JP2006021579A - Air-conditioner for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent a window pane from blurring in the heater mode automatically on the basis of the data obtainable from an existing sensor without providing a particular sensor to sense the blur of the window pane. <P>SOLUTION: If the outer air temperature Tout is below the middle outer air temperature TO (S5) and an air-conditioning clutch 14 remains off (S6) when the blowout hole mode set first after the engine is started is the heater mode in which the air heated by a heater core 33 is blown out of a heater duct 24 (S3), the air-conditioning clutch 14 is turned on (S7), and the dehumidified air is blown out of the heater duct 24 to prevent a windshield etc. from blurring. When the difference between the set temperature Ts set by a cabin temperature setting switch and the intra-cabin temperature Tin becomes within the set temperature difference Td, the air-conditioning clutch 14 is turned off (S9), and transition is made to the normal control (S10). <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a vehicle air conditioner configured to dehumidify air blown into a passenger compartment in an environment in which the window glass is likely to be fogged when the air outlet mode is set to the heater mode.

  In general, when the engine is started when the outside air temperature is relatively low, even after the engine is started, even if the auto switch provided in the air conditioner is turned on and the heat mode is set, the cooling water temperature is low, so Although it cannot be heated, the air passing through the heater core is warmed as the cooling water temperature rises, so the temperature in the passenger compartment is gradually raised.

  If you board a vehicle when it is raining and the sun is weak and rainwater is attached to your clothes or umbrella, the outside air temperature and the cabin temperature are almost the same immediately after boarding. The window glass such as the windshield and side glass is not fogged.

  However, after boarding, the cooling water temperature rises, the air warmed through the heater core is blown into the passenger compartment, and when the passenger compartment temperature rises, the rainwater adhering to clothes, umbrellas, etc. evaporates and the passenger compartment The relative humidity (hereinafter referred to as “humidity”) increases and the temperature difference between the glass and the window glass increases, so that it becomes easily cloudy. Further, in the heat mode, at the time of start-up, that is, at the time of transition until the room temperature reaches around the set temperature, the air compressor does not operate, so that the generated fog cannot be removed.

  Thus, in the heat mode, when the vehicle window glass is fogged, the air conditioner is operated to blow air from the front defroster, or the air conditioner switch is turned on and the air conditioner compressor is operated to dehumidify the vehicle interior. However, since these operations are manually performed by the driver, the operations are complicated.

  In addition, since the defogging operation is performed after the windshield has been fogged, the driver has a problem of temporarily hindering the field of view.

For example, in Patent Document 1 (Japanese Patent Laid-Open No. 2003-326936), the surface temperature of a window glass is measured using an infrared sensor, and the humidity inside the vehicle interior is measured using a humidity sensor installed in the vehicle interior. And a technique for calculating the dew point temperature of the glass surface based on both of these measured values, and blowing the air from the defroster when the dew point temperature is equal to or higher than the surface temperature of the window glass to remove fogging of the window glass is disclosed. Yes.
JP 2003-326936 A

  However, in the technique disclosed in Patent Document 1, since it is necessary to separately provide an infrared sensor and a humidity sensor in order to detect fogging of the window glass, not only the number of parts increases and the product cost increases, Since it cannot be applied to existing vehicles, there is a problem that lacks versatility.

  In view of the above circumstances, the present invention automatically performs antifogging of the window glass in the heater mode based on data obtained from an existing sensor without specially providing a sensor for detecting fogging of the window glass. An object of the present invention is to provide a vehicle air conditioner that can achieve high versatility.

  In order to achieve the above object, the present invention provides at least an evaporator that constitutes a refrigeration cycle and a heater core that circulates cooling water, and the air heated by the heater core is set as an air outlet mode that sets an air outlet. In a vehicle air conditioner having a heater mode that blows out from at least a heater outlet, the refrigeration cycle is driven when the outside air temperature when the outlet mode is set to the heater mode is equal to or lower than a set temperature.

  According to the present invention, the window glass in the heater mode is automatically fogged based on the data obtained from the existing sensor without specially providing a sensor for detecting the fogging of the window glass such as the windshield. Excellent effects such as high versatility can be obtained.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows a schematic configuration diagram of a vehicle air conditioner.

  The vehicle air conditioner 1 according to this embodiment includes a blower / cooling unit 2 in which a blower unit and a cooling unit are integrated, and a heater unit 3 that communicates with the downstream side of the blower / cooling unit 2.

  The blower / cooling unit 2 is provided with an outside air inlet 5 that opens to the engine room and an inside air inlet 6 that opens to the vehicle compartment. In addition, a pair of inside / outside air switching doors 7 are respectively attached to both the introduction ports 5 and 6. Each of the inside / outside air switching doors 7 is opened / closed by a pair of inside / outside air switching actuators 8a, 8b. When one of the introduction ports 5, 6 is closed, the other is opened, and when the other is opened. One closes.

  A blower fan 10 is disposed downstream of the inside / outside air switching door 7 to pressure-feed the air introduced from the outside air introduction port 5 or the inside air introduction port 6 into the vehicle interior. A blower drive motor 11 is provided to the blower fan 10. It is connected.

  Further, an evaporator 12 is disposed on the downstream side of the blower fan 10. The evaporator 12 constitutes a refrigeration cycle together with an air conditioner compressor 13 and a condenser, a receiver tank, an expansion valve (not shown) and the like, and cools and dehumidifies when the introduced air blown from the blower fan 10 passes through. . The air conditioner compressor 13 is connected to an engine output shaft (not shown) via an air conditioner clutch 14 formed of an electromagnetic clutch or the like, and drive control (ON / OFF) of the air conditioner compressor 13 is performed by ON / OFF control of the air conditioner clutch 14. Control).

  The heater unit 3 includes a defroster outlet 21 that communicates with the defroster 20, a ventilation outlet 25 that communicates with a ventilation duct 23 provided on an instrument panel (not shown), and a heater that communicates with the heater duct 24. An air outlet 26 is provided. Further, a defroster door 28, a ventilation door 29, and a heater door 30 for opening and closing the air outlets 21, 25, 26 are provided at the air outlets 21, 25, 26, respectively. The doors 28, 29 and 30 are controlled to be opened and closed by door switching actuators 31a to 31c.

  The heater unit 3 is provided with a heater core 33 for circulating cooling water therein. The heater core 33 is disposed obliquely in the heater unit 3, and one corner is in contact with or close to the lower side of the heater unit 3, and the air mix door is on the surface facing the upper side of the heater unit 3. 34 is arranged. The opening of the air mix door 34 is controlled by an actuator 35 for adjusting the opening of the air mix door. The amount of air passing through the heater core 33 is adjusted by the opening degree of the air mix door 34, and the temperature of the air blown out from each of the outlets 21, 25, 26 is adjusted.

  The air conditioner control unit 40 controls the blower drive motor 11, the air conditioner clutch 14, and the actuators 8a, 8b, 31a to 31c, 35. On the input side of the air conditioning control unit 40, there are an operation panel 41, an inside air sensor 42 as an inside air detecting means for detecting the cabin temperature Tin, an outside air sensor 43 as an outside air detecting means for detecting the outside air temperature Tout, Various sensors such as a solar radiation sensor 44 that detects the amount of solar radiation Q that enters and a water temperature sensor 45 that detects the cooling water temperature Tw are connected. The operation panel 41 is also provided with a room temperature setting switch as a room temperature setting means for setting the room temperature, an auto switch for turning on / off the automatic operation mode, an air conditioner switch for turning on / off the air conditioner, and the like.

  In the air-conditioning control unit 40, in the automatic operation mode, the actuators 8 a, 8 b, 8 b, 8 b, 8 b, 8 b are based on the vehicle interior temperature Tin, the outside air temperature Tout, the solar radiation amount Q, 31 a to 31 c and 35, the air volume control by the blower drive motor 11 that drives the blower fan 10, and the control to turn on / off the air conditioner compressor 13 through the air conditioner clutch 14, are performed. Run exit mode.

  The blower outlet mode sets which blower outlets 21, 25, and 26 are blown, and has five modes of a defroster mode, a defroster / heater mode, a heater mode, a bi-level mode, and a ventilation mode. .

  In the defroster mode, the air mix door 34 is opened to guide the introduced air discharged from the evaporator 12 to the heater core 33, the defroster door 28 is opened, and the heater door 30 and the ventilation door 29 are closed. As a result, the air that has passed through the evaporator 12 passes through the heater core 33 and becomes warm air, and is blown out from the defroster 20 so that the maximum defrosting performance is exhibited.

  In the defroster / heater mode, the air mix door 34 is opened, the defroster door 28 and the heater door 30 are opened, and the ventilation door 29 is closed. As a result, the air that has been heated through the heater core 33 is blown out from both the heater duct 24 and the defroster 20 to warm the interior of the vehicle and remove the fogging of the window glass.

  In the heater mode, the opening degree of the air mix door 34 is appropriately controlled, the heater door 30 is opened, the defroster door 28 is slightly opened, and the ventilation door 29 is closed. As a result, the warm air that has passed through the heater core 33 is blown out of the heater duct 24. Further, since the defroster door 28 is slightly opened, warm air is also blown out slightly from the defroster 20. However, in the heater mode, the air is mainly blown from the heater outlet 26 and the air blown from the defroster door 28 is very small. Therefore, the fogging of the window glass at high humidity is not sufficient.

  In the bi-level mode, the opening degree of the air mix door 34 is appropriately controlled, the ventilation door 29 and the heater door 30 are opened, and the defroster door 28 is closed. As a result, the air that has passed through the evaporator 12 is branched into two, one is warmed by the heater core 33 and becomes warm air, and the other is not passed through the heater core 33 and is sent as cold air. Then, hot air and cold air are mixed on the downstream side of the heater core 33, and the mixed air is blown out from the ventilation duct 23 and the heater duct 24, respectively.

  In the ventilation mode, the opening degree of the air mix door 34 is appropriately controlled, the ventilation door 29 is opened, and the defroster door 28 and the heat door 30 are closed. As a result, part of the air cooled by the evaporator 12 is warmed by the heater core 33 according to the set temperature Ts set by the room temperature setting switch, and becomes warm air and cold air downstream of the heater core 33. Are mixed, and the mixed air is blown out of the ventilation duct 23.

  When the auto switch provided on the operation panel 41 is turned ON, the air conditioning control unit 40 sets the set temperature Ts set by the room temperature setting switch, the vehicle interior temperature Tin detected by the inside air sensor 42, and the outside air detected by the outside air sensor 43. Based on the temperature Tout, the solar radiation amount Q detected by the solar radiation sensor 44, the cooling water temperature Tw detected by the water temperature sensor 45, etc., the necessary blowout temperature and the air volume are automatically set, and based on this necessary blowout temperature, The air outlet mode for setting air to be blown out from the air outlets 21, 25, 26 is set. At this time, when the cooling water temperature Tw is equal to or lower than the set water temperature, the defroster mode is set until the cooling water temperature Tw reaches the set water temperature, so that cold air is not blown out to the feet.

  By the way, when it is raining, when the humidity is high and the solar radiation is weak and the outside air temperature Tout is low, such as 10 to 15 ° C. In this case, since the outside air temperature Tout and the vehicle interior temperature Tin are almost the same immediately after boarding, the window glass such as the windshield and the side glass is not fogged, but the set temperature Ts set by the room temperature setting switch is 25, for example. When the cooling water temperature reaches the set water temperature after the engine is started, the air outlet mode is set to the heater mode, and the warm air heated by the heater core 33 is blown out from the heater duct 24.

  Then, the vehicle interior temperature Tin rises, rainwater adhering to clothes, umbrellas, etc. evaporates and the vehicle interior humidity increases, and when the vehicle interior humidity reaches the dew point temperature on the window glass surface, the window glass begins to cloud. Here, in the heater mode, the air compressor does not operate at the time of transition until the room temperature reaches around the set temperature, and the air blown from the defroster is also minute, so that the fog cannot be sufficiently removed.

  The air conditioning control unit 40 according to the present embodiment automatically turns on the air conditioner clutch 14 that constitutes the refrigeration cycle and drives the air conditioner compressor 13 to dehumidify and automatically prevent the occurrence of fogging under such environmental conditions. .

  Specifically, the antifogging control processed by the air conditioning control unit 40 is executed in the air outlet mode setting routine shown in FIG.

  In this routine, first, in step S1, the process waits until the ignition switch is turned on. When the ignition switch is turned on (tim 1 in FIG. 3), the process proceeds to step S 2 to check whether or not the auto switch for operating the auto air conditioner provided on the operation panel 41 is ON. Exit the routine. On the other hand, when it is ON, the process proceeds to step S3, and the air outlet mode for determining which air is to be blown from which air outlet 21, 25, 26 is the set temperature Ts set by the room temperature setting switch of the operation panel 41, the vehicle interior The temperature is set based on the temperature Tin, the outside air temperature Tout, the solar radiation amount Q, the cooling water temperature Tw, and the like.

  In an environment where the solar radiation is weak and the outside air temperature Tout is low, such as in rainy weather, after turning on the ignition switch (time tim1 in FIG. 3), until the cooling water temperature Tw reaches a set temperature Th (for example, 30 to 40 ° C.) The outlet mode is set to the defroster mode (time tim1 to tim2 in FIG. 3). When the cooling water temperature Tw reaches a set temperature (for example, 30 to 40 ° C.) (time tim2 in FIG. 3), the heater mode is set.

  In step S4, it is checked whether or not the air outlet mode is the heater mode. If the heater mode is set, the process proceeds to step S5. If the blower outlet mode other than the heater mode such as the defroster mode is set, the process jumps to step S10 to perform normal control.

  When the heater mode is determined and the process proceeds to step S5, the outside air temperature Tout is compared with a preset intermediate outside air temperature T0 (for example, 10 to 15 ° C.).

  If the heater mode is set in an environment where the sunlight is weak and the outside air temperature Tout is low, such as when it rains, the cabin temperature Tin rises due to the warm air blown from the heater duct 24 and adheres to clothes, umbrellas, etc. As the rainwater that has been evaporated evaporates, the humidity in the passenger compartment increases. On the other hand, since the surface temperature of the window glass such as the windshield and side glass facing the vehicle interior is almost the same as the outside air temperature and hardly changes, the temperature difference between the vehicle interior temperature Tin and the window glass surface temperature becomes large. When the humidity in the passenger compartment exceeds the dew point of the glass surface, it begins to cloud. The intermediate outside air temperature T0 is related to the dew point temperature of the window glass surface in an environment where the sun is weak and the humidity is high, such as when it is raining, and when the air outlet mode is set to the heater mode. Based on the experiment and the like based on the setting.

  When the outside air temperature Tout is equal to or higher than the intermediate outside air temperature T0 (Tout ≧ T0), the window glass is not fogged or is in an environment where fogging is difficult to occur, so the process jumps to step S10. On the other hand, when the outside air temperature Tout is lower than the intermediate outside air temperature T0 (Tout <T0), the window glass is in an environment where fogging is likely to occur, and thus the process proceeds to step S6.

  In step S6, it is checked whether the air conditioner clutch 14 is ON. When the air outlet mode is set to the heater mode, as shown after time tim3 in FIG. 3, after the vehicle interior temperature Tin exceeds the set temperature Ts, the air conditioner compressor 13 constituting the refrigeration cycle is driven, The blowing temperature is adjusted so that the vehicle interior temperature Tin becomes the set temperature Ts. When the air conditioner compressor 13 is driven, air is cooled by the evaporator 12 and dehumidified at the same time, so that the window glass is automatically fogged.

  Accordingly, when it is determined in step S6 that the air conditioner clutch 14 is ON, the window glass is not fogged, and the process jumps to step S10. On the other hand, since the air passing through the evaporator 12 is not dehumidified when the air conditioner clutch 14 is OFF, the process proceeds to step S7, the air conditioner clutch 14 is turned ON, and the air passing through the evaporator 12 is dehumidified by driving the air conditioner compressor 13. .

  As a result, when the outside air temperature Tout when the heater mode is first set to the heater mode after the engine is started is equal to or lower than the intermediate outside air temperature T0, the air conditioner compressor 13 is driven by the air conditioner clutch 14 being turned on and dehumidified by the evaporator 12. Air is blown into the passenger compartment. As a result, even after the vehicle is started, even if the heater mode is entered and the vehicle interior temperature Tin rises, dehumidified air is supplied to the vehicle interior, so the window glass is not fogged and is automatically fogged. And a good field of view can be secured.

  Thereafter, the process proceeds to step S8. In step S8, the end time of driving of the air conditioner compressor 13 is determined. That is, it is checked whether or not the absolute value (| Ts−Tin |) of the difference between the set temperature Ts and the passenger compartment temperature Tin falls within the set differential temperature Td, and when it does not fall within the range (| Ts−Tin |> Td), returning to step S7, the air conditioner compressor 13 is continuously driven. On the other hand, when it is within the range (| Ts−Tin | ≦ Td), the process proceeds to step S9, the air conditioner clutch 14 is turned OFF, the drive of the air conditioner compressor 13 is stopped, and the process proceeds to step S10.

  The set temperature difference Td is obtained by previously determining a temperature range in which the window glass is not fogged even if the driving of the air conditioner compressor 13 is stopped before the vehicle interior temperature Tin reaches the set temperature Ts. It is.

  In this embodiment, by determining the end time of driving of the air conditioner compressor 13, the air conditioner is not operated more than necessary, the engine load is reduced, and the fuel efficiency can be improved accordingly. In this case, since the air conditioner compressor 13 is stopped before the vehicle interior temperature Tin reaches the set temperature Ts, further reduction in fuel consumption can be realized.

  In addition, you may make it determine the completion | finish time of the drive of the air-conditioner compressor 13 by time-measurement of a timer. The timer timing at this time is the time when the heater mode is set for the first time after the engine is started, or when the air-conditioner clutch 14 is turned on in step S7, and a set time (for example, 5 minutes) has elapsed from the start of timing. Thereafter, the driving of the air conditioner compressor 13 is stopped. Further, the set time at this time is a variable value that is set longer as the environmental temperature is lower, based on any one of the cooling water temperature Tw, the outside air temperature Tout, the vehicle interior temperature Tin when the ignition switch is turned on, or a combination thereof. Also good.

  And if it progresses to step S10 from step S4 to S6 or step S9, normal control will be performed and a routine will be exited.

  In the normal control, the control corresponding to the air outlet mode (defroster mode, defroster / heater mode, heater mode, bi-level mode, or ventilation mode) set in step S3 is executed as usual. While opening the blower outlet corresponding to each set mode, the blowout temperature and the air volume are set.

  As described above, in this embodiment, after the engine is started, the heater mode is first set and the outside air temperature Tout is equal to or lower than the intermediate outside air temperature T0 in the transitional region where the vehicle interior temperature Tin is to be raised to the set temperature Ts. When the air-conditioner compressor 13 is driven, the dehumidified air is blown into the passenger compartment, so that the window glass is not fogged and a good field of view can be secured. Further, since the window glass is prevented from being fogged based on the detection value from the existing sensors without providing special sensors, high versatility can be obtained.

  Furthermore, when the air outlet mode is set to the heater mode simply by turning on the auto switch, if a certain condition is satisfied, the dehumidified air is automatically blown out into the passenger compartment. A good field of view can always be ensured without performing complicated operations.

  The present invention is not limited to the above-described embodiment. For example, in the case of a manual air conditioner, when the heater mode is set and the conditions in steps S5 and S6 in FIG. 2 described above are satisfied, The air conditioner clutch 14 may be turned on, and the air dehumidified by driving the air conditioner compressor 13 may be blown into the passenger compartment.

Schematic configuration diagram of a vehicle air conditioner Flowchart showing air outlet mode setting routine Explanatory drawing which shows the relationship between the rise characteristic of the vehicle interior temperature after engine starting, and the blower outlet mode set

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Vehicle air conditioner, 3 ... Heater unit, 12 ... Evaporator, 13 ... Air conditioner compressor, 14 ... Air conditioner clutch, 20 ... Defroster, 21 ... Defroster outlet, 23 ... Ventilation duct, 24 ... Heater duct, 25 ... Ventilation Outlet, 26 ... Heater outlet, 28 ... Defroster door, 29 ... Ventilation door, 30 ... Heater door, 31a-31c ... Door switching actuator, 33 ... Heater core, 34 ... Air mix door, 35 ... Air mix door opening Adjusting actuator, 40 ... air conditioning control unit, 41 ... operation panel, 42 ... inside air sensor, 43 ... outside air sensor, 44 ... solar radiation sensor, 45 ... water temperature sensor, Q ... solar radiation amount, T0 ... intermediate outside air temperature, Tin ... vehicle interior Temperature, Tout: outside air temperature, Td: set differential temperature, Th, Ts: set temperature , Tw ... cooling water temperature
Agent Patent Attorney Susumu Ito

Claims (7)

At least an evaporator constituting a refrigeration cycle and a heater core for circulating cooling water are disposed,
In a vehicle air conditioner provided with a heater mode in which air heated by the heater core is blown out from at least the heater outlet as an outlet mode for setting an air outlet.
A vehicle air conditioner that drives the refrigeration cycle when an outside air temperature when the air outlet mode is set to a heater mode is equal to or lower than a preset temperature.   2. The vehicle air conditioner according to claim 1, wherein the set temperature is set based on a relationship between solar radiation, a relative humidity in the passenger compartment, and a dew point temperature of the window glass surface.   The vehicle air conditioner according to claim 1 or 2, wherein the driving of the refrigeration cycle is stopped when a temperature difference between the temperature in the vehicle compartment and the temperature set by the room temperature setting means is within a setting range.   3. The vehicle air conditioner according to claim 1, wherein the refrigeration cycle is stopped when an elapsed time after the start reaches a set time.   The vehicle air conditioner according to claim 1 or 2, wherein the refrigeration cycle is stopped when an elapsed time after the air outlet mode is set to the heater mode reaches a set time.   3. The vehicle air conditioner according to claim 1, wherein the refrigeration cycle is stopped when an elapsed time after the refrigeration cycle is driven reaches a set time.   The vehicle air conditioner according to any one of claims 4 to 6, wherein the set time is set longer as the environmental temperature is lower based on the environmental temperature.

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