JP4160407B2 - Variable capacity swash plate compressor - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a variable capacity swash plate type compressor that controls an inclination angle of a swash plate according to a difference between a pressure in a crank chamber and a suction pressure via a piston.
[0002]
[Prior art]
Recently, variable capacity swash plate compressors have often been incorporated into cooling circuits used in vehicle air conditioning systems. As this compressor, one having a structure as shown in FIG. 4 is known (see, for example, Patent Document 1 and Patent Document 2).
[0003]
The compressor includes a first housing 103 having a plurality of cylinder bores 101 and a crank chamber 102, a piston 104 slidably accommodated in each cylinder bore 101, and a suction chamber 106 communicating with the cylinder bore 101 via a suction valve 105. And a second housing 109 having a discharge chamber 108 that communicates with each other via a discharge valve 107, a pressure in the crank chamber 102 that is housed in the crank chamber 102 and connected to each piston 104 and sandwiching the piston 104. A swash plate 110 whose tilt angle is controlled by a difference from the suction pressure and a capacity control means 111 for controlling the tilt angle of the swash plate 110 by adjusting the pressure in the crank chamber 102 are provided.
[0004]
Here, the capacity control means 111 includes a pressure introduction passage 112 that introduces the pressure in the discharge pressure region into the crank chamber 102, and a capacity control valve 113 that is interposed in the middle of the pressure introduction passage 112 and controls the opening and closing of the pressure introduction passage 112. And a pressure derivation passage 115 provided with a fixed throttle 114 for deriving the pressure in the crank chamber 102 to the suction pressure region.
[0005]
In this compressor, when the displacement control valve 113 is opened and the pressure in the discharge pressure region is introduced into the crank chamber 102, the inclination of the swash plate 110 is reduced due to the increase in the back pressure acting on the piston 104, and the piston stroke is reduced. It becomes smaller and the discharge capacity decreases. Further, when the displacement control valve 113 is closed and the pressure in the discharge pressure region is not introduced into the crank chamber 102, the inclination of the swash plate 110 increases due to the drop in the back pressure acting on the piston 104, and the piston stroke increases. The discharge capacity increases.
[0006]
For example, when the capacity control valve 113 is a bellows type, when the cooling load is small, the suction pressure decreases, so the bellows expands and the capacity control valve 113 opens, and the discharge pressure is introduced into the crank chamber 102. As a result, the piston stroke becomes smaller and the discharge capacity decreases. Further, when the cooling load is large, the suction pressure becomes high, so that the bellows contracts and the capacity control valve 113 is closed, and the discharge pressure is not introduced into the crank chamber 102, the piston stroke becomes large and the discharge capacity increases.
[0007]
[Patent Document 1]
JP 2002-250277 A (FIG. 1)
[0008]
[Patent Document 2]
Japanese Patent No. 3289454
[0009]
[Problems to be solved by the invention]
By the way, in the conventional compressor, a large amount of liquid refrigerant is accumulated in the crank chamber 102 due to the state in which the vehicle is left while the compressor is stopped (outside air state, etc.). This makes it difficult for the liquid refrigerant to escape, so that the startability of the swash plate 110 is deteriorated (the swash plate start-up delay occurs), and there is a problem that it takes time for the air conditioner to emit cold air.
[0010]
Therefore, in order to quickly extract the liquid refrigerant from the crank chamber 102, attempts have been made to increase the cross-sectional area of the pressure derivation passage 115 from the crank chamber 102 to the suction chamber 106 as much as possible, but the performance during normal operation is considered. And it had a limit. That is, if the passage sectional area of the pressure derivation passage 115 is widened to improve the escape of the liquid refrigerant, a phenomenon that the amount of high pressure introduced into the crank chamber 102 becomes insufficient during low load operation occurs, and the pressure in the crank chamber 102 is reduced. As a result, the operation of the swash plate 110 remains large, that is, the operation is continued with a large discharge capacity, and there is a possibility that problems such as freezing of the evaporator occur.
[0011]
Therefore, for example, when demisting is performed by a low load operation, the cooling is excessively effective and the problem of freezing may occur.
[0012]
In view of the above circumstances, an object of the present invention is to provide a variable capacity swash plate compressor that can achieve both the startability of the swash plate and the demist performance.
[0013]
[Means for Solving the Problems]
  According to a 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 via a suction valve are provided. A second housing having a discharge chamber communicating therewith, a swash plate housed in the crank chamber and connected to each piston, the inclination angle of which is controlled by the difference between the pressure in the crank chamber sandwiching the piston and the suction pressure; Capacity control means for controlling the inclination angle of the swash plate by adjusting the pressure in the chamber, the capacity control means introducing a pressure in the discharge pressure region into the crank chamber, and a pressure introduction passage for the pressure introduction passage. A variable capacity swash plate type composed of a capacity control valve that controls the opening and closing of the pressure introduction passage interposed in the middle, and a pressure derivation passage that guides the pressure in the crank chamber to the suction pressure region In the compressor, as the pressure derivation passage, the first pressure derivation passage with a fixed opening that is always open and the capacity control valve interposed in the pressure introduction passage are opened to the closed side, and the capacity control valve is opened. A second pressure derivation passage having an on-off valve that is closed when actuated to the open side;A flow path switching valve that functions as the on-off valve is provided in the middle of the pressure introduction path, and the flow path switching valve is located upstream of the flow path switching valve in the pressure introduction path and on the same downstream side. The second passage and the third passage communicating with the first pressure introduction passage closer to the suction chamber than the fixed throttle, and the capacity control valve is closed. When actuated, the first switching position is operated to connect the second passage and the third passage, and the first passage is shut off. When the capacity control valve is actuated to the open side, When the second switching position is operated, the first passage and the second passage are communicated with each other and the third passage is blocked. When the flow path switching valve is operated to the first switching position That the second passage and the third passage serve as the second pressure derivation passage. And butterflies.
[0015]
  Claim2The invention of claim1In the variable capacity swash plate compressor described above, the flow path switching valve includes a valve body that switches the flow path and a spring that biases the valve body in a certain direction, and the flow path switching valve is When the displacement control valve interposed in the pressure introduction passage is operated to the closed side, the valve body is displaced to the first switching position by the force of the spring as the pressure in the first passage decreases. When the second passage and the third passage are communicated and the first passage is shut off, and the capacity control valve is operated to the open side, the valve body is resisted against the force of the spring by the increase in the pressure of the first passage. By being displaced to the second switching position, the first passage and the second passage are communicated and the third passage is blocked.
[0016]
  Claim3The invention of claim 1Or claim 2The variable displacement swash plate type compressor described above is characterized in that the downstream portion of the pressure introduction passage passes through the inside of a drive shaft connected to the swash plate and opens to the outer peripheral surface of the shaft.
[0017]
【The invention's effect】
  According to the first aspect of the present invention, at the time of high load operation such as when the air conditioner is started, the second pressure deriving passage is opened as the displacement control valve operates to the closed side. In addition, the pressure in the crank chamber can be released from the second pressure derivation passage. Accordingly, the pressure in the crank chamber can be quickly released by substantially increasing the passage cross-sectional area of the pressure derivation passage, and the startability of the swash plate can be improved, and the cooling performance especially at the start can be improved. Also, during low load operation such as when the temperature is close to the required temperature, the second pressure derivation passage is closed as the displacement control valve is opened, so the first pressure with a fixed throttle is provided. The pressure in the crank chamber is released only from the outlet passage. Therefore, it becomes difficult for the pressure in the crank chamber to be released, so that the pressure in the crank chamber is not insufficient, and the inclination angle of the swash plate is kept small, and low discharge capacity is maintained, thereby causing problems such as freezing. No longer. Therefore, according to the present invention, it is possible to improve the operation performance of the swash plate at the time of starting the compressor while maintaining the demist performance (the ability to maintain the dehumidifying capacity by cooling without freezing), and when the air conditioner is ON. Increased cooling power.Further, a flow path switching valve is provided in the middle of the pressure introduction passage, and when the capacity control valve is operated to the closed side, the downstream second passage divided by the flow path switching valve is replaced with the second pressure derivation passage. Since it is shared as a part, the extra processing of the second pressure derivation passage can be reduced by the shared amount. Therefore, the second pressure derivation passage can be secured without excessive processing, and a wider passage cross-sectional area can be easily secured.
[0019]
  That is, in the conventional compressor, the pressure introduction passage is used only for pressure introduction, and the pressure derivation passage is used only for pressure derivation.1In this invention, when the pressure introduction passage is not used (when no pressure is introduced into the crank chamber), a part of the pressure introduction passage (second passage on the downstream side) is used as a part of the second pressure lead-out passage. I am trying to use it. Therefore, there is no need to forcibly lay out the second pressure derivation passage, processing becomes easy, and passage cross-sectional area can be easily secured.
[0020]
  Claim2According to the invention, the flow path switching valve is constituted by a valve body and a spring, and the flow path switching is automatically performed by the pressure on the upstream side (first path) of the pressure introduction path. Is simple and not costly. That is, the previous claim1In the present invention, for example, the use of an electromagnetic flow path switching valve was included as a possibility.2In this invention, the cost is reduced by using a flow path switching valve having a simple structure constituted by a valve body and a spring.
[0021]
  Claim3According to the invention, since the downstream portion of the pressure introducing passage is opened to the outer peripheral surface of the shaft through the inside of the drive shaft, the lubricating oil is uniformly included in the surroundings by the centrifugal force due to the rotation of the drive shaft. The refrigerant can be sprinkled.
[0022]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0023]
FIG. 1 is a cross-sectional view showing an overall configuration of a variable capacity swash plate compressor according to an embodiment. In the figure, 1 is a housing of the compressor. The housing 1 includes a cylinder block 2 having a plurality of cylinder bores 3, a front housing 4 joined to the front end face of the cylinder block 2 and forming a crank chamber 5 between the cylinder block 2, A rear housing 6 that forms a suction chamber 7 and a discharge chamber 8 by being joined to the rear end surface via a valve plate 9 is provided. The cylinder block 2, the front housing 4, and the rear housing 6 are fixed by through bolts B. Here, the cylinder block 2 and the front housing 4 correspond to a first housing, and the rear housing 6 corresponds to a second housing.
[0024]
The valve plate 9 includes a suction hole 11 that communicates the cylinder bore 3 and the suction chamber 7, and a discharge hole 12 that communicates 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) 13v for opening and closing the suction hole 11 is provided, while on the rear housing 6 side of the valve plate 9, discharge is performed. 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 of the reed valve 14v are provided.
[0025]
A shaft support hole having bearings 17 and 18 of 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 outward from the front housing 4, and a pulley 51 is fixed to the protruding end via an electromagnetic clutch 50. The pulley 51 is connected to the vehicle engine via a belt (not shown), receives the rotation of the engine, and transmits power to the drive shaft S via the electric clutch 50.
[0026]
Inside the crank chamber 5, a drive plate 21 fixed to the drive shaft S, a journal 24 slidably connected to a sleeve 22 slidably fitted on the drive shaft S by a pin 23, and the 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 the hinge arms 21h and 24h via the arc-shaped long hole 27 and the pin 28. Further, an inclination angle reducing spring 19 is interposed between the drive plate 21 and the swash plate 26. The inclination-decreasing spring 19 urges the swash plate 26 in a direction to reduce the inclination angle of the swash plate 26.
[0027]
The pistons 29 accommodated in the respective cylinder bores 3 are connected to the swash plate 26 via the connecting rods 30 and perform piston movement using the rotational movement 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 movement of the piston 29 and discharge the refrigerant from the cylinder bore 3 to the discharge chamber 8 through the discharge hole 12. That's it.
[0028]
As a capacity control means 60 for making the discharge capacity variable, in this compressor, a first pressure deriving passage 61 and a second pressure deriving passage 68 (described later) communicating the crank chamber 5 and the suction chamber 7 are provided. A pressure introduction passage 62 that communicates the crank chamber 5 and the discharge chamber 8 and a capacity control valve 65 that controls the opening and closing of the pressure introduction passage 62 are provided. The capacity control valve 65 controls the amount of refrigerant flowing through the pressure introduction passage 62, thereby adjusting the pressure in the crank chamber 5 and changing the piston stroke to change the discharge capacity.
[0029]
The first pressure derivation passage 61 has a refrigerant flow rate fed back from the crank chamber 5 to the suction chamber 7 (the refrigerant introduced into the crank chamber 5 from the discharge chamber 8 and the blow-by gas suction chamber 7 accompanying the compression operation of the piston 29). The function of limiting the return refrigerant flow rate).
[0030]
That is, the fixed throttle portion 64 provided in the middle of the first pressure derivation path 61 limits the flow rate of the refrigerant flowing from the crank chamber 5 to the suction chamber 7. The fixed throttle portion 64 is provided if the amount of refrigerant flowing through the first pressure derivation passage 61 (refrigerant flow rate fed back from the crank chamber 5 to the suction chamber 7) can be strictly managed, and the crank chamber 5 and the suction chamber 7 are provided. This is because the pressure balance with the discharge chamber 8 can be maintained in a good state, and the discharge capacity of the compressor can be easily controlled.
[0031]
The pressure introduction passage 62 includes a passage 62a formed in the rear housing 6 and the valve plate 9 that sequentially communicate with each other, a space 62b formed on the rear end surface of the cylinder block 2 so as to surround the end of the drive shaft S, An internal shaft longitudinal hole 62c that has one end opened in 62b and the other end extends in the axial direction inside the drive shaft S, and extends in the radial direction of the drive shaft S from the longitudinal hole 62c and opens on the outer peripheral surface of the drive shaft S. In this way, it is constituted by a shaft inner side hole 62d facing the space in the crank chamber 5. In the figure, the arrow indicates the path.
[0032]
The internal shaft longitudinal hole 62c and the shaft lateral hole 62d constituting the pressure introduction passage 62 are provided inside the drive shaft S in addition to the layout advantage. This is because the refrigerant containing the lubricating oil can be sprinkled all around by the centrifugal force generated by the rotation of the drive shaft S.
[0033]
In addition, the first pressure derivation passage 61 is configured as a passage with a fixed throttle 64 that is always open. However, a second pressure derivation passage 68 that is controlled to open and close by the on-off valve 70 is newly provided. Is provided. The on-off valve 70 is opened when the displacement control valve 65 is actuated to the closed side, and is closed when the displacement control valve 65 is actuated to the open side. In the compressor of this embodiment, pressure introduction is performed. A flow path switching valve is provided in the middle of the passage 62. That is, a flow path switching valve that functions as an on-off valve 70 that opens and closes the second pressure derivation passage 68 is interposed near the pressure introduction passages 62a to 62b connected from the valve plate 9 side to the cylinder block 2 side. .
[0034]
2 and 3 are cross-sectional views schematically showing details of the capacity control means 60 including the capacity control valve 65, the pressure introduction passage 62, the pressure derivation passages 61 and 68, the on-off valve 70, and the like.
[0035]
Since the above-described opening / closing valve 70 as the flow path switching valve is interposed in the middle of the upstream portion of the pressure introducing passage 62, the pressure introducing passage 62 is located downstream from the first passage 81 upstream of the opening / closing valve 70. It is divided into a second passage 82 on the side. Further, a third passage 83 communicating with the first pressure introduction passage 61 is further connected to the opening / closing valve 70 on the suction chamber 7 side of the fixed throttle 64, so that the opening / closing valve 70 is connected to the first to first valves. The three passages 81 to 83 are connected to and cut off from each other.
[0036]
The on-off valve 70 includes a valve body 71 that switches a flow path and a spring 72 that biases the valve body 71 in a certain direction. That is, a working chamber 73 in which the valve body 71 slides is formed in the cylinder block 2 and the valve plate 9 (the installation location is not particularly limited), and the valve body 71 is slidably accommodated in the working chamber 73. The first passage 81, the second passage 82, and the third passage 83 are connected to the inner wall of the working chamber 73, and the valve body 71 is biased to the first switching position shown in FIG. Has been.
[0037]
The valve body 71 is positioned at the first switching position by the force of the spring 72 when the pressure in the first passage 81 is low, and when the pressure is in the first switching position, the valve body 71 shields the first passage 81. At the same time, the second passage 82 and the third passage 83 are communicated. Further, when the pressure in the first passage 81 is high, the valve body 71 is pushed against the spring 72 to the second switching position shown in FIG. 3 by the pressure, and when in the second switching position, the valve The body 71 shields the third passage 83 and allows the first passage 81 and the second passage 82 to communicate with each other.
[0038]
That is, as shown in FIG. 2, the on-off valve 70 as the flow path switching valve is operated to the first switching position when the displacement control valve 65 is operated to the closed side, thereby As shown in FIG. 3, when the displacement control valve 65 is operated to the open side as shown in FIG. The first passage 81 and the second passage 82 are communicated and the third passage 83 is blocked. The second passage 82 and the third passage 83 function as the second pressure derivation passage 68 when the on-off valve 70 is operated to the first switching position shown in FIG.
[0039]
Next, the operation will be described.
[0040]
In this compressor, when the capacity control valve 65 is opened and the pressure of the discharge chamber 8 is introduced into the crank chamber 5, the inclination of the swash plate 29 is reduced due to the increase of the back pressure acting on the piston 29, and the piston stroke is reduced. It becomes smaller and the discharge capacity decreases.
[0041]
Further, when the capacity control valve 65 is closed and the pressure of the discharge chamber 8 is not introduced into the crank chamber 5, the inclination of the swash plate 26 increases due to the fall of the back pressure acting on the piston 29, and the piston stroke increases. The discharge capacity increases.
[0042]
The capacity control valve 65 may be an electromagnetic control valve or a bellows type control valve. For example, when the capacity control valve 65 is a bellows type valve, when the cooling load is small, the suction chamber 7 Since the pressure is lowered, the bellows is extended and the capacity control valve 65 is opened, the pressure in the discharge chamber 8 is introduced into the crank chamber 5, the piston stroke is reduced, and the discharge capacity is reduced. Further, when the cooling load is large, the pressure in the suction chamber 7 increases, so that the bellows contracts, the capacity control valve 65 is closed, the pressure in the discharge chamber 8 is not introduced into the crank chamber 5, and the piston stroke becomes large. The discharge capacity increases.
[0043]
Here, when the air conditioner is turned on while liquid refrigerant is accumulated in the crank chamber 5 while the compressor is stopped, as shown in FIG. The introduction of the discharge pressure into the chamber 5 is stopped. At that time, the valve element 71 of the on-off valve 70 is positioned at the first switching position by the force of the spring 72 as the pressure in the first passage 81 decreases. Thus, the second passage 82 and the third passage 83 communicate with each other and the first passage 81 is closed. Accordingly, the second pressure derivation passage 68 is opened, and passes through the second passage 82 (the shaft inner side hole 62d, the shaft inner hole 62c, the shaft end space 62b, etc.) and the third passage 83. Then, the refrigerant in the crank chamber 5 joins the portion of the first pressure derivation passage 61 closer to the suction chamber 7 than the fixed throttle portion 64 and flows into the suction chamber 7.
[0044]
That is, the pressure in the crank chamber 5 can be released from the second pressure deriving passage 68 in addition to the first pressure deriving passage 61 which has the fixed throttle portion 64 but is always open. The refrigerant is discharged quickly, the swash plate 26 smoothly strokes, the startup delay of the swash plate 26 is eliminated, and it takes less time to cool the air conditioner.
[0045]
Further, when the load is low during normal operation (such as when the vehicle interior temperature is close to the required temperature), the capacity control valve 65 is operated to open as shown in FIG. Accordingly, the valve body 71 of the on-off valve 70 is positioned at the second switching position against the force of the spring 72 due to the pressure increase in the first passage 81, so that the first passage 81 and the second passage 82 are moved. The third passage 83 is closed while communicating. Accordingly, the pressure introduction passage 62 is opened, and the pressure in the discharge chamber 8 is introduced into the crank chamber 5 through the pressure introduction passage 62, and the inclination angle of the swash plate 26 is reduced, so that the piston stroke is reduced. The discharge capacity decreases.
[0046]
At this time, since the second pressure derivation passage 68 is closed by the valve body 71 of the on-off valve 70, the pressure in the crank chamber 5 is released only through the first pressure derivation passage 61 having the fixed throttle portion 64. Accordingly, it is difficult for the pressure in the crank chamber 5 to be released, the pressure in the crank chamber 5 is not insufficient, the inclination angle of the swash plate 26 is kept small, and the low discharge capacity is maintained. There will be no problems such as freezing.
[0047]
Therefore, it is possible to improve the operation performance of the swash plate at the start of the compressor while maintaining the demist performance (the ability to maintain the dehumidifying capacity by cooling without freezing) and increase the cooling power when the air conditioner is ON. Can be planned.
[0048]
Further, in this compressor, an on-off valve 70 as a flow path switching valve is provided in the middle of the pressure introduction passage 61, and when the capacity control valve 65 is operated to the close side, the downstream side divided by the on-off valve 70 is provided. Since the second passage 82 is shared as a part of the second pressure derivation passage 68, the extra processing of the second pressure derivation passage 68 can be reduced by that amount. Therefore, the second pressure derivation passage 68 can be secured without excessive processing, and a wider passage cross-sectional area can be easily secured.
[0049]
That is, in the conventional compressor, the pressure introducing passage is used only for pressure introduction and the pressure deriving passage is used only for pressure deriving. However, in the above compressor, when the pressure introducing passage 61 is not used ( When pressure is not introduced into the crank chamber 5, a part of the pressure introduction passage 61 (second passage 82 on the downstream side) is used as a part of the second pressure derivation passage 68. There is no need to forcibly lay out the second pressure derivation passage 68, the processing is facilitated, and the passage cross-sectional area is easily secured.
[0050]
Further, the on-off valve 70 having the flow path switching function is constituted by a valve body 71 and a spring 72 so that the flow path is automatically switched by the pressure upstream of the pressure introduction path 61 (first path 81). Therefore, the configuration is simple and the cost is low.
[0051]
Further, in this compressor, since the downstream portion of the pressure introducing passage 62 is opened to the outer peripheral surface of the shaft S through the inside of the drive shaft S, the surroundings are uniformly lubricated by the centrifugal force due to the rotation of the drive shaft S. The oil-containing refrigerant can be sprinkled and the lubrication performance can be improved.
[0052]
The present invention is not limited to the above embodiment, and can be modified without departing from the technical idea of the present invention. For example, in the above-described embodiment, the case where the on-off valve 70 is one whose position is automatically switched according to the pressure generated in the first passage 81 has been shown, but the position is determined according to an external signal such as an electromagnetic valve. It is also possible to use a structure that switches between.
[0053]
In the above-described embodiment, the case where the second pressure derivation passage 68 is shared by a part of the pressure introduction passage 61 on the downstream side (second passage 82) has been described. The second pressure outlet passage 68 may be formed completely separately.
[0054]
Further, a gap between a through hole formed in the cylinder block 3 through which the through bolt B is inserted and the through bolt B inserted through the through hole is configured as a “first pressure introducing passage fixed throttle portion”. By forming the second pressure introduction passage 68 in communication, the first pressure introduction passage 61 having the fixed throttle portion 64 in the above embodiment may be used.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing the overall configuration of a variable capacity swash plate compressor according to an embodiment of the present invention.
FIG. 2 is a cross-sectional view schematically showing details of a capacity control means 60 in the compressor, in which a capacity control valve 65 is closed and an on-off valve (flow path switching valve) 70 is connected to a second pressure derivation path 68. It is a figure which shows the open state.
FIG. 3 is a cross-sectional view schematically showing details of a capacity control means 60 in the compressor, in which the capacity control valve 65 is open and the on-off valve (flow path switching valve) 70 is connected to the second pressure derivation path 68; It is a figure which shows the closed state.
FIG. 4 is a cross-sectional view showing the overall configuration of a conventional variable capacity swash plate compressor.
[Explanation of symbols]
2 Cylinder block (first housing)
3 Cylinder bore
4 Front housing (first housing)
5 Crank chamber
6 Rear housing (second housing)
7 Suction chamber
8 Discharge chamber
13v suction valve
14v discharge valve
26 Swashplate
29 piston
60 Capacity control means
61 First pressure outlet passage
62 Pressure introduction passage
62c Vertical hole in shaft
62d Lateral hole in shaft
64 Fixed throttle
65 Capacity control valve
70 On-off valve (channel switching valve)
71 Disc
72 Spring
81 1st passage
82 Second passage
83 3rd passage
S drive shaft

Claims (3)

A first housing (2, 4) having a plurality of cylinder bores (3) and a crank chamber (5), a piston (29) slidably accommodated in each cylinder bore (3), and a suction valve in the cylinder bore (3) A second housing (6) having a suction chamber (7) communicating via (13v) and a discharge chamber (8) communicating via a discharge valve (14v), and housed in the crank chamber (5). A swash plate (26) connected to each piston (29) and having a tilt angle controlled by the difference between the pressure in the crank chamber (5) sandwiching the piston (29) and the suction pressure; and in the crank chamber (5) Capacity control means (60) for controlling the inclination angle of the swash plate (26) by adjusting the pressure of
The capacity control means (60) introduces the pressure in the discharge pressure region into the crank chamber (5), and the pressure introduction passage (62) is interposed in the middle of the pressure introduction passage (62). In a variable capacity swash plate compressor comprising a capacity control valve (65) for controlling the opening and closing of the engine and a pressure derivation passage for deriving the pressure in the crank chamber (5) to the suction pressure region,
As the pressure outlet passage,
A first pressure outlet passage (61) with a fixed throttle (64) that is always open;
An on-off valve (70) that opens when the capacity control valve (65) interposed in the pressure introduction passage (62) is operated to the closed side and is closed when the capacity control valve (65) is operated to the open side. A second pressure outlet passage (68) comprising:
A flow path switching valve (70) that functions as the on-off valve (70) is provided in the middle of the pressure introduction passage (62),
The flow path switching valve (70) includes a first path (81) on the upstream side of the flow path switching valve (70) in the pressure introduction path (62), a second path (82) on the downstream side, A third passage (83) communicating with the first pressure introduction passage (61) closer to the suction chamber (7) than the fixed restrictor (64) is connected to and blocked from each other; When the control valve (65) is operated to the closed side, the second passage (82) and the third passage (83) are communicated with each other by being operated to the first switching position and the first passage (81). When the capacity control valve (65) is operated to the open side, the first passage (81) and the second passage (82) are communicated with each other by being operated to the second switching position. Having a function of blocking the third passage (83);
The second passage (82) and the third passage (83) when the passage switching valve (70) is operated to the first switching position serve as the second pressure derivation passage (68). A variable capacity swash plate compressor characterized by The variable capacity swash plate compressor according to claim 1 ,
The flow path switching valve (70) includes a valve body (71) that switches the flow path and a spring (72) that biases the valve body (71) in a fixed direction.
The flow path switching valve (70)
When the displacement control valve (65) interposed in the pressure introduction passage (62) is operated to the closed side, the valve body (72) is forced by the force of the spring (72) as the pressure in the first passage (81) decreases. 71) is displaced to the first switching position, whereby the second passage (82) and the third passage (83) are communicated and the first passage (81) is shut off, and the capacity control valve (65). When the valve body (71) is displaced to the second switching position against the force of the spring (72) due to an increase in the pressure of the first passage (81). A variable capacity swash plate compressor characterized in that it communicates the first passage (81) and the second passage (82) and blocks the third passage (83). A claim 1 or claim 2 Symbol placement variable displacement swash plate type compressor,
The downstream part (62c, 62d) of the pressure introducing passage (62) passes through the inside of the drive shaft (S) connected to the swash plate (26) and opens to the outer peripheral surface of the shaft (S). A variable capacity swash plate compressor.

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