JPS63246487A - Multicylinder rotary compressor - Google Patents

Abstract

PURPOSE:To reduce lost work so as to prevent the temperature of exhaust gas from rising by providing an unloaded cylinder with a bypass piping, which is connected from a compression chamber to the suction side via a valve mechanism, in the compressor of freezing cycle system. CONSTITUTION:A crankshaft transmits a turning force to a rolling piston 5b within a cylinder 7b. On the midway of a refrigerant intake pipe 16b, an unloaded cylinder control mechanism opening and closing the refrigerant intake pipe 16b is provided. A bypass piping 27 allows the compression chamber 14 and the intake chamber 12 of a cylinder 7b to be connected to each other via a muffler 28 having fins 29. On the opening of the compression chamber 13 side, a slider 30 is provided to open and close the bypass piping 27. Hence lost work is reduced and the temperature of the exhaust gas can be prevented from rising.

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention relates to a multi-cylinder rotary compressor that is installed in a refrigeration cycle system and whose capacity can be controlled by cylinder deactivation when the system load is light. be.

[Conventional technology]

FIG. 5 is a vertical sectional view showing a conventional multi-cylinder rotary compressor capable of controlling capacity by cylinder deactivation, which was previously proposed by the applicant in Japanese Patent Application No. 61-232604 (filed on September 30, 1986). be. In the figure, l is an electric element, 2 is a crankshaft that transmits the rotational output of this electric element l to the compression element 3, and 4a
, 4b are eccentric parts provided on the crankshaft 2 with a phase shift of 180 degrees, and 5a and 5b are eccentric parts 4a and 4b.
This is a rolling piston that is rotatably fitted and supported by the piston. The rolling pistons 5a and 5b each have two cylinders 7a arranged vertically in parallel via a partition plate 6,
It rotates inside 7b. Further, the crankshaft 2 has each cylinder 7a.

The radial direction is supported by an upper bearing 8a and a lower bearing 8b that close the shaft 7b. Further, in the axial direction, it is supported by the thrust surface 9 of the lower bearing 8b.

The electric element 1 and compression element 3 configured in this way are
It is housed inside a sealed container 10, and the lubricating oil A is contained in the lower part of the container.
is stored. Furthermore, as shown in the cross section in FIG. 6, the insides of the cylinders 7a and 7b are provided with gas suction chambers 12 by vanes 11 that abut against the rolling pistons 5a and 5b and reciprocate inside the vane grooves 14. and compression chamber 1
It is divided into 3. Note that lla is a vane spring, and 15 is a compressed gas discharge valve. The suction chamber 12 has an accumulator 17 for compressed gas from an external refrigerant circuit.
are communicated with each other by suction pipes 16a and 16b. The cylinder deactivation control mechanism 20 includes a housing 20 in which a slider 18 and a spring 19 are inserted in the middle of the lower suction pipe 16b, and a solenoid valve 23 that connects the slider]8 lower space and high pressure section.
pipes 22 and 24 for cylinder deactivation control communicated via a, and a gas venting pipe 25 that communicates the gas suction chamber 12 side and the lower space of the slider 18 via a solenoid valve 23b and a capillary tube 26. It is equipped with

Next, the operation will be explained. When the crankshaft 2 is rotationally driven by the electric element 1, the rolling piston 5a,
5b is each cylinder? It rotates in a predetermined direction inside a and 7b. Here, the solenoid valve 23a is closed and the slider 18
The flow of high pressure gas into the lower space is stopped, the solenoid valve 23b is opened, and the lower space of the slider 18 is communicated with the suction chamber 12.
By making the pressure low, the slider J8 is also urged by the flow of the compressed gas from the accumulator 17, overcomes the force of the spring 19, and descends, thereby communicating the accumulator 17 and the suction chamber 12. Therefore, in FIG. 6, when the rolling piston 5b rotates inside the cylinder 7b in the counterclockwise direction indicated by the arrow B, compressed refrigerant gas is sucked into the suction chamber 12 from the suction pipe 16b. On the other hand, in the compression chamber 13, the refrigerant gas that has already been sucked in in the previous cycle is compressed as its volume is reduced, and this compressed refrigerant gas pushes the discharge valve 15 open and flows outside the cylinder, that is, into the closed container 10. It is discharged. Above this behavior.

Inside the lower cylinders 7a and 7b, by simultaneously rotating the rotation angle of the crankshaft 2 with a phase difference of 180 degrees, compressed refrigerant gas is supplied to the refrigeration cycle system and the refrigeration cycle is operated. .

Next, when shutting down the cylinder, the solenoid valve 23b is closed to block the degassing pipe 25, the solenoid valve 23a is opened, high pressure gas is sent to a part of the space of the slider 18V, the slider 18 is raised, and the slider j8 Suction pipe 16b on the upper end surface and side surface
By closing the lower cylinder 5b, the lower cylinder 5b is deactivated and the compression force is controlled.

[Problem that the invention seeks to solve]

A conventional multi-cylinder rotary compressor whose capacity can be controlled by cylinder deactivation is configured as described above, so that the suction chamber is evacuated during cylinder deactivation operation, and high temperature and high pressure gas is removed from the clearance of each sliding part. Since the gas enters the suction chamber and is recompressed, reactive work increases and efficiency decreases, and the temperature of the discharged gas increases to recompress the high-temperature gas, narrowing the operating condition range of the compressor. was there.

This invention was made to solve the above-mentioned problems, and improves efficiency by reducing the vacuum state during cylinder shutdown operation and suppressing the decrease in efficiency due to recompression and the increase in discharge gas temperature. The objective is to obtain a multi-cylinder rotary compressor that can be used in a wide range of operating conditions.

[Means for solving problems]

A multi-cylinder rotary compressor whose capacity can be controlled by cylinder deactivation according to the present invention is such that the cylinder to be deactivated is provided with bypass piping that communicates from the compression chamber to the suction side via a pulp mechanism.

[Effect]

The multi-cylinder rotary compressor of this invention whose capacity can be controlled by cylinder deactivation communicates the suction chamber and compression chamber in the cylinder by opening the valve mechanism of the bypass piping during cylinder deactivation, so that it can perform vacuum drawing operation. It is possible to prevent a decrease in efficiency due to an increase in useless work due to the recompression of the refrigerant gas that has entered due to a leak, and an increase in the temperature of the discharged gas due to the recompression of the high pressure gas.

〔Example〕

Hereinafter, one embodiment of a multi-cylinder rotary compressor according to the present invention will be described with reference to the drawings. In FIG. 1, the same parts as in FIGS. 5 and 6 are denoted by the same reference numerals, and detailed explanation thereof will be omitted. In the figure, 27 is connected to the compression chamber 13 of the cylinder 7b via a muffler 28 having fins 29.
Bypass piping that communicates the suction chamber 12 with the compression chamber 13
A slider 30 that opens and closes the bypass piping 27 is provided in the opening in the example. FIGS. 2 and 3 are enlarged longitudinal cross-sectional views of essential parts of the opening of the bypass piping 27 on the compression chamber 13 side, and the same parts as in FIGS. 1 and 5 are denoted by the same reference numerals. Reference numeral 33 denotes a slider sliding hole into which the slider 30 and spring 32 are inserted, and is provided in the cylinder in a manner perpendicular to the bypass pipe 27. Further, high pressure gas or low pressure gas is applied to the space below the slider 30 through a control pipe 31.

Next, the operation of the multi-cylinder rotary compressor configured as described above whose capacity can be controlled by cylinder deactivation will be explained with reference to FIGS. 1, 2, and 3. First, during normal operation without cylinder deactivation control, high pressure is applied to the control pipe 31 and the slider 30 is raised as shown in FIG. 3, thereby closing the compression chamber 3 side opening of the bypass pipe 27. Therefore, the refrigerant gas in the compression chamber 13 is compressed as the rolling piston 5b rotates, and is discharged into the closed container 10 from the discharge valve 15.

In addition, during operation to perform cylinder deactivation control, as shown in FIG. 2, by applying low pressure to the control piping 31 and lowering the slider 30, the opening of the bypass piping 27 on the compression chamber 13 side opens and the muffler The compression chamber 13 and the suction chamber 12 communicate with each other via the bypass pipe 27 via 28 . Therefore, compression chamber 1
The refrigerant gas in the compression chamber 1 passes through the bypass pipe 27 and enters the compression chamber 1.
The air is discharged within 2 days from a muffler with a sufficient capacity for 3, with almost no resistance, and the air is radiated by the fins 29 to lower the temperature and enters the suction chamber 12. In other words, the power required to circulate the low-temperature gas through the closed circuit consisting of the suction chamber 12 compression chamber 13 bypass piping 27 and muffler 28 becomes reactive work, but this is significantly reduced compared to conventional recompression reactive work. Compressor efficiency increases and discharge gas temperature decreases.

In the above embodiment, in order to improve the performance when the cylinder is out of operation, the cylindrical cylinder 7b is provided with a bypass pipe 27 that communicates the compression chamber 13 and the suction chamber 12. As shown, during normal operation without cylinder shutdown, the bypass piping 27
The opening position of the bypass piping 27 on the compression chamber 13 side is determined so that the capacity can be controlled by the cylinder deactivation and the capacity is intermediate between cylinder deactivation and all cylinders full operation. You can get a compressor.

〔Effect of the invention〕

As described above, according to the present invention, by providing the bypass piping that communicates the compression chamber and the suction chamber during cylinder shutdown operation, the vacuum state of the suction chamber due to the transfer of the rolling piston and the leakage of gas can be prevented. Since recompression in the compression chamber can be prevented, idle work is reduced and discharged gas temperature is prevented from rising, resulting in high efficiency, a wide range of operating conditions, and highly reliable capacity control through cylinder shutdown. This has the effect of providing a multi-cylinder rotary compressor.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of a cylinder section that performs cylinder deactivation of a multi-cylinder rotary compressor according to an embodiment of the present invention, and FIGS.
The figure is an enlarged longitudinal cross-sectional view of the main part during cylinder deactivation control and normal operation, showing the opening of the bypass piping on the compression chamber side. FIG. figure,
FIG. 5 is a longitudinal cross-sectional view of a conventional multi-cylinder rotary compressor, and FIG. 6 is a cross-sectional view of a cylinder section of the conventional multi-cylinder rotary compressor where the cylinders are inactive. ■ is an electric element, 2 is a crankshaft, 3 is a compression element, 4a,
4b is an eccentric part, 5a and 5b are rolling pistons, 6
Is it a partition plate? a, 7b are cylinders, 8a is upper bearing, 8b
10 is a lower bearing, 10 is a closed container, 12 is a suction chamber, 13 is a compression chamber, 16a, 16b are suction pipes, 17 is an accumulator,
18 is a slider, 19 is a spring, 20 is a housing, 21 is a cylinder deactivation control mechanism, 22.24 is a cylinder deactivation control pipe,
23a. 23b is a solenoid valve, 25 is a gas venting pipe, 26 is a capillary tube, 27 is a bypass pipe, 28 is a muffler, 29 is a heat radiation fin, 30 is a slider, 31 is a control fffll pipe, 3
2 is a spring, and 33 is a slider sliding hole. Note that in FIG. 11, the same reference numerals indicate the same or corresponding parts. Representative: Masuo Oiwa (2 others) ゛Figure 5-〇0)～ -～

Claims (4)

[Claims] (1) An upper bearing and a lower bearing that close the upper and lower sides of multiple cylinders arranged vertically in parallel via a partition plate, and are supported by these lower bearings and transmit rotational force to the rolling piston inside the cylinder. a crankshaft, and a refrigerant suction pipe that communicates independently with each of the cylinders;
In a multi-cylinder rotary compressor equipped with a cylinder deactivation control mechanism that is installed in the middle of at least one of these suction pipes and opens and closes this suction pipe, a valve is installed in the deactivated cylinder from the compression chamber to the suction side. A multi-cylinder rotary compressor characterized by having bypass piping that communicates through a mechanism. (2) The multi-cylinder rotary compressor according to claim 1, wherein the bypass piping is provided with a muffler in the middle. (3) The multi-cylinder rotary compressor according to claim 1 or 2, wherein the bypass piping is provided with fins that enhance the heat dissipation effect. (4) The opening position of the bypass piping on the compression chamber side is determined so that capacity control is performed during normal operation without cylinder deactivation, and a capacity intermediate between cylinder deactivation and all-cylinder full operation is determined. The multi-cylinder rotary compressor according to item 1, 2 or 3.