JPH0745877B2 - Vane back pressure application device for sliding vane compressor - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vane back pressure applying device used in a sliding vane compressor used for an air conditioner for automobiles and the like.

As is well known in the art, in a sliding vane compressor, high pressure lubricating oil is applied to the rear end of the vane by a pressure difference so that the vane makes a rotary sliding motion by contacting the tip of the vane with the inner wall of the cylinder as the rotor rotates. Supplying configurations are widely used.

An example of the above-mentioned conventional vane back pressure applying device for a sliding vane compressor will be described below with reference to the drawings.

6 to 8 show a specific configuration of a sliding vane type compressor having a conventional differential pressure oil supply type vane back pressure applying device. In the figure, 1 is a cylinder having a cylindrical inner wall, 2 is a rotor whose outer periphery partially forms a minute gap with the inner wall of the cylinder 1, 3 is a plurality of vane slots provided in the rotor 2, and 4 is a vane slot 4. A plurality of vanes 5 slidably inserted into the rotor 5 are drive shafts formed integrally with the rotor 2 and rotatably supported therein. Reference numerals 6 and 7 respectively close both ends of the cylinder 1 to provide a working chamber 8 inside. Are a front side plate and a rear side plate that form a. Reference numeral 9 is an intake port communicating with the low pressure side working chamber 8, 10 is a discharge port communicating with the high pressure side working chamber 8, 11 is a discharge valve arranged at the discharge port, 12 is a high pressure chamber communicating with the high pressure passage 13. This is a high-pressure case in which a screen 15 for forming and forming a screen 14 for separating and capturing the lubricating oil in the compressed high-pressure fluid is arranged. Reference numeral 16 is a main body of the vane back pressure applying device disposed on the rear side plate 7, and supplies the lubricating oil in the oil reservoir below the high pressure chamber 14 to the vane back pressure chamber 17. Reference numeral 18 is an oil supply passage that connects the oil reservoir below the high pressure chamber 14 and the vane back pressure chamber 17, 19 is a passage for limiting the amount of oil supply by differential pressure, 20 is a first ball seat provided in the middle of the oil supply passage 18, Reference numeral 21 is a first spherical body that separates from or abuts the first ball seat 20 to cut off the communication of the oil supply passage 18, 22 is a first plunger chamber that opens to the first ball seat 20 on the side opposite to the first spherical body 21, and 23 is a first The first plunger, which is slidably disposed inside the first plunger chamber 22 and separates the first spherical body 21 from the first spherical seat 20 when moved to the first spherical seat 20 side, 24 is the first lower end of the first plunger. It is a first pressure introducing passage that connects the lower plunger chamber 25 and the working chamber 8 immediately before the discharge valve 11.

The operation of the vane back pressure applying device of the sliding vane type compressor configured as described above will be described below.

When the drive shaft 5 and the rotor 2 rotate clockwise in FIG. 4 in response to power transmission from a drive source such as an engine,
Along with this, the low-pressure fluid flows into the working chamber 8 through the suction port 9. The high-pressure fluid compressed by the rotation of the rotor 2 pushes up the discharge valve 11 from the discharge port 10 and pushes the discharge valve 11 from the high-pressure passage 13 into the high-pressure chamber.
It flows into 14, and the lubricating oil is separated and captured by the screen 15. On the other hand, since the overcompressed gas in the working chamber 8 having a pressure enough to overcome the pressure of the high-pressure fluid and push up the discharge valve 11 is supplied to the first lower plunger chamber 25 from the first press-fit introduction passage 24, the first plunger Moves to the side of the first ball seat 20 and releases the first ball body 21 from the first ball seat 20. Therefore, since the oil supply passage 18 is communicated, the lubricating oil separated from the high-pressure fluid and stored in the lower portion of the high-pressure chamber 14 is provided with a passage 19,
It is supplied from the oil supply passage 18 to the vane back pressure chamber 17 and is used for pressing the vane 4 to flow into the working chamber 8 through the gap between the rotor 2 and the front side plate 6 and the rear side plate 7. Further, when the compressor stops, the pressure in the working chamber 8 drops rapidly to the pressure of the low-pressure side fluid, so the first lower plunger chamber 25
The internal pressure also drops to the pressure of the low pressure side fluid and the first plunger
Since the pressure at the lower end of 23 is lower than the pressure at the upper end of the first plunger 23, the first plunger 23 moves to the first lower plunger chamber 25 side. Therefore, the first spherical body 21 contacts the first spherical seat 20 and the oil supply passage 18 is blocked. Therefore, since the lubricating oil is not supplied any more, it is possible to prevent the liquid compression at the time of starting the compressor, which is caused by the accumulation of the lubricating oil in the working chamber 8.

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention However, in the above-mentioned conventional vane back pressure imparting device, the pressure of the fluid on the low pressure side becomes equal to the pressure of the fluid on the high pressure side as in the case where a certain time has elapsed after the compressor is stopped. When the compressor is started in this state, the vane 4 rotates with the rotation of the rotor 2 and there is no differential pressure for supplying the lubricating oil even if the vane slot 3 tries to extend and retract. Due to the large resistance to the beginning of flow due to viscosity and inertia, as a result, a sufficient amount of lubricating oil cannot be supplied with respect to the volume fluctuation of the vane back pressure chamber 17 that occurs when the vane 4 is extended and retracted. For this reason, particularly when the rotational speed at the time of starting the compressor is low, a pressure drop in the vane back pressure chamber 17 occurs, and the well-known malfunction phenomenon in which the vane 4 separates from the inner wall of the cylinder 1 and collides again, or the poor compression phenomenon in which the fluid is not compressed occurs. Had the problem.

Further, increasing the passage area of the passage 19 in order to secure the amount of lubricating oil causes the vane 4 to be excessively pressed against the inner wall of the cylinder 1 during steady operation, resulting in increased wear of the tip of the vane 4 and the inner wall of the cylinder 1 and input of the compressor. As a result, there is a problem that the durability and efficiency of the compressor are deteriorated as a result of the increase, and there is a problem that the centrifugal force of the vane 4 which increases at a high rotation speed further promotes this tendency.

In view of the above problems, the present invention can prevent vane malfunction phenomenon and compression failure phenomenon even when the compressor is started at low speed when there is no or small pressure difference of the compressor and does not impair durability and efficiency. Provided is a vane back pressure applying device for a sliding vane compressor.

Means for Solving the Problems In order to solve the above problems, a vane back pressure applying device for a sliding vane compressor according to the present invention is provided with one end in addition to an oil supply passage and an oil passage opening / closing means in a conventional compressor. A first gas supply passage communicating with the vane back pressure chamber, a second gas supply passage having one end communicating with the first gas supply passage and introducing a refrigerant gas from the other end, the first gas supply passage and the first gas supply passage. 2 a ball seat provided in a communication portion of the gas supply passage; a sphere that separates or abuts the ball seat to disconnect the first gas supply passage and the second gas supply passage from each other; A plunger chamber that opens on the opposite side of the sphere; a plunger that is slidably disposed inside the plunger chamber to release the sphere from the sphere when moved to the ball seat side; and a lower plunger chamber at the lower end of the plunger. Yes Via plunger And a pressure introducing passage for introducing a pressure lower than that in the second gas supply passage into the lower plunger chamber at least during normal operation of the compressor. Is.

Effect of the Invention According to the present invention, the rotor for opening and closing the gas passage communicates with the first gas supply passage and the second gas supply passage even when the compressor is started in the state where there is no or a small pressure difference between the high and low pressures. The gaseous fluid is instantaneously supplied from the second gas supply passage and the first gas supply passage with respect to the volume fluctuation of the back pressure chamber of the vane, which occurs when the vane rotates and expands and retracts in the vane slot as the vane rotates. it can. Therefore, since the pressure in the back pressure chamber of the vane does not decrease, the phenomenon of malfunction of the vane and the phenomenon of defective compression can be prevented. Further, since the gas passage opening / closing means shuts off the first gas supply passage and the second gas supply passage after the start-up, an appropriate amount of lubricating oil is supplied to the vane back pressure chamber from the oil supply passage, which may impair durability and efficiency. Absent.

Example Hereinafter, an example of the present invention will be described with reference to FIGS. 1 to 5 of the accompanying drawings.

In the figure, components having the same effects as those of the conventional vane back pressure imparting device of the sliding vane compressor are designated by the same reference numerals and the description thereof will be omitted.

In the figure, 26 is the main body of the vane back pressure applying device disposed on the rear side plate 7, 27 is the first gas supply passage communicating one end with the vane back pressure chamber 17, and 28 is one end above the high pressure chamber 14. Second gas supply passage communicating with the part, 29 is the first gas supply passage
A second ball seat 30 provided at a communication portion between the second gas supply passage 28 and the second gas supply passage 28 separates or abuts the second ball seat 29 so as to disconnect the first gas supply passage 27 and the second gas supply passage 28 from each other. 2nd spherical body, 31 is a stopper that restricts movement of the second spherical body 30, 32 is a second plunger chamber that opens to the second spherical seat 29 on the side opposite to the second spherical body 30, and 33 is inside the second plunger chamber 32. When it is slidably arranged and moves to the side of the second ball seat 29, the second ball 30 is moved to the second ball seat 29.
The second plunger to be released from the second plunger 35 is the second plunger 33.
Located in the second lower plunger chamber 34 at the lower end of the second plunger
A spring 36 for urging the second spherical body 30 in a direction to separate from the second spherical seat 29 via 33, 36 communicates with the second lower plunger chamber 34 at the lower end of the second plunger 33 and the intermediate pressure portion of the working chamber 8. Second
A pressure introducing passage, 37 is a third ball seat provided in the middle of the first gas supply passage 27 communicating with the vane back pressure chamber 17, and 38 is only one flow of the gas fluid in the first gas supply passage 27. It is a third sphere that cuts off the flow in the first gas supply passage 27.

The operation of the vane back pressure imparting device of the sliding vane compressor configured as described above will be described below.

In a steady operation state in which there is a sufficient pressure difference between the high-pressure side and the low-pressure side for refueling after a lapse of a certain time after the start of the compressor, the pressure of the high-pressure fluid is overcome from the first pressure introducing passage 24 and the discharge valve Since the over-compressed gas in the working chamber 8 having a pressure enough to push up 11 is supplied to the first lower plunger chamber 25, the first plunger 23 moves to the first ball seat 20 side and the first spherical body 21 moves to the first ball seat 21 side. It is released from the first ball seat 20. Further, since the second gas supply passage 28 communicates with the upper portion of the high pressure chamber 14,
The second plunger 33 is held at the position shown in FIG. 1 by overcoming the intermediate pressure of the working chamber 8 flowing into the second lower plunger chamber 34 from the pressure introducing passage 36 and the biasing force of the spring 35. That is, the second spherical body 38 abuts on the second spherical seat 37 and contacts the first gas supply passage.
27 and the second gas supply passage 28 are shut off.

In addition, the third sphere 38 provided in the middle of the first gas supply passage 27
Since the pressure on the vane back pressure chamber 17 side of the first gas supply passage 27 is high, the first gas supply passage 27 comes into contact with the third ball seat 37 and shuts off the first gas supply passage 27. Therefore, the lubricating oil stored in the oil reservoir below the high pressure chamber 14 is supplied to the vane back pressure chamber 17 from the passage 19 and the oil supply passage 18 and is used for pressing the vane 4 by the conventional sliding vane compression method. It is similar to the vane back pressure application device of the machine.

Further, when the compressor stops, the pressure in the working chamber 8 rapidly drops to the pressure of the low pressure side fluid, so the pressure in the first lower plunger chamber 25 also drops to the pressure of the low pressure side fluid, and the pressure at the lower end of the first plunger 23 becomes lower. Since the pressure is lower than the pressure at the upper end of the first plunger 23, the first plunger 23 moves to the lower plunger chamber side and the first spherical body 21 contacts the first spherical seat 20. Further, since the high pressure side in the refrigeration cycle and the inside of the compressor are partitioned by the first sphere 21, the pressure in the upper portion of the high pressure chamber 14 is high and the second plunger 33 is held at the position shown in FIG. That is, the second spherical body contacts the second spherical seat 37, and the first gas supply passage 27
Then, the second gas supply passage 28 is shut off. Also, the pressure inside the compressor drops to the pressure of the low pressure side fluid, so the third sphere 38
Is released from the third ball seat 37. Therefore, the inflow of the lubricating oil into the working chamber 8 can be prevented as in the conventional vane back pressure applying device for the sliding vane compressor.

When a certain time passes after the compressor is stopped and the pressure difference between the high pressure side and the low pressure side becomes small, the spring 35 causes the second plunger to move to the second ball seat.
In order to move it to the 29 side, the state shown in FIG. 3 is entered, and when the compressor is started from this state, the gaseous fluid instantly flows from the second gas supply passage 28 to the first gas supply passage 27, the oil supply passage 18
Is supplied to the vane back pressure chamber 17 via.

As described above, according to the present embodiment, as the vane back pressure applying device of the sliding vane compressor, the oil supply passage that connects the vane back pressure chamber and the oil sump of the high pressure chamber, and the oil passage that cuts off the oil supply passage. An opening / closing means, a first gas supply passage whose one end communicates with the vane back pressure chamber, a check valve having only one flow of the gaseous fluid in the middle of the first gas supply passage, and one end of which is an upper portion of the high pressure chamber. A second gas supply passage communicating with the first gas supply passage, a first gas supply passage and a ball seat provided in the middle of supplying the second gas, and a first gas supply passage and a second gas supply passage that come into contact with or separate from the ball seat. A sphere that connects and disconnects the sphere, a plunger chamber that opens to the sphere side, a plunger that is slidably arranged inside the plunger chamber and that releases the sphere from the sphere when moved to the sphere seat side, and a lower plunger at the lower end of the plunger. In the room via the plunger There is no pressure difference between the high-pressure side fluid and the low-pressure side fluid by providing a spring that biases the ball seat away from the ball seat and a pressure introduction path that communicates with the lower plunger chamber and the intermediate pressure portion of the compressor. When the compressor is started from a small state, the gas supply passage is in communication, so the vane rotates with the rotation of the rotor, and against the volume fluctuation of the vane back pressure chamber that occurs when trying to extend and retract in the vane slot. Since the gaseous fluid can be instantaneously supplied from the second and first gas supply passages, a pressure drop in the back pressure chamber of the vane does not occur, so that the vane malfunction phenomenon or the compression failure phenomenon can be prevented. Also, after the start, the sphere comes into contact with the ball seat, and the second and first
Since the gas supply passage is shut off, an appropriate amount of lubricating oil is supplied to the vane back pressure chamber from the oil supply passage, and durability and efficiency are not impaired.

In the embodiment, the first gas supply passage 27 is the oil supply passage 18
However, the first gas supply passage may be communicated with the vane back pressure chamber 17 independently of the oil supply passage 18.

In the embodiment, one end of the second gas supply passage 28 communicates with the upper portion of the high pressure chamber 14 and one end of the second pressure introduction passage 36 communicates with the intermediate pressure portion of the working chamber 8. If the combination is such that there is a pressure difference that allows the second spherical body 30 to abut the second spherical seat 29 by overcoming the biasing force of the spring 35, it is configured to communicate not only with the compressor but also with any part in the refrigeration cycle. I don't care. Further, in the embodiment, the first gas supply passage 27, the second gas supply passage 28, the second ball seat 29, the second spherical body 30, the stopper 31, the second plunger chamber 32 are provided.
The gas passage opening / closing means including the second plunger 33, the second plunger chamber 34, the spring 35, and the second pressure introducing passage 37 is provided downstream of the oil passage opening / closing means of the oil supply passage 18, but the first lower plunger chamber The gas passage opening / closing means may be provided upstream of the oil passage opening / closing means of the oil supply passage 18 by providing a spring for biasing the first spherical body 21 in the direction in which the first spherical body 21 is released.
Also, in the middle of the first gas supply passage 27, the third ball seat 37, the third ball 38
Although the second gas supply passage 28 and the second pressure introduction passage 37 are connected to each other, the second gas supply passage 28 side and the second plunger chamber 32 are connected to the second gas supply passage 28 side or the second plunger chamber 32. It may not be provided if there is no flow of the gaseous fluid to the pressure introducing passage 36 side. Further, in the embodiment, the check valve including the third ball seat 37 and the third ball is provided in the first gas supply passage. However, the check valve including the valve body and the valve seat has only one direction of reverse flow. Any stop valve will do.

Further, in the embodiment, the sliding vane type compressor has a perfect circular type having only one suction port 9 and one discharge port 10. However, a type having a plurality of suction ports 9 and discharge ports 10 may be used. Although the number of sheets is four, it may be any number.

As described above, according to the present invention, even when the compressor is started when there is no or a small pressure difference between the compressor and the compressor, the pressure drop in the vane back pressure chamber caused immediately after the start is reduced by the gaseous state from the gas supply passage. It can be prevented by the supply of fluid, and in a steady operation state, by shutting off the gas supply passage, an appropriate amount of lubricating oil can be supplied to the vane back pressure chamber.
It is possible to prevent the vane malfunction phenomenon and the compression failure phenomenon without impairing the durability and efficiency of the compressor.

[Brief description of drawings]

1, 2, and 3 are enlarged cross-sectional views of a main part of a vane back pressure applying device according to an embodiment of the present invention, and FIG. 4 is provided with a vane back pressure applying device according to an embodiment of the present invention. FIG. 5 is a vertical sectional view of a sliding vane compressor, FIG. 5 is a sectional view taken along line YY of FIG. 4, and FIG. 6 is a vertical sectional view of a sliding vane compressor equipped with a conventional vane back pressure applying device. FIG. 7 is a sectional view taken along line XX of FIG. 6, and FIG. 8 is an enlarged sectional view of essential parts of a conventional vane back pressure applying device. 1 ... Cylinder, 2 ... Rotor, 3 ... Vane slot, 4 ... Vane, 8 ... Working chamber, 9 ... Suction port, 10 ...
… Discharge port, 14 …… High pressure chamber, 17 …… Vane back pressure chamber, 18 ……
Oil supply passage, 27 ... first gas supply passage, 28 ... second gas supply passage.

Claims (2)

[Claims] Claim: What is claimed is: 1. A cylinder having a cylindrical inner wall, a rotor arranged inside the cylinder and having a part of its outer periphery forming a minute gap with the inner wall of the cylinder, and sliding in a vane slot provided in the rotor. A plurality of freely inserted vanes, a drive shaft integrally formed with the rotor and rotatably supported, and a front side plate and a rear side plate that close both ends of the cylinder to form a working chamber inside. A suction port and a discharge port that communicate with the working chamber across a portion where the outer circumference of the rotor and the inner wall of the cylinder are close to each other; a discharge valve provided at this discharge port; and a high pressure compressed to communicate with the discharge port. A high-pressure case having a high-pressure chamber for separating lubricating oil in the fluid and including an oil reservoir in a lower portion thereof, a vane back pressure chamber formed by the vane slot and a vane end, and an oil reservoir of the high-pressure chamber Refueling communicating with Passage, an oil passage opening / closing means for disconnecting and connecting the oil supply passage, a first gas supply passage having one end communicating with the vane back pressure chamber, one end communicating with the first gas supply passage, and a refrigerant gas from the other end. A second gas supply passage for introducing the gas, a ball seat provided in a communication portion between the first gas supply passage and the second gas supply passage, and a first gas supply passage that is separated from or abuts against the ball seat. 2 A sphere that connects and disconnects the gas supply passage, a plunger chamber that opens on the opposite side of the sphere to the sphere, and a sphere that is slidably disposed inside the plunger chamber and moves toward the sphere. To disengage the sphere from the ball seat, a spring in the lower plunger chamber at the lower end of the plunger that urges the sphere in a direction to disengage the sphere from the ball seat via the plunger, and at least the second gas supply during steady operation of the compressor. Lower pressure than in passage Vane back pressure imparting device sliding vane type compressor having a pressure introducing passage for introducing into the lower plunger chamber. 2. A check valve according to claim 1, wherein a check valve is provided in the middle of the first gas supply passage to allow only one of the flow of the gas fluid from the second gas supply passage to the first gas supply passage. Vane back pressure application device for sliding vane type compressor.