JPH0542963U - Air conditioner - Google Patents

Abstract

(57) [Abstract] [Purpose] When the air conditioner is left stopped for a long time, the refrigerant liquefies and collects in the oil separator 17, and this liquid refrigerant is stored in the compressor 4 when the air conditioner restarts operation. It prevents the liquid from flowing into and causing liquid compression. [Structure] An on-off valve 19 is provided in the refrigerant gas introduction pipe of the oil separator 17,
An on-off valve 20 is provided in the discharge pipe and an on-off valve 21 is provided in the oil return pipe 18, and these on-off valves 19 and 2 are provided while the air conditioner is not operating.
By closing 0 and 21, the refrigerant is prevented from entering the oil separator 17.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an air conditioner suitable for buses, trucks, passenger cars and the like.

[0002]

[Prior Art]

 A system diagram of a conventional air conditioner of this type is shown in FIG. When the compressor 4 is driven from the pulley 1 of the internal combustion engine via the compressor pulley 2 and the electromagnetic clutch 3, the refrigerant gas discharged from this compressor 4 enters the oil separator 17, where the refrigerant gas The oil contained in is separated. The separated oil returns to the compressor 4 via the oil return pipe 18. The gas refrigerant flowing out from the oil separator 17 flows into the condenser 6, where it is condensed and liquefied by radiating heat from the fan 8 driven by the fan motor 7 to the outside air. This liquid refrigerant flows into the expansion valve 11 via the receiver 9 and the dryer strainer 10, and is adiabatically expanded by being throttled there. Next, this refrigerant flows into the evaporator 12, where the vehicle interior air blown from the evaporator fan 13 is cooled to be evaporated and vaporized and returned to the compressor 4 as a gas refrigerant. Condensed water dropped from the evaporator 12 is collected in the drain pan 15 and discharged to the outside of the vehicle via the drain hose 16.

[0003]

[Problems to be solved by the device]

 When the above conventional air conditioner is stopped for a long time, such as at night, the refrigerant in the refrigerant circuit flows into the oil separator 17 and is liquefied as the outside air temperature decreases. Then, this liquid refrigerant is separated from the oil in the oil separator 17 due to the difference in specific gravity, and the oil stays in the upper layer and the liquid refrigerant stays in the lower layer. When the operation of the air conditioner is started in this state, the liquid refrigerant is supplied to the compressor 4 from the oil separator 17, so that the compressor 4 may be compressed and damaged.

[0004]

[Means for Solving the Problems]

 The present invention has been proposed to solve the above problems, and its gist is to provide an oil separator for separating the oil in the refrigerant gas discharged from the compressor and the oil separator for separating the oil. In an air conditioner equipped with an oil return pipe for returning the recovered oil to the compressor, an on-off valve is provided in each of the refrigerant gas introduction pipe and the discharge pipe of the oil separator and the oil return pipe, and each of these on-off valves is connected to the air conditioner. The air conditioner is characterized by being provided with a controller that is closed during the operation stop.

[0005]

[Action]

 In the present invention, since the refrigerant is shut off by each on-off valve while the air conditioner is not in operation, it does not flow into the oil separator and remain there as a liquid refrigerant.

[0006]

【Example】

 One embodiment of the present invention is shown in FIG. 1, and the same members as the conventional one are designated by the same reference numerals. The refrigerant gas introduction pipe of the oil separator 17 is provided with an electromagnetic on-off valve 19, the refrigerant gas discharge pipe is provided with an electromagnetic on-off valve 20, and the oil return pipe 18 is provided with an electromagnetic on-off valve 21. These electromagnetic on-off valves 19, 20, 21 are opened and closed by a signal from the controller 22. 23 is an operation switch.

FIG. 2 shows an electric control circuit diagram of the controller 22. When the operation switch 23 is turned on, the relay 24 is excited, its contact 24a is turned on, and the electromagnetic clutch 3 and the electromagnetic on-off valves 19, 20, 21 are energized. , 20 and 21 are opened and the operation of the air conditioner is started. When the operation of the air conditioner is stopped, the relay 24 is demagnetized by shutting off the operation switch 23, so that the electromagnetic clutch 3 is disengaged and the electromagnetic on-off valves 19, 20, 21 are closed. As a result, the refrigerant is blocked by the electromagnetic on-off valves 19, 20, and 21 during the operation stop of the air conditioner, so that the refrigerant does not flow into the oil separator 17 and liquefy.

Thus, since the liquid refrigerant does not stay in the lower layer of the oil separator 17, the liquid refrigerant is not supplied to the compressor 4 when the operation of the air conditioner is restarted, and therefore the compressor 4 It is possible to solve the problem caused by the compression of the liquid refrigerant at the time of restart of the. In addition, since the oil in the compressor 4 is not diluted by the liquid refrigerant, it is possible to effectively prevent defective lubrication of the compressor and abnormal wear and seizure of the sliding portion due to this.

[0009]

[Effect of the device]

 In the present invention, the refrigerant does not flow into the oil separator while the air conditioner is stopped. As a result, it is possible to prevent liquid compression and poor lubrication of the compressor when the operation of the air conditioner is restarted, and thus it is possible to improve the efficiency and reliability of the air conditioner.

[Brief description of drawings]

FIG. 1 is a system diagram showing an embodiment of the present invention.

FIG. 2 is an electrical control circuit diagram of the above embodiment.

FIG. 3 is a system diagram of a conventional air conditioner.

[Explanation of symbols]

 4 Compressor 17 Oil separator 18 Oil return pipe 19, 20, 21 Electromagnetic on-off valve 22 Controller

Claims (1)

[Scope of utility model registration request] 1. An air conditioner comprising an oil separator for separating oil in refrigerant gas discharged from a compressor, and an oil return pipe for returning the oil separated by the oil separator to the compressor,
An air conditioner characterized in that an opening / closing valve is provided in each of the refrigerant gas introduction pipe and the discharge pipe of the oil separator and the oil return pipe, and a controller that closes each of the opening / closing valves while the air conditioner is not operating is provided. apparatus.