EP0945618B1 - 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
- EP0945618B1 EP0945618B1 EP19990105500 EP99105500A EP0945618B1 EP 0945618 B1 EP0945618 B1 EP 0945618B1 EP 19990105500 EP19990105500 EP 19990105500 EP 99105500 A EP99105500 A EP 99105500A EP 0945618 B1 EP0945618 B1 EP 0945618B1
- Authority
- EP
- European Patent Office
- Prior art keywords
- pressure
- chamber
- valve
- control valve
- displacement
- 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
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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
- 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
- F04B2027/1831—Valve-controlled fluid connection between crankcase and suction 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
- F04B2027/184—Valve controlling parameter
- F04B2027/185—Discharge pressure
Definitions
- the present invention relates to a variable displacement compressor which is suitable for being used in an air conditioner of a vehicle, particularly of an automotive vehicle.
- variable displacement compressor is, for example, disclosed in USP No. 4,960,367 under a title of "swash plate type compressor with a variable displacement mechanism".
- the compressor includes pistons, a swash plate mounted on a main shaft and a mechanism for converting a rotation of the swash plate into reciprocation of the pistons. A fluid is compressed in accordance with reciprocation of the pistons.
- the swash plate is structured such that an angle of incline with respect to the main shaft can be varied.
- a stroke of the piston is changed in accordance with a variation of the angle of incline.
- a compression displacement of the compressor is changed.
- the angle of incline of the swash plate is controlled by a displacement control valve for controlling a communication between a crank chamber and a suction chamber in the compressor.
- a displacement control valve for use in a variable displacement compressor according to the preamble of claim 1 can be derived.
- the pressure transmission control means of the displacement control valve is arranged in the cylinder block of the variable displacement compressor. Therefore, according to this disclosure, not only the pressure of the discharge chamber is applied to the pressure transmission control means, but also the pressure of the suction chamber can be applied to the pressure transmission control means, thus resulting in a complicated structure.
- variable displacement compressor according to claim 8.
- the displacement control valve shown in Fig. 1 corresponds to a structure described in USP No. 4,960,367 mentioned above, which includes a cup-shaped valve casing 2 having an end opened, and a pedestal 3 mounted in an opening of the casing 2. Two through holes 4 are formed in the other end of the casing 2 to communicate with a crank chamber of a compressor through a first passage known in the art.
- the pedestal 3 has communication holes 3a and 3b.
- the communication hole 3a is connected to a suction chamber through a second passage known in the art.
- a combination of the first and the second passages is referred to as a communication passage.
- the pedestal 3 integrally has a valve cylinder 12 facing to a discharge chamber 251 of the compressor.
- the valve cylinder 12 is integrally fixed to a valve plate 125 by bolts 17 and 18 in addition to a suction valve 14, a discharge valve 15 and a retainer 16.
- a transmission rod 21 is slidably inserted to the valve cylinder 12.
- a gap between the valve cylinder 12 and the transmission rod 21 is sealed by a seal member 22 such as a rubber.
- the transmission rod 21 is urged upward in the drawing by a spring 23.
- a lower end of the spring 23 is brought into contact with the valve body 7.
- a stopper 24 is fixed to the transmission rod 21.
- variable displacement compressor provided with a displacement control valve in accordance with a first embodiment of the present invention.
- the compressor is designated by a reference numeral 100 and is of a swash plate type compressor, specifically a wobble plate type refrigerant compressor.
- the compressor 100 includes a cylindrical housing assembly 120 including a cylinder block 121, a front end plate 123 at one end of the cylinder block 121, a crank chamber 122 formed between the cylinder block 121 and the front end plate 123, and a rear end plate 124 attached to the other end of the cylinder block 121.
- the front end plate 123 is mounted on the cylinder block 121 forward (to the left in Fig. 2) of the crank chamber 122 by a plurality of bolts.
- the rear end plate 124 is mounted on the cylinder block 121 at its opposite end by a plurality of bolts 102.
- a valve plate 125 is located between the rear end plate 124 and the cylinder block 121.
- An opening 231 is centrally formed in the front end plate 123 for supporting a drive shaft 126 by a bearing 130 disposed in the opening.
- the inner end portion of the drive shaft 126 is rotatably supported by a bearing 131 disposed within a central bore 210 of the cylinder block 121.
- the bore 210 extends to a rearward end surface of the cylinder block 121 to dispose a displacement control valve 119 which will later be described in detail.
- a cam rotor 140 is fixed on the drive shaft 126 by a pin member 261 and rotates with the shaft 126.
- a thrust needle bearing 132 is disposed between the inner end surface of the front end plate 123 and the adjacent axial end surface of the cam rotor 140.
- the cam rotor 140 includes an arm 141 having a pin member 142 extending therefrom.
- a swash plate 150 is adjacent to the cam rotor 140 and includes an opening 153 through which passes the drive shaft 126.
- the swash plate 150 includes an arm 151 having a slot 152.
- the cam rotor 140 and the swash plate 150 are connected by the pin member 142, which is inserted in the slot 152 to create a hinged joint.
- the pin member 142 is slidable within the slot 152 to allow adjustment of the angular position of the swash plate 150 with respect to the longitudinal axis of the drive shaft 126.
- the rear end plate 124 includes a peripherally located annular suction chamber 241 and a centrally located discharge chamber 251.
- the valve plate 125 is located between the cylinder block 121 and the rear end plate 124 and includes a plurality of valved suction ports 242 linking the suction chamber 241 with the respective cylinders 170.
- the valve plate 125 also includes a plurality of valved discharge ports 252 linking the discharge chamber 251 with the respective cylinders 170.
- the suction ports 242 and the discharge ports 252 are provided with suitable reed valves as described in U.S. Pat. No. 4,011,029 to Shimizu.
- the suction chamber 241 includes an inlet portion 241a which is connected to an evaporator of the external cooling circuit (not shown).
- the discharge chamber 251 is provided with an outlet portion 251a connected to a condenser of the cooling circuit (not shown).
- Gaskets 127 and 128 are located between the cylinder block 121 and the inner surface of the valve plate 125, and the outer surface of the valve plate 125 and the rear end plate 124 respectively, to seal the mating surfaces of the cylinder block 121, the valve plate 125 and the rear end plate 124.
- a displacement control valve 119 is coaxially arranged with the central drive shaft 126 of the cylinder block 121, and a valve cylinder 12 is integrally fixed to the valve plate 125 by bolts 17 and 18 in addition to a suction valve 14, a discharge valve 15 and a retainer 16.
- the displacement control valve 119 will be described below.
- the same reference numerals are assigned to the same or like elements as those of the displacement control valve shown in Fig. 1, and an explanation thereof will be omitted.
- the displacement control valve further includes a rod cover 25 which is fixed as a chamber defining arrangement to the valve cylinder 12 and covers the upper end of the transmission rod 21.
- An orifice 27 is formed in a orifice defining arrangement or a cover body 26 of the rod cover 25.
- the orifice 27 is structured such that an upper end of the transmission rod 21 can receive a pressure of the discharge chamber 251.
- the rod cover 25 forms a kind of a pressure chamber 28. Accordingly, a pressure change in the discharge chamber 251 is damped through the orifice 27 so as to act on the transmission rod 21. Therefore, the transmission rod 21 does not directly receive a sudden pressure change.
- a seal member 22 is compressed between the valve cylinder 12 and the rod cover 25.
- a combination of the rod cover 25, the cover body 26, the orifice 27, and the pressure chamber 28 is referred to as a pressure transmission control arrangement.
- the operating point is changed due to the pressure of the discharge chamber applied to the transmission rod 21. That is, when the pressure of the discharge chamber increases, the operating point is lowered, and on the contrary, when the pressure of the discharge chamber is reduced, the operating point is increased. In this case, when the pressure of the discharge chamber is lowered in comparison with a predetermined value, the stopper 24 is brought into contact with the valve cylinder 12, so that the operating point becomes constant without being affected by the pressure of the discharge chamber.
- the structure is made such as not to respond to the instantaneous pressure change within the discharge chamber in a moment, no excessive load is applied to the bellows, so that a durability and a reliability of the displacement control valve are improved. Further, since the structure is made in a very simple manner, a protecting function can be achieved without involving a characteristic change due to a repeating of the bellows or the like even when the discharge pressure becomes an abnormally high pressure by the liquid compression state.
- a rod cover 25 is integrally formed with a valve cylinder 12.
- a stop member 29 is adhered within the rod cover 25.
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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)
Description
- The present invention relates to a variable displacement compressor which is suitable for being used in an air conditioner of a vehicle, particularly of an automotive vehicle.
- Such a variable displacement compressor is, for example, disclosed in USP No. 4,960,367 under a title of "swash plate type compressor with a variable displacement mechanism". The compressor includes pistons, a swash plate mounted on a main shaft and a mechanism for converting a rotation of the swash plate into reciprocation of the pistons. A fluid is compressed in accordance with reciprocation of the pistons.
- The swash plate is structured such that an angle of incline with respect to the main shaft can be varied. A stroke of the piston is changed in accordance with a variation of the angle of incline. Of course, when the stroke of the piston is changed, a compression displacement of the compressor is changed. The angle of incline of the swash plate is controlled by a displacement control valve for controlling a communication between a crank chamber and a suction chamber in the compressor.
- The displacement control valve is structured such as to be opened and closed by an expansion and contraction of the bellows, and to be opened larger as a pressure of the discharge chamber in the compressor is higher. As a result, the higher the pressure of the discharge chamber in the compressor is, the more the pressure of the crank chamber in the compressor is reduced. In accordance of a reduction of the pressure of the crank chamber, the angle of incline of the swash plate in the compressor is increased, so as to direct the compression displacement to an increasing direction.
- Now, when the compressor is started in the state that a liquid refrigerant is stored in the suction side of the compressor, a liquid compression state is achieved. At this time, there is a case that the pressure of the discharge chamber becomes an abnormally high pressure (for example, 100 kg/cm2G) in a moment.
- In the conventional displacement control valve, a protecting mechanism for treating the abnormally high pressure is not provided. Accordingly, when the liquid compression state mentioned above is repeated, an expansion and contraction characteristic of the bellows is changed and an operating point for the displacement control valve is changed, so that a normal operation is prevented. In the case that the variable displacement compressor is used in the air conditioner, there is a risk that a freezing is generated in an evaporator of the air conditioner.
- In addition, from EP 0 366 348 A1 a displacement control valve for use in a variable displacement compressor according to the preamble of claim 1 can be derived. In the variable displacement compressor the pressure transmission control means of the displacement control valve is arranged in the cylinder block of the variable displacement compressor. Therefore, according to this disclosure, not only the pressure of the discharge chamber is applied to the pressure transmission control means, but also the pressure of the suction chamber can be applied to the pressure transmission control means, thus resulting in a complicated structure.
- It is therefore an object of the present invention to provide a displacement control valve which can treat an abnormally high pressure in a discharge chamber of a variable displacement compressor, wherein the arrangement can be kept simple.
- Such an object is solved by a displacement control valve for use in a variable displacement compressor according to the independent claim 1.
- Preferred developments of the invention are given in the dependent claims.
- The object is also solved by a variable displacement compressor according to
claim 8. -
- Fig. 1 is a vertical cross sectional view of a conventional displacement control valve;
- Fig. 2 is a vertical cross sectional view of a variable displacement compressor provided with a displacement control valve in accordance with a first embodiment of the present invention;
- Fig. 3 is a vertical cross sectional view of the displacement control valve;
- Fig. 4 is a graph which shows a control characteristic of a pressure of a suction chamber in a variable displacement compressor in Fig. 2; and
- Fig. 5 is a vertical cross sectional view of a displacement control valve in accordance with a second embodiment of the present invention.
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- With reference to Fig. 1, description will be made as regards a conventional displacement control valve for a better understanding of the present invention.
- The displacement control valve shown in Fig. 1 corresponds to a structure described in USP No. 4,960,367 mentioned above, which includes a cup-
shaped valve casing 2 having an end opened, and apedestal 3 mounted in an opening of thecasing 2. Two throughholes 4 are formed in the other end of thecasing 2 to communicate with a crank chamber of a compressor through a first passage known in the art. Thepedestal 3 hascommunication holes communication hole 3a is connected to a suction chamber through a second passage known in the art. A combination of the first and the second passages is referred to as a communication passage. - The
casing 2 forms avalve chest 5 in cooperation with thepedestal 3. Abellows 6 is arranged in thevalve chest 5. An inner portion of thebellows 6 is substantially vacuum. Thebellows 6 has a size variable in a predetermined direction in the manner known in the art. Avalve body 7 is provided in an end of thebellows 6. The other end of thebellows 6 is connected to thecasing 2 by an adjustingscrew 8. Thebellows 6 is referred to as a pressure sensing member. - The
pedestal 3 integrally has avalve cylinder 12 facing to adischarge chamber 251 of the compressor. Thevalve cylinder 12 is integrally fixed to avalve plate 125 bybolts suction valve 14, adischarge valve 15 and aretainer 16. Atransmission rod 21 is slidably inserted to thevalve cylinder 12. A gap between thevalve cylinder 12 and thetransmission rod 21 is sealed by aseal member 22 such as a rubber. Thetransmission rod 21 is urged upward in the drawing by aspring 23. A lower end of thespring 23 is brought into contact with thevalve body 7. Astopper 24 is fixed to thetransmission rod 21. - A gas of the crank chamber in the compressor enters into the
valve chest 5 from thecommunication passage 4, passes through thecommunication holes valve body 7 and reaches the suction chamber in the compressor. Thetransmission rod 21 is pushed against thespring 23 due to the discharge pressure of thedischarge chamber 251. The force for pushing thetransmission rod 21 is applied to thevalve body 7. - Now, when the compressor is started in the state that a liquid refrigerant is stored in the suction side of the compressor, a liquid compression state is achieved. At this time, there is a case that the pressure of the discharge chamber becomes an abnormally high pressure (for example, 100 kg/cm2G) in a moment. At this time, in the displacement control valve, the
transmission rod 21 overcomes the urging force of thespring 23 and moves in a moment. Accordingly, a front end of thetransmission rod 21 strikes thevalve body 7 so as to apply an excessive load to thebellows 6. - In the displacement control valve shown in Fig. 1, a protecting mechanism for treating the abnormally high pressure is not provided. Accordingly, when the liquid compression state mentioned above is repeated, an expansion and contraction characteristic of the
bellows 6 is changed and an operating point for the displacement control valve is changed, so that a normal operation is prevented. - With reference to Fig. 2, the description will be made as regards a variable displacement compressor provided with a displacement control valve in accordance with a first embodiment of the present invention.
- The compressor is designated by a
reference numeral 100 and is of a swash plate type compressor, specifically a wobble plate type refrigerant compressor. Thecompressor 100 includes acylindrical housing assembly 120 including acylinder block 121, afront end plate 123 at one end of thecylinder block 121, a crank chamber 122 formed between thecylinder block 121 and thefront end plate 123, and arear end plate 124 attached to the other end of thecylinder block 121. Thefront end plate 123 is mounted on thecylinder block 121 forward (to the left in Fig. 2) of the crank chamber 122 by a plurality of bolts. Therear end plate 124 is mounted on thecylinder block 121 at its opposite end by a plurality ofbolts 102. Avalve plate 125 is located between therear end plate 124 and thecylinder block 121. Anopening 231 is centrally formed in thefront end plate 123 for supporting adrive shaft 126 by abearing 130 disposed in the opening. The inner end portion of thedrive shaft 126 is rotatably supported by abearing 131 disposed within acentral bore 210 of thecylinder block 121. Thebore 210 extends to a rearward end surface of thecylinder block 121 to dispose adisplacement control valve 119 which will later be described in detail. - A
cam rotor 140 is fixed on thedrive shaft 126 by apin member 261 and rotates with theshaft 126. Athrust needle bearing 132 is disposed between the inner end surface of thefront end plate 123 and the adjacent axial end surface of thecam rotor 140. Thecam rotor 140 includes anarm 141 having apin member 142 extending therefrom. Aswash plate 150 is adjacent to thecam rotor 140 and includes anopening 153 through which passes thedrive shaft 126. Theswash plate 150 includes anarm 151 having aslot 152. Thecam rotor 140 and theswash plate 150 are connected by thepin member 142, which is inserted in theslot 152 to create a hinged joint. Thepin member 142 is slidable within theslot 152 to allow adjustment of the angular position of theswash plate 150 with respect to the longitudinal axis of thedrive shaft 126. - A
wobble plate 160 is rotatably mounted on theswash plate 150 throughbearings slider 163 is attached to the outer peripheral end of thewobble plate 160 and is slidably mounted on a slidingrail 164 held between thefront end plate 123 and thecylinder block 121. The fork shapedslider 163 prevents rotation of thewobble plate 160 and thewobble plate 160 nutates along therail 164 when thecam rotor 140 rotates. Thecylinder block 121 includes a plurality of peripherally locatedcylinder chambers 170 in whichpistons 171 reciprocate. Eachpiston 171 is connected to thewobble plate 160 by a corresponding connectingrod 172. - The
rear end plate 124 includes a peripherally locatedannular suction chamber 241 and a centrally locateddischarge chamber 251. Thevalve plate 125 is located between thecylinder block 121 and therear end plate 124 and includes a plurality ofvalved suction ports 242 linking thesuction chamber 241 with therespective cylinders 170. Thevalve plate 125 also includes a plurality ofvalved discharge ports 252 linking thedischarge chamber 251 with therespective cylinders 170. Thesuction ports 242 and thedischarge ports 252 are provided with suitable reed valves as described in U.S. Pat. No. 4,011,029 to Shimizu. - The
suction chamber 241 includes an inlet portion 241a which is connected to an evaporator of the external cooling circuit (not shown). Thedischarge chamber 251 is provided with an outlet portion 251a connected to a condenser of the cooling circuit (not shown).Gaskets cylinder block 121 and the inner surface of thevalve plate 125, and the outer surface of thevalve plate 125 and therear end plate 124 respectively, to seal the mating surfaces of thecylinder block 121, thevalve plate 125 and therear end plate 124. - A
displacement control valve 119 is coaxially arranged with thecentral drive shaft 126 of thecylinder block 121, and avalve cylinder 12 is integrally fixed to thevalve plate 125 bybolts suction valve 14, adischarge valve 15 and aretainer 16. - Further, also with reference to Fig. 3, the
displacement control valve 119 will be described below. The same reference numerals are assigned to the same or like elements as those of the displacement control valve shown in Fig. 1, and an explanation thereof will be omitted. - In the displacement control valve in Fig. 3, the
bellows 6 is structured such that an inner portion is vacuumed and an expansion and contraction amount is adjusted by the adjustingscrew 8 adhered to a lower end portion. Thetransmission rod 21 has a first or upper end and a second or lower end opposite to the first end in the predetermined direction. Thestopper 24 is fixed to the lower end of thetransmission rod 21. Thespring 23 is interposed between thestopper 24 and thevalve body 7. A combination of thetransmission rod 21, thespring 23, and thestopper 24 is referred to as an operating point control arrangement. - The displacement control valve further includes a
rod cover 25 which is fixed as a chamber defining arrangement to thevalve cylinder 12 and covers the upper end of thetransmission rod 21. Anorifice 27 is formed in a orifice defining arrangement or acover body 26 of therod cover 25. In accordance with theorifice 27, it is structured such that an upper end of thetransmission rod 21 can receive a pressure of thedischarge chamber 251. In this manner, therod cover 25 forms a kind of apressure chamber 28. Accordingly, a pressure change in thedischarge chamber 251 is damped through theorifice 27 so as to act on thetransmission rod 21. Therefore, thetransmission rod 21 does not directly receive a sudden pressure change. In this case, aseal member 22 is compressed between thevalve cylinder 12 and therod cover 25. A combination of therod cover 25, thecover body 26, theorifice 27, and thepressure chamber 28 is referred to as a pressure transmission control arrangement. - Next, with respect to Fig. 4 in addition, the description will be directed to control characteristic of the pressure of the suction chamber in the variable displacement compressor in Fig. 2.
- In the control characteristic of the pressure of the suction chamber, the operating point is changed due to the pressure of the discharge chamber applied to the
transmission rod 21. That is, when the pressure of the discharge chamber increases, the operating point is lowered, and on the contrary, when the pressure of the discharge chamber is reduced, the operating point is increased. In this case, when the pressure of the discharge chamber is lowered in comparison with a predetermined value, thestopper 24 is brought into contact with thevalve cylinder 12, so that the operating point becomes constant without being affected by the pressure of the discharge chamber. - When starting the variable displacement compressor in the state that a liquid refrigerant exists in the suction side of the compressor, a liquid compression state is achieved, and the
discharge chamber 251 becomes an abnormally high pressure in a moment. However, since thepressure chamber 28 within therod cover 25 is communicated with thedischarge chamber 251 via theorifice 27, a pressure thereof is reduced by theorifice 27, so that no excessive pressure is applied to thetransmission rod 21 in a moment. That is, due to the pressure reduction effect in theorifice 27, thetransmission 21 hardly responds to the instantaneous change of the pressure of the discharge chamber, but operates so as to respond to a gentle change of the pressure of the discharge chamber. - As mentioned above, since the structure is made such as not to respond to the instantaneous pressure change within the discharge chamber in a moment, no excessive load is applied to the bellows, so that a durability and a reliability of the displacement control valve are improved. Further, since the structure is made in a very simple manner, a protecting function can be achieved without involving a characteristic change due to a repeating of the bellows or the like even when the discharge pressure becomes an abnormally high pressure by the liquid compression state.
- A volume of the
pressure chamber 28 and a diameter of theorifice 27 can be properly obtained with respect to the discharge pressure as a result of an experiment, so that those skilled in the art can select an effective one. For example, it is possible to prepare some rod covers having different volumes of thepressure chamber 28 and different diameters of the orifice for therod cover 25 and replace as occasion demands. - With reference to Fig. 5 in addition, the description will be made as regards a displacement control valve in accordance with a second embodiment of the present invention. The same reference numerals are assigned to the same or like elements as those of the displacement control valve in Fig. 3, and an explanation thereof will be omitted.
- In the displacement control valve in Fig. 5, a
rod cover 25 is integrally formed with avalve cylinder 12. In order to compress aseal member 22, astop member 29 is adhered within therod cover 25. - In this case, it is a matter of course that the present invention can be used for the other compressor which generates a sudden liquid compression state and a pressure change.
Claims (8)
- A displacement control valve (119) for use in a variable displacement compressor (100) comprising:a discharge chamber (251) with discharge pressure;a suction chamber (241) with suction pressure,a crank chamber (122) with crank pressure;a communication passage between said crank chamber (122) and said suction chamber (241),said variable displacement compressor (100) having a displacement variable with opening and closing of said communication passage,said displacement control valve (119) comprising a pressure sensing member (6) for sensing, as sensed pressure, one of said suction pressure and said crank pressure to have a size variable in a predetermined direction in response to said sensed pressure;a valve body (7) connected to said pressure sensing member (6) for operating in response to said size of the pressure sensing member (6) to open and close said communication passage,said valve body (7) having an operation point between opening and closing of said communication passage;operating point control means (21, 23, 24) coupled to one of said valve body (7) and said pressure sensing member (6) for transmitting said discharge pressure to said valve body (7) in said predetermined direction to control said operating point of the valve body (7);pressure transmission control means (25, 26, 27, 28) interposed between said discharge chamber (251) and said operating point control means (21, 23, 24) for controlling transmission of said discharge pressure to said operating point control means (21, 23, 24);
- A displacement control valve as claimed in claim 1, wherein said pressure transmission control means (25, 26, 27, 28) comprises chamber defining means (25) for defining a pressure chamber (28) adjacent to said operating point control means (21, 23, 24) and orifice defining means (26) for defining an orifice (27) between said discharge chamber (251) and said pressure chamber (28).
- A displacement control valve as claimed in claim 2, wherein said operating point control means (21, 23, 24) comprises a transmission rod (21) extending in said predetermined direction and having a first end placed in said pressure chamber (28).
- A displacement control valve as claimed in claim 3, wherein said transmission rod (21) is movable in said predetermined direction and has a second end opposite to said first end, said operating point control means (21, 23, 24) further comprises a spring (23) interposed between said valve body (7) and said second end of the transmission rod (21), said valve body (7) being interposed between said pressure sensing member (6) and said spring (23).
- A displacement control valve as claimed in one of claims 2 to 4, further comprising a valve cylinder (12) fixed to said variable displacement compressor (100), said chamber defining means (25) being coupled to said valve cylinder (12).
- A displacement control valve as claimed in claim 5, wherein said chamber defining means (25) is formed separately from said valve cylinder (12) and fixedly connected to said valve cylinder (12).
- A displacement control valve as claimed in claim 5, wherein said chamber defining means (25) is formed integral with said valve cylinder (12).
- A variable displacement compressor comprising a discharge chamber (251) with discharge pressure, a suction chamber (241) with suction pressure, a crank chamber (122) with crank pressure, a communication passage between said crank chamber (122) and said suction chamber (241), and a displacement control valve (119) claimed in anyone of claims 1 through 7.
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP9675098 | 1998-03-25 | ||
JP10096750A JPH11280658A (en) | 1998-03-25 | 1998-03-25 | Capacity control valve of variable capacity compressor |
Publications (3)
Publication Number | Publication Date |
---|---|
EP0945618A2 EP0945618A2 (en) | 1999-09-29 |
EP0945618A3 EP0945618A3 (en) | 2000-03-01 |
EP0945618B1 true EP0945618B1 (en) | 2002-06-19 |
Family
ID=14173359
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP19990105500 Expired - Lifetime EP0945618B1 (en) | 1998-03-25 | 1999-03-17 | Displacement control valve for use in a variable displacement compressor |
Country Status (3)
Country | Link |
---|---|
EP (1) | EP0945618B1 (en) |
JP (1) | JPH11280658A (en) |
DE (1) | DE69901855T2 (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP4234997A3 (en) * | 2019-04-03 | 2023-10-11 | Eagle Industry Co., Ltd. | Capacity control valve |
Families Citing this family (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP4000767B2 (en) | 2000-11-08 | 2007-10-31 | 株式会社豊田自動織機 | Control device for variable capacity compressor |
KR101319566B1 (en) * | 2010-04-29 | 2013-10-23 | 이구루코교 가부시기가이샤 | Capacity control valve |
Family Cites Families (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4011029A (en) | 1974-05-17 | 1977-03-08 | Sankyo Electric Company Limited | Fluid suction and discharge apparatus |
JPH01142276A (en) | 1987-11-27 | 1989-06-05 | Sanden Corp | Variable displacement swash-plate type compressor |
JPH02115577A (en) * | 1988-10-24 | 1990-04-27 | Sanden Corp | Variable capacity type swingable compressor |
JPH04342883A (en) * | 1991-05-17 | 1992-11-30 | Sanden Corp | Variable delivery swash plate type compressor |
-
1998
- 1998-03-25 JP JP10096750A patent/JPH11280658A/en active Pending
-
1999
- 1999-03-17 DE DE1999601855 patent/DE69901855T2/en not_active Expired - Fee Related
- 1999-03-17 EP EP19990105500 patent/EP0945618B1/en not_active Expired - Lifetime
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP4234997A3 (en) * | 2019-04-03 | 2023-10-11 | Eagle Industry Co., Ltd. | Capacity control valve |
Also Published As
Publication number | Publication date |
---|---|
DE69901855T2 (en) | 2002-11-28 |
JPH11280658A (en) | 1999-10-15 |
DE69901855D1 (en) | 2002-07-25 |
EP0945618A2 (en) | 1999-09-29 |
EP0945618A3 (en) | 2000-03-01 |
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