JPH0687318A - Air conditioner for vehicle - Google Patents

Abstract

PURPOSE:To provide an air conditioner for vehicle, which restricts the cloudiness of window glass and holds a cooling load or heating load at a low value. CONSTITUTION:An inside and outside air switching means 3 to switch inside air and outside air and a blower 11 are provided upstream of a duct 2 for sending air into a car cabin. In the duct 2, a cooling means 12 and heating means 13 are arranged to cool and heat the air to be blown into the room. A controller 10 for controlling an air conditioner 1 is provided with a solar radiation sensor 30, and even when conditions, under which glass is liable to be clouded due to the relation ship between the temperature of inside air and the temperature of outside air, are settled, if the solar radiation detected by the solar radiation sensor 30 is intensive, the car cabin is cooled or heated by inside air introduction at a small cooling load or heating load.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle air conditioner for controlling the temperature of a vehicle compartment by cooling or heating.

[0002]

2. Description of the Related Art An air conditioner for a vehicle operates a cooling means and a heating means (temperature changing means) arranged in a duct to adjust the temperature of air blown into the passenger compartment to control the temperature inside the passenger compartment. Making adjustments. Further, the vehicle air conditioner includes an inside / outside air switching unit that switches between the outside air and the inside air and guides the inside air into the duct.

[0003]

When the inside air is selected and the temperature inside the vehicle compartment is adjusted, the inside or inside of the vehicle compartment can be heated or cooled by heating or cooling the air-conditioned air inside the vehicle interior. . Therefore, it is possible to reduce the load on the temperature changing means that changes the temperature of the air. However, when performing air conditioning by introducing internal air,
Moisture and carbon dioxide released by the occupant's breath, etc. are not released to the outside, and as a result, the air in the vehicle compartment may become dirty, or the humidity in the vehicle compartment may rise and the window glass may become cloudy. Therefore, when outside air is selected and the temperature inside the vehicle compartment is adjusted, fresh air is introduced into the vehicle interior, so that moisture released in the vehicle interior is discharged to the outside of the vehicle and air conditioning in the vehicle interior can be performed. it can. However, for example, when performing heating operation in winter, it is necessary to heat the outside cold air to warm the vehicle interior, and the heating load becomes very large. Further, when the cooling operation is performed in the summer, it is necessary to cool the outside hot air to cool the passenger compartment, and the cooling load becomes very large.
That is, when the outside air is selected and the temperature is adjusted, the load of the temperature changing means for changing the temperature of the air becomes very large.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a vehicle air conditioner capable of suppressing a load applied to a temperature changing means and suppressing fogging of a window glass. In offer.

[0005]

SUMMARY OF THE INVENTION An air conditioner for a vehicle according to the present invention comprises a duct for sending air into the vehicle compartment, and a blower for producing an air flow toward the vehicle interior in the duct.
Inside / outside air switching means for switching the air outside the vehicle compartment or the air inside the vehicle compartment to introduce the air into the duct, and arranged in the duct,
Temperature change means for changing the temperature of the air blown into the vehicle compartment, and a solar radiation sensor for detecting the amount of solar radiation, when the solar radiation detected by this solar radiation sensor is strong, by controlling the inside / outside air switching means, The technical means including a control device for guiding the air inside the vehicle into the duct is adopted. Further, the vehicle air conditioner of the present invention can employ the following technical means. The control device includes an air quality sensor for detecting the air quality in the vehicle interior, and when it determines that the air in the vehicle interior detected by the air quality sensor is dirty, regardless of the intensity of the solar radiation, the inside / outside air The switching means is controlled to guide the air outside the vehicle compartment into the duct.

[0006]

When the solar radiation detected by the solar radiation sensor is strong,
The control device controls the inside / outside air switching means to guide the inside air into the duct. By introducing the inside air into the duct, the temperature changing means changes the temperature of the air-conditioned air in the vehicle compartment. Therefore, the load of the temperature changing means can be small.
In addition, the inside air is circulated in the vehicle compartment, and moisture released by the occupant is not easily released to the outside of the vehicle.

[0007]

As described above, the vehicle air conditioner of the present invention can suppress the fogging of the window glass and the load on the temperature changing means when the sunlight is strong.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, a vehicle air conditioner of the present invention will be described based on an embodiment shown in the drawings. [Configuration of Embodiments] FIGS. 1 to 3 show a first embodiment of the present invention, and FIG. 1 is a schematic configuration diagram of a vehicle air conditioner. The vehicle air conditioner 1 includes a duct 2 for sending air toward the passenger compartment. Upstream of the duct 2, an inside air / outside air switching means 3 is provided to switch the outside air or the inside air to the inside of the duct 2. The inside / outside air switching means 3 includes an inside / outside air switching box 6 including two inside air inlets 4 for sucking inside air and two outside air inlets 5 for sucking outside air.
Equipped with. Inside the inside / outside air switching box 6, an inside / outside air switching damper 7 for closing one of the inside air introducing port 4 and the outside air introducing port 5 is provided. The two inside / outside air switching dampers 7 have negative pressure actuators 8 respectively.
This negative pressure actuator 8
Operates when the negative pressure switching valve 9 switches between atmospheric pressure and negative pressure. The two negative pressure switching valves 9 are controlled by the control device 10 described below.

Inside the duct 2, a blower 11, a cooling means 12, and a heating means 13 are sequentially arranged from the upstream side to the downstream side, and the air that has passed through the heating means 13 is blown at each downstream end of the duct 2. It is blown out from the exit 14 into the passenger compartment. The blower 11 generates an air flow in the duct 2 and blows out the air sucked from the inside air inlet 4 or the outside air inlet 5 into the passenger compartment. The cooling means 12 is an example of the temperature changing means of the present invention for cooling the air flowing in the duct 2, and in this embodiment, it is a refrigerant evaporator of a refrigeration cycle. The refrigeration cycle has a well-known structure, and the air passing through the cooling means 12 is cooled by operating the refrigerant compressor 15 of the refrigeration cycle. The operation of the refrigerant compressor 15 is controlled by the control device 10 described later. The heating means 13 is an example of the temperature changing means of the present invention for heating the air flowing in the duct 2, and is a heater core 16 that uses engine cooling water (warm water) as a heat source, a bypass passage 17 that bypasses the heater core 16, and a heater core 16. The air mix damper 18 controls the ratio of the air passing through the bypass passage 17 to the air passing through the bypass passage 17. Then, by changing the opening degree of the air mix damper 18, the amount of air passing through the heater core 16 changes, and as a result, the heating capacity of air changes. The air mix damper 18
It is driven by the power servo 19 which operates by the pressure difference. This power servo 19 has a double negative pressure switching valve 2
This double negative pressure switching valve 20 is operated by 0
Is controlled by the controller 10 described below. Further, the circulation of the cooling water to the heater core 16 is controlled by a water valve 21 operated by a negative pressure, and the water valve 21 is operated by a negative pressure switching valve 22 controlled by the control device 10 described below. In addition, the outlet 14
The blower outlet switching damper 23 that performs switching is operated by the negative pressure actuator 24, and the negative pressure switching valve 25 that operates the negative pressure actuator 24 is controlled by the control device 10 described below.

The control device 10 includes an inside air sensor 26 for detecting the temperature inside the vehicle and an outside air sensor 2 for detecting the temperature outside the vehicle.
7. CO2 that detects CO2 concentration as air quality in the passenger compartment
A sensor 28 (air quality sensor), a water temperature sensor 29 that detects a cooling water temperature of the engine, a solar radiation sensor 30 that detects the amount of solar radiation entering the vehicle interior, an evaporator sensor 31 that detects a temperature of the cooling means 12 on the air downstream side, and an air. Signals from the potentiometer 32 for detecting the opening degree of the mix damper 18, the operation panel 33 operated by the user, and the like are read, and air conditioning control is performed based on these signals. The control device 10 that performs this air-conditioning control uses a microcomputer.
The control of each electric component is performed based on the control written in advance.

Next, the inside / outside air automatic switching control by the control device 10 will be described. The inside / outside air switching means 3 of the present embodiment automatically switches between the inside air introduction and the outside air introduction according to the vehicle state, and its control will be described with reference to the flowchart of FIG. First, the air conditioner switch (not shown) is turned on.
It is judged whether or not it has been done (step S1). If this determination result is NO, the process ends. In addition, the judgment result is YES
In the case of, it is judged whether or not the CO2 concentration in the vehicle compartment detected by the CO2 sensor 28 is a predetermined value (for example, 0.2%) or more (step S2). If the result of this determination is YES, the inside / outside air switching means 3 is controlled to introduce outside air into the vehicle compartment (step S3), and thereafter, the set temperature, the inside air temperature,
Based on the vehicle state such as the outside air temperature, air conditioning is performed to control the operation of the refrigerant compressor 15 and the opening degree of the air mix damper 18 (step S4), and then the process returns to step S1. If the result of the determination in step S2 is NO, it is determined whether or not the amount of solar radiation detected by the solar radiation sensor 30 is equal to or greater than a predetermined value (for example, a value at which the window glass is not heated and clouded by solar radiation) (step). S5). If the result of this determination is YES, the inside / outside air switching means 3 is controlled to control the duct 2
The inside air is guided into the inside to circulate the inside air (step S6), and then the process proceeds to step S4. If the decision result in the step S5 is NO, the inside air temperature detected by the inside air sensor 26 is
It is determined whether or not the outside air temperature detected by the outside air sensor 27 is higher than or equal to the outside air temperature (step S7). If the result of this determination is YES, the process proceeds to steps S3 and S4 to perform air conditioning for introducing the outside air, and if NO, the process proceeds to steps S6 and S4 to perform air conditioning for introducing the inside air.

[Operation of Embodiment] Next, the operation of the above embodiment will be briefly described. When the air conditioner switch is turned on, when the control device 10 determines that the CO2 concentration in the vehicle interior is high and the air inside the vehicle interior is dirty, or the amount of solar radiation is low and the inside air temperature is higher than the outside air temperature, the window glass becomes cloudy. When it is determined that it is easy, the outside air is sucked into the duct 2 and fresh outside air is introduced into the passenger compartment, and the inside air having the humidity increased by the moisture released by the occupant is discharged to the outside of the vehicle. This purifies the air inside the vehicle or prevents the window glass from fogging. When the sunlight is strong, that is, the humidity is low on a sunny day, and the window glass is heated by the sunlight, so that the window glass does not fog. Specifically, as shown in the moist air diagram of FIG. 3, for example, if the inside air temperature is 25 ° C. and the outside air temperature (window glass temperature) is 20 ° C., the window glass will be fogged unless the relative humidity becomes 75% or more. Does not occur. That is, when the window glass is heated by solar radiation, or when the window glass is fine and the humidity is low, the window glass does not fog. And when the CO2 concentration in the passenger compartment is low and there is no need to introduce outside air, and there is no strong possibility of clouding on the window glass due to strong sunlight.
The control device 10 controls the inside / outside air switching means 3 to circulate the inside air, and during the cooling operation, sucks the cold air in the passenger compartment into the duct 2 for air conditioning, and conversely during the heating operation. The heated air in the passenger compartment is sucked into the duct 2 for air conditioning.

[Effects of the Embodiment] In the present embodiment, as shown in the above operation, when the air in the passenger compartment is dirty,
When there is a possibility that the window glass will be fogged, air conditioning is performed by the outside air to purify the interior of the vehicle or air conditioning is performed by suppressing the occurrence of fogging on the window glass. And
When the air in the passenger compartment is clean and there is no possibility of fogging on the window glass, air conditioning is performed by circulating the inside air, so that the load for changing the temperature of the air flowing through the duct 2 is reduced. That is, in the cooling operation, the operating rate of the refrigerant compressor 15 in the refrigeration cycle can be suppressed low, and in the heating operation, the vehicle interior can be sufficiently heated even with a low cooling water temperature.

[Second Embodiment] FIG. 4 shows a flowchart of a control device 10 for controlling the inside / outside air switching means 3 according to a second embodiment. In this embodiment, the inside / outside air switching means 3 can be operated by a user's manual operation. When the air conditioner switch is turned on in step S1, it is determined whether the mode selected by the user is the outside air mode. (Step S8). If the result of this determination is YES, the program proceeds to steps S3 and S4 to perform air conditioning for introducing the outside air. If the determination result is NO, the process proceeds to step S2, and the outside air is introduced when the air inside the vehicle is dirty or when the window glass tends to be fogged. If no fog occurs, air conditioning is performed by introducing the inside air.

[Third Embodiment] FIG. 5 shows a flowchart of a control device 10 for controlling the inside / outside air switching means 3 according to a third embodiment. This embodiment secures the heating performance of a vehicle such as a diesel engine vehicle in which the amount of heat of cooling water is small. First, it is determined whether or not the ignition switch is turned on (step S9). This judgment result is NO
If YES, the process ends, and if YES, it is determined whether the outside air temperature is equal to or higher than a set temperature (for example, 5 ° C.) (step S10). If the result of this determination is YES, the heating load is small even if the heating operation is performed in the outside air, so the inside / outside air is selected according to the instruction of the manual operation (step S11), and then the air conditioning control is performed in step S4. If the decision result in the step S10 is NO, the process proceeds to a step S8, the outside air is introduced manually when the outside air is manually selected, the air in the passenger compartment is dirty, or the amount of solar radiation is small, and the inside air is introduced. Is manually selected, the air inside the vehicle is clean, and when there is a lot of sunlight, the air is conditioned by introducing the inside air.

[Modification] In the above embodiment, an example in which both the cooling means and the heating means are mounted in the duct has been shown, but the invention may be applied to a vehicle in which only one such as the heating means is mounted. Also, the heater core using cooling water as the heating means is shown as an example, but other heating means such as a PTC heater, a combustion heater, a refrigerant condenser of a refrigeration cycle, etc. may be applied. Although an example is shown in which the window glass is determined to be easily fogged when the inside air temperature is higher than the outside temperature, it is determined that the window glass is easily fogged when the inside air temperature is higher than the outside temperature by a predetermined value or more,
Use a humidity sensor to judge whether it is easy to fog,
The easiness of fogging may be determined by other factors, such as by comparing the inside air temperature with the set temperature to determine whether or not it is likely to fog.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a vehicle air conditioner (first
Example).

FIG. 2 is a flow chart of inside / outside air switching control (first)
Example).

FIG. 3 is a moist air diagram (first embodiment).

FIG. 4 is a flowchart of inside / outside air switching control (second)
Example).

FIG. 5 is a flowchart of inside / outside air switching control (third embodiment)
Example).

[Explanation of symbols]

 1 Vehicle Air Conditioner 2 Duct 3 Inside / Outside Air Switching Means 10 Controller 11 Blower 12 Cooling Means (Temperature Changing Means) 13 Heating Means (Temperature Changing Means) 28 CO2 Sensor (Air Quality Sensor) 30 Solar Radiation Sensor

Claims (2)

[Claims] 1. (a) a duct for sending air toward the passenger compartment; (b) a blower for generating an air flow toward the passenger compartment in the duct; and (c) switching between air outside the passenger compartment or air inside the passenger compartment. An inside / outside air switching unit that guides the air into the duct; (d) a temperature changing unit that is arranged in the duct and changes the temperature of the air blown into the vehicle compartment; and (e) a solar radiation sensor that detects the amount of solar radiation. An air conditioner for a vehicle, comprising: a control device for controlling the inside / outside air switching means to guide the air in the vehicle interior into the duct when the solar radiation detected by the solar radiation sensor is strong. 2. The control device comprises an air quality sensor for detecting the air quality in the vehicle interior, and when it is determined that the air in the vehicle interior detected by the air quality sensor is dirty, regardless of the intensity of the solar radiation. 2. The vehicle air conditioner according to claim 1, wherein the inside / outside air switching means is controlled so that the outside air of the vehicle compartment is guided into the duct.