JPH1044758A - Heat pump-type air conditioner for automobile - Google Patents

Abstract

PROBLEM TO BE SOLVED: To compensate the shortage of heating performance at the heating, by a compressor using a refrigerant of high temperature and high pressure. SOLUTION: A refrigerant expanding member 5 used in an ordinary cooling cycle, and an internal heat exchanger E are connected by the order of the first flow adjusting valve 5a, an auxiliary internal heat exchanger Ea, the second flow adjusting valve 5b, and a main internal heat exchanger Eb, the operation of the various configurations can be performed by adjusting the opening the flow adjusting valve 5, and the air heating is compensated by the auxiliary internal heat ecxhanger in which the refrigerant of high temperature and high pressure flows, to remarkably improve the heating performance.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat pump type air conditioner for a vehicle, in which the interior of a vehicle is cooled and heated using engine cooling water and a refrigerant.

[0002]

2. Description of the Related Art Generally, in a cooling cycle of an air conditioner for a vehicle, a refrigerant discharged from a compressor is provided with an external heat exchanger (functioning as a condenser during cooling), a refrigerant expansion member and an internal heat exchanger (evaporator during cooling). It is well known that the compressor is fed back to the compressor.

As shown in FIG. 7, for example, as shown in FIG. 7, a vehicle air conditioner incorporating such a cooling cycle is provided with a vehicle interior air (inside air) and a vehicle interior air from an intake unit 11 provided at an end of a unit case 10. Outdoor air (outside air) is selectively introduced into the air passage 10f, and the air is conditioned and blown out toward the vehicle interior.

In this case, the engine 1 is located in the air passage 10f.
A heater core 13 into which engine cooling water (indicated by a broken line in the drawing) heated by the heater is introduced through a hot water cock 12;
The refrigerant discharged from the compressor 2 is supplied to the external heat exchanger 3,
An internal heat exchanger E that flows through the liquid tank 4 and the refrigerant expansion member 5, and a mix door 15 that adjusts a ratio at which air cooled by the internal heat exchanger E passes through the heater core 13 and the bypass passage 14. Is provided.

The cool air that has been cooled and dehumidified by the internal heat exchanger E is branched by the mix door 15 into the heater core 13 and the bypass passage 14, and the high-temperature air heated by the heater core 13 passes through the bypass passage. 1
After being mixed with the low-temperature air passing through the heater core 13 in the downstream area of the heater core 13 and reaching a predetermined temperature, the air distribution door 16 is moved forward from predetermined outlets (vent opening 17v, differential opening 17d, foot opening 17f) to the front of the passenger compartment. It is blown out toward. In the figure, reference numeral "F" indicates a fan, and "M" indicates a fan motor.

[0006]

However, when the air conditioner for a vehicle performs a heating operation, for example, when the outside air temperature is low, such as in the morning of winter, the temperature of the engine cooling water is low at the time of starting, and the comfort is low. Heater core 1 as a guide for
Heating up slowly until the temperature of the air blown from 3 becomes about 50 ° C. In addition, the temperature of the refrigerant itself is not agile, so that warm air is blown out at the same time as the operation starts,
There is a possibility that the so-called immediate heating property is insufficient, and the heating performance tends to be insufficient. In particular, when the engine is idling or under a low load, the temperature of the engine cooling water is as low as about 40 ° C. or less, and a sufficient cooling water temperature cannot be obtained, and there is a tendency that both the immediate warming property and the heating performance are insufficient.

[0007] The present invention has been made in view of such problems of the prior art, and compensates for insufficient heating performance during heating by using a refrigerant whose temperature and pressure are made high by a compressor, thereby improving immediate heating and heating performance. It is an object of the present invention to provide a heat pump type air conditioner for a vehicle which is designed to be enhanced.

[0008]

According to a first aspect of the present invention, there is provided a heat pump type air conditioner for a vehicle, which comprises: an external heat exchanger for supplying a refrigerant discharged from a compressor to an external heat exchanger; Having a cooling cycle to return to the compressor via an expansion member and an internal heat exchanger,
In a heat pump type air conditioner for a vehicle in which a heater core through which the internal heat exchanger and the engine cooling water circulate is disposed in an air passage of a unit case, the refrigerant expansion member and the internal heat exchanger are provided with a first flow rate adjusting device. A valve, an auxiliary internal heat exchanger, a second flow control valve, and a main internal heat exchanger are connected in series in this order, and the auxiliary internal heat exchanger and the main internal heat exchanger are opposed to each other in the air passage. The auxiliary internal heat exchanger and the main internal heat exchanger function as an evaporator or a condenser, respectively, by adjusting the opening of the first flow control valve and the second flow control valve. It is characterized by the following.

With this configuration, when heating is started, the air is heated not only by the heater core through which the engine cooling water flows but also by the auxiliary internal heat exchanger through which the high-temperature and high-pressure refrigerant flows, so that the heating performance is dramatically improved. be able to.

Further, by adjusting the opening degree of the first or second flow control valve, the auxiliary internal heat exchanger or the main internal heat exchanger can be used as a condenser or an evaporator with a simple circuit configuration. Thus, it is possible to prevent dehumidifying heating and excessive cooling, to create a so-called dry air conditioner, perform various operations, and further improve cooling performance.

The invention according to claim 2 is characterized in that a refrigerant expansion member is constituted by a first flow control valve and a second flow control valve which can selectively switch between an open state and a throttle state. .

With this configuration, the auxiliary internal heat exchanger or the main internal heat exchanger can be used as a condenser or an evaporator by the switching operation, so that the desired temperature control can be easily performed without switching the flow direction of the refrigerant. Becomes

According to a third aspect of the present invention, the first flow control valve is constituted by a switching valve capable of selectively switching between an open state and a throttle state, and the second flow control valve is provided with the main internal heat exchange. The opening degree is adjusted according to the temperature of the refrigerant flowing out of the vessel.

With this configuration, the first flow control valve capable of selecting the open state and the throttle state can be used in combination with the second flow control valve which is a temperature-type expansion valve. Can function as an evaporator, and when opened, it can function as a condenser, so when the auxiliary internal heat exchanger functions as an evaporator, dehumidifying heating can be easily performed, and even if heating by internal air circulation, the windshield Without fogging, safe driving is possible. In addition, since the opening of the temperature type expansion valve is controlled by the temperature of the refrigerant on the outlet side of the main internal heat exchanger, accurate refrigerant control is possible.

The invention according to claim 4 is characterized in that the refrigerant discharged from the compressor during heating flows through a bypass circuit that bypasses the external heat exchanger and is guided to the internal heat exchanger.

With this configuration, during the heating operation, the high-temperature refrigerant flows by bypassing the large-capacity external heat exchanger, so that it easily flows into the auxiliary internal heat exchanger, and the heating performance is improved.

According to a fifth aspect of the present invention, a sub heat exchanger is provided between the main internal heat exchanger and the compressor, and the refrigerant flowing out of the main internal heat exchanger in the sub heat exchanger is used as engine cooling water. Characterized in that it is configured to heat by a part of the.

With this configuration, the refrigerant flowing out of the main internal heat exchanger is heated by the heat of the engine cooling water in the sub heat exchanger, so that there is no danger that the liquid refrigerant returns to the compressor. This prevents damage due to liquid compression and protects the compressor. Further, at the time of heating, the refrigerant is heated using the heat of the engine cooling water, and heating is performed using the refrigerant whose entropy has changed, so that higher heating performance can be exhibited.

According to a sixth aspect of the present invention, there is provided a return circuit for recovering the refrigerant stored in the external heat exchanger to the compressor when heating is started.

In this way, a large amount of refrigerant can be returned to the compressor when heating is started, so that heating performance can be further improved.

[0021]

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

FIGS. 1 and 2 are schematic diagrams showing a heat pump type air conditioner for a vehicle according to a first embodiment of the present invention. FIG. 1 shows a state during a heating operation, and FIG. 2 shows a state during a cooling operation. FIG. 3 is an explanatory diagram showing operating characteristics of a flow control valve capable of selectively switching between an open state and a throttle state, and FIG. 4 is an operation diagram of the automotive air conditioner and the operation of the flow control valve. Explanatory diagrams showing the operation, FIGS.
FIG. 5 is a schematic configuration diagram illustrating Embodiment 2, FIG. 5 illustrates a state during a heating operation, and FIG. 6 illustrates a state during a cooling operation. Note that members common to those in FIG. 7 are denoted by the same reference numerals and description thereof is partially omitted. In the drawing, white arrows indicate the flow of air, solid arrows indicate the flow of refrigerant, and broken arrows indicate the flow of engine cooling water.

(Embodiment 1) A heat pump type air conditioner for a vehicle according to Embodiment 1 is configured as shown in FIG. 1. In general, the refrigerant discharged from the compressor 2 is: External heat exchanger 3, liquid tank 4,
This constitutes a cooling cycle in which the refrigerant is returned to the compressor 2 via the refrigerant expansion member 5 and the internal heat exchanger E.

On the high pressure side of the cooling cycle of the first embodiment, the bypass circuit B, the on-off valve V1 and the two on-off valves are provided so that the refrigerant discharged from the compressor 2 at the time of heating flows by bypassing the external heat exchanger 3. A check valve VC is provided.

On the other hand, on the low pressure side, the above-described refrigerant expansion member 5 and the internal heat exchanger E are provided in a pair. That is, the first flow control valve 5a which is opened and throttled, the auxiliary internal heat exchanger Ea, the second flow control valve 5b similar to the first flow control valve 5a, and the main internal heat exchanger E
They are connected in series in the order of b.

As shown in FIG. 3, the flow control valves 5a and 5b are opened (substantially fully open) and throttled by turning on a switch (not shown) for operating the auxiliary internal heat exchanger. (A state in which the refrigerant passage is slightly open rather than a completely closed state), which functions as a so-called solenoid valve.

As described above, in the first embodiment, since the refrigerant expansion member is configured to selectively switch between the open state and the throttle state, the auxiliary internal heat exchanger Ea or the main internal heat exchanger is operated by the switching operation. Since Eb can be used as a condenser or as an evaporator, there is also an advantage that desired temperature control can be easily performed without switching the flow direction of the refrigerant.

The above-described components are provided in the unit case 10.
In the air passage 10f, the main internal heat is supplied from the upstream side in the flow direction (indicated by a white arrow) of the air introduced from an intake unit 11 which is an air introduction unit having an intake door (not shown) and a blower motor M. The heat exchanger Eb, the auxiliary internal heat exchanger Ea, the air mix door 15, and the heater core 13 are arranged in this order. The auxiliary internal heat exchanger Ea and the main internal heat exchanger Eb are mutually connected in the air passage 10f. They are arranged close to each other.

The refrigerant flowing out of the main internal heat exchanger Eb passes through a sub heat exchanger 30 provided between the main internal heat exchanger Eb and the compressor 2 so that the compressor 2
Is to be returned to. The sub heat exchanger 30 is provided outside the air passage 10f of the unit case 10, and heats the refrigerant flowing inside by the heat of the engine cooling water introduced through the hot water cock 12, and removes the refrigerant having changed entropy. It is returned to the compressor 2 so as to exhibit higher heating performance.

Various air outlets 17 (for example, a differential air outlet 17d, a vent air outlet 17) through which conditioned air is blown out toward a predetermined portion in the vehicle compartment are provided at the outlet side of the air passage 10f.
v, foot outlet 17f).

Next, the operation of the first embodiment will be described. Heating operation When the outside air temperature is low at the start of the heating operation (for example,-
If the engine cooling water temperature is so low that it cannot be used for heating, such as immediately after engine start, when the engine is under low load, or when idling, the on-off valve V1 is closed (fully closed state). The switch for operating the auxiliary internal heat exchanger is turned on to open the first flow control valve 5a and throttle the second flow control valve 5b.

When the compressor 2 is operated in this state,
The high-temperature and high-pressure refrigerant discharged from the compressor 2 flows through the bypass circuit B, the liquid tank 4, and the first flow control valve 5a. The liquid tank 4 in this case is merely one container through which the refrigerant passes.

Therefore, the auxiliary internal heat exchanger Ea includes:
Since the refrigerant in the high-temperature and high-pressure state bypassing the large-capacity external heat exchanger 3 flows into the auxiliary internal heat exchanger Ea as it is, the air passing therethrough is heated, and the heating performance is improved. Here, the refrigerant is condensed to some extent.

Further, the refrigerant that has flowed down is the second restricted refrigerant.
Since the flow rate is restricted by the flow rate regulating valve 5b and is adiabatically expanded to become a low-temperature low-pressure refrigerant, the main internal heat exchanger Eb
The air passing through is dehumidified and cooled. Here, the refrigerant evaporates and becomes gaseous.

Therefore, the air sent from the intake unit 11 is cooled by the main internal heat exchanger Eb,
Immediately after that, it is heated by the auxiliary internal heat exchanger Ea. That is, the dehumidifying and heating operation is performed. Here, even when the engine cooling water cannot be used for heating due to its low temperature, the air is heated by flowing the refrigerant that becomes high-temperature and high-pressure in a relatively short time through the auxiliary internal heat exchanger, so that high heating performance is achieved. And instantaneous warming is also improved.

Since the refrigerant flowing down the main internal heat exchanger Eb is not always in a completely gaseous state, in the first embodiment, the refrigerant is heated by the engine cooling water in the sub heat exchanger 30 and completely cooled. The gas is returned to the compressor in the gasified state. Engine cooling water at the start of heating is
Although the temperature is too low to use for heating, it has enough capacity to evaporate a very low-temperature refrigerant, so when the sub-heat exchanger 30 exchanges heat between the refrigerant and the engine cooling water, The refrigerant gasifies almost completely, preventing liquid compression in the compressor and preventing damage to valves and the like.

Further, if the refrigerant is heated by the engine cooling water in the sub heat exchanger 30 as described above, the heat of the engine cooling water can be effectively taken into the refrigerant. When the compressor is pressurized again, the refrigerant discharged from the compressor becomes a higher-temperature refrigerant whose entropy has changed. When the air is heated again in the auxiliary internal heat exchanger Ea, the air can be converted to a considerably high-temperature air. Performance can be demonstrated.

The air heated in the auxiliary internal heat exchanger Ea flows down in the air passage 10f and reaches the heater core 13. Here, the heater core 1
In No. 3, engine cooling water whose temperature has increased to some extent due to the start of the engine 1 flows, but since the engine cooling water at this time has not yet sufficiently increased in temperature, it is not preferable to use it for heating.

Therefore, the hot water cock 12 is closed to prevent the engine cooling water from flowing into the heater core 13 or to prevent the air from passing through the heater core 13 by the air mixing door 15.

Thus, the air path 1 from the intake unit
The air introduced into f of No. 0 is dehumidified in the main internal heat exchanger Eb, becomes considerably high temperature air heated by the auxiliary internal heat exchanger Ea, and is blown into the vehicle interior.

In particular, since the auxiliary internal heat exchanger Ea heats the air dehumidified by the main internal heat exchanger Eb, the windshield does not become cloudy even when heated in a so-called internal air circulation mode, and the window is kept clear. Driving is possible and driving safety is enhanced.

When the outside air temperature is high (for example, from + 5 ° C. to +
When the engine is under high load operation, or the like, the engine cooling water becomes high enough to be used for heating. Therefore, it is not necessary to heat using a high-temperature refrigerant pressurized by a compressor. Therefore, in the first embodiment, for example, the clutch or the like connecting the engine and the compressor 2 is disengaged, the operation of the compressor 2 is stopped, and the heating operation is performed only by the heater core 13. With this configuration, unnecessary load is not applied to the engine, and the fuel-saving heating operation can be performed.

The cooling operation outside air temperature is, for example, when the order of + 15 ℃ ~ + 30 ℃, when performing cooling operation, opens the on-off valve V1,
The first flow control valve 5a is throttled, and the second flow control valve 5b is opened.

When the compressor 2 is operated in this state,
The discharged refrigerant enters the external heat exchanger 3 through the on-off valve V1, as shown in FIG. 2, and is cooled and condensed. The low-temperature and high-pressure refrigerant is stored in the liquid tank 4 to some extent, and then its flow rate is restricted by the throttled first flow control valve 5a, where it is adiabatically expanded to become a lower-temperature low-pressure refrigerant and becomes an auxiliary internal refrigerant. It flows into the heat exchanger Ea. Further, the refrigerant that has flowed down passes through the opened second flow control valve 5b and evaporates in the main internal heat exchanger Eb to become gaseous.

Therefore, the air sent from intake unit 11 is first cooled to some extent by main internal heat exchanger Eb, and then further cooled by auxiliary internal heat exchanger Ea immediately after that.

However, when the outside air temperature is about 15 ° C. to 20 ° C., there is a possibility that the occupants may experience excessive cooling.
The opening degree of the air mix door 15 on the front surface of the heater core 13 is adjusted, cold air is branched to the heater core 13 side and the bypass passage 14 side, and they are mixed again to reach a predetermined temperature and then blown into the vehicle interior.

When the outside air temperature is, for example, + 30 ° C. or higher, the on-off valve V1 is opened, and the first flow control valve 5a is throttled.
The second flow control valve 5b is also throttled.

In this way, the flow of the medium-temperature and high-pressure refrigerant flowing down from the liquid tank 4 is restricted by the first flow control valve 5a, where it is adiabatically expanded to become a lower-temperature low-pressure refrigerant and becomes an auxiliary internal refrigerant. The flow rate of the refrigerant flowing into the heat exchanger Ea and further flowing down is restricted by the throttled second flow rate control valve 5b, where it is adiabatically expanded to become a lower-temperature low-pressure refrigerant, and becomes a main internal heat exchanger Eb. to go into.

Therefore, the air sent from the intake unit 11 is first dehumidified and cooled by the main internal heat exchanger Eb, and further cooled by the auxiliary internal heat exchanger Ea disposed immediately thereafter. In other words, so-called multi-stage cooling is performed, and high cooling motive performance is exhibited.

(Embodiment 2) Embodiment 2 is different from Embodiment 1 in that a return circuit R is provided and that the configuration of the above-mentioned second flow rate regulating valve 5b is different. The other points are the same.

Normally, the refrigerant does not return to the compressor after the operation is stopped, but often stays in each component constituting the cooling cycle, and is not present in the compressor 2 much. If the compressor 2 is operated in this state and the heating operation is started, the operation cannot be performed using a large amount of refrigerant, and the deterioration of the heating performance cannot be denied. Therefore, at the start of operation, it is preferable to temporarily return the refrigerant lying inside the external heat exchanger 3 and the like to the compressor 2 once.

For this reason, in the second embodiment, a four-way valve 6 is provided between the compressor 2 and the external heat exchanger 3, and the external heat exchanger 3 is connected to the compressor 2 via the four-way valve 6. A circuit R is formed, and the refrigerant lying inside the external heat exchanger 3 and the like through the return circuit R is cooled by the compressor 2.
To be collected.

Here, the four-way valve 6 is provided with one inlet port Pi and three outlet ports Po in the closed case 7,
In the closed case 7, two of the three outlet ports Po are provided.
A slide member S communicating with the two outlet ports Po is provided, and an outlet port Po other than the outlet port Po selected by the slide member S is configured to communicate with the inlet port Pi. Therefore, the outlet port P communicated with the inlet port Pi depending on the position where the slide member S is set.
o will be selected.

Therefore, when the four-way valve 6 is set to the state shown in FIG. 5 at the start of the heating operation, the suction side of the compressor 2 and the external heat exchanger 3 are communicated via the return circuit R. The stagnation refrigerant in the external heat exchanger 3 is recovered by the compressor 2 due to the suction force of the compressor 2, and the amount of refrigerant discharged from the compressor 2 increases,
A decrease in heating performance is prevented.

In the second embodiment, the second flow control valve 5b is a temperature control type expansion valve. Since the temperature-controlled expansion valve belongs to the public domain, its description is omitted. However, the temperature of the outlet refrigerant of the main internal heat exchanger Eb is sensed by a temperature-sensitive cylinder (not shown), and the valve opening is adjusted with high accuracy. The refrigerant is caused to flow at a desired flow rate. That is, when the outlet refrigerant temperature of the main internal heat exchanger Eb decreases, the opening degree is reduced to restrict the flow rate, and when the refrigerant temperature increases, the opening degree is increased to allow a large amount of refrigerant to flow. The difference between the evaporation temperature of the refrigerant and the temperature of the refrigerant at the outlet of the main internal heat exchanger Eb is kept constant.

With this arrangement, the switching valve and the temperature type expansion valve, which can select the open state and the throttle state, are used together, so that the dehumidifying heating can be reliably performed as will be described later, and the heating by the internal air circulation. Even when driving, the windshield is not fogged, and driving safety is improved. Also,
Since the opening of the temperature type expansion valve is controlled by the temperature of the refrigerant on the outlet side of the main internal heat exchanger, accurate refrigerant control is possible.

Heating operation The heating operation when the outside air temperature is about -10 ° C. to + 5 ° C.
The four-way valve 6 is operated to collect the refrigerant, the first flow control valve 5a is opened, and the second flow control valve 5b is operated.

When the compressor 2 is operated in this state,
A large amount of high-temperature and high-pressure refrigerant is discharged from the compressor 2, and flows into the auxiliary internal heat exchanger Ea in the same manner as in the first embodiment. Further, the refrigerant flowing down passes through the second flow control valve 5b. Since this control valve 5b is of a temperature-sensitive type, the opening degree of the refrigerant is set to a predetermined value according to the outlet refrigerant temperature of the main internal heat exchanger Eb. Is adjusted to That is, since the temperature of the refrigerant at the outlet of the main internal heat exchanger Eb becomes low, the refrigerant is made to flow at a reduced opening degree to restrict the flow rate.

Therefore, the air sent from the intake unit 11 is first cooled only to some extent by the main internal heat exchanger Eb, and is heated by the auxiliary internal heat exchanger Ea disposed immediately after that. , And dehumidifying heating is performed.

When the outside air temperature is, for example, about + 5 ° C. to + 15 ° C., as in the first embodiment, the compressor does not operate, and the heating operation is performed only by the heater core 13.

Cooling operation When the outside air temperature is about + 15 ° C. to + 30 ° C., the cooling operation is performed. In the second embodiment, the refrigerant enters the external heat exchanger 3 directly through the four-way valve 6. In addition, the first flow control valve 5a is throttled, and the second flow control valve 5b is also adjusted in opening degree and operates to throttle. Note that this “throttle operation by adjusting the opening degree” is only described as “operation” in FIG. 4 for simplicity.

The refrigerant, which has been made low-temperature and high-pressure by the external heat exchanger 3, is stored in the liquid tank 4 to some extent,
The flow rate is restricted in the flow rate regulating valve 5a, where the flow rate is adiabatically expanded, becomes a low-temperature low-pressure refrigerant, and flows into the auxiliary internal heat exchanger Ea. Further, the flow rate of the flowing-down refrigerant is restricted by the second flow control valve 5b, and the refrigerant evaporates in the main internal heat exchanger Eb and becomes gaseous.

Therefore, the air sent from the intake unit 11 is first cooled to some extent by the main internal heat exchanger Eb, and further cooled by the auxiliary internal heat exchanger Ea disposed immediately after that.

In the second embodiment, even when the outside air temperature is equal to or higher than + 30 ° C., the cooling operation is basically the same as the cooling operation at + 15 ° C. to + 30 ° C.

The present invention is not limited to the above-described embodiment, but can be variously modified within the scope of the claims.

For example, in the first and second embodiments, the bypass circuit B for bypassing the external heat exchanger 3 is provided, but the air is heated by the auxiliary internal heat exchanger Ea through which the high-temperature and high-pressure refrigerant flows. If the heating can be performed, such a bypass circuit B is not necessarily required.

In the second embodiment, the four-way valve 6 and the return circuit R are provided to return the stagnation refrigerant to the compressor 2. However, in the present invention, the operation is performed without necessarily returning the stagnation refrigerant to the compressor 2. May go.

Further, in the first and second embodiments, the refrigerant is heated by using the sub heat exchanger 30, but if the sub heat exchanger 30 is provided, it is more preferable, but not necessary.

[0069]

As described above, the invention described in claim 1 is characterized in that at the time of heating start, not only the heater core through which the engine cooling water flows but also the auxiliary internal heat exchanger through which the high-temperature and high-pressure refrigerant flows. Since the air is heated, the heating performance can be dramatically improved.
By adjusting the opening of the flow control valve, the auxiliary internal heat exchanger or main internal heat exchanger can be used as a condenser or evaporator with a simple circuit configuration, thereby preventing dehumidifying heating and cooling. However, a so-called dry air conditioner can be created, various operations can be performed, and the cooling performance can be further improved.

According to the second aspect of the present invention, since the refrigerant expansion member is selectively switched between the open state and the throttle state, the switching operation causes the auxiliary internal heat exchanger or the main internal heat exchanger to be used as a condenser or a condenser. It can be used as an evaporator, and desired temperature control can be easily performed without switching the flow direction of the refrigerant.

According to the third aspect of the present invention, since the refrigerant expansion member is a combination of the selective switching valve and the temperature type expansion valve, dehumidifying and heating can be easily performed. The glass is not fogged, safe driving is possible, and accurate refrigerant control is also possible.

According to the fourth aspect of the present invention, since the refrigerant at the time of heating flows in the cooling cycle by bypassing the external heat exchanger, the heating performance is improved.

According to the fifth aspect of the invention, since the sub-heat exchanger is provided in the cooling cycle, the compressor is protected,
Also, high heating performance can be exhibited.

According to the sixth aspect of the present invention, since the cooling cycle is provided with the return circuit for collecting the sleeping refrigerant, the heating performance can be further improved.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing Embodiment 1 of the present invention.

FIG. 2 is a schematic configuration diagram showing a state during a cooling operation of the embodiment.

FIG. 3 is an explanatory diagram showing operating characteristics of a flow control valve.

FIG. 4 is an explanatory diagram showing the operation of a flow control valve.

FIG. 5 is a schematic configuration diagram showing Embodiment 2 of the present invention.

FIG. 6 is a schematic configuration diagram showing a state during a cooling operation of the embodiment.

FIG. 7 is a schematic configuration diagram of a conventional automotive air conditioner.

[Explanation of symbols]

 2 compressor, 3 external heat exchanger, 5 refrigerant expansion member, 5a first flow control valve, 5b second flow control valve, 10 unit case, 13 heater core, 30 sub heat exchanger, B ... bypass circuit, E: internal heat exchanger, Ea: auxiliary internal heat exchanger, Eb: main internal heat exchanger, R: return circuit.

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[Procedure amendment]

[Submission date] October 28, 1997

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0047

[Correction method] Deleted

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0048

[Correction method] Deleted

[Procedure amendment 3]

[Document name to be amended] Statement

[Correction target item name] 0049

[Correction method] Deleted

[Procedure amendment]

[Submission date] October 28, 1997

[Procedure amendment 4]

[Document name to be amended] Drawing

[Correction target item name] Fig. 4

[Correction method] Change

[Correction contents]

FIG. 4

Claims (6)

[Claims] 1. A cooling cycle in which refrigerant discharged from a compressor (2) is returned to the compressor (2) via an external heat exchanger (3), a refrigerant expansion member (5) and an internal heat exchanger (E). Wherein the internal heat exchanger (E) and the heater core (13) through which the engine cooling water flows are arranged in the air passage (10f) of the unit case (10). The refrigerant expansion member (5) and the internal heat exchanger (E) include a first flow control valve (5a), an auxiliary internal heat exchanger (Ea), and a second flow control valve.
(5b) and the main internal heat exchanger (Eb) are connected in series in this order, and the auxiliary internal heat exchanger (Ea) and the main internal heat exchanger (Eb) are connected in the air passage (10f). The auxiliary internal heat exchanger (Ea) and the main internal heat exchanger are controlled by adjusting the opening of the first flow control valve (5a) and the second flow control valve (5b). (Eb) each functioning as an evaporator or a condenser. 2. The refrigerant expansion member (5) comprises a first flow control valve (5a) and a second flow control valve (5b) that can selectively switch between an open state and a throttle state. The heat pump type air conditioner for a vehicle according to claim 1, wherein 3. The refrigerant expansion member (5) is constituted by a switching valve capable of selectively switching the first flow rate control valve (5a) between an open state and a throttle state, and the second flow rate control valve (5). The heat pump type automobile air according to claim 1, wherein 5b) is a thermal expansion valve whose opening is adjusted according to the temperature of the refrigerant flowing out of the main internal heat exchanger (Eb). Harmony equipment. 4. In the cooling cycle, the refrigerant discharged from the compressor (2) during heating is supplied to the external heat exchanger.
4. The air for a heat pump type vehicle according to claim 1, wherein the air is passed through a bypass circuit (B) for bypassing (3) and guided to the internal heat exchanger (E). Harmony equipment. 5. The cooling cycle includes a sub heat exchanger (30) between the main internal heat exchanger (Eb) and the compressor (2), and the sub heat exchanger (30) uses the sub heat exchanger (30). Internal heat exchanger (Eb)
The heat pump type air conditioner for a vehicle according to any one of claims 1 to 4, wherein the refrigerant that has flowed out is heated by a part of the engine cooling water. 6. The cooling cycle according to claim 1, further comprising a return circuit for recovering the refrigerant stored in the external heat exchanger at the time of starting heating. A heat pump type air conditioner for a vehicle according to any one of claims 1 to 5.