JPH01193568A - Air conditioner for vehicle - Google Patents

Abstract

PURPOSE:To efficiently recover the cooling medium by connecting a cooling medium recovery tank to a gas/liquid separator via line shutoff valve. CONSTITUTION:When the recovery switch 32 is turned on, the compressor 2 is started, and an electrical signal is transmitted from a control circuit 7 to a line shutoff valve 11 to attract the needle valve 631 of the line shutoff valve 11 by electrical magnetism away from the valve seat 632. As the line shutoff valve 11 is opened, a gas/liquid separator 4 and a cooling medium recovery tank 15 are mutually connected via a connecting pipe 41, the line shutoff valve 11 and a connecting pipe 43. The liquid cooling medium that has been separated in the gas/liquid separator 4 flows into the recovery tank 15. At this moment, a signal is sent from the control circuit 7 to an expansion valve 5 to limit the cooling medium flow rate. That is, an electric current is supplied to the coil 53 to excite same, and its excited magnetism attracts a plunger 52 toward the stationary iron core 50. As a result, the valve body 57 shifts toward the valve seat 54, and the expansion valve 5 is throttled to such an extent that only the gaseous cooling medium coming from the gas/liquid separator 4 is allowed to pass through.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a vehicle air conditioner equipped with a refrigerant recovery device.

[Conventional technology]

Conventionally, the refrigerant used in vehicle air conditioners has been discarded into the atmosphere when the vehicle is scrapped. However, some of the refrigerant released into the atmosphere reaches the stratosphere and destroys the ozone layer within the stratosphere.

As a result, harmful ultraviolet rays that were previously absorbed by the ozone layer reach the earth's surface without being absorbed, causing problems such as harmful effects on human skin, and problems such as the harmful ultraviolet rays that surround the earth like carbon dioxide gas, creating a greenhouse effect, There have been reports of adverse effects such as raising the temperature of the air.

Under these circumstances, there is a desire to recover refrigerants that were conventionally discarded into the atmosphere.

[Problem to be solved by the invention]

In response to the above-mentioned requirements, the present invention provides a vehicle equipped with a recovery device that recovers refrigerant used in vehicles, which is difficult to recover because it is in a gaseous state at room temperature, with a simple configuration and an inexpensive device. The objective is to obtain an air conditioning system for use in air conditioning.

[Means to solve the problem]

In order to solve this problem, the present invention includes a compressor, a condenser,
In a vehicle air conditioning system in which a gas-liquid separator, an expansion valve-1 evaporator, etc. are sequentially connected, a refrigerant recovery tank for recovering condensed refrigerant separated by the gas-liquid separator is communicated with the gas-liquid separator, A communication on-off valve was placed between the refrigerant recovery tank and the gas-liquid separator to allow communication between the two only during refrigerant recovery.

The gas-liquid separator is used to separate the refrigerant flowing out of the condenser into condensed refrigerant and uncondensed refrigerant. Further, the gas-liquid separator is used to separate the refrigerant flowing out from the evaporator into condensed refrigerant and uncondensed refrigerant.

[Effect]

When recovering refrigerant, the communication on-off valve is opened and the compressor is operated.

Then, the liquid refrigerant separated in the gas-liquid separator 4 flows into the refrigerant recovery tank via the communication on-off valve.

During normal operation, the communication on-off valve is closed and the compressor is operated to perform normal cooling operation.

〔Effect of the invention〕

Therefore, the refrigerant, which is in a gaseous state at room temperature, can be separated into liquid refrigerant and gaseous refrigerant by the gas-liquid separator, and this liquid refrigerant can be recovered in the refrigerant recovery tank 15, which is simple and inexpensive. The refrigerant can be recovered with the device.

- (Example) FIG. 1 is a circuit diagram showing an air conditioner according to the present invention.

A compressor 2 receives driving force from a vehicle engine (not shown) via an electromagnetic clutch 2a, and compresses refrigerant into a high-temperature, high-pressure gaseous refrigerant. This compressed refrigerant flows into the condenser 3 through the pipe 101.

The refrigerant flowing through the condenser 3 exchanges heat with the external air passing through the condenser 3, and the high temperature and high pressure gas refrigerant is condensed into liquid refrigerant. This liquid condensed refrigerant flows into the gas-liquid separator 4 through the pipe 102. In the gas-liquid separator 4, the refrigerant is separated into a liquid condensed refrigerant that has been condensed by the condenser 3 and a gaseous refrigerant that has not been condensed. Then, only the liquid refrigerant flows through the pipe 103 to the expansion valve 5.

The expansion valve 5 increases or decreases the flow area of the refrigerant flowing through the piping 103 and the piping 104 to cause expansion. The refrigerant, which is turned into a low-pressure liquid refrigerant by the expansion valve 5, flows into the evaporator 6 through the pipe 104. While flowing through the evaporator 6, the refrigerant exchanges heat with external air and evaporates, becoming a gas refrigerant and flowing into the compressor again. In the evaporator 6, external air is cooled by exchanging heat with the refrigerant, and this cooled air is blown out to the vehicle.

A temperature sensor 21 for detecting the refrigerant temperature on the exit side of the evaporator 6 is disposed in the pipe 104 on the exit side of the evaporator 6 . The signal detected by the temperature sensor 21 is sent to the control circuit 7, and based on this signal, the control circuit 7 sends a signal to the expansion valve 5 via the lead wire 60. The expansion valve 5 receives this signal and increases or decreases its flow path area.

A connecting pipe 41 is connected to the lower end surface of the gas-liquid separator 4,
A communication on-off valve 11 is provided in this connection pipe 41 . Further, this communication on-off valve 11 has a connecting pipe 43.
A refrigerant recovery tank 15 is connected thereto. The communication on-off valve 11 is connected to the control circuit 7 which is transmitted via a lead wire 66.
The connecting pipes 41 and 43 are opened and closed in response to signals from the connecting pipes 41 and 43.

Connected to the control circuit 7 are an operation switch 31 that is turned on when performing normal cooling operation, and a recovery switch 32 that is turned on when recovering refrigerant. When the operation switch 31 is turned on, a current is transmitted from the control circuit 7 to the electromagnetic clutch 2a via the lead wire 68, the electromagnetic flange is connected, and the driving force from the engine is transmitted to the compressor 2. Furthermore, when the recovery switch 32 is turned on, the electromagnetic clutch 2a is also connected, and at the same time the communication on-off valve 1 is connected via the lead wire 66.
1, and the communication on-off valve 11 is opened.

Further, a pressure cassette 20 for detecting the pressure of the refrigerant flowing inside the pipe 101 is disposed on the pipe 101 on the outlet side of the compressor 2 . A pressure signal detected by this pressure switch is transmitted to the control circuit 7 via a lead wire 69.

FIG. 2 is a sectional view showing the expansion valve 5. FIG. The expansion valve housing 55 includes an inlet joint 55a to which the pipe 103 is connected;
An outlet joint 55b to which the pipe 104 is connected is formed. A valve seat 54 is formed within the expansion valve housing 55, and a valve body 57 is disposed so as to be able to come into contact with the valve seat 54.

The valve body 57 is integrally molded with the shaft 56 and the plunger 52.

A fixed iron core 50 is arranged around the outer periphery of the plunger 52, and a coil 53 is further wound around the outer periphery of the fixed iron core 50. A valve body 57 is provided between the plunger 52 and the fixed iron core 50.
A plunger spring 51 is arranged to urge the valve away from the valve seat 54. Further, an opposing spring 58 that applies a biasing force in the opposite direction to the plunger spring 51 is engaged with the valve body 57 .

An excitation current is supplied to the coil 53 from the control circuit 7 via a lead wire 60 . An electromagnetic force is generated by supplying current to the coil 53, and the plunger 52 is attracted toward the fixed iron core 50 against the force of the plunger spring 51. That is, the valve body 57 moves in the direction closer to the valve seat 54, and the flow path area of the refrigerant flowing from the inlet joint 55a side to the outlet joint 55b side is narrowed.

As the amount of refrigerant flowing through the evaporator 6 decreases, the temperature of the refrigerant flowing out of the evaporator 6 increases. The temperature sensor 21 detects this, and a control signal is sent to the coil 53 of the expansion valve 5 via the control circuit 7, and the electromagnetic force generated by the coil 53 is weakened, so that the valve body 57 moves away from the valve seat 54. Move to.

As a result, the flow path area of the refrigerant flowing through this expansion valve increases, and more refrigerant flows into the evaporator 6.

On the other hand, when the amount of refrigerant flowing into the evaporator 6 becomes excessive, the temperature of the refrigerant flowing through the pipe 104 becomes low.

The temperature sensor 21 detects this, and a large amount of current is supplied to the coil 53 via the control circuit 7. As a result, the plunger 52 is attracted toward the fixed iron core 50, and the valve body 57 moves toward the valve seat 54, thereby restricting the refrigerant flow rate.

FIG. 3 is a sectional view showing the communication on-off valve 11 disposed between the gas-liquid separator 4 and the refrigerant recovery tank 15. The gas-liquid separator 4 has a cylindrical shape, and a threaded portion 80 is formed on the bottom surface of the gas-liquid separator 4. A worm valve 81 is disposed within the threaded portion 80. This insect valve 81 is normally in an open state,
Communication is established by inserting a pin 82, which will be described later, into the insect valve 81.

The connecting pipe 41 can be connected to this threaded portion 80 by inserting a nut 83 into the threaded portion 80. A pin 82 is disposed at the tip of the connecting pipe 41, that is, inside the nut 83, and this pin 82 connects the insect valve 8.
1, the insect valve 81 opens. Thereby, the inside of the gas-liquid separator 4 and the connection pipe 41 are communicated with each other.

An on-off valve housing 110 is connected to the other end of the connecting pipe 41 by a flare nut 42.

A valve seat 632 is provided inside this communication opening/closing valve housing 110.
A needle valve 63 is formed on this valve seat 632.
1 are arranged so that they can come into contact with each other.

The needle valve 631 is fixed to the plunger 62,
The plunger 62 is arranged so as to be slidable within the coil 61 wound in a cylindrical shape.

The coil 61 is connected to the control circuit 7 via a lead wire 66 and a connector 67, and generates magnetic force by receiving an excitation current from the control circuit 7. This results in
By attracting the plunger 62 against the force of the biasing spring 62a and adjusting the force, the needle valve 63
1 and the valve seat 632 are adjusted. Note that this coil 61 and the on-off valve housing 110 are connected by a connecting member 111.
are screwed together.

A connecting pipe 43 of the refrigerant recovery tank 15 is connected to the outlet side 65 of the on-off valve housing 110 by a flared nut 42 . The refrigerant recovery tank 15 is a cylindrical tank having a closed space inside, and has a capacity sufficient to recover and store all of the liquid refrigerant flowing through the refrigerant circuit.

Next, the operation of this embodiment will be explained based on FIG. 4.

FIG. 4 is a flowchart showing the operation. Step 4
At step 01, it is determined whether refrigerant recovery or normal operation is performed. That is, if the operation switch 31 is turned on, it is normal operation, and if the recovery switch 32 is turned on, it is refrigerant recovery. If the operation switch is turned on, step 40
2, and the communication on-off valve 11 remains closed.

Then, the electromagnetic clutch 2a is connected, the compressor 2 is operated, and a normal cooling cycle is operated.

When the recovery switch 32 is turned on, the process moves to step 404, where a signal is sent from the control circuit 7 to the electromagnetic clutch 2a, the electromagnetic clutch 2a is connected, and the compressor 2 is operated. At the same time, a current signal is sent from the control circuit 7 to the communication on-off valve 11, and the communication on-off valve 11 opens and separates from the valve seat 632 by attracting the needle valve 631 with electromagnetic force. As a result, the communication on-off valve 11 is opened, and the gas-liquid separator 4 and the refrigerant recovery tank 15 are connected to the connection pipe 41 and the communication on-off valve 1.
1 and a connecting pipe 43. The liquid refrigerant separated in the gas-liquid separator 4 is then transferred to the recovery tank 1.
5 and is collected.

At this time, as shown in step 406, a signal is sent to the expansion valve 5 from the control circuit 7 to throttle the refrigerant flow rate. That is, the coil 53 is excited by being supplied with a current, and the excitation force causes the plunger 52 to move toward the fixed core 5.
It is attracted to the 0 side.

As a result, the valve body 57 moves to the valve seat 54 side, and the expansion valve 5 is throttled until only the gas refrigerant flowing out from the gas-liquid separator 4 passes through.

By continuously performing such operations, the refrigerant flowing in the refrigerant circuit is gradually recovered into the refrigerant recovery tank 15. A pressure switch 20 detects the pressure of the refrigerant discharged from the compressor 2, and as the refrigerant is gradually recovered and decreased, the pressure detected by the pressure switch 20 also decreases. Therefore, in step 407, if the high pressure detected by the pressure switch 20 is higher than a specified value, this recovery operation is continued, but when the refrigerant decreases and falls below a certain specified value, the detection signal is sent to the pressure switch 20.
0 to the control circuit 7, and the control circuit 7 sends a signal to close the communication on-off valve 11 (steve 408), and then a signal to disconnect the electromagnetic clutch 2a is sent to complete the refrigerant recovery ( Step 409).

In addition, the pin 82 at the tip of the connecting pipe 41 is connected to the insect valve 8.
1, the nut 83 remains closed unless it is inserted into the gas-liquid separator 4.
The refrigerant removed from the screw part 80 and recovered in the recovery tank 15 is separated from the vehicle and stored at another location. The remaining vehicles and air conditioning equipment will then be disposed of.

FIG. 5 is a sectional view showing another embodiment of the communication on-off valve 11. In the above embodiment, the communication on-off valve 11 is a so-called electromagnetic valve having a coil 61, but it may be a manual valve as shown in FIG. That is, in this example, a spindle 72 having a handle 71 is screwed into the valve housing 110. A thrust shoe is disposed at the tip of the spindle 72, and a diaphragm 75 is in contact with the thrust shoe 74. and,
A valve body 78 is connected to the diaphragm 75, and by adjusting the screwing position of the spindle 72, the valve body 78 is connected to the diaphragm 75.
is pressed toward the valve seat 78b or opened and closed by the force of the spring 76, thereby opening and closing the communication.

Further, in the above embodiment, as shown in FIG. 2, the expansion valve 5
Although an electric expansion valve is used, it is also possible to replace it with a conventionally known mechanical expansion valve.

Further, although the gas-liquid separator 4 was placed between the condenser 3 and the expansion valve 5 and used as a so-called receiver, it may be placed between the evaporator and the compressor and used as a so-called accumulator. That is, the liquid refrigerant that has passed through the evaporator 6 and has not been completely evaporated may be separated, and the separated liquid refrigerant may be collected into the refrigerant recovery tank 15.

As described above, in the refrigerant air conditioner of this embodiment, refrigerant can be efficiently recovered in the conventional air conditioner simply by connecting the refrigerant recovery tank to the gas-liquid separator via the communication on-off valve.

[Brief explanation of the drawing]

Fig. 1 is a refrigeration cycle diagram showing an embodiment of the present invention, Fig. 2 is a sectional view of an expansion valve, Fig. 3 is a sectional view of a communication opening/closing valve, and Fig. 4 is a sectional view of a communication valve.
The figure is a flowchart showing the operation, and FIG. 5 is a sectional view showing another example of the communication on-off valve. 2... Compressor, 3... Condenser, 4... Gas-liquid separator, 5... Expansion valve, 6... Evaporator, 11... Communication on/off valve, 15... Refrigerant recovery tank.

Claims (1)

[Claims] (1) A compressor that compresses refrigerant, a condenser that condenses the compressed refrigerant, and a gas-liquid separation that separates the refrigerant flowing out from the condenser into condensed refrigerant and uncondensed refrigerant. A refrigerant recovery tank for recovering the separated condensed refrigerant in a vehicle air conditioner comprising a refrigerant, an expansion valve for expanding the separated condensed refrigerant, and an evaporator for evaporating the expanded refrigerant. is disposed so as to be able to communicate with the gas-liquid separator, and a communication on-off valve is disposed between the refrigerant recovery tank and the gas-liquid separator for communicating between the two only during refrigerant recovery. Vehicle air conditioning system. (2) The vehicle air conditioner according to claim 1, wherein the gas-liquid separator separates the refrigerant flowing out from the evaporator into condensed refrigerant and uncondensed refrigerant. (3) The vehicle air conditioner according to claim 1, wherein the refrigerant recovery tank is detachably connected to the gas-liquid separator. (4) The vehicle air conditioner according to claim 1, wherein the refrigerant recovery tank is integrally fixed to the gas-liquid separator.