Patent Application
20190085834
The present invention relates to a variable displacement compressor, and specifically, relates to a variable displacement compressor in which a discharge displacement is controlled by pressure regulation in a crank chamber.
Patent Documents 1 and 2 each disclose a variable displacement compressor including: a supply passage for supplying a refrigerant in a discharge pressure area to a crank chamber; a bleed passage for discharging the refrigerant in the crank chamber to a suction pressure area; a first control valve that adjusts a passage cross-sectional area of the supply passage; a second control valve that closes the bleed passage when a downstream pressure of the first control valve becomes high; a check valve that is disposed in the supply passage between the first control valve and the crank chamber and blocks a flow of the refrigerant directed toward the first control valve from the crank chamber.
Patent Document 1: Japanese Patent Application Laid-open Publication No. 2010-106677
Patent Document 2: Japanese Patent Application Laid-open Publication No. 2011-185138
Incidentally, in such a variable displacement compressor individually including: a first valve device that controls supply of a working fluid to the crank chamber; a second valve device that controls discharge of the working fluid from the crank chamber; and a third valve device that blocks a reverse flow of the working fluid directed toward the first valve device from the crank chamber, a structure of the variable displacement compressor becomes complicated, and moreover, it is difficult to lay out the second valve device and the third valve device in the compressor without increasing a size of the compressor.
In this connection, it is an object of the present invention to provide a variable displacement compressor in which a structure is simple and it is easy to lay out valves.
In order to achieve the foregoing object, a variable displacement compressor according to the present invention is a variable displacement compressor in which a discharge displacement is controlled by pressure regulation in the crank chamber, including: a first control valve that controls an opening degree of a pressure supply passage that causes a discharge chamber and the crank chamber to communicate with each other; and a second control valve including a spool having a first valve portion that opens and closes the pressure supply passage between the first control valve and the crank chamber and a second valve portion that opens and closes a pressure release passage that causes the crank chamber and a suction chamber to communicate with each other,
wherein the spool moves in response to a difference between a pressure of the pressure supply passage between the first control valve and the second control valve and a pressure of the crank chamber,
when the pressure of the pressure supply passage between the first control valve and the second control valve is higher than the pressure of the crank chamber, the first valve portion opens the pressure supply passage to supply a fluid from the discharge chamber to the crank chamber, and the second valve portion sets an opening degree of the pressure release passage to a minimum opening degree, and
when the pressure of the pressure supply passage between the first control valve and the second control valve is lower than the pressure of the crank chamber, the first valve portion closes the pressure supply passage to block a reverse flow of the fluid directed from the crank chamber toward the first control valve, and the second valve portion sets the opening degree of the pressure release passage to a maximum opening degree.
According to the variable displacement compressor of the present invention, the second control valve has such a function to control the discharge of the fluid from the crank chamber and such a function to block the reverse flow of the fluid from the crank chamber to the discharge chamber side, and the structure of the compressor becomes more simple and it becomes easier to lay out the valve devices in the compressor than in the case where the valve devices which exert the respective functions are individually provided.
Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.
A variable displacement compressor 100 illustrated in
A crank chamber 140 is formed of the cylinder block 101 and the front housing 102, and a drive shaft 110 is provided across an inside of the crank chamber 140.
A swash plate 111 is disposed around an axially intermediate portion of the drive shaft 110.
The swash plate 111 is coupled to a rotor 112, which is fixed to the drive shaft 110, via a link mechanism 120, and is configured so that an inclination angle of the swash plate 111 along the drive shaft 110 can be changeable.
The link mechanism 120 includes: a first arm 112a protruded from the rotor 112; a second arm 111a protruded from the swash plate 111; and a link arm 121, in which one end is rotatably coupled to the first arm 112a via a first coupling pin 122, and other end is rotatably coupled to the second arm 111a via a second coupling pin 123.
A through hole 111b of the swash plate 111 is formed into such a shape that the swash plate 111 is capable of tilting within a range between a maximum inclination angle and a minimum inclination angle, and in the through hole 111b, a minimum inclination angle restricting portion (not illustrated) that abuts against the drive shaft 110 is formed.
When an inclination angle of the swash plate 111 when the swash plate 111 is perpendicular to the drive shaft 110 is 0 degrees, the minimum inclination angle restricting portion of the through hole 111b is formed such that the swash plate 111 can be inclined and displaced up to approximately 0 degrees. Moreover, the maximum inclination angle of the swash plate 111 is regulated in such a manner that the swash plate 111 abuts against the rotor 112.
An inclination angle decreasing spring 114 that urges the swash plate 111 toward the minimum inclination angle is mounted between the rotor 112 and the swash plate 111, and an inclination angle increasing spring 115 that urges the swash plate 111 toward a direction of increasing the inclination angle thereof is mounted between the swash plate 111 and a spring support member 116 provided on the drive shaft 110.
Here, urging force of the inclination angle increasing spring 115 at the minimum inclination angle is set larger than urging force of the inclination angle decreasing spring 114, and when the drive shaft 110 does not rotate, the swash plate 111 is positioned at an inclination angle at which the urging force of the inclination angle decreasing spring 114 and the urging force of the inclination angle increasing spring 115 are balanced with each other.
One end of the drive shaft 110 penetrates an inside of a boss portion 102a protruding to an outside of the front housing 102, extends to the outside of the front housing 102, and is coupled to a power transmission device (not illustrated).
A shaft sealing device 130 is inserted between the drive shaft 110 and the boss portion 102a, and shields the crank chamber 140 and an external space from each other.
A coupled body of the drive shaft 110 and the rotor 112 is supported by bearings 131 and 132 in a radial direction, and is supported by a bearing 133 and a thrust plate 134 in a thrust direction.
Then, power from an external drive source is transmitted to a power transmission device, and the drive shaft 110 is rotatable in synchronization with rotation of the power transmission device.
Note that a clearance between the thrust plate 134 and a portion of the drive shaft 110 against which the thrust plate 134 abuts is adjusted to a predetermined clearance by an adjustment screw 135.
A piston 136 is disposed in the cylinder bore 101a, an outer peripheral portion of the swash plate 111 is housed in an inner space of an end portion of the piston 136, which protrudes toward the crank chamber 140, and the swash plate 111 is configured to be linked with the piston 136 via a pair of shoes 137. Then, the piston 136 reciprocates in the cylinder bore 101a by rotation of the swash plate 111.
In the cylinder head 104, a suction chamber 141 is formed in a center portion thereof, and in addition, a discharge chamber 142 that annularly surrounds a radially outer side of the suction chamber 141 is defined and formed.
The suction chamber 141 and the cylinder bore 101a communicate with each other via a communication hole 103a provided in the valve plate 103 and via a suction valve (not illustrated) formed in a suction valve forming plate 150. The discharge chamber 142 and the cylinder bore 101a communicate with each other via a discharge valve (not illustrated) formed in a discharge valve forming plate 151 and via a communication hole 103b provided in the valve plate 103.
The above-described front housing 102, a center gasket (not illustrated), the cylinder block 101, a cylinder gasket 152, the suction valve forming plate 150, the valve plate 103, the discharge valve forming plate 151, a head gasket 153 and the cylinder head 104 are sequentially connected to one another, and are fastened by a plurality of through bolts 105, whereby a compressor housing is formed.
Moreover, a muffler is provided in an upper portion of the cylinder block 101 in
A discharge check valve 200 is disposed in a muffler space 143 surrounded by the lid member 106 and the formed wall 101b.
The discharge check valve 200 is disposed at a connecting portion between the muffler space 143 and the communication passage 144 that causes the discharge chamber 142 and the muffler space 143 to communicate with each other. The discharge check valve 200 operates in response to a pressure difference between the communication passage 144 (an upstream side) and the muffler space 143 (a downstream side), shuts off the communication passage 144 when the pressure difference is smaller than a predetermined value, and opens the communication passage 144 when the pressure difference is larger than the predetermined value.
Hence, the discharge chamber 142 is connected to a discharge-side refrigerant circuit of the air conditioning system via a discharge passage formed of the communication passage 144, the discharge check valve 200, the muffler space 143 and the discharge port 106a.
In the cylinder head 104, a suction passage composed of a suction port (not illustrated) and a communication passage 104a is linearly extended so as to cross a part of the discharge chamber 142 from a radially outside of the cylinder head 104. The suction chamber 141 is connected to a suction-side refrigerant circuit of the air conditioning system via this suction passage.
A pressure supply passage 145 that causes the discharge chamber 142 and the crank chamber 140 to communicate with each other is formed in the cylinder head 104, and a first control valve 300 that controls an opening area (an opening degree) of the pressure supply passage 145 is provided.
The first control valve 300 is housed in a housing hole 104b formed along such a radial direction of the cylinder head 104. The first control valve 300 adjusts the opening degree of the pressure supply passage 145 in response to a pressure of the suction chamber 141, which is introduced via a communication passage 104c, and in response to electromagnetic force generated by a current flowing through a solenoid according to an external signal, thereby controlling a discharge gas introduction amount (a pressure supply amount) to the crank chamber 140.
In the pressure supply passage 145 located downstream of the first control valve 300, a second control valve 350 is disposed.
As illustrated in
The spool 352 moves in response to a difference between a pressure of the pressure supply passage 145 between the first control valve 300 and the second control valve 350 and a pressure of the crank chamber 140. In this way, the second control valve 350 has a function as a check valve that blocks a reverse flow of the refrigerant (a fluid), which is directed from the crank chamber 140 toward the first control valve 300, and a function to control discharge of the refrigerant from the crank chamber 140 to the suction chamber 141.
Moreover, as the pressure release passage 146 that discharges the refrigerant in the crank chamber 140 to the suction chamber 141, a pressure release passage 146b (a first pressure release passage), which passes via the second control valve 350 and is opened and closed by the second control valve 350, is provided. In addition, as the pressure release passage 146, a pressure release passage 146a (a second pressure release passage), which passes via a communication passage 101c, a space 101d and a fixed throttle 103c formed in the valve plate 103 and bypasses the second control valve 350, is provided.
Note that a flow passage cross-sectional area of the first pressure release passage 146b when the first pressure release passage 146b is opened by the second control valve 350 is set larger than a flow passage cross-sectional area of the fixed throttle 103c of the second pressure release passage 146a.
Then, when the first control valve 300 closes, and a pressure of the pressure supply passage 145 between the first control valve 300 and the second control valve 350 becomes lower than a pressure of the crank chamber 140, then the second control valve 350 closes the pressure supply passage 145 to block the reverse flow of the refrigerant directed from the crank chamber 140 to the first control valve 300, and meanwhile, sets an opening degree of the first pressure release passage 146b to a maximum opening degree.
In this way, the refrigerant in the crank chamber 140 is rapidly discharged into the suction chamber 141 via the second pressure release passage 146a and the first pressure release passage 146b, and the pressure of the crank chamber 140 becomes equivalent to the pressure of the suction chamber 141 to bring the maximum inclination angle of the swash plate, whereby a piston stroke (a discharge displacement) becomes maximum
Moreover, when the first control valve 300 opens, and the pressure of the pressure supply passage 145 between the first control valve 300 and the second control valve 350 becomes higher than the pressure of the crank chamber 140, then the second control valve 350 opens the pressure supply passage 145 and closes the first pressure release passage 146b.
In this way, the refrigerant in the discharge chamber 142 is supplied to the crank chamber 140 via the pressure supply passage 145, and meanwhile, the refrigerant in the crank chamber 140 is restricted from flowing into the suction chamber 141, and the pressure of the crank chamber 140 becomes likely to rise. Then, the pressure of the crank chamber 140 rises in response to the opening degree of the first control valve 300, and the inclination angle of the swash plate 111 decreases from the maximum, whereby the piston stroke can be variably controlled.
As described above, the variable displacement compressor 100 is a compressor in which a discharge displacement is controlled by the pressure regulation in the crank chamber 140.
Note that a structure and functions of the second control valve 350 will be described later in detail.
Oil for lubrication is sealed in an inside of the variable displacement compressor 100, and the inside of the variable displacement compressor 100 is lubricated by agitation of the oil, which accompanies the rotation of the drive shaft 110, and by movement of the oil, which accompanies the movement of the refrigerant gas.
The first control valve 300 in
The valve unit of the first control valve 300 includes a cylindrical valve housing 301, and in an inside of the valve housing 301, a first pressure sensing chamber 302, a valve chamber 303 and a second pressure sensing chamber 307 are formed in an axial direction in this order.
The first pressure sensing chamber 302 communicates with the crank chamber 140 via a communication hole 301a formed on an outer circumferential surface of the valve housing 301, and via a housing hole 104b and a communication passage 104f, which are formed in the cylinder head 104.
The second pressure sensing chamber 307 communicates with the suction chamber 141 via a communication hole 301e formed on the outer circumferential surface of the valve housing 301, and via the communication passage 104c formed in the cylinder head 104.
The valve chamber 303 communicates with the discharge chamber 142 via a communication hole 301b formed on the outer circumferential surface of the valve housing 301, and via a communication passage 104k formed in the cylinder head 104.
The first pressure sensing chamber 302 and the valve chamber 303 are made communicable with each other via a valve hole 301c.
A support hole 301d is formed between the valve chamber 303 and the second pressure sensing chamber 307.
In the first pressure sensing chamber 302, a bellows 305 is disposed. The bellows 305 evacuates an inside thereof and incorporates a spring therein, is disposed so as to be displaceable in the axial direction of the valve housing 301, and has a function as pressure sensing means for receiving the pressure of the first pressure sensing chamber 302, that is, in the crank chamber 140.
In the valve chamber 303, a columnar valve body 304 is housed. The valve body 304 is slidable in the support hole 301d while an outer circumferential surface thereof is in close contact with an inner circumferential surface of the support hole 301d, and is movable in the axial direction of the valve housing 301. One end of the valve body 304 is capable of opening and closing the valve hole 301c, and other end of the valve body 304 protrudes into the second pressure sensing chamber 307.
One end of a rod-like coupling portion 306 is fixed to one end of the valve body 304. Other end of the coupling portion 306 is disposed so as to be capable of abutting against the bellows 305, and has a function to transmit such displacement of the bellows 305 to the valve body 304.
The drive unit has a cylindrical solenoid housing 312, and the solenoid housing 312 is coupled to other end of the valve housing 301 coaxially therewith.
In the solenoid housing 312, a molded coil 314 in which an electromagnetic coil is covered with resin is housed.
Moreover, a cylindrical fixed core 310 is housed in the solenoid housing 312 concentrically with the molded coil 314, and the fixed core 310 is extended from the valve housing 301 to a vicinity of a center of the molded coil 314. An end portion of the fixed core 310 on a side opposite with the valve housing 301 is closed by being surrounded by a tubular sleeve 313.
The fixed core 310 has an insertion hole 310a in a center thereof, and one end of the insertion hole 310a is opened to the second pressure sensing chamber 307. Furthermore, between the fixed core 310 and a closed end of the sleeve 313, a cylindrical movable core 308 is housed.
A solenoid rod 309 is inserted into the insertion hole 310a, and one end of the solenoid rod 309 is fixed to a base end side of the valve body 304 by press fitting. Other end portion of the solenoid rod 309 is press-fitted into a through hole formed in the movable core 308, and the solenoid rod 309 and the movable core 308 are integrated with each other. Moreover, between the fixed core 310 and the movable core 308, a forced release spring 311 that urges the movable core 308 in a direction (a valve opening direction) of separating from the fixed core 310 is provided.
The movable core 308, the fixed core 310 and the solenoid housing 312 are formed of a magnetic material, and compose a magnetic circuit. Meanwhile, the sleeve 313 is formed of a non-magnetic material, for example, such as a stainless steel material.
A control device (not illustrated) provided on an outside of the variable displacement compressor 100 is connected to the molded coil 314 via a signal line. Upon being supplied with a control current i from the control device, the molded coil 314 generates electromagnetic force F(i). The electromagnetic force F(i) of the molded coil 314 attracts the movable core 308 toward the fixed core 310, and drives the valve body 304 in a valve closing direction.
On the valve body 304 of the first control valve 300, there act urging force fs by the forced release spring 311, force due to a pressure (a discharge pressure Pd) of the valve chamber 303, force due to a pressure (a crank chamber pressure Pc) of the first pressure sensing chamber 302, force due to a pressure (a suction pressure Ps) of the second pressure sensing chamber 307, and urging force F by the spring incorporated in the bellows 305, as well as the electromagnetic force F(i) by the molded coil 314.
Here, an effective pressure receiving area in an expansion/contraction direction of the bellows 305 is defined as Sb, a receiving area of the pressure of the crank chamber, which acts on the valve body 304 from the valve hole 301c side, is defined as Sv, a cross-sectional area of the cylindrical outer circumferential surface of the valve body 304 is defined as Sr, and a relationship thereamong is established as Sb=Sv=Sr. Accordingly, a relationship among the forces which act on the valve body 304 is expressed by Equation 1. Note that, in Equation 1, “+” indicates the valve closing direction of the valve body 304, and “−” indicates the valve opening direction thereof.
When the pressure of the suction chamber 141 becomes higher than a set pressure, a coupled body of the bellows 305, the coupling portion 306 and the valve body 304 decreases the opening degree of the pressure supply passage 145 and decreases the pressure of the crank chamber 140 in order to increase the discharge displacement. When the pressure of the suction chamber 141 falls down below the set pressure, the coupled body increases the opening degree of the pressure supply passage 145 and raises the pressure of the crank chamber 140 in order to decrease the discharge displacement.
That is, the first control valve 300 autonomously controls the opening degree (the opening area) of the pressure supply passage 145 so that the pressure of the suction chamber 141 can approach the set pressure.
The electromagnetic force of the molded coil 314 acts on the valve body 304 via the solenoid rod 309 in the valve closing direction, and accordingly, when an energization amount to the molded coil 314 increases, force in a direction of decreasing the opening degree of the pressure supply passage 145 increases, and as illustrated in
The control device (a drive unit) controls such energization to the molded coil 314 by pulse width modulation (PWM control) at a predetermined frequency, for example, in a range of 400 Hz to 500 Hz, and changes a pulse width (a duty ratio) so that a value of a current flowing through the molded coil 314 can reach a desired value.
When the air conditioning system is in operation, that is, in an operating state of the variable displacement compressor 100, the energization amount to the molded coil 314 is adjusted by the control device based on air conditioning setting such as a set temperature and on an external environment, and the discharge displacement is controlled so that the pressure of the suction chamber 141 can become the set pressure corresponding to the energization amount.
Meanwhile, when the air conditioning system is not in operation, that is, in a non-operating state of the variable displacement compressor 100, the control device turns off the energization to the molded coil 314. In this way, the pressure supply passage 145 is opened by the forced release spring 311, and the discharge displacement of the variable displacement compressor 100 is controlled to a minimum state.
The second control valve 350 includes: a housing chamber 104e, which is formed on an open end surface 104d side of the cylinder head 104, and is closed by a closing member formed of the discharge valve forming plate 151; the spool 352, which is housed in the housing chamber 104e, and moves in the axial direction in the housing chamber 104e; and a partition member 351, which is fixed in the housing chamber 104e, and partitions the housing chamber 104e into a first housing chamber (a first space) 104e1 and a second housing chamber (a second space) 104e2 along the axial direction.
The housing chamber 104e has: a first valve hole 104e32 opened to one end side in a moving direction of the spool 352; and a second valve hole 151a opened to other end side in the moving direction of the spool 352; and further, a pressure release hole 104g1 opened to an inner circumferential wall on the second housing chamber 104e2 side of the housing chamber 104e.
The first valve hole 104e32 communicates with a downstream side of the valve hole 301c of the first control valve 300 via the communication passage 104f. That is, the first valve hole 104e32 communicates with the discharge chamber 142 via the communication passage 104f, the housing hole 104b, the first control valve 300 and the communication passage 104k.
Moreover, the second valve hole 151a communicates with the crank chamber 140 via the communication hole of the valve plate 103, the communication hole of the suction valve forming plate 150, the communication hole of the cylinder gasket 152, and the communication passage 101e formed in the cylinder block 101.
Furthermore, the pressure release hole 104g1 communicates with the suction chamber 141 via the communication passage 104g.
Meanwhile, the spool 352 integrally includes: a first valve portion 352a, which contacts and separates from a first valve seat 104e31 provided around the first valve hole 104e32; and a second valve portion 352b, which contacts and separates from a second valve seat 151b provided around the second valve hole 151a.
Then, when a pressure of the communication passage 104f (the pressure supply passage 145 between the first control valve 300 and the second control valve 350) is lower than a pressure of the communication passage 101e (the crank chamber 140), the spool 352 moves in a right direction of
Moreover, when the pressure of the communication passage 104f is higher than the pressure in the communication passage 101e, the spool 352 moves in a left direction of
Hereinafter, the configuration of the second control valve 350 will be described in more detail.
The housing chamber 104e is formed into a cylindrical shape along an axis parallel to an axis of the drive shaft 110. Moreover, the housing chamber 104e has: a large diameter portion on the open end surface 104d side (a side close to the crank chamber 140) of the cylinder head 104; and a small diameter portion smaller in diameter than the large diameter portion on a back side (a far side from the crank chamber 140) thereof. Then, by the partition member 351 fixed to the large diameter portion of the housing chamber 104e, the small diameter portion composes the first housing chamber 104e1, and the large diameter portion composes the second housing chamber 104e2.
The first valve seat 104e31 on which one end surface (the first valve portion 352a) of the spool 352 is seated is formed on an end surface 104e3 in the axial direction, which composes the first housing chamber 104e1, and the first valve hole 104e32 is opened on an inside of the first valve seat 104e31.
The first valve hole 104e32 communicates with a crank chamber pressure area in the housing hole 104b, which is located downstream of the valve hole 301c of the first control valve 300, via the communication passage 104f extended coaxially with the housing chamber 104e. Moreover, the crank chamber pressure area in the housing hole 104b, which is located downstream of the valve hole 301c of the first control valve 300, communicates with the discharge chamber 142 via the first control valve 300 and the communication passage 104k, and the first valve hole 104e32 communicates with the discharge chamber 142 via the pressure supply passage 145 including the communication passage 104f.
Then, hence, the first housing chamber 101e1 composes a part of the pressure supply passage 145, and at the same time, composes a so-called back pressure chamber of the second control valve 350.
Moreover, the communication passage 104g, which causes the second housing chamber 104e2 and the suction chamber 141 to communicate with each other, is connected to a circumferential wall of the second housing chamber 104e2, and one end of the communication passage 104g, which is opened to such an inner circumferential wall of the second housing chamber 104e2, composes the pressure release hole 104g1.
The second valve hole 151a is opened in the discharge valve forming plate 151 (the closing member) that closes an open end surface in the axial direction of the second housing chamber 104e2, and the second valve seat 151b on which such other end surface (the second valve portion 352b) of the spool 352 is seated is formed on the closing member formed around an opening portion of the second valve hole 151a.
The second housing chamber 104e2 communicates with the crank chamber 140 via the second valve hole 151a, the communication hole of the valve plate 103, the communication hole of the suction valve forming plate 150, the communication hole of the cylinder gasket 152, and the communication passage 101e formed in the cylinder block 101.
As the closing member that closes the open end surface in the axial direction of the second housing chamber 104e2, other compressor constituent members between the cylinder block 101 and the cylinder head 104 can be used in place of the discharge valve forming plate 151, and a dedicated closing member can also be added.
However, if any one of the suction valve forming plate 150, the discharge valve forming plate 151 and the valve plate 103 is used as the closing member, then it is not necessary to add the dedicated closing member, moreover, good accuracy of flatness is brought, and accordingly, any one thereof is suitable as the closing member that forms the valve seat.
The partition member 351 is composed of: a cylindrical side wall 351a, which is press-fitted into the circumferential wall of the second housing chamber 104e2, and partitions the second housing chamber 104e2 into an inner cylindrical space and an annular space that communicates with the suction chamber 141; and an end wall 351b, which partitions the first housing chamber 104e1 and the inner cylindrical space of the second housing chamber 104e2 from each other, and has an insertion hole 351b1 formed in a center portion thereof, the insertion hole 351b1 receiving insertion of the spool 352 (a shaft portion 352c).
In other words, the end wall 351b separates an annular space around the spool 352 into the first annular space 104e1 on the first valve hole 104e32 side and the second annular space 104e2 on the second valve hole 151a side, and the pressure release hole 104g1 is opened to the second annular space 104e2, and causes the suction chamber 141 and the second annular space 104e2 to communicate with each other.
The cylindrical space in the inside of the second housing chamber 104e2, which is partitioned by the side wall 351a and the end wall 351b, compose the valve chamber 351c.
The partition member 351 is positioned in the second housing chamber 104e2 so that an open end surface 351a1 of the side wall 351a can abut against the discharge valve forming plate 151. In the side wall 351a, there is formed a communication hole 351a2 that causes the valve chamber 351c and the annular space to communicate with each other, the annular space being sandwiched between the side wall 351a and the inner circumferential wall of the second housing chamber 104e2.
The spool 352 is composed of: the first valve portion 352a, which is housed in the first housing chamber 101e1, and has one end surface 352a1 contact and separate from the first valve seat 104e31; the second valve portion 352b, which is housed in the valve chamber 351c, and has other end surface 352b1 (an annular seating surface) contact and separate from the second valve seat 151b; and the shaft portion 352c, which is smaller in diameter than the first valve portion 352a and the second valve portion 352b, and couples the first valve portion 352a and the second valve portion 352b to each other.
The first valve portion 352a contacts and separates from the first valve seat 104e31, thereby opening and closing the first valve hole 104e32.
Moreover, the second valve portion 352b separates from the second valve seat 151b, whereby a gap (communication portion) 151b1 is formed between the second valve portion 352b and the second valve seat 151b, and the communication passage 101e (the second valve hole 151a) and the communication passage 101g (the pressure release hole 104g1) communicate with each other via such a gap 151b1.
Meanwhile, the second valve portion 352b is seated on the second valve seat 151b, whereby the gap (communication portion) 151b1 between the second valve portion 352b and the second valve seat 151b is closed, the communication between the communication passage 101e (the second valve hole 151a) and the communication passage 101g (the pressure release hole 104g1) is blocked.
While the shaft portion 352c is formed as an integral part with the first valve portion 352a, the second valve portion 352b is formed as a separate part, and the shaft portion 352c is press-fitted into the second valve portion 352b in a state in which the shaft portion 352c is inserted into the insertion hole 351b1 of the partition member 351. In this way, the second valve portion 352b is fixed to such an integral part of the shaft portion 352c and the first valve portion 352a, whereby the spool 352 is composed.
Here, such a press-fitted position of the first valve portion 352a to the second valve portion 352b in the axial direction is adjusted so that other end surface 352a2 (pressure receiving portion) of the first valve portion 352a can abut against one end surface 351b2 of the end wall 351b of the partition member 351 in the axial direction simultaneously when the one end surface 352b1 of the second valve portion 352b is seated on the valve seat 151b provided on the discharge valve forming plate 151.
Note that, if there is adopted such a structure of press-fitting the first valve portion 352a into the shaft portion 352c, then as will be described later, since the other end surface 352a2 of the first valve portion 352a composes valve means, it is necessary to form a second communication hole 352d3 in consideration of a state in which the first valve portion 352a is press-fitted into the shaft portion 352c, and the passage formation becomes complicated. In contrast, if the first valve portion 352a and the shaft portion 352c are formed integrally with each other, then it is not necessary to consider deviation of the press-fitted position, and the second communication hole 352d3 can be formed with ease.
In the spool 352, there is formed an internal communication passage 352d composed of: an internal passage 352d2, which is opened to the end surface 352b1 of the second valve portion 352b, is extended toward the first valve portion 352a in the axial direction, and has the first valve portion 352a side closed; and a first communication hole 352d1, which is extended from an outer circumferential surface of the first valve portion 352a toward an inside thereof in the radial direction, and communicates with an internal passage 352d2.
The one end surface (seating surface) 352b1 of the second valve portion 352b is formed into an annular shape in such a manner that the internal passage 352d2 is opened.
Moreover, between the other end surface 352a2 of the first valve portion 352a and the one end surface 352a1 thereof, the spool 352 is provided with an outermost circumferential surface (sliding contact portion) 352a3 slidably supported on an inner circumferential surface of the first housing chamber 101e1, and the first communication hole 352d1 is provided on the one end surface 352a1 side of the outermost circumferential surface (sliding contact portion) 352a3.
Furthermore, the second communication hole 352d3 is formed, which causes the internal passage 352d2 and an outer circumferential surface to communicate with each other, the outer circumferential being located between the other end surface 352a2 of the first valve portion 352a and the outermost circumferential surface 352a3 thereof.
As illustrated in
That is, the second valve portion 352b is separated from the second valve seat 151b, whereby the gap 151b1 is formed between the second valve portion 352b and the second valve seat 151b, the communication portion between the communication passage 101e and the communication passage 104g is opened, the opening degree of the first pressure release passage 146b becomes the maximum opening degree, and the refrigerant in the crank chamber 140 is discharged to the suction chamber 141.
Moreover, when the second valve portion 352b is separated from the second valve seat 151b, the first valve portion 352a is seated on the first valve seat 104e31, the first valve hole 104e32 is closed, and the pressure supply passage 145 composed by including the first valve hole 104e32 is closed.
Meanwhile, as illustrated in
Here, when the second valve portion 352b is seated on the second valve seat 151b, then the first valve portion 352a is separated from the first valve seat 104e31, and the first valve hole 104e32 is opened.
In this way, the communication passage 104k, the first control valve 300, the housing hole 104b, the communication passage 104f, the first valve hole 104e32, the first housing chamber (a first space) 104e1, the first communication hole 352d1, the internal passage 352d2, the second valve hole 151a, the communication hole of the valve plate 103, the communication hole of the suction valve forming plate 150, the communication hole of the cylinder gasket 152 and the communication passage 101e compose the pressure supply passage 145 that causes the crank chamber 140 and the discharge chamber 142 to communicate with each other, and the refrigerant in the discharge chamber 142 is supplied to the crank chamber 140 via the pressure supply passage 145.
As described above, the second valve hole 151a, the communication hole of the valve plate 103, the communication hole of the suction valve forming plate 150, the communication hole of the cylinder gasket 152 and the communication passage 101e also serve as the first pressure release passage 146b and the pressure supply passage 145, and a flow direction of the refrigerant in the communication passage 101e is reversed between when the pressure is released from the crank chamber 140 and when the pressure is supplied to the crank chamber 140.
In other words, the communication passage that causes the second valve hole 151a and the crank chamber 140 to communicate with each other is switched, in response to the position of the spool 352, between a state in which the communication passage concerned composes a part of the first pressure release passage 146b and a state in which the communication passage concerned composes a part of the pressure supply passage 145.
When the second valve portion 352b is seated on the second valve seat 151b, and the first valve portion 352a is separated from the first valve seat 104e31, then the refrigerant flows from the second valve hole 151a toward the crank chamber 140 through the communication passage 101e, which causes the second valve hole 151a and the crank chamber 140 to communicate with each other, and the communication passage 101e functions as the pressure supply passage 145.
Meanwhile, when the second valve portion 352b is separated from the second valve seat 151b, and the first valve portion 352a is seated on the first valve seat 104e31, then the refrigerant flows from the crank chamber 140 toward the second valve hole 151a through the communication passage 101e, which causes the second valve hole 151a and the crank chamber 140 to communicate with each other, and the communication passage 101e functions as the first pressure release passage 146b.
Note that a minute gap is formed between the outermost circumferential surface 352a3 of the first valve portion 352a of the spool 352 and the inner circumferential surface of the first housing chamber 104e1.
Therefore, in a state in which the one end surface 352a1 of the first valve portion 352a is slightly separated from the first valve seat 104e31, the refrigerant gas, which has flown into the first housing chamber 104e1 from the communication passage 104f, flows into the valve chamber 351c (the second housing chamber 104e2) via a gap between the outermost circumferential surface 352a3 and the inner circumferential surface of the first housing chamber 104e1 and a gap between the outer circumferential surface of the shaft portion 352c and the inner circumferential surface of the insertion hole 351b1.
Meanwhile, a configuration is adopted so that the other end surface 352a2 of the first valve portion 352a can abut against the one end surface 351b2 of the end wall 351b in a state in which the end surface 352b1 of the second valve portion 352b is seated on the second valve seat 151b and the one end surface 352a1 of the first valve portion 352a is separated from the first valve seat 104e31 to the maximum. Accordingly, the flow of the refrigerant from the first housing chamber 104e1 to the valve chamber 351c, the flow passing via the gap between the outer circumferential surface of the shaft portion 352c and the inner circumferential surface of the insertion hole 351b1, is blocked.
That is, the other end surface 352a2 of the first valve portion 352a and the one end surface 351b2 of the end wall 351b compose valve means (a valve device) for blocking the flow of the refrigerant from the first housing chamber 104e1 to the valve chamber 351c, the flow passing via the gap between the outer circumferential surface of the shaft portion 352c and the inner circumferential surface of the insertion hole 351b1.
Hence, when the first housing chamber 101e1 functions as the pressure supply passage 145, the refrigerant is suppressed from flowing out from the first housing chamber 101e1 to the suction chamber 141 via the valve chamber 351c, and most of the refrigerant gas, which has flown into the first housing chamber 101e1, can be supplied to the crank chamber 140.
Note that, in the spool 352, there is formed the second communication hole 352d3, in which one end is opened between the other end surface 352a2 of the first valve portion 352a of the spool 352 and the outermost circumferential surface 352a3 thereof, and other end is opened to the inner passage 352d2 as a result of extending the second communication hole 352d3 concerned from such an opening portion in the radial direction.
Therefore, the refrigerant gas, which has flown into the gap between the outermost circumferential surface 352a3 of the first valve portion 352a and the inner circumferential surface of the first housing chamber 104e1, flows into the internal passage 352d2 via the second communication hole 352d3, and merges into the refrigerant that has flown into the internal passage 352d2 via the first communication hole 352d1.
The refrigerant gas sometimes contains minute contaminants. Although the gap between the outermost circumferential surface 352a3 of the first valve portion 352a and the inner circumferential surface of the first housing chamber 104e1 has an opening area sufficient for causing the contaminants to pass therethrough, since the second communication hole 352d3 is formed, the refrigerant gas is enabled to flow through the gap between the outermost circumferential surface 352a3 of the first valve portion 352a and the inner circumferential surface of the first housing chamber 104e1, so that the contaminants are suppressed from being accumulated in the gap. In this way, the movement of the spool 352 can be suppressed from being hindered by the accumulation of the contaminants.
Moreover, by the contact between the other end surface 352a2 of the first valve portion 352a and the one end surface 351b2 of the end wall 351b, leakage through the gap between the outer circumferential surface of the shaft portion 352c and the inner circumferential surface of the insertion hole 351b1 is suppressed, and accordingly, the configuration of the valve means for suppressing the leakage is simple.
A region of the pressure supply passage 145 between the first control valve 300 and the second control valve 350 communicates with the suction chamber 141 via a throttle passage 104h. Since the throttle passage 104h has a throttle, the amount of the refrigerant flowing out from the pressure supply passage 145 to the suction chamber 141 via the throttle passage 104h is small.
Hence, when the first control valve 300 closes, and further, the one end surface 352a1 of the first valve portion 352a is seated on the first valve seat 104e31 to close the pressure supply passage 145, then the back pressure Pm that acts on the one end surface of the spool 352 becomes equivalent to the pressure of the suction chamber 141.
Moreover, when the first control valve 300 opens, and further, the one end surface 352a1 of the first valve portion 352a is separated from the first valve seat 104e31 to open the pressure supply passage 145, then the back pressure Pm that acts on the one end surface of the spool 352 becomes higher than the pressure of the suction chamber 141.
One end surface (the one end surface 352a1 of the first valve portion 352a) of the spool 352 receives the pressure of the pressure supply passage 145 on an upstream side (between the first control valve 300 and the second control valve 350) thereof, that is, a so-called back pressure Pm.
Meanwhile, other end surface (the one end surface 352b1 of the second valve portion 352b) of the spool 352 receives the pressure Pc of the crank chamber 140. Then, the spool 352 moves in the axial direction in response to a pressure difference ΔP (ΔP=Pm−Pc) between the back pressure Pm and the pressure Pc.
When the first control valve 300 opens, and the back pressure Pm of the spool 352 becomes higher than the pressure Pc of the crank chamber 140 (that is, in a state of Pm−Pc>0), the one end surface 352b1 of the second valve portion 352b of the spool 352 is seated on the second valve seat 151b, and closes the communication portion 151b1 between the communication passage 104g and the communication passage 101e. Simultaneously, the one end surface 352a1 of the first valve portion 352a is separated from the first valve seat 104e31, and the communication passage (the pressure supply passage 145) between the discharge chamber 142 and the crank chamber 140 is opened.
That is, when the first control valve 300 opens, then the first valve portion 352a is separated from the first valve seat 104e31, and the first valve hole 104e32 is opened, and the refrigerant in the discharge chamber 142 is supplied to the crank chamber 140 via the pressure supply passage 145 composed of the communication passage 104k, the first control valve 300, the housing hole 104b, the communication passage 104f, the first valve hole 104e32, the first housing chamber (the first space) 104e1, the first communication hole 352d1, the internal passage 352d2, the second valve hole 151a, the communication hole of the valve plate 103, the communication hole of the suction valve forming plate 150, the communication hole of the cylinder gasket 152 and the communication passage 101e.
In this way, only the second pressure release passage 146a between the second pressure release passage 146a and the first pressure release passage 146b is opened, and a minimum opening area of the pressure release passage 146 becomes an opening area of the fixed throttle 103c. Therefore, the pressure of the crank chamber 140 becomes easy to rise, the pressure in the crank chamber 140 rises in response to the opening degree of the first control valve 300, the inclination angle of the swash plate 111 decreases from the maximum, and the piston stroke can be controlled variably.
Meanwhile, when the first control valve 300 closes, and the back pressure Pm of the spool 352 becomes lower than the pressure Pc of the crank chamber 140 (that is, in a state of Pm−Pc<0), then the one end surface 352a1 of the first valve portion 352a is seated on the first valve seat 104e31, and closes the first valve hole 104e32 (the pressure supply passage 145). Simultaneously, the one end surface 352b1 of the second valve portion 352b of the spool 352 is separated from the second valve seat 151b, an opening degree (an opening area) of the communication portion 151b1 between the communication passage 104g and the communication passage 101e becomes the maximum opening degree, and the opening degree of the first pressure release passage 146b between the crank chamber 140 and the suction chamber 141 becomes the maximum opening degree.
That is, when the first control valve 300 closes, then the second valve portion 352b is separated from the second valve seat 151b, the communication portion 151b1 is opened, and the refrigerant in the crank chamber 140 is discharged to the suction chamber 141 via the first pressure release passage 146b and the second pressure release passage 146a, which are composed of the communication passage 101e, the communication hole of the cylinder gasket 152, the communication hole of the suction valve forming plate 150, the communication hole of the valve plate 103, the second valve hole 151a, the communication portion 151b1, the valve chamber 351c, the communication hole 351a2, the annular space sandwiched between the side wall 351a and the inner circumferential wall of the second housing chamber (a second space) 104e2, the pressure release hole 104g1 and the communication passage 104g.
In this way, the supply of the refrigerant from the discharge chamber 142 to the crank chamber 140 is stopped, and meanwhile, the refrigerant in the crank chamber 140 is rapidly discharged to the suction chamber 141 via the second pressure release passage 146a (the fixed throttle 103c) and the first pressure release passage 146b. Therefore, the pressure of the crank chamber 140 becomes equivalent to the pressure of the suction chamber 141, the inclination angle of the swash plate becomes the maximum, and the piston stroke (the discharge displacement) becomes the maximum.
At this time, the first valve portion 352a is seated on the first valve seat 104e31 and closes the first valve hole 104e32, and accordingly, the refrigerant is hindered from flowing backward to the first control valve 300 side via the first valve hole 104e32 (the pressure supply passage 145).
Note that a pressure receiving area S1 of the spool 352 in the axial direction, which receives the back pressure Pm, and a pressure receiving area S2 of the spool 352, which receives the pressure Pc of the crank chamber 140, are set, for example, to S1=S2; however, can be set to S1>S2 or S1<S2 in order to adjust the operation of the spool 352.
As described above, the second control valve 350 is provided with a function to control the opening degree of the pressure release passage 146 to the minimum opening degree by closing the first pressure release passage 146b when the first control valve 300 opens, and to control the opening degree of the first pressure release passage 146b to the maximum opening degree when the first control valve 300 closes, and simultaneously, is provided with a function as a check valve that blocks the flow of the refrigerant directed from the crank chamber 140 toward the first control valve 300 when the first control valve 300 closes.
Hence, in the variable displacement compressor 100, a structure thereof is simpler and a valve layout thereof is easier in comparison with such a case of separately providing a control valve that opens and closes the first pressure release passage 146b in response to the opening and closing of the first control valve 300 and a check valve that blocks the reverse flow of the refrigerant directed toward the first control valve 300.
When the energization to the molded coil 314 of the first control valve 300 is interrupted in a state in which the variable displacement compressor 100 is in operation, the opening area of the first control valve 300 is maximized, the pressure supply passage 145 is opened, and the back pressure Pm of the spool 352 of the second control valve 350 rises.
Therefore, when the one end surface 352a1 of the first valve portion 352a is seated on the first valve seat 104e31 (in the maximum discharge displacement state), the spool 352 moves in a direction of approaching the crank chamber 140 (the second valve seat 151b), and the one end 352a1 of the first valve portion 352a is separated from the first valve seat 104e31, and simultaneously, the one end surface 352b1 of the second valve portion 352b is seated on the second valve seat 151b, and closes the communicating portion 151b1 (the first pressure release passage 146b) between the communication passage 104g and the communication passage 101e.
That is, when the first control valve 300 opens, the pressure release passage 146 becomes only the second pressure release passage 146a (the opening area of the pressure release passage is minimized), and meanwhile, the pressure supply passage 145 that causes the discharge chamber 142 and the crank chamber 140 to communicate with each other is opened. As a result, the pressure of the crank chamber 140 rises, the inclination angle of the swash plate 111 decreases, and the discharge displacement is changed to the minimum and is maintained.
As mentioned above, such a dynamic pressure of the refrigerant flowing through the pressure supply passage 145 acts on the spool 352, whereby the one end surface 352b1 of the second valve portion 352b is seated on the second valve seat 151b. In such a seated state of the second valve portion 352b, such a dynamic pressure of pressing the first pressure release passage 146b in a direction of opening the same does not act on the second valve portion 352b, and the closed state of the first pressure release passage 146b (that is, a state of the minimum opening degree of the pressure release passage 146) can be maintained stably.
Moreover, in the closed state of the first pressure release passage 146b, the pressure release is performed via the second pressure release passage 146a, and accordingly, it is possible to dispose the second pressure release passage 146a appropriately in consideration of lubrication and the like without being bound by the position of the second control valve 350.
In such a minimum discharge displacement state, the discharge check valve 200 shuts off the connection portion (discharge passage) between the communication passage 144 and the muffler space 143, and the refrigerant gas discharged with the minimum discharge displacement does not flow to the external refrigerant circuit, but circulates through an internal circulation passage composed of the discharge chamber 142, the pressure supply passage 145, the crank chamber 140, the second pressure release passage 146a, the suction chamber 141 and the cylinder bore 101a. At this time, the refrigerant of the pressure supply passage 145 between the first control valve 300 and the second control valve 350 slightly flows out to the suction chamber 141 via the throttle passage 104h.
When the molded coil 314 of the first control valve 300 is energized from this state (the minimum discharge displacement state), the first control valve 300 closes, and the pressure supply passage 145 is closed. Hence, the refrigerant in the pressure supply passage 145 between the first control valve 300 and the second control valve 350 flows out into the suction chamber 141 via the throttle passage 104h, and the pressure (the back pressure Pm) of the pressure supply passage 145 between the first control valve 300 and the second control valve 350 decreases.
In response to such a decrease of the back pressure Pm, the spool 352 moves in a direction of going away from the crank chamber 140 (the second valve seat 151b), whereby the first valve portion 352a is seated on the first valve seat 104e31 to close the first valve hole 104e32 (the pressure supply passage 145). Accordingly, the refrigerant is hindered from flowing backward from the crank chamber 140 via the communication passage 101e to the pressure supply passage 145 located upstream of the second control valve 350. Simultaneously, the one end surface 352b1 of the second valve portion 352b is separated from the second valve seat 151b, whereby the communication portion 151b1 (the first pressure release passage 146b) between the communication passage 104g and the communication passage 101e is opened.
As described above, by the movement of the spool 352 due to such a pressure difference between the front and back thereof, the opening degree of the first pressure release passage 146b can be switched with ease between the maximum opening degree (the open state) and the minimum opening degree (the closed state).
Note that, when the first valve portion 352a includes urging means (an elastic member, a spring or the like) for urging the spool 352 in a direction of being seated on the first valve seat 104e31, when the air conditioning system is driven in a state in which the variable displacement compressor 100 is not operated, and the pressure difference between the discharge chamber 142 and the suction chamber 141 becomes extremely small, then there is a possibility that the state of the variable displacement compressor 100 may suddenly turn to state in which the pressure supply passage is closed and the first pressure release passage 146b is opened by urging force of the urging means, and the discharge displacement may increase rapidly and abruptly.
In contrast, the variable displacement compressor 100 of this embodiment does not include the urging means for urging the spool 352, and the spool 352 moves in response to the pressure difference between the front and back thereof. Accordingly, even if the pressure difference between the discharge chamber 142 and the suction chamber 141 becomes extremely small, there can be suppressed such a phenomenon that the discharge displacement is increased rapidly and abruptly by the fact that the state of the variable displacement compressor 100 turns to the state in which the pressure supply passage is closed and the first pressure release passage 146b is opened.
When the molded coil 314 is energized to close the first control valve 300, the opening degree of the first pressure release passage 146b becomes the maximum opening degree, and the refrigerant of the crank chamber 140 is discharged into the suction chamber 141 via the two pressure release passages 146a and 146b.
The flow passage cross-sectional area of the first pressure release passage 146b in the second control valve 350 is set larger than the flow passage cross-sectional area of the fixed throttle 103c (the second pressure release passage 146a). Accordingly, when the opening degree of the first pressure release passage 146b is controlled to the maximum opening degree by the second control valve 350, the refrigerant in the crank chamber 140 quickly flows into the suction chamber 141, the pressure of the crank chamber 140 decreases, and the discharge displacement quickly increases from the state of the minimum to the maximum discharge displacement.
In this way, the pressure of the discharge chamber 142 rises suddenly to open the discharge check valve 200, the refrigerant gas is discharged from the variable displacement compressor 100, the refrigerant circulates through the external refrigerant circuit, and the air conditioning system turns to an operating state.
When the air conditioning system operates, and the pressure in the suction chamber 141 decreases and reaches the set pressure set by the current flowing through the molded coil 314, then the first control valve 300 opens. When the first control valve 300 opens, the back pressure Pm of the spool 352 of the second control valve 350 rises, and accordingly, the second control valve 350 opens the pressure supply passage 145, and at the same time, closes the first pressure release passage 146b.
At this time, only the second pressure release passage 146a between the pressure release passages 146a and 146b is opened. In this way, the refrigerant in the crank chamber 140 is restricted from flowing out into the suction chamber 141, the pressure of the crank chamber 140 becomes easy to rise, the opening degree of the first control valve 300 is adjusted so that the pressure of the suction chamber 141 can maintain the set pressure, and the discharge displacement is variably controlled.
That is, the second control valve 350 operates in conjunction with the opening and closing of the first control valve 300, when the first control valve 300 closes, the opening degree of the first pressure release passage 146b is set to the maximum opening degree, and when the first control valve 300 is opened, the opening degree of the first pressure release passage 146b is set to the minimum opening degree.
In the first embodiment illustrated in
In such a second control valve 350 illustrated in
Note that the configuration of the second embodiment is the same as that of the first embodiment illustrated in
In the second control valve 350 in which the notch groove portion 352b3 is formed on the end surface 352b1 of the second valve portion 352b, the internal passage 352d2 and the valve chamber 351c communicate with each other via the notch groove portion 352b3 when the second valve portion 352b is seated on the second valve seat 151b. In this way, the communication passage 101e and the communication passage 104g communicate with each other, and the refrigerant in the crank chamber 140 is discharged into the suction chamber 141 via the notch groove portion 352b3.
That is, the minimum opening degree of the communication portion 151b1 between the communication passage 101e and the communication passage 104g, in other words, the minimum opening degree of the first pressure release passage 146b becomes an opening area of the notch groove portion 352b3, and even when the second valve portion 352b is seated on the second valve seat 151b, the first pressure release passage 146b is not closed, but opens by the minimum opening degree that coincides with a cross-sectional area of the notch groove portion 352b3.
In this way, the refrigerant in the crank chamber 140 flows out into the suction chamber 141 via the first pressure release passage 146b composed of the communication passage 101e, the communication hole of the cylinder gasket 152, the communication hole of the suction valve forming plate 150, the communication hole of the valve plate 103, the second valve hole 151a, the notch groove portion 352b3, the valve chamber 351c, the communication hole 351a2, the annular space sandwiched between the side wall 351a and the inner circumferential wall of the second housing chamber (the second space) 104e2, the pressure release hole 104g1 and the communication passage 104g.
Hence, if a cross-sectional area of the notch groove portion 352b3 is made equivalent to the opening area of the fixed throttle 103c of the second pressure release passage 146a in the first embodiment, then the first pressure release passage 146b also has the function of the second pressure release passage 146a, and the second pressure release passage 146a can be omitted.
In the above-described first and second embodiments, the passage portion, which is composed of the second valve hole 151a, the communication hole of the valve plate 103, the communication hole of the suction valve forming plate 150, the communication hole of the cylinder gasket 152, and the communication passage 101e, also serves as the first pressure release passage 146b and the pressure supply passage 145; however, the first pressure release passage 146b and the pressure supply passage 145 can be provided as separate routes.
Note that
In the second control valve 350 illustrated in
The communication passage 104m, which communicates with the first housing chamber 104e1 and the crank chamber 140, is composed of: a communication passage 104m1 formed in the cylinder head 104; a communication hole of the discharge valve forming plate 151; the communication hole of the valve plate 103; the communication hole of the suction valve forming plate 150; the communication hole of the cylinder gasket 152; and a communication passage 104m2 formed in the cylinder block 101.
Moreover, a communication hole 352d4, which causes the first housing chamber (the first space) 104e1 and the communication passage 104m (the communication passage 104m1) to communicate with each other, is formed, the first housing chamber 104e1 being formed between the outermost circumferential surface 352a3 and the partition member 351.
Meanwhile, the internal passage 352d2, the first communication hole 352d1 and the second communication hole 352d2, which are formed in the first and second embodiments, are not formed in the spool 352.
The second control valve 350 of the third embodiment is different from the second control valve 350 of the first embodiment in that the second control valve 350 of the third embodiment includes the communication passage 104m and the communication hole 352d4, and does not include the internal passage 352d2, the first communication hole 352d1 and the second communication hole 352d2. However, except for the above, the second control valve 350 of the third embodiment has a same configuration as that of the second control valve 350 of the first embodiment illustrated in
In the second control valve 350 of the third embodiment, when the first control valve 300 opens, the first valve portion 352a is separated from the first valve seat 104e31, and the second valve portion 352b is seated on the second valve seat 151b, then the first valve hole 104e32 opens, and the refrigerant in the discharge chamber 142 is supplied to the crank chamber 140 via the pressure supply passage 145 composed of: the communication passage 104k; the first control valve 300; the housing hole 104b; the communication passage 104f; the first valve hole 104e32; the first housing chamber (the first space) 104e1; the pressure supply hole 104j; the communication passage 104m1; the communication hole of the discharge valve forming plate 151; the communication hole of the valve plate 103; the communicating hole of the suction valve forming plate 150; the communication hole of the cylinder gasket 152; and the communication passage 104m2.
Moreover, when the first control valve 300 closes, the first valve portion 352a is seated on the first valve seat 104e31, and the second valve portion 352b is separated from the second valve seat 151b, then the pressure supply passage 145 composed by including the communication passage 104m is closed in such a manner that the first valve hole 104e32 is closed, and the reverse flow of the refrigerant directed toward the first control valve 300 is blocked, and meanwhile, the communication portion 151b1 between the communication passage 101e and the communication passage 104g opens.
In this way, the opening degree of the first pressure release passage 146b becomes the maximum opening degree, the first pressure release passage 146b being composed of: the communication passage 101e; the communication hole of the cylinder gasket 152; the communication hole of the suction valve forming plate 150; the communication hole of the valve plate 103; the second valve hole 151a; the gap (the communication portion) 151b1 between the second valve portion 352b and the second valve seat 151b; the valve chamber 351c; the communication hole 351a2; the annular space in the second housing chamber (the second space) 104e2 on the outside of the side wall 351a; the pressure release hole 104g1; and the communication passage 104g. Then, the refrigerant in the crank chamber 140 is discharged into the suction chamber 141 via the second pressure release passage 146a and the first pressure release passage 146b.
As described above, in a similar way to the second control valves 350 of the first and second embodiments, the second control valve 350 of the third embodiment also combines the function to open and close the first pressure release passage 146b in response to the opening and closing of the first control valve 300 and the function to block the reverse flow of the refrigerant toward the first control valve 300. Accordingly, in the second control valve 350 of the third embodiment, a structure thereof is simpler and a valve layout thereof is easier in comparison with such a case of separately providing the control valve that opens and closes the first pressure release passage 146b in response to the opening and closing of the first control valve 300 and the check valve that blocks the reverse flow of the refrigerant directed toward the first control valve 300.
Moreover, the refrigerant gas that has flown into the gap between the outermost circumferential surface 352a3 of the first valve portion 352a and the inner circumferential surface of the first housing chamber 104e1 flows into the communication passage 104m (the communication passage 104m1) via the communication hole 352d4, and merges into the refrigerant flowing through the inside of the communication passage 104m.
In this way, the refrigerant gas is caused to flow into the gap between the outermost circumferential surface 352a3 of the first valve portion 352a and the inner circumferential surface of the first housing chamber 104e1, and the accumulation of the contaminants in the gap is suppressed. In a similar way to the second control valves 350 of the first and second embodiments, the movement of the spool 352 can be suppressed from being hindered by the accumulation of the contaminants.
In the second control valve 350 of the third embodiment illustrated in
Note that
In the second control valve 350 illustrated in
Note that the second control valve 350 of the fourth embodiment is similar to that of the third embodiment in that the communication passage 104m and the communication hole 352d4 are provided, and that the internal passage 352d2, the first communication hole 352d1 and the second communication hole 352d2 are not provided, and is different from the second control valve 350 of the third embodiment in that the notch groove portion 352b3 is added.
As described above, in the second control valve 350 in which the notch groove portion 352b3 is formed on the end surface 352b1 of the second valve portion 352b, the communication passage 101e and the communication passage 104g communicate with each other via the notch groove portion 352b3 when the second valve portion 352b is seated on the second valve seat 151b, and the refrigerant in the crank chamber 140 is discharged into the suction chamber 141 via the notch groove portion 352b3.
That is, the minimum opening degree of the communication portion 151b1 between the communication passage 101e and the communication passage 104g, in other words, the minimum opening degree of the first pressure release passage 146b becomes such an opening area of the notch groove portion 352b3, and even when the second valve portion 352b is seated on the second valve seat 151b, the first pressure release passage 146b is not closed, but opens by the minimum opening degree that coincides with a cross-sectional area of the notch groove portion 352b3.
In this way, the refrigerant in the crank chamber 140 flows out into the suction chamber 141 via the first pressure release passage 146b composed of the communication passage 101e, the communication hole of the cylinder gasket 152, the communication hole of the suction valve forming plate 150, the communication hole of the valve plate 103, the second valve hole 151a, the notch groove portion 352b3, the valve chamber 351c, the communication hole 351a2, the annular space sandwiched between the side wall 351a and the inner circumferential wall of the second housing chamber (the second space) 104e2, the pressure release hole 104g1 and the communication passage 104g.
Hence, if such a cross-sectional area of the notch groove portion 352b3 is made equivalent to the opening area of the fixed throttle 103c of the second pressure release passage 146a, then the first pressure release passage 146b also has the function of the second pressure release passage 146a, and the second pressure release passage 146a can be omitted.
As above, the specific description has been made of the contents of the present invention with reference to the preferred embodiments; however, it is self-evident that those skilled in the art can adopt a variety of modified forms based on the basic technical idea and teaching of the present invention.
For example, a structure can be adopted, in which, when the first valve portion 352a of the spool 352 is seated on the first valve seat 104e31, leakage is allowed within a range that does not hinder the reduction of the back pressure Pm.
Moreover, in each of the above-described embodiments, the second control valve 350 is disposed in the cylinder head 104; however, the second control valve 350 can be disposed in other members, each of which composes the housing, for example, the cylinder block, or alternatively, the second control valve 350 can be housed in a valve housing dedicated thereto, and can be disposed in the compressor housing.
Moreover, a mechanical control valve that does not include such a solenoid can be used as the first control valve 300.
Moreover, in each of the above-described embodiments, the variable displacement compressor 100 is defined to be the swash plate-type clutchless variable displacement compressor. However, the present invention is not limited to this, and the variable displacement compressor 100 can be defined to a variable displacement compressor equipped with an electromagnetic clutch or a variable displacement compressor driven by a motor.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2014-244252 | Dec 2014 | JP | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/JP2015/083693 | 12/1/2015 | WO | 00 |
