JP2019099045A - Vehicle air conditioning device - Google Patents

Abstract

To prevent a window glass from fogging even in a circumstance where a temperature detection sensor cannot support variation in temperature of the window glass.SOLUTION: A vehicle air conditioning device acquires variation in outside air temperature based on a detection result of an outside air temperature detection sensor. When variation in outside air temperature exceeds a predetermined level, the vehicle air conditioning device controls an inside/outside air switching damper so as to lower an upper limit of an inside air circulation amount as compared to that when the variation in outside air temperature is equal to or lower than the predetermined level.SELECTED DRAWING: Figure 12

Description

  The present invention relates to a vehicle air conditioner mounted on, for example, an automobile or the like, and more particularly to the technical field of a structure for simultaneously introducing air outside the vehicle and air in the vehicle room as conditioned air and adjusting the temperature.

  In general, an air conditioner for a vehicle is provided with an inside / outside air switching device for selecting air in the vehicle compartment (inside air) and air outside the vehicle compartment (outside air) and introducing it as air for air conditioning. The inside / outside air switching device includes a blower casing in which an inside air introduction port for introducing inside air and an outside air introduction port for introducing outside air are formed. The outside air introduction port communicates with the outside of the vehicle through an opening formed in a cowl or the like in the vehicle body. Inside the air-blowing casing, an inside / outside air switching damper is provided for opening and closing the inside air introduction port and the outside air introduction port. The introduced air conditioning air is temperature-controlled by a heat exchanger for cooling, a heat exchanger for heating, etc., and then blown out to the vehicle compartment from the selected air outlet among the defroster air outlet, the vent air outlet and the heat air outlet. It is supposed to be.

  The vehicle air conditioners of Patent Documents 1 and 2 introduce inside air and control the temperature by controlling the inside and outside air switching damper, and then, after introducing the outside air and adjusting the temperature, the inside air circulation mode to be supplied to the vehicle interior , It is configured to be able to switch to the three intake modes of the outside air introduction mode to be supplied into the vehicle compartment and the inside / outside air mixing mode to be supplied into the vehicle compartment after introducing and adjusting both the inside air and the outside air. There is. Then, the automatic air conditioner control automatically sets the intake mode, the blowout mode, the air flow rate, the blowout temperature, etc. based on the condition outside the vehicle interior (vehicle interior temperature, outside air temperature, solar radiation amount) and the set temperature set by the occupant. It will be.

  In Patent Document 1, the introduction ratio of the outside air and the inside air can be changed in the inside / outside air mixing mode, and the inside air circulation mode is set as long as the vehicle interior humidity measured by the humidity sensor provided in the vehicle interior is 20% or less If so, it is in the open air introduction mode.

  In Patent Document 2, a determination means for determining whether the window glass is likely to be fogged is provided, and when the determination means determines that the window glass is not likely to be fogged, it circulates at least internal air and determines that the window glass is likely to be fogged. As the outside air introduction mode, the window glass is prevented from fogging. The control mode further includes a control mode for gradually increasing the amount of circulating internal air in the internal / external air mixing mode, a control mode for maintaining the ratio of internal air and external air, and a control mode for gradually increasing the amount of external air introduced in the internal / external air mixing mode. The control mode is selected based on the degree of fogging of the window glass. There is an advantage that the amount of energy required for heating can be reduced by reducing the amount of ventilation by increasing the amount of circulation of internal air within the range in which the window glass does not become cloudy.

  Further, Patent Document 3 also controls the inside / outside air switching damper based on a humidity sensor provided in the vehicle compartment as in Patent Document 1.

Japanese Examined Patent Publication No. 1-27891 Patent No. 5152355 Japanese Utility Model Publication No. 56-70311

  By the way, as described above, the cloudiness of the window glass of the vehicle is detected by the humidity sensor, and when the window glass tends to be fogged based on the detection result, the inside / outside air switching damper is operated in the direction of increasing the outside air introduction amount In the case where the window glass is less likely to be fogged, it is considered that accurate control can be performed by operating the inside / outside air switching damper in the direction in which the amount of inside air circulation increases. However, in general, there is a problem that the humidity sensor can not quickly follow when the degree of fogging in the vehicle cabin changes suddenly.

  Therefore, for example, a temperature sensor for detecting the temperature of a window glass such as a front window glass is disposed in the vehicle compartment, and the target dew point temperature is calculated based on the detection result of this temperature sensor. It is conceivable to operate the inside / outside air switching damper so as to increase the amount of internal air, while operating the inside / outside air switching damper so as to increase the introduction amount, and when the window glass is hard to fog.

  However, for example, if you move a car that has been parked for a long time in a parking lot that is shut off to some extent, such as underground parking lot, multi-level parking lot, tower parking, garage with shutter, etc. Therefore, the outside air temperature will drop sharply. In such a situation, the actual temperature of the window glass decreases rapidly, but the temperature sensor generally provided in the vehicle compartment is configured so as to be covered with a cover or the like and not exposed in the vehicle compartment from the viewpoint of appearance etc. Since it is difficult to detect the temperature of the window glass in real time.

  That is, as an ideal phenomenon, when the outside air temperature falls sharply and the window glass temperature falls, the temperature detection value of the window glass by the temperature sensor also falls sharply and the target dew point temperature also falls accordingly. As a result, the dew point temperature is lowered to prevent the window glass from fogging, but the phenomenon that actually occurs is that the window by the temperature sensor even if the outside air temperature suddenly falls and the window glass temperature suddenly falls Since the decrease in the temperature detection value of the glass becomes gentle, the decrease of the target dew point temperature also becomes gentle, and the target dew point temperature becomes higher than the actual window glass temperature, and as a result, the dew point temperature rises and the window The glass tends to be cloudy. This problem tends to occur particularly in cold regions.

  The present invention has been made in view of such a point, and the purpose of the present invention is to control the temperature of the window glass when controlling the inside / outside air switching damper based on the temperature detection sensor disposed in the vehicle compartment. Another object of the present invention is to prevent the window glass from fogging even in a situation where the temperature detection sensor can not cope with the change.

  In order to achieve the above object, in the present invention, when the change of the outside air temperature exceeds a predetermined level, the upper limit of the amount of circulation of inside air is lowered.

  According to a first aspect of the present invention, there is provided an air blowing casing having an inside air introduction port for introducing air in a vehicle compartment to circulate in the vehicle interior and an outside air introduction port for introducing air outside the vehicle exterior, and the air blowing casing. An inside / outside air switching damper for opening / closing the inside air introduction port and the outside air introduction port, an inside / outside air switching damper driving means for driving the inside / outside air switching damper, and a temperature of a window glass in the compartment. And a control device for controlling the inside and outside air switching damper drive means. The control device is likely to cause the window glass to fog based on the detection result of the window glass temperature detection sensor. In this case, the inside / outside air switching damper drive means is controlled to operate the inside / outside air switching damper in the direction in which the outside air introduction amount increases, while the inside air circulation amount is In the vehicle air conditioner configured to be able to select the inside / outside air mixing mode for controlling the inside / outside air switching damper driving means so as to operate the inside / outside air switching damper in the direction shown, the vehicle air conditioner detects the outside air temperature The control device obtains a change in the outside air temperature based on the detection result of the outside air temperature detection sensor, and when the change in the outside air temperature exceeds a predetermined magnitude, the outside air temperature The internal and external air switching damper driving means is controlled so that the upper limit of the amount of internal air circulation is lower than when the change of the internal pressure is smaller than a predetermined value.

  According to this configuration, based on the detection result of the window glass temperature detection sensor, when the window glass tends to be fogged, the inside / outside air switching damper operates in the direction to increase the outside air introduction amount, while the window glass is difficult to fog The internal / external air switching damper operates in the direction in which the amount of internal air circulation increases. Therefore, the fogging of the window glass is suppressed while increasing the inside air circulation amount to improve the heating efficiency.

  For example, when the vehicle parked for a long time in a parking lot which is shut off to the outside air to a certain extent in winter is moved to the outside, the outside air temperature drops sharply, and the window glass temperature drops rapidly. At this time, since the window glass temperature detection sensor is generally covered with a cover or the like, even if the window glass temperature drops rapidly, the decrease in the temperature detection value of the window glass becomes moderate, and the target The decrease in the dew point temperature also becomes gentle, and the target dew point temperature becomes higher than the temperature of the actual window glass, and the dew point temperature may increase, and the window glass may be easily fogged.

  In the present invention, when the change in the outside air temperature exceeds a predetermined magnitude by obtaining the change in the outside air temperature, the upper limit of the internal air circulation amount is higher than in the case where the change in the outside air temperature is equal to or less than the predetermined magnitude. The inside / outside air switching damper drive means is controlled to be low. The outside air temperature detection sensor can generally detect the temperature change more quickly than the temperature detection sensor in the vehicle compartment, so that it can be obtained quickly when the outside air temperature changes. If the change in the outside air temperature is large, it can be estimated that the window glass temperature is rapidly decreasing. In this case, the upper limit of the amount of inside air circulation becomes low, that is, the amount of circulation of high humidity air in the vehicle compartment is small Therefore, the fogging of the window glass is suppressed.

  In a second aspect based on the first aspect, the control device calculates the outside air temperature reduction rate based on the detection result of the outside air temperature detection sensor, and the calculated outside air temperature reduction rate exceeds a predetermined threshold value. The present invention is characterized in that the inside / outside air switching damper drive means is controlled so that the upper limit of the amount of circulating inside air is lower than when the outside air temperature decrease rate is less than or equal to a predetermined threshold.

  According to this configuration, it is possible to set the upper limit of the amount of circulation of the inside air based on the outside air temperature decrease rate calculated based on the detection result of the outside air temperature detection sensor.

  A third invention is characterized in that, in the second invention, the control device controls the inside / outside air switching damper drive means so that the upper limit of the amount of circulation of inside air becomes lower as the outside air temperature decrease rate becomes larger. Do.

  That is, when the outside air temperature decrease rate is large, it can be estimated that the outside air temperature has changed rapidly, and in this case, the haze of the window glass is suppressed by lowering the upper limit of the circulation amount of inside air.

  According to a fourth aspect of the present invention, in the second or third aspect, the control device is configured to reduce the upper limit of the amount of circulating internal air as the external air temperature decreases based on the detection result of the external air temperature detection sensor. A switching damper drive means is controlled.

  That is, generally, the lower the outside air temperature is, the more easily the window glass becomes cloudy. In this case, by lowering the upper limit of the circulating amount of inside air, the clouding of the window glass is suppressed.

  A fifth invention is according to any one of the second to fourth inventions, wherein the control device is a temperature of the window glass detected by the window glass temperature detection sensor when the inside / outside air mixing mode is selected. When the difference between the outside air temperature detected by the outside air temperature detection sensor and the outside air temperature detection sensor is less than a predetermined value, the drying correction control is performed to increase the amount of inside air circulation.

  That is, when the difference between the temperature of the window glass and the outside air temperature is less than the predetermined value, it is estimated that the window glass is less likely to be fogged, and in this case, the heating efficiency is improved by increasing the amount of circulating the inside air.

  A sixth invention is characterized in that in the fifth invention, the control device prohibits the drying correction control when the change of the outside air temperature exceeds a predetermined magnitude.

  A seventh invention is according to any one of the second to sixth inventions, wherein the control device controls the temperature of the window glass detected by the window glass temperature detection sensor, when the inside / outside air mixing mode is selected. When the difference between the outside air temperature detected by the outside air temperature detection sensor and the outside air temperature sensor is a predetermined value or more, the humidity correction control is performed to increase the outside air introduction amount.

  That is, when the difference between the temperature of the window glass and the outside air temperature is equal to or more than a predetermined value, it can be estimated that the window glass is likely to be cloudy, and in this case the amount of outside air introduced is increased. Cloudiness of the window glass is suppressed.

  An eighth invention is characterized in that, in the seventh invention, the control device executes the moisture correction control when the change of the outside air temperature exceeds a predetermined magnitude.

  In a ninth invention according to any one of the second to eighth inventions, the control device calculates the current outside air temperature average value and the past outside air temperature average value, and the current outside air temperature average value and the past outside air temperature average value The outside air temperature decrease rate is calculated based on the difference between

  For example, as the difference between the current outside air temperature average value and the past outside air temperature average value increases, it is estimated that the outside air temperature drops sharply, and the difference between the current outside air temperature average value and the past outside air temperature average value It is estimated that the smaller the change in the outside air temperature is, the smaller the value of. Since the outside air temperature average value is used at the time of calculation, the instantaneous change in the outside air temperature is not reflected in the control.

  In a tenth invention according to the ninth invention, when the elapsed time from the time when the ignition of the vehicle is switched from OFF to ON is less than the first predetermined time, the control device determines the outside air temperature within that time The present invention is characterized in that it is configured to make the average value of the current outside air temperature average value.

  In an eleventh aspect based on the tenth aspect, the control device causes an elapsed time from when the ignition of the vehicle is switched from OFF to ON to exceed the first predetermined time, and to be longer than the first predetermined time. When it is less than the long second predetermined time, the average value of the outside air temperature within the first predetermined time is set as the past outside air temperature average value.

  In a twelfth aspect based on the eleventh aspect, the control device causes the ignition of the vehicle to be switched off when the elapsed time from when the ignition of the vehicle is switched from off to on is less than a first predetermined time. It is characterized in that it is configured to use the outside air temperature at the time of being turned ON as the past outside air temperature average value.

  According to the first aspect of the invention, the upper limit of the circulating amount of internal air is lowered when the change in the outside air temperature exceeds a predetermined value, so the window glass temperature detection sensor provided in the vehicle compartment is the temperature of the window glass It is possible to prevent the window glass from fogging even in a situation where it is not possible to cope with changes in

  According to the second aspect of the invention, the upper limit of the circulating amount of internal air is lowered when the outdoor air temperature decrease rate calculated based on the detection result of the outdoor air temperature detection sensor exceeds a predetermined threshold, so more accurate control is performed. be able to.

  According to the third aspect of the invention, the upper limit of the amount of circulation of inside air decreases as the rate of decrease in outside air temperature increases, so control appropriate for the outside air temperature can be performed.

  According to the fourth invention, the lower the outside air temperature is, the lower the upper limit of the amount of circulation of the inside air is. Therefore, the control adapted to the outside air temperature can be performed.

  According to the fifth invention, when the difference between the temperature of the window glass and the outside air temperature is less than the predetermined value, it is estimated that the window glass is less likely to be fogged, and in this case, the heating efficiency is improved by increasing the amount of circulating the inside air. Do.

  According to the sixth aspect of the invention, by prohibiting the dry correction control when the change in the outside air temperature exceeds a predetermined size, the increase in the amount of the inside air circulation is suppressed and the effect of suppressing the fogging of the window glass is more It will be higher.

  According to the seventh invention, when the difference between the temperature of the window glass and the temperature of the outside air is equal to or more than the predetermined value, the outside air introduction amount can be increased, so the effect of suppressing the fogging of the window glass is further enhanced.

  According to the eighth invention, when the change of the outside air temperature exceeds the predetermined size, the outside air introduction amount is increased and the effect of suppressing the fogging of the window glass is further enhanced by executing the moisture correction control. .

  According to the ninth invention, by calculating the outside air temperature decrease rate based on the difference between the current outside air temperature average value and the past outside air temperature average value, a momentary change in the outside air temperature is not reflected in the control. And accurate control can be performed.

  According to the tenth invention, when the elapsed time after the ignition of the vehicle is turned on is short, the average value of the outside air temperature within that time can be made the current outside air temperature average value.

  According to the eleventh aspect of the present invention, it is possible to calculate both the past outside air temperature average value and the current outside air temperature average value when an elapsed time since the ignition of the vehicle is turned on has elapsed to some extent.

  According to the twelfth invention, when the elapsed time after the ignition of the vehicle is turned on is short, it may be difficult to calculate the past outside air temperature average value, and in this case, the ignition of the vehicle is exceptionally exceptional. By using the outside air temperature at the time of turning ON as the past outside air temperature average value, more accurate control can be performed.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows schematic structure of the vehicle air conditioner which concerns on embodiment. It is a block diagram of a vehicle air conditioner. It is a flowchart which shows the control procedure by a control apparatus. It is a flowchart which shows an intake control procedure. It is a flow chart which shows a correction procedure of dew point temperature. It is a graph for calculating wet dew point temperature correction value. It is a graph for calculating the threshold value A. It is a graph for calculating the threshold value B. It is a graph for calculating dry dew point temperature correction value. It is a flowchart which shows the procedure of outside air temperature decreasing rate determination processing. It is a table which shows the calculation object time of the present outside air temperature average value and the past outside air temperature average value. It is a flow chart which shows a processing procedure at the time of being judged effective by outside air temperature reduction rate judging processing. It is a flowchart which shows the process sequence at the time of being judged invalid by external temperature fall rate determination processing.

  Hereinafter, embodiments of the present invention will be described in detail based on the drawings. The following description of the preferred embodiments is merely illustrative in nature, and is not intended to limit the present invention, its applications, or its applications.

  FIG. 1 is a schematic configuration diagram of a vehicle air conditioner 1 according to an embodiment of the present invention. The vehicle air conditioner 1 is mounted, for example, on a vehicle such as a car, and after introducing one or both of the air inside the vehicle compartment (inside air) and the air outside the vehicle compartment (outside air) to adjust the temperature, It is configured to supply each part of the cabin. Although not shown, a front seat including a driver's seat and a front passenger seat and a rear seat disposed behind the front seat are provided in a cabin of the vehicle.

  The vehicle air conditioner 1 includes an air conditioning casing 10 and a control device (shown in FIG. 2) 30. The air conditioning casing 10 is accommodated, for example, in an instrument panel (not shown) disposed at a front end of a vehicle compartment. The air conditioning casing 10 includes a blower casing 11, a temperature control unit 12, and a blowing direction switching unit 13 in order from the upstream side to the downstream side in the air flow direction. An outside air introduction port 11 a and an inside air introduction port 11 b are formed in the blower casing 11. The outside air introduction port 11a communicates with the outside of the vehicle through, for example, an intake duct (not shown), and introduces air (outside air) outside the vehicle. The inside air introduction port 11 b is opened inside the instrument panel, and introduces air (inside air) inside the vehicle compartment to circulate in the vehicle interior. The amount of outside air introduced from the outside air introduction port 11a is the outside air introduction amount. The amount of inside air introduced from the inside air introduction port 11 b is the inside air circulation amount.

  Inside the air blowing casing 11, an inside / outside air switching damper 11c is disposed which opens and closes the outside air introduction port 11a and the inside air introduction port 11b. The inside / outside air switching damper 11 c can be constituted by, for example, a cantilever damper made of a plate-like member, a rotary damper, or the like, and is rotatably supported on the side wall of the blower casing 11. Although the inside-and-outside air switching damper 11c is not shown in figure, it can also be comprised with a film damper etc.

  The inside / outside air switching damper 11c is driven by the inside / outside air switching actuator (the inside / outside air switching damper driving means) 11d to have an arbitrary rotation angle. Thus, the intake mode is switched. The inside / outside air switching actuator 11 d is controlled by the control device 30 as described later.

  For example, as shown by a solid line in FIG. 1, when the outside air introduction port 11a is fully closed and the inside / outside air switching damper 11c is rotated until the inside air introduction port 11b is fully opened, the intake mode becomes the inside air circulation mode. The opening degree of the inside / outside air switching damper 11c at this time is 100%. On the other hand, when the outside air introduction port 11a is fully opened as shown by a virtual line in FIG. 1 and the inside / outside air switching damper 11c is rotated until the inside air introduction port 11b is fully closed, the intake mode becomes the outside air introduction mode. . The opening degree of the inside / outside air switching damper 11c at this time is 0%. When the opening degree of the inside / outside air switching damper 11c is between 1% and 99%, both the outside air inlet 11a and the inside air inlet 11b are opened, and both inside air and outside air are introduced into the temperature control unit 12. Be done. This intake mode is an internal / external air mixing mode. In the inside / outside air mixing mode, the introduction ratio of inside air to outside air is changed according to the opening degree of the inside / outside air switching damper 11c, whereby the outside air introduction amount and the inside air circulation amount change. The details of the switching control of the intake mode will be described later.

  Further, since both the outside air inlet 11a and the inside air inlet 11b are opened in the inside / outside air mixing mode, for example, if the traveling wind is strong, after the traveling wind enters the inside of the blower casing 11 from the outside air inlet 11a. Some of the air may flow into the passenger compartment from the inside air inlet 11b. At this time, if it is snowing, for example, it is conceivable that the snow on the traveling wind enters the inside of the blower casing 11 from the outside air inlet 11a and enters the vehicle compartment from the inside air inlet 11b. In step SB11 of the flowchart shown in FIG. 4, snow is prevented from entering the passenger compartment.

  As shown in FIG. 1, the blower casing 11 is provided with a blower 15. The blower 15 includes a fan 15a and a blower motor 15b that drives the fan 15a. After the fan 15 a rotates, at least one of the inside air and the outside air is introduced into the blower casing 11, and is then blown to the temperature control unit 12 provided on the downstream side of the blower casing 11. The blower motor 15b is configured to be able to adjust the number of revolutions per unit time by changing the voltage applied. The air blowing amount is changed according to the rotational speed of the blower motor 15b. The blower motor 15 b is controlled by the control device 30.

  The temperature control unit 12 is a portion for controlling the temperature of the air conditioning air introduced from the blower casing 11. Inside the temperature control unit 12, a heat exchanger 16 for cooling, a heat exchanger 17 for heating, and an air mix door 18 are disposed. That is, inside the temperature control unit 12, a cold air passage R1 is formed on the upstream side in the air flow direction, and the cooling heat exchanger 16 is accommodated in the cold air passage R1. Further, the downstream side of the cold air passage R1 is branched into the hot air passage R2 and the bypass passage R3, and the heating heat exchanger 17 is accommodated in the hot air passage R2.

  The heat exchanger 16 for cooling can be comprised, for example with the refrigerant evaporator of a heat pump apparatus, but it is not restricted to this, What is necessary is just to be able to cool air. Further, the heating heat exchanger 17 can be constituted by, for example, a heater core or the like to which cooling water for an engine (not shown) mounted in an engine room of a vehicle is supplied, but is not limited thereto. For example, any heater such as an electric heater may be used as long as it can heat the air. Also, an electric heater can be added as an auxiliary heat source.

  The air mix door 18 is disposed between the cooling heat exchanger 16 and the heating heat exchanger 17, and opens and closes the upstream end of the warm air passage R2 and the upstream end of the bypass passage R3. The air mix door 18 can be formed of, for example, a plate-like member, and is rotatably supported on the side wall of the temperature control unit 12. The air mix door 18 is driven by the air mix actuator 18 a to have an arbitrary rotation angle. The air mix actuator 18 a is controlled by the controller 30.

  When the air mix door 18 fully opens the upstream end of the hot air passage R2 and fully closes the upstream end of the bypass passage R3, all the cold air generated in the cold air passage R1 flows into the hot air passage R2 and is heated As a result, warm air flows into the blowout direction switching unit 13. On the other hand, when the air mix door 18 fully closes the upstream end of the warm air passage R2 and fully opens the upstream end of the bypass passage R3, all the cold air generated in the cold air passage R1 flows into the bypass passage R3. The cold air flows into the blowing direction switching unit 13. When the air mix door 18 is in a rotational position where the upstream end of the hot air passage R2 and the upstream end of the bypass passage R3 are open, the cold air and the hot air flow into the blowing direction switching unit 13 in a mixed state. The amount of cold air and the amount of warm air flowing into the blowout direction switching unit 13 are changed according to the rotational position of the air mix door 18, and conditioned air of a desired temperature is generated. The air mix door 18 is not limited to the above-described plate-like door, and may have any configuration as long as it can change the amount of cold air and the amount of warm air. For example, a rotary door, a film door, a louver damper, etc. may be used. Moreover, the structure of temperature control does not need to be a structure mentioned above, and should just be the structure which can change cold air volume and warm air volume.

  The blowing direction switching unit 13 is a portion for supplying the conditioned air whose temperature has been adjusted by the temperature adjustment unit 12 to each part of the vehicle compartment. The blowout direction switching unit 13 is formed with a defroster blowout opening 21, a vent blowout opening 22, and a heat blowout opening 23. The defroster air outlet 21 is connected to a defroster nozzle 24 formed in an instrument panel. The defroster outlet 21 is for supplying conditioned air to the interior surface of the windshield G (window glass). A defroster door 21 a for opening and closing the defroster vent 21 is provided in the defroster vent 21.

  The vent blower outlet 22 is connected to a vent nozzle 25 formed in an instrument panel. The vent nozzle 25 is for supplying conditioned air to the upper body of the front seat occupant, and is provided at the center in the vehicle width direction of the instrument panel and on both the left and right sides. Inside the vent outlet 22, a vent door 22a for opening and closing the vent outlet 22 is provided.

  The heat outlet 23 is connected to a heat duct 26 extending to the vicinity of the foot of the occupant. The heat duct 26 is for supplying conditioned air to the feet of the occupant. Inside the heat outlet 23, a heat door 23a for opening and closing the heat outlet 23 is provided.

  The defroster door 21a, the vent door 22a and the heat door 23a are driven by the blowout direction switching actuator 27 to open and close. The blowing direction switching actuator 2 is controlled by the control device 30. The defroster door 21a, the vent door 22a and the heat door 23a are interlocked via a link (not shown). For example, the defroster mode, the defroster mode in which the vent door 22a and the heat door 23a are closed when the defroster door 21a is open. The vent mode in which the vent door 22a is opened with the door 21a and the heat door 23a closed, the heat mode in which the heat door 23a is opened with the defroster door 21a and the vent door 22a closed, and the defrost door 21a and the vent door 22a opened. In the defrost mode in which the heat door 23a is closed, the blower door 22a is switched on in the open state, and the blower door 22a is closed, and the blower door is switched to any blow mode among a plurality of blow modes such as bilevel mode. That.

  As shown in FIG. 2, the vehicle air conditioner 1 includes an outside air temperature sensor (outside air temperature detection sensor) 31, an inside air temperature sensor 32, a solar radiation amount sensor (solar radiation detection means) 33, a cooling water temperature sensor 34, an evaporator sensor 35, A windshield vicinity temperature / humidity sensor 37, an operation switch 39, an occupant sensor 40, a vehicle speed sensor (vehicle speed detecting means) 41, a wiper switch 42, and an engine water temperature sensor 43 are provided. The sensors 31 to 35, 37, 40, 41, 43 are connected to the control device 30 and output signals to the control device 30. Further, the operation switch 39 is connected to the control device 30 so that the control device 30 can detect the operation state by the occupant. Further, the wiper switch 42 is connected to the control device 30.

  The outside air temperature sensor 31 is disposed, for example, at the front or side of the vehicle outside the vehicle, and detects an air temperature (outside air temperature) around the vehicle. The inside air temperature sensor 32 is disposed, for example, in the vicinity of an instrument panel in a vehicle compartment, and detects an air temperature (inside air temperature) inside the vehicle compartment. The solar radiation amount sensor 33 is disposed, for example, in the vicinity of an instrument panel in a vehicle compartment, and detects the amount of solar radiation irradiated to the vehicle compartment.

  The inside air temperature sensor 32, the outside air temperature sensor 31, and the solar radiation amount sensor 33 can detect information related to cold heat felt by the occupant. That is, the inside air temperature output from the inside air temperature sensor 32 is a temperature substantially equal to the atmosphere temperature of the occupant, a high inside air temperature indicates that the occupant is warm, and a low inside air temperature indicates that the occupant is cold. . If the outside air temperature output from the outside air temperature sensor 31 is high, the occupant feels warm, and if the outside air temperature is low, the occupant feels cold. Furthermore, when the amount of solar radiation output from the solar radiation amount sensor 33 is large, the occupant feels warm, and when the amount of solar radiation is small, the occupant feels cold.

  The cooling water temperature sensor 34 is an engine water temperature detection means that detects the temperature (engine water temperature) of the cooling water of the engine mounted on the vehicle. The coolant temperature sensor 34 can estimate the temperature of engine coolant flowing into the heating heat exchanger 17. Moreover, while the warm water state of an engine can be estimated by the cooling water temperature sensor 34, the temperature of a heating heat source can be obtained. The evaporator sensor 35 is disposed downstream of the cooling heat exchanger 16 in the air flow direction, and detects the surface temperature of the cooling heat exchanger 16.

  The windshield vicinity temperature / humidity sensor 37 constitutes the window glass temperature detection sensor of the present invention. The windshield vicinity temperature / humidity sensor 37 is disposed in the vicinity of the inner surface of the windshield G away from the vehicle interior surface, and detects the temperature in the vicinity of the interior surface of the windshield G by the window glass And a humidity sensor (not shown) for detecting the humidity in the vicinity of the interior surface of the windshield G of the vehicle. The temperature sensor and the humidity sensor are mounted on a substrate (not shown). The windshield vicinity temperature / humidity sensor 37 is covered with a cover (not shown) made of, for example, a resin material or the like, and is not exposed to the vehicle interior.

  The operation switch 39 is disposed, for example, on an instrument panel or the like, and is, for example, a switch for switching the air conditioner 1 on / off, an air flow switch for increasing or decreasing the air flow, a temperature setting switch for setting the temperature of the cabin, It comprises an inside / outside air switching switch that switches inside air circulation, outside air introduction, and inside / outside air mixing modes, an auto switch that selects whether or not to perform automatic air conditioner control, a blowout mode switch switch that switches blowout direction, a defroster switch, and the like.

  The occupant sensor 40 can detect whether an occupant is seated in the front seat and can also detect whether an occupant is seated in the rear seat. Specifically, for example, pressure sensors are built in the front and rear seat cushions, respectively, and it is possible to detect whether the occupant is seated or not by the pressure sensors. In addition, since a sensor that detects whether or not the front and rear seat belts are in a mounted state is provided in a general vehicle, the occupant can be seated if the seat belt is mounted using this sensor You can detect what you are doing. The vehicle speed sensor 41 can detect the speed of the vehicle, and can use conventionally known sensors. The signal output from the occupant sensor 40 may or may not be used for control according to the present embodiment.

  The wiper switch (wiper operation state detecting means) 42 is for operating the wiper provided in the vehicle, and has at least an ON position for activating the wiper and an OFF position for stopping the wiper. doing. Further, in the ON position, the operation speed of the wiper can be switched to high speed, medium speed, and low speed, and intermittent operation can also be performed. The wiper switch 42 is connected to the control device 30 so that the control device 30 can detect the operation state of the vehicle wiper by the wiper switch 42.

  The control device 30 controls the inside / outside air switching actuator 11 d based on the signals (output values) output from the sensors 31 to 35, 37, 40, 41, 43 and the operation states of the operation switch 39 and the wiper switch 42. The air mix actuator 18a, the blowing direction switching actuator 27, and the blower motor 15b are controlled. That is, when the automatic air conditioner control is selected by the auto switch of the operation switch 39, the temperature outside the vehicle, the temperature inside the vehicle compartment, the amount of solar radiation, the temperature of the engine coolant, the surface temperature of the heat exchanger 16 for cooling, the set temperature While determining the target blowing temperature of the conditioned air supplied to the vehicle interior based on the above, the opening degree of the air mix door 18 is calculated so that the target blowing temperature is achieved, and the air mixing door 18 becomes this opening degree As described above, the air mix actuator 18 a is controlled to rotate the air mix door 18. Thereby, the temperature of the conditioned air becomes the target blowing temperature.

  Further, the control device 30 controls the blowout direction switching actuator 27 so that the blowout mode is mainly in the vent mode during cooling, and the blowout direction switching actuator 27 so that the blowout mode is mainly in the defroster mode or the heat mode during heating. Control. Further, in the case of weakening even at the time of cooling or heating, the blowout direction switching actuator 27 is controlled to be in the bi-level mode or the defvent mode. Furthermore, when the defroster switch of the operation switch 39 is turned ON, the blowout direction switching actuator 27 is controlled so that the blowout mode becomes the defroster mode.

  For example, when heating is performed by a vehicle left for a long time in winter or when cooling is performed by a vehicle left for a long time in summer, the difference between the target blowing temperature and the inside air temperature becomes large. In such a case, the control device 30 controls the blower motor 15b so that the air volume is increased, but the occupant can operate the air volume switching switch so as to obtain a desired air volume. Further, in the automatic air-conditioner control, the blower motor 15b is controlled so that the air volume decreases as the difference between the target air outlet temperature and the inside air temperature decreases. The control of the blower motor 15b is performed by changing the applied voltage, but the invention is not limited to this, as long as the number of rotations of the blower motor 15b can be changed.

  The amount of air blown to the upper body of the occupant can be detected by the control of the blower motor 15b by the control device 30 and the switching control of the blowout mode. That is, when the blowout mode is the vent mode, the conditioned air is mainly blown to the upper body of the occupant, and the voltage applied to the blower motor 15b in the vent mode is detected to the upper body of the occupant. The air flow can be detected. Further, in the heat mode, the amount of air blown to the upper body of the occupant as a whole is smaller than that in the vent mode, which can also be detected by the control device 30.

  Further, the control device 3 controls the inside / outside air switching actuator 27 in accordance with the procedure of the flowchart shown in FIG. The control of the inside / outside air switching actuator 27 is performed at a predetermined timing when it is determined that the ignition switch of the vehicle is ON and the vehicle air conditioner 1 is ON and the control device 3 needs to perform heating. It is repeated. During cooling, basically, the inside / outside air switching actuator 27 is controlled so as to be in a mode (outside air introduction mode or inside air circulation mode) selected by the occupant.

  In step SA1 after the start, the output values of the sensors 31 to 35, 37, 40, 41, 43 are read, and the operation states of the operation switch 39 and the wiper switch 42 are read. Each of the sensors 31 to 35, 37, 40, 41, 43 detects and outputs each value continuously when the ignition switch is turned on from the OFF state and thereafter.

  In step SA2 following step SA1, the windshield glass dew point temperature is calculated. The windshield glass dew point temperature is basically based on the temperature in the vicinity of the interior surface of the windshield G and the humidity in the vicinity of the interior surface of the windshield G output from the temperature and humidity sensor 37 near the windshield. It is obtained. The windshield glass dew point temperature is continuously calculated when the ignition switch is turned on from the off state and thereafter.

  In step SA3 following step SA2, dew point temperature correction is performed. The dew point temperature correction is control to add the dew point temperature correction value (° C.) to the windshield glass dew point temperature calculated in step SA2. The dew point temperature correction value (° C.) includes a wet dew point temperature correction value (° C.) and a dry dew point temperature correction value (° C.), and how to obtain these correction values will be described later.

  In step SA4 following step SA3, a target dew point temperature is calculated. The target dew point temperature is lower than the temperature in the vicinity of the vehicle interior surface of the windshield G output from the windshield vicinity temperature and humidity sensor 37. For example, when the temperature in the vicinity of the vehicle interior surface of the windshield G is 10 ° C., a temperature about 2 to 3 ° C. lower than that is set as the target dew point temperature. The target dew point temperature can be obtained according to known techniques. Thereafter, at step SA5, intake control is performed. The blowout mode and the air volume (voltage applied to the fan drive motor 15b) are also determined based on a known control method.

(Contents of intake control)
The specific content of intake control performed in step SA5 is shown in the flowchart of FIG. In step SB1 of the flowchart of FIG. 4, it is determined whether automatic control is selected, that is, which one of automatic air-conditioner control and manual operation by a passenger is selected. Whether or not the automatic air-conditioner control is to be performed can be determined by whether or not the auto switch of the operation switch 39 is pressed. If it is determined NO in step SB1 and manual control is selected instead of automatic air-conditioner control, the process proceeds to step SB2 to determine whether the intake mode is the open air introduction mode. In addition, since it is not possible to select the inside / outside air mixing mode in the manual operation, in step SB2, it is determined which of the outside air introduction mode and the inside air circulation mode.

  If it is determined YES in step SB2 and it is in the outside air introduction mode, it means that the occupant is actively selecting the outside air introduction mode, so the process proceeds to step SB3 and the target opening degree of the inside / outside air switching damper 11c To the open air introduction degree. The outside air introduction opening degree is an opening degree at which the outside air introduction port 11a is fully opened and the inside air introduction port 11b is fully closed, and is 0%. On the other hand, if it is determined NO in step SB2 and the inside air circulation mode is in effect, it means that the occupant is actively selecting the inside air circulation mode, so the process proceeds to step SB4, and the inside / outside air switching damper 11c is selected. Make the target opening degree the inside air circulation opening degree. The inside air circulation opening degree is an opening degree at which the outside air introduction port 11a is fully closed and the inside air introduction port 11b is fully opened, and is 100%.

  If YES is determined in step SB1 and automatic air-conditioner control is performed, the process proceeds to step SB5. In step SB5, the corrected windshield glass dew point temperature after step SA3 of the flowchart shown in FIG. 3 is used. Then, the target opening degree (f) of the inside / outside air switching damper 11c is calculated so that the target dew point temperature calculated in step SA4 is obtained.

  For example, when the windshield temperature dew point temperature is higher than the target dew point temperature in step SB5, the target opening degree (f) of the inside / outside air switching damper 11c is calculated to increase the outside air introduction amount, and the windshield temperature dew point temperature is If the temperature is lower than the target dew point temperature, the target opening degree (f) of the inside / outside air switching damper 11c is calculated so as to increase the amount of circulation of inside air. When the windshield glass dew point temperature is higher than the target dew point temperature, the amount of outside air introduction increases as the difference becomes larger, and as the windshield glass dew point temperature is lower than the target dew point temperature, the difference becomes larger, Increase the amount of inside air circulation.

  That is, the control device 30 detects the ease of fogging of the windshield G based on the output value of the temperature and humidity sensor 37 near the windshield, and basically, the windshield G tends to fog based on the detection result. In this case, the outside air introduction amount is increased, while the inside air circulation amount is increased when the windscreen glass G is less likely to be fogged. As described above, in the automatic air-conditioner control, basically, the inside / outside air mixing mode in which the outside air introduction amount and the inside air circulation amount are changed on the basis of the cloudiness of the windshield G is selected.

  After calculating the target opening degree (f) of the inside / outside air switching damper 11c in step SB5, the process proceeds to step SB6 and it is determined whether the current outside air temperature detected by the outside air temperature sensor 31 is less than a predetermined temperature. The predetermined temperature in step SB6 is a temperature low enough to snow, and can be, for example, 3 ° C. or less, 2 ° C. or less, 1 ° C. or less, 0 ° C. or less, or below freezing.

  If it is determined NO in step SB6 and the current outside air temperature is higher than the predetermined temperature and snow is unlikely to fall, the process proceeds to step SB7. In step SB7, the opening degree (f) obtained in step SB5 is set as the opening degree of the inside / outside air switching damper 11c.

  If it is determined YES in step SB6 and the current outside air temperature is low enough to cause snow, the process proceeds to step SB8 and whether the current amount of solar radiation detected by the solar radiation amount sensor 33 is equal to or less than a predetermined amount Determine if The predetermined amount in step SB8 is a strong amount of solar radiation that melts in the middle of snowing even if it is snowing. If it is determined NO in step SB8 and the amount of solar radiation is large and the snow is likely to be melted by solar radiation, the process proceeds to step SB7.

  If it is determined YES in step SB8 and the present amount of solar radiation is high enough to melt snow, the process proceeds to step SB9 and it is determined whether the wiper switch 42 is ON. When the wiper switch 42 is ON, it means that snow has fallen to the surface of the windshield G, and in this case, the process proceeds to step SB10. On the other hand, if it is determined NO in step SB10 and snow is falling, but the snow does not adhere to the surface of the windshield G, the process proceeds to step SB7.

  In step SB10, it is determined whether the vehicle speed detected by the vehicle speed sensor 41 is equal to or higher than a predetermined vehicle speed. The predetermined vehicle speed in step SB10 is a speed serving as a reference for determining whether the vehicle is traveling at a high speed, and can be set, for example, in a range of 60 km / h to 80 km / h. In step SB10, it may be determined whether the vehicle is traveling by lowering the determination reference speed. If it is determined YES in step SB10 and the vehicle is traveling at high speed, the process proceeds to step SB11. In step SB11, the target opening degree of the inside / outside air switching damper 11c is set to the outside air introduction opening degree regardless of the opening degree calculated in step SB5.

  On the other hand, when NO is determined in step SB10 and the vehicle is not traveling at a high speed, the momentum of the traveling wind is weak even if it is snowing, and the possibility that the snow gets into the vehicle cabin by riding the traveling wind is low. In this case, the process proceeds to step SB7.

  After the opening degree of the air mix door 18 is determined as described above, the process proceeds to step SA6 in the flowchart shown in FIG. 3 to perform drive processing of the inside / outside air switching actuator 11d. Specifically, the inside / outside air switching actuator 11d is operated such that the opening degree of the inside / outside air switching damper 11c becomes the opening degree set in steps SB11 and SB7 in the flowchart shown in FIG.

(Wind glass dew point temperature correction control)
Next, the windshield glass dew point temperature correction control will be described based on the flowchart shown in FIG. The windshield glass dew point temperature correction control includes a wetness correction control that performs correction that increases the amount of outside air introduced, and a dryness correction control that performs correction that increases the amount of internal air circulation, and is switched according to the situation.

  In step SC1 of the flowchart shown in FIG. 5, it is determined whether the ignition of the vehicle is switched from OFF to ON. When it is determined YES in step SC1 and the ignition of the vehicle is switched from OFF to ON, the process proceeds to step SC2. On the other hand, when it is determined as NO in step SC1 and the ignition of the vehicle is in the ON state (during IG ON), the process proceeds to step SC15.

  In step SC2, the temperature near the interior surface of the windshield glass G detected by the windshield vicinity temperature / humidity sensor 37 is equal to or higher than a value obtained by adding a predetermined value to the current outside air temperature detected by the outside air temperature sensor 31. It is determined whether or not. That is, a value (difference) obtained by subtracting the current outside air temperature detected by the outside air temperature sensor 31 from the temperature in the vicinity of the vehicle interior surface of the front window glass G detected by the front window vicinity temperature and humidity sensor 37 is a predetermined value or more It is determined whether or not.

  The predetermined value used in step SC2 is not always constant, and changes so as to increase as the current outside air temperature detected by the outside air temperature sensor 31 decreases. For example, if the current outside air temperature detected by the outside air temperature sensor 31 is -20 ° C or less, the predetermined value is "3", and if it is higher than -20 ° C and -10 ° C or less, the predetermined value is " If the temperature is higher than -10 ° C. and lower than or equal to 0 ° C., the predetermined value may be “2”. If the temperature is higher than 0 ° C., the predetermined value may be “2”. This predetermined value is an example, and is not limited to the listed values.

  The difference between the temperature in the vicinity of the vehicle interior surface of the front windshield glass G, which is determined as YES in step SC2 and detected by the windshield vicinity temperature / humidity sensor 37, and the current outside air temperature detected by the outside air temperature sensor 31 is a predetermined value If it is above, the process proceeds to step SC3. On the other hand, the difference between the temperature in the vicinity of the vehicle interior surface of the windshield glass G, which is determined as NO in step SC2 and detected by the windshield vicinity temperature and humidity sensor 37, and the current outside temperature detected by the outside air temperature sensor 31 If it is less than the predetermined value, the difference between the temperature in the vicinity of the interior surface of the windshield G and the current outside air temperature is small, and the windshield G is less likely to be fogged, and the process proceeds to step SC8.

  In step SC3, it is determined whether the engine water temperature detected by the engine water temperature sensor 43 is less than or equal to a predetermined water temperature. The value of the predetermined water temperature used in the determination of step SC3 can be set, for example, to 60 ° C., but it is not limited to this, as long as it can be determined that the engine is not completely warmed up.

  If it is determined as YES in step SC3 and the engine water temperature detected by the engine water temperature sensor 43 is equal to or less than the predetermined water temperature, the process proceeds to step SC4. On the other hand, if it is determined NO in step SC3 and the engine water temperature detected by the engine water temperature sensor 43 is higher than the predetermined water temperature, engine warm-up is almost complete, and the process proceeds to step SC8.

  In step SC4, the wetness correction control is performed, and the wetness correction flag F1 is set to 1. In the wet correction control, a wet dew point temperature correction value (° C.) is obtained based on the graph shown in FIG. The horizontal axis of the graph in FIG. 6 represents the current outside air temperature Ta detected by the outside air temperature sensor 31 from the temperature Tow (° C.) near the interior surface of the windshield G detected by the windshield vicinity temperature / humidity sensor 37. C), and the vertical axis is a wet dew point temperature correction value (.degree. C.). The horizontal axes STP2 and STP3 are not always constant, and change so as to increase as the current outside air temperature detected by the outside air temperature sensor 31 decreases. For example, if the current outside air temperature detected by the outside air temperature sensor 31 is −20 ° C. or lower, STP2 and STP3 are 3 and 12, respectively, and if higher than −20 ° C. and −10 ° C. or less, STP2 and STP2 If STP3 is 2.5 and 11.5 respectively, higher than -10 ° C and lower than 0 ° C STP2 and STP3 are respectively 2 and 11; if higher than 0 ° C, STP2 and STP3 each is 2 and It should be 11. This predetermined value is an example, and is not limited to the listed values.

  And if the value of Tow (° C.)-Ta (° C.) is STP2, the dew point temperature correction value (° C.) becomes 0, and the value of Tow (° C.)-Ta (° C.) exceeds STP2 to STP3 The wet dew point temperature correction value (° C.) is set to be high in a direct proportion relationship with the value of Tow (° C.) − Ta (° C.). In this embodiment, the wet dew point temperature correction value (° C.) is set to 4 when the value of Tow (° C.)-Ta (° C.) becomes STP 3, but the present invention is limited thereto. Absent. Further, the upper limit value is set so that the wet dew point temperature correction value (° C.) does not exceed 4 even if the value of Tow (° C.)-Ta (° C.) exceeds STP3.

  In step SC5 following step SC4, a wetness correction control cancellation condition determination process for ending wetness correction control is performed. Specifically, processing is performed to measure an elapsed time after the determination in step SC1 is YES, that is, since the ignition is switched from OFF to ON.

  In step SC6 following step SC5, it is determined whether the wet correction control cancellation condition is satisfied. Specifically, it is considered that when the elapsed time from when the ignition is switched from OFF to ON is, for example, 20 minutes, the temperature in the passenger compartment rises and the front window glass G is less likely to be fogged, so the moisture correction control release It is determined that the condition is satisfied (YES), and the process proceeds to step SC7. On the other hand, when the elapsed time after the ignition is switched from OFF to ON has not passed, for example, 20 minutes, it is considered that the windshield G is less likely to be fogged, so the wetness correction control cancellation condition is not satisfied It is judged as NO) and the step SC7 is skipped. In step SC7, the wet correction control is ended, and the wet correction flag F1 is set to 0.

  On the other hand, in step SC8, which is determined as NO in step SC2 and proceeds as determined as NO in step SC3, it is determined whether the current outside air temperature detected by the outside air temperature sensor 31 is within a predetermined range. . In step SC8, for example, it is determined whether the outside air temperature detected by the outside air temperature sensor 31 is in a range (predetermined range) of -15 ° C. or more and 10 ° C. or less. That is, if the outside air temperature is lower than -15 ° C. or higher than 10 ° C., it is determined as NO and the process proceeds to step SC14, so the dryness correction control of step SC11 is prohibited. On the other hand, if the outside air temperature detected by the outside air temperature sensor 31 is in the range of -15 ° C. or more and 10 ° C. or less, it is determined as YES and the process proceeds to step SC9.

  In step SC9, it is determined whether the engine water temperature is equal to or less than a predetermined threshold A. That is, the engine water temperature obtained when the ignition switch in the OFF state is turned on is obtained from the cooling water temperature sensor 34 and stored temporarily in the control device 30, and the engine water temperature stored in the control device 30 The above determination is made in step SC9 based on

  The predetermined threshold A in step SC4 is a first threshold, which is obtained based on the graph shown in FIG. The horizontal axis of the graph of FIG. 7 is the outside air temperature (° C.) detected by the outside air temperature sensor 31, and the vertical axis is the threshold A (° C.). The threshold A is 5 ° C. when the outside air temperature is −15 ° C., and the threshold A is 20 ° C. when the outside air temperature is 10 ° C. When the outside air temperature is in the range of -15 ° C. to 10 ° C., the threshold A increases in proportion to the increase in the outside air temperature. That is, the control device 30 is configured to increase the threshold A as the outside air temperature detected by the outside air temperature sensor 31 becomes higher. In the graph of FIG. 7, the outside air temperature and the threshold value A are examples, and the specific temperature can be changed within the range in which the effect of the present embodiment is exhibited.

  If the engine coolant temperature at the time when the ignition switch in the OFF state is turned on as determined YES in step SC9 of the flowchart shown in FIG. 5 is equal to or less than the predetermined threshold A, the process proceeds to step SC10. If the engine water temperature is higher than the predetermined threshold A when the ignition switch in the OFF state is turned on, as determined NO in step SC9, the process proceeds to step SC14, so the dew point temperature correction process of step SC11 It will be prohibited.

  In step SC10, it is determined whether the windshield temperature dew point temperature when the ignition switch of the vehicle is turned on (IG ON) from the OFF (IG OFF) state is equal to or lower than a predetermined threshold value B. That is, the controller 30 temporarily stores the windshield glass dew point temperature calculated when the ignition switch in the OFF state is turned ON, based on the windshield glass dew point temperature stored in the controller 30. The above determination is performed in step SC10.

  The predetermined threshold B in step SC10 is a second threshold, which is obtained based on the graph shown in FIG. The horizontal axis of the graph of FIG. 8 is the outside air temperature (° C.) detected by the outside air temperature sensor 31, and the vertical axis is the threshold B (° C.). When the outside air temperature is -15.degree. C., the threshold B is -16.5.degree. C., and when the outside air temperature is 10.degree. C., the threshold B is 12.5.degree. When the outside air temperature is in the range of −15 ° C. to 10 ° C., the threshold B increases in proportion to the increase of the outside air temperature. That is, the control device 30 is configured to lower the threshold B as the outside air temperature detected by the outside air temperature sensor 31 becomes lower. In the graph of FIG. 8, the outside air temperature and the threshold value B are examples, and the specific temperature can be changed within the range in which the effect of the present embodiment is exhibited.

  When it is determined as YES in step SC10 and the ignition switch in the OFF state is turned on, the process proceeds to step SC11. If the windshield switch dew point temperature is higher than the predetermined threshold B when the ignition switch in the OFF state is determined to be NO in step SC10 and the process proceeds to step SC14, the dew point temperature of step SC11 is determined. Correction processing will be prohibited.

  In step SC11, the dry correction control is performed, and the dry correction flag F2 is set to 1. In the dry correction control, a dry dew point temperature correction value (° C.) is obtained based on the graph shown in FIG. The horizontal axis of the graph of FIG. 9 is the outside air temperature (° C.) detected by the outside air temperature sensor 31, and the vertical axis is the dry dew point temperature correction value (° C.). When the outside air temperature is -15 ° C, the dry dew point temperature correction value (° C) is -2 ° C, and when the outside air temperature is 10 ° C, the dry dew point temperature correction value (° C) is -1 ° C. When the outside air temperature is in the range of -15 ° C to 10 ° C, the dry dew point temperature correction value (° C) becomes higher in proportion to the increase of the outside air temperature.

  In step SC12 following step SC11, dry correction control cancellation condition determination processing for ending dry correction control is performed. Specifically, a process of reading the engine water temperature detected by the engine water temperature sensor 43 as needed is performed.

  In step SC13 following step SC12, it is determined whether the dry correction control cancellation condition is satisfied. Specifically, when the engine water temperature detected by the engine water temperature sensor 43 exceeds 70 ° C., for example, it is determined that the dry correction control cancellation condition is satisfied (YES), and the process proceeds to step SC14. On the other hand, when the engine water temperature detected by the engine water temperature sensor 43 does not exceed 70 ° C., for example, it is determined that the dry correction control cancellation condition is not established (NO), and the step SC14 is skipped. In step SC14, the dry correction control is ended and the dry correction flag F2 is set to 0.

  In step SC15, which is determined as NO in step SC1 and the ignition is in the on state, it is determined whether the wetness correction flag F1 is 1 or not. If it is determined as YES in step SC15 and the wetness correction flag F1 is 1, the process proceeds to step SC5 and the wetness correction control cancellation condition determination processing is performed. On the other hand, if it is determined NO in step SC15 and the wetness correction flag F1 is 0, the process proceeds to step SC16.

  In step SC16, it is determined whether the dryness correction flag F2 is one. If it is determined YES in step SC16 and the dry correction flag F2 is 1, the process proceeds to step SC12 to perform dry correction control cancellation condition determination processing. On the other hand, when it is determined NO in step SC16 and the dry correction flag F2 is 0, the process proceeds to the end. The dew point temperature correction control is repeated at a predetermined timing.

(Fogging suppression control by change of outside air temperature)
Next, fogging suppression control based on changes in the outside air temperature will be described. For example, if you move a car that has been parked for a long time in a parking lot that has been shut off to some extent, such as underground parking lots, multi-level parking lots, tower parking, garages with shutters, etc. The outside air temperature will drop sharply. In such a situation, the actual temperature of the windshield G decreases rapidly, but the temperature sensor of the windshield vicinity temperature / humidity sensor 37 is covered with a cover from the viewpoint of appearance etc. so that it is not exposed in the vehicle compartment Because it is configured, it is difficult to detect the temperature of the windshield G in real time. Therefore, even if the outside air temperature drops sharply and the temperature of the windscreen glass G drops rapidly, the drop in the temperature detection value of the windscreen glass G by the temperature sensor becomes gradual, so the drop in the target dew point temperature is also slow As a result, the target dew point temperature becomes higher than the temperature of the actual windshield glass G, and as a result, it is conceivable that the dew point temperature rises and the windshield G tends to become cloudy. This problem tends to occur particularly in cold regions.

  On the other hand, in the present embodiment, the control device 30 obtains the change of the outside air temperature based on the detection result of the outside air temperature sensor 31, and when the change of the outside air temperature exceeds a predetermined magnitude, the outside air The internal / external air switching actuator 11 d is controlled so that the upper limit of the amount of circulation of internal air is lower than when the change in temperature is less than or equal to a predetermined value. Specifically, control device 30 calculates the outside air temperature reduction rate based on the detection result of outside air temperature sensor 31, and when the calculated outside air temperature reduction rate exceeds a predetermined threshold value, the outside air temperature reduction rate is The inside / outside air switching actuator 11 d is controlled so that the upper limit of the amount of circulation of inside air is lower than in the case where the inside or outside of the inside of the room is below a predetermined threshold.

  Hereinafter, the fogging suppression control by the control device 30 will be described based on FIGS. 10 to 13. At step SD1 in FIG. 10, the current outside air temperature average value TaAVE (n) is calculated. At step SD2, the past outside air temperature average value TaAVE (n-1) is calculated. If the elapsed time from when the vehicle ignition is switched from OFF to ON is less than the first predetermined time (for example, one minute), the average value of the outside air temperature within that time is compared to the current outside air temperature average TaAVE (n And).

  When calculating the current outside air temperature average value TaAVE (n) and the past outside air temperature average value TaAVE (n-1), the outside air temperature is measured and stored every time much shorter than the first predetermined time. It can be obtained by adding these measured values and dividing by the number of measurements. For example, assuming that the first predetermined time is one minute, and the measurement result of the outside air temperature is obtained every one second, the measurement results for 60 times are stored. It is possible to obtain an outside air temperature average value (current outside air temperature average value TaAVE (n) or past outside air temperature average value TaAVE (n-1)) by adding all of the 60 measured values and dividing by 60. it can. In principle, the calculation method of the present outside air temperature average value TaAVE (n) and the past outside air temperature average value TaAVE (n-1) can be the same, but in the following case, the calculation method is changed In addition, it is possible to exceptionally use a value other than the average value as the average value.

  For example, the elapsed time from when the ignition of the vehicle is switched from OFF to ON exceeds the first predetermined time (for example, one minute) and is less than the second predetermined time (for example, two minutes) longer than the first predetermined time. In some cases, the average value of the outside air temperature within the first predetermined time is taken as the past outside air temperature average value TaAVE (n-1). Also, if the elapsed time from when the vehicle ignition is switched from OFF to ON is less than the first predetermined time (for example, one minute), the outside air temperature at the time when the vehicle ignition is switched from OFF to ON is past It can also be used as the outside air temperature average value TaAVE (n-1).

  A more specific example is shown in the table of FIG. The left column of the table of FIG. 11 shows the time elapsed from when the ignition of the vehicle is switched from OFF to ON, and in this example, it is divided every 20 seconds. The column in the center of the table of FIG. 11 shows the time for calculating the current outside air temperature average value TaAVE (n), and it takes 60 seconds (first predetermined time) from the time when the vehicle ignition is turned on from off. Until the time elapses, the time for calculating the current outside air temperature average value TaAVE (n) is extended, and thereafter, 60 seconds is set as the time for calculating the current outside air temperature average value TaAVE (n).

  The right column of the table in FIG. 11 shows the time for which the past outside air temperature average value TaAVE (n-1) is to be calculated, and for 60 seconds (from the time when the vehicle ignition is turned on to off) Until one predetermined time period elapses, the outside air temperature at the time when the ignition of the vehicle is switched from OFF to ON is used as the past outside air temperature average value TaAVE (n-1). Until the passage of 60 seconds (first predetermined time) from the time when the ignition of the vehicle is turned ON to ON, and until 120 seconds (second predetermined time) elapse, the past outside air temperature average value TaAVE (n-1) The time to calculate is extended, and after that, 60 seconds is set as the time to calculate the past outside air temperature average value TaAVE (n-1). The table of FIG. 11 is an example, and it is possible to change the first predetermined time and the second predetermined time to any time. The order of calculation of the current outside air temperature average value TaAVE (n) and the past outside air temperature average value TaAVE (n-1) is not particularly limited, and either one may be calculated first.

  For example, it is estimated that the larger the difference between the current outside air temperature average value TaAVE (n) and the past outside air temperature average value TaAVE (n-1) is, the more the outside air temperature drops sharply, and the current outside air temperature average It is estimated that the smaller the difference between the value TaAVE (n) and the past outside air temperature average value TaAVE (n-1), the smaller the change in outside air temperature. Since the outside air temperature average value is used at the time of calculation, the instantaneous change in the outside air temperature is not reflected in the control.

  After the current outside air temperature average value TaAVE (n) and the past outside air temperature average value TaAVE (n-1) are calculated in steps SD1 and SD2 of the flowchart shown in FIG. 10, the process proceeds to step SD3. In step SD3, the outside air temperature decrease rate ΔTa is calculated based on the difference between the current outside air temperature average value TaAVE (n) and the past outside air temperature average value TaAVE (n-1). ΔTa is obtained by subtracting the past outside air temperature average value TaAVE (n−1) from the current outside air temperature average value TaAVE (n), and the calculation formula is expressed by the following equation (1).

ΔTa = TaAVE (n) −TaAVE (n−1) (1)
As shown in the table of FIG. 11, the present outside air temperature average value TaAVE (n) can be an average value of Ta (outside air temperature) up to one minute before the present, and the past outside air temperature average value TaAVE (n) n-1) can be an average value of Ta (outside air temperature) from 1 minute ago to 2 minutes ago.

  After the outside air temperature decrease rate ΔTa is calculated, the outside air temperature decrease rate determination is performed in step SD4 shown in FIG. In the outside air temperature decrease rate determination, it is determined whether it is effective to perform the fogging suppression control by the change of the outside air temperature or whether the effect can not be expected (invalid) even if the fogging suppression control by the change of the outside air temperature is performed. As shown in step SD4 of FIG. 10, when the outside air temperature decrease rate ΔTa goes to a temperature lower than -1.0 ° C. by more than -1.0 ° C., the fogging suppression control by the change of the outside air temperature is effective. judge. That is, when the change in the outside air temperature exceeds a predetermined level, the fogging suppression control by the change in the outside air temperature becomes effective. In addition, when the outside air temperature decrease rate ΔTa is on the plus side, it can be estimated that the windshield glass G is in a state of being hardly fogged, so the fogging suppression control due to the change of the outside air temperature is invalidated.

  On the other hand, when the outside air temperature decrease rate ΔTa becomes smaller from the state where the fog reduction control by the change of the outside air temperature is effective and becomes −0.5 ° C., it is determined that the fog reduction control by the change of the outside air temperature is not effective. That is, when the change in the outside air temperature is small, it can be estimated that the windshield G is in a state of being hard to fog, so the fogging suppression control due to the change in the outside air temperature is invalidated. The above “−1.0” and “−0.5” are an example and can be changed to any value.

  In step SD5, it is determined whether the result obtained in step SD4 is "valid". If the result obtained in step SD4 is valid, YES is determined in step SD5, and the process proceeds to the flowchart shown in FIG. On the other hand, if the result obtained in step SD4 is invalid, it is determined as NO in step SD5, and the process proceeds to the flowchart shown in FIG.

  At step SE1 of the flowchart shown in FIG. 12, start processing of maximum internal air circulation amount regulation control is performed. The maximum internal air circulation amount (INTmax) restriction flag is set to 1. After setting the INTmax restriction flag to 1, the process proceeds to step SE2.

  In step SE2, maximum internal air circulation amount regulation processing is performed. If the outside air temperature reduction rate ΔTa is −1.0 ° C. or more, the opening degree of the inside / outside air switching damper 11 c is ΔTaA (%), and if the outside air temperature reduction rate ΔTa is −5.0 ° C. or less, the inside / outside air switching The opening degree of the damper 11c is ΔTaB (%). The upper limit (upper limit of the circulating amount of internal air) of ΔTaA (%) is 50%, and the upper limit (upper limit of the circulating amount of internal air) of ΔTaB (%) is 20%. That is, when the change in the outside air temperature Ta exceeds a predetermined magnitude, the upper limit of the amount of circulation of the inside air becomes lower than in the case where the change in the outside air temperature Ta is equal to or less than the predetermined magnitude. Further, the lower limit of ΔTaA (%) (lower limit of the circulating amount of internal air) is 30%, and the lower limit of ΔTaB (%) (lower limit of the circulating amount of internal air) is 0%. As shown in the graph of FIG. 12, ΔTaA (%) and ΔTaB (%) are set to be larger as the outside air temperature Ta becomes higher.

  When the outside air temperature decrease rate ΔTa exceeds −5.0 ° C. and is less than −1.0 ° C., as shown in the graph of FIG. It gets lower.

  When the inside / outside air mixing mode is selected, the control device 30 determines the difference between the temperature of the windshield G detected by the windshield vicinity temperature / humidity sensor 37 and the outside air temperature detected by the outside air temperature sensor 31. If it is less than the predetermined value, the drying correction control is performed so that the amount of circulation of the inside air is increased.

  In step SE3, the dry correction flag F2 is set to 0, and the dry correction control is prohibited. At step SE4, the wetness correction flag F1 is set to one. In step SE5, the above-mentioned wetness correction control is performed. When the inside / outside air mixing mode is selected, as described above, control device 30 measures the temperature of front windshield glass G detected by front windshield temperature / humidity sensor 37 and the outside air temperature detected by outside air temperature sensor 31. The humidity correction control is performed so that the outside air introduction amount increases when the difference between the above

  In step SF1 of the flowchart shown in FIG. 13, it is determined whether the INTmax restriction flag is one. If the INTmax restriction flag is set to 1 in step SE1 of the flowchart shown in FIG. 12 before step SF1, YES is determined in step SF1, and the process proceeds to step SF2. In step SF2, the INTmax restriction flag is set to 0. If NO in step SF1 and the INTmax restriction flag is 0, the process of step SF2 is skipped.

  In step SF3, it is determined whether the wetness correction flag F1 is one. If wet correction control is being performed before step SF3, YES is determined in step SF3 and the process proceeds to step SF4. At step SF4, the wetness correction flag F1 is set to zero. In step SF5, the process of canceling the wetness correction control, that is, the wetness correction control is not performed. On the other hand, when the wetness correction flag F1 is 0 in step SF3 and it is determined as NO, the processing of step SF4 and step SF5 is skipped.

(Operation and effect of the embodiment)
As described above, according to the vehicle air conditioner 1 according to this embodiment, when the inside / outside air mixing mode is selected, the outside air introduction amount and the inside air circulation amount are on the basis of the foginess of the front window glass G. Since the change is made, it is possible to increase the amount of circulation of the inside air within the range in which the windshield glass G does not fog, thereby reducing the amount of ventilation and reducing the energy consumption required for heating.

  In addition, when the engine water temperature is low and the outside air temperature is low, it can be estimated that the temperature and humidity sensor 37 near the windshield is cooled at a low temperature. When the engine is started from there, the temperature of the air blown out from the defroster outlet 21 rises with the rise of the engine water temperature, and the temperature of the windshield G rises rapidly, but the temperature and humidity sensor 37 near the windshield is low temperature Since it is kept cold and covered with a cover, the warm air blown out from the defroster outlet 21 hardly hits and the temperature hardly rises, and the temperature and humidity sensor 37 near the windshield is the actual temperature of the windshield G It is possible to output a lower temperature than that.

  In this embodiment, when it is detected that the outside air temperature is low outside the predetermined temperature and the engine water temperature is below the first threshold and cold start is detected, the internal air circulation amount is increased. Since the drying correction processing can be performed, the amount of internal air circulation can be increased even in a situation where the temperature around the windshield can not cope with the change in the temperature of the windshield glass G.

  In addition, when the windshield temperature dew point temperature is low, the number of occupants is small and the windows are not easily fogged, and when the windshield temperature dew point temperature is high, it is considered that the occupants tend to be clouded easily. Normally, when the temperature near the windshield is kept cold at low temperature together with the cover, the dew point temperature of the windshield is low, and the dew point rises rapidly after the passenger gets on the vehicle. In particular, when a plurality of passengers get on at one time, a sharp rise in the dew point temperature of the windscreen becomes noticeable. On the other hand, when the number of occupants is small, the dew point temperature of the windshield is difficult to rise and the windows are not easily fogged, but when the number of occupants is large, the dew point temperature of the windshield is likely to rise and the windows are also easily fogged. In this embodiment, by performing the drying correction process, it is possible to increase the amount of inside air circulation when the windshield glass dew point temperature is low and the window is not easily fogged.

  Further, in the present embodiment, when the ignition of the vehicle is switched from OFF to ON, the difference between the temperature near the windshield G and the outside air temperature is a predetermined value or more (YES in step SC2), and the engine water temperature is low. In the case of (YES in step SC3), the wetness correction control is performed in step SC4. In this wet correction control, as shown in FIG. 6, a positive value is obtained as the wet dew point temperature correction value (° C.). Then, in step SA3 in the flowchart shown in FIG. 3, a wet dew point temperature correction value (° C.) is added to the windshield wind point temperature calculated in step SA2. As a result, the amount of outside air introduced is controlled to increase, so that the occurrence of fogging on the windshield G is suppressed.

  In addition, for example, when the vehicle parked for a long time in a parking lot which is shut off to the outside air to a certain extent in winter is moved to the outside, the temperature of the front window glass G drops rapidly because the outside air temperature drops sharply. At this time, since the windshield vicinity temperature / humidity sensor 37 is covered with a cover or the like, even if the temperature of the windshield G decreases rapidly, the temperature detection value of the windshield G by the windshield vicinity temperature / humidity sensor 37 The decrease is gradual, and as a result, the decrease in the target dew point temperature is also gradual. Therefore, the target dew point temperature becomes higher than the actual temperature of the windshield glass G, the dew point temperature rises, and there is a possibility that the windshield glass G tends to be fogged.

  In this embodiment, when the change in the outside air temperature is obtained by the outside air temperature sensor 31 and the change in the outside air temperature detected by the outside air temperature sensor 31 exceeds a predetermined magnitude, the change in the outside air temperature is a predetermined magnitude. The inside / outside air switching actuator 11d can be controlled so that the upper limit of the amount of circulation of inside air is lower than in the case below. Since the outside air temperature sensor 31 can generally detect the temperature change more quickly than the temperature detection sensor in the vehicle compartment, this can be quickly obtained when the outside air temperature changes. If the change in the outside air temperature is large, it can be estimated that the temperature of the windshield glass G is rapidly decreasing, and in this case, the upper limit of the amount of inside air circulation becomes low, that is, the circulation of humid air in the vehicle compartment As the amount decreases, the fogging of the windshield G is suppressed.

  Moreover, the upper limit of the amount of circulation of inside air can be set by the outside air temperature reduction rate. In this case, when the outside air temperature decrease rate is large, it can be estimated that the outside air temperature has changed rapidly, and by lowering the upper limit of the circulation amount of inside air at this time, the fogging of the windshield G is suppressed. .

  The embodiments described above are merely illustrative in every respect and should not be construed as limiting. Furthermore, all variations and modifications that fall within the equivalent scope of the claims fall within the scope of the present invention.

  As described above, the vehicle air conditioner according to the present invention can be used, for example, when air conditioning the interior of a vehicle.

1 Vehicle air conditioner 11 Blast casing 11a Outside air introduction port 11b Inside air introduction port 11c Inside / outside air switching damper 11d Inside / outside air switching actuator (inside / outside air switching damper drive means)
30 control device 31 outside air temperature sensor (outside air temperature detection sensor)
33 Solar radiation sensor 34 Cooling water temperature sensor (engine water temperature detection means)
37 Temperature and humidity sensor near the windshield (window glass temperature sensor)
41 Vehicle speed sensor (vehicle speed detection means)
42 Wiper switch G Front window glass (window glass)

Claims (12)

A blower casing in which an inside air introduction port for introducing air in the vehicle compartment to circulate in the vehicle compartment and an outside air introduction port for introducing air outside the vehicle compartment are formed;
An inside / outside air switching damper provided in the air blowing casing and opening / closing the inside air introduction port and the outside air introduction port;
Inside and outside air switching damper driving means for driving the above inside and outside air switching damper,
A window glass temperature detection sensor disposed in the vehicle compartment and detecting the temperature of the window glass in the vehicle compartment;
A control device for controlling the inside / outside air switching damper driving means;
The control device operates the inside / outside air switching damper drive means to operate the inside / outside air switching damper in the direction in which the outside air introduction amount increases when the window glass tends to be cloudy based on the detection result of the window glass temperature detection sensor In the case where the window glass is hard to be fogged, it is possible to select the inside / outside air mixing mode for controlling the inside / outside air switching damper drive means to operate the inside / outside air switching damper in the direction of increasing the amount of inside air circulation. In the vehicle air conditioner,
The vehicle air conditioner includes an outside air temperature detection sensor for detecting outside air temperature,
The control device obtains a change in the outside air temperature based on the detection result of the outside air temperature detection sensor, and when the change in the outside air temperature exceeds a predetermined magnitude, the change in the outside air temperature is less than the predetermined magnitude A vehicle air conditioner characterized in that the inside / outside air switching damper drive means is controlled so that the upper limit of the amount of circulation of inside air becomes lower than in the case of. In the vehicle air conditioner according to claim 1,
The control device calculates the outside air temperature reduction rate based on the detection result of the outside air temperature detection sensor, and when the calculated outside air temperature reduction rate exceeds a predetermined threshold, the outside air temperature reduction rate is less than the predetermined threshold A vehicle air conditioner characterized in that the inside / outside air switching damper drive means is controlled so that the upper limit of the amount of circulation of inside air becomes lower than in the case of. In the vehicle air conditioner according to claim 2,
A vehicle air conditioner characterized in that the control device controls the inside / outside air switching damper drive means so that the upper limit of the amount of circulation of inside air decreases as the rate of decrease in outside air temperature increases. In the vehicle air conditioner according to claim 2 or 3,
The control device controls the inside / outside air switching damper drive means so that the upper limit of the amount of circulation of inside air decreases as the outside air temperature decreases based on the detection result of the outside air temperature detection sensor. Air conditioner. In the vehicle air conditioner according to any one of claims 2 to 4,
When the inside / outside air mixing mode is selected, the control device determines that the difference between the temperature of the window glass detected by the window glass temperature detection sensor and the outside air temperature detected by the outside air temperature detection sensor is predetermined. A vehicle air conditioner characterized by performing dry correction control so that the amount of internal air circulation increases when the value is less than the value. In the vehicle air conditioner according to claim 5,
The vehicle air conditioner characterized in that the control device prohibits the dry correction control when the change in the outside air temperature exceeds a predetermined magnitude. In the vehicle air conditioner according to any one of claims 2 to 6,
When the inside / outside air mixing mode is selected, the control device determines that the difference between the temperature of the window glass detected by the window glass temperature detection sensor and the outside air temperature detected by the outside air temperature detection sensor is a predetermined value. A vehicle air conditioner characterized by performing wetness correction control so that the amount of outside air introduction increases as it is above. In the vehicle air conditioner according to claim 7,
An air conditioner for a vehicle, wherein the control device executes wetness correction control when a change in the outside air temperature exceeds a predetermined value. The vehicle air conditioner according to any one of claims 2 to 8.
The control device is configured to calculate the current outside air temperature average value and the past outside air temperature average value, and to calculate the outside air temperature decrease rate based on the difference between the current outside air temperature average value and the past outside air temperature average value A vehicle air conditioner characterized in that In the vehicle air conditioner according to claim 9,
When the elapsed time from the time when the ignition of the vehicle is switched from OFF to ON is less than the first predetermined time, the control device sets the average value of the outside air temperature within that time as the current outside air temperature average value An air conditioner for a vehicle, comprising: In the vehicle air conditioner according to claim 10,
When the elapsed time from the time when the ignition of the vehicle is switched from OFF to ON exceeds the first predetermined time and is less than the second predetermined time, which is longer than the first predetermined time, A vehicle air conditioner characterized in that the average value of the outside air temperature within the first predetermined time is made the past outside air temperature average value. In the vehicle air conditioner according to claim 11,
When the elapsed time from the time when the ignition of the vehicle is switched from OFF to ON is less than the first predetermined time, the control device sets the outside air temperature at the time when the ignition of the vehicle is switched from OFF to ON to the past outside air temperature An air conditioner for a vehicle, which is configured to be used as an average value.

Images