JP5669407B2 - Electric box for outdoor unit, outdoor unit and air conditioner - Google Patents

Description

  The present invention relates to an electrical box for an outdoor unit housed in an outdoor unit of an air conditioner.

  In the conventional outdoor unit of an air conditioner, a commercial AC power source is once rectified to DC by a converter unit, and then converted to AC of variable voltage and variable current again by an inverter unit, and a compressor using an induction motor, a DC brushless motor, etc. An inverter control circuit device that controls driving of the motor is provided.

  This inverter control circuit device is composed of electronic components such as a power transistor, a noise filter, a diode stack, and various capacitors. These electronic components are mounted on a substrate, and the substrate on which the electronic component is mounted is an outdoor unit in the outdoor unit. It is stored in the electrical equipment box.

When a current is passed through the inverter control circuit, heat is released from each electronic component, particularly the power transistor, so that the temperature inside the outdoor unit electrical box may be high, which may cause various problems.
Therefore, in order to suppress the release of heat from the power transistor, etc., a method for suppressing the current value flowing through the power transistor, etc. A method of releasing is known.

  Furthermore, there is a method in which a part of the air that has been attracted by the outdoor fan and passed through the outdoor heat exchanger is caused to flow around the radiating fins attached to the power transistor or the like, and the heat generated from the power transistor or the like is released to the air. It is known (for example, refer to Patent Document 1).

Japanese Unexamined Patent Publication No. 63-140232

  However, in the method of suppressing the current value flowing through the power transistor or the like, in other words, the method of setting the current safe value that is the current limiting value in the power transistor or the like, the driving force of the compressor motor is also suppressed, and cooling or heating in the air conditioner There is a risk that the ability will be low.

In the method using a heat sink or the like, the temperature rise in the outdoor unit electrical box can be suppressed by increasing the heat sink or the like, but if the heat sink or the like formed of aluminum having high thermal conductivity is enlarged, the manufacturing cost is reduced. There was a problem of becoming higher.
Furthermore, when a space for arranging the heat sink or the like cannot be secured, there is a problem that the temperature rise in the outdoor unit electrical box cannot be suppressed by increasing the heat sink or the like.

On the other hand, the power transistor and the like are disposed so that the attached heat sink and the like are exposed from the electrical box for the outdoor unit for heat dissipation. In this state, when a substrate on which electronic components such as a power transistor are mounted is burned, members that support the power transistor and the like are lost, and the power transistor, the heat sink, and the like are dropped from the electrical unit box for the outdoor unit.
Here, when the electrical unit box for the outdoor unit is disposed above the outdoor fan or the like, the dropped power transistor, the heat sink, or the like hits the outdoor fan. Then, the outdoor fan was damaged, and when the outdoor fan was rotating, the damaged part was scattered around and the damage was further increased.

  The present invention has been made to solve the above-described problem, and suppresses a temperature rise of a power transistor and the like, and can prevent the power transistor from dropping, and an outdoor unit electrical unit box and an outdoor unit And it aims at providing an air conditioner.

In order to achieve the above object, the present invention provides the following means.
The electric box for the outdoor unit of the present invention is an electric box for an outdoor unit that is provided inside the outdoor unit of the air conditioner, and in which an electronic component that controls the operation of the outdoor unit is housed in a sheet metal casing. The housing is provided with an opening in which a heat radiating portion for releasing heat generated from the electronic component protrudes downward, along the heat radiating portion and the opening, and a part of the heat radiating portion and the opening. A metal air guide portion that forms a cooling air flow path that is attached to the housing so as to cover the lower surface of the housing and guides a part of the air flowing through the outdoor unit together with the lower surface of the housing to the heat radiating portion. Provided, the heat dissipating part is disposed so as to extend along the cooling air flow path, and the flow passage cross-sectional area of the cooling air flow path increases toward the upstream of the air flow, the upstream end of the air flow, those And the outdoor air exchanger of the outdoor unit is disposed in contact with the outdoor air exchanger via the contact portion, and the contact portion includes the air guide portion and the outdoor heat exchange. thermal insulation to prevent heat transfer between the vessel and characterized Rukoto to have a resilient.

  According to the present invention, since a part of the air flowing inside the outdoor unit is efficiently guided to the heat radiating part by the air guide part, the temperature of the electronic components stored in the electrical unit box for the outdoor unit, particularly the power transistor, etc. The rise can be suppressed.

  Here, an outdoor fan (propeller fan) that attracts outdoor air is attached to the outdoor unit in order to promote heat exchange in the outdoor unit heat exchanger, and the outdoor unit is installed inside the outdoor unit by the outdoor fan. The outdoor air after heat exchange in the machine heat exchanger flows. Since the upstream end portion of the air guide portion is disposed in contact with the outdoor heat exchanger, a larger amount of air is guided to the cooling air flow path than in the case where the air guide portion is disposed with a space therebetween. . In other words, since there is no gap between the air guide section and the outdoor heat exchanger, the air flowing toward the cooling air flow path does not escape to the outside from this gap. Therefore, a lot of cooling air can be forced to flow around the heat radiating portion.

  Furthermore, since the air guide portion is formed in a shape in which the flow passage cross-sectional area of the cooling air flow passage increases toward the upstream side, more air can be taken into the cooling air flow passage. If the cross-sectional area of the cooling air flow path is increased toward the upstream with a gap between the air guide section and the outdoor heat exchanger, air will not easily flow into the cooling air flow path. The air flowing toward the cooling air flow path escapes to the outside through the gap, and more air cannot be taken into the cooling air flow path.

On the other hand, even if the substrate on which electronic components that control the operation of the outdoor unit are mounted or the resin part of the electrical unit box for the outdoor unit is burnt, it is made of metal attached to the sheet metal casing. The air guide portion can receive the electronic component and the heat radiating portion, and the electronic component and the heat radiating portion can be prevented from falling.
In particular, when the electric box for the outdoor unit is arranged above the inside of the outdoor unit, it collides with other components in the outdoor unit such as an outdoor fan due to the dropped electronic components and the heat radiating part, Although there is a possibility of damage, since the electronic component and the heat radiating part falling by the air guide part can be received, damage to other components can be prevented.

  ADVANTAGE OF THE INVENTION According to this invention, transmission of the heat between an outdoor heat exchanger and the electrical equipment box for outdoor units can be suppressed, and the temperature rise of an electronic component can be suppressed.

For example, when a cooling operation is performed in an air conditioner, high-temperature and high-pressure refrigerant discharged from an electric compressor flows into an outdoor heat exchanger. For this reason, when the air guide section and the outdoor heat exchanger are in direct contact, the heat of the refrigerant is transmitted to the electronic components through the metal air guide section and the sheet metal casing, and the temperature is likely to rise. Become.
On the other hand, since the heat of the refrigerant is hardly transmitted to the air guide portion by bringing the air guide portion and the outdoor heat exchanger into contact with each other through the heat-insulating contact portion, the temperature of the electronic component is increased. Can be suppressed.

  Furthermore, since the contact portion has elasticity, damage to the outdoor heat exchanger can be suppressed. When the outdoor unit to which the outdoor unit electrical box of the present invention is attached is subjected to vibration, for example, when shipped from a manufacturing factory and transported, the wind guide unit and the outdoor heat exchanger repeatedly collide due to vibration. However, the outdoor heat exchanger may be damaged. However, by bringing the wind guide portion and the outdoor heat exchanger into contact with each other through the abutment portion, the outdoor heat exchanger can be used even if the wind guide portion and the outdoor heat exchanger collide repeatedly due to vibration as described above. Hard to damage.

The outdoor unit of the present invention is an outdoor heat exchanger that exchanges heat between the electric compressor that compresses the refrigerant and circulates the refrigerant between the indoor unit of the air conditioner and the refrigerant and outdoor air. vessels and the outdoor fan to attract toward the outdoor air to the outdoor heat exchanger by being rotated, the outdoor of the present invention that the electronic components for controlling the power supplied to the electric compressor is housed An electrical equipment box is provided.

  According to the present invention, since the electrical equipment box for the outdoor unit of the present invention is provided, the temperature rise of the electronic component and the like is suppressed without increasing the size of the outdoor unit, and the electronic component and the heat sink are dropped. It is possible to prevent the outdoor unit from being damaged.

  In the above invention, it is preferable that a control unit is provided that increases the rotational speed of the outdoor fan when the current value supplied from the electronic component to the electric compressor approaches a current limit value.

  According to the present invention, when the current value supplied from the electronic component to the electric compressor becomes large and approaches the current limit value, the rotational speed of the outdoor fan is increased to increase the flow rate of air guided to the heat radiating unit. Thus, even if the amount of heat generated from the electronic component increases, the temperature rise of the electronic component or the like can be suppressed. Therefore, compared with the case where the rotation speed of an outdoor fan is not increased, the current limit value can be increased while suppressing the temperature rise of the electronic component or the like.

  In the above invention, an outdoor air temperature sensor for measuring the temperature of the outdoor air is further provided, and the control unit decreases the current limit value when the temperature of the outdoor air measured by the outdoor air temperature sensor increases. Thus, it is desirable to control the rotational speed of the outdoor fan.

ADVANTAGE OF THE INVENTION According to this invention, even if the temperature of the outdoor air which cools an electronic component rises, the temperature rise of an electronic component etc. can be suppressed.
Specifically, when the temperature of the outdoor air measured by the outdoor air temperature sensor rises, the current limit value is reduced accordingly, and the timing for increasing the rotational speed of the outdoor fan is advanced. Then, since the amount of heat generated from the electronic component or the like is relatively small, the flow rate of the air guided to the heat radiating portion is increased. Therefore, even if the temperature of outdoor air rises and the cooling capacity of electronic components and the like is reduced, the temperature rise of electronic components and the like can be suppressed.

The air conditioner of the present invention is characterized in that an indoor unit and the outdoor unit of the present invention are provided.
According to the present invention, since the outdoor unit of the present invention is provided, the outdoor unit is prevented from increasing in temperature without increasing the size of the outdoor unit, and the electronic unit and the heat radiating unit are dropped. Unit damage can be prevented.

  According to the outdoor unit electrical box, the outdoor unit, and the air conditioner of the present invention, a cooling air flow path that guides a part of the air flowing inside the outdoor unit to the heat radiating part while guiding the heat radiating part from below is introduced. By forming the wind section and bringing the upstream end of the wind guide section into contact with the outdoor heat exchanger, the temperature rise of the power transistor and the like can be suppressed, and the power transistor can be prevented from falling. Play.

It is a perspective view which shows the air conditioner which concerns on one Embodiment of this invention. It is a perspective view which shows the structure of the outdoor unit of FIG. It is a partial front view explaining the arrangement | positioning relationship of an outdoor heat exchanger, a propeller fan, an electrical equipment box, etc. in the outdoor unit of FIG. It is a top view explaining the arrangement | positioning relationship of an outdoor heat exchanger, a propeller fan, an electrical equipment box, etc. in the outdoor unit of FIG. FIG. 5 is a cross-sectional view taken along the line AA for explaining the arrangement relationship of an outdoor heat exchanger, a propeller fan, an electrical box, and the like in the outdoor unit of FIG. It is an upper perspective view explaining the structure of the electrical equipment box of FIG. It is a downward perspective view explaining the structure of the electrical equipment box of FIG. It is a disassembled upper perspective view explaining the structure of the air guide part and storage box of FIG. It is a disassembled lower perspective view explaining the structure of the air guide part and storage box of FIG. It is a block diagram explaining the structure of the control part which controls rotation of the propeller fan of FIG. It is a graph explaining rotation control of the propeller fan by the control part of FIG.

An air conditioner according to an embodiment of the present invention will be described with reference to FIGS.
FIG. 1 is a perspective view showing an air conditioner according to an embodiment of the present invention, and FIG. 2 is a perspective view showing a configuration of the outdoor unit of FIG.
As shown in FIG. 1, the air conditioner 10 includes an indoor unit 20 and an outdoor unit 30. The indoor unit 20 and the outdoor unit 30 are connected to each other by a refrigerant pipe 40 through which the refrigerant conducts, electric wiring (not shown), and the like. Two refrigerant pipes 40 are provided, and the refrigerant flows from the indoor unit 20 to the outdoor unit 30 on one side and from the outdoor unit 30 to the indoor unit 20 on the other side.

  The indoor unit 20 is configured such that a rear base (not shown) and a front panel 21 are integrally formed. The base includes various devices such as a plate fin tube type indoor heat exchanger 22, a substantially cylindrical cross flow fan 23, and a control unit 24 composed of various electric circuit elements for controlling the operation of the indoor unit 20. Is provided.

  The front panel 21 has suction grilles 21a formed on the front and top surfaces, respectively. Indoor air is sucked into the indoor unit 20 from multiple directions by the suction grille 21a. In addition, an air filter 21b is provided behind the suction grille portion 21a to remove dust such as sucked air. Further, the front panel 21 is formed with an air outlet 21c below, from which warmed air or cooled air is blown out. The air suction and air blowing are performed by the rotation of the cross flow fan 23.

3 is a partial front view for explaining the arrangement of the outdoor heat exchanger, the propeller fan, the electrical box, etc. in the outdoor unit of FIG. 2, FIG. 4 is a top view of FIG. 3, and FIG. It is A sectional view.
As shown in FIG. 1 or 2, the outdoor unit 30 includes an outdoor heat exchanger 32, a propeller fan (outdoor fan) 33, an electric compressor 34, and an outdoor unit electrical box 50 (hereinafter, Etc.), etc. are provided. As shown in FIGS. 2 to 4, the outdoor unit 30 is provided with a baffle plate 35 that divides the space in the outdoor unit 30 into two substantially at the center.

  A propeller fan 33 is disposed in a space on the left side (left side in FIG. 3) of the outdoor unit 30 in a front view, and an electric compressor 34 is disposed in a space on the right side (right side in FIG. 3). As shown in FIGS. 2, 3, and 5, an electrical box 50 is disposed above the electric compressor 34, and a propeller fan 33 is disposed at the left end of the electrical box 50 beyond the baffle plate 35. It is arranged to protrude into the space.

The outdoor heat exchanger 32 is configured by a refrigerant pipe having a large number of corrugated fins around it, and realizes heat exchange between the refrigerant and the outdoor air . The propeller fan 33 is provided in order to constantly take in new air into the unit body 31 and improve heat exchange efficiency. When the propeller fan 33 is driven to rotate, wind is generated in the unit body 31 from the outdoor heat exchanger 32 to the propeller fan 33 (from left to right in FIG. 5).

  Note that an opening 31 a for taking in air outside the outdoor unit 30 into the electrical box 50 is provided on one side surface of the unit main body 31. Further, a fingered (not shown) and a fan guard 36 are provided on the back and front of the unit main body 31 where the outdoor heat exchanger 32 and the propeller fan 33 face each other. The fingered is provided so that the corrugated fin is not damaged by an unexpected impact from the outside. Similarly to this, the fan guard 36 is provided for the purpose of protecting the propeller fan 33 from external impact and for the purpose of preventing dust contained in the outside air from being taken into the unit main body 31. Is.

  The electric compressor 34 converts a low-temperature and low-pressure gas refrigerant into a high-temperature and high-pressure gas refrigerant and discharges it. The electric compressor 34 plays a central role among the components constituting the refrigerant circuit. Here, in addition to the electric compressor 34, the refrigerant circuit is a four-way valve (an expansion valve and a four-way valve) that regulates the flow direction of the indoor heat exchanger 22, the outdoor heat exchanger 32, the refrigerant pipe 40, the expansion valve, and the refrigerant. The valve is a circuit that is roughly configured to circulate the refrigerant between the indoor unit 20 and the outdoor unit 30.

6 is an upper perspective view illustrating the configuration of the electrical box shown in FIG. 3, and FIG. 7 is a lower perspective view illustrating the configuration of the electrical box shown in FIG. FIG. 8 is an exploded upper perspective view for explaining the configuration of the air guide portion and the storage box in FIG. 6, and FIG. 9 is an exploded lower perspective view for explaining the configuration of the air guide portion and the storage box in FIG.
As shown in FIGS. 6 to 9, the electrical box 50 is a sheet metal storage box that houses a board (not shown) on which an electronic component (not shown) (for example, a power transistor) that drives and controls the electric compressor 34 is mounted. (Housing) 51, a sheet metal lid (housing) 52, and a plastic (resin) made of plastic (resin) that is housed in the storage box 51 and forms an air discharge channel (not shown). And a guide wall (not shown).

In addition, electronic components for controlling the operation of the electric compressor 34 are mounted on the board, and there are radiating fins that release heat of the electronic components that generate heat (for example, power transistors) to the outside of the electrical box 50. A heat sink (heat radiating part) HS is provided.
Further, the electrical box 50 is provided with a sheet metal (metal) air guide section 60 that guides cooling air to the heat sink HS and prevents the power transistor and the heat sink HS from falling.

The storage box 51 is formed with a frame-like portion 51a in which electronic components that generate a large amount of heat, such as a power transistor, and a storage portion 51b in which other electronic components are stored.
The frame-like portion 51a is formed by connecting a frame in a substantially square shape to the propeller fan 33 side (right side in FIG. 6) of the electrical equipment box 50, and when the electrical equipment box 50 is attached to the outdoor unit 30. This is a portion located in the space where the propeller fan 33 is disposed. An opening (not shown) through which the heat sink HS protrudes downward (downward in FIG. 6) is formed in the frame-like portion 51a.
The storage portion 51b is formed in a bottomed rectangular tube shape on the electric compressor 34 side (left side in FIG. 6) in the electrical box 50, and when the electrical box 50 is attached to the outdoor unit 30, It is a part located in the space where the electric compressor 34 is arranged.

  The storage box 51 is provided with a suction port 53 for air flowing into the electrical equipment box 50 on the side wall located on the left side in FIGS. 6 and 8. On the other hand, a discharge port 54 for air flowing in from the suction port 53 is provided in a side wall portion (side wall portion located on the left side in FIGS. 7 and 9) facing the suction port 53 in the storage box 51.

  An inclined plate 55 that extends obliquely downward and outward from the lower end of the suction port 53 and engages with the lower end of the opening 31 a of the outdoor unit 30 is provided outside the side wall portion where the suction port 53 is provided. Yes. The inclined plate 55 guides air flowing into the electrical box 50 from the opening 31 a to the suction port 53.

  The heat sink HS is formed of a material having high thermal conductivity such as aluminum, and is attached to an electronic component such as a power transistor so as to be able to conduct heat. The heat sink HS is provided with a plurality of radiating fins that increase the contact area with the cooling air, and these radiating fins are arranged so as to extend along the flow of outdoor air by the propeller fan 33 (in the left-right direction in FIG. 5). Has been.

The air guide 60 forms a cooling air flow path that guides outdoor air that has passed through the outdoor heat exchanger 32 to the heat sink HS, together with the frame-like part 51a and the storage part 51b of the storage box 51.
The air guide portion 60 is mainly provided with a bottom surface portion 61 formed by bending one metal plate, a side surface portion 62, an inclined portion 63, and a pair of side wall portions 64.

The bottom surface portion 61 is a plate-like member that extends laterally from the side wall portion of the storage portion 51b along the lower end of the heat sink HS. The side surface portion 62 is a plate-like member extending downward from the lower surface of the frame-shaped portion 51a along the side surface of the heat sink HS. The bottom surface portion 61 and the side surface portion 62 cover the periphery of the heat sink HS to form a cooling air flow path, and receive these when the power transistor and the heat sink HS are dropped. Bottom portion 61 and side portion 62, a part of the outdoor heat exchanger 32 side in the heat sink HS, Ru Tei covers such as about a half.
The bottom surface portion 61 is fixed to the side wall portion of the storage portion 51b, and the side surface portion 62 is fixed to the frame-shaped portion 51a by fixing means such as screws.

The inclined portion 63 is a plate-like member that extends from the end of the bottom surface portion 61 toward the outdoor heat exchanger 32 and inclines in a direction away from the heat sink HS (downward in FIG. 6). The side wall portion 64 is a plate-like member that extends from both side ends of the inclined portion 63 toward the outdoor heat exchanger 32. The inclined portion 63 and the side wall portion 64 form a portion of the cooling air flow path that guides outdoor air that has passed through the outdoor heat exchanger 32 to the heat sink HS. The cooling air flow passage surrounded by the inclined portion 63 and the side wall portion 64 has a flow passage cross-sectional area that increases from the heat sink HS toward the outdoor heat exchanger 32.

Furthermore, an insulation part (contact part) 65 is provided at the lower end of the inclined part 63 and the end of the side wall part 64 on the outdoor heat exchanger 32 side, as shown in FIGS. .
The insulation portion 65 is formed from a material having heat insulation properties and elasticity, and as shown in FIGS. 4 and 5, when the electrical box 50 is attached to the outdoor unit 30, outdoor heat exchange is performed. Which is in contact with the vessel 32.

FIG. 10 is a block diagram illustrating the configuration of a control unit that controls the rotation of the propeller fan in FIG. 1.
As shown in FIG. 10, the outdoor unit 30 includes a control unit 70 that controls the rotation speed of the propeller fan 33 and an inverter current that is a current supplied to the electric compressor 34 from an electronic component such as a power transistor. , Further provided. The control unit 70 receives the inverter current value CT measured by the current sensor 71 and the outdoor air temperature ThO-A sucked into the outdoor heat exchanger 32 measured by the outdoor air temperature sensor 72.
Details of control of the rotation speed of the propeller fan 33 and the inverter current value CT in the control unit 70 will be described later.

  Next, the operation of the air conditioner 10 having the above-described configuration will be described separately for the heating operation and the cooling operation.

  First, at the time of heating operation, the gas refrigerant that has become high temperature and high pressure in the electric compressor 34 passes through the refrigerant pipe 40 and is pumped to the indoor heat exchanger 22 of the indoor unit 20 as shown in FIG. In the indoor unit 20, heat is given from the high-temperature and high-pressure refrigerant flowing through the indoor heat exchanger 22 to the indoor air taken in from the suction grille portion 21 a by the cross flow fan 23. Thereby, warm air is blown out from the blower outlet 21c. At the same time, the high-temperature and high-pressure gaseous refrigerant is condensed and liquefied in the indoor heat exchanger 22 to become a high-temperature and high-pressure liquid refrigerant.

  The high-temperature and high-pressure liquid refrigerant is decompressed by the expansion valve while being sent to the outdoor heat exchanger 32 of the outdoor unit 30 and becomes a low-temperature and low-pressure liquid refrigerant. In the outdoor unit 30, the low-temperature and low-pressure liquid refrigerant flowing through the outdoor heat exchanger 32 takes heat from new outdoor air taken into the unit main body 31 by the propeller fan 33. The low-temperature and low-pressure liquid refrigerant evaporates and vaporizes by taking heat, and becomes a low-temperature and low-pressure gas refrigerant. This is sent again to the electric compressor 34, and the above process is repeated.

  During the cooling operation, the refrigerant flows in the refrigerant circuit in the opposite direction to the above. That is, the high-temperature and high-pressure gas refrigerant in the electric compressor 34 passes through the refrigerant pipe 40 and is pumped to the outdoor heat exchanger 32, where heat is taken away by the outdoor air to condense and liquefy, and the high-temperature and high-pressure liquid refrigerant. It becomes. The high-temperature and high-pressure liquid refrigerant is decompressed by the expansion valve to become a low-temperature and low-pressure liquid refrigerant, and is sent again to the indoor heat exchanger 22 through the refrigerant pipe 40. Here, the low-temperature and low-pressure liquid refrigerant takes heat from the indoor unit and blows out cold air from the outlet 21c, and the refrigerant itself evaporates to become a low-temperature and low-pressure gaseous refrigerant. This is sent again to the electric compressor 34, and the above process is repeated.

  In any of the above heating operation and cooling operation, as shown in FIGS. 2, 3, and 5, the propeller fan 33 rotates in the outdoor unit 30, and the outdoor heat exchanger 32 of the outdoor unit 30. The outdoor air is flowing from the propeller fan 33 toward the propeller fan 33. Most of the outdoor air heat-exchanged in the outdoor heat exchanger 32 is discharged to the outside of the outdoor unit 30 as it is.

On the other hand, as shown in FIGS. 3 to 5, the outdoor air that has passed through the region facing the air guide portion 60 in the outdoor heat exchanger 32 flows into the cooling air flow path formed by the air guide portion 60. . The outdoor air (cooling air) that has flowed into the cooling air flow path is guided to the heat sink HS and flows around the heat sink HS.
Here, since the cross-sectional area of the cooling air flow path formed by the air guide section 60 is narrowed from the outdoor heat exchanger 32 toward the heat sink HS, the outdoor air that has flowed into the cooling air flow path has a flow velocity. Flows toward the heat sink HS.
The heat sink HS is deprived of heat by this air flow, and releases heat generated in electronic components such as a power transistor.

  Furthermore, since air flows in the space where the propeller fan 33 is disposed, the pressure of the air in the space is lower than the pressure of the air around the outside of the outdoor unit 30. Due to this pressure difference, the air outside the outdoor unit 30 is introduced into the electrical box 50 from the opening 31 a through the suction port 53, and flows out of the electrical box 50 through the discharge port 54.

  The air flowing into the electrical box 50 from the suction port 53 flows toward the inlet of the exhaust passage facing the suction port 53 while spreading uniformly in the electrical box 50, and the electrons stored in the electrical box 50. Heat is taken from the parts and cooled, and flows into the inlet of the exhaust passage. The air that has flowed into the exhaust passage from the inlet of the exhaust passage passes through the discharge port 54 and is discharged out of the electrical box 50, that is, into the space where the propeller fan 33 is disposed.

Next, control of the rotation speed of the propeller fan 33 and the inverter current value CT by the control unit 70 will be described with reference to FIGS. 10 and 11.
FIG. 11 is a map for explaining the rotation speed control and inverter current control of the propeller fan by the control unit of FIG.

  When the air conditioner 10 is in a cooling operation and the inverter current value CT increases and approaches the current safe upper limit value (current limit value) CS as shown in FIG. The number of rotations of 33 is forcibly increased and control is performed to operate at the maximum number of rotations.

  Here, the current safe upper limit value CS is a value set for the purpose of preventing the occurrence of a malfunction based on heat generated from an electronic component such as a power transistor. Furthermore, the current safe upper limit CS is a value that varies depending on the outdoor air temperature ThO-A. Specifically, when the outdoor air temperature ThO-A is equal to or lower than the first predetermined temperature T1, the current safe upper limit value CS is a constant value A1, and in the region from the first predetermined temperature T1 to the second predetermined temperature T2. As the outdoor air temperature ThO-A rises, the current safe upper limit CS decreases. When the outdoor air temperature ThO-A is equal to or higher than the second predetermined temperature T2, the current safe upper limit CS is another constant value A2.

  The map shown in FIG. 11 is obtained in advance by experiments or the like, and is stored in the control unit 70 in advance. The map of FIG. 11 is provided with a first area, a second area, and a third area depending on the contents of control. A part between the first region and the third region, and a region between the second region and the third region are partitioned by the current safe upper limit CS, and a threshold value TH is provided between the first region and the second region. It is divided by.

  Here, the threshold value TH becomes a constant value A3 having a current value smaller than the constant value A1 when the outdoor air temperature ThO-A is equal to or lower than the first predetermined temperature T1. When the outdoor air temperature ThO-A becomes higher than the first predetermined temperature T1, the threshold value TH decreases as the outdoor air temperature ThO-A increases to another constant value A2, and then the outdoor air temperature ThO. Regardless of the increase of -A, it becomes another constant value A2.

  In other words, the first region is a region where the inverter current value CT is smaller than the current safe upper limit value CS and the threshold value TH, and the second region is a region surrounded by the current safe upper limit value CS and the threshold value TH. Further, the third region is a region where the inverter current value CT is larger than the current safe upper limit value CS.

For example, when the outdoor air temperature ThO-A is equal to or lower than the second predetermined temperature T2, when the inverter current value CT gradually increases, the control unit 70 first controls the first region.
That is, in the first region, the control unit 70 controls the rotation speed of the propeller fan 33 in accordance with conditions such as the operating state of the air conditioner 10 and the temperature of outdoor air. The control performed here can use a known control method, and is not particularly limited.

Thereafter, when the inverter current value CT becomes equal to or higher than the threshold value TH and equal to or lower than the current safe upper limit value CS, the control unit 70 controls the second region.
That is, in the second region, the control unit 70 performs control to increase the rotation speed of the propeller fan 33 and rotate it at the maximum rotation speed regardless of the operating condition of the air conditioner 10 and the conditions such as the temperature of the outdoor air. . For this reason, since the amount of heat released from the heat sink HS is larger than when the second region is not controlled, the current safe upper limit CS is increased when the upper limit temperature of the electronic components such as the power transistor is the same. can do.

Further, when the inverter current value CT becomes larger than the current safe upper limit value CS, the control unit 70 controls the third region.
That is, in the third region, the control unit 70 performs control to suppress an increase in the inverter current value CT regardless of conditions such as the operating state of the air conditioner 10 and the temperature of outdoor air. Therefore, an increase in the amount of heat generated from the electronic component such as a power transistor can be suppressed, and a temperature increase of the electronic component or the like can be suppressed.

  Further, when the outdoor air temperature ThO-A is higher than the second predetermined temperature T2, as shown in FIG. 11, the controller 70 first controls the first region, and the inverter current value CT becomes the current safe upper limit. When it becomes larger than the value CS, the third region is controlled. In other words, the third region is directly controlled without controlling the second region.

According to the above configuration, since a part of the outdoor air flowing inside the outdoor unit 30 is efficiently guided to the heat sink HS by the air guide unit 60, the electronic components stored in the electrical box 50, particularly the power transistor, etc. Temperature rise can be suppressed.
Furthermore, it is possible to suppress an increase in the temperature of the electronic component or the like without increasing the size of the heat sink HS, that is, without increasing the size of the outdoor unit 30.

  Since the upstream end portion of the wind guide portion 60 is disposed in contact with the outdoor heat exchanger 32, a large amount of outdoor air is generated in the wind guide portion 60 as compared with the case where the air guide portion 60 is disposed at a distance. Guided to the cooling air flow path. In other words, since there is no gap between the air guide section 60 and the outdoor heat exchanger 32, the air flowing toward the cooling air flow path does not escape to the outside from this gap. Therefore, a lot of outdoor air (cooling air) can be forced to flow around the heat sink HS.

  Furthermore, since the air guide section 60 is formed in a shape in which the flow passage cross-sectional area of the cooling air flow passage increases toward the upstream side, more outdoor air can be taken into the cooling air flow passage. That is, in the state where there is a gap between the air guide section 60 and the outdoor heat exchanger 32, when the flow passage cross-sectional area of the cooling air passage is increased toward the upstream, the outdoor air becomes the cooling air passage. Since it becomes difficult to flow in, the air that has flowed toward the cooling air flow path escapes to the outside through this gap, and more outdoor air cannot be taken into the cooling air flow path.

On the other hand, even if the substrate on which the electronic components for controlling the operation of the outdoor unit 30 are mounted or the resin part of the electrical box 50 is burnt, the metal lead attached to the sheet metal storage box 51 is burned. The wind part 60 can receive the electronic component and the heat sink HS, and the electronic component and the heat sink HS can be prevented from falling.
In particular, as in the present embodiment, when the electrical box 50 is arranged above the outdoor unit 30, it may collide with the propeller fan 33 due to the dropped electronic components and the heat sink HS, and may be damaged. However, since the electronic component and the heat sink HS that are dropped by the air guide portion 60 can be received, the propeller fan 33 can be prevented from being damaged.

Lower end of the inclined portion 63 of the airflow guidance section 60, and the outdoor heat exchanger 32 side of the end of the side wall portions 6 4, by providing the insulation portion 65, the outdoor heat exchanger 32 and the electrical component box 50 Heat transfer between them and the temperature rise of the electronic component can be suppressed.

In particular, when a cooling operation is performed in the air conditioner 10, the high-temperature and high-pressure refrigerant discharged from the electric compressor 34 flows into the outdoor heat exchanger 32. Therefore, if the air guide 60 and the outdoor heat exchanger 32 are in direct contact, the heat of the refrigerant is transmitted to the electronic component through the metal air guide 60 and the sheet metal storage box 51, and the temperature Tends to rise.
On the other hand, it is difficult for the heat of the refrigerant to be transmitted to the air guide portion 60 by bringing the air guide portion 60 and the outdoor heat exchanger 32 into contact with each other via the insulation portion 65 having heat insulation properties. Temperature rise can be suppressed.

  Furthermore, since the insulation part 65 has elasticity, damage to the outdoor heat exchanger 32 can be suppressed. In a state where vibration is applied to the outdoor unit 30 to which the electrical box 50 of this embodiment is attached, for example, when shipped from a manufacturing factory and transported, the wind guide section 60 and the outdoor heat exchanger 32 are repeatedly caused by vibration. The outdoor heat exchanger 32 may be damaged due to a collision. However, by bringing the air guide portion 60 and the outdoor heat exchanger 32 into contact with each other via the insulation portion 65, even if the air guide portion 60 and the outdoor heat exchanger 32 repeatedly collide due to vibration as described above, The outdoor heat exchanger 32 is not easily damaged.

  By controlling the rotation speed of the propeller fan 33 by the control unit 70, that is, when the inverter current value CT supplied from the electronic component to the electric compressor 34 becomes large and approaches the current safe upper limit CS, the propeller fan By increasing the number of rotations 33 and increasing the flow rate of outdoor air guided to the heat sink HS, even if the amount of heat generated from the electronic components increases, the temperature rise of the electronic components can be suppressed. Therefore, compared with the case where the rotation speed of the propeller fan 33 is not increased, the current safe upper limit CS can be increased while suppressing the temperature rise of the electronic components and the like.

More specifically, even if the temperature ThO-A of the outdoor air that cools the electronic component rises, the temperature rise of the electronic component or the like can be suppressed.
That is, when the outdoor air temperature ThO-A rises, the current safe upper limit value CS is reduced accordingly, and the timing for increasing the rotation speed of the propeller fan 33 is advanced. Then, since the amount of heat generated from the electronic component or the like is relatively small, the flow rate of the air guided to the heat sink HS is increased. Therefore, even if the outdoor air temperature ThO-A is increased and the cooling capacity of the electronic component or the like is lowered, the temperature increase of the electronic component or the like can be suppressed.

The technical scope of the present invention is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the present invention.
For example, in the above-described embodiment, the present invention has been described by applying the present invention to an air conditioner in which the outdoor unit and the indoor unit correspond one-to-one. However, a plurality of indoor units are included in one outdoor unit. The present invention can be applied to the provided air conditioner and is not particularly limited.

DESCRIPTION OF SYMBOLS 10 Air conditioner 20 Indoor unit 30 Outdoor unit 32 Outdoor heat exchanger 33 Propeller fan (outdoor fan)
34 Electric compressor 50 Electric box for outdoor unit 51 Storage box (housing)
52 Lid (housing)
60 Air guide part 65 Insulation part (contact part)
70 Control unit 72 Outside air temperature sensor HS Heat sink (heat dissipation unit)

Claims (5)

An electrical unit box for an outdoor unit that is provided inside an outdoor unit of an air conditioner and stores electronic components that control the operation of the outdoor unit in a sheet metal casing,
The housing is provided with an opening from which a heat radiating part that releases heat generated from the electronic component protrudes downward.
A part of the air that flows along the heat radiating portion and the opening and that covers the heat radiating portion and a part of the opening from below is attached to the housing, and flows inside the outdoor unit together with the lower surface of the housing. A metal air guide part is provided that forms a cooling air flow path leading to the heat radiating part,
The heat dissipating part is arranged to extend along the cooling air flow path,
The channel cross-sectional area of the cooling air channel increases toward the upstream of the air flow,
A contact portion is provided at an upstream end of the air flow in the air guide portion ,
The air guide part and the outdoor heat exchanger of the outdoor unit are arranged in contact with each other via the contact part,
The abutment, heat insulating properties and electrical component box for an outdoor unit, characterized in Rukoto to have a resilient preventing the transfer of heat between the air guide portion and the outdoor heat exchanger. An electric compressor that compresses the refrigerant and circulates the refrigerant between the indoor unit of the air conditioner;
An outdoor heat exchanger that exchanges heat between the refrigerant and outdoor air;
An outdoor fan that attracts the outdoor air toward the outdoor heat exchanger by being driven to rotate;
The electrical equipment box for the outdoor unit according to claim 1, wherein electronic components for controlling electric power supplied to the electric compressor are stored.
Is provided with an outdoor unit. The control unit according to claim 2 , further comprising a controller that increases a rotational speed of the outdoor fan when a current value supplied from the electronic component to the electric compressor approaches a current limit value. Outdoor unit. Furthermore, an outside air temperature sensor for measuring the temperature of the outdoor air is provided,
Wherein, when the temperature of the outdoor air that is measured by the ambient temperature sensor is increased, by reducing the current limit value, according to claim 3, characterized in that to control the rotational speed of the outdoor fan Outdoor unit. An indoor unit,
The outdoor unit according to any one of claims 2 to 4 ,
Is provided with an air conditioner.

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