body 54 is provided at the top of the needle 55, while the low pressure side valve body 52 is provided at the lower portion of the needle 55. The plunger 56 and the solenoid coil 57 are housed in a case body 58, and the upper opening of the case body 58 is closed by a displacable diaphragm 59, thereby being sealed from the refrigerant. The needle 55 is disposed on the plunger 56 via the diaphragm 59.
[0022]
A spring 60 is provided above the high-pressure side valve body 54 to urge a spring force that presses the needle 55 against the plunger 56 via the diaphragm 59. On the other hand, below the plunger 56, the high pressure side valve body 54 opens the high pressure side valve port 53 and the low pressure side valve body 52 energizes a spring force that moves the plunger 56 in a direction to close the low pressure side valve port 51. A spring 61 is provided.
[0023]
The solenoid coil 57 is applied with a current based on a signal from the auto amplifier 80 to generate the magnetic force, and the low pressure side valve port 51 and the high pressure side valve are balanced by a balance between the magnetic force and the spring force of the two springs 60 and 61. The opening degree of the port 53 is adjusted by each of the low pressure side valve body 52 and the high pressure side valve body 54. These valve bodies 52 and 54 operate in conjunction with each other. When the low pressure side valve body 52 increases the opening degree of the low pressure side valve port 51, the high pressure side valve body 54 increases the opening degree of the high pressure side valve port 53. On the contrary, when the low pressure side valve body 52 reduces the opening degree of the low pressure side valve port 51, the high pressure side valve body 54 increases the opening degree of the high pressure side valve port 53. Operates to
[0024]
The control valve Cv operates as follows.
When the thermal load in the cooling cycle is small, the autoamplifier 80 determines that the required amount of the cooling capacity may be small and outputs a signal for reducing the current flowing through the solenoid coil 57. As the current decreases, the magnetic force acting downward on the plunger 56 decreases, the needle 55 on the diaphragm 59 is pushed up by the spring force of the set spring 61, and the high-pressure side valve element 54 is in the high-pressure side valve port 53. The low-pressure side valve body 52 moves in the direction in which the low-pressure side valve port 51 is closed. As a result, a part of the high-pressure refrigerant (discharge pressure Pd) compressed by the piston 31 is introduced from the discharge-side pressure chamber 14 into the crank chamber 16 through the passage 62 → the center hole 63 from the high-pressure side valve port 53. The internal pressure of the crank chamber 16 (crank chamber pressure Pc) is increased.
[0025]
Here, the inclination angle of the socket plate 26 (inclination angle from the direction orthogonal to the drive shaft 18) is controlled by the pressure balance before and after being applied to the plurality of pistons 31. That is, when the crank chamber pressure Pc is slightly larger than the suction pressure Ps, the combined force of the forces applied to the back surfaces of the plurality of pistons 31 acts on the socket plate 26 as a moment centering on the pin 22, It acts to reduce the tilt angle.
[0026]
For this reason, the piston 31 in the suction process cannot be retracted to have a sufficiently large stroke, and only a small compression stroke can be taken when the compression process is entered next. Therefore, the amount of refrigerant compressed is small, the amount of refrigerant discharged is small, the flow rate of refrigerant circulating in the cooling cycle is reduced, and an appropriate amount of refrigerant corresponding to a low heat load is obtained.
[0027]
On the other hand, when the heat load in the cooling cycle is large, the auto amplifier 80 determines that the required amount of cooling capacity is large, and outputs a signal for applying a current to the solenoid coil 57. As the current is applied, a downward magnetic force is generated in the plunger 56, the needle 55 on the diaphragm 59 is pushed down against the spring force of the set spring 61, and the high pressure side valve element 54 is in the high pressure side valve port 53. The low pressure side valve body 52 moves in the direction of opening the low pressure side valve port 51 in the direction of closing the valve. As a result, the high discharge pressure Pd is not introduced into the crank chamber 16, and if the suction pressure Ps is smaller than the crank chamber pressure Pc, the refrigerant in the crank chamber 16 passes through the cylinder passage 64 → the low pressure side valve port 51. The refrigerant flows into the suction side pressure chamber 13, whereby the crank chamber pressure Pc and the suction pressure Ps become substantially equal.
[0028]
For this reason, the socket plate 26 is inclined to the maximum by the action of the moment described above, and the reciprocating stroke of the piston 31 becomes long. Therefore, if compression is performed in this state, the amount of refrigerant discharged increases, the flow rate of refrigerant circulating in the cooling cycle increases, and the refrigerant flow rate becomes appropriate according to a high heat load.
[0029]
In the variable displacement swash plate compressor 10 of the present embodiment, the low-pressure side communication passage 70 including the low-pressure side valve port 51 is configured so that the refrigerant flows around the solenoid coil 57 of the control valve Cv.
[0030]
That is, the solenoid coil 57 is disposed so as to face the suction side pressure chamber 13 of the rear head 15 via the partition wall 71, and a hole 72 is formed in a portion of the partition wall 71 facing the solenoid coil 57. The refrigerant in the suction side pressure chamber 13 is guided through the hole 72 to a passage 73 formed around the solenoid coil 57. The passage 73 communicates with the low pressure side valve port 51.
[0031]
Further, as clearly shown in FIG. 2, a partition wall 75 is provided in a portion of the suction side pressure chamber 13 that is substantially opposite to the hole 72 with respect to the center of the head. Due to the partition wall 75, the return refrigerant that has flowed into the suction side pressure chamber 13 through the passage 35 flows along the one direction indicated by the arrow A in the suction side pressure chamber 13. Thus, the return refrigerant does not flow in two directions by the partition wall 75, and the return refrigerant surely flows toward the hole 72 and is reliably guided around the solenoid coil 57.
[0032]
In the present embodiment in which the low-pressure side communication path 70 is configured as described above, the solenoid coil 57 of the control valve Cv becomes relatively high temperature (about 100 ° C. to 120 ° C.) due to generation of Joule heat accompanying energization. However, around the solenoid coil 57, the return refrigerant from the evaporator 33 and the refrigerant in the crank chamber 16 accompanying the operation of the control valve Cv are led. The temperature of the return refrigerant is much lower than the temperature of the solenoid coil 57 and is about 0 ° C. to 30 ° C. When these refrigerants pass around the solenoid coil 57, the solenoid coil 57 is cooled.
[0033]
When the cooling of the solenoid coil 57 is promoted in this way, the resistance value of the coil 57 is decreased and the flowing current is increased as compared with the case where the cooling is not promoted, and a sufficiently large magnetic force can be generated. . For this reason, it is not necessary to expect a large safety factor when designing the solenoid coil 57. As a result, the solenoid coil 57 is downsized, and thus the capacity variable swash plate compressor 10 provided with the external control type control valve Cv is reduced. Can be achieved. In addition, power consumption in the solenoid coil 57 can be reduced.
[0034]
【The invention's effect】
As described above, according to the first aspect of the invention, the cooling of the solenoid coil of the external control type control valve is promoted, so that the solenoid coil can be reduced in size and the power consumption can be reduced. I can . Further, the medium flowing into the suction side pressure chamber of the first head is reliably guided around the solenoid coil by the partition wall, and the above-described effect becomes more remarkable.
[Brief description of the drawings]
FIG. 1 is a partial sectional view showing an electronically controlled variable displacement swash plate compressor including an externally controlled control valve according to an embodiment of the present invention.
FIG. 2 is a front view showing a rear head shown in FIG.
FIG. 3 is a cross-sectional view showing a control valve.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 ... Variable displacement swash plate type compressor 11 ... Cylinder bore 12 ... Cylinder block 13 ... Suction side pressure chamber 14 ... Discharge side pressure chamber 15 ... Rear head (first head)
16 ... Crank chamber 17 ... Front head (second head)
18 ... Drive shaft 21 ... Drive swash plate 51 ... Low pressure side valve port 52 ... Low pressure side valve element (valve element)
53 ... High-pressure side valve port 54 ... High-pressure side valve element 57 ... Solenoid coil 70 ... Low-pressure side communication path (communication path)
71 ... partition wall 72 ... hole 75 ... partition wall Cv ... external control type control valve

Claims (1)

A cylinder block (12) formed with a plurality of cylinder bores (11);
A first head (15) attached to one side surface of the cylinder block (12) and forming a suction side pressure chamber (13) and a discharge side pressure chamber (14);
A second head (17) attached to the other side of the cylinder block (12) and forming a crank chamber (16);
A drive swash plate (21) variably connected to the drive shaft (18);
External control type that opens and closes the communication passage (70) between the suction side pressure chamber (13) and the crank chamber (16) by moving the valve element (52) in response to energization to the solenoid coil (57). Control valve (Cv),
A variable capacity swash plate type in which the pressure in the crank chamber (16) is adjusted by the operation of the control valve (Cv), and the discharge angle of the medium is controlled by changing the inclination angle of the drive swash plate (21). In the variable displacement swash plate type compressor, the communication path (70) is configured so that the medium flows around the solenoid coil (57) of the control valve (Cv).
The solenoid coil (57) of the control valve (Cv) is disposed so as to face the suction side pressure chamber (13) of the first head (15) through a partition wall (71),
A hole (72) is formed in the partition wall (71) facing the solenoid coil (57) to constitute the communication path (70),
Further, a partition wall (13) is formed in the suction side pressure chamber (13) so that the medium flowing into the suction side pressure chamber (13) of the first head (15) flows toward the hole (72). 75) . A variable displacement swash plate compressor characterized in that 75) is provided .

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