JP3832351B2 - Air-conditioning anti-fogging control device for vehicles - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a vehicle air-conditioning and anti-fogging control device that achieves both reduction in driving power of an air-conditioning compressor and securing of anti-fogging property of a window glass.
[0002]
[Prior art]
Conventionally, in Japanese Patent Application Laid-Open No. 11-291753, by controlling the operation of an air conditioning compressor, the evaporator temperature (specifically, the temperature of the blown air from the evaporator) is set to a lower first target temperature near the freezing temperature of the condensed water ( For example, a maximum cooling mode (generally referred to as an air conditioner mode) controlled to about 3 ° C. to 4 ° C., and a second target temperature (for example, 10 ° C.) sufficiently higher than the lower first target temperature. There is described a vehicle air conditioner that can be switched between a power saving cooling mode (generally referred to as an economy mode) that is controlled to about ~ 12 ° C.
[0003]
That is, in the maximum cooling mode, the operation of the air conditioning compressor is controlled so that the actual evaporator temperature becomes the lower first target temperature, and in the power saving cooling mode, the actual evaporator temperature is increased to the higher first target temperature. 2. Control the operation of the air conditioning compressor so that the target temperature is reached.
[0004]
By the way, in the power saving cooling mode, the evaporator temperature becomes the second higher target temperature, and the driving power of the air conditioning compressor can be reduced. On the other hand, the dehumidifying capacity of the air blown out from the passenger compartment is lower than that in the maximum cooling mode. As a result, the window glass of the vehicle tends to become cloudy.
[0005]
Therefore, in the above-described conventional device, when the window glass of the vehicle is fogged due to the execution of the power saving cooling mode, and the occupant performs the setting operation of the defroster mode, the air conditioning blowing mode is switched to the defroster mode, and at the same time, the compression for air conditioning is performed. The machine's operation mode is automatically switched to the maximum cooling mode to improve the anti-fogging performance of the window glass.
[0006]
When the fogging of the window glass is removed, and when the occupant selects another blowing mode other than the defroster mode and the defroster mode is canceled, the maximum cooling mode is immediately stopped, the dehumidifying capacity of the vehicle cabin blowing air is reduced. The window glass may become fogged again due to the decrease. Therefore, in the above-described conventional apparatus, the maximum cooling mode is maintained for a predetermined time even after the defroster mode is canceled, and the power saving cooling mode is switched to only after the predetermined time has elapsed.
[0007]
[Problems to be solved by the invention]
However, since the maximum cooling mode state is maintained for a predetermined time even after the defroster mode is canceled, the state where the driving power of the air conditioning compressor is large is continued for a long time, and the vehicle engine which is the driving source of the compressor This is a cause of worsening the fuel economy.
[0008]
An object of this invention is to reduce the drive power of the compressor for an air conditioning, ensuring the anti-fogging property of a window glass in view of the said point.
[0009]
Another object of the present invention is to provide a vehicle air-conditioning and anti-fogging control device that can effectively improve the anti-fogging performance in the defroster mode.
[0010]
[Means for Solving the Problems]
In order to achieve the above object, according to the first aspect of the present invention, in a vehicle including an electric heating element (61) that directly heats the front window glass (W), the air conditioning compressor (11) is operated for cooling. The maximum cooling mode for controlling the temperature of the heat exchanger (9) to the first target temperature near the freezing temperature of the condensed water, and the temperature of the cooling heat exchanger (9) by the operation control of the air conditioning compressor (11). A defroster that can switch between a power saving cooling mode that controls the first target temperature to a higher second target temperature and blows the conditioned air that has passed through the cooling heat exchanger (9) to the inner surface of the front window glass (W). When the maximum cooling mode is set in the mode and the defroster mode is canceled, the maximum cooling mode is switched to the power saving cooling mode, and the electric heating element (61) is energized.
[0011]
Thereby, the maximum cooling mode can be set as the operation mode of the air conditioning compressor (11) in the defroster mode, and the dehumidifying capacity of the cooling heat exchanger (9) can be maximized. Therefore, the anti-fogging performance by defroster mode can be improved and the fogging of the front window glass (W) can be removed rapidly.
[0012]
Further, when the defroster mode is canceled, the maximum cooling mode is switched to the power saving cooling mode, and the driving power of the air conditioning compressor (11) can be immediately reduced. Therefore, when the air conditioning compressor (11) is driven by the vehicle engine, the fuel efficiency of the vehicle engine can be improved.
[0013]
In addition, even if the maximum cooling mode is switched to the power saving cooling mode, the electric heating element (61) is energized to directly heat the front window glass (W) and raise the temperature of the front window glass (W). The antifogging property of the window glass after mode release can be ensured satisfactorily.
[0014]
In the invention according to claim 2, in the vehicle including the electric heating element (61) for directly heating the front window glass (W), the cooling heat exchanger (9) is controlled by the operation control of the air conditioning compressor (11). The maximum cooling mode for controlling the temperature to the first target temperature in the vicinity of the freezing temperature of the condensed water and the operation of the air conditioning compressor (11) control the temperature of the cooling heat exchanger (9), and the first target temperature. Switching to power-saving cooling mode that controls to a high second target temperature is possible, and the maximum cooling mode is set in the defroster mode in which the conditioned air that has passed through the cooling heat exchanger (9) is blown to the inner surface of the front window glass (W) In the defroster mode, when the elapsed time after setting the maximum cooling mode is equal to or longer than a predetermined time, the electric heating element (61) is energized while the maximum cooling mode is maintained.
[0015]
Thereby, the maximum cooling mode can be set as the operation mode of the air conditioning compressor (11) in the defroster mode, and the dehumidifying capacity of the cooling heat exchanger (9) can be maximized. Therefore, the anti-fogging performance by defroster mode can be improved. In addition, when the elapsed time after setting the maximum cooling mode is equal to or longer than a predetermined time, the electric heating element (61) is energized while maintaining the maximum cooling mode, so the front window glass (W) is directly attached to the electric heating element (61). The temperature of the front window glass (W) can be raised by heating. As a result, the anti-fogging performance of the window glass in the defroster mode can be further improved, and the fogging of the front window glass (W) can be rapidly removed even under conditions where fogging easily occurs.
[0016]
According to a third aspect of the present invention, in the second aspect, when the elapsed time after energization of the electric heating element (61) in the defroster mode is equal to or longer than a predetermined time, the electric heating element (61) is kept energized while maintaining the energization. The cooling mode is switched to the power saving cooling mode.
[0017]
According to this, even if the defroster mode is not canceled, the state where the compressor driving power in the maximum cooling mode is large can be limited within a predetermined time. Therefore, when the air conditioning compressor (11) is driven by a vehicle engine, the fuel efficiency of the vehicle engine can be improved.
[0018]
Even when the maximum cooling mode is switched to the power saving cooling mode, the electric heating element (61) is kept energized to directly heat the front window glass (W), thereby increasing the temperature of the front window glass (W). Therefore, the antifogging property of the window glass can be ensured satisfactorily.
[0019]
According to a fourth aspect of the present invention, in any one of the first to third aspects, after the defroster mode is released, the front window glass (W) is judged to be anti-fogged and the front window glass (W) is anti-fogged. If it determines with being in a state, electricity supply of an electric heating element (61) will be stopped, It is characterized by the above-mentioned.
[0020]
Thereby, unnecessary power consumption of the electric heating element (61) can be prevented in advance.
[0021]
According to a fifth aspect of the present invention, in any one of the first to fourth aspects, the conditioned air that has passed through the cooling heat exchanger (9) is applied to both the inner surface of the front window glass (W) and the occupant foot. When the foot defroster mode that blows out is selected, a power-saving cooling mode is set and the electric heating element (61) is energized.
[0022]
By the way, the foot defroster mode is selected when the degree of urgency with respect to defogging of the window glass is lower than that in the defroster mode. Therefore, in view of this point, in claim 5, in the foot defroster mode, the anti-fogging performance can be secured by setting the power saving cooling mode and energizing the electric heating element (61), and the compressor driving power can be reduced.
[0023]
In addition, the code | symbol in the bracket | parenthesis of each said means shows the correspondence with the specific means as described in embodiment mentioned later.
[0024]
DETAILED DESCRIPTION OF THE INVENTION
(First embodiment)
FIG. 1 shows a schematic configuration of an entire vehicle air conditioner including a vehicle air conditioner anti-fogging control device according to the first embodiment, and the front window glass W is directly heated as an antifogging means for the front window glass W of the vehicle. An electric heating element 61 that removes fogging of the front window glass W is provided. The electric heating element 61 is composed of an electric heating element made of a transparent conductive thin film that generates heat when electric power is supplied from the battery B of the vehicle.
[0025]
Further, another anti-fogging means for the front window glass W of the vehicle is constituted by the blower 8 of the air conditioner 1, the evaporator 9 of the refrigeration cycle 10, the heater core 15, etc., and is dehumidified by the evaporator 9 of the refrigeration cycle 10, The dehumidified warm air heated by the heater core 15 is blown out toward the front window glass W of the vehicle by the blower 8 to remove the fog on the front window glass W.
[0026]
The vehicle air conditioner 1 has a case 2 that constitutes an air passage through which air is blown toward the vehicle interior, and has an inside air introduction port 3 and an outside air introduction port 4 at the most upstream portion of the air passage of the case 2. An inside / outside air switching box 5 is arranged. Inside / outside air switching box 5, an inside / outside air switching door 6 as inside / outside air switching means is rotatably arranged.
[0027]
The inside / outside air switching door 6 is driven by a servo motor 7, and an inside air mode for introducing inside air (vehicle compartment air) from the inside air introduction port 3 and an outside air mode for introducing outside air (vehicle compartment outside air) from the outside air introduction port 4. And switch.
[0028]
On the downstream side of the inside / outside air switching box 5, an electric blower 8 that generates an air flow toward the vehicle interior is disposed. The blower 8 is configured to drive a centrifugal blower fan 8a by a motor 8b. An evaporator 9 that cools the air flowing in the case 2 is disposed on the downstream side of the blower 8. The evaporator 9 is a cooling heat exchanger that cools the air blown from the blower 8, and is one of the elements constituting the refrigeration cycle 10.
[0029]
The refrigeration cycle 10 is a well-known one that is formed so that the refrigerant circulates from the discharge side of the compressor 11 to the evaporator 9 through the condenser 12, the receiver 13, and the expansion valve 14 that forms a pressure reducing device. . The compressor 11 is rotationally driven by the rotational power of a vehicle engine (not shown) being transmitted through an electromagnetic clutch 11a.
[0030]
A heater core 15 for heating the air flowing in the case 2 is disposed on the downstream side of the evaporator 9. The heater core 15 is a heating heat exchanger that heats the air (cold air) after passing through the evaporator 9 by using cooling water (hereinafter referred to as hot water) of the vehicle engine as a heat source, and bypasses the heater core 15 on its side. A bypass passage 16 through which air flows is formed.
[0031]
An air mix door 17 is rotatably disposed between the evaporator 9 and the heater core 15. The air mix door 17 is driven by a servo motor 18 so that its rotational position (opening) can be continuously adjusted. The amount of air passing through the heater core 15 (warm air amount) and the amount of air passing through the bypass passage 16 and bypassing the heater core 15 (cold air amount) are adjusted by the opening degree of the air mix door 17 and thereby blown out into the vehicle interior. The temperature of the air is adjusted. Therefore, in this example, the air mix door 17 constitutes temperature adjusting means for the air blown into the vehicle interior.
[0032]
At the most downstream part of the air passage of the case 2, a defroster outlet 19 for blowing conditioned air toward the front window glass W of the vehicle, a face outlet 20 for blowing conditioned air toward the upper body of the occupant, and an occupant There are a total of three types of air outlets 21, which are foot outlets 21 for blowing air-conditioned air toward the lower body.
[0033]
A defroster door 22, a face door 23, and a foot door 24 are rotatably disposed upstream of the air outlets 19 to 21. The defroster door 22, the face door 23, and the foot door 24 are driven by a common servo motor 25 via a link mechanism (not shown).
[0034]
The control device 30 as a control means includes a CPU 31, a ROM 32, a RAM 33, and the like. A control program for anti-fogging control and air conditioning control in the passenger compartment is stored in the ROM 32 in advance, and the control is performed. Various calculations and processing are performed based on the program. The control device 30 is connected to the battery B. When power is supplied from the battery B, the control program is started.
[0035]
The servo motors 7, 18, 25, the blower drive circuit 34, the clutch drive circuit 35, and the electric heating element 61 are connected to the output side of the control device 30, respectively. By controlling the applied voltage of the blower motor 8b by the blower drive circuit 34, the rotational speed (air volume) of the blower motor 8b is controlled. Further, the energization of the electromagnetic clutch 11 a of the compressor 11 is intermittently controlled by the clutch drive circuit 35 to control the operation of the compressor 11 intermittently. Further, the control device 30 intermittently controls energization to the electric heating element 61.
[0036]
Operation switches 37 to 42 of an air conditioning operation panel 36 provided on an instrument panel (not shown) in front of the driver's seat in the passenger compartment are connected to the input side of the control device 30. Among the operation switches 37 to 42, the inside / outside air switching switch 37 has an inside air switch 37a for manually setting the inside air mode and an outside air switch 37b for manually setting the outside air mode.
[0037]
The temperature setting switch 38 outputs a signal of the set temperature in the passenger compartment, and the blowing mode switch 39 is a signal for manually setting the face mode, the bi-level mode, the foot mode, the foot defroster mode, and the defroster mode as the blowing mode. It is something that gives out. The air volume changeover switch 40 outputs a signal for manually setting on / off of the blower 8 and airflow change of the blower 8, and the air conditioner switch 41 outputs an on / off signal of energization of the electromagnetic clutch 11a to intermittently operate the compressor 11. To do. The anti-fogging switch 42 outputs a signal for manually setting on / off of the electric heating element 61 of the front window glass W.
[0038]
The face mode is a mode in which the face air outlet 20 is fully opened, the defroster air outlet 19 and the foot air outlet 21 are closed, and the conditioned air is blown out only from the face air outlet 20 toward the passenger's upper body side in the passenger compartment. In the bi-level mode, the face air outlet 20 and the foot air outlet 21 are fully opened, the defroster air outlet 19 is closed, and conditioned air is sent from both the face air outlet 20 and the foot air outlet 21 to the occupant upper body side and the occupant foot side. It is a mode that blows out approximately the same amount.
[0039]
In the foot mode, the face air outlet 20 is closed, the foot air outlet 21 is fully opened, the defroster air outlet 19 is opened by a small opening, and the conditioned air is blown mainly from the foot air outlet 21 toward the passenger's feet. In this mode, a small amount of conditioned air is blown from the defroster outlet 19 to the inner surface of the window glass inside the vehicle cabin.
[0040]
The defroster mode is a mode in which the face outlet 20 and the foot outlet 21 are closed, the defroster outlet 19 is fully opened, and the conditioned air is blown from the defroster outlet 19 to the inner surface side of the front window glass W. The foot defroster mode is a mode in which the face air outlet 20 is closed, the defroster air outlet 19 and the foot air outlet 21 are fully opened, and the conditioned air is blown out from the foot air outlet 21 and the defroster air outlet 19 by substantially the same amount.
[0041]
An internal air sensor 50, an outdoor air sensor 51, a solar radiation sensor 52, a water temperature sensor 53, an evaporator temperature sensor 54, and a humidity sensor 55 are connected to the input side of the control device 30 as sensors for detecting an air conditioning environment condition.
[0042]
The inside air sensor 50 detects the inside air temperature, and generates an inside air temperature signal Tr corresponding to the detected temperature. The outside air sensor 51 detects the outside air temperature and generates an outside air temperature signal Tam corresponding to the detected temperature. The solar radiation sensor 52 detects the amount of solar radiation incident on the passenger compartment, and generates a solar radiation amount signal Ts corresponding to the detected amount of solar radiation. The water temperature sensor 53 detects the temperature of the hot water circulating in the heater core 15 and generates a water temperature signal Tw corresponding to the detected water temperature. The evaporator temperature sensor 54 detects the temperature of air blown from the evaporator 9 and generates an evaporator temperature signal Te corresponding to the detected temperature. And the humidity sensor 55 as a humidity detection means is installed near the front window glass W in the vehicle interior, for example, and generates the humidity signal RH according to the relative humidity near the vehicle interior window glass.
[0043]
Next, the operation of the first embodiment in the above configuration will be described with reference to FIG. When an ignition switch of a vehicle engine (not shown) is set to the ON position and power is supplied from the battery B to the control device 30, the control device 30 starts a control program. The control routine of FIG. 2 starts when the air conditioner switch 41 of the air conditioning operation panel 36 is turned on and the energization on signal of the electromagnetic clutch 11a is output. First, in step S10, the maximum cooling mode is set as the operation mode of the compressor 11. To do. That is, a lower first target temperature (for example, about 3 ° C. to 4 ° C.) near the freezing temperature of the condensed water is set as the target temperature of the evaporator outlet air temperature.
[0044]
Thus, in the maximum cooling mode, when the actual evaporator blown air temperature falls below the first target temperature, the electromagnetic clutch 11a is turned off and the operation of the compressor 11 is stopped. When the actual evaporator blown air temperature exceeds the first target temperature, energization of the electromagnetic clutch 11a is returned to the on state, and the compressor 11 is returned to the operating state. In this way, by intermittently controlling the operation of the compressor 11 in accordance with the fluctuation of the actual evaporator blown air temperature, the actual evaporator blown air temperature is maintained at a lower first target temperature near the freezing temperature.
[0045]
In the next step S20, it is determined whether the elapsed time after setting the maximum cooling mode has reached a predetermined time t1 (for example, about 5 minutes), and the maximum cooling mode is set until the elapsed time reaches the predetermined time t1. maintain. Thereby, the vehicle interior can be rapidly cooled. When the elapsed time reaches the predetermined time t1, the process proceeds to step S30, and the power saving cooling mode is set as the operation mode of the compressor 11. That is, the second target temperature (for example, about 10 ° C. to 12 ° C.) sufficiently higher than the first target temperature (for example, about 3 ° C. to 4 ° C.) is set as the target temperature of the evaporator blown air temperature.
[0046]
Thus, in the power saving cooling mode, when the actual evaporator blown air temperature falls below the second target temperature, the electromagnetic clutch 11a is turned off and the operation of the compressor 11 is stopped. When the actual evaporator blown air temperature exceeds the second target temperature, the energization of the electromagnetic clutch 11a is returned to the on state, and the compressor 11 is returned to the operating state. In this way, the actual operation of the compressor 11 is intermittently controlled in accordance with the variation of the actual evaporator blown air temperature, thereby maintaining the actual evaporator blown air temperature at a higher second target temperature.
[0047]
In the next step S40, the blowing mode is determined. Specifically, when a mode other than the defroster mode and the foot defroster mode, that is, the face mode, the bi-level mode, and the foot mode is selected as the blowing mode, the setting state of the power saving cooling mode in step S30 is set. maintain.
[0048]
On the other hand, conditions such as when the air humidity is high and the vehicle window glass tends to fog up occur during rain, and the occupant operates the blowing mode switch 39 of the air conditioning operation panel 36 to select the defroster mode from among the blowing modes. If so, the process proceeds to step S50 to set the defroster mode and the maximum cooling mode.
[0049]
Specifically, the face air outlet 20 and the foot air outlet 21 are closed by the doors 23 and 24, the defroster air outlet 19 is fully opened by the door 22, and the conditioned air is sent from the defroster air outlet 19 to the inner surface side of the front window glass W. Set the defroster mode to blow out. In addition, a lower first target temperature (for example, about 3 ° C. to 4 ° C.) near the freezing temperature is set as the target temperature of the evaporator outlet air temperature, and the maximum cooling mode is set.
[0050]
In the next step S60, it is determined whether or not the defroster mode is released. Specifically, it is determined whether the occupant has operated the blow mode switch 39 of the air conditioning operation panel 36 to select a blow mode other than the defroster mode. While the defroster mode is maintained, the settings of the defroster mode and the maximum cooling mode in step S50 are maintained.
[0051]
Then, when the occupant selects a blowing mode other than the defroster mode, the defroster mode is canceled. Therefore, the process proceeds to step S70, the power saving cooling mode is set, and the electric heating element 61 is turned on.
[0052]
In the next step S80, the anti-fogging determination of the vehicle front window glass W is performed based on the relative humidity RH near the inner surface of the front window glass W detected by the humidity sensor 55. Specifically, when the relative humidity RH in the vicinity of the inner surface of the front window glass W is equal to or higher than a predetermined value, the front window glass W is likely to be fogged. Returning to S70, the setting of the power saving cooling mode and the ON state of the electric heating element 61 are maintained.
[0053]
On the other hand, when the relative humidity RH in the vicinity of the inner surface of the front window glass W falls below a predetermined value, the front window glass W is not fogged, so the anti-fog determination is determined to be anti-fogging OK (YES). In step S90, the electric heating element 61 is turned off, and the process returns to step S30.
[0054]
On the other hand, conditions such as the anti-fogging performance of the vehicle window glass and the heating effect of the occupant's feet occur at the same time as during the rain in winter, and the occupant operates the blowing mode switch 39 of the air conditioning operation panel 36 to blow out the air. When the foot defroster mode is selected from the modes, the process proceeds from step S40 to step S100, and the foot defroster mode, the power saving cooling mode, and the ON state of the electric heating element 61 are set.
[0055]
Specifically, the face air outlet 20 is closed by the door 23, the defroster air outlet 19 and the foot air outlet 21 are both opened by the doors 22 and 24, and the conditioned air is sent from the defroster air outlet 19 to the inner surface of the front window glass W. Simultaneously, the air-conditioned air is blown out from the foot outlet 21 to the occupant's feet.
[0056]
Here, the blowout temperature of the conditioned air can be adjusted by the opening degree of the air mix door 17, and in the winter season, the ratio of the amount of hot air passing through the heater core 15 is larger than the amount of cold air passing through the bypass passage 16. And the warm air of desired temperature can be blown out to the inner surface side of the front window glass W, and a passenger | crew's foot part side.
[0057]
In the next step S110, it is determined whether the foot defroster mode has been canceled. This determination can be made based on whether or not a blowing mode other than the foot defroster mode has been selected, similar to the determination in step S60 described above. While the selection of the foot defroster mode is maintained, the process returns to step S100 and the foot defroster mode, the power saving cooling mode, and the ON state of the electric heating element 61 are maintained.
[0058]
On the other hand, when it is determined that the foot defroster mode is to be released, the process proceeds to step S90, the electric heating element 61 is turned off, and the process returns to step S30.
[0059]
Next, operations and effects of the first embodiment will be described. (1) When the defroster mode is selected, the maximum cooling mode is set simultaneously with the setting of the defroster mode in step S50. In this maximum cooling mode, a lower first target temperature (for example, about 3 ° C. to 4 ° C.) near the freezing temperature is set as the target temperature of the evaporator blow-off air temperature to maximize the cooling and dehumidifying performance by the evaporator 9. Therefore, the low-humidity conditioned air cooled and dehumidified to the maximum by the evaporator 9 can be blown out from the defroster outlet 19 to the inner surface side of the front window glass W.
[0060]
The selection of the defroster mode by the occupant is generally based on an urgent judgment that it is desired to quickly remove the obstruction of the vehicle front view due to the fogging of the front window glass W. However, as described above, the cooling dehumidification performance of the evaporator 9 By maximally exhibiting the above, fogging of the front window glass W can be rapidly removed, and the vehicle front view can be secured quickly. Therefore, it is possible to satisfactorily fulfill the urgent defogging function required for the defroster mode.
[0061]
(2) Moreover, since the operation mode of the compressor 11 is immediately switched from the maximum cooling mode to the power saving cooling mode in step S70 when the defroster mode is released, the driving power of the compressor 11 can be immediately reduced. That is, in the power saving cooling mode, the target temperature of the evaporator blown air temperature is set to a second target temperature (for example, about 10 ° C. to 12 ° C.) that is sufficiently higher than the first target temperature. In this intermittent control, the compressor operating rate is reduced, and the driving power of the compressor 11 can be reduced.
[0062]
At this time, by switching the operation mode of the compressor 11 to the power saving cooling mode, the cooling and dehumidifying performance of the evaporator 9 is lowered. In step S70, the electric heating element 61 is turned on simultaneously with the setting of the power saving cooling mode. Thus, the front window glass W can be directly heated by the electric heating element 61 to raise the temperature of the front window glass W. Thereby, the relative humidity of the air near the inner surface of the front window glass W can be reduced, and the front window glass W can be prevented from being fogged again after the defroster mode is canceled.
[0063]
Incidentally, as the electric heating element 61 is turned on, the power generation load of the on-vehicle battery charging generator (not shown) increases and the generator driving power of the vehicle engine increases. Since the increase in the drive power is significantly smaller than the decrease in the drive power of the compressor 11 described above, the drive load of the entire vehicle engine is reduced and the fuel efficiency of the vehicle engine can be improved.
[0064]
(3) Since the foot defroster mode is inherently less urgent with respect to defogging of the front window glass W than the defroster mode, there is no need to increase the antifogging performance as well as the defroster mode. Therefore, in the first embodiment, when the foot defroster mode is selected, the power saving cooling mode and the ON state of the electric heating element 61 are set simultaneously with the setting of the foot defroster mode in step S100.
[0065]
Thereby, while ensuring a certain amount of anti-fogging performance, the driving power of the compressor 11 can be reduced to improve the fuel efficiency of the vehicle engine.
[0066]
(Second Embodiment)
FIG. 3 shows a second embodiment. Steps equivalent to those in FIG. 2 are denoted by the same reference numerals, description thereof is omitted, and differences from the first embodiment are mainly described. In the first embodiment, when the release of the defroster mode is not determined in step S60 (when the determination is NO), the process directly returns to step S50. In the second embodiment, the release of the defroster mode is determined in step S60. If not (when the determination is NO), the process proceeds to step S120, and it is determined whether the elapse time of the maximum cooling mode set in step S50 has passed a predetermined time t2 (for example, about 5 minutes).
[0067]
When the elapsed time of the maximum cooling mode is within the predetermined time t2, the process returns to step S50, and the settings of the defroster mode and the maximum cooling mode are maintained. When the elapsed time in the maximum cooling mode exceeds the predetermined time t2, the process proceeds to step S130, and the electric heating element 61 is set to the ON state simultaneously with the setting of the defroster mode and the maximum cooling mode.
[0068]
Thus, the low-humidity conditioned air cooled and dehumidified to the maximum by the evaporator 9 can be blown out from the defroster outlet 19 to the inner surface side of the front window glass W, and the front heating window 61 is turned on. The temperature of the front window glass W can be raised by directly heating the glass W by the electric heating element 61. As a result, the antifogging performance of the front window glass W can be further improved. Therefore, even when the front window glass W is in a condition where it is very likely to be clouded, such as when it is raining in winter or when there are many passengers, the fog on the front window glass W can be rapidly removed.
[0069]
In the next step S140, it is determined again whether or not the defroster mode is released. When the defroster mode is not released, the process proceeds to step S150, and the elapsed time of the defroster mode in which the maximum cooling mode and the ON state of the electric heating element 61 are simultaneously set in step S130 is a predetermined time t3 (for example, 1 minute to 2). Judge whether or not it has passed.
[0070]
While the elapsed time in the defroster mode in step S130 is within the predetermined time t3, the defroster mode in step S130 is maintained. When the elapsed time of the defroster mode in step S130 exceeds the predetermined time t3, the process proceeds to step S160, the operation mode of the compressor 11 is switched to the power saving cooling mode, and the power saving cooling mode and the electric heating element 61 are turned on. Execute defroster mode by simultaneous setting.
[0071]
In the next step S170, it is determined again whether or not the defroster mode has been released, and the defroster mode in which the power saving cooling mode in step S160 and the ON state of the electric heating element 61 are simultaneously set is maintained until the defroster mode is released. .
[0072]
If it is determined in each of steps S60, S140, and S170 that the defroster mode is canceled, the process proceeds to step S70, and the power saving cooling mode and the ON state of the electric heating element 61 are maintained in the same manner as in the first embodiment. The glass W is prevented from being fogged again.
[0073]
(Other embodiments)
The present invention is not limited to the above-described embodiment and can be variously modified.
(1) In the above-described embodiment, the anti-fogging determination in step S80 is performed based on the relative humidity RH near the inner surface of the front window glass W detected by the humidity sensor 55, but means other than the humidity sensor 55, for example, Presence or absence of rain, specifically, when the wiper switch is turned on (when it is raining) may be determined to be non-fogging, and when the wiper switch is not turned on (when it is not raining), it may be determined that anti-fogging is OK.
[0074]
(2) Although the above-described embodiment does not particularly refer to the restriction on the ON (energization) state of the electric heating element 61, the power consumption by energizing the electric heating element 61 is large. It becomes. Therefore, when the in-vehicle battery B is charged based on the voltage of the in-vehicle battery B or the like, and when it is determined that the in-vehicle battery B is in a charged state below a predetermined level, the ON (energized) state of the electric heating element 61 is changed. It is possible to cancel automatically and thereby prevent over-discharge of the in-vehicle battery B.
[0075]
In addition, when the vehicle engine control device (engine ECU) has a function of determining the charge state of the in-vehicle battery B, the electric heating element 61 is turned on using the battery charge state determination signal from the engine control device. Automatic cancellation of the (energized) state may be performed.
[0076]
(3) In the above-described embodiment, a normal fixed capacity compressor having a discharge capacity fixed to a predetermined capacity is used as the air conditioning compressor 11, and the operation of the fixed capacity compressor 11 is intermittently evaporated. The air blower air temperature is controlled so as to be the target temperature, but the variable capacity compressor capable of changing the discharge capacity as the air conditioning compressor 11 (for example, a well-known swash plate variable capacity compressor) , And the evaporator discharge air temperature may be controlled to the target temperature by changing the discharge capacity of the variable capacity compressor.
[0077]
(4) In the above-described embodiment, the temperature to be controlled by the operation control of the air conditioning compressor 11 is the evaporator blown air temperature, but the fin surface temperature of the evaporator 9 is controlled instead of the evaporator blown air temperature. It is good also as object temperature.
[Brief description of the drawings]
FIG. 1 is an overall schematic diagram of a first embodiment of the present invention.
FIG. 2 is a flowchart showing air-conditioning anti-fogging control of the first embodiment.
FIG. 3 is a flowchart showing air-conditioning anti-fogging control of a second embodiment.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 9 ... Evaporator, 11 ... Compressor for air conditioning, 61 ... Electric heating element, W ... Front window glass.

Claims (5)

In a vehicle including an electric heating element (61) for directly heating the front window glass (W),
A maximum cooling mode for controlling the temperature of the cooling heat exchanger (9) to a first target temperature near the freezing temperature of the condensed water by operation control of the air conditioning compressor (11);
The operation control of the air conditioning compressor (11) enables switching of the temperature of the cooling heat exchanger (9) between a power saving cooling mode for controlling the first target temperature to a higher second target temperature,
The maximum cooling mode is set in the defroster mode in which the conditioned air that has passed through the cooling heat exchanger (9) is blown to the inner surface of the front window glass (W),
When the defroster mode is canceled, the maximum cooling mode is switched to the power-saving cooling mode, and the electric heating element (61) is energized. In a vehicle including an electric heating element (61) for directly heating the front window glass (W),
A maximum cooling mode for controlling the temperature of the cooling heat exchanger (9) to a first target temperature near the freezing temperature of the condensed water by operation control of the air conditioning compressor (11);
The operation control of the air conditioning compressor (11) enables switching of the temperature of the cooling heat exchanger (9) between a power saving cooling mode for controlling the first target temperature to a higher second target temperature,
The maximum cooling mode is set in the defroster mode in which the conditioned air that has passed through the cooling heat exchanger (9) is blown to the inner surface of the front window glass (W),
In the defroster mode, when the elapsed time after the setting of the maximum cooling mode is equal to or longer than a predetermined time, the electric heating element (61) is energized while maintaining the maximum cooling mode. apparatus. In the defroster mode, when the elapsed time after energization of the electric heating element (61) reaches a predetermined time or more, the maximum cooling mode is switched to the power saving cooling mode while energization of the electric heating element (61) is maintained. The vehicular air-conditioning and anti-fogging control device according to claim 2. When the front window glass (W) is determined to be in an anti-fogging state after the defroster mode is released, and the front window glass (W) is determined to be in an anti-fogging state, energization of the electric heating element (61) is stopped. The vehicular air-conditioning and anti-fogging control device according to any one of claims 1 to 3. When the foot defroster mode in which the conditioned air that has passed through the cooling heat exchanger (9) is blown to both the inner surface of the front window glass (W) and the occupant's feet is selected, the power saving cooling mode is set. The vehicle air conditioning defrost control device according to any one of claims 1 to 4, wherein the electric heating element (61) is energized.

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