Abstract:
An air conditioner for an automobile uses a non-azeotropic mixture refrigerant. The air conditioner has an evaporator for evaporating the refrigerant and cooling air passing through the evaporator. The air has a temperature slope after passing through the evaporator. An air dividing damper disposed downstream of the evaporator divides the cooled air into cold air and not-so-cold air for use in various ways in the passenger compartment.

Description:
This is a continuation of application Ser. No. 07/615,629, filed Nov. 19, 1990, which will become abandoned upon the filing hereof. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates to an air-conditioner for an automobile wherein a non-azeotropic mixture refrigerant is used. 
     BACKGROUND OF THE INVENTION 
     A Japanese unexamined patent (Kokai) 63-294459 shows an air-conditioner using a non-azeotropic mixture refrigerant. In such an air-conditioner, the temperature of the air passed through an evaporator varies widely along a passage of the refrigerant. It is not always comfortable for passengers to receive such air. 
     SUMMARY OF THE INVENTION 
     An object of the present invention is to put the variety of temperatures of the air to good use. 
     To achieve the object mentioned above, the air-conditioner of the present invention has an air dividing damper downstream of an evaporator for dividing the air passed through the evaporator into two streams. The one stream is relatively high in temperature and the other is relatively low in temperature. The colder air is directed towards a passenger&#39;s face for a better feeling, while the warmer air if used is directed below the passenger&#39;s face. 
     Other objects and advantages will occur to those skilled in the art upon obtaining an understanding of this invention by the following description thereof in conjunction with the attached drawings, in which: 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a schematic view of the embodiment, 
     FIG. 2 is a diagram showing the temperature of the refrigerant in the evaporator, 
     FIG. 3 is a front view of the instrument panel of the embodiment, 
     FIG. 4 is a diagram showing a relation of entropy and absolute temperature, 
     FIG. 5 is a diagram showing the temperature of the refrigerant in the evaporator, and 
     FIG. 6 is a diagram showing the relation of the temperature of the air and absolute humidity. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     FIG. 1 shows a schematic structure of an air-conditioner for an automobile wherein a non-azeotropic mixture refrigerant includes a main-refrigerant and a sub-refrigerant. The main-refrigerant is chosen from Freons R12, Freons R124, Freon R142b and Freon R134a. The sub-refrigerant is sen from Freons R23 and Freons R116. Freons R14 is less than 3% of the mixture refrigerant in weight thereof, Freons R23 is less than 10% and Freons R116 is less than 10%. 
     A compressor 1 is driven by an engine 26 through a magnetic clutch Ia, a belt 27 and a pulley 26a. The magnetic clutch 1a is controlled electrically to connect or disconnect the compressor 1 from the engine 26. The compressor 1 compresses the refrigerant to a certain high pressure value. 
     A condenser 2 comprises a winding tube through which the compressed refrigerant passes. A fan 2b driven by a motor 2a is disposed in front of the condenser 2 for supplying air to the condenser 2. The refrigerant passing through the condenser 2 is condensed. 
     The condensed refrigerant comes into a receiver 3. The receiver 3 separates the liquid phase refrigerant from the gas phase refrigerant. 
     An expansion valve 4 is disposed downstream of the receiver 3 and expands the condensed refrigerant for reducing the pressure value thereof. The expansion valve 4 has a sensing tube 4a for sensing the temperature of the refrigerant downstream of the expansion valve 4. The same kind of refrigerant is in the sensing tube 4a. 
     An evaporator 5 comprises a serpentine tube through which the expanded refrigerant passes. The refrigerant absorbs heat from air passing around the evaporator 5 and evaporates as it goes through the evaporator 5. The air for heat-exchanging comes from a fan 6a driven by a motor 6. The fan 6a, the motor 6 and the evaporator 5 are disposed in a case 9 made from resin. An outlet of the refrigerant from the evaporator 5 is disposed on the lower side of case 9. 
     An air switching box 7 is connected to the case 9 which has an inside air inlet 7a and an outside air inlet 7b. The inside air of an automobile is introduced into the air switching box 7 through the inside air inlet 7a, and outside air of the automobile is introduced into the air switching box 7 through the outside air inlet 7b. A damper 8 shaped like a plate is disposed in the air switching box 7 for alternately opening and closing the inside air inlet 7a and the outside air inlet 7b. The air introduced by the fan 6a flows through the evaporator 5 around the tube. 
     At the air downstream side of the evaporator 5, an air dividing damper 10 is provided. The air dividing damper 10 is shaped like a plate and is pivoted on a case 12 at one end thereof. The other end of the damper 10 confronts the evaporator 5. The damper 10 takes a position within a range from a position X to a position Y in an air mixing space 16. The positions X and Y are represented by broken lines in FIG. 1. 
     A heater 11 is disposed in the case 12. Hot water from the engine 26 flows in the heater 11 and heats air passing through the heater 11. A first bypass passage 13 is formed on an upper side of the heater 11 and a second bypass passage 14 is formed on a lower side of the heater 11. An air mixing damper 15 is disposed in the first bypass passage. Air received from evaporator 5 and which flows toward the first bypass passage 13 may be partially diverted by damper 15 from a side of the first bypass passage 13 to a side of the second bypass passage 14 through the heater 11. The damper 15 controls the amount of air which flows toward the heater 11 and the air which flows through the first bypass passage 13. 
     A defroster outlet 18 which has a plurality of openings one of which is shown at 18a is formed on the case 12. The air in air mixing room 17 is introduced toward a front window of the automobile through the defroster outlet 18 and the openings 18a. 
     A face outlet 20 is formed in the case 12 and introduces the air toward a passenger&#39;s face. 
     A room outlet 21 is formed on the case 12 and introduces the air toward a passenger&#39;s body. 
     A foot outlet 19 is formed on the case 12 and introduces the air toward a passenger&#39;s foot. 
     A face damper 22 is pivoted on the case 12 for opening and closing the face outlet 20 and the defroster outlet 18. A room damper 23 is pivoted on the case 12 for opening and closing the room outlet 21. A foot damper 26 is pivoted on the case 12 for opening and closing the foot outlet 19. 
     FIG. 3 shows an instrument panel 25 of the automobile. The face outlets 20 are disposed on a center portion of the instrument panel 25 and have louvers 20a for varying the blowing direction of the air. The room outlets 21 are disposed under the face outlets 20 and on both sides of the instrument panel 25. The room outlets 21 also have louvers 21a for varying the blowing direction of the air. 
     The positions of all dampers mentioned above are controlled by levers (not shown) provided on the instrument panel 25. 
     The operation of the air-conditioner is now described. 
     When the magnetic clutch is turned on, a driving force is transmitted from the engine 26 to the compressor 1 through the belt 27, so that the compressor 1 begins to compress the refrigerant. The compressed refrigerant goes through the condenser 2, the receiver 3 and the expansion valve 4 and then evaporates in the evaporator 5. The evaporated refrigerant comes back to the compressor 1. 
     FIG. 4 shows the relation of entropy and absolute temperature in the present embodiment. The refrigerant evaporates under a constant pressure and the temperature of the refrigerant increases in the evaporator 5. 
     FIG. 5 shows the temperature of the refrigerant in the evaporator 5 along a refrigerant passage. The temperature of a single refrigerant is almost constant in the whole passage. The temperature of the non-azeotropic mixture refrigerant increases as it gets closer to the outlet of the refrigerant, so that the temperature of the air passing through and around the evaporator 5 increases as it goes from the inlet to the outlet. That is, the temperature of the air passing through and around a lower portion of the evaporator 5 is higher than that of the air passing through and around an upper portion of the evaporator 5. 
     When the fan 6a is driven, air is introduced into the air switching box 7 through the inside air inlet or the outside air inlet, and then the air flows through and around the evaporator 5. The air passing through the evaporator 5 is cooled down by exchanging heat with the refrigerant flowing through the evaporator 5. 
     As shown in FIG. 2 the temperature of a non-azeotropic mixture refrigerant varies from -5° C. to 15° C. as the refrigerant flows from the inlet to the outlet of the evaporator 5. The air passed through the evaporator 5 also varies its temperature from -5° C. to 15° C. However, the single refrigerant stays substantially steady at 5° C. 
     The air dividing damper 10 divides the air passed through the evaporator 5 into two streams, one of which (the upper or upstream) is lower in temperature, the other (lower or downstream) is higher in temperature. When the damper 10 is positioned at the position Z, the air is divided at the center portion of the evaporator 5. The temperature of the air passed above the damper 10 averages 0° C. and the temperature of the air passed under the damper 10 averages 10° C. 
     When the air mixing damper 15 is positioned horizontally along the broken line, the air passed through the upper portion of the evaporator 5 flows through the first bypass passage 13 and the air passed through the lower portion of the evaporator 5 flows through the second bypass passage 14. 
     When the face damper 22 closes the defrost outlet 18 and opens the face outlet 20, the room damper 23 opens the room outlet 21, and the foot damper 24 closes the foot outlet 19, the cool air passed through the first bypass passage 13 comes out from the face outlet 20 toward the passenger&#39;s face, and the not-so-cool or warmer cool air passed through the second bypass passage 14 comes out from the room outlet 21 for direction below the passenger&#39;s face and at both sides of the instrument panel 25. 
     FIG. 6 shows the relationship between temperature of the air and the amount of moisture contained in the air. The 0° C. air has 0.60 sensible heat factor (S.H.F.) and the 10° C. air has 0.67 sensible heat factor. The divided air has 0.635 sensible heat factor on the average. When the single refrigerant is used, the air passed through the evaporator 5 is 5° C. in temperature and 0.61 in sensible heat factor. Point A represents air coming into the evaporator 5, which is 27° C. in temperature and 50% relative humidity. 
     In the present embodiment, the average sensible heat factor is 1.04 (=0.635/0.61) times and the humidity is reduced 4%, so that the ability to cool the air increases 4%. 
     When the air dividing damper 10 is positioned at the position Y so as not to divide the air but to close the second bypass passage 14, the air passed through the evaporator 5 is mixed in the room 16 and flows through the first bypass passage 13. The flowing air is 5° C. in temperature and comes out from the face outlet 20 and the room outlets 21. 
     When heating is required, the air dividing damper lo is positioned at the position Y to close the second bypass passage 14, and the air mixing damper 15 controls the amount of air flowing through the heater 11. 
     It is possible to dispose the outlet 51 of the refrigerant 5 on the upper side of the case 9 instead of the lower side. In that case, the face outlet 20 is disposed on the lower side of the case 12 and the room outlet 21 is disposed on the upper side of the 12. It is also possible to make subsidiary passages in the air mixing room 17 for introducing the cooled air toward the face outlet 20 and for introducing the warmer cool air toward the room outlet 21. 
     It is possible to provide more than two air dividing dampers to divide the air into more than two streams. 
     Other variations and modifications will be apparent to those skilled in the art, all of which are comprehended by the following claims.