FORM 2
THE PATENTS ACT, 1970
(39 of 1970)
&
THE PATENTS RULES, 2003
COMPLETE SPECIFICATION
[See section 10, Rule 13]
COOLING STRUCTURE AND OUTDOOR UNIT INCLUDING COOLING STRUCTURE
MITSUBISHI ELECTRIC CORPORATION, A CORPORATION ORGANISED AND
EXISTING UNDER THE LAWS OF JAPAN, WHOSE ADDRESS IS 7-3, MARUNOUCHI
2-CHOME, CHIYODA-KU, TOKYO 100-8310, JAPAN
THE FOLLOWING SPECIFICATION PARTICULARLY DESCRIBES THE INVENTION
AND THE MANNER IN WHICH IT IS TO BE PERFORMED.
2
Description
Title of Invention: COOLING STRUCTURE AND OUTDOOR UNIT INCLUDING
COOLING STRUCTURE
5 Technical Field
[0001] The present invention relates to a cooling structure
for an electric circuit board and an outdoor unit for an air
conditioner, which includes the cooling structure for an electric
circuit board.
10
Background Art
[0002] Hitherto, an outdoor unit for an air conditioner is
partitioned into two chambers, specifically, a fan chamber in which
an air-sending fan and a heat exchanger are arranged and a machine
15 chamber in which a compressor and a refrigerant pipe are arranged.
Further, an electric circuit board is mounted to the outdoor unit.
The electric circuit board is arranged across the fan chamber and
the machine chamber.
[0003] A power supply control component is mounted on the
20 electric circuit board. The power supply control component is
caused to generate heat. Therefore, a heat sink including a
plurality of fins configured to radiate the generated heat is
mounted to the power supply control component. However, the
cooling efficiency of the power supply control component to be
25 attained by only mounting the heat sink is still low.
3
[0004] In view this, the cooling efficiency of the heat sink
to be mounted to the power supply control component is improved
by utilizing an air flow generated by the air-sending fan. Further,
there has been known a configuration in which each fin of the heat
sink and a cover that covers a distal end of each 5 fin are integrated
with each other such that the entire heat sink is efficiently cooled
(see, for example, Patent Literature 1).
Citation List
10 Patent Literature
[0005] [PTL 1] JP 2009-29907 A
Summary of Invention
Technical Problem
15 [0006] However, in the structure of Patent Literature 1, the
pressure loss of the air flow passing between the fins of the heat
sink is large. Therefore, there is a problem in that the speed of
the air flow passing between the fins is decreased, and the flow
rate of the air flow passing between the fins is reduced, with the
20 result that the cooling effect by the heat sink cannot be
sufficiently obtained.
[0007] The present invention has been made in order to solve
the problem as described above, and obtains a cooling structure
capable of improving the cooling efficiency achieved by a heat sink,
25 and an outdoor unit including the cooling structure.
4
Solution to Problem
[0008] A cooling structure according to the present invention,
includes: a heat sink to be mounted to a heat generator; and a duct
mounted to the heat sink and configured to guide an 5 air flow flowing
around the heat sink to the heat sink, wherein the heat sink has
an air flow passage configured to allow the air flow to pass through
the air flow passage, wherein one end side of the duct is to be
mounted to an upstream side of the air flow passage, and wherein
10 another end side of the duct is extended from an upstream end portion
of the air flow passage to an upstream side of the air flow.
Advantageous Effects of Invention
[0009] In the present invention, the duct extended from the
15 heat sink is mounted to the upstream side of the air flow passage
of the heat sink, which is configured to cool the heat generator
such that a large amount of air flow is guided to the air flow passage.
With this, the flow rate of the air flow passing through the air
flow passage of the heat sink can be increased, and the cooling
20 efficiency of the heat sink can be improved.
Brief Description of Drawings
[0010] FIG. 1 is a perspective view of an outdoor unit
including a cooling structure according to a first embodiment of
25 the present invention as viewed from the front in a state in which
5
a part of a casing is transparent.
FIG. 2 is a sectional view of the outdoor unit taken along
the plane S1 of FIG. 1 as viewed from above.
FIG. 3 is a sectional view of the outdoor unit taken along
the plane S2 of FIG. 1 as viewed from a 5 fan chamber side.
FIG. 4 is an enlarged view of the part A of FIG. 1 as viewed
from the back side.
FIG. 5 is an enlarged view of the part A of FIG. 1.
FIG. 6 is an enlarged view of the part B of FIG. 3.
10 FIG. 7 is a perspective view of an outdoor unit including a
cooling structure according to a second embodiment of the present
invention as viewed from the front in a state in which a part of
the casing is transparent.
FIG. 8 is a sectional view of the outdoor unit taken along
15 the plane S3 of FIG. 7 as viewed from above.
FIG. 9 is a sectional view of the outdoor unit taken along
the plane S4 of FIG. 7 as viewed from the fan chamber side.
FIG. 10 is an enlarged view of the part C of FIG. 7 as viewed
from the back side.
20 FIG. 11 is an enlarged view of the part D of FIG. 9.
FIG. 12 is a view of a first modification example of the cooling
structure according to the second embodiment of the present
invention as viewed from the same position as that of FIG. 11.
FIG. 13 is a view of a second modification example of the
25 cooling structure according to the second embodiment of the present
6
invention as viewed from the same position as that of FIG. 10.
FIG. 14 is a view of a second modification example of the
cooling structure according to the second embodiment of the present
invention as viewed from the same position as that of FIG. 12.
5
Description of Embodiments
[0010] Now, with reference to the drawings, a cooling
structure and an outdoor unit including the cooling structure
according to exemplary embodiments of the present invention is
10 described. The embodiments described below are merely examples,
and the present invention is not limited to those embodiments.
[0012] First Embodiment
FIG. 1 is a perspective view of an outdoor unit 100 including
15 a cooling structure according to a first embodiment of the present
invention as viewed from a front under a state in which a part of
a casing 200 is transparent. FIG. 2 is a sectional view for
illustrating the outdoor unit 100 taken along the plane S1 of FIG.
1. FIG. 3 is a sectional view for illustrating the outdoor unit
20 100 taken along the plane S2 of FIG. 1. Further, FIG. 4 is an
enlarged view of the part A of FIG. 1 as viewed from the back side.
FIG. 5 is an enlarged view of the part A of FIG. 1. FIG. 6 is an
enlarged view of the part B of FIG. 3. In FIG. 5, a state in which
a lid 22 of an electric component box 20 is removed is illustrated.
25 [0013] Further, for convenience of description, in the outdoor
7
unit 100 of FIG. 1, the front of the outdoor unit 100 may be referred
to as a front side, a back thereof may be referred to as a back
side, a left side as viewed from the front may be referred to as
a fan chamber side, and a right side as viewed from the front may
be referred to as a machine 5 chamber side.
[0014] FIG. 1 is a perspective view of the outdoor unit 100
for an air conditioner, which includes a cooling structure 50,
according to the first embodiment as viewed from the front.
[0015] The outdoor unit 100 is installed outdoors. The
10 outdoor unit 100 is connected to an indoor unit (not shown) installed
indoors by a refrigerant pipe to form a refrigeration cycle. The
indoor unit and the outdoor unit 100 are connected to each other
by a power supply line and a signal line configured to control an
operation of the refrigeration cycle.
15 [0016] As illustrated in FIG. 1 to FIG. 3, the outdoor unit
100 includes the casing 200. FIG. 1 is an illustration of the state
in which a part of the casing 200 is transparent. In an inside of
the casing 200, there are accommodated the electric component box
20 receiving a power supply control component 33 (see FIG. 5) serving
20 as a heat generator, the cooling structure 50 configured to cool
the power supply control component 33, and a heat exchanger 103.
The cooling structure 50 includes a heat sink 51 mounted to the
power supply control component 33, and a duct 52 configured to guide
an air flow surrounding the heat sink 51 to the heat sink 51.
25 [0017] The casing 200 includes a top panel 201, a bottom panel
8
202, a front panel 203, a back panel 204, a side panel 205, and
a side panel 206, which are formed by sheet metal processing. The
top panel 201, the bottom panel 202, the front panel 203, the back
panel 204, the side panel 205, and the side panel 206 each may be
formed as an independent panel, or two or more 5 panels such as the
back panel 204 and the side panel 205 may be integrated with each
other.
[0018] The inside of the casing 200 is divided into two spaces
arranged in a right and left lateral direction by a partition plate
10 102 formed by sheet metal processing. One space is a machine chamber
110 located on the right side as viewed from the front of FIG. 1.
Another space is a fan chamber 120 located on the left side as viewed
from the front of FIG. 1. The upper portions of the machine chamber
110 and the fan chamber 120 are covered by the top panel 201.
15 [0019] In the machine chamber 110, there are arranged the
electric component box 20, a compressor 7, a reactor 8, the
refrigerant pipe (not shown), and the like. The compressor 7 has
a function of causing the refrigerant to circulate through the
refrigeration cycle. The compressor 7 is fixed to the bottom panel
20 202 through intermediation of an anti-vibration rubber 71.
[0020] The reactor 8 is mounted above the compressor 7. The
reactor 8 has a function of improving a power factor of an AC power
supply. The reactor 8 includes a core 81, a coil 82 such as a copper
wire, and a base plate made of metal (not shown). The core 81 is
25 obtained by stacking magnetic steel sheets. The coil 82 is wound
9
around the core 81. The base plate is welded to an end surface of
the core 81. The base plate of the reactor 8 is fixed to the
partition plate 102 with a fixing member such as a screw.
[0021] The electric component box 20 is arranged above the
reactor 8. The electric component box 20 is arranged 5 across the
machine chamber 110 and the fan chamber 120 above the partition
plate 102. In the machine chamber 110, there are further arranged
an expansion valve, a four-way valve, a refrigerant pipe, and the
like forming the refrigeration cycle. Further, in the machine
10 chamber 110, there are arranged a wire for connecting electrical
components, and the like.
[0022] Meanwhile, in the fan chamber 120, there are arranged
the electric component box 20, an air-sending fan 3, the heat
exchanger 103, and a bellmouth 5 serving as an exhaust port of the
15 casing 200. The air-sending fan 3 is fixed to a support plate 104
provided inside the casing 200 with a screw.
[0023] The heat exchanger 103 has an L shape, and is arranged
along the side panel 205 on the fan chamber side of the casing 200
and the back panel 204. Inlet ports (not shown) formed by a
20 plurality of through holes are formed in the side panel 205 and
the back panel 204. When the air-sending fan 3 is rotated, outside
air is taken into the fan chamber 120 through the inlet ports.
[0024] The heat exchanger 103 includes a plurality of fins made
of metal and a plurality of refrigerant pipes passing through the
25 plurality of fins. The outside air having been taken into the fan
10
chamber 120 passes between the plurality of fins of the heat
exchanger 103. The heat exchanger 103 exchanges heat between the
air passing between the plurality of fins and refrigerant flowing
through the refrigerant pipes.
[0025] The bellmouth 5 is arranged on the fan 5 chamber 120 side
of the front panel 203. An annular protruding portion 5a protruding
to the inner side of the casing 200 is formed on a peripheral edge
portion of an opening of the bellmouth 5. The protruding portion
5a is configured to guide an air flow generated by the air-sending
10 fan 3 to a direction of being exhausted through the bellmouth 5.
[0026] FIG. 4 is an enlarged view of the part A of FIG. 1 as
viewed from the back side. As illustrated in FIG. 4, the electric
component box 20 includes a cover 21 made of resin and the lid 22
made of metal.
15 [0027] An electric circuit board 30 is accommodated in the
electric component box 20. The electric circuit board 30 includes
a printed circuit board and a plurality of electronic components
mounted on the printed circuit board. The electric circuit board
30 is configured to control a power supply of the air conditioner
20 and control an operation of a device such as the compressor 7.
[0028] The periphery of the printed circuit board of the
electric circuit board 30 and a surface opposite to the mounting
surface of the printed circuit board are covered by the cover 21.
The electric circuit board 30 is fixed to the cover 21 with a screw.
11
The cover 21 is fixed to the partition plate 102 with a screw. The
lid 22 is mounted on the cover 21 with a screw or by snap-fitting.
[0029] In FIG. 5, the part A of FIG. 1 is enlarged, and the
state in which the cover 21 and the lid 22 forming the electric
component box 20 are removed 5 is illustrated.
[0030] In a region of the electric circuit board 30 on the fan
chamber 120 side, the power supply control component 33 being a
power device is mounted. The power supply control component 33 is
mounted to the electric circuit board 30 through intermediation
10 of a spacer made of resin. A terminal of the power supply control
component 33 is soldered to the electric circuit board 30. The power
supply control component 33 is a component having the largest heat
generation amount among the plurality of electronic components
mounted on the electric circuit board 30.
15 [0031] As illustrated in FIG. 5, the heat sink 51 configured
to radiate heat generated from the power supply control component
33 is mounted to the power supply control component 33. The heat
sink 51 includes a heat sink base plate 51a and a plurality of
heat-radiating fins 51b.
20 [0032] The periphery of the heat sink base plate 51a is
supported by a heat sink holder 54 made of resin in a downward
direction, that is, a gravity direction. The heat sink holder 54
is fixed to a heat sink support 55 formed by sheet metal processing
with a screw. The heat sink support 55 is fixed to the partition
25 plate 102 with a screw, or the like.
12
[0033] The plurality of heat-radiating fins 51b are arranged
on one surface of the heat sink base plate 51a. Each of the
heat-radiating fins 51b is a plate-shaped member extending downward
perpendicularly from the heat sink base plate 51a, and has
rectangular heat radiation surfaces on the front 5 and back. The
heat-radiating fins 51b are arranged at given intervals from each
other.
[0034] Another surface of the heat sink base plate 51a, that
is, a surface opposite to the surface on which the heat-radiating
10 fins 51b are provided is brought into abutment against the power
supply control component 33 through heat conductive grease or a
heat conductive sheet.
[0035] An end portion of the heat sink base plate 51a on the
heat sink support 55 side extends in a direction of the heat sink
15 support 55 with respect to the heat-radiating fin 51b located at
an end portion of the plurality of heat-radiating fins 51b on the
heat sink support 55 side. Meanwhile, an end portion of the heat
sink base plate 51a opposite to the heat sink support 55 extends
in a direction opposite to the heat sink support 55 with respect
20 to the heat-radiating fin 51b located at an end portion of the
plurality of heat-radiating fins 51b opposite to the heat sink
support 55.
[0036] A gap between the adjacent heat-radiating fins 51b of
the plurality of heat-radiating fins 51b forms air flow passages
25 AP. The air flow passage AP is formed with the heat sink base plate
13
51a as a top surface and the heat radiation surfaces of the adjacent
heat-radiating fins 51b as both side surfaces. A bottom side, that
is, a downward direction of the air flow passage AP is opened to
the outside.
[0037] As illustrated in FIG. 4 and FIG. 5 5, the duct 52
configured to guide an air flow to the air flow passages AP is mounted
to a side being an inlet side of the air flow passages AP, and faces
the back side of the outdoor unit 100. The duct 52 is made of resin,
and is fixed to the heat sink support 55.
10 [0038] The duct 52 has an L shape in cross section taken along
a perpendicular plane. That is, the duct 52 includes a side plate
opposite to the heat sink support 55, and a bottom plate opposite
to the heat sink holder 54. A direction of the duct 52 on the back
side of the outdoor unit 100, that is, a direction of an upstream
15 side of the air flow passages AP is opened.
[0039] The duct 52 may include one or both of a side plate on
the heat sink support 55 side and a top plate facing the heat sink
holder 54. When the top plate is provided on the duct 52, it is
preferred that a cutout or an opening be formed in the top plate
20 in order to avoid interference with the region in which the heat
sink base plate 51a and the power supply control component 33 are
held in contact with each other.
[0040] The inlet of the air flow passage AP is formed by an
end portion of each of the heat-radiating fins 51b. In the air flow
25 flowing toward the air flow passages AP, an air flow that collides
14
with the end portion of each of the heat-radiating fins 51b becomes
a turbulent flow in the vicinity of the inlets of the air flow
passages AP. The turbulent flow in the vicinity of the inlets of
the air flow passages AP hinders a flow of the air flow introduced
into the air flow passages AP. Thus, the flow rate 5 of the air flow
passing through the air flow passages AP is reduced.
[0041] In view of this, as illustrated in FIG. 4, in the cooling
structure 50 according to the first embodiment, the end portion
of the duct 52 in the back side direction of the outdoor unit 100
10 is extended from the inlets of the air flow passages AP to the back
side of the outdoor unit 100, that is, the back panel 204 direction.
The length of extending the end portion of the duct 52 is set to
be larger than the interval at which the heat-radiating fins 51b
are arranged. The periphery of the inlets of the air flow passages
15 AP is surrounded by the heat sink base plate 51a, the heat sink
support 55, and the side plate and the bottom plate of the duct
52.
[0042] With this, even when the flow of the air current toward
the air flow passages AP is disturbed by the turbulent flow in the
20 vicinity of the inlets of the air flow passages AP, the disturbed
air flow is suppressed from flowing toward the outside of the air
flow passages AP. Accordingly, reduction in the flow rate of the
air flow passing through the air flow passages AP can be suppressed.
[0043] FIG. 6 is an enlarged view of the part B of FIG. 3.
25 Through rotation of the air-sending fan 3, air in the fan chamber
15
120 is exhausted to the outside through the opening of the bellmouth
5. Then, the inside of the fan chamber 120 becomes a negative
pressure, and the outside air is taken into the fan chamber 120
through the inlet ports of the back panel 204. The outside air
having been taken into the fan chamber 120 passes 5 through the heat
exchanger 103 to become a plurality of air flows as indicated by,
for example, the white arrows shown in FIG. 6.
[0044] Among the plurality of air flows illustrated in FIG.
6, an air flow linearly exhausted to the outside through the opening
10 of the bellmouth 5 from the back side of the outdoor unit 100 to
the front side is defined as a main flow MF, and other air flows
are defined as subsidiary flows SF. The heat sink 51 is arranged
so that the direction of the air flow passages AP matches the
direction of the main flow MF. In the following, based on the
15 flowing direction of the main flow MF being a reference, a side
of each element, which corresponds to the back side of the outdoor
unit 100, may be referred to as an upstream side, and a side of
each element, which corresponds to the front side of the outdoor
unit 100, may be referred to as a downstream side.
20 [0045] In FIG. 6, three subsidiary flows SF1 to SF3 are
illustrated. The subsidiary flow SF1 is an air flow flowing toward
the air flow passages AP of the heat sink 51. The subsidiary flow
SF2 is an air flow flowing downward from below the heat sink 51
toward the opening of the bellmouth 5. The subsidiary flow SF3 is
16
an air flow flowing toward a gap defined between an upper surface
of the electric component box 20 and the top panel 201.
[0046] Further, although not illustrated in FIG. 6, an air flow
flowing from the machine chamber 110 side to the fan chamber 120
side is also present on the side of the heat sink 5 51 being the inlet
side of the air flow passages AP and facing the back side of the
outdoor unit 100.
[0047] Here, the downstream end portions of the air flow
passages AP formed by the plurality of heat-radiating fins 51b
10 extend toward the vicinity of the front panel 203. Therefore, when
the lower side of the air flow passages AP that are opened is entirely
covered by the bottom plate of the duct 52, it is difficult for
the air flow to pass through the air flow passages AP, and the flow
speed of the air flow in the air flow passages AP is decreased.
15 Further, when the lower side of the air flow passages AP that is
opened is entirely covered by the bottom plate of the duct 52, all
the air flows passing through the air flow passages AP collide with
the inner wall of the front panel 203.
[0048] The air flow that collides with the inner wall of the
20 front panel 203 is, for example, bent downward as in an air flow
HF1 illustrated in FIG. 6, and thus the flow speed is decreased.
The air flow HF1 decreased in the flow speed stagnates between the
downstream end portions of the air flow passages AP and the front
panel 203, and thus hinders the air flow passing through the air
25 flow passages AP. Consequently, the speed of the air flow flowing
17
through the air flow passages AP is decreased. As a result, the
flow rate of the air flow in the air flow passages AP is reduced,
and hence the heat radiation effect of the heat sink 51 is reduced.
[0049] Further, the air flow HF1 having collided with the inner
wall of the front panel 203 flows along the inner 5 wall of the front
panel 203. A part of the air flow flowing along the inner wall of
the front panel 203 flows in a direction opposite to the main flow
MF, as in an air flow RF illustrated in FIG. 6, with the partition
plate 102 and the protruding portion 5a of the bellmouth 5 serving
10 as barriers.
[0050] The air flow RF flowing in the opposite direction
collides with the subsidiary flow SF2 flowing to the front side,
and disturbs the flow of the subsidiary flow SF2. When the flow
of the subsidiary flow SF2 is disturbed, the flow of the subsidiary
15 flow SF1 flowing above the subsidiary flow SF2 becomes unstable.
When the flow of the subsidiary flow SF1 becomes unstable, the flow
rate of the air flow introduced into the air flow passages AP is
reduced. Consequently, the speed of the air flow flowing through
the air flow passage AP is further decreased. As a result, the heat
20 radiation effect of the heat sink 51 is further reduced.
[0051] In view of this, as illustrated in FIG. 4 to FIG. 6,
in the cooling structure 50 according to the first embodiment, a
downstream end portion 52b of the duct 52 is arranged at the middle
position of the air flow passages AP. In addition, the upstream
25 side of the air flow passages AP is covered by the duct 52, and
18
the downstream side of the air flow passages AP is exposed. With
this, a part of the air flow passing through the air flow passages
AP flows out from the vicinity of the middle of the air flow passages
AP to the outside of the air flow passages AP as in an air flow
HF2 illustrated 5 in FIG. 6.
[0052] With this, the ratio of the air flow HF1 that collides
with the inner wall of the front panel 203 to the air flow passing
through the air flow passages AP can be reduced. Accordingly,
reduction in speed of the air flow in the air flow passages AP,
10 which is caused due to stagnation of the air flow HF1 in the vicinity
of the outlets of the air flow passages AP, can be suppressed.
Further, the air flow RF flowing in the direction opposite to the
main flow MF below the heat sink 51 can be reduced. In addition,
generation of the air flow that collides with the subsidiary flow
15 SF2 to disturb the flows of the subsidiary flow SF2 and the
subsidiary flow SF1 can be suppressed.
[0053] Further, as illustrated in FIG. 6, in the cooling
structure 50 according to the first embodiment, the downstream end
portion 52b of the duct 52 is arranged at a position spaced away
20 by a length L1 to the upstream side of the air flow with respect
to an upstream end portion of the protruding portion 5a of the
bellmouth 5. Moreover, the lower surface of the duct 52 is arranged
at a position spaced away by a length L2 to the upper side with
respect to an uppermost portion of the protruding portion 5a of
25 the bellmouth 5. The length L1 and the length L2 are appropriately
19
determined based on the shape of the fan chamber 120, arrangement
of each element, and the flow of the air flow analyzed based on
the performance of the air-sending fan 3, and the like.
[0054] With this, the protruding portion 5a of the bellmouth
5 is suppressed from becoming the barrier of the 5 air flow HF2, and
the air flow HF2 can be efficiently directed to the opening of the
bellmouth 5.
[0055] As described above, in the cooling structure 50
according to the first embodiment, through arrangement of the duct
10 52, the decrease of the flow speed of the air flow passing through
the air flow passages AP and the reduction in flow rate of the air
flow introduced into the air flow passages AP are suppressed. As
a result, the reduction of the heat radiation effect of the heat
sink 51 can be suppressed.
15 [0056] Next, actions of the cooling structure 50 according to
the first embodiment are described.
[0057] When electric power is supplied to the air conditioner
to operate the refrigeration cycle, power is supplied to the
electric circuit board 30 of the outdoor unit 100. Then, the power
20 supply control component 33 mounted to the electric circuit board
30 starts control of a power supply configured to energize a device
such as a motor of the air-sending fan 3 to generate heat. When
the motor of the air-sending fan 3 is energized, the air-sending
fan 3 is rotated. When the air-sending fan 3 is rotated, air in
25 the fan chamber 120 is exhausted through the opening of the bellmouth
20
5.
[0058] When the air in the fan chamber 120 is exhausted, the
pressure inside the casing 200 becomes a negative pressure with
respect to the outside. When the pressure inside the casing 200
becomes a negative pressure with respect to the outside, 5 the outside
air is taken into the fan chamber 120 through the plurality of inlet
ports formed in the back panel 204 and the side panel 205.
[0059] The outside air having been taken into the fan chamber
120 becomes an air flow in the fan chamber 120, and passes between
10 the plurality of fins of the heat exchanger 103. The air flow
passing between the plurality of fins of the heat exchanger 103
exchanges heat with refrigerant flowing through the refrigerant
pipes. During a cooling operation of the air conditioner, the
refrigerant gives heat to the air flow, and hence the temperature
15 of the air flow passing through the heat exchanger 103 is higher
than the temperature of the outside air. Meanwhile, during a
heating operation of the air conditioner, the refrigerant takes
heat from the air flow. Thus, the temperature of the air flow
passing through the heat exchanger 103 becomes lower than the
20 temperature of the outside air.
[0060] In the air flow generated in the fan chamber 120, the
main flow MF is linearly exhausted from the back side of the outdoor
unit 100 to the front side through the opening of the bellmouth
5. Meanwhile, the subsidiary flows SF other than the main flow MF
25 perform a direction change to be exhausted through the opening of
21
the bellmouth 5.
[0061] Some of the subsidiary flows SF are guided to the duct
52 to be introduced into the air flow passages AP of the heat sink
51. Some of the subsidiary flows SF having been introduced into
the air flow passages AP become the air flow HF1 that 5 flows straight
through the air flow passages AP and collide with the front panel
203 and the air flow HF2 flowing from the middle of the air flow
passages AP to the outside of the air flow passages AP. The ratio
of the flow rates of the air flow HF1 and the air flow HF2 varies
10 depending on, for example, the positional relationship between the
heat sink 51 and the air-sending fan 3.
[0062] The air flow HF1 and the air flow HF2 take heat from
the heat-radiating fins 51b of the heat sink 51 when passing through
the air flow passages AP. The heat-radiating fins 51b lowered in
15 the temperature take heat from the heat sink base plate 51a. The
heat sink base plate 51a lowered in the temperature takes heat from
the power supply control component 33 held in contact with the heat
sink base plate 51a with the heat conductive grease or the heat
conductive sheet. With this, heat generated from the power supply
20 control component 33 is radiated.
[0063] In the cooling structure 50 according to the first
embodiment, among the end portions of the duct 52 on the back side
of the outdoor unit 100, only the side plate and the bottom plate
are extended to the back side of the outdoor unit 100, that is,
25 in the upstream side direction of the air flow. However, the shape
22
of the duct 52 is not limited thereto. For example, only one of
the side plate and the bottom plate may be extended. Further, when
the duct 52 includes the top plate and the side plate on the heat
sink support 55 side, the top plate, the bottom plate, and both
the side plates of the duct 52 may be appropriately 5 extended in
accordance with a positional relationship between the heat sink
51 and a peripheral device such as the air-sending fan 3.
[0064] Further, in the cooling structure 50 according to the
first embodiment, the outdoor unit 100 includes one air-sending
10 fan 3, but the number of the air-sending fans 3 is not limited thereto.
For example, two or more air-sending fans 3 may be arranged. In
this case, the end portions of the duct 52 on the +Y side are
appropriately extended in accordance with the air flow generated
in the fan chamber 120 so that the same effects as those of the
15 first embodiment can be obtained.
[0065] Second Embodiment
FIG. 7 is a perspective view of an outdoor unit 100A including
a cooling structure 50A according to a second embodiment as viewed
from the front in a state in which a part of the casing 200 is
20 transparent. FIG. 8 is a sectional view of the outdoor unit taken
along the plane S3 of FIG. 7 as viewed from above. FIG. 9 is a
sectional view of the outdoor unit taken along the plane S4 of FIG.
7 as viewed from the fan chamber side. FIG. 10 is an enlarged view
of the part C of FIG. 7 as viewed from the back side. FIG. 11 is
25 an enlarged view of the part D of FIG. 9.
23
[0066] The cooling structure 50A according to the second
embodiment is different from the cooling structure 50 according
to the first embodiment in a shape of an end portion of a duct 52A
on the back side of the outdoor unit 100. Other configurations are
the same as those of the 5 first embodiment.
[0067] As illustrated in FIG. 8 to FIG. 10, in the duct 52A
in the cooling structure 50A according to the second embodiment,
an extending portion 52e is formed on the end portion on the back
side of the outdoor unit 100, that is, the upstream side of the
10 air flow.
[0068] The extending portion 52e is formed by extending the
side plate at an angle of 45° from the end portion on the back side
of the outdoor unit 100 outward in the lateral and downward
directions. Further, the extending portion 52e is formed by
15 extending the bottom plate at an angle of 45°from the end portion
on the back side of the outdoor unit 100 outward in the downward
and lateral directions. That is, the side plate and the bottom plate
of the extending portion 52e are extended in a direction in which
an opening of the duct 52A becomes larger as being spaced away from
20 the heat sink 51, that is, as approaching to the back panel 204.
[0069] FIG. 11 is an enlarged view of the part D in FIG. 9 and
is an explanatory view of the flow of the air flow. As illustrated
in FIG. 11, the extending portion 52e formed on the duct 52A is
configured to guide, to the air flow passages AP, the subsidiary
25 flow SF2 flowing below the heat sink 51 as well as the subsidiary
24
flow SF1 flowing linearly toward the air flow passages AP of the
heat sink 51.
[0070] Further, although not illustrated in FIG. 11, with the
extending portion 52e formed on the duct 52A, on the side of the
heat sink 51 being the inlet side of the air flow 5 passages AP and
facing the back side of the outdoor unit 100, the air flow flowing
from the machine chamber 110 side to the fan chamber 120 side is
also guided to the air flow passages AP.
[0071] As described above, in the cooling structure 50A
10 according to the second embodiment, with the extending portion 52e
formed on the duct 52A, a larger amount of the air flow flowing
on the upstream side of the heat sink 51 can be guided to the air
flow passages AP. With this, the flow rate of the air flow passing
through the air flow passages AP can be increased. Accordingly,
15 the heat radiation effect of the heat sink 51 can be improved.
[0072] In the cooling structure 50A according to the second
embodiment, the angle of expansion of each of the side plate and
the bottom plate of the extending portion 52e is 45° from the end
portion on the back side of the outdoor unit 100. However, the angle
20 of expansion of each of the side plate and the bottom plate is not
limited thereto. For example, the angle of expansion of each of
the side plate and the bottom plate may be 45° or more or less than
45° from the end portion on the back side of the outdoor unit 100.
Further, the angles of expansions of the side plate and the bottom
25 plate may be set to be different from each other. The angle of
25
expansion of each of the side plate and the bottom plate is
appropriately determined in accordance with, for example, the
direction or the flow rate of the air flow generated around the
heat sink 51.
[0073] Further, as in a first modification example 5 illustrated
in FIG. 12, a baffle plate 107 may be mounted to the inner wall
of the front panel 203, which faces the outlets of the air flow
passages AP.
[0074] The gap is defined between the electric component box
10 20 and the top panel 201. A part of the subsidiary flow SF3 becomes
an air flow UF flowing through the gap from the upstream side to
the downstream side. The air flow UF collides with the front panel
203, and flows downward along the inner wall of the front panel
203. The air flow UF flowing downward along the inner wall of the
15 front panel 203 flows into the vicinity of the outlets of the air
flow passages AP. The air flow UF having flowed into the vicinity
of the outlets of the air flow passages AP passes through the air
flow passages AP, and is merged into an air flow HF11 that collides
with the front panel 203.
20 [0075] When the baffle plate 107 is not provided, as
illustrated in FIG. 11, the air flow UF having been merged into
the air flow HF1 collides with the protruding portion 5a of the
bellmouth 5 to be changed in direction to an upward direction, and
becomes the air flow RF flowing reverse to the main flow MF. Further,
25 the air flow RF is caused to collide with the air flow HF2 flowing
26
out from the vicinity of the middle of the air flow passages AP
to the outside of the air flow passages AP. Then, the flow speed
of the air flow HF2 flowing out from the air flow passages AP is
decreased. As a result, the flow rate of the air flow flowing
through the air flow passages AP is reduced, 5 and hence the heat
radiation effect of the heat sink 51 is reduced.
[0076] The baffle plate 107 to be mounted to the inner wall
of the front panel 203 is bent at an obtuse angle by sheet metal
processing. Then, the baffle plate 107 is mounted to the inner wall
10 of the front panel 203 with a fastening member such as a screw or
by welding. The bending portion of the baffle plate 107 is set to
an obtuse angle in order to suppress the decrease in speed of the
air flow. The bending portion of the baffle plate 107 may have a
curved shape.
15 [0077] As illustrated in FIG. 12, the baffle plate 107 is
mounted so that the bending portion is directed downward from the
inner wall of the front panel 203 toward the back panel 204. In
this case, the end portion of the baffle plate 107 on the lower
side is mounted so as to be directed to the end portion of the
20 protruding portion 5a of the bellmouth 5 on the upper side.
[0078] The air flow HF11 passing through the air flow passages
AP is guided to the opening of the bellmouth 5 along the baffle
plate 107 mounted to the front panel 203. With this, generation
of the air flow RF is suppressed, and an air flow HF21 flows toward
25 the opening of the bellmouth 5 without colliding with the air flow
27
RF. As a result, the heat radiation effect of the heat sink 51 is
improved.
[0079] The shape and the arrangement of the baffle plate 107
can be appropriately changed depending on the positional
relationship between the heat sink 51 and 5 the bellmouth 5.
[0080] Further, as in the second modification example
illustrated in FIG. 13 and FIG. 14, a foamed resin member 105 may
be arranged on the electric component box 20 located on the fan
chamber 120 side as a blocking member for blocking the air flow
10 UF.
[0081] As illustrated in FIG. 13, the foamed resin member 105
is attached to the upper surface of the lid 22 of the electric
component box 20 along the outer periphery of the lid 22. As
illustrated in FIG. 14, the foamed resin member 105 is pressed to
15 be compressed by the top panel 201. Accordingly, the gap between
the electric component box 20 in the fan chamber 120 and the top
panel 201 is blocked by the foamed resin member 105 without any
gap.
[0082] The subsidiary flow SF3 is prevented from flowing into
20 the gap between the electric component box 20 and the top panel
201, and flows toward the duct 52A. With this, the flow rate of
the air flow introduced into the air flow passages AP is increased.
As a result, the heat radiation effect of the heat sink 51 is further
improved.
28
[0083] The blocking member is not limited to the foamed resin
member 105, but may be any member as long as the member can close
the gap between the electric component box 20 and the top panel
201.
[0084] Further, in FIG. 13, the foamed resin 5 member 105 is
mounted along four sides of the upper surface of the lid 22. However,
the arrangement of the foamed resin member 105 is not limited thereto.
For example, the foamed resin member 105 may be attached to the
entire upper surface of the lid 22, or may be mounted to only the
10 side of the upper surface of the lid 22 on the back side of the
outdoor unit 100 and both sides on side surface sides.
[0085] The first and second embodiments of the present
invention have been described, and the present invention is not
limited to those embodiments. It is apparent to those skilled in
15 the art that variations and modifications may be made to those
embodiments without departing from the scope of the present
invention. The scope of the present invention is defined by the
appended claims and their equivalents.
20 Reference Signs List
[0086] 3 air-sending fan, 5 bellmouth, 5a annular protruding
portion, 7 compressor, 71 anti-vibration rubber, 8 reactor, 20
electric component box, 21 cover, 22 lid, 30 electric circuit board,
33 power supply control component (heat generator), 50,50A cooling
25 structure, 51 heat sink, 51a heat sink base plate, 51b
29
heat-radiating fins, 52,52A duct, 52b downstream end portion, 52e
extending portion, 54 heat sink holder, 55 heat sink support, 81
core, 82 coil, 100,100A outdoor unit, 102 partition plate, 103 heat
exchanger, 104 support plate, 105 foamed resin member, 107 baffle
plate, 110 machine chamber, 120 fan chamber, 200 5 casing, 201 top
panel, 202 bottom panel, 203 front panel, 204 back panel, 205,206
side panel.
30
We Claim :
[Claim 1] A cooling structure, comprising:
a heat sink to be mounted to a heat generator; and
a duct, which is mounted to the heat sink, and is configured
to guide an air flow flowing around the heat sink 5 to the heat sink,
wherein the heat sink has an air flow passage configured to
allow the air flow to pass through the air flow passage,
wherein one end side of the duct is to be mounted to an upstream
side of the air flow passage, and
10 wherein another end side of the duct is to be extended from
an upstream end portion of the air flow passage to an upstream side
of the air flow.
[Claim 2] The cooling structure according to claim 1, wherein the
15 one end side of the duct is configured to cover an outer periphery
of the air flow passage from the upstream end portion of the air
flow passage to a middle position of the air flow passage.
[Claim 3] The cooling structure according to claim 1 or 2, wherein
20 at least one surface of surfaces of the duct that form the another
end side is extended to the upstream side of the air flow with respect
to another surface of the surfaces of the duct that form the another
end side.
25 [Claim 4] The cooling structure according to claim 3, wherein the
31
extended surface comprises two surfaces forming a corner portion
of the duct.
[Claim 5] The cooling structure according to claim 3 or 4, wherein
the another end side of the duct is extended 5 in a direction of
expanding outward as being spaced away from the upstream end portion
of the air flow passage.
[Claim 6] The cooling structure according to claim 5, wherein the
10 extended surface is expanded outward from the upstream end portion
of the air flow passage at an inclination of 45°.
[Claim 7] The cooling structure according to any one of claims 1
to 6,
15 wherein the heat sink includes a plurality of heat-radiating
fins arranged so as to be spaced away from each other, and
wherein the air flow passage is formed by a gap defined between
the heat-radiating fins adjacent to each other.
20 [Claim 8] The cooling structure according to any one of claims 1
to 7, further comprising:
a casing in which the heat generator, the heat sink, and the
duct are accommodated; and
an air-sending fan configured to generate the air flow,
25 wherein the casing has an inlet port and an exhaust port,
32
wherein a peripheral edge portion of the exhaust port includes
an annular protruding portion that protrudes to an inner side of
the casing, and
wherein an end portion of the one end side of the duct is
arranged on the upstream side of the air flow 5 with respect to an
end portion of the protruding portion.
[Claim 9] The cooling structure according to claim 8, wherein the
end portion of the one end side of the duct is located on an upper
10 side with respect to an uppermost portion of the end portion of
the protruding portion.
[Claim 10] The cooling structure according to claim 8 or 9, further
comprising a baffle plate configured to guide an air flow flowing
15 out from the air flow passage toward the exhaust port,
wherein the baffle plate is mounted to an inner wall of the
casing that faces a downstream end portion of the air flow passage.
[Claim 11] An outdoor unit, comprising the cooling structure of
20 any one of claims 1 to 10.
[Claim 12] An outdoor unit, comprising:
the cooling structure of any one of claims 8 to 10;
a partition plate configured to partition the casing into a
25 machine chamber in which a compressor and other components are
arranged and a fan chamber in which
an electric component box in which
is to be accommodated
a blocking member
wherein the electric 5 component box
machine chamber and the fan chamber above
wherein, in a region of
accommodated in the electric component box
an electronic component
10 wherein the heat sink
and
wherein the blocking member
portion of the electric component box
panel forming a top surface of the