Technical Field
[0001] The present invention relates to an air conditioner and, more particularly, to an
electrical component box for the air conditioner.
Background Art
[0002] A conventional air conditioner is used with an electrical component box having a
control substrate, on which a plurality of electrical components are mounted, to control
the air conditioner (see, for example, Patent Document 1).
[0003] Fig. 6 is an exploded perspective view depicting an example of a construction of
an electrical component box as disclosed in Patent Document 1. As shown in Fig. 6,
the electrical component box 21 for an air conditioner includes substrate holders
22, 23 each having electrical components such as, for example, an inverter and the
like, a printed wiring board 27 mounted horizontally on the substrate holder 22 so
as to cover an upper surface thereof, and a printed wiring board 30 mounted vertically
on the substrate holder 23 so as to cover a rear surface thereof. The printed wiring
board 27 includes a set of radiating fins 26 exposed on one side of the substrate
holder 22 and having exothermic electronic elements 24, 25 mounted thereon that are
cooled by a cooling fan, while the printed wiring board 30 includes a set of radiating
fins 29 exposed on the rear surface side of the substrate holder 23 and having an
exothermic electronic element 28 mounted thereon that is cooled by the cooling fan.
[0004] The substrate holders 22, 23 accommodate a reactor 31 therein such that an upper
surface and a rear surface of the reactor 31 may be covered with the printed wiring
board 27 and the printed wiring board 30, respectively.
[0005] An inverter control device for driving a motor has been also proposed to control
an air conditioner (see, for example, Patent Document 2).
[0006] Fig. 7 is a block diagram of such an inverter control device. As shown in Fig. 7,
a main circuit includes an AC power source 51, a diode bridge 52 for converting an
AC power to a DC power, a reactor 61 having a small capacity less than 2mH, a capacitor
62 having a small capacity less than 100µF, an inverter 53 for converting a DC power
to an AC power, and a motor 54 driven with the AC power converted by the inverter
53. On the other hand, a control circuit includes a motor voltage command preparing
means 64 for preparing a voltage command value for each phase of the motor 54 depending
on a speed command ω* for the motor 54 given from outside, a PN voltage detecting
means 65 for detecting a DC voltage value applied to the inverter 53, and a PN voltage
predicting means 69 for calculating a predicted DC voltage value at a timing when
the inverter 53 actually outputs a voltage. The control circuit also includes a PN
voltage correcting means 66 for first deriving a PN voltage correction factor by dividing
a previously set DC voltage reference value of the inverter 53 by the predicted DC
voltage value calculated by the PN voltage predicting means 69, and for subsequently
setting, when the detected DC voltage value is less than zero, a previously set maximum
value of the PN voltage correction factor to the PN voltage correction factor. The
control circuit further includes a motor voltage command correcting means 67 for correcting
the voltage command value for each phase by multiplying the voltage command value
for each phase, prepared by the motor voltage command preparing means 64, by the PN
voltage correction factor outputted from the PN voltage correcting means 66, and a
PWM control means 68 for producing a PWM signal for the inverter 53 so that a motor
voltage command correction value obtained by the motor voltage command correcting
means 67 may be applied to the motor 54.
[0007] By this construction, the use of the small-capacity capacitor and the small-capacity
reactor realizes a small-sized, lightweight, and inexpensive inverter control device
for drive of the motor, with which even if the motor drive becomes difficult or impossible
due to considerable changes in inverter DC voltage, the inverter is operated to make
the voltage applied to the motor substantially constant, thereby making it possible
to ensure the motor drive.
- Patent Document 1: Japanese Laid-Open Patent Publication No. 11-63574
- Patent Document 2: Japanese Laid-Open Patent Publication No. 2005-304248
Disclosure of the Invention
Problems to be Solved by the Invention
[0008] In the case of the conventional electrical component box for the air conditioner
as described above, however, because the exothermic elements are separately mounted
on the first printed wiring board and the second printed wiring board, two sets of
radiating fins are required. Also, because the reactor is independently arranged,
and the first printed wiring board and the second printed wiring board are arranged
so as to cover the reactor, miniaturization of the whole electrical component box
may be difficult.
[0009] The present invention has been developed to overcome the above-described disadvantages.
[0010] It is accordingly an objective of the present invention to provide an electrical
component box that can be reduced in size.
Means to Solve the Problems
[0011] In accomplishing the above objective, the electrical component box for an air conditioner
according to the present invention includes a first control substrate having an exothermic
element mounted thereon, a first substrate holder disposed above a partition plate,
which partitions a compressor and a cooling fan from each other, to hold the first
control substrate, a second control substrate having a non-exothermic element mounted
thereon, a second substrate holder disposed generally perpendicular to the first substrate
holder or generally horizontally on a compressor side with respect to the partition
plate to hold the second control substrate, and a set of radiating fins mounted on
the first control substrate so as to protrude therefrom on a fan side with respect
to the partition plate.
Effects of the Invention
[0012] According to the present invention, not only can the size of the electrical component
box for an air compressor be reduced, but the size of the air conditioner can also
be reduced.
Brief Description of the Drawings
[0013]
Fig. 1. is an exploded perspective view depicting a construction of an electrical
component box for an air conditioner according to a first embodiment of the present
invention.
Fig. 2 is a front view of an outdoor unit provided with the electrical component box
of Fig. 1.
Fig. 3 is an exploded perspective view depicting a construction of an electrical component
box for an air conditioner according to a second embodiment of the present invention.
Fig. 4 is a front view of an outdoor unit provided with the electrical component box
of Fig. 3.
Fig. 5 is a front view of an outdoor unit provided with an electrical component box
according to a third embodiment of the present invention.
Fig. 6 is an exploded perspective view depicting a construction of a conventional
electrical component box for an air conditioner.
Fig. 7 is a block diagram of a conventional inverter control device for drive of a
motor.
Explanation of Reference Numerals
[0014]
- 1
- Electrical component box
- 2
- Substrate holder
- 3
- Substrate holder
- 4
- Control substrate
- 5
- Exothermic component
- 6
- Radiating fins
- 7
- Control substrate
- 8
- Slot
- 9
- Reactor
- 10
- Outdoor unit
- 11
- Compressor
- 12
- Cooling fan
- 13
- Partition plate
- 14
- Fan motor
- 15
- Opening
- 16
- Side surface of outdoor unit
- 17
- Electrical component box
- 18
- Fixing plate
- 101
- Electrical component box
- 102
- Substrate holder
- 103
- Substrate holder
Best Mode for Carrying out the Invention
[0015] A first invention includes a first control substrate having an exothermic element
mounted thereon, a first substrate holder disposed above a partition plate, which
partitions a compressor and a cooling fan from each other, to hold the first control
substrate, a second control substrate having a non-exothermic element mounted thereon,
a second substrate holder disposed generally perpendicular to the first substrate
holder or generally horizontally on a compressor side with respect to the partition
plate to hold the second control substrate, and a set of radiating fins mounted on
the first control substrate so as to protrude therefrom on a fan side with respect
to the partition plate. This construction can reduce the size of an electrical component
box.
[0016] In a second invention, the second substrate holder provided in the first invention
has a slot defined therein into which the second control substrate is inserted. By
this construction, not only can the size of the electrical component box be reduced,
but the second control substrate can also be easily attached.
[0017] In the first or second invention, a third invention further includes a reactor mounted
on the second control substrate. This construction can reduce the size of the electrical
component box.
[0018] A fourth invention is directed to an air conditioner including the electrical component
box according to any one of the first to third inventions. This invention can reduce
the size of the air conditioner. Embodiment 1.
[0019] Fig. 1 is an exploded perspective view depicting a construction of an electrical
component box for an air conditioner according to a first embodiment of the present
invention.
[0020] As shown in Fig. 1, the electrical component box 1 is integrally formed of a resinous
material and includes a substrate holder 2 constituting a first substrate holder,
and a substrate holder 3 constituting a second substrate holder and extending in a
direction generally perpendicular to the substrate holder 2 (substantially vertically
downwardly).
[0021] A control substrate 4 constituting a first control substrate includes a plurality
of electrical components mounted thereon and including an exothermic element 5, and
is mounted on the substrate holder 2. A set of radiating fins 6 are mounted on the
control substrate 4 to radiate heat emitted from the exothermic element 5. It is noted
here that the exothermic element is an element that gives rise to a considerable power
loss and heat generation incidental thereto and, hence, requires radiating fins for
cooling. Exothermic elements include a diode for use in a rectifying circuit that
constitutes an inverter control device for a motor required to drive an air conditioner
to convert an AC power to a DC power, as disclosed in Patent Document 2, an IGBT for
use in an inverter circuit for converting a DC power to an AC power, and the like.
[0022] A control substrate 7 constituting a second control substrate includes a reactor
9 and a plurality of electrical elements mounted thereon and including no exothermic
elements (electrical elements not producing much heat and requiring no radiating fins,
or non-exothermic elements). This control substrate 7 is inserted into a slot 8 defined
in the substrate holder 3. Because of this, the control substrate 4 and the control
substrate 7 are arranged generally perpendicular to each other. By performing the
control as proposed in Patent Document 2 in which an inverter control device for drive
of a motor is disclosed, even the use of a small-capacity reactor can ensure the motor
drive, i.e., the operation of the air conditioner. Accordingly, the reactor can be
reduced in size and weight and, hence, the illustrated reactor 9 can be readily attached
to the control substrate 7.
[0023] Fig. 2 is a front view of an outdoor unit 10 of an air conditioner provided with
the electrical component box according to this embodiment. As shown in Fig. 2, the
outdoor unit 10 accommodates a compressor 11 and a cooling fan 12 therein, and the
compressor 11 and the cooling fan 12 are separated by a vertically extending partition
plate 13. The electrical component box 1 is disposed above the partition plate 13
within the outdoor unit 10.
[0024] The control substrate 7 is disposed in a compressor side compartment with respect
to the partition plate 13 so as to extend parallel to the partition plate 13.
[0025] The radiating fins 6 protrude downwardly through an opening 15 defined in the substrate
holder 2 within a fan side compartment with respect to the partition plate 13. Accordingly,
radiation from the radiating fins 6 is promoted by the cooling fan 12 driven by a
fan motor 14.
[0026] It is noted here that the control substrate 4, the control substrate 7, the compressor
11, and the fan motor 14 are connected to one another by a wire harness or the like.
[0027] In the electrical component box 1 structured as described above, the control substrate
4 and the control substrate 7 are disposed generally perpendicular to each other,
and the reactor 9 is mounted on the control substrate 7. This construction can reduce
the size of the whole electrical component box, thereby making it possible to locate
the electrical component box 1 at a position not interfering with the compressor 11
or the cooling fan 12.
[0028] Also, because the electrical component box 1 can be efficiently accommodated within
a space delimited by the compressor 11, the partition plate 13, and a rear surface
(not shown) and a side surface 16 of the outdoor unit 10, the outdoor unit 10 can
be reduced in size.
[0029] Further, because the control substrate 7 is attached to the electrical component
box 1 by inserting the former into the slot 8 in the latter, attachment of the control
substrate 7 is easy. Embodiment 2.
[0030] Fig. 3 is an exploded perspective view depicting a construction of an electrical
component box for an air conditioner according to a second embodiment of the present
invention. In this embodiment and the first embodiment, like parts are designated
by like reference numerals, and explanation thereof is omitted.
[0031] As shown in Fig. 3, the electrical component box 101 is integrally formed of a resinous
material and includes a substrate holder 102 constituting a first substrate holder,
and a substrate holder 103 constituting a second substrate holder and extending in
a direction generally parallel to the substrate holder 102.
[0032] A control substrate 104 constituting a first control substrate includes a plurality
of electrical components mounted thereon and including an exothermic element 5, and
is mounted on the substrate holder 102. A set of radiating fins 6 are mounted on the
control substrate 104 to radiate heat emitted from the exothermic element 5.
[0033] A control substrate 107 constituting a second control substrate includes a reactor
9 and a plurality of electrical elements mounted thereon and including no exothermic
elements. This control substrate 107 is inserted into a slot 108 defined in the substrate
holder 103. Because of this, the control substrate 104 and the control substrate 107
are both arranged generally horizontally. As described above, because the reactor
9 can be reduced in size and weight, it can be readily attached to the control substrate
107.
[0034] It is noted here that high lead elements such as, for example, capacitors, reactors,
and the like are mounted on the control substrate 104 and the control substrate 107.
[0035] The control substrate 104 and the control substrate 107 are both attached to the
electrical component box 101 such that an element surface of the former on which the
lead elements are mounted and an element surface of the latter on which the lead elements
are mounted are opposed to each other and, hence, all the lead elements mounted on
the two control substrates 104, 107 are positioned so as not to be in contact with
each other.
[0036] By way of example, in applications where a single-sided substrate is used for the
control substrate 104, and surface-mount elements such as a microcomputer 117 and
the like are mounted on the control substrate 104, a space is created on a surface
(lead element surface) opposite to the surface on which the surface-mount elements
are mounted. By designing the control substrate 107 such that the high elements mounted
thereon and including the reactor 9 are positioned in such a space, the control substrates
can be efficiently accommodated in the electrical component box 101.
[0037] Fig. 4 is a front view of an outdoor unit 10 of an air conditioner provided with
the electrical component box 101 according to this embodiment. As shown in Fig. 4,
the outdoor unit 10 accommodates a compressor 11 and a cooling fan 12 therein, and
the compressor 11 and the cooling fan 12 are separated by a vertically extending partition
plate 13. The electrical component box 101 is disposed above the partition plate 13
within the outdoor unit 10.
[0038] The control substrate 107 is disposed in a compressor side compartment with respect
to the partition plate 13. The radiating fins 6 protrude downwardly through an opening
15 defined in the substrate holder 102 within a fan side compartment with respect
to the partition plate 13. Accordingly, radiation from the radiating fins 6 is promoted
by the cooling fan 12 driven by a fan motor 14.
[0039] It is noted here that the control substrate 104, the control substrate 107, the compressor
11, and the fan motor 14 are connected to one another by a wire harness or the like.
[0040] In the electrical component box 101 structured as described above, the control substrate
104 and the control substrate 107 are disposed generally horizontally, and the reactor
9 is mounted on the control substrate 107. This construction can reduce the size of
the whole electrical component box, thereby making it possible to locate the electrical
component box 101 at a position not interfering with the compressor 11 or the cooling
fan 12.
[0041] Also, because the electrical component box 101 can be efficiently accommodated within
a space delimited by the compressor 11, the partition plate 13, and a rear surface
(not shown) and a side surface 16 of the outdoor unit 10, the size of the outdoor
unit 10 can be reduced.
[0042] Further, because the control substrate 107 is attached to the electrical component
box by inserting the former into the slot 108 in the latter, attachment of the control
substrate 107 is easy. Embodiment 3.
[0043] An electrical component box for an air conditioner according to a third embodiment
of the present invention is explained hereinafter with reference to the drawings.
In this embodiment and the first embodiment, like parts are designated by like reference
numerals, and explanation thereof is omitted.
[0044] Fig. 5 is a front view of an outdoor unit 10 of an air conditioner provided with
the electrical component box according to this embodiment.
[0045] In this embodiment as shown in Fig. 5, the electrical component box 17 constituting
a first substrate holder and a fixing plate 18 constituting a second substrate holder
are separated from each other. The electrical component box 17 is disposed above the
partition plate 13, while the fixing plate 18 is placed on the partition plate 13
on the side of the compressor 11.
[0046] By arranging the electrical component box 17 above the partition plate 13 and arranging
a control substrate 7 on a side surface of the partition plate 13 in the aforementioned
manner, not only can the size of the electrical component box 17 be reduced, but the
electrical component box 17 and the control substrate 7 can also be efficiently accommodated
within a space delimited by the compressor 11, the partition plate 13, and a rear
surface (not shown) and a side surface 16 of the outdoor unit 10, thereby making it
possible to reduce the size of the outdoor unit 10.
Industrial Applicability
[0047] As described hereinabove, because the electrical component box according to the present
invention can be reduced in size, it can be effectively utilized as an electrical
component box for an air conditioner.