EP1363021A1 - Compression displacement controller of refrigerating cycle - Google Patents
Compression displacement controller of refrigerating cycle Download PDFInfo
- Publication number
- EP1363021A1 EP1363021A1 EP02715833A EP02715833A EP1363021A1 EP 1363021 A1 EP1363021 A1 EP 1363021A1 EP 02715833 A EP02715833 A EP 02715833A EP 02715833 A EP02715833 A EP 02715833A EP 1363021 A1 EP1363021 A1 EP 1363021A1
- Authority
- EP
- European Patent Office
- Prior art keywords
- pressure
- chamber
- control valve
- refrigerant
- electromagnetic
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
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Classifications
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
- F04B27/00—Multi-cylinder pumps specially adapted for elastic fluids and characterised by number or arrangement of cylinders
- F04B27/08—Multi-cylinder pumps specially adapted for elastic fluids and characterised by number or arrangement of cylinders having cylinders coaxial with, or parallel or inclined to, main shaft axis
- F04B27/14—Control
- F04B27/16—Control of pumps with stationary cylinders
- F04B27/18—Control of pumps with stationary cylinders by varying the relative positions of a swash plate and a cylinder block
- F04B27/1804—Controlled by crankcase pressure
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
- F04B49/00—Control, e.g. of pump delivery, or pump pressure of, or safety measures for, machines, pumps, or pumping installations, not otherwise provided for, or of interest apart from, groups F04B1/00 - F04B47/00
- F04B49/22—Control, e.g. of pump delivery, or pump pressure of, or safety measures for, machines, pumps, or pumping installations, not otherwise provided for, or of interest apart from, groups F04B1/00 - F04B47/00 by means of valves
- F04B49/225—Control, e.g. of pump delivery, or pump pressure of, or safety measures for, machines, pumps, or pumping installations, not otherwise provided for, or of interest apart from, groups F04B1/00 - F04B47/00 by means of valves with throttling valves or valves varying the pump inlet opening or the outlet opening
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
- F04B27/00—Multi-cylinder pumps specially adapted for elastic fluids and characterised by number or arrangement of cylinders
- F04B27/08—Multi-cylinder pumps specially adapted for elastic fluids and characterised by number or arrangement of cylinders having cylinders coaxial with, or parallel or inclined to, main shaft axis
- F04B27/14—Control
- F04B27/16—Control of pumps with stationary cylinders
- F04B27/18—Control of pumps with stationary cylinders by varying the relative positions of a swash plate and a cylinder block
- F04B27/1804—Controlled by crankcase pressure
- F04B2027/1809—Controlled pressure
- F04B2027/1813—Crankcase pressure
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
- F04B27/00—Multi-cylinder pumps specially adapted for elastic fluids and characterised by number or arrangement of cylinders
- F04B27/08—Multi-cylinder pumps specially adapted for elastic fluids and characterised by number or arrangement of cylinders having cylinders coaxial with, or parallel or inclined to, main shaft axis
- F04B27/14—Control
- F04B27/16—Control of pumps with stationary cylinders
- F04B27/18—Control of pumps with stationary cylinders by varying the relative positions of a swash plate and a cylinder block
- F04B27/1804—Controlled by crankcase pressure
- F04B2027/1822—Valve-controlled fluid connection
- F04B2027/1827—Valve-controlled fluid connection between crankcase and discharge chamber
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
- F04B27/00—Multi-cylinder pumps specially adapted for elastic fluids and characterised by number or arrangement of cylinders
- F04B27/08—Multi-cylinder pumps specially adapted for elastic fluids and characterised by number or arrangement of cylinders having cylinders coaxial with, or parallel or inclined to, main shaft axis
- F04B27/14—Control
- F04B27/16—Control of pumps with stationary cylinders
- F04B27/18—Control of pumps with stationary cylinders by varying the relative positions of a swash plate and a cylinder block
- F04B27/1804—Controlled by crankcase pressure
- F04B2027/1886—Open (not controlling) fluid passage
- F04B2027/1895—Open (not controlling) fluid passage between crankcase and suction chamber
Definitions
- This invention relates to a compression capacity control device for a refrigeration cycle used in an automotive air conditioner or the like.
- a compressor used in a refrigeration cycle for an automotive air conditioner is directly connected to an engine by a belt, and hence is not capable of controlling the rotational speed thereof. For this reason, a variable displacement compressor capable of changing the compression capacity (delivery quantity) is employed so as to obtain an adequate refrigerating capability without being constrained by the rotational speed of the engine.
- variable displacement compressor is generally configured such that it compresses a refrigerant sucked from a suction chamber communicating with a suction line, and discharges the refrigerant into a discharge chamber communicating with a discharge line, while varying a delivery quantity of the refrigerant by changing pressure in a pressure-regulating chamber which has the pressure therein controlled by an electromagnetic control valve or the like.
- a pulley receiving the rotation of the belt directly connected to the engine is provided with an electromagnetic clutch or the like so as to inhibit the compressor from being driven when it is in an operating condition in which compression of the refrigerant is not required.
- an electromagnetic clutch or the like so as to inhibit the compressor from being driven when it is in an operating condition in which compression of the refrigerant is not required.
- a compression capacity control device for a refrigeration cycle including a variable displacement compressor that compresses refrigerant sucked from a suction chamber communicating with a suction line, and discharges the refrigerant into a discharge chamber communicating with a discharge line, while varying a delivery quantity of the refrigerant by changing pressure in a pressure-regulating chamber, the pressure in the pressure-regulating chamber being controlled by an electromagnetic control valve, characterized in that the compression capacity control valve is configured to place the variable displacement compressor in a state with a minimum delivery quantity within a variable range, when the electromagnetic control valve is in a deenergized state.
- the compression capacity control device may be configured such that the electromagnetic control valve opens and closes communication between pressure in the discharge chamber and the pressure-regulating chamber and the discharge chamber such that differential pressure between at least one of pressure in the pressure-regulating chamber and pressure in the suction chamber is held at a predetermined differential pressure, and that an electromagnetic force of the electromagnetic control valve is changed to thereby change the differential pressure to change the pressure in the pressure-regulating chamber, whereby the delivery quantity of the refrigerant is controlled.
- the compression capacity control device may be configured such that urging means is arranged for holding the electromagnetic control valve in an open state when the electromagnetic control valve is in the deenergized state, whereby by controlling the electromagnetic control valve in the open state, the variable displacement compressor is placed in the state with the minimum delivery quantity within the variable range.
- the compression capacity control device may be configured such that a suction line opening/closing valve is arranged for closing communication between the suction line and the suction chamber when the differential pressure between the pressure in the discharge chamber and the pressure in the suction chamber becomes equal to or smaller than a predetermined value.
- reference numeral 10 denotes a swash plate variable displacement compressor which is used in a refrigeration cycle for air conditioning of an automotive vehicle.
- R134A or the like is used as refrigerant, the invention may be applied to a refrigeration cycle using carbon dioxide as refrigerant.
- Reference numeral 11 denotes a rotational shaft arranged in a hermetically sealed crankcase 12 (pressure-regulating chamber).
- the rotational shaft 11 is connected to an axial portion of a pulley 13 which is driven for rotation by a drive belt, not shown, directly connected to an engine.
- a wobble plate 14 performs wobbling motion which is arranged in the crankcase 12 in a manner inclined with respect to the rotational shaft 11.
- the crankcase 12 has cylinders 15 arranged at a peripheral portion thereof.
- Each cylinder 15 has a piston 17 arranged therein such that the piston 17 can perform reciprocating motion.
- the piston 17 and the wobble plate 14 are connected to each other by a rod 18.
- each piston 17 is caused to reciprocate within the cylinder 15, whereby a low-pressure (suction pressure Ps) refrigerant is sucked from a suction chamber 3 into the cylinder 15 to be compressed therein.
- the refrigerant compressed to a high-pressure (discharge pressure Pd) is delivered into a discharge chamber 4.
- the suction chamber 3 has a refrigerant supplied therein from an evaporator, not shown, which is arranged at a location upstream thereof, via a suction line 1.
- the discharge chamber 4 delivers the high-pressure refrigerant to a condenser, not shown, which is arranged at a location downstream thereof, via a discharge line 2.
- the degree of inclination of the wobble plate 14 is changed according to pressure (crankcase pressure Pc) in the crankcase 12, and the quantity (delivery quantity, i.e. compression capacity) of the refrigerant delivered from the cylinder 15 is changed according to the degree of inclination of the wobble plate 14.
- the delivery quantity is increased when the wobble plate 14 is inclined as indicated by a solid line, whereas when the wobble plate 14 is not inclined as indicated by a two-dot chain line, the delivery quantity is small.
- the delivery quantity is reduced to zero if the wobble plate 14 becomes perpendicular to the rotational shaft 11.
- a minimum-securing spring 19 mounted in the manner surrounding the rotational shaft 11 is progressively compressed by the wobble plate 14.
- the minimum operation The above operating condition in which the delivery quantity is controlled to be minimum is referred to as "the minimum operation”. It should be noted that the minimum-securing spring 19 is known in the art and formed e.g. by a combination of a wavy spring and a coil spring.
- Reference numeral 20 denotes a capacity control electromagnetic valve which is controlled by an electromagnetic solenoid (electromagnetic control valve) for carrying out compression capacity control by automatically controlling the crankcase pressure (Pc).
- Reference numerals 21 and 22 denote an electromagnetic coil and a fixed core, respectively.
- a movable core 23 and a valve element 25 are connected to each other by an axially movable rod 24 that is arranged in a state extending through the fixed core 22, and are urged from opposite ends thereof by respective compression coil springs 27, 28.
- Reference numeral 29 denotes O rings as sealing members. It should be noted that the urging forces of the two compression coil springs 27, 28 are set such that the urging force of the spring 28 for opening the valve is larger than that of the spring 27 for closing the valve.
- a valve seat 26 is formed between a crankcase communication passage 5 for communication with the crankcase 12, and a discharge chamber communication passage 6 for communication with the discharge chamber 4.
- the valve element 25 is arranged in a manner opposed to the valve seat 26 from the side of the crankcase communication passage 5.
- the crankcase communication passage 5 and the suction line 1 are communicated with each other via a thin leak passage 7.
- the above construction permits the differential pressure (Pd - Pc) between the discharge pressure (Pd) and the crankcase pressure (Pc) to act on the valve element 25 in the valve-opening direction, and the electromagnetic force (including the urging forces of the compression coil springs 27, 28) of the capacity control electromagnetic valve 20 to act on the valve element 25 in the valve-closing direction.
- the valve element 25 is opened and closed in accordance with changes in the differential pressure (Pd - Pc) between the discharge pressure (Pd) and the crankcase pressure (Pc) such that the differential pressure (Pd - Pc) is held constant, whereby the crankcase pressure (Pc) is controlled to have a value corresponding to a value of the discharge pressure (Pd), for holding constant the compression capacity (delivery quantity).
- the differential pressure (Pd - Pc) to be held constant is varied in a manner corresponding to the change, whereby the compression capacity (delivery quantity) is held constant at a level different from that of the above compression capacity (delivery quantity).
- the differential pressure (Pd - Pc) to be held constant is reduced, so that the crankcase pressure (Pc) is increased to become closer to the discharge pressure (Pd), and the wobble plate 14 becomes closer to a position where it is perpendicular to the rotational shaft 11, resulting in a reduced delivery quantity of refrigerant.
- signals from a plurality of sensors for detecting various conditions are input to a control section 40 incorporating a CPU, etc., and a control signal based on results of computations thereof is delivered from the control section 40 to the electromagnetic coil 21.
- the drive circuit of the electromagnetic coil 21 is omitted from illustration.
- valve element 25 is moved away from the valve seat 26 to open the capacity control electromagnetic valve 20, due to the difference between the urging forces of the two compression coil springs 27, 28 urging the valve element 25 of the capacity control electromagnetic valve 20.
- the compressor 10 starts the minimum operation, so that even if it is not necessary to operate the compressor 10, the rotational shaft 11 can continue to be driven for rotation.
- FIG. 2 shows a capacity control electromagnetic valve 20 according to a second embodiment of the invention. Since a compressor 10 is similar to the compressor of the first embodiment, it is omitted from illustration. Further, the leak passage is arranged as appropriate.
- the valve element 25 has a piston rod 25p integrally formed therewith on a rear side thereof.
- the piston rod 25p has a pressure-receiving area equal to that of the valve seat 26.
- the piston rod 25p has a rear surface facing a space which is communicated with a suction chamber communication passage 8, and a side surface facing a space which is communicated with the crankcase communication passage 5. Further, a space on a rear side of the valve seat 26 as viewed from a valve element side is communicated with the discharge chamber communication passage 6.
- valve element 25 is moved away from the valve seat 26 to open the capacity control electromagnetic valve 20, by the difference between the urging forces of the two compression coil springs 27, 28, which maintains the minimum operation of the compressor 10.
- the present invention can be applied to a device in which communication between the crankcase 12 and the discharge chamber 4 is opened and closed such that differential pressure between the pressure (Pd) in the discharge chamber 4 and at least one of the pressure (Pc) in the crankcase 12 and the pressure (Ps) in the suction line 1 is held at a predetermined differential pressure, and the electromagnetic force of the capacity control electromagnetic valve 20 is changed to thereby change the above differential pressure to change the pressure (Pc) in the crankcase 12 whereby the delivery quantity is varied. Further, it is also possible to apply the present invention to a device which is controlled by a method other than the above.
- FIG. 3 shows a third embodiment of the invention.
- the device having the same construction as the device according to the first embodiment further includes a suction line opening/closing valve 30 for closing communication between the suction line 1 and the suction chamber 3 when the differential pressure between the pressure in the discharge chamber 4 and the pressure in the suction chamber 3 becomes equal to or lower than a predetermined value.
- a valve element 32 is arranged in a manner opposed to a valve seat 31 which is formed between the suction line 1 and the suction chamber 3, from the suction line side.
- the valve element 32 is urged by a compression coil spring 33 in the valve-closing direction.
- Reference numeral 34 denotes a spring receiver having a large cut-away portion formed such that it does not obstruct passing of the refrigerant.
- a pressure-receiving piston 35 which receives the pressure (Pd) from the discharge chamber 4 and the pressure (Ps) in the suction chamber 3 from a front side and a rear side thereof, respectively, is connected to the valve element 32.
- differential pressure (Pd - Ps) between the pressure (Pd) in the discharge chamber 4 and the pressure (Ps) in the suction chamber 3 is larger than a predetermined value, the valve element 32 is away from the valve seat 31 to open the suction line opening/closing valve 30, whereas when the compressor 10 starts the minimum operation and the differential pressure (Pd - Ps) becomes smaller than the predetermined value, the valve element 32 is pressed against the valve seat 31 to close the suction line opening/closing valve 30.
- the above construction makes it possible to prevent fins of the evaporator from collecting ice during the minimum operation under a low operating load e.g. in winter, since a low-pressure refrigerant in the suction line 1 is not sucked into the compressor 10.
- variable displacement compressor maintains the minimum delivery quantity within a variable range when the electromagnetic control valve is not energized. This makes it possible to dispense with a clutch for inhibiting operation of the compressor, thereby largely reducing the device cost.
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- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Compressors, Vaccum Pumps And Other Relevant Systems (AREA)
- Control Of Positive-Displacement Pumps (AREA)
- Air-Conditioning For Vehicles (AREA)
Abstract
In a compression capacity control device for a
refrigeration cycle including a variable displacement
compressor (10) that compresses refrigerant sucked from a
suction chamber (3) communicating with a suction line (1),
and discharges the refrigerant into a discharge chamber
(4) communicating with a discharge line (2), while varying
the delivery quantity of the refrigerant by changing
pressure in a pressure-regulating chamber (12) which has
the pressure therein controlled by an electromagnetic
control valve (20), the electromagnetic control valve (20)
arranged between the discharge chamber (4) and the
pressure-regulating chamber (12) is held in an open state
to place the variable displacement compressor (10) in a
state with the minimum delivery quantity within a variable
range, when the electromagnetic control valve (20) is in a
deenergized state. This makes it possible to dispense with
a clutch for inhibiting operation of the compressor,
thereby largely reducing the device cost.
Description
- This invention relates to a compression capacity control device for a refrigeration cycle used in an automotive air conditioner or the like.
- A compressor used in a refrigeration cycle for an automotive air conditioner is directly connected to an engine by a belt, and hence is not capable of controlling the rotational speed thereof. For this reason, a variable displacement compressor capable of changing the compression capacity (delivery quantity) is employed so as to obtain an adequate refrigerating capability without being constrained by the rotational speed of the engine.
- Such a variable displacement compressor is generally configured such that it compresses a refrigerant sucked from a suction chamber communicating with a suction line, and discharges the refrigerant into a discharge chamber communicating with a discharge line, while varying a delivery quantity of the refrigerant by changing pressure in a pressure-regulating chamber which has the pressure therein controlled by an electromagnetic control valve or the like.
- In the conventional device, a pulley receiving the rotation of the belt directly connected to the engine is provided with an electromagnetic clutch or the like so as to inhibit the compressor from being driven when it is in an operating condition in which compression of the refrigerant is not required. Thus, the trouble of increasing the device cost is taken only for inhibiting operation of the compressor.
- It is an object of the invention to provide a compression capacity control device for a refrigeration cycle, which is capable of dispensing with a clutch for inhibiting operation of a compressor, thereby largely reducing the device cost.
- To attain the above object, there is provided a compression capacity control device for a refrigeration cycle including a variable displacement compressor that compresses refrigerant sucked from a suction chamber communicating with a suction line, and discharges the refrigerant into a discharge chamber communicating with a discharge line, while varying a delivery quantity of the refrigerant by changing pressure in a pressure-regulating chamber, the pressure in the pressure-regulating chamber being controlled by an electromagnetic control valve, characterized in that the compression capacity control valve is configured to place the variable displacement compressor in a state with a minimum delivery quantity within a variable range, when the electromagnetic control valve is in a deenergized state.
- Further, the compression capacity control device may be configured such that the electromagnetic control valve opens and closes communication between pressure in the discharge chamber and the pressure-regulating chamber and the discharge chamber such that differential pressure between at least one of pressure in the pressure-regulating chamber and pressure in the suction chamber is held at a predetermined differential pressure, and that an electromagnetic force of the electromagnetic control valve is changed to thereby change the differential pressure to change the pressure in the pressure-regulating chamber, whereby the delivery quantity of the refrigerant is controlled.
- Further, the compression capacity control device may be configured such that urging means is arranged for holding the electromagnetic control valve in an open state when the electromagnetic control valve is in the deenergized state, whereby by controlling the electromagnetic control valve in the open state, the variable displacement compressor is placed in the state with the minimum delivery quantity within the variable range.
- Still further, the compression capacity control device may be configured such that a suction line opening/closing valve is arranged for closing communication between the suction line and the suction chamber when the differential pressure between the pressure in the discharge chamber and the pressure in the suction chamber becomes equal to or smaller than a predetermined value.
- The above and other objects, features and advantages of the present invention will become apparent from the following description when taken in conjunction with the accompanying drawings which illustrate preferred embodiments of the present invention by way of example.
-
- FIG. 1 is a longitudinal sectional view showing the whole arrangement of a compression capacity control device for a refrigeration cycle, according to a first embodiment of the invention;
- FIG. 2 is a longitudinal sectional view showing a capacity control electromagnetic valve according to a second embodiment of the invention; and
- FIG. 3 is a longitudinal sectional view showing the whole arrangement of a compression capacity control device for a refrigeration cycle, according to a third embodiment of the invention.
-
- The present invention will now be described hereafter with reference to the accompanying drawings.
- In FIG. 1,
reference numeral 10 denotes a swash plate variable displacement compressor which is used in a refrigeration cycle for air conditioning of an automotive vehicle. Although R134A or the like is used as refrigerant, the invention may be applied to a refrigeration cycle using carbon dioxide as refrigerant. -
Reference numeral 11 denotes a rotational shaft arranged in a hermetically sealed crankcase 12 (pressure-regulating chamber). Therotational shaft 11 is connected to an axial portion of apulley 13 which is driven for rotation by a drive belt, not shown, directly connected to an engine. As therotational shaft 11 rotates, awobble plate 14 performs wobbling motion which is arranged in thecrankcase 12 in a manner inclined with respect to therotational shaft 11. - The
crankcase 12 hascylinders 15 arranged at a peripheral portion thereof. Eachcylinder 15 has apiston 17 arranged therein such that thepiston 17 can perform reciprocating motion. Thepiston 17 and thewobble plate 14 are connected to each other by arod 18. - As a result, when the
wobble plate 14 performs wobbling motion, eachpiston 17 is caused to reciprocate within thecylinder 15, whereby a low-pressure (suction pressure Ps) refrigerant is sucked from asuction chamber 3 into thecylinder 15 to be compressed therein. The refrigerant compressed to a high-pressure (discharge pressure Pd) is delivered into adischarge chamber 4. - The
suction chamber 3 has a refrigerant supplied therein from an evaporator, not shown, which is arranged at a location upstream thereof, via a suction line 1. Thedischarge chamber 4 delivers the high-pressure refrigerant to a condenser, not shown, which is arranged at a location downstream thereof, via adischarge line 2. - The degree of inclination of the
wobble plate 14 is changed according to pressure (crankcase pressure Pc) in thecrankcase 12, and the quantity (delivery quantity, i.e. compression capacity) of the refrigerant delivered from thecylinder 15 is changed according to the degree of inclination of thewobble plate 14. - The delivery quantity is increased when the
wobble plate 14 is inclined as indicated by a solid line, whereas when thewobble plate 14 is not inclined as indicated by a two-dot chain line, the delivery quantity is small. The delivery quantity is reduced to zero if thewobble plate 14 becomes perpendicular to therotational shaft 11. - However, as the
wobble plate 14 is progressively brought into a state in which the degree of inclination thereof is being reduced to zero (state in which thewobble plate 14 is approaching the two-dot chain line), a minimum-securingspring 19 mounted in the manner surrounding therotational shaft 11 is progressively compressed by thewobble plate 14. - As a result, a reaction force exerted from the minimum-securing
spring 19 to thewobble plate 14 is progressively increased whereby thewobble plate 14 is inhibited from becoming perpendicular to therotational shaft 11 to prevent the delivery quantity from being smaller than e.g. approximately 3 to 5 % of the maximum delivery quantity. - The above operating condition in which the delivery quantity is controlled to be minimum is referred to as "the minimum operation". It should be noted that the minimum-securing
spring 19 is known in the art and formed e.g. by a combination of a wavy spring and a coil spring. -
Reference numeral 20 denotes a capacity control electromagnetic valve which is controlled by an electromagnetic solenoid (electromagnetic control valve) for carrying out compression capacity control by automatically controlling the crankcase pressure (Pc).Reference numerals - A
movable core 23 and avalve element 25 are connected to each other by an axiallymovable rod 24 that is arranged in a state extending through the fixedcore 22, and are urged from opposite ends thereof by respectivecompression coil springs -
Reference numeral 29 denotes O rings as sealing members. It should be noted that the urging forces of the twocompression coil springs spring 28 for opening the valve is larger than that of thespring 27 for closing the valve. - A
valve seat 26 is formed between acrankcase communication passage 5 for communication with thecrankcase 12, and a dischargechamber communication passage 6 for communication with thedischarge chamber 4. Thevalve element 25 is arranged in a manner opposed to thevalve seat 26 from the side of thecrankcase communication passage 5. Thecrankcase communication passage 5 and the suction line 1 are communicated with each other via athin leak passage 7. - The above construction permits the differential pressure (Pd - Pc) between the discharge pressure (Pd) and the crankcase pressure (Pc) to act on the
valve element 25 in the valve-opening direction, and the electromagnetic force (including the urging forces of thecompression coil springs 27, 28) of the capacity controlelectromagnetic valve 20 to act on thevalve element 25 in the valve-closing direction. - Therefore, when the current value of current for energizing the
electromagnetic coil 21 is constant and hence the electromagnetic force of the capacity controlelectromagnetic valve 20 is constant, thevalve element 25 is opened and closed in accordance with changes in the differential pressure (Pd - Pc) between the discharge pressure (Pd) and the crankcase pressure (Pc) such that the differential pressure (Pd - Pc) is held constant, whereby the crankcase pressure (Pc) is controlled to have a value corresponding to a value of the discharge pressure (Pd), for holding constant the compression capacity (delivery quantity). - Then, when the current value of the current for energizing the
electromagnetic coil 21 is changed to change the electromagnetic force of the capacity controlelectromagnetic valve 20, the differential pressure (Pd - Pc) to be held constant is varied in a manner corresponding to the change, whereby the compression capacity (delivery quantity) is held constant at a level different from that of the above compression capacity (delivery quantity). - More specifically, when the electromagnetic force of the capacity control
electromagnetic valve 20 is reduced, the differential pressure (Pd - Pc) to be held constant is reduced, so that the crankcase pressure (Pc) is increased to become closer to the discharge pressure (Pd), and thewobble plate 14 becomes closer to a position where it is perpendicular to therotational shaft 11, resulting in a reduced delivery quantity of refrigerant. - Inversely, when the electromagnetic force of the capacity control
electromagnetic valve 20 is increased, the differential pressure (Pd - Pc) to be held constant is increased, so that the crankcase pressure (Pc) is decreased to be increasingly different from the discharge pressure (Pd), whereby the degree of inclination of thewobble plate 14 toward therotational shaft 11 is increased, which results in an increased delivery quantity of refrigerant. - It should be noted that to control the current value of the current for energizing the
electromagnetic coil 21, signals from a plurality of sensors for detecting various conditions, such as conditions of an engine, temperatures inside and outside the vehicle cabin, and an evaporator sensor, are input to acontrol section 40 incorporating a CPU, etc., and a control signal based on results of computations thereof is delivered from thecontrol section 40 to theelectromagnetic coil 21. The drive circuit of theelectromagnetic coil 21 is omitted from illustration. - If energization of the
electromagnetic coil 21 is stopped, thevalve element 25 is moved away from thevalve seat 26 to open the capacity controlelectromagnetic valve 20, due to the difference between the urging forces of the twocompression coil springs valve element 25 of the capacity controlelectromagnetic valve 20. - Then, the differential pressure between the discharge pressure (Pd) and the crankcase pressure (Pc) is reduced to zero (i.e. Pd - PC ≒ 0), so that the
wobble plate 14 is about to be perpendicular to therotational shaft 11. However, before this position, the inclination of thewobble plate 14 is balanced with the reaction force from the minimum-securingspring 19, whereby thecompressor 10 is placed in a state maintaining the minimum operation. - As described above, if energization of the
electromagnetic coil 21 of the capacity controlelectromagnetic valve 20 is stopped, thecompressor 10 starts the minimum operation, so that even if it is not necessary to operate thecompressor 10, therotational shaft 11 can continue to be driven for rotation. - FIG. 2 shows a capacity control
electromagnetic valve 20 according to a second embodiment of the invention. Since acompressor 10 is similar to the compressor of the first embodiment, it is omitted from illustration. Further, the leak passage is arranged as appropriate. - In this embodiment, the
valve element 25 has apiston rod 25p integrally formed therewith on a rear side thereof. Thepiston rod 25p has a pressure-receiving area equal to that of thevalve seat 26. Thepiston rod 25p has a rear surface facing a space which is communicated with a suctionchamber communication passage 8, and a side surface facing a space which is communicated with thecrankcase communication passage 5. Further, a space on a rear side of thevalve seat 26 as viewed from a valve element side is communicated with the dischargechamber communication passage 6. - As a result, the crankcase pressure (Pc) applied to the
piston rod 25p, thevalve element 25, and so forth is canceled out, and thevalve element 25 is opened and closed by the differential pressure (Pd - Ps) between the discharge pressure (Pd) and the suction pressure (Ps), whereby communication between thecrankcase 12 and thedischarge chamber 4 is opened and closed for execution of compression capacity control. - If energization of the
electromagnetic coil 21 is stopped, thevalve element 25 is moved away from thevalve seat 26 to open the capacity controlelectromagnetic valve 20, by the difference between the urging forces of the two compression coil springs 27, 28, which maintains the minimum operation of thecompressor 10. - As described above, the present invention can be applied to a device in which communication between the
crankcase 12 and thedischarge chamber 4 is opened and closed such that differential pressure between the pressure (Pd) in thedischarge chamber 4 and at least one of the pressure (Pc) in thecrankcase 12 and the pressure (Ps) in the suction line 1 is held at a predetermined differential pressure, and the electromagnetic force of the capacity controlelectromagnetic valve 20 is changed to thereby change the above differential pressure to change the pressure (Pc) in thecrankcase 12 whereby the delivery quantity is varied. Further, it is also possible to apply the present invention to a device which is controlled by a method other than the above. - FIG. 3 shows a third embodiment of the invention. In this embodiment, the device having the same construction as the device according to the first embodiment further includes a suction line opening/closing
valve 30 for closing communication between the suction line 1 and thesuction chamber 3 when the differential pressure between the pressure in thedischarge chamber 4 and the pressure in thesuction chamber 3 becomes equal to or lower than a predetermined value. - In this embodiment, a
valve element 32 is arranged in a manner opposed to avalve seat 31 which is formed between the suction line 1 and thesuction chamber 3, from the suction line side. Thevalve element 32 is urged by acompression coil spring 33 in the valve-closing direction.Reference numeral 34 denotes a spring receiver having a large cut-away portion formed such that it does not obstruct passing of the refrigerant. - A pressure-receiving
piston 35, which receives the pressure (Pd) from thedischarge chamber 4 and the pressure (Ps) in thesuction chamber 3 from a front side and a rear side thereof, respectively, is connected to thevalve element 32. When then differential pressure (Pd - Ps) between the pressure (Pd) in thedischarge chamber 4 and the pressure (Ps) in thesuction chamber 3 is larger than a predetermined value, thevalve element 32 is away from thevalve seat 31 to open the suction line opening/closingvalve 30, whereas when thecompressor 10 starts the minimum operation and the differential pressure (Pd - Ps) becomes smaller than the predetermined value, thevalve element 32 is pressed against thevalve seat 31 to close the suction line opening/closingvalve 30. - The above construction makes it possible to prevent fins of the evaporator from collecting ice during the minimum operation under a low operating load e.g. in winter, since a low-pressure refrigerant in the suction line 1 is not sucked into the
compressor 10. - According to the present invention, the variable displacement compressor maintains the minimum delivery quantity within a variable range when the electromagnetic control valve is not energized. This makes it possible to dispense with a clutch for inhibiting operation of the compressor, thereby largely reducing the device cost.
- The foregoing is considered as illustrative only of the principles of the present invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and applications shown and described, and accordingly, all suitable modifications and equivalents may be regarded as falling within the scope of the invention in the appended claims and their equivalents.
Claims (4)
- A compression capacity control device for a refrigeration cycle including a variable displacement compressor that compresses refrigerant sucked from a suction chamber communicating with a suction line, and discharges the refrigerant into a discharge chamber communicating with a discharge line, while varying a delivery quantity of the refrigerant by changing pressure in a pressure-regulating chamber, the pressure in the pressure-regulating chamber being controlled by an electromagnetic control valve,
wherein the compression capacity control device is configured to place the variable displacement compressor in a state with a minimum delivery quantity within a variable range, when the electromagnetic control valve is in a deenergized state. - The compression capacity control device according to claim 1, wherein the electromagnetic control valve opens and closes communication between the pressure-regulating chamber and the discharge chamber such that differential pressure between pressure in the discharge chamber and at least one of pressure in the pressure-regulating chamber and pressure in the suction chamber is held at a predetermined differential pressure, and wherein an electromagnetic force of the electromagnetic control valve is changed to thereby change the differential pressure to change the pressure in the pressure-regulating chamber, whereby the delivery quantity of the refrigerant is controlled.
- The compression capacity control device according to claim 1 or 2, wherein urging means is arranged for holding the electromagnetic control valve in an open state when the electromagnetic control valve is in the deenergized state, whereby by holding the electromagnetic control valve in the open state, the variable displacement compressor is placed in the state with the minimum delivery quantity within the variable range.
- The compression capacity control device according to claims 1, 2, or 3, wherein a suction line opening/closing valve is arranged for closing communication between the suction line and the suction chamber when the differential pressure between the pressure in the discharge chamber and the pressure in the suction chamber becomes equal to or smaller than a predetermined value.
Applications Claiming Priority (5)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2001011513 | 2001-01-19 | ||
JP2001011513 | 2001-01-19 | ||
JP2001123750 | 2001-04-23 | ||
JP2001123750A JP4070425B2 (en) | 2001-01-19 | 2001-04-23 | Compression capacity controller for refrigeration cycle |
PCT/JP2002/000364 WO2002057628A1 (en) | 2001-01-19 | 2002-01-18 | Compression displacement controller of refrigerating cycle |
Publications (1)
Publication Number | Publication Date |
---|---|
EP1363021A1 true EP1363021A1 (en) | 2003-11-19 |
Family
ID=26607967
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP02715833A Withdrawn EP1363021A1 (en) | 2001-01-19 | 2002-01-18 | Compression displacement controller of refrigerating cycle |
Country Status (4)
Country | Link |
---|---|
US (1) | US20030035733A1 (en) |
EP (1) | EP1363021A1 (en) |
JP (1) | JP4070425B2 (en) |
WO (1) | WO2002057628A1 (en) |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP1696123A1 (en) * | 2005-01-27 | 2006-08-30 | Kabushiki Kaisha Toyota Jidoshokki | Variable displacement compressor |
DE112008001914B4 (en) | 2007-07-17 | 2018-12-27 | Sanden Holdings Corporation | Displacement control system for variable displacement compressor |
Families Citing this family (11)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP4152674B2 (en) * | 2002-06-04 | 2008-09-17 | 株式会社テージーケー | Capacity control valve for variable capacity compressor |
JP2004067042A (en) * | 2002-08-09 | 2004-03-04 | Tgk Co Ltd | Air-conditioner |
JP4107141B2 (en) * | 2003-02-21 | 2008-06-25 | 株式会社デンソー | Limiter device |
JP2005098597A (en) * | 2003-09-25 | 2005-04-14 | Tgk Co Ltd | Refrigerating cycle |
US20050089417A1 (en) * | 2003-10-27 | 2005-04-28 | Thar Technologies, Inc. | Positive displacement pump |
KR101186459B1 (en) * | 2005-04-08 | 2012-09-27 | 이글 고오교 가부시키가이샤 | Capacity control valve |
JP2007177627A (en) * | 2005-12-27 | 2007-07-12 | Sanden Corp | Discharge capacity control valve of variable displacement compressor |
CN101815866B (en) | 2007-10-02 | 2012-07-04 | 三电有限公司 | Variable displacement compressor |
JP5075682B2 (en) * | 2008-03-05 | 2012-11-21 | サンデン株式会社 | Capacity control system for variable capacity compressor |
JP5281320B2 (en) * | 2008-05-28 | 2013-09-04 | サンデン株式会社 | Capacity control system for variable capacity compressor |
US20160053755A1 (en) * | 2013-03-22 | 2016-02-25 | Sanden Holdings Corporation | Control Valve And Variable Capacity Compressor Provided With Said Control Valve |
Family Cites Families (12)
Publication number | Priority date | Publication date | Assignee | Title |
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JP2567947B2 (en) * | 1989-06-16 | 1996-12-25 | 株式会社豊田自動織機製作所 | Variable capacity compressor |
JPH07189899A (en) * | 1993-12-27 | 1995-07-28 | Toyota Autom Loom Works Ltd | Variable displacement compressor |
JP3254872B2 (en) * | 1993-12-27 | 2002-02-12 | 株式会社豊田自動織機 | Clutchless one-sided piston type variable displacement compressor |
JPH08109880A (en) * | 1994-10-11 | 1996-04-30 | Toyota Autom Loom Works Ltd | Operation control system for variable displacement type compressor |
JP3941141B2 (en) * | 1996-11-22 | 2007-07-04 | 株式会社豊田自動織機 | Variable capacity compressor |
DE69822686T2 (en) * | 1997-01-24 | 2004-09-23 | Kabushiki Kaisha Toyota Jidoshokki, Kariya | Variable flow compressor |
JPH10325393A (en) * | 1997-05-26 | 1998-12-08 | Zexel Corp | Variable displacement swash plate type clutchless compressor |
JPH1182297A (en) * | 1997-09-08 | 1999-03-26 | Toyota Autom Loom Works Ltd | Variable delivery compressor |
JP4160669B2 (en) * | 1997-11-28 | 2008-10-01 | 株式会社不二工機 | Control valve for variable displacement compressor |
JP3783434B2 (en) * | 1998-04-13 | 2006-06-07 | 株式会社豊田自動織機 | Variable capacity swash plate compressor and air conditioning cooling circuit |
JP4031128B2 (en) * | 1998-11-27 | 2008-01-09 | カルソニックカンセイ株式会社 | Swash plate type variable capacity compressor |
JP2000346241A (en) * | 1999-06-07 | 2000-12-15 | Toyota Autom Loom Works Ltd | Check valve |
-
2001
- 2001-04-23 JP JP2001123750A patent/JP4070425B2/en not_active Expired - Fee Related
-
2002
- 2002-01-18 EP EP02715833A patent/EP1363021A1/en not_active Withdrawn
- 2002-01-18 WO PCT/JP2002/000364 patent/WO2002057628A1/en active Application Filing
- 2002-08-13 US US10/217,556 patent/US20030035733A1/en not_active Abandoned
Non-Patent Citations (1)
Title |
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See references of WO02057628A1 * |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP1696123A1 (en) * | 2005-01-27 | 2006-08-30 | Kabushiki Kaisha Toyota Jidoshokki | Variable displacement compressor |
US7651321B2 (en) | 2005-01-27 | 2010-01-26 | Kabushiki Kaisha Toyota Jidoshokki | Variable displacement compressor |
DE112008001914B4 (en) | 2007-07-17 | 2018-12-27 | Sanden Holdings Corporation | Displacement control system for variable displacement compressor |
Also Published As
Publication number | Publication date |
---|---|
US20030035733A1 (en) | 2003-02-20 |
JP4070425B2 (en) | 2008-04-02 |
WO2002057628A1 (en) | 2002-07-25 |
JP2002285973A (en) | 2002-10-03 |
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