JP3293141B2 - 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 an air conditioner for a vehicle, and more particularly, to an air conditioner suitable for a vehicle having no hot water heat source for heating, such as an electric vehicle.

[0002]

2. Description of the Related Art Conventionally, a heat pump type air conditioner has been considered because an electric vehicle does not have a hot water heat source for heating. In other words, a refrigeration cycle having an indoor heat exchanger and an outdoor heat exchanger is provided. In the case of heating, the indoor heat exchanger is used as a condenser, and the outdoor heat exchanger is used as an evaporator. Uses an indoor heat exchanger as an evaporator and uses an outdoor heat exchanger as a condenser.

[0003]

However, when switching from the cooling operation to the heating operation by mistake, a large amount of condensed water adheres to the indoor heat exchanger in the conventional cooling operation. When switched, there is a possibility that the gas will evaporate and be blown out into the vehicle interior to fog the window glass. Adhesion amount of the dew condensation water varies depending on the type of heat exchanger, for example in a serpentine tube heat exchangers commonly used in car air conditioner is about 800 cc, and water retention capacity of about 200cc per surface area 1 m ² of the heat exchanger It is said.

[0004] It is an object of the present invention to provide an air conditioner for a vehicle which can avoid the troubles caused by mode switching.

[0005]

SUMMARY OF THE INVENTION The present invention relates to a duct for guiding indoor or outdoor air from a blower into a vehicle interior, an indoor heat exchanger disposed in the duct, through which a cold / hot heat source passes, and the indoor heat exchanger. An automotive air conditioner comprising an operation switch for switching between a cold heat source passing mode for passing a cold heat source through an exchanger and a warm heat source passing mode for passing a warm heat source through the indoor heat exchanger, When the mode is switched from the cold-source passing mode to the hot-source passing mode by the operation switch , the vehicle air is configured to permit the mode change only when a vehicle stop signal is input as a final signal for permitting the mode change. The gist is a harmony device.

[0006]

[0007]

When the mode is switched from the cold-source passing mode to the hot-source passing mode by the operation switch, the mode change is permitted only when a vehicle stop signal is input as a decision signal for permitting the mode change. As a result, the dew condensation water adheres to the indoor heat exchanger in the cold heat source passage mode, but when there is no vehicle stop signal , the indoor heat exchanger does not switch to the hot heat source passage mode and condenses as the indoor heat exchanger passes through the heat source. Water is prevented from evaporating and being blown out into the vehicle interior.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows a configuration of an indoor unit 1 of an air conditioner for a vehicle. The indoor unit 1 includes a blower unit 2, a first unit 3, and a second unit 4. The blower unit 2 is provided with an inside / outside air switching device 5. The inside / outside air switching device 5 changes the position of the switching damper 6 to separate the inside air from the room air introduction hole 7 and the outside air from the outside air introduction hole 8. It can be selectively introduced. A blower 9 is provided in the blower unit 2, and inside air or outside air is introduced into the first unit 3 via the inside / outside air switching device 5 by driving a blower motor 9 a. A duct 10 is formed by the first unit 3 and the second unit 4 on the downstream side, and an indoor first heat exchanger 11 is disposed in the first unit 3. On the other hand, in the second unit 4, an indoor second heat exchanger 12 and auxiliary heaters 13 and 14 are arranged. The auxiliary heaters 13 and 14 have, for example, an output 5
A PTC element of about 00 watts is used.

[0009] Each outlet is branched into the second unit 4. That is, the differential outlet 1 that blows out toward the automobile window
5 and a heat outlet 16 which blows out toward the feet of the occupant
And the vent outlet 17 that blows out toward the occupant's head and chest
a, 17b, and 17c are provided. Vent outlet 1
7a is provided at the center of the vehicle interior,
b and 17c are provided on both sides in the vehicle interior. or,
Each of the outlets 15, 16, 17a, 17b, 17c is provided with an outlet switching damper 18-22.

FIG. 2 shows a refrigerant circuit of an air conditioner for an automobile. FIG. 3 shows a state in which the vehicle air conditioner is attached to a vehicle. The compressor 23 sucks, compresses, and discharges the refrigerant, is housed in a closed container 24 shown in FIG. 3 together with an electric motor (not shown), and is driven by the motor. A four-way electromagnetic switching valve 2 is provided on the discharge passage side of the compressor 23.
The refrigerant discharged from the compressor 23 is supplied to the indoor second heat exchanger 12 or the outdoor heat exchanger 26 by switching the four-way electromagnetic switching valve 25. The outdoor heat exchanger 26 is arranged at a position where it is easy to take in outdoor air during both the cooling operation and the heating operation. The indoor second heat exchanger 12 and the indoor first heat exchanger 11 are connected in series via a dehumidifying capillary tube 27. A reversible solenoid valve 28 is connected to the capillary tube 27 in parallel, and this reversible solenoid valve 28 always allows a refrigerant flow from the indoor first heat exchanger 11 to the indoor second heat exchanger 12, The flow is made conductive when the solenoid valve coil is energized, and is made non-conductive when it is not energized.

The outdoor heat exchanger 26 and the indoor first heat exchanger 11 are connected in series with capillary tubes 29,
30 are connected. A check valve 31 is connected to the cooling capillary tube 29 in parallel.
A check valve 32 is connected in parallel to the heating capillary tube 30. Further, a bypass passage 33 for dehumidification is branched from the middle of the piping between the indoor first heat exchanger 11 and the cooling capillary tube 29, and the other end of the bypass passage 33 is connected between the four-way electromagnetic switching valve 25 and the accumulator 34. Have been. Further, a normally closed solenoid valve 35 that opens only when power is supplied is disposed in the bypass passage 33. The accumulator 34 separates the refrigerant introduced into the compressor 23 into gas and liquid, stores the liquid refrigerant, and leads only the gas refrigerant to the compressor 23. The accumulator 34 has a capacity capable of accommodating 50 to 100% of the total refrigerant charge. In this embodiment, the accumulator 34 is
The first accumulator 34a is directly attached to the compressor 23, and the second accumulator 34b is provided separately from the compressor 23.
The total refrigerant storage capacity of 4a and the second accumulator 34b is about 1300 cc. This is because the refrigerant flow rate of the refrigeration cycle of this example is about 1500 cc.

As shown in FIG. 4, the compressor 23 is connected to the power supply 48 via the inverter 36. As shown in FIG. 3, the inverter 36 is housed in an electric box 37. FIG. 5 shows a control panel 38. On the control panel 38, a mode switching lever 39, a temperature adjusting lever 40, an inside / outside air switching lever 41, a blower switch 42, and an air conditioner switch 43 as an operation switch are arranged. The mode switching lever 39 controls the opening / closing of the outlet switching dampers 18 to 22 to vent the air blown into the passenger compartment toward the occupant's head and chest, the bi-level mode toward both the occupant's head and chest and the feet, The mode is switched between a heat mode toward the foot of the occupant, a heater differential mode toward both the foot of the occupant and the window glass, and a differential mode toward the window glass. The air conditioner switch 43 switches not only the operation of the air conditioner on / off, but also the cooling operation / heating operation, and the dehumidifying operation.

As shown in FIG. 3, a confirmation operation switch 44 is disposed in the passenger compartment, and the switch 44 is provided with a lamp 45. As shown in FIG. 4, a microcomputer 47 is built in the controller 46. The control panel 38 is connected to the controller 46, and the microcomputer 47 detects the operation states of the operation levers 39, 40, 41 and the switches 42, 43 of the control panel 38. A confirmation operation switch 44 is connected to the controller 46, and the microcomputer 47 is connected to the confirmation operation switch 4.
The presence or absence of operation 4 is detected. Further, the controller 46
Is connected to a vehicle speed sensor 50, and the microcomputer 47 detects a vehicle speed based on a signal from the vehicle speed sensor 50. The controller 46 includes an inverter 36, a blower motor 9 a for the indoor unit 1, a blower motor 51 for the outdoor heat exchanger 26, a four-way electromagnetic switching valve 25, electromagnetic valves 28 and 35, and a lamp 45.
Is connected, and the microcomputer 47 drives and controls each of these electric devices.

Next, the operation of the air conditioner for a vehicle configured as described above will be described. During the cooling operation, the microcomputer 47 switches the four-way electromagnetic switching valve 25 in FIG. 2 so that the refrigerant discharged from the compressor 23 flows toward the outdoor heat exchanger 26. As a result, the high-temperature and high-pressure refrigerant discharged from the compressor 23 is condensed in the outdoor heat exchanger 26 and liquefied at a high temperature,
Next, the air passes through the check valve 32 and is adiabatically expanded in the cooling capillary tube 29 to be in a low-temperature and low-pressure atomized state.
It flows into the heat exchanger 11. The indoor first heat exchanger 11 exchanges heat with the air blown from the blower 9 to take vaporization heat from the air and cool the air. On the other hand, the refrigerant evaporates due to this heat exchange and flows into the indoor second heat exchanger 12 via the reversible solenoid valve 28, and after the same heat exchange, the accumulator 34
Flows into Then, the gas refrigerant and the liquid refrigerant are separated by the accumulator 34 and only the gas refrigerant is sucked into the compressor 23. In this cooling operation, the indoor heat exchangers 11, 12
Dew water adheres to the surface.

In the heating operation, the microcomputer 47 switches the four-way electromagnetic switching valve 25 so that the high-temperature and high-pressure refrigerant discharged from the compressor 23 flows toward the indoor second heat exchanger 12. Further, the microcomputer 47 opens the reversible electromagnetic valve 28 so that the refrigerant flows toward the indoor first heat exchanger 11 without passing through the dehumidifying capillary tube 27. As a result, the refrigerant discharged from the compressor 23 is condensed in both the indoor second heat exchanger 12 and the indoor first heat exchanger 11. At this time, the heat of condensation is released to the air flowing through the duct 10 to heat the air. The refrigerant condensed in the indoor heat exchangers 12 and 11 passes through the check valve 31 and the heating capillary tube 3
Flows into zero. Then, when the refrigerant passes through the heating capillary tube 30, the refrigerant adiabatically expands and becomes a low-temperature and low-pressure atomized state. The low-temperature refrigerant exchanges heat with outdoor air by the outdoor heat exchanger 26 and evaporates to become a gas refrigerant. Next, the refrigerant flows into the accumulator 34 via the four-way electromagnetic switching valve 25, and after the liquid refrigerant is separated, only the gas refrigerant is sucked into the compressor 23.

Further, during the dehumidifying operation, the microcomputer 47
Makes the four-way electromagnetic switching valve 25 allow the refrigerant from the compressor 23 to flow toward the indoor second heat exchanger 12 in the same manner as during heating.
Further, the microcomputer 47 closes the reversible electromagnetic valve 28 and opens the electromagnetic valve 35 to open the bypass passage 33. As a result, the high-temperature and high-pressure refrigerant discharged from the compressor 23 flows into the indoor second heat exchanger 12 and is condensed. Then, the condensed refrigerant adiabatically expands when passing through the capillary tube 27, becomes a low-temperature and low-pressure atomized state, and flows into the first indoor heat exchanger 11. Further, the refrigerant evaporates in the indoor first heat exchanger 11, and the gas refrigerant flows into the accumulator 34 via the electromagnetic valve 35. That is, the indoor first heat exchanger 11 acts as an evaporator to cool the air, condenses moisture in the air and discharges it as drain water, and the indoor second heat exchanger 12 acts as a condenser. The air from which the moisture has been removed is heated, and the dried air is blown into the room. In this dehumidifying operation, dew water adheres to the indoor first heat exchanger 11.

On the other hand, the microcomputer 47 executes a flowchart shown in FIG. 6 for preventing the indoor heat exchangers 11 and 12 from fogging the glass due to the dew water. That is, the microcomputer 47
Are switched from the cooling operation mode to the heating operation mode, from the dehumidification operation mode to the heating operation mode, and from the cooling operation mode to the dehumidification operation mode by operating the air conditioner switch 43 of the control panel 38. If so, the routine processing of FIG. 6 is started.

First, the microcomputer 47 determines in step 100 the time before (from the time of switching from the cooling operation mode to the heating operation mode, from the dehumidification operation mode to the heating operation mode, and from the cooling operation mode to the dehumidification operation mode). It is determined whether the cooling operation (or the dehumidifying operation) has been performed within eight hours. If the cooling operation (or the dehumidifying operation) has been performed within eight hours, the microcomputer 47 proceeds to step 1.
In 01, it is determined whether or not the cooling operation (or dehumidifying operation) is a cooling operation (or dehumidifying operation) for 5 minutes or more.
This is because if the dew condensation water does not adhere to the indoor heat exchangers 11 and 12, the fogging does not occur in the glass, so that the cooling operation (or dehumidification operation) for 5 minutes or less is the same as the cooling operation (or dehumidification operation). It is assumed that moisture does not evaporate after cooling operation (or dehumidification operation) is stopped for more than 5 minutes.

If the cooling operation (or the dehumidifying operation) is longer than 5 minutes, the microcomputer 47 proceeds to step 102.
To turn on the lamp 45 to notify the driver that there is a possibility of fogging due to the water vapor released into the vehicle interior and that the blown air may be uncomfortable due to high humidity. The microcomputer 47 determines in step 103 that the vehicle speed is “0”,
It is determined whether the vehicle is stopped. If the vehicle speed is “0”, the microcomputer 47 determines in step 104 that the confirmation operation switch 4
It is determined whether or not 4 has been pressed, and if the confirmation operation switch 44 has been pressed, the heating operation is executed in step 105.
The microcomputer 47 does not perform the heating operation unless the vehicle speed is “0” in step 103 or the confirmation operation switch 44 is not pressed in step 104. Therefore, mode switching (cooling operation mode → heating operation mode, dehumidification operation mode → heating operation mode, cooling operation mode → dehumidification operation mode) is performed when the vehicle is stopped and the confirmation operation switch 44 is not operated. This is not performed, and the fogging of the window glass during traveling is prevented beforehand.

As described above, in this embodiment, when the air conditioner switch 43 (operation switch) of the control panel 38 switches the mode from the cold-source passing mode to the hot-source passing mode, the microcomputer 47 causes the decision signal to permit the mode change, That is, the mode change is allowed only when the operation signal of the confirmation operation switch 44 is present and the vehicle speed is “0”. As a result, the mode is switched when the vehicle is stopped and the confirmation operation switch 44 is not operated (cooling operation mode → heating operation mode, dehumidification operation mode → heating operation mode, cooling operation mode → dehumidification operation mode). Is not performed, and the fogging of the window glass during running is prevented.

The present invention is not limited to the above-described embodiment. For example, in the above-described embodiment, the mode switching is permitted only when the confirmation operation switch 44 is operated and the vehicle speed is "0". but was, mode when the car speed is "0" may be allowed to switch.

In the above embodiment, the stop of the vehicle is detected by a signal from the vehicle speed sensor 50. Alternatively, the stop of the vehicle may be detected by a signal from a parking brake switch which is turned on by operating the parking brake. Further, in the above embodiment, the present invention is embodied in a heat pump type air conditioner, but as shown in FIG.
It may be embodied in an air conditioner through which a heated medium or a cooled medium passes. That is, the indoor heat exchanger 52
In contrast, the medium can be circulated by the brine pump 53 and the medium can be heated by the combustor 54. Further, a refrigerating cycle is formed by the compressor 55, the outdoor heat exchanger 56, the capillary tube 57, the brine cooler 58, and the accumulator 59, and the medium from the indoor heat exchanger 52 is supplied by the three-way valve 60 to the combustor 54 or the brine. This passes through the cooler 58.

[0023]

As described in detail above, according to the present invention,
Exhibits an excellent effect kill the bug associated with the mode switched avoid.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of an indoor unit in a vehicle air conditioner of an embodiment.

FIG. 2 is a refrigerant circuit diagram.

FIG. 3 is a perspective view showing an attached state of each device.

FIG. 4 is a diagram showing an electrical configuration.

FIG. 5 is a front view of a control panel.

FIG. 6 is a flowchart.

FIG. 7 is a refrigerant circuit diagram of another example.

[Explanation of symbols]

9 blower, 10 duct, 11 indoor first heat exchanger,
12 indoor second heat exchanger, 38 control panel
43 air conditioner switch as operation switch, 44
Confirmation operation switch, 50 vehicle speed sensor

Continuation of the front page (72) Inventor Yoji Nishimura 1 Toyota Town, Toyota City, Aichi Prefecture Inside Toyota Motor Corporation (56) References JP-A-1-239353 (JP, A) (58) Field surveyed (Int .Cl. ⁷ , DB name) B60H 1/00

Claims (1)

(57) [Claims] 1. A duct for guiding indoor or outdoor air from a blower into a vehicle interior, an indoor heat exchanger disposed in the duct, through which a cold / hot heat source passes, and a cold heat source passing through the indoor heat exchanger. An air conditioner for a vehicle, comprising: an operation switch for switching between a cold heat source passing mode for heating and a warm heat source passing mode for passing a warm heat source to the indoor heat exchanger. An air conditioner for a vehicle, wherein the mode change is permitted only when a vehicle stop signal is input as a decision signal for permitting the mode change when the mode is switched to the heat source passage mode.