JPH0424559B2 - - Google Patents

Description

Detailed Description of the Invention Technical Field The present invention provides a system for sucking gas from the suction chambers through a suction port into a plurality of compression chambers whose volumes change when a rotor holding a plurality of vanes is rotated within a housing. Regarding the vane compressor that discharges from the outlet, in particular, a variable displacement vane compressor (hereinafter referred to as
(abbreviated as compressor unless otherwise necessary).

BACKGROUND ART 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. When the compressor shifts to the heat retention mode, it does not require as much discharge capacity, so it is desirable to shift the compressor to partial load operation, that is, to small discharge capacity operation.

Therefore, the inventors of the present invention
In No. 222994, a bypass passage is provided to communicate the compression chamber and the suction chamber during the compression stroke, and the bypass passage is made openable and closable by an opening/closing member, and when the cooling load becomes small, the bypass passage is opened and closed. We proposed that the refrigerant gas in the process of being compressed be opened to allow the refrigerant gas to escape into the suction chamber, thereby enabling small-capacity operation.

In addition, in Japanese Patent Application No. 57-209016, a spool type on-off valve is installed in the suction passage communicating with the compression chamber in the middle of the suction stroke, and when the cooling load becomes small, the effective suction area of the suction passage is reduced. The authors proposed a method that would enable small-capacity operation.

Furthermore, in Japanese Patent Application No. 59-171209, a bypass groove is provided to communicate the compression chamber in the middle of the compression stroke with the suction chamber in the middle of the suction stroke, and the end of the bypass groove on the side closer to the discharge port in the rotor rotational direction is provided. It was also proposed that by changing the position, the compression start time could be delayed to enable small capacity operation.

Problems to be solved With the above method, when the cooling load decreases, the compressor automatically shifts to a low-capacity operating state, which is convenient, but it has been found that there are further improvements that need to be made. did.

In other words, if the compression chamber in the middle of the compression stroke is communicated with the suction chamber to allow some of the compressed gas to escape to the suction chamber, as the rotational speed of the compressor increases and the inertia of the gas increases, the bypass Even if the passage is opened, gas in the compression chamber that is in the middle of the compression stroke has difficulty escaping to the suction chamber, and the effect of reducing capacity cannot necessarily be said to be sufficient.On the other hand, when reducing the effective suction area using a spool-type on-off valve, However, when the rotational speed of the compressor 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 addition, if the end position of the bypass groove on the discharge port side is shifted to delay the start of compression, the inertia of the gas in the high-speed rotation region of the compressor causes the gas that flows into the compression chamber to suddenly flow into the compression chamber during the suction stroke. It is difficult to move to the compression chamber, and the effect of reducing capacity is low in high-speed rotation areas.Also, the closer the end of the bypass groove is to the outlet, the later the compression start time will be and the capacity will be lower. This is effective for shutting down the system, but when returning to high-capacity operation,
Since the position of the end on the side of the discharge port must be returned to its original position, it is difficult to say that it is a good idea to move the position of the end on the side of the discharge port by an excessively large distance.

Solution The present invention has been made in order to provide a compressor that enables more effective small-capacity operation against the background of the above-mentioned circumstances, and the gist thereof is that in a vane compressor, In addition to providing two types of bypass passages, a first bypass passage and a second bypass passage,
A first bypass passage opening end position changing device and a second bypass passage opening/closing device are provided, and a variable throttle device is further provided in the suction passage connected to the suction port to increase or decrease the flow rate of the intake gas.

The first bypass passage communicates the compression chamber in the middle of the compression stroke among the plurality of compression chambers with the compression chamber in the middle of the suction stroke, and the first bypass passage is configured to connect the compression chamber in the middle of the compression stroke to the compression chamber in the middle of the suction stroke. The position of the end closer to the discharge port can be changed in the rotational direction of the rotor. The first bypass passage opening end position changing device changes the compression start timing by changing the discharge port side end position of the first bypass passage.

On the other hand, the second bypass passage is normally blocked, but when the discharge port side end of the first bypass passage is moved to the vicinity of the position closest to the discharge port, the second bypass passage is closed during the compression stroke. The chamber is communicated with the suction chamber or the suction side space that is constantly in communication with the suction chamber at a position closer to the discharge port than the discharge port side end position of the first bypass passage, and a part of the compressed gas is transferred to the suction chamber or the suction side. It plays the role of escaping into space. In other words, the first bypass passage can change its discharge port side end position, while the second bypass passage can be switched between a blocked state and a communicating state, and can It is also different from the first bypass passage in that the opening on the chamber side is formed in a shape and size that is once completely blocked by the vane when the vane passes through the opening as the rotor rotates. .
The second bypass passage opening/closing device switches the second bypass passage between a blocked state and a communication state.

Function In this vane compressor, the second bypass passage opens to the compression chamber side, and as the rotor rotates, each vane passes over the opening. As a result, it is once completely blocked, thereby preventing gas from blowing from the compression chamber in front of the vane to the compression chamber behind the vane. if,
If this opening is not completely blocked by the vane when the vane passes, the compression chamber in front of the vane and the compression chamber behind the vane are temporarily closed each time the vane passes through the opening of the second bypass passage. This results in gas flowing from the former, which has higher pressure, to the latter, which has lower pressure. Since the second bypass passage is opened at a position relatively close to the discharge port, if blow-by occurs, the compression efficiency will be greatly reduced, but according to the present invention, this inconvenience can be avoided. .

In the compressor of the present invention, the first bypass passage opening end position changing device moves the position of the discharge port side end of the opening of the first bypass passage to a side closer to the discharge port to delay the compression start timing. , a variable throttle device reduces the flow rate of the intake gas;
The second bypass passage opening/closing device opens the second bypass passage and releases the compressed gas to the suction chamber or the suction side space, thereby making a transition to the small capacity operating state. Reducing the flow rate of intake gas using a variable throttle device has a large effect of reducing capacity, especially in the high-speed rotation region of the compressor, and delaying the start of compression by changing the position of the end of the first bypass passage on the discharge port side reduces the speed at low speeds. The ability reduction effect is large in the rotation area. In addition, releasing compressed gas to the suction chamber etc. through the second bypass passage has a large effect of reducing performance, especially in the low-speed rotation range, but if this second bypass passage is brought into communication, then the first bypass Since small-capacity operation can be effectively performed without bringing the end position of the passageway closer to the discharge port, a relatively small amount of change in the end position of the first bypass passage on the discharge port side is sufficient. Moreover, in a state where the end position of the first bypass passage on the discharge port side is brought closer to the discharge port while the second bypass passage is blocked, so to speak, medium capacity operation is possible.

The present invention continuously changes the discharge capacity by changing the compression start timing by continuously changing the position of the end of the opening of the first bypass passage on the discharge port side, and the continuous change function reaches its limit. One of the important features is that the second bypass passage is opened at about the same time to release a part of the compressed gas, thereby achieving a significant reduction in discharge capacity. In other words, the compression start timing changing function by the first bypass passage and the relief function by the second bypass passage are not simply combined so that they always act in parallel, but the compression start timing changing function reaches its limit. The combination is designed so that a relief function can be obtained at the same time, the discharge capacity can be continuously reduced in many cases, and special cases where an extremely small discharge capacity is required, and the first bypass This avoids increasing the size of the compressor by requiring only a small amount of change in the position of the end of the passage opening on the discharge port side.

In addition, in addition to the compression start timing change function and the relief function, a suction gas throttling function is also used to effectively perform small discharge capacity operation in all operating ranges regardless of the speed of rotation. This is one of the important features of the present invention.

Embodiments Hereinafter, one or two embodiments in which the present invention is applied to a vane compressor for compressing refrigerant gas 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;
The openings at both ends are respectively closed by the front side plate 4 and the rear side plate 6, so that a rotor chamber 8 having an elliptical cross section is formed inside thereof. On the other hand, the outside thereof is 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. This rotor 1
A rotating shaft 18 projects from the center of both end faces of the rotating shaft 18 and is rotatably supported by both side plates 4 and 6 via bearings 20 and 22. The front end of the rotating shaft 18 extends into a center hole 24 formed in the center of the front housing 10, and the airtightness between the front housing 10 and the rotating shaft 18 is maintained by a shaft sealing device 26.

As is clear from FIG. 2, the rotor 16 has four
The vanes 28 are held by vane grooves 30 such that they can move in and out of the outer circumferential surface of the rotor 16, and the vane tips are pressed against the inner circumferential surface of the cylinder 2 by lubricating oil, which will be described later. There is. As a result, adjacent vanes 28, rotor 1
6, the inner circumferential surface of cylinder 2, and the front
A plurality of airtight compression chambers 32 surrounded by the inner surfaces of both rear side plates 4 and 6 are formed at symmetrical positions with respect to the axis of the rotor 16, and are surrounded by the inner surfaces of the rear side plates 4 and 6.
As the rotor 16 is rotated in the direction shown by the arrow, the volumes of the compression chambers 32 increase once and then decrease.

Returning to FIG. 1, a suction chamber 34 is provided between the front side plate 4 and the front housing 10.
The refrigerant gas is sucked into this suction chamber 34 from the compressor inlet 36 formed in the front housing 10, and is further sucked into the compression chamber 32, which is in the process of increasing its volume, from the main suction port 38 and the auxiliary suction port 40. It is becoming more and more inhaled. 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 discharged through a plurality of discharge ports 4 formed in the cylinder 2.
2 into the discharge chamber 44. These discharge ports 4
2, the rotor 16 is moved from the position communicating with the compression chamber 32 at the end of the compression stroke, that is, the two positions where the outer circumferential surface of the rotor 16 is closest to the inner circumferential surface of the cylinder 2.
They are formed at positions separated by a short distance in the direction opposite to the direction of rotation. Further, the discharge chamber 44 is formed between a notch formed in the outer peripheral surface of the cylinder 2 and the rear housing 12.
A reed valve 46 as a discharge valve and a regulating member 48 for regulating the amount of lift thereof are disposed within the reed valve 4 . The refrigerant gas discharged into the discharge chamber 44 is
It passes through a communication hole 50 formed in the rear side plate 6 to an oil separation chamber 52 formed in the rear housing 12, where the mist of oil is separated, and then passes through the compressor outlet formed in the rear housing 12. 54 to the refrigeration circuit of the passenger compartment cooling system.

The mist-like oil separated in the oil separation 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. Further, the oil is supplied to the annular oil groove 58 formed in the rear side plate 6, the vane groove 30, and the oil groove 60 formed in the front side plate 4, and the oil is supplied to the rotor 16, the vane 28, and between the side plates 4 and 6. In addition to providing lubrication, the oil that has entered the inner end of the vane groove 30 serves to push the vane 28 out of the vane groove 30. 62 is an O-ring.

An annular rotating plate 64 is provided between the cylinder 2 and the front side plate 4. The rotating plate 64 is rotatably held around the center line of the cylinder 2 by a shallow annular groove 65 formed on the inner surface of the front side plate 4 so as to communicate with the oil groove 60. , and one plate surface thereof forms a continuous plane with the inner surface of the front side plate 4, and is in contact with or very close to the end surfaces of the rotor 16 and the vane 28.

Two first 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, and
The front side plate 4 has two holes that pass through it in the thickness direction and communicate with these first through holes 66.
The second through holes 68 are formed at symmetrical positions with respect to the center line. And these first through holes 6
6 and the second through hole 68 constitute a main 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. There is. Furthermore, two auxiliary suction passages 69 are formed spanning the front side plate 4 and the cylinder 2.
The auxiliary suction port 40 communicates with the compression chamber 32 which is in the process of increasing its volume. The first through hole 66 is formed in an arc shape along the rotational direction of the rotor 16, has a length sufficiently longer than the thickness of the vane 28, and is located on the front side (leading side) of the vane 28.
The second through hole 68 functions as a first bypass passage that communicates the compression chamber 32 in the middle of the compression stroke with the compression chamber 32 in the rear (trailing side) in the middle of the suction stroke. It is formed to have the same size as the continuous hole 66.

Further, as shown in FIG. 3, the rotary plate 64 is provided with two third through holes 70 in the thickness direction at positions closer to the discharge port 42 in the rotational direction of the rotor 16 than the first through holes 66. These third through holes 70 are formed in a size that can be closed by the side ends of the vanes 28, and are smaller than the first through holes 66. On the other hand, in the front side plate 4, two fourth through holes 71 in the thickness direction are located closer to the discharge port 42 than the second through hole 68 in the rotational direction of the rotor 16. is formed with the same size. Normally, the third through hole 70 of the rotating plate 64 is located between the second through hole 68 and the fourth through hole 71 of the front side plate 4 and is closed by the front side plate 4. The third through hole 70 and the fourth through hole 71 are in a blocked state, but when they are brought into communication with each other by the rotation of the rotating plate 64, the compression chamber 32, which is in the middle of the compression stroke, is communicated with the suction chamber 34. These third through holes 70 and fourth through holes 71
This will serve as the second bypass passage.

The rotating plate 64 has a rotor 1 as shown in FIG.
A pin 72 protruding on the opposite side from the piston 76 is fixedly installed, and passes through an arcuate hole 74 formed in the front side plate 4 to a long hole 7 formed in the piston 76.
8 is fitted loosely. This piston 76
is arranged within a piston chamber 80 formed in the front side plate 4.

As is clear from FIG. 3, the piston chamber 80 is connected to the rotation shaft 18 of the front side plate 4
The opening of the bottomed hole formed in the vicinity of the boss portion supporting the piston is closed by the closing member 82, and the piston 76 is inserted into the piston chamber 80 along the tangent of the rotating plate 64. They are slidably fitted in a direction parallel to the direction. 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, and the piston 76 is connected to a precompressed spring 88.
is biased toward the first chamber 84 by.

As is clear from FIG. 1, the first chamber 84 includes:
The oil stored in the lower part of the oil separation chamber 52 is guided through an oil passage 56, a bearing 22, an oil groove 58, a vane groove 30, an oil groove 60, an annular groove 65, and an arcuate hole 74. However, since the oil passes through such a narrow passage and leaks to some extent along the way, the pressure is reduced appropriately (for example, the discharge pressure is 15 Kg/cm ² and 10 Kg/cm ²
is supplied to the first chamber 84 and transferred to the first pressure receiving surface 90 of the piston 76 into the second chamber 86.
It is designed to act in the direction of moving it to the side.

On the other hand, the second chamber 86 includes a communication passage 9 formed across the front side plate 4 and the cylinder 2.
2 communicates with the compression chamber 32 that is in the middle of the compression stroke, and the refrigerant gas pressure that is being compressed is supplied to the second chamber 86 through this communication path 92, and is applied to the second pressure receiving surface 94 of the piston 76. It is designed to act in a direction to move the air to the first chamber 84 side.

An on-off valve 96 is provided in the middle of the communication path 92, as shown in FIG. This on-off valve 96 is
A spherical valve 98 that receives refrigerant gas pressure during compression
A valve seat 100 cooperates with this valve element 98 to shut off the communication passage 92. Normally, the valve element 98 is allowed to sit on the valve seat 100, but when the refrigerant gas pressure in the suction chamber 34 is at a set value. When it drops below, move forward,
Piston 10 that pushes the valve element 98 away from the valve seat 100
2. The piston 102 is located in the suction chamber 3
The valve element 98 is fitted airtightly and slidably into a piston chamber 104 that opens into the valve seat 100, and is biased by a spring 106 in a direction to push the valve element 98 away from the valve seat 100. In addition, this piston 102 has
Communication hole 10 formed in front housing 10
8, the atmospheric pressure acts in the same direction as the biasing direction of the spring 106, while the suction refrigerant gas pressure in the suction chamber 34 acts in the opposite direction, that is, in the backward direction.

Such an on-off valve 96 blocks the communication path 92,
As shown in FIG. 3, the first pressure receiving surface 9 of the piston 76
When the hydraulic pressure acting on the rotary plate 64 overcomes the biasing force of the spring 88, the first through hole 6 of the rotating plate
6 and the second through hole 68 of the front side plate 4
overlap, the communication area between them is maximum, and the third through hole 70 and the fourth through hole 71 are in the most separated state, but the on-off valve 96 opens the communication path 92 and When the piston 76 is moved toward the first chamber 84 based on the pressure of the compressed refrigerant gas being supplied to the second chamber 86, the pin 72 and the elongated hole 78 engage to move the rotating plate 64 as shown in FIG. is rotated clockwise by a small angle to reduce the communication area between the first through hole 66 and the second through hole 68, and at the same time to Shifting the position of the end near the discharge port 42 to the discharge port 42 side, and
The third through hole 70 is brought closer to the fourth through hole 71 side, and the third through hole 70 and the fourth through hole 71 are brought into communication when the rotation angle of the rotating plate 64 becomes maximum.

As is clear from the above description, in this embodiment, the rotating plate driving device is mainly composed of the piston 76 connected to the pin 72 of the rotating plate 64, and the rotating plate driving device is the first rotating plate driving device. It functions as a first bypass passage opening end position changing device for changing the discharge port side end position of the through hole 66 serving as a bypass passage, and further includes a rotating plate driving device, the rotating plate 64, and the second through hole 68. The front side plate 4 constitutes a variable aperture device, and the rotary plate drive device controls the third through hole 70 and the fourth through hole 71, which form the second bypass passage, between a blocked state and a communicating state. It also serves as a second bypass passage opening/closing device.

Next, the operation of the refrigerant gas compression vane compressor configured 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). Since the gas suction pressure is high, the piston 102 shown in FIG.
By sitting in position 0, the communication path 92 is blocked. On the other hand, the oil stored in the lower part of the oil separation chamber 52 is forced into the first chamber 84 shown in FIG. 3 through the oil passage 56, vane groove, 30 oil groove 60, etc. Therefore, the piston 76 resists the biasing force of the spring 88 based on the pressure of the oil and moves into the second chamber 86 as shown in the figure.
It is in a state where it is moved to the side. At this time,
As is clear from FIGS. 5 and 8, the first through hole 66 and the second through hole 68 overlap and have the maximum communication area, and the third through hole 7
0 and the fourth through hole 71 are separated from each other and do not communicate with each other, and the end of the first through hole 66 on the discharge port side is located at a position P ₁ farthest from the discharge port 42. Therefore, the refrigerant gas to be sucked is hardly subjected to a throttling action at the communication portion between the first through hole 66 and the second through hole 68, and the vane 28 on the trailing side that partitions the compression chamber 32 is inserted into the first through hole 68. The volume of the compression chamber 32 reaches its maximum immediately before passing the discharge port side end position _P1 , and compression starts from this position _P1 , so the compressor operates at a large capacity and a large cooling capacity is obtained.

By maintaining this high-capacity operating state for a certain period of time, the room temperature gradually approaches the comfortable temperature.
When the cooling load becomes smaller, the evaporation temperature of the refrigerant gas in the evaporator (not shown) becomes lower, so the evaporation pressure also becomes lower, and the suction pressure of the refrigerant gas decreases, causing the piston 102 shown in FIG. When the valve element 98 is pushed forward from the valve seat 100, the communication passage 92 is opened. As a result, the partially compressed refrigerant gas is supplied to the second chamber 86 shown in FIG. 3 through this communication path 92 and acts on the second pressure receiving surface 94 of the piston 76, so that the piston 76 moves toward the first chamber 84. I am made to do so. At this time, as the volume of the first chamber 84 decreases, the oil therein is pushed out toward the rotor 16, but because the aforementioned passage is narrow, the oil does not flow out suddenly, reducing the moving speed of the piston 76. The effect of acting as an oil damper is obtained, and the piston 76 is gradually moved toward the first chamber 84 side.

This piston 76 rotates the rotating plate 64 clockwise in FIG. 3, for example in FIGS.
In the state shown in the figure, although the third through hole 70 does not communicate with the fourth through hole 71, the communication area between the first through hole 66 and the second through hole 68 decreases, and the suction refrigerant gas At the same time, the end of the first through hole 66 on the discharge port side is moved to position P ₂ on the side closer to the discharge port 42, and the compression start time is delayed accordingly. That is, the amount of refrigerant gas sucked in decreases due to the effect of the above-mentioned throttling, and until the vane 28 on the trailing side that partitions one compression chamber 32 passes the position P ₂ of the end of the discharge port side of the first through hole 66. 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 across the vane 28 through the first through hole 66 serving as the first bypass passage, the vane 28 Refrigerant gas leaks through the side ends from the high pressure side to the low pressure side, and no effective compression work is performed. The synergistic effect of this delay in the start of compression and the reduction in the amount of refrigerant gas sucked in due to the above-mentioned throttling effect causes the discharge capacity to decrease. The suction amount also decreases and the suction pressure increases. If the degree of rise is such that it overcomes the spring 106 and atmospheric pressure shown in FIG.
2, the pressure feeding of the refrigerant gas during compression to the second chamber 86 is stopped. As a result, piston 7
6 does not move further toward the first chamber 84, but stops at a position between the first chamber 84 and the second chamber 86, and the rotary plate 64 is placed in the state shown in FIGS. 6 and 9. The compressor is operated at medium capacity.

However, if the degree of decrease in the cooling load of the compressor (thermal load of the refrigeration circuit) is large, that is, if the suction pressure of refrigerant gas is significantly reduced, the piston 102
is kept in the advanced position for a relatively long time based on the biasing force of the spring 106, and the valve element 98 is pushed away from the valve seat 100 for a long time, so the on-off valve 96 is kept open, so to speak. A sufficient amount of compressed refrigerant gas is supplied to the second chamber 86 through the communication path 92 .

As a result, the piston 76 is moved to the end of the movement on the side of the first chamber 84, and the rotating plate 64 is rotated to its maximum rotation angle position as shown in FIGS. 7 and 10. As a result, the communication area between the first through hole 66 and the second through hole 68 is further reduced, and the discharge port side end of the first through hole 66 is connected to the discharge port 42.
The _third through hole 70 and the fourth through hole 71 are brought into communication with each other. Therefore, the amount of refrigerant gas sucked in is further reduced, and the compression start time is further delayed since it starts from position _P3 . However, the compression chamber 32 in the middle of the compression stroke is communicated with the suction chamber 34 at a side closer to the discharge port 42 than the position P ₃ of the discharge port side end of the first through hole 66,
A state is reached in which a portion of the compressed refrigerant gas is released into the suction chamber 34. Looking at it from another perspective, the communication between the third through hole 70 and the fourth through hole 71 delays the compression start time to position Q, and the compressor enters a small capacity operating state where the discharge capacity is the smallest. This avoids performing more compression work than necessary and reduces the load on the engine.

By the way, when the compressor rotates at low speed, the throttling effect on the suction refrigerant gas due to the reduction in the communication area between the first through hole 66 and the second through hole 68 is not so large; By blowing the refrigerant gas from the high-pressure side to the low-pressure side, and by letting the refrigerant gas in the middle of compression escape to the suction chamber 34 through the third through hole 70 and the fourth through hole 71, both of these functions reduce the capacity reduction at low speeds. Great effect.
On the other hand, when the compressor rotates at high speed, the effect of reducing the capacity due to the reduction in the amount of refrigerant gas sucked by the throttle is large, and since the absolute amount of refrigerant gas sucked is small, it passes through the first through hole 66. Since refrigerant gas tends to blow through the sides of the inner vanes 28, and refrigerant gas that is being compressed easily escapes to the suction chamber 34 through the third through hole 70 and the fourth through hole 71, such blow-through or escape of refrigerant gas does not occur. The effect of capacity reduction is relatively large even at high speeds. As the rotating plate 64 rotates, the discharge capacity decreases continuously from the high capacity operation state shown in FIG. 5 until just before the third through hole 70 and the fourth through hole 71 become in communication. However, at the time they are brought into communication, the discharge capacity will be significantly reduced.

When the cooling load increases due to the continuation of the small-capacity operation state as described above, the piston 102 moves back as the suction pressure of the refrigerant gas increases, causing the valve 9 to close.
8 blocks the communication path 92, the piston 76 shown in FIG. 3 moves toward the second chamber 86,
Transition to the above-mentioned medium capacity operating state or large capacity operating state. Thereafter, small capacity operation, medium capacity operation, and large capacity operation will be repeated depending on the magnitude of the refrigerant load.

When the compressor is stopped, oil in the first chamber 84 leaks from the gaps between the rotor 16 and the front side plate 4 and rear side plate 6 to the compression chamber 32 side, and the pressure in the first chamber 84 becomes equal to the pressure in the suction chamber 34. In addition, the refrigerant gas in the second chamber 86 flows back to the compression chamber 32 through the communication path 92, so that the pressure becomes equal to the pressure in the suction chamber 34, and the piston 76 is moved toward the first chamber 84 by the spring 88. When the compressor is started, operation is started from a state where the discharge capacity is the minimum. Therefore, the rise in engine load at startup is gradual, the shock is small, and the occurrence of liquid compression is effectively avoided.

Next, another embodiment of the present invention will be described based on FIGS. 11 and 12.

In this embodiment, the second through hole 68 formed in the front side plate 4 is made longer than the first through hole 66 formed in the rotating plate 64, so that even when the rotating plate 64 is rotated, These first through holes 66
The communication area between the first through hole 66 and the second through hole 68 is approximately given by the opening area of the first through hole 66, and does not play the role of a variable throttle for suction refrigerant gas. Instead, as shown in FIG. 12, the flow rate of the suction refrigerant gas is increased or decreased by changing the opening area of the opening on the opposite side of the suction chamber 34 of the compressor inlet 36 connected to the suction chamber 34. A variable throttle device is provided. This variable throttle device includes a plate-shaped throttle valve 110 large enough to cover the opening of the variable throttle device. This throttle valve 110 is rotatably attached to the front housing 10 around a shaft 112, is biased by a spring 114 in a direction to increase the opening area, and is connected to a conduit of a refrigeration circuit (not shown). The dynamic pressure of the refrigerant gas flowing toward the suction chamber 34 is applied in a direction that reduces the opening area, and the stopper 116 prevents the opening from being completely blocked.

Then, when the automobile is accelerated and the engine speed increases, and the compressor speed increases accordingly, the flow velocity of the refrigerant gas flowing from the compressor inlet 36 toward the suction chamber 34 increases, causing the throttle valve 110 to Since the applied dynamic pressure increases, the throttle valve 110 is rotated in a direction to close the opening of the compressor inlet 36, reducing the flow rate of the suction refrigerant gas, contributing to a reduction in the capacity of the compressor.

Other configurations and functions are the same as those of the previous embodiment, so corresponding parts are given the same reference numerals and explanations are omitted. However, in this embodiment, the effective suction area is narrowed at the compressor inlet 36, and the suction chamber 34 Since the amount of the suction refrigerant gas itself sucked into the refrigerant gas is reduced, there are the following advantages compared to adding a restriction in the suction passage between the suction chamber 34 and the compression chamber 32 as in the previous embodiment. That is, in the case of applying a restriction between the suction chamber 34 and the compression chamber 32, when the capacity is to be reduced during high speed rotation of the compressor, the compression chamber 3
However, this implementation By doing as in the example, in the volume reduction process of the compression chamber 32, the blow-through effect of the refrigerant gas by the first through hole 66 can be more reliably obtained.

Above, the first and second embodiments of the present invention have been described in detail, but these are literally examples, and other embodiments, for example, when the rotating plate is included, the first chamber 84 of the piston chamber 80 is While communicating with the compression chamber 32 in the middle of the compression stroke, the second chamber 8
6 to the suction chamber 34 so that the compressed refrigerant gas pressure acts on the first pressure receiving surface 90 of the piston 76 and the suction refrigerant gas pressure acts on the second pressure receiving surface 94. . In that case, when the cooling load on the compressor is large,
A state in which the piston 76 is moved toward the second chamber 86 against the biasing force of the spring 88 based on the pressure difference ΔP because the pressure difference ΔP between the compressed refrigerant gas pressure and the suction refrigerant gas pressure is large. The compressor operates at high capacity. However, as the cooling load decreases, the pressure difference ΔP also decreases, so the piston 76 moves toward the first chamber 8 until the pressure difference ΔP and the biasing force of the spring 88 are balanced.
As a result of moving to the 4th side and rotating the rotating plate 64, the compressor shifts to a medium capacity operating state or a small capacity operating state as in the above embodiment, depending on the degree of decrease in the pressure difference ΔP. That will happen.

In addition, the second through hole 68 is omitted (the refrigerant gas is sucked through the suction passage 69), and
A variable throttle device as shown in FIG. 12 may be provided, and a bypass groove with a bottom may be provided in the rotary plate 64 instead of the first through hole 6, and this may function as the first bypass passage. It is possible. Additionally, in order to drive the rotating plate, a rack fixed to the piston and a pinion fixed to the rotating plate may be engaged with each other, or the rotating plate may be rotated by a stepping motor, etc. can. Furthermore, a type of vane compressor in which the rotor is eccentrically arranged in close proximity to one location on the inner peripheral surface of the cylindrical cylinder;
Alternatively, the present invention may be applied to other vane compressors such as a rotasco type in which the rotor is rotated eccentrically while slidingly contacting the inner peripheral surface of the cylinder, or the present invention may be applied to a vane compressor that compresses gas other than refrigerant gas. Based on the knowledge of those skilled in the art, including
It goes without saying that the present invention can be practiced with various changes, improvements, etc.

Effects of the Invention As detailed above, the present invention provides a vane compressor equipped with a plurality of compression chambers, which includes a first bypass passage that communicates a compression chamber in the middle of a compression stroke with a compression chamber in the middle of a suction stroke. By changing the position of the discharge port side end of the opening on the compression chamber side in the middle of the compression stroke of the first bypass passage, the compression start timing is delayed, and the flow rate of the intake gas is reduced by a variable throttle device. and releasing the compressed gas to the suction chamber or the suction side space through the second bypass passage in a state where the discharge port side end of the first bypass passage is moved to the vicinity of the position closest to the discharge port. By combining them, the discharge capacity can be continuously reduced in many cases, and even when operation with a significantly small discharge capacity is required, it can be sufficiently handled, and it can be used in all situations from low speed rotation range to high speed rotation range. In addition, by providing the second bypass passage, only a small amount of change in the position of the discharge end of the first bypass passage is required, and the position changing device can be simplified. Moreover, it has the effect of making it possible to make it compact.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view of a vane compressor for compressing refrigerant gas, which is an embodiment of the present invention. 2 and 3 are a cross-sectional view and a cross-sectional view, respectively, of FIG. 1. 4 is a partial sectional view showing a part of the compressor shown in FIG. 1, and FIGS. 5, 6, and 7 are partial sectional views showing different operating states of the compressor shown in FIG. FIG. Figures 8, 9 and 10
The figure is a sectional view, partially in longitudinal section, schematically showing different operating states corresponding to FIGS. 5, 6 and 7. FIG. 11 is a cross-sectional view of a vane compressor for compressing refrigerant gas, which is another embodiment of the present invention, and FIG. 12 is a partial cross-sectional view showing another part of the compressor shown in FIG. 10. be. 2: 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, 56: Oil passage, 64: Rotating plate, 66: First through hole (first bypass passage), 68: Second through hole,
{70: Third through hole, 71: Fourth through hole} (second bypass passage), 72: Pin, 74: Arc hole, 7
6: Piston, 78: Long hole, 84: First chamber, 8
6: 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, 110: Throttle valve (variable throttle device), 11
2: shaft, 114: spring, 116: stopper.

Claims (1)

[Claims] 1. Vane compression in which gas from the suction chambers is sucked from the suction port into a plurality of compression chambers whose volume changes as a rotor holding a plurality of vanes is rotated in a housing, and the gas is discharged from the discharge port. a first bypass passage that communicates a compression chamber in the middle of the compression stroke among the plurality of compression chambers with a compression chamber in the middle of the suction stroke; and a compression chamber in the middle of the compression stroke of the first bypass passage. a first bypass passage opening end position changing device that changes compression start timing by changing the position of an end of a side opening closer to the discharge port with respect to the rotational direction of the rotor; and a suction passage connected to the suction port. a variable throttle device that is installed in the first bypass passage to increase or decrease the flow rate of the intake gas; and a variable throttle device that is normally shut off, but is moved to a position near a position where the discharge port side end of the opening of the first bypass passage is closest to the discharge port. In the situation where
The compression chamber, which is in the middle of the compression stroke, is communicated with the suction chamber or a suction side space that is constantly in communication with the suction chamber at a position closer to the discharge port than the end position on the discharge port side of the first bypass passage, and the compression chamber is compressed. A part of the gas is released into the suction chamber or the suction side space, and the opening on the compression chamber side that is in the middle of the compression stroke is once completely filled by the vane when the vane passes through the opening as the rotor rotates. A variable capacity vane comprising: a second bypass passage formed in a shape and size that allows it to be closed; and a second bypass passage opening/closing device that switches the second bypass passage between the blocking state and the communicating state. compressor. 2. The housing includes a cylinder and a side plate fixed to an open end of the cylinder, and the rotor and the plurality of rotors are rotatable approximately around the center line of the cylinder on the cylinder side surface of the side plate. A rotating plate is provided in contact with or very close to a side end surface of the vane, the first bypass passage is constituted by a first through hole formed in the rotating plate, and the opening end position of the first bypass passage is The changing device includes a rotating plate driving device that rotates the rotating plate, and the suction passage is capable of communicating with the first through hole and the first through hole in the side plate, and the rotating plate is rotated. a second through hole formed in such a manner that the area of communication with the first through hole increases or decreases as a plate and the rotary plate driving device, the second bypass passage includes a third through hole formed in a portion of the rotary plate closer to the discharge port than the first through hole, and the side Normally, the plate is misaligned with the third through hole, but when the rotating plate is in a state where the end of the first through hole on the discharge port side is brought closest to the discharge port, the rotating plate is aligned with the third through hole. 2. The variable displacement vane compressor according to claim 1, further comprising a fourth through hole formed therein, and wherein the rotary plate driving device also serves as the second bypass passage opening/closing device. 3. The housing includes a cylinder and a side plate fixed to an open end of the cylinder, and the rotor and the plurality of housings are rotatable approximately around the center line of the cylinder and mounted on a cylinder-side surface of the side plate. A rotating plate is provided in contact with or very close to a side end surface of the vane, the first bypass passage is constituted by a first through hole formed in the rotating plate, and the opening end position of the first bypass passage is The changing device is constituted by a rotary plate driving device that rotates the rotary plate, and the variable throttle device is provided in the suction passage and increases or decreases the effective suction area of the suction passage using dynamic pressure based on the flow of suction gas. The second bypass passage includes a third through hole formed in a portion of the rotary plate closer to the discharge port than the first through hole, and a third through hole formed in a portion of the rotating plate that is closer to the discharge port than the first through hole; A fourth through hole is formed in a portion that is misaligned with the third through hole but coincides with the third through hole when the rotary plate is brought closest to the discharge port side end of the first through hole. 2. The variable displacement vane compressor according to claim 1, further comprising a hole, and wherein the rotary plate driving device also serves as the second bypass passage opening/closing device.