Abstract:
An air-conditioning device for a vehicle comprising in a housing ( 13 ) a first conduit ( 20 ) for transmitting a cool air flow (F 1 ) and a second conduit ( 22 ), wherein is installed a heat exchanger ( 24 ) for transmitting a warm air flow (F 2 ). The conduits ( 20, 22 ) are interposed between an air intake ( 14 ) and a mixing zone ( 31 ) delivering mixed air. A system splitting ( 40 ) the air flows (F 1 , F 2 ), delivered by the conduits ( 20, 22 ) is provided at the junction of the two conduits and in the second conduit ( 22 ) downstream of the heat exchanger ( 24 ). The splitting system ( 40 ) comprises transversely alternating a plurality of cool air passages ( 46 ) and a plurality of warm air passages ( 49 ). The passages emerge into two separate mixing zones ( 31, 25 ).

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention. 
     The invention relates to the field of air-conditioning apparatus, especially for motor vehicles. 
     2. Description of Related Art 
     The air-conditioning apparatus for vehicles generally includes an air-inlet duct fed selectively with outside air or with recycled air taken up from the passenger compartment, in which are mounted a blower and an evaporator, an air-conditioning casing receiving the cold air from the evaporator and including a cold-air transmission duct and a bypass duct in which is mounted a heat exchanger, these two ducts joining together in a mixing region intended to deliver air at the required temperature, and a distribution casing receiving the air from the mixing region and delivering it to various air-diffusion vents provided in the passenger compartment. 
     In the conditioning casing, a mixing flap is provided in order to share out the cold air delivered by the evaporator between a cold flow and an airflow passing through the heat exchanger. In an extreme position of this flap, all the air travels through the heat exchanger and, in another extreme position, no air travels through the exchanger. 
     The air-mixing region situated at the intersection of the cold-air duct and of the heating duct receives a cold-air flow and a hot-air flow at different speeds and in different directions. These two airflows would have to be mixed intimately, in order for the mixing region to deliver air at a uniform temperature. 
     However, it is observed that stratification of the air occurs. At the outlet from the mixing region, the air is colder on the cold-air-duct side and hotter on the bypass-duct-outlet side. In the distribution casing, the ducts for delivering air to the aeration vents are connected in such a way that the foot-aeration ducts, also called heating ducts, receive hotter air than that feeding the central or lateral aeration ducts of the passenger compartment. However, in general, the de-icing ducts receive colder air than that delivered by the aeration vents, which does not encourage demisting of the windscreen. 
     The mixing region is usually arranged in the upper part of the air-conditioning casing. The foot-aeration ducts, or more generally the ducts for aerating the lower regions of the passenger compartment and the rear region, therefore extend over the entire height of the said casing, and take up a not inconsiderable amount of space. 
     In certain air-conditioning apparatus, two mixing regions are provided, an upper mixing region intended to supply air to the de-icing vents and to the central and lateral aeration vents mounted on the dashboard, and a lower mixing region intended for supplying conditioned air into the lower part and the rear part of the passenger compartment. In other apparatus, the upper mixing region is intended for the front diffusion (de-icing, central and lateral aeration, front passengers&#39; feet), and the lower mixing region is intended for the diffusion to the rear of the passenger compartment. In this case, a supplementary duct is provided for transmitting cold air into the air-conditioning casing in order to feed this second mixing region. The heating duct is arranged between the two cold-air transmission ducts and supplies the two mixing regions with hot air. The additional duct also takes up a not inconsiderable amount of space, and it is necessary to provide a second mixing system in order to control the temperature of the air in the second mixing region, and a number of anti-return flaps. 
     SUMMARY OF THE INVENTION 
     The object of the invention is to propose an air-conditioning device for a motor vehicle which makes it possible to feed two mixing regions with a single mixing system, without requiring anti-return flaps and while ensuring homogenisation of the temperatures in each of the mixing regions. 
     The object of the invention is also to make the air circuit to the lower part of the apparatus more permeable and thus to benefit from a more substantial air throughput. 
     The object of the invention is also to propose a device for conditioning the air of the passenger compartment of a vehicle, which is compact, easy to produce and easy to assemble. 
     The invention therefore relates to a device for heating, ventilating and/or air-conditioning the passenger compartment of a motor vehicle, of the type including, in a casing, a first duct for transmitting a cold-air flow and a second duct, in which a heat exchanger is installed, for transmitting hot air, the said ducts being interposed between an air inlet and a mixing region delivering the mixed air. 
     According to the invention, this device is characterised in that it further includes an airflow-divider system which shares out the cold-air flow delivered by the first duct and the hot-air flow delivered by the second duct into a number of secondary flows, this divider system including, transversely and alternately, a number of cola-air passages having their inlets in the first duct and a number of hot-air passages having their inlets in the second duct, and in that the said passages feature a first series of outlets alternately delivering cold air and hot air into a first mixing region and a second series of outlets alternately delivering hot air and cold air into a second mixing region. 
     Advantageously, the airflow-divider system includes a number of parallel plates arranged transversely in the casing, at the junction of the first duct and of the second duct, these plates being linked in pairs in the first duct and the second duct by means of junction walls, so as to define the inlets of the cold-air passages in the first duct and the inlets of the hot-air passages in the second duct. 
     The following provisions are furthermore preferably adopted: 
     the plates, between the two series of outlets, includes edges attached to a transverse wall of the casing; 
     the said plates have an oblong shape and extend downstream of the heat exchanger in the second duct and across the outlets of the first duct and of the second duct; 
     the two mixing regions are arranged respectively at the extremities of the said plates. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Other advantages and characteristics of the invention will emerge on reading the following description given by way of example and by referring to the attached drawings, in which: 
     FIG. 1 is a sectional view of an air-conditioning device according to the invention, this section being taken along the median plane of a cold-air passage of the flow-divider system; 
     FIG. 2 is similar to FIG. 1, but this section is along a median plane of a hot-air passage of the flow-divider system; 
     FIG. 3 is a view in perspective of the flow-divider system of the conditioning device; 
     FIGS. 4 and 5 are similar to FIGS. 1 and 2 and show an air-conditioning device in which the mixing flaps are mounted in the divider system; 
     FIG. 6 shows, in perspective, a mixing flap of the conditioning device of FIGS. 4 and 5; 
     FIG. 7 is a section along the line VII—VII of FIG. 2; 
     FIGS. 8 and 9 are similar to FIGS. 1 and 2 and show a divider system some of the walls of which include orifices; 
     FIGS. 10 and 11 are similar to FIGS. 1 and 2 and show a divider system equipped with deflecting walls in order to make it possible to supply de-icing air which is hotter than the ventilation air; 
     FIGS. 12 and 13 are similar to FIGS. 1 and 2 and show a variant de-icing flap which makes it possible to adjust the inlets of the cold-air massages; 
     FIGS. 14 and 15 are similar to FIGS. 1 and 2 and show an air-conditioning device with an additional flap; 
     FIG. 16 is a view in perspective of the additional flap of FIGS. 14 and 15; 
     FIGS. 17 to  19  respectively show a variant embodiment of the air-conditioning device of FIGS. 14 to  16 ; 
     FIGS. 20 and 21, similar to FIGS. 1 and 2, show an air-conditioning device equipped with means for adjusting the hot and cold air throughputs assigned to each mixing chamber; 
     FIGS. 22 and 23 show a variant of the adjusting means of FIGS. 20 and 21; 
     FIG. 24 is a section along the line XXIV—XXIV of FIG. 25 of another variant of the divider system; and 
     FIG. 25 is a section along the line XXV—XXV of FIG.  24 . 
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     FIGS. 1 and 2 show an air-conditioning device  10  for a vehicle, which includes, downstream of an evaporator  11  mounted at the outlet of a blown-air inlet duct  12 , a casing  13  having an inlet  14  for receiving cold air supplied by the evaporator  11 . 
     This casing  13  conventionally includes an upper wall  15 , a U-shaped lower wall  16  and a back wall  17 . The walls  15 ,  16  and  17  extend between two side walls not referenced in the drawings. A crosspiece  18  furthermore links the side walls. This crosspiece  18  divides up the interior of the casing  13  into two air ducts: a first duct  20  directed overall upwards and linking the inlet  14  to an outlet  21  formed between the upper wall  15  and the back wall  17 , and a second U-shaped duct  22 , arranged in parallel between the inlet  14  and the outlet  23  formed between the crosspiece  18  and the upper part of the sack wall  17 . A heat exchanger  24  is installed in the second duct  22 . This exchanger extends between the crosspiece  18  and the lower part of the lower wall  16 . 
     The heat exchanger  24  is substantially parallel to the back wall  17 . 
     Between the back wing  16   a  of the lower wall  16  and the lower part of the back wall  17   a  lower mixing chamber  25  is provided, intended to supply conditioned air to the lower parts and the rear part of the passenger compartment of the vehicle equipped with the device  10 . This mixing chamber  25  communicates with the interior of the casing  13  via an orifice  26 . 
     The casing  13  is connected to a distribution casing  30  in the region of the outlet  21 . This casing  30  defines an upper mixing region  31  which feeds a de-icing duct  32  and an aeration duct  33 , these ducts  32  and  33  being intended to deliver conditioned air to de-icing nozzles and to aeration vents mounted on the dashboard of the vehicle. Distribution flaps  34  and  35 , of the butterfly type, are mounted respectively in the de-icing duct  32  and the aeration duct  33 . The orifice  26  provided at the inlet of the lower mixing chamber  25  can also be shut off by a flag flap  36 . 
     The sharing of the cold air delivered by the evaporator  11  between the first duct  20  and the second duct  22  is carried out by means of two combined butterfly flaps  37  and  38 . The flap  37  makes it possible to adjust the opening of the passage situated between the upper wall  15  and the crosspiece  18 , while the flap  38  makes it possible to adjust the opening of the inlet  39  of the second duct  22 , this inlet  39  being delimited by the crosspiece  18  and the lower wall  16 . When the flap  37  is in the extreme position for closing of the first duct  20 , the flap  38  opens the inlet  39  and all the cold air delivered by the evaporator  11  travels through the heat exchanger  24 . In contrast, when the flap  38  closes off the inlet  39  of the second duct  22 , the flap  37  is in a position for maximum opening of the first duct  20 . In this latter position, all the cold air delivered by the evaporator  11  passes into the first duct  20  and is directed towards the upper part of the casing  13 . 
     The flaps  34 ,  35 ,  36 ,  37  and  38  are mounted pivoting about transverse spindles which are substantially parallel to the crosspiece  18  and carried by the side walls of the casing  13 . 
     According to the invention, a system  40  for dividing the cold-air flow F 1  which travels through the first duct  20  and the hot-air flow F 2  which travels through the heat exchanger  24  is provided in these ducts downstream of the heat exchanger  24  and of the mixing flap  37 . This divider system  40 , shown in detail in FIG. 3, includes a number of parallel plates  41 , of oblong shape overall, which extend in height between the inlet orifice  26  in the lower mixing chamber  25  and the outlet  21  formed between the upper wall  15  and the back wall  17  of the casing  13 , and which extend in the longitudinal direction of the casing  13  between the crosspiece  18  and the back wall  17 . These plates  41  are, moreover, parallel to the side walls of the casing  13 . The plates  41  feature rear edges  42  which have a configuration which is complementary to that of the back wall  17  and are attached to the latter. 
     The front edges  43   a  of the plates  41 , situated in the first duct  20 , are linked in pairs by means of linking walls  44 , in such a way as to define inlets  45  of cold-air passages  46 , in the duct  20 . In the same way, the front edges  43   b  of the plates  41 , situated in the second duct  22 , are linked in pairs by means of linking walls  47 , in such a way as to define inlets  48  of hot-air passage  49  between the linking walls  47 . The linking walls  44  and  47  are arranged alternately in the transverse direction. Thus, a place  41  is linked to an adjacent plate by a linking wall  44  in the region of its upper front edge  43   a  and to the other adjacent plate by a linking wall  47  in the region of its lower front edge  43   b.    
     The cold-air passages  46  and the hot-air passages  49  are thus arranged alternately in the transverse direction of the casing  13 , and each passage  46  or  49  opens out into the upper mixing region  31  via an upper outlet  50  and opens out into the lower mixing region  25  via a lower outlet  51 . 
     The upper outlets  50  situated in the outlet  21  of the casing  13  thus deliver secondary, alternate cold-air and hot-air flows in the upper mixing region  31 . The lower outlets  51  situated in the lower orifice  26  of the casing  13  likewise deliver alternate, secondary hot-air and cold-air flows. 
     With the divider system  40  being placed essentially in the second duct  20 , downstream of the heat exchanger  24 , and across the outlets of the first duct  20  and of the second duct  22 , it occupies a space which is not occupied by a traditional air-conditioning casing, while allowing two separate mixing regions  31  and  25  to be fed with hot air and with cold air. 
     Furthermore, the cold-air and hot-air flows delivered in the mixing regions are divided into a number of alternately hot and cold secondary flows in the transverse direction, which ensures homogenisation of the temperature of the air at the outlet from the mixing regions. 
     Moreover, with the cold air and the hot air flowing in counter-current mode in the central region of the divider system  40 , a heat exchange is already being produced between the two flows in this region. 
     FIGS. 4 to  6  show a variant embodiment of an air-conditioning device in accordance with the invention in which the two mixing flaps  37  and  38  described above are replaced by two multiple flaps  52  and  53  shown in detail in FIG.  6 . Each of the flaps  52  and  53  includes a number of walls  54  capable of closing off the outlets  50  or  51  of the cold-air passages  46  and a number of walls  55  capable of closing off the outlets  50  or  51  of the hot-air passages. The walls  55  are offset in angle with respect to the walls  54 . In the “all hot” position of the flaps  52  and  53 , shown in bold in FIGS. 4 and 5, the outlets of all the cold-air passages  46  are closed off, and in the “all cold” position, the outlets of all the hot-air passages  49  are closed off. The controls for the two flaps  52  and  53  can be combined or independent. 
     The plates  41  can be flat, but they can have other configurations, so as to promote a temperature difference between the airs delivered by the upper mixing region  31  and the lower mixing region  25  or between different regions of the apparatus, for example the central region and the side region, or between the de-icing duct  32  and the aeration duct  33 . In general, hotter air is required in the lower parts of the passenger compartment of the vehicle. The device  10  described above favours this situation. 
     The spacings between the various plates  41  can be identical, or can be different. FIG. 7 shows a divider system  40  which includes three cold-air passages  46  and four hot-air passages  49 . The two lateral hot-air passages  49  are wider than the central hot-air passages, and the central cold-air passage  46  is wider than the other two cold-air passages. It can be envisaged that, with such a configuration, the two mixing regions  31  and  25  will receive hotter air in their lateral regions and colder air in their central region. 
     FIGS. 8 and 9 show a divider system  40  in which certain plates  41  include orifices  56  which allow exchanges of air between the hot-air and cold-air layers. Complementary orifices  57  can also be formed in the linking walls  44  and  47  so as to allow a slight cold-air or hot-air throughout into the passages  46  or  49 . 
     In order to arrange for the de-icing duct  32  to deliver hotter air than the ventilation duct  33  in combined de-icing/ventilation mode, the divider system  40 , as it is shown in FIGS. 10 and 11, can be equipped with deflecting walls. Deflecting walls  58  are therefore provided in the upper branches of the hot-air passages  49 , so as to direct the hot air arriving through the orifices  50  towards the de-icing duct  32 . The upper branches of the cold-air passages  46  can also be equipped, in the upper part of their inlet  45 , with deflecting walls  59  which direct the cold-air flows arriving through the orifices  50  towards the ventilation duct  33 . 
     FIGS. 12 and 13 show an air-conditioning device  10  in accordance with the one described above in which the de-icing flap  34  is of butterfly type and is mounted pivoting about a spindle  60  situated close to the upper wall  15  of the casing  13  and in the outlet  21 . The upper wing  61  of this flap  34  is capable of closing off the de-icing duct  32 , while the lower wing  62  of this flap  34  is situated in the first duct  20  downstream of the divider system  40 . In open position (position A) of the flap  34 , the lower wing  62  is pressed against the linking walls  44 , which reduces the cross-section of the inlets  45  of the cold-air passages  46 . In closed position (position B) of the flap  34 , the lower wing  62  frees a larger cross-section of the inlets  45  of the cold-air passages  46 . For the same quantity of hot air, there is more cold air in heating and ventilation mode than in heating and de-icing mode. 
     FIGS. 14 to  16  show an air-conditioning device  10  in accordance with the one shown in FIGS. 1 and 2, in which, in the upper mixing region  31 , an additional flap  63  is provided which includes two series of walls  64 ,  65  offset in angle and extending from a spindle  66 . The spindle  66  is arranged close to the upper wall  15  of the casing  13  and in the outlet  21 . The walls  64  make it possible to adjust the cross-sections of the outlets  50  of the cold-air passages  46  and the walls  65  adjust the cross-sections of the outlets  50  of the hot-air passages  49 . When the additional flap  63  is in the position denoted “A” in FIGS. 14 and 15, there is a reduction in the cross-section of the hot-air passage towards the upper mixing region  31  without any alteration in the cross-section of the cold-air passage. When the additional flap  63  is in the position denoted “B”, there is a reduction in the cross-section of the cold-air passage towards the upper mixing region  31 , with no alteration in the cross-section of the hot-air passage. 
     FIGS. 17 to  19  show a variant embodiment of the foregoing air-conditioning device. The additional flap  63  includes two series of walls  64 ,  65  of the butterfly type offset by about 90°. The spindle  66  of this flap  63  is arranged substantially in the central region of the outlet  21  and is mounted on the divider system  40 . 
     The embodiments shown in FIGS. 10 to  19  make it possible to create a difference in temperature between the air delivered to the de-icing duct  32  and the air delivered to the ventilation duct  33 . 
     FIGS. 20 to  23  show air-conditioning devices in which the divider system  40  is equipped with means for adjusting the hot-air and cold-air throughputs assigned to the first mixing region  31  and the second mixing region  25 . According to a first variant embodiment, shown in FIGS. 20 and 21, these means include two series of flaps  70  and  71 . The flaps of the first series of flaps  70 , of flag type, are arranged in the upper region of the cold-air passages  46  and pivot about a spindle  72  situated close to the back wall  17  of the casing  13 . The flaps of the second series of flaps  71 , of flag type, are arranged in the lower region of the hot-air passages  49  and pivot about a spindle  73  situated close to the back wall  17  of the casing  13 . The two series of flaps  70  and  71  are combined or have independent controls. 
     According to a second variant embodiment shown in FIGS. 22 and 23, these adjusting means include drum flaps  74  in the cold-air passages  46  and the hot-air passages  49  which are carried by a spindle  75  situated in the vicinity of the crosspiece  18 . The cylindrical walls of the drum flaps  74  are in the vicinity of the back wall  17  of the casing  13 , in an intermediate position. When they are in low position, there is a reduction in the hot-air and cold-air throughputs to the lower mixing region  25 . When they are in high position, there is a reduction in the hot- and cold-air throughputs to the upper mixing region  31 . 
     FIGS. 24 and 25 show an air-conditioning device, in which the distributor  40  features a configuration in its lower part as well as means for adjusting the hot-air throughputs of the de-icing. The distributor system  40  laterally features hot-air passages  49  which include narrowed inlets  80  obtained by virtue of a complementary linking plate. Fins  82  which are independent of the flap  36  control the additional hot-air throughput sent into the mixing region  31  in the de-icing modes. In the position referenced  0  of the fins  82 , they close off the lateral hot-air passages  49 . In the position referenced  1  of the fins  82 , they free the lateral hot-air passages  49  and close off the lateral hot-air outlets  51 . In the heating and central and lateral aeration mode, the flap  36  is in position referenced  1  and the fins  82  are in position referenced  0 . In the heating and de-icing mode, the flap  36  is in position referenced land the fins  82  are in position referenced  1 . In our example, represented in FIGS. 24 and 25, and advantageously, the fins  82  and the flap  36  pivot about the same spindle. 
     The different embodiment variants described above make it possible to manage variable temperature differences between the lower mixing region  25  and the upper mixing region  31 , depending on the distribution modes chosen, or to manage the variations in throughput between the two mixing regions  25  and  31 . For example, it is possible to obtain a lower temperature difference for the feet aeration and de-icing mode than for the feet aeration and central and lateral aeration mode. 
     Finally, the device  10  does not require any anti-return flaps, which are found in the traditional devices which have two mixing chambers each having its mixing system, these anti-return flaps preventing the passage of air from one chamber to the other, for the distribution modes using only the upper vents or the lower vents for the intermediate positions of the mixing flaps. 
     The use of the divider system  40  described above also makes it possible to get round problems of parasitic heating in cold position. This is because, when the flap  38  is closed, the cold air flows through the first duct  20  and cannot come into contact with the hot surface of the core of the heat exchanger  14  until after a very complex circuit between the plates of the divider system. The resulting loss of pressure head will be so great that the cold air will use the most direct path towards the open outlet vents.