EP0908624B1 - Displacement control valve for use in a variable displacement compressor - Google Patents
Displacement control valve for use in a variable displacement compressor Download PDFInfo
- Publication number
- EP0908624B1 EP0908624B1 EP19980118877 EP98118877A EP0908624B1 EP 0908624 B1 EP0908624 B1 EP 0908624B1 EP 19980118877 EP19980118877 EP 19980118877 EP 98118877 A EP98118877 A EP 98118877A EP 0908624 B1 EP0908624 B1 EP 0908624B1
- Authority
- EP
- European Patent Office
- Prior art keywords
- compressor
- valve
- predetermined direction
- pressure sensitive
- chamber
- 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.)
- Expired - Lifetime
Links
Images
Classifications
-
- 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
-
- 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
-
- 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
-
- 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
- F04B2027/184—Valve controlling parameter
- F04B2027/1854—External parameters
-
- 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
- F04B2027/184—Valve controlling parameter
- F04B2027/1859—Suction pressure
Definitions
- the present invention relates to a displacement control valve for use in a variable displacement compressor which is included in, for example, a vehicle air conditioner.
- variable displacement compressor there has been a type having a piston.
- the compressor of the type comprises a crank chamber, a suction chamber, and a discharge chamber.
- the piston has a piston stroke controlled in response to the pressure in the crank chamber. Therefore, the compressor has a displacement which is variable and determined in accordance with the piston stroke.
- a displacement control valve is assembled to the variable displacement compressor to control the piston stroke.
- Various displacement control valves have been known in the art.
- the shown displacement control valve monitors the pressure in the suction chamber by means of a bellows 1 and opens/closes a ball valve 2 depending on the monitored suction chamber pressure so as to adjust the amount of gas introduced into the crank chamber from the discharge chamber.
- This is a bellows valve structure of a so-called internal control type.
- an electromagnetic actuator 3 is further disposed over the ball valve 2 so that an electromagnetic force is exerted on the ball valve 2.
- the operation point of the bellows valve i.e. the pressure control point of the suction chamber, can be changed according to the current amount supplied to the electromagnetic actuator 3.
- Fig. 6 it is assumed that the pressure in the discharge chamber is constant.
- suction chamber pressure can not be controlled over 3.7kg/cm 2 G.
- the pressure in the suction chamber is controlled across 2kg/cm 2 G so that no problem is raised.
- the discharge displacement may be reduced for enhancing the acceleration performance.
- the discharge displacement is reduced while the pressure in the suction chamber increases.
- the pressure in the suction chamber increases up to 3.7kg/cm 2 G, the discharge displacement is controlled to keep this pressure. Accordingly, depending on the vehicle operating condition, the required minimum displacement cannot be achieved to given a serious influence onto the vehicle run performance.
- variable displacement compressor with a control valve can also be taken from US patent 5,531,572, which also forms the basis for the precharacterizing part of claim 1.
- variable displacement compressor comprising a displacement control valve as is specified in claim 1.
- variable displacement compressor including a displacement control valve according to a first embodiment of the present invention.
- the shown compressor is used for a vehicle air conditioner and comprises a tubular casing 31, a front housing 32 closing one axial end of the casing 31, and a cylinder head 34 attached to the other axial end of the casing 31 via a valve plate assembly 33.
- the casing 31, the front housing 32 and the cylinder head 34 are fixed together by means of bolts 35.
- the casing 31 is integrally provided with a cylinder block 36 therein.
- a shaft 37 axially extends at the center of the casing 31.
- the shaft 37 is rotatably supported by the front housing 32 and the cylinder block 36.
- a pulley 38 is rotatably supported on the front housing 32.
- the pulley 38 is driven by an engine of the vehicle.
- a ring-shaped armature 41 is supported on an outer end of the shaft 37 via a rubber member 39 so as to be movable axially.
- the armature 41 confronts an axial end surface of the pulley 38 and is controlled to be attached to or detached from the pulley 38 by means of an electromagnetic attracting unit 42. Specifically, when the electromagnetic attracting unit 42 is energized, the armature 41 is attracted and attached to the pulley 38 by an electromagnetic force, so that the torque of the engine is transmitted to the shaft 37. On the other hand, when the energization to the electromagnetic attracting unit 42 is stopped, the armature 41 is detached from the pulley 38 by a restoring force of the rubber member 39, so that the torque of the engine is not transmitted to the shaft 37.
- a crank chamber 43 is defined between the front housing 32 and the cylinder block 36.
- a rotor 44 is fixed on the shaft 37.
- a swash plate 46 is coupled to the rotor 44 via a hinge mechanism 45.
- the hinge mechanism 45 renders variable an inclination of the swash plate 46 relative to an axis of the shaft 37.
- the swash plate 46 rotates together with the rotor 44.
- a plurality of pistons 47 engage with peripheral portions of the swash plate 46 via shoes, respectively.
- the pistons 47 are received in corresponding cylinder bores 48 formed in the cylinder block 36 so as to be axially slidable.
- each of the pistons 47 makes a reciprocating motion in the corresponding cylinder bore 48 with a stroke determined by an inclination of the swash plate 46.
- the cylinder head 34 is formed with a suction chamber 51 along its peripheral portion and with a discharge chamber 52 at the center thereof. Between the suction chamber 51 and the discharge chamber 52 is connected a known refrigeration circuit.
- the valve plate assembly 33 is provided with suction holes 53 and discharge holes 54 for establishing communication of the cylinder bores 48 with the suction chamber 51 and the discharge chamber 52, and with valve mechanisms for those holes.
- variable displacement compressor depends on the stroke of the pistons 47 determined by the inclination of the swash plate 46.
- a displacement control valve 10 is further provided in a control valve chamber 55 formed in the cylinder head 34.
- the control valve chamber 55 communicates with the crank chamber 43, the suction chamber 51 and the discharge chamber 52 via passages 56, 57 and 58, respectively. Further, the suction chamber 51 communicates with the crank chamber 43 via a narrow passage 59.
- the displacement control valve 10 adjusts the pressure in the crank chamber 43 so as to control the stroke of the pistons 47.
- the displacement control valve 10 comprises a valve casing 11 having an opening at its lower end in the figures and a bellows 12 disposed as a pressure sensitive member in the cavity of the valve casing 11.
- the inside of the bellows 12 is under vacuum and provided with a spring.
- the displacement control valve 10 further comprises a guide 13 receiving a lower end (in the figures) of the bellows 12 and disposed in the cavity of the valve casing 11 so as to be slidable along the valve casing 11 in an upward and downward direction in the figures, a compressed coil spring 14 as an elastic member for biasing the guide 13 upward (in the figures) in the cavity of the valve casing 11, and an adjusting screw 15 screwed in the opening of the valve casing 11 to close the opening and adjusting the expansion/contraction amount of the bellows 12.
- the adjusting screw 15 is movable in the upward and downward direction so at to enable adjustment of urging force of the spring 14.
- a transfer rod 16 engages at its one end with an upper end (in the figures) of the bellows 12 and supported by the valve casing 11 so as to be movable.
- a valve member 18 engages with the other end of the transfer rod 16 so as to open/close a communication passage 17 between the discharge chamber 52 and the crank chamber 43 depending on the expansion/contraction of the bellows 12.
- the valve member is coupled to the communication passage 17 and is movable between a open position and a close position in a predetermined direction or the upward and down ward direction to open the communication passage 17 at the open position and to close the communication passage at the close position.
- an electromagnetic coil 21 generates an electromagnetic force urging the valve member 18 in a valve closing direction via a plunger 19 and a transfer rod 20.
- a combination of the electromagnetic coil 21, the plunger 19, and the transfer rod 20 is referred to as an externally biasing mechanism which is supplied with an external signal and is for generating a biasing force to apply the biasing force to the valve member towards the close position.
- the valve casing 11 has a plurality of lateral holes 11a.
- the adjusting screw 15 has a through hole 15a.
- Each of the lateral holes 11a and the through hole 15a communicates the cavity of the valve casing 11 with the suction chamber 51 through the passage 57 and the control valve chamber 55. Therefore, the cavity of the valve casing 11 is subjected to the pressure of the suction chamber 51.
- the biasing force of the spring 14 is set to be small, for example, smaller than an electromagnetic force generated by a current value i0(A) supplied to the electromagnetic coil 21.
- the valve member 18 can be closed in a current region of i0(A) or greater.
- the bellows 12 As the pressure in the suction chamber 51 is lowered, the bellows 12 is expanded to cause a lower end (in the figures) of the guide 13 to abut the adjusting screw 15, so that a function of the spring 14 is lost, and thus, the same function as the conventional displacement control valve shown in Fig. 6 is obtained. Specifically, when the pressure in the suction chamber 51 is lowered to 2kg/cm 2 G, the bellows 12 is expanded to move the valve member 18 in a valve opening direction. Therefore, the gas in the discharge chamber 52 is introduced into the crank chamber 43 to increase a pressure differential between the crank chamber 43 and the suction chamber 51, so that the discharge displacement is reduced.
- the opening degree of the valve member 18 is adjusted to converge the pressure in the suction chamber 51 to a given value, so that the discharge displacement is controlled. If the current value is set to be zero in this state, the bellows 12 is expanded to cause the valve member 18 to be fully open. Thus, since a pressure differential between the crank chamber 43 and the suction chamber 51 highly increases, the minimum displacement is realized. Even if this increases the pressure in the suction chamber 51 up to greater than 3.5kg/cm 2 G in Fig. 3 to contract the bellows 12, since the valve member 18 is urged upward (in the figures) by the spring 14 to be constantly opened, the compressor is kept at the minimum displacement.
- the displacement control valve is also designated by the reference numeral 10 and comprises similar parts designated by like reference numerals.
- the valve casing 11 has a flange portion 11b at its lower end.
- the flange portion 11b is inwardly extended to define the opening of the valve casing 11.
- the opening has a relatively small portion 11c and a relatively large portion 11d.
- the adjusting screw 15 is screwed in the relatively small portion 11c of the opening and receives the spring 14 thereon.
- the guide 13 is slidably inserted in the relatively large portion 11d.
- the spring 14 is in contact with the adjusting screw 15, while the guide 13 is in contact with the valve casing 11 in an axial direction or the upward and downward direction in the figure. It should be noted here that the guide 13 is placed between the valve casing 11 and the bellows 12 in the predetermined direction.
- a biasing force of the spring 14 can be desirably adjusted by operating the adjusting screw 15.
- the displacement control valve shown in Fig. 4 is operated like the displacement control valve shown in Figs. 2A and 2B.
- Fig. 5 the description will be directed to a displacement control valve according to a third embodiment of the present invention.
- the displacement control valve is also designated by the reverence numeral 10 and comprises similar part designated by like reference numerals.
- the guide 13 is fixed to an upper end (in the figure) of the bellows 12 and slidable along the valve casing 11 in the upward and downward direction.
- the adjusting screw 15 is screwed in the opening of the valve casing 11.
- the through hole 15a of the adjusting screw 15 is slidably received with an attachment 22 attached to a lower end of the bellows 12.
- the spring 14 is placed between the guide 13 and the adjusting screw 15 to surround the bellows 12 and urges the guide 13 upwardly.
- the displacement control valve shown in Fig. 5 is also operated like the displacement control valve shown in Figs. 2A and 2B. It should be noted here that the bellows 12 is placed between the guide 13 and the adjusting screw 15 in the predetermined direction.
- the cavity of the valve casing may communicate with the crank chamber in addition to the suction chamber or in place of the suction chamber.
- the spring may comprise a coil spring, a leaf spring, or the like.
- the elastic member use may be made of a plastic member or a rubber member in place of the spring.
Landscapes
- 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)
Description
- The present invention relates to a displacement control valve for use in a variable displacement compressor which is included in, for example, a vehicle air conditioner.
- As such a variable displacement compressor, there has been a type having a piston. In the manner known in the art, the compressor of the type comprises a crank chamber, a suction chamber, and a discharge chamber. The piston has a piston stroke controlled in response to the pressure in the crank chamber. Therefore, the compressor has a displacement which is variable and determined in accordance with the piston stroke.
- For making the displacement be variable, a displacement control valve is assembled to the variable displacement compressor to control the piston stroke. Various displacement control valves have been known in the art.
- Referring now to Fig. 6, description will be made as regards an example of the conventional displacement control valves. The shown displacement control valve monitors the pressure in the suction chamber by means of a
bellows 1 and opens/closes aball valve 2 depending on the monitored suction chamber pressure so as to adjust the amount of gas introduced into the crank chamber from the discharge chamber. This is a bellows valve structure of a so-called internal control type. - On the basis of the bellows valve structure of this type, an
electromagnetic actuator 3 is further disposed over theball valve 2 so that an electromagnetic force is exerted on theball valve 2. Thus, the operation point of the bellows valve, i.e. the pressure control point of the suction chamber, can be changed according to the current amount supplied to theelectromagnetic actuator 3. In Fig. 6, it is assumed that the pressure in the discharge chamber is constant. - According to the structure shown in Fig. 6, there should be an upper limit in suction chamber pressure. For example, in Fig. 7, the suction chamber pressure can not be controlled over 3.7kg/cm2G.
- During the normal running of the vehicle, the pressure in the suction chamber is controlled across 2kg/cm2G so that no problem is raised. On the other hand, during acceleration of the vehicle, the discharge displacement may be reduced for enhancing the acceleration performance. In this case, the discharge displacement is reduced while the pressure in the suction chamber increases. When the pressure in the suction chamber increases up to 3.7kg/cm2G, the discharge displacement is controlled to keep this pressure. Accordingly, depending on the vehicle operating condition, the required minimum displacement cannot be achieved to given a serious influence onto the vehicle run performance.
- Such a variable displacement compressor with a control valve can also be taken from US patent 5,531,572, which also forms the basis for the precharacterizing part of
claim 1. - It is therefore an object of the present invention to provide a variable displacement compressor with a displacement control valve which makes it possible to keep the variable displacement compressor at the minimum displacement.
- Such an object is solved by a variable displacement compressor comprising a displacement control valve as is specified in
claim 1. - Preferred developments are given in the dependent claims.
-
- Fig. 1 is a longitudinal sectional view showing the overall structure of a variable displacement compressor;
- Figs. 2A and 2B are longitudinal sectional views of a displacement control valve according to a first embodiment of the present invention, wherein Fig. 2A shows the state of a normal operation of the compressor while Fig. 2B shows the state of the minimum displacement of the compressor;
- Fig. 3 is a graph showing a pressure control characteristic of the displacement control valve shown in Figs. 2A and 2B;
- Fig. 4 is a longitudinal sectional view of a second embodiment of the present invention;
- Fig. 5 is a longitudinal sectional view of a third embodiment of the displacement control valve shown in Figs. 2A and 2B;
- Fig. 6 is a longitudinal sectional view of a conventional displacement control valve; and
- Fig. 7. is a graph showing a pressure control characteristic of the displacement control valve shown in Fig. 6.
-
- Referring to Fig. 1, description will at first be made as regards a variable displacement compressor including a displacement control valve according to a first embodiment of the present invention.
- The shown compressor is used for a vehicle air conditioner and comprises a
tubular casing 31, afront housing 32 closing one axial end of thecasing 31, and acylinder head 34 attached to the other axial end of thecasing 31 via avalve plate assembly 33. Thecasing 31, thefront housing 32 and thecylinder head 34 are fixed together by means ofbolts 35. - The
casing 31 is integrally provided with acylinder block 36 therein. Ashaft 37 axially extends at the center of thecasing 31. Theshaft 37 is rotatably supported by thefront housing 32 and thecylinder block 36. - A
pulley 38 is rotatably supported on thefront housing 32. Thepulley 38 is driven by an engine of the vehicle. A ring-shaped armature 41 is supported on an outer end of theshaft 37 via arubber member 39 so as to be movable axially. - The
armature 41 confronts an axial end surface of thepulley 38 and is controlled to be attached to or detached from thepulley 38 by means of an electromagnetic attractingunit 42. Specifically, when the electromagnetic attractingunit 42 is energized, thearmature 41 is attracted and attached to thepulley 38 by an electromagnetic force, so that the torque of the engine is transmitted to theshaft 37. On the other hand, when the energization to the electromagnetic attractingunit 42 is stopped, thearmature 41 is detached from thepulley 38 by a restoring force of therubber member 39, so that the torque of the engine is not transmitted to theshaft 37. - A
crank chamber 43 is defined between thefront housing 32 and thecylinder block 36. In thecrank chamber 43, a rotor 44 is fixed on theshaft 37. Aswash plate 46 is coupled to the rotor 44 via ahinge mechanism 45. Thehinge mechanism 45 renders variable an inclination of theswash plate 46 relative to an axis of theshaft 37. Theswash plate 46 rotates together with the rotor 44. - A plurality of
pistons 47 engage with peripheral portions of theswash plate 46 via shoes, respectively. Thepistons 47 are received incorresponding cylinder bores 48 formed in thecylinder block 36 so as to be axially slidable. When theswash plate 46 rotates, each of thepistons 47 makes a reciprocating motion in the corresponding cylinder bore 48 with a stroke determined by an inclination of theswash plate 46. - The
cylinder head 34 is formed with asuction chamber 51 along its peripheral portion and with a discharge chamber 52 at the center thereof. Between thesuction chamber 51 and the discharge chamber 52 is connected a known refrigeration circuit. - The
valve plate assembly 33 is provided withsuction holes 53 anddischarge holes 54 for establishing communication of thecylinder bores 48 with thesuction chamber 51 and the discharge chamber 52, and with valve mechanisms for those holes. - When the
shaft 37 rotates, thepistons 47 make the reciprocating motion in thecylinder cores 48, respectively. Following the reciprocating motion of thepistons 47, refrigerant gas in the refrigeration circuit is sucked into the cylinder bores 48 from thesuction chamber 51 and discharged into the refrigeration circuit from the discharge chamber 52. - The compression displacement of the variable displacement compressor depends on the stroke of the
pistons 47 determined by the inclination of theswash plate 46. For controlling the inclination of theswash plate 46, adisplacement control valve 10 is further provided in acontrol valve chamber 55 formed in thecylinder head 34. - The
control valve chamber 55 communicates with thecrank chamber 43, thesuction chamber 51 and the discharge chamber 52 viapassages suction chamber 51 communicates with thecrank chamber 43 via anarrow passage 59. - Referring now to Figs. 2A and 2B in addition, the
displacement control valve 10 will be described. - The
displacement control valve 10 adjusts the pressure in thecrank chamber 43 so as to control the stroke of thepistons 47. Thedisplacement control valve 10 comprises avalve casing 11 having an opening at its lower end in the figures and abellows 12 disposed as a pressure sensitive member in the cavity of thevalve casing 11. The inside of thebellows 12 is under vacuum and provided with a spring. - The
displacement control valve 10 further comprises aguide 13 receiving a lower end (in the figures) of thebellows 12 and disposed in the cavity of thevalve casing 11 so as to be slidable along thevalve casing 11 in an upward and downward direction in the figures, acompressed coil spring 14 as an elastic member for biasing theguide 13 upward (in the figures) in the cavity of thevalve casing 11, and an adjustingscrew 15 screwed in the opening of thevalve casing 11 to close the opening and adjusting the expansion/contraction amount of thebellows 12. The adjustingscrew 15 is movable in the upward and downward direction so at to enable adjustment of urging force of thespring 14. Form figs. 2A and 2B, it will be noted that the guide is placed between thebellows 12 and the adjustingscrew 15 in the upward and downward direction. - A
transfer rod 16 engages at its one end with an upper end (in the figures) of thebellows 12 and supported by thevalve casing 11 so as to be movable. Avalve member 18 engages with the other end of thetransfer rod 16 so as to open/close acommunication passage 17 between the discharge chamber 52 and thecrank chamber 43 depending on the expansion/contraction of thebellows 12. In other words, the valve member is coupled to thecommunication passage 17 and is movable between a open position and a close position in a predetermined direction or the upward and down ward direction to open thecommunication passage 17 at the open position and to close the communication passage at the close position. - In addition, an
electromagnetic coil 21 generates an electromagnetic force urging thevalve member 18 in a valve closing direction via aplunger 19 and atransfer rod 20. A combination of theelectromagnetic coil 21, theplunger 19, and thetransfer rod 20 is referred to as an externally biasing mechanism which is supplied with an external signal and is for generating a biasing force to apply the biasing force to the valve member towards the close position. - The
valve casing 11 has a plurality of lateral holes 11a. The adjustingscrew 15 has a throughhole 15a. Each of the lateral holes 11a and the throughhole 15a communicates the cavity of thevalve casing 11 with thesuction chamber 51 through thepassage 57 and thecontrol valve chamber 55. Therefore, the cavity of thevalve casing 11 is subjected to the pressure of thesuction chamber 51. - Referring now to Fig. 3 in addition, the description will be made as regards an operation of the
displacement control valve 10. It is assumed that the pressure in the discharge chamber 52 is constant. - Since no electromagnetic force is generated in the state where the
electromagnetic coil 21 is not energized, there is no force urging thevalve member 18 in the valve closing direction in a pressure balanced state. Thus, although thebellows 12 is contracted when the pressure in thesuction chamber 51 is high, since thevalve member 18 is biased upward (in the figures) by means of thespring 14, thevalve member 18 is constantly opened. If the compressor is activated in this state, the gas in the discharge chamber 52 is constantly introduced into thecrank chamber 43 to increase a pressure differential between thecrank chamber 43 and thesuction chamber 51, so that the compressor is kept at the minimum displacement. - The biasing force of the
spring 14 is set to be small, for example, smaller than an electromagnetic force generated by a current value i0(A) supplied to theelectromagnetic coil 21. Thus, thevalve member 18 can be closed in a current region of i0(A) or greater. - Assuming that the compressor is activated in the state where the pressures are balanced under 6kg/cm2G and that the current amount supplied to the
electromagnetic coil 21 is adjusted to a current value i3(A) for controlling the pressure in thesuction chamber 51 to be 2kg/cm2G, since an electromagnetic force generated by theelectromagnetic coil 21 is greater than the biasing force of thespring 14, thevalve member 18 is closed. Thus, the pressure in thecrank chamber 43 is lowered to be equal to the pressure in thesuction chamber 51. Therefore, the compressor is kept at the maximum displacement, and the pressure in thesuction chamber 51 is gradually lowered.
As the pressure in thesuction chamber 51 is lowered, thebellows 12 is expanded to cause a lower end (in the figures) of theguide 13 to abut the adjustingscrew 15, so that a function of thespring 14 is lost, and thus, the same function as the conventional displacement control valve shown in Fig. 6 is obtained. Specifically, when the pressure in thesuction chamber 51 is lowered to 2kg/cm2G, thebellows 12 is expanded to move thevalve member 18 in a valve opening direction. Therefore, the gas in the discharge chamber 52 is introduced into thecrank chamber 43 to increase a pressure differential between thecrank chamber 43 and thesuction chamber 51, so that the discharge displacement is reduced. Following this, when the pressure in thesuction chamber 51 increases, thebellows 12 is contracted to move thevalve member 18 in the valve closing direction. Accordingly, the pressure in thecrank chamber 43 is lowered to reduce a pressure differential between thecrank chamber 43 and thesuction chamber 51, so that the discharge displacement increases. - In this fashion, the opening degree of the
valve member 18 is adjusted to converge the pressure in thesuction chamber 51 to a given value, so that the discharge displacement is controlled. If the current value is set to be zero in this state, thebellows 12 is expanded to cause thevalve member 18 to be fully open. Thus, since a pressure differential between thecrank chamber 43 and thesuction chamber 51 highly increases, the minimum displacement is realized. Even if this increases the pressure in thesuction chamber 51 up to greater than 3.5kg/cm2G in Fig. 3 to contract thebellows 12, since thevalve member 18 is urged upward (in the figures) by thespring 14 to be constantly opened, the compressor is kept at the minimum displacement. - Turning to Fig. 4, the description will be directed to a displacement control valve according to a second embodiment of the present invention. The displacement control valve is also designated by the
reference numeral 10 and comprises similar parts designated by like reference numerals. - In the
displacement control valve 10, thevalve casing 11 has a flange portion 11b at its lower end. The flange portion 11b is inwardly extended to define the opening of thevalve casing 11. The opening has a relatively small portion 11c and a relatively large portion 11d. The adjustingscrew 15 is screwed in the relatively small portion 11c of the opening and receives thespring 14 thereon. On the other hand, theguide 13 is slidably inserted in the relatively large portion 11d. As a result, thespring 14 is in contact with the adjustingscrew 15, while theguide 13 is in contact with thevalve casing 11 in an axial direction or the upward and downward direction in the figure. It should be noted here that theguide 13 is placed between thevalve casing 11 and thebellows 12 in the predetermined direction. - According to this structure, a biasing force of the
spring 14 can be desirably adjusted by operating the adjustingscrew 15. The displacement control valve shown in Fig. 4 is operated like the displacement control valve shown in Figs. 2A and 2B. - Turning to Fig. 5, the description will be directed to a displacement control valve according to a third embodiment of the present invention. The displacement control valve is also designated by the
reverence numeral 10 and comprises similar part designated by like reference numerals. - In the
displacement control valve 10, theguide 13 is fixed to an upper end (in the figure) of thebellows 12 and slidable along thevalve casing 11 in the upward and downward direction. The adjustingscrew 15 is screwed in the opening of thevalve casing 11. The throughhole 15a of the adjustingscrew 15 is slidably received with anattachment 22 attached to a lower end of thebellows 12. Thespring 14 is placed between theguide 13 and the adjustingscrew 15 to surround thebellows 12 and urges theguide 13 upwardly. The displacement control valve shown in Fig. 5 is also operated like the displacement control valve shown in Figs. 2A and 2B. It should be noted here that thebellows 12 is placed between theguide 13 and the adjustingscrew 15 in the predetermined direction. - While the present invention has thus far been described in connection with a few embodiments thereof, it will readily be possible for those skilled in the art to put this invention into practice in various other manners. For example, the cavity of the valve casing may communicate with the crank chamber in addition to the suction chamber or in place of the suction chamber. The spring may comprise a coil spring, a leaf spring, or the like. As the elastic member, use may be made of a plastic member or a rubber member in place of the spring.
Claims (10)
- A variable displacement compressor comprising :a displacement control valve (10), a suction chamber (51), a crank chamber (43), and a discharge chamber (52); said displacement control valve (10) comprising a valve casing (11) defining a communication passage (17) for communicating said discharge chamber (52) with said crank chamber (43) to conduct gas from said discharge chamber (52) to said crank chamber (43),a valve member (18) coupled to said communication passage (17) and movable between an open position and a close position in a predetermined direction to open said communication passage (17) at said open position and to close said communication passage (17) at said close position, anda pressure sensitive member (12) for causing expansion thereof in said predetermined direction in response to a pressure in at least one of said suction chamber (51) and said crank chamber (43) to bias said valve member (18) towards said open position on said expansion;by further comprising an elastic member (14) for urging said pressure sensitive member (12) as such in said predetermined direction to make said pressure sensitive member (12) urge said valve member (18) towards said open position.
- A compressor as claimed in claim 1, wherein said valve casing (11) defines a cavity containing said pressure sensitive member (12) therein, further comprising a guide (13) coupled to said pressure sensitive member (12) in said cavity and slidable along said valve casing (11) in said predetermined direction and an adjusting member (15) attached to said valve casing (11) to face said guide in said predetermined direction, said elastic member (14) being placed between said adjusting member (15) and said guide (13), said adjusting member (15) being movable in said predetermined direction so as to enable adjustment of urging force of said elastic member (14).
- A compressor as claimed in claim 2, wherein said guide (13) is placed between said pressure sensitive member (12) and said adjusting member (15) in said predetermined direction.
- A compressor as claimed in claim 2, wherein said guide (13) is placed between said valve casing (11) and said pressure sensitive member (12) in said predetermined direction.
- A compressor as claimed in claim 2, wherein said pressure sensitive member (12) is placed between said guide (13) and said adjusting member (15).
- A compressor as claimed in any one of claims 2 through 5, wherein said adjusting member (15) is screwed in said valve casing (11) to close an opening of said cavity.
- A compressor as claimed in any one of claims 2 through 6, further comprising at least one hole (11a, 15a) for communicating said cavity with at least one of said suction chamber (51) and said crank chamber (43).
- A compressor as claimed in any one of claims 1 through 7, wherein said pressure sensitive member comprises a bellows (12) causing expansion/contraction thereof in said predetermined direction in response to a change of said pressure.
- A compressor as claimed in any one of claims 1 through 8, further comprising an externally biasing mechanism (19, 20, 21) supplied with an external signal for generating a biasing force to apply said biasing force to said valve member (18) towards said close position.
- A compressor as claimed in any one of claims 1 through 9, wherein said elastic member comprises a spring (14).
Applications Claiming Priority (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP27297297 | 1997-10-06 | ||
JP27297297A JP3862380B2 (en) | 1997-10-06 | 1997-10-06 | Volume control valve for variable capacity compressor |
JP272972/97 | 1997-10-06 |
Publications (3)
Publication Number | Publication Date |
---|---|
EP0908624A2 EP0908624A2 (en) | 1999-04-14 |
EP0908624A3 EP0908624A3 (en) | 1999-09-08 |
EP0908624B1 true EP0908624B1 (en) | 2001-12-12 |
Family
ID=17521363
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP19980118877 Expired - Lifetime EP0908624B1 (en) | 1997-10-06 | 1998-10-06 | Displacement control valve for use in a variable displacement compressor |
Country Status (3)
Country | Link |
---|---|
EP (1) | EP0908624B1 (en) |
JP (1) | JP3862380B2 (en) |
DE (1) | DE69802885T2 (en) |
Families Citing this family (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
KR100340606B1 (en) * | 1999-09-10 | 2002-06-15 | 이시카와 타다시 | Control valve for variable capacity compressor |
JP4121785B2 (en) * | 2002-06-12 | 2008-07-23 | サンデン株式会社 | Control device for variable capacity compressor |
US7063511B2 (en) * | 2003-07-28 | 2006-06-20 | Delphi Technologies, Inc. | Integrated control valve for a variable capacity compressor |
JP2006200435A (en) * | 2005-01-20 | 2006-08-03 | Fuji Koki Corp | Control valve for variable displacement compressor |
JP2008274756A (en) | 2007-04-25 | 2008-11-13 | Sanden Corp | Control device of variable displacement compressor |
Family Cites Families (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2661121B2 (en) * | 1988-03-31 | 1997-10-08 | 日産自動車株式会社 | Vehicle air conditioners and variable displacement compressors |
JPH0331581A (en) * | 1989-06-28 | 1991-02-12 | Sanden Corp | Variable-capacity swash plate type compressor |
JPH04342883A (en) * | 1991-05-17 | 1992-11-30 | Sanden Corp | Variable delivery swash plate type compressor |
JP3178631B2 (en) * | 1993-01-11 | 2001-06-25 | 株式会社豊田自動織機製作所 | Control valve for variable displacement compressor |
JP3355002B2 (en) * | 1993-10-15 | 2002-12-09 | 株式会社豊田自動織機 | Control valve for variable displacement compressor |
-
1997
- 1997-10-06 JP JP27297297A patent/JP3862380B2/en not_active Expired - Fee Related
-
1998
- 1998-10-06 EP EP19980118877 patent/EP0908624B1/en not_active Expired - Lifetime
- 1998-10-06 DE DE1998602885 patent/DE69802885T2/en not_active Expired - Lifetime
Also Published As
Publication number | Publication date |
---|---|
JPH11107930A (en) | 1999-04-20 |
DE69802885D1 (en) | 2002-01-24 |
EP0908624A3 (en) | 1999-09-08 |
EP0908624A2 (en) | 1999-04-14 |
DE69802885T2 (en) | 2002-08-01 |
JP3862380B2 (en) | 2006-12-27 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US8021124B2 (en) | Capacity control valve | |
JP3242496B2 (en) | External switching type displacement control valve for variable displacement compressor | |
KR100215158B1 (en) | Variable capacity type compressor and method therefor | |
JP4436295B2 (en) | Variable capacity compressor | |
CA2037968C (en) | Slant plate type compressor with control valve pressure response adjusting means | |
CA1324361C (en) | Variable displacement compressor with biased inclined member | |
KR100325789B1 (en) | Variable displacement compressors and control valves for variable displacement compressors | |
US5318410A (en) | Variable displacement compressor | |
KR100270472B1 (en) | Electromagenetic valve | |
US6257836B1 (en) | Displacement control valve for variable displacement compressor | |
JPH0312674B2 (en) | ||
EP0945617B1 (en) | Displacement control valve for use in variable displacement compressor | |
WO2003085260A1 (en) | Variable displacement compressor | |
CA2020332C (en) | Slant plate type compressor with variable displacement mechanism | |
KR20060043852A (en) | Control valve for variable displacement compressor | |
KR970001753B1 (en) | Wobble plate type compressor with variable displacement mechanism | |
JPH1182296A (en) | Variable delivery compressor | |
EP0907021B1 (en) | Displacement control valve for use in a variable displacement compressor | |
JPH10141223A (en) | Variable displacement compressor | |
US6074173A (en) | Variable displacement compressor in which a liquid refrigerant can be prevented from flowing into a crank chamber | |
EP0908624B1 (en) | Displacement control valve for use in a variable displacement compressor | |
EP0855506B1 (en) | Variable-displacement compressor | |
US20060039799A1 (en) | Control valve for variable displacement compressor | |
JP5142212B2 (en) | Variable capacity compressor | |
KR100302993B1 (en) | Control valve in variable displacement compressor |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
PUAI | Public reference made under article 153(3) epc to a published international application that has entered the european phase |
Free format text: ORIGINAL CODE: 0009012 |
|
AK | Designated contracting states |
Kind code of ref document: A2 Designated state(s): DE FR |
|
AX | Request for extension of the european patent |
Free format text: AL;LT;LV;MK;RO;SI |
|
PUAL | Search report despatched |
Free format text: ORIGINAL CODE: 0009013 |
|
AK | Designated contracting states |
Kind code of ref document: A3 Designated state(s): AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE |
|
AX | Request for extension of the european patent |
Free format text: AL;LT;LV;MK;RO;SI |
|
17P | Request for examination filed |
Effective date: 20000210 |
|
AKX | Designation fees paid |
Free format text: DE FR |
|
17Q | First examination report despatched |
Effective date: 20000615 |
|
GRAG | Despatch of communication of intention to grant |
Free format text: ORIGINAL CODE: EPIDOS AGRA |
|
GRAG | Despatch of communication of intention to grant |
Free format text: ORIGINAL CODE: EPIDOS AGRA |
|
GRAH | Despatch of communication of intention to grant a patent |
Free format text: ORIGINAL CODE: EPIDOS IGRA |
|
GRAA | (expected) grant |
Free format text: ORIGINAL CODE: 0009210 |
|
AK | Designated contracting states |
Kind code of ref document: B1 Designated state(s): DE FR |
|
REF | Corresponds to: |
Ref document number: 69802885 Country of ref document: DE Date of ref document: 20020124 |
|
ET | Fr: translation filed | ||
PLBE | No opposition filed within time limit |
Free format text: ORIGINAL CODE: 0009261 |
|
STAA | Information on the status of an ep patent application or granted ep patent |
Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT |
|
26N | No opposition filed | ||
PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: FR Payment date: 20131022 Year of fee payment: 16 |
|
PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: DE Payment date: 20141022 Year of fee payment: 17 |
|
REG | Reference to a national code |
Ref country code: FR Ref legal event code: ST Effective date: 20150630 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: FR Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20141031 |
|
REG | Reference to a national code |
Ref country code: DE Ref legal event code: R082 Ref document number: 69802885 Country of ref document: DE Representative=s name: PRUEFER & PARTNER MBB PATENTANWAELTE RECHTSANW, DE Ref country code: DE Ref legal event code: R081 Ref document number: 69802885 Country of ref document: DE Owner name: SANDEN HOLDINGS CORPORATION, LSESAKI-SHI, JP Free format text: FORMER OWNER: SANDEN CORP., ISESAKI, GUNMA, JP |
|
REG | Reference to a national code |
Ref country code: DE Ref legal event code: R119 Ref document number: 69802885 Country of ref document: DE |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: DE Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20160503 |