BACKGROUND
1. Technical Field
[0001] The present disclosure relates to an air-conditioner.
2. Related Art
[0002] In some cases, in an outdoor unit, an air blowing fan outside a room is reversely
rotated in a direction opposite to a rotation direction in normal operation.
JP-A-2013-36716 discloses an outdoor unit configured such that an air blowing fan outside a room
is reversely rotated until a lapse of predetermined time for the purpose of controlling
entrance of water vapor generated due to defrosting operation into a control device.
SUMMARY
[0003] An air-conditioner according to an embodiment of the present disclosure includes:
a housing; an air blowing fan configured to send air to an outdoor heat exchanger;
a fixing member configured to fix the air blowing fan to the housing; and a control
section configured to control an acceleration or the number of rotations per unit
time in rotation of the air blowing fan. A rotation direction of the air blowing fan
includes at least a first direction of loosening the fixing member due to the rotation
of the air blowing fan.
DETAILED DESCRIPTION
[0004] In the following detailed description, for purpose of explanation, numerous specific
details are set forth in order to provide a thorough understanding of the disclosed
embodiments. It will be apparent, however, that one or more embodiments may be practiced
without these specific details. In other instances, well-known structures and devices
are schematically shown in order to simplify the drawing.
[0005] There is a probability that reverse rotation of the air blowing fan outside the room
causes a problem that the air blowing fan is detached due to looseness of a nut fixing
the air blowing fan.
[0006] For this reason, an air-conditioner according to the present embodiment is intended
to reduce the probability of detaching an air blowing fan outside a room.
[0007] An air-conditioner according to the present embodiment includes: a housing; an air
blowing fan configured to send air to an outdoor heat exchanger; a fixing member configured
to fix the air blowing fan to the housing; and a control section configured to control
an acceleration or the number of rotations per unit time in rotation of the air blowing
fan. A rotation direction of the air blowing fan includes at least a first direction
of loosening the fixing member due to the rotation of the air blowing fan.
[0008] According to the air-conditioner of the embodiment of the present disclosure, the
probability of detaching the air blowing fan outside the room can be reduced.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009]
Fig. 1 is an external view illustrating a configuration of an air-conditioner according
to the present embodiment;
Fig. 2 is a diagram illustrating a refrigerant circuit of the air-conditioner according
to the present embodiment;
Figs. 3A and 3B are views illustrating a configuration of an outdoor fan of the air-conditioner
according to the present embodiment; and
Fig. 4 is a graph showing control profiles of the air-conditioner according to the
present embodiment.
[0010] Hereinafter, the present embodiment will be described based on the drawings.
[0011] Fig. 1 is an external view illustrating a configuration of an air-conditioner 1 according
to the present embodiment. The air-conditioner 1 circulates refrigerant in a refrigeration
cycle (a heat pump cycle) to perform air conditioning. As illustrated in Fig. 1, the
air-conditioner 1 includes an indoor unit 10 placed inside a room (an air-conditioning
target space), an outdoor unit 20 placed outside (outside the room), and a remote
controller 30 to be operated by a user.
[0012] The indoor unit 10 includes a remote controller communication section 11. The remote
controller communication section 11 transmits a predetermined signal to the remote
controller 30 or receives a predetermined signal from the remote controller 30 via,
e.g., infrared communication. For example, the remote controller communication section
11 receives, from the remote controller 30, a signal of an operation command, a stop
command, a set temperature change, an operation mode change, or a timer setting. Moreover,
the remote controller communication section 11 transmits, e.g., an indoor temperature
detection value to the remote controller 30. In other examples, the remote controller
30 may perform only transmission to the remote controller communication section 11,
and the remote controller communication section 11 may perform only reception from
the remote controller 30. That is, communication between the remote controller 30
and the remote controller communication section 11 may be only in one direction. Note
that although not clearly illustrated in Fig. 1, the indoor unit 10 and the outdoor
unit 20 are connected to each other through a refrigerant pipe, and are connected
to each other through a communication line.
[0013] Fig. 2 is a diagram illustrating a refrigerant circuit Q of the air-conditioner 1
according to the embodiment. Note that solid arrows in Fig. 2 indicate the flow of
refrigerant in air-heating operation. Moreover, dashed arrows in Fig. 2 indicate the
flow of refrigerant in air-cooling operation.
[0014] As illustrated in Fig. 2, the indoor unit 10 includes, in addition to the remote
controller communication section 11, an indoor heat exchanger 12 and an indoor fan
14. In the indoor heat exchanger 12, heat is exchanged between refrigerant flowing
in a heat transfer pipe (not shown) of the indoor heat exchanger 12 and indoor air
sent from the indoor fan 14. The indoor heat exchanger 12 operates as a condenser
or an evaporator by switching of a later-described four-way valve 25.
[0015] As illustrated in Fig. 2, the outdoor unit 20 includes a compressor 21, an outdoor
heat exchanger 22, an outdoor fan 23, an outdoor expansion valve 24 (an expansion
valve), the four-way valve 25, and a control board 26. The compressor 21 is equipment
configured to compress low-temperature low-pressure gas refrigerant by drive of a
compressor motor 21a to discharge the compressed gas refrigerant as high-temperature
high-pressure gas refrigerant. In the outdoor heat exchanger 22, heat is exchanged
between refrigerant flowing in a heat transfer pipe (not shown) of the outdoor heat
exchanger 22 and external air sent from the outdoor fan 23. The outdoor heat exchanger
22 operates as the condenser or the evaporator by switching of the four-way valve
25. The outdoor fan 23 is one example of an air blowing fan.
[0016] The outdoor fan 23 is placed in the vicinity of the outdoor heat exchanger 22. The
outdoor fan 23 sends the external air to the outdoor heat exchanger 22 by drive of
an outdoor fan motor 23a. The outdoor expansion valve 24 has the function of depressurizing
refrigerant condensed in the "condenser" (one of the outdoor heat exchanger 22 or
the indoor heat exchanger 12). Note that the refrigerant depressurized in the outdoor
expansion valve 24 is guided to the "evaporator" (the other one of the outdoor heat
exchanger 22 or the indoor heat exchanger 12).
[0017] The four-way valve 25 is a valve configured to switch a refrigerant flow path according
to an operation mode of the air-conditioner 1. In the refrigeration cycle of the air-cooling
operation executed by switching of the four-way valve 25, refrigerant circulates through
the compressor 21, the outdoor heat exchanger 22 (the condenser), the outdoor expansion
valve 24, and the indoor heat exchanger 12 (the evaporator) in this order as indicated
by the dashed arrows. Moreover, in the refrigeration cycle of the air-heating operation
executed by switching of the four-way valve 25, refrigerant circulates through the
compressor 21, the indoor heat exchanger 12 (the condenser), the outdoor expansion
valve 24, and the outdoor heat exchanger 22 (the evaporator) in this order as indicated
by the solid arrows. That is, in the refrigerant circuit Q illustrated in Fig. 2,
refrigerant sequentially circulates through the compressor 21, the "condenser," the
outdoor expansion valve 24, and the "evaporator." In the refrigerant circuit Q, one
of the "condenser" or the "evaporator" as described above is the outdoor heat exchanger
22, and the other one of the "condenser" or the "evaporator" is the indoor heat exchanger
12.
[0018] The control board 26 includes, for example, a not-shown compressor control circuit,
a not-shown outdoor expansion valve control circuit, and a not-shown outdoor fan control
circuit. The compressor control circuit controls operation of the compressor 21. The
outdoor expansion valve control circuit transmits a pulse signal for driving a pulse
motor of the outdoor expansion valve 24. The outdoor fan control circuit controls,
e.g., drive of the outdoor fan motor 23a of the outdoor fan 23 attached to the outdoor
heat exchanger 22. The control board 26 is one example of a control section.
[0019] Figs. 3A and 3B are views illustrating a configuration of the outdoor fan 23 of the
air-conditioner according to the present embodiment. Fig. 3A is an exploded perspective
view of the outdoor fan 23 and the like. Fig. 3B is a sectional view of the outdoor
fan 23 and the like. The outdoor fan motor 23a is attached to a motor support 23c
with screws 23b. The outdoor fan 23 is attached to a motor shaft of the outdoor fan
motor 23a with a nut 23e. That is, the outdoor fan 23 is attached to the motor support
23c through the outdoor fan motor 23a, and is fixed with the nut 23e. Further, the
motor support 23c is directly attached to a housing 28, or is attached to the housing
28 through other members. The nut 23e described herein is one example of a fixing
member. Note that the fixing member for fixing the outdoor fan 23 may be a member
configured to directly or indirectly fix the outdoor fan 23 to the housing. Thus,
the above-described fixing member is not limited to the nut 23e. For example, a bolt
or a screw may be used as other fixing members.
[0020] The outdoor unit 20 of the present embodiment performs air-conditioning operation,
and further performs dust removal operation after the air-conditioning operation.
The dust removal operation described herein is the operation of removing dust adhering
to the outdoor fan 23. In the dust removal operation, the outdoor fan 23 rotates in
a direction opposite to a rotation direction of the outdoor fan 23 in the air-conditioning
operation. Hereinafter, rotation of the outdoor fan 23 in the air-conditioning operation
will be referred to as "forward rotation." Moreover, rotation of the outdoor fan 23
in a rotation direction opposite to the rotation direction of the outdoor fan 23 in
the air-conditioning operation, i.e., rotation of the outdoor fan 23 in the dust removal
operation, will be referred to as "reverse rotation." The outdoor unit 20 of the present
embodiment is designed such that the direction of the forward rotation of the fan
and the direction of tightening the nut 23e are coincident with each other. That is,
in the dust removal operation, the outdoor fan 23 rotates in the direction of loosening
the nut 23e. On the other hand, the control board 26 of the outdoor unit 20 of the
air-conditioner according to the present embodiment performs the following control
to prevent loosening of the nut 23e.
[0021] Hereinafter, control of the reverse rotation of the outdoor fan 23 by the control
board 26 will be described. By operation of the remote controller 30, the user instructs
stop of the air-conditioning operation of the indoor unit 10. Then, the control board
26 stops the air-conditioning operation to start the dust removal operation. More
specifically, the control board 26 instructs the outdoor fan motor 23a to start the
reverse rotation. Thereafter, the control board 26 performs control of the acceleration
of the reverse rotation according to an acceleration control profile 401 illustrated
in Fig. 4. The horizontal axis of a graph illustrated in Fig. 4 indicates time. The
vertical axis of the graph indicates a rotation speed (the number of rotations per
unit time). The graph of Fig. 4 shows not only the control profile 401 for the reverse
rotation but also a control profile 402 for the forward rotation.
[0022] Note that in a case where both of the dust removal operation and other types of cleaning
operation are executed after stop of the air-conditioning operation, the control board
26 starts the dust removal operation in advance of the other types of cleaning operation.
The other types of cleaning operation indicate operation for which operation of equipment
in the outdoor unit 20 is necessary. For example, the other types of cleaning operation
include the operation of washing dust adhering to the outdoor heat exchanger 22 with
dew condensation water generated in the outdoor heat exchanger 22. Cleaning operation
for which the operation of the equipment in the outdoor unit 20 is not necessary may
be performed at the same time as the dust removal operation. Alternatively, either
one of the cleaning operation or the dust removal operation may be performed first.
[0023] The control board 26 controls, for certain time (until time t1 from start-up in an
example of Fig. 4) after the start-up of the outdoor fan motor 23a, the outdoor fan
motor 23a such that an equal acceleration is provided between the case of the forward
rotation and the case of the reverse rotation.
[0024] After a lapse of the time t1, the control board 26 controls the outdoor fan motor
23a such that the acceleration in the case of the reverse rotation of the outdoor
fan 23 is lower than that in the case of the forward rotation of the outdoor fan 23.
Note that the acceleration for the forward rotation and the acceleration for the reverse
rotation after a lapse of the time t1 can be set in advance. For example, in a case
where the acceleration for the forward rotation is set to 24 rpm/s, the acceleration
for the reverse rotation is set to 20 rpm/s. Thus, force (the force of tightening
the nut 23e) on the nut 23e in the forward rotation is greater than force (the force
of loosening the nut 23e) on the nut 23e in the reverse rotation. Consequently, the
probability of detaching the outdoor fan 23 due to looseness of the nut 23e due to
the reverse rotation can be reduced.
[0025] As described above, before a lapse of the time t1, the acceleration for the reverse
rotation and the acceleration for the forward rotation are equal to each other. This
is because in a case where a value smaller than the acceleration for the forward rotation
is set as the value of the acceleration for the reverse rotation upon the start-up,
there is a probability that the acceleration becomes too low and poses a problem for
the start-up.
[0026] Note that for the certain time (until the time t1 after the start-up in the example
of Fig. 4) after the start-up, any of the acceleration for the forward rotation and
the acceleration for the reverse rotation may be equal to or higher than a predetermined
value. That is, the outdoor fan motor 23a is not necessarily controlled such that
the acceleration for the forward rotation and the acceleration for the reverse rotation
are equal to each other. Note that such a predetermined value is preferably greater
than the acceleration for the reverse rotation for certain time (from the time t1
to time t2 in Fig. 4). That is, in the case of the reverse rotation of the outdoor
fan 23, the control board 26 controls the outdoor fan motor 23a such that the acceleration
from the start of rotation to the time t1 is higher than the acceleration from the
time t1 to the time t2.
[0027] Further, the control board 26 controls, after stop of acceleration (after the time
t2 in Fig. 4), the outdoor fan motor 23a such that the maximum number of rotations
per unit time in the reverse rotation of the outdoor fan 23 is lower than that in
the forward rotation of the outdoor fan 23. More specifically, a value lower than
the preset maximum number of rotations per unit time in the forward rotation may be
set in advance as the maximum number of rotations per unit time in the reverse rotation.
Then, the control board 26 controls, during the reverse rotation, the outdoor fan
motor 23a not to exceed the set maximum number of rotations per unit time in the reverse
rotation. Accordingly, the probability of loosening the nut 23e due to the reverse
rotation can be reduced.
[0028] Further, reverse rotation time for which the reverse rotation of the outdoor fan
23 is performed in the dust removal operation can be set in advance. The reverse rotation
time described herein is a period shorter than minimum thermo-ON operation time. There
are a thermo-ON period and a thermo-OFF period during the air-conditioning operation.
Thermo-OFF indicates, for example, a period for which the compressor 21 and the outdoor
fan 23 are stopped after a room temperature has reached a target value. On the other
hand, thermo-ON indicates a period for which the compressor 21 or the outdoor fan
23 is driven. The minimum thermo-ON operation time can be set in advance. In the case
of performing the reverse rotation, the control board 26 stops the reverse rotation
after a lapse of the reverse rotation time. Thus, the reverse rotation time exceeds
forward rotation time. Consequently, the probability of loosening the nut 23e can
be reduced.
[0029] The control board 26 ends the dust removal operation when the reverse rotation of
the outdoor fan 23 is performed with the above-described acceleration for certain
time. At this point, the control board 26 controls the outdoor fan motor 23a such
that a deceleration until stop of the reverse rotation of the outdoor fan 23 is higher
than the acceleration in the case of the reverse rotation of the outdoor fan 23. More
specifically, the control board 26 stops power supply to the outdoor fan motor 23a
at the end of the dust removal operation. That is, the control board 26 does not perform
the deceleration control of gradually decreasing the speed in the case of stopping
the reverse rotation of the outdoor fan 23. Thus, the outdoor fan 23 is suddenly decelerated.
As described above, the control board 26 controls, upon deceleration of the reverse
rotation, the outdoor fan motor 23a such that the deceleration is higher than the
acceleration for the reverse rotation. Thus, loosening of the nut 23e due to the reverse
rotation can be also prevented even upon deceleration of the reverse rotation.
[0030] As described above, in the air-conditioner 1 according to the present embodiment,
the acceleration or the number of rotations per unit time in the reverse rotation
of the outdoor fan 23 is controlled so that the probability of detaching the outdoor
fan 23 can be reduced.
[0031] Note that the timing of performing the reverse rotation is not limited to timing
at the end of the air-conditioning operation. For example, the reverse rotation may
be executed at optional timing according to user's operation. Moreover, in the present
embodiment, the dust removal operation has been described as an example of the control
of the reverse rotation of the outdoor fan 23. Note that the example of the control
of the reverse rotation of the outdoor fan 23 is not limited to the dust removal operation.
[0032] One example of embodiments of the present disclosure has been described above in
detail. Note that the embodiments of the present disclosure are not limited to the
above-described specific embodiment.
[0033] The foregoing detailed description has been presented for the purposes of illustration
and description. Many modifications and variations are possible in light of the above
teaching. It is not intended to be exhaustive or to limit the subject matter described
herein to the precise form disclosed. Although the subject matter has been described
in language specific to structural features and/or methodological acts, it is to be
understood that the subject matter defined in the appended claims is not necessarily
limited to the specific features or acts described above. Rather, the specific features
and acts described above are disclosed as example forms of implementing the claims
appended hereto.
1. An air-conditioner comprising:
a housing;
an air blowing fan configured to send air to an outdoor heat exchanger;
a fixing member configured to fix the air blowing fan to the housing; and
a control section configured to control an acceleration or the number of rotations
per unit time in rotation of the air blowing fan,
wherein a rotation direction of the air blowing fan includes at least a first direction
of loosening the fixing member due to the rotation of the air blowing fan.
2. The air-conditioner according to claim 1, wherein
the rotation direction of the air blowing fan further includes a second direction
opposite to the first direction, and
the control section controls the acceleration or the number of rotations per unit
time in the rotation of the air blowing fan such that the acceleration or the number
of rotations per unit time in rotation of the air blowing fan in the first direction
is less than the acceleration or the number of rotations per unit time in rotation
of the air blowing fan in the second direction.
3. The air-conditioner according to claim 1 or 2, wherein
the control section controls the acceleration or the number of rotations per unit
time in the rotation of the air blowing fan such that the acceleration of the rotation
of the air blowing fan in the first direction is lower than a deceleration for stopping
the rotation of the air blowing fan in the first direction.
4. The air-conditioner according to any one of claims 1 to 3, wherein
the control section controls the number of rotations per unit time in the rotation
of the air blowing fan such that the maximum number of rotations per unit time in
the rotation of the air blowing fan in the first direction is smaller than the maximum
number of rotations per unit time in the rotation of the air blowing fan in the second
direction.
5. The air-conditioner according to any one of claims 1 to 4, wherein
the control section stops the air blowing fan before a lapse of minimum thermo-ON
operation time after the rotation of the air blowing fan in the first direction has
been started.
6. The air-conditioner according to any one of claims 1 to 5, wherein
the control sections controls, during an air-conditioning operation, the acceleration
or the number of rotations per unit time in the rotation of the air blowing fan in
a second direction opposite to the first direction, and after an end of the air-conditioning
operation, controls the acceleration or the number of rotations per unit time in the
rotation of the air blowing fan in the first direction.
7. The air-conditioner according to any one of claims 1 to 6, wherein
the control section controls the acceleration of the rotation of the air blowing fan
such that the acceleration of the rotation of the air blowing fan in the first direction
until a lapse of first time after a start of the rotation of the air blowing fan in
the first direction is higher than the acceleration of the rotation of the air blowing
fan in the first direction after a lapse of the first time.