JP2004211589A - Compressor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce manufacturing cost by decreasing the number of man-hours for processing. <P>SOLUTION: In this compressor that controls the inclination angle of a swash plate 26 by a difference between pressure within a crank chamber 5 and inhale pressure where a piston 29 is held therebetween, a check valve 150 for preventing back-flow of refrigerant to the compressor is formed integrally on a valve housing 101 of an electromagnetic control valve 100 which is a main component of capacity control means, which is inserted into a valve containing hole 90 formed on a housing 6 of the compressor. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention is of a variable capacity swash plate type that controls the inclination angle of a swash plate according to a difference between a pressure in a crank chamber and a suction pressure through a piston, and a check valve that prevents return of refrigerant from an external refrigerant circuit. The present invention relates to a compressor including:
[0002]
[Prior art]
Recently, a variable capacity swash plate type compressor has often been incorporated in a cooling circuit used in a vehicle air conditioning system. In this compressor, the discharge capacity is controlled by adjusting the pressure in the crank chamber to adjust the inclination angle of the swash plate, and a capacity control means for that is introduced by introducing the pressure in the discharge pressure area into the crank chamber. A pressure introducing passage, a pressure introducing passage with a throttle for introducing the pressure in the crank chamber to the suction pressure region, and a control valve interposed in the pressure introducing passage to control the opening and closing of the pressure introducing passage. .
[0003]
In this compressor, a check valve is provided to prevent high-pressure refrigerant gas from flowing back into the compressor from the external refrigerant circuit when the compressor is stopped. The storage of the liquid refrigerant in the compressor is prevented as much as possible. This is because, when the storage of the liquid refrigerant is prevented as much as possible by the check valve, an excessive increase in the pressure in the compressor can be prevented, and the inclination angle of the swash plate at the time of start-up and the capacity return are speeded up. This is because rapid cooling is possible.
[0004]
At present, in a conventional compressor, a control valve for performing such a capacity control function and the above-described check valve are completely and separately assembled into two holes formed in a housing of the compressor. For example, see Patent Documents 1 and 2.)
[0005]
[Patent Document 1]
JP-A-10-205446
[0006]
[Patent Document 2]
Japanese Patent Publication No. 1-257777
[0007]
[Problems to be solved by the invention]
In the conventional compressor, since the control valve and the check valve for controlling the capacity are individually assembled in the holes machined in the compressor housing, there is a problem that the number of machining steps increases and the manufacturing cost increases. .
[0008]
The present invention has been made in view of the above circumstances, and has as its object to provide a compressor capable of reducing the number of processing steps and reducing costs.
[0009]
[Means for Solving the Problems]
According to the first aspect of the present invention, a first housing having a plurality of cylinder bores and a crank chamber, a piston slidably accommodated in each cylinder bore, and a suction chamber and a discharge valve communicating with the cylinder bore through a suction valve are provided. A second housing having a discharge chamber communicating therewith, a swash plate housed in the crank chamber, connected to each piston, and having a tilt angle controlled by a difference between a pressure in the crank chamber and a suction pressure across the piston; A capacity control unit that controls the inclination angle of the swash plate by adjusting the pressure in the crank chamber, and is interposed between the discharge chamber and a discharge port connected to an external refrigerant circuit, and is opened with a differential pressure equal to or higher than a set pressure. A check valve for permitting the flow of the refrigerant from the discharge chamber to the discharge port and constantly preventing the reverse flow of the refrigerant from the discharge port to the discharge chamber. Form one valve accommodating bore in managing, characterized in that incorporates a control valve which is the main element of the capacity control means to the valve accommodating hole and said check valve.
[0010]
According to a second aspect of the present invention, in the first aspect, the check valve is integrated with a valve housing of the control valve.
[0011]
According to a third aspect of the present invention, in the second aspect, the displacement control means includes a pressure introduction passage for introducing the pressure in the discharge pressure region to the crank chamber, and a pressure derivation with a throttle for leading the pressure in the crank chamber to the suction pressure region. A passage, and an electromagnetic control valve interposed in the pressure introduction passage for controlling opening and closing of the pressure introduction passage, and wherein the check valve is incorporated in a valve housing of the electromagnetic control valve, The check valve and the electromagnetic control valve are combined so that the set pressure of the check valve when the electromagnetic control valve is controlled to close is larger than the set pressure of the check valve when the control valve is fully open. It is characterized by having been done.
[0012]
The invention according to claim 4 is the compressor according to any one of claims 1 to 3, wherein the compressor is constantly rotated while the external drive source is being driven by directly connecting the external drive source to the drive shaft without a clutch mechanism. It is a clutchless compressor.
[0013]
【The invention's effect】
According to the first aspect of the present invention, one valve housing hole is formed in the compressor housing, and the control valve which is the main element of the capacity control means and the check valve for preventing the backflow of the refrigerant are incorporated in the valve housing hole. Therefore, the number of processes for the compressor housing can be reduced, and the manufacturing cost can be reduced.
[0014]
According to the second aspect of the present invention, since the check valve is integrally incorporated in the valve housing of the control valve, the valve housing is previously installed in the valve housing of the control valve and the valve housing is inserted into the valve housing hole of the compressor. , The assembly can be completed, the production is easy, and the cost can be further reduced.
[0015]
According to the third aspect of the present invention, the displacement control means includes: a pressure introduction passage for introducing the pressure in the discharge pressure region to the crank chamber; a pressure derived passage with a throttle for leading the pressure in the crank chamber to the suction pressure region; An electromagnetic control valve interposed in the middle of the introduction passage to control the opening and closing of the pressure introduction passage, and a check valve is incorporated in a valve housing of the electromagnetic control valve. Since the set pressure of the check valve when the electromagnetic control valve is controlled to close is larger than the set pressure of the check valve when the control valve is fully open, the capacity control by the electromagnetic control valve is started. The pressure in the discharge chamber at the time can be kept high, and the differential pressure between the crank chamber and the discharge chamber can be increased, so that the control response of the stroke adjustment by the electromagnetic control valve is improved. That is, since the pressure difference between the discharge chamber and the crank chamber can be increased, the responsiveness when the electromagnetic control valve is opened to change the pressure in the crank chamber is improved, and the displacement control can be speeded up.
[0016]
According to the invention of claim 4, since the compressor is a clutchless compressor, the compressor rotates even when the air conditioner is off. However, by using the opening force of the check valve (set pressure of the spring), the refrigerant can be circulated in the compressor with a low capacity when the air conditioner is turned off, and the discharge of the refrigerant to the external refrigerant circuit can be prevented. That is, when there is no check valve, when there is no check valve, the compressor rotates at the minimum inclination when the air conditioner is turned off, and the refrigerant gas is discharged from the compressor to the external refrigerant circuit. Even when the discharge capacity of the refrigerant is small compared to the normal operation, the evaporator produces a cooling action. However, since the fan is stopped when the air conditioner is off, if the air conditioner is off for a long time, cooling of the evaporator proceeds, and frost occurs in the evaporator. The occurrence of frost hinders the heat exchange action in the evaporator, and causes a situation in which a cooling action cannot be obtained when the air conditioner is restarted. However, according to the fourth aspect of the present invention, the check valve can prevent the refrigerant from being discharged to the external refrigerant circuit during low-volume circulation, thereby preventing the occurrence of frost in the evaporator.
[0017]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0018]
FIG. 1 is a cross-sectional view showing the overall configuration of the compressor of the embodiment, and FIGS. 2 to 5 are cross-sectional views showing the configuration and operation of a capacity control system centering on an electromagnetic control valve.
[0019]
First, an overall configuration of a compressor according to an embodiment will be described with reference to FIG. The compressor of this embodiment is a clutchless compressor and a swash plate type variable displacement compressor. In FIG. 1, reference numeral 1 denotes a housing of a swash plate type variable displacement compressor. A housing 1 of the swash plate type variable displacement compressor has a cylinder block 2 having a plurality of cylinder bores 3 and a front housing joined to a front end surface of the cylinder block 2 to form a crank chamber 5 with the cylinder block 2. And a rear housing 6 joined to the rear end face of the cylinder block 2 via a valve plate 9 to form a suction chamber 7 and a discharge chamber 8. The cylinder block 2, the front housing 4 and the rear housing 6 are fixed by through bolts. Here, the cylinder block 2 and the front housing 4 correspond to a first housing in claims, and the rear housing 6 corresponds to a second housing.
[0020]
The valve plate 9 includes a suction hole 11 that connects the cylinder bore 3 and the suction chamber 7, and a discharge hole 12 that connects the cylinder bore 3 and the discharge chamber 8. On the cylinder block 2 side of the valve plate 9, a metal suction plate 13 having a reed valve (suction valve) 13 v for opening and closing the suction hole 11 is provided, while on the rear housing 6 side of the valve plate 9, a discharge is provided. A metal discharge plate 14 having a reed valve (discharge valve) 14v for opening and closing the hole 12 and a retainer 15 for holding the discharge plate 14 and restricting the opening limit of the reed valve 14v are provided.
[0021]
A shaft support hole having bearings 17 and 18 for the drive shaft S is provided at the center of the cylinder block 2 and the front housing 4, and the drive shaft S is rotatably supported in the crank chamber 5. The front end of the drive shaft S protrudes outside from the front housing 4, and a pulley 50 is fixed to the protruding end. The pulley 50 is connected to the vehicle engine via a belt (not shown), and transmits the rotation of the engine to the drive shaft S without a clutch.
[0022]
Inside the crank chamber 5, a drive plate 21 fixed to the drive shaft S, a journal 24 swingably connected by a pin 23 to a sleeve 22 slidably fitted to the drive shaft S, and a journal 24. And a swash plate 26 fixed to the boss portion 25 via a bearing 20. The drive plate 21 and the journal 24 regulate the swing of the swash plate 26 by connecting their hinge arms 21h and 24h via an arc-shaped long hole 27 and a pin 28. Further, an inclination-reducing spring 19 is interposed between the drive plate 21 and the swash plate 26. The inclination reducing spring 19 biases the swash plate 26 in a direction to decrease the inclination of the swash plate 26.
[0023]
The piston 29 accommodated in each cylinder bore 3 is connected to the swash plate 26 via a connecting rod 30 and performs a piston motion using the rotational motion of the drive shaft S as a driving force. The basic function of the compressor is to compress the refrigerant sucked into the cylinder bore 3 through the suction chamber 7 and the suction hole 11 by the piston motion of the piston 29 and discharge the refrigerant from the cylinder bore 3 to the discharge chamber 8 through the discharge hole 12. That is.
[0024]
In this embodiment, as a capacity control means for making the discharge capacity variable, in the present embodiment, a pressure lead-out passage 31 communicating the crank chamber 5 with the suction chamber 7 and a pressure introduction passage communicating the crank chamber 5 with the discharge chamber 8. 32 and an electromagnetic control valve 100 that controls opening and closing of the pressure introduction passage 32. The electromagnetic control valve 100 controls the amount of refrigerant flowing through the pressure introduction passage 32, thereby adjusting the pressure in the crank chamber 5, changing the piston stroke, and changing the discharge capacity.
[0025]
The pressure outlet passage 31 limits the flow rate of the refrigerant (blow-by gas) fed back from the crank chamber 5 to the suction chamber 7. That is, the fixed throttle portion 35 provided in the pressure derivation path 31 for limiting the amount of refrigerant restricts the flow rate. The reason why the fixed throttle portion 35 is provided is that when the amount of the refrigerant flowing through the pressure lead-out passage 31 (the flow rate of the refrigerant fed back from the crank chamber 5 to the suction chamber 7) can be strictly controlled, the crank chamber 5, the suction chamber 7, and the protrusion chamber This is because it is possible to maintain the pressure balance with the compressor 8 in a favorable state, and it becomes easy to control the discharge capacity of the compressor. Actually, the pressure lead-out passage 31 is provided with a through-bolt through-hole for a through-bolt provided over the cylinder block 2, the valve plate 9 and the rear housing 6, and a through-hole through-hole in the rear housing and the suction chamber 7. And a through-hole communicating the above. A fixed throttle portion with a reduced passage area is provided on the way.
[0026]
The pressure introduction passage 32 has a passage 32 a formed in the rear housing 6 and the valve plate 9, a space 32 b formed so as to surround an end of the drive shaft S, and an end opened in the space 32 b. The other end of the shaft inside the drive shaft S extends in the axial direction of the shaft 32, and extends in the radial direction of the drive shaft S from the vertical hole 32 c and opens on the outer peripheral surface of the drive shaft S, thereby opening the inside of the crank chamber 5. It is composed of a shaft inner side hole 32d facing the space. In the figure, reference numerals are attached to arrows to indicate the passages.
[0027]
The provision of the vertical shaft hole 32c and the horizontal shaft hole 32d that constitute the pressure introduction passage 32 inside the drive shaft S is advantageous not only in terms of layout, but also in that the refrigerant finally enters the crank chamber 5 in the crank chamber 5. This is because the refrigerant containing the lubricating oil can be evenly distributed around the periphery by the centrifugal force generated by the rotation of the drive shaft S when the refrigerant is introduced into the drive shaft S.
[0028]
Next, the configuration of the electromagnetic control valve 100 for capacity control will be described in detail with reference to FIGS. 1 and 2 to 5.
[0029]
The electromagnetic control valve 100 incorporates a capacity control valve 130 as a main valve and a check valve 150 for preventing the refrigerant from flowing back to the compressor. The check valve 150 is interposed between the discharge chamber 8 and the discharge port 110 connected to the external refrigerant circuit 200. The check valve 150 opens at a differential pressure equal to or higher than the set pressure and opens from the discharge chamber 8 to the discharge port 110. The function of allowing the flow of the refrigerant to the discharge chamber 110 and preventing the backflow of the refrigerant from the discharge port 110 to the discharge chamber 8 at all times.
[0030]
The electromagnetic control valve 100 integrally provided with the check valve 150 inserts the valve housing 101 into the valve housing hole 90 formed in the rear housing 6 and snaps the solenoid case 102 provided at the rear part of the valve housing 101 into a snap ring. By fixing at 99, it is assembled to the rear housing 6. Here, by inserting the valve housing 101 of the electromagnetic control valve 100 into the valve housing hole 90 via the O-rings 91 to 94, various ports (described later) of the electromagnetic control valve 100 and the passages formed in the rear housing 6 are formed. Communication with the room is secured.
[0031]
The electromagnetic control valve 100 includes a solenoid case 102 at a rear portion in the insertion direction with respect to the valve housing hole 90, includes a solenoid 103 that is energized and controlled by a control device (not shown) inside the solenoid case 102, and includes a solenoid case 102 and a valve housing. A rod 105 having an armature 104 at a rear end is provided at the center of the center 101 so as to be slidable in the axial direction.
[0032]
The rod 105 is urged by a first spring 106 toward a lower end position shown in the figure, and is displaced to an upper position shown in the figure against the first spring 106 by energizing the solenoid 103. Here, when the solenoid 103 is not energized, the displacement control rod 130 is opened by the rod 105 being displaced downward by the force of the first spring 106, and the rod 105 is displaced upward by the magnetic force of the solenoid 103 when energized. The capacity control valve 130 is set to close.
[0033]
Inside the valve housing 101, a first chamber 121, a second chamber 122, and a third chamber 123 are formed in order from the solenoid 103 side. A valve hole 131 of the capacity control valve 130 is provided in a partition wall 125 between the first chamber 121 and the second chamber 122. The capacity control valve 130 includes the valve hole 131, a valve seat 132 around the valve hole 131, and a valve body 133 provided integrally with the rod 105 and housed in the first chamber 121. When the valve body 133 comes into contact with and separates from the valve seat 132, the valve hole 131 is opened and closed, and the first chamber 121 and the second chamber 122 are communicated or blocked.
[0034]
A first port 141 communicates with the first chamber 121, and the discharge chamber 8 communicates with the first port 141. A second port 142 communicates with the second chamber 122, and an opening end of the pressure introducing passage 32 on the rear housing 6 side communicates with the second port 142. Therefore, by controlling the opening / closing of the capacity control valve 130, the communication / cutoff between the discharge chamber 8 and the pressure introduction passage 32 can be controlled.
[0035]
The second chamber 122 and the third chamber 123 are partitioned by a partition wall 126, and the partition wall 126 is provided with a slide hole 127 through which the rod 105 passes. As described above, the rod 105 has the armature 104 at the base end in the longitudinal direction, and the valve body 133 of the capacity control valve 130 at the middle, and further has a sufficient distance between the rod 105 and the inner periphery of the valve hole 131 at the tip. A small-diameter cylindrical portion 105a that secures a large gap, a sliding cylindrical portion 105b that slides into the slide hole 127 as little as possible at the distal end, a spring receiving portion 105c at the distal end, and a distal cylindrical portion 105d at the further distal end. are doing.
[0036]
The spring receiving portion 105c and the distal end cylindrical portion 105d provided at the distal end of the rod 105 are housed in the third chamber 123 located ahead of the slide hole 127. The third chamber 123 has a front end surface opened, and a cap 155 having a valve hole 151 and a valve seat 152 of the check valve 150 is fixed to the front end opening. The valve hole 151 communicates with the discharge chamber 8 as a fourth port 144.
[0037]
The valve body 153 of the check valve 150 that opens and closes the valve hole 151 by coming into contact with and separating from the valve seat 152 is housed inside the third chamber 123. The lower end of the valve body 153 and the upper surface of the cylindrical end portion 105d of the rod 105 are opposed to each other with a predetermined interval (interval larger than the maximum displacement of the rod 105) in the initial state. A second spring 154 that regulates the set pressure (valve opening force) of the check valve 150 is interposed between the second spring 154 and the spring receiving portion 105c at the distal end of the second spring 154.
[0038]
The second spring 154 urges the valve body 153 in the closing direction, and the second spring 154, the valve body 153, the valve hole 151, and the valve seat 152 constitute a check valve 150. The third chamber 123 is a space on the downstream side of the check valve 150, and the third port 143 formed in the third chamber 123 communicates with the discharge port 110 formed in the rear housing 6.
[0039]
Here, the second spring 154 that regulates the set pressure of the check valve 150 with respect to the valve body 153 is interposed between the spring receiving portion 105c at the tip of the rod 105 and the valve body 153 as described above, and the valve body 153 is provided. Since a predetermined distance is provided between the valve 153 and the rod 105, the set pressure of the check valve 150 when the capacity control valve 130 is fully opened (when the rod 105 is at the lower end position) is smaller than the set pressure of the check valve 150. Is controlled to the closed side (when the rod 105 is displaced upward from the lower end position), the set pressure of the check valve 150 is increased by the amount by which the second spring 154 is compressed.
[0040]
When the external refrigerant circuit 300 is connected to the compressor having the electromagnetic control valve 100 having the above configuration, both ends of the external refrigerant circuit 300 are connected to the discharge port 110 and a suction port (not shown) communicating with the suction chamber 7. On the same circuit, a condenser 301, an expansion valve 302, and an evaporator 303 are arranged in this order from the discharge port 110 side. This will complete the cooling cycle.
[0041]
In the case of this compressor, as described above, one valve accommodating hole 90 is formed in the rear housing 6 of the compressor, and the capacity control valve 130 and the check valve 150 are integrally assembled in the valve accommodating hole 90. Since the control valve 100 is inserted and arranged, the number of holes formed in the rear housing 6 can be reduced, and the manufacturing cost can be reduced. In particular, since two valves (capacity control valve 130 and check valve 150) that perform different functions are incorporated in the same valve housing 101, the electromagnetic control valve 100 is assembled outside in advance and set in the valve housing hole 90. Only the assembly can be completed, the production is easy, and the cost can be reduced.
[0042]
Next, the operation will be described mainly with reference to FIGS.
[0043]
In the case of this compressor, since the clutch is not used, the drive shaft S constantly rotates while the vehicle engine is driven. The compressor control device (not shown) energizes the solenoid 103 of the electromagnetic control valve 100 when the air conditioner switch is turned on (air conditioner is turned on) (this state is also simply referred to as “electromagnetic control valve ON”), and the air conditioner switch is turned off (air conditioner is turned off) To stop the energization of the solenoid 103 (this state is also simply referred to as "electromagnetic control valve OFF"). In addition, the control device controls the energization of the solenoid 103 according to the cooling load in a state where a cooling request is made (the air conditioner is ON) in the form of a current value control, a duty control, or the like.
[0044]
In the following description, for convenience, the following symbols are used as the pressure of each part.
[0045]
Pd1: pressure mainly in the discharge chamber 8
Pd: Pressure after passing through check valve 150 (compressor discharge port pressure)
Pc: pressure in crankcase 5
Pd2: Pd1 itself or a pressure obtained by reducing Pd1 with a throttle
(However, Pd1>Pd2> Pc)
Ps: suction pressure
First, the case where the electromagnetic control valve 100 is OFF (the air conditioner is OFF) will be described.
At this time, as shown in FIG. 2, since the rod 105 is displaced to the lower position by the force of the first spring 104, the valve body 133 is separated from the valve seat 132, and the displacement control valve 130 is fully opened.
[0046]
Since the swash plate 26 has a minimum inclination angle set to a value slightly larger than “0 °” to maintain the pressure balance in the compressor, the pressure Pd1 is applied to the discharge chamber 8 as long as the drive shaft S is rotating. Occurs and the displacement control valve 130 is "open" when the electromagnetic control valve is turned off, and the pressure Pd2 generated based on the pressure Pd1 of the discharge chamber 8 (the pressure in the discharge pressure region) is reduced by the pressure introduction passage. It is introduced into the crankcase 5 through 32.
[0047]
That is, even when the swash plate 26 is at the minimum inclination angle, the refrigerant gas is discharged from the cylinder bore 2 into the discharge chamber 8, and the refrigerant gas flows into the crank chamber 5 through the capacity control valve 130 and the pressure introduction passage 32. Further, the refrigerant gas in the crank chamber 5 flows into the suction chamber 7 through the pressure outlet passage 31, and the refrigerant gas in the suction chamber 7 is sucked into the cylinder bore 2 again and discharged to the discharge chamber 8. At this time, the swash plate 26 is held at the destroke position by the pressure difference between the pressure Pc of the crank chamber 5 and the suction pressure Ps.
[0048]
Here, as described in the description of the reference numerals, the pressure Pd2 actually introduced into the crank chamber 5 may be the pressure Pd1 of the discharge chamber 8 itself (Pd1 = Pd2), but Pd1> Pd2 (however, , Pd2> Pc). Hereinafter, description will be made assuming that “Pd1 = Pd2” for simplification.
[0049]
In the case of the minimum discharge capacity operation in the destroke state, the difference (Pd1−Pd) = ΔPd between the pressure Pd1 of the discharge chamber 8 and the pressure Pd of the discharge port 110 is small, and the differential pressure (Pd1−Pd) is reduced by the second spring. Since the setting of the force of the second spring 154 is set such that the force of the second spring 154 is greater than that of the second spring 154, the check valve 150 maintains the closed state. When the displacement control valve 130 is opened and the pressure Pd1 (= Pd2) of the discharge chamber 8 is continuously supplied to the crank chamber 5, the pressure Pc of the crank chamber 5 increases, and the inclination angle of the swash plate 26 is substantially reduced. The operation is maintained at zero and the operation with the minimum capacity is continued. When the check valve 150 is closed, the refrigerant does not flow out to the external refrigerant circuit 300 and circulates in the compressor with the minimum capacity.
[0050]
That is, when the swash plate 26 is at the minimum inclination angle, the refrigerant circulates in a route that sequentially passes through the discharge chamber 8, the pressure introduction passage 32, the crank chamber 5, the pressure derivation passage 31, the suction chamber 7, and the cylinder bore 2. Further, when the refrigerant gas circulates through the compressor, the lubricating oil flowing together with the refrigerant gas lubricates each part in the compressor.
[0051]
Therefore, in this case, since the refrigerant does not go out to the external refrigerant circuit 300, there is no fear of occurrence of frost in the evaporator 303.
[0052]
Next, a case where the electromagnetic control valve 100 is ON (the air conditioner is ON) will be described.
[0053]
When the air conditioner switches from the air conditioner OFF state to the air conditioner ON state, the electromagnetic control valve 100 is turned from OFF to ON, so that the rod 105 is displaced to the upper position by the magnetic force of the solenoid 103 as shown in FIG. The valve body 133 comes into close contact with the valve seat 132, and the capacity control valve 130 is closed.
[0054]
When the displacement control valve 130 is closed, the supply of the refrigerant gas from the discharge chamber 8 to the crank chamber 5 is shut off, so that the refrigerant gas in the crank chamber 5 flows out to the suction chamber 7 via the pressure lead-out passage 31. The pressure Pc in the crank chamber 5 approaches the low pressure (suction pressure) Ps in the suction chamber 7. Therefore, the inclination angle of the swash plate 26 increases, and the discharge capacity increases accordingly.
In the initial stage of turning on the air conditioner, the push-up of the rod 105 compresses the second spring 154 of the check valve 150 more than when the air conditioner is turned off, so that the set pressure of the check valve 150 increases (that is, the valve is opened). As a result, the discharge pressure Pd1 is kept high.
[0055]
Eventually, as the displacement increases due to the increase in the inclination angle of the swash plate 26, the differential pressure (Pd1-Pd) before and after the check valve 150 increases, and when the differential pressure exceeds the set pressure of the second spring 154. As shown in FIG. 4, the valve body 153 of the check valve 150 is pushed down, the check valve 150 opens, and the refrigerant gas in the discharge chamber 8 flows to the discharge port 110, and from the discharge port 110 to the external refrigerant circuit 300. Flowing out.
[0056]
FIG. 4 shows a state in which the second spring 154 is compressed to the maximum, and the valve body 153 of the check valve 150 is in contact with the tip of the rod 105.
[0057]
Thereafter, by adjusting the substantial opening of the capacity control valve 130 in accordance with the cooling load, the pressure in the crank chamber 5 is adjusted, and the discharge capacity of the compressor is controlled.
[0058]
For example, when the cooling load is high, the amount of refrigerant gas discharged from the discharge chamber 8 to the crank chamber 5 decreases, so that the pressure Pc in the crank chamber 5 decreases. As a result, the discharge capacity increases. When the cooling load is low, the amount of refrigerant gas discharged from the discharge chamber 8 to the crank chamber 5 increases, so that the pressure Pc in the crank chamber 5 increases. It becomes smaller and the discharge capacity decreases.
As described above, the set pressure (valve opening pressure) of the check valve 150 is changed according to the switching of the air conditioner from OFF to ON, so that when the electromagnetic control valve 100 is energized, the set pressure (valve opening pressure) is high. The check valve 150 will operate. As a result, the pressure in the discharge chamber 8 at the time when the check valve 150 is opened is maintained high, and the pressure difference between the crank chamber 5 and the discharge chamber 8 can be increased. The control response of the stroke adjustment is improved. That is, as the differential pressure between the discharge chamber 8 and the crank chamber 5 is larger, the response when the electromagnetic control valve 100 is opened to change the pressure in the crank chamber 5 (when performing capacity control) is improved, and the variable capacity compressor as a variable capacity compressor is improved. Performance is improved.
[0059]
FIG. 6 shows the relationship between the differential pressure ΔPd = Pd1−Pd of the check valve 150 and the discharge flow rate Q. Due to the change of the set pressure of the check valve 150 when the electromagnetic control valve is ON (the curve shown by the dotted line), the pressure Pd1 of the discharge chamber 8 is maintained higher than in the conventional case where the set pressure is not changed (solid line). You.
[0060]
Conversely, since the set pressure of the check valve 150 at the time of OFF can be made lower than that at the time of the electromagnetic control valve being ON, the discharge chamber when the compressor is running with the minimum discharge capacity when the power supply is OFF. The relief pressure can be set low, and the safety when the pressure rises when power is turned off can be improved.
[0061]
If the discharge pressure Pd1 rises abnormally while the compressor is being controlled by turning on the electromagnetic control valve 100, for example, if the piston stroke is too large, the pressure Pd1 of the discharge chamber 8 becomes abnormally high. In the case where the displacement has occurred, as shown in FIG. 5, the second spring 154 of the check valve 150 is compressed to the maximum, the valve body 154 hits the tip of the rod 105, and pushes down the rod 105. 130 is opened. Thereby, the refrigerant flows from the discharge chamber 8 to the crank chamber 5, and the pressure Pc of the crank chamber 5 increases, thereby reducing the piston stroke. That is, a safety function for recovering from the abnormal state to the normal state automatically operates.
[0062]
The force when the rod 105 is actually pushed down is as follows.
[0063]
The downward resultant force acting on the upper portion of the rod 105 (the force in the direction of opening the capacity control valve 130) is
(Pd1 × E) + Pd (CE) −Pc (CB)
The upward resultant force acting on the lower portion (the force in the direction of closing the capacity control valve 130) is
(Pd2 × A) -Pc (AB) -f1 + Fisol
When the downward force exceeds the upward force, the rod 105 is pushed down, the capacity control valve 130 is opened, and the pressure of the discharge chamber 8 flows into the crank chamber 5.
[0064]
However, in the above equation,
A: Area of valve hole 131 of displacement control valve 130
B: Cross-sectional area of small-diameter cylindrical portion 105a of rod 105
C: cross-sectional area of the sliding portion 105b of the rod 105
E: cross-sectional area of the end cylindrical portion 105d of the rod 105
f1: force by the first spring 104
Fisol: Force by solenoid 103
It is.
[0065]
Next, a case where the vehicle engine is stopped will be described.
[0066]
When the vehicle engine stops, the compressor also stops, and the rotation of the swash plate 26 stops. Also, the electromagnetic control valve 100 is turned off, and the inclination angle of the swash plate 26 is minimized. If the operation stoppage of the compressor continues, the pressure in the compressor becomes uniform, but the inclination angle of the swash plate 26 is maintained at the minimum inclination angle by the spring force of the inclination reduction spring 19. Therefore, the next time the compressor is started to operate by starting the vehicle engine, the swash plate 26 starts to rotate from the minimum tilt state where the load torque is the least, and there is almost no shock when the compressor is started.
[0067]
Also, the compressor has a characteristic that it is harder to warm up and cools more easily than the condenser 301 and the evaporator 303 which are heat exchangers on the external refrigerant circuit 300. The refrigerant in the circuit 300 flows into the compressor, liquefies in the compressor, and the liquid refrigerant easily accumulates in the compressor. However, since the check valve 150 prevents the refrigerant from flowing back from the external refrigerant circuit 300, the liquid in the compressor is It is possible to avoid adverse effects such as wear and seizure in the compressor due to accumulation of the refrigerant. In addition, since the check valve 150 prevents the backflow of the refrigerant, the capacity can be quickly restored when the air conditioner is turned on.
[0068]
Further, in the case of the clutchless compressor, the engine load increases because the number of revolutions of the compressor increases when the vehicle is requested to accelerate. At that time, the power supply to the electromagnetic control valve 100 is turned off to turn off the displacement control valve. By opening 130 and controlling the swash plate 26 to the minimum displacement position, the engine load can be reduced, and fuel efficiency can be improved and acceleration can be improved.
[0069]
In the above-described embodiment, the control valve is configured by an electromagnetic control valve. However, in the present invention, the control valve may be a mechanical control valve using, for example, a bellows. In the above-described embodiment, the compressor is a clutchless compressor, but may be a compressor with a clutch in the present invention.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view illustrating an overall configuration of a compressor according to an embodiment of the present invention.
FIG. 2 is a configuration diagram centering on an electromagnetic control valve 100 of a displacement control system of the compressor, and is a cross-sectional view showing a state when the electromagnetic control valve 100 is OFF.
FIG. 3 is a cross-sectional view showing a state when the electromagnetic control valve 100 is ON and a check valve 150 is closed.
FIG. 4 is a cross-sectional view showing a state when the electromagnetic control valve 100 is turned on, a check valve 150 is opened, and a valve body 153 of the check valve 150 comes into contact with a tip of a rod 105 of the electromagnetic control valve 100. is there.
FIG. 5 is a diagram showing a state in which the electromagnetic control valve 100 is turned on. When the discharge pressure is excessively increased, the valve body 153 of the check valve 150 pushes down the rod 105 of the electromagnetic control valve 100 to forcibly perform electromagnetic control. FIG. 3 is a cross-sectional view illustrating a state in which a capacity control valve 130 that is a main valve of the valve 100 is opened.
FIG. 6 is a diagram showing characteristics of the compressor of the embodiment.
[Explanation of symbols]
2 Cylinder block (first housing)
3 Cylinder bore
4 Front housing (first housing)
5 Crankcase
6. Rear housing (second housing)
7 Inhalation chamber
8 Discharge chamber
13v suction valve
14v discharge valve
26 Swash plate
29 piston
31 Pressure lead-out passage (capacity control means)
32 pressure introduction passage (capacity control means)
35 Fixed throttle
90 Valve accommodation hole
100 Electromagnetic control valve (capacity control means)
110 Discharge port
150 check valve
300 External refrigerant circuit

Claims (4)

A first housing (2, 4) having a plurality of cylinder bores (3) and a crank chamber (5), a piston (29) slidably housed in each cylinder bore (3), and a suction valve in the cylinder bore (3) A second housing (6) having a suction chamber (7) communicating through the (13v) and a discharge chamber (8) communicating through the discharge valve (14v); and a second housing (6) housed in the crank chamber (5). A swash plate (26) connected to each piston (29) and having a tilt angle controlled by a difference between a pressure in the crank chamber (5) and a suction pressure across the piston (29); Capacity control means (100, 31, 32) for controlling the tilt angle of the swash plate (26) by adjusting the internal pressure, and a discharge port () connected to the discharge chamber (8) and the external refrigerant circuit (300). 110) and between the set pressure Check valve that opens at the pressure difference between the front and rear to allow the flow of the refrigerant from the discharge chamber (8) to the discharge port (110) and always prevents the backflow of the refrigerant from the discharge port (110) to the discharge chamber (8). (150).
One valve housing hole (90) is formed in the second housing (6), and the control valve (100) and the check valve (150), which are main elements of the capacity control means, are formed in the valve housing hole (90). ). The compressor according to claim 1, wherein the check valve (150) is integrated into a valve housing (101) of the control valve (100). The displacement control means includes a pressure introduction passage (32) for introducing pressure in a discharge pressure region to the crank chamber (5), and a pressure with a throttle (35) for leading pressure in the crank chamber (5) to a suction pressure region. An electromagnetic control valve (100) interposed in the middle of the pressure introducing passage (32) and controlling opening and closing of the pressure introducing passage (32); and the electromagnetic control valve (100). ), The check valve (150) is incorporated in the valve housing (101);
The set pressure of the check valve (150) when the electromagnetic control valve (100) is controlled to close is larger than the set pressure of the check valve (150) when the electromagnetic control valve (100) is fully opened. The compressor according to claim 2, characterized in that the check valve (150) and the electromagnetic control valve (100) are combined so that the check valve (150) and the electromagnetic control valve (100) are combined. The compressor according to any one of claims 1 to 3,
The compressor according to claim 1, wherein the compressor is a clutchless compressor that is always rotated during driving of the external drive source by directly connecting the external drive source to the drive shaft (S) without a clutch mechanism.

Images