JPH01187375A - Variable displacement swash plate type compressor - Google Patents

Abstract

PURPOSE:To lower pressure in a control pressure chamber in an early stage after stopping a compressor and make it settable to the minimum capacity all the time at the time of starting by interconnecting the control pressure chamber to a part being opposed to a piston side face in a cylinder space with a pressure leading passage. CONSTITUTION:In a shaft 1, a swash plate 10, solidly rotating together with this shaft, is set up free of rocking motion. A piston 7 is reciprocated by rocking motion of this swash plate 10, while a fluid in an operating chamber is fed or exhausted. A support part supporting the swash plate rockably is displaced in the axial direction of the shaft 1 by a spool 30, while a control pressure chamber 200 is formed at the opposite side to the support part in this spool 30. In addition, a control valve 400 is set up in this control pressure chamber 200, while this control valve 400 is controlled by a control circuit 500. At this time, one end of a pressure leading passage 600 is opened to the control pressure chamber 200, while the other end is opened to a part being opposed to a side face of the piston 7 in a cylinder space 64 of a cylinder block 6 at the rear side likewise.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to capacity control of a swash plate compressor.
For example, it is effective when used as a refrigerant compressor for an automobile air conditioner.

(Background of the Invention) The present inventors previously developed a variable displacement mechanism for a swash plate type compressor, in which the center point of the swash plate is swingably supported, and the center point of the swash plate is aligned in the axial direction of the shaft. We proposed that the tilt angle of the swash plate be controlled by the displacement of the spool.In other words, the spool is displaced in the shaft axial direction according to the pressure in the control pressure chamber, and the swash plate is tilted as the spool is displaced. We have proposed a compressor configured to vary the angle and also displace the center point position.According to the compressor proposed by the present inventors, in the working chamber located on one side of the piston, the swash plate Although there is a significant increase in dead polyneme depending on the tilt angle displacement, in the working chamber located on the other side,
Capacity can be gradually reduced without a significant increase in dead volume.

, [Problems to be Solved by the Invention] The present invention is related to the improvement of the compressor previously proposed by the present inventors. The purpose is to

[Configuration and operation]

In order to achieve the above object, the present invention controls the inclination angle of the compressor by the displacement of the spool, and also controls the tilt angle of the compressor by the displacement of the spool.
- The displacement of the spool is controlled by the pressure in the control pressure chamber on the back of the spool. The signal pressure supplied to the control pressure chamber is adjusted between the high pressure side pressure and the low pressure side pressure generated within the cylinder of the compressor.

Further, in the present invention, a pressure guiding passage is provided that communicates between the control pressure chamber and a portion of the cylinder chamber that faces the side surface of the piston.

A minute clearance is formed between the inner surface of the cylinder and the outer circumference of the piston to allow the piston to slide back and forth.

Therefore, when the compressor is operating, high pressure is generated in this area due to the compression action of the piston, but once the compressor stops, the pressure inside the cylinder quickly decreases to the suction side pressure via the above clearance. Become. Therefore, after the compressor is stopped, high pressure is not introduced into the control pressure chamber via the pressure guiding path. Therefore, the pressure within the control pressure chamber becomes low. In response to this pressure displacement, the spool will displace the swash plate toward the minimum capacity state.

In this way, the compressor of the present invention makes effective use of pressure fluctuations between the cylinder chamber and the side surface of the piston to determine whether to start or stop the compressor. It can be displaced to the capacitive part side.

〔Example] An embodiment of the present invention will be described below based on the drawings.

FIG. 1 is a longitudinal sectional view of a variable displacement swash plate compressor. The front housing 4, front sight plate 8, suction valve 9, front cylinder block 5, rear cylinder block 6, suction valve 12, rear sight plate 11, and rear housing 13 made of aluminum alloy are integrally fixed by through bolts (not shown). It forms the outer shell of the compressor.

The cylinder block 5.6 has five cylinders 64 (641 to 645) as shown in FIG.
4 are formed parallel to each other. A shaft 1 that rotates under the driving force of an automobile engine (not shown) is rotatably supported by a front housing 4 and a front cylinder block 5 via bearings 2 and 3, respectively. Further, the thrust force applied to the shaft l (force acting in the left direction in the figure) is received by the front cylinder block 5 via the thrust bearing 15, and the movement of the shaft l in the right direction in the figure is restricted by a retaining ring 16. . Note that the retaining ring 16 is retained by an annular groove formed in the shaft l.

The rear shaft 40 connects to the spool 3 via the bearing 14.
0 and is rotatably supported. The thrust force acting on the rear shaft 40 (the force acting in the right direction in the figure) is generated by the thrust bearing 1.
The rear shaft 40 is received by the spool 30 via the rear shaft 16, and a retaining ring 17 prevents the rear shaft 40 from coming off the spool 30. This retaining ring is also locked in an annular groove formed in the rear shaft 40. The spool 30 includes a cylindrical portion 65 of the rear cylinder block 6 and a cylindrical portion 13 of the rear housing 13.
5 so as to be slidable in the axial direction.

A spherical part 107 is formed in the center of the swash plate 10, and a spherical support part 405 fixed to the end of the rear shaft 40 is disposed on this spherical part 107. It is supported by a support section 405.

A slit 105 is formed on the side surface of the shaft l of the swash plate lO, and a flat plate portion 16 is formed on the end surface of the shirt) 1 on the swash plate 10 side.
5 is formed. And the flat plate part 165 is sulin)
By being placed in surface contact with the inner wall of the shaft 105, the U rotation driving force applied to the shaft l is transmitted to the swash plate 10.

Furthermore, shoes 18 and 19 are slidably disposed on both sides of the swash plate 10. On the other hand, screws I/N 7 are slidably disposed within the cylinders 64 of the front cylinder block 5 and the cylinders 64 of the rear cylinder block 6. As described above, the shoes 18 and 19 are slidably attached to the swash plate 10. Furthermore, the shoes 18 and 19 are rotatably engaged with the inner surface of the piston 7. Therefore, the rocking motion accompanying the rotation of the swash plate 10 is transmitted to the piston via the shoes 18 and 19 as a reciprocating motion. The shoes 18 and 19 are formed so that their outer surfaces lie on the same spherical surface when assembled on the swash plate 10.

A long groove 166 is provided in the flat plate portion 165 of the shaft 1, and a pin hole is formed in the swash plate 10. After the flat plate portion 165 of the shaft 1 is disposed in the slit 105 of the swash plate 10, it is locked by the pin 80 and the retaining ring 81 to the pin holes 106, 108 and the long groove 166 of the shaft l.

The inclination of the swash plate changes depending on the position of the pin 80 in the long groove 166, and as the inclination changes, the position of the center of the swash plate (the spherical support portion 405 of the spherical portion 107) also changes. That is, in the second working chamber 60 on the right side in FIG.
The long groove 166 is provided so that even if the inclination of O changes and the stroke of the piston 7 changes, the top dead center of the piston 7 on the working chamber 60 side will hardly change and the dead volume will not substantially increase. . On the other hand, the working chamber 5 on the left side in the figure
At 0, the top dead center of the piston 7 changes as the slope of the swash plate changes, so the dead volume also changes.

In this example, as described above, the long groove 166 is formed in such a shape that the top dead center position of the working chamber 60 of the piston 7 does not change even if the inclination angle of the swash plate lO changes. Therefore, strictly speaking, the long groove 166 has a curved shape, but in actual formation, it can be approximated by a substantially straight long groove. Furthermore, in this example, the long grooves 166 are arranged on the axis of the shaft 1 so that the shape of the flat plate portion 165 does not become excessively large due to the formation of the long grooves 166. Forming the long groove 166 on the axis of the shirt +-1 and reducing the size of the flat plate part 165 is particularly effective in a swash plate type compressor in which the flat plate part 165 is disposed inside the piston 7. It is.

Reference numeral 21 in the figure is a shaft sealing device, which prevents refrigerant gas and lubricating oil from leaking to the outside along the shaft 1. Reference numeral 24 in the figure opens into the working chamber 50.60, and the discharge chamber 90.60.
The discharge port 24 is opened and closed by the discharge valve 22 . The discharge valve 22 has a valve holder 23
It is also fixed to the front side plate 8 and the rear side plate 11 by bolts (not shown). In the drawing, reference numeral 25 denotes a suction port that communicates the working chamber 50.60 and the suction chamber 72.74, and is opened and closed by the suction valve 9 and the suction valve 12.

Reference numeral 400 in the figure is an electric CF main valve for controlling the internal pressure of the control pressure space 200, and is controlled by a control circuit 500. One end of the solenoid valve 400 is connected to the rear suction space 74 by a low pressure introduction passage 97. The other end is connected to the control pressure chamber 200 via a control pressure passage 98 . When the electromagnetic valve 400 is not energized, the space 200 and the suction space 74 are cut off.

A discharge space 90 on the front side in FIG. It is guided to a discharge boat 95. Since the discharge boat 92 and the discharge boat 95 are connected by external piping, the discharge space 90 and the discharge space 9
The three internal pressures are the same pressure. Further, the intake space 72 on the front side is led to the intake space 70 formed in the center of the housing by the intake passage 71, and similarly the intake space 72 on the rear side is guided to the intake space 70 formed in the center of the housing.
The suction passage 73 also leads to the suction space 70 . In addition, the symbols 51, 52, 53, 54, 55, and 56 in the figure are O-rings.

600 is a pressure passage, one end of which is connected to the control pressure chamber 200.
Open to. The other end of the pressure guiding passage 600 opens to a portion of the cylinder space 64 of the rear cylinder block 6 that opposes the side surface of the piston 7. Here, in order to allow the piston 7 to reciprocate within the cylinder space 64, the side surface of the piston 7 and the cylinder space 64 are connected to each other.
4, a clearance of about 10 microns is provided between the inner surface and the inner surface.

The other end of the pressure guiding passage 600 opposes the side surface of the piston 7 via this minute clearance.

Furthermore, a throttle 601 and a check valve 602 are arranged in series in the middle of the pressure guiding passage 60. Here, the throttle 601 is configured such that pressure fluctuations in the second working chamber 60 are immediately caused by the control pressure chamber 200.
This is because it is prevented from being transmitted to Second working chamber 6
0 changes greatly from suction pressure to discharge pressure according to the displacement of the piston, so that pressure immediately moves to the control pressure chamber 200.
In this case, accurate position control of the spool 30 becomes impossible. Therefore, in this example, a check valve 602 and a throttle 601 are arranged in the pressure guiding passage 600 so that approximately the peak pressure in the second working chamber 60 is supplied to the control pressure chamber 200.

That is, the pressure in the second working chamber 60 fluctuates greatly from the suction pressure to the discharge pressure as described above, but when the pressure in the second working chamber decreases, the check valve 602 closes and the pressure in the control pressure chamber 200 decreases. This prevents pressure from flowing to the second working chamber 60 side.

Due to the above throttle 601° and check valve 602, the pressure at both ends of the pressure guiding passage 600 becomes as shown in FIG. 3 when the control valve 400 is in the closed state. A solid line A in FIG. 3 shows the pressure fluctuation at the opening end from the second working chamber 60 in the pressure guiding passage 600, and a solid line B in FIG. Shows pressure fluctuations at the side edges.

The operation of the compressor with the above configuration will be described.

When an electromagnetic clutch (not shown) is connected and driving force from the engine is transmitted to the shaft 1, the compressor is started.

Here, if a long time has passed after the compressor stopped,
Since the refrigerant pressure in the refrigeration cycle is equalized, as a result, the pressure before and after the spool valve, that is, the pressure in the control pressure chamber 200 and the pressure in the suction space 74 are equalized. If the pressure is equalized in this manner, the spool 30 is displaced to the right in the figure by the urging force of the spring 308.

In this way, if the spool 30 is displaced to the right in the figure,
In response to the displacement of the spool, the suction spherical support portion 405 is also displaced to the right in the figure, and as a result, the inclination angle of the swash plate 10 is minimized. Therefore, when the compressor is restarted after a long period of time after it has been stopped, the compressor will inevitably be started at the minimum capacity.

However, if the compressor is restarted in a relatively short time after it has stopped, a predetermined high pressure may still remain in the control pressure chamber 200, and the discharge capacity of the compressor may not be the minimum capacity. be.

Here, if the compressor is started with a large capacity, the torque required for starting the compressor will be large, causing a shock at the time of starting and discomfort to the occupants.

Therefore, it is desirable that the compressor capacity is always at the minimum capacity at startup. In contrast, in the compressor of the present invention, the control pressure chamber 200 is communicated with the side surface of the cylinder space 64 using the pressure guiding passage 600, so that the control pressure chamber 200 is connected to the side surface of the cylinder space 64 quickly after the compressor is stopped.
The pressure inside 00 can be reduced.

A predetermined clearance is provided between the cylinder space 64 and the piston 7 to allow the piston 7 to slide back and forth. This clearance is the first clearance when the compressor is operating.
1. This brings about a sufficient pressure rise in the second working chamber 50, 60, but once the compressor stops, the control pressure chamber 50,
The pressure inside 60 flows through this clearance to the suction space 70.
It's something to run away to. According to studies by the present inventors, after the piston 7 stops reciprocating sliding, the working chamber 50.
It has been confirmed that the pressure inside 60 escapes to the suction space 70 side. Therefore, after the compressor is stopped, the pressure at the open end of the pressure guiding passage 600 on the cylinder space 64 side decreases quickly.

Therefore, by opening the control valve after the compressor is stopped, the pressure within the control pressure chamber 200 is released to the suction space 74 side. As a result, the pressure in the control pressure chamber 200 decreases and becomes approximately balanced with the pressure in the suction chamber 74. As a result, the spool 3I is no longer subjected to a large pressure difference between its ends, and is displaced to the left in the figure by the biasing force of the spring 308. By displacing the spool 30 in this way, the angle of inclination with respect to the swash plate 10 becomes the minimum, and the discharge capacity of the compressor becomes the minimum capacity.

That is, in the compressor of this example, even if the compressor is restarted within a short time after being stopped, the compressor can always be started at the minimum capacity.

When the shaft 1 starts rotating in this state, the rotation of the shaft 1 causes the piston 7 to reciprocate via the swash plate 10. As the piston 7 moves back and forth, the refrigerant is sucked, compressed, and discharged within the working chamber 50, 60.

However, in this case, a force based on the pressure difference between the rear working chamber 60 and the front working chamber 50 is applied to the swash plate 10 via the piston 7 and the shoes 18, 19. In particular, since the swash plate 10 is swingably supported by the spherical support part 405 and receives the rotational force of the shaft 1 by fitting the slit 105 and the flat plate part 165, the force applied to the piston 7 acts as a moment in the direction of decreasing the inclination angle of the swash plate 10.

For example, when the pin 80 is located on the axis X in FIG. 2, the piston disposed in the first cylinder space 641 does not generate a moment that changes the inclination angle with respect to the swash plate lO. However, a rotational moment is generated from the pistons 7 disposed in the second to fifth cylinder spaces 642, 643, 644, 645 in a direction that reduces the inclination angle of the swash plate 10. This rotational moment FiXRi
is received by the moment FpmXR generated around the pin 80 (as shown in FIG. 5). Further, the rotational moment generated by this piston 7 is
A pressing force of Fbx will be applied to 05.

That is, when the control valve introduces suction pressure into the control pressure chamber 200, the spherical support portion 405 and the spool 30 are displaced to the right in the figure. As a result, the swash plate lO reduces its angle of inclination. However, the swash plate lO is the long groove 16 of the shirt l-1.
6 is regulated by a pin 80, the swash plate 10 reduces its inclination, and the ball portion 40 at the center of the swash plate 10
A force is applied to the ball 405 to the right in the figure to move the ball 405 to the right. Rear shaft 4 via spherical support part 405
The force acting in the right direction in the figure at zero is transmitted to the spool 30 via the thrust bearing 16, and the spool 30 moves until it hits the bottom of the rear housing 13.

The refrigerant gas sucked from a suction boat (not shown) (connected to the evaporator of the refrigeration cycle) enters the central suction space 70, then passes through suction passages 71 and 73.
Enter the front and rear suction chambers 72 and 74. after that,
During the suction stroke of the piston 7, air is sucked into the working chamber 50, 60 from the suction port 25 via the suction valve 12. The sucked refrigerant gas is compressed in the compression stroke, and when it is compressed to a predetermined pressure, the discharge valve 22 is pushed open from the discharge port 24 and the discharge chamber 9 is discharged.
It is discharged to 0.93. High-pressure refrigerant gas is discharged through the discharge passage 91
．． 94 and is discharged from discharge boats 92 and 95 to a condenser (not shown) of the refrigeration cycle.

At this time, since the first working chamber 50 on the front side has a large dead volume, the compression ratio is smaller than that of the second working chamber 60 on the rear side (the pressure of the refrigerant gas in the first working chamber 50 is lower than that in the discharge space 90). It is lower than the internal pressure (from which the discharge pressure of the second working chamber 60 on the rear side is led), and the action of sucking and discharging refrigerant gas in the first working chamber 50 on the front side is not performed.

When starting the compressor, the compressor discharge capacity is set to the minimum capacity as described above. However, when the compressor capacity required by the refrigeration cycle is high, the control valve 400 shuts off the control pressure passage 98 and the low pressure introduction passage 97. Here, in this example, the control pressure chamber 200 is connected to the cylinder space 6 by the pressure guiding passage 600 via the check valve 602 and the throttle 601.
The pressure generated in step 4 is introduced. Therefore, in this state where the connection with the low pressure introduction passage 97 is cut off, the pressure within the control pressure chamber 200 increases.

Therefore, the force acting on the spool 30 in the left direction in FIG. 6 due to the pressure difference (due to the pressure difference between the control pressure chamber 200 and the suction space 74) gradually increases as the compressor rotates. When this force overcomes the force pushing the spherical support portion 405 to the right in the figure, the spool 30 gradually begins to move to the left in the figure. Then, due to the action of the long groove 166 of the shaft 1 and the pin 80, the swash plate lO moves its center of rotation (spherical support portion 405) to the left in the figure and increases its inclination. As the pressure inside the control pressure chamber 200 further increases, the spool 30 moves to the left in the figure until its shoulder 305 touches the rear side plate 11, achieving the maximum capacity state. This is the situation shown in FIG. In the state shown in FIG. 1, refrigerant gas sucked from a suction boat (not shown) enters the central suction space 70, passes through suction passages 71 and 73, and flows into suction chambers 72 and 74, respectively. and,
In the suction stroke, it enters the working chambers 50 and 60 from the suction port 25 through the suction valves 9 and 12, respectively, and is then compressed with the displacement of the piston 7, and flows from the discharge port 24 through the discharge valve 22 into the discharge spaces 90 and 60, respectively. 93, passes through discharge passages 91 and 94, is discharged from discharge boats 92 and 95, and joins at an external pipe. In this state, both the working chamber 50 and the working chamber 60 perform the action of sucking in and discharging refrigerant gas.

A solid line a in FIG. 4 is a diagram showing the relationship between the piston stroke and compressor capacity of the variable displacement swash plate compressor according to the present invention. In the capacity control system according to this example, by changing the inclination of the swash plate 10, the stroke of the piston 7 is changed and the center position of the swash plate 10 is also changed. There is almost no increase in Therefore, as shown by the - dotted chain line, the discharge capacity gradually decreases according to the piston stroke. On the contrary, in the front side first working chamber 50, the dead volume increases as the piston stroke decreases, and the compression ratio decreases due to the increase in dead volume, and the discharge capacity rapidly increases as shown by the solid line C in FIG. Decrease.

And the maximum pressure at the front (!! 11 working chamber 50 (
At the point when the discharge pressure (discharge pressure) in the working chamber 60 becomes lower than the discharge pressure in the working chamber 60 (point d in FIG. 4), the suction in the front working chamber 50,
The discharge action is no longer performed, and the refrigerant gas suction, compression, and discharge actions are performed only in the rear working chamber 60. This first working chamber 50 takes in and discharges refrigerant gas (the piston stroke d is the maximum piston stroke, the suction pressure P s (kg/cd-abs), the discharge pressure P
d (kg/cnT-abs), adiabatic index k of refrigerant gas, piston radius R1 pi, then P s ・(πR”L)'=Pd ・(πR2・(L
-d))", and the capacity 1b in this case becomes.

Here, Ps=3kg/cJ・ab's, Pb=16kg
/cd・abs,=1.14, then d=0.77
L b = 38.5 (%).

Note that this piston stroke is almost proportional to the amount of movement of the spool 30, and the state in which the spool 30 has gone all the way to the right in FIG. Then, the relationship between the amount of spool movement and the compressor capacity can be seen as shown in FIG. 4 (Locl).

Now, the solid line part a in FIG. Although the compressor capacity changes linearly with respect to the amount of spool movement as shown in the figure, the slope is steep and the controllability is poor.However, in the spool displacement range from lie to 0, the capacity changes as shown by the solid line at in the figure. The slope is gentler than that of the thin line f, and the controllability is particularly excellent at low capacity.

Next, when the cooling load decreases, the control circuit 500 alternately switches the solenoid valve 400 between the ON state and the OFF state (for example, duty ratio control).
The capacity can be reduced by gradually lowering the internal pressure of the space 200 from the discharge pressure and moving the spool 30 in the right direction in FIG. 1. In order to obtain the lowest capacity, the internal pressure of the space 200 is communicated with the suction space 74.

Note that in the above example, a solenoid valve is used as the control valve 400, and the control pressure chamber 20 is
Although the pressure within 0 is adjusted, the discharge capacity may be automatically controlled by the suction side pressure of the compressor without using an electric signal.

That is, it is known that the suction side pressure of the compressor increases or decreases in value depending on the cooling state of the refrigeration cycle. When the cooling capacity of the refrigeration cycle is insufficient, the suction pressure becomes high, and conversely, when the cooling capacity is excessive, the suction pressure becomes low. Therefore, by adjusting the pressure within the control pressure chamber 200 using the pressure fluctuation, the discharge capacity of the compressor can be automatically controlled.

FIG. 6 shows another example of the control valve 400.

In this example, the control pressure chamber 200 is configured to receive pressure within the second working chamber 60 via a passage 600. Since the check valve 602 and the throttle 601 are disposed in the passage 600, a predetermined high pressure is supplied to the control pressure chamber 200 through this passage 600 when the compressor is in operation, as described above.

Further, the control pressure chamber communicates with the suction pressure chamber 74 via a signal pressure passage 98 and a suction pressure passage 97. Therefore, control valve 4
00 communicates between the passages 98 and 97, the control pressure chamber 20
The pressure within 0 will drop to the suction pressure side. Conversely, if the control valve 400 blocks the passages 98 and 97, the passage 600
The high pressure received through the control pressure chamber 200 will be maintained within the control pressure chamber 200.

The control valve 400 has a suction pressure chamber 410 that receives suction pressure through a suction pressure passage 97 and an atmospheric pressure chamber 412 that communicates with the atmosphere through an atmospheric pressure port 411 through a diaphragm 41.
Separated by 3.

Therefore, the diaphragm 413 is displaced in the vertical direction in FIG. 6 according to the differential pressure between the atmospheric pressure and the suction pressure.

This displacement of diaphragm 413 is transmitted to ball valve 415 via rod 414. Ball valve 415 normally closes port 417 under the biasing force of spring 416. Therefore, when the pressure inside the suction pressure chamber 74 is high, the diaphragm 413 overcomes the biasing force of the spring 420 and is displaced upward in the figure. Along with its displacement, the rod 414
is separated from the ball 415, and the ball valve 415 closes the port 417 by the biasing force of the spring 416.

Here, as mentioned above, the suction pressure becomes high when the capacity required of the refrigeration cycle is insufficient, and it is necessary to increase the discharge capacity of the compressor. Therefore, by increasing the pressure within the control pressure chamber 200, the spool 30 is displaced to the left in the figure, and the inclination angle of the swash plate 10 is increased. As a result, the reciprocating stroke of the piston 7 increases, and the discharge capacity of the compressor increases.

Conversely, when the load required for the refrigeration cycle is reduced, the pressure within the suction pressure chamber 74 is reduced. the result,
The pressure in the suction pressure chamber 410 decreases, and the pressure difference with the atmospheric pressure chamber 412 becomes smaller. Accordingly, the diaphragm 413 is displaced downward in FIG. 6 due to the urging force of the spring 420. This displacement is applied to the ball valve body 4 via the rod 414.
15, and the ball valve body 415 opens the port 417. As a result, the pressure in the control pressure chamber 200 is returned to the suction pressure chamber 74 side via the passages 98 and 97.

As a result, the pressure within the control pressure chamber 200 decreases, and the spool 30 is displaced to the right in the figure due to the biasing force of the spring 30B. With this displacement of the spool 3o, the inclination angle of the swash plate 10 becomes smaller, and the discharge capacity of the compressor decreases.

When the compressor is stopped, the suction pressure increases and the control valve 40 closes the control pressure chamber 200 and the suction pressure chamber 74. , 604, enters the cylinder chamber, and decreases to the suction pressure through the clearance between the cylinder and the piston. This will cause the compressor to immediately go to minimum capacity and restart at minimum capacity.

Furthermore, in the embodiment shown in FIG. 6, since the shaft 1 is structured to penetrate the spherical support part 405,
1 is supported at both ends by bearings 3 and 14. This results in
The support function of the shaft 1 can be improved. In addition, in the embodiment shown in FIG. 6, since the pin 80 is rotatably held via a bearing 909, the pin 8o and the long groove 166
Frictional resistance between the two can be significantly reduced.

〔effect〕

As explained above, in the compressor of the present invention, the control pressure chamber 2
Since a pressure guiding passage is provided that communicates between 00 and the portion of the cylinder space that faces the piston side, the pressure in the control pressure chamber can be reduced quickly after the compressor is stopped. Therefore, according to the compressor of the present invention, the inclination angle of the swash plate can be minimized early after the compressor is stopped, and the capacity can always be minimized when starting up.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view showing one embodiment of the compressor of the present invention, FIG. 2 is a cross-sectional view taken along arrows -■ in FIG. The graph shown in Figure 4 is the first
FIG. 5 is an explanatory diagram showing the pressure state applied to the compressor shown in FIG. 1. FIG. 5 is an explanatory diagram showing the relationship between spool displacement and capacity of the compressor shown in FIG. FIG. DESCRIPTION OF SYMBOLS 1... Shaft, 7... Piston, 10... Swash plate, 64... Cylinder chamber, 200... Control pressure chamber, 40
0... Control valve, 600... Pressure guiding passage, 601...
Throttle, 602...Check valve, 603...Bypass passage.

Claims (1)

[Claims] (1) A cylinder block having a cylinder chamber inside, a shaft rotatably supported within the cylinder block, and a swash plate pivotally connected to the shaft and rotating integrally with the shaft. a piston that is slidably disposed within the cylinder chamber and reciprocates within the cylinder chamber in response to the rocking motion of the swash plate; a working chamber for suctioning, compressing, and discharging fluid; a support part disposed coaxially with the shaft and swingably supporting the center point of the swash plate; a spool for displacing the spool in the axial direction of the shaft; a control pressure chamber formed in a portion of the spool on the opposite side of the support portion for displacing the spool in the axial direction of the shaft in accordance with internal pressure; The spool displaces the center point position of the swash plate in the axial direction of the shaft according to the signal pressure supplied to the control pressure chamber, and changes the inclination angle of the swash plate. A variable capacity type, comprising: a control valve that is controlled to be driven to cause displacement; and a pressure guiding passage that communicates the control pressure chamber with a portion of the cylinder chamber that faces the side surface of the piston. Swash plate compressor. (2) The control valve switches and controls the signal pressure supplied to the control pressure chamber to open or close the suction side pressure of the compressor and the control pressure chamber, and the control valve controls the signal pressure supplied to the control pressure chamber to open or close the suction side pressure of the compressor. When the pressure and the control pressure chamber are closed, the spool displaces the support portion in a direction that increases the inclination angle of the swash plate based on the pressure in the control pressure chamber, and the control valve adjusts the suction side pressure of the compressor. and the control pressure chamber, the compression reaction force of the piston causes the support portion and the spool to be displaced in a direction that is smaller than the inclination angle of the swash plate, and one end surface side of the piston in the working chamber In the working chamber formed in the working chamber, the piston can move forward to a predetermined position for suctioning, compressing, and discharging fluid regardless of the inclination angle displacement of the swash plate, and the other side of the piston is formed in the working chamber. 2. The variable displacement swash plate type compressor according to claim 1, wherein the working chamber is configured such that a dead space is generated in the working chamber depending on the inclination angle of the swash plate. (3) The variable capacity swash plate compressor according to claim 1, further comprising a throttle in the middle of the pressure guiding path. (4) The variable displacement swash plate according to claim 1 or 2, further comprising a check valve in the middle of the pressure guiding passage that allows fluid to flow only from the cylinder chamber side to the control pressure chamber side. mold compressor. (5) A bypass passage is formed in the pressure guiding passage in parallel with the check valve, and a throttle that provides resistance to the flow of fluid is disposed in the middle of the bypass passage. 4. The variable capacity swash plate compressor according to 4.