Abstract:
A distribution housing including an upstream portion and a widened downstream portion along the transverse axis relative to the upstream portion, in which an air inlet formed in the upstream portion is adapted to correspond to an outlet of an air conditioning apparatus, first and second outlets formed in the downstream portion are respectively adapted to correspond with a duct network for distributing blown air towards a de-icing board and side louvers, first pipes connect the inlet to the first outlets and extend between separation walls of the ducts and side walls of the housing, and a second pipe connects the inlet to the second outlet and extends at least partially between the duct separation walls. The second pipe opens, on the air inlet side, at the center of the air inlet, and the first pipes open on both sides of the first pipe. The housing has a different profile along the plane between the first and second pipes.

Description:
BACKGROUND 
     The present invention relates to an air conditioning device of a vehicle comprising a network of defrosting ducts in an instrument panel. 
     It relates in particular to such a device in which the network comprises a distribution housing which has a downstream portion and an upstream portion and wherein:
         an air inlet is adapted to correspond with a defrosting opening of an air conditioning apparatus,   first outlets are adapted to correspond with a windshield defrosting frieze,   a second outlet is adapted to correspond with side defrosting outlets,   first pipes connect the inlet to the first outlets, and extend between duct-separating walls and side walls of the housing,   a second pipe connects the inlet to the second outlet, and extends at least partly between the duct-separating walls,   the second pipe leads, on the air inlet side, to the center of the air inlet, and   the first pipes lead to either side of the second pipe.       

     DESCRIPTION OF THE RELATED ART 
     Such a device is described in document FR2876958, in which a separation is made between a central duct and two distinct side ducts in order to allow a better distribution of the air flow over the extent of a windshield defrosting frieze and an improvement of the defrosting of the side windows by blowing an air flow through side outlets. 
     However, this device is not entirely satisfactory because considerable pressure losses appear that are caused by swirling separations, making the air speed in the ducts unequal. Moreover, the central zone of the windshield defrosting frieze is then insufficiently supplied with air. Finally, resistances to the flow hamper the flow of air toward the side ducts, rendering the defrosting of the side windows insufficient. 
     BRIEF SUMMARY 
     The object of the invention is to propose a distribution housing for an air conditioning device of a vehicle comprising a network of defrosting ducts in an instrument panel which no longer has the abovementioned disadvantages. 
     The subject of the invention is a distribution housing which furthermore complies with the aforementioned preamble having a differentiated profile on the plane L-V between the first pipe ( 340 ) and second pipe ( 350 ). 
     According to particular embodiments, the distribution housing comprises one or more of the following features:
         the downstream portion of the second pipe comprises a first wall and a second wall which extend sideways between the duct-separating walls, these walls being substantially parallel with one another, and extending generally in a rectilinear manner, so as to limit the resistance to the air flow emitted by the air conditioning apparatus;   the first outlets are two in number and are placed laterally around the second outlet, each pipe corresponding with an orifice of the frieze, the frieze comprising two distant orifices;   the first pipes have an S-shaped profile in the plane L-V;   a baffle is placed, in the second pipe, at the front walls of the side ducts, this baffle having a convexity toward the upstream that is substantially half-way between the duct-separating walls in order to guide the air flow toward the side outlets;   a baffle is placed, in the second pipe, at the front walls of the side ducts, this baffle comprising an additional orifice for the defrosting of the central zone of the windshield, and convexities toward the upstream around this additional orifice, in order to guide the air flow toward the side outlets;   an additional orifice extends between the additional duct walls placed in the second pipe, the air destined for the side outlets passing on either side of the additional orifice, between the duct-separating walls and side baffles which extend between the upstream ridges of the additional duct walls and the front wall of the side ducts;   the side baffles have a curved shape in order to limit the resistance to the air flow toward the side outlets;   the duct-separating walls and/or the additional duct walls can be moved in translation and/or in rotation so as to change the proportion of air flow between the outlets of the distribution housing;   the distribution housing is formed of a first element and a second element which forms a cover, at least one of them supporting a seal.       

     A further subject of the invention is an air conditioning device for a vehicle comprising a network of defrosting ducts in an instrument panel, said network comprising a distribution housing according to the invention which has a downstream portion corresponding with a network of ducts in order to distribute the air blown toward a defrosting frieze and side outlets, and an upstream portion corresponding with an outlet of an air conditioning apparatus. 
     The invention also relates to a vehicle comprising an air conditioning device according to the invention fitted into the instrument panel of the vehicle so that the air emitted by the air conditioning apparatus travels to the windshield frieze and to the side outlets. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Other features and advantages of the invention will clearly appear on reading the following description of the nonlimiting embodiment of the latter, with reference to the appended drawings in which: 
         FIG. 1  is a three-quarter top and rear view in perspective of an instrument panel adapted to receive a device according to the invention, 
         FIG. 2  is a three-quarter rear view in perspective of a distribution housing according to the invention, 
         FIG. 3  is a three-quarter front view in perspective of the housing of  FIG. 2 , 
         FIG. 4  is a view in section of the housing of  FIG. 3  along the section IV-IV, 
         FIG. 5  is a view in section of the housing of  FIG. 3  along the section V-V, 
         FIG. 6A  is a three-quarter top and rear view in perspective of the network of ducts and of the side ducts, 
         FIG. 6B  is a diagram showing the air flow in the pipes according to a first embodiment, 
         FIG. 7  is a diagram showing the air flow in the pipes according to a second embodiment, 
         FIG. 8  is a diagram showing the air flow in the pipes according to a third embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     In the following description, the direction designated L is the longitudinal direction corresponding to the axis of travel of a vehicle, the direction designated T is transverse, the direction designated V is vertical. The axis L is oriented from the front to the rear of the vehicle, the axis T from left to right and the axis V from bottom to top. Furthermore, the elements will be designated according to their position in the air flow, the air therefore passing by elements called “upstream” before passing by elements called “downstream”. 
     Conventionally, as shown in  FIG. 1 , a motor vehicle is fitted with a driving position comprising an instrument panel  10  and an air conditioning apparatus hidden from the view of a user by the instrument panel  10 . The air conditioning apparatus is designed to deliver air to the passenger compartment, heated if necessary, and even cooled in certain cases. 
     For the defrosting or demisting of the windshield, the air comes out into the passenger compartment through a defrosting frieze  14  arranged in the instrument panel  10 . In this context a frieze, also referred to as a strip, is a wide central opening. For the defrosting or demisting of the front side windows, the air comes out into the passenger compartment through side outlets  16  arranged in the instrument panel  16 . 
     The defrosting frieze  14  and the side outlets  16  are connected to the air conditioning apparatus by means of a network of ducts. In particular, they are connected to a single defrosting outlet through which provision is made for the apparatus to deliver the air intended for defrosting or demisting. 
     Air vents  18  are also arranged in the instrument panel  10  for the comfort of the occupants. The air vents  18  are also connected to at least one air vent opening of the air conditioning apparatus via pipes. 
     Here, the defrosting frieze  14  is placed substantially in the middle of the windshield. It extends in the transverse direction. In the example shown, the length of the frieze represents substantially a quarter to a third of the transverse extent of the panel. In order to optimize the air flow onto the windshield, the frieze  14  comprises two orifices  22  that are transversely distant from one another. The orifices  22  are each furnished with a grille. The distinct, independent, separated and transversely offset orifices  22  make it possible, while having a central frieze, to correctly distribute the blowing of air in the zones of the windshield through which the driver must be able to see to drive. 
     A transverse cover  24  separates the grilles. In the example shown, the cover  24  delimits a hole in correspondence with a sunlight sensor  26 , the measurement of which sunlight is used by the air conditioning apparatus. 
     A distance of approximately sixty to seventy centimeters separates the outlets  16  from the middle of the opening  20  of the apparatus while a distance of ten to twenty centimeters separates the opening  20  from the frieze  14 . The section of the pipes connecting the opening  20  to the outlets  16  is different from that of the pipes connecting the opening  20  to the openings  22  of the frieze  14 . The pressure loss in the pipes connecting the opening  20  to the outlets  16  is different from that in the pipes connecting the opening  20  to the openings  22  of the frieze  14 . 
     The rate of air flow for the defrosting function must be substantially distributed in the following manner: 60% to 90% for the frieze  14 , 5% to 20% for each of the outlets  16 , since, in the example described, the distance between the frieze and the zones of the windshield to be defrosted is substantially equal to the distance between each outlet and the corresponding side window. 
       FIGS. 2 and 3  represent a distribution housing  30  for the air flow generated by the air conditioning apparatus. 
     It is possible to distinguish two portions of this distribution housing  30 , a first portion called the upstream portion  31  and a second portion called the downstream portion  32 . Usually, this distribution housing  30  is placed in the instrument panel  10  substantially vertically, such that the upstream portion  31  may be designated as lower and the downstream portion  32  may be designated as upper. 
     In its upstream portion  31 , the distribution housing  30  has an inlet  33  which interacts with an outlet of the air conditioning apparatus. 
     In its downstream portion  32 , the distribution housing  30  has first outlets  34  and a second outlet  35 . 
     The first outlets  34  are placed in the upper portion  32  of the housing  30 , laterally on either side of the second outlet  35  and cooperate with ducts of the frieze  14  of the windshield. 
     The second outlet  35  is placed generally in the center of the upper portion  32  of the distribution housing  30  and interacts with side ducts  28  which make it possible to carry the air to the side outlets  16 . 
     Generally, on a plane V-T, the distribution housing has a flared shape delimited by side walls  36 , the dimensions of the inlet orifice  33  being reduced relative to the dimensions of all of the first outlets  34  and the second outlet  35  situated in the upper portion  32 . 
     The distribution housing  30  is substantially symmetrical relative to the plane L-V passing through the center of the second outlet  35 . 
     The distribution housing  30  has a differentiated profile along this plane L-V between a central zone and the side zones of the housing  30 , and in particular the profiles of the first walls and second wall which extend sideways between the side walls  36  of the housing. These first and second walls extend substantially parallel with one another. 
       FIG. 4  shows a section of the distribution housing  30  at one of its side zones, along the axis IV-IV. In the side zones, the first walls  37 L and second wall  38 L have an S-shaped profile with a first and a second curvature. 
     The first curvature extends generally in the upstream or lower portion  31  of the housing  30 . This curvature forms a concavity on the outer face of the first wall  37 L, which, when the housing  30  is situated in the instrument panel  10 , is placed in front of the second wall  38 L. 
     The second curvature extends generally in the downstream or upper portion  32  of the housing  30 . This curvature forms a concavity on the outer face of the second wall  38 L, which, when the housing  30  is situated in the instrument panel  10 , is placed above the first wall  37 L. 
     The first curvature makes it possible to carry the air to the front and the upper portion of the instrument panel  10  from the air conditioning apparatus which is usually situated in the lower portion and behind the instrument panel  10 . 
     The second curvature makes it possible to carry the air to the first outlets  34  and to direct the air flow toward the defrosting frieze  14 . 
     The radii of the first and second curvatures are adapted to limit the pressure losses. 
       FIG. 5  shows a section of the distribution housing at the central zone along the axis V-V and in particular at the first walls  37 C and second wall  38 C of the distribution housing  30 . 
     In this central zone and in its upstream portion  31 , the distribution housing  30  has a curvature similar to the first curvature formed in the side zones but differs in its downstream portion  32 . 
     In this portion  32 , the first wall  37 C and second wall  38 C extend generally parallel and in a rectilinear manner relative to one another. When the housing  30  is situated in the instrument panel  10 , the first wall  37 C is situated beneath the second wall  38 C. 
     This downstream portion  32  of the distribution housing  30  is in its central zone, with no chicane or other obstacle to flow and makes it possible to increase the air flow to the side ducts  28  and therefore to the side outlets  16 . 
     During the use of a distribution housing according to document FR2876958, the air flow is distributed at substantially approximately 85% for the windshield frieze, also distributed between the driver and the passenger, and approximately 7.5% on each side outlet. With a distribution housing  30  according to the invention, a relative increase of between 15 and 30% of the air flow is obtained in the side outlets  16 . 
       FIG. 6A  shows the positioning of the side ducts  28  on the distribution housing  30 . These side ducts  28  have a common inlet  28 E which interacts with the second outlet  35  of the distribution housing  30  and two portions which extend sideways on either side of the housing  30  toward the side edges of the instrument panel  10  until they emerge at the side outlets  16 . 
     In its upper portion  32 , the distribution housing  30  has duct-separating walls  39 . 
     The first, side, pipes  34  are then delimited by the first wall  37 L and second wall  38 L in the plane V-L and by the side walls  36  and the duct-separating walls  39  of the housing  30  in the plane V-T, and extend to the first outlets  34 . 
     The second, central, pipe  35  is then delimited by the first wall  37 L and second wall  38 L in the plane V-L and by the duct-separating walls  39  of the housing  30  in the plane V-T, and extends to the second outlet  35 . 
     The flow is then divided into three pipes, first side pipes  34  being two in number and a second single central pipe  35 . 
       FIG. 6B  shows schematically the air flows travelling in the various pipes of the distribution housing  30  according to a first embodiment. 
     According to this first embodiment, the duct-separating walls  39  extend, from upstream to downstream, substantially parallel with one another. 
     At the outlet to the side ducts  28 , the second central pipe  350  comprises a baffle  40  which extends sideways between the duct-separating walls  39  at the front walls of the side ducts  28 . The purpose of this baffle  40  is to divide, in a substantially equal manner, the central air flow to the side ducts  28 . According to this first embodiment, the flow is divided by a convexity  41  directed downstream placed substantially half-way between the two duct-separating walls  39 . 
     Advantageously, the ridges of the convexity  41  are rounded in order to optimize the flow of air. 
     Since the flow is separated into two portions as far downstream as possible, the duct-separating walls  39  can be brought closer together which arranges an additional space for directing the flow. Furthermore, bringing the walls  39  closer together makes it possible to increase the size of the first side pipes  340  and consequently the air flow onto the windshield. 
     Consequently, the radius of curvature of the trajectory of the flow is reduced, the flow of the air is less constricted, the pressure loss is reduced, which makes it possible to increase the air flow captured in the side ducts  28 . 
       FIG. 7  shows schematically the air flows travelling in the various pipes of the distribution housing  30  according to a second embodiment. 
     This second embodiment differs from the first by the change in the baffle  400  placed in the second central pipe  350 . The baffle  400  has an additional air-passage orifice  420  situated substantially half-way between the two duct-separating walls  39  and around which two convexities  410  in the upstream direction are formed. 
     Advantageously, the ridges of the convexities  410 ,  411  are rounded to optimize the flow of air. 
     The additional orifice  420  interacts with an additional windshield defrosting duct. This additional duct makes it possible to defrost the windshield in its central portion. 
     By virtue of this additional orifice  420 , the air flow on the windshield is better distributed than in the first embodiment, the air flow on the windshield coming from the first two side pipes  34  but also from the additional central duct  421 . 
       FIG. 8  shows schematically the air flows travelling in the various pipes of the distribution housing  30  according to a third embodiment. 
     According to this embodiment, the dimensions of the first side pipes  36  are reduced to the detriment of the first central pipe  350  by a transverse positioning of the duct-separating walls  39  closer to the side walls  36  of the housing  30  than in the first two embodiments. The duct-separating walls  39  form an angle approaching the angles of the side walls  36  of the housing  30 . 
     The second central pipe  350  accommodates an additional widened duct  4200 . This additional duct  4200  is delimited by additional walls  430 A,  430 B. The duct-separating walls  39  and the additional walls  430 A,  430 B extend over a substantially equal length. 
     Curve-shape baffles  4000  connect the upstream ridges  431 A,  431 B of the additional walls  430 A,  430 B to their respective side ducts  28 . The curvature of these baffles  4000  makes it possible to direct the air flow in the side ducts  28  progressively in order to limit the pressure losses. 
     This embodiment is particularly suited to a defrosting frieze  14  in three portions, for defrosting of the windshield that is increased in its central portion. 
     As a variant, it is possible to provide that the upstream ridges  431 A,  431 B of the additional walls  430 A,  430 B are rounded so as to limit the resistances to the flow of air. 
     With reference to manufacture and assembly, the distribution housing  30  may be made in two elements: a first element  310  forming a duct and a second element  320  which is included in the instrument panel  10 . The second element  320  then forms a cover to close off the housing  30  by inserting a seal between these two elements  310 ,  320 . 
     Advantageously, if the profile of the faces of the elements is not very angular, a simple straight seal may be bonded to at least one of the elements  310 ,  320  in order to achieve the seal. 
     According to a first variant embodiment, the duct-separating walls  39  and/or the additional duct walls  430 A,  430 B can be moved in translation and/or in rotation so as to change the proportion of the air flow between the outlets of the distribution housing  30 . As shown in  FIG. 8 , dotted lines represent the position of walls  430  as they may be rotated. 
     According to a second variant embodiment, the second central pipe  350  directing the air to the second outlet  35  situated in the center of the distribution housing  30  may be formed by an element independent of the other elements of the housing  30 . 
     According to a third variant embodiment, ribs for guiding the air may be placed on the front inner wall of the upstream portion of the housing  30  in order to increase the air flow travelling in the second central pipe  350 .