JPS6149190A - Variable displacement type rotary compressor - Google Patents

Abstract

PURPOSE:To make it possible to efficiently operate a vane type compressor at a small discharge rate, by providing a bypass device for communicating a working chamber during compression stroke with a working chamber during suction stroke and a variable restrictor device for constricting a suction passage, in the rotary compressor. CONSTITUTION:In a vane type rotary compressor, a rotary plate 64 for communicating a working chamber 32 during compression stroke with a working chamber during suction stroke, is provided in a position facing the opening section of a cylinder on a front end plate 4. Meanwhile, a variable restrictor member 140 which may block a suction passage 138 under the dynamic pressure of sucked fluid is disposed in the suction passage 138. Therefore, upon high rotational speed operation the compressor may be efficiently driven at a small discharge rate due to the bypass action of the rotary plate and the suction constricting action of the variable restrictor.

Description

DETAILED DESCRIPTION OF THE INVENTION 1. Gotachikawa The present invention relates to a rotary compressor that sucks gas from an inlet into a plurality of compression chambers whose volumes change by rotating a rotor within a housing, and discharges gas from an outlet. In particular, the present invention relates to a variable displacement rotary compressor in which the discharge capacity can be reduced by setting the compression chamber in a state in which no compression work is completely performed.

Such a compressor is suitably used, for example, as a refrigerant gas compressor for an automobile cabin cooling system.

While the air conditioner is operating in a cooling mode that lowers the temperature of the passenger compartment, the compressor is required to have a large discharge capacity. If the compressor is shifted to a heat retention mode that requires less heat, such a large discharge capacity is not required (this is why it is desirable for the compressor to shift to partial load operation, that is, a small discharge capacity operation).

Therefore, the inventors of the present invention, etc.
In No. 6, the part of the suction port near the discharge port in the rotor rotational direction (hereinafter simply referred to as the discharge port side part) can be closed and opened by a closing member, and when the cooling load becomes small, the closing member is closed. By moving the suction port to the open side, the end position of the suction port on the discharge port side is shifted toward the discharge port side.
A proposal was made to enable small-capacity operation by delaying the start of compression.

In addition, in Japanese Patent Application No. 57-209016, instead of such a closing member, a spool-type on-off valve is provided in the suction passage communicating with the compression chamber in the middle of the suction stroke, and when the cooling load becomes small, We proposed reducing the effective suction area of the suction passage to enable small capacity operation.

Toyoji Katsutan: If we do the above, the compressor will automatically shift to a low-capacity operating state when the cooling load decreases, which is convenient, but there are still points that need to be improved. There was found.

In other words, if the start of compression is delayed by shifting the position of the end of the suction port on the discharge port side, as the rotational speed of the compressor increases and the inertia of the gas increases, the gas that has flowed into the compression chamber will slow down. , it is difficult to move to the suction chamber or the compression chamber in the middle of the suction stroke, and the effect of reducing capacity cannot necessarily be said to be sufficient.On the other hand, when reducing the effective suction area with a spool-type on-off valve, When the number of rotations is low, a sufficient amount of gas is sucked in even from the reduced effective suction area, and the capacity reduction effect cannot be said to be sufficient. In the latter case, there is also the disadvantage that the former, that is, shifting the position of the end of the suction port on the discharge port side, is less effective in preventing the occurrence of liquid compression and sudden increase in engine load when the compressor is started. be.

SUMMARY OF THE INVENTION In view of the above-mentioned circumstances, the present invention has been made to provide a compressor that enables more effective small-capacity operation. In a rotary compressor, gas is sucked in from an inlet into a plurality of compression chambers whose volume changes as a rotor is rotated within a housing, and gas is discharged from an outlet. The present invention includes a bypass passage that communicates one compression chamber with a compression chamber in the middle of the suction stroke, a bypass passage opening end position changing device, and a variable throttle device.

This bypass passage opening end position changing device changes the compression start timing by changing the position of the end of the opening on the compression chamber side in the middle of the compression stroke on the side closer to the discharge port with respect to the rotor rotation direction. The variable throttle device is provided in the suction passage connected to the suction port and increases or decreases the flow rate of the intake gas.

In such a rotary compressor, the bypass passage opening end position changing device moves the position of the opening end of the bypass passage on the discharge port side closer to the discharge port to delay the compression start time. , the variable throttling device reduces the flow rate of the intake gas, resulting in a transition to a small capacity operating state.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Below, several embodiments in which the present invention is applied to a vane-type refrigerant gas compressor used in an automobile cabin cooling system will be described in detail with reference to the drawings.

In FIG. 1, 2 is a cylindrical cylinder, and its openings at both ends are closed by a front side plate 4 and a rear side plate 6, respectively, so that a rotor chamber 8 having a cross section or an elliptical shape is formed inside the cylinder. There is. On the other hand, their outsides are covered by a front housing 10 and a rear housing 12, and both housings 10.12, cylinder 2, and both side plates 4.6 are fastened with bolts (not shown) to form an integral housing 14. It consists of

In the rotor chamber 8, a rotor 16 having a circular cross section is arranged in close proximity to two locations on the short axis of the elliptical inner peripheral surface of the cylinder 2. A rotating shaft 18 projects from the center of both end faces of the rotor 16, and is rotatably supported by both side plates 4.about.6 via bearings 20,22. The front end of the rotating shaft 18 is connected to the front housing 10.
A shaft sealing device 26 extends into a center hole 24 formed in the center of the front housing 10 and the rotating shaft 18.
maintained by.

As is clear from FIG. 2, four vanes 28 are held in the rotor 16 by vanes i30 so as to be able to move in and out from the outer circumferential surface of the rotor 16, and the tips of the vanes are moved inside the cylinder 2 by oil pressure, which will be described later. It is pressed against the surrounding surface. As a result, adjacent vanes 28
．． A plurality of airtight compression chambers 32 surrounded by the outer peripheral surface of the rotor 16, the inner peripheral surface of the cylinder 2, and the inner surfaces of both the front and rear side plates 4, 6 are formed at symmetrical positions with respect to the axis of the rotor 16, As the rotor 16 is rotated by the rotating shaft 18 in the direction indicated by the arrow, the volumes of the compression chambers 32 increase once and then decrease.

The front side plate 4 and the front housing 1
A suction chamber 34 is formed between the front housing 10 and the front housing 10, and refrigerant gas is sucked into this suction chamber 34 from a compressor port 36 formed in the front housing 10, and further from a main suction port 38 and a sub suction port 40. It is designed to be sucked into the compression chamber 32 which is in the process of increasing its volume. The main suction port 38 and the sub suction port 40 are respectively formed at positions separated by a small distance in the rotor rotational direction from two positions where the outer circumferential surface of the rotor 16 is closest to the inner circumferential surface of the cylinder 2.

The refrigerant gas compressed by the reduction in the volume of the compression chamber 32 is
From the plurality of discharge ports 42 formed in the cylinder 2 to the discharge chamber 4
It is discharged at 4. These discharge ports 42 are located at a position communicating with the compression chamber 32 at the end of the compression stroke, that is, at a position where the rotor 16
The outer peripheral surfaces of the cylinders 1 and 2 are respectively formed at positions separated by a short distance from the two positions closest to the inner peripheral surface of the cylinder 2 in a direction opposite to the rotational direction of the rotor 16. Further, the discharge chamber 44 is formed by a notch formed on the outer peripheral surface of the cylinder 2 and a rear housing 1.
2, and in this discharge chamber 44, there is disposed a stacked valve 46 as a discharge valve and a regulating member 48 for regulating its lift amount. The refrigerant gas discharged into the discharge chamber 44 passes through a communication hole 50 formed in the rear side plate 6 and reaches an oil separation chamber 52 formed in the rear housing 12, where the mist of oil is separated. , a compressor outlet 54 formed in the rear housing 12
from there to the refrigeration circuit of the passenger compartment cooling system.

The mist oil separated in the oil condensing chamber 52 is stored in the lower part thereof, and is guided to the bearing 22 through an oil passage 56 formed in the rear side plate 6. The oil is also supplied to the annular oil groove 58 formed in the rear side plate 6 to close the sliding portion between the inner surface of the rear side plate 6 and the end surface of the rotor 16. It is also supplied to the annular /EIl+ groove 60 formed in the front side plate 4, which serves to push the vane 28 out of the vane groove 30 and to provide lubrication between the inner surface of the front side plate 4 and the end surface of the rotor 16. It is designed to do this. 62 is a sticker.

It's a ring.

An annular rotating plate 64 is provided between the cylinder 2 and the front side plate 4. This rotating plate 64 is
The front side plate 4 is rotatably held around the center line of the cylinder 2 by a shallow ring 'a65 formed on the inner surface thereof so as to communicate with the oil groove 60, and its -plate surface is connected to the front side plate. The rotor 16 and the vane 28 form a continuous plane with the inner surface of the rotor 16.
is in contact with or very close to the end face of the

Two through holes 66 passing through the rotating plate 64 in the thickness direction are provided at symmetrical positions with respect to the center line of the rotating plate 64 itself.
, these first through holes 6 are inserted through it in the thickness direction.
Two second through holes 68 communicating with the second through holes 6 are formed at symmetrical positions with respect to the center line.

These first through holes 66 and second through holes 68 are
The main suction port 38 constitutes a suction passage that communicates the suction chamber 34 and the compression chamber 32, and the opening of the first through hole 66 on the compression chamber 32 side is the main suction port 38. Further, two communication holes 70 are formed in the cylinder 2 on an extension line of each second through hole 68 and communicate with the first through hole 66.
0 is communicated with the compression chamber 32 which is in the process of increasing its volume through the auxiliary suction port 40, and constitutes a part of the suction passage. In addition, the first through hole 66 connects the compression chamber 32 in the middle of the compression stroke on the front side (advance side) of the vane 28 to the compression chamber 32 on the rear side (
It also functions as a bypass passage communicating with the compression chamber 32 in the middle of the suction stroke (on the trailing side).

A pin 72 that protrudes on the side opposite to the rotor 16 is fixed to the rotating plate 64, and is inserted into an elongated hole 78 formed on the piston 76 through an arcuate hole 74 formed on the front side plate 4. This piston 76 is fitted.
is arranged in a piston chamber 8o formed in the front side plate 4.

As is clear from FIG. 3, the opening of the piston chamber 80 is a bottomed hole formed near the boss portion of the front side plate 4 that supports the rotating shaft 18, and is closed by a closing member 82. The piston 7 is formed by
6 is fitted into this piston chamber 80 oil-tightly and slidably in the tangential direction of the rotating plate 64. Thereby,
The piston chamber 80 is partitioned into a first chamber 84 on one end side of the piston 76 and a second chamber 86 on the other end side.
is biased toward the -th chamber 84 by a precompressed spring 88.

As is clear from FIG. 1, the oil stored in the lower part of the oil separation chamber 52 is in the oil passage 56. Bearing 22. Oil groove 58. vane a30. Oil m6o, annular groove 65
The oil is guided through the circular arc hole 74, but since it passes through such a narrow oil passage and leaks to some extent along the way, the pressure is appropriately reduced (for example, 1 for a discharge pressure of 15 kg/cffl).
0 kg/cnl) is supplied to the first chamber 84 and transferred to the first pressure receiving surface 90 of the piston 76 into the second chamber 8.
It acts in the direction of moving it toward the 6th side.

On the other hand, the second chamber 86 is communicated with the compression chamber 32 in the middle of the compression stroke by a communication passage 92 formed across the front side plate 4 and the cylinder 2. The refrigerant gas pressure during compression is in the second chamber 86.
is supplied to the second pressure receiving surface 94 of the piston 76 to move it toward the -th chamber 84 side.

In the middle of the communication path 92, there is an on-off valve 96 as shown in FIG.
is provided. This on-off valve 96 includes a spherical valve element 98 that receives refrigerant gas pressure during compression, and a valve element 98 that cooperates with the valve element 98.
tb, the valve seat 100 blocks the communication path 92, and normally allows the valve element 98 to sit on the valve seat 100, but when the refrigerant gas pressure in the suction chamber 34 falls below a set value, it moves forward. , and a piston 102 that pushes the valve element 98 up from the valve seat 100. The piston 102 is located in the suction chamber 3
The valve valve 98 is fitted airtightly and slidably into a piston chamber 104 that opens to the valve 98 .
is urged in a direction to push away from the valve seat 100. The piston 102 is also supplied with atmospheric pressure to the spring 10 through a communication hole 108 formed in the front housing 10.
6, while the suction refrigerant gas pressure in the suction chamber 34 acts in the opposite direction, that is, in the backward direction.

When the on-off valve 96 shuts off the communication path 92 and the hydraulic pressure acting on the first pressure receiving surface 90 of the piston 76 overcomes the biasing force of the spring 88 as shown in FIG. The first through hole 66 and the second through hole 68 of the front side plate 4 almost overlap, and the communication area between them is maximized, but the on-off valve 96 opens the communication path 92 and the second chamber 86 When the piston 76 is moved toward the -th chamber 84 side based on the supply of compressed refrigerant gas pressure, the rotation plate 6 is moved by the engagement between the pin 72 and the long 7th
4 by a small angle counterclockwise in FIG.
Furthermore, as shown in FIG. The position of the end near the discharge port 42 with respect to the discharge port 4
Move to the 2nd side.

As is clear from the above explanation, in this example,
A rotating plate driving device is mainly composed of a piston 76 connected to a pin 72 of the rotating plate 64, and the rotating plate driving device and the rotating plate 64 connect the first through hole 66, which is a bypass passage. A bypass passage opening end position changing device is configured to change the position of the discharge port side end of the main suction port 38, which forms the opening on the compression chamber side in the middle of the compression stroke, and further includes a rotating plate drive device and a rotating plate 64. and the front side plate 4 provided with the second through hole 68 constitute a variable aperture device.

Next, the operation of the vane type refrigerant gas compressor constructed as above will be explained.

This compressor is used with the rotating shaft 18 connected to the engine, which is the drive source of the automobile, via an electromagnetic clutch (not shown), but if the compressor is left in a stopped state for a long time, the compression The pressure in all the spaces inside the machine becomes equal, and the piston 76 connected to the rotating plate 64 moves until it comes into contact with the end face of the second chamber 84 by the spring 88.
It is in a state where it has been moved to the chamber 84 side. At this time, the first through hole 66 formed in the rotating plate 64 connects with the second through hole 68 formed in the front side plate 4 and the communication hole 70 formed in the cylinder 2, as shown in FIG. The area of communication with the second M passer 68 and the like is the smallest in the device, and the position of the outlet side end P of the main suction port 38, which is the opening of the first through hole 66, is as follows. , located on the side closest to the discharge port 42 in the rotational direction of the rotor 16. Also,
The piston 102 in FIG. 4 is maintained in the retracted position by the pressure of the suction chamber 34 against the biasing force of the spring 106, and the valve element 98 is in a state where it can be seated on the valve seat 100.

In this state, the clutch is connected and the rotating shaft is 18°.
6 and the vane 28 start rotating, the refrigerant gas in the suction chamber 34 is compressed and is in the process of increasing its volume from the main suction port 38 and the sub suction port 40 through the communication portion between the second through hole 68 and the first through hole 66. Although the refrigerant gas is sucked into the compression chamber 32, since a throttling effect is provided at the communication portion between the first through hole 66 and the second through hole 68, the amount of refrigerant gas sucked into the compression chamber 32 is small, and the main The discharge port side end P of the suction port 38 is the discharge port 4
The refrigerant gas in the compression chamber 32, which is in the middle of the compression stroke, is bypassed to the compression chamber 32 and suction chamber 34, which are in the middle of the suction stroke on the trailing side, and the compression start time is delayed. At the beginning of startup, the compressor operates at a small capacity.

Therefore, when the compressor is started up, the engine load rises gently and the shock is small, and the occurrence of liquid compression can be effectively avoided.

When compression is started in this way, the flow of refrigerant gas from the compression chamber 32 in the middle of compression toward the communication path 92 causes
The valve element 98 is pressed against the valve 1ioo and blocks the communication path 92. On the other hand, when the above-mentioned small capacity operation is performed for a short time and the pressure in the discharge chamber 44 and the oil separation chamber 52 rises sufficiently, the oil stored in the lower part of the oil separation chamber 52 flows into the oil passage 5.
6. Vane groove 30. /lJ3 through the groove 60, etc., to the -th chamber 84 shown in FIG.
It is moved to the second chamber 86 side as shown in the figure against the urging force of 8°. As a result, the rotating plate 64 is rotated, and as shown in FIG. 3 or 6, the first through hole 66 and the second through hole 68 are almost aligned, and their communication area is reduced. Maximum. Further, the end P of the main suction port 38 on the discharge port side is the farthest from the discharge port 42 in the rotational direction of the rotor 16.

Therefore, the refrigerant gas sucked into the compression chamber 32 from the suction chamber 34 is hardly subjected to a throttling action at the communication portion between the second through hole 68 and the first through hole 66, so that the amount of refrigerant gas sucked is reduced. The vane 28 on the trailing side passes the end P on the discharge port side of the main suction port 38 when the volume of the compression chamber 32 is almost at its maximum, and compression starts from that time. is in a high-capacity operation state, and a large cooling capacity can be obtained.

By maintaining such a large-capacity operating state for a certain period of time, the room temperature gradually approaches a comfortable temperature and the cooling load decreases, the suction pressure of refrigerant gas decreases, and the piston 102 shown in FIG. The valve element 98 is pushed forward based on the urging force of the valve seat 100 to open the communication passage 92 (as a result, the refrigerant gas in the process of being compressed passes through the communication passage 92 and flows into the second passage shown in FIG. 3). The second pressure receiving surface 94 of the piston 76 receives it from the second chamber 86 .
4 side, the piston 76 is moved until the force applied to the piston 76 by the pressure of the refrigerant gas during compression and the spring 88 is balanced with the force applied to the piston 76 by the oil pressure in the -th chamber 84. It is moved to the -th chamber 84 side. At this time, as the volume of the -th chamber 84 decreases,
Some or all of the oil there is pushed out toward the rotor 16, but because the passage is narrow in that case, the curve does not flow out suddenly, and the oil acts as an oil damper to reduce the moving speed of the piston 76. As a result, the piston 76 is gradually moved to the above-mentioned balanced position.

As a result of this piston 76 rotating the rotating plate 64 counterclockwise in FIG. 3, the communication area between the first through hole 66 and the second through hole 68 is increased, as shown in FIG. 2 or FIG. 5, for example. The intake refrigerant gas decreases.

at the same time as the main inlet 38
The discharge port side end P passes through the second through hole 68 and is moved to the side closer to the discharge port 42, and the compression start time is delayed accordingly. That is, the amount of refrigerant gas sucked is reduced due to the effect of the throttle, and the vane 28 on the trailing side that partitions one compression chamber 30 passes through the discharge port side end P of the main suction port 38. Since the compression chamber 32 on the high pressure side and the compression chamber 32 on the low pressure side are in communication with each other with the first through hole 66 serving as a bypass passage across the vane 28, the compression chamber 32 on the high pressure side and the compression chamber 32 on the low pressure side are in communication with each other through the first through hole 66 as a bypass passage. Refrigerant gas leaks to the low pressure side and no effective compression work is performed. Due to the synergistic effect of this delay in the start of compression and the reduction in the amount of refrigerant gas taken in due to the above-mentioned throttling effect, the compressor shifts to a small capacity operation state, and it is avoided to perform more compression work than necessary, and the engine The burden of this will be reduced.

In addition, due to the late start of compression, the amount of suction refrigerant gas decreases and the suction refrigerant gas pressure does not drop much, causing the vane 2
8 is reduced, the driving torque for rotating the rotor 16 is reduced, leakage is reduced, and efficient compression work is performed, especially during low speed operation. Furthermore, the throttling effect on the suction refrigerant gas becomes thicker as the rotation speed of the compressor increases, which contributes to avoiding excessive cooling and improving the acceleration of the automobile. Since the amount of gas is kept small, refrigerant gas can easily blow out from the compression chamber 32 on the high pressure side to the compression chamber 32 on the low pressure side through the side of the vane 28 passing through the main suction port 38, which makes it difficult to start compression. This leads to reliably preventing this up to the discharge side end P of the main suction port 38.

By the way, if only the suction refrigerant gas is throttled or the compression start timing is changed, as shown in Figure 7, if only the throttle is used, the effect of reducing the capacity will be small in the low speed range of the compressor. In addition, if only the compression start timing is changed, the effect of reducing capacity tends to be smaller in the high-speed range, but in the case of this example, since the two are done at the same time, the effect of each other is weaker. By complementing each other in the rotational speed range, an effective performance reduction effect can be obtained over the entire range from low speed to high speed.

When the cooling load increases due to continued small capacity operation, the piston 102 moves back as the suction pressure of refrigerant gas increases, and the valve 98 blocks the communication path 92, causing the piston 76 moves to the second chamber 86 side and shifts to the above-mentioned large capacity operation state. Thereafter, small-capacity operation and large-capacity operation will be repeated depending on the magnitude of the cooling load.

When the compressor is stopped, the oil in the first chamber 84 flows into the rotor 1.
6 and the front side plate 4 and rear side plate 6 to the compression chamber 32 side, the pressure in the first chamber 84 becomes equal to the pressure in the suction chamber 34, and the refrigerant gas in the second chamber 86 also flows through the communication passage 92. The pressure then flows back to the compression chamber 32 and becomes equal to the pressure in the suction chamber 34, causing the piston 76 to
is moved toward the -th chamber 84 side by the spring 88, and upon restart, operation is started from a state where the discharge volume is at its minimum.

In order to move the piston 76, as shown in FIG. Through passage 110 to room 84
It is also possible to adopt a configuration in which an electromagnetic on-off valve 114 operated by a command from a controller 112 is provided in the middle of this oil passage 110. A pressure signal is supplied to this controller 112 from a sensor 116 that detects the pressure of suction refrigerant gas in the suction chamber 34, and when the cooling load is large and the suction refrigerant gas pressure is higher than a set value, , the controller 112 is the electromagnetic on-off valve 1
14 is kept open, and the -th chamber 8 is passed through the oil passage 110.
4, the piston 76 is moved toward the second chamber 86 against the biasing force of the spring 88, and the rotating position of the rotating plate 64 is changed to a large extent to the compressor. It is maintained in a position where capacity operation is performed. However, when the suction refrigerant gas pressure falls below the set value due to a decrease in the cooling load, the controller 11
2 causes the electromagnetic on-off valve 114 to close the oil passage 110. As a result, the piston 76 moves toward the -th chamber 84 based on the biasing force of the spring 88, and the oil in the -th chamber 84 is released from the plate hole 1.
It is allowed to leak to the suction chamber 34 via the piston 17 , leak to the second chamber 86 side from the gap between the piston 76 and the piston chamber 80 , and further flow out to the suction chamber 34 via the relief passage 118 . The piston 76 moved in this manner rotates the rotary plate 64, thereby shifting the compressor to a small capacity operating state.

Note that by changing the duty ratio of the drive current supplied from the controller 112, the opening time and closing time of the electromagnetic on-off valve 114 are controlled, and thereby the flow rate of the oil passage 110 is adjusted according to the magnitude of the suction refrigerant gas pressure. By controlling the piston 76, it is possible to stop the piston 76 not only at the two positions as described above but also at any arbitrary position, thereby making it possible to reduce the capacity in a detailed manner according to the magnitude of the cooling load.

Next, another embodiment of the present invention will be described based on FIGS. 9 and 10, and parts similar to those in the embodiment shown in FIG. , detailed explanation will be omitted.

In this embodiment, the rotor 16 is eccentrically arranged in close proximity to one location (sealed position) on the inner circumferential surface of the cylindrical cylinder 2, and the discharge port 42 is placed on either side of the sealed position.
and an inlet 1'20 are provided. This intake port 1
2o is a first suction port 122 and a second suction port 12 that are formed long on the front side plate 4 along the rotational direction of the rotor 16, and are connected to each other in the rotational direction.
4, the first suction port 122 is located near the sealing position, and the second suction port 124 is located near the sealing position.
6 from the first suction port 122 to the discharge port 4
It is located close to 2.

A closing block 126 is provided as a closing member for closing the second suction port 124. This closing block 126 is held movably by the front side plate 4 between a position in which it closes and a position in which it opens the second suction port 124 in a direction perpendicular to the axis of the rotor 16, and is held by a spring 128. It is biased toward the open position. When the closing block 126 is moved to the closing position, the inner surface of the front side plate 4 that is in contact with or very close to the end surface of the vane 28 and the inner surface of the closing block 126 are in a continuous state on one plane. It is designed to be.

The closing block 126 includes a first pressure receiving surface 130 on the side facing the second suction port 124 and a second pressure receiving surface 132 on the opposite side thereof, and the second pressure receiving surface 132 is formed on the front side plate 4. It faces an airtight pressurized chamber 134. This pressurized chamber 134 includes a gas passage 13
6, the refrigerant gas in the compression chamber 32 that is in the middle of the compression stroke is guided, and the pressure of this refrigerant gas in the middle of compression is applied to the block block 126.
acts on the second pressure receiving surface 132, and also acts on the first pressure receiving surface 13
The suction refrigerant gas pressure acts on 0. Therefore, depending on the magnitude of the force based on the refrigerant gas pressure during compression and the force based on the spring 128 and suction refrigerant gas pressure, the closing block 126 is driven between the open position and the closed position. block 1
26 in both directions constitutes a driving device thereof, and the driving device and the closing block 126 constitute a device for changing the position of the end of the suction port 120 near the outlet 42. There is. That is, depending on whether the closing block 126 is in the closed position or the open position, the intake port 12
The position of the end of the rotor 16 in the rotational direction is changed. And a passage connected to this inlet 120,
In particular, the passage connected to the second suction port 124 functions as a suction passage, and also functions as a bypass passage that connects the compression chamber 32 on the front side of the vane 28 and the compression chamber 32 on the rear side through the side of the vane 28. Inlet port 1
Changing the position of the opening end on the side closer to the discharge port 42 of the bypass passage 20 essentially changes the position of the end position of the opening of the bypass passage on the discharge port side. Therefore, this device is a bypass passage opening end position changing device. This will constitute the following.

On the other hand, as shown in FIG. 10, the opening on the suction chamber 34 side of the suction passage 138 connected to the suction port 120 is provided with a variable throttle device that increases or decreases the flow rate of the suction refrigerant gas by changing the opening area of the opening. It is provided. This variable aperture device has an aperture plate 14 large enough to cover the aperture of the variable aperture device.
0, this aperture plate 140 is rotatably attached to the front side plate 4 around an axis 142,
It is biased by a spring 144 in a direction to increase the opening area. And the aperture plate 140 is
The dynamic pressure of the refrigerant gas flowing inside the suction chamber 34 toward the suction passage 38 is received in a direction that reduces the opening area, and the stop collar 146 prevents the opening from being completely blocked. Prevented.

In the compressor configured as described above, when the cooling load is large, the second pressure receiving surface 132 of the blocking block 126
The closing block 126 is moved to a position where it closes the second suction port 124 of the suction port 120 due to the refrigerant gas pressure acting on the refrigerant during compression, and the compressor is in a high capacity operation state.

However, when the cooling load decreases, the suction pressure of refrigerant gas decreases, and the pressure difference between the refrigerant gas pressure in the middle of compression and the suction refrigerant gas pressure decreases accordingly.

This is due to the following reason. Generally, the pressure is PX
If the pressure when a gas whose volume is Vi is compressed to a volume of ■2 is P2, then P2 = Ps (Vl /
V2) ” holds true, so the pressure difference ΔP is Δ
It is expressed as: P = P2 - P = P ((Vl/V2) - 1). In other words, the smaller the pressure P before compression, the smaller the pressure difference ΔP. As the difference in refrigerant gas pressure acting on the first pressure receiving surface 130 and the second pressure receiving surface 132 decreases, the closing block 126 is moved to the position where the second suction port 124 is opened based on the biasing force of the spring 128. As a result, the position of the end of the suction port 120 on the side of the discharge port, that is, the position of the end of the opening on the side of the compression chamber 32 in the middle of the compression stroke of the bypass passage, changes depending on the position of the end of the second suction port 124 on the side of the discharge port. By delaying the compression start timing by that amount, the compressor shifts to a small capacity operation state.

Also, as the car accelerates, the engine speed increases,
When the rotational speed of the compressor increases accordingly, the flow velocity of the refrigerant gas flowing from the suction chamber 34 toward the suction passage 138 shown in FIG. 10 increases, and the dynamic pressure applied to the throttle plate 140 increases. The plate 140 is rotated in a direction to close the opening of the suction passage 138, and the flow rate of suction refrigerant gas is reduced. Therefore, 4. the discharge capacity of the compressor is reduced to prevent excessive cooling, and the required power of the engine is reduced, improving the acceleration of the automobile.

Reducing the flow rate of this suction refrigerant gas has the effect of reducing the capacity of the compressor, especially when the compressor is running at high speed. The effect of reducing the capacity is particularly large at low speeds, and the combination of these makes it possible to effectively reduce the capacity over a wide range of rotation speeds, that is, to operate with a small discharge capacity.

Several embodiments of the present invention have been described in detail above, but these are literally just examples, and other embodiments, for example, when the rotating plate is included, as shown in FIG. 11,
A bypass groove 148 is formed in the rotary plate 64 in a portion that is not connected to the first through hole 66 and is closer to the discharge port in the rotor rotational direction, and this bypass groove 148 is opened toward the rotor side so that the bypass groove 148 is opened toward the rotor side. The intake refrigerant gas amount can be increased or decreased by increasing or decreasing the communication area of the first and second through holes 6G and 68, or by changing the communication area of the first and second through holes 6G and 68, or by changing the communication area of the first and second through holes 6G and 68. It is also possible to adopt an embodiment in which the through holes 66 and 68 are not provided (the suction passage is formed separately) and a variable throttle device as shown in FIG. 10 is used.

In addition, in order to drive the rotary plate, it is possible to mesh a rack fixed to the piston with a pinion fixed to the rotary plate, or to rotate the rotary plate by a stepping motor, etc. The present invention can be applied to a rotary compressor such as a rolling piston that is rotated eccentrically while slidingly contacting the inner peripheral surface of a cylinder, and the present invention can also be applied to a rotary compressor that compresses gas other than refrigerant gas. It goes without saying that the present invention can be practiced with various modifications and improvements based on the knowledge of those skilled in the art.

As detailed above, the present invention provides a bypass passage for bypassing gas in a leading compression chamber to a trailing compression chamber in a rotary compressor having a plurality of compression chambers, and a bypass passage for bypassing gas in a leading compression chamber to a trailing compression chamber. A bypass passage opening end position changing device that changes the compression start timing by changing the position of the discharge port side end of the opening with respect to the compression chamber on the leading side of the passage, and a variable throttle device that increases or decreases the flow rate of intake gas are provided. The combination of delaying the compression start time and reducing the flow rate of intake gas has the effect of effectively reducing performance in all rotational speed ranges from low to high rotational speeds. It is something that plays.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal cross-sectional view of a vane-type refrigerant gas compressor that is an embodiment of the present invention. 2 and 3 are a cross-sectional view taken along the line ■-■ and a cross-sectional view taken along the line I[II[I] in FIG. 1, respectively. 4 is a sectional view of the TV-TV in FIG. 3, and FIGS. 5 and 6 are partial sectional views showing different operating states of the rotary plate shown in FIG. 1. FIG. 7 is a graph showing the effect of reducing the capacity of the compressor shown in FIG. 1 etc., and FIG. 8 conceptually shows a drive device for driving a rotating plate in another embodiment of the present invention It is a simplified diagram. FIG. 9 is a cross-sectional view of a vane-type refrigerant gas compressor that is another embodiment of the present invention, and FIG. 10 is a partial cross-sectional view showing another part of the compressor shown in FIG. 9. . Figure 11 shows
FIG. 7 is a partial cross-sectional view schematically showing the main parts of another embodiment of the present invention. 2 Niji cylinder 4: Front side plate 6: Rear side plate 10: Front housing 12: Rear housing 14: Housing 16: Rotor 18: Rotating shaft 28: Vane 32: Compression chamber 34: Suction chamber 38: Main suction port 42: Discharge port 44 : Discharge chamber 52: Oil separation chamber s6.1io: Oil passage 64: Rotating plate 66: First through hole (bypass passage) 68: Second xa hole 72: Pin 74: Arc hole 76: Piston 78: Long hole 84: Second chamber 86: Second chamber 88 Spring 90: First pressure receiving surface 92: Communication path 94: Second pressure receiving surface 96: Opening/closing valve 98; Valve element 100: Valve seat 102; Piston 112: Controller 114: Solenoid Open/close valve 116; pressure sensor 120; suction port 1
22: First suction port part 124: Second suction port part 126; Closing block (closing member) 128 Spring 13o: First pressure receiving surface 132: Second pressure receiving surface 138: Suction passage 140: Throttle plate 148: Pie bus groove ( (bypass passage) Applicant Toyota Automobile Co., Ltd. Figure 5 Figure 6 Figure 7 Rotary beast rρm

Claims (3)

[Claims] (1) A rotary compressor that sucks gas from an inlet into a plurality of compression chambers whose volume changes as a rotor is rotated within a housing, and discharges gas from a discharge port, the compressor being compressed among the plurality of compression chambers. a bypass passage that communicates a compression chamber that is in the middle of a stroke with a compression chamber that is in the middle of a suction stroke, and an opening of the bypass passage on the side of the compression chamber that is in the middle of the compression stroke, on a side that is closer to the discharge port with respect to the rotational direction of the rotor. a bypass passage opening end position changing device that changes the compression start timing by changing the position of the end of the bypass passage, and a variable throttle device that is provided in the suction passage connected to the suction port and increases or decreases the flow rate of the intake gas. Characteristic variable capacity rotary compressor. (2) the housing includes a cylinder and a side plate fixed to an open end of the cylinder;
The rotor rotates while holding vanes that are slidably in contact with the inner peripheral surface of the cylinder, and a rotating plate having a first through hole in the thickness direction is provided between the cylinder and the side plate. The first plate is provided rotatably around the center line of the cylinder and in contact with or very close to the end surfaces of the rotor and the vane, and is provided through the side plate in the thickness direction. A second through hole is formed that communicates with the through hole, and when the rotary plate is rotated to change the position of the end of the first through hole closer to the discharge port, the first through hole is changed. A rotary plate drive device is provided that increases or decreases a communication area with the second through hole, the first through hole forms the bypass passage, and the rotary plate drive device and the rotary plate communicate with the bypass passage. Claim 1, wherein the passage opening end position changing device is configured, and the rotating plate drive device, the rotating plate, and the side plate provided with the second through hole constitute the variable diaphragm device. Variable capacity rotary compressor as described in . (3) The housing includes a cylinder and a side plate fixed to an open end of the cylinder, and the side plate has a first suction port portion and a second suction port portion that are connected to each other in the rotational direction of the rotor. a suction port is provided to form the suction port, and a passage connected to the first and second suction ports forms the bypass passage, and
A side that is moved relative to the side plate and is substantially continuous with a surface of the side plate that is in contact with or very close to the end surface of the vane, and is closer to the discharge port of both the suction ports. A closing member for closing the second suction port, and a closing member driving device for moving the closing member between a position where the second suction port is closed and a position where the second suction port is opened are provided. 2. The variable displacement rotary compressor according to claim 1, wherein said bypass passage opening end position changing device is constituted by a drive device.