CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to Japanese Patent Application Serial No. 2016-234035, filed Dec. 1, 2016, the entire disclosure of which is hereby incorporated by reference.

TECHNICAL FIELD

The present invention relates to a gas-liquid separator.

BACKGROUND

In JP 2013-535372 A, an air conditioning loop that can be switched between a cooling mode and a heating mode is disclosed. The air conditioning loop is provided with the gas-liquid separator, that separates the refrigerant guided from an external heat exchanger into a gas phase refrigerant and a liquid phase refrigerant from each other, and that exhausts the refrigerant out of the first outlet or the second outlet in accordance with the operation mode of the air conditioning loop.

In the gas-liquid separator of the JP 2013-535372 A, however, the first outlet and the second outlet are provided in the upper portion and the lower portion, respectively. Therefore, the structure of the container of the gas-liquid separator and the structure of the connection unit of the piping may become complicated.

SUMMARY

An object of the present invention is to simplify the piping, connecting the a system having a gas-liquid separator and the other components.

In an aspect of the present invention, a gas-liquid separator applied to a refrigerating cycle comprises: a compressor for compressing refrigerant; an exterior heat exchanger for exchanging heat between the refrigerant and external air; an evaporator for evaporating the refrigerant by having the refrigerant absorb the heat of the air guided into a vehicle compartment; a heater for heating the air guided into the vehicle compartment by using the heat of the refrigerant compressed by the compressor; and an expansion valve for decompressing and expanding the refrigerant that has passed through the exterior heat exchanger; wherein the gas-liquid separator guides the incoming refrigerant from the exterior heat exchanger into the compressor during heating operation, and guides the incoming refrigerant from the exterior heat exchanger into the expansion valve during cooling operation; wherein the gas-liquid separator includes a tank unit storing refrigerant to separate a gas phase refrigerant and a liquid phase refrigerant from each other, and a piping connection unit provided on top of the tank unit, forming an inlet and outlet of the refrigerant from the tank unit; wherein the piping connection unit comprises: a first connection unit connected to a first connection piping for guiding the refrigerant into the expansion valve; a second connection unit connected to a second connection piping in which the refrigerant that has passed through the evaporator returns; a third connection unit connected to a third connection piping for guiding the refrigerant into the compressor; a fourth connection unit connected to a fourth connection piping for guiding the refrigerant from the exterior heat exchanger into the tank unit; and a switching valve for allowing the interior of the tank unit to communicate with the third connection piping during heating operation, and allowing the second connection piping to communicate with the third connection piping during cooling operation.

In the above aspect, the first connection piping, the second connection piping, the third connection piping, and the fourth connection piping are all connected to the piping connection unit in the upper unit of the tank unit, and an switching valve for switching the path of the refrigerant during heating operation and the cooling operation is provided in the piping connection unit. Therefore, all the pipings connected to the gas-liquid separator can be integrated into the piping connection unit, the piping necessary for providing the switching valve to the outside can be omitted. Therefore, the piping, connecting the gas-liquid separator and the other components, can be made simplified.

