VEHICLE AIR CONDITIONER

• US 20100330895A1
• Filed: 02/06/2009
• Published: 12/30/2010
• Est. Priority Date: 02/08/2008
• Status: Active Grant

• Current Assignee: Mitsubishi Heavy Industries, Ltd.
• Original Assignee: Mitsubishi Heavy Industries, Ltd.
• Inventors: Suetake, Hideki, Ishida, Toshiyuki, Mitsui, Masatoshi
• Granted Patent: US 8,932,119 B2
• Time in Patent Office: Days
• US Class Current: 454/75
• CPC Class Codes: B60H 1/00785 by the detection of humidity or frost
• CPC Class Codes: B60H 1/008 the input being air quality
• CPC Class Codes: B60H 1/00849 for selectively commanding the induction of outside or inside air B60H1/00842 takes precedence
• CPC Class Codes: B60H 1/3207 for minimizing the humidity of the air
• CPC Class Codes: B60H 2001/3245 of air
• CPC Class Codes: B60H 2001/327 related to a compressing unit

Abstract

It is an object of the present invention to provide a vehicle air conditioner that can perform air conditioning operation in an inside air circulating mode while suppressing the mist on a windshield and prevent deterioration in an inside air quality. When exhaust gas concentration on the outside of a vehicle is high, an outside air lead-in mode is switched to an inside air circulating mode and window mist limit humidity at that point is calculated. When inside humidity is close to the window mist limit, a compressor is actuated, the air is blown out from a DEF blowout port into a cabin, or an air volume in a blower is increased to prevent the mist on the windshield and delay switching to the outside air lead-in mode as much as possible. Consequently, air conditioning operation in the inside air circulating mode is performed while the mist on the windshield is suppressed to prevent deterioration in the inside air quality.

Claims

1. A vehicle air conditioner comprising a control unit that switches an outside air conditioning mode for leading in outside air to perform air conditioning and an inside air circulating mode for circulating air in a vehicle to perform air conditioning, wherein

the control unit calculates surface temperature on an interior side of a window glass on the basis of, among outside temperature, inside temperature, and vehicle speed, at least the outside temperature and the inside temperature, sets window mist occurrence limit humidity at which a mist occurs on the window glass from absolute humidity at which dews concentrate at the surface temperature, and, when inside humidity is within a predetermined range with respect to the mist occurrence limit humidity, performs operation control for reducing the inside humidity.

2. The vehicle air conditioner according to claim 1, wherein the control unit controls at least one of actuation of a compressor that circulates a coolant to an evaporator, a blowing-out direction of the air into the vehicle, and an air volume as the operation control for reducing the inside humidity.

3. The vehicle air conditioner according to claim 2, wherein

the compressor is engine-driven, and

the control unit executes at least one of switching of the compressor to ON, setting of a blowing-out direction of the air toward a surface on the interior side of the window glass, and an increase in the air volume as the operation control for reducing the inside humidity.

4. The vehicle air conditioner according to claim 2, wherein

the compressor is electrically-driven, and

the control unit executes at least one of an increase in the number of revolutions of the compressor, setting of a blowing-out direction of the air toward a surface on the interior side of the window glass, and an increase in the air volume as the operation control for reducing the inside humidity.

5. The vehicle air conditioner according to claim 1, wherein the control unit executes the control using the inside humidity and the mist occurrence limit humidity when the air conditioning is performed in the inside air circulating mode.

6. The vehicle air conditioner according to claim 5, wherein the control unit performs the air conditioning in the inside air circulating mode when exhaust gas concentration in the outside air is equal to or higher than a predetermined level.

7. The vehicle air conditioner according to claim 1, wherein the control unit performs the air conditioning while switching the inside air circulating mode to the outside air lead-in mode when the inside humidity is within the predetermined range with respect to the mist occurrence limit humidity as a result of performing all kinds of operation control for reducing the inside humidity.