Patent Description:
<CIT> describes an example of an impeller and a cross-flow fan that has a blow-out flow path which guides blown-out-air from the impeller to an outlet.

<CIT> describes a wall-mounted type air conditioner indoor unit provided with an air guiding plate, an air channel plate and a flow guiding plate, wherein the air guiding plate is used for adjusting the vertical air outlet direction of the air conditioner indoor unit, and the air channel plate is used for adjusting the flow guiding length and the air outlet area of an air outlet channel.

Document <CIT> discloses an indoor unit according to the preamble of claim <NUM>.

There is a need for increasing the outer diameter of the impeller of the cross-flow fan to lower power consumption and reduce noise. However, increasing the height dimension of the indoor unit main body is not preferred since this would hinder installation of the indoor unit. Accordingly, if the outer diameter of the impeller is increased without increasing the height dimension of the indoor unit main body, the region that forms the blow-out flow path of the cross-flow fan would be decreased. This may adversely affect the performance of the indoor unit.

One objective of the present disclosure is to provide an indoor unit of an air conditioner that limits decreases in the performance of the indoor unit.

In particular, an indoor unit of an air conditioner that solves the above problems 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. When a distance in the lower wall from an intersection, where a tangent inscribing a tongue of the cross-flow fan orthogonally intersects the lower wall, to a lower end of the indoor unit main body is referred to as distance L, a ratio (L/D) of the distance L to outer diameter D of an impeller of the cross-flow fan is less than <NUM>. At least part of the blow-out flow path is formed to project out of the outlet at least when an air conditioning operation is performed.

This structure limits decreases in the ease of installation of the indoor unit main body and allows power consumption and noise to be reduced by increasing the outer diameter D of the impeller of the cross-flow fan. Also, at least part of the blow-out flow path projects out of the outlet so that the diffuser has a sufficient length. This maintains the functionality of the diffuser. Consequently, adverse effects on the performance of the indoor unit will be limited.

In the above-described indoor unit of an air conditioner, the indoor unit further includes a movement mechanism configured to switch between a stored state that does not project an element forming the blow-out flow path out of the outlet and a projected state that projects at least part of the element out of the outlet. 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.

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.

The side walls each include a movable side wall, the lower wall includes a movable lower wall, and the upper wall includes a movable upper wall. The movement mechanism includes a first movement mechanism configured to move the movable side walls and a second movement mechanism configured to move the movable lower wall and the movable upper wall,.

In the above-described indoor unit of an air conditioner, it is preferred that the two side walls be arranged to project out of the outlet at least when an air conditioning operation is performed.

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.

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 restricts the air blown out of the outlet from flowing 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 upper 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 lower part of the outlet is restricted. Thus, surging is even less likely to occur.

In the above-described indoor unit of an air conditioner, it is preferred that the upper wall be arranged to project out of the outlet at least when an air conditioning operation is performed.

With this structure, the upper wall restricts the air blown out of the outlet from flowing upward 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 upper 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 lower part of the outlet is restricted. Thus, surging is even less likely to occur.

In the above-described indoor unit of an air conditioner, it is preferred that a ratio (H/D) of height H of the indoor unit main body to the outer diameter D of the impeller of the cross-flow fan be less than <NUM>.

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.

An indoor unit <NUM> of an air conditioner in accordance with a first embodiment will now be described with reference to <FIG> and <FIG>.

The indoor unit <NUM> of the present embodiment is of a wall-mounted type and includes a rear portion attached to an indoor wall WL. The indoor unit <NUM> is, for example, configured to perform a cooling operation that cools an indoor space and a heating operation that heats an indoor space.

As shown in <FIG> and <FIG>, the indoor unit <NUM> includes an indoor unit main body <NUM>. The indoor unit main body <NUM> has the form of a box, in which a lateral direction (sideward direction of indoor unit <NUM>) coincides with the longitudinal direction, and includes an inner space surrounded by a top surface portion <NUM>, a front surface portion <NUM>, a rear surface portion <NUM>, two side surface portions <NUM>, and a bottom surface portion <NUM>. The indoor unit <NUM> is mounted on the wall WL by coupling the rear surface portion <NUM> to a mounting panel (not shown) on the wall WL with screws or the like. The top surface portion <NUM> of the indoor unit main body <NUM> includes an inlet <NUM>, and the bottom surface portion <NUM> includes an outlet <NUM>. The inlet <NUM> and the outlet <NUM> are each arranged so that the lateral direction (sideward direction) coincides with the longitudinal direction. The inlet <NUM> is formed along the top surface portion <NUM>. The outlet <NUM> is formed along the bottom surface portion <NUM>.

As shown in <FIG>, the indoor unit <NUM> includes an air filter <NUM>, an indoor heat exchanger <NUM>, a cross-flow fan <NUM>, and a flap <NUM>. The air filter <NUM>, the indoor heat exchanger <NUM>, and the cross-flow fan <NUM> are accommodated in the indoor unit main body <NUM>.

The air filter <NUM> is coupled to the indoor unit main body <NUM> in a removable manner. The air filter <NUM> removes dust from indoor air drawn in from the inlet <NUM>. In a state in which the air filter <NUM> is attached to the indoor unit main body <NUM>, the air filter <NUM> is located between the top surface portion <NUM> and the indoor heat exchanger <NUM> of the indoor unit main body <NUM>. In this manner, the air filter <NUM> limits the collection of dust, which is suspended in the indoor air, on the surface of the indoor heat exchanger <NUM>.

The indoor heat exchanger <NUM> includes a plurality of fins and a plurality of heat transfer tubes that extend through the fins. The indoor heat exchanger <NUM> serves as an evaporator or a condenser in accordance with an operation state of the indoor unit <NUM> and exchanges heat between a refrigerant flowing through the heat transfer tubes and air flowing through the indoor heat exchanger <NUM>.

The indoor heat exchanger <NUM> is arranged so that its front end and rear end are bent downward in a side view. The indoor heat exchanger <NUM> is arranged to surround the cross-flow fan <NUM> from above.

The cross-flow fan <NUM> is located inside the indoor unit main body <NUM> at a substantially central portion. The cross-flow fan <NUM> includes an impeller <NUM> and a fan case <NUM>. The impeller <NUM> is substantially cylindrical and has a lateral direction (sideward direction) that coincides with the longitudinal direction. The fan case <NUM> forms a blow-out flow path <NUM> that extends to the outlet <NUM>. The blow-out flow path <NUM> is formed by a lower wall <NUM>, left and right side walls <NUM>, 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 <NUM> increases toward the outlet <NUM>. In this manner, the blow-out flow path <NUM> functions as a diffuser.

When the cross-flow fan <NUM> is being rotated and operated, the indoor air drawn in from the inlet <NUM> flows through the indoor heat exchanger <NUM> to the cross-flow fan <NUM>. Then, the indoor air flows from the cross-flow fan <NUM> through the blow-out flow path <NUM> and is blown out of the outlet <NUM> into the room.

The impeller <NUM> of the cross-flow fan <NUM> has an outer diameter D, and the rear surface portion <NUM> of the indoor unit main body <NUM> has a vertical dimension (up-down dimension) that corresponds to a height H of the indoor unit main body <NUM>. Preferably, the outer diameter D is <NUM> or greater and less than <NUM>. Further preferably, the outer diameter D is <NUM> or greater and less than <NUM>. Preferably, the height H of the indoor unit main body <NUM> is <NUM> or less. Further preferably, the height H of the indoor unit main body <NUM> is <NUM> or greater and <NUM> or less. Preferably, a ratio (H/D) of the height H of the indoor unit main body <NUM> to the outer diameter D is less than <NUM>. Further preferably, the ratio (H/D) of the height H of the indoor unit main body <NUM> to the outer diameter D is <NUM> or greater and less than <NUM>.

The flap <NUM> is arranged at a lower edge of the outlet <NUM> and is pivotal relative to the indoor unit main body <NUM>. The flap <NUM> has the form of a flat plate and its lateral direction (sideward direction) coincides with the longitudinal direction. The flap <NUM> has a length in the longitudinal direction that is substantially the same as that of the outlet <NUM>. The flap <NUM> is configured to be pivoted by a flap driving motor <NUM> (refer to <FIG>) about a rotation axis C1.

The indoor unit <NUM> of the present embodiment includes a movement mechanism <NUM> that is configured to move the two side walls <NUM> of the blow-out flow path <NUM>. More specifically, the two side walls <NUM> 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 <NUM>. The movement mechanism <NUM> moves the movable side walls 26SM. The movement mechanism <NUM> 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 <NUM> is a feed-screw mechanism. Further, in a state in which the movable side walls 26SM project out of the outlet <NUM>, the movement mechanism <NUM> 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 <NUM> includes a second motor (not shown) that pivots each movable side wall 26SM about a rotation axis C2 (refer to <FIG>). 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 <NUM> 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 <NUM>.

As shown in <FIG>, the air conditioner includes an outdoor control unit <NUM> that controls each of a compressor <NUM> of an outdoor unit <NUM>, a four-way switching valve <NUM>, an outdoor fan <NUM>, and an expansion valve <NUM>. In one example, the outdoor control unit <NUM> controls the operational frequency (Hz) of the compressor <NUM>, the rotational speed (rpm) of a motor of the outdoor fan <NUM>, and the open degree of the expansion valve <NUM>. Further, the outdoor control unit <NUM> switches the four-way switching valve <NUM> 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.

The indoor unit <NUM> includes an indoor control unit <NUM>. The indoor control unit <NUM> 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 <NUM> may include one or more microcomputers. The outdoor control unit <NUM> may be configured in the same manner as the indoor control unit <NUM>.

The indoor control unit <NUM> is configured to establish wired or wireless communication with the outdoor control unit <NUM>. Further, the indoor control unit <NUM> is configured to establish wireless communication with a remote controller <NUM>. The indoor control unit <NUM> controls the cross-flow fan <NUM>, the flap driving motor <NUM>, and the movement mechanism <NUM> based on operation instructions from the remote controller <NUM>. Further, the indoor control unit <NUM> transmits the contents of an operation instruction from the remote controller <NUM> to the outdoor control unit <NUM>. Based on the operation instruction from the remote controller <NUM>, the outdoor control unit <NUM> controls the operational frequency (Hz) of the compressor <NUM>, the rotational speed (rpm) of the outdoor fan <NUM>, the open degree of the expansion valve <NUM>, and switching of the four-way switching valve <NUM> between the first state and the second state.

The indoor control unit <NUM> of the present embodiment controls the movement mechanism <NUM> to switch between the stored state, in which the movable side walls 26SM do not project out of the outlet <NUM> as shown in <FIG> and <FIG>, and the projected state, in which the movable side walls 26SM project out of the outlet <NUM> as shown in <FIG> and <FIG>. In one example, the indoor control unit <NUM> controls the movement mechanism <NUM> to be in the projected state when an air conditioning operation is performed and controls the movement mechanism <NUM> to be in the stored state when an air conditioning operation is stopped. In one example, as shown in <FIG> and <FIG>, in the projected state, the movable side walls 26SM are configured to entirely cover transverse sides (up-down sides) of the outlet <NUM> in the projected state.

Also, when an air conditioning operation is stopped, the indoor control unit <NUM> controls the flap driving motor <NUM> so that the flap <NUM> covers the outlet <NUM> as shown in <FIG> and <FIG>. Further, when an air conditioning operation is performed, the indoor control unit <NUM> controls the flap driving motor <NUM> so that the flap <NUM> opens the outlet <NUM> as shown in <FIG> and <FIG>. In this manner, when an air conditioning operation is stopped, the indoor unit <NUM> shown in <FIG> and <FIG> is in a state in which the movable side walls 26SM and the flap <NUM> do not project out of the indoor unit main body <NUM>. Further, when an air conditioning operation is performed, the indoor unit <NUM> shown in <FIG> and <FIG> is in a state in which the movable side walls 26SM and the flap <NUM> project out of the indoor unit main body <NUM>.

When an air conditioning operation is performed, the pivotal position of the flap <NUM> can be freely changed. In one example, the pivotal position of the flap <NUM> is changeable by an instruction from the remote controller <NUM>.

Further, when surging occurs, the indoor control unit <NUM> controls the movement mechanism <NUM> 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>). In the restricted state, the cross-sectional area of the blow-out flow path <NUM> at a downstream side of the outlet <NUM> is smaller than the cross-sectional area of the outlet <NUM>. This increases the velocity of the indoor air in the blow-out flow path <NUM> and impedes surging. Further, when surging is impeded, the indoor control unit <NUM> controls the movement mechanism <NUM> 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 <NUM> becomes unstable and backflow forms at the outlet <NUM>. Surging is likely to occur, for example, when the air filter <NUM> is clogged with dust and the air flow resistance is increased or when condensation is formed on the indoor heat exchanger <NUM>.

In one example, surging is detected from the rotational speed (rpm) of a fan motor (not shown) of the cross-flow fan <NUM>. More specifically, the indoor control unit <NUM> sets the rotational speed of the fan motor in accordance with the operation instruction from the remote controller <NUM>. The rotational speed of the fan motor that is set will be referred to as the set rotational speed. The indoor control unit <NUM> 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 <NUM> 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 <NUM> 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.

Alternatively, surging may be detected from the current supplied to the fan motor of the cross-flow fan <NUM>. More specifically, the indoor control unit <NUM> 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 <NUM> 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 <NUM> 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.

One example of a processing procedure for a movement control of the movement mechanism <NUM> executed by the indoor control unit <NUM> will now be described with reference to <FIG>. This movement control is executed over a period of time from when an air conditioning operation starts to when it ends.

In step S11, the indoor control unit <NUM> determines whether to start an air conditioning operation. In one example, when an operation start instruction has been received from the remote controller <NUM>, the indoor control unit <NUM> determines to start an air conditioning operation. Further, when an operation start instruction has not been received, the indoor control unit <NUM> determines not to start an air conditioning operation.

When the indoor control unit <NUM> determines not to start an air conditioning operation (step S11: NO), the indoor control unit <NUM> ends the process. In this case, the movable side walls 26SM are maintained to be in the stored state. When the indoor control unit <NUM> determines to start an air conditioning operation (step S11: YES), the indoor control unit <NUM> sets the movable side walls 26SM in the projected state in step <NUM>. This projects the movable side walls 26SM out of the outlet <NUM>. Subsequently, in step S13, the indoor control unit <NUM> determines whether surging has occurred.

When determining that surging has occurred (step S13: YES), the indoor control unit <NUM> controls the second motor of the movement mechanism <NUM> 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 <NUM> determines whether to end the air conditioning operation. In one example, when an operation end instruction has been received from the remote controller <NUM>, the indoor control unit <NUM> determines to end the air conditioning operation. Further, when an operation end instruction has not been received, the indoor control unit <NUM> determines not to end the air conditioning operation.

When the indoor control unit <NUM> determines not to end the air conditioning operation (step S15: NO), the indoor control unit <NUM> proceeds to step S13. When the indoor control unit <NUM> determines to end the air conditioning operation (step S15: YES), the indoor control unit <NUM> 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 <NUM>.

Further, when surging has not occurred (step S13: NO), the indoor control unit <NUM> 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 <NUM> 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 <NUM> maintains the movable side walls 26SM in the normal state and then proceeds to step S15.

The operation of the present embodiment will now be described.

If the outer diameter D of the impeller <NUM> of the cross-flow fan <NUM> is increased to lower power consumption and reduce noise without increasing the height H of the indoor unit main body <NUM> so as to limit decreases in the ease of installation of the indoor unit main body <NUM>, the region that defines the blow-out flow path <NUM> of the cross-flow fan <NUM> in the indoor unit main body <NUM> would be decreased and the blow-out flow path <NUM> would be shortened. When the blow-out flow path <NUM> is shortened, the dynamic pressure of the indoor air will not be sufficiently converted into the static pressure in the blow-out flow path <NUM>. This would decrease the air volume and pressure in the cross-flow fan <NUM>.

Also, when the air flow resistance inside the indoor unit main body <NUM> is increased due to condensation on the indoor heat exchanger <NUM> or clogging of the air filter <NUM>, the velocity of the indoor air in the blow-out flow path <NUM> will be decreased and backflow from the outlet <NUM> is likely to be generated. As a result, backflow of indoor air from the outlet <NUM> may cause surging that destabilizes the flow of the indoor air blown out of the cross-flow fan <NUM>. Particularly, it is known that the velocity of indoor air at the two sideward ends of the outlet <NUM> is slower than that at a laterally central part of the outlet <NUM>. Accordingly, backflow from the outlet <NUM> is more likely to be generated at the two sideward ends of the outlet <NUM>.

In this respect, in the present embodiment, the movable side walls 26SM project out of the outlet <NUM> when an air conditioning operation is performed. This allows the blow-out flow path <NUM> 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 <NUM> to project out of the outlet <NUM>. This limits backflow of indoor air into the outlet <NUM> from an outer side of the two sideward ends of the outlet <NUM>. Consequently, surging is impeded and changes in the air volume and pressure in the cross-flow fan <NUM> are limited.

The present embodiment has the following advantages.

An indoor unit <NUM> of an air conditioner in accordance with a second embodiment will now be described with reference to <FIG> and <FIG>. The indoor unit <NUM> of the present embodiment differs from the indoor unit <NUM> of the first embodiment in that the lower wall <NUM> of the blow-out flow path <NUM> is projected out of the outlet <NUM> together with the two side walls <NUM> 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 <NUM> of the first embodiment. Such elements will not be described in detail.

As shown in <FIG> and <FIG>, the lower wall <NUM> includes a fixed lower wall 26LF and a movable lower wall 26LM. The flap <NUM> 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 <NUM>.

The movement mechanism <NUM> 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 <NUM> 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 <NUM> 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 <NUM> of the present embodiment moves the movable side walls 26SM and the movable lower wall 26LM with a single drive source.

The indoor control unit <NUM> of the present embodiment (refer to <FIG>) controls the movement mechanism <NUM> 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 <NUM> as shown in <FIG> and <FIG>, and a projected state, in which the movable side walls 26SM and the movable lower wall 26LM project out of the outlet <NUM> as shown in <FIG> and <FIG>. In one example, the indoor control unit <NUM> controls the movement mechanism <NUM> in the projected state when an air conditioning operation is performed and controls the movement mechanism <NUM> in the stored state when an air conditioning operation is stopped.

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.

Also, the relationship of the outer diameter D of the impeller <NUM> of the cross-flow fan <NUM> and the height H of the indoor unit main body <NUM> of the present embodiment is the same as the relationship of the outer diameter D of the impeller <NUM> of the cross-flow fan <NUM> and the height H of the indoor unit main body <NUM> of the first embodiment.

The present embodiment has the following advantages in addition to the advantages of the first embodiment.

An indoor unit <NUM> of an air conditioner in accordance with a third embodiment will now be described with reference to <FIG> and <FIG>. The indoor unit <NUM> of the present embodiment differs from the indoor unit <NUM> of the second embodiment in that the upper wall 26U projects out of the outlet <NUM> together with the two side walls <NUM> and the lower wall <NUM> of the blow-out flow path <NUM> 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 <NUM> of the second embodiment. Such elements will not be described in detail.

The upper wall 26U of the present embodiment includes a fixed upper wall 26UF and a movable upper wall <NUM>. The fixed upper wall 26UF and the movable upper wall <NUM> are overlapped with each other in the vertical direction (up-down direction). The movable upper wall <NUM> is configured to be movable so as to slide relative to the fixed upper wall 26UF and project out of the outlet <NUM>.

The movement mechanism <NUM> of the present embodiment is configured to move the movable side walls 26SM, the movable lower wall 26LM, and the movable upper wall <NUM>. In one example, the movement mechanism <NUM> 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 <NUM> relative to the fixed upper wall 26UF. The movement mechanism <NUM> 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 <NUM>. In other words, the movement mechanism <NUM> of the present embodiment moves the movable side walls 26SM, the movable lower wall 26LM, and the movable upper wall <NUM> with a single drive source.

The indoor control unit <NUM> of the present embodiment (refer to <FIG>) controls the movement mechanism <NUM> and switches between a stored state, in which the movable side walls 26SM, the movable lower wall 26LM, and the movable upper wall <NUM> do not project out of the outlet <NUM> as shown in <FIG> and <FIG>, and a projected state, in which the movable side walls 26SM, the movable lower wall 26LM, and the movable upper wall <NUM> project out of the outlet <NUM> as shown in <FIG> and <FIG>. In one example, the indoor control unit <NUM> controls the movement mechanism <NUM> to be in the projected state when an air conditioning operation is performed and controls the movement mechanism <NUM> to be in the stored state when an air conditioning operation is stopped.

In the present embodiment, as shown in <FIG> and <FIG>, 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 <NUM> 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 <NUM> in the vertical direction and at sideward ends of the movable lower wall 26LM and the movable upper wall <NUM>. 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 <NUM> and the movable lower wall 26LM.

The present embodiment has the following advantages in addition to the advantages of the first and second embodiments.

An indoor unit <NUM> of an air conditioner in accordance with a fourth embodiment will now be described with reference to <FIG>. The indoor unit <NUM> of the present embodiment differs from the indoor unit <NUM> of the first embodiment in the structure of the cross-flow fan <NUM>. In the description hereafter, same reference numerals are given to those elements that are the same as the indoor unit <NUM> of the first embodiment. Such elements will not be described in detail.

As shown in <FIG>, in the indoor unit <NUM>, the cross-flow fan <NUM> includes a support <NUM> that pivotally supports the flap <NUM> about the rotation axis C1. The support <NUM> is coupled to the lower end of the indoor unit main body <NUM> in the vicinity of the outlet <NUM>. In other words, the support <NUM> forms the lower end of the indoor unit main body <NUM>. The support <NUM> has a portion located closer to the outlet <NUM> to form part of the blow-out flow path <NUM> (lower wall <NUM>). The support <NUM> is faced toward a tongue 26A of the upper wall 26U in a direction traversing the blow-out flow path <NUM>.

As shown in <FIG>, the distance between an intersection point A, which is where a tangent VL of the tongue 26A of the upper wall 26U orthogonally intersects a flow path formation surface 32X of the support <NUM> opposing the tongue 26A, and point B, which is the lower end of the indoor unit main body <NUM>, is referred to as distance L. Further, the outer diameter of the impeller <NUM> of the cross-flow fan <NUM> 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 <NUM>. Point B is located at the downstream-most portion of the lower wall <NUM> of the blow-out flow path <NUM>. In the present embodiment, as shown in <FIG>, point B is the lowermost point of the flow path formation surface 32X of the support <NUM>.

In the present embodiment, the movable side walls 26SM are omitted from the two side walls <NUM>. Further, in the present embodiment, the movement mechanism <NUM> includes the flap driving motor <NUM> (refer to <FIG>). The movement mechanism <NUM> is configured to allow for switching between a stored state, in which the flap <NUM> forming the blow-out flow path <NUM> covers the outlet <NUM>, and a projected state, in which the flap <NUM> projects out of the outlet <NUM>. In the same manner as the first embodiment, the movement mechanism <NUM> 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>, the flap <NUM> is pivoted relative to the support <NUM> to cover the outlet <NUM> when an air conditioning operation is stopped. Further, as shown by the solid lines in <FIG>, the flap <NUM> is pivoted relative to the support <NUM> to open the outlet <NUM> when an air conditioning operation is performed. In the projected state, the flap <NUM> is faced toward a flow path formation surface 26X of the upper wall 26U.

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 invention. In addition to the embodiments described above, the indoor unit of an air conditioner in accordance with the present invention 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.

In the first to third embodiments, at least one of the two side walls <NUM>, the lower wall <NUM>, and the upper wall 26U of the blow-out flow path <NUM> may include a movable wall and a fixed wall. More specifically, the indoor unit <NUM> may be configured in any one of following manners (A1) to (A4).

In the above-described first to third embodiments, the two side walls <NUM> may be changed to have following configurations in (B1) to (B3).

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 <NUM>.

In the second and third embodiments, as shown in <FIG>, the movable lower wall 26LM of the lower wall <NUM> arranged at the distal end of the fixed lower wall 26LF, which is the lower end of the indoor unit main body <NUM>, may be pivotal about a rotation axis C5. The flap <NUM> is pivotally arranged at the distal end of the movable lower wall 26LM. As shown in <FIG>, when an air conditioning operation is stopped, the movement mechanism <NUM> pivots the movable lower wall 26LM to cover the outlet <NUM> in the stored state. In this case, the outlet <NUM> is covered by the movable lower wall 26LM and the flap <NUM>. As shown in <FIG>, when an air conditioning operation is performed, the movement mechanism <NUM> pivots and projects the movable lower wall 26LM out of the outlet <NUM> in the projected state. In this case, the outlet <NUM> is not covered by the movable lower wall 26LM or the flap <NUM>. In the projected state, the flap driving motor <NUM> (refer to <FIG>) may freely change a pivotal position of the flap <NUM> relative to the movable lower wall 26LM.

In the third embodiment, as shown in <FIG>, the movable upper wall <NUM> 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>, when an air conditioning operation is stopped, the movement mechanism <NUM> pivots the movable upper wall <NUM> to cover the outlet <NUM> in the stored state. When an air conditioning operation is stopped, the flap driving motor <NUM> (refer to <FIG>) moves the flap <NUM> so that the flap <NUM> also covers the outlet <NUM>. In this manner, the movable upper wall <NUM> and the flap <NUM> entirely cover the outlet <NUM>. As shown in <FIG>, when an air conditioning operation is performed, the movement mechanism <NUM> pivots and projects the movable upper wall <NUM> out of the outlet <NUM> in the projected state. In this case, the outlet <NUM> is not covered by the movable upper wall <NUM> or the flap <NUM>.

In the second embodiment, the movement mechanism <NUM> 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.

In the second and third embodiments, when surging occurs, the movement mechanism <NUM> may rotate the flap <NUM> to decrease the cross-sectional area of the blow-out flow path <NUM> at a downstream side of the outlet <NUM>.

In the third embodiment, the movement mechanism <NUM> 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 <NUM>. 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 movable side walls 26SM, the movable lower wall 26LM, and the movable upper wall <NUM>.

In the third embodiment, the movement mechanism <NUM> includes a first 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 <NUM>. 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 to be controlled separately from the movable lower wall 26LM and the movable upper wall <NUM>.

In the third embodiment, the blow-out flow path <NUM> may be formed to project out of the outlet <NUM> so that the cross-sectional area of the blow-out flow path <NUM> at a downstream side of the outlet <NUM> is smaller than the cross-sectional area of the outlet <NUM>. In one example, at least one of the movable side walls 26SM, the movable lower wall 26LM, and the movable upper wall <NUM> is moved by the movement mechanism <NUM> so that the cross-sectional area surrounded by the movable side walls 26SM, the movable lower wall 26LM, and the movable upper wall <NUM>, which are elements of the blow-out flow path <NUM>, is smaller than the cross-sectional area of the outlet <NUM>. This increases the velocity in the blow-out flow path <NUM> at a downstream side and restricts backflow of indoor air from the outlet <NUM>. Thus, surging is even less likely to occur.

In the fourth embodiment, the indoor unit <NUM> may be changed in any one of following manners (C1) to (C4).

In embodiments not part of the invention, the movement mechanism <NUM> may be omitted. In this case, the elements of the blow-out flow path <NUM> are constantly in the projected state. In other words, at least one of the two side walls <NUM>, the upper wall 26U, and the lower wall <NUM> is arranged to project out of the outlet <NUM>. In one example, in the indoor unit <NUM> shown in <FIG>, the two side walls <NUM>, the upper wall 26U, and the lower wall <NUM>, which are the elements of the blow-out flow path <NUM>, are arranged to project out of the outlet <NUM>. In this case, for example, a projection 26P may be arranged on each side wall <NUM> at a downstream side of the outlet <NUM> so that the distance between the two side walls <NUM> in the sideward direction at a downstream side of the outlet <NUM> in the blow-out flow path <NUM> is less than the sideward length of the outlet <NUM>. In one example, as shown in <FIG>, each projection 26P has the form of a substantially three-sided pyramid such that the distance between the two side walls <NUM> (distance between projections 26P in sideward direction) decreases from the upper wall 26U toward the lower wall <NUM>. 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 <NUM>. The projection 26P may have any shape as long as the distance between the two side walls <NUM> in the blow-out flow path <NUM> at a downstream side of the outlet <NUM> is less than the sideward length of the outlet <NUM>.

In the first to third embodiments, the projections 26P may be arranged so that the distance between the two side walls <NUM> in the sideward direction at a downstream side in the blow-out flow path <NUM>, which is extended by the two side walls <NUM> projected out of the outlet <NUM>, is constantly smaller than the distance between the two side walls <NUM> in the sideward direction in the blow-out flow path <NUM> at the side of the outlet <NUM> (upstream side). Thus, the velocity in the blow-out flow path <NUM> at a downstream side is increased. This restricts backflow of indoor air from the outlet <NUM> and thus surging is even less likely to occur.

Claim 1:
An indoor unit (<NUM>) of an air conditioner, comprising:
an indoor unit main body (<NUM>) including an inlet (<NUM>) and an outlet (<NUM>);
a heat exchanger (<NUM>) configured to perform heat exchange on air drawn in from the inlet (<NUM>);
a cross-flow fan (<NUM>) configured to blow out air, which has undergone heat exchange performed by the heat exchanger (<NUM>), from the outlet (<NUM>),
wherein the cross-flow fan (<NUM>) includes a blow-out flow path (<NUM>) formed by a lower wall (<NUM>), left and right side walls (<NUM>), and an upper wall (26U) so that a cross-sectional area gradually increases downward, with the blow-out flow path (<NUM>) guiding blown-out air to the outlet (<NUM>), and
wherein at least part of the blow-out flow path (<NUM>) is formed to project out of the outlet (<NUM>) at least when an air conditioning operation is performed;
a movement mechanism (<NUM>) configured to switch between a stored state that does not project an element (<NUM>, <NUM>, 26U) forming the blow-out flow path (<NUM>) out of the outlet (<NUM>) and a projected state that projects at least part of the element (<NUM>, <NUM>, 26U) out of the outlet (<NUM>),
wherein the movement mechanism (<NUM>) is configured to be in the projected state when an air conditioning operation is performed, and the movement mechanism (<NUM>) is configured to be in the stored state when an air conditioning operation is stopped,
wherein the side walls (<NUM>) each include a movable side wall (26SM), the lower wall (<NUM>) includes a movable lower wall (26LM), the upper wall (26U) includes a movable upper wall (<NUM>), characterized in that
when a distance in the lower wall (<NUM>) from an intersection (A), where a tangent (VL) of a tongue (26A) of the cross-flow fan (<NUM>) orthogonally intersects the lower wall (<NUM>), to a lower end of the indoor unit main body (<NUM>) is referred to as distance L, a ratio (L/D) of the distance L to outer diameter D of an impeller (<NUM>) of the cross-flow fan (<NUM>) is less than <NUM>,
and
the movement mechanism (<NUM>) includes a first movement mechanism configured to move the movable side walls (26SM) and a second movement mechanism configured to move the movable lower wall (26LM) and the movable upper wall (<NUM>)such that the movable side walls (26SM) of the side walls (<NUM>) are configured to be controlled separately from the movable lower wall (26LM) of the lower wall (<NUM>) and the movable upper wall (<NUM>) of the upper wall (26U).