JP3253501B2 - Cooling and heating system for electric vehicles - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cooling and heating apparatus for an electric vehicle which can appropriately maintain the amount of refrigerant in a cooling and heating cycle when an operation mode is switched, and more particularly to a method for heating refrigerant accumulated in a condenser outside a vehicle compartment during a heating operation. The present invention relates to a cooling and heating device for an electric vehicle that can be returned to a cycle.

[0002]

2. Description of the Related Art An electric vehicle whose driving source is an electric motor has less heat energy as a heating heat source than an engine vehicle that can use high-temperature engine cooling water. For this reason, as a cooling and heating device that can be used for electric vehicles, an air conditioning system has been developed that enables dehumidifying heating by heating and cooling the interior of the vehicle while preventing fogging of windows by performing a cycle operation using a refrigerant for both cooling and heating. (See, for example, Japanese Patent Application Laid-Open No. 5-201243).

As shown in FIG. 7, this type of air conditioner has a duct 2 for sending air taken in by a blower device 1 toward a vehicle interior. An evaporator 3 and a vehicle interior condenser 4 mainly working during a heating operation are arranged in this order from the side.
Outside the duct 2, a vehicle exterior condenser 5 mainly working during cooling operation is arranged.

[0004] The cooling cycle is configured by connecting a compressor 6, a condenser 5 outside a vehicle compartment, a condenser 4 inside a vehicle, a liquid tank 7, an expansion valve 8 and an evaporator 3 by piping, and sealing a refrigerant therein. Further, a three-way valve 9 for switching the flow of the refrigerant is provided at the inlet of the outside condenser 5 in order to switch the condensers 4 and 5 which function during the heating operation and the cooling operation. 5 is connected.

[0005] A condenser fan device 12 for supplying air for heat exchange to the vehicle exterior condenser 5 is provided on the rear side of the vehicle exterior condenser 5. Also,
An air mix door 13 is rotatably mounted upstream of the vehicle interior condenser 4 to adjust the temperature of the air blown into the vehicle interior.

[0006] During the cooling operation, the three-way valve 9 guides the refrigerant to the outside condenser 5 side, and the compressor 6, the outside condenser 5, the inside condenser 4, the liquid tank 7, the expansion valve 8, and the evaporator 3 in this order. Flow. Thus, in the evaporator 3, heat exchange between the liquid refrigerant and the intake air is performed, and the intake air passing around the refrigerant passage is cooled while the liquid refrigerant evaporates, so that the vehicle interior is cooled. Further, in the exterior condenser 5, the heat taken by the evaporator 3 is released to the outside by heat exchange with the outside air to cool the gaseous refrigerant and condense and liquefy it.
At this time, the vehicle interior condenser 4 hardly functions as a heat exchanger.

On the other hand, in the heating operation, the three-way valve 9 allows the refrigerant to bypass the condenser 5 outside the vehicle compartment. That is, the compressor 6, the vehicle interior condenser 4,
The refrigerant flows in the order of liquid tank 7, expansion valve 8, and evaporator 3. Thereby, the gaseous refrigerant discharged from the compressor 6 and bypassing the exterior condenser 5 by the three-way valve 9 is condensed and liquefied by the interior condenser 3 to radiate heat, and the air cooled by the evaporator 3 is heated and heated. And the vehicle interior is heated. that time,
Since the evaporator 3 cools the air to perform dehumidification, eventually, dehumidification heating is realized. At this time, the temperature of the air blown into the vehicle interior is adjusted by adjusting the opening of the air mix door 13 disposed upstream of the vehicle interior condenser 4.

The switching between the cooling operation mode and the heating operation mode is controlled by the set temperature. For example, when the set temperature is 24 ° C. or less, the cooling operation mode is set, and when the set temperature is 26 ° C. or more, the heating operation mode is set. Has been stopped.

[0009]

In such a cooling and heating apparatus for an electric vehicle, since the refrigerant circuit length is different between the cooling operation mode and the heating operation mode as described above, the respective appropriate refrigerant amounts are also different. That is, the appropriate refrigerant amount in the heating operation mode is smaller than that in the cooling operation mode. Therefore, it is important to manage an appropriate amount of refrigerant in each of the cooling operation mode and the heating operation mode in order to exert the capability of the system.

However, the compressor 6 is not used when parking.
Is stopped, the cooling cycle described above does not function, and the refrigerant in the cycle may move under the influence of cycle balance, vehicle conditions, outside air conditions, and the like.

For example, since the refrigerant has the property of moving to a lower temperature, the temperature in the engine room becomes too low due to the temperature difference between day and night, and the refrigerant flows out of the vehicle interior condenser 4 to the vehicle exterior condenser 5 and flows out. Outside condenser 5
May accumulate excess refrigerant. If the heating operation is performed in this state, the amount of the circulating refrigerant is insufficient because the cycle bypasses the exterior condenser 5, and there is a possibility that the heating performance is reduced or the lubricity is reduced. Although the refrigerant stays in the bypass pipe even during the cooling operation, the same problem is caused. However, the condenser 5 outside the vehicle compartment is particularly remarkable when performing the heating operation due to its large storage capacity.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the related art, and has been made in consideration of a cooling cycle during a cooling operation.
And to provide an electric vehicle air conditioner capable of optimizing the refrigerant quantity in the refrigerant amount and the heating cycle during the heating operation of the inner.

[0013]

In order to achieve the above object, a cooling and heating device for an electric vehicle according to the present invention comprises a compressor, a condenser outside a vehicle, a condenser inside a vehicle, an expansion valve, and an evaporator connected in this order by refrigerant piping. ,
Downstream of the refrigerant pipe of the compressor in order to switch the bypass pipe refrigerant discharged from the pre-Symbol compressor is guided to the passenger compartment capacitor bypassing said vehicle exterior condenser, the flow path of the refrigerant discharged from the pre-Symbol compressor and a refrigerant flow switching means provided, refrigerant discharged from the pre-Symbol compressor, during cooling operation is introduced into the vehicle outside the capacitor by said refrigerant flow path switching means, during heating operation the refrigerant flow switching A cooling / heating device for an electric vehicle, which is directly introduced into the vehicle interior condenser through the bypass pipe by means , provided in the bypass pipe.
The check valve, the exterior capacitor, and the interior
The bypass pipe is connected to the refrigerant pipe connecting to the capacitor.
Is provided closer to the outside condenser than the position
Through the check valve and the refrigerant flow switching means during the cooling operation.
To communicate with the bypass pipe and stay in the bypass pipe.
Returned to the suction side of the compressor, and during the heating operation, the refrigerant outside the vehicle compartment through the refrigerant flow switching means.
A refrigerant collection pipe that communicates with the condenser and returns the refrigerant accumulated in the external condenser to the suction side of the compressor; and a pilot differential pressure actuated electromagnetic valve provided in the refrigerant collection pipe in a positive direction with respect to the flow direction of the refrigerant. And a valve. Further, the pilot differential pressure actuated solenoid valve,
After a predetermined time has elapsed since the start of heating operation,
Be moved.

In the cooling / heating device for an electric vehicle according to the present invention, during the cooling operation, the refrigerant discharged from the compressor is introduced into the exterior condenser by operating the refrigerant flow switching means. In other words, a cooling cycle consisting of the compressor → the exterior condenser → the interior condenser → the expansion valve → the evaporator → the compressor is formed. This allows
In the evaporator, heat exchange between the liquid refrigerant and the intake air is performed, the intake air passing around the refrigerant passage is cooled while the liquid refrigerant evaporates, and the vehicle interior is cooled. Also, in the condenser outside the vehicle, the heat taken by the evaporator is released outside by heat exchange with the outside air,
The gaseous refrigerant is cooled and condensed and liquefied. At this time, the cabin condenser hardly functions as a heat exchanger.

On the other hand, during the heating operation, the refrigerant discharged from the compressor is bypassed through the exterior condenser by operating the refrigerant flow switching means, and is directly introduced into the interior condenser. In other words, a heating cycle consisting of a compressor → a bypass pipe → a vehicle interior condenser → an expansion valve → an evaporator → a compressor is formed without using a condenser outside the vehicle compartment. As a result, the gaseous refrigerant discharged from the compressor and bypassing the exterior condenser by the refrigerant flow switching means is condensed and liquefied by the interior condenser to release heat, and the air cooled by the evaporator is heated and blown into the interior of the vehicle. As a result, the vehicle interior is heated.
At that time, the evaporator cools the air to perform dehumidification, so that dehumidification heating is realized.

In a conventional air conditioner for an electric vehicle, a heating cycle is performed in which the condenser outside the vehicle compartment is bypassed during the heating operation. Therefore, there is a possibility that the amount of refrigerant circulating in the heating cycle becomes insufficient due to the refrigerant remaining in the condenser outside the vehicle compartment. However, in the cooling and heating device for an electric vehicle according to the present invention, the refrigerant accumulated in the bypass pipe is cooled by the refrigerant recovery pipe.
Return to the suction side of the presser for cooling in the cooling cycle.
The amount of the medium can be appropriately maintained , and the amount of the refrigerant in the heating cycle can be appropriately maintained by returning the refrigerant remaining in the condenser outside the vehicle compartment to the suction side of the compressor by the refrigerant recovery pipe.

Further, when the refrigerant recovery from the bypass pipe or the condenser outside the vehicle compartment is completed, it is necessary to shut off the refrigerant recovery pipe. In the air conditioner for an electric vehicle according to the present invention, a pilot differential pressure actuation type having such a function is required. Since the solenoid valve is provided in the refrigerant recovery pipe, cost increase can be minimized. The pilot differential pressure actuated solenoid valve is a valve that can control only one-way refrigerant, but in the electric vehicle cooling / heating device of the present invention, the refrigerant flowing through the refrigerant recovery pipe is always one-way, and the pilot differential pressure Since the actuated solenoid valve is provided in the forward direction with respect to the flow direction of the refrigerant, appropriate control can be performed.

[0018]

Embodiments of the present invention will be described below with reference to the drawings.

FIGS. 1 and 2 are block diagrams showing a cooling and heating device for an electric vehicle according to an embodiment of the present invention.
2 shows a cooling operation, and FIG. 2 shows a heating operation. FIG. 3 is a sectional view showing a pilot differential pressure operated solenoid valve according to the embodiment of the present invention, and FIG. 4 is a sectional view showing a four-way valve according to the embodiment of the present invention.

As shown in FIGS. 1 and 2, the electric vehicle cooling and heating apparatus according to the present embodiment has a duct 2 for sending air taken in by a blower apparatus 1 toward the interior of a vehicle. In the duct 2, an evaporator 3 and a vehicle interior condenser 4 mainly working during the heating operation are arranged in the duct 2 in order from the upstream side, and outside the duct 2, a vehicle exterior condenser 5 mainly working during the cooling operation is provided. It is arranged.
At one end of the duct 2, an intake door 16 for selectively taking in outside air or inside air is provided, and at the other end of the duct 2, a differential air outlet 17 for blowing conditioned air to the inner surface of the windshield, an upper body of the occupant A vent outlet 18 for blowing conditioned air and a foot outlet 19 for blowing warm air to the feet of the occupant are provided. Each of the outlets is provided with a differential door 17D, a vent door 18D, and a foot door 19D for opening and closing the outlet. ing.

This electric vehicle cooling / heating device performs cooling and heating in a vehicle compartment by performing cycle operation using a refrigerant for cooling and heating, similarly to the conventional device shown in FIG. Has the same refrigeration cycle as.

That is, the refrigeration cycle of this apparatus includes a compressor 6, a main condenser 5 as an exterior condenser, a sub-condenser 4 as an interior condenser,
The liquid tank 7, the expansion valve 8, and the evaporator 3 are connected by a refrigerant pipe 11, and a refrigerant is sealed therein. Further, in order to switch the condensers 4 and 5 which function between the heating operation and the cooling operation, a main condenser 5 is provided.
A four-way valve 90 for switching the refrigerant flow
(For example, a pilot differential pressure actuated solenoid valve) is provided as refrigerant flow switching means, and a bypass pipe 10 for bypassing the main condenser 5 is connected to the four-way valve 90.
Further, the bypass pipe 10 is connected to a pipe 11 connecting an outlet of the main condenser 5 and an inlet of the sub-condenser 4.

As shown in FIGS. 4A and 4B, a four-way valve 90 for switching the flow path of the refrigerant discharged from the compressor 6 includes a closed cylinder 91 and a left and right inside of the cylinder 91 in the figure. Piston 92 slidably provided on
And a control valve 93 for sending control air for moving the piston to the left and right. The cylinder 91 has three refrigerant ports 94, 95, 96 on the upper side in the figure and one refrigerant port on the lower side in the figure. 97 are formed. The piston 92 has a space 9 for communicating only two adjacent refrigerant ports.
8 are formed, and the refrigerant ports other than the two refrigerant ports connected in the space 98 are connected in the piston 92. That is, during the cooling operation shown in FIG. 4A, the piston 92 moves to the right in the drawing, so that the refrigerant inlets and outlets 95 and 96 communicate with each other.
4,97 communicate. In the heating operation shown in FIG. 4B, the pistons 92 move to the left in the drawing, so that the refrigerant ports 94 and 95 communicate with each other.
7 communicates.

On the back of the main condenser 5, a condenser fan unit 12 is provided as a blower for sending air to the condenser 5.

Although not shown in this cycle,
A high-pressure cut switch for turning off the compressor 6 and the like are provided to protect the cycle when the pressure or temperature of the refrigerant discharged from the compressor 6 increases.
In some cases, both or one of the liquid tank 7 and the accumulator may be omitted to simplify the configuration.

In the air conditioner for an electric vehicle according to the present embodiment, refrigerant is collected between the four-way valve 90 and the upstream side of the compressor 6 in order to return the refrigerant retained in the main condenser 5 to the suction side of the compressor 6. A pipe 50 is provided, and a pilot differential pressure operated solenoid valve 60 is attached to the refrigerant recovery pipe 50. Since the pilot differential pressure actuated solenoid valve 60 is a valve that can control only the refrigerant flowing in one direction, it is mounted in the forward direction with respect to the flow of the recovered refrigerant indicated by the dotted arrow in FIGS. Have been.

This pilot differential pressure actuated solenoid valve 60 is
As shown in FIGS. 3A and 3B, a main port 61 to which a refrigerant pipe is connected, a diaphragm valve 62 that opens and closes the main port 61, and a back surface of the diaphragm valve 62 and a downstream side of the main port 61. Pilot port 63 to be connected
And a pilot valve 64 that opens and closes the pilot port 63. As shown in FIG. 3B, when the plunger 66 is raised against the force of the spring 67a by turning on the electromagnetic coil 65, the pilot valve 64 is closed by the force of the spring 67b. Further, as shown in FIG. 3A, when the electromagnetic coil 65 is de-energized, the plunger 66 is pushed down by the force of the spring 67a, and the pilot valve 64 is opened against the force of the spring 67b. .

Since the diaphragm valve 62 is provided with a through hole 68, when the refrigerant is recovered, the plunger 66 is lowered by turning off the electromagnetic coil 65 as shown in FIG. Open 64. Thereby, the refrigerant that has passed through the diaphragm valve 62 from the main port 61 through the through hole 68 reaches the downstream side of the main port 61 through the pilot port 63, so that the pressure on the back side of the diaphragm valve 62 decreases. As a result, a pressure difference is generated between the front surface and the rear surface of the diaphragm valve 62, so that the diaphragm valve 62 maintains the open state.

On the other hand, when the collection of the refrigerant is completed,
Since it is necessary to shut off the refrigerant recovery pipe 50, the electromagnetic coil 65 is turned on. Thus, as shown in FIG. 3B, the plunger 66 is raised and the pilot valve 64 is closed, so that the pressure on the back surface of the diaphragm valve 62 is increased, and the diaphragm valve 62 is pushed down. as a result,
The diaphragm valve 62 will maintain the closed state.

The pilot differential pressure actuated solenoid valve 6
0 can be attached to the inlet side of the main condenser 5 as shown in FIGS. However, if the cooling / heating cycle is configured as shown in FIGS. 5 and 6, the direction of the refrigerant flowing through the pilot differential pressure actuated solenoid valve 60 during the cooling operation shown in FIG. 5 and the refrigerant recovery (and heating) shown in FIG. At this time, the directions of the refrigerant flowing through the pilot differential pressure actuated solenoid valve 60 are opposite to each other, and in consideration of the above-described operation method of the solenoid valve 60, the operation of the solenoid valve 60 during refrigerant recovery becomes unstable, There is a problem that the refrigerant cannot be sufficiently recovered. In addition, if the solenoid valve is a direct-acting, two-flow control type, it is possible to sufficiently recover the refrigerant even if the solenoid valve is mounted on the inlet side of the main condenser 5, but the cost of the solenoid valve itself increases and power consumption is reduced. Because of the increase, it is not realistic to mount it on an electric vehicle.

The above is the configuration and operation of the four-way valve 90 and the pilot differential pressure actuated solenoid valve 60, all of which are controlled by the controller 80.

That is, during the cooling operation, the four-way valve 90 is switched to the state shown in FIG. 4A, and the refrigerant discharged from the compressor 6 is supplied to the main condenser 5 as shown in FIG.
A cooling cycle is formed in which the refrigerant is guided to the compressor 6 → the main condenser 5 → the sub condenser 4 → the liquid tank 7 → the expansion valve 8 → the evaporator 3 → the compressor 6. In this process, the evaporator 3 evaporates the liquid refrigerant by heat exchange and cools the intake air passing around the refrigerant passage, thereby cooling the vehicle interior. The main condenser 5 discharges the heat taken by the evaporator 3 to the outside by exchanging heat with air to cool the gaseous refrigerant and condense and liquefy it. At this time, the sub capacitor 4
Hardly functions as a heat exchanger.

On the other hand, during the heating operation, the four-way valve 90
(B), the refrigerant discharged from the compressor 6 is guided directly to the sub-condenser 4 via the bypass pipe 10 as shown in FIG. 2, and the compressor 6 → the sub-condenser 4 → the liquid tank 7 → the expansion valve 8 A heating cycle for circulating from the evaporator 3 to the compressor 6 is formed. In this process, the gaseous refrigerant discharged from the compressor 6 and bypassed the main condenser 5 by the four-way valve 90 is condensed and liquefied by the sub condenser 4 and radiates heat. As a result, the air cooled by the evaporator 3 is heated and blown out into the vehicle interior, thereby heating the vehicle interior. At that time, the evaporator 3 cools the air to perform the dehumidification, so that the dehumidification heating is realized. At this time, the temperature of the air blown into the vehicle interior is adjusted by adjusting the opening of the air mix door 13 disposed upstream of the sub-condenser 4.

The switching between the cooling operation mode and the heating operation mode can be controlled by the set temperature. For example, when the set temperature is 24 ° C. or less, the cooling operation mode is set, and when the set temperature is 26 ° C. or more, the heating operation mode is set. Stop.

Although not shown, the compressor 6 is driven by an electric motor which is different from a drive source of the electric vehicle. That is, the compressor 6 of the electric vehicle is driven by driving the electric motor with a battery (not shown).

When a large amount of refrigerant stays in the main condenser 5 due to a temperature difference between day and night, if the heating operation is performed as it is, the amount of refrigerant flowing through the heating cycle becomes insufficient, and the desired heating performance cannot be exhibited. And the lubricity is reduced. Therefore, in the present embodiment, the refrigerant that has accumulated in the main condenser 5 is recovered into the heating cycle before performing the heating operation.

That is, the pilot differential pressure actuated solenoid valve 6
At 0, the plunger 66 is lowered by turning off the electromagnetic coil 65 and the pilot valve 64 is opened.
As a result, the refrigerant that has passed through the diaphragm valve 62 from the main port 61 through the through hole 68 is
3, the pressure on the back side of the diaphragm valve 62 decreases. as a result,
Since a pressure difference is generated between the front surface and the rear surface of the diaphragm valve 62, the diaphragm valve 62 maintains the open state. Therefore, the refrigerant retained in the main condenser 5 is guided to the suction side of the compressor 6 via the refrigerant recovery pipe 50,
It will be taken into the heating cycle.

Such a refrigerant recovery time can be appropriately selected. For example, it is about 90 seconds after the heating operation is started, and after the lapse of time, the electromagnetic coil 65 is energized and the pilot valve 64 is closed. To continue the heating operation. After the refrigerant recovery is completed, the solenoid valve 60 is closed to stabilize the cycle balance.
Since 0 is provided in the normal flow direction with respect to the flow direction of the refrigerant, the valve closing operation can be smoothly performed.

As described above, in the present embodiment, when switching between cooling and heating, the refrigerant that has accumulated in the main condenser 5 can be recovered. Can be prevented.
In addition, the difference in the amount of refrigerant flowing in the cycle during cooling and heating is reduced, and the amount of charged refrigerant can be easily managed.

[0040]

As described above, according to the present invention, cooling is provided.
Refrigerant accumulated in the bypass pipe by the refrigerant recovery pipe during operation
Cooling cycle by returning air to the suction side of the compressor.
The amount of refrigerant in the heating cycle can be appropriately maintained, and the refrigerant remaining in the condenser outside the vehicle compartment is returned to the suction side of the compressor by the refrigerant recovery pipe during the heating operation, whereby the amount of refrigerant in the heating cycle can be appropriately maintained. At this time, the bypass pipe
Becomes Upon completion of the refrigerant recovery from al refrigerant recovery and exterior capacitor is necessary to shut off the refrigerant recovery pipe, an electric automobile air conditioner of the present invention, the pilot differential pressure operated solenoid valve which controls such functions Since it is provided in the refrigerant recovery pipe, it is possible to minimize cost increase. Also, the pilot differential pressure actuated solenoid valve is a valve that can control only one-way refrigerant, but in the electric vehicle cooling / heating device of the present invention, the refrigerant flowing through the refrigerant recovery pipe is always one-way, Since the differential pressure operated solenoid valve is provided in the positive direction with respect to the flow direction of the refrigerant, appropriate control can be performed. Further, according to the invention described in claim 2,
If the condenser outside the vehicle compartment has a large capacity, it can be heated
Can be solved.

[Brief description of the drawings]

FIG. 1 is a configuration diagram (at the time of cooling operation) showing a cooling and heating device for an electric vehicle according to an embodiment of the present invention.

FIG. 2 is a configuration diagram (at the time of a heating operation) showing a cooling and heating device for an electric vehicle according to an embodiment of the present invention.

FIG. 3 is a sectional view showing a pilot differential pressure operated solenoid valve according to the embodiment of the present invention.

FIG. 4 is a sectional view showing a four-way valve according to the embodiment of the present invention.

FIG. 5 is a configuration diagram (at the time of cooling operation) showing a cooling and heating device for an electric vehicle, which is a comparative example of the present invention.

FIG. 6 is a configuration diagram (at the time of heating operation) showing a cooling and heating device for an electric vehicle, which is a comparative example of the present invention.

FIG. 7 is a configuration diagram showing a conventional air conditioner for an electric vehicle.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 3 ... Evaporator 4 ... Sub-condenser (in-cabin condenser) 5 ... Main condenser (outside-cabin condenser) 6 ... Compressor 8 ... Expansion valve 11 ... Refrigerant piping 10 ... Bypass pipe 14, 15 ... Check valve 50 ... Refrigerant recovery pipe 60 ... Pilot differential pressure actuated solenoid valve 90 ... 4-way valve (refrigerant flow path switching means )

Continuation of front page (56) References JP-A-6-278451 (JP, A) JP-A-4-262181 (JP, A) JP-A-7-108817 (JP, A) JP-A-5-201243 (JP) JP-A-7-285317 (JP, A) JP-A-8-40060 (JP, A) JP-A-5-8153 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB Name) B60H 1/32 624 B60H 1/32 102 F25B 41/04

Claims (2)

(57) [Claims] 1. A compressor (6), a condenser outside the vehicle compartment
(5), cabin condenser (4), the expansion valve (8) and the evaporator (3) is connected in this order by the refrigerant pipe (11), before Symbol refrigerant discharged from the compressor (6) is the vehicle exterior condenser (5) a bypass pipe which is guided into the passenger compartment capacitor bypassing (4) and (10), the compressor in order to switch the front Symbol flow path of the refrigerant discharged from the compressor (6) downstream of the (6) and a refrigerant flow switching means (90) provided in the refrigerant pipe, the vehicle exterior condenser refrigerant discharged from the pre-Symbol compressor (6) is, by the refrigerant flow switching means at the time of cooling operation (90) ( is introduced into 5), during heating operation in an electric vehicle air conditioner to be introduced directly into the passenger compartment condenser (4) through the bypass pipe (10) by the refrigerant flow switching means (90), the bypass tube a check valve (15) provided in the (10), the vehicle exterior condenser (5) before The passenger compartment capacitor and (4)
The bypass pipe (10) of the refrigerant pipe (11) connecting
Closer to the outside capacitor (5) than the position where it is connected
The check valve provided (14), during the cooling operation, via the refrigerant flow switching means (90)
Communicates with the bypass pipe (10) and stays in the bypass pipe (10).
Returning the refrigerant to the suction side of the compressor (6) and during the heating operation, the refrigerant through the refrigerant flow switching means (90).
Communicates with the external condenser (5) to connect the external condenser
(5) a refrigerant recovery pipe (50) for returning the refrigerant accumulated in the compressor (6) to the suction side of the compressor (6), and a pilot differential pressure provided in the refrigerant recovery pipe (50) in a positive direction with respect to the refrigerant flow direction. An air conditioner for an electric vehicle, comprising: an actuated solenoid valve (60). 2. The pilot differential pressure actuated solenoid valve (60).
Is open to closed after a predetermined time has elapsed since the start of heating operation.
2. The cooling and heating system for an electric vehicle according to claim 1, wherein
apparatus.