JP3436872B2 - Automotive air conditioners - Google Patents

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 automobile air conditioner capable of both cooling and heating the interior of a vehicle.

[0002]

2. Description of the Related Art A heat pump type air conditioner for an automobile basically has heat exchangers arranged indoors and outdoors.
During cooling, the refrigerant pipes are switched so that the indoor heat exchanger serves as an evaporator and the outdoor heat exchanger serves as a condenser, and during heating, the indoor side serves as a condenser and the outdoor side serves as an evaporator.

Further, since the dehumidifying mode cannot be realized only by the indoor heat exchanger and the outdoor heat exchanger, the sub-condenser is arranged in the vehicle compartment to perform dehumidification (Japanese Patent Laid-Open No. 9-29138). -79689 and JP-A-9-951
No. 23).

[0004]

However, in the conventional air conditioner for a vehicle as described above, both the indoor heat exchanger and the outdoor heat exchanger become evaporators or condensers during cooling and heating. Since both heat exchangers need to be constructed with the same strength as the condenser, which requires much higher pressure resistance than the evaporator, there is a disadvantage in that the cost of the device is very high.

Further, in the case where the sub-condenser is arranged in the vehicle compartment, it is possible to simply dehumidify, but it is not possible to dehumidify during heating or dehumidify in a weak cooling state. A wide dehumidifying function cannot be obtained.

Therefore, the present invention provides a heat pump type air conditioner for a vehicle, which can use the indoor heat exchanger only as an evaporator, can reduce the cost of the apparatus, and can obtain a wide range of dehumidifying functions. The purpose is to do.

[0007]

In order to achieve the above object, an automobile air conditioner according to the present invention has a refrigerant flow path switching valve disposed downstream of a compressor of a refrigeration cycle. In the air conditioning system for an automobile, the connection order of the indoor heat exchanger and the outdoor heat exchanger connected in series is switched in the middle of the pipeline that returns from the refrigerant flow path switching valve and returns again by switching , A sub-condenser disposed in the vehicle compartment is connected between the compressor and the refrigerant flow path switching valve, and the refrigerant flow path switching valve is provided upstream and downstream of the indoor heat exchanger. Is connected to a valve for acting as an expansion valve when it is switched to the upstream side of the indoor heat exchanger.

A sub-condenser heat exchange control means may be provided for controlling the flow rate of the air in the passenger compartment that exchanges heat with the refrigerant in the sub-condenser. Also, a bypass line that directly connects between the line connecting the indoor heat exchanger and the outdoor heat exchanger and the line extending from the refrigerant flow switching valve to the compressor inlet, and An on-off valve for opening and closing the bypass line may be provided.

In this case, an openable / closable valve for closing the conduit connecting the indoor heat exchanger and the outdoor heat exchanger is provided from the connection portion with the bypass conduit to the outdoor heat exchanger. It is recommended that it be provided at a position closer to it.

Then, in the middle of the pipeline from the refrigerant flow path switching valve to the compressor inlet and upstream of the connection with the bypass pipeline, the direction from the refrigerant flow path switching valve to the compressor inlet It is preferable that a check valve that allows the refrigerant to pass therethrough be inserted.

Further, the valve acting as the expansion valve may be a control valve capable of controlling the opening degree, and the valve acting as the expansion valve may be a refrigerant only in the direction in which it goes out of the indoor heat exchanger. It is also possible to connect a check valve capable of passing through and a throttle whose pipe diameter is narrowed in parallel to each other. In that case, the throttle diameter may be variable according to the differential pressure across the refrigerant passing therethrough, and the like.

Further, an accumulator is connected to the upstream side of the compressor of the refrigeration cycle, and heat for exchanging heat between the heat emitted from the energy source of the vehicle equipped with the refrigeration cycle and the refrigerant. The exchanger may be built in the accumulator.

Alternatively, an accumulator is connected to the upstream side of the compressor of the refrigeration cycle, and heat for exchanging heat between the refrigerant and the heat emitted from the energy source of the automobile in which the refrigeration cycle is mounted. The exchanger may be connected to a pipeline on the upstream side of the accumulator, and an openable and closable bypass pipeline for bypassing the heat exchanger may be provided.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described with reference to the drawings. 1 to 3 show a heat pump type air conditioner for a vehicle according to a first embodiment of the present invention. FIG. 1 is a heating / dehumidifying mode during severe cold, FIG. 2 is a cooling / dehumidifying mode, and FIG. The heating / dehumidifying mode is shown.

Reference numeral 1 is a compressor for compressing a refrigerant in a refrigeration cycle. The sub-condenser 2 is first inserted and connected to the downstream side refrigerant pipe line connected to the refrigerant outlet of the compressor 1. This sub-condenser 2 is arranged in an air duct that communicates with the vehicle interior.

A four-way switching valve 3 is connected downstream of the sub-condenser 2. This four-way switching valve 3 has connection ports A, B, C and D to which four pipelines are connected, a first state in which A and D are connected and B and C are connected, and A and B are Connected C
And the second state in which D is connected in one operation, and the refrigerant pipeline coming from the refrigerant outlet of the sub-condenser 2 is A
It is connected to the connection port of.

The B connection port and the D connection port are connected by a pipe in which various members are inserted and connected in the middle.
The connection port of C is connected to the inlet of the accumulator 4 for storing the low-pressure refrigerant, and the outlet of the accumulator 4 is connected to the inlet of the compressor 1.

In the middle of the refrigerant pipe connecting the connection port of B and the connection port of D, an outdoor heat exchanger 5 placed outside the vehicle compartment and an indoor heat exchanger placed in an air duct communicating with the vehicle interior. 6 and 6 are connected in series.

The outdoor heat exchanger 5 is connected to the D connection port side of the four-way switching valve 3, and the indoor heat exchanger 6 is connected to the B connection port side to switch the four-way switching valve 3. As a result, the connection order of the outdoor heat exchanger 5 and the indoor heat exchanger 6 with respect to the connection ports of A and D is switched to the opposite.

A first electromagnetic control valve 7 having a variable cross-sectional area of the refrigerant passage is interposed between the connection port B of the four-way switching valve 3 and the indoor heat exchanger 6. The first electromagnetic control valve 7 does not have to be closed.

Reference numeral 11 designates an outdoor heat exchanger 5 and an indoor heat exchanger 6.
Is a bypass line connecting the midway of the line connecting the and the midway of the line extending from the connection port of C of the four-way switching valve 3 to the accumulator 4, and an electromagnetic opening / closing valve 12 is inserted in the middle of the bypass line. Has been done.

In addition, a bypass line 11 is provided in the refrigerant line extending from the C connection port of the four-way switching valve 3 toward the accumulator 4.
To the upstream side (that is, the four-way switching valve 3 side) from the connection part with
A check valve 13 through which the refrigerant can pass is inserted and connected only in the direction from the four-way switching valve 3 to the accumulator 4.

Further, in the middle of the pipe connecting the outdoor heat exchanger 5 and the indoor heat exchanger 6, a second electromagnetic control is provided at a position closer to the outdoor heat exchanger 5 than the connecting portion with the bypass pipe 11. Valve 8
Are connected by insertion. The second electromagnetic control valve 8 has a function of closing.

A blower fan 15 for sending the air, which has been heat-exchanged with the refrigerant in the indoor heat exchanger 6 and the sub-condenser 2, to the passenger compartment is arranged in the air duct leading to the passenger compartment. However, an air mix door 16 that is driven to open and close by a motor actuator or the like (not shown) is provided, and the flow rate of air that is heat-exchanged with the refrigerant in the sub-condenser 2 can be controlled.

Reference numeral 17 denotes a control unit having a built-in microprocessor, which controls the switching operation of the four-way switching valve 3 and the states of the first electromagnetic control valve 7, the second electromagnetic control valve 8 and the electromagnetic on-off valve 12. Control in conjunction. Further, the state of the air mix door 16 may be controlled in conjunction with each other.

The air conditioner for an automobile according to the first embodiment of the present invention is configured in this way, and in the cooling / dehumidifying mode shown in FIG. 2, the connection ports of A and D of the four-way switching valve 3 are connected. , B and C are connected to each other, the refrigerant discharged from the sub-condenser 2 passes through the outdoor heat exchanger 5 first, and then through the indoor heat exchanger 6, and is sent to the accumulator 4 to be sent to the compressor 1 Returned to.

At this time, the electromagnetic opening / closing valve 12 of the bypass line 11 is closed and the first electromagnetic control valve 7 is fully opened.
Therefore, the presence of the bypass line 11 and the presence of the first electromagnetic control valve 7 have no influence on others. The opening degree of the second electromagnetic control valve 8 is controlled by the temperature of the refrigerant on the outlet side of the indoor heat exchanger 6, and the like, and functions as an expansion valve.

As a result, the outdoor heat exchanger 5 functions as a condenser and the indoor heat exchanger 6 functions as an evaporator. Therefore, the interior of the vehicle is in a cooling state, and when the opening degree of the air mix door 16 through which the sub-condenser 2 is ventilated is increased, the cooling function is lowered and the dehumidifying state under weak cooling is achieved.

In the heating / dehumidifying mode shown in FIG. 3, the connection ports A and B and the connection ports C and D of the four-way switching valve 3 are connected to each other, and the refrigerant discharged from the sub-condenser 2 is stored in the room. After passing through the heat exchanger 6 first, it passes through the outdoor heat exchanger 5, is sent to the accumulator 4, and is returned to the compressor 1.

At this time, the electromagnetic opening / closing valve 12 of the bypass line 11 is closed and the second electromagnetic control valve 8 is fully opened.
Therefore, the presence of the bypass line 11 and the presence of the second electromagnetic control valve 8 have no influence on others. The opening of the first electromagnetic control valve 7 is controlled by the temperature of the refrigerant on the outlet side of the outdoor heat exchanger 5 and the like, and functions as an expansion valve.

As a result, both the outdoor heat exchanger 5 and the indoor heat exchanger 6 function as an evaporator, and the condenser is only the sub-condenser 2 in the vehicle compartment. Therefore, the interior of the vehicle is heated and dehumidified in the indoor heat exchanger 6, so that the windows are prevented from fogging.

In the severe cold heating / dehumidifying mode shown in FIG. 1, the refrigerant flowing out of the sub-condenser 2 is connected to the connection ports A and B and the connection ports C and D of the four-way switching valve 3, respectively. Passes through the indoor heat exchanger 6 first, then passes through the outdoor heat exchanger 5, is sent to the accumulator 4, and is returned to the compressor 1. The first electromagnetic control valve 7 functions as an expansion valve. These points are the same as the heating / dehumidifying mode of FIG.

However, in this mode, the bypass line 1
The first electromagnetic opening / closing valve 12 is opened and the second electromagnetic control valve 8 is closed. Therefore, the refrigerant exiting the indoor heat exchanger 6 is sent to the accumulator 4 as it is through the bypass pipe line 11 without returning to the outdoor heat exchanger 5, and is returned to the compressor 1. The refrigerant accumulated in the outdoor heat exchanger 5 is recovered by the accumulator 4 via the four-way switching valve 3 and the check valve 13
Prevents backflow.

As a result, the outdoor heat exchanger 5 does not have any function, and by keeping the air mix door 16 fully opened, the energy input to the compressor 1 is released to the interior of the vehicle as it is for heating. The effect is obtained, and the indoor heat exchanger 6 also dehumidifies.

For example, in a severe cold state such as 20 ° C. below zero, the heating function does not work in the ordinary heat pump system. However, by doing so, a considerable heating effect can be obtained. Very useful. Even in the case of a gasoline engine vehicle, it is extremely useful in an environment where the temperature of engine cooling water does not rise.

FIG. 4 shows an automobile air conditioner according to a second embodiment of the present invention. Instead of the first electromagnetic control valve 7 in the first embodiment, an indoor heat exchanger 6 is used. A check valve 21 through which the refrigerant can pass only in the outgoing direction and a throttle 22 with a narrow pipe diameter are connected in parallel.

As a result, when the flow of the refrigerant flows from the four-way switching valve 3 to the indoor heat exchanger 6, the throttle 22 functions as an expansion valve, and when the flow of the refrigerant is reverse, the refrigerant simply passes through the check valve 21. To do.

Further, instead of the second electromagnetic control valve 8 in the first embodiment, the check valve 23 through which the refrigerant can pass only in the direction in which the indoor heat exchanger 6 exits and the pipe diameter are narrowed. The restricted throttle 24 is connected in parallel, and the electromagnetic opening / closing valve 25 is connected in series to it.

As a result, when the flow of the refrigerant flows from the outdoor heat exchanger 5 to the indoor heat exchanger 6, the throttle 24 functions as an expansion valve, and when the flow of the refrigerant is reverse, the refrigerant simply passes through the check valve 23. To do. Further, when the electromagnetic opening / closing valve 12 of the bypass pipe line 11 is opened to enter the heating / dehumidifying mode in the severe cold, the electromagnetic opening / closing valve 25 is closed.

The automobile air conditioner of the second embodiment having the above-mentioned configuration is the same as that of the first embodiment except that the expansion valve of the indoor heat exchanger 6 does not have the function of adjusting the flow rate of the refrigerant. It works like the form. In addition, the diameters of the diaphragms 22 and 24 are
If it is made variable according to the differential pressure across the refrigerant passing through it, it can also have a flow rate adjusting function.

FIG. 5 shows an automotive air conditioner according to a third embodiment of the present invention, in which the bypass pipe line 11 is removed from the first embodiment. Even if the bypass conduit 11 is simply removed from the configuration of the first embodiment, the cooling / dehumidifying mode and the heating / dehumidifying mode operate exactly the same as in the first embodiment.

In order to suppress the heat exchange capacity of the outdoor heat exchanger 5, for example, if the wind shield plate 27 is arranged along the outdoor heat exchanger 5, the heating / dehumidifying mode during the severe cold is also the first. It can be realized at a level close to that of the embodiment.

FIG. 6 shows an automobile air conditioner according to a fourth embodiment of the present invention. Compared with the automobile air conditioner according to the first embodiment, an automobile engine, a motor, a battery, or the like is used. A heat exchanger 31 for exchanging the released heat with the refrigerant is added to the accumulator 4.
Reference numeral 32 is a flow rate control valve for controlling the flow rate of water or the like that is a medium that transfers waste heat.

Cooling water for the engine or the motor is circulated in the pipe of the heat exchanger 31, and the waste heat can be recovered to the refrigerant by evaporating the refrigerant in the accumulator 4. As a result, even when the engine cooling water has a low temperature such as 20 to 50 ° C., the heat can be recovered and the heating can be operated.

FIG. 7 shows an automobile air conditioner according to a fifth embodiment of the present invention, which is a heat exchanger for exchanging heat released from an automobile engine, motor, battery or the like with a refrigerant. 33 is arranged between the four-way switching valve 3 and the accumulator 4, and it is possible to obtain the same effect as that of the fourth embodiment.

In addition, in this embodiment, a bypass pipe 34 that bypasses the heat exchanger 33 is provided,
The pipeline is opened and closed by an electromagnetic opening / closing valve 35.

With this configuration, in an environment where it is desired to avoid pressure loss in the refrigeration cycle in the heat exchanger 33, the bypass pipe 34 is opened so that the refrigerant hardly passes through the heat exchanger 33. Can be

[0048]

According to the present invention, the sub-condenser arranged in the passenger compartment is connected between the compressor and the refrigerant flow path switching valve, and the upstream and downstream sides of the indoor heat exchanger are interposed. , By connecting the valve that acts as an expansion valve when the refrigerant flow path switching valve is switched to the upstream side of the indoor heat exchanger,
Since the indoor heat exchanger always acts as an evaporator, the indoor heat exchanger can have a structure with low pressure resistance, and the device cost can be reduced. Further, it is possible to obtain the dehumidifying function in any use condition of the heating and cooling, and it is possible to reliably prevent the occurrence of fogging on the window of the automobile.

[Brief description of drawings]

FIG. 1 is a configuration block diagram of an air conditioner for a vehicle according to a first embodiment of the present invention in a heating / dehumidifying mode during severe cold.

FIG. 2 is a configuration block diagram of the automobile air conditioner according to the first embodiment of the present invention in a cooling / dehumidifying mode.

FIG. 3 is a configuration block diagram of the automobile air conditioner according to the first embodiment of the present invention in a heating / dehumidifying mode.

FIG. 4 is a configuration block diagram of an automobile air conditioner according to a second embodiment of the present invention.

FIG. 5 is a configuration block diagram of an automobile air conditioner according to a third embodiment of the present invention.

FIG. 6 is a configuration block diagram of an automobile air conditioner according to a fourth embodiment of the present invention.

FIG. 7 is a configuration block diagram of an automobile air conditioner according to a fifth embodiment of the present invention.

[Explanation of symbols]

1 compressor 2 Sub condenser 3 four-way switching valve 4 Accumulator 5 outdoor heat exchanger 6 Indoor heat exchanger 7 First solenoid control valve 8 Second solenoid control valve 11 Bypass pipeline 12 solenoid valve 13 Check valve 16 air mix door 17 Control unit

Continuation of the front page (56) Reference JP-A-9-95123 (JP, A) JP-A-9-79689 (JP, A) JP-A-9-39555 (JP, A) JP-A-56-20964 (JP , A) JP 7-301459 (JP, A) JP 6-255351 (JP, A) JP 61-289275 (JP, A) JP 8-20236 (JP, A) 62-171862 (JP, U) Actual Kaihei 2-73569 (JP, U) (58) Fields investigated (Int.Cl. ⁷ , DB name) B60H 1/32 624 B60H 1/22 F25B 29/00 411

Claims (10)

(57) [Claims] 1. A refrigerant flow path switching valve is disposed downstream of a compressor of a refrigeration cycle, and by switching the refrigerant flow path switching valve, a pipe line that comes out of the refrigerant flow path switching valve and returns again. In an automobile air conditioner in which the connection order of an indoor heat exchanger and an outdoor heat exchanger that are connected in series on the way is interchanged, a sub-condenser placed in the vehicle compartment is replaced by the compressor and the refrigerant flow path switching valve. And acts as an expansion valve when the refrigerant flow path switching valve is switched to the upstream side of the indoor heat exchanger, with the indoor heat exchanger being sandwiched between the upstream side and the downstream side. An air conditioner for an automobile, characterized in that a valve for connecting the air conditioner is connected. 2. The air conditioner for a vehicle according to claim 1, further comprising a sub-condenser heat exchange control means for controlling a flow rate of air in the passenger compartment that exchanges heat with the refrigerant in the sub-condenser. 3. A bypass pipe line that directly connects a pipe line connecting the indoor heat exchanger and the outdoor heat exchanger and a pipe line extending from the refrigerant flow path switching valve to the compressor inlet. The vehicle air conditioner according to claim 1 or 2, further comprising: an opening and closing valve for opening and closing the bypass pipe. 4. A valve which is openable and closable for closing a pipe line connecting the indoor heat exchanger and the outdoor heat exchanger, is located closer to the outdoor heat exchanger than a connecting portion with the bypass pipe line. The vehicle air conditioner according to claim 3, wherein the air conditioner is provided at the position. 5. A refrigerant passage switching valve extending from the refrigerant passage switching valve toward the compressor inlet in the middle of a pipe passage extending from the refrigerant passage switching valve to the compressor inlet and upstream of a connecting portion with the bypass pipe passage. The air conditioner for a vehicle according to claim 3 or 4, wherein a check valve through which the refrigerant can pass is inserted. 6. The air conditioner for a vehicle according to claim 1, wherein the valve acting as the expansion valve is a control valve capable of controlling the opening degree. 7. A valve acting as the expansion valve is formed by connecting in parallel a check valve capable of passing a refrigerant only in a direction in which it exits from the indoor heat exchanger and a throttle having a narrow pipe diameter. The air conditioner for an automobile according to any one of claims 1 to 5, which is configured. 8. The air conditioner for an automobile according to claim 7, wherein the throttle diameter is variable in accordance with the differential pressure across the refrigerant passing therethrough. 9. An accumulator is connected to an upstream side of the compressor of the refrigeration cycle, and heat for exchanging heat between a refrigerant and heat emitted from an energy source of an automobile in which the refrigeration cycle is mounted. The vehicle air conditioner according to any one of claims 1 to 7, wherein an exchanger is built in the accumulator. 10. An accumulator is connected to an upstream side of the compressor of the refrigeration cycle, and heat for exchanging heat between a refrigerant and heat generated from an energy source of an automobile in which the refrigeration cycle is mounted. The air conditioner for vehicles according to any one of claims 1 to 7, wherein the exchanger is connected to a pipeline on the upstream side of the accumulator, and an openable and closable bypass pipeline is provided to bypass the heat exchanger. apparatus.