JP2007145214A - Window fog detection device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a window fog detection device of a humidity detection method capable of precisely carrying out humidity detection for a long period of time. <P>SOLUTION: Relative humidity of air on the indoor side is detected by a humidity sensor 17 by detecting fog of a window glass by an optical type fog detection sensor constituted of a luminous element and a light receiving element 16. This window fog detection device has a relative humidity operation circuit 20b to operate relative humidity of the indoor side air in a specified operation expression in accordance with an output value of the humidity sensor 17 and self-compensates the humidity operation expression by a compensation circuit 20e when the fog of the window glass 12 is determined in accordance with an output value of the optical type fog detection sensor. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a window fogging detection apparatus, and is suitable for use in controlling a vehicle air conditioner.

  Conventionally, a window fogging detection device for a vehicle can be classified mainly into the following two types. The first is a method for estimating window fogging (hereinafter referred to as a humidity detection method) from a comparison between the glass temperature and the dew point temperature of the surrounding air. Here, the dew point temperature is obtained by a calculation formula from the output of the humidity sensor installed in the passenger compartment and the output of the air temperature sensor. The glass temperature includes a method of detecting contact with a temperature sensor disposed on the inner surface of the glass, a method of detecting non-contact with an infrared sensor, and a method of estimating with a calculation formula from the outside temperature, vehicle speed, vehicle interior temperature, and the like.

  In such a humidity detection method, instead of comparing the glass temperature and the dew point temperature, the relative humidity of the room air is converted to the relative humidity at the glass temperature (hereinafter referred to as the glass surface relative humidity), Some of them are cloudy, and the explanation will be made in this manner.

  The second method is a non-contact method (hereinafter referred to as an optical method) for detecting fogging generated on the inner surface of the glass by an optical sensor. This optical system includes a light receiving element and a light emitting element, and detects a decrease in directly reflected light due to window fogging (see, for example, Patent Document 1), and detects an increase in scattered reflected light due to window fogging (for example, Patent Documents 2 and 3). Furthermore, there is a method for determining that fogging has occurred due to image processing among optical methods (see, for example, Patent Document 4).

  In these prior arts, the aim of window fogging detection is to exhibit the following three effects a to c.

  (A) The dehumidifying operation (compressor operation) of the air-conditioning refrigeration cycle is reduced within a range where the vehicle window is not fogged, thereby reducing the operating rate of the dehumidifying operation and reducing the compressor power. This can contribute to a reduction in fuel consumption of the vehicle engine that drives the compressor.

  (B) The window fogging of the vehicle is prevented by determining the window fogging of the vehicle and performing control to improve the window fogging prevention performance of the vehicle air conditioner.

(C) At the time of low temperatures in winter, the ratio of the intake air in the vehicle air conditioner is increased within a range in which the window is not fogged, thereby reducing ventilation heat loss and improving heating performance.
JP 59-108939 A JP 2000-296762 A JP-A-5-294139 JP 2004-212404 A

  By the way, in the former humidity detection method, since there are variations in detection accuracy and durability deterioration of the humidity sensor, in order to control so that window fogging does not occur, it is larger than the output value of the humidity sensor in the window fogging determination. It is necessary to set a safety factor. As a result, the compressor power reduction effect a and the ventilation heat loss reduction effect c cannot be sufficiently exhibited.

  In the latter optical method, since the detection accuracy is higher than the humidity detection method, it is not necessary to increase the safety factor of the fogging determination of the window, and the above effects a and c can be sufficiently exhibited. On the other hand, since only clouding of the part where the sensor is installed is detected in the window glass, there is a risk that window fogging occurs in an area other than the sensor installation part. In addition, since the position at which window fogging starts varies depending on the vehicle, there is a problem such that the adaptation work for determining the sensor installation site during vehicle development becomes complicated.

  The present invention has been made in view of the above points, and an object of the present invention is to enable humidity detection to be performed accurately over a long period of time in a humidity detection type window fogging detection apparatus.

  Another object of the present invention is to make it possible to accurately detect fogging in an optical window fogging detection apparatus over a long period of time.

In order to achieve the above object, according to the first aspect of the present invention, an optical fog detection sensor (15, 16) for optically detecting fogging of the window glass (12),
A humidity sensor (17) for detecting the relative humidity of the indoor air;
Sensor output correcting means (20e) for correcting the output value of the humidity sensor (17) when the fogging of the window glass (12) is determined based on the output value of the optical fogging detection sensor (15, 16). , S20, S90).

  By the way, the time when the window glass (12) is fogged is when the surface relative humidity of the window glass (12) reaches 100%. The fogging of the window glass (12) can be accurately determined based on the output values of the optical fogging detection sensors (15, 16).

  Therefore, according to the first aspect, the measurement variation and the durability deterioration of the humidity sensor (17) can be self-corrected by the sensor output correcting means (20e, S20, S90) on the basis of the surface relative humidity = 100%. As a result, it is possible to accurately perform humidity detection over a long period of time by eliminating the influence of measurement variations and durability deterioration.

  In addition, according to only the optical method, there is a problem that only the cloudy part of the window glass where the sensor is installed can be detected, but the invention of claim 1 is basically a humidity detection type window fogging detection device. Such inconvenience does not occur and window fogging over the entire window glass can be detected appropriately.

In the invention according to claim 2, in the window fogging detecting device according to claim 1, further, an air temperature sensor (18) for detecting the temperature of the indoor air,
A glass temperature sensor (23) for detecting the temperature of the window glass (12);
Glass surface relative humidity calculating means (20f, S50) for calculating the glass surface relative humidity based on the output values of the humidity sensor (17), the air temperature sensor (18) and the glass temperature sensor (23). It is characterized by that.

  According to this, since the window glass surface relative humidity directly connected to the presence or absence of fogging of the window glass can be calculated, the anti-fog control of the air conditioning can be executed using the calculated value of the window glass surface relative humidity.

According to a third aspect of the present invention, in the window fogging detecting device according to the first or second aspect, the relative humidity of the indoor air is calculated by a predetermined arithmetic expression based on the output value of the humidity sensor (17). A relative humidity calculating means (20b, S20),
The sensor output correcting means (20e, S20, S90) calculates the relative humidity when the fogging of the window glass (12) is determined based on the output value of the optical fogging detection sensor (15, 16). The arithmetic expression is corrected so that the calculated value of the means (20b, S20) is the relative humidity at the indoor air temperature when the glass surface relative humidity is 100%.

  According to this, by correcting the calculation formula in the relative humidity calculation means (20b, S20), the calculated value of the relative humidity can be corrected to an appropriate value.

According to a fourth aspect of the present invention, in the window fogging detection device according to the second aspect, the optical fogging detection sensor includes a light emitting element (15) and a light receiving element (16).
The light emitting element (15), the light receiving element (16), the humidity sensor (17), the air temperature sensor (18) and the glass temperature sensor (23) are on the inner surface (12a) of the window glass (12). It is characterized by being configured as an integral structure.

  Thereby, various sensors can be integrated and the mounting work etc. to a vehicle can be performed easily.

  According to a fifth aspect of the present invention, in the window fogging detecting device according to the fourth aspect, the light emitting element (15), the light receiving element (16), the humidity sensor (17), and the air temperature sensor (18). Are arranged on the same circuit board (14).

  Thereby, various sensors can be integrated on the same circuit board (14).

In invention of Claim 6, in the window fogging detection apparatus of Claim 4 or 5, it is arrange | positioned on the inner surface (12a) of the said window glass (12), and inner space of the said window glass (12) A case (11) having a communication opening (11a) formed therein,
The light emitting element (15), the light receiving element (16), the humidity sensor (17), the air temperature sensor (18), and the glass temperature sensor (23) are accommodated in the one case (11). It is characterized by that.

  According to this, various sensors can be accommodated in one common case (11).

  According to a seventh aspect of the present invention, in the window fogging detecting device according to the sixth aspect, the distance between the light emitting element (15) and the light receiving element (16) and the inner surface (12a) of the window glass (12) is set. The positioning means (11b) for defining is provided in the case (11).

  According to this, the accuracy of optical fog detection can be ensured by defining the distance between the light emitting / receiving elements (15, 16) and the inner surface (12a) of the window glass (12) constant.

In invention of Claim 8, in the window fogging detection apparatus as described in any one of Claim 4 thru | or 7, it is excellent in thermal conductivity and light reflectivity on the inner surface (12a) of the said window glass (12). A shading film (13) was affixed,
The light from the light emitting element (15) is reflected by the light shielding film (13) and is incident on the light receiving element (16).

  According to this, since the light shielding film (13) is excellent in thermal conductivity, the temperature of the light shielding film (13) is almost the same as the inner surface temperature of the window glass (12). Clouding occurs under the same temperature conditions as the window glass (12). Since the disturbance light passing through the window glass (12) can be blocked by the light shielding film (13) from being incident on the light receiving element (16), the accuracy of fog detection by the light receiving and emitting elements (15, 16) can be improved. .

  As in the ninth aspect of the present invention, in the window fogging detection apparatus according to the eighth aspect, the glass temperature sensor (23) may be integrally disposed on the light shielding film (13).

  According to a tenth aspect of the present invention, in the window fogging detecting device according to any one of the fourth to ninth aspects, the light emitting element (15) emits pulses at predetermined time intervals. And

  According to this, an increase in ambient ambient temperature due to heat generation of the light emitting element (15) can be suppressed.

In invention of Claim 11, the optical fog detection sensor (15, 16) which optically detects the fog of the window glass (12),
A humidity sensor (17) for detecting the relative humidity of the indoor air;
An air temperature sensor (18) for detecting the temperature of the indoor air,
The optical clouding detection sensor includes an infrared light emitting element (15) and an infrared light receiving element (16).
The infrared light emitting element (15) is caused to emit pulse light at a predetermined time interval,
When the infrared light emitting element (15) emits light, clouding of the window glass (12) is detected based on the amount of light received by the infrared light receiving element (16). On the other hand, when the infrared light emitting element (15) does not emit light, the infrared light receiving element is received. The temperature of the window glass (12) is detected by the amount of light received by the element (16),
And sensor output correction means (20e, S90) for correcting the output value of the humidity sensor (17) when the infrared light receiving element (16) detects fogging of the window glass (12);
Glass surface relative humidity for calculating the glass surface relative humidity based on the output values of the humidity sensor (17) and the air temperature sensor (18) and the output value of the glass temperature detected by the infrared light receiving element (16). And an arithmetic means (20f, S50).

  According to this, since the measurement variation and durability deterioration of the humidity sensor (17) can be self-corrected by the sensor output correction means (20e, S20, S90) as in claim 1, the measurement variation and durability deterioration can be corrected. The humidity can be detected accurately over a long period of time by eliminating the influence. And since the window glass surface relative humidity directly linked to the presence or absence of fogging of the window glass can be calculated in the same manner as in claim 2, the anti-fogging control of the air conditioning can be executed using the calculated value of the window glass surface relative humidity.

  Moreover, when the infrared light emitting element (15) constituting the optical fogging detection sensor emits light, the fogging of the window glass (12) is detected based on the amount of light received by the infrared light receiving element (16), while the infrared light emitting element (15) When the light is not emitted, the temperature of the window glass (12) is detected based on the amount of light received by the infrared light receiving element (16). Therefore, the infrared light receiving element (16) can also function as a window glass temperature detecting function in addition to the fogging detecting function. Therefore, a temperature sensor dedicated to window glass temperature detection can be eliminated.

In the invention according to claim 12, the inside / outside air switching means (35) for opening and closing the inside air introduction port (33) and the outside air introduction port (34) to switch between the intake of the inside air and the outside air,
A blowing means (37) for blowing air introduced through the inside air introduction port (33) and the outside air introduction port (34) toward the vehicle interior;
A cooling heat exchanger (38) for cooling the blowing air of the blowing means (37);
A heating heat exchanger (44) for heating the blown air of the blowing means (37);
A plurality of outlets (48, 49, 50) through which the air whose temperature is adjusted after passing through the cooling heat exchanger (38) and the heating heat exchanger (44) are blown into the vehicle interior;
A blow mode door (51, 52, 53) for switching the blow mode by opening and closing the plurality of blow outlets (48, 49, 50);
The plurality of air outlets (48, 49, 50) are provided with a defroster air outlet (48) for blowing air toward the front window glass (12) of the vehicle,
A window fogging detection device according to any one of claims 2, 4 to 11 is arranged on the inner surface of the front window glass (12),
Based on the calculated value of the glass surface relative humidity calculating means (20f, S50), the inside / outside air switching control by the inside / outside air switching means (35), the air volume control by the air blowing means (37), and the blowing mode door (51 , 52, 53) is characterized by a vehicle air conditioner that executes at least one of the blowing mode switching control.

  According to this, at least one of the inside / outside air switching control, the air volume control of the blowing means (37), and the blowing mode switching control is executed based on the relative humidity on the glass surface, and the antifogging control of the vehicle window glass by the air conditioner is performed. It can be done automatically.

  In addition, when the inside / outside air suction control is performed so that the inside / outside air suction is switched so that the inside air ratio is increased in a range where the window is not fogged, the ventilation heat loss can be reduced and the heating performance can be improved.

In invention of Claim 13, in the vehicle air conditioner of Claim 12, it has a compressor (40) which circulates a refrigerant | coolant to the said heat exchanger (38) for cooling,
Set a target value of the cooling degree of the cooling heat exchanger (38) so that the glass surface relative humidity is within a predetermined range,
The capacity of the compressor (40) is controlled so that the actual cooling degree of the cooling heat exchanger (38) becomes the target value.

  According to this, by controlling the cooling degree of the cooling heat exchanger (38), the glass surface relative humidity can be controlled within a predetermined range, and the anti-fogging control of the vehicle window glass can be automatically performed.

In invention of Claim 14, the light emitting element (15) which irradiates light toward a window glass (12), The light receiving element (16) which receives the reflected light (B) from the said window glass (12), An optical fog detection sensor comprising:
A haze degree calculating means (S60a) for calculating a haze degree determination value (Fw) based on the ratio (B / A) of the irradiation light (A) from the light emitting element (15) and the reflected light (B);
Fogging determination means (S70a) for determining the fogging of the window glass (12) based on the fogging degree determination value (Fw);
When it is determined by the fogging determination means (S70a) that the window glass (12) is not fogged, the fog degree determination value (Fw) is a value indicating a state in which the window glass (12) is not fogged. The first correction means (S140) for correcting the calculation formula of the cloudiness degree determination value (Fw) is provided.

  According to this, even when it is determined that the window glass (12) is not fogged, even if the light emitting element (15) itself is deteriorated in durability, or the window glass reflecting surface is stained due to adhesion of tobacco fat or the like. The cloudiness degree determination value (Fw) can be normalized in a state where these error factors are eliminated. As a result, the optical fogging detection accuracy can be improved for a long time without being affected by a decrease in irradiation light (A) due to durability deterioration of the light emitting element (15) and a decrease in reflected light (B) due to dirt on the window glass reflection surface. Can be maintained well over.

As in the invention described in claim 15, in the window fogging detecting device according to claim 14, specifically, the fogging degree calculating means (S60a) is in a state where the window glass (12) is not fogged. 1 or a value in the vicinity of 1 is calculated as the cloudiness degree determination value (Fw),
The fog determination means (S70a) sets a predetermined threshold value smaller than 1, and determines the fogging of the window glass (12) when the fog degree determination value (Fw) decreases below the threshold value. ,
The first correction means (S140) may correct the arithmetic expression so that the cloudiness degree determination value (Fw) is 1 or a value close to 1.

According to a sixteenth aspect of the present invention, in the window fogging detecting device according to the fourteenth or fifteenth aspect, there is provided an ambient temperature determination means (S110) for determining whether the ambient temperature of the optical fogging detection sensor is a predetermined temperature or less. And
Only when the ambient temperature is equal to or lower than a predetermined temperature, the optical cloudiness detection sensor is activated to calculate the cloudiness degree determination value (Fw).

  Here, the predetermined temperature is a temperature in a high temperature range in which fogging of the window glass does not occur, and specifically, for example, a temperature of about 35 ° C.

  According to the sixteenth aspect, since the cloudiness determination is performed only when the ambient temperature is equal to or lower than the predetermined temperature (low temperature), the luminance characteristic of the light emitting element (15) decreases at a high temperature, and the influence of the temperature characteristic that the reflected light decreases. Not receive. In addition, since the optical fogging detection sensor is activated only when the ambient temperature is lower than a predetermined temperature, the high-temperature deterioration of the light emitting element (15) can be suppressed and the cumulative use time of the light emitting element (15) can be reduced. Thus, the durable life of the light emitting element (15) can be extended.

  Moreover, since the window glass does not fog when the ambient temperature is higher than the predetermined temperature, there is no practical problem even if the fog determination is stopped when the ambient temperature is high.

  In the invention according to claim 17, in the window fogging detecting device according to any one of claims 14 to 16, when it is determined that the window glass (12) is not fogged, the calculation formula correction is performed. The arithmetic equation is corrected only when a predetermined period has elapsed from the previous execution time.

  By the way, the phenomenon in which the cigarette fat or the like adheres to the window glass reflecting surface and the durability deterioration of the light emitting element (15) proceeds very slowly over time. Therefore, in claim 17, the correction of the next calculation formula is performed unnecessarily frequently by correcting the next calculation formula only when a predetermined period (for example, 30 days) has elapsed from the previous execution timing of the calculation formula correction. Can be prevented.

In the invention according to claim 18, in the window fogging detecting device according to any one of claims 14 to 17, a humidity sensor (17) for detecting a relative humidity of indoor air;
Humidity calculating means (S20) for calculating the output value of the humidity sensor (17);
And second correction means (S90) for correcting a humidity calculation formula in the humidity calculation means (S20) when the fogging determination means (S70a) determines that the window glass (12) is fogged. It is characterized by that.

  According to this, the optical fog detection accuracy can be maintained well over a long period of time, and at the same time, as in the case of claim 1, measurement variations and durability deterioration of the humidity sensor (17) can be self-corrected. It can be performed accurately over a long period of time.

  In addition, the code | symbol in the bracket | parenthesis of each said means shows the correspondence with the specific means as described in embodiment mentioned later.

(First embodiment)
The first embodiment relates to a window fogging detection device and a vehicle air conditioner using the window fogging detection device. FIG. 1 shows a state in which the window fogging detection device according to this embodiment is mounted on the inner surface of a vehicle window glass. FIG. 2 is a schematic perspective view of FIG. FIG. 3 is a system configuration diagram of electrical control in the first embodiment.

  First, a specific example of the window fogging detection device portion will be described with reference to FIGS. The window fogging detection device 10 has a case 11 formed of resin or the like. The case 11 has a thin rectangular parallelepiped shape with a low height, and has a bottom surface that is fully open.

  Convex openings 11 a are formed on the front and back wall surfaces of the case 11. The front and rear openings 11a allow the internal space of the case 11 to always communicate with the surrounding space, that is, the vehicle interior space. Of the wall surfaces of the front surface and the back surface of the case 11, the left and right side portions of the opening portion 11 a constitute an attachment stay portion 11 b to the inner surface 12 a of the window glass 12.

  The window glass 12 is a front (front) glass of the vehicle in this example, and the upper surface side of FIG. 1 is an inner surface 12a facing the vehicle interior, and the lower surface side of FIG. 1 is an outer surface 12b facing the vehicle interior. Accordingly, FIG. 2 illustrates the inner surface 12 a of the window glass 12. The light shielding film 13 is affixed to the lower end surface of the attachment stay part 11b, and further, the light shielding film 13 is affixed to the inner surface 12a of the window glass 12.

  The light shielding film 13 is a thin film member made of a metal light shielding material having a high thermal conductivity such as aluminum, and prevents light from entering the case 11 through the window glass 12. In addition, what is necessary is just to affix the light shielding film 13 on the lower end surface of the attachment stay part 11b, and the inner surface of the window glass 12 by means, such as adhesion | attachment.

  In the internal space of the case 11, the circuit board 14 is disposed parallel to the surface of the window glass 12 between the upper end portion of the opening 11 a and the upper wall surface 11 c, and the circuit board 14 is attached to the inner wall surface of the case 11 by attachment means (not shown). Fixed to. The circuit board 14 is a member generally called a printed circuit board that constitutes a conductor circuit section on an insulating substrate, and is mounted with sensors and circuit sections described below.

  A light emitting element 15, a light receiving element 16, a humidity sensor 17, an air temperature detecting temperature sensor 18, an amplifier 19, an arithmetic circuit 20, A communication circuit 21 is mounted.

  The humidity sensor 17 and the temperature sensor 18 are arranged in the center of the circuit board 14 in the longitudinal direction (left and right direction in FIGS. 1 and 2), and are near the upper end of the opening 11a, that is, at the communication part to the vehicle interior space. Has been placed. For this reason, the humidity sensor 17 and the temperature sensor 18 can detect the typical humidity and temperature of the air near the inner surface of the window glass in the vehicle interior.

  A temperature sensor 23 for detecting the glass temperature is integrally arranged at one location on the surface of the light shielding film 13 on the sensor side. Since the light shielding film 13 is a thin film-like member having a high thermal conductivity as described above, the temperature is substantially the same as the vehicle interior side surface temperature (inner surface temperature) of the window glass 12.

  In this example, the humidity sensor 17 is a capacitance change type sensor in which the dielectric constant of the moisture sensitive film changes according to the relative humidity of the air, whereby the capacitance changes according to the relative humidity of the air. Used. As the temperature sensors 18 and 23, thermistors whose resistance values change according to the temperature are used. In addition, a light emitting diode is used as the light emitting element 15, and a photodiode whose output current changes according to the amount of received light is used as the light receiving element 16.

  The photodiode constituting the light receiving element 16 has a characteristic that the output current increases as the amount of received light increases. When fogging occurs on the window glass, more specifically, the light-shielding film 13, scattered light is generated by the cloudy water droplets, and the reflected light toward the photodiode is reduced. Output current decreases.

  A lens 22 is disposed at the light exit portion of the light emitting element 15. When the light from the light emitting element 15 is reflected by the surface of the light shielding film 13 and reaches the light receiving element 16, the lens 22 collects the reflected light so that the light receiving element 16 focuses. A filter 24 is disposed on the entrance side of the light receiving element 16. This filter 24 passes only light around the wavelength range of the light emitted by the light emitting element 15.

  In addition, the surface (upper side surface in FIG. 1) on the sensor side of the light shielding film 13 is glossed so that the light reflectance of the light shielding film 13 is increased. Thus, a large difference is produced in the amount of light reflected toward the light receiving element 16 depending on whether or not the surface of the light shielding film 13 is clouded, thereby facilitating cloud detection.

  The lead wire 25 is a power supply line and a communication line that are taken out from the internal space of the case 11 to the outside of the case 11. The air-conditioning control device 26 of FIG. 4 described later, a vehicle power source, etc.) are electrically connected.

  The mounting stay 11b of the case 11 described above serves as a positioning means for defining the distance between the circuit board 14 and various sensors mounted on the circuit board 14 and the inner surface 12a of the window glass 12.

  Next, the system configuration of electrical control will be described with reference to FIG. 3. The output signals of the light receiving element 16 and the sensors 17, 18 and 23 are amplified by the amplifiers 19a to 19d and applied to the arithmetic circuits 20a to 20d.

  Then, an arithmetic expression correction circuit 20e that corrects the humidity arithmetic expression based on the arithmetic value of the fogging determination arithmetic circuit 20a, an arithmetic value of the relative humidity arithmetic circuit 20b, an arithmetic value of the air temperature arithmetic circuit 20c, and a glass temperature arithmetic circuit A glass surface relative humidity calculation circuit 20f for calculating the glass surface relative humidity based on the calculated value of 20d is provided, and the calculated value of the calculation circuit 20f and the calculated value of the fogging determination calculation circuit 20a are transmitted through the communication circuit 21 to the air conditioning control device 26. To output.

  Next, the outline of the entire system of the vehicle air conditioner will be described with reference to FIG. The indoor air conditioning unit 30 is disposed on the inside of the instrument panel (instrument panel) at the forefront of the vehicle interior. The indoor air conditioning unit 30 has a case 31 and constitutes an air passage through which air is blown toward the vehicle interior.

  An inside / outside air switching box 32 is arranged at the most upstream part of the air passage of the case 31, and the inside / outside air inlet 33 and the outside air inlet 34 are switched by an inside / outside air switching door 35. The inside / outside air switching door 35 is driven by a servo motor 36.

  On the downstream side of the inside / outside air switching box 32, an electric blower 37 that blows air toward the passenger compartment is disposed. The blower 37 is configured to drive a centrifugal blower fan 37a by a motor 37b. An evaporator 38 serving as a cooling heat exchanger for cooling the blown air is disposed on the downstream side of the blower 37.

  The evaporator 38 is one of the elements constituting the refrigeration cycle apparatus 39, and cools the blown air by evaporating the low-temperature and low-pressure refrigerant by absorbing heat from the blown air. Note that the refrigeration cycle apparatus 39 is a well-known one so that the refrigerant circulates from the discharge side of the compressor 40 to the evaporator 38 via the condenser 41, the liquid receiver 42, and the expansion valve 43 serving as a pressure reducing means. It is configured. Outdoor air (cooling air) is blown to the condenser 41 by an electric cooling fan 41a. The cooling fan 41a is driven by a motor 41b.

  In the refrigeration cycle apparatus 39, the compressor 40 is driven by a vehicle engine (not shown) via an electromagnetic clutch 40a. Therefore, the operation of the compressor 40 can be intermittently controlled by the energization of the electromagnetic clutch 40a.

  On the other hand, in the indoor air conditioning unit 30, a heater core 44 that heats the air flowing in the case 31 is disposed downstream of the evaporator 38. The heater core 44 is a heating heat exchanger that heats the air (cold air) that has passed through the evaporator 38 using hot water (engine cooling water) of the vehicle engine as a heat source. A bypass passage 45 is formed on the side of the heater core 44, and the bypass air of the heater core 44 flows through the bypass passage 45.

  Between the evaporator 38 and the heater core 44, an air mix door 46 serving as a temperature adjusting means is rotatably arranged. The air mix door 46 is driven by a servo motor 47 so that its rotational position (opening) can be continuously adjusted.

  The ratio of the amount of air passing through the heater core 44 (warm air amount) and the amount of air passing through the bypass passage 45 and bypassing the heater core 44 (cold air amount) is adjusted by the opening of the air mix door 46, The temperature of the air blown into the room is adjusted.

  At the most downstream part of the air passage of the case 31, a defroster outlet 48 for blowing conditioned air toward the front window glass 12 of the vehicle, a face outlet 49 for blowing conditioned air toward the face of the occupant, In addition, there are provided a total of three types of air outlets, foot outlets 50 for blowing air-conditioned air toward the feet of passengers.

  A defroster door 51, a face door 52, and a foot door 53 are rotatably disposed upstream of the air outlets 48 to 50. These doors 51 to 53 are opened and closed by a common servo motor 54 through a link mechanism (not shown).

  The air conditioning control device 26 includes a known microcomputer including a CPU, a ROM, a RAM, and the like and peripheral circuits thereof. The air conditioning control device 26 stores a control program for air conditioning control in its ROM, and performs various calculations and processes based on the control program.

  In addition to the calculation value of the detection device 10 described above being input to the air conditioning control device 26, detection signals from the well-known air conditioning sensor groups 61 to 65 and various operation signals from the air conditioning operation panel 70 are input. .

  Specifically, the air conditioning sensor group includes an outside air sensor 61 that detects an outside air temperature (outside temperature of the passenger compartment) Tam, an inside air sensor 62 that detects an inside air temperature (inside temperature of the passenger compartment) Tr, and an amount of solar radiation Ts incident on the inside of the passenger compartment. A solar radiation sensor 63 for detecting the temperature, an evaporator temperature sensor 64 for detecting the evaporator blown air temperature Te disposed in the air blowing portion of the evaporator 38, and a water temperature for detecting the temperature Tw of hot water (engine cooling water) flowing into the heater core 44. A sensor 65 or the like is provided.

  In addition, the air conditioning operation panel 70 includes various air conditioning operation members, such as a temperature setting switch 71 serving as a temperature setting means for setting the vehicle interior temperature, a blow mode switch 72 for manually setting the blow mode switched by the blow mode doors 51 to 53, and the inside and outside. Inside / outside air switching switch 73 for manually setting the inside / outside air suction mode by the air switching door 35, an air conditioner switch 74 for issuing an operation command signal for the compressor 40 (ON signal of the electromagnetic clutch 40a), and a blower operation for manually setting the air volume of the blower 37 A switch 75, an auto switch 76 for outputting a command signal for the air conditioning automatic control state, and the like are provided.

  On the output side of the air-conditioning control device 26, there are an electromagnetic clutch 40a of the compressor 40, servo motors 36, 47, 54 as electric drive means for each device, a motor 37b of the blower 37, a motor 41b of the condenser cooling fan 41a, and the like. The operation of these devices is controlled by the output signal of the air conditioning control device 26.

  Next, the operation of this embodiment in the above configuration will be described. First, the outline of the operation of the indoor air conditioning unit 30 will be described. By operating the blower 37, the air introduced from the inside air introduction port 33 or the outside air introduction port 34 is blown into the vehicle interior through the case 31. . Also, the refrigerant is circulated in the refrigeration cycle device 39 by energizing the electromagnetic clutch 40a to bring the electromagnetic clutch 40a into a connected state and driving the compressor 40 with a vehicle engine.

  The air blown from the blower 37 is first cooled and dehumidified through the evaporator 38, and this cold air is then passed through the heater core 44 according to the rotational position (opening) of the air mix door 46 (warm air). The flow passes through the bypass passage 45 (cold air).

  Therefore, by adjusting the ratio of the amount of air passing through the heater core 44 (warm air amount) and the amount of air passing through the bypass passage 45 (cold air amount) by the opening of the air mix door 46, the temperature of the air blown into the vehicle interior Can be adjusted.

  Then, the temperature-conditioned conditioned air is supplied from any one or a plurality of outlets among the defroster outlet 48, the face outlet 49 and the foot outlet 50 located at the most downstream portion of the air passage of the case 31. It blows out into the passenger compartment to air-condition the passenger compartment and prevent fogging of the front window glass 12 of the vehicle.

  Next, the operation of the fog detection device 10 according to the present embodiment will be described with reference to FIG. FIG. 5 is a control routine executed by the arithmetic circuit 20 of FIG. 3. This control routine is started by the start of operation of the vehicle or the start of operation of the air conditioner. 23 is read (actually, the output values amplified by the amplifiers 19a to 19d) (S10).

  Next, the relative humidity RH of the passenger compartment air near the window glass is calculated based on the output value V of the humidity sensor 17 (S20). That is, a predetermined arithmetic expression for converting the output value V of the humidity sensor 17 into the relative humidity RH is set in advance, and the relative humidity RH is calculated by applying the output value V to this arithmetic expression. The following formula (1) is a specific example of this humidity calculation formula.

RH = αV + β (1)
Where α is a control coefficient and β is a constant.

  Next, the air temperature in the vicinity of the window glass is calculated by applying the output value of the air temperature sensor 18 to a predetermined arithmetic expression set in advance (S30). Next, the window glass temperature (glass room inner surface temperature) is calculated by applying the output value of the glass temperature sensor 23 to a predetermined arithmetic expression set in advance (S40).

  Next, based on the relative humidity RH, the air temperature, and the window glass temperature calculated in the above steps S20 to S40, the window glass surface relative humidity (the relative humidity of the window glass indoor side surface) RHw is calculated (S50). That is, by using the wet air diagram, the window glass surface relative humidity RHw can be calculated from the relative humidity RH, the air temperature, and the window glass temperature.

  Next, the fogging degree determination value is calculated by applying the output value of the light receiving element 16 constituting the optical fogging detection sensor to a predetermined arithmetic expression set in advance (S60). The fogging degree determination value is a value obtained by converting the output value (raw value) of the light receiving element 16 so as to match the actual fogging degree of the window glass. Note that the output value (photodiode output current) of the light receiving element 16 has a relationship of decreasing due to fogging of the window glass as described above. The fogging degree determination value is calculated to be a value that increases as the fogging degree of the window glass increases or a value that decreases as the fogging degree of the window glass increases.

  By the way, in the present embodiment, the light emitting element 15 constituting the optical fogging detection sensor is caused to emit light at predetermined time intervals. In this way, by causing the light emitting element 15 to emit light in pulses, an increase in temperature in the case 11 due to heat generation of the light emitting element 15 can be suppressed. Accordingly, it is possible to suppress an adverse effect on the detected temperatures of the temperature sensors 18 and 23 due to the heat generation of the light emitting element 15.

  Next, the presence or absence of fogging of the window glass is determined based on the fogging degree determination value which is the calculated value of S60 (S70). In this determination, it is determined whether or not the cloudiness degree determination value in step S60 changes at a predetermined speed or higher.

  In other words, the contamination of the window glass due to the attachment of cigarette fat or fine dust proceeds very slowly over a long period of time. On the other hand, fogging of the window glass proceeds at a much faster rate. Therefore, in the present embodiment, paying attention to this point, when the cloudiness degree determination value is changed at a predetermined speed or higher in step S70, that is, the change speed of the cloudiness degree determination value is higher than the predetermined value. When it becomes, it determines with fogging of a window glass.

  The change rate of the cloudiness degree determination value can be obtained as a determination value change rate before and after a predetermined time interval when the light emitting element 15 emits pulses.

According to such fogging determination, it is possible to accurately determine window fogging by avoiding erroneous determination of window fogging due to dirt on the window glass due to the attachment of tobacco fat or fine dust, etc.
If it is determined in step S70 that there is cloudiness, the process proceeds to step S80, and the window glass surface relative humidity RHw = 100%. That is, the window glass surface relative humidity RHw calculated based on the humidity sensor output value calculated in step S50 is forcibly replaced with 100%. In step S90, the humidity calculation formula (1) is self-corrected.

  By the way, in the air-conditioning control apparatus 26, the antifogging control after FIG. 6 mentioned later is performed based on the window glass surface relative humidity RHw. Nevertheless, the occurrence of fogging of the window glass means that the relative humidity RH calculated based on the output value of the humidity sensor 17 is shifted to a side smaller than the actual relative humidity.

Therefore, in step S90, the humidity calculation formula (1) is self-corrected to the side where the calculated value of the relative humidity RH increases. Specifically, when the humidity sensor output value V and the relative humidity RH are expressed by RH = αV + β as in the humidity calculation formula (1), the window glass surface relative humidity RHw = 100% at the air temperature. A value converted into relative humidity is obtained from an air wetting diagram, and this is defined as RH ′. When the corrected humidity calculation formula is RH = αV + β ′,
β ′ = β + (RH′−RH) → β ′ = β−RH + RH ′.

  By correcting the humidity calculation formula in this way, in the calculation process of the relative humidity RH in the next and subsequent steps in step S20, a calculation process approximating the actual relative humidity can be performed.

  In step S <b> 100, the finally obtained window glass surface relative humidity RHw is output to the air conditioning controller 26. That is, when it is determined that the window glass is fogged, the value of the window glass surface relative humidity RHw = 100% replaced in step S80 is output to the air conditioning controller 26, and it is determined that the window glass is not fogged. If so, the window glass surface relative humidity RHw calculated in step S50 is output to the air conditioning controller 26. Further, in step S100, in addition to the window glass surface relative humidity RHw, the fogging degree determination value calculated in step S60 is also output to the air conditioning control device 26.

  In the specific example of the humidity equation correction, the example in which the constant β is corrected has been described. However, the control coefficient α may be corrected instead of the constant β, and both the constant β and the control coefficient α are corrected. May be.

  Next, air conditioning control based on the window glass surface relative humidity RHw will be described. FIG. 6 is a control routine executed by the air conditioning control device 26. First, the window glass surface relative humidity RHw calculated in the control routine of FIG. 5 and the window glass fogging determination result of S70 of FIG. 5 are read (S200). .

  Next, it is determined whether the inside / outside air suction mode has been manually set to the inside / outside air mode by the inside / outside air changeover switch 73 of the air conditioning operation panel 70 (S210). If the determination is NO, the cloudiness determination result of S70 of FIG. It is determined whether or not clouding is present (S220). When the window glass is not fogged, the inside / outside air control command value S is calculated (S230).

  Here, the inside / outside air control command value S is a numerical value that determines the inside air ratio of the air sucked into the air conditioner as shown in FIG. 7, and in the example of FIG. 7, the inside air ratio = 0% when S = 0 (that is, outside air: 100% outside air mode), and when S = 7, the inside air ratio = 100% (that is, the inside air mode), and the inside air ratio sequentially increases from S = 1 to S = 7.

  FIG. 8 is a control routine showing a specific example of S230. First, it is determined based on the map of FIG. 9 whether the vehicle speed SPD is in the low speed range A or the high speed range B (S300). When the vehicle speed SPD is in the high speed range B, the inside / outside air control command value S is determined based on the window glass surface relative humidity RHw as shown in the map of FIG. 10 (S310).

  That is, when the window glass surface relative humidity RHw rises above the predetermined target window glass surface relative humidity TRHw, S = 0 (outside air mode), and when the window glass surface relative humidity RHw falls below (TRHw−a). S = 7 (inside air mode). The target window glass surface relative humidity TRHw is, for example, about 85% relative humidity at a level that can sufficiently prevent fogging of the window glass.

  On the other hand, when the vehicle speed SPD is in the low speed range A, the control modes 1, 2, and 3 shown in the map of FIG. 11 are determined based on the window glass surface relative humidity RHw (S320).

  That is, when the window glass surface relative humidity RHw rises above a predetermined target window glass surface relative humidity TRHw (for example, 85%), the control mode 3 is determined, and the window glass surface relative humidity RHw becomes the target window glass surface relative humidity TRHw. And (TRHw-b), control mode 2 is determined. Furthermore, when the window glass surface relative humidity RHw is lower than (TRHw−b), the control mode 1 is determined.

  When the control mode 1 is determined, the control process of S = S + 1 is performed every predetermined time (S330). That is, a control process is performed in which the value of the inside / outside air control command value S is increased by “1” every time a predetermined time elapses, and the inside air ratio is sequentially increased by a predetermined ratio.

  When control mode 2 is determined, since the window glass surface relative humidity RHw is in the vicinity of the target window glass surface relative humidity TRHw, the control process of S = S, that is, the value of the inside / outside air control command value S is calculated last time. A control process for maintaining the value of S is performed (S340).

  When the control mode 3 is determined, the control process of S = S-1 is performed every predetermined time (S350). That is, a control process is performed in which the value of the inside / outside air control command value S is decreased by “1” every time a predetermined time elapses, and the inside air ratio is decreased by a predetermined rate.

  Note that a and b in FIGS. 10 and 11 are predetermined values for setting a hysteresis width for preventing hunting of the inside / outside air control.

  Returning to FIG. 6 again, in step S240, it is determined whether the inside / outside air control command value S is the outside air mode value (S = 0). When this determination is NO, the process proceeds to step S250, and the position of the inside / outside air switching door 35 (inside / outside air suction mode) is controlled so that the inside air ratio is based on the inside / outside air control command value S.

  In this inside / outside air suction mode control, the target window glass surface relative humidity TRHw is set near the upper limit humidity at which the window glass does not fog, so that the inside / outside air is constantly increased so that the window glass does not fog. The suction mode can be controlled. Thereby, by raising the inside air ratio at the start of heating in winter, it is possible to reduce the ventilation heat loss and promote the startup of the vehicle interior heating effect.

  On the other hand, when the determinations of steps S210, S220, and S240 in FIG. 6 are YES, it is when the necessity of anti-fogging of the window glass is high. In this case, the process proceeds to step S260 and anti-fogging control of the window glass is performed.

  FIG. 12 is a control routine showing a specific example of this anti-fogging control, and it is determined whether the fogging determination result in step S70 of FIG. 5 is the presence or absence of fogging (S400). When there is no fogging, the antifogging control in steps S410 to S510 is performed.

  On the other hand, when there is cloudiness, the fog removal control mode is executed in step S520. That is, the inside / outside air suction mode is forcibly switched to the outside air mode, the blower level of the air-conditioning electric blower 37 is increased by 6 levels, and the blowing mode is switched to the defroster mode. The blower level is the motor applied voltage level of the air-conditioning electric blower 37, and the air volume is increased or decreased in accordance with the increase or decrease of the motor applied voltage level. Therefore, the blower level means the air volume level of the air-conditioning electric blower 37. Will do.

  By executing step S520, hot air heated by introducing low-humidity outside air is blown from the defroster outlet 48 to the inner surface of the window glass 12, and the amount of hot air blown is increased to thereby increase the relative humidity of the window glass surface. The fogging of the window glass 12 can be removed by quickly reducing the RHw.

  On the other hand, the determination of the control mode 10 to the control mode 50 in steps S410 to S450 is determined according to the window glass surface relative humidity RHw as shown in the map of FIG. In the control example of FIG. 13, a target window glass surface relative humidity TRHw (for example, 85%) and a total of five determination threshold values obtained by increasing or decreasing the predetermined amounts c1, c2, c3, and c4 are set. One of the six control modes 10 to 60 is selected according to the change in the surface relative humidity RHw.

  Steps S460 to S510 of FIG. 12 select and execute any one of the six control modes 10 to 60. In steps S460 to S510, “AUTO” is normal automatic control in which each control of the inside / outside air suction mode, the blower level, and the blowing mode is performed based on the target blowing temperature TAO of the blowing air into the vehicle interior. Represents.

  Also, “Face”, “B / L”, “Foot”, “F / D”, and “DEF” in the blowing mode are a face mode in which air is blown out from the face blowing port 49, the face blowing port 49 and the foot blowing port 50, respectively. A bi-level mode for blowing air from both, a foot mode for blowing air from the foot outlet 50, a foot defroster mode for blowing air from both the foot outlet 50 and the defroster outlet 48, and a defroster for blowing air from the defroster outlet 48 Represents the mode.

  In addition, the transition of the blowing mode in step S490 (control mode 40) is specifically performed as follows. That is, when the blowing mode of the control mode before shifting to the control mode 40 is the F / D mode, the mode shifts to the DEF mode, and when it is other than the F / D mode, the mode shifts to the F / D mode. When the control mode 40 shifts to the F / D mode, the F / D mode is maintained even if the control mode 40 continues.

  Moreover, in step S460 to S500 of FIG. 12, when the inside air mode is set manually, the inside / outside air suction mode is maintained in the inside air mode.

  According to the anti-fogging control of FIGS. 12 and 13, the control mode 10 can be sequentially switched from the control mode 10 to the control mode 60 according to the increase in the relative humidity RHw of the window glass, to the control mode having a high effect of reducing the RHw. Thus, the window glass can be automatically and antifogged properly.

  Next, FIG. 14 is a flowchart showing compressor control according to this embodiment. Since this compressor control is basically the same as that disclosed in Japanese Patent Laid-Open No. 7-179120, an outline of compressor control will be described. First, a target evaporator temperature (that is, a target cooling heat exchanger temperature) TEOa for controlling the passenger compartment temperature is calculated based on the target outlet temperature TAO of the air blown into the passenger compartment (S600).

  Specifically, the TEOa is calculated so as to increase from the lowest temperature (for example, 3 ° C.) toward the highest temperature (for example, 11 ° C.) as the target blowing temperature TAO increases.

  The target blowing temperature TAO is a vehicle cabin blowout air temperature necessary for maintaining the vehicle cabin temperature (inside air temperature) Tr at the set temperature Tset set by the temperature setting switch 71 regardless of the air conditioning thermal load fluctuation. As is well known, this TAO can be calculated based on the set temperature Tset, the outside air temperature Tam, the inside air temperature Tr, and the solar radiation amount Ts.

  Next, a target evaporator temperature TEOb for vehicle interior humidity control is calculated based on the vehicle interior humidity RHr detected by the humidity sensor 17 (S610). This TEOb is calculated so that the vehicle interior humidity RHr is maintained within a predetermined comfortable range, for example, a range of 50 to 60%.

  Therefore, when the vehicle interior humidity RHr rises to, for example, 60% or more, the value of TEOb is shifted to the low temperature side. Further, when the vehicle interior humidity RHr decreases to, for example, 50% or less, the value of TEOb is shifted to the high temperature side.

  Next, the target evaporator temperature TEOc for anti-fogging control is calculated (S620). This TEOc is calculated so that the anti-fogging control can be performed by the cooling (dehumidifying) ability of the evaporator 38.

  Specifically, an evaporator temperature at which the window glass surface relative humidity RHw can be maintained between the target window glass surface relative humidity TRHw and (TRHw−b) in FIG. 11 is defined as a target evaporator temperature TEOc. The target evaporator temperature TEOc can be obtained from the glass temperature, the TRHw and (TRHw−b1), and the relative humidity (≈95%) of the evaporator blowing air by using a wet air diagram.

  Next, among the three target evaporator temperatures TEOa, TEOb, and TEOc, the lowest temperature is calculated as the final target evaporator temperature TEO (S630). Next, the capacity control of the compressor 40 is performed based on the final target evaporator temperature TEO (S640). The capacity control of the compressor 40 is performed by comparing the target evaporator temperature TEO with the evaporator blown air temperature Te detected by the evaporator temperature sensor 64.

  That is, when the evaporator blown air temperature Te rises above the target evaporator temperature TEO, the electromagnetic clutch 40a is energized to turn on the compressor 40. On the other hand, when the evaporator blown air temperature Te falls below a temperature (TEO-z) lower than the target evaporator temperature TEO by a predetermined temperature z (for example, 1 ° C.), the compressor 40 is stopped (OFF).

  The actual evaporator blown air temperature Te is controlled in the vicinity of the target evaporator temperature TEO by such intermittent control of the operation of the compressor 40. In addition, the target evaporator temperature TEO is selected from among the target evaporator temperature TEOa for vehicle interior temperature control, the target evaporator temperature TEOb for vehicle interior humidity control, and the target evaporator temperature TEOc for antifogging control. Since the minimum temperature is set, the degree of cooling of the evaporator is controlled by the capacity control of the compressor 40, so that the vehicle interior temperature control, the vehicle interior humidity control, and the anti-fogging control can be executed.

  In the above-described capacity control of the compressor 40, a fixed capacity compressor is used as the compressor 40, and the operation rate of the compressor is changed by the intermittent operation of the fixed capacity compressor. As a variable capacity compressor, the capacity control of the compressor 40 may be controlled by changing the discharge capacity of the compressor.

  The term “target evaporator temperature” is a term that represents a target value for the degree of cooling of the evaporator 38. The degree of cooling of the evaporator 38 is not limited to the evaporator blown air temperature Te, but the evaporator fin surface temperature, etc. You may measure with.

(Second Embodiment)
In the first embodiment, the calculated value of the output value of the humidity sensor 17 is shifted to a lower side than the actual humidity, and as a result, the air conditioner is performing anti-fogging control, but the window Although the correction of the humidity calculation formula in the case where fogging occurs has been described, in the second embodiment, the humidity calculation formula in the case where the calculated value of the output value of the humidity sensor 17 shifts to a higher side than the actual humidity. Related to the correction.

  In addition, when the calculated value of the output value of the humidity sensor 17 shifts to a higher side than the actual humidity, it acts on the safe side for the anti-fogging control of the air conditioner. This is not preferable in practice because it leads to the problem of increasing the heat loss of ventilation and increasing the loss of ventilation heat and the problem of increasing the compression function force more than necessary and increasing the compressor power wastefully.

  By the way, when the occupant manually operates the air conditioner switch 74 of the air conditioning operation panel 70 to the OFF position, the air conditioning control device 26 cuts off the energization to the electromagnetic clutch 40a of the compressor 40, so that the compressor 40 is forcibly stopped. Become. As a result, the cooling and dehumidifying capacity of the evaporator 38 is also forcibly stopped. As a result, the vehicle interior relative humidity RHr may increase and the window may become cloudy.

  Similarly, when the occupant manually operates the inside / outside air changeover switch 73 of the air conditioning operation panel 70 to the inside air mode position, the air conditioning control device 26 moves the inside / outside air switching door 35 via the servo motor 36 to the inside air mode position (outside air introduction port 34: Fully closed, inside air inlet 33: fully open). As a result, the inside air having a higher absolute humidity than the outside air is recirculated to air-condition the vehicle interior, so that the vehicle interior relative humidity RHr may increase and the window may be clouded.

  In this way, when window fogging occurs due to the manual operation of the occupant, in the second embodiment, even if the glass surface relative humidity RHw exceeds the threshold value of fog prevention control (TRHw in FIG. 11). The above-described anti-fogging control is started until the fogging of the window is determined based on the calculation value of the fog determination calculation circuit 20a that calculates the output value of the optical fog detection sensor (light emitting / receiving elements 15 and 16). Delay.

  When the fogging of the window is determined based on the calculated value of the fog determination calculation circuit 20a, the glass surface relative humidity RHw = 100% as shown in step S80 of FIG. Make corrections.

  As described above, when the calculated value of the output value of the humidity sensor 17 is shifted to a higher side than the actual humidity, the safety factor of the antifogging control is increased and the antifogging control is executed at an earlier timing. Therefore, in general, the fogging of the window does not occur. However, if the opportunity for fogging of the window to be generated by the manual operation of the occupant is used as in the second embodiment, the operation value of the output value of the humidity sensor 17 is calculated. However, even if it is shifted to a higher side than the actual humidity, the humidity calculation formula can be corrected.

(Third embodiment)
In the second embodiment, the correction method in the case where clouding occurs due to the manual operation of the occupant has been described, but a similar correction can be performed at the time of heating start-up at a low temperature. When the outside air temperature is low, such as in winter, the engine water temperature drops while parking (when the engine is stopped), so the air-conditioning air is not blown out until the engine water temperature rises above a certain level at the start of air conditioning after the next engine start. (Warm-up control) is often performed.

  In this warm-up control, the conditioned air is not blown out, so that window fogging may occur in the meantime, so that the humidity calculation formula can be corrected at that occasion.

  Thus, when the fogging of the window occurs due to the delay of the air-conditioning air blowing of the air conditioner, blowing the air-conditioning air deteriorates passenger comfort. Therefore, it is easier to obtain the occupant's consent if the fogging control is performed after the occurrence of window fogging is confirmed by the optical fogging detection sensor (light emitting / receiving elements 15 and 16).

  Therefore, when the engine water temperature is lower than the threshold value for blowing out the conditioned air, the threshold value for anti-fogging control (TRHw in FIG. 11) is increased, and the optical fog detection sensor (light emitting / receiving elements 15 and 16) is increased. The start of the above-described anti-fogging control is delayed until the fogging of the window is determined based on the calculation value of the fog determination calculation circuit 20a that calculates the output value.

  When the fogging of the window is determined based on the calculated value of the fog determination calculation circuit 20a, the glass surface relative humidity RHw = 100% as shown in step S80 of FIG. Make corrections.

  As in the third embodiment, if an opportunity for fogging of the window to occur during delay control (warm-up control) at a low water temperature is used, the calculated value of the output value of the humidity sensor 17 is greater than the actual humidity. Even when it is shifted to the higher side, the humidity calculation formula can be corrected.

(Fourth embodiment)
In the first embodiment, the light emitting element 15 and the light receiving element 16 constituting the optical fogging detection sensor and the humidity sensor 17 are mounted on the same circuit board 14, but the optical fogging detection sensor is constituted. The light emitting element 15 and the light receiving element 16 and the humidity sensor 17 may be mounted on separate circuit boards.

  As described above, even if different circuit boards are used for the optical fog detection sensor and the humidity sensor 17, they can be accommodated in the same case 11 and integrated.

(Fifth embodiment)
In the first embodiment, the light emitting element 15 and the light receiving element 16 constituting the optical fogging detection sensor and the humidity sensor 17 are mounted on the same circuit board 14 in the same case 11. The clouding detection sensor and the humidity sensor 17 may be arranged in different places.

  For example, in the case of an air conditioner for a vehicle (automobile), an internal air sensor 62 (FIG. 4) that detects the vehicle interior temperature (inside air temperature) Tr is arranged near the instrument panel in the vehicle interior to detect a representative temperature in the vehicle interior. Like to do. Therefore, the humidity sensor 17 is arranged at the same place (near the instrument panel) as the inside air sensor 62, the humidity sensor 17 and the inside air sensor 62 are integrated, and the optical fogging detection sensor is arranged on the inner surface of the front window glass of the vehicle. You can do it.

  According to this, since the inside air sensor 62 also serves as the air temperature sensor 18 of the first embodiment, the air temperature sensor 18 can be eliminated.

(Sixth embodiment)
In the first embodiment, the light emitting element 15 constituting the optical fogging detection sensor is constituted by a light emitting diode, and the light receiving element 16 is constituted by a photodiode. However, the light emitting element 15 is constituted by an infrared light emitting element and receives light. The element 16 may be composed of an infrared light receiving element.

  Here, since the infrared light receiving element has a function capable of detecting the temperature of the detection object in a non-contact manner based on the amount of infrared light received from the detection object, it is also referred to as an IR sensor. And also in 4th Embodiment, an infrared rays light emitting element is light-emitted at a predetermined time interval.

  Thereby, when the infrared light emitting element emits light, the fogging of the window glass 12 is detected based on the amount of light received by the infrared light receiving element. On the other hand, when the infrared light emitting element is not emitting light (when the light is turned off), the amount of infrared light emitted from the window glass 12 is received by the infrared light receiving element, and the temperature of the window glass 12 is detected based on the amount of light received by the infrared light receiving element.

  According to this, since the infrared light receiving element of the optical fog detection sensor also serves as a window glass temperature detection, the glass temperature sensor 23 can be eliminated.

(Seventh embodiment)
In the first embodiment, the arithmetic circuit 20 is provided on the circuit board 14 disposed in the case 11 of the fogging detection device 10. However, the function of the arithmetic circuit 20 may be set in the air conditioning control device 26. Good.

(Eighth embodiment)
In the first embodiment, when the occurrence of fogging is determined in step S70 of FIG. 5, the window glass surface relative humidity RHw calculated based on the humidity sensor output value or the like is forcibly replaced with 100% (S80), and In step S90, the humidity calculation formula (1) is self-corrected. For example, after determining the occurrence of fogging in step S70, the humidity sensor output value is stored a plurality of times, and the plurality of humidity sensors are stored. Self-correction (correction of one or both of the constant β and the coefficient α) of the humidity calculation equation (1) may be performed using the average value of the output values.

(Ninth embodiment)
In the above-described embodiment, correction of the humidity calculation formula for preventing a decrease in humidity detection accuracy due to durability deterioration of the humidity sensor 17 has been described, but in the ninth embodiment, the light emitting element 15 constituting the optical cloudiness detection sensor. This prevents a decrease in the determination accuracy of the degree of cloudiness due to deterioration of the durability.

  First, FIG. 15 is a schematic cross-sectional view of the window fogging detecting device according to the ninth embodiment, and the same parts as those in the first embodiment (FIG. 1) are denoted by the same reference numerals and the description thereof is omitted. In the ninth embodiment, the light emitting element 15 and the light receiving element 16 constituting the optical fogging detection sensor are arranged directly adjacent to each other.

  Specifically, the light emitting element 15 is formed of a light emitting diode as in the first embodiment, and the light receiving element 16 is specifically formed of a photodiode as in the first embodiment. Irradiation light A emitted from the light emitting element 15 is reflected on the light shielding film 13 on the inner surface of the window glass 12, and the light receiving element 16 receives the reflected light B.

  Here, in the optical fog detection sensor, (1) the phenomenon that the luminance of the light emitting element 15 decreases due to deterioration of the durability of the light emitting element 15 itself, the irradiation light A decreases, and the reflected light B decreases accordingly. Happens.

  (2) Besides the occurrence of fogging, the window glass reflecting surface (the surface of the light-shielding film 13 in this example) adheres to cigarette oil, dust, etc. and the window glass reflecting surface becomes dirty, resulting in scattered light, The reflected light B toward the light receiving element 16 decreases.

  (3) The forward voltage (Vf) of the light-emitting diode constituting the light-emitting element 15 has a temperature characteristic that it decreases as the ambient temperature increases, and the irradiation light A decreases due to the decrease in the forward voltage (Vf) at high temperatures. Thereby, the reflected light B decreases.

  When the reflected light B decreases due to these causes, the amount of light received by the light receiving element 16 is reduced in the same manner as when the window glass 12 is clouded. When the cloudiness is determined, even if the window glass 12 is not fogged, the cloudiness may be determined (incorrect determination).

  Therefore, in the ninth embodiment, the cloudiness degree determination value Fw is calculated based on the ratio (B / A) between the reflected light B and the irradiated light A, and when the window glass 12 is not fogged, the reflection is performed. By executing the correction of the arithmetic expression based on the light amount normalization process for normalizing the light B with the irradiation light A, it is possible to prevent the determination accuracy of the cloudiness degree based on the causes (1) and (2) from being lowered.

  Here, the correction of the arithmetic expression based on the light amount normalization process means that the window glass 12 is not fogged even when the reflected light B actually decreases from the irradiation light A at the time when the process is executed. In other words, the calculation formula of the cloudiness degree determination value Fw is corrected so that the ratio, that is, the ratio (B / A) of the reflected light B to the irradiated light A = 1.

  Then, when the fogging of the window glass 12 actually occurs after performing the correction process of the arithmetic expression, the reflected light B is reduced from the time of the arithmetic expression correction process, so the cloudiness degree determination value Fw is a value smaller than 1. Thus, the fogging of the window glass 12 can be reliably determined by decreasing from a predetermined threshold value.

  For the cause (3), calculation and determination of the degree of fogging is prohibited when the temperature is higher than a predetermined temperature at which the irradiation light A decreases due to the temperature characteristics of the light emitting element 15, and only when the temperature is lower than the predetermined temperature. If the cloudiness determination is performed, it is possible to eliminate the influence of the decrease in the irradiation light A based on the temperature characteristics of the light emitting element 15 at a high temperature.

  Here, the predetermined temperature is, for example, a temperature equivalent to an outside air temperature in midsummer of about 35 ° C., and at such a high temperature, the window glass 12 is in a similar high temperature state. Therefore, since the temperature of the window glass 12 is sufficiently higher than the dew point temperature of the passenger compartment air, the surface of the window glass 12 is not fogged. Therefore, there is no practical problem even if the determination of the degree of fogging is prohibited when the temperature is higher than the predetermined temperature.

  Rather, prohibiting the use of the light-emitting element 15 at a high temperature can suppress the high-temperature deterioration of the light-emitting element 15 and at the same time reduce the cumulative use time of the light-emitting element 15. It is extremely useful for.

  Next, a specific operation of the fogging detection apparatus of the present embodiment based on the above concept will be described with reference to FIG. FIG. 16 is a flowchart corresponding to FIG. 5, and the same reference numerals are given to the same control processing parts as those in FIG. In step S110, it is determined whether the air temperature calculation value calculated in step S30 is equal to or less than a predetermined value. This air temperature is the air temperature in the passenger compartment near the window glass 12, and is also the ambient temperature of the optical fog detection sensor (15, 16). In addition, the predetermined value in step S110 is a temperature corresponding to the above-described midsummer outside air temperature of about 35 ° C.

  When the determination in step S110 is YES, fogging of the window glass 12 may occur. Then, it progresses to step S120 and turns on an optical cloudiness detection sensor (15, 16). Specifically, similarly to the first embodiment, the light-emitting diodes constituting the light-emitting element 15 are caused to emit pulses at predetermined time intervals, and the reflected light B from the surface of the window glass 12 is received by the light-receiving element 16. Receive light.

  In the next step S60a, the cloudiness degree determination value Fw is calculated based on the ratio (B / A) between the reflected light B and the irradiated light A. Specifically, the determination value Fw is calculated by the calculation formula of Fw = γ · (B / A).

  Here, γ is a control coefficient. As will be described later, this control coefficient γ is self-corrected so that Fw = 1 every predetermined period when the window glass 12 is not fogged. Therefore, when the window glass 12 is not fogged, the fogging degree determination value Fw is calculated to be 1 or a value close to 1.

  Then, when fogging occurs on the surface of the window glass 12, the reflected light B decreases as described above, so that the determination value Fw decreases from 1 or a value in the vicinity of 1.

  In the above arithmetic expression, the reflected light B is obtained from the output value (light receiving amount) of the light receiving element 16. Moreover, since the irradiation light A has a proportional relationship with the forward current of the light emitting diode which comprises the light emitting element 15, the irradiation light A can be calculated | required from this forward current.

  In the next step S70a, whether or not the surface of the window glass 12 is fogged is determined based on the determination value Fw. Specifically, a value that is a predetermined amount smaller than 1 is set as a threshold value for the determination value Fw. When the determination value Fw decreases below this threshold value, it is determined that there is cloudiness, and the determination value Fw is a predetermined threshold value. When larger, it is determined that there is no cloudiness.

  When it is cloudy, the processes in steps S80 and S90 are performed as in the first embodiment, and then output to the air conditioning control device in step S100 is performed.

  On the other hand, when there is no cloudiness, the process proceeds to step S130, where it is determined whether a predetermined period has elapsed since the previous correction time of the cloudiness degree determination value calculation formula.

  Specifically, the previous correction time (year / month / day) of the cloudiness degree determination value calculation formula in step S140 described later is stored, and it is determined whether a predetermined period (for example, 30 days) has elapsed from the previous correction time. To do. Or you may determine whether it is a specific day every month (for example, 1st of every month) for the calendar function of a computer.

  When the determination in step S130 is NO, the process proceeds to step S100, and the cloudiness degree determination value calculation formula is not corrected.

  On the other hand, when a predetermined period has elapsed from the previous correction time of the cloudiness degree determination value calculation expression, the determination in step S130 is YES, and the process proceeds to step S140 to correct the cloudiness degree determination value calculation expression. This arithmetic expression correction process is based on the light quantity normalization process that normalizes the reflected light B with the irradiation light A described above.

  Specifically, the control coefficient γ is corrected so that Fw = 1 in the arithmetic expression of Fw = γ · (B / A) described above. Therefore, thereafter, as long as the amount of the reflected light B is the same as the amount of the reflected light B at the time of correction, the haze degree determination value Fw in step S130 is maintained at “1”. As a result, in step S70a, it is reliably determined that there is no fog.

  Then, when fogging occurs in the window glass 12, the reflected light B decreases, whereby the fogging degree determination value Fw becomes smaller than “1”. In step S70a, the determination value Fw is smaller than the predetermined threshold value, so that it can be reliably determined that there is cloudiness.

  Note that the phenomenon that the window glass reflecting surface is soiled due to the attachment of tobacco grease or the like proceeds very slowly over time, so that it is not necessary to frequently perform the correction processing (S140) of the above-described arithmetic expression. Therefore, in the present embodiment, only when it is determined in step S130 that a predetermined period (for example, 30 days) has elapsed from the previous correction time, the calculation formula is corrected.

  According to the present embodiment, the light irradiation element 15 is affected by a phenomenon in which the irradiation light A decreases due to deterioration of the durability of the light emitting element 15 itself, or a phenomenon in which the reflection light B decreases due to contamination of the window glass reflection surface due to adhesion of tobacco grease or the like. Therefore, the optical fog detection accuracy can be maintained well over a long period of time.

  Moreover, since the cloudiness determination is performed only when the ambient temperature is equal to or lower than a predetermined temperature (for example, 35 ° C.), it is not affected by the temperature characteristic that the luminance of the light emitting element 15 decreases at high temperatures. Further, since the cloudiness determination is performed only when the ambient temperature is equal to or lower than the predetermined temperature, the light emitting element 15 can be prevented from being deteriorated at high temperature, and the accumulated use time of the light emitting element 15 can be reduced to extend the durable life of the light emitting element 15. be able to.

  In the present embodiment, the control coefficient γ is corrected so that Fw = 1 when the cloudiness degree determination value Fw is calculated by the calculation formula Fw = γ · (B / A). For example, when the cloudiness degree determination value Fw is calculated by the calculation formula of Fw = γ · (B / A) + δ (where δ is a constant), the constant δ may be corrected so that Fw = 1. . Further, both the control coefficient γ and the constant δ may be corrected so that Fw = 1.

  Further, when correcting the control coefficient γ and the constant δ, the control coefficient γ and the constant δ may be corrected so that Fw becomes a value in the vicinity of 1 without strictly correcting Fw = 1. .

(Other embodiments)
In the first embodiment, the window fogging detection device disposed on the front (front) glass of the vehicle has been described. However, the present invention may be applied to a window fogging detection device disposed on the rear (rear) glass of the vehicle. Good. Further, the present invention can also be applied to a window fogging detection apparatus for uses other than vehicles.

  In the ninth embodiment, the light emitting element 15 is composed of a light emitting diode, and the light receiving element 16 is composed of a photodiode. However, the light emitting element 15 is an element other than the light emitting diode, for example, an infrared ray as in the sixth embodiment. You may comprise with a light emitting element. Further, the light receiving element 16 may be configured by an element other than the photodiode, for example, an infrared light receiving element as in the sixth embodiment.

It is a schematic sectional drawing of the window fogging detection apparatus by 1st Embodiment of this invention. It is a schematic perspective view of the window fogging detection apparatus of FIG. It is an electrical block diagram of the window fogging detection apparatus of FIG. 1 is an overall system configuration diagram of a vehicle air conditioner according to a first embodiment of the present invention. It is a flowchart of the arithmetic processing performed by the arithmetic circuit shown in FIG. It is a flowchart which shows the basic logic of the air-conditioner side control by 1st Embodiment. It is a characteristic view which shows the relationship between inside / outside air control command value and inside air ratio. It is a flowchart which shows the inside / outside air control logic by 1st Embodiment. It is a characteristic view of the vehicle speed determination in the inside / outside air control. It is a characteristic view which shows the relationship between the window glass surface relative humidity and inside / outside air control command value (inside / outside air suction mode). It is a characteristic view which shows the relationship between a window glass surface relative humidity and an inside / outside air control mode. It is a flowchart which shows the anti-fogging control logic by 1st Embodiment. It is a characteristic view which shows the relationship between window glass surface relative humidity and anti-fogging control mode. It is a flowchart which shows the compressor control logic by 1st Embodiment. It is a schematic sectional drawing of the window fogging detection apparatus by 9th Embodiment. It is a flowchart which shows the window fogging detection operation | movement by 9th Embodiment.

Explanation of symbols

12 ... Window glass, 15 ... Light emitting element, 16 ... Light receiving element, 17 ... Humidity sensor,
20: arithmetic circuit.

Claims (18)

An optical fog detection sensor (15, 16) for optically detecting fogging of the window glass (12);
A humidity sensor (17) for detecting the relative humidity of the indoor air;
Sensor output correcting means (20e) for correcting the output value of the humidity sensor (17) when the fogging of the window glass (12) is determined based on the output value of the optical fogging detection sensor (15, 16). , S20, S90). An air temperature sensor (18) for detecting the temperature of the indoor air;
A glass temperature sensor (23) for detecting the temperature of the window glass (12);
Glass surface relative humidity calculating means (20f, S50) for calculating the glass surface relative humidity based on the output values of the humidity sensor (17), the air temperature sensor (18) and the glass temperature sensor (23). The window fogging detection apparatus according to claim 1, wherein Relative humidity calculation means (20b, S20) for calculating the relative humidity of the indoor air based on the output value of the humidity sensor (17) using a predetermined calculation formula,
The sensor output correcting means (20e, S20, S90) calculates the relative humidity when the fogging of the window glass (12) is determined based on the output value of the optical fogging detection sensor (15, 16). The calculation formula is corrected so that the calculation value of the means (20b, S20) is a relative humidity at the indoor air temperature when the glass surface relative humidity is 100%. Window fogging detector. The optical fogging detection sensor includes a light emitting element (15) and a light receiving element (16),
The light emitting element (15), the light receiving element (16), the humidity sensor (17), the air temperature sensor (18) and the glass temperature sensor (23) are on the inner surface (12a) of the window glass (12). The window fogging detection apparatus according to claim 2, wherein the window fogging detection apparatus is configured as an integral structure. The light emitting element (15), the light receiving element (16), the humidity sensor (17), and the air temperature sensor (18) are arranged on the same circuit board (14). The window fogging detection apparatus according to 4. A case (11) disposed on the inner surface (12a) of the window glass (12) and having an opening (11a) for communication with the inner space of the window glass (12);
The light emitting element (15), the light receiving element (16), the humidity sensor (17), the air temperature sensor (18), and the glass temperature sensor (23) are accommodated in the one case (11). The window fogging detection apparatus according to claim 4 or 5, wherein Positioning means (11b) for defining the distance between the light emitting element (15) and the light receiving element (16) and the inner surface (12a) of the window glass (12) is provided in the case (11). The window fogging detection apparatus according to claim 6. On the inner surface (12a) of the window glass (12), a light shielding film (13) excellent in thermal conductivity and light reflectivity is attached,
The light from the light emitting element (15) is reflected by the light shielding film (13) and is incident on the light receiving element (16). Window fogging detector. The window fogging detecting device according to claim 8, wherein the glass temperature sensor (23) is integrally disposed on the light shielding film (13). The window fogging detecting device according to any one of claims 4 to 9, wherein the light emitting element (15) emits pulses at predetermined time intervals. An optical fog detection sensor (15, 16) for optically detecting fogging of the window glass (12);
A humidity sensor (17) for detecting the relative humidity of the indoor air;
An air temperature sensor (18) for detecting the temperature of the indoor air,
The optical clouding detection sensor includes an infrared light emitting element (15) and an infrared light receiving element (16).
The infrared light emitting element (15) is caused to emit pulse light at a predetermined time interval,
When the infrared light emitting element (15) emits light, clouding of the window glass (12) is detected based on the amount of light received by the infrared light receiving element (16). On the other hand, when the infrared light emitting element (15) does not emit light, the infrared light receiving element is received. The temperature of the window glass (12) is detected by the amount of light received by the element (16),
And sensor output correction means (20e, S90) for correcting the output value of the humidity sensor (17) when the infrared light receiving element (16) detects fogging of the window glass (12);
Glass surface relative humidity for calculating the glass surface relative humidity based on the output values of the humidity sensor (17) and the air temperature sensor (18) and the output value of the glass temperature detected by the infrared light receiving element (16). A window fogging detecting device comprising a calculation means (20f, S50). An inside / outside air switching means (35) that opens and closes the inside air introduction port (33) and the outside air introduction port (34) to switch between the intake of the inside air and the outside air,
A blowing means (37) for blowing air introduced through the inside air introduction port (33) and the outside air introduction port (34) toward the vehicle interior;
A cooling heat exchanger (38) for cooling the air blown by the blowing means (37);
A heating heat exchanger (44) for heating the blown air of the blowing means (37);
A plurality of air outlets (48, 49, 50) for blowing out the air whose temperature is adjusted by passing through the cooling heat exchanger (38) and the heating heat exchanger (44);
A blow mode door (51, 52, 53) for switching the blow mode by opening and closing the plurality of blow outlets (48, 49, 50);
The plurality of air outlets (48, 49, 50) are provided with a defroster air outlet (48) for blowing air toward the front window glass (12) of the vehicle,
A window fogging detection device according to any one of claims 2, 4 to 11 is arranged on the inner surface of the front window glass (12),
Based on the calculated value of the glass surface relative humidity calculating means (20f, S50), the inside / outside air switching control by the inside / outside air switching means (35), the air volume control by the air blowing means (37), and the blowing mode door (51 , 52, 53) executing at least one of the blowout mode switching control. A compressor (40) for circulating a refrigerant in the cooling heat exchanger (38);
Set a target value of the cooling degree of the cooling heat exchanger (38) so that the glass surface relative humidity is within a predetermined range,
The vehicle air conditioner according to claim 12, wherein the capacity of the compressor (40) is controlled so that an actual cooling degree of the cooling heat exchanger (38) becomes the target value. An optical fogging sensor comprising a light emitting element (15) for irradiating light toward the window glass (12) and a light receiving element (16) for receiving the reflected light (B) from the window glass (12);
A haze degree calculating means (S60a) for calculating a haze degree determination value (Fw) based on the ratio (B / A) of the irradiation light (A) from the light emitting element (15) and the reflected light (B);
Fogging determination means (S70a) for determining the fogging of the window glass (12) based on the fogging degree determination value (Fw);
When it is determined by the fogging determination means (S70a) that the window glass (12) is not fogged, the fog degree determination value (Fw) is a value indicating a state in which the window glass (12) is not fogged. A window fogging detection apparatus comprising first correction means (S140) for correcting an arithmetic expression of the fogging degree determination value (Fw). The fogging degree calculating means (S60a) calculates a value near 1 or 1 as the fogging degree determination value (Fw) when the window glass (12) is not fogged.
The fog determination means (S70a) sets a predetermined threshold value smaller than 1, and determines the fogging of the window glass (12) when the fog degree determination value (Fw) decreases below the threshold value. ,
The window fogging detection apparatus according to claim 14, wherein the first correction means (S140) corrects the arithmetic expression so that the fogging degree determination value (Fw) is 1 or a value close to 1. . Ambient temperature determination means (S110) for determining whether the ambient temperature of the optical cloudiness detection sensor is equal to or lower than a predetermined temperature,
The window fogging according to claim 14 or 15, wherein the fogging degree determination value (Fw) is calculated only when the ambient temperature is equal to or lower than a predetermined temperature, with the optical fogging detection sensor being in an activated state. Detection device. The correction of the calculation formula is performed only when a predetermined period has elapsed from the previous execution time of the calculation formula correction when it is determined that the window glass (12) is not fogged. The window fogging detection apparatus according to any one of 16. A humidity sensor (17) for detecting the relative humidity of the indoor air;
Humidity calculating means (S20) for calculating the output value of the humidity sensor (17);
And second correction means (S90) for correcting a humidity calculation formula in the humidity calculation means (S20) when the fogging determination means (S70a) determines that the window glass (12) is fogged. The window fogging detection device according to any one of claims 14 to 17.

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