Vehicle air conditioning apparatus with two mixing zones

p0001The invention relates to a heating / ventilating or air conditioning the cabin of a vehicle.

p0002It is sometimes desired for optimal and personalized comfort of the occupants of the vehicle, to send into different occupation zones air whose temperature is set independently.

p0003In particular, it is desired to send, in at least one area of ​​the front seats and into at least one area of ​​the rear seat, air at controlled temperature independently. The known installations allowing adjustment of the temperatures in the different areas have a hot-air channel situated between an upper cold-air channel and a lower channel of cold air. The upper channel and the lower channel open out respectively into an upper air-mixing region, supplying treated air the front region of the vehicle by means of distribution ducts, and into a lower air-mixing region, supplying treated air the rear region via rear ducts.<patcit id="pcit0001" dnum="FR2778152A"><text>FR 2778152 A</text></patcit> describes such an installation, and discloses in housing containing means for processing a flow of air delivered into the cabin, the said means comprising at least a first source of heat or of cold and switching elements controlled to define variable paths for said airflow between at least one inlet and various outlets associated with respective regions of the passenger compartment, the housing defining a first mixing zone connected to at least one of said outlets and a second area of mixing connected to at least another of said outputs, each of said mixing zones being able to receive in adjustable proportions a first airflow having passed through said first source and a second airflow having bypassed thereof. The document<patcit id="pcit0002" dnum="DE19739578"><text>DE 197 39 578</text></patcit> discloses all features of the preamble part of claim 1.

p0004The presence of the cold air channel upper lengthens the path of the hot air between the heating radiator and the de-icing outlet, which is located in the upper housing part, and therefore the time required for air to reach this output. However, the speed of access of hot air to defrost output is an important element when defrost or quick demisting is required for security reasons.

p0005The object of the invention is to shorten the path of the air between the heater core and the defrost output, and more generally between the primary source of heat or cold and outputs associated with the first mixing zone.

p0006The invention is particularly an installation of the type defined in the introduction and provides that said second air flow bypass both the first source from below.

p0007Optional features of the invention, complementary or alternative, are set out below:<ul><li>The first mixing zone is connected to at least one outlet associated with a front region of the passenger compartment and the second mixing zone is connected to at least one outlet associated with a rear region of the passenger.</li><li>Said first source is a heat source and the processing means further include a cold source that said first and second airflow through before crossing or bypass the heat source.</li><li>The housing defines a single bypass line below the first source and means for subdividing, in the lateral direction of the housing, a second air flow that has passed through said bypass line into at least one first fraction directed towards the first mixing region and a second fraction directed towards the second mixing zone.</li><li>Said means for subdividing the second airflow comprise a first substantially vertical partition laterally juxtaposed with the second mixing region.</li><li>The housing defines below the first source a first bypass pipe connected to the first mixing region and a second bypass line leading to the second mixing region, mutually juxtaposed in the lateral direction of the housing, the second bypass duct and the second mixing region being separated from the first bypass duct by a first substantially vertical partition.</li><li>Said second bypass line comprises a flap movable between an extreme position closing off the inlet of said second duct and another extreme position where it prevents access by the air to a part of the first source.</li><li>Said flap extends continuously in the housing to move between an extreme position for simultaneous closing of the first bypass duct and the second bypass duct and another extreme position where it prevents access of air a portion of the first source.</li><li>Said flap is constituted by at least two flaps, said flaps may move independently between an extreme position during which it closes simultaneously a part of the first bypass duct and part of the second bypass duct and another extreme position where it prohibits the access of air to a portion of the first source. </li><li>Said flap is constituted by three components, two of these components can move independently between an extreme position during which it closes off a part of the first bypass duct and another extreme position where it prevents the access of air to a portion the first source, the third component can move independently between an extreme position during which it closes off the second bypass duct and another extreme position where it prevents access by the air to a part of the first source.</li><li>Said first partition is connected to an intermediate wall and passes through an outer wall both extending in the lateral direction and delimiting the bypass or the pipes, the intermediate wall separating these from the first source.</li><li>Said intermediate wall is able to provide thermal insulation between the first source and the inside of the or bypass pipes.</li><li>The first mixing zone has an extent in the lateral direction coinciding substantially with that of the bypass duct or of the set of bypass ducts and is separated from the second mixing zone by a second partition extending in the same direction and adjoining the first wall.</li><li>The housing comprises a main body housing the first source and defining the first or only bypass duct, and at least one attached part forming the first and second partitions and defining an outlet duct extending outside the main body until said another output.</li><li>The first and second mixing regions communicate with a single volume situated immediately downstream of the first source.</li><li>The first and second mixing regions communicate with respective volumes situated immediately downstream of the first source on either side of a partition wall extending in the lateral direction.</li><li>Said partition wall is formed by said insert.</li><li>Said dividing partition is able to pivot about a substantially horizontal axis for varying the relative size of said respective volumes.</li><li>The housing is substantially symmetrical about a vertical plane and defines at least a second mixing zone situated in a central position and, on either side thereof, at least an outlet pipe left and at least one line Release right connected downstream of the first mixing region.</li><li>The housing is substantially symmetrical about a vertical plane and defines at least one outlet duct connected downstream of the first mixing zone and situated in a central position and, on either side thereof, a second zone left and second right mixing zone mixing.</li><li>The housing defines below the first source a single bypass line connected to the first mixing zone, the bypass duct and the first mixing zone having an extent in the lateral direction which coincides substantially with that of the first source, and at least a first bypass and a second bypass line starting respectively from a volume situated immediately downstream of the first source and from the bypass duct to lead to the second mixing zone, said bypass lines and the second mixing zone being laterally offset from the first source.</li><li>The housing defines below the first source a first bypass duct connected to the first mixing region and a second bypass line leading to the second mixing zone and situated below the first bypass duct.</li><li>Said bypass conduits and said mixing regions feature an extent in the lateral direction which coincides substantially with that of the first source, the housing further defining below the first source at least a bypass line beginning at a volume immediately downstream of the first source to lead to the second mixing region, said bypass duct being laterally offset from the first source.</li><li>Is provided to adjust the flow of the first air flow at the inlet of the first mixing region a specific component to pivot about an axis located within the latter, this flap having a cylindrical shape generatrix parallel to said axis and having in cross section a middle region in the form of a circular arc centered on the axis, joined to two marginal regions that deviate from the axis, the said marginal regions coming to bear on a separating wall to define a sealed closed position of the flap.</li></ul>

p0008The characteristics and advantages of the invention will be discussed in more detail in the following description, with reference to the accompanying drawings.

p0009The <figref idrefs="f0001">figure 1</figref> is a schematic sectional view along line II of <figref idrefs="f0003">5</figref>Showing the housing of an air conditioning installation according to the invention and the essential ingredients thereof.

p0010The <figref idrefs="f0001">2</figref> is a sectional view according to line II-II of <figref idrefs="f0003">5</figref>.

p0011The <figref idrefs="f0002">Figures 3 and 4</figref> are views similar to <figref idrefs="f0001">figure 1</figref>Showing modified housings which can be obtained by a minor adjustment of the tooling used to manufacture the housing shown in <figref idrefs="f0001">figure 1</figref>.

p0012The <figref idrefs="f0003">5</figref> is a schematic section along the line VV <figref idrefs="f0001">figure 1</figref>.

p0013The <figref idrefs="f0003">Figures 6 and 7</figref> are views similar to <figref idrefs="f0003">5</figref>Showing the housings <figref idrefs="f0002">Figures 3 and 4</figref> respectively.

p0014The <figref idrefs="f0004 f0005 f0006 f0007 f0008 f0009">Figures 8 to 15</figref> are views similar to <figref idrefs="f0001">figure 1</figref>, Relating to installation variations.

p0015The <figref idrefs="f0010">16 to 18</figref> are views similar to <figref idrefs="f0003">5</figref>Relating to other variants.

p0016The <figref idrefs="f0011">Figure 19</figref> is a view similar to <figref idrefs="f0001">2</figref>, Relating to another installation according to the invention.

p0017The <figref idrefs="f0012 f0013 f0014">Figures 20-24</figref> are details of the <figref idrefs="f0011">Figure 19</figref> showing changes in the installation.

p0018The <figref idrefs="f0015">Figure 25</figref> is a view similar to <figref idrefs="f0011">Figure 19</figref>Showing other modifications.

p0019The <figref idrefs="f0016">figures 26</figref> and <figref idrefs="f0017">27</figref> are views similar to <figref idrefs="f0001">Figures 1 and 2</figref> respectively, relating to another installation according to the invention.

p0020In the present description, the term "continuous" refers to a component which extends substantially over the entire width of the housing in the left-right direction of the vehicle, and thus can not practically be laterally bypassed by the air flow flowing therein.

p0021The installation shown in <figref idrefs="f0001">Figures 1, 2</figref> and <figref idrefs="f0003">5</figref> 1 includes a blower capable of circulating an airflow in a pipe 2, a filter 3 and an evaporator 4 disposed in the pipe 2, and a 5 Heating radiator disposed downstream of the evaporator in the path of flow 'air. These components, as well as partitions and pivoting flaps which will be described later, are housed in a case main body 6. The radiator 5 is continuous and extends substantially from an upper wall 7 to an intermediate wall 8, themselves continuous. The intermediate wall 8 defines, with a bottom wall 9 of the body 6, a conduit continuously bypass 10 that passes below the radiator 5. The radiator 5 is oriented such that its front face 5a or entrance face of air and its rear face 5b or air outlet side forms a small angle with the vertical. The top wall 7 extends towards the rear of the radiator, and the intermediate wall 8 also extends rearwardly up opposite the face 5b, to a horizontal top edge 11. The walls 7 and 8 define between therebetween a volume 12 adjacent the face 5b, communicating by an opening 13 with a first mixing zone 14. the opening 13 is continuous and extends in height from the edge 11 to the level of the wall 7.

p0022The wall 9 also extends to the rear of the radiator 5 in a curve upward to delimit the extension of the intermediate wall 8 a rear duct 15 which communicates with the bypass line 10 and leads to the mixing zone 14 .

p0023A continuous wall 16 extends downwardly from the top wall 7, between the evaporator 4 and the front face 5a of the radiator, its lower edge 16a located at a certain distance above the front edge 17a of a continuous wall 17 which extends forwardly from the face 5a. The interval between the edges 16a and 17a may be closed or released by a mixing flap 18 butterfly. The flap 18 is controlled in synchronism with another mixing flap 19 of the flag type, mounted pivoting about an axis extending along the edge 11, between an extreme position, shown in solid lines<figref idrefs="f0001">Figures 1 and 2</figref>, In which it closes the opening 13, and another extreme position in which it closes the outlet line 15 to the mixing region 14. Another part 20 of the flag type, continuous as the shutters 18 and 19, whose axis of rotation is close to the edge 11 and the opposite edge is close to the face 5b, subdivided volume 12 unsealed manner between a sub-volume 12a upper and lower sub-volume 12b.

p0024As seen in <figref idrefs="f0003">5</figref>, Continuous mixing region 14 communicates upwards with a central outlet pipe 25 containing a throttle valve 26 and leading to a defroster outlet 27, and the left and right output lines 28 containing adjusting flaps 29 and leading to the outputs 30 for aeration of the left and right portions of the vehicle cabin.

p0025Similarly, the mixing region 14 communicates downwardly with left outlet ducts and right 31, which pass back to the line 15 containing adjusting flaps 32 and leading to various outlets 33 serving the seats base areas front of the vehicle.

p0026The installation housing comprises besides the main body 6, an insert 40 which has the general shape of a variable rectangular section tube. The part 40 extends over a middle portion of the width of the housing intermediate between the lower outlet ducts 31. The tube 40 is oriented substantially in the front-rear direction, its front end 41 entering into an opening 42 formed for this purpose in the partition 8, so that the tube communicates with the sub-volume 12b. The tube 40 is composed of an upper wall 43, a bottom wall 44 and vertical left and right walls 45, 46, the walls 43, 45 and 46 extending from the edges of the opening 42 in the end back 47 of the tube, forming an outlet opening, and through an opening 48 provided therefor in the outer wall 9 of the body 6 and the wall 44 extending from the lower edge of the opening 48 at the rear end 47. the interior of the tube 40 communicates so, firstly with the sub-volume 12b through the opening 42, on the other hand with the bypass line 10 through an opening 50 extending from the lower edge of the opening 42 and the front edge of the wall 44. the interior of the tube thus forms a second mixing region 51 may receive air heated by the radiator 5 and unheated air from line 10. a shutter mixer 52 housed in the box 51 can move between an extreme position indicated in solid lines in<figref idrefs="f0001">figure 1</figref>, In which it closes the inlet heated air, and an extreme position indicated in broken lines in which it closes the cold air inlet. The mixed air exiting the outlet 47 is sent to a region of the passenger other than those served from the mixing zone 14, for example to the rear seats.

p0027The invention allows to independently adjust the temperature of the air in the two mixing regions, while providing a hot air path towards the opening of 27 defrost shortest possible given the space reserved in the housing the vehicle.

p0028To achieve the mixing zone 14, cold air from the duct 10 passes laterally on either side of the piece 40. The shutter 20, depending on its position, allows to convey the hot air or in part to the mixing zone 14 and partly towards the mixing zone 51 or in whole to the mixing zone 14.

p0029The <figref idrefs="f0002">Figures 3, 4</figref>, <figref idrefs="f0003">6 and 7</figref> non-compliant facilities illustrate the invention and show that we can get by the fittings minors of the same tool, a housing for installation according to the invention and cases for simplified installations for other versions a same base vehicle.

p0030Specifically, for these other facilities, the mold used for making the main body 6 of the case is changed by removal of detachable parts, to remove the openings 42 and 48, the patch 40 is also removed and the flap 52 mounted therein and the flap 20. the air from both the volume 12 located downstream of the radiator 5 that the bypass pipe 10 only reaches the mixing region 14.

p0031In the case of the housing <figref idrefs="f0002">figures 3</figref> and <figref idrefs="f0003">6</figref>Another amendment allows the mold to provide an opening 60 at the base of the zone 14 between the two pipes 31, which is mounted on an insert 61 defining an outlet pipe which can be connected to the interior of the same manner as the tube 40. This simplified setup is used for supplying the same areas of the passenger compartment as described above, but with air at the same temperature as supplying the other areas.

p0032In the case of <figref idrefs="f0002">figures 4</figref> and <figref idrefs="f0003">7</figref>On the contrary, the opening 60 and the workpiece 61 do not exist. This leads to an even simpler installation with only the outlet lines 25, 28 and 31.

p0033The <figref idrefs="f0004">figures 8</figref> and following illustrate new air conditioning systems according to the invention.

p0034In the housing of the <figref idrefs="f0004">8</figref>, The insert 40 described in connection with the <figref idrefs="f0001">figures 1</figref> and <figref idrefs="f0003">5</figref> is replaced by a part 70 defining a further tube 71 extending as above the opening 42 to the outlet opening 47, another pipe 72 connecting to the tube 71 and engaging the bypass duct 10 of which it occupies the full height until its upstream end. The tube 72 has for this purpose an upper wall 73 adjacent to the intermediate wall 8, and a bottom wall 74 adjacent the bottom wall 9 of the body 6 of the housing interconnected by extensions forward vertical side walls 45 , 46 (<figref idrefs="f0003">5</figref>). The mixing flap 52 is replaced by a flag flap 75 mounted on the workpiece 70 at the upstream end of the tube 72 and movable between an extreme position in which it closes the inlet thereof and another extreme position where it prohibits the access of air to the part of the input face 5a of the radiator 5 located below the partition 17.

p0035The installation shown in the <figref idrefs="f0005">8A</figref> is an alternative design of the <figref idrefs="f0004">8</figref>. Indeed, the flap 19 is deleted in favor of the flap 75 which can be broken down into three versions. This component is represented at 75<figref idrefs="f0005">8A</figref>, <figref idrefs="f0006">8B and 8C</figref> connected to the flap 18 so that their movements are conducted in the same time. Also shown on this figure, the partitions 17 and 73 defining the first and second leads 10 and 72 and the inlet to the radiator 5.

p0036The <figref idrefs="f0006">8B</figref> and more particularly illustrates schematically the basic version of the flap 75 which extends over the entire width of the housing 6 so as to simultaneously close off the first bypass duct 10 and the second bypass duct 72. The shutter 75 moves from one extreme position in which it closes simultaneously the first bypass line 10 and the second bypass duct 72 to another extreme position where it prevents access by the air to a part of the radiator 5 (position represented in broken lines) .

p0037A second version of flap 75, shown in <figref idrefs="f0006">8C</figref>Advantageously employed in a system with two independent temperature zones, it is split to form two flaps 75a and 75b, coaxial or not, having the ability to simultaneously close off a portion of the first bypass duct 10 and a portion of the second bypass line 72. the temperature of the air flowing in the second bypass line 72 is then a function of the opening of the flaps 75a and 75b. The latter move from one extreme position in which they close simultaneously a part of the first bypass duct 10 and a portion of the second bypass duct 72 to another extreme position where it prevents access by the air to a part of the radiator 5 (position represented in broken lines).

p0038In a third version of the component 75 illustrated in <figref idrefs="f0006">8D</figref> and used advantageously in systems with three independent temperature zones, it is split into three independent entities 75a, 75b, 75c, coaxial or not. Two of these entities 75a and 75b manage the flow of air to be circulated in the two parts of the first conduit 10 located bypass each side of the second bypass line 72. The latter is in turn closed more or less by the third 75c entity of the flap 75. the entity 75a moves from one extreme position in which it closes a part of the first bypass duct 10 to another extreme position where it prevents the access of air to a radiator portion 5 (position represented in broken lines). The entity 75b moves from one extreme position in which it closes a part of the first bypass duct 10 to another extreme position where it prevents access by the air to a part of the radiator 5 (position represented in broken lines interrupted). The entity 75c moves from an extreme position in which it closes off the second bypass duct 72 to another extreme position where it prevents access by the air to a part of the radiator 5 (position represented in broken lines). In the case of designs illustrated in<figref idrefs="f0006">Figures 8C and 8D</figref>, It is understood that the flaps 75a, 75b and 75c may be coaxial with the set of axes 97 and 98 of different diameters threaded one inside the other. However, these axes may also not be confused by arranging them in two or three different points in order to solve congestion problems architecture of the installation.

p0039The installation of the <figref idrefs="f0004">9</figref> differs from that of the <figref idrefs="f0004">8</figref> in that the tube 72 of the insert 70 is shorter and extends only over part of the length of the bypass duct 10. The mixing flap 75 is replaced by two shutters butterflies 76, 77 which may close or respectively release the tube inlet 72 and the opening 42.

p0040The installation shown in <figref idrefs="f0007">Figure 10</figref> differs from that of the <figref idrefs="f0001">figure 1</figref> in that the mixing flap 19 of the flag type is replaced by a flap 80 butterfly type which can close or open the passage opening 12a between the sub-volume and the mixing zone 14, but can not close the outlet the cold air duct 15 to this same area. This is added another 81 own butterfly flap to seal or release the entrance to the bypass line 10.

p0041The installation shown in <figref idrefs="f0007">11</figref> differs from that of the <figref idrefs="f0001">figure 1</figref> by removing the partition 17 and flaps 18 and 20, and by the addition of a valve 82 for interrupting the hot fluid circulating in the radiator 5.

p0042The system in accordance <figref idrefs="f0008">Figure 12</figref> differs from that of the <figref idrefs="f0001">figure 1</figref> in that the flag flap 20 between 12a subvolumes and 12b is replaced by a fixed partition 83 belonging to the main body 6 of the casing.

p0043In the installation of the <figref idrefs="f0008">13</figref>, The same component is also replaced by a fixed partition 84, which belongs to this time the insert 40 and is formed by an extension of the top wall 43 thereof. The bottom wall 44, beyond opening 50, and the side walls 45 and 46 (<figref idrefs="f0003">5</figref>) Are also extended inside the volume 12, so as to define a tube 40 to the opening 85 hot air inlet adjacent to the output face 5b of the radiator. The sub-volume 12b connected to the mixing region 51 is therefore located inside the tube 40 and thus extends across the width thereof, and not over the entire width of the housing. In this variation, the partition 17 and the flap 18 are also removed.

p0044The system in accordance <figref idrefs="f0009">Figure 14</figref> differs from that of the <figref idrefs="f0001">figure 1</figref> by striking flap 20, and by replacing the insert 40 by at least one insert 86 fixing externally on one of the side faces 88 (<figref idrefs="f0003">5</figref>) Of the main body 6 of the case. The openings 42, 48 provided for the passage of the part 40 are also removed, and other openings 89, 90 are formed in the wall 88 adjacent to the volume 12 and to the bypass duct 10 respectively. The part 86 is therefore situated outside the lateral extent of the body 6 and defines a hot air inlet pipe 91 adjacent the opening 89, a cold air duct 92 adjacent the inlet 90, a mixing region 93 containing a mixing flap 94 for the metered mixing of the airflows from the two pipes, and an outlet pipe 95 from the area 93 to an outlet opening 96. in this variant, the air cold flows to the upper mixing region 14 continuously over the entire width of the body 6. Advantageously, there are provided two inserts 86 mounted on either side of the body 6 and air feeding Treaty different areas of the cockpit. 94 corresponding mixing of the components can be controlled independently from each other for differential temperature control.

p0045Found on the <figref idrefs="f0009">Figure 15</figref> an insert 40 similar to the <figref idrefs="f0001">figure 1</figref>Which passes through this time sealed manner not only the outer wall 9 delimiting the ducts 10 and 15 but also the front and rear walls 100, 101 a DC output line 102 replacing the left and right output lines 31 of the <figref idrefs="f0003">5</figref>.

p0046The <figref idrefs="f0010">Figure 16</figref> shows a configuration of the lower outlet ducts inverted with respect to that of the <figref idrefs="f0003">5</figref>, The left and right ducts 110, defined by respective inserts 111, similar to the part 40 and housing respective mixing flaps, framing a single line 112 defined by the main body 6 of the casing and connected to the upper mixing region 14. in the example shown, the line 112 is connected to two lateral outlet openings 113 and to a center outlet opening 114.

p0047In the embodiment of the <figref idrefs="f0010">Figure 17</figref>, The insert 40 is modified to define, in addition to a central outlet duct 120, two outlet pipes 121, 122 disposed laterally on either side thereof, these three pipes being connected to the same mixing zone 51 (<figref idrefs="f0001">figure 1</figref>). The side outlet pipes 31 of the body 6 are narrowed to accommodate the part 40 and expanded.

p0048In the variant of the <figref idrefs="f0010">Figure 18</figref>, The insert 40 is similar in its outer configuration to that of <figref idrefs="f0001">figures 1</figref> and <figref idrefs="f0003">5</figref>But the tube it defines is divided internally over its entire length, by a vertical partition 124. On either side of the partition 124 are formed two mixing regions containing respective mixing flaps 125, 126, and two outlet ducts intended to serve left and right areas of the cabin. The housing body 6 is also divided by a median vertical partition 127, on either side of which are defined two mixing regions 128, 129, replacing the mixing region 14 and containing respective mixing flaps 130, 131, and two outlet pipes 132, 133 replacing the conduit 25 and containing respective settings panes 134, 135.

p0049The housing 200 of the installation subject of the <figref idrefs="f0011">Figure 19</figref> contains a blower 201, an evaporator 202 and a heater core 203, the relative arrangement is similar to that illustrated in <figref idrefs="f0001">figure 1</figref>. On the downstream side 203b of the radiator 203 is further provided an auxiliary heat source 204 such as an electrical resistance with a positive temperature coefficient. The housing 200 defines, below the radiator 203, two superimposed bypass pipes, namely a conduit 205 defined by an intermediate wall 206 adjacent to the radiator and by a bottom wall 207, and a conduit 208 disposed below the driving 205. the walls 206 and 207 are curved rearwardly and upwardly to define an upward downstream portion 209 of the conduit 205 leading to a first mixing zone 210. the mixing zone 210 is located immediately behind the upper half of the volume of hot air 211 adjacent to the side 203b, and can be separated from this volume or in communication therewith by a mixing flap 212 of curvilinear shape and offset from its axis of rotation 213 located within the area 210.

p0050Line 208 leads to a second mixing zone 214 which is also connected to the volume 211 via one or two hot air ducts 215 which laterally bypass line 205-209, and which communicate with the volume 211 by an opening 216 formed in the wall 206 and adjacent the lower part of the volume 211. the opening 216 may be closed or released by a drum flap 217 housed in the volume 211. another drum flap 218 is used to block either the input line 205, namely access to the lower half of the upstream face 203a of the radiator 203. the mixing zone 214 comprises a mixing flap 219 of the butterfly type and is connected to an outlet opening 220 which acts same function as the outlet opening 47 of the installation of the <figref idrefs="f0001">figure 1</figref>. In addition, the air mixed in the zone 210 can be sent to various outlet conduits upper 221, 222, 223 provided with adjusting flaps 224, 225, 226.

p0051The <figref idrefs="f0012">Figure 20</figref> is a partial view of a variant of the installation of the <figref idrefs="f0011">Figure 19</figref>In which the butterfly valve 225 controls the entry of line 222 is replaced by a flag flap 227 similar to component 226 that controls the entrance to the pipe 221.

p0052In the variant of the <figref idrefs="f0012">Figure 21</figref>, The drum flap 218 of the <figref idrefs="f0011">Figure 19</figref>, Whose concavity is turned towards the front, is replaced by a drum flap 228 having the same function and whose concavity is turned towards the rear.

p0053In the variant of the <figref idrefs="f0013">Figure 22</figref>Is the mixing flap 212 is replaced by a drum flap 230 which can either block the passage between the volume of hot air 211 and the mixing area 210, being placed in the extension upwardly and forward wall 206, or free passage in fading over the top wall 231 of volume 211.

p0054On the <figref idrefs="f0013">Figure 23</figref>, The drum flap 218 is replaced by a flag flap 232 which can move between an extreme position in which it closes the inlet of the bypass line 205 and an extreme position where it covers the lower half of the entrance face 203a of the radiator 203.

p0055In the variant of the <figref idrefs="f0014">Figure 24</figref>, The drum flap 218 is replaced by a curvilinear butterfly flap 230 which can close or open the entrance to the bypass duct 205. The mixing valve 212 is removed, so that the mixing zone 210 is always fed with air through the radiator 203. It is necessary to provide a valve for interrupting the supply of the radiator 203 in heat transfer fluid when the area 210 does not receive hot air.

p0056The installation shown in <figref idrefs="f0015">Figure 25</figref> essentially repeats that of the elements of the <figref idrefs="f0011">Figure 19</figref>, The differences being outlined below. The provision of driving compared to 223 lines 221 and 222 is changed, and the associated component 226 is removed. The shape of the mixing flap 212 is changed, and it contains its axis of rotation 213. In the extreme position it enables a maximum hot air flow to the mixing zone 210, it blocks the cold air supply to thereof from the driver 209. Finally, an opening 240 adjacent the upper edge of the front face 203a of the radiator 203, controlled by a drum flap 241, allows air from the evaporator 202 to access pipe upper outlets 221, 222, 223 without passing through the mixing zone 210.

p0057Here again, the arrangement of two bypass pipes 205 and 208 below the heater 203 shortens the path of the warm air heater 203 to the outlet line of defrost 221, relative to an installation in which the a bypass pipe pass over the radiator.

p0058The installation shown in <figref idrefs="f0016">figures 26</figref> and <figref idrefs="f0017">27</figref> comprises a blower 201, an evaporator 202, a heater core 203, an auxiliary heat source 204, mixing zone 210, a drum flap 218, outlet pipes 221, 222, 223 and flaps 226, 227 associated with thereof, similar to the corresponding elements of <figref idrefs="f0011">figures 19</figref> and <figref idrefs="f0012">20</figref> and substantially housed in the same arrangement in a housing 300.

p0059The housing 300 further defines at least two bypass conduits passing beneath the radiator 203, mutually juxtaposed in the lateral direction, namely one or more conduits 301 each ending in a mixing region below 302, itself connected to the rear part of the cabin through an outlet 303, and one or more conduits 304 connected to the upper mixing zone 210. vertical walls laterally delimit the or pipes 301, or the mixing zones 302 and 304 or the conduits . As described in connection with <figref idrefs="f0003">figures 5</figref> and <figref idrefs="f0010">16</figref>That may especially provide a single median lower mixing region, flanked by two lateral lines 304, or two mixing zones 302 side, flanking a median conduct 304.

p0060The flap 212 of the <figref idrefs="f0011">Figure 19</figref> is replaced by a flap 305 of particular shape, comprising, in cross-section by a plane perpendicular to its pivot axis 306, a central portion 307 in a circular arc centered on the axis 306, spool-like component which adjoins marginal portions 308, 309 which are away from the axis from the region 307. the axis 306 is located inside the area 210. This configuration allows a reduced size of the pane, and a seal improved in the closed position.

p0061Cold air intake or in the pipes 304 and the hot air inlet in the mixing zone 210 may be closed, and open gradually, by the flaps 218 and 305 respectively so as to adjust the air temperature in the region 210. Two other components are associated with the or each lower mixing region 302, namely a butterfly valve 310 can close or open gradually, the access of hot air to this area and a flag flap 311 movable between two extreme positions in which the output 303 es t exclusively connected to the cold air supply and only the arrival of warm air respectively. The flap 218 is recessed opposite the or conduits 301 to allow cold air entering it in all its positions.

p0062Simplified installation, without separated from the rear part of the cabin supply, can be carried out without any modification of the housing illustrated in <figref idrefs="f0016">figures 26</figref> and <figref idrefs="f0017">27</figref>. Simply immobilize the flaps 310 and 311 in the positions where they close off respectively the heat registers and cold air from the mixing zone 302, so that the latter, and Consequently, the output 303, do not receive air.

p0063In the illustrated case, the wall 312 separating the bypass pipes 301 and 304 of radiator 203 is dual so as to improve the thermal insulation between the latter and the cold air flowing in the bypass pipes. Alternatively, this effect could be achieved by appropriate selection of the thickness or material of the wall.