JP3312378B2 - Solar radiation sensor for car 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 solar radiation sensor for a car air conditioner mounted on a vehicle for detecting a change in the amount of solar radiation due to sunlight.

[0002]

2. Description of the Related Art In general, when sunlight is taken into the interior of a vehicle, a part of the energy of the light is converted into thermal energy, and the temperature of the interior of the vehicle rises due to the heat received in the interior of the vehicle. In order to maintain the vehicle interior temperature at a comfortable temperature, appropriate control of air conditioning in the vehicle interior is achieved by correcting an increase in the amount of heat according to the amount of heat received by sunlight. Therefore, it is desired to propose a method for detecting the amount of heat due to the light taken into the vehicle compartment as accurately as possible. However, since the amount of light received from the sun changes according to the latitude at which the vehicle exists, the type of vehicle, the inclination of the window glass, the material thereof, the position of the roof, the direction of solar radiation, the left and right solar radiation angles, the upper and lower solar radiation angles, etc. It is not easy to find a method for accurately detecting the amount of heat due to sunlight taken into a vehicle cabin from an optical signal.
DESCRIPTION OF RELATED ART Conventionally, the insolation sensor for car air conditioners which detects the sunlight taken in a vehicle interior is Unexamined-Japanese-Patent No. 1-136811,
As shown in JP-A-1-136812 and JP-A-63-006, the light receiving surface of the sensor receiving the sun light is directed forward or upward of the vehicle body. Installed at an angle.
Japanese Unexamined Patent Publication No. 1-136811 discloses a vehicle air conditioner that corrects the amount of solar radiation based on the detection values of both light receiving elements provided on both the right and left sides of the vehicle. Japanese Unexamined Patent Publication No. 136812 discloses a method in which the solar radiation direction of a vehicle obtains a difference value between the magnitude of the solar radiation in the right region and the magnitude of the solar radiation in the left region, and controls the air conditioner by the output of the calculating means using the difference value. Is what you do. Japanese Patent Application Publication No. 63-006 discloses an insolation sensor body inclined toward the south-central altitude of the sun.

[0003]

All of the publications disclosed in the above-mentioned patent publications and the above-mentioned publications are for detecting the state of solar radiation by a light receiving portion in accordance with the solar radiation angle of the sun. Although it is disclosed that all the surfaces are mounted to be inclined forward or upward of the vehicle body, there is no description about how to specify the inclination angle of the sensor light receiving surface. That is, the conventional solar radiation sensor does not consider the heat receiving characteristics that the vehicle receives due to the light from the sun. According to a conventional vehicle air conditioner using a solar radiation sensor, for example, as shown in FIG. 6, when the sensor light receiving surface is directed upward, the "solar elevation angle at which the maximum amount of received light" and the "solar elevation angle at which the maximum amount of received heat are obtained" Does not match, it is difficult to perform appropriate control of air conditioning based on such sensor output. SUMMARY OF THE INVENTION It is an object of the present invention to provide a vehicle in which the amount of solar radiation capable of properly performing air conditioning control in a vehicle cabin is detected in accordance with the heat receiving load of a vehicle received from sunlight even when the latitude indicating the location of the vehicle changes. An object is to provide a solar radiation sensor for an air conditioner.

[0004]

For this purpose, the solar radiation sensor for a car air conditioner according to the first aspect of the present invention is mounted at a position where sunlight is taken into a vehicle cabin, and the amount of received light increases or decreases according to the elevation angle of the solar radiation. When the vehicle receives heat due to sunlight taken into the vehicle interior, the maximum amount of heat load in the vehicle interior, which varies according to the solar elevation angle, becomes the maximum light reception amount at the solar elevation angle. The light receiving surface is provided to be inclined. The solar radiation sensor for a car air conditioner according to claim 2 of the present invention has a solar radiation elevation angle of 50 ° to 70 °.
The light receiving surface is provided to be inclined so that the maximum light receiving amount is obtained in the range of °. A solar radiation sensor for a car air conditioner according to a third aspect of the present invention is characterized in that a light receiving surface is inclined by approximately 30 ° from a horizontal plane.

[0005]

The amount of heat from the sun received in the cabin of the vehicle changes according to the type of vehicle. For example, it changes in accordance with the inclination of the window glass in front of or behind the vehicle, the area of the window, the roof, the sensor mounting position, and the like. The amount of heat received in the vehicle compartment also changes according to the solar radiation elevation angle θ. In the solar radiation sensor for a car air conditioner of the present invention, the light receiving surface of the sensor is directed in consideration of the heat receiving characteristic of the vehicle according to the elevation angle of the solar radiation. That is, the sensor light-receiving surface is directed so that the amount of light detected by the sensor at the solar radiation elevation angle at which the amount of heat received by the sunlight (the amount of increase in heat load) out of the total amount of heat received by the vehicle compartment becomes the maximum is the maximum. Even if the latitude and the solar elevation angle at which there is a change, the output of the solar radiation sensor capable of appropriately controlling the air conditioning in the vehicle cabin is output.

[0006]

Embodiments of the present invention will be described below with reference to the drawings. FIGS. 1 and 4 show solar radiation sensors for detecting sunlight.
The solar radiation sensor is mounted on a vehicle as shown in FIGS. 2 and 3. The solar radiation sensor
As shown in FIG. 2, the front dash panel 2 of the vehicle 1
Attached to The attachment position of the solar radiation sensor is the central portion 3 or the left position portion 4 of the front dash panel 2. When the solar radiation sensor is attached to the central portion 3, the sensitivity of the solar radiation from the left and right due to pillars and the like is symmetrical, so that the sensitivity is excellent. When the solar radiation sensor is attached to the left position 4, the design is excellent. Therefore, such usage may be performed. The solar radiation sensor of the present invention does not limit the mounting position to the above position. Also, as shown in FIG.
The solar radiation sensor 10 is arranged inside the front window glass 5 on the horizontal top surface 2 a of the front dash panel 2.

As shown in FIG. 4, the solar radiation sensor 10 has a pedestal 12 mounted on a top surface 2a of a front dash panel 2. On this pedestal 12, a sensor light receiving portion 13 is disposed forward of the vehicle with an inclination angle θ from a horizontal plane. Installed at an angle. The inclination angle θ is about 30 °. A hemispherical cover filter 14 is attached to the circular outer peripheral surface of the base 12 so as to cover the sensor light receiving unit 13. The cover filter 14
It is a filter that cuts visible light. This is because it is only necessary to receive light having a wavelength of infrared or far-infrared rays that affects the amount of heat in sunlight, and if the inside of the sensor can be grasped visually, it will impair the aesthetics of the vehicle interior. is there. The sensor detection circuit is configured as shown in FIG. The sensor light receiving unit 13 uses, for example, a solar cell in which the amount of light to be detected is proportional to the output current. Terminal 20
5V is applied, and the terminal 21 is grounded. R ₁ , R ₂ and R ₃ are resistors. When the light in the light-receiving unit 13 is irradiated, reduces the combined resistance between terminals c, d a current flows through the light-receiving unit 13, Vs is generated across the resistor R ₂ by a current flowing through the resistor R ₂ . This voltage Vs is proportional to the amount of solar radiation.

Next, experimental data will be shown. The thermal load received by the solar radiation sensor attached to the vehicle has a relationship between the solar radiation elevation angle θ and the thermal load increase amount as shown in FIG. 6 when the sun is on the front extension of the vehicle. According to this data, when the solar elevation angle θ is 60 °, the heat load increase amount is almost maximum,
The solar radiation elevation angle at which the maximum heat load increases varies depending on the vehicle type. In this embodiment, the sensor light receiving surface is inclined forward by an elevation angle of 30 ° so that the maximum amount of received light is obtained when the solar radiation angle is 60 °. The thermal load characteristic of the solar radiation sensor has a characteristic corresponding to the solar elevation angle θ so as to be similar to the thermal load characteristic of the vehicle. The comparative example shown in FIG. 6 shows a conventional solar radiation sensor. When the solar elevation angle θ is 90 °, the sensor output becomes maximum. In this case, the correlation between the heat load characteristic received by the vehicle and the output of the solar radiation sensor is not considered.

In the solar radiation sensor according to the embodiment of the present invention, the maximum amount of received light (sensor output) is set to the solar radiation elevation angle θ = 60 ° when the maximum heat load applied to the vehicle is the solar radiation elevation angle θ = 60 °. In consideration of this, the position of the vehicle changes its latitude due to its movement, and the solar elevation angle from the sun also changes. FIG. 7 shows a comparison between the embodiment of the present invention and a comparative example with respect to the stable state at room temperature. As shown in FIG. 7, the solar radiation elevation angle of the embodiment of the present invention is 0 ° compared to the comparative example.
The cooling capacity of the air conditioner is increased in the entire angle range from to 90 °, and in particular, at the solar elevation angle of 60 ° where the heat load of the vehicle is maximized, the cooling capacity of the embodiment of the present invention is much higher than that of the comparative example. It turns out that it can be enhanced.

Next, a method for controlling an air conditioner using the solar radiation sensor of the present invention will be described. As shown in FIG. 8, a fan 32 rotated by a blower motor 31, a cooler 33, a heater core 34, and an air mix door 35 are provided in a duct 30. Inside and outside air intakes 36 of the duct 30 are provided with dampers 37, 3 opened and closed by a servomotor 40.
8 is attached. In the opening of the duct 30 with the cabin 42, a defroster 44, a face outlet 46, a foot outlet 48
Are formed, and dampers 50, 52, and 54 are attached to each of them so as to be freely opened and closed. A cooler outlet temperature sensor 56 is attached to the wall of the cooler 33. An air mix potentiometer 58 for detecting the position of the air mix door 35 is attached so as to detect the opening of the air mix door 35. Inside the room 42, a temperature setting switch 60, a room temperature sensor 62, and a solar radiation sensor 10 are mounted. The controller 66 constituting the control device includes the servo motor 40, the blower fan 3
1. A signal for driving the compressor 68, the air mix damper driving motor 78, the water pump motor 70, and the respective damper switching motors 72 is output. As input signals of the controller 66, signals of the outside air temperature sensor 74, the water temperature sensor 76, the temperature setting switch 60, the inside air temperature sensor 62, the solar radiation sensor 10, and the cooler outlet temperature sensor 56 are input.

The outside air or the inside air sucked from the inside / outside air intake 36 is switched by the servo motor 40 to the damper 3.
7, 38. The air taken into the duct 30 from the inside / outside air intake 36 is accelerated by the fan 32 and cooled through the cooler 33. The cooled air is divided into a warm air side and a cool air side by the opening degree of the air mix door 35, and the warm air side air passes through the heater core 34. The air on the cool air side bypasses the heater core 34 and flows downstream of the heater core 34. Here, the air that has passed through the heater core 34 and the air that has not passed are mixed, and the air-mixed air is blown into the room 42 from one of the defroster 44, the face outlet 46, and the foot outlet 48. Thereby, the inside of the room 42 is air-conditioned.

Next, the operation of the automatic air conditioner will be described with reference to FIG. First, the controller 66 reads the set temperature TSET, the inside air temperature TR, the outside air temperature TAM, the amount of solar radiation TS, the water temperature TW, and the cooler outlet temperature TE by various sensors or switches (step 80), and then calculates the required outlet temperature TAO by the following equation. (Step 81). TAO = KSET × TSET−KR × TR−KAM × TAM−KS × TS + C Here, KSET, KR, KAM, and KS indicate coefficients to be multiplied by each sensor output signal value. Next, the required blowing air volume is calculated (step 82). The required blowing air amount is a blower air amount shown in FIG. 10 having a certain correlation according to the required blowing temperature TAO. Next, the air mix opening degree SW of the air mix door 35 is calculated by the following equation.

(Equation 1) The opening of the air mix door 35 is detected by an air mix potentiometer 58, and a detection signal is input to a controller 66. The controller 66 controls the air mix damper 35 based on an input signal from the air mix potentiometer 58. The motor 78 is controlled so that the actual opening of the motor 78 is positioned at the target opening. Here, the room temperature control based on the output signal of the solar radiation sensor 10 is performed such that the peak light receiving amount of the sensor light receiving surface is adjusted so as to coincide with the solar radiation elevation angle θ at which the maximum amount of heat load applied to the vehicle takes as shown in FIG. The solar elevation angle θ is set, so the output signal of the solar radiation sensor corresponds to the amount of heat received without being affected by the latitude of the position of the solar radiation or the position of the vehicle. This has the effect that the indoor temperature feeling can be properly controlled.

[0013]

As described above, according to the solar radiation sensor for a car air conditioner of the present invention, the light receiving surface of the solar radiation sensor is oriented so as to coincide with the peak of the amount of heat received according to the heat receiving characteristic of the vehicle. The amount of heat received in the vehicle cabin due to sunlight can be properly corrected for the increased heat in the cabin, so the amount of heat received is reduced by air conditioning control by the car air conditioner according to the solar elevation angle so that the increased heat is canceled out However, there is an effect that good air conditioning control is achieved.

[Brief description of the drawings]

FIG. 1A is a plan view of a solar radiation sensor according to an embodiment of the present invention. (B) is a side view thereof.

FIG. 2 is a plan view of a vehicle on which a solar radiation sensor is mounted.

FIG. 3 is a cross-sectional view showing a mounting state of the solar radiation sensor.

FIG. 4 is a perspective view of a solar radiation sensor.

FIG. 5 is a circuit diagram illustrating a detection circuit of the solar radiation sensor.

FIG. 6 is a characteristic diagram showing a relationship between a solar radiation elevation angle of a solar radiation sensor and a thermal load increase amount received by a vehicle.

FIG. 7 is a characteristic diagram showing a relationship between a solar radiation elevation angle and a room temperature, in which an example of the present invention and a comparative example are compared.

FIG. 8 is a schematic configuration diagram illustrating an air conditioner using a solar radiation sensor according to an embodiment of the present invention.

FIG. 9 is a flowchart illustrating a control method of the air conditioner.

FIG. 10 is a characteristic diagram showing a relationship between a required blowing temperature and a blower air volume.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Vehicle 2 Front dash panel (vehicle) 10 Solar radiation sensor 13 Sensor light receiving part 42 Cabin

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-1-136811 (JP, A) JP-A-1-136812 (JP, A) JP-A-62-66109 (JP, A) 189908 (JP, U) (58) Field surveyed (Int. Cl. ⁷ , DB name) B60H 1/00-1/34

Claims (3)

(57) [Claims] An insolation sensor that is mounted at a position where sunlight is taken into a vehicle compartment of a vehicle and increases or decreases the amount of received light according to the elevation angle of sunlight, wherein when the vehicle receives heat due to sunlight taken into the vehicle compartment, A solar radiation sensor for a car air conditioner, wherein a light receiving surface is provided so as to be inclined such that the maximum amount of received light is obtained at a solar radiation elevation angle at which a heat load increase in a vehicle compartment that changes in accordance with a solar radiation elevation angle is maximized. 2. The solar radiation sensor for a car air conditioner according to claim 1, wherein the light receiving surface is provided so as to be inclined so that the maximum amount of light is received when the solar radiation elevation angle is in the range of 50 ° to 70 °. 3. The solar radiation sensor for a car air conditioner according to claim 1, wherein said light receiving surface is inclined by approximately 30 ° from a horizontal plane.