Automobile air conditioner

An automobile air conditioner which has a generally elongated casing having air intake and outlet grilles defined at opposite sides thereof, a generally elongated evaporator accommodated within the casing so as to extend generally parallel to the direction of elongation of the casing and positioned adjacent the air intake grille, at least one cross-flow fan accommodated within the casing so as to extend generally parallel to the direction of elongation of the casing and positioned between the evaporator and the air outlet grille, and a drive unit for driving the cross-flow fan in one direction for blowing air from the inlet grille to the air outlet grille. The evaporator is supported in position within the casing in a tilted fashion with its upper edge towards the cross-flow fan.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The present invention generally relates to an air conditioner and, more 
particularly, to the air conditioner particularly suited for use in an 
automobile. 
2. Description of the Prior Art 
An automobile air conditioner of a type installed in the ceiling in the 
passenger s compartment of an automobile body structure is well known in 
the art and is disclosed in, for example, the Japanese Laid-open Utility 
Model Publications No. 63-22213 and No. 63-24011 published in 1988. 
According to these publications, the prior art automobile air conditioner 
employs a blower in the form of a centrifugal fan. 
Where a centrifugal fan is employed for the blower, the assembly as a whole 
tends to be relatively bulky with no opportunity available for reducing 
the thickness thereof as measured from the ceiling down to the bottom of 
the assembly. As is well known to those skilled in the art, the blower 
assembly employing a centrifugal fan has a construction wherein air is 
sucked into the assembly in an axial direction along the shaft about with 
the fan rotates and is discharged from the circumference of the assembly 
radially outwardly, i.e., in a centrifugal direction. Therefore, drastic 
reduction of the diameter of the centrifugal fan is not possible. 
In particular, the first mentioned Japanese publication discloses the 
disposition of the blower assembly with the fan shaft lying horizontal, 
i.e., generally parallel to the ceiling. The horizontal disposition of the 
fan shaft causes the fan casing for encasing the centrifugal fan to 
protrude downwards from the ceiling and into the interior of the 
automobile body structure through a distance corresponding to the diameter 
of the centrifugal fan. 
Also, the width of the centrifugal fan as measured in a direction parallel 
to the fan shaft is considered to be an optimum value if it is generally 
equal to the radius of the centrifugal fan. Accordingly, where the blower 
assembly is installed with the fan shaft lying vertical, i.e., generally 
perpendicular to the ceiling, such as disclosed in the second mentioned 
Japanese publication, the blower assembly not only requires a width 
somewhat proportional to the diameter of the centrifugal fan, but also the 
disposition of a fan drive motor so as to be oriented in a direction 
parallel to the fan shaft. Because of these factors, the thickness of the 
blower assembly as measured from the ceiling down to the bottom of the 
blower assembly cannot be drastically reduced. 
Considering now the layout of an automobile body structure in general, the 
height is generally limited from the standpoint of body aerodynamics, body 
stability, and other factors and/or by law and, therefore, it has long 
been considered a problem to reduce the bulkiness of the blower assembly 
in order for it to be installed inside the passenger's compartment. 
Also, regardless of the type of the automobile air conditioner particularly 
suited for installation in the ceiling in the passenger's compartment, the 
apparatus is required to have a relatively high durability and rigidity in 
view of the fact that any automobile during running undergoes bumpy 
motions and tilts and that the apparatus is therefore subjected to severe 
vibrations. 
SUMMARY OF THE INVENTION 
The present invention is therefore intended to provide an improved 
automobile air conditioner having a drastically reduced thickness to 
permit it to be installed in the ceiling of the automobile body structure 
without substantially adversely affecting the aesthetic feature of the 
automobile interior finish. 
Another important object of the present invention is to provide an improved 
automobile air conditioner of the type referred to above wherein as a 
blower at least one cylindrical fan generally known as a cross-flow fan is 
employed to accomplish the drastic reduction in thickness of the apparatus 
as a whole. 
A further object of the present invention is to provide an improved 
automobile air conditioner of the type referred to above, which can 
satisfactorily withstand the severe vibrations and drastic changes in 
temperature. 
The air conditioner according to the present invention employs not only the 
cross-flow fan, but also an evaporator. As is well known to those skilled 
in the art, an evaporator has an evaporator coil for the flow of a liquid 
medium therethrough and a number of evaporator fins for facilitating heat 
exchange between the liquid medium flowing through the evaporator coil and 
the air flowing through the air conditioner. Where the liquid medium is a 
coolant for cooling the air, the heat exchange results in formation of 
condensed water drops. Accordingly, the installation of the air 
conditioner in the ceiling of the automobile body structure requires 
utmost care to avoid any possible fall of the condensed water drops down 
onto the interior boot floor and, possibly, on some passengers occupying 
the seat. 
Therefore, a still further object of the present invention is to provide an 
improved automobile air conditioner of the type referred to above, wherein 
means is provided to avoid the fall of the condensed water drops down onto 
the interior boot floor. 
In order to accomplish these and other objects of the present invention, 
the present invention in one aspect provides an automobile air conditioner 
which comprises a generally elongated casing having air intake and outlet 
grilles defined at opposite sides thereof, a generally elongated 
evaporator accommodated within the casing so as to extend generally in the 
direction elongation of the casing and positioned adjacent the air intake 
grille, at least one cross-flow fan accommodated within the casing so as 
to extend generally in the direction of elongation of the casing and 
positioned between the evaporator and the air outlet grille, and a drive 
unit for driving the cross-flow fan in one direction from top to bottom as 
viewed from the air outlet grille. The evaporator is supported in position 
within the casing in a tilted fashion with its upper edge towards the 
cross-flow fan. 
The use of the cross-flow fan for the blower and the tilted support of the 
evaporator make it possible to reduce the thickness of the automobile air 
conditioner as a whole, which thickness is as measured from the ceiling 
down to the bottom of the apparatus in a direction of height of the 
automobile body. Also, since the cross-flow fan is so supported as to be 
rotated from top to bottom as viewed from the air outlet grille and, at 
the same time, the evaporator is supported with its upper edge towards the 
cross-flow fan, a smooth flow of air through the cross-flow fan can be 
advantageously attained to such an extent that not only can a sufficient 
flow of air be secured, but any possible generation of noise resulting 
from the flow of air can also be minimized. 
According to another aspect of the present invention, the generally 
elongated casing of the automobile air conditioner of the above described 
construction is shaped and curved so as to have a portion intermediate 
levels of thereof raised to a level higher than the levels of the opposite 
ends of the casing. 
The curved feature advantageously permits the air conditioner casing not 
only to follow the curvature of the ceiling when the air conditioner is 
installed on the ceiling, but also to exhibit an increased physical 
strength. 
According to a third aspect of the present invention, the evaporator 
supported within the casing is shaped and curved so as to follow the 
curvature of the casing. With this feature, the evaporator may serve as a 
frame structure for the casing and, therefore, the rigidity and the 
resistance of the casing as a whole to vibrations can be advantageously 
increased. Moreover, the employment of the curved evaporator results in an 
increase of the total surface area of contact thereof with air which in 
turn increases the heat exchange efficiency. 
According to a fourth aspect of the present invention, the automobile air 
conditioner is further provided with a drain duct defined in the casing 
immediately beneath the evaporator with a lower edge of the evaporator 
protruding into the drain duct. The drain duct is communicated at its 
opposite ends with drain ports for fluid connection with external drain 
pipes. 
The provision of the drain duct having the drain ports at the opposite ends 
thereof ensures that condensed water drops can be positively drained 
outside the casing through the external drain pipes regardless of the 
direction of tilt of the automobile during running. Where the air 
conditioner casing is curved as hereinbefore discussed, the drainage of 
the condensed water drops by the effect of gravitational force takes place 
even when the automobile is parked. 
According to a fifth aspect of the present invention, there is provided an 
automobile air conditioner which comprises a generally elongated casing 
having air intake and outlet grilles defined at opposite sides thereof, a 
generally elongated evaporator supported in tilted fashion within the 
casing and so curved as to follow the curvature of the casing, a pair of 
cross-flow fans accommodated within the casing in end-to-end fashion so as 
to extend generally in the direction of elongation of the casing and 
positioned between the evaporator and the air outlet grille, and a drive 
motor or driving each of the cross-flow fans. The casing is shaped and 
curved so as to have a portion intermediate the length thereof raised to a 
level higher than the level of the opposite ends of the casing and, at the 
same time, the evaporator supported within the casing is so shaped and so 
curved as to follow the curvature of the casing, the two drive motors are 
positioned intermediate the length of the casing and are drivingly coupled 
with the cross-flow fans positioned on respective sides of the drive 
motors. 
In this automobile air conditioner according to the fifth aspect of the 
present invention, the use of the cross-flow fan for the blower and the 
tilted support of the evaporator make it possible to reduce the thickness 
of the automobile air conditioner as a whole. Also, since the casing is so 
shaped and so curved as to have a portion intermediate the length thereof 
raised to a level higher than the level of the opposite ends of the 
casing, not only can the air conditioner casing follow the curvature of 
the ceiling when the air conditioner is installed on the ceiling, but it 
can also exhibit an increased physical strength particularly in a 
direction widthwise of thereof. 
Also, since the evaporator supported within the casing is so shaped and so 
curved as to follow the curvature of the casing, not only can the rigidity 
and the resistance of the casing as a whole to vibrations be 
advantageously increased, but also the total surface area of contact 
thereof with air can be increased which in turn increases the heat 
exchange efficiency. Furthermore, since the drive motors which are 
relatively heavy and have a substantial weight altogether are mounted 
intermediate the length of the casing, any possible deformation of the 
casing which would otherwise result from vibration can be advantageously 
avoided. 
According to a sixth aspect of the present invention, the automobile air 
conditioner according to the fifth aspect of the present invention may be 
provided with a drain duct defined in the casing immediately beneath the 
evaporator with a lower edge of the evaporator protruding into the drain 
duct. The drain duct is communicated at its opposite ends with drain ports 
for fluid connection with external drain pipes. 
According to a seventh aspect of the present invention, there is provided 
an automobile air conditioner system which comprises an interior air 
conditioner comprising a generally elongated casing having air intake and 
outlet grilles defined at opposite sides thereof and secured to the 
ceiling in a passenger's compartment of an automobile body structure, said 
casing being so shaped and so curved as to have a portion intermediate the 
length thereof raised to a level higher than the level of the opposite 
ends of the casing, a generally elongated evaporator supported in tilted 
fashion within the casing and so curved as to follow the curvature of the 
casing, at least one cross-flow fan accommodated within the casing so as 
to extend generally in to the direction of elongation of the casing and 
positioned between the evaporator and the air outlet grille, and a drive 
unit for driving the cross-flow fan. The system also comprises an exterior 
unit positioned inside an engine space of the automobile body structure 
and including a condenser and a compressor, said evaporator in the 
interior air conditioner being fluid-connected with the exterior unit. 
In this automobile air conditioner according to the seventh aspect of the 
present invention, the use of the cross-flow fan for the blower and the 
tilted support of the evaporator make it possible to reduce the thickness 
of the automobile air conditioner as a whole. Also, since the casing is so 
shaped and so curved as to have a portion intermediate the length thereof 
raised to a level higher than the level of the opposite ends of the 
casing, not only can the air conditioner casing follow the curvature of 
the ceiling when the air conditioner is installed on the ceiling, but it 
can also exhibit an increased physical strength particularly in a 
direction widthwise of thereof. 
Also, since the evaporator supported within the casing is so shaped and so 
curved as to follow the curvature of the casing, not only can the rigidity 
and the resistance of the casing as a whole to vibrations be 
advantageously increased, but also the total surface area of contact 
thereof with air can be increased which in turn increases the heat 
exchange efficiency. Furthermore, since the air conditioner is so 
supported to the ceiling of the automobile body structure with the air 
outlet grille facing towards a rear seat, one or more passengers sitting 
on the rear seat can be placed in a comfortable position.

DETAILED DESCRIPTION OF THE EMBODIMENTS 
An automobile air conditioner according to a first preferred embodiment of 
the present invention comprises a generally elongated and flattened casing 
1 including upper and lower casing halves 2 and 6 which are best shown in 
FIGS. 1 and 2. Referring first to FIG. 1 showing the upper casing half 2 
turned upside down, two cross-flow fans 2 a and 2b and respective fan 
drive motors 3a and 3b for driving the cross-flow fans 2a and 2b are 
mounted on the upper casing half 2. The upper casing half 2 has an inner 
surface (or an upper surface as viewed in FIG. 1) having integrally formed 
evaporator support ribs 5a and 5b and also has an exit grille structure 
provided with a stabilizer and a deflector blade for adjusting the 
direction of flow of cooled air as will be described later, said exit 
grille structure extending widthwise of the elongated casing 1. 
Referring to FIG. 2 showing the lower casing half 6, the lower casing half 
6 has an inner surface with integrally formed fan support ribs 7a to 7d 
and also has a generally curved evaporator 8 mounted thereon. The 
evaporator is of any known construction including an evaporator coil and a 
plurality of evaporator fins, said evaporator coil being fluid-coupled 
with connection ports 11a and 11b with an expansion valve disposed 
thereon. It is to be noted that of the fan support ribs 7a to 7d the fan 
support ribs 7a and 7b have integrally formed evaporator support ribs for 
the support of opposite end portions of the evaporator 8. 
Hereinafter, the manner by which the automobile air conditioner of the 
above described construction is secured to the ceiling in a passenger's 
compartment of an automobile body structure will be described. 
In the first place, the cross-flow fans 2a and 2b and the respective drive 
motors 3a and 3b are fitted to the upper casing half 1. The upper casing 
half 1 is then secured to the ceiling by the use of any suitable fastening 
means such as, for example, set bolts, with the cross-flow fans 2a and 2b 
oriented downwards towards the passenger's compartment. Subsequently, the 
evaporator 8 is mounted on the lower casing half 6, followed by the 
mounting of the lower casing half 6 on the upper casing half 1 from below 
so that the opposite end portions of the evaporator 8 can be engaged 
respectively with the evaporator support ribs 4a and 4b. At this time, the 
cross-flow fan 2a is disposed and supported between the fan support ribs 
7a and 7d whereas the cross-flow fan 2b is disposed and supported between 
the fan support ribs 7a and 7c. At the same time, the fan drive motors 3a 
and 3a are disposed and supported between the fan support ribs 7c and 7d. 
FIG. 3 is a plan view, with a portion cut away, of the automobile air 
conditioner according to the first embodiment of the present invention as 
viewed from below. As shown therein, the generally elongated flattened 
casing 1 has air intake and outlet grilles 12 and 13 defined at respective 
opposite sides thereof. Reference numeral 14a represents a blow direction 
adjusting knob which, when manipulated, rotates deflector blade 14b for 
deflecting the air current up and down. 
FIGS. 4 and 5 illustrate the automobile air conditioner as viewed from the 
exit grille 13 and from the intake grille 12, respectively. As shown 
therein, a portion of the casing 1 intermediate the length thereof is 
raised to a level higher than the level of the opposite ends of the casing 
1. In other words, the casing 1 comprised of the upper and lower casing 
halves 2 and 6 is so curved as to follow the curvature of the ceiling or a 
roof panel of the automobile body structure. Reference numerals 15a and 
15b shown therein designate respective drain ports. 
FIG. 6 is a top plan view of the lower casing half 6. As shown therein, the 
lower casing half 6 is formed with parallel ribs 16a and 16b extending 
lengthwise of the lower casing half 6 in spaced relation with each other 
an positioned inwardly adjacent the air intake grille. The parallel ribs 
16a and 16b cooperate with each to define a drain duct 16 therebetween, 
said drain duct 16 having its opposite ends communicated with the drain 
ports 15a and 5b as shown in FIGS. 6 and 7. It is to be noted that FIG. 7 
is a longitudinal sectional view of the lower casing half 6 showing the 
details of the drain duct 16. 
FIG. 8 is a top plan view of the evaporator 8. As shown therein, the 
evaporator 8 is curved to follow the inner surface of the casing. 
FIG. 9 is a longitudinal sectional view of the automobile air conditioner 
showing the disposition of the cross-flow fans 2a and 2b. As shown 
therein, the fan drive motors 3a and 3b are mounted on a portion of the 
lower casing half 6 intermediate the length thereof in symmetrical 
relationship with each other. The cross-flow fans 2a and 2b are drivingly 
coupled with the drive motors 3a and 3b, respectively. It is to be noted 
that, since the casing 1 has the intermediate portion positioned at a 
level higher than the level of the opposite ends thereof, the cross-flow 
fans 2a and 2b extending in respective directions away from each other are 
slightly inclined downwards away from the associated drive motors 3a and 
3b. 
FIG. 10 is a schematic side sectional view of the automobile air 
conditioner according to the first preferred embodiment of the present 
invention. As shown therein, the automobile air conditioner comprises a 
first stabilizer 17 integrally formed with the upper casing half 1, a 
second stabilizer 18 integrally formed with the lower casing half 6 and a 
diffuser 19. The first stabilizer 17 has a cross-sectional shape generally 
similar to the shape of a right triangle wherein the hypotenuse is 
occupied by a downwardly inclined wall extending downwardly from an apex 
portion adjacent the cross-flow fan 2 towards the exit grille 13. The 
first and second stabilizers 17 and 18 serve to stabilize forced eddy 
currents of air which would otherwise affect the flow of forced air 
produced by the cross-flow fan 2. Accordingly, the first stabilizer 17 is 
positioned on a downstream side of a vertical plane containing the axis of 
rotation of the cross-flow fan 2 with respect to the direction of flow of 
the forced air, whereas the second stabilizer 18 is positioned on an 
upstream side of the vertical plane containing the axis of rotation of the 
cross-flow fan 2. The diffuser 19 extends so as to be flared outwardly 
thereby to form an air exit region in cooperation with the wall of the 
first stabilizer 17 which extends from the apex portion thereof down to 
the exit grille 13. 
Hereinafter, the operation of the automobile air conditioner resulting from 
the above described construction will be described. 
By employing the cross-flow fans 2a and 2b as a blower, and by causing the 
evaporator 8 to be inclined, the thickness of the casing as measured in a 
direction heightwise of the automobile body structure can be reduced. 
Also, by placing the intermediate portion of the casing at a level higher 
than the level of the opposite ends thereof and, at the same time, curving 
the evaporator 8, and by dividing the cross flow fan into the two fans, 
the thickness of the casing can further be reduced. Since, by causing the 
casing to be curved, the casing can follow the curvature of the ceiling 
inside the automobile body structure, the thickness reducing effect can be 
enhanced. 
Moreover, since the exit grille 13 can be formed, elongated in a widthwise 
direction, a relatively wide current of forced air emerging from the exit 
grille 13 can be obtained to provide a comfortable environment in the 
passenger compartment. 
Although a problem associated with the strength will occur if the air 
conditioner is flattened and widened as hereinabove described, the present 
invention is substantially free from such a problem since the duct 
defining ribs 16a and 16b are formed so as to extend in the widthwise 
direction and, also, the evaporator 8 concurrently serves as a frame for 
the casing thereby to increase the rigidity of the casing in a direction 
widthwise thereof. 
Yet, since the evaporator 8 is so curved as to follow the casing, any 
possible gap between the evaporator 8 and the casing can be substantially 
eliminated and, also, since the total contact surface area of the 
evaporator 8 itself can be increased, an increased heat-exchange 
efficiency can be obtained. 
Also, since the intermediate portion of the lower casing half 6 is raised 
relative to the opposite ends thereof and the lower casing half 6 is 
provided with the drain ports 15a and 15b at respective ends thereof, 
water components can be positively drained either from the drain port 15a 
or the drain port 15b when the air conditioner tilts incident to the tilt 
of the automobile during running. 
As shown in FIG. 10, the cross-flow fan 2 is adapted to be driven in a 
direction from top to bottom as viewed from the exit grille 13, i.e., 
counterclockwise about the axis of rotation thereof as viewed in FIG. 10. 
At the same time, the evaporator 8 is so supported and so inclined with an 
upper edge thereof towards the cross-flow fan. Therefore, not only can a 
smooth flow of air towards the cross-flow fan 2 as shown by the 
arrow-headed lines be accomplished, but a substantial flow of air can also 
be obtained while the generation of noises resulting from the flow of the 
forced air can also be minimized. 
Yet, since the drive motors 3a and 3b which have a substantial weight are 
mounted intermediate the casing 1, any possible deformation of the casing 
resulting from the vibration can be avoided. 
FIG. 11 illustrates another preferred embodiment of the present invention. 
According to the embodiment shown in FIG. 11, the evaporator 8 is so 
supported and so inclined within the casing with its upper edge is 
positioned remote from the cross-flow fan 2 as compared with the lower 
edge. With this arrangement, the opening of the casing which defines the 
air intake grille 12 can be allowed to lie in a plane confronting 
generally downwardly and towards a rear seat in the automobile body 
structure. 
The air conditioner according to the present invention which has the above 
described construction is installed in the automobile in the following 
manner which will now be described with reference to FIG. 12. 
Referring now to FIG. 12, an indoor air conditioner unit 20 which has been 
described in connection with the foregoing embodiments is secured to the 
ceiling in the automobile body structure, particularly, an undersurface of 
the roof panel thereof, with the intake grille oriented towards a 
dashboard 32. An exit grille 23 of another indoor air conditioner unit 
having an evaporator 22 and a blower (not shown) is installed inside the 
dashboard 21. Within an engine room 24, a condenser 25, a compressor 26 
and a dryer receiver 27 are installed and are communicated with the 
evaporator of the indoor air conditioner unit 20 and the evaporator 22 of 
such another indoor air conditioner unit by way of piping 28. 
By the provision of the indoor air conditioner unit 20 and the other indoor 
air conditioner unit arranged in the manner as shown in FIG. 12, the 
indoor air conditioner unit 20 and the other indoor air conditioner unit 
can be used for providing conditioned air towards the rear seat and the 
front seat, respectively, within the automobile body structure. 
Particularly, where the indoor air conditioner units are simultaneously 
operated, a continued stream of conditioned air can be attained extending 
from the dashboard 21 towards a rear window along the ceiling of the 
automobile body structure. Specifically, when the cooling air flows along 
the ceiling where a substantial amount of radiant heat builds up, the 
interior of the automobile can be substantially uniformly air-conditioned 
quickly. 
Although the present invention has fully been described in connection with 
the preferred embodiments thereof with reference to the accompanying 
drawings, it is to be noted that various changes and modifications will be 
apparent to those skilled in the art. By way of example, although in the 
foregoing embodiments the upper and lower casing halves 2 and 6 have been 
described as curved, at least one of the upper and lower casing halves 2 
and 6 may be flat. Even with this alternative design, the thickness of the 
device as a whole can be advantageously reduced. In such case, instead of 
the use of two fan drive motors, one fan drive motor may be installed 
adjacent one end of the casing for driving both of the cross-flow fans. 
Also, instead of the use of two fan drive motors, one drive motor having a 
single drive shaft extending in opposite directions away from each other 
through the body of the motor may be employed and may be installed 
intermediate the length of the casing for driving both of the cross-flow 
fans. 
Also, instead of the use of the parallel ribs 16a and 16b used to define 
the drain duct 16, the drain duct 16 may be defined in the form of a 
generally elongated recess formed in the lower casing half 6. 
Accordingly, such changes and modifications are to be understood as 
included within the scope of the present invention as defined by the 
appended claims unless they depart therefrom.