JP2605926Y2 - 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 detects two data of a relative humidity inside a vehicle and an inner surface temperature of a window glass, which are necessary for controlling humidity for preventing fogging of a window. Regarding what can be done.

[0002]

2. Description of the Related Art One of the performances required of an air conditioner for an automobile is to prevent the occurrence of fogging of a window and to ensure the safe operation of a vehicle. It is affected not only by the amount of water vapor contained in the air, but also by the temperature of the inner surface of the window glass (hereinafter simply referred to as the window temperature),
This window temperature is the outside air temperature, vehicle interior temperature, solar radiation, vehicle speed,
It depends on the weather. Therefore, conventionally, in order to accurately detect a window temperature that is likely to change due to such various factors and to effectively prevent window fogging, a window temperature sensor that directly detects a window temperature is provided, and a window glass is provided. Techniques have been devised for controlling the humidity in a vehicle cabin so that fogging does not occur on the inner surface. For example, in an air conditioner for an automobile described in Japanese Patent Application Laid-Open No. 56-63513, the window temperature is detected by a window temperature sensor, while the relative humidity in the vehicle is detected by a humidity sensor. The dew point temperature is calculated from the relative humidity, and humidity control for preventing fogging of the window is performed based on the temperature difference between the dew point temperature and the window temperature.

[0003]

However, in such a conventional technique, although the accuracy of the dew condensation prediction is considerably improved because the window temperature is directly detected, a window for detecting the window temperature is used. Since it is necessary to newly provide a sensor separately, the number of parts and the number of mounting steps are increased, which may lead to an increase in cost.

In this regard, focusing on the fact that a humidity sensor is generally composed of a humidity sensing element and a temperature sensing element (for example, a thermistor), detecting the window temperature with a thermistor in the humidity sensor, that is, using a humidity sensor It would be advantageous if it could also be used as a window temperature sensor. However, since the humidity sensor is configured by connecting both the humidity sensing element and the temperature sensing element in series and is driven by an AC bias, only the temperature sensing element (thermistor) is used for other purposes (windows). Temperature detection).

The present invention has been made in view of such problems of the prior art, and an air conditioner for an automobile which can detect both data of the relative humidity of the vehicle interior and the temperature of the inner surface of the window glass with one sensor is provided. The purpose is to provide.

[0006]

In order to achieve the above object, the present invention calculates the dew point temperature from the relative humidity in the vehicle compartment and the temperature on the inner surface of the window glass, and calculates the temperature between the dew point temperature and the inner surface temperature of the window glass. In an automotive air conditioner that performs humidity control in the cabin to prevent the occurrence of window fogging based on the difference,
One of the two sides of the board attached in the sensor case
One side has a humidity sensor and the other has a temperature sensor.
And one or more sensors on the moisture sensitive element side of the sensor case.
Forming a hole for moisture sensitivity, the temperature-sensitive element by the substrate
The thermosensitive element is configured so as to be insulated from the space on the moisture sensitive element side.
The surface where the element is present is the window glass side and the presence of the moisture sensitive element is
Surface on the inside of the window glass
And a drive unit for driving the sensor unit so as to switch between input and output with respect to the humidity-sensitive element and the temperature-sensitive element to detect the vehicle interior relative humidity and the window glass inner surface temperature in a time-division manner. And

[0007]

According to the present invention configured as described above, the sensor
The unit consists of a humidity sensor and a temperature sensor on both sides of the board.
Are mounted independently in a spatially separated state.
The surface on which the temperature sensitive element is located
The surface on which the element is located is taken
The driving unit drives the sensor unit so as to switch input and output to and from the humidity sensing element and the temperature sensing element in such a sensor unit. At this time,
Since the sensor case has holes for moisture sensitivity,
The wet element communicates with the space inside the cabin, while the temperature sensitive element is
It is insulated from the interior space by the board. Thus, the sensor unit accurately detects the two data of the vehicle interior relative humidity and the window glass inner surface temperature in a time-division manner, and outputs the data to the outside.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. 1 is a block diagram showing a configuration of an air conditioner for a vehicle according to an embodiment of the present invention, FIG. 2 is a perspective view showing the structure of the sensor unit of FIG. 1, and FIG. 3 is an assembled state of the sensor unit of FIG. FIG. 4 is a diagram showing an example of installation of the sensor unit of the embodiment, FIG. 5 is a diagram showing a configuration example of a driving circuit of the sensor unit of the embodiment, and FIG. 7 is a flowchart showing the contents of the subroutine of FIG. 6, and FIG. 8 is a flowchart showing the contents of another subroutine of FIG.

The air conditioner for a vehicle shown in FIG. 1 has a control unit 1 for performing various types of input signals by a built-in microcomputer to perform various air conditioning controls. On the input side of the control unit 1, as a sensor group, a sensor unit 2 for detecting the relative humidity in the vehicle interior and the temperature of the inner surface of the window glass, a room temperature sensor 3 for detecting the temperature in the vehicle interior, and other various sensors 4
(For example, an outside air sensor that detects the temperature outside the vehicle, a water temperature sensor that detects the temperature of the engine cooling water, a suction temperature sensor that detects the air temperature immediately after passing through the evaporator, and the like) are connected. The sensor unit 2 includes a moisture-sensitive element 5 and a temperature-sensitive element 6 (for example, a thermistor). The specific structure will be described later. Also, this sensor unit 2
Has the function of a solar radiation sensor for detecting the amount of solar radiation, as will be described later. A control panel 7 is further connected to the input side of the control unit 1. The control panel 7 includes various operation switches (for example, a temperature setting switch for setting the temperature in the vehicle compartment).
An automatic switch for selecting automatic control, an air conditioner switch for turning on / off a compressor, a fan switch for selecting a fan air volume, a mode switch for selecting an outlet, and the like are provided. The various sensors 2 to 4 described above are respectively mounted at appropriate locations inside and outside the vehicle interior, and the control panel 7 is installed at the center of the instrument panel in the vehicle interior.

On the output side of the control unit 1 are a magnet clutch 9 for turning on and off the compressor 8, an intake door actuator 11 such as a motor actuator for driving the intake door 10, and various mode doors 1.
2, a mode door actuator 13 such as a motor actuator that drives the air mix door, an air mix door actuator 15 such as a motor actuator that drives the air mix door 14, and a fan motor 17 that rotates a blower fan 16 are connected to each other. The compressor 8 is for operating a cooling cycle. When the compressor 8 is turned on with the magnetic clutch 9 engaged, the cooling cycle is operated, and the intake air is cooled and dehumidified by the evaporator. The intake door 10 is for selecting the inside air and the outside air of the intake air. The mode door 12 includes, for example, a differential door, a vent door, and a foot door, which are rotatably attached to a differential outlet, a vent outlet, and a foot outlet, respectively, and are opened and closed by a mode door actuator 13 via a link. Depending on the combination of opening and closing of the mode door 12, the outlet mode includes a differential mode (DEF) for guiding warm air to the inner surface of the windshield to remove fogging of the glass, a vent mode (VENT), and a bi-level. A mode (B / L), a foot mode (FOOT) and the like are generally provided. The air mix door 14 is for changing the mixing ratio of cold air and hot air, and the outlet temperature is adjusted by changing the opening degree. The magnitude of the blown air volume is adjusted by changing the voltage applied to the fan motor 17 and switching the rotation speed of the blower fan 16.

The control unit 1 includes a control panel 7
And input signals from the various sensors 2 to 4 and the like, and the magnetic clutch 9 and the intake door actuator 1 are processed.
1. Comprehensively control the mode door actuator 13, the air mix door actuator 15, the fan motor 17, and the like. An example of the control will be described later.

As shown in FIGS. 2 and 3, the sensor unit 2 has a humidity sensing element 5 and a thermistor 6 as a temperature sensing element mounted on both sides of a substrate 18, respectively, and a sensor case 19 made of a transparent material. It has a structure inserted in. The reason why the sensor case 19 is made of a transparent material is to make it easier to detect the amount of solar radiation, and the sensor case 19 is made of, for example, a black smoke material. In mounting the sensor unit 2, the surface where the thermistor 6 is located is located on the side of the window glass and the surface where the moisture sensitive element 5 is located is located on the side of the vehicle cabin with respect to the substrate 18. This is thermistor 6
Is to detect the window temperature and the amount of solar radiation, and to detect the humidity in the vehicle cabin by the humidity sensing element 5, thereby improving the respective detection sensitivity. On the vehicle interior side of the sensor cover 19, a large number of moisture-sensitive holes 20 for contacting the moisture-sensitive element 5 with the vehicle interior air are formed. However, the thermistor 6 is isolated from the vehicle interior by the substrate 18 so as not to be affected by the vehicle interior. In FIGS. 2 and 3,
“21” is an adhesive portion to which an adhesive for attaching the sensor unit 2 to the window glass is applied, and “22” is a connector for connecting the humidity sensing element 5 and the thermistor 6 to the outside.

The sensor unit 2 is, for example, shown in FIG.
As shown in FIG. 1, the adhesive 22 is attached to the upper portion of the inner surface of the windshield 23 of the vehicle. At this time, as described above, the moisture-sensitive element 5 in the sensor unit 2 is disposed on the vehicle interior side, and the temperature-sensitive element 6 is disposed on the windshield 23 side.

FIG. 5 shows an example of a specific circuit configuration for driving the sensor unit 2. The control unit 1 serving as a driving unit includes an arithmetic processing circuit 24 that performs arithmetic processing by inputting a signal from each sensor and the like, an AC bias circuit 25 that supplies an AC bias to the moisture-sensitive element 5 in the sensor unit 2, Thermistor 6 in unit 2
And a DC bias circuit 26 for supplying a DC bias to the power supply. The AC bias circuit 25 is connected to one terminal B of the humidity sensing element 5 in the sensor unit 2, and the other terminal C of the humidity sensing element 5 is connected to one terminal of the thermistor 6 in the sensor unit 2 via the switch SW1. It is connected to an A / D converter 29 in an arithmetic processing circuit 24 via a switch SW4, a linearization circuit 27, and an amplifier 28. The DC bias circuit 26 is connected to the terminal D of the thermistor 6 in the sensor unit 2 via the switch SW2. The terminal D of the thermistor 6 is connected to the switch SW3.
And A / D converter 2 in arithmetic processing circuit 24 through resistor 30
9 is connected. The other terminal E of the thermistor 6
Is grounded. Each of the switches SW1 to SW4 is opened and closed by a signal from the arithmetic processing circuit 24. The switches SW2 and SW3 are connected to an inverter.
31 is connected to the arithmetic processing circuit 24. The room temperature sensor 3 is directly connected to the A / D converter 32 in the arithmetic processing circuit 24. This is the same for each of the other sensors. Note that the sensor unit 2 driving circuit (excluding the arithmetic processing circuit 24) in the control unit 1 may be hybridized and mounted in the sensor unit 2.

With such a circuit configuration, the outputs of the humidity sensing element 5 and the temperature sensing element 6 in the sensor unit 2 are individually taken out. By switching, it is possible to obtain two data of the vehicle interior relative humidity and the window temperature in a time sharing manner.

That is, the specific operation of this circuit is as follows. The arithmetic processing circuit 2
4 outputs a high (Hi) signal. At this time, the switches SW1 and SW4 are turned on, and the switch SW2 is turned on.
And the switch SW3 is turned off. As a result, a closed circuit is formed in which the AC bias circuit 25, the humidity sensing element 5 and the temperature sensing element 6 are connected and flows to the ground. Is input to the A / D converter 29 in the arithmetic processing circuit 24. On the other hand, when the window temperature is input, the arithmetic processing circuit 2
4 outputs a low (Lo) signal. At this time, the switches SW1 and SW4 are turned off, and the switch SW2 is turned off.
And the switch SW3 is turned on. This forms a closed circuit in which the DC bias circuit 26 and the temperature sensing element 6 are connected and flows to the ground, and a signal corresponding to the window temperature is transmitted to the switch SW.
A / D in the arithmetic processing circuit 24 via the resistor 30 via
It is input to the converter 29. Thus, each switch SW
By performing the switching operation and the input operation of 1 to SW4 in a time sharing manner, it is possible to simultaneously input the signal of the relative humidity of the vehicle compartment and the signal of the window temperature.

In this embodiment, the thermistor 6 in the sensor unit 2 is also used for detecting the amount of solar radiation.
Since the thermistor 6 is arranged on the window glass side of the substrate 18, that is, on the sunlight receiving side, and is isolated from the vehicle interior by the substrate 18, the thermal effect due to the heat storage in the vehicle interior can be reduced. In addition, by calculating the amount of solar radiation by processing the window temperature data from the thermistor 6 and the vehicle interior temperature data from the room temperature sensor 3, it is possible to minimize the effect of heat storage in the vehicle interior on control. . The method of calculating the solar radiation amount data will be described later.

Next, the operation of the air conditioner for a vehicle configured as described above will be described with reference to the flowcharts of FIGS. Here, it is assumed that, for example, the automatic switch is turned on and automatic control is performed.

First, the basic operation of this device is as shown in FIG. That is, the control unit 1 drives the sensor unit 2 and inputs each data of the vehicle interior relative humidity and the window temperature by time sharing (S1). Then, based on the vehicle interior relative humidity and the window temperature (T _W ), the arithmetic processing circuit 24 calculates the dew point temperature (T _F ) at which water vapor in the air starts to condense according to a predetermined well-known arithmetic expression. After (S
2) The window temperature and the dew point temperature are compared, and control for preventing window fogging is executed step by step. For example, in the present embodiment, the temperature difference between the window temperature and the dew point temperature (T _W -T _F )
Is compared with three reference values P, Q, and R (P>Q>R> 0). The reference value P is a value for determining the necessity of the humidity control described later. R is a reference value for switching the content of humidity control according to the degree of possibility of window fogging. Here, first, it is determined whether or not the temperature difference (T _W -T _F ) between the window temperature and the dew point temperature is larger than the reference value P (S3). if (i.e. T _W -T _F ≦ P), it is determined that it is necessary humidity control because of possible window fog performing humidity control (S4) is, if the temperature difference is greater than the reference value P First, it is determined that there is no possibility of window fogging and that humidity control is unnecessary, and normal air conditioner control is executed (S5).

The humidity control in step 4 is performed according to the flowchart shown in FIG. That is, the control unit 1
The temperature difference (T _W -T _F ) between the window temperature and the dew point temperature is the reference value Q.
When it is determined that the pressure is larger than the predetermined value (S6), the compressor 8 is turned on by the magnetic clutch 9 and the intake door 10 is operated by the intake door actuator 11.
To set the suction port to the outside air introduction (S7, S7)
8). Further, the temperature difference between the window temperature and the dew point temperature (T _W -T
When it is determined that _F ) is equal to or smaller than the reference value Q and larger than the reference value R (S6, S9), the compressor 8 is turned on and the suction port is set to the outside air introduction (S10, S1).
1) Mode door 1 by mode door actuator 13
2 is driven to set the outlet to the DEF mode (S12). Further, the temperature difference between the window temperature and the dew point temperature (T
When it is determined that ( _W− T _F ) is equal to or less than the reference value R (S9), the compressor 8 is turned on, the suction port is set to the outside air introduction, and the air outlet is set to the differential mode because the window fogging is very likely to occur. (S13, S1
In addition to (4, S15), the voltage applied to the fan motor 17 is increased to increase the amount of blown air (S16). in this way,
In the humidity control, the window temperature and the dew point temperature are compared, and based on the temperature difference, air conditioning control for preventing window fogging is performed stepwise according to the level of window fogging possibility. It is also effective to increase the temperature of the blowing air to prevent fogging of the window.

The normal control in step 5 in FIG. 6 is performed according to the flowchart in FIG. That is, after inputting the vehicle interior temperature (T _INC ) from the room temperature sensor 3 (S17), the control unit 1 outputs the sensor unit 2
The temperature data (T _W ) detected by the thermistor 6 in the vehicle is once calculated as insolation data (S18), and the vehicle interior temperature (T _W ) is calculated.
_INC ), and the solar temperature (T
_sun ) (S19). In other words, in the present embodiment, the sensor unit 2 also serves as the solar radiation sensor. However, as described above, the temperature stored in the sheet material or the like in the vehicle interior causes the actual output of the sensor to be increased. Must be corrected to obtain solar radiation data. Here, for example, when the window temperature (T _W ) is higher than the vehicle interior temperature (T _INC ) (T
_W > T _INC ), the window temperature is directly used as the solar radiation temperature (that is, T
_sun = T _W ), the window temperature (T _W ) is the vehicle interior temperature (T _INC )
In the following cases (T _W ≦ T _INC ), an average of the insolation correction is performed, and T _sun = T _W − (T _INC −T _W ) is used as the insolation data. Then, various kinds of input data (for example, set temperature, outside air temperature, solar radiation amount, vehicle interior temperature, etc.) are subjected to arithmetic processing (S20), and the blow temperature, the blow air volume, the blow air volume, etc. The switching of the outlet and the suction port is comprehensively controlled (S21).

Therefore, according to this embodiment, the humidity sensor and the window temperature sensor are configured as one sensor unit 2 and this sensor unit 2 is also used as a solar radiation sensor, so that the number of sensors is reduced, and the cost is reduced. And the number of installation steps can be reduced.

In this embodiment, since the window temperature is directly detected by using the thermistor 6, it is possible to accurately recognize the window temperature without being affected by the weather or the running condition. Prediction can be made easily. Therefore, it is possible to accurately detect the occurrence of window fogging, and to perform fine humidity control (step control) according to the situation, thereby effectively and efficiently preventing window fogging.

[0024]

As described above, according to the present invention, two sensors, ie, the relative humidity inside the vehicle and the temperature inside the window glass, which are necessary for controlling the humidity for preventing fogging of the window, are respectively detected by one sensor.
It is possible to detect accurately, and the accuracy of control
As a result, the number of sensors can be reduced, leading to a reduction in cost and man-hours for mounting.

[Brief description of the drawings]

FIG. 1 is a block diagram of an air conditioner for a vehicle according to an embodiment of the present invention.

FIG. 2 is a perspective view showing the structure of the sensor unit of FIG.

FIG. 3 is a cross-sectional equivalent view taken along line AA in a state where the sensor unit of FIG. 2 is assembled.

FIG. 4 is a diagram showing an installation example of the sensor unit of the embodiment.

FIG. 5 is a diagram showing a configuration example of a drive circuit of the sensor unit of the embodiment.

FIG. 6 is a main flowchart processed by the embodiment.

FIG. 7 is a flowchart showing the contents of a subroutine of FIG. 6;

FIG. 8 is a flowchart showing the contents of another subroutine of FIG. 6;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Control unit (drive means) 2 ... Sensor unit 5 ... Moisture sensitive element 6 ... Thermistor (temperature sensitive element)

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-56-63513 (JP, A) JP-A-57-172239 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B60H 3/00 B60H 1/00 101

Claims (1)

(57) [Scope of request for utility model registration] 1. A dew point temperature is calculated from a relative humidity in a vehicle interior and a temperature on an inner surface of a window glass, and the humidity in the vehicle interior is controlled based on a temperature difference between the dew point temperature and the inner surface temperature of the window glass to prevent fogging of the window. In the automotive air conditioner that performs control , both the substrate (18) mounted in the sensor case (19)
Moisture sensitive element (5) on one side and temperature sensitive on the other
Each of the elements (6) is mounted, and the sensor case (19) is mounted.
One or more holes for moisture sensitivity (2
0), and the temperature-sensitive element (6) is attached to the substrate (18).
And is isolated from the space on the side of the moisture sensitive element (5).
The surface where the temperature-sensitive element (6) is located is the window glass side and in front
The surface on which the moisture sensitive element (5) is located
A sensor unit (2) attached to the inner surface of the vehicle, and switching between input and output for the humidity sensor (5) and the temperature sensor (6) to detect the vehicle interior relative humidity and the window glass inner surface temperature in a time sharing manner. Driving means (1) for driving the sensor unit (2), and an air conditioner for a vehicle, comprising: