JP2819346B2 - Electric vehicle air conditioner - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a heat pump type electric vehicle air conditioner that effectively uses waste heat of a vehicle driving electric motor during heating.

2. Description of the Related Art As disclosed in Japanese Utility Model Laid-Open No. 57-131305 and Japanese Patent Laid-Open No. 47-31317, there is known a device that uses waste heat of a motor for driving a vehicle indirectly or directly for indoor heating. However, it cannot be said that the indoor heating capacity is sufficient, and if a combustor is used, exhaust gas is generated and the function as a pollution-free vehicle is impaired.

Therefore, it is preferable to install a heat pump air conditioner that does not require a heat source in electric vehicles.However, the heat pump air conditioner lacks the ability to heat outside air at low temperatures, and it is difficult to prevent the outdoor heat exchanger from freezing. is there.

[Problems to be Solved by the Invention] In view of the above problems, an object of the present invention is to perform heating operation by supplementing a heating capacity by using waste heat of a vehicle drive motor and simultaneously preventing freezing of an outdoor heat exchanger. An object of the present invention is to provide an air conditioner for an electric vehicle, which can expand the area.

[Means for Solving the Problem] To achieve the above object, the configuration of the present invention is a heating operation, in which a four-way switching valve is provided from a refrigerant compressor driven by an electric motor,
The refrigerant circuit returns to the refrigerant compressor via the indoor heat exchanger, the decompressor, the outdoor heat exchanger, and the four-way switching valve, and guides the cooling air of the vehicle drive motor to the outdoor heat exchanger through a duct.

[Function] During heating operation, waste heat of the motor for driving the vehicle is introduced into the outdoor heat exchanger to suppress the temperature drop of the outdoor heat exchanger and prevent the moisture of the air passing through the outdoor heat exchanger from adhering and freezing. I do.

At the same time, the refrigerant whose temperature is lowered by radiating heat in the indoor heat exchanger is heated by the waste heat of the vehicle drive motor in the outdoor heat exchanger, thereby increasing the heating capacity.

FIG. 1 is a schematic configuration diagram of an electric vehicle air conditioner according to the present invention. The heat pump type air conditioner is configured such that the outlet of the heating-time refrigerant compressor 15 is connected to the pipe 21, the four-way switching valve 14, the pipe 22, the indoor heat exchanger 18, the pipe 23, the pressure reducer 17, the pipe 24, the outdoor heat exchanger 13, and the pipe. Two
5. Connected to the suction port of the refrigerant compressor 15 via the four-way switching valve 14, the pipe 26, the accumulator 16, and the pipe 27 to form a refrigeration cycle.

The present invention uses the waste heat of the motor 5 for driving the front wheels 2 to heat the outdoor heat exchanger 13. For this reason, the motor 5 for driving the vehicle is covered by a case 4 having an air inlet 3, and the case 4 is connected to a case of an outdoor heat exchanger 13 via a duct 6, a switching valve 7, and a duct 10, and an outdoor heat exchanger is provided. By the blower 12 arranged inside the case of the vessel 13,
It is configured to guide the waste heat of the vehicle drive motor 5 to the outdoor heat exchanger 13.

During the heating operation, the refrigerant discharged from the refrigerant compressor 15 driven by the vehicle driving electric motor 5 or another electric motor,
Circulate through the refrigeration cycle described above. That is, the compressed high-temperature refrigerant dissipates heat in the indoor heat exchanger 18 to warm the vehicle interior air, and its temperature decreases. The low-temperature refrigerant is heated by the waste heat of the motor 5 for driving the vehicle in the outdoor heat exchanger 13 and is cooled by the refrigerant compressor 15.
Returned to Accordingly, the amount of heat radiated from the indoor heat exchanger 18 is increased by the amount of heat absorbed by the outdoor heat exchanger 13, and the heating capacity is improved.

If waste heat is not introduced into the low-temperature outdoor heat exchanger 13, that is, if heat is absorbed from the outside air, if moisture in the outside air adheres and freezes on the wall of the outdoor heat exchanger 13, the outdoor heat exchanger
The heat-absorbing capacity of 13 is significantly reduced, and the heating operation cannot be continued.

However, according to the present invention, the waste heat of the vehicle drive motor 5 is constantly supplied to the outdoor heat exchanger 13 while the vehicle is running, so even when the outside air temperature reaches, for example, −10 ° C.
Heating operation is possible, and the heating operation area is greatly expanded.

In the cooling operation, the four-way switching valve 14 is switched to switch the pipe 21.
Is connected to the pipe 25 and the pipe 22 is connected to the pipe 26, the refrigerant compressed by the refrigerant compressor 15 radiates heat in the outdoor heat exchanger 13 to be cooled, and the refrigerant expanded in the decompressor 17 is cooled by the indoor heat exchanger. The heat is absorbed by 18 (takes heat from the cabin air) to reach a high temperature, and returns to the refrigerant compressor 15. During the cooling operation, the switching valve 7 is rotated 90 ° clockwise, and the waste heat of the vehicle drive motor 5 is discharged to the outlet 8 through the dove 6 and the switching valve 7, while fresh outside air is supplied from the inlet 9 to the switching valve 7. , And is introduced into the outdoor heat exchanger 13 through the duct 10.

The switching valve 7 switches between a position where the hot air that has cooled the vehicle drive motor 5 is guided from the duct 6 to the duct 10 and a position where fresh outside air is guided from the inlet 9 to the duct 10, and is configured by combining two shutters. May be. The blower 12 may be provided inside the duct 6 or the case 4.

[Effects of the Invention] As described above, the present invention provides a refrigerant compressor that is driven by a motor in a heating operation, passes through a four-way switching valve, an indoor heat exchanger, a decompressor, an outdoor heat exchanger, and a four-way switching valve. A refrigerant circuit is configured to return to the outdoor heat exchanger through a duct to guide the cooling air of the vehicle drive motor. Since the heating is performed by the waste heat of the vehicle drive motor, the heating capacity is increased, and the outdoor heat exchanger does not freeze even when the outside air temperature is below freezing, and the heating operation area is expanded.

Even if the power consumption of the electric motor driving the refrigerant compressor is the same, the cooling capacity is increased and a combustor is not used as a heat source, which is useful for preventing pollution.

The blower to guide the waste heat of the motor to the outdoor heat exchanger is
Since a blower for cooling the motor for driving the vehicle may be used, the cost can be reduced in this respect as well.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of an electric vehicle air conditioner according to the present invention. 5: motor, 6, 10: duct, 14: four-way switching valve, 13: outdoor heat exchanger, 15: refrigerant compressor, 17: decompressor, 18: indoor heat exchanger

Claims (1)

(57) [Claims] 1. A refrigerant circuit that returns from a refrigerant compressor driven by a motor in a heating operation to a refrigerant compressor via a four-way switching valve, an indoor heat exchanger, a decompressor, an outdoor heat exchanger, and a four-way switching valve, An air conditioner for an electric vehicle, wherein cooling air of a motor for driving a vehicle is guided to an outdoor heat exchanger by a duct.