Abstract:
An air guide housing for an air supply for an input fan of an air conditioner, including a housing wall with a side wall having a first opening therethrough for circulating air, a second opening therethrough for fresh air, and a third opening in the side wall for air drawn in by the fan, where the first opening is adjacent the second opening. The housing also includes an adjustment element pivotally mounted in the housing wall, where the adjustment element includes a peripheral section defining a closure element of the air guide housing adapted to block selected portions of the first and second openings. The peripheral section has a cross-section smaller than the sum of the cross-sections of the first and second openings.

Description:
CROSS REFERENCE TO RELATED APPLICATION(S)  
       [0001]     Not applicable.  
       STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT  
       [0002]     Not applicable.  
       REFERENCE TO A MICROFICHE APPENDIX  
       [0003]     Not applicable.  
       TECHNICAL FIELD  
       [0004]     The present invention relates to air guide housings, and more particularly to adjustable housings for guiding an air conditioned air supply produced by a fan.  
       BACKGROUND OF THE INVENTION AND TECHNICAL PROBLEMS POSED BY THE PRIOR ART  
       [0005]     Air guide housings are provided, for example, to guide fresh and recirculated air to the passenger compartment of a vehicle. DE 197 33 052 A1 discloses one such air guide, which has a relatively costly and demanding mounting and guiding of the rotatable air vent body. The bell-like air vent body sits on the lower edge of the fan housing. The intake housing, which has the same bell shape but has two openings (one for fresh air and one for circulating air) is situated around the air vent body. The air leaves the intake housing downward, almost through the bottom of the bell, in order to be drawn in by the fan. When both housing openings are closed, no air is fed to the fan and the air is not circulated in the passenger compartment. In some conditions (e.g., in winter), fogging of the windshield and resulting dangerously poor driver visibility can occur. Also, a comfortable, persistent temperature in the passenger compartment cannot be guaranteed due to no air is passed through the heater or air conditioner. Overall, this is a relatively costly design which can be unreliable in everyday operation.  
         [0006]     Another air guide housing, with a pivoting vent or semi-cylindrical drum vent, is described in DE 199 15 966 A1. This structure may be used to supply fresh air and/or circulating air to a fan by means of ribs integrated in the housing, which ribs are supposed to divert the air stream at the entry to the fan and prevent mixing of circulating air and fresh air in front of the fan. However, during slow rotation of the pivot vent or drum vent between the selected positions of fresh air to circulating air, fresh air may flow around the rib directly into the passenger compartment through the circulation inlet. This can be in different conditions be undesirable, particularly in winter.  
         [0007]     The present invention is directed toward overcoming one or more of the problems set forth above.  
       SUMMARY OF THE INVENTION  
       [0008]     In one aspect of the present invention, an air guide housing for an air supply for an input fan of an air conditioner is provided. The housing includes a housing wall including a side wall having a first opening therethrough for circulating air, a second opening therethrough for fresh air, and a third opening in the side wall for air drawn in by the fan, where the first opening is adjacent the second opening. The housing also includes an adjustment element pivotally mounted in the housing wall, where the adjustment element includes a peripheral section defining a closure element of the air guide housing adapted to block selected portions of the first and second openings. The peripheral section has a cross-section smaller than the sum of the cross-sections of the first and second openings.  
         [0009]     In one form of this aspect of the present invention, the housing wall is substantially barrel-like with a generally circular bottom and a generally circular cover, and the adjustment element includes generally circular plates pivotally secured to the bottom and the cover with the peripheral section secured between the arms.  
         [0010]     In another form of this aspect of the present invention, the peripheral section extends over a selected arc around at least ⅓ of the housing, and the first and second openings extend over an arc greater than the selected arc, where the selected arc and the arc of the first and second openings extend about the axis about which the adjustable element is pivotally mounted. In a further form, the housing wall is substantially barrel-like with a generally circular bottom and a generally circular cover, and the adjustment element includes generally circular plates pivotally secured to the bottom and the cover with the peripheral section secured between the arms.  
         [0011]     In still another form of this aspect of the present invention, stops are fixed relative to the housing wall for limiting pivoting of the adjustment element.  
         [0012]     In yet another form of this aspect of the present invention, concentric grooves are provided between the adjustment element plates and the housing wall bottom and cover. In a further form, the concentric grooves define seals between the adjustment element plates and the housing wall bottom and cover.  
         [0013]     In a further form of this aspect of the present invention, the housing wall comprises two housing parts releasably connected to each other with the adjustment element pivotally secured therebetween.  
         [0014]     In yet another aspect of the present invention, an air supplier is provided, including first and second air guide housings, and a fan drive unit between the first and second air guide housings. Each of the housings includes a housing wall including a side wall having a first opening therethrough for circulating air, a second opening therethrough for fresh air, and a third opening in the side wall for air drawn in by the fan, where the first opening is adjacent the second opening. The housings also each include an adjustment element pivotally mounted in the housing wall, where the adjustment element includes a peripheral section defining a closure element of the air guide housing adapted to block selected portions of the first and second openings. The peripheral section of each housing has a cross-section smaller than the sum of the cross-sections of the first and second openings. The fan drive unit is adapted to receive air from the third opening of both of the housings. A position control for the adjustment elements of both of the housings includes a common drive for controlling the position of both of the adjustment elements.  
         [0015]     In one form of this aspect of the present invention, the common drive is a servo motor. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0016]      FIG. 1  is a perspective view of an air guide housing according to the present invention in one position for admitting fresh air;  
         [0017]      FIG. 2  is a cross-sectional view of the housing of  FIG. 1 ;  
         [0018]      FIG. 3  is a perspective view of the air guide housing, showing the position of the revolving door in 80% dynamic pressure compensation of the fresh air;  
         [0019]      FIG. 4  is a cross-sectional view of the housing of  FIG. 3 ;  
         [0020]      FIG. 5  is a perspective view of the air guide housing showing the position of the revolving door in the circulating air position;  
         [0021]      FIG. 6  is a cross-sectional view of the housing of  FIG. 5 ;  
         [0022]      FIG. 7  is a perspective view of a pair of air guides according to the present invention as used in a vehicle; and  
         [0023]      FIG. 8  schematically illustrates the operable coupling of the revolving doors of the two air guide housings in  FIG. 7 . 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0024]     An air guide housing  10  according to the present invention is shown in  FIG. 1 . The housing  10  includes a generally barrel shaped wall  14  between a cover  16  and bottom  18 . For assembly purposes in particular, the air guide housing  10  may advantageously be made of two parts: an upper housing part  10   a  and a lower housing part  10   b . The housing parts  10   a ,  10   b  may advantageously be made from plastic with an injection molding process, with a seam  20  (which may advantageously be sealed) formed between the housing parts  10   a ,  10   b.    
         [0025]     Three openings are provided in the barrel shaped wall  14 . One opening  22  is for receiving circulating air (e.g., recirculating air from a vehicle passenger cabin). A second opening  24  is for receiving fresh air. A third opening  26  is for outputting air as described in greater detail hereafter.  
         [0026]     A connector  30  is associated with the fresh air opening  24  and includes a flange  34  which may be mounted to suitably seal on an opening in the separation wall between the engine compartment and the passenger compartment. In the illustrated embodiment, the housing  10  is inside the passenger compartment, and air entering through the connector from the engine compartment would be fresh air from outside the passenger compartment.  
         [0027]     Another connector  36  is associated with the output air opening  26  and may be suitably mounted to a fan  40  such as described in greater detail below in connection with  FIG. 7 . The fan  40  and the air guide housing  10  may be parts of, for example, a heater/air conditioning unit used to temper the air of the passenger compartment of the vehicle. Such a heater/air conditioner as a whole may be surrounded by a housing (not shown here).  
         [0028]     No connector is required for the circulating air, since it can flow unhampered from the passenger compartment into the heater/air conditioner and is drawn in by the fan through the air guide housing  10  when the control of the heater/air conditioner requires switching to circulating air.  
         [0029]     An adjustable door  50  is provided in the housing  10  to control air flow through the housing  10  as described below. The door  50  may be suitably mounted for selected pivoting inside the barrel shaped wall  14 . In the illustrated embodiment, the door  50  includes one arm pivotally connected to the housing cover  16  and a second arm pivotally connected to the housing bottom  18 . Specifically, a circular mounting disk  52  is pivotally secured to the housing bottom  18 , and a similar mounting disk is pivotally secured to the housing cover  16 , for example, by pivot supports  56  through central openings in the similarly circular cover  16  and bottom  18  which together define the pivot axis  58 .  
         [0030]     A closure element  60  is suitably connected to the mounting disks  52  so as to be positioned adjacent the barrel shaped wall  14 , and pivotable with the disks between different positions therein.  
         [0031]     A groove  62  with a suitable seal such as a labyrinth seal may be advantageously provided inside the edge of the cover  16  and the bottom  18 . This groove  24  assists in preventing clattering noises of the door  50 , which is sealed relative to flowing air and dammed-up air (as described further below) by the labyrinth seal in the groove  62 .  
         [0032]     It should be appreciated that the door  50  may be assembled in the housing  10  by first placing the door  50  between the housing parts  10   a ,  10   b  and then securing the parts  10   a ,  10   b  together, such as by screwing them together or by a releasable connection such as the illustrated fastening device  64 .  
         [0033]     As described further below, the closure element  60  may advantageously extend over a selected arc (around the pivot axis  58 ) around at least about ⅓ of the housing wall  14 , with the circulated air and fresh air openings  22 ,  24  extending over an arc greater than the selected arc. As such and as further described below, it should be appreciated that the closure element  60  will not be large enough to be positioned to fully close both the circulated air and fresh air openings  22 ,  24  at the same time. Also, the door  50  can be rotated between stops  68 , which are positioned so as to prevent the closure element  60  from blocking the outlet air opening  26 . As a result, air can always be drawn through one or both of the circulated air and fresh air openings  22 ,  24  and then out the opening  26  by the fan  40 , since at least one of the circulated air and fresh air openings  22 ,  24  is always partially or fully opened.  
         [0034]     As illustrated in  FIGS. 1 and 2 , the door  50  is positioned so that the closure element  60  fully closes the circulated air opening  22 , whereby only fresh air reaches the air guide housing  10  through the opening  24  and the fresh air connector  30 . Because the circulating air opening  22  is closed, the circulating air, indicated by arrow  70 , dams up in front of closure element  60  of the door  50 . As best illustrated in  FIG. 2 , the fresh air, shown by arrow  72 , can pass unhampered through the fresh air connector  30  and opening  24  and flow through the air guide housing  10  and connector  36  to the fan  40 .  
         [0035]      FIGS. 3 and 4  show the air guide housing  10  in the position in which the dynamic pressure developed, for example, by a strong relative wind may be compensated for. In this position, the fresh air opening  24  is closed by the closure element  60  of the door  50 , but with a small gap  76  remaining open to admit some fresh air into the air guide housing  10 . At the same time, given its size as previously described, the closure element  60  ensures that the opening  22  for circulating air remains closed. This condition thus restricts flow of fresh air  72  into the air guide housing  10 . At higher vehicle speeds, for example, the dynamic pressure is increased and therefore the fresh air opening  24  is largely but not completely closed to compensate for that dynamic pressure.  
         [0036]     It should be appreciated that pivoting of the door  50  to reduce the size of the gap  76  could open a gap at the circulating air opening  22 , as a result of which circulating air and fresh air can both flow into the air guide housing  10  without the fresh air passing through the circulating air opening  22  directly into the passenger compartment. This is achieved by the fact that the dynamic pressure of the fresh air is always compensated and the suction force of the fan  40  stipulates the direction in which the air can flow.  
         [0037]     When circulating air is desired for flow through the air guide housing  10 , the closure element  60  of the door  50  is pivoted to completely close off the fresh air opening  22 , with the circulating air opening  24  remaining fully open at the same time as shown in  FIGS. 5 and 6 . The labyrinth seal in the groove  62  serves to prevent undesired noise that could develop from the dynamic pressure of the fresh air. In the condition illustrated in  FIGS. 5 and 6 , the fresh air  72  dams up in front of the closure element  60  of the door  50 , and the circulating air  70  is diverted in the air guide housing  10 .  
         [0038]      FIG. 7  illustrates an advantageous embodiment in which two air guide housings  10  according to the present invention may be used. In this embodiment, the air guide housings  10  are mounted directly on fan  40  to the right and left in mirror symmetry relative to a drive unit  80  that drives two fans  40 . The connector  36  of each housing  10  may advantageously include a suitable fastening device  84  to facilitate easy connection of the fan  40 .  
         [0039]     In the  FIG. 7  configuration, the revolving doors  50  of both housings  10  may be advantageously moved together by a suitable drive, such as the servo motor  90  shown in  FIG. 8 . As schematically illustrated in  FIG. 8 , the servo motor  90  drives a coupling element  92  extending in diametrically opposite directions to the two housings, with the coupling element  92  drivably engaging pinions  94  on the pivot supports  56  of the doors  50  to move the doors  50  in mirror symmetry relative to each other. Suitable mounts  98  may also be provided to enable easy and secure fastening of the entire unit to the intermediate wall between the engine compartment and the passenger compartment. It should be understood, however, that the illustrated drive and connecting structures are merely exemplary, and that still other structures could be used for securing the housings  10  and driving the doors  50  within the broad scope of the present invention.  
         [0040]     It should thus be appreciated that air guide housings provided according to the present invention may be reliably used to provide an advantageous air flow, where air supply to the passenger compartment of a vehicle is possible in all operating situations of the air conditioner. Further, such housings are simple so as to be reliably and cost-effectively manufactured, and reliably and inexpensively installed, operated and maintained. Moreover, advantageous smooth and noise free operation is provided while also guaranteeing dynamic pressure compensation necessary at higher driving speeds.  
         [0041]     Still other aspects, objects, and advantages of the present invention can be obtained from a study of the specification, the drawings, and the appended claims. It should be understood, however, that the present invention could be used in alternate forms where less than all of the objects and advantages of the present invention and preferred embodiment as described above would be obtained.