Heating and/or air conditioning apparatus for an automotive vehicle

A heating and/or air conditioning apparatus for an automotive vehicle includes an inlet duct for supplying ambient air from outside the vehicle and dividing into a first branch and a second branch. A heat exchanger is mounted in the second branch, and the first and second branches communicate with each other through a junction, at which a control means is situated. The latter enables the temperature of the air leaving the outlets from the apparatus to be varied. A flap valve with two flaps, pivotting about an axis, is arranged in the said junction close to that edge of the junction which is nearest to the heat exchanger.

FIELD OF THE INVENTION 
This invention relates to a heating and/or air conditioning apparatus for 
an automotive vehicle. 
BACKGROUND OF THE INVENTION 
Conventionally, a heating and/or air conditioning apparatus for an 
automotive vehicle includes an air supply duct for delivering external 
air, i.e. ambient air from outside the vehicle, with this duct dividing 
into a first branch and a second branch, the first branch having first 
outlet means into the interior of the vehicle, the second branch 
comprising a heat exchanger for heating air passing through it, the second 
branch having second outlet means for delivery of air into the interior of 
the vehicle, the apparatus further comprising junction means for bringing 
the first and second branches into communication with each other and 
control means for adjusting the temperature of the air delivered from the 
various said outlet means. 
The means for regulating the temperature of the air delivered via the 
outlets may for example be a valve, and is so arranged that this air may 
be delivered at the same temperature through the first and second outlets, 
or with the air from the first outlets being at a different temperature 
from that at the second outlets. In this latter case, the apparatus can 
function in a "bi-level" manner, in which the temperature levels are 
stratified in such a way as to cause the temperature to be different as 
between the first and second branches. 
It has however been established that such an arrangement has some 
disadvantages. In the embodiments known at the present time, the different 
air outlets include flap valves in the vicinity of their outlets, allowing 
the flow of air delivered to be regulated. When for example the flap 
valves of the outlets of the first branch are closed, there is a back flow 
of air into the junction region, and this back flow mixes with treated air 
inside the apparatus, so disturbing the temperature of the latter. 
SUMMARY OF THE INVENTION 
It is an object of the present invention to avoid this major disadvantage. 
Another object of the invention is to provide a simple and compact heating 
apparatus. 
To these ends, according to the invention, there is provided a heating 
and/or air conditioning apparatus for an automotive vehicle, comprising a 
supply duct for supplying external air, with the supply duct being divided 
into a first branch and a second branch, the first branch having first 
outlet means into the interior of the vehicle, the second branch 
comprising a heat exchanger for heating air passing through it, the second 
branch having second outlet means for delivery of air into the interior of 
the vehicle, the apparatus further comprising junction means for bringing 
the first and second branches into communication with each other and 
control means for adjusting the temperature of the air delivered from the 
various said outlet means, the apparatus further comprising a flap valve, 
having two flaps and pivotable about an axis disposed transversely to the 
general direction of air flow, the flap valve being situated in the said 
junction close to that terminal edge of the said junction which is nearest 
to the heat exchanger. 
Preferably, in one extreme position, the flap valve 17 blocks the said 
junction while allowing free flow through the said first branch, and vice 
versa. This arrangement prevents air from the first branch flowing 
backwards into the outlet portion of the second branch. 
According to another feature of the invention, one flap of the said flap 
valve is arranged so that it can act as a mask for the heat exchanger. In 
this case the temperature of the air at the outlet of the second branch 
has two temperature levels. 
According to a further feature of the invention, the flaps of the flap 
valve are arranged to act as deflectors. These deflectors allow the 
division or mixing of the various air streams to be improved. 
The other features and advantages of the invention will become more 
apparent from the description which follows, and which is given with 
reference to the accompanying drawings.

DESCRIPTION OF PREFERRED EMBODIMENTS 
Reference is first made to FIG. 1. The apparatus for heating and/or air 
conditioning shown in this Figure includes a duct 1 for the supply of 
external air, which may be air that has been treated by passing through an 
evaporator which forms part of an air conditioning circuit. The duct 1 
divides into a first branch 2 exhausting into the passenger compartment of 
the vehicle through a first duct 3. This is provided with a plurality of 
first outlets 4 located at floor level. Opening and closing of these 
outlets is controlled by a flap valve 5. 
The air supply duct 1 also has a second branch 6 which includes a heat 
exchanger 7. A fluid circulating in the latter may be controlled by a 
control means such as a valve 8. The outlet portion 9 of the branch 6, 
that is to say the portion of the latter situated downstream of the heat 
exchanger 7 in the direction of flow of the air, is itself split into a 
second duct 10 and a third duct 13. The second duct 10 leads towards 
second outlets 11, which are controllable by a flap valve 12 and which may 
for example be directed into the lower part of the passenger compartment. 
The third duct 13 leads towards a third set of outlets 14, controlled by a 
flap valve 14' and directed, for example, towards the windscreen of the 
vehicle for deicing of the latter or removal of condensation. 
The outlet portion 9 divides not only into the ducts 10 and 13, but also 
into a short branch 15, extending around the heat exchanger 7 as seen in 
FIG. 1 and joining the branch 2 at a junction 16. In this example the 
junction 16 is situated upstream of the heat exchanger 7, and brings the 
outlet portion 9 of the branch 6 into communication with the first duct 3 
of the branch 2, while also providing a mixing zone, as will be seen. 
A flap valve 17, having two flaps 18 and 19 pivotting about an axis 20, 
generally transverse to the direction of air flow, is arranged in this 
junction 16. 
As can be seen more clearly from the Figure, the axis 20 of the flap valve 
17 is situated at the junction 16, and more particularly at the terminal 
edge 21 of the junction which is nearest to the heat exchanger 7. 
The apparatus shown in FIG. 1 operates in the following manner. 
The occupant of the vehicle controls the temperature in the passenger 
compartment to a desired value using the control means, in this example 
the valve 8, which regulates the flow of heat exchange fluid through the 
heat exchanger 7. 
In the case where fresh air is required in the passenger compartment, that 
is to say where the air delivered via the outlets 4, 11 and 14 is fresh 
air, the valve 8 is closed, and the flap valve 17 is preferably in the 
position shown in full lines in the Figure. 
In this position, the flap 19 of the valve 17 blocks the junction 16, while 
the flap 18 masks part of the inlet 22 of the branch 6. The inlet 22 is, 
in this example, the upstream face of the heat exchanger 7. 
Fresh air arriving through the duct 1 divides into a first air stream 
passing through the heat exchanger 7, and another air stream which 
impinges on the flap 18. The temperature of the first air stream remains 
substantially unchanged, this stream being directed from the heat 
exchanger 7 into the ducts 10 and 13, and also into the branch 15 
(although the latter is of course blocked by the flap 18). The flap 18 
acts as a deflector for the second air stream, which is thus deflected 
into the inlet 23 of the branch 2. 
With this arrangement, and in particular with the flap 18 of the flap valve 
17 partly masking the heat exchanger, the air flow in the branch 2 can be 
made substantially identical with that in the branch 6, by suitable 
adjustment of the position of the flap 18. 
When warm air is required in the passenger compartment of the vehicle, the 
heat exchanger valve 8 is opened, and the flap valve 17 is in the position 
shown in broken lines in FIG. 1, in which it blocks the inlet 23 of the 
branch 2 while leaving the junction 16 between the branches 15 and 2 free. 
Fresh air arriving through the duct 1 passes through the heat exchanger 7, 
in which it is heated. It then passes to the outlet portion 9 of the 
branch 6 and splits into two air streams, one of which is directed into 
the ducts 10 and 13 while the other passes through the branch 15 and 
thence into the duct 3 via the open junction 16, so admitting warm air 
into the duct 3. 
If the occupant of the vehicle requires fresh air to be delivered from the 
first branch 2 via the air outlets 4, but also requires warm air from the 
second branch 6, the heat exchanger valve 8 is opened and the flap valve 
17 is put into the position shown in full lines. Fresh air arriving 
through the supply duct 1 then divides into a first air stream passing 
through the heat exchanger 7 and a second air stream directed towards the 
branch 2. The air stream passing through the heat exchanger is there 
heated, and is then directed towards the ducts 10 and 13 and towards the 
branch 15, the latter being once again blocked by the flap 19 of the valve 
17. The other air stream passes through the branch 2 in the same way as 
described above for the case where fresh air was admitted directly. 
Here, fresh air can be delivered via the first outlets 4 while heated air 
is delivered by the outlets 11 and 14. 
Should the occupant want to have a very small quantity of fresh air 
delivered via the outlets 4, he adjusts the flap valve 5 in such a way as 
to restrict the air flow through the outlets 4. In this case, the air 
stream passing through the branch 2 tends to flow backwards towards the 
inlet 23 of that branch. Since the junction 16 is blocked, this back flow 
of air has no option but to pass through the heat exchanger 7. 
If the temperature required at the outlets 4 is higher than the ambient air 
temperature outside the vehicle, but less than the temperature of the air 
heated by passing through the heat exchanger 7 under the control of the 
valve 8, the occupant adjusts the flap valve 17 into an intermediate 
position, for example that shown in phantom lines in FIG. 1. In this case, 
the flow of fresh air arriving via the duct 1 divides into a first air 
stream deflected by the flap 18 of the valve 17, so as to pass into the 
branch 2; and a second air stream which passes directly through the heat 
exchanger, in which it is heated. This heated air has two levels of 
temperature in the outlet portion 9, namely a first level which obtains in 
the lower part of the passenger compartment of the vehicle, and a second 
level resulting from the action of the flap 18 of the valve 17. In its 
intermediate position, the valve 17 has the effect of reducing the flow of 
the air downstream of its surface. This reduced flow passes through the 
adjacent portion of the heat exchanger and is heated to a temperature 
different from that to which the remainder of the air, unaffected by the 
flap 18, is heated. 
The air that is heated to a first level of temperature tends to pass into 
the ducts 10 and 13, while the air at the second temperature level tends 
to pass into the branch 15 and thence into the duct 3, via the junction 16 
which is partly obstructed by the flap 19 of the valve 17. In the mixing 
zone at the junction 16, this air at the second temperature level mixes 
with the fresh air which is also present in the mixing zone, so that the 
air delivered by the outlets 4 consists of this mixture. In this way, the 
temperature of the air delivered by the outlets 4 can be regulated by the 
combined action of the flaps 18 and 19 of the valve 17, while the flap 19 
forms a partial obstruction to the backward flow of any air from the duct 
3. 
Referring now to FIG. 2, this shows a modified embodiment of the heating 
and/or air conditioning apparatus. In FIG. 2, the branch 15 is provided 
with a flap valve 25 which allows the volume of air admitted towards the 
junction 16 to be controlled, and which consequently allows the 
temperature of the air leaving the outlets 4 to be varied. 
The valve 25 may be coupled with the flap valve 17, in such a way that, in 
the extreme, i.e. fully open and fully closed, positions of the valve 17, 
the valve 25 is also in the corresponding position, while in the 
intermediate positions of the valve 17 the valve 25 can be in 
corresponding intermediate positions which may be identical to, or 
different from, those of the valve 17. For example, the valve 17 may be in 
a closed position when the valve 25 is in control of the outlets 4, and 
this has the effect of preventing backward flow of air from the branch 2 
into the outlet portion 9 of the branch 6. 
FIG. 3 shows another modified arrangement, in which a flap valve 30 is 
situated in the branch 15. In one of the extreme positions, 30', of the 
valve 30, the latter defines a duct portion 31 in communication with the 
branch 15. In its other extreme position, 30", the valve 30 brings the 
duct portion 31 into communication with the ducts 10 and 13. The valve 30 
can be arranged to assume the same positions as described above for the 
valve 25 in FIG. 2. 
In the modified arrangement shown in FIG. 4, the heating and/or air 
conditioning device includes a heat exchanger 7 which is not provided with 
any means for regulating the flow of the heat exchange fluid circulating 
in it. Instead, control of the action of the heat exchanger is provided 
for as follows. The ducts 10 and 13 are connected directly to the outlet 
portion 9 of the branch 6, and to a branch 40 which extends around the 
heat exchanger 7 in the same way as does the branch 15 in all of FIGS. 1 
to 4. 
The branch 40 is in communication with the ducts 10 and 13 via a junction 
42, in which is located a flap valve 43, similar to the flap valve 17 and 
mounted in the same way. It will be seen that the outlet portion of the 
branch 6 can only exhaust into the branches 15 and 40, and these can be 
blocked by the valves 17 and 43. The apparatus shown in FIG. 4 operates in 
an identical way to that shown in FIG. 1, except in respect of the way in 
which the temperature of the air for heating the passenger compartment is 
regulated. This is effected by means of the valve 43, which can be 
adjusted between its two extreme positions shown in FIG. 4. Thus, when the 
valve 43 is in the closed position shown in full lines in FIG. 4, the air 
passing into the passenger compartment through the ducts 10 and 13 is 
fresh air, while the air passing through the duct 3 may be hot or cold or 
mixed, depending on the position to which the valve 17 is set. When the 
valve 43 is in its fully open position shown in broken lines in FIG. 4, 
the air in the ducts 10 and 13 is hot air, while that in the duct 3 can be 
hot or cold or mixed, again depending on the setting of the valve 17. 
The intermediate positions of the valve 43 allow the temperature of the air 
admitted into the ducts 10 and 13 to be regulated by mixing the hot air 
circulating in the branch 40 with that of the cold air delivered via the 
air supply duct 1. In this last mentioned position, the air temperature in 
the duct 3, regulated by the valve 17, is independent of the air 
temperature in the ducts 10 and 13. 
The invention may be applied to an air conditioning apparatus, as mentioned 
above, in which an evaporator, for cooling the external air, is located in 
the duct 1 upstream of the heat exchanger 7.