JPH049983B2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to a heat pump air conditioner that selectively performs cooling operation and heating operation by changing the flow direction of refrigerant using a four-way valve.
In particular, the present invention relates to a heat pump air conditioner that allows defrosting operation to be performed in parallel with heating operation.

[Technical background of the invention]

In the heat pump air conditioner mentioned above,
Defrosting operations for removing frost on the heat exchanger include a so-called reverse cycle in which the flow direction of the refrigerant is changed using a four-way valve, as well as a hot gas bypass cycle as shown in FIG.

The one in FIG. 1 connects a pipe line 4 containing an indoor heat exchanger 1, an expansion valve 2, and an outdoor heat exchanger 3 to a pipe line 6 containing a compressor 5 via a four-way valve 7. Furthermore, the pipeline 4a between the expansion valve 2 and the outdoor heat exchanger 3 and the downstream pipeline 6a of the compressor 5 are connected by a bypass pipeline 9 provided with a two-way valve 8. The expansion valve 2 is a proportional control valve whose valve body is driven by a motor to vary the distance between the valve seat and the valve body, so that the expansion state of the refrigerant can be freely controlled according to the outside air condition. It's getting old. Note that the solid line in the four-way valve 7 indicates the flow of refrigerant during cooling operation, and the broken line indicates the flow of refrigerant during heating operation.

According to the above-described configuration, by switching the four-way valve 7, the compressor 5 is connected to the outdoor heat exchanger 3, the expansion valve 2,
The refrigerant flows in this order from the indoor heat exchanger 1 to perform cooling operation, and the refrigerant flows from the compressor 5 to the indoor heat exchanger 1, the expansion valve 2, and the outdoor heat exchanger 3 in this order to perform heating operation. It is done. Furthermore, in order to perform defrosting operation during heating operation, when the two-way valve 8 installed in the bypass pipe 9 is opened, the high-temperature refrigerant from the compressor 5 is directly supplied to the room via the bypass pipe 9. It is introduced into the outside heat exchanger 3, and frost on the outdoor heat exchanger 3 is removed. Moreover, at this time, since a small amount of refrigerant also flows through the indoor heat exchanger 1 and the expansion valve 2, the heating operation is also performed intermittently.

[Problems with background technology]

By the way, the rotor (not shown) inside the expansion valve 2 rotates while being supported by a bearing, and since the refrigerant inside the expansion valve 2 becomes low in temperature, the lubricating oil increases its viscosity due to this low temperature, causing the rotor to become viscous. This may adversely affect rotation. Furthermore, since the expansion valve 2 and the two-way valve 8 are provided separately, the cost of both is high and the number of brazing points increases.

[Purpose of the invention]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a heat pump type air conditioner that eliminates the drawbacks of the conventional ones described above, has an electric drive means that operates stably, can be easily connected, and can be manufactured at a low cost. .

[Summary of the invention]

The present invention provides a first valve body that opens and closes the pipeline from both heat exchangers by coming into contact with and separating from the valve seat, and a first valve body that opens and closes the pipeline from both heat exchangers by coming into contact with and separating from the valve seat. A three-way control valve is provided, which includes a bypass line that bypasses the downstream side line of the compressor and a second valve body that opens and closes the line from the outdoor heat exchanger, and the first valve body is The electric driving means moves the refrigerant away from the valve seat to expand the refrigerant passing between the two heat exchangers, and when the distance from the valve seat increases, the second valve element is pushed away from the valve seat. It is something to do.

[Embodiments of the invention]

The present invention will be explained below with reference to embodiments shown in the drawings. Note that the same components as those of the conventional device described above are indicated by the same reference numerals in the drawings, and their explanations will be omitted.

FIG. 2 shows the entire refrigeration cycle of the heat pump air conditioner according to the present invention, in which the pipe line 4 between the indoor heat exchanger 1 and the outdoor heat exchanger 3
A three-way control valve 10, which is shown in detail in FIG. 3, is interposed therein. The three-way control valve 10 also includes a bypass pipe 9 connected to the downstream pipe 6a of the compressor 5.
is connected.

The three-way control valve 10, as shown in FIG.
It has a cylindrical casing 11, and the bypass pipe 9 and the pipe 4a from the outdoor heat exchanger 3 are connected to the lower peripheral wall 12 of the casing 11.
They are connected by brazing so that the bypass pipe line 9 is positioned above. In addition, the casing 1
The pipe line 4 from the indoor heat exchanger 1 is connected to the low wall 13 of 1.
b are connected by brazing. Each of the conduits 4a, 4b, and 9 communicates with an internal cavity 14 in the casing 11, and a valve seat 15 is formed on the peripheral wall of the internal cavity 14 near the conduit 4b.
Further, another valve seat 16 is formed on the peripheral wall of the internal space 14 between the conduits 9 and 4b.

A reversible rotary motor 17 is disposed above the casing 11, and a stator 18 of the motor 17 is attached to the outside of the thin peripheral wall 12a of the casing 11. On the other hand, the casing 11
A shaft 20 extending from the upper end to the lower end of the casing 11 is disposed inside the casing 11, and a rotor 21 is fitted onto the shaft 20 so as to face the stator 18. Further, a male thread 22 is formed at the upper end of the shaft 20, and this male thread 22 is screwed into a male thread cylinder 24 vertically provided on the top wall 23 of the casing 11. Therefore, the rotation of the rotor 21 causes the shaft 20 to move up and down within the casing 11. A first valve body 25 is protruded from the lower end of the shaft 20, and this first valve body 25 is connected to the shaft 20.
0 continues against the valve seat 15 as the valve moves up and down.

A cup-shaped second valve body 26 is slidably inserted into the shaft 20 between the rotor 21 and the first valve body 25, and this second valve body 26 is inserted into the shaft 20 between the rotor 21 and the first valve body 25.
6.It is designed so that you can sit on it. Further, a flange 27 is provided around the upper end of the second valve body 26, and a minute gap is formed between the flange 27 and the inner peripheral surface of the casing 11. Therefore, the high-pressure gas introduced from the bypass pipe line 9 into the central cavity 14 reaches the interior cavity 14 above the second valve body 26 through this minute gap, and passes through the second valve body 26. Press it so that it comes into pressure contact with the valve seat 16.

The drive of the motor 17 is controlled by a control section (not shown) in response to room temperature and the like.

Next, the operation of the embodiment described above will be explained.

In the state shown in FIG. 3, the first valve body 25 is seated on the valve seat 15, and the pipe line 4a from the outdoor heat exchanger 3 and the pipe line 4b from the indoor heat exchanger 1
are not connected, and neither cooling nor heating operation can be performed. Therefore, when performing cooling/heating operation, the motor 17 is driven to rotate the rotor 21, and the shaft 20 is raised by the screw engagement between the male thread 22 and the female thread cylinder 24, and the first valve body 25 is separated from the valve seat 15. urge Then, both the pipes 4
a, 4b communicate with each other and the refrigerant flows between the heat exchangers 3, 1, but the communication port formed by separating the first valve body 25 from the valve seat 15 is smaller than the diameter of both the pipes 4a, 4b. Because of the cross-sectional area, the refrigerant is condensed and becomes a low-temperature, low-pressure liquid refrigerant. In addition, both pipe lines 4
The flow rate of the refrigerant flowing between a and 4b is directly proportional to the stroke of the first valve body 25, as shown by the broken line in FIG.

Next, when performing defrosting operation, the motor 17 is further driven to further raise the first valve body 25, the upper end of the first valve body 25 is brought into contact with the lower end of the second valve body 26, and the first valve body 25 is brought into contact with the lower end of the second valve body 26. 2 valve body 26 is pushed upward against the gas pressure of the refrigerant. Then, both the pipes 4
Bypass pipe 9 is connected to a and 4b, cooling operation,
Although it differs depending on the heating operation, high-temperature refrigerant gas on the downstream side of the compressor 5 flows from the bypass pipe line 9 into the pipe line 4b or 4a, warms the indoor heat exchanger 1 or the outdoor heat exchanger 3, and removes it. frost As shown by the solid line in FIG. 4, the flow rate of the refrigerant from the bypass pipe 9 becomes large at once when the second valve element 26 is separated from the valve seat 16.

Note that when switching to defrosting operation during heating, a small portion of the refrigerant discharged from the compressor 5 flows from the four-way valve 7 to the indoor heat exchanger 1, so that a small amount of heating operation is performed.

According to the above-mentioned embodiment, since the three-way control valve 10 has the functions of a proportional control type expansion valve and an on-off valve, heating operation and defrosting operation can be performed in parallel. Since the high temperature refrigerant is introduced from the bypass pipe line 9, there is no fear that the viscosity of the lubricating oil will increase. Furthermore, since the three-way control valve 10 is a combination of the conventional expansion valve 2 and the two-way valve 8, the number of brazed piping points is reduced from the conventional four to three, and the cost of the valve is also reduced. Become.

Note that various types of electric drive means can be considered, such as a pulse motor electromagnetic coil, a bimetal heater, and a shape memory alloy.

〔Effect of the invention〕

As explained above, the heat pump type air conditioner according to the present invention opens and closes the pipes from both the indoor and outdoor heat exchangers by engaging and separating the valve seats. A three-way control valve includes a first valve body and a second valve body that opens and closes a bypass line bypassing the downstream side line of the compressor and a line from the outdoor heat exchanger by coming into contact with and separating from the valve seat. The first valve body is separated from the valve seat by an electric drive means to expand the refrigerant passing through both heat exchangers, and when the distance from the valve seat becomes large, the second valve body
Since it is configured to push the valve body away from its valve seat, when the electric drive means operates stably, the valve connection work can be easily performed and furthermore, it can be manufactured at low cost. It has this excellent effect.

[Brief explanation of drawings]

FIG. 1 is a pipe diagram showing a conventional heat pump type air conditioner, FIG. 2 is a pipe diagram showing an embodiment of the heat pump type air conditioner according to the present invention, and FIG.
FIG. 4 is a sectional view of the three-way control valve shown in the figure, and FIG. 4 is a graph showing the refrigerant flow rate characteristics in the three-way control valve shown in FIG. 1... Indoor heat exchanger, 2... Expansion valve, 3...
Outdoor heat exchanger, 5... Compressor, 7... Four-way valve,
8... Two-way valve, 9... Bypass pipe line, 10... Three-way control valve, 11... Casing, 14... Internal cavity, 15, 16... Valve seat, 17... Motor, 18
... Stator, 20 ... Shaft, 21 ... Rotor, 24 ... Female thread cylinder, 25 ... First valve body, 26
...Second valve body.

Claims (1)

[Claims] 1. In an air conditioner in which a pipe line including an indoor heat exchanger and an outdoor heat exchanger and a pipe line containing a compressor are connected via a four-way valve, a valve is installed in the pipe line between the two heat exchangers. a first valve element that opens and closes the pipelines from both heat exchangers when coming into contact with and separating from the valve seat; a bypass pipeline that bypasses the downstream pipeline of the compressor when coming into contact with and separating from the valve seat; and the outdoor heat exchanger. A three-way control valve is provided with a second valve body that opens and closes a pipe line from the heat exchanger. A heat pump type air conditioner characterized in that the second valve element is pushed away from the valve seat when the distance from the valve seat increases.