JPH06191267A - Air conditioner for automobile - Google Patents

Abstract

PURPOSE:To prevent a windshield from being fogged even when a cooling device serving as a dehumidifying means is stopped at the time of low outside air temperature where the windshield may be fogged. CONSTITUTION:An air conditioner 1 for an automobile is provided with a cooling device 29 for generating dehumidified cold air, defroster blowoff openings 13 for blowing off conditioning air toward a windshield, an outside air temperature sensor 63, and a blowoff stop means 67 receiving the outside air temperature signal of the outside air temperature sensor 63 so as to stop the blowoff of conditioning air from the windshield when the dehumidifying action of the cooling device 29 is stopped and the outside air temperature is the specified temperature or lower where the windshield is fogged.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle air conditioner, and more particularly to measures for preventing fogging of window glass when dehumidification is stopped.

[0002]

2. Description of the Related Art Conventionally, an air conditioning system for an automobile enhances the comfort of the passenger compartment by heating, cooling and dehumidifying the air and blows the dehumidified air to the windshield to prevent the windshield from fogging at low outside temperatures. To secure the driver's view.

As the above-mentioned automobile air conditioner, for example, as disclosed in JP-A-62-258808,
In the reheat / air mix type auto air conditioner,
Usually, a heater core for heating and a cooling device for cooling and dehumidifying are provided, and temperature control from cooling to heating is performed by mixing cool air conditioned by the cooling device and warm air conditioned by the heater core with an air mix damper. is doing. Then, the mixed conditioned air is blown into the vehicle compartment from the air outlet. The vents are generally vent vents that blow toward the passenger's upper body, heat vents that blow toward the passenger's feet, and defrosters to prevent windshield fog by blowing toward windshields and other windshields. A blowout port or the like is provided, and switching control is appropriately performed to a blowout port mode in which air is blown out from at least one of these blowout ports.

The cooling device comprises a refrigerant circuit in which a compressor, a condenser, an expansion mechanism and an evaporator are connected in sequence so that the refrigerant can circulate. The compressor is driven by an engine and turned on and off by an electromagnetic clutch. The operation control of the compressor is controlled not only by the necessity of air conditioning but also by the need of the engine side, for example, Japanese Patent Laid-Open No. 62-2535.
As disclosed in Japanese Unexamined Patent Publication No. 12, the engine load is reduced by stopping the operation of the compressor when the engine has a high load such as immediately after the start of traveling or during acceleration.

[0005]

By the way, in the above-mentioned automobile air conditioner, in order to maintain the comfort in the passenger compartment even if the operation of the compressor is stopped by the high load control of the engine,
Continue to blow conditioned air. Since dehumidification is not performed in the air conditioner, undehumidified air is supplied to the vehicle interior. Therefore, in spring and autumn when the temperature is relatively low (0 to 20 ° C.) and is not as dry as in winter, high-humidity inside air and outside air are blown out from the air outlet as they are.

On the other hand, at this time, in order to prevent the fogging of the windshield, the outlet mode is often set to the defroster outlet mode in which air is blown out from the defroster outlet by the control of the air conditioner side. There is a problem in that the operation of the compressor is stopped by the control on the engine side regardless of the control on the device side, and high-humidity air is blown to the windshield to cause fogging.

The present invention has been made in view of the above point, and at the time of low outside temperature where the windshield may fog, the windshield does not fog even if the dehumidifying means (cooling device) is stopped. The purpose is to do so.

[0008]

In order to achieve the above-mentioned object, a solution means provided by the invention according to claim 1 is a window when dehumidification is stopped and the outside air temperature is below a predetermined temperature at which the windshield becomes cloudy. The blowout stopping means for stopping the blowout of the conditioned air from the glass is provided to prevent the windshield from being fogged.

[0009] Specifically, the solution means devised by the invention according to claim 1 is a dehumidifying means for dehumidifying the intake air, and a windshield side outlet for blowing air-conditioned conditioned air toward the windshield. Targeting an air conditioner for an automobile equipped with, an outside air temperature detecting means for detecting an outside air temperature and outputting an outside air temperature signal, and an outside air temperature signal of the outside air temperature detecting means, and the dehumidifying means stops dehumidification. And a blowing stop means for stopping the conditioned air from blowing out from the windshield side outlet when the outside air temperature is equal to or lower than a predetermined temperature at which the windshield becomes cloudy.

Furthermore, the solution means taken by the invention according to claim 2 not only stops the conditioned air from blowing out from the windshield side outlet, but also causes the conditioned air to be blown out only from the passenger side outlet. A switching control means for controlling is provided to continue air conditioning without causing the windshield to fog.

Specifically, the solution means taken by the invention according to claim 2 is a dehumidifying means for dehumidifying the intake air, a wind glass side outlet for blowing the conditioned air toward the window glass, and the conditioned air. An occupant side outlet that blows out toward the occupant, and an outlet switching means that switches the outlet so that the conditioned air is blown out from at least one of the windshield side outlet and the occupant side outlet. For an automobile air conditioner, an outside air temperature detecting means for detecting an outside air temperature and outputting an outside air temperature signal, and an outside air temperature signal from the outside air temperature detecting means are received, and the dehumidifying means has stopped dehumidification. Switching control means for controlling the outlet switching means so that conditioned air is blown out only from the passenger side outlet when the temperature is below a predetermined temperature at which the windshield becomes cloudy. A configuration with a.

[0012]

With the above construction, in the invention according to claim 1,
The suction air is dehumidified by the dehumidifying means, and the dehumidified conditioned air is blown out from the windshield side outlet toward the windshield.

On the other hand, when the blowout stopping means receives the outside air temperature signal from the outside air temperature detecting means, when the outside dehumidifying means has stopped dehumidifying and the outside air temperature is below a predetermined temperature at which the windshield becomes cloudy, the windshield side blows. Stop the conditioned air from exiting. Therefore, even if the dehumidifying device is stopped at a low outdoor temperature, the conditioned air of high humidity cannot be blown to the windshield, so that the windshield does not become fogged.

Further, in the invention according to claim 2, the air conditioner for an automobile is provided with an occupant side air outlet for blowing out conditioned air toward the occupant in addition to the wind glass side air outlet, and the air outlet switching means is used to blow the wind glass side air. The air outlets are switched so that air is blown out from at least one of the air outlets and the passenger side air outlets.

On the other hand, when the switching control means receives the outside air temperature signal from the outside air temperature detecting means, the dehumidifying means stops dehumidifying, and the outside air temperature is below a predetermined temperature at which the windshield becomes cloudy, only the passenger side air outlet is provided. The outlet switching means is controlled so that the conditioned air is blown from the outlet. Therefore, air conditioning can be continued without causing the windshield to fog.

[0016]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows an automobile air conditioner according to a first embodiment of the present invention. The automobile air conditioner 1 is a reheat
It is an air-mix type and includes a casing 3 that harmonizes air while circulating intake air. An outside air suction port 5 and an inside air suction port 7 are provided at one end of the casing 3, and the other end is provided. A vent outlet 9 as an occupant-side outlet that blows conditioned air toward the upper body of the occupant.
9 ..., a heat outlet 11 as an occupant-side outlet that blows conditioned air toward the feet of the occupant, and a window for blowing conditioned air toward a windshield such as a windshield to prevent fogging of the windshield. Defroster outlets 13, 13 are provided as glass-side outlets. The window glass is a member attached to the window, and its material is not limited to glass.

Inside the casing 3, a blower 17 having a variable air volume driven by a motor 15 from the inlet side, an evaporator 19 for cooling the intake air and producing dehumidified cool air,
A heater core 21 that heats cold air to generate warm air is provided.

Further, in the automobile air conditioner 1, a compressor 23, a condenser 25, an expansion valve (not shown), and the evaporator 19 are sequentially connected by a refrigerant pipe 27 so that refrigerant can be circulated. A device 29 is provided. The cooling device 29 is configured to function as a cooling unit that cools the intake air by the evaporator 19 to generate cold air, and also as a dehumidifying unit that dehumidifies by dew condensation separation of water during cooling.

The compressor 23 is configured to be driven by the engine 33 via the V-belt 31 and intermittently driven by the electromagnetic clutch 35. In the heater core 21, the cooling water heated between the heater core 21 and the engine 33 is circulated by the water pipe 37 to heat the intake air in the casing 3 to generate warm air. A water valve 21 is provided as a flow rate control valve for controlling the heating capacity.

Further, in the casing 3, there are provided a suction port switching damper 39 for switching between the outside air suction port 5 and the inside air suction port 7 to select inside air or outside air as the suction air, and an air mix damper 41. Has been. The air mix damper 41 forms a flow of dehumidified cool air toward the heater core 21 (warm air after passing through the heater core 21) and a flow (cold air) bypassing the heater core 21, and the warm air is provided downstream of the heater core 21. It is configured to adjust the flow rate ratio of the two flows so as to control the temperature of the air where the cold air and the cool air merge. The suction port switching damper 39 is driven by the suction port side actuator 43, and the air mix damper 41 is driven by the air mix side actuator 45.

The vehicle air conditioner 1 sucks the outside air or the inside air by the switching operation of the suction port switching damper 39, cools the suction air by the evaporator 19 to generate the dehumidified cold air, and the air mix damper. A part of the cold air is heated again by the heater core 21 by 41 to generate hot air,
Cold air and warm air are mixed on the downstream side of the heater core 21, and the temperature is controlled from heating to cooling by the opening degree of the air mix damper 41 and the opening degree of the water valve, and at the same time, dehumidification is performed.

Inside the casing 3 on the downstream side of the heater core 21, a vent side damper 47 for adjusting the amount of air blown to the vent outlet 9 and a heat side damper 49 for adjusting the amount of air blown to the heat outlet 11 are provided. A defroster-side damper 51 for adjusting the amount of air blown to the defroster outlet 13 is provided,
These dampers 47, 49, 51 are configured to be driven by the outlet-side actuator 53.

On an instrument panel (not shown) of the automobile air conditioner 1, an air conditioner auto switch 5 for selecting whether to control the air conditioner 1 automatically by the control unit 55 or manually by an occupant.
7, a temperature setting switch 59, a display device 61 for displaying various vehicle information, and the like are provided.

The air conditioner 1 for an automobile is provided with an outside air temperature sensor 63 as an outside air temperature detecting means for detecting an outside air temperature and outputting an outside air temperature signal as a temperature sensor. Various temperature sensors for detecting the evaporator temperature, engine cooling water temperature, etc. are provided, and a solar radiation sensor for detecting the amount of solar radiation is provided above the instrument panel. The air conditioner auto switch 57, the temperature setting switch 59, the display device 61, the outside air temperature sensor 63 and other temperature sensors are connected to the control unit 55.

The control unit 55 includes a temperature setting switch 5
The total temperature is corrected in accordance with the set temperature input by 9, the outside air temperature, the inside air temperature and the evaporator temperature input from the outside air temperature sensor 63 and other temperature sensors, and the insolation amount input from the insolation sensor. Calculated based on the comprehensive data, the air flow rate control of the blower 17, the air mix damper opening control for the blown air temperature control, the ON-OFF control of the electromagnetic clutch 35 for the operation control of the compressor 23 (output Line Sa), and is configured to perform blowout mode control.

The blowout mode control is performed by the vent side damper 47,
By operating the heat-side damper 49 and the defroster-side damper 51, the vent mode, the heat mode and the defroster mode in which conditioned air is blown out only from any of the vent outlet 9, the heat outlet 11 and the defroster outlet 13, and the defroster blowing are performed. It is configured to switch to any one of a diff heat mode in which conditioned air is blown out from the outlet 13 and the heat outlet 11 and a bi-level mode in which conditioned air is blown out from the vent outlet 9 and the heat outlet 11. .

Further, the control unit 55 includes the engine 3
3 is connected to an overload detection means 65 for detecting an overload state of the engine 33 when the cooling water of the engine 33 is overheated, the output shaft is rotated at a high speed, immediately after starting traveling, or during acceleration. When the overload signal from the detecting means 65 is received, the electromagnetic clutch 35 is turned off (output line Sa) to stop the compressor 23. That is, the compressor 23 is configured to stop not only under the control of the air conditioner 1 side but also under the control of the engine 33 side.

Further, the control unit 55 is provided with an outlet stop means 67. The blowout stop means 67 receives the outside air temperature signal from the outside air temperature sensor 63 and receives the overload detection means 65.
When the cooling device 29 has stopped dehumidifying due to the stop of the compressor 23 based on the overload signal from, and the outside air temperature is below a predetermined temperature (for example, 20 ° C.) at which the windshield becomes cloudy, the defroster-side damper 51 is turned on. The closing operation prohibits the defroster mode and the differential heat mode, and stops blowing out the conditioned air from the defroster outlet 13.

Here, the term "fog on the window glass" means both the case where water vapor is condensed on the window glass and the case where it adheres as frost.

The operation of the automobile air conditioner 1 will be described. The cooling air is dehumidified by the cooling device 29.
When the blowout modes are the defroster mode and the differential heat mode, the dehumidified conditioned air is blown out from the vent outlet 9 toward the windshield.

On the other hand, when the blowout stopping means 67 receives the outside air temperature signal from the outside air temperature sensor 63, the cooling device 29 stops dehumidification by stopping the compressor 23 based on the overload signal from the overload detecting means 65. Further, when the outside air temperature is equal to or lower than a predetermined temperature at which the windshield becomes cloudy, the conditioned air is stopped from being blown out from the defroster outlet 13. Therefore, even if the cooling device 29 for dehumidifying under the control of the engine 33 side is stopped at the time of low outside air temperature, the conditioned air of high humidity cannot be blown to the windshield, so that it is possible to prevent the windshield from becoming clouded. Therefore, driving safety can be ensured.

Next, FIGS. 2 and 3 show a second embodiment of the present invention. As shown in FIG. 2, the vehicle air conditioner 1 according to the present embodiment is provided with a vent side damper 47, a heat side damper 49, and a defroster side damper 5 as the outlet switching means.
1, the blowout in various blowout modes is possible as in the first embodiment, while the control unit 55 is provided with the switching control means 69 instead of the blowout stop means 67.

The switching control means 69 receives the outside air temperature signal from the outside air temperature sensor 63, and the cooling device 29 has stopped dehumidification by stopping the compressor 23 based on the overload signal from the overload detection means 65. When the temperature is lower than a predetermined temperature (for example, 20 ° C.) at which the windshield becomes cloudy, the blowing mode is set to the vent mode so that the conditioned air is blown out only from the vent outlet 9 as the passenger side outlet. The heat-side damper 49 and the defroster-side damper 51 are controlled.

Next, the operation of the outlet control in the vehicle air conditioner 1 of this embodiment will be described based on the control flow of FIG. First, in step ST1, it is determined whether the air conditioner auto switch (A / C auto switch) 57 is ON, that is, whether the air conditioner 1 is automatically controlled. If the air conditioner 1 is not automatically controlled, the automatic control is performed. While the determination is repeated until that time, when the air conditioner 1 is automatically controlled, the process proceeds to step ST2 and it is determined whether or not the operation of the compressor 23 is stopped. When the operation of the compressor 23 is stopped, it is determined that the suction air has not been dehumidified by the control of the engine 33 side, and step ST3
Then, it is determined whether the outside air temperature is 20 ° C. or lower.

When the outside air temperature is 20 ° C. or lower, it is determined that the conditioned air may cause fogging on the windshield, and the process proceeds to step ST4 to determine whether the blowing mode is the defroster mode (DEF). When the blowout mode is the defroster mode (DEF), it is determined that the windshield will be fogged, and the process proceeds to step ST5, where the vent side damper 47 is opened and the heat side damper 49 and the defroster side damper 51 are closed. Then, the blowout mode is switched to the vent mode (VENT) and set, and the process returns.

In step ST4, if the blowout mode is not the defroster mode (DEF), step ST4
Moving to 6, it is determined whether the blowout mode is the differential heat mode (D / H). Blowout mode is differential heat mode (D /
If it is H), it is determined that the windshield will be fogged, and the process proceeds to step ST5 to switch the blowout mode to the vent mode (VENT) and return.

On the other hand, in step ST6, if the blowing mode is not the differential heat mode (D / H), it is judged that no fog will occur because the wind glass is not blown even if it is conditioned air of high humidity. In ST7, the normal mode control is set and the current blowing mode is maintained and the process returns.

In step ST2, the compressor 23
If the intake air is dehumidified and the outside air temperature exceeds 20 ° C. in step ST3, it is determined that there is no fear that the windshield will fog, and the process proceeds to step ST7 and the current blowing mode is maintained. Return with.

According to the present embodiment, the switching control means 69 receives the outside air temperature signal from the outside air temperature sensor 63, the cooling device 29 has stopped dehumidification, and the outside air temperature is below a predetermined temperature at which the windshield becomes cloudy. Sometimes vent mode (VENT)
Vent side damper 47, Heat side damper 49
Further, since the defroster-side damper 51 is controlled, it is possible to continue air conditioning without causing the windshield to become cloudy, and it is possible to ensure safety in traveling and comfort in the passenger compartment.

The outlet stop means 6 according to the first embodiment.
The switching control means 69 according to the seventh and second embodiments may be applied to the case where the dehumidification is stopped by stopping the operation of the compressor 23 of the cooling device 29 by the manual operation of the occupant.

The switching control means 69 according to the second embodiment.
May be set to a bi-level mode other than the vent mode (VENT) as the blowing mode for switching at a predetermined temperature or lower.

[0043]

As described above, according to the first aspect of the invention, when the blowout stopping means receives the outside air temperature signal from the outside air temperature detecting means, the dehumidifying means has stopped dehumidification and the outside air temperature is in the window. Since the conditioned air is stopped from blowing out from the windshield side outlet when the temperature is below a predetermined temperature at which the glass becomes cloudy, even if the dehumidifying means is stopped at a low outside temperature, the windshield will be clouded by the high humidity conditioned air. You can prevent it from happening.

Further, according to the second aspect of the invention, the switching control means receives the outside air temperature signal of the outside air temperature detecting means, the dehumidifying means stops dehumidification, and the outside air temperature is predetermined to cause fog on the windshield. Since the outlet switching means is controlled so that the conditioned air is blown out only from the passenger side outlet when the temperature is lower than the temperature, it is possible to continue the air conditioning without causing the windshield to fog and to improve the running safety. It is possible to ensure comfort in the passenger compartment.

[Brief description of drawings]

FIG. 1 is a configuration diagram of an automobile air conditioner according to a first embodiment of the present invention.

FIG. 2 is a configuration diagram of an automobile air conditioner according to a second embodiment of the present invention.

FIG. 3 is a flow chart of air outlet control in the automobile air conditioner.

[Explanation of symbols]

 9 Vent air outlet (passenger side air outlet) 11 Heat air outlet (passenger side air outlet) 13 Defroster air outlet (window glass air outlet) 29 Cooling device (dehumidifying means) 47 Vent side damper (air outlet switching means) 49 Heat side Damper (blowout outlet switching means) 51 Defroster side damper (blowout outlet switching means) 63 Outside air temperature sensor (outside air temperature detecting means) 67 Outlet stop means 69 Switching control means

Claims (2)

[Claims] 1. An air conditioner for a vehicle, comprising: a dehumidifying means for dehumidifying intake air; and a windshield-side outlet for blowing conditioned air that has been air-conditioned toward a windshield. An outside air temperature detecting means for outputting an outside air temperature signal and an outside air temperature signal from the outside air temperature detecting means, the dehumidifying means has stopped dehumidifying, and the outside air temperature is below a predetermined temperature at which the windshield becomes cloudy. At this time, a blowout stop means for stopping blowout of conditioned air from the windshield side outlet is provided. 2. A dehumidifying means for dehumidifying the intake air, a windshield side outlet for blowing conditioned air toward the windshield, an occupant side outlet for blowing conditioned air toward an occupant, and the conditioned air An air conditioner for an automobile, comprising: an outlet switching means for switching the outlet so that the outlet is blown out from at least one of the windshield outlet and the passenger side outlet. When the outside air temperature detecting means for outputting an air temperature signal and the outside air temperature signal of the outside air temperature detecting means are received, the dehumidifying means has stopped dehumidifying, and the outside air temperature is equal to or lower than a predetermined temperature at which the windshield becomes cloudy. An air conditioner for a vehicle, comprising: a switching control means for controlling the outlet switching means so that conditioned air is blown out only from the passenger side outlet.