OUTDOOR UNIT OF AIR CONDITIONER

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of International Application No. PCT/KR2024/006060 designating the United States, filed on May 7, 2024, in the Korean Intellectual Property Receiving Office and claiming priority to Korean Patent Application No. 10-2023-0084508, filed on Jun. 29, 2023, in the Korean Intellectual Property Office, the disclosures of each of which are incorporated by reference herein in their entireties.

BACKGROUND

Field

The disclosure relates to an outdoor unit of an air conditioner.

Description of Related Art

An air conditioner may have an indoor unit and an outdoor unit connected to each other by a refrigerant pipe. The outdoor unit performs heat exchange between a refrigerant and the outdoor air using a phase change of the refrigerant. The outdoor unit includes a fan that forms a flow of air, that is, cooling air, that passes through a heat exchanger and is discharged to the outside. A safety guard is arranged at the downstream side of the fan with respect to the direction of the flow of cooling air. The safety guard has a grid shape to form an exhaust path for the cooling air, protect the fan, and prevent/block foreign substances from entering the outdoor unit.

SUMMARY

An outdoor unit of an air conditioner according to an example embodiment of the present disclosure may include a heat exchanger, a fan, and a safety guard. The fan is positioned at a downstream side of the heat exchanger and is configured to generate a flow of air passing through the heat exchanger. The safety guard includes a plurality of main ribs and a plurality of auxiliary ribs and is positioned at a downstream side of the fan. The plurality of auxiliary ribs intersect with the plurality of main ribs and connect the plurality of main ribs. A thickness reduction region is provided in a region of an auxiliary rib, the region being connected to a main rib.

An outdoor unit of an air conditioner according to an example embodiment of the present disclosure may include a heat exchanger, a fan, and a safety guard. The fan is positioned at the downstream side of the heat exchanger and is configured to generate a flow of air passing through the heat exchanger. The safety guard is positioned at the downstream side of the fan. The safety guard includes a plurality of main ribs and a plurality of auxiliary ribs. The plurality of main ribs are formed such that at least one surface of two surfaces in an arrangement direction is inclined with respect to a blowing direction of air flow generated by the fan. The plurality of auxiliary ribs extend to intersect the plurality of main ribs and connect the plurality of main ribs. Two adjacent main ribs are referred to as a first main rib and a second main rib, respectively, an auxiliary rib includes a first portion connected to the first main rib, a second portion connected to the second main rib, and a third portion connecting the first portion and the second portion between the first portion and the second portion. With respect to the blowing direction of air flow generated by the fan, a length of the first portion is longer than a length of the second portion, and a downstream end of the first portion is positioned downstream of a downstream end of the second portion.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other aspects, features and advantages of certain embodiments of the present disclosure will be more apparent from the following detailed description, taken in conjunction with the accompanying drawings, in which:

FIG. 1 is an exploded perspective view of an outdoor unit according to various embodiments;

FIG. 2 is a diagram illustrating a partial front view of a safety guard illustrated in FIG. 1 according to various embodiments;

FIG. 3 is a cross-sectional view taken along line Y-Y′ of FIG. 2 according to various embodiments;

FIGS. 4A, 4B, 4C and 4D are diagrams illustrating various example shapes of a downstream end of a first portion of an auxiliary rib according to various embodiments;

FIG. 5 is a cross-sectional view of a safety guard according to various embodiments;

FIGS. 6A and 6B are diagrams illustrating various example shapes of a downstream end of a third portion of the auxiliary rib according to various embodiments;

FIG. 7 is a partial rear perspective view of a safety guard according to various embodiments;

FIG. 8 is a partial cross-sectional view of a safety guard according to various embodiments;

FIG. 9 is a diagram illustrating a safety guard according to a comparative example;

FIG. 10 is a diagram illustrating a safety guard according to various embodiments;

FIG. 11 is a diagram illustrating a plan view of a safety guard according to various embodiments; and

FIG. 12 is a diagram illustrating a plan view of a safety guard according to various embodiments.

DETAILED DESCRIPTION

It should be understood that various example embodiments and terms used in the present disclosure are not intended to limit the technical features described in the present disclosure to specific embodiments, but rather to encompass various modifications, equivalents, or alternatives.

In connection with the description of the drawings, similar reference numerals may be used for similar or related components.

The singular form of a noun corresponding to an item may include one or more of said items, unless the relevant context clearly indicates otherwise.

In the present disclosure, each of the phrases “A or B”, “at least one of A and B”, “at least one of A or B”, “A, B, or C”, “at least one of A, B, and C”, and “at least one of A, B, or C” may include any one of the items listed together in that phrase, or all possible combinations thereof.

The term “and/or” includes any combination of a plurality of related described elements or any one of a plurality of related described elements.

Terms such as “first” or “second” may be used simply to distinguish one component from another and do not qualify the components in any other respect (e.g., importance or order).

When a component (e.g., a first component) is referred to as being “coupled” or “connected” to another component (e.g., a second component), with or without the terms “functionally” or “communicatively,” it indicates that the component may be connected to the other component directly (e.g., in a wired manner), wirelessly, or through a third component.

In the present disclosure, terms such as “include” or “have” are intended to specify the presence of a feature, number, step, operation, component, part or combination thereof described in the disclosure, but do not exclude in advance the possibility of the presence or addition of one or more other features, numbers, steps, operations, components, parts or combinations thereof.

When a component is said to be “connected,” “coupled,” “supported,” or “in contact with” another component, this includes not only cases where the components are directly connected, coupled, supported, or in contact, but also cases where the components are indirectly connected, coupled, supported, or in contact through a third component.

When a component is referred to as being “on” another component, this includes not only cases where the component is in contact with the other component, but also cases where there is another component between the two components.

An air conditioner according to various example embodiments is a device that performs functions such as air purification, ventilation, humidity control, cooling or heating in an air-conditioned space (hereinafter referred to as “indoor”), and refers to a device having at least one of these functions.

According to an embodiment, the air conditioner may include a heat pump device to perform a cooling function or a heating function. The heat pump device may include a refrigeration cycle in which a refrigerant circulates along a compressor, a first heat exchanger, an expansion device, and a second heat exchanger. Components of the heat pump device may be built into a single housing that forms the exterior of the air conditioner, such as window air conditioners or portable air conditioners. Some components of the heat pump device may be divided and built into a plurality of housings forming a single air conditioner, including wall-mounted air conditioners, stand-alone air conditioners, and system air conditioners.

An air conditioner including a plurality of housings may include at least one outdoor unit installed outdoors and at least one indoor unit installed indoors. For example, an air conditioner may be configured such that one outdoor unit and one indoor unit are connected to each other via a refrigerant pipe. For example, an air conditioner may be configured such that one outdoor unit is connected to two or more indoor units through refrigerant pipes. For example, an air conditioner may be configured such that two or more outdoor units and two or more indoor units are connected to each other through a plurality of refrigerant pipes.

An outdoor unit may be electrically connected to an indoor unit. For example, information (or commands) for controlling an air conditioner may be input through an input interface provided on an outdoor unit or an indoor unit, and the outdoor unit and the indoor unit may operate simultaneously or sequentially in response to a user input.

An air conditioner may include an outdoor heat exchanger provided in an outdoor unit, an indoor heat exchanger provided in an indoor unit, and a refrigerant pipe connecting the outdoor heat exchanger and the indoor heat exchanger.

The outdoor heat exchanger may perform heat exchange between a refrigerant and outdoor air using a phase change of the refrigerant (e.g., evaporation or condensation). For example, while the refrigerant condenses in the outdoor heat exchanger, the refrigerant may release heat to the outdoor air, and while the refrigerant flowing in the outdoor heat exchanger evaporates, the refrigerant may absorb heat from the outdoor air.

The indoor unit is installed indoors. For example, indoor units may be classified into ceiling-mounted indoor units, stand-alone indoor units, and wall-mounted indoor units depending on a method of arranging the same. For example, ceiling-type indoor units may be classified into 4-way indoor units, 1-way indoor units, and duct-type indoor units depending on the method by which air is discharged.

An indoor heat exchanger may perform heat exchange between a refrigerant and indoor air using a phase change of the refrigerant (e.g., evaporation or condensation). For example, while the refrigerant evaporates in the indoor unit, the refrigerant may absorb heat from the indoor air, and the room may be cooled by blowing the cooled indoor air through the cooled indoor heat exchanger. While the refrigerant is condensing in the indoor heat exchanger, the refrigerant may release heat to the indoor air, and the indoor space may be heated by blowing the heated indoor air through the high-temperature indoor heat exchanger.

For example, the air conditioner performs a cooling or heating function through a phase change process of a refrigerant circulating between the outdoor heat exchanger and the indoor heat exchanger. For this circulation of the refrigerant, the air conditioner may include a compressor that compresses the refrigerant. The compressor may suck in refrigerant gas through a suction portion and compress the refrigerant gas. The compressor may discharge high-temperature and high-pressure refrigerant gas through a discharge portion. The compressor may be arranged inside the outdoor unit.

The refrigerant may circulate through the refrigerant pipes in the order of the compressor, the outdoor heat exchanger, the expansion device, and the indoor heat exchanger, or in the order of the compressor, the indoor heat exchanger, the expansion device, and the outdoor heat exchanger.

For example, in an air conditioner, if one outdoor unit and one indoor unit are directly connected to each other through a refrigerant pipe, the refrigerant may be arranged to circulate between the one outdoor unit and the one indoor unit through the refrigerant pipe.

For example, in an air conditioner, if one outdoor unit is connected to two or more indoor units through refrigerant pipes, the refrigerant may flow to the plurality of indoor units through refrigerant pipes branching from the outdoor unit. The refrigerant discharged from the plurality of indoor units may be combined and circulated to the outdoor unit. For example, the plurality of indoor units may be directly connected in parallel to one outdoor unit through separate refrigerant pipes.

The plurality of indoor units may be operated independently according to an operating mode set by a user. For example, some of the plurality of indoor units may operate in a cooling mode while others operate in a heating mode at the same time. The refrigerant may be selectively introduced into each indoor unit at a high or low pressure along a designated circulation path through a flow path switching valve to be described later, and discharged therefrom to be circulated to the outdoor unit.

For example, when two or more outdoor units and two or more indoor units in an air conditioner are connected through a plurality of refrigerant pipes, the refrigerants discharged from the plurality of outdoor units may be combined and flow through one refrigerant pipe, then branch off again at a certain point and flow into the plurality of indoor units.

The plurality of outdoor units may all be driven or at least some thereof may not be driven, depending on the operating load according to the operating amount of the plurality of indoor units. The refrigerant may be arranged to be introduced into an outdoor unit that is selectively driven through the flow path switching valve, and be circulated. The air conditioner may include an expansion device to reduce the pressure of the refrigerant entering the heat exchanger. For example, the expansion device may be arranged inside the indoor unit or inside the outdoor unit, or may be arranged in both.

The expansion device may lower the temperature and pressure of the refrigerant by, for example, using a throttling effect. The expansion device may include an orifice capable of reducing the cross-sectional area of a flow path. The refrigerant passing through the orifice may have a lower temperature and pressure.

The expansion device may be implemented as an electronic expansion valve, for example, capable of controlling the opening ratio (the ratio of the cross-sectional area of the valve's flow path in a partially open state to the cross-sectional area of the valve's flow path in a fully open state). The amount of refrigerant passing through the expansion device may be controlled depending on the opening ratio of the electronic expansion valve.

The air conditioner may further include a flow path switching valve disposed on a refrigerant circulation path. The flow path switching valve may include, for example, a 4-way valve. The flow path switching valve may determine a circulation path of a refrigerant depending on the operating mode of the indoor unit (e.g. cooling operation or heating operation). The flow path switching valve may be connected to a discharge portion of the compressor.

The air conditioner may include an accumulator. The accumulator may be connected to a suction portion of the compressor. The accumulator may receive a low-temperature and low-pressure refrigerant evaporated from the indoor heat exchanger or the outdoor heat exchanger.

The accumulator may separate a refrigerant liquid from a refrigerant gas when a refrigerant mixture of refrigerant liquid and refrigerant gas is introduced, and provide the refrigerant gas from which the refrigerant liquid has been separated, to the compressor.

An outdoor fan may be provided near the outdoor heat exchanger. The outdoor fan may blow outdoor air to the outdoor heat exchanger to promote heat exchange between the refrigerant and the outdoor air.

The outdoor unit of the air conditioner may include at least one sensor. For example, the sensor of the outdoor unit may be provided as an environmental sensor. An outdoor unit sensor may be arranged at any location inside or outside the outdoor unit. For example, the outdoor unit sensor may include a temperature sensor for detecting air temperature around the outdoor unit, a humidity sensor for detecting air humidity around the outdoor unit, a refrigerant temperature sensor for detecting refrigerant temperature in a refrigerant pipe passing through the outdoor unit, or a refrigerant pressure sensor for detecting refrigerant pressure in a refrigerant pipe passing through the outdoor unit.

The outdoor unit of the air conditioner may include an outdoor unit communication unit. The outdoor unit communication unit may be provided to receive a control signal from a control unit of the indoor unit of the air conditioner, which will be described in greater detail below. The outdoor unit may control the operation of the compressor, the outdoor heat exchanger, the expansion device, the flow path switching valve, the accumulator, or the outdoor fan based on a control signal received through the outdoor unit communication unit. The outdoor unit may transmit a sensing value detected from the sensor of the outdoor unit to the control unit of the indoor unit through the outdoor unit communication unit.

The indoor unit of the air conditioner may include a housing, a blower for circulating air into or out of the housing, and an indoor heat exchanger for exchanging heat with air flowing into the interior of the housing.

The housing may include an intake port. Through the intake port, indoor air may be drawn into the interior of the housing.

The indoor unit of the air conditioner may include a filter that is provided to filter foreign substances in the air that flows into the housing through the intake port.

The housing may include an exhaust port. Air flowing inside the housing may be discharged to the outside of the housing through the exhaust port.

The housing of the indoor unit may include an airflow guide that guides the direction of air discharged through the exhaust port. For example, the airflow guide may include blades positioned above the exhaust port. For example, the airflow guide may include an auxiliary fan to regulate the exhaust airflow. Without limitation, the airflow guide may be omitted.

An indoor heat exchanger and a blower may be provided inside the housing of the indoor unit, which are arranged on a flow path connecting the intake port and the exhaust port.

The blower may include an indoor fan and a fan motor. For example, indoor fans may include axial fans, diffusion fans, crossflow fans, and centrifugal fans.

The indoor heat exchanger may be positioned between the blower and the exhaust port, or between the intake port and the blower. The indoor heat exchanger may absorb heat from air drawn in through the intake port or transfer heat to air drawn in through the intake port. The indoor heat exchanger may include heat exchange tubes through which refrigerant flows, and heat exchange fins that are in contact with the heat exchange tubes to increase a heat transfer area.

The indoor unit of the air conditioner may include a drain tray that is arranged below the indoor heat exchanger and collects condensate generated in the indoor heat exchanger. Condensate collected in the drain tray may be drained to the outside through a drain hose. The drain tray may be provided to support the indoor heat exchanger.

The indoor unit of the air conditioner may include an input interface. The input interface may include any type of user input means, including buttons, switches, a touch screen, and/or a touch pad. The user may directly input setting data (e.g., desired indoor temperature, operation mode setting for cooling/heating/dehumidification/air purification, outlet selection setting, and/or wind volume setting) through the input interface.

The input interface may also be connected to an external input device. For example, the input interface may be electrically connected to a wired remote controller. The wired remote controller may be installed in a specific location in the indoor space (e.g., a section of a wall). The user may input setting data regarding the operation of the air conditioner by operating the wired remote controller. An electrical signal corresponding to setting data obtained through the wired remote controller may be transmitted to the input interface. Additionally, the input interface may include an infrared sensor. The user may remotely input setting data regarding the operation of the air conditioner using the wireless remote controller. Setting data input via the wireless remote controller may be transmitted to the input interface as an infrared signal.

The input interface may include a microphone. The user's voice command may be obtained through the microphone. The microphone may convert the user's voice command into an electrical signal and transmit the converted electrical signal to an indoor unit control unit. The indoor unit control unit may control the components of the air conditioner to execute a function corresponding to the user's voice command. The setting data obtained through the input interface (e.g., desired indoor temperature, operation mode setting for cooling/heating/dehumidification/air purification, outlet selection setting, and/or wind volume setting) may be transmitted to the indoor unit control unit that will be described later. In an example, setting data obtained through the input interface may be transmitted to the outside, e.g., to an outdoor unit or server, through an indoor unit communication unit that will be described later.

The indoor unit of the air conditioner may include a power module. The power module may include a power supply and may be connected to an external power source to supply power to the components of the indoor unit.

The indoor unit of the air conditioner may include an indoor unit sensor. The indoor unit sensor may be an environmental sensor arranged in a space inside or outside the housing. For example, the indoor unit sensor may include one or more temperature sensors and/or humidity sensors arranged in a predetermined space inside or outside the housing of the indoor unit. For example, the indoor unit sensor may include a refrigerant temperature sensor for detecting the refrigerant temperature of a refrigerant pipe passing through the indoor unit. For example, the indoor unit sensor may include a respective refrigerant temperature sensor that detects the inlet, middle, and/or outlet temperatures of the refrigerant tubes passing through the indoor heat exchanger.

For example, each piece of environmental information detected by the indoor unit sensor may be transmitted to the indoor unit control unit described later or transmitted externally through the indoor unit communication unit described in greater detail below.

The indoor unit of the air conditioner may include an indoor unit communication unit. The indoor unit communication unit may include at least one of a short-range communication module or a long-range communication module. The indoor unit communication unit may include at least one antenna for wirelessly communicating with other devices. The outdoor unit may include the outdoor unit communication unit. The outdoor unit communication unit may also include at least one of a short-range communication module or a long-range communication module.

The short-range wireless communication module may include, but is not limited to, a Bluetooth communication module, a BLE (Bluetooth Low Energy) communication module, a Near Field Communication module, a WLAN (Wi-Fi) communication module, a Zigbee communication module, an infrared (IrDA, infrared Data Association) communication module, a WFD (Wi-Fi Direct) communication module, an UWB (ultrawideband) communication module, an Ant+ communication module, a microwave (uWave) communication module, etc.

The long-range communication module may include a communication module that performs various types of long-range communication and may include a mobile communication unit. The mobile communication unit transmits or receives a wireless signal to or from at least one of a base station, an external terminal, and a server on a mobile communication network.

The indoor unit communication unit may communicate with external devices such as servers, mobile devices, and other home appliances through surrounding access points (AP). An access point (AP) may connect a local area network (LAN) where an air conditioner or a user equipment is connected to a wide area network (WAN) where servers are connected. The air conditioner or the user equipment may be connected to a server via a wide area network (WAN). The indoor unit of the air conditioner may include the indoor unit control unit that controls components of the indoor unit, including a blower, etc. The outdoor unit of the air conditioner may include an outdoor unit control unit that controls components of the outdoor unit, including a compressor, etc. The indoor unit control unit may communicate with the outdoor unit control unit through the indoor unit communication unit and the outdoor unit communication unit. The outdoor unit communication unit may transmit a control signal generated by the outdoor unit control unit, to the indoor unit communication unit, or may transmit a control signal transmitted from the indoor unit communication unit, to the outdoor unit control unit. That is, the outdoor unit and the indoor unit may communicate in both directions. The outdoor unit and the indoor unit may transmit and receive various signals generated during the operation of the air conditioner.

The outdoor unit control unit may be electrically connected to the components of the outdoor unit and control the operation of each component. For example, the outdoor unit control unit may adjust the frequency of the compressor and control the flow path switching valve to change the circulation direction of the refrigerant. The outdoor unit control unit may control the rotation speed of the outdoor fan. The outdoor unit control unit may generate a control signal to adjust the opening of an expansion valve. Under the control by the outdoor unit control unit, the refrigerant may circulate along a refrigerant circulation circuit including a compressor, a flow path switching valve, an outdoor heat exchanger, an expansion valve, and an indoor heat exchanger.

Various temperature sensors included in the outdoor unit and the indoor unit may transmit electrical signals corresponding to the detected temperature to the outdoor unit control unit and/or the indoor unit control unit. For example, humidity sensors included in the outdoor unit and the indoor unit may transmit electrical signals corresponding to the detected humidity to the outdoor unit control unit and/or the indoor unit control unit.

The indoor unit control unit may obtain user input from a user device, including a mobile device, through the indoor unit communication unit, and may obtain user input directly through the input interface or through a remote controller. The indoor unit control unit may control the components of the indoor unit, including a blower, in response to received user input. The indoor unit control unit may transmit information about the received user input to the outdoor unit control unit of the outdoor unit.

The outdoor unit control unit may control the components of the outdoor unit, including the compressor, based on information about user input received from the indoor unit. For example, when a control signal corresponding to a user input for selecting an operation mode such as cooling operation, heating operation, ventilation operation, defrosting operation, or dehumidifying operation is received from the indoor unit, the outdoor unit control unit may control the components of the outdoor unit such that the operation of the air conditioner corresponding to the selected operation mode is performed.

The outdoor unit control unit and the indoor unit control unit may each include a processor and memory. The indoor unit control unit may include at least one first processor and at least one first memory, and the outdoor unit control unit may include at least one second processor and at least one second memory.

The memory may remember/store various information necessary for the operation of the air conditioner. The memory may store instructions, applications, data and/or programs necessary for the operation of the air conditioner. For example, the memory may store various programs for cooling operation, heating operation, dehumidification operation and/or defrosting operation of the air conditioner. The memory may include volatile memory such as S-RAM (static random access memory) and D-RAM (dynamic random access memory) for temporarily storing data. Additionally, the memory may include non-volatile memory such as ROM (Read Only Memory), EPROM (Erasable Programmable Read Only Memory), and EEPROM (Electrically Erasable Programmable Read Only Memory) for long-term storage of data.

The processor may include various processing circuitry and generate a control signal for controlling the operation of the air conditioner based on instructions, applications, data and/or programs stored in the memory. The processor may include a piece of hardware that may include logic circuits and arithmetic circuits. The processor may process data according to a program and/or instruction provided from the memory and generate a control signal according to a processing result. The memory and the processor may be implemented as a single control circuit or as a plurality of circuits.

The indoor unit of the air conditioner may include an output interface. The output interface may be electrically connected to the indoor unit control unit and output information related to the operation of the air conditioner under the control by the indoor unit control unit. For example, information such as operation mode, wind direction, wind volume, and temperature selected by user input may be output. Additionally, the output interface may output sensing information and warning/error messages obtained from the indoor unit sensor or the outdoor unit sensor.

The output interface may include a display and a speaker. The speaker is an audio device that may output various sounds. The display may display information input by the user or information provided to the user using various graphic elements. For example, operation information of the air conditioner may be displayed as at least one of an image or text. Additionally, the display may include indicators that provide certain information. The display may include an LCD panel (liquid crystal display panel), a LED panel (light-emitting diode panel), an OLED panel (organic light-emitting diode panel), a micro led panel, and/or a plurality of LEDs.

The present disclosure relates to an outdoor unit of an air conditioner or the like. The present disclosure provides an outdoor unit having a safety guard capable of reducing the flow resistance of air (cooling air). The present disclosure provides an outdoor unit having a safety guard capable of preventing/blocking/reducing introduction of foreign substances. The present disclosure provides an outdoor unit having a safety guard with reinforced rigidity. However, the present disclosure are not limited to the technical aspects mentioned above, and other technical aspects not mentioned herein may be clearly understood from the description below by one skilled in the technical field to which the present disclosure belongs.

Hereinafter, various example embodiments will be described in greater detail with reference to the attached drawings. The same reference numbers or symbols illustrated in each drawing indicate parts or components that perform substantially the same function.

FIG. 1 is a partially exploded perspective view of an outdoor unit 1 according to various embodiments. FIG. 2 is a diagram illustrating a partial front view of a safety guard 30 illustrated in FIG. 1 according to various embodiments. Referring to FIGS. 1 and 2, the outdoor unit 1 according to an embodiment of the present disclosure may include a heat exchanger 10, a fan 20, and the safety guard 30. The fan 20 generates a flow of air passing through the heat exchanger 10. In the present embodiment, the fan 20 may be positioned downstream of the heat exchanger 10 with respect to a blowing direction. The safety guard 30 is positioned at a downstream side of the fan 20 with respect to the blowing direction. The safety guard 30 may include a plurality of main ribs 310 and a plurality of auxiliary ribs 320. The plurality of auxiliary ribs 320 intersect with the plurality of main ribs 310. The plurality of auxiliary ribs 320 connect the plurality of main ribs 310. The main ribs 310 and the auxiliary ribs 320 are described in greater detail below.

The heat exchanger 10 is an air-cooled heat exchanger that exchanges heat between air and refrigerant. Air is supplied to the heat exchanger 10 by the fan 20, and heat exchange is performed between a refrigerant flowing along the inside of the heat exchanger 10 and the air. Accordingly, a gas-liquid phase change of the refrigerant may occur inside the heat exchanger 10. Although not illustrated in the drawings, the outdoor unit 1 may further include a compressor. The compressor may compress a low-temperature and low-pressure gaseous refrigerant into a high-temperature and high-pressure gaseous refrigerant. The compressor is connected to the heat exchanger 10. By compressing the refrigerant using the compressor in the preceding stage of the heat exchanger 10, the gas-liquid phase change of the refrigerant may be easily performed at a high temperature. Although not illustrated in the drawings, the outdoor unit 1 may include at least one sensor. For example, the sensor may include a temperature sensor for detecting the air temperature around the outdoor unit 1, a humidity sensor for detecting the air humidity around the outdoor unit 1, a refrigerant temperature sensor for detecting the refrigerant temperature of a refrigerant pipe passing through the outdoor unit 1, a refrigerant pressure sensor for detecting the refrigerant pressure of the refrigerant pipe passing through the outdoor unit 1, etc. The outdoor unit 1 may further include a processor. The processor may control the operation of the components of the outdoor unit 1. As an embodiment, the processor may be implemented by a hardware circuit such as a central processing unit (CPU), a microprocessor, a chipset, or a system-on-chip (SOC).

The outdoor unit 1 has a housing 40 that forms the exterior. The housing 40 may include one or more parts. The components forming the outdoor unit 1, such as the heat exchanger 10 and the fan 20, are accommodated inside the housing 40. An exhaust port 42 through which air is discharged is provided on a front side 41 of the housing 40. The safety guard 30 is installed on the exhaust port 42. The air introduced into the housing 40 by the fan 20 passes through the heat exchanger 10, absorbs heat of the refrigerant, and is then discharged to the outside of the housing 40 through the safety guard 30. The safety guard 30 has a structure that may prevent/block foreign substances from entering the housing 40 through the exhaust port 42. The safety guard 30 has a structure that may secure a flow path for the exhausted air.

As described above, the safety guard 30 has the plurality of main ribs 310 and the plurality of auxiliary ribs 320. In order to reduce or prevent the risk of damage to the safety guard 30 due to external impact, the plurality of auxiliary ribs 320 connect the plurality of main ribs 310 to each other to strengthen the rigidity of the safety guard 30. In order to secure a flow path of the air, the safety guard 30 has a grid structure.

The blowing direction of blowing by the fan 20 is indicated as Z1. Each of the plurality of main ribs 310 extends in a direction intersecting the blowing direction Z1. The extension direction of the plurality of main ribs 310 is indicated as Z2. In an example embodiment, the extension direction Z2 is orthogonal to the blowing direction Z1. The plurality of main ribs 310 are arranged at intervals in an arrangement direction thereof intersecting with the blowing direction Z1 and the extension direction Z2. The arrangement direction is indicated by Z3. In the present embodiment, for example, the arrangement direction Z3 is orthogonal to the blowing direction Z1 and the extension direction Z2.

Each of the plurality of auxiliary ribs 320 intersects with the plurality of main ribs 310 and sequentially connects the plurality of main ribs 310 to each other. In an example embodiment, the plurality of auxiliary ribs 320 extend in the arrangement direction Z3 of the plurality of main ribs 310. The plurality of auxiliary ribs 320 are arranged at intervals in a direction intersecting the extension direction thereof. In the present embodiment, the plurality of auxiliary ribs 320 are arranged at intervals in the extension direction Z2 of the plurality of main ribs 310. By the plurality of main ribs 310 and the plurality of auxiliary ribs 320, a plurality of grid flow paths 31 which are opened in the blowing direction Z1 and have a horizontal spacing 31L and a vertical spacing 31T are formed in the safety guard 30. The air that is induced by the fan 20 and passes through the heat exchanger 10 is discharged to the outside of the housing 40 through the plurality of grid flow paths 31.

FIG. 3 is a cross-sectional view taken along line Y-Y′ of FIG. 2 according to various embodiments. Referring to FIG. 3, two adjacent main ribs are referred to as a first main rib 310A and a second main rib 310B, respectively. For example, the first main rib 310A is a relatively upper rib, and the second main rib 310B is a relatively lower rib. The auxiliary rib 320 may have a first portion 321, a second portion 322, and a third portion 323. The first portion 321 is connected to the first main rib 310A. For example, the first portion 321 is connected to a lower surface 310A-b of the first main rib 310A and extends in the arrangement direction Z3 toward the second main rib 310B. The second portion 322 is connected to the second main rib 310B. For example, the second portion 322 is connected to an upper surface 320B-a of the second main rib 310B and extends in the arrangement direction Z3 toward the first main rib 310A. The third portion 323 connects the first portion 321 and the second portion 322 between the first portion 321 and the second portion 322.

For example, the auxiliary rib 320 may have an upstream end 320U. The first, second, and third portions 321, 322, and 323 each extend from the upstream end 320U in the blowing direction Z1. The first, second, and third portions 321, 322, and 323 have a downstream end 321D, 322D, and 323D, respectively. The downstream end 323D of the third portion 323 connects the downstream ends 321D and 322D of the first portion 321 and the second portion 322. The downstream ends 321D, 322D, and 323D of the first, second, and third portions 321, 322, and 323 form a downstream end 320D of the auxiliary rib 320. An upstream end 310U of the main rib 310 may be positioned upstream or downstream of the upstream end 320U of the auxiliary rib 320. In an embodiment, the upstream end 310U of the main rib 310 is positioned downstream of the upstream end 320U of the auxiliary rib 320. The downstream end 320D of the auxiliary rib 320 may be positioned upstream of a downstream end 310D of the main rib 310. In other words, the downstream ends 321D, 322D, and 323D of the first, second, and third portions 323 are positioned upstream of the downstream end 310D of the main rib 310. According to this, the downstream ends 321D, 322D, and 323D of the auxiliary rib 320 do not protrude outward from the downstream end 310D of the main rib 310.

Air passes through the grid flow paths 31 and is discharged to the outside of the housing 40. A pair of adjacent main ribs 310 and a pair of adjacent auxiliary ribs 320 respectively form side walls of the grid flow path 31 in the extension direction Z2 and the arrangement direction Z3. The main flow direction of air passing through the grid flow path 31 is the blowing direction Z1, but in reality, the air flows in a spiral direction with the blowing direction Z1 as the axis, as indicated by reference symbol TA in FIG. 1, due to the rotation of the fan 20. Thus, the length of the auxiliary rib 320 in the blowing direction Z1 along with the cross-sectional area perpendicular to the blowing direction Z1 of the grid flow path 31 may also affect the flow rate of air passing through the grid flow path 31. The longer the length of the blowing direction Z1 of the auxiliary rib 320, the greater the amount of air blocked by the auxiliary rib 320 among the air flowing in a spiral direction along the grid flow path 31, and the greater the air flow resistance. By forming the downstream ends 321D, 322D, and 323D of the auxiliary rib 320 to be positioned upstream of the downstream end 310D of the main rib 310, a length of the auxiliary rib 320 in the blowing direction Z1 may be relatively short, thereby reducing the air flow resistance and increasing the flow rate of air passing through the grid flow path 31 having a cross-sectional area in the given blowing direction Z1. In addition, the cross-sectional area of the grid flow path 31 may be made small to secure the same air flow rate, which is advantageous in preventing/blocking/reducing introduction of foreign substances through the grid flow path 31.

The first portion 321 of the auxiliary rib 320 has a significant length in the extension direction of the auxiliary rib 320 (the arrangement direction Z3 in the present embodiment). For example, the downstream end 321D of the first portion 321 has a length 321W in the arrangement direction Z3. As illustrated in FIG. 3, the downstream end 321D of the first portion 321 may be in the form of a straight line extending parallel to the arrangement direction Z3. The downstream end 321D of the first portion 321 may have various shapes as long as the downstream end 321D has a significant length in the arrangement direction Z3. For example, FIGS. 4A, 4B, 4C and 4D are diagrams illustrating various example shapes of the downstream end 321D of the first portion 321 of the auxiliary rib 320 according to various embodiments. As illustrated in FIG. 4A, the downstream end 321D of the first portion 321 may be in the form of a straight line that is inclined upstream with respect to the arrangement direction Z3 toward the second main rib 310B. As illustrated in FIG. 4B, the downstream end 321D of the first portion 321 may have a convex curve shape toward the downstream side. As illustrated in FIG. 4C, the downstream end 321D of the first portion 321 may be a straight line that is inclined downstream with respect to the arrangement direction Z3 toward the second main rib 310B. As illustrated in FIG. 4D, the downstream end 321D of the first portion 321 may have a concave curved shape toward the upstream side.

In this way, according to the configuration in which the downstream end 321D of the first portion 321 of the auxiliary rib 320 has the significant length 321W in the arrangement direction Z3, the rigidity against the load applied to the main rib 310 may be strengthened. Accordingly, the reduction in the cross-sectional area of the grid flow path 31 due to the sagging of the main rib 310 and the resulting decrease in the air flow rate may be reduced or prevented. The risk of damage to the safety guard 30 due to external force acting on the safety guard 30 may be reduced or prevented. The arrangement spacing between the auxiliary ribs 320 may be made relatively large. This indicates an increase in the horizontal length 31L of the grid flow path 31 in FIG. 2, which is advantageous for increasing the air flow rate.

According to an embodiment, with respect to the blowing direction Z1, the lengths of the first portion 321 and the second portion 322 may be different from each other. For example, referring to FIG. 3, a length 321L of the first portion 321 in the blowing direction Z1 may be longer than a length 322L of the second portion 322 in the blowing direction Z1. For example, with respect to the blowing direction Z1, the downstream end 321D of the first portion 321 may be positioned downstream of the downstream end 322D of the second portion 322. According to this configuration, not only is the exhaust passage of air flowing in a spiral direction increased, as indicated by TA in FIG. 1 by an area FAI between the downstream end 321D of the first portion 321 and the downstream end 322D of the second portion 322, but the air resistance by the auxiliary rib 320 may be reduced as the length 322L of the second portion 322 in the blowing direction Z1 is shortened. Thus, the flow rate of air passing through the grid flow path 31 may be further increased.

According to an embodiment, the length 321W of the downstream end 321D of the first portion 321 and a length 322W of the downstream end 321D of the second portion 322 may be different from each other with respect to the extension direction of the auxiliary rib 320, e.g., the arrangement direction Z3. For example, as illustrated in FIG. 3, the length 321W of the downstream end 321D of the first portion 321 may be longer than the length 322W of the downstream end 322D of the second portion 322 with respect to the arrangement direction Z3. According to this configuration, the rigidity of the first portion 321 is strengthened, which may be advantageous in preventing/reducing sagging of the main rib 310 and strengthening the rigidity of the safety guard 30.

FIG. 5 is a cross-sectional view of the safety guard 30 according to various embodiments. FIG. 5 corresponds to a cross-sectional view taken along line Y-Y′ of FIG. 2. Referring to FIG. 5, the length 321W of the downstream end 321D of the first portion 321 may be shorter than the length 322W of the downstream end 322D of the second portion 322 with respect to the arrangement direction Z3. According to this configuration, the first portion 321 having a relatively long length 321L in the blowing direction Z1 has a relatively short length 321W in the arrangement direction Z3. Accordingly, the amount of air blocked by the first portion 321 among the air flowing in the spiral direction may be reduced, and the flow resistance by the first portion 321 may also be reduced, thereby increasing the flow rate of air passing through the grid flow path 31.

Referring back to FIG. 3, the downstream end 323D of the third portion 323 connects the downstream end 321D of the first portion 321 and the downstream end 322D of the second portion 322. For example, as illustrated in FIG. 3, the downstream end 323D of the third portion 323 may be in a diagonal shape inclined with respect to the arrangement direction Z3. According to this configuration, the amount of air blocked by the third portion 323 among the air flowing in the spiral direction may be reduced and the flow resistance by the third portion 323 may be reduced. The strength of the first portion 321 may be reinforced. The shape of the downstream end 323D of the third portion 323 is not limited thereto. FIGS. 6A and 6B are diagrams illustrating various example shapes of the downstream end 323D of the third portion 323 of the auxiliary rib 320 according to various embodiments. As illustrated in FIG. 6A, the downstream end 323D of the third portion 323 may have a concave curved shape toward the upstream side. As illustrated in FIG. 6B, the downstream end 323D of the third portion 323 may have a convex curve shape toward the downstream side. Although not illustrated in the drawing, the downstream end 323D of the third portion 323 may be a combination of two or more diagonal lines, a combination of a diagonal line and a curve, etc. The downstream end 323D of the third portion 323 may have various shapes suitable for increasing the flow rate of air passing through the grid flow path 31 and reinforcing the strength of the first portion 321, etc.

According to an embodiment of the present disclosure, a thickness reduction region having a reduced thickness less that a thickness of the other region of the auxiliary rib 320 may be provided in an area where the auxiliary rib 320 is connected to the main rib 310. The ‘thickness’ associated with the auxiliary rib 320 may refer, for example, to the thickness of in a direction perpendicular to the extension direction of the auxiliary rib 320. In an embodiment, the ‘thickness’ associated with the auxiliary rib 320 is a thickness in the extension direction Z2 of the main rib 310. At least one of the first portion 321 and the second portion 322 of the auxiliary rib 320 may have a thickness reduction region having a thickness that is thinner than a thickness of the third portion 323 of the auxiliary rib 320. According to an embodiment of the present disclosure, at least one of the first portion 321 and the second portion 322 of the auxiliary rib 320 may have a thickness reduction region having a thickness that is thinner than that of the main rib 310. The ‘thickness’ associated with the main rib 310 may refer, for example, to the thickness in the arrangement direction Z3 orthogonal to the extension direction Z2 of the main rib 310. For example, the thickness reduction region may include a region where the first and second portions 321 and 322 are connected to the main rib 310.

The plurality of main ribs 310 and the plurality of auxiliary ribs 320 may be formed integrally. For example, the safety guard 30 may be manufactured by plastic injection molding. Referring to FIG. 3, the first portion 321 of the auxiliary rib 320 is connected, in a “T” shape, to the first main rib 310A positioned in a relatively upper portion. The second portion 322 of the auxiliary rib 320 is connected, in a “T” shape, to the second main rib 310B positioned in a relatively lower portion. The auxiliary rib 320 connects a plurality of main ribs 310 to maintain the rigidity of the safety guard 30 as a whole, thereby preventing/reducing damage or deformation of the safety guard 30 due to external impact. From this point of view, the thicker the auxiliary rib 320, the more advantageous it is.

In an embodiment as illustrated in FIG. 3, with respect to the blowing direction Z1, the length 321W of the first portion 321 of the auxiliary rib 320 is longer than the length 322W of the second portion 322. In a region of the first portion 321 in the blowing direction Z1, in a region overlapping with the second portion 322 in the arrangement direction Z3, the main rib 310 is connected to the first and second portions 321 and 322 of the auxiliary rib 320 in a “+” shape. In this regard, in the remaining area of the first portion 321, e.g., the area that does not overlap with the second portion 322 in the arrangement direction Z3, the main rib 310 is connected to the first portion 321 of the auxiliary rib 320 in a “T” shape. If a thickness of the first portion 321 of the auxiliary rib 320 is thick, sink marks due to molding shrinkage may occur in the main rib 310, for example, in areas 310A-a1 and 310B-a1 that overlap the above remaining area of the first portion 321 of the auxiliary rib 320 in the arrangement direction Z3 among upper surfaces 310A-a and 310B-a of the first and second main ribs 310A and 310B in FIG. 3. As the areas 310A-a1 and 310B-a1 where the sink marks occur is an area that is easily visible from the outside of the safety guard 30, the appearance of the safety guard 30 and the outdoor unit 1 may be degraded. Additionally, the sink marks of the main rib 310 may cause bending of the main rib 310, which may distort the grid flow path 31, resulting in a reduction in the cross-sectional area of the grid flow path 31 and a consequent decrease in the air flow rate. Additionally, the sink marks of the main rib 310 may reduce the strength of the safety guard 30.

FIG. 7 is a partial rear perspective view of the safety guard 30 according to various embodiments. Referring to FIG. 7, a thickness 310-T of the main rib 310 in the arrangement direction Z3 and a thickness 323-T of the auxiliary rib 320 in the extension direction Z2 may be the same or different. The auxiliary rib 320 may have a first portion 321, a second portion 322, and a third portion 323. As described above, with respect to the blowing direction Z1, a length of the first portion 321 (e.g., FIG. 3: 321W) is longer than a length of the second portion 322 (e.g., FIG. 3: 322W). In this case, the first portion 321 may have a thickness reduction region 321C. The thickness reduction region 321C includes a region where the first portion 321 and the main rib 310 are connected to each other. A thickness 321C-T of the thickness reduction region 321C may be thinner than a thickness 323-T of the third portion 323. The first portion 321 of the auxiliary rib 320 may be thinner overall than the third portion 323. Only the thickness reduction region 321C including at least a region of the auxiliary rib 320, the region being connected to a lower surface 310-a of the main rib 310, may be thinner than the thickness 323-T of the third portion 323. A thickness of the first portion 321 excluding the thickness reduction region 321C may be the same as the thickness 323-T of the third portion 323. A thickness of the second portion 322 may be the same as the thickness 323-T of the third portion 323. Accordingly, the auxiliary rib 320 as a whole has a shape in which thick and thin portions thereof are repeated in the arrangement direction Z3.

The thickness 321C-T of the thickness reduction region 321C may be thinner than the thickness 310-T of the main rib 310. The thickness 321C-T of the thickness reduction region 321C may be determined to such an extent that no molding shrinkage occurs in the main rib 310. The thickness 321C-T of the thickness reduction region 321C may be, for example, about 40% to 80% of the thickness 310-T of the main rib 310. According to this configuration, molding shrinkage of the upper surface 310-a of the main rib 310 due to the thickness of the auxiliary rib 320 may be prevented/reduced, and accompanying sagging of the main rib 310, reduction in strength thereof, etc. may be reduced or prevented.

Referring back to FIG. 2, the horizontal length 31L and the vertical length 31T of the grid flow path 31 affect the flow rate of air passing through the grid flow path 31. The longer the horizontal and vertical lengths 31L and 31T of the grid flow path 31, the greater may be the air flow rate. The vertical length 31T of the grid flow path 31 is regulated for the purpose of preventing/blocking/reducing foreign substances from entering. In the regulation for preventing/blocking/reducing foreign substances from entering, the vertical length 31T of the grid flow path 31 is defined as a shortest distance between two adjacent main ribs 310 in the arrangement direction Z3. Thus, a method is needed to satisfy the regulation on the vertical length 31T while increasing an actual distance between two adjacent main ribs 310.

FIG. 8 is a partial cross-sectional view of the safety guard 30 according to various embodiments. FIG. 8 corresponds to the Y-Y′ cross-sectional view of FIG. 2. Referring to FIG. 8, as an embodiment, at least one of the two sides (FIG. 8: 310-a, 310-b) of the main rib 310 in the arrangement direction Z3 may be formed to be inclined with respect to the blowing direction Z1. For example, at least a portion of the upper surface (FIG. 8: 310-a) of the main rib 310 may be formed to be inclined in a direction approaching a lower surface 310-b of another adjacent main rib 310 toward the upstream side with respect to the blowing direction Z1. For example, at least a portion 310-b1 of the lower surface 310-b of the main rib 310 may be formed to be inclined in a direction away from the upper surface 310-a of another adjacent main rib 310 toward the upstream side with respect to the blowing direction Z1. As an embodiment, the main rib 310 may be formed to be inclined overall with respect to the blowing direction Z1.

For example, in FIG. 8, if two adjacent main ribs are referred to as the first and second main ribs 310A 310B, respectively, the grid flow path 31 is formed between the first and second main ribs 310A and 310B. The upper surfaces 310A-a and 310B-a of the first and second main ribs 310A and 310B are formed to be at least partially inclined with respect to the blowing direction Z1. For example, the upper surface 310B-a of the second main rib 310B is formed to be at least partially inclined upward in a direction opposite to the direction of air flow, that is, in a direction approaching the lower surface 310A-b of the first main rib 310A toward the upstream side. The vertical length 31T of the grid flow path 31 is defined as a closest distance between the upper surface 310B-a of the second main rib 310B and the lower surface 310A-b of the first main rib 310A. On the other hand, a maximum vertical length 31TM between the first and second main ribs 310A and 310B at the outlet of the grid flow path 31, e.g., the downstream side, is greater than the vertical length 31T of the grid flow path 31 that is a subject of regulation due to the upper surface 310B-a that is inclined downward toward the downstream side. Accordingly, the preventing/blocking/reducing foreign substances from entering may be achieved while at the same time increasing the actual vertical spacing of the grid flow path 31, thereby increasing the flow rate of air passing through the grid flow path 31.

An inclination angle θ1 of the upper surface 310-a of the main rib 310 with respect to the blowing direction Z1 may be determined such that the vertical length 31T of the grid flow path 31 is suitable for the purpose of preventing/reducing introduction of a predetermined foreign substance by considering a length of the main rib 310 in the blowing direction Z1 and/or that the regulations of each country according to product liability are satisfied. For example, the inclination angle θ1 may be about 1 degrees to about 20 degrees. The upper surface 310A-a of the first main rib 310A may have the same shape as the upper surface 310B-a of the second main rib 310B.

Referring back to FIG. 8, a portion 310A-b1 of the lower surface 310A-b of the first main rib 310A is formed to be inclined in a direction away from the upper surface 310B-a of the second main rib 310B toward the upstream side. The inclination of the portion 310A-b1 of the lower surface 310A-b of the first main rib 310A reduces flow resistance by increasing the vertical spacing of the grid flow path 31 at the upstream side without affecting the vertical length 31T of the grid flow path 31 that is the subject of regulation.

An inclination angle θ2 of the lower surface 310-b of the main rib 310 with respect to the blowing direction Z1 may be appropriately determined by considering the length of the main rib 310 in the blowing direction Z1. For example, the inclination angle θ2 may be about 1 degrees to 20 degrees. The inclination angle θ2 may be the same as or different from the inclination angle θ1. When the inclination angle θ1 and the inclination angle θ2 are the same, the main rib 310 is inclined overall with respect to the blowing direction Z1, and the overall inclination angle of the main rib 310 with respect to the blowing direction Z1 may be about 1 degrees to about 20 degrees. A lower surface 310B-b and a portion thereof 310B-b1 of the second main rib 310B may have the same shape as the lower surface 310A-b and the portion thereof 310A-b1 of the first main rib 310A.

According to this configuration, the actual vertical spacing of the grid flow path 31 may be increased to secure an appropriate air flow rate, while preventing/blocking/reducing foreign substances from entering and satisfying the regulations on the vertical spacing 31T according to the product liability regulations. The inclination angle of the main rib 310, the thickness of the main rib 310, the spacing between the main ribs 310, and the length of the main rib 310 in the blowing direction Z1 may be determined such that the inside of the outdoor unit is not easily visible through the spacing between the main ribs 310.

FIG. 9 is a diagram illustrating a safety guard 3000 according to a comparative example. Referring to FIG. 9, the safety guard 3000 according to the comparative example has a length and width of 579 mm and 653 mm, respectively. The horizontal and vertical lengths of a grid flow path 3010 are 58 mm and 12 mm, respectively. A length of a main rib 3100 in the blowing direction Z1 is 11 mm, and a thickness thereof is 2.5 mm. Upper and lower surfaces of the main rib 3100 are parallel to the blowing direction Z1. An auxiliary rib 3200 has a uniform length of 6 mm in the blowing direction Z1. A thickness of the auxiliary rib 3200 is uniform at 1.8 mm. The safety guard 3000 is fixed at all four corners using screws.

FIG. 10 is a diagram illustrating an example safety guard 30 according to various embodiments. Referring to FIG. 10, the safety guard 30 according to an embodiment of the present disclosure has a length and width of 711 mm and 788 mm, respectively. The horizontal and vertical lengths of the grid flow path 31 are 84 mm and 16 mm, respectively. The length of the main rib 310 in the blowing direction Z1 is 18 mm, and the thickness thereof is 2.5 mm. The inclination angle θ1 of the upper surface of the main rib 310 with respect to the blowing direction Z1 is 6 degrees. The auxiliary rib 320 has the shape illustrated in FIG. 3. The length of the second portion 322 of the auxiliary rib 320 in the blowing direction Z1 is 8 mm. The overall thickness of the auxiliary rib 320 is 1.9 mm, and the thickness 321C-T of the thickness reduction region 321C is about 0.93 mm, which is about 62.8% of the thickness of the main rib 310. The safety guard 30 is fixed at four corners with screws.

Below, load-deformation simulation results for a safety guard according to a comparative example (e.g., FIG. 9: 3000) and a safety guard according to an example embodiment of the present disclosure (e.g., FIG. 10: 30) are described. The load is applied to points expected to be the main damage points in the ball drop test. In this simulation, a load of 50 N is applied to two points F1 and F2 adjacent to the center of each of the safety guard 3000 and the safety guard 30 and two points F3 and F4 at about a ¼ distance diagonally from one corner of each of the safety guard 3000 and the safety guard 30. Table 1 shows the load-deformation simulation results.

	TABLE 1
	Safety guard 3000 according to	Safety guard 30 according to
	comparative example	embodiment

	F1	F2	F3	F4	F1	F2	F3	F4

stress	34.6	28.3	33.2	26.7	10.1	9.4	9.4	8.2
(MPa)
displacement	17.3	17.2	11.5	10.2	6.5	6.8	4.3	3.7
(mm)

Referring to Table 1, the stress of the safety guard 30 according to an embodiment of the present disclosure is about ⅓ or less than that of the safety guard 3000 according to the comparative example. In addition, in the case of the safety guard 30 according to an embodiment of the present disclosure, the deformation amount is about 1/2.5 or less of that of the safety guard 3000 according to the comparative example. This indicates that the safety guard 30 according to an embodiment of the present disclosure has higher rigidity than the safety guard 3000 according to the comparative example, and thus may withstand greater external impact. In addition, the safety guard 30 according to the present disclosure has the grid flow path 31 having horizontal and vertical lengths that are greater than those of the safety guard 3000 according to the comparative example. This indicates that, by applying the inclination angle θ1 to the main rib 310, the vertical length for preventing/blocking/reducing foreign substances from entering may be secured while the actual cross-sectional area of the grid flow path 31 may be expanded. Thus, a relatively large amount of air may pass through the grid flow path 31, thereby increasing the heat exchange efficiency of the heat exchanger 10.

The extension direction and the arrangement direction of the main ribs and the auxiliary ribs are not limited to the various embodiments described above. For example, the main ribs and the auxiliary ribs may be arranged radially.

FIG. 11 is a diagram illustrating a plan view of a safety guard 30R according to various embodiments. Referring to FIG. 11, the safety guard 30R includes a plurality of main ribs 310R and a plurality of auxiliary ribs 320R connecting the same. The extension direction Z2 of the plurality of main ribs 310R is a circumferential direction perpendicular to the blowing direction Z1. The arrangement direction Z3 of the plurality of main ribs 310R is a radial direction orthogonal to the blowing direction Z1 and the extension direction Z2. The plurality of main ribs 310R are arranged radially spaced apart from each other. The plurality of auxiliary ribs 320R intersect with the plurality of main ribs 310R and connect the plurality of main ribs 310R. According to an embodiment, the plurality of auxiliary ribs 320R may extend radially and be arranged at intervals in the circumferential direction. The description of the main ribs 310 and the auxiliary ribs 320 provided above applies equally to the main ribs 310R and the auxiliary ribs 320R.

The main ribs and the auxiliary ribs may not be perpendicular to each other. FIG. 12 is a schematic cross-sectional view of a safety guard 30X according to an embodiment of the present disclosure. Referring to FIG. 12, the safety guard 30X includes the plurality of main ribs 310 and a plurality of auxiliary ribs 320X connecting the same. The extension direction Z2 of the plurality of main ribs 310 is perpendicular to the blowing direction Z1. The plurality of main ribs 310 are arranged spaced apart from each other in the arrangement direction Z3 orthogonal to the blowing direction Z1 and the extension direction Z2. The plurality of auxiliary ribs 320X intersect with the plurality of main ribs 310 and connect the plurality of main ribs 310. The plurality of auxiliary ribs 320X extend obliquely with respect to the arrangement direction Z3 of the plurality of main ribs 310. The plurality of auxiliary ribs 320X are arranged at intervals in an inclined direction with respect to the extension direction Z2 of the plurality of main ribs 310. The description of the main ribs 310 and the auxiliary ribs 320 provided above applies equally to the main ribs 310 and the auxiliary ribs 320X.

An outdoor unit of an air conditioner, according to an example embodiment of the present disclosure, includes: a heat exchanger; a fan positioned at a downstream side of the heat exchanger and configured to generate a flow of air passing through the heat exchanger; a safety guard including a plurality of main ribs and a plurality of auxiliary ribs intersecting and connecting the plurality of main ribs, the safety guard being positioned downstream of the fan. A thickness reduction region with a reduced thickness is provided in a region of the auxiliary rib, the region being connected to the main rib.

As an example embodiment, when two adjacent main ribs are referred to as a first main rib and a second main rib, respectively, the auxiliary rib may include a first portion connected to the first main rib, a second portion connected to the second main rib, and a third portion connecting the first portion and the second portion between the first portion and the second portion. With respect to a blowing direction of blowing by the fan, a length of the first portion may be longer than a length of the second portion. The thickness reduction region may be provided in the first portion.

As an example embodiment, the thickness of the thickness reduction region may be 40% to 80% of the thickness of the main rib.

As an example embodiment, with respect to the blowing direction, downstream ends of the first portion and the second portion may be positioned upstream of downstream ends of the main rib.

As an example embodiment, with respect to the blowing direction, the downstream end of the second portion may be positioned upstream of the downstream end of the first portion.

As an example embodiment, a downstream end of the third portion may have a diagonal form and connect the downstream end of the first portion and the downstream end of the second portion.

As an example embodiment, the downstream end of the third portion may have a curved shape and connect the downstream end of the first portion and the downstream end of the second portion.

As an example embodiment, with respect to an extension direction of the auxiliary rib, the length of the downstream end of the first portion may be longer than the length of the downstream end of the second portion.

As an example embodiment, with respect to the extension direction of the auxiliary rib, the length of the downstream end of the first portion may be shorter than the length of the downstream end of the second portion.

As an example embodiment, at least one of upper and lower surfaces of the plurality of main ribs may be inclined with respect to the blowing direction based on an arrangement direction of the plurality of main ribs.

An outdoor unit of an air conditioner, according to an example embodiment of the present disclosure includes: a heat exchanger; a fan positioned at a downstream side of the heat exchanger and configured to generate a flow of air passing through the heat exchanger; a safety guard including a plurality of main ribs, at least one surface of two surfaces of which in an arrangement direction is inclined with respect to a blowing direction of blowing by the fan, and a plurality of auxiliary ribs extending to intersect the plurality of main ribs and connecting the plurality of main ribs, the safety guard being positioned downstream of the fan, wherein, when two adjacent main ribs are respectively referred to as a first main rib and a second main rib, the auxiliary rib includes a first portion connected to the first main rib, a second portion connected to the second main rib, and a third portion connecting the first portion and the second portion between the first portion and the second portion, and with respect to the blowing direction by the fan, a length of the first portion is longer than a length of the second portion, and a downstream end of the first portion is positioned downstream of a downstream end of the second portion.

As an example embodiment, the downstream end of the third portion may be connected to the downstream end of the first portion and the downstream end of the second portion.

As an example embodiment, the downstream end of the first portion may have a length in an extension direction of the auxiliary rib.

As an example embodiment, a thickness reduction region with a reduced thickness may be provided in a connection region between the first portion and the main rib.

As an example embodiment, the thickness of the thickness reduction region may be 40% to 80% of the thickness of the main rib.

However, the technical effects to be achieved in the present disclosure are not limited to the technical effects mentioned above, and other effects not mentioned may be clearly understood from the description of the present disclosure by one skilled in the technical field to which the present disclosure belongs.

While various example embodiments have been described with reference to the figures, the scope of the present disclosure is not limited thereto, and it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope including the appended claims and their equivalents. It will also be understood that any of the embodiment(s) described herein may be used in conjunction with any other embodiment(s) described herein.