AU2019246289B2

AU2019246289B2 - Indoor unit of air conditioner

Info

Publication number: AU2019246289B2
Application number: AU2019246289A
Authority: AU
Inventors: Zuozhou CHEN; Masahito Higashida; Kaname Maruyama; Satoshi Nakai; Hideshi Tanaka; Hironobu Teraoka; Masafumi UDA
Original assignee: Daikin Industries Ltd
Current assignee: Daikin Industries Ltd
Priority date: 2018-03-30
Filing date: 2019-02-26
Publication date: 2022-02-10
Anticipated expiration: 2039-02-26
Also published as: AU2019246289A1; EP3779296B1; EP3779296A4; US20210033288A1; EP3779296A1; CN111902679A; WO2019187895A1; JP6926024B2; JP2019178851A

Abstract

This indoor unit of an air conditioner comprises: an indoor unit body having an intake opening and a discharge opening; a heat exchanger that exchanges heat with air taken in from the intake opening; and a crossflow fan that is configured so as to discharge, from the discharge opening, air subjected to heat exchange by the heat exchanger. The crossflow fan has formed therein a discharge flow path that guides discharge air to the discharge opening, the discharge flow path being constituted by a lower wall, left and right side walls, and an upper wall such that the cross-sectional area thereof increases in a fan shape. The side walls are provided so as to protrude from the discharge opening at least during air conditioning operation.

Description

DESCRIPTION INDOOR UNIT OF AIR CONDITIONER TECHNICAL FIELD

[0001] The present disclosure relates to an indoor unit of an air conditioner.

BACKGROUND ART

[0002] Patent Document 1discloses one example of the structure of an indoor unit of an air conditioner in which a wall portion extends upward from a guide surface of a flap at each of two longitudinal ends of the flap.

PRIOR ART DOCUMENT

Patent Document

[0003] Patent Document 1: International Publication No. 2014/199590

SUMMARY OF THE INVENTION

[0004] In the indoor unit in Patent Document 1, when the flap is located at a position such that air blown out of an outlet is directed downward from the indoor unit, a gap becomes large between the side walls of the flap and the outlet. This causes the blown-out air to flow backward between the side walls and the outlet, which results in surging.

[0005] It is an object of the present invention to substantially overcome or at least ameliorate one or more of the above disadvantages. Some embodiments are intended to provide an indoor unit of an air conditioner that reduces the occurrence of surging.

[0005a] One aspect of the present disclosure provides an indoor unit of an air conditioner, comprising: an indoor unit main body including an inlet and a main body outlet; a heat exchanger that performs heat exchange on air drawn in from the inlet; and a cross-flow fan configured to blow out air, which has undergone heat exchange performed by the heat exchanger, from the main body outlet, wherein: the cross-flow fan includes a blow-out flow path formed by a lower wall, left and right side walls, and an upper wall so that a cross-sectional area of the blow-out flow path gradually increases downward along the blow-out flow path, with the blow-out flow path guiding blown-out air to the main body outlet, the two side walls are arranged to project out of the main body outlet at least when an air conditioning operation is la performed, in the projected state, the side walls are configured to entirely cover transverse sides of the main body outlet, and the lower wall is arranged to project out of the main body outlet at least when an air conditioning operation is performed.

[0006] Also disclosed herein is an indoor unit of an air conditioner includes an indoor unit main body, a heat exchanger, and a cross-flow fan. The indoor unit main body includes an inlet and an outlet. The heat exchanger performs heat exchange on air drawn in from the inlet. The cross-flow fan is configured to blow out air, which has undergone heat exchange performed by the heat exchanger, from the outlet. The cross-flow fan includes a blow-out flow path formed by a lower wall, left and right side walls, and an upper wall so that a cross-sectional area gradually increases downward. The blow-out flow path guides blown-out air to the outlet. The side walls are arranged to project out of the outlet at least when an air conditioning operation is performed.

[0007] With this structure, the side walls restrict the air blown out of the outlet from

flowing sideward from the outlet. This allows the blow-out flow path to be extended from

the outlet. In this manner, the static pressure in the blow-out flow path is increased to

increase the air volume of the blow-out flow path is increased. Further, when the air flow

resistance (internal pressure loss) in the indoor unit main body is high, backflow of air from

the two sideward ends of the outlet is restricted. Thus, surging is unlikely to occur.

[0008] In the above-described indoor unit of an air conditioner, it is preferred that the lower

wall be arranged to project out of the outlet at least when an air conditioning operation is

performed.

With this structure, the lower wall projects out of the outlet with the two side walls.

Thus, the two side walls and the lower wall restrict the air blown out of the outlet from

flowing sideward and downward from the outlet. This allows the blow-out flow path to be

extended from the outlet. In this manner, the blow-out flow path serving as a diffuser is

lengthened compared to a structure that does not project the two side walls and the lower

wall out of the outlet. This further increases the static pressure in the blow-out flow path and

further increases the air volume of the blow-out flow path. Also, when the air flow resistance

(internal pressure loss) in the indoor unit main body is high, backflow of air from the two

sideward ends and the lower part of the outlet is restricted. Thus, surging is even less likely

to occur.

[0009] In the above-described indoor unit of an air conditioner, it is preferred that the upper

performed.

With this structure, the upper wall projects out of the outlet with the two side walls.

Thus, the two side walls and the upper wall restrict the air blown out of the outlet from

flowing sideward and upward from the outlet. This allows the blow-out flow path to be

lengthened compared to a structure that does not project the two side walls and the upper

sideward ends and the upper part of the outlet is restricted. Thus, surging is even less likely

to occur.

[0010] In the above-described indoor unit of an air conditioner, it is preferred that the blow

out flow path be formed to project out of the outlet so that a distance between the left and

right side walls in a sideward direction in the blow-out flow path at a downstream side of the

outlet is less than a sideward length of the outlet.

[0011] With this structure, the cross-sectional area of the blow-out flow path at a

downstream side of the outlet is decreased so that the velocity of the air in the blow-out flow

path at the downstream side of the outlet is increased. This restricts backflow of air from the

outlet. Thus, surging is even less likely to occur.

[0012] In the above-described indoor unit of an air conditioner, it is preferred that the

indoor unit further include a movement mechanism configured to switch between a stored

state that does not project an element forming the blow-out flow path including the side

walls out of the outlet and a projected state that projects at least the side walls out of the outlet. Preferably, the movement mechanism is in the projected state when an air conditioning operation is performed and in the stored state when an air conditioning operation is stopped.

[0013] With this structure, the blow-out flow path projects out of the indoor unit main body

when an air conditioning operation is performed. Thus, surging is unlikely to occur. Further,

the blow-out flow path is stored in the indoor unit main body when an air conditioning

operation is stopped. Thus, the aesthetic appearance of the indoor unit is improved.

[0014] In the above-described indoor unit of an air conditioner, it is preferred that when

surging occurs, the movement mechanism move the element to decrease a cross-sectional

area of the blow-out flow path at a portion projecting from the outlet.

[0015] With this structure, when surging occurs, the cross-sectional area of the blow-out

flow path at a downstream side of the outlet is decreased so that the velocity in the air in the

blow-out flow path at the downstream side of the outlet is increased. This restricts backflow

of air from the outlet thereby impeding surging.

[0016] In the above-described indoor unit of an air conditioner, it is preferred that the

indoor unit be configured so that a ratio (H/D) of height H of the indoor unit main body to

outer diameter D of an impeller of the cross-flow fan is less than 2.2.

[0017] With this structure, the indoor unit main body uses the cross-flow fan including the

impeller with a relatively large outer diameter. This allows noise and power consumption to

be reduced when an air conditioning operation is performed.

BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Fig. 1 shows diagrams of an indoor unit of an air conditioner in accordance with a

first embodiment, in which Fig. 1A is a perspective view of the indoor unit in a stored state,

and Fig. 1B is a perspective view of the indoor unit in a projected state.

Fig. 2 shows diagrams of the indoor unit in Fig. 1, in which Fig. 2A is a cross

sectional view of the indoor unit in the stored state, and Fig. 2B is a cross-sectional view of

the indoor unit in the projected state.

Fig. 3 is a block diagram showing the electrical structure of the air conditioner.

Fig. 4 is a flowchart illustrating one example of a procedure for processing

movement control executed by a control unit of the indoor unit.

Fig. 5 shows diagrams of an indoor unit of an air conditioner in accordance with a

second embodiment, in which Fig. 5A is a perspective view of the indoor unit in a stored

state, and Fig. 5B is a perspective view of the indoor unit in a projected state.

Fig. 6 shows diagrams of the indoor unit in Fig. 5, in which Fig. 6A is a cross

sectional view of the indoor unit in the stored state, and Fig. 6B is a cross-sectional view of

the indoor unit in the projected state.

Fig. 7 shows diagrams of an indoor unit of an air conditioner in accordance with a

third embodiment, in which Fig. 7A is a perspective view of the indoor unit in a stored state,

and Fig. 7B is a perspective view of the indoor unit in a projected state.

Fig. 8 shows diagrams of the indoor unit in Fig. 7, in which Fig. 8A is a cross

sectional view of the indoor unit in the stored state, and Fig. 8B is a cross-sectional view of

the indoor unit in the projected state.

Fig. 9 shows diagrams of an indoor unit of an air conditioner in accordance with a

fourth embodiment, in which Fig. 9A is a cross-sectional view of the indoor unit, and Fig.

9B is an enlarged view of a blow-out flow path and its periphery shown in Fig. 9A.

Fig. 10 shows diagrams of an indoor unit of an air conditioner of a modified

example, in which Fig. 1OA is a perspective view of the indoor unit in a stored state, and Fig.

1OB is a perspective view of the indoor unit in a projected state.

Fig. 11 shows diagrams of an indoor unit of an air conditioner of a modified example, in which Fig. 11A is a perspective view of the indoor unit in a stored state, and Fig.

11B is a perspective view of the indoor unit in a projected state.

Fig. 12 shows diagrams of an indoor unit of an air conditioner of a modified

example, in which Fig. 12A is a perspective view of the indoor unit in a stored state, and Fig.

12B is a perspective view of the indoor unit in a projected state.

Fig. 13 shows diagrams of an indoor unit of an air conditioner of a modified

example, in which Fig. 13A is a cross-sectional view of the indoor unit in a stored state, and

Fig. 13B is a cross-sectional view of the indoor unit in a projected state.

Fig. 14 shows diagrams of an indoor unit of an air conditioner of a modified

example, in which Fig. 14A is a cross-sectional view of the indoor unit in a stored state, and

Fig. 14B is a cross-sectional view of the indoor unit in a projected state.

Fig. 15 shows diagrams of an indoor unit of an air conditioner of a modified

example, in which Fig. 15A is a perspective view of the indoor unit, and Fig. 15B is an

enlarged view of part of Fig. 15A.

MODES FOR CARRYING OUT THE INVENTION

[0019] First Embodiment

An indoor unit 1 of an air conditioner in accordance with afirst embodiment will

now be described with reference to Figs. 1 and 4.

The indoor unit 1 of the present embodiment is of a wall-mounted type and includes

a rear portion attached to an indoor wall WL. The indoor unit 1 is, for example, configured

to perform a cooling operation that cools an indoor space and a heating operation that heats

an indoor space.

[0020] As shown in Figs. 1 and 2, the indoor unit 1 includes an indoor unit main body 10.

The indoor unit main body 10 has the form of a box, in which a lateral direction (sideward direction of indoor unit 1) coincides with the longitudinal direction, and includes an inner space surrounded by a top surface portion 11, a front surface portion 12, a rear surface portion 13, two side surface portions 14, and a bottom surface portion 15. The indoor unit 1 is mounted on the wall WL by coupling the rear surface portion 13 to a mounting panel (not shown) on the wall WL with screws or the like. The top surface portion 11 of the indoor unit main body 10 includes an inlet 16, and the bottom surface portion 15 includes an outlet 17.

The inlet 16 and the outlet 17 are each arranged so that the lateral direction (sideward

direction) coincides with the longitudinal direction. The inlet 16 is formed along the top

surface portion 11. The outlet 17 is formed along the bottom surface portion 15.

[0021] As shown in Fig. 2, the indoor unit 1 includes an air filter 21, an indoor heat

exchanger 22, a cross-flow fan 23, and a flap 24. The air filter 21, the indoor heat exchanger

22, and the cross-flow fan 23 are accommodated in the indoor unit main body 10.

[0022] The air filter 21 is coupled to the indoor unit main body 10 in a removable manner.

The air filter 21 removes dust from indoor air drawn in from the inlet 16. In a state in which

the air filter 21 is attached to the indoor unit main body 10, the air filter 21 is located

between the top surface portion 11 and the indoor heat exchanger 22 of the indoor unit main

body 10. In this manner, the air filter 21 limits the collection of dust, which is suspended in

the indoor air, on the surface of the indoor heat exchanger 22.

[0023] The indoor heat exchanger 22 includes a plurality of fins and a plurality of heat

transfer tubes that extend through the fins. The indoor heat exchanger 22 serves as an

evaporator or a condenser in accordance with an operation state of the indoor unit 1 and

exchanges heat between a refrigerant flowing through the heat transfer tubes and air flowing

through the indoor heat exchanger 22.

[0024] The indoor heat exchanger 22 is arranged so that its front end and rear end are bent

downward in a side view. The indoor heat exchanger 22 is arranged to surround the cross flow fan 23 from above.

[0025] The cross-flow fan 23 is located inside the indoor unit main body 10 at a

substantially central portion. The cross-flow fan 23 includes an impeller 25 and a fan case 27.

The impeller 25 is substantially cylindrical and has a lateral direction (sideward direction)

that coincides with the longitudinal direction. The fan case 27 forms a blow-out flow path 26

that extends to the outlet 17. The blow-out flow path 26 is formed by a lower wall 26L, left

and right side walls 26S, and an upper wall 26U in a manner so that its cross-sectional area

gradually increases downward. In other words, the cross-sectional area of the blow-out flow

path 26 increases toward the outlet 17. In this manner, the blow-out flow path 26 functions

as a diffuser.

[0026] When the cross-flow fan 23 is being rotated and operated, the indoor air drawn in

from the inlet 16 flows through the indoor heat exchanger 22 to the cross-flow fan 23. Then,

the indoor air flows from the cross-flow fan 23 through the blow-out flow path 26 and is

blown out of the outlet 17 into the room.

[0027] The impeller 25 of the cross-flow fan 23 has an outer diameter D, and the rear

surface portion 13 of the indoor unit main body 10 has a vertical dimension (up-down

dimension) that corresponds to a height H of the indoor unit main body 10. Preferably, the

outer diameter D is 126 mm or greater and less than 150 mm. Further preferably, the outer

diameter D is 135 mm or greater and less than 150 mm. Preferably, the height H of the

indoor unit main body 10 is 295 mm or less. Further preferably, the height H of the indoor

unit main body 10 is 250 mm or greater and 295 mm or less. Preferably, a ratio (H/D) of the

height H of the indoor unit main body 10 to the outer diameter D is less than 2.2. Further

preferably, the ratio (H/D) of the height H of the indoor unit main body 10 to the outer

diameter D is 1.6 or greater and less than 2.2.

[0028] The flap 24 is arranged at a lower edge of the outlet 17 and is rotatable relative to the indoor unit main body 10. The flap 24 has the form of a flat plate and its lateral direction

(sideward direction) coincides with the longitudinal direction. The flap 24 has a length in the

longitudinal direction that is substantially the same as that of the outlet 17. The flap 24 is

configured to be pivoted by a flap driving motor 28 (refer to Fig. 3) about a rotation axis C1.

[0029] The indoor unit 1 of the present embodiment includes a movement mechanism 29

that is configured to move the two side walls 26S of the blow-out flow path 26. More

specifically, the two side walls 26S each include a fixed side wall 26SF and a movable side

wall 26SM. The fixed side wall SF and the movable side wall 26SM are arranged to be

overlapped with each other in the lateral direction (sideward direction). The movable side

wall 26SM is configured to be movable so as to slide relative to the fixed side wall SF and

project out of the outlet 17. The movement mechanism 29 moves the movable side walls

26SM. The movement mechanism 29 includes a first motor (not shown), which serves a

drive source, and a rotation-linear movement conversion mechanism (not shown), which

converts rotation of the first motor into linear movement in a predetermined direction. One

example of the movement mechanism 29 is a feed-screw mechanism. Further, in a state in

which the movable side walls 26SM project out of the outlet 17, the movement mechanism

29 is configured to move the movable side walls 26SM so as to decrease the cross-sectional

area between the left and right movable side walls 26SM. In one example, the movement

mechanism 29 includes a second motor (not shown) that pivots each movable side wall

26SM about a rotation axis C2 (refer to Fig. 2B). This allows the distance between the left

and right movable side walls 26SM in the sideward direction to be changed at a projected

end side. In this manner, the movement mechanism 29 allows for switching between a

restricted state, in which the cross-sectional area between the left and right movable side

walls 26SM is decreased, and a normal state, in which the cross-sectional area between the

left and right movable side walls 26SM is not decreased. In one example, in the restricted state, the distance between the left and right movable side walls 26SM in the sideward direction at the projected end side is less than the sideward length of the outlet 17.

[0030] As shown in Fig. 3, the air conditioner includes an outdoor control unit 7 that

controls each of a compressor 3 of an outdoor unit 2, a four-way switching valve 4, an

outdoor fan 5, and an expansion valve 6. In one example, the outdoor control unit 7 controls

the operational frequency (Hz) of the compressor 3, the rotational speed (rpm) of a motor of

the outdoor fan 5, and the open degree of the expansion valve 6. Further, the outdoor control

unit 7 switches the four-way switching valve 4 between a first state, in which a refrigerant

circuit of the air conditioner (not shown) is in a cooling cycle, and a second state, in which

the refrigerant circuit is in a heating cycle.

[0031] The indoor unit 1 includes an indoor control unit 30. The indoor control unit 30

includes a processor and storage. The processor executes predetermined control programs,

and the storage stores information used for various types of control programs and control

processes. The processor includes, for example, a central processing unit (CPU) or a micro

processing unit (MPU). The storage includes, for example, a nonvolatile memory and a

volatile memory. The non-volatile memory includes, for example, a read-only memory

(ROM), a hard disk, and a flash memory. The volatile memory includes, for example, a

random-access memory (RAM). The indoor control unit 30 may include one or more

microcomputers. The outdoor control unit 7 may be configured in the same manner as the

indoor control unit 30.

[0032] The indoor control unit 30 is configured to establish wired or wireless

communication with the outdoor control unit 7. Further, the indoor control unit 30 is

configured to establish wireless communication with a remote controller 31. The indoor

control unit 30 controls the cross-flow fan 23, the flap driving motor 28, and the movement

mechanism 29 based on operation instructions from the remote controller 31. Further, the indoor control unit 30 transmits the contents of an operation instruction from the remote controller 31 to the outdoor control unit 7. Based on the operation instruction from the remote controller 31, the outdoor control unit 7 controls the operational frequency (Hz) of the compressor 3, the rotational speed (rpm) of the outdoor fan 5, the open degree of the expansion valve 6, and switching of the four-way switching valve 4 between the first state and the second state.

[0033] The indoor control unit 30 of the present embodiment controls the movement

mechanism 29 to switch between the stored state, in which the movable side walls 26SM do

not project out of the outlet 17 as shown in Figs. 1A and 2A, and the projected state, in

which the movable side walls 26SM project out of the outlet 17 as shown in Figs. 1B and 2B.

In one example, the indoor control unit 30 controls the movement mechanism 29 to be in the

projected state when an air conditioning operation is performed and controls the movement

mechanism 29 to be in the stored state when an air conditioning operation is stopped. In one

example, as shown in Fig. 1B and 2B, in the projected state, the movable side walls 26SM

are configured to entirely cover transverse sides (up-down sides) of the outlet 17 in the

projected state.

[0034] Also, when an air conditioning operation is stopped, the indoor control unit 30

controls the flap driving motor 28 so that the flap 24 covers the outlet 17 as shown in Figs.

1A and 2A. Further, when an air conditioning operation is performed, the indoor control unit

controls the flap driving motor 28 so that the flap 24 opens the outlet 17 as shown in Figs.

lB and 2B. In this manner, when an air conditioning operation is stopped, the indoor unit 1

shown in Figs. 1A and 2A is in a state in which the movable side walls 26SM and the flap 24

do not project out of the indoor unit main body 10. Further, when an air conditioning

operation is performed, the indoor unit 1shown in Figs. B and 2B is in a state in which the

movable side walls 26SM and the flap 24 project out of the indoor unit main body 10.

[0035] When an air conditioning operation is performed, the pivotal position of the flap 24

can be freely changed. In one example, the pivotal position of the flap 24 is changeable by

an instruction from the remote controller 31.

[0036] Further, when surging occurs, the indoor control unit 30 controls the movement

mechanism 29 in the restricted state to decrease the cross-sectional area between the left and

right movable side walls 26SM with the second motor that pivots each movable side wall

26SM about the rotation axis C2 (refer to Fig. 2B). In the restricted state, the cross-sectional

area of the blow-out flow path 26 at a downstream side of the outlet 17 is smaller than the

cross-sectional area of the outlet 17. This increases the velocity of the indoor air in the blow

out flow path 26 and impedes surging. Further, when surging is impeded, the indoor control

unit 30 controls the movement mechanism 29 to switch from the restricted state to the

normal state with the second motor. Here, surging refers to noise (for example, rustling

noise) produced when the volume or pressure of the indoor air blown out of the outlet 17

becomes unstable and backflow forms at the outlet 17. Surging is likely to occur, for

example, when the air filter 21 is clogged with dust and the air flow resistance is increased

or when condensation is formed on the indoor heat exchanger 22.

[0037] In one example, surging is detected from the rotational speed (rpm) of a fan motor

(not shown) of the cross-flow fan 23. More specifically, the indoor control unit 30 sets the

rotational speed of the fan motor in accordance with the operation instruction from the

remote controller 31. The rotational speed of the fan motor that is set will be referred to as

the set rotational speed. The indoor control unit 30 determines whether the rotational speed

of the fan motor is in a tolerable rotational speed range that has a predetermined width

centered on the set rotational speed. When the rotational speed of the fan motor is in the

tolerable rotational speed range, the rotational speed of the fan motor is stable and the

volume and pressure of the indoor air are less likely to be unstable. Accordingly, the indoor control unit 30 determines that surging has not occurred. When the rotational speed of the motor is outside the tolerable rotational speed range, the rotational speed of the fan motor is unstable and the volume and pressure of the indoor air are likely to be unstable. Accordingly, the indoor control unit 30 determines that surging has occurred. In the above-described detection of surging, the predetermined width is used to determine whether surging has occurred due to variations in the rotational speed of the fan motor and is set in advance through tests or the like.

[0038] Alternatively, surging may be detected from the current supplied to the fan motor of

the cross-flow fan 23. More specifically, the indoor control unit 30 determines whether the

current supplied to the fan motor is in a tolerable current range that has a predetermined

width centered on a current value corresponding to the set rotational speed. When the current

supplied to the fan motor is in the tolerable current range, the volume and pressure of the

indoor air are stable and the current supplied to the fan motor is stable. Accordingly, the

indoor control unit 30 determines that surging has not occurred. When the current supplied to

the fan motor is outside the tolerable current range, the volume and pressure of the indoor air

are unstable and the current supplied to the fan motor is unstable. Accordingly, the indoor

control unit 30 determines that surging has occurred. The predetermined width is used to

determine whether surging has occurred due to variations in the current supplied to the fan

motor and is set in advance through tests or the like.

[0039] One example of a processing procedure for a movement control of the movement

mechanism 29 executed by the indoor control unit 30 will now be described with reference

to Fig. 4. This movement control is executed over a period of time from when an air

conditioning operation starts to when it ends.

[0040] Instep Si1, the indoor control unit 30 determines whether to start an air

conditioning operation. In one example, when an operation start instruction has been received from the remote controller 31, the indoor control unit 30 determines to start an air conditioning operation. Further, when an operation start instruction has not been received, the indoor control unit 30 determines not to start an air conditioning operation.

[0041] When the indoor control unit 30 determines not to start an air conditioning

operation (step S11: NO), the indoor control unit 30 ends the process. In this case, the

movable side walls 26SM are maintained to be in the stored state. When the indoor control

unit 30 determines to start an air conditioning operation (step S11: YES), the indoor control

unit 30 sets the movable side walls 26SM in the projected state in step 12. This projects the

movable side walls 26SM out of the outlet 17. Subsequently, in step S13, the indoor control

unit 30 determines whether surging has occurred.

[0042] When determining that surging has occurred (step S13: YES), the indoor control

unit 30 controls the second motor of the movement mechanism 29 to switch to the restricted

state, in which the cross-sectional area between the left and right movable side walls 26SM

is decreased, in step S14. Then, in step S15, the indoor control unit 30 determines whether to

end the air conditioning operation. In one example, when an operation end instruction has

been received from the remote controller 31, the indoor control unit 30 determines to end the

air conditioning operation. Further, when an operation end instruction has not been received,

the indoor control unit 30 determines not to end the air conditioning operation.

[0043] When the indoor control unit 30 determines not to end the air conditioning

operation (step S15: NO), the indoor control unit 30 proceeds to step S13. When the indoor

control unit 30 determines to end the air conditioning operation (step S15: YES), the indoor

control unit 30 sets the movable side walls 26SM in the stored state in step S16. This stores

the movable side walls 26SM in the indoor unit main body 10.

[0044] Further, when surging has not occurred (step S13: NO), the indoor control unit 30

determines whether the movable side walls 26SM are in the restricted state in step S17.

When the movable side walls 26SM are in the restricted state (step S17: YES), the indoor

control unit 30 changes the movable side walls 26SM to the normal state in step S18 and

then proceeds to step S15. When the movable side walls 26SM are in the normal state (step

S17: NO), the indoor control unit 30 maintains the movable side walls 26SM in the normal

state and then proceeds to step S15.

[0045] The operation of the present embodiment will now be described.

If the outer diameter D of the impeller 25 of the cross-flow fan 23 is increased to

lower power consumption and reduce noise without increasing the height H of the indoor

unit main body 10 so as to limit decreases in the ease of installation of the indoor unit main

body 10, the region that defines the blow-out flow path 26 of the cross-flow fan 23 in the

indoor unit main body 10 would be decreased and the blow-out flow path 26 would be

shortened. When the blow-out flow path 26 is shortened, the dynamic pressure of the indoor

air will not be sufficiently converted into the static pressure in the blow-out flow path 26.

This would decrease the air volume and pressure in the cross-flow fan 23.

[0046] Also, when the air flow resistance inside the indoor unit main body 10 is increased

due to condensation on the indoor heat exchanger 22 or clogging of the air filter 21, the

velocity of the indoor air in the blow-out flow path 26 will be decreased and backflow from

the outlet 17 is likely to be generated. As a result, backflow of indoor air from the outlet 17

may cause surging that destabilizes the flow of the indoor air blown out of the cross-flow fan

23. Particularly, it is known that the velocity of indoor air at the two sideward ends of the

outlet 17 is slower than that at a laterally central part of the outlet 17. Accordingly, backflow

from the outlet 17 is more likely to be generated at the two sideward ends of the outlet 17.

[0047] In this respect, in the present embodiment, the movable side walls 26SM project out

of the outlet 17 when an air conditioning operation is performed. This allows the blow-out

flow path 26 to be extended by an amount corresponding to the length of the movable side walls 26SM. Furthermore, the movable side walls 26SM extend from the two sideward ends of the outlet 17 to project out of the outlet 17. This limits backflow of indoor air into the outlet 17 from an outer side of the two sideward ends of the outlet 17. Consequently, surging is impeded and changes in the air volume and pressure in the cross-flow fan 23 are limited.

[0048] The present embodiment has the following advantages.

(1-1) The movable side walls 26SM of the two side walls 26S are arranged to

project out of the outlet 17 at least when an air conditioning operation is performed. With

this structure, the movable side walls 26SM restrict the indoor air blown out of the outlet 17

from flowing sideward from the outlet 17. This allows the blow-out flow path 26 to be

extended from the outlet 17. In this manner, the static pressure in the blow-out flow path 26

is increased to increase the air volume of the blow-out flow path 26. Further, when the air

flow resistance (internal pressure loss) inside the indoor unit main body 10 is increased due

to, for example, condensation on the indoor heat exchanger 22, clogging of the air filter 21,

or the like, backflow of indoor air from the two ends of the outlet 17 is restricted. Thus,

surging is unlikely to occur.

[0049] (1-2) When surging occurs, the movement mechanism 29 decreases the distance

between the two movable side walls 26SM so that the distance is less than the sideward

length of the outlet 17. With this structure, the cross-sectional area of the blow-out flow path

26 at a downstream side of the outlet 17 is decreased so that the velocity of indoor air in the

blow-out flow path 26 at the downstream side of the outlet 17 is increased. This restricts

backflow of indoor air from the outlet 17 and thereby impedes surging.

[0050] (1-3) The indoor unit 1 includes the movement mechanism 29 that switches to the

projected state, in which the movable side walls 26SM project out of the outlet 17, when an

air conditioning operation is performed and switches to the stored state, in which the

movable side walls 26SM do not project out of the outlet 17, when an air conditioning operation is stopped. With this structure, the movable side walls 26SM project out of the indoor unit main body 10 when an air conditioning operation is performed. Thus, surging is unlikely to occur. Further, the movable side walls 26SM are stored in the indoor unit main body 10 when an air conditioning operation is stopped. Thus, the aesthetic appearance of the indoor unit 1 is improved.

[0051] (1-4) The indoor unit 1 is configured so that the ratio (H/D) of the height H of the

indoor unit main body 10 to the outer diameter D of the impeller 25 of the cross-flow fan 23

is less than 2.2. With this structure, the indoor unit main body 10 uses the cross-flow fan 23

including the impeller 25 with a relatively large outer diameter D. This allows noise and

power consumption to be reduced when the indoor unit 1 is operating.

[0052] (1-5) The indoor unit 1 is configured so that the ratio (H/D) of the height H of the

is greater than or equal to 1.6 and less than 2.2. This structure limits decreases in the ease of

setting of the indoor unit main body 10 in addition to obtaining advantage (1-4).

[0053] (1-6) The height Hof the indoorunit main body 10 is less than or equal to 295 mm.

This limits decreases in the ease of installation of the indoor unit main body 10. Particularly,

the height H of the indoor unit main body 10 is greater than or equal to 250 mm and less

than or equal to 295 mm. In this case, the cross-flow fan 23 including the impeller 25 that

has a relatively large outer diameter D can be used. This allows power consumption and

noise to be reduced while limiting decrease in the ease of setting of the indoor unit main

body 10.

[0054] Second Embodiment

An indoor unit 1 of an air conditioner in accordance with a second embodiment will

now be described with reference to Figs. 5 and 6. The indoor unit 1 of the present

embodiment differs from the indoor unit 1 of the first embodiment in that the lower wall 26L of the blow-out flow path 26 is projected out of the outlet 17 together with the two side walls

26S when an air conditioning operation is performed. In the description hereafter, same

reference numerals are given to those elements that are the same as the indoor unit 1 of the

first embodiment. Such elements will not be described in detail.

[0055] As shown in Figs. 5B and 6B, the lower wall 26L includes a fixed lower wall 26LF

and a movable lower wall 26LM. The flap 24 is coupled to a distal end of the movable lower

wall 26LM and is pivotal relative to the movable lower wall 26LM. The fixed lower wall

26LF and the movable lower wall 26LM are overlapped with each other in the vertical

direction (up-down direction). The movable lower wall 26LM is configured to be movable

so as to slide relative to the fixed lower wall 26LF and project out of the outlet 17.

[0056] The movement mechanism 29 of the present embodiment is configured to move the

movable side walls 26SM and the movable lower wall 26LM. In one example, the

movement mechanism 29 is configured to move and slide the movable side walls 26SM

relative to the fixed side walls SF and move and slide the movable lower wall 26LM relative

to the fixed lower wall 26LF. The movement mechanism 29 includes a first motor, a first

rotation-linear movement conversion mechanism that converts rotation of the first motor into

linear movement of the movable side walls 26SM, and a second rotation-linear movement

conversion mechanism that converts rotation of the first motor into linear movement of the

movable lower wall 26LM. In other words, the movement mechanism 29 of the present

embodiment moves the movable side walls 26SM and the movable lower wall 26LM with a

single drive source.

[0057] The indoor control unit 30 of the present embodiment (refer to Fig. 3) controls the

movement mechanism 29 to switch between a stored state, in which the movable side walls

26SM and the movable lower wall 26LM do not project out of the outlet 17 as shown in Figs.

A and 6A, and a projected state, in which the movable side walls 26SM and the movable lower wall 26LM project out of the outlet 17 as shown in Figs. 5B and 6B. In one example, the indoor control unit 30 controls the movement mechanism 29 in the projected state when an air conditioning operation is performed and controls the movement mechanism 29 in the stored state when an air conditioning operation is stopped.

[0058] In the projected state, the movable side walls 26SM are located above the sideward

ends of the movable lower wall 26LM. The movable side walls SM are arranged so that no

gap is formed between the movable side walls 26SM and the movable lower wall 26LM in

the vertical direction. Further, each movable side wall 26SM is pivotal about the rotation

axis C2 between the upper wall 26U and the movable lower wall 26LM.

[0059] Also, the relationship of the outer diameter D of the impeller 25 of the cross-flow

fan 23 and the height H of the indoor unit main body 10 of the present embodiment is the

same as the relationship of the outer diameter D of the impeller 25 of the cross-flow fan 23

and the height H of the indoor unit main body 10 of the first embodiment.

[0060] The present embodiment has the following advantages in addition to the advantages

of the first embodiment.

(2-1) The movable side walls 26SM of the two side walls 26S and the movable

lower wall 26LM of the lower wall 26L are arranged to project out of the outlet 17 at least

when an air conditioning operation is performed. With this structure, the movable side walls

26SM and the movable lower walls 26LM restrict the indoor air blown out of the outlet 17

from flowing sideward and downward from the outlet 17. This allows the blow-out flow path

26 to be extended from the outlet 17. In this manner, the blow-out flow path 26 serving as a

diffuser is lengthened compared to a structure that does not project the two side walls 26S

and the lower wall 26L out of the outlet 17. This further increases the static pressure in the

blow-out flow path 26 and further increases the air volume of the blow-out flow path 26.

Also, when the air flow resistance (internal pressure loss) in the indoor unit main body 10 is high, backflow of indoor air from the two sideward ends and the lower part of the outlet 17 is restricted. Thus, surging is even less likely to occur.

[0061] (2-2) The indoor unit 1 includes the movement mechanism 29 that projects the

movable side walls 26SM and the movable lower wall 26LM out of the outlet 17 in the

projected state when an air conditioning operation is performed and does not project the

stored state when an air conditioning operation is stopped. With this structure, the movable

side walls 26SM and the movable lower wall 26LM project out of the indoor unit main body

when an air conditioning operation is performed. Thus, surging is unlikely to occur.

Further, the movable side walls 26SM and the movable lower wall 26LM are stored in the

indoor unit main body 10. Thus, the aesthetic appearance of the indoor unit 1 is improved.

[0062] Third Embodiment

An indoor unit 1 of an air conditioner in accordance with a third embodiment will

now be described with reference to Figs. 7 and 8. The indoor unit 1 of the present

embodiment differs from the indoor unit 1 of the second embodiment in that the upper wall

26U projects out of the outlet 17 together with the two side walls 26S and the lower wall 26L

of the blow-out flow path 26 when an air conditioning operation is performed. In the

description hereafter, same reference numerals are given to those elements that are the same

as the indoor unit 1 of the second embodiment. Such elements will not be described in detail.

[0063] The upper wall 26U of the present embodiment includes a fixed upper wall 26UF

and a movable upper wall 26UM. The fixed upper wall 26UF and the movable upper wall

26UM are overlapped with each other in the vertical direction (up-down direction). The

movable upper wall 26UM is configured to be movable so as to slide relative to the fixed

upper wall 26UF and project out of the outlet 17.

[0064] The movement mechanism 29 of the present embodiment is configured to move the movable side walls 26SM, the movable lower wall 26LM, and the movable upper wall 26UM. In one example, the movement mechanism 29 is configured to move and slide the movable side walls 26SM relative to the fixed side walls SF, move and slide the movable lower wall 26LM relative to the fixed lower wall 26LF, and move and slide the movable upper wall 26UM relative to the fixed upper wall 26UF. The movement mechanism 29 includes a first motor, a first rotation-linear movement conversion mechanism that converts rotation of the first motor into linear movement of the movable side walls 26SM, a second rotation-linear movement conversion mechanism that converts rotation of the first motor into linear movement of the movable lower wall 26LM, and a third rotation-linear movement conversion mechanism that converts rotation of the first motor into linear movement of the movable upper wall 26UM. In other words, the movement mechanism 29 of the present embodiment moves the movable side walls 26SM, the movable lower wall 26LM, and the movable upper wall 26UM with a single drive source.

[0065] The indoor control unit 30 of the present embodiment (refer to Fig. 3) controls the movement mechanism 29 and switches between a stored state, in which the movable side walls 26SM, the movable lower wall 26LM, and the movable upper wall 26UM do not project out of the outlet 17 as shown in Figs. 7A and 8A, and a projected state, in which the movable side walls 26SM, the movable lower wall 26LM, and the movable upper wall 26UM project out of the outlet 17 as shown in Figs. 7B and 8B. In one example, the indoor control unit 30 controls the movement mechanism 29 to be in the projected state when an air conditioning operation is performed and controls the movement mechanism 29 to be in the stored state when an air conditioning operation is stopped.

[0066] In the present embodiment, as shown in Figs. 7B and 8B, the movable side walls 26SM are configured to entirely cover vertical sides (up-down sides) of the movable lower wall 26LM and the movable upper wall 26UM in the projected state. Specifically, in the projected state, the movable side walls 26SM are located between the movable lower wall

26LM and the movable upper wall 26UM in the vertical direction and at sideward ends of

the movable lower wall 26LM and the movable upper wall 26UM. The movable side walls

SM are arranged so that no gap is formed between the movable side walls 26SM and the

movable lower wall 26LM in the vertical direction. Further, each movable side wall 26SM is

pivotal about the rotation axis C2 between the movable upper wall 26UM and the movable

lower wall 26LM.

[0067] Also, the relationship of the outer diameter D of the impeller 25 of the cross-flow

and the height H of the indoor unit main body 10 of the first embodiment.

[0068] The present embodiment has the following advantages in addition to the advantages

of the first and second embodiments.

(3-1) The movable side walls 26SM of the two side walls 26S, the movable lower

wall 26LM of the lower wall 26L, and the movable upper wall 26UM of the upper wall 26U

are arranged to project out of the outlet 17 at least when an air conditioning operation is

performed. This allows the blow-out flow path 26, which is surrounded by wall portions at

the sideward sides and the vertical sides, to be extended from the outlet 17. In this manner,

the blow-out flow path 26 serving as a diffuser is lengthened compared to a structure that

does not project the two side walls 26S, the lower wall 26L, and the upper wall 26U out of

the outlet 17. This further increases the static pressure in the blow-out flow path 26 and

further increases the air volume of the blow-out flow path 26. Also, when the air flow

resistance (internal pressure loss) in the indoor unit main body 10 is high, backflow of

indoor air from the two sideward ends, the upper end, and the lower end of the outlet 17 is

restricted. Thus, surging is even less likely to occur.

[0069] (3-2) The indoor unit 1 includes the movement mechanism 29 that projects the

movable side walls 26SM, the movable lower wall 26LM, and the movable upper wall

26UM project out of the outlet 17 in the projected state when an air conditioning operation is

performed and does not project the movable side walls 26SM, the movable lower wall 26LM,

and the movable upper wall 26UM out of the outlet 17 in the stored state when an air

conditioning operation is stopped. With this structure, the movable side walls 26SM, the

movable lower wall 26LM, and the movable upper wall 26UM project out of the indoor unit

main body 10 when an air conditioning operation is performed. Thus, surging is unlikely to

occur. Further, the movable side walls 26SM, the movable lower wall 26LM, and the

movable upper wall 26UM are stored in the indoor unit main body 10 when an air

conditioning operation is stopped. This improves the aesthetic appearance of the indoor unit

1.

[0070] Fourth Embodiment

An indoor unit 1 of an air conditioner in accordance with a fourth embodiment will

now be described with reference to Fig. 9. The indoor unit 1 of the present embodiment

differs from the indoor unit 1 of the first embodiment in the structure of the cross-flow fan

23. In the description hereafter, same reference numerals are given to those elements that are

the same as the indoor unit 1 of the first embodiment. Such elements will not be described in

detail.

[0071] As shown in Figs. 9A and 9B, in the indoor unit 1, the cross-flow fan 23 includes a

support 32 that pivotally supports the flap 24 about the rotation axis C1. The support 32 is

coupled to the lower end of the indoor unit main body 10 in the vicinity of the outlet 17. In

other words, the support 32 forms the lower end of the indoor unit main body 10. The

support 32 has a portion located closer to the outlet 17 to form part of the blow-out flow path

26 (lower wall 26L). The support 32 is faced toward a tongue 26A of the upper wall 26U in a direction traversing the blow-out flow path 26.

[0072] As shown in Fig. 9B, the distance between an intersection point A, which is where a

tangent VL inscribing the tongue 26A of the upper wall 26U orthogonally intersects a flow

path formation surface 32X of the support 32 opposing the tongue 26A, and point B, which

is the lower end of the indoor unit main body 10, is referred to as distance L. Further, the

outer diameter of the impeller 25 of the cross-flow fan 23 is referred to as the outer diameter

D. In the present embodiment, a ratio (L/D) of the distance L to the outer diameter D is set to

less than 0.05. Point B is located at the downstream-most portion of the lower wall 26L of

the blow-out flow path 26. In the present embodiment, as shown in Fig. 9B, point B is the

lowermost point of the flow path formation surface 32X of the support 32.

[0073] In the present embodiment, the movable side walls 26SM are omitted from the two

side walls 26S. Further, in the present embodiment, the movement mechanism 29 includes

the flap driving motor 28 (refer to Fig. 3). The movement mechanism 29 is configured to

allow for switching between a stored state, in which the flap 24 forming the blow-out flow

path 26 covers the outlet 17, and a projected state, in which the flap 24 projects out of the

outlet 17. In the same manner as the first embodiment, the movement mechanism 29 is in the

projected state when an air conditioning operation is performed and in the stored state when

an air conditioning operation is stopped. In other words, as shown by the broken lines in Fig.

9A, the flap 24 is pivoted relative to the support 32 to cover the outlet 17 when an air

conditioning operation is stopped. Further, as shown by the solid lines in Fig. 9A, the flap 24

is pivoted relative to the support 32 to open the outlet 17 when an air conditioning operation

is performed. In the projected state, the flap 24 is faced toward a flow path formation surface

26X of the upper wall 26U.

[0074] The present embodiment has the following advantages.

(4-1) The flap 24 forming the lower wall of the blow-out flow path 26 is configured to project out of the outlet 17 at least when an air conditioning operation is performed.

Further, the ratio (L/D) of the distance L from the tangent VL, which inscribes the tongue

26A of the cross-flow fan 23, to the point B, which is located at the lower end of the indoor

unit main body 10, to the outer diameter D of the impeller 25 of the cross-flow fan 23 is less

than 0.05. This limits decreases in the ease of installation of the indoor unit main body 10

and allows power consumption and noise to be reduced by increasing and the outer diameter

D of the impeller 25 of the cross-flow fan 23. Also, the flap 24 projects out of the outlet 17

so that the blow-out flow path 26, or the diffuser, has a sufficient length. This maintains the

functionality of the diffuser. Consequently, adverse effects on the performance of the indoor

unit 1 will be limited.

[0075] (4-2) The indoor unit 1 includes the movement mechanism 29 that projects the flap

24 out of the outlet 17 in the projected state when an air conditioning operation is performed

and does not project the flap 24 out of the outlet 17 in the stored state when an air

conditioning operation is stopped. This projects the flap 24 out of the indoor unit main body

Further, the flap 24 is stored in the indoor unit main body 10 when an air conditioning

operation is stopped. Thus, the aesthetic appearance of the indoor unit 1 is improved.

[0076] Modified Examples

The description related with the above embodiments exemplifies, without any

intention to limit, applicable forms of an indoor unit of an air conditioner according to the

present disclosure. In addition to the embodiments described above, the indoor unit of an air

conditioner in accordance with the present disclosure is applicable to, for example, modified

examples of the above embodiments that are described below and combinations of at least

two of the modified examples that do not contradict each other. In the modified examples

described hereafter, same reference numerals are given to those components that are the same as the corresponding components of the above embodiments. Such components will not be described in detail.

[0077] In the first to third embodiments, at least one of the two side walls 26S, the lower

wall 26L, and the upper wall 26U of the blow-out flow path 26 may include a movable wall

and a fixed wall. More specifically, the indoor unit 1 may be configured in any one of

following manners (Al) to (A4).

[0078] (Al) The indoor unit 1 is configured so that each side wall 26S of the blow-out flow

path 26 includes the movable side wall 26SM, the upper wall 26U includes the movable

upper wall 26UM, and the lower wall 26L does not include the movable lower wall 26LM.

With this structure, the movable side walls 26SM and the movable upper wall 26UM project

out of the outlet 17. Thus, the movable side walls 26SM and the movable upper wall 26UM

restrict the indoor air blown out of the outlet 17 from flowing sideward and upward from the

outlet 17. This allows the blow-out flow path 26 to be extended from the outlet 17. In this

manner, the blow-out flow path 26 serving as a diffuser is lengthened compared to a

structure that does not project the two side walls 26S and the upper wall 26U out of the

outlet 17. This increases the static pressure in the blow-out flow path 26 and increases the air

volume of the blow-out flow path 26. Further, when the air flow resistance (internal pressure

loss) in the indoor unit main body 10 is high, backflow of air from the two sideward ends

and the upper part of the outlet 17 is restricted. Thus, surging is even less likely to occur.

[0079] (A2) The indoor unit 1 is configured so that the lower wall 26L of the blow-out flow

path 26 includes the movable lower wall 26LM, the upper wall 26U includes the movable

upper wall 26UM, and the two side walls 26S do not include the movable side walls 26SM.

With this structure, the movable lower wall 26LM projects out of the outlet 17. Thus, the

movable lower wall 26LM restricts the indoor air blown out of the outlet 17 from flowing

downward from the outlet 17. This allows the blow-out flow path 26 to be extended from the outlet 17. In this manner, the blow-out flow path 26 serving as a diffuser is lengthened compared to a structure that does not project the lower wall 26L out of the outlet 17. This increases the static pressure in the blow-out flow path 26 and increases the air volume of the blow-out flow path 26. Further, when the air flow resistance (internal pressure loss) in the indoor unit main body 10 is high, backflow of air from the lower part of the outlet 17 is restricted. Thus, surging is even less likely to occur.

[0080] (A3) The indoor unit 1 is configured so that the lower wall 26L of the blow-out flow

path 26 includes the movable lower wall 26LM, the two side walls 26S do not include the

movable side walls 26SM, and the upper wall 26U does not include the movable upper wall

26UM. With this structure, the movable lower wall 26LM projects out of the outlet 17. Thus,

the movable lower wall 26LM restricts the indoor air blown out of the outlet 17 from

flowing downward from the outlet 17. This allows the blow-out flow path 26 to be extended

from the outlet 17. In this manner, the blow-out flow path 26 serving as a diffuser is

lengthened compared to a structure that does not project the lower wall 26L out of the outlet

17. This increases the static pressure in the blow-out flow path 26 and increases the air

loss) in the indoor unit main body 10 is high, backflow of air from the lower part of the

outlet 17 is restricted. Thus, surging is even less likely to occur.

[0081] (A4) The indoor unit 1 is configured so that the upper wall 26U of the blow-out

flow path 26 includes the movable upper wall 26UM, the two side walls 26S do not include

the movable side walls 26SM, and the lower wall 26L does not include the movable lower

wall 26LM. With this structure, the movable upper wall 26UM projects out of the outlet 17.

Thus, movable upper wall 26UM restricts the indoor air blown out of the outlet 17 from

flowing upward from the outlet 17. This allows the blow-out flow path 26 to be extended

from the outlet 17. In this manner, the blow-out flow path 26 serving as a diffuser is lengthened compared to a structure that does not project the upper wall 26U out of the outlet

loss) in the indoor unit main body 10 is high, backflow of air from the upper part of the

outlet 17 is restricted. Thus, surging is even less likely to occur.

[0082] In the above-described first to third embodiments, the two side walls 26S may be

changed to have following configurations in (BI) to (B3).

(BI) As shown in Figs. 10A and 1OB, the two side walls 26S each include the

movable side wall 26SM that is sectoral and extends about rotation axis C3. The movement

mechanism 29 includes a driving motor that rotates the movable side walls 26SM about the

rotation axis C3. An output shaft of the driving motor may be directly connected to the

movable side walls 26SM. Alternatively, the output shaft of the driving motor may be

connected to the movable side walls 26SM by a decelerator. The movement mechanism 29

moves and switches the movable side walls 26SM between a stored state shown in Fig. 10A

and a projected state shown in Fig. 1OB. As shown in Fig. 10A, in the stored state, the

movable side walls 26SM are stored in the indoor unit main body 10, that is, the movable

side walls 26SM do not project out of the outlet 17. As shown in Fig. 1OB, in the projected

state, the movable side walls 26SM are in a state projected out of the indoor unit main body

, that is, the movable side walls 26SM project out of the outlet 17. The movable side walls

26SM shown in Figs. 1OA and lOB are arranged next to lateral (sideward) end surfaces of

the flap 24. Preferably, no gap is formed between the movable side walls 26SM and the

sideward end surfaces of the flap 24.

[0083] (B2) As shown in Figs. 11A and 1IB, the two side walls 26S each include the

movable side wall 26SM that is rotated about a rotation axis C4. The movement mechanism

29 includes a driving motor that rotates the movable side walls 26SM about the rotation axis

C4. The output shaft of the driving motor may be directly connected to the movable side

walls 26SM. Alternatively, the output shaft of the driving motor may be connected to the

movable side walls 26SM by a decelerator. The movement mechanism 29 moves and

switches the movable side walls 26SM between a stored state shown in Fig. 11A and a

projected state shown in Fig. 11B. As shown in Fig. 11A, in the stored state, the movable

side walls 26SM cover the lateral (sideward) ends of the outlet 17, that is, the movable side

walls 26SM do not project out of the outlet 17. In the stored state, the flap 24 is moved by

the flap driving motor 28 (refer to Fig. 3) to cover the outlet 17. In the stored state, the

movable side walls 26SM are rotated to cover the lateral (sideward) ends of the flap 24. As

shown in Fig. 1IB, in the projected state, the movable side walls 26SM are in a state

projected out of the indoor unit main body 10, that is the movable side walls 26SM project

out of the outlet 17. In one example, when the stored state is changed to the projected state,

the movable side walls 26SM are pivoted and moved to an outer side of the flap 24 in the

lateral direction (sideward direction). Then, the flap 24 is pivoted to project out of the outlet

17.

[0084] (B3) As shown in Figs. 12A and 12B, the two side walls 26S each include the

movable side wall 26SM that is expandable. The movable side wall 26SM has an accordion

structure. The movement mechanism 29 includes a motor that serves as a drive source and a

rotation-linear movement conversion mechanism that converts rotation of the motor into

linear movement of the movable side walls 26SM in an expanding direction. The movement

mechanism 29 moves and switches the movable side walls 26SM between a stored state

shown in Fig. 12A and a projected state shown in Fig. 12B. As shown in Fig. 12A, in the

stored state, the movable side walls 26SM are retracted to be stored in the indoor unit main

body 10, that is, the movable side walls 26SM do not project out of the outlet 17. As shown

in Fig. 12B, in the projected state, the movable side walls SM are expanded to project out of the indoor unit main body 10, that is, the movable side walls SM are in a state projected out of the outlet 17. The movable side walls 26SM in Figs. 12A and 12B are arranged adjacent to the flap 24 in the lateral direction (sideward direction). Preferably, no gap is formed between the movable side walls 26SM and the sideward end surfaces of the flap 24.

[0085] In the first to third embodiments, the movable side walls 26SM do not have to be

configured to be rotated about the rotation axis C2. In this case, the movable side walls

26SM may be configured so that the distance between the movable side walls 26SM in the

sideward direction decreases toward the downstream side in the blow-out flow path 26.

[0086] In the second and third embodiments, as shown in Figs. 13A and 13B, the movable

lower wall 26LM of the lower wall 26L arranged at the distal end of the fixed lower wall

26LF, which is the lower end of the indoor unit main body 10, may be pivotal about a

rotation axis C5. The flap 24 is pivotally arranged at the distal end of the movable lower wall

26LM. As shown in Fig. 13A, when an air conditioning operation is stopped, the movement

mechanism 29 pivots the movable lower wall 26LM to cover the outlet 17 in the stored state.

In this case, the outlet 17 is covered by the movable lower wall 26LM and the flap 24. As

shown in Fig. 13B, when an air conditioning operation is performed, the movement

mechanism 29 pivots and projects the movable lower wall 26LM out of the outlet 17 in the

projected state. In this case, the outlet 17 is not covered by the movable lower wall 26LM or

the flap 24. In the projected state, the flap driving motor 28 (refer to Fig. 3) may freely

change a pivotal position of the flap 24 relative to the movable lower wall 26LM.

[0087] In the third embodiment, as shown in Figs. 14A and 14B, the movable upper wall

26UM of the upper wall 26U arranged at the distal end of the fixed upper wall 26UF may be

rotatable about a rotation axis C6. As shown in Fig. 14A, when an air conditioning operation

is stopped, the movement mechanism 29 pivots the movable upper wall 26UM to cover the

outlet 17 in the stored state. When an air conditioning operation is stopped, the flap driving motor 28 (refer to Fig. 3) moves the flap 24 so that the flap 24 also covers the outlet 17. In this manner, the movable upper wall 26UM and the flap 24 entirely cover the outlet 17. As shown in Fig. 14B, when an air conditioning operation is performed, the movement mechanism 29 pivots and projects the movable upper wall 26UM out of the outlet 17 in the projected state. In this case, the outlet 17 is not covered by the movable upper wall 26UM or the flap 24.

[0088] In the second embodiment, the movement mechanism 29 may include a first

movement mechanism that moves the movable side walls 26SM and a second movement

mechanism that moves the movable lower wall 26LM. The first movement mechanism and

the second movement mechanism each include a motor and a rotation-linear movement

conversion mechanism that converts rotation of the corresponding motor into linear

movement. This allows the movable side walls 26SM to be controlled separately from the

movable lower wall 26LM.

[0089] In the second and third embodiments, when surging occurs, the movement

mechanism 29 may rotate the flap 24 to decrease the cross-sectional area of the blow-out

flow path 26 at a downstream side of the outlet 17.

[0090] In the third embodiment, the movement mechanism 29 may include a first

movement mechanism that moves the movable side walls 26SM, a second movement

mechanism that moves the movable lower wall 26LM, and a third movement mechanism

that moves the movable upper wall 26UM. The first to third movement mechanisms each

include a motor and a rotation-linear movement conversion mechanism that converts rotation

of the corresponding motor into linear movement. This allows for separate control of the

26UM.

[0091] In the third embodiment, the movement mechanism 29 may include a first movement mechanism that moves the movable side walls 26SM and the movable lower wall

26LM and a second movement mechanism that moves the movable upper wall 26UM. The

first and second movement mechanisms each include a motor and a rotation-linear

movement conversion mechanism that converts rotation of the corresponding motor into

linear movement. This allows the movable side walls 26SM and the movable lower wall

26LM to be controlled separately from the movable upper wall 26UM.

[0092] In third embodiment, the movement mechanism 29 may include afirst movement

mechanism that moves the movable side walls 26SM and a second movement mechanism

that moves the movable lower wall 26LM and the movable upper wall 26UM. The first and

second movement mechanisms each include a motor and a rotation-linear movement

movable lower wall 26LM and the movable upper wall 26UM.

[0093] In the third embodiment, the movement mechanism 29 may include a first

movement mechanism that moves the movable side walls 26SM and the movable upper wall

26UM and a second movement mechanism that moves the movable lower wall 26LM. The

first and second movement mechanisms each include a motor and a rotation-linear

linear movement. This allows the movable side walls 26SM and the movable upper wall

26UM to be controlled separately from the movable lower wall 26LM.

[0094] In the third embodiment, the blow-out flow path 26 may be formed to project out of

the outlet 17 so that the cross-sectional area of the blow-out flow path 26 at a downstream

side of the outlet 17 is smaller than the cross-sectional area of the outlet 17. In one example,

at least one of the movable side walls 26SM, the movable lower wall 26LM, and the

movable upper wall 26UM is moved by the movement mechanism 29 so that the cross sectional area surrounded by the movable side walls 26SM, the movable lower wall 26LM, and the movable upper wall 26UM, which are elements of the blow-out flow path 26, is smaller than the cross-sectional area of the outlet 17. This increases the velocity in the blow out flow path 26 at a downstream side and restricts backflow of indoor air from the outlet 17.

Thus, surging is even less likely to occur.

[0095] In the fourth embodiment, the indoor unit 1 may be changed in any one of following

manners (C1) to (C4).

(C1) The indoor unit 1 further includes the movable side walls 26SM and the

movement mechanism 29 that moves the movable side walls 26SM. In one example, the

movable side walls 26SM and the movement mechanism 29 have the same structure as the

movable side walls 26SM and the movement mechanism 29 of the first embodiment. With

this structure, the movable side walls 26SM project out of the outlet 17. Thus, the movable

side walls 26SM and the movable upper wall 26UM restrict the indoor air blown out of the

outlet 17 from flowing sideward from the outlet 17. This allows the blow-out flow path 26 to

be extended from the outlet 17. In this manner, the blow-out flow path 26 is lengthened

compared to a structure that does not project the two side walls 26S and the upper wall 26U

out of the outlet 17. This increases the static pressure in the blow-out flow path 26 and

increases the air volume of the blow-out flow path 26. Further, when the air flow resistance

(internal pressure loss) in the indoor unit main body 10 is high, backflow of air from the two

sideward ends of the outlet 17 is restricted. Thus, surging is even less likely to occur.

[0096] (C2) The indoor unit 1 further includes the movable lower wall 26LM and the

movement mechanism 29 that moves the movable lower wall 26LM. In one example, the

movable lower wall 26LM and the movement mechanism 29 have the same structure as the

movable lower wall 26LM and the movement mechanism 29 of the second embodiment. In

this case, the flap 24 is rotatably arranged at the distal end of the movable lower wall 26LM.

downward from the outlet 17. This allows the blow-out flow path 26 to be extended from the

outlet 17. In this manner, the blow-out flow path 26 serving as a diffuser is lengthened

compared to a structure that does not project the lower wall 26L out of the outlet 17. This

increases the static pressure in the blow-out flow path 26 and increases the air volume of the

blow-out flow path 26. Further, when the air flow resistance (internal pressure loss) in the

indoor unit main body 10 is high, backflow of air from the lower part of the outlet 17 is

restricted. Thus, surging is even less likely to occur.

[0097] (C3) The indoor unit 1 further includes the movable upper wall 26UM and the

movement mechanism 29 that moves the movable upper wall 26UM. In one example, the

movable upper wall 26UM and the movement mechanism 29 have the same structure as the

movable upper wall 26UM and the movement mechanism 29 of the third embodiment. With

this structure, the movable upper wall 26UM projects out of the outlet 17 and thus the

movable upper wall 26UM restricts the indoor air blown out of the outlet 17 from flowing

upward from the outlet 17. This allows the blow-out flow path 26 to be extended from the

outlet 17. In this manner, the blow-out flow path 26, which functions as a diffuser, is

lengthened compared to a structure that does not project the upper wall 26U out of the outlet

outlet 17 is restricted. Thus, surging is even less likely to occur.

[0098] (C4) The indoor unit 1 further includes at least one of the movable side walls 26SM,

the movable lower wall 26LM, and the movable upper wall 26UM and the movement

mechanism 29 that moves at least one of the movable side walls 26SM, the movable lower wall 26LM, and the movable upper wall 26UM. This structure has an advantage of at least one of the above-described modified examples (C1) to (C3).

[0099] In the first to fourth embodiments, the movement mechanism 29 may be omitted. In

this case, the elements of the blow-out flow path 26 are constantly in the projected state. In

other words, at least one of the two side walls 26S, the upper wall 26U, and the lower wall

26L is arranged to project out of the outlet 17. In one example, in the indoor unit 1 shown in

Figs. 15A and 15B, the two side walls 26S, the upper wall 26U, and the lower wall 26L,

which are the elements of the blow-out flow path 26, are arranged to project out of the outlet

17. In this case, for example, a projection 26P may be arranged on each side wall 26S at a

downstream side of the outlet 17 so that the distance between the two side walls 26S in the

sideward direction at a downstream side of the outlet 17 in the blow-out flow path 26 is less

than the sideward length of the outlet 17. In one example, as shown in Figs. 15A and 15B,

each projection 26P has the form of a substantially three-sided pyramid such that the

distance between the two side walls 26S (distance between projections 26P in sideward

direction) decreases from the upper wall 26U toward the lower wall 26L. Further, the

projections 26P include surfaces 26PA opposed toward each other in the sideward direction.

The surfaces 26PA are formed so that the distance between the projections 26P in the

sideward direction decreases toward a downstream side in the blow-out flow path 26. The

projection 26P may have any shape as long as the distance between the two side walls 26S in

the blow-out flow path 26 at a downstream side of the outlet 17 is less than the sideward

length of the outlet 17.

[0100] In the first to third embodiments, the projections 26P maybe arranged so that the

distance between the two side walls 26S in the sideward direction at a downstream side in

the blow-out flow path 26, which is extended by the two side walls 26S projected out of the

outlet 17, is constantly smaller than the distance between the two side walls 26S in the sideward direction in the blow-out flow path 26 at the side of the outlet 17 (upstream side).

Thus, the velocity in the blow-out flow path 26 at a downstream side is increased. This

restricts backflow of indoor air from the outlet 17 and thus surging is even less likely to

occur.

[0101] It should be understood that the above-described disclosure of the indoor unit of an

air conditioner may be embodied in many other specific forms within the scope and

equivalence of the present disclosure described in the appended claims.

Claims

1. An indoor unit of an air conditioner, comprising: an indoor unit main body including an inlet and a main body outlet; a heat exchanger that performs heat exchange on air drawn in from the inlet; and a cross-flow fan configured to blow out air, which has undergone heat exchange performed by the heat exchanger, from the main body outlet, wherein: the cross-flow fan includes a blow-out flow path formed by a lower wall, left and right side walls, and an upper wall so that a cross-sectional area of the blow-out flow path gradually increases downward along the blow-out flow path, with the blow-out flow path guiding blown out air to the main body outlet, the two side walls are arranged to project out of the main body outlet at least when an air conditioning operation is performed,

in the projected state, the side walls are configured to entirely cover transverse sides of the main body outlet, and

the lower wall is arranged to project out of the main body outlet at least when an air conditioning operation is performed.

2. The indoor unit of an air conditioner according to claim 1, wherein the upper wall is arranged to project out of the main body outlet at least when an air conditioning operation is performed.

3. The indoor unit of an air conditioner according to any one of claims 1 or 2, wherein the blow-out flow path is formed to project out of the main body outlet and so that a distance between the two side walls in a sideward direction in the blow-out flow path at a downstream side of the main body outlet is less than a sideward length of the main body outlet.

4. The indoor unit of an air conditioner according to any one of claims I to 3, further comprising: a movement mechanism configured to switch between a stored state that does not project an element forming the blow-out flow path including the side walls out of the main body outlet and a projected state that projects at least the side walls out of the main body outlet, wherein the movement mechanism is in the projected state when an air conditioning operation is performed, and the movement mechanism is in the stored state when an air conditioning operation is stopped.

5. The indoor unit of an air conditioner according to claim 4, wherein the movement mechanism moves the element to decrease a cross-sectional area of the blow-out flow path at a portion projecting from the main body outlet.

6. The indoor unit of an air conditioner according to any one of claims I to 5, wherein the indoor unit is configured so that a ratio (H/D) of height H of the indoor unit main body to outer diameter D of an impeller of the cross-flow fan is less than 2.2.

Daikin Industries, Ltd. Patent Attorneys for the Applicant/Nominated Person SPRUSON & FERGUSON