EP1081379A1 - Vanne de reglage a deplacement variable pour compresseur - Google Patents

Vanne de reglage a deplacement variable pour compresseur Download PDF

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Publication number
EP1081379A1
EP1081379A1 EP99905271A EP99905271A EP1081379A1 EP 1081379 A1 EP1081379 A1 EP 1081379A1 EP 99905271 A EP99905271 A EP 99905271A EP 99905271 A EP99905271 A EP 99905271A EP 1081379 A1 EP1081379 A1 EP 1081379A1
Authority
EP
European Patent Office
Prior art keywords
rod
chamber
pressure
valve
valve body
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.)
Withdrawn
Application number
EP99905271A
Other languages
German (de)
English (en)
Other versions
EP1081379A4 (fr
Inventor
Kazuya Kabushiki Kaisha Toyoda KIMURA
Hiroaki Kabushiki Kaisha Toyoda KAYUKAWA
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Toyota Industries Corp
Original Assignee
Toyoda Jidoshokki Seisakusho KK
Toyoda Automatic Loom Works Ltd
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Toyoda Jidoshokki Seisakusho KK, Toyoda Automatic Loom Works Ltd filed Critical Toyoda Jidoshokki Seisakusho KK
Publication of EP1081379A1 publication Critical patent/EP1081379A1/fr
Publication of EP1081379A4 publication Critical patent/EP1081379A4/fr
Withdrawn legal-status Critical Current

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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
    • F04B2027/184—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 control valve for variable displacement compressors that are used in vehicle air conditioners.
  • a typical variable displacement compressor includes a control passage for connecting a discharge pressure zone with a crank chamber.
  • the pressure in the crank chamber is adjusted to change the inclination of a cam plate. Accordingly, the displacement is controlled.
  • Japanese Unexamined Patent Publication No. 4-119271 discloses a typical control valve for variable displacement compressors. As shown in Fig. 7, this control valve has a valve chamber 101 in a distal portion of a valve housing 102. The valve chamber 101 is connected to a discharge pressure zone by the upstream portion of a control passage 103. The valve chamber 101 is also connected to a crank chamber by a valve hole 104, a port 105 and the downstream portion of the control passage 103. The valve hole 104 is formed axially in the housing 102 and the port 105 is perpendicular to the valve hole 104. A valve body 106 is housed in the valve chamber 101 to open and close the valve hole 104.
  • a pressure sensing chamber 107 is formed adjacent to the valve chamber 101 and is connected to a suction pressure zone.
  • a bellows 108 is housed in the pressure sensing chamber 107 to detect the pressure of the suction pressure zone.
  • the pressure sensing chamber 107 is separated from the valve chamber 101 by a dividing wall 102a.
  • a guide hole 109 is formed in the dividing wall 102a to be continuous with the valve hole 104.
  • the chambers 101 and 107 are therefore connected to each other.
  • a rod 110 is slidably fitted in the guide hole 109 to couple the bellows 108 with the valve body 106.
  • the bellows 108 is deformed in accordance with the suction pressure of the refrigerant gas. The deformation of the bellows 108 is transmitted to the valve body 106 by the rod 110.
  • a solenoid portion 111 is attached to a proximal portion of the valve housing 102 and is coupled to the valve body 106 by the bellows 108.
  • the solenoid portion 111 is excited and de-excited for changing the attraction force between a fixed iron core 112 and a movable iron core 113. Accordingly, the load acting on the valve body 106 is changed. Therefore, the opening size of the control passage 103 is determined by the equilibrium of forces, such as the force of the solenoid portion 111 and the force of the bellows 108.
  • the pressure in the port 105 is relatively high and the pressure in the pressure sensing chamber 107 is relatively low.
  • the rod 110 and the guide hole 109 are machined with meticulous care for allowing the rod 110 to slide in the hole 109 and for preventing leakage of gas between the port 105 and the pressure sensing chamber 107.
  • small machining errors are inevitable, and the space between the surface of the rod 110 and the surface of the guide hole 109 is different between a location near the port 105 and a location near the pressure sensing chamber 107.
  • the space near the port 105 is smaller than the space near the pressure sensing chamber 107, the pressure difference between the port 105 and the pressure sensing chamber 107 generates a lateral force acting on the rod 110.
  • the lateral force presses the rod 110 against the surface of the guide hole 109, which increases the sliding resistance between the rod 110 and the guide hole 109 (this phenomena will hereafter be referred to as fluid fixation).
  • a recent trend is to reduce the size of the solenoid portion 111 to reduce the size of the compressor.
  • the bellows 108 is relatively small and the valve body 106 is moved by the equilibrium of the difference between small forces, that is, the force of the solenoid portion 111 and the force of the bellows 108. Therefore, the control valve is easily affected by an increase of the sliding resistance between the rod 110 and the guide hole 109 due to the fluid fixation. As a result, even a small sliding resistance, which would be negligible if the bellows 108 were large, causes hysteresis. Therefore, the controllability of the displacement significantly deteriorates.
  • the present invention was made in view of drawbacks in the above described prior art. Accordingly, it is an objective of the present invention to provide a control valve for a variable displacement compressor that reduces sliding resistance between a rod and a guide hole.
  • the present invention provides a control valve for a variable displacement compressor.
  • the control valve includes a valve body.
  • the valve body opens and closes a control passage, which connects a control pressure chamber with a suction pressure zone or with a discharge pressure zone, to adjust the opening size of the control passage for varying the displacement of the compressor.
  • the valve body is opened and closed by a drive member.
  • a dividing wall separates a portion that accommodates the valve body from a portion that accommodates the drive member.
  • a guide hole is formed in the dividing wall to communicate the valve body accommodating portion with the drive member accommodating portion.
  • a sliding rod is located in the guide hole to operably couple the valve body to the drive member.
  • the control valve is characterized by means for preventing fluid fixation.
  • the fluid fixation preventing means is located on at least one of the outer surface of the rod and on the inner surface of the guide hole.
  • the invention of the above structure has the means for preventing fluid fixation between the rod and the guide hole, which decreases the hysteresis of the control valve and prevents deterioration of the displacement controlling performance of the control valve.
  • the means may include a tapered surface formed on at least one of the outer surface of the rod and the inner surface of the guide hole such that the space between the outer surface of the rod and the inner surface of the guide hole widens toward one of the valve body accommodating portion and the drive member accommodating portion that has a higher pressure.
  • the rod receives a lateral force, the direction of which is opposite to the displacement direction.
  • the misalignment of the axes is automatically corrected.
  • the tapered surface may be one of a plurality of tapered surfaces formed along the axial direction of the rod.
  • the cross-sectional area of the space between the outer surface of the rod and the inner surface of the guide hole changes in the axial direction in a completed fashion and functions like a labyrinth seal. This effectively prevents pressure leakage and refrigerant gas leakage between the high pressure location and the low pressure location.
  • the outer surface of the rod may be tapered such that the diameter of the rod decreases toward one of the valve body accommodating portion and the drive member accommodating portion that has higher pressure. This eliminates the necessity for tapering the inner wall of the guide hole, which is formed in the dividing wall and has a small cross-section, by inserting a tool into the guide hole.
  • the means may include a circumferential annular groove formed in at least one of the outer surface of the rod and the inner surface of the guide hole.
  • the annular groove circumferentially equalizes the pressure in the space between the outer surface of the rod and the inner surface of the guide hole. Accordingly, fluid fixation does not occur between the rod and the guide hole.
  • the groove is easily formed.
  • the drive member may include a pressure sensing mechanism having a pressure sensing chamber and a pressure sensing member located in the pressure sensing chamber.
  • the pressure sensing chamber is connected either with the suction pressure zone or with the control pressure chamber by a pressure introduction passage.
  • the rod operably couples the pressure sensing member with the valve body.
  • the pressure sensing member is deformed by pressure in the pressure sensing chamber, that is, by either the pressure of the suction pressure zone or the pressure in the control pressure chamber.
  • the deformation is transmitted to the valve body by the rod.
  • the drive member may include a solenoid portion.
  • the solenoid portion is excited and de-excited to actuate a plunger accommodated in a plunger chamber.
  • the rod operably couples the plunger with the valve body.
  • the plunger is moved by excitation and de-excitation of the solenoid portion.
  • the movement of the plunger is transmitted to the valve body by the rod.
  • the drive member may include a pressure sensing mechanism and a solenoid portion.
  • the pressure sensing mechanism may include a pressure sensing chamber and a pressure sensing member located in the pressure sensing chamber.
  • the pressure sensing chamber is connected either with the suction pressure zone or with the control pressure chamber by a pressure introduction passage.
  • the solenoid portion is excited and de-excited to actuate a plunger accommodated in a plunger chamber.
  • the rod may include a first rod portion, which operably couples the pressure sensing member with the valve body, and a second rod portion, which operably couples the plunger with the valve body.
  • the opening size of the control passage is determined by the position of the valve body, which is determined by the equilibrium of the force of the pressure sensing mechanism and the force of the solenoid portion.
  • control passage may connect the discharge pressure zone with the control pressure chamber.
  • the amount of refrigerant gas drawn into the control pressure chamber is adjusted for controlling the displacement.
  • Highly pressurized gas is introduced into the control valve. Fluid fixation between the rod and the guide hole causes the rod to be pressed against the guide hole by a greater force compared to a control valve that adjusts the amount of refrigerant gas discharged from the control pressure chamber to control the compressor displacement. Therefore, the present invention has a great advantage.
  • Displacement control valves used in variable displacement compressors according to first to third embodiments will now be described.
  • the displacement control valves of the first and second embodiments are used in a clutchless type variable displacement compressor, while the control valve according to the third embodiment is used in another type variable displacement compressor.
  • the second and third embodiments only differences from the first embodiment will be discussed.
  • Like or the same reference numerals are given to those components that are like or the same as the corresponding components of the first embodiment.
  • a front housing 11 is secured to the front end face of a cylinder block 12.
  • a rear housing 13 is secured to the rear end face of the cylinder block 12, and a valve plate 14 is located between the rear housing 13 and the cylinder block 12.
  • the front housing 11 and the cylinder block 12 define a control pressure chamber, which is a crank chamber 15.
  • a drive shaft 16 extends through the crank chamber 15 and is rotatably supported by the front housing 11 and the cylinder block 12.
  • a pulley 17 is rotatably supported by the front housing 11. The pulley 17 is coupled to the drive shaft 16.
  • a belt 19 is engaged with the periphery of the pulley 17 to directly couple the pulley 17 with a vehicle engine 20 without a clutch such as an electromagnetic clutch.
  • a lug plate 22 is secured to the drive shaft 16 in the crank chamber 15.
  • a swash plate 23 is supported by the lug plate 22 to slide axially and to incline with respect to the axis L of the drive shaft 16.
  • a hinge mechanism 24 is located between the lug plate 22 and the swash plate 23. The hinge mechanism 24 permits the swash plate 23 to incline with respect to the axis L of the drive shaft 16 and to rotate integrally with the drive shaft 16. As the radial center of the swash plate 23 slides toward the cylinder block 12, the inclination of the swash plate 23 decreases.
  • a spring 26 for decreasing the inclination is located between the lug plate 22 and the swash plate 23. The spring 26 urges the swash plate 23 in the direction of disinclination of the swash plate 23. The maximum inclination of the swash plate 23 is defined by contact between the swash plate 23 and the lug plate 22.
  • an accommodation chamber 27 is formed in the center of the cylinder block 12 and extends along the axis L of the drive shaft 16.
  • a sliding cylindrical shutter 28 is accommodated in the accommodation chamber 27.
  • a spring 29 for opening a suction passage is located between an end of the chamber 27 and the shutter 28 and urges the shutter 28 toward the swash plate 23.
  • the rear end portion of the drive shaft 16 is located in the shutter 28.
  • a radial bearing 30 is located between the rear end portion of the drive shaft 16 and the inner wall of the shutter 28. The radial bearing 30 slides with the shutter 28 with respect to the drive shaft 16 along the axis L.
  • a suction passage 32 which is part of the suction pressure zone, is formed in the center of the rear housing 13 and the valve plate 14.
  • the suction passage 32 communicates with the accommodation chamber 27.
  • a positioning surface 33 is defined on the valve plate 14 about an opening of the passage 32.
  • a shutting surface 34 is defined on an end of the shutter 28. The shutting surface 34 contacts and separates from the positioning surface 33 in accordance with the position of the shutter 28. When the shutting surface 34 contacts the positioning surface 33, the surfaces 33, 34 seal the interior of the accommodation chamber 27 from the suction passage 32.
  • a thrust bearing 35 is located between the swash plate 23 and the shutter 28 such that the swash plate 23 slides along the drive shaft 16.
  • the thrust bearing 35 is urged by the spring 29 and is normally held between the swash plate 23 and the shutter 28.
  • the inclination of the swash plate 23 is transmitted to the shutter 28 through the thrust bearing 35.
  • the shutter 28 is moved toward the positioning surface 33 against the force of the spring 29 and the shutting surface 34 of the shutter 28 contacts the positioning surface 33.
  • the contact between the shutting surface 34 and the positioning surface 33 prevents the swash plate 23 from being further inclined. In this state, the swash plate 23 is at the minimum inclination, which is slightly more than zero degrees.
  • Cylinder bores 12a are formed in the cylinder block 12.
  • a single-headed piston 36 is accommodated in each cylinder bore 12a.
  • Each piston 36 is coupled to the periphery of the swash plate 23 by way of a pair of shoes 37.
  • the pistons 36 are reciprocated by rotation of the swash plate 23.
  • Suction ports 40, suction valve flaps 41, discharge ports 42 and discharge valve flaps 43 are formed in the valve plate 14.
  • Each suction valve flap 41 opens and closes one of the suction ports 40 and each discharge valve flap 43 opens and closes one of the discharge ports 42.
  • each piston 36 draws refrigerant gas from the suction chamber 38 to the associated cylinder bore 12a via the associated suction port 40 and the associated suction valve flap 41.
  • Refrigerant gas in each cylinder bore 12a is compressed to reach a predetermined pressure as the associated piston 36 is moved from the bottom dead center to the top dead center and is discharged to the discharge chamber 39 via the associated discharge port 42 and the associated discharge valve flap 43.
  • the suction chamber 38 communicates with the accommodation chamber 27 via a communication hole 45.
  • the communication hole 45 is disconnected from the suction passage 32.
  • a passage 46 axially extends in the drive shaft 16 to connect the crank chamber 25 with the interior of the shutter 28.
  • a pressure release hole 47 is formed in the peripheral wall of the shutter 28 to communicate the interior of the shutter 28 with the accommodation chamber 27.
  • a control passage 48 connects the discharge chamber 39 with the crank chamber 15.
  • a displacement control valve 49 is located in the control passage 48.
  • the suction passage 32 is connected to the control valve 49 by a pressure introduction passage 50.
  • the suction passage 32 draws refrigerant gas to the suction chamber 38.
  • a discharge outlet 51 discharges refrigerant gas from the discharge chamber 39.
  • the suction passage 32 is connected to the discharge outlet 51 by an external refrigerant circuit 52.
  • the circuit 52 includes a condenser 53, an expansion valve 54 and an evaporator 55.
  • a sensor 56 is located in the vicinity of the evaporator 55.
  • the sensor 56 detects the temperature of the evaporator 55 and sends the detected temperature information to a computer 57.
  • the computer 57 is connected to a temperature adjuster 58, a sensor 59 and an air conditioner switch 60.
  • the temperature adjuster 58 sets the temperature in the passenger compartment.
  • the sensor 59 detects the temperature of the passenger compartment.
  • the computer 57 receives various information including a target temperature set by the temperature adjuster 58, the temperature detected by the sensor 56, the temperature detected by the sensor 59 and an ON/OFF signal from the air-conditioner switch 60. Based on this information, the computer 57 computes the value of a current supplied to a drive circuit 61. Accordingly, the drive circuit 61 sends a current having the computed value to the control valve 49. In addition to the above listed data, the computer 57 may use other data such as the temperature outside the compartment and the engine speed for determining the magnitude of electric current sent to the control valve 49.
  • control valve 49 The structure of the control valve 49 will now be described.
  • the control valve 49 includes a valve housing 71 and a solenoid portion 72.
  • the valve housing 71 and the solenoid portion 72 are coupled at the center of the control valve 49.
  • a valve chamber 73 is defined between the valve housing 71 and the solenoid portion 72.
  • the valve chamber 73 is connected to the discharge chamber 39 through a port 77 and the upstream portion of the control passage 48.
  • a valve body 74 is accommodated in the valve chamber 73.
  • a valve hole 75 opens in the valve chamber 73 to face the valve body 74.
  • the valve hole 75 extends along the axis of the valve housing 71.
  • a spring 76 is located between the valve body 74 and the inner wall of the valve chamber 73 to urge the valve body 74 in the direction for opening the valve hole 75.
  • a pressure sensing chamber 84 is defined in the distal portion of the valve housing 71.
  • the pressure introduction passage 50 is connected to the pressure sensing chamber 84. Therefore, the pressure sensing chamber 84 is connected to the suction passage 32 through a port 86 and the pressure introduction passage 50.
  • a guide hole 88 is formed in a dividing wall 71a of the valve housing 71, which divides the pressure sensing chamber 84 from the valve chamber 73.
  • the guide hole 88 connects the pressure sensing chamber 84 with the valve chamber 73.
  • the guide hole 88 is formed continuously with the valve hole 75.
  • a sliding rod 89 is located in the guide hole 88. The distal end of the rod 89 is engaged with the bellows 87.
  • the rod 89 is integral with the valve body 74 to operably couple the bellows 87 with the valve body 74.
  • a part of the rod 89 that is connected to the valve body 74 has a small diameter to define a gas passage in the valve hole 75.
  • a port 90 is formed in the dividing wall 71a between the valve chamber 73 and the pressure sensing chamber 84.
  • the port 90 is perpendicular to the valve hole 75.
  • the port 90 is connected to the crank chamber 15 through the downstream portion of the control passage 48. That is, the port 77, the valve chamber 73, the valve hole 75 and the port 90 form part of the control passage 48.
  • a plunger chamber 91 is defined in the solenoid portion 72.
  • a fixed iron core 92 is fitted in the upper opening of the plunger chamber 91.
  • the fixed core 92 separates the plunger chamber 91 from the valve chamber 73.
  • a plunger which is a cup-shaped movable iron core 93, is accommodated in the plunger chamber 91.
  • the movable core 93 reciprocates in the axial direction of the valve housing 71.
  • a follower spring 94 is located between the movable core 93 and the bottom surface of the plunger chamber 91.
  • a guide hole 95 is formed in the fixed iron core 92, which functions as a dividing wall, to connect the plunger chamber 91 with the valve chamber 73.
  • a sliding rod 96 is integral with the valve body 74 and is fitted in the guide hole 95. The end of the rod 96 that is closer to the movable core 93 is pressed against the movable core 93 by the force of the spring 76 and the follower spring 94. Therefore, the movable core 93 and the valve body 74 are operably coupled to each other by the rod 96.
  • a communication groove 81 is formed in the side of the fixed core 92.
  • a communication hole 82 is formed in the valve housing 71.
  • a small chamber 83 is defined between the control valve 49 and an inner wall of the rear housing 13.
  • the plunger chamber 91 is connected to the port 90 through the groove 81, the hole 82 and the chamber 83. That is, the pressure in the plunger chamber 91 is the crank chamber pressure, which is the same as the pressure in the port 90.
  • a cylindrical coil 97 is located radially outward of both the fixed core 92 and the movable core 93.
  • the coil 97 is connected to a drive circuit 61.
  • the drive circuit 61 supplies current to the coil 97 in accordance with command signals from the computer 57.
  • the part of the rod 89 that faces the inner surface 88a of the guide hole 88 includes a cylindrical seal surface 89a and a tapered surface 89b.
  • the tapered surface 89b is adjacent to the seal surface 89a and is closer to the port 90 (to the valve body).
  • the diameter of the tapered surface 89b decreases toward the port 90. Therefore, the space between the tapered surface 89b of the rod 89 and the inner surface 88a of the guide hole 88 is greater in the vicinity of the port 90 than in the vicinity of the pressure sensing chamber 84 (drive member).
  • part of the rod 96 that faces the inner surface 95a of the guide hole 95 includes a cylindrical seal surface 96a and a tapered surface 96b.
  • the tapered surface 96b is adjacent to the seal surface 96 and is closer to the valve chamber 73.
  • the diameter of the tapered surface 96b decreases toward the valve chamber 73. Therefore, the space between the tapered surface 96b of the rod 96 and the inner surface 95a of the guide hole 95 is greater in the vicinity of the valve chamber 73 than in the vicinity of the plunger chamber 91 (drive member).
  • the tapered surfaces 89b, 96b of the rods 89, 96 are machined such that parts adjacent to the port 90 and the valve chamber 73 have smaller diameters even if there are machining errors. That is, this embodiment is characterized in that the outer surfaces of the rods 89,96 are machined such that the spaces between the surfaces of the rods 89, 96 and the inner surfaces 88a, 95a of the guide holes 88, 95 increase toward the high pressure locations.
  • the tapered surfaces 89b, 96b are exaggerated for purposes of illustration. Actually, the diameter difference between each large diameter portion and the corresponding small diameter portion is between a few micro meters to a few tens of micro meters.
  • the computer 57 commands the solenoid portion 72 to be excited if the temperature detected by the compartment temperature sensor 59 exceeds the target temperature set by the temperature adjuster 58. Accordingly, a current is supplied to the coil 97 through the drive circuit 61, which generates an attraction force between the cores 92, 93. The attraction force is transmitted to the valve body 74 against the force of the spring 76 and moves the valve body 74 in the direction reducing the opening size of the valve hole 75.
  • the bellows 87 When the solenoid portion 72 is excited, the bellows 87 is deformed in accordance with variation of the suction pressure, which is applied to the pressure sensing chamber 84 from the suction passage 32 through the pressure introduction passage 50. The deformation of the bellows 87 is transmitted to the valve body 74 by the rod 89. The opening size of the valve hole 75 is therefore determined by the equilibrium of the force of the solenoid portion 72, the force of the bellows 87 and the force of the spring 76.
  • the computer 57 controls the current value to change the target suction pressure based on the detected temperature and the target temperature. Particularly, the computer 57 commands the drive circuit 61 to increase the magnitude of the current as the detected temperature increases. A higher current magnitude increases the attractive force between the fixed core 92 and the movable core 93 thereby increasing the force that causes the valve body 74 to close the valve hole 75. Accordingly, the valve body 74 opens and closes the valve hole 75 at a lower suction pressure. Therefore, a greater current magnitude causes the control valve 49 to maintain a lower suction pressure.
  • a smaller opening size of the valve hole 75 represents less refrigerant gas supplied to the crank chamber 15 from the discharge chamber 39 through the control passage 48.
  • refrigerant gas in the crank chamber 15 flows to the suction chamber 38 through the passage 46, the pressure release hole 47, the accommodation chamber 27 and a communication hole 45, which lowers the pressure in the crank chamber 15.
  • the pressure in the suction chamber 38 is high and the difference between the pressure in the crank chamber 15 and the pressure in the cylinder bores 12a is small. Accordingly, the inclination of the swash plate 23 is increased.
  • the cooling load is small.
  • the computer 57 commands the drive circuit 61 to decrease the magnitude of the current as the detected temperature decreases.
  • a lower current magnitude decreases the attractive force between the fixed core 92 and the movable core 93 thereby decreasing the force that causes the valve body 74 to close the valve hole 75.
  • the valve body 74 opens and closes the valve hole 75 at a higher suction pressure. Therefore, a smaller current magnitude causes the control valve 49 to maintain a higher suction pressure.
  • a greater opening size of the valve hole 75 increases the amount of refrigerant gas from the discharge chamber 39 to the crank chamber 15, which raises the pressure in the crank chamber 15.
  • the pressure in the suction chamber 38 is small and the difference between the pressure in the crank chamber 15 and the pressure in the cylinder bores 12a is great. Accordingly, the inclination of the swash plate 23 is decreased.
  • the temperature of the evaporator 55 drops to a frost forming temperature.
  • the computer 57 commands the drive circuit 61 to de-excite the solenoid portion 72.
  • the predetermined temperature is a temperature at which frost is likely to form in the evaporator 55. Accordingly, current to the coil 97 is stopped and the solenoid portion 72 is de-excited, which eliminates the attraction force between the fixed core 92 and the movable core 93.
  • valve body 74 is then moved downward by the force of the spring 76 against the force of the follower spring 94, which acts on the valve body 74 through the movable core 93. Eventually, the valve body 74 fully opens the valve hole 75. Therefore, a great amount of highly pressurized refrigerant gas is supplied to the crank chamber 15 from the discharge chamber 39 through the control passage 48 and the pressure in the crank chamber 15 is raised. The raised pressure in the crank chamber 15 minimizes the inclination of the swash plate 23 as shown in Fig. 3.
  • the computer 57 commands the solenoid portion 72 to be de-excited. This also minimizes the inclination of the swash plate 23.
  • the valve 49 is controlled in accordance with the magnitude of the current supplied to the coil 97 of the solenoid portion 72.
  • the valve 49 regulates the control passage 48 at a lower suction pressure.
  • the valve 49 regulates the control passage 48 at a higher suction pressure.
  • the inclination of the swash plate 23 is changed to maintain the target suction pressure. Accordingly, the displacement of the compressor is varied.
  • control valve 49 changes the target value of the suction pressure in accordance with the value of the current supplied thereto. Also, the valve 49 can cause the compressor to operate at the minimum displacement for any given suction pressure.
  • a compressor equipped with the control valve 49 varies the cooling ability of the refrigerant circuit.
  • the shutting surface 34 of the shutter 28 abuts against the positioning surface 33, which closes the suction passage 32.
  • the cross-sectional area of the suction passage 32 is zero, and refrigerant gas cannot flow from the external refrigerant circuit 52 to the suction chamber 38.
  • the shutter 28 is at a closed position, at which the shutter 28 disconnects the accommodation chamber 27 from the suction passage 32, the inclination of the swash plate 23 is minimized.
  • the minimum inclination of the swash plate 23 is slightly more than zero degrees. The shutter 28 is moved between the positions for closing and opening the suction passage 32 in accordance with the inclination of the swash plate 23.
  • the discharge of the refrigerant gas in the cylinder bores 12a to the discharge chamber 38 is maintained.
  • the refrigerant gas sent to the discharge chamber 38 flows in the control passage 48 and then enters the crank chamber 15.
  • the gas in the crank chamber 15 flows to the suction chamber 38 through the passage 46, the interior of the shutter, the pressure release hole 47, the accommodation chamber 27 and the communication hole 45.
  • the gas in the suction chamber 38 is introduced in the cylinder bores 12a and is returned to the discharge chamber 39.
  • the circulation passage includes the discharge chamber 39, which is discharge pressure zone, the control passage 48, the crank chamber 15, the passage 46, the interior of the shutter 28, the pressure release hole 47, the accommodation chamber 27, the hole 45, the suction chamber 38, which is suction pressure zone, and the cylinder bores 12a. Since the pressures in the discharge chamber 39, the crank chamber 15 and the suction chamber 38 are different, refrigerant gas circulates within the circulation passage. The circulation of refrigerant gas causes lubricant oil contained in the gas to lubricate the moving parts of the compressor.
  • the tapered surfaces are formed on the rods 89, 96.
  • tapered surfaces may be formed in the guide holes 88, 95.
  • the spaces between the outer surface of the rods 89, 96 and the inner surfaces of the guide holes 88, 95 are wider in the vicinity of the high pressure locations compared to the vicinity of the low pressure locations. In this case, the diameter of the tapered surfaces increase toward the high pressure locations.
  • tapered surfaces may be formed both on rods 89, 96 and the guide holes 88, 95. According to these structures, the spaces between the outer surfaces of the guide rods 89, 96 and the inner surface of the guide holes 88, 95 are wider in the vicinity of the high pressure locations than in the vicinity of the low pressure locations.
  • tapered surfaces on the outer surface of the rods 89, 96 as shown in Fig. 1A. This is because forming tapered surface on the guide holes is troublesome. Specifically, the guide holes 88, 95 are formed in the dividing walls 71a, 92. Then, a tool must be inserted into the narrow guide holes 88, 95 to taper the inner surfaces.
  • Fig. 5A illustrates a second embodiment.
  • the rods 89, 96 have axially arranged tapered surfaces 89b, 96b, respectively.
  • the space between each tapered surface 89b, 96b and the corresponding inner surface 88a, 95a increases in size toward the high pressure locations (73, 90) from the low pressure zone (84, 91).
  • This embodiment has the same advantages as the first embodiment. Further, the cross-sectional areas of the spaces between the tapered surfaces 89b, 96b of the rods 89, 96 and the inner surfaces 88a, 95a of the guide holes 88, 95 are complicated in the axial directions. The spaces therefore function as labyrinth seals. The structure thus prevents refrigerant gas leakage between the high pressure location (73, 90) and the low pressure location (84, 91), which improves the displacement control performance of the control valve 49.
  • tapered surfaces may be formed on the guide holes 88, 95 as shown in Fig. 5B instead of the tapered surfaces on the rods 89, 96.
  • tapered surfaces may be formed both on the rods 89, 96 and the guide holes 88, 95.
  • Fig. 6A illustrates a third embodiment.
  • a displacement control valve 98 of this embodiment is used for a variable displacement compressor (not shown) that is different from the variable displacement compressor of the first and second embodiments.
  • the control valve 98 only functions as a pressure sensing valve and includes a pressure sensing member, which is a diaphragm 99.
  • the valve 98 has a cylindrical rod 100 to operably couple the valve body 74 with the diaphragm 99.
  • Annular grooves 100b are formed on the outer surface 100a of the rod 100 to face the guide hole 88.
  • the annular grooves 100b are axially arranged at equal intervals.
  • the third embodiment has the advantage (1) of the first embodiment.
  • annular grooves 88b may be formed on the inner surface 88a of the guide hole 88 as shown in an enlarged oblong window C' of Fig. 6B.
  • annular grooves may be formed both on the outer surface 100a of the rod 100 and on the inner surface 88a of the guide hole 88.
  • annular grooves on the outer surface 100a of the rod 100. This is because forming annular grooves on the inner surface 88a of the guide hole 88 is troublesome. Specifically, the guide hole 88 is formed in the dividing walls 71a. Then, a tool must be inserted into the narrow guide hole 88 to form annular grooves.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Compressors, Vaccum Pumps And Other Relevant Systems (AREA)
EP99905271A 1999-02-23 1999-02-23 Vanne de reglage a deplacement variable pour compresseur Withdrawn EP1081379A4 (fr)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/JP1999/000786 WO2000050775A1 (fr) 1997-08-27 1999-02-23 Vanne de reglage a deplacement variable pour compresseur

Publications (2)

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EP1081379A1 true EP1081379A1 (fr) 2001-03-07
EP1081379A4 EP1081379A4 (fr) 2004-07-07

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EP (1) EP1081379A4 (fr)
WO (1) WO2000050775A1 (fr)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1467098A2 (fr) * 2003-04-09 2004-10-13 Fujikoki Corporation Valve de commande pour un compresseur à capacité variable
DE10315781B4 (de) * 2002-04-09 2010-06-02 Sanden Corp., Isesaki Verdrängungssteuerventil für einen verstellbaren Kompressor, Kompressor mit einem solchen Ventil und Verfahren zur Herstellung solcher Kompressoren

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JP6663227B2 (ja) * 2016-01-19 2020-03-11 サンデン・オートモーティブコンポーネント株式会社 可変容量圧縮機の容量制御弁

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JPS56120873A (en) 1981-01-29 1981-09-22 Toyooki Kogyo Co Ltd Solenoid vavle
JPH04350372A (ja) 1991-05-27 1992-12-04 Toyota Autom Loom Works Ltd 可変容量型揺動斜板式圧縮機における容量制御弁
JPH06346843A (ja) 1993-06-11 1994-12-20 Toyota Autom Loom Works Ltd クラッチレス片側ピストン式可変容量圧縮機及びその容量制御方法

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JPS56120873A (en) 1981-01-29 1981-09-22 Toyooki Kogyo Co Ltd Solenoid vavle
JPH04350372A (ja) 1991-05-27 1992-12-04 Toyota Autom Loom Works Ltd 可変容量型揺動斜板式圧縮機における容量制御弁
JPH06346843A (ja) 1993-06-11 1994-12-20 Toyota Autom Loom Works Ltd クラッチレス片側ピストン式可変容量圧縮機及びその容量制御方法

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JAPAN SOCIETY OF MECHANICAL ENGINEERS, MARUZEN CO., LTD.: "JSME mechanical engineers' handbook", 15 April 1987, ISBN: 4-88898-057-8, pages: B5-204 - B5-205, XP002997811
See also references of WO0050775A1

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE10315781B4 (de) * 2002-04-09 2010-06-02 Sanden Corp., Isesaki Verdrängungssteuerventil für einen verstellbaren Kompressor, Kompressor mit einem solchen Ventil und Verfahren zur Herstellung solcher Kompressoren
DE10362313B4 (de) * 2002-04-09 2015-03-05 Sanden Corporation VeVerstellbarer Kompressor mit einem verbesserten Verdrängungssteuerventil zur Abfuhr von Fremdstoffen
DE10362313B8 (de) * 2002-04-09 2015-07-02 Sanden Corporation Verstellbarer Kompressor mit einem verbesserten Verdrängungssteuerventil zur Abfuhr von Fremdstoffen
EP1467098A2 (fr) * 2003-04-09 2004-10-13 Fujikoki Corporation Valve de commande pour un compresseur à capacité variable
EP1467098A3 (fr) * 2003-04-09 2004-12-01 Fujikoki Corporation Valve de commande pour un compresseur à capacité variable

Also Published As

Publication number Publication date
EP1081379A4 (fr) 2004-07-07
WO2000050775A1 (fr) 2000-08-31

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