Casing for an interior unit of a split type of an air conditioning apparatus

A casing for an interior unit of a split type air conditioner including a one piece, molded fan casing housing an upper wall, a curved rear wall connected to the upper wall, side walls connected to each of upper wall and the curved wall and a separator including a flat portion generally parallel with the upper wall.

FIELD OF THE INVENTION 
The present invention concerns an integrally molded air conditioner casing 
for the interior fan unit. 
BACKGROUND OF THE PRESENT INVENTION 
The present invention relates to casings for interior units of split type 
air conditioning apparatus. 
Split type air conditioning apparatus is constructed with exterior and 
interior units. The exterior unit includes a compressor for compressing 
refrigerant and a condenser for condensing the refrigerant while the 
interior unit includes an evaporator which acts as a heat exchanger for 
evaporating the refrigerator fed from the exterior unit and a fan for 
circulating air in the room through the heat exchanger. These units are, 
of course, interconnected and together complete a refrigerant cycle. 
FIG. 1 shows the approach used by the prior art for the formation of the 
case for the interior portion of air conditioning apparatus. The interior 
unit is substantially divided into upper and lower compartments by an 
L-shaped separator. The upper compartment is defined between a top wall, 
an arcuate rear wall, side walls and a separator and serves as a fan 
casing. A fan is disposed therein so that it lies along the arcuate rear 
wall. The configuration of the arcuate rear wall is important for it 
affects the fan's efficiency and is usually a spiral or scroll. One end of 
the separator which opposes the arcuate rear wall and one end of the 
arcuate rear wall adjacent the fan cooperate with the fan to form 
cross-flow blowers. These are also important for fan efficiency. In such a 
conventional interior unit, careful adjustment of the relationship between 
the separator and the arcuate rear wall must be carried out for realizing 
the desired fan efficiency after assembly of the unit because the arcuate 
rear wall and the separator are separate pieces. In spite of the ability 
to adjust these pieces, uniformity of fan efficiency for each assembled 
interior unit is not always attained. 
SUMMARY OF THE INVENTION 
The present invention overcomes these problems. In the present invention, a 
fan casing for the interior unit of a split type air conditioning 
apparatus which includes a curved rear wall and a separator is integrally 
molded in one piece. In this manner, adjustment of the relationship 
between the curved rear wall and the separator for realizing the desired 
fan efficiency is no longer needed and the same fan efficiency for each 
interior unit is guaranteed.

DETAILED DESCRIPTION OF THE PREFERRED EXEMPLARY EMBODIMENT OF THE PRESENT 
INVENTION 
As indicated previously, FIG. 1 shows a prior art casing concept where a 
plurality of separately manufactured casing pieces are joined together and 
thereafter adjusted to form the fan housing. 
Referring now to FIG. 2, the preferred exemplary embodiment of the present 
invention is shown. 
The interior unit generally indicated at 200 of a split type air 
conditioner is shown as being comprised of a main blower assembly 20, a 
front cover 22 and a rear panel 24. The front cover includes a panel 
member 30 in which an upper grill 26 for taking in air and a lower grill 
28 for taking out the air are provided. An air filter (not shown) can be 
detachably mounted to the cover 22 behind over upper grill 26. A plurality 
of blades 32 for adjusting the direction of air flow are in parallel 
arrangement over the lower grill. 
The main blower assembly 20 includes a case member 34, in which a 
cross-flow fan 36 and an evaporator 38 which acts as a heat exchanger, are 
disposed. Case member 34 is an integrally molded structure and is molded 
from a variety of moldable resins or plastics. 
Turning now to FIGS. 2 and 4, the latter showing a representative view of 
one end of the case member, it can be seen that case member 34 is 
comprised of an upper top wall 40 and side walls 42 and 43 which together 
form a box like structure. A motor 44, shown in FIG. 2, or other 
electrical or mechanical parts 46 are housed in an area surrounded by side 
wall 43 and another interior wall or vertical separator 48. Hereinafter, 
separator 48 will be referred to as the first separator 48. Double wall 
portions 50 and 52 are respectively provided on the inside surface of side 
wall 42 and first separator 48 with wall portions 50 and 52 being spaced 
from side wall 42 and separator 48 so that an air chamber is defined 
therebetween. 
The area defined between side wall 42 and first separator 48 is divided 
into an upper chamber 54 and lower chamber 56 by an inverted L-shaped 
separator 62, hereinafter called the second separator 62. Fan 36 is 
disposed in the upper chamber 54 and heat exchanger 38 is disposed in the 
lower chamber 56. Upper chamber 54 constitutes a fan casing with a curved 
rear wall 60, connected to top wall 40 at a portion 43 facing toward front 
unit 22, side wall 42, first separator 48 and a second separator 62. 
Second separator 62, which extends between side wall 42 and first separator 
48, includes an upper flat portion 64 and a depending front flap portion 
66. Air taken in through the upper grill 26 and the air filter is 
prevented from entering the lower chamber 56 by flap portion 66. Instead, 
air is pulled into the upper chamber 54 by the fan 36. One end of flat 
portion 64 is bent upwardly as shown at 64a, referred to as a nose 
portion, and extends rearwardly beneath fan 36 in the form of another flat 
area 67. A plurality of ribs 68 are formed together with separator 62 on 
the nose portion 64a and are spaced apart and extended between the nose 
portion 64a and the curved rear wall 60 so as to support one end of rear 
wall 60 thereby. Passages 69 lie between ribs 68 for communicating each 
spaces 54 and 56 therewith. Ribs 68 are formed when case member 34 is 
molded. Accordingly, the mutual positions between nose portion 64a and 
rear wall 60, and especially side wall 42 where rear wall 60 starts to 
curve are fixed as previously designed as an integral unit so that fan 
efficiency can be easily attained and maintained during the life of the 
apparatus. 
A pair of openings 70, including guide slits 70a and a pair of holes 72 and 
74 on opposite sides of opening 70, are provided on side walls 42 and 
first separator 48 and these openings are used to attach fan 34 to the 
casing. 
As shown in FIG. 4, a bearing 76 having a central hole 78 with a coaxial 
flange 80 is inserted in opening 70. Flange 80 is inserted in guide slit 
70a. A metal clasp 82 of which U-shaped bent blades 82a and 82b are 
inserted in holes 72 and 74, respectively, is utilized to fix bearing 76 
at side wall 43 and first separator wall 48. Projections 84a and 84b 
provided on the outer surface of blades 82a and 82b secure the insertion 
of metal clasp 82 in holes 72 and 74. By using a structural metal clasp 
82, the U-shaped blades 82a and 82b serve as plate springs and they absorb 
the vibration transferred from the shaft of fan 36 (not shown) through 
bearing 76 during the rotation of fan 36. First separator wall 48 includes 
an opening 83 for extending one end of the fan shaft therethrough to 
connect to motor 44. 
A drain guide 86 is also formed in lower chamber 56 when case member 34 is 
molded. A drain pan 88, whose configuration is shown in FIG. 5, is 
disposed in the lower chamber 56 as indicated by a phantom line in FIG. 4. 
A nipple 90 having outlets 92a and 92b is provided beneath the outlet 
opening found in drain pan 88. We prefer to attach a drain hose 94 to one 
of the outlets 92a and 92b and to place a dead end valve 96 to close the 
other one of outlets. Drain guide 86 and drain pan 88 are both covered 
with a heat insulating material 100. 
Turning now to FIGS. 3 and 6, the drain gutter 102 is formed as a V-shaped 
member having two opposing sides 102a and 102b and is attached along the 
lower or bottom end of flap portion 66. As shown in FIGS. 2 and 3, a 
plurality of ribs 104 are molded on inner surface of one side 102a of the 
gutter 102, with ribs 104 extending toward the other side 102b but are 
spaced therefrom so that that lower end of flap portion 66 can fit within 
the space formed therebetween and be held by the inner surface of side 
102b and ribs 104. A plurality of triangular shaped auxiliary ribs 106 
having a number of faces are provided on top of each rib 104. One face on 
each auxiliary rib 106 is to be parallel to flap portion 66 so as to lie 
there against and firmly secure drain gutter 102 thereto. The bottom of 
drain gutter 102 gradually descends or slopes from the midportion toward 
each end thereof at which an opening 108 is formed for leading drained 
fluid produced during cooling operation toward and onto drain guide 86 and 
ultimately into drain pan 88. The inner surface of flap portion 60 is 
covered with the heat insulating material 100. 
Heat exchanger 38 is diagonally supported between flap portion 66 and drain 
pan 88 in the lower chamber 56. A pipe 110, which is a main part of heat 
exchanger 38, is used for transporting refrigerant and is elongated at 
each side of heat exchanger 38. A holder 112, shown in FIG. 6, including a 
rounded guide 112a for receiving the lowest portion of pipe 110 is 
disposed on each longitudinal end of drain pain 88 so that heat exchanger 
38 is supported at its lowest ends. A triangular shaped lever 114 is 
detachably hinged to the flat portion 64 by a hook 114a which can extend 
through an opening 117 provided on flat portion 64. Each of the openings 
117 may be formed after unit body 34 is molded. Each lever 114 has a key 
114b designed to be inserted between portion of pipe 104 and the hold 
levers 114 in place. Lever 114 is engaged with different portion of pipe 
104 to lean heat exchanger 38 toward flap portion 66 when key 114b is 
inserted as shown in FIG. 6. 
As shown in FIG. 2, a tube 116 is connected to one open end of pipe 110 at 
the lower side of heat exchanger 38 while a tube 118 is connected to the 
other open end of pipe 110 but at the upper side of heat exchanger. Tube 
116 transports the refrigerant to the heat exchanger from the condensor 
disposed in the exterior unit (not shown) while tube 118 transports 
refrigerant back to the compressor disposed in the exterior unit to 
complete the refrigerant cycle. Tube 116 extends upwardly from one open 
end of pipe 110 to near other open end of pipe 110 along heat exchanger 
38. Both of tubes 116 and 118 are extended parallel to drain guide 86 with 
a curved part having curvature of about 100 mm. These tubes 116 and 118 
are wrapped by the heat insulating material 100, which makes an X-crossing 
with heat exchanger 38. Tubes 116 and 118 also extend beneath drain guide 
86 and drain pan 88 until interior unit 20 is equipped on the wall of a 
room. Open ends of tubes 116 and 118 are prevented from projecting from 
beneath drain pan 88 and drain guide by nipple 90 as shown in FIG. 5. 
Having provided adequate curvature, tubes 116 and 118 are easily bent 
almost 90.degree. around the curved part toward the wall without any 
damage to tubes 116 and 118 when interior unit 200 is mounted as shown in 
FIG. 3. 
Operation of the interior unit of the air conditioning apparatus described 
above is as follows. Warm air taken in through upper grill 26 by fan 36 is 
sent from upper chamber 54 to the lower chamber 56 through passages 69. As 
the warm air passes through heat exchanger 38, its temperature is 
decreased and substantially cooled. Cooled air is thereafter blown out 
from the lower grill 28 as directed by the adjustable blades. Due to the 
temperature differences between inside and outside of flap portion 66, 
drains are produced on the outside of that flap portion. Drainage fluid is 
also produced by heat exchanger 38 and all the draining fluid is collected 
by drain pan 88 and finally lead out by hose 94. 
As mentioned above, a fan casing for an interior unit of a split type air 
condition is disclosed, which is comprised of a curved rear wall 
integrally connected to a top wall and side walls and a separator 
including a flat portion extending generally parallel with the top wall 
and a flap portion bent downwardly at the front end of the flat portion. 
Accordingly, adjustment of the relationship between the curved rear wall 
and the separator for realizing the desired fan efficiency is no longer 
needed and the same fan efficiency for each unit as manufactured in the 
factory is guaranteed. 
While the invention has been described in connection with what is presently 
considered to be the most practical and preferred embodiment, it is to be 
understood that the invention is not to be limited to the disclosed 
embodiment but on the contrary, is intended to cover various modifications 
and equivalent arrangements, included within the spirit and scope of the 
appended claims, which scope is to be accorded the broadest interpretation 
so as to encompass all such modifications and equivalent structures.