JP2004276857A - Windowpane defogging system for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a novel defogging system for a vehicle for controlling heat quantity given from an electric heater 92 to a windowpane 91. <P>SOLUTION: A windowpane defogging system for the vehicle has the electric heater 92 arranged along the windowpane 91 of the vehicle and an ECU 26 for calculating the heat quantity required for defogging the windowpane 91. The ECU 26 controls the electric heater 92 so as to heat the windowpane 91 based on the calculated heat quantity. Thus, the defogging of the windowpane 91 can be executed controlling the heat quantity given from the electric heater 92 to the windowpane 91 without disturbing air conditioning state within a cabin according to the state of the windowpane 91. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a vehicle windowpane anti-fog device for heating a vehicle windowpane.
[0002]
[Prior art]
Conventionally, a vehicle windowpane anti-fog device has been proposed in which the degree of drying of air blown from an evaporator is adjusted by adjusting the cooling capacity of an evaporator of an air conditioner, and the adjusted dry air is blown toward the windowpane. (For example, see Patent Document 1).
[0003]
[Patent Document 1]
JP-A-2002-137627
[Problems to be solved by the invention]
However, in this anti-fog device, noise is generated from a blower for blowing out dry air, the dry air blown out to the window glass is reflected by the window glass and hits the occupant's head, or the dry air is There are disadvantages such as disturbing the air condition.
[0005]
Therefore, in recent years, in order to avoid the above-described disadvantage, an electric heating glass configured to attach an electric heater to the window glass and directly heat the window glass has been proposed.
[0006]
However, a conventional control method for adjusting the cooling capacity of the evaporator cannot be used to prevent the fogging of the window glass with the electric heater, and the electric heater applies the window glass to the window glass according to the state of the window glass. It is considered that a new control method for controlling the amount of heat is required.
[0007]
In view of the above, an object of the present invention is to provide a novel vehicle windowpane anti-fog device for controlling the amount of heat given to the windowpane from an electric heater according to the state of the windowpane.
[0008]
[Means for Solving the Problems]
In order to achieve the above object, according to the first aspect of the present invention, an electric heater (92) for directly heating a window glass of an automobile and a heating amount required for anti-fog of the window glass are calculated. (S110), and control means (S130, S140) for controlling the electric heater to heat the window glass based on the calculated heating amount.
[0009]
Accordingly, it is possible to provide a novel vehicle windowpane anti-fog device for controlling the amount of heat given to the windowpane from the electric heater according to the state of the windowpane.
[0010]
According to the third aspect of the present invention, when the necessary heating amount is calculated by the calculating means, the temperature inside the vehicle detected by the inside air temperature sensor (28) and the temperature detected by the outside air temperature sensor (29) are detected. It is preferable to use the temperature outside the passenger compartment.
[0011]
Here, as in the invention according to claim 4, the calculating means calculates the required heating amount based on the vehicle interior temperature, the vehicle exterior temperature, and the moving speed detected by the vehicle speed sensor (42). Then, since the required heating amount can be calculated in consideration of the moving speed of the vehicle, the required heating amount can be accurately calculated.
[0012]
In addition, as in the invention described in claim 5, it is preferable to use an electric heater formed in a film shape along the window glass.
[0013]
In addition, if the electric heater is operated when the remaining capacity of the vehicle-mounted battery is low, the remaining capacity of the vehicle-mounted battery may be insufficient due to the operation of the electric heater, and the battery may run out.
[0014]
Therefore, as in the second aspect of the present invention, there is provided an air conditioner (6, 7, 8, 20, 21) for blowing out the conditioned air toward the window glass, and detects the remaining capacity of the vehicle-mounted battery (B). Then, when it is determined that the detected remaining capacity of the vehicle-mounted battery is less than the predetermined level, the control unit controls the electric heater to heat the window glass based on the calculated heating amount. In addition, it is preferable to control the air conditioning means so as to blow out the conditioned air toward the window glass.
[0015]
Incidentally, reference numerals in parentheses of the above-mentioned units are examples showing the correspondence with specific units described in the embodiments described later.
[0016]
BEST MODE FOR CARRYING OUT THE INVENTION
FIG. 1 is a schematic diagram of an air conditioner for a vehicle to which an anti-fog device for a vehicle of the present invention is applied, according to the present embodiment. The air conditioner for a vehicle includes an air conditioning unit 1, An air-conditioning casing 2 constituting a passage for air blown into the vehicle interior of the vehicle.
[0017]
At the air upstream side of the air-conditioning casing 2, there are formed an inside air inlet 3 for sucking the air inside the vehicle and an outside air inlet 4 for sucking the air outside the vehicle. An inlet switching door 5 that selectively opens and closes 3, 4 is provided. The suction port switching door 5 is opened and closed by a servomotor (drive means) 6.
[0018]
A blower 7 is disposed at a downstream side of the inlet switching door 5, and air sucked from both the inlets 3, 4 by the blower 7 is directed to respective outlets 13, 14, 15 described later. Blown.
[0019]
An evaporator (air cooling means) 8 for cooling the air blown by the blower 7 is disposed downstream of the air from the blower 7, and a traveling engine ( (Not shown)), a heater core (air heating means) 9 for heating the air passing through the evaporator 8 using the waste heat as a heat source is provided.
[0020]
The evaporator 8 is a heat exchanger on the low pressure side of a vapor compression refrigeration cycle that exhibits a refrigeration capacity (cooling capacity) by evaporating a refrigerant such as Freon. 23 is a radiator (condenser) for cooling (condensing) the refrigerant discharged from the compressor 22, and 24 is a compressor for vapor-phase refrigerant and liquid-phase refrigerant. Is a receiver (gas-liquid separation means) for storing the surplus refrigerant while flowing out the liquid-phase refrigerant, and a decompressor 25 for decompressing the refrigerant flowing out of the receiver 24.
[0021]
In the air-conditioning casing 2, there is formed a bypass passage 10 that allows air that has passed through the evaporator 8 to bypass the heater core 9 and flow to the downstream side. An air mix door 11 is provided for adjusting the ratio of the air flow to the air flow passing through the bypass passage 10.
[0022]
In this embodiment, the evaporator 8, the heater core 9, the bypass passage 10, and the air mix door 11 constitute a temperature adjusting means for adjusting the temperature of the air blown into the vehicle interior.
[0023]
Further, at the most downstream side of the air-conditioning casing 2, a face outlet 12 for blowing out conditioned air to the upper body of the passenger in the passenger compartment, a foot outlet 13 for blowing air to the feet of the passenger in the passenger compartment, and a front side And a defroster outlet 14 for blowing air toward the inner surface of the windshield 9 with a built-in electric heater. The configuration of the windshield 9 will be described later.
[0024]
The air outlet mode switching doors 15 to 17 are disposed at the air upstream side of the air outlets 12 to 14, respectively. The air outlet mode switching doors 15 to 17 and the air mix door 11 are provided with servo motors ( (Drive means) 18 to 21. The servo motors 6, 20, 21, the blower 7, and the evaporator 8 constitute an air conditioning unit described in the claims.
[0025]
Reference numeral 26 denotes an electronic control unit (hereinafter, referred to as an ECU) that controls the servomotors 6, 18 to 21, the blower 7, and the electromagnetic clutch 22a that transmits power from the engine to the compressor in an intermittent manner. The ECU 26 includes a temperature sensor 27 for detecting an air temperature immediately after passing through the evaporator 8 (hereinafter, this temperature is referred to as an evaporator outlet temperature Te), an inside air temperature sensor 28 for detecting an air temperature in the vehicle compartment, An outside air temperature sensor 29 for detecting the temperature of the air outside the vehicle compartment; a solar radiation sensor 30 for detecting the amount of solar radiation falling into the vehicle; a humidity sensor 40 for detecting the humidity in the vehicle interior; and a windshield 9 with a built-in electric heater on the front side. The detection value of the air conditioning sensor 31 such as the temperature sensor 41 for detecting the temperature of the inner surface of the vehicle, the moving speed of the vehicle detected by the vehicle speed sensor 42, and the vehicle interior temperature (desired) desired by the occupant (person) by manual operation of the occupant A set temperature Tset of a temperature setter (temperature setting means) 32 for setting (inputting) the room temperature is input.
[0026]
Here, a sensor such as a thermistor is used as the temperature sensor 31 to detect the temperature of the inner surface of the inner window glass 91 of the windshield (EHW) 9 with a built-in electric heater. As the vehicle speed sensor 42, a sensor that detects a moving speed of a driving wheel of an automobile based on a rotation speed is used.
[0027]
Reference numeral 33 denotes an inside / outside air switching switch for switching between an inside air mode for introducing room air and an outside air mode for introducing outdoor air, a reference numeral 34 denotes a differential switch for selecting a differential mode, and a reference numeral 35 denotes an evaporator outlet temperature Te of approximately 3 A / C mode for controlling the cooling capacity (electromagnetic clutch 22a) generated in the evaporator 8 so as to maintain the temperature at about ℃, and the cooling capacity generated in the evaporator 8 so that the blowout temperature of the evaporator becomes approximately 12 ° C or less. An ECO (economy) switch for switching to an ECO (economy) mode for controlling the (electromagnetic clutch 22a). Signals from these switches 33 to 35 are also input to the ECU 26.
[0028]
Here, the configuration of the windshield 9 with a built-in electric heater on the front side will be described with reference to FIG. 2. The windshield 9 with a built-in electric heater has an electric heater 92 and a reinforcement between plate-like window glass members 90 and 91. It is configured with the resin film 93 interposed therebetween. As the electric heater 92, a conductive heat generating film formed in a film shape along the outer window glass member 90 is used, and the heat generating film generates heat when electric power is supplied from the ECU 26.
[0029]
Next, the operation of the present embodiment will be described. The ECU 26 executes the anti-fog processing according to the flowchart of FIG. This anti-fog processing is repeatedly executed when the differential switch 34 is turned on manually.
[0030]
First, when the differential switch 34 is turned on manually, the sensor detection values output from the sensors 27 to 30 and 40 to 42 and the set temperature Tset output from the temperature setting device 32 are obtained (S100). . Accordingly, the heat quantity Qdm required for the anti-fog of the windshield 9 with a built-in electric heater is calculated based on the following equation 1 (S110).
[0031]
[Formula 1]
Qdm = Qglass + Qouter + Qinner
Here, Qglass sets the window glass 91 from the current temperature of the window glass 91 to the anti-fog target temperature “TAO (= dew point + constant temperature: α (° C.))” when heat radiation to the outside of the vehicle is not considered. It is the amount of heat required to heat. Then, the heat quantity Qglass is calculated by the following equation 2.
[0032]
[Formula 2]
Qglass = Tg · a1 + Tr · a2 + a3
Here, Tg represents the inner surface temperature of the window glass 91 detected by the temperature sensor 31, and Tr represents the dew point, based on the inner surface temperature Tg and the vehicle interior humidity detected by the humidity sensor 40. Is calculated. Note that a1 and a2 are coefficients, and a3 is a correction constant.
[0033]
Further, Qouter in Equation 1 indicates the amount of heat radiated from the built-in windshield 9 to the outside of the vehicle compartment, and this amount of heat is calculated by the following Equation 3.
[0034]
(Equation 3)
Qouter = Tg · b1 + Tam · b2 + So · b3 + b4
Here, Tam is the outdoor air temperature detected by the outside air temperature sensor 29, and So is the moving speed of the automobile detected by the vehicle speed sensor 42. b1, b2, and b3 are coefficients, respectively, and b4 is a correction constant.
[0035]
Further, Qinner in Equation 1 indicates the amount of heat radiated from the built-in windshield 9 into the vehicle interior, and the amount of heat is calculated by the following Equation 4.
[0036]
(Equation 4)
Qinner = Tg · c1 + Tr · c2 + c3
Here, Tr is the air temperature in the vehicle cabin detected by the inside air temperature sensor 28, c1 and c2 indicate coefficients, and c3 indicates a correction constant.
[0037]
Based on the required heat quantity Qdm calculated as described above, it is determined whether or not the built-in windshield 9 needs anti-fog (S110a). If the required heat quantity Qdm is smaller than zero (Qdm ≦ 0), it is determined that there is no need to prevent the built-in windshield 9 from fogging, and the determination is NO. When the required heat quantity Qdm is greater than zero (Qdm> 0), it is determined that anti-fog on the built-in windshield 9 is necessary, and the determination is YES.
[0038]
When the determination is YES, the voltage of the positive terminal of the on-vehicle battery B (hereinafter referred to as the battery voltage) is sampled, and based on the sampled battery voltage, the anti-fogging to the built-in windshield 9 is performed. It is determined whether only the electric heater 92 is to be used or air-conditioned air is blown out from the defroster outlet 14 to the windshield 9 in addition to the electric heater 92.
[0039]
Specifically, the maximum energizable power Q of the vehicle-mounted battery B is calculated based on the battery voltage based on a characteristic table stored in the memory in advance. As shown in FIG. 4, the characteristic table shows each of the battery voltage, the remaining battery capacity, and the maximum operable power so that the battery voltage, the remaining battery capacity, and the maximum operable power are specified at 1: 1: 1. It contains data.
[0040]
When the maximum energizable power Qehw is calculated based on the characteristic table and the battery voltage in this manner, the maximum energizable power Qehw is compared with the required heat quantity Qdm, and the maximum energizable power Qehw is larger than the required heat quantity Qdm. At this time (0 <Qdm <Qehw), it is determined that only the electric heater 92 should be used to prevent the built-in windshield 9 from fogging. Along with this, based on the power supply from the vehicle-mounted battery B, energization of the electric heater 92 is started, and heating of the window glasses 91, 92 from the electric heater 92 is started. Thereafter, the processing of steps S100 to S130 is repeated until the required heat quantity Qdm is smaller than zero (Qdm ≦ 0) and it is determined that anti-fog is not necessary.
[0041]
When the maximum energizable electric power Qehw is smaller than the required heat quantity Qdm (Qdm ≧ Qehw), air-conditioning air is used in addition to heating by the electric heater 92 to perform anti-fog on the built-in windshield 9. It should be determined.
[0042]
In this case, based on power supply from the vehicle-mounted battery B, energization of the electric heater 92 is started to start heating the window glasses 91, 92 from the electric heater 92, and the servo motors 6, 20, By driving the air conditioner 21 and the like, the conditioned air is blown from the air conditioning unit 1 through the defroster outlet 14 toward the inner surface of the windshield 9.
[0043]
That is, the suction port switching door 5 is rotated by the servo motor 6 to open the inside air suction port 3 and close the outside air suction port 4. Further, the opening degree SW of the air mix door 11 is determined based on the anti-fog target temperature TAO obtained by adding the constant temperature α to the above-described dew point Tr. Then, the air mix door 11 is rotated by the servo motor 21 so that the opening of the door is made to approach the above-mentioned determined opening SW. Further, the electromagnetic clutch 22a (that is, the operating rate of the compressor 22) is controlled so that the evaporator blowout temperature approaches a constant temperature. Further, a constant voltage is output to the electric motor of the blower 7.
[0044]
The opening degree SW of the air mix door 11 is determined based on the following equation (5).
[0045]
(Equation 5)
SW (%) = (TAO-Te) / (Tw-Te) × 100
Te: Evaporator outlet temperature (temperature detected by sensor 27)
Tw: When the servo motors 6, 20, 21 and the like are driven at a temperature equal to or higher than the temperature of the hot water flowing into the heater core 9, air is sucked from the vehicle interior by the blower 7 through the inside air suction port 3. Then, the air is dehumidified by the evaporator 8, and the dehumidified air flow is divided by the air mix door 11 into an air flow flowing into the bypass passage 10 and an air flow flowing into the heater core 9. Further, the two air flows are mixed and air is blown out from the defroster outlet 14 toward the inner surface of the windshield 9 with a built-in electric heater on the front side as conditioned air. Accordingly, the windshield 9 is prevented from fogging by using the conditioned air in addition to the heating by the electric heater 92.
[0046]
Next, the operation and effect of the present embodiment will be described. That is, it has an electric heater 92 mounted along the window glass 91 of the automobile, and an ECU 26 for calculating a heating amount necessary for anti-fog of the window glass 91. The ECU 26 calculates the heating amount based on the calculated heating amount. The electric heater 92 is controlled so that the window glass 91 is heated. Thus, it is possible to provide a novel device for controlling the amount of heat applied from the electric heater 92 to the window glass 91 in accordance with the state of the window glass 91 without disturbing the air conditioning state in the vehicle interior.
[0047]
Here, although the amount of heat radiated from the front windshield 9 to the outside of the vehicle compartment greatly changes according to the traveling speed of the vehicle, in the present embodiment, the ECU 26 determines the vehicle interior temperature, the vehicle exterior temperature, and the vehicle traveling speed. , The required heating amount is calculated, and thus the required heating amount can be accurately calculated. Thus, the amount of heat given from the electric heater 92 to the window glass 91 can be controlled with high accuracy.
[0048]
Further, if the electric heater 92 is operated when the remaining capacity of the vehicle-mounted battery B is small, the remaining capacity of the vehicle-mounted battery B may be insufficient due to the operation of the electric heater 92, which may cause the battery to run down.
[0049]
Therefore, the air conditioner unit 1 that blows out conditioned air toward the window glass detects the remaining capacity of the vehicle-mounted battery (B), and determines that the detected remaining capacity of the vehicle-mounted battery is less than a predetermined level. At this time, based on the necessary heating amount calculated as described above, the electric heater 92 is controlled so as to heat the window glass 91, and the servomotors 6, 20, and 21. The electric motor of the blower 7 is controlled.
[0050]
As a result, the fogging of the window glass 91 is performed by the electric heater 92 and the conditioned air, so that the power consumption of the vehicle-mounted battery B can be reduced and the battery can be prevented from running out.
[0051]
(Other embodiments)
In the above-described embodiment, an example has been described in which the temperature of the inner surface of the window glass 91 of the front windshield 9 (hereinafter, referred to as a glass temperature) is detected using the temperature sensor 41 such as a thermistor. Without using a temperature sensor 41 such as a thermistor, the air temperature in the vehicle interior, the air temperature outside the vehicle interior, the vehicle speed, the amount of solar radiation, the amount of current (current value) from the ECU 26 to the electric heater 92, the time of energization and the glass temperature Stores a characteristic table (data map) specified by 1: 1: 1: 1: 1: 1: 1, respectively, and stores the characteristic table, vehicle interior air temperature, vehicle exterior air temperature, vehicle speed, and solar radiation. The window glass temperature may be estimated on the basis of the amount of current and the time of energization.
[0052]
In the above-described embodiment, the electric heater 92 is controlled using the glass temperature. However, instead of this, not only the glass temperature but also the temperature change characteristic (temperature change) of the inner surface of the window glass 91 due to energization of the electric heater 92. The anti-fogging may be performed by controlling the amount of current (current value) to the electric heater 92 by using the (change speed) to adjust the amount of heating from the electric heater 92 to the window glass 91.
[0053]
In the above-described embodiment, an example has been described in which the windshield on the front side is directly heated by the electric heater 92 to prevent fogging (defrosting). Anti-fog (thaw) may be performed by directly heating the side windshield or the back side windshield.
[Brief description of the drawings]
FIG. 1 is a schematic diagram showing one embodiment of an automotive air conditioner according to the present invention.
FIG. 2 is a sectional view showing a configuration of the windshield of FIG.
FIG. 3 is a flowchart showing an anti-fogging process of the ECU of FIG. 1;
FIG. 4 is a chart showing a characteristic table required for calculating a maximum energizable capacity of a battery.
[Explanation of symbols]
18-21: Servo motor, 26: ECU,
91: window glass, 92: electric heater.

Claims (5)

An electric heater (92) for directly heating a window glass of an automobile;
Calculating means (S110) for calculating a heating amount required for anti-fog of the window glass;
Control means (S130, S140) for controlling the electric heater so as to heat the window glass based on the calculated amount of heating. Air-conditioning means (6, 7, 8, 20, 21) for blowing air-conditioned air toward the window glass;
When the remaining capacity of the vehicle-mounted battery (B) is detected, and it is determined that the detected remaining capacity of the vehicle-mounted battery is less than the predetermined level, the control unit performs, based on the calculated heating amount, 2. The vehicle windowpane according to claim 1, wherein the electric heater is controlled so as to heat the windowpane, and the air-conditioning unit is controlled so as to blow conditioned air toward the windowpane. 3. Fogging equipment. An inside air temperature sensor (28) for detecting a vehicle interior temperature;
An outside air temperature sensor (29) for detecting a vehicle outside temperature,
The vehicle window glass anti-fog device according to claim 1, wherein the calculation unit calculates the required heating amount based on the vehicle interior temperature and the vehicle exterior temperature. The said calculation means calculates the said required heating amount based on the vehicle interior temperature, the vehicle exterior temperature, and the moving speed detected by the speed sensor (42) of a vehicle. Anti-fog equipment for vehicle window glass. The fogging device according to any one of claims 1 to 4, wherein the electric heater is formed in a film shape along the window glass.

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