JPH0774638B2 - Rotary compressor - Google Patents

Description

Description: TECHNICAL FIELD OF THE INVENTION The present invention relates to an improvement of a rotary compressor with variable capacity.

[Technical background of the invention and its problems]

BACKGROUND ART Conventionally, for example, a structure has been developed in which a variable capacity rotary compressor is connected to a refrigeration cycle of an air conditioner. In this type of rotary compressor, a roller fitted to the eccentric part of the crankshaft is arranged in the cylinder chamber formed in the rotary compressor body, and the peripheral wall surface of the cylinder chamber is accompanied by the rotation operation of the crankshaft. The roller is eccentrically driven along the axis. Further, on the peripheral wall surface of the cylinder chamber, a blade (partition plate) mounted so as to be capable of projecting and retracting in the cylinder chamber is arranged. This blade is always held in pressure contact with the outer peripheral surface of the roller by a biasing member such as a spring, and this blade divides the internal space between the roller and the cylinder chamber into two chambers. A suction port connected to the refrigerant inflow passage of the main circuit of the refrigeration cycle and a discharge port connected to the refrigerant outflow passage of the main circuit are formed on the peripheral wall surface of the cylinder chamber.
In this case, the suction port is connected to one indoor space side between the roller partitioned by the blade and the cylinder chamber, and the discharge port is connected to the other indoor space side.
Further, a release port is formed on the peripheral wall surface of the cylinder chamber to allow a part of the refrigerant in the cylinder to flow into the suction port side. This release port is designed to be opened and closed by a release valve. By holding the release port in the closed state, 100% of the capacity of the rotary compressor main body is exhibited, and by opening the release port, a part of the refrigerant in the cylinder chamber is made to flow out to the suction port side. It reduces the capacity of the rotary compressor itself.

By the way, the capacity reduction rate (release rate) of the rotary compressor main body due to the release port changes according to the angle (θ) between the installation position of the blade and the installation position of the release port as shown in FIG. It is known. In FIG. 4, the dotted line shows the theoretical release rate, and the solid line shows the actual release rate. As is clear from FIG. 4, the actual release rate depends on the flow friction and inertial force of the refrigerant. , It can be seen that it is lower than the theoretical release rate. Therefore, for example, when the release port is installed on the low pressure side as in the case where the angle θ between the blade installation position and the release port installation position is about 150 degrees, the capacity reduction rate of the rotary compressor body is About 20 to 30%, the capacity of the rotary compressor body is 70 to 80% and 100%
There was a problem that only a relatively narrow variable range between and could be obtained. In addition, for example, when the release port is installed on the high pressure side as in the case where the angle θ between the installation position of the blade and the installation position of the release port is about 210 degrees, the capacity reduction rate of the rotary compressor body is It becomes about 60-70%, and the capacity of the rotary compressor main body can obtain a relatively wide variable range between 30-40% and 100%, but in this case, the release refrigerant amount becomes excessive. Therefore, the outflow resistance of the release refrigerant increases, and the loss increases. Therefore, the energy efficiency during release operation decreases,
There was a problem that reduction of power consumption was insufficient.

[Object of the Invention]

The present invention can relatively widen the variable range of the capacity of the rotary compressor body, can increase the energy efficiency during the release operation, reduce the power consumption, and perform the economical release operation. The object is to provide a rotary compressor capable of

[Outline of Invention]

This invention relates to a low pressure release port arranged on the suction port side along the rotation direction of a roller in the cylinder, on the cylinder wall surface between the suction port and the discharge port connected to the cylinder of the rotary compressor body. And a high-pressure release port arranged on the discharge port side, and a release passage through which a part of the refrigerant inside the cylinder flows out to the suction port side via the low-pressure release port and the high-pressure release port. At the same time, a first state in which both the release ports are opened, a second state in which only the high pressure release port is opened, a third state in which only the low pressure release port is opened, and a fourth state in which both release ports are closed In each state, the capacity of the rotary compressor body is changed by selectively opening and closing the both release ports. It is provided with a capacity changing means.

Example of Invention

1 to 3 show an embodiment of the present invention. FIG. 1 shows a schematic structure of a main part of a rotary compressor. Reference numeral 1 is a main body of the rotary compressor, 2 is a cylinder chamber formed in the main body 1, and 3 is a cylinder chamber 2. It is a roller. The roller 3 is fitted in the eccentric portion of the crankshaft 4, and is eccentrically driven along the peripheral wall surface of the cylinder chamber 2 as the crankshaft 4 rotates. Further, on the peripheral wall surface of the cylinder chamber 2, a blade (partition plate) 5 mounted so as to be capable of projecting and retracting in the cylinder chamber 2 is arranged. The blade 5 is held by the biasing member such as a spring 6 in a state in which the blade 5 is constantly pressed against the outer peripheral surface of the roller 3.
The inner space between and is divided into two chambers. A suction port 8 is formed on the peripheral wall surface of the cylinder chamber 2 in a state of being connected to one indoor space 7 side partitioned by the blade 5, and the other indoor space 9 side partitioned by the blade 5 is formed. Discharge port 10 when connected to
Are formed. The suction port 8 is connected to the refrigerant inflow passage 12 of the main circuit 11 of the heat pump type refrigeration cycle shown in FIG. 2, and the discharge port 10 is connected to the refrigerant outflow passage 13 of the main circuit 11.

Furthermore, a low pressure release port is provided on the peripheral wall surface of the cylinder chamber 2.
Multiple release ports are formed, consisting of 14 and high pressure release ports 15. In this case, the low-pressure release port 14 has, for example, an angle?
The high-pressure release port 15 is installed on the low-pressure side at 150 degrees, and the high-pressure release port 15 is installed on the high-pressure side at an angle θ with the installation position of the blade 5 of about 210 degrees. A release passage 17 is formed inside the peripheral wall 16 of the cylinder chamber 2. The release passage 17 is formed along the inner peripheral surface of the cylinder chamber 2. Further, one end of the release passage 17 is connected to the high pressure release port 15 and the other end is connected to the suction port 8, and the middle portion of the release passage 17 is connected to the low pressure release port 14. Further, inside the peripheral wall 16 of the cylinder chamber 2, outside the release passage 17, first and second release port opening / closing operation mechanisms are provided.
18 and 19 drive cylinders 20 and 21 are respectively formed.
These drive cylinders 20 and 21 are formed at positions corresponding to the low pressure release port 14 and the high pressure release port 15, respectively. Further, drive pistons 22 and 23 are mounted inside the drive cylinders 20 and 21, respectively, and one drive piston 22 has a low pressure side release valve 24 for opening and closing the low pressure release port 14 and the other drive piston. 2
A high pressure side release valve 25 for opening and closing the high pressure release port 15 is connected to each of the three. In addition, inside the drive cylinders 20 and 21, return springs 24a and 25a of the low pressure side release valve 24 and the high pressure release valve 25 are respectively arranged, and these return springs 24a and 25a are used to release the low pressure side release valve 24 and the high pressure side. The side release valve 25 is always held in a state of being biased in the direction of opening the low pressure release port 14 and the high pressure release port 15.

Further, high pressure refrigerant introduction paths 26, 27 for introducing the high pressure refrigerant discharged from the discharge port 10 are connected to the drive cylinders 20, 21, respectively. In this case, one high pressure refrigerant introduction path 26
Is connected to the first pressure control circuit 28, and the other high pressure refrigerant introduction path 27 is connected to the second pressure control circuit 29. Furthermore, these first and second pressure control circuits 2
8, 29 has one end connected to the refrigerant outflow passage 13 on the discharge port 10 side and the other end connected in parallel to a refrigerant passage 30 connected to the refrigerant inflow passage 12 on the suction port 8 side. Further, the first pressure control circuit 28 includes a low pressure side solenoid valve 31, a high pressure refrigerant introduction path 26 and a suction port 8 side (low pressure side) between the high pressure refrigerant introduction path 26 and the discharge port 10 side (high pressure side). Capillary tubes 32 for depressurizing are respectively interposed between the high pressure side and high pressure side between the high pressure refrigerant introduction path 27 and the discharge port 10 side (high pressure side) in the second pressure control circuit 29. Solenoid valve 33, high pressure refrigerant introduction path 27 and suction port 8 side (low pressure side)
Capillary tubes 34 for decompression are respectively interposed between and. Therefore, when the low-pressure side solenoid valve 31 is held in the open state, the high-pressure refrigerant is introduced into the drive cylinder 20 via the high-pressure refrigerant introduction path 26, and the drive pressure of the drive piston 22 is pushed by this refrigerant pressure to lower the pressure. The low pressure release port 14 is held in a closed state in which the side release valve 24 closes the low pressure release port 14. Further, when the low-pressure side solenoid valve 31 is closed, the introduction of high-pressure refrigerant from the high-pressure refrigerant introduction path 26 into the drive cylinder 20 is stopped, and the return spring
Since the drive piston 22 is pressed in the direction away from the cylinder chamber 2 side by the spring force of 24a and the refrigerant pressure in the cylinder chamber 2, the low pressure side release valve 24 is moved to the open position where the low pressure release port 14 is opened. A part of the refrigerant in the chamber 2 is released through the low pressure release port 14 to the release passage.
It is supposed to be leaked into the inside. Further, when the high-pressure side solenoid valve 33 is held in the open state, high-pressure refrigerant is introduced into the drive cylinder 21 via the high-pressure refrigerant introduction path 27,
Similarly, the driving piston 23 is pushed in by this refrigerant pressure and is held in a closed state in which the high pressure side release valve 25 is closed by the high pressure side release valve 25, and when the high pressure side solenoid valve 33 is operated to be high pressure. Refrigerant introduction path 27
From the introduction of high pressure refrigerant into the drive cylinder 21 from,
Since the drive piston 23 is pressed in the direction away from the cylinder chamber 2 side by the spring force of the return spring 25a and the refrigerant pressure in the cylinder chamber 2, the high pressure side release valve 25 is moved to the open position where the high pressure release port 15 is opened and closed. A part of the refrigerant in the cylinder chamber 2 is made to flow out into the release passage 17 via the high pressure release port 15. And
By selectively opening and closing the low pressure release port 14 and the high pressure release port 15, the capacity of the rotary compressor body 1 can be varied. For example, both release ports 14 and 15 are opened. In the order of the first state, the second state in which only the high pressure release port 15 is opened, the third state in which only the low pressure release port 14 is opened, and the fourth state in which both the release ports 14 and 15 are closed. By opening and closing both of the release ports 14 and 15, the capacity variable rate of the rotary compressor body 1 can be sequentially changed.

The main circuit 11 of the refrigeration cycle has a four-way switching valve 3
5, outdoor heat exchanger 36, expansion valve 37 and indoor heat exchanger 38
Are sequentially connected, and the high-pressure refrigerant gas discharged from the discharge port 10 of the rotary compressor body 1 is connected to the main circuit.
11 is circulated from the refrigerant outflow passage 13 to the respective refrigeration cycle constituent devices via the four-way switching valve 35, is circulated to the respective refrigeration cycle constituent devices, and is then circulated via the four-way switching valve 35 and the refrigerant inflow passage 12 of the main circuit 11. It is designed to be introduced into the suction port 8 of the compressor body 1.

Next, the operation of the above-described configuration will be described by taking as an example the case where the refrigeration cycle is heated. For example, when the room temperature at the time of heating operation startup is low, the low-pressure side solenoid valve 31 and the high-pressure side solenoid valve 33 are respectively held in the open state, and the inside of the drive cylinders 20, 21 via the high pressure refrigerant introduction paths 26, 27. A high-pressure refrigerant is introduced and the drive piston 23 is pushed in by this refrigerant pressure to operate by the low-pressure side release valve 24 and the high-pressure side release valve 25, and the low-pressure release port 14 and the high-pressure release port.
Hold 15 in the closed fourth position. Then, when the room temperature becomes slightly warm, only the low pressure side solenoid valve 31 is closed. When the low-pressure side solenoid valve 31 is closed, the introduction of high-pressure refrigerant from the high-pressure refrigerant introduction path 26 into the drive cylinder 20 is stopped, and the drive piston 22 is driven by the spring force of the return spring 24a and the refrigerant pressure in the cylinder chamber 2. Since the low pressure side release valve 24 is pushed in the direction away from the cylinder chamber 2 side and moved to the open position where the low pressure release port 14 is opened,
A part of the refrigerant in the cylinder chamber 2 is held in a third state in which it is discharged into the release passage 17 via the low pressure release port 14. When a part of the refrigerant in the cylinder chamber 2 flows into the release passage 17 through the low pressure release port 14 in this way, the capacity of the rotary compressor body 1 is reduced by about 20 to 30%.

When the room temperature further rises, the high-pressure side solenoid valve 33 is closed to open the high-pressure release port 15, and then the low-pressure side solenoid valve 31 is opened to close the low-pressure release port 14. In this case, a part of the refrigerant in the cylinder chamber 2 is held in the second state in which it is discharged into the release passage 17 via the high pressure release port 15. When a part of the refrigerant in the cylinder chamber 2 flows out into the release passage 17 via the high pressure release port 15 in this way, the capacity of the rotary compressor body 1 is reduced by about 50%.

Further, when the room temperature rises to a temperature close to the set temperature, the low-pressure side solenoid valve 31 and the high-pressure side solenoid valve 33 are closed, and the low-pressure release port 14 and the high-pressure release port 15 are switched to the first state. Held in a state. In this case, since the refrigerant in the cylinder chamber 2 flows out into the release passage 17 via the low pressure release port 14 and the high pressure release port 15, respectively, the capacity of the rotary compressor body 1 is reduced by about 60 to 70%. . Therefore,
In this way, when the capacity of the rotary compressor main body 1 is reduced most, the refrigerant in the cylinder chamber 2 is simultaneously discharged from the plural release ports of the low pressure release port 14 and the high pressure release port 15 to the release passage 17 side. Therefore, the outflow resistance of the release refrigerant can be reduced and the compression load can be reduced as compared with the conventional case. Furthermore, since the release passage 17 is formed inside the peripheral wall 16 of the cylinder chamber 2, the length of the release passage 17 can be made relatively short, and the flow resistance of the release refrigerant can be further reduced. Therefore, it is possible to improve the energy efficiency during the release operation, reduce the power consumption, and perform the economical release operation.

Also, low pressure release port 14 and high pressure release port
A first state in which 15 is opened, a second state in which only the high pressure release port 15 is opened, a third state in which only the low pressure release port 14 is opened, and a fourth state in which both the release ports 14 and 15 are closed Since the capacity varying rate of the rotary compressor body 1 can be sequentially changed by opening and closing both the release ports 14 and 15 in order of state, the rotary compressor body 1 can be operated efficiently according to the load. be able to. In this case, since the suction pressure of the rotary compressor body 1 rises and the discharge pressure falls as the capacity of the rotary compressor body 1 decreases, the compression ratio can be sequentially reduced. Therefore, as shown in FIG. 3, energy efficiency can be increased and economic operation can be performed as the release rate is increased. Furthermore, when the low pressure release port 14 and the high pressure release port 15 are opened and closed respectively, they are operated with a time lag between them.
The flow path of the refrigerant can be prevented from changing suddenly, and the capacity varying operation of the rotary compressor body 1 can be smoothly performed. Further, drive pistons 22 and 23 that operate by a pressure difference between the discharge refrigerant pressure on the discharge port 10 side and the suction refrigerant pressure on the suction port 8 side are provided, and the low pressure side release valve 24 and the high pressure side release valve are provided to these drive pistons 22 and 23. Since the first and second release port opening / closing operation mechanisms 18 and 19 for connecting the valve 25 and opening / closing the low pressure release port 14 and the high pressure release port 15 respectively are provided, the capacity switching operation of the rotary compressor body 1 can be performed. It can be performed stably.

The present invention is not limited to the above embodiment. For example, the rotary compressor body may be configured such that at the time of startup, at least one release port of the plurality of release ports is operated in an open state. In this case, the rotary compressor body is started up. The operation can be performed more smoothly. Further, the rotary compressor body is not necessarily in the first state where the low pressure release port 14 and the high pressure release port 15 are opened, the second state where only the high pressure release port 15 is opened, and the low pressure release port.
It is not necessary to open and close both release ports in the order of the third state in which only 14 is opened and the fourth state in which both release ports 14 and 15 are closed. Alternatively, the capacity variable rate may be appropriately changed. Furthermore, it goes without saying that various modifications can be made without departing from the scope of the present invention.

〔The invention's effect〕

According to the present invention, the low pressure is arranged on the cylinder wall surface between the suction port and the discharge port connected to the cylinder of the rotary compressor body along the direction of rotation of the rollers in the cylinder on the suction port side. A release passage and a high pressure release port arranged on the discharge port side are provided, and a release passage for letting a part of the refrigerant inside the cylinder flow out to the suction port side through the low pressure release port and the high pressure release port. And the first state in which both release ports are opened,
The two release ports are selectively opened and closed in a second state in which only the high pressure release port is opened, in a third state in which only the low pressure release port is opened, and in a fourth state in which both release ports are closed. Since the capacity changing means for changing the capacity of the rotary compressor main body by operation is provided, the variable range of the capacity of the rotary compressor main body can be made relatively wide and the energy efficiency during the release operation can be increased. Therefore, the power consumption can be reduced and the economical release operation can be performed.

[Brief description of drawings]

1 to 3 show an embodiment of the present invention.
FIG. 1 is a cross-sectional view showing a schematic configuration of a main part of a rotary compressor, FIG. 2 is a schematic configuration diagram showing a refrigeration cycle in which a rotary compressor is connected, and FIG. 3 is a capability of the rotary compressor. Diagram showing the relationship between energy efficiency and energy efficiency, No. 4
The figure is a characteristic diagram showing the relationship between the position of the release port and the capacity reduction rate of the rotary compressor. 1 ... Rotary compressor body, 8 ... Suction port,
10 ... Discharge port, 11 ... Main circuit of refrigeration cycle, 12 ...
… Refrigerant inflow passage, 13 …… Refrigerant outflow passage, 14 …… Low pressure release port, 15 …… High pressure release port.

Claims (3)

[Claims] Claim: What is claimed is: 1. A low pressure system, which is arranged on a cylinder wall between a suction port and a discharge port connected to a cylinder of a rotary compressor body, on the suction port side along a rotation direction of a roller in the cylinder. Release port,
A high-pressure release port disposed on the discharge port side, and a release passage for allowing a part of the refrigerant inside the cylinder to flow out to the suction port side through the low-pressure release port and the high-pressure release port. In a first state where both release ports are opened, a second state where only the high pressure release port is opened, a third state where only the low pressure release port is opened, and both release In each of the fourth states in which the ports are closed, capacity changing means for changing the capacity of the rotary compressor main body by selectively opening and closing the both release ports with a time difference from each other is provided. And rotary compressor. 2. The rotary compressor main body is adapted to operate when at least one of the plurality of release ports is opened at the time of start-up. Rotary compressor. 3. A release port formed by a release valve, which is connected to a drive piston operated by a pressure difference between a discharge refrigerant pressure on a discharge port side and a suction refrigerant pressure on a suction port side, to open and close the release port. The rotary compressor according to claim 1, further comprising an opening and closing operation mechanism.