JPH089580Y2 - Air conditioner - Google Patents

Description

[Detailed description of the device]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air conditioner having a so-called hot gas bypass type defrosting function.

[0002]

2. Description of the Related Art Hot gas bypass defrosting is widely used because it has no noise due to no switching noise of the four-way selector valve and has the advantage of preventing room temperature drop during defrosting operation. There is. Conventionally, as an air conditioner adopting this defrosting method, for example, one as shown in FIG. 3 is known (Japanese Patent Laid-Open No. 57-169567). This air conditioner includes a compressor 11, a four-way switching valve 12, an indoor heat exchanger 13,
The pressure reducing device 14 and the outdoor heat exchanger 15 are sequentially connected to the pipe line 16a.
16 f, and the conduit 16 d on the outdoor heat exchanger 15 side of the decompression device 14 is connected to the compressor 16 side conduit 16 a of the four-way switching valve 12 by a bypass conduit 18 having an electromagnetic opening / closing valve 17. are doing.

During the cooling operation, the four-way switching valve 12
To the passage indicated by the broken line, and the gas refrigerant discharged from the compressor 11 is transferred to the outdoor heat exchanger 1 as indicated by the broken line arrow in FIG.
5 is circulated in the direction in which it is condensed in the indoor heat exchanger 5 and evaporated in the indoor heat exchanger 13. On the other hand, during heating operation, the four-way switching valve 12
To the passage indicated by the solid line, and the gas refrigerant is circulated in the direction in which it is condensed in the indoor heat exchanger 13 and evaporated in the outdoor heat exchanger 15 as indicated by the solid arrow in FIG. When frost adheres to the outdoor heat exchanger 15 during the heating operation, the outdoor fan and the indoor fan (not shown) are stopped, the four-way switching valve 12 is left in the heating operation state, and the electromagnetic opening / closing valve 17 is opened. To do. Then, the hot gas (gas refrigerant) from the compressor 11 is transferred to the pipeline 16a, the bypass pipeline 18, the pipeline 16d, the outdoor heat exchanger 15, as indicated by the one-dot chain line arrow in FIG.
Defrosting is performed by returning to the compressor 11 via the pipelines 16e and 16f. Thereby, the discharged hot gas is caused to flow to the outdoor heat exchanger 15 to shorten the defrosting operation time and improve the heating operation rate.

[0004]

In the above conventional air conditioner, the stop button is pressed during the cooling operation, or the temperature detected by the room temperature sensor becomes lower than the set temperature by a certain value (so-called "thermo off"). become)
Then, the compressor 11 is stopped by the control unit. In this case, in order to facilitate the next start of the compressor, the four-way switching valve 12 is switched to the heating passage shown by the solid line, and the pressure is high until then. The pipeline 16e communicates with the pipeline 16f on the low pressure side, and the pipeline 16b having a low pressure until then communicates with the pipeline 16a on the high pressure side, so that the pipelines are pressure-equalized. At this time, the pressure before and after the electromagnetic on-off valve 17 closed except the defrosting operation is
The A port that directly communicates with the pipeline 16a where the discharge has stopped
As shown by the curve A in FIG. 4, the port B, which rapidly decreases and communicates with the suction side conduit 16f of the compressor through the outdoor heat exchanger 15, gradually decreases as shown by the curve B in FIG. Therefore, the pressure at the B port becomes higher than the pressure at the A port after t ₀ seconds have elapsed from the stop of the compressor. However, since the solenoid on-off valve 17 has a structure in which the valve body is seated against the pressure applied by the spring against the pressure acting on the B port to close the passage at the time of demagnetization other than the defrosting operation, as described above, When the pressure is increased, so-called chattering occurs in which the valve element repeatedly comes into contact with and separates from the valve seat in a short cycle, which causes noise and may damage the valve. Then, in order to eliminate this drawback, it is necessary to enlarge the spring to increase the urging force. Then, the solenoid also needs to be increased in size to increase the exciting force, resulting in an increase in the cost of the air conditioner. The problem arises.

Therefore, an object of the present invention is to prevent chattering without increasing the size of the solenoid on-off valve by devising control of the solenoid on-off valve and the like, and to prolong the life of the valve and reduce noise with an inexpensive structure. An object is to provide an air conditioner capable of achieving the above.

[0006]

In order to achieve the above object, the air conditioner of the present invention is, as illustrated in FIG.
The compressor 11, the four-way switching valve 12, the indoor heat exchanger 13, the pressure reducing device 14, and the outdoor heat exchanger 15 are sequentially connected to the pipelines 16a to 16f.
And the conduit 16d on the outdoor heat exchanger 15 side of the pressure reducing device 14 is connected to the bypass conduit 18 having the electromagnetic opening / closing valve 17.
In the four-way switching valve 12 connected to the compressor 11 side or the indoor heat exchanger 13 side pipe lines 16a, 16b,
When the cooling operation is interrupted, the four-way switching valve 12 is provided with a switching signal for switching the valve to the heating operation side, and at the same time, the electromagnetic opening / closing valve 17 is provided with a controller 1 for outputting a control signal for opening the valve for a predetermined time. It is characterized by that.

[0007]

The controller 1 controls the four-way switching valve 1 when the cooling operation is interrupted.
2 and a control signal to the electromagnetic on-off valve 17, respectively. Then, the four-way switching valve 12 is switched to the passage side at the time of heating, and the pipe line 16e on the outdoor heat exchanger 15 side of the four-way switching valve 12 that has been at a high pressure until then becomes the suction side pipe of the compressor 11. The pipe 16b, which is in communication with the passage 16f and which is on the indoor heat exchanger 13 side of the four-way switching valve 12 which has been low in pressure until then, is communicated with the discharge-side pipe 16a of the compressor 11, so that the equalization of the pipe is achieved. Done. At the same time, the electromagnetic opening / closing valve 17 is opened for a certain period of time, and the pipe line 16d on the outdoor heat exchanger 15 side of the decompression device 14 and the compressor 11 side of the four-way switching valve 12 or the indoor heat exchanger 13 is opened.
The bypass pipe line 18 connecting the side pipe lines 16a and 16b is opened. Therefore, the pressure before and after the electromagnetic on-off valve 17 becomes equal, and unlike the conventional case in which the electromagnetic on-off valve 17 is closed by the spring force in the demagnetized state, the electromagnetic on-off valve 17 causes chattering due to the pressure difference between the front and back. Never.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to the illustrated embodiments. FIG. 1 shows an example of the air conditioner of the present invention. This air conditioner is different only in that a controller 1 is newly provided in the same refrigerant circuit as described in FIG. That is,
In this air conditioner, the compressor 11, the four-way switching valve 12, the indoor heat exchanger 13, the pressure reducing device 14, and the outdoor heat exchanger 15 are sequentially connected by pipelines 16a to 16f, and the pipelines 16d and 16a are connected. The controller 1 is newly provided in the refrigerant circuit formed by connecting the above with a bypass line 18 having an electromagnetic opening / closing valve 17.
An accumulator 19 is provided in the suction-side conduit 16f of the compressor 11. The controller 1 is a so-called
When the cooling operation is interrupted by "thermo off" or by pressing the stop button, the four-way switching valve 12 is switched to the heating operation side (refer to the path indicated by the solid line in FIG. 1) and a switching signal is output. An excitation signal is output to the on-off valve 17 for a fixed time (for example, 30 seconds).

The controller 1 having the above structure operates as follows. The controller 1 controls a switching signal to the four-way switching valve 12 and a solenoid opening / closing valve 17 when the compressor 11 is stopped by "thermo off" or pressing the stop button during the cooling operation (see step S1 in FIG. 2). The signals are output respectively (see step S2 in FIG. 2). Then, the four-way switching valve 12 is
The four-way switching valve 1 that was switched from the cooling passage shown by the broken line to the heating passage shown by the solid line and was at high pressure until then.
2, the pipe line 16e on the outdoor heat exchanger 15 side is closer to the compressor 11
Of the four-way switching valve 12, which was in low pressure until then, is connected to the suction-side pipe line 16f, and the pipe line 16b on the indoor heat exchanger 13 side is
The pipe line 16a is communicated with the discharge side pipe line 16a of the compressor 11 to equalize the pressure of the pipe line. At the same time, the electromagnetic opening / closing valve 17 is opened for a certain period of time, and the conduit 1 on the outdoor heat exchanger 15 side of the pressure reducing device 14 is
The bypass pipe line 18 connecting the 6d and the pipe line 16a of the four-way switching valve 12 on the compressor 11 side is opened. Therefore, the pressures of the ports A and B before and after the electromagnetic on-off valve 17 are equalized immediately after the compressor is stopped, unlike the conventional case shown in FIG. 4 (closed by the spring force in the demagnetized state). The valve body does not chatter due to the pressure difference. Therefore, it is possible to prevent chattering by using a small-sized and inexpensive electromagnetic on-off valve without requiring a large spring or solenoid, and to achieve a long service life of the valve and a reduction in noise. Since the compressor 11 is stopped and pressure equalization of the pipeline is completed in a short time, the electromagnetic opening / closing valve 1
It is enough to output the excitation signal to 7 for about 30 seconds.
In the above embodiment, the pressure reducing device 14 is provided by the bypass line 18.
The pipe line 16d on the side of the outdoor heat exchanger 15 was connected to the pipe line 16a on the discharge side of the compressor 11.
Even if it is connected to the conduit 16b on the side, the same action and effect as described above can be obtained.

[0010]

As is apparent from the above description, in the air conditioner of the present invention, the compressor, the four-way switching valve, the indoor heat exchanger, the decompression device, and the outdoor heat exchanger are sequentially connected by pipelines. The outdoor heat exchanger side pipe of the decompression device is connected to the compressor side or indoor heat exchanger side pipe of the four-way switching valve by a bypass line having an electromagnetic opening / closing valve, and the cooling operation is interrupted. At the same time, the four-way switching valve is provided with a controller that outputs a switching signal for switching this valve to the heating operation side, and at the same time a controller for outputting a control signal for opening the valve for a certain time to the electromagnetic opening / closing valve. Chattering can be prevented without increasing the size of the valve, and the valve can have a long life and noise with a simple and inexpensive structure.

[Brief description of drawings]

FIG. 1 is a refrigerant circuit diagram showing an example of an air conditioner of the present invention.

FIG. 2 is a flowchart showing a control flow of the controller of FIG.

FIG. 3 is a refrigerant circuit diagram of a conventional air conditioner.

FIG. 4 is a diagram showing changes in pressure at ports A and B of the solenoid opening / closing valve of FIG. 3 after the compressor is stopped.

[Explanation of symbols]

1 ... Controller, 11 ... Compressor, 12 ... Four-way switching valve, 13 ...
Indoor heat exchanger, 14 ... Pressure reducing device, 15 ... Outdoor heat exchanger,
16a to 16f ... Pipe line, 17 ... Electromagnetic on-off valve, 18 ... Bypass pipe line.

Claims (1)

[Scope of utility model registration request] 1. A compressor (11), a four-way switching valve (12), an indoor heat exchanger (13), a pressure reducing device (14) and an outdoor heat exchanger (1).
5) are sequentially connected by pipelines (16a to 16f),
The conduit (16d) of the outdoor heat exchanger (15) of (14) is connected to the compressor (11) side of the four-way switching valve (12) by a bypass conduit (18) having an electromagnetic opening / closing valve (17). Or indoor heat exchanger (13)
In the air conditioner connected to the side pipes (16a, 16b), when the cooling operation is interrupted, a switching signal for switching the valve to the heating operation side is output to the four-way switching valve (12), and at the same time, the solenoid opening / closing valve An air conditioner characterized in that (17) is provided with a controller (1) for outputting a control signal for opening this valve for a certain period of time.