WO2020071674A1

WO2020071674A1 - Water purifier having improved fixing structure of power semiconductor element

Info

Publication number: WO2020071674A1
Application number: PCT/KR2019/012359
Authority: WO
Inventors: Jea Shik Heo; Seungje Park; Heejun Lee
Original assignee: LG Electronics Inc
Current assignee: LG Electronics Inc
Priority date: 2018-10-02
Filing date: 2019-09-23
Publication date: 2020-04-09
Anticipated expiration: 2021-04-02
Also published as: KR102055441B1; MY204891A

Abstract

The present disclosure relates to a water purifier having an improved fixing structure of a power semiconductor element. The water purifier according to an embodiment of the present disclosure includes a noise printed circuit board configured to reduce noise of alternating current (AC) power outputted from an input power supply, and an induction heating printed circuit board configured to receive the AC power with reduced noise from the noise printed circuit board, and to control an operation of induction heating of a working coil based on the received AC power. The induction heating printed circuit board includes a rectifier configured to rectify AC power received from the noise printed circuit board into direct current (DC) power, an induction heating driver configured to perform a switching operation by receiving the DC power from the rectifier, a liquid-cooled heat sink configured to perform a heat radiating operation on the rectifier and the induction heating driver, and a fixing member configured to fix the rectifier and the induction heating driver to the liquid-cooled heat sink.

Description

WATER PURIFIER HAVING IMPROVED FIXING STRUCTURE OF POWER SEMICONDUCTOR ELEMENT

The present disclosure relates to a water purifier having an improved fixing structure of a power semiconductor element.

In general, a water purifier is an apparatus for filtering out various hazardous ingredients harmful to a human body contained in raw water such as tap water, underground water, or the like by several stages of filters installed within a main body thereof to change such water into stable　and hygienic　drinking water.

The water purifier may be classified into a tank type water purifier and a direct type water purifier. The tank type water purifier is configured to keep purified water in a water tank and provide water kept in the water tank when a user operates a water dispensing unit.

In contrast, the direct type water purifier is configured to filter raw water immediately when a user operates a water dispensing unit to provide purified water to the user, without a water tank.

Such a direct type water purifier supplies hot water and cold water in addition to room temperature water. The water purifier providing hot water and cold water has a heating device and a cooling device, separately, therein. The heating device is configured to heat purified water to produce hot water, and the cooling device is configured to cool purified water to produce cold water.

It is required for the direct type water purifier to heat or cool purified water within a short period of time so as to provide hot water or cold water. Through various methods, the heating device may heat purified water within a short period of time.　

For example, Korean Patent Application Publication No. 10-2005-0103723 (published on November 1, 2005) discloses a configuration of heating purified water using an induction heating method.

　Induction heating is a heating method that heats an object to be heated using electromagnetic induction. When a current is supplied to a coil, an eddy current is generated on the object to be heated. Joule heating generated by the resistance of metal increases a temperature of the object to be heated.

That is, the direct type water purifier that heats purified water using the induction heating method may heat a hot water tank by controlling an operation of induction heating of a working coil according to a temperature of water selected by a user, thereby allowing hot water to be dispensed.

However, in the case of the direct type water purifier using the induction heating method, heat is generated in a power semiconductor element (for example, a bridge diode or a switch) provided in a heating device thereof (that is, an induction heating module), and thus a heat radiating plate is required to perform a heat radiating operation on the power semiconductor element.

In a conventional direct type water purifier using the induction heating method, an air-cooled heat sink (a heat radiating plate having a structure for radiating heat in air) has been used to radiate heat generated in the power semiconductor element.

The air-cooled heat sink performs a heat radiating operation on the power semiconductor element through a natural air-cooling method, and the power semiconductor element is fixed to the air-cooled heat sink through a screw.

As a result, even when an abnormal operation or insulation breakdown of the power element occurs, there is no risk of electric shock to the user.

However, the air-cooled heat sink has a limit that hot water dispensing performance depends on a size of the air-cooled heat sink. In addition, when an amount of dispensing hot water is exceeded, the operation of a water purifier may be limited due to a temperature increase of the power semiconductor element.

In order to solve the above problem, a liquid-cooled heat sink (a heat radiating plate having a structure for radiating heat by using water in the water purifier), which can increase the amount of continuous hot water output, has been introduced into a direct type water purifier using an induction heating method.

A liquid-cooled heat sink is about 20% smaller than the air-cooled heat sink in terms of a size, and thus it is advantageous that reducing a volume of an induction heating printed circuit board is possible.

However, when the power semiconductor element is fixed to the liquid-cooled heat sink through a screw in the same manner as described above, electricity may be conducted to the screw at the time of insulation breakdown, and the electricity conducted to the screw may be transferred to water, resulting in an electric shock accident.

Accordingly, there is a need for a fixing structure of the power semiconductor element capable of stably fixing the power semiconductor element to the liquid-cooled heat sink and preventing an electric shock accident.

An aspect of the present disclosure is to provide a water purifier in which heat radiation performance of a power semiconductor element and an amount of continuously dispensing hot water are improved.

Another aspect of the present disclosure is to provide a water purifier capable of stably fixing a power semiconductor element and preventing an electric shock accident.

The technical aspects of the present disclosure are not limited to the above-mentioned aspects, and the other aspects and the advantages of the present disclosure which are not mentioned can be understood by the following description, and more clearly understood by embodiments of the present disclosure. It will be also readily seen that the aspects and the advantages of the present disclosure may be realized by means indicated in the patent claims and a combination thereof.

A water purifier according to the present disclosure may include a liquid-cooled heat sink configured to perform a heat radiating operation on a power semiconductor element, thereby improving heat radiation performance of the power semiconductor element and an amount of continuously dispensing hot water.

Further, the water purifier according to the present disclosure may include a fixing member configured to fix the power semiconductor element to the liquid-cooled heat sink, thereby stably fixing the power semiconductor element and preventing an electric shock accident.

A water purifier according to the present disclosure may improve heat radiation performance of a power semiconductor element and an amount of continuously dispensing hot water through a liquid-cooled heat sink. In addition, a size of the liquid-cooled heat sink is smaller than that of a conventional air-cooled heat sink, thereby reducing a volume of an induction heating printed circuit board. Furthermore, water is preheated through the liquid-cooled heat sink, and accordingly it is possible to reduce an output of an induction heating driver (or a working coil) required to reach a target temperature, thereby saving power.

Further, in the water purifier according to the present disclosure, the power semiconductor element may be stably fixed to the liquid-cooled heat sink. Furthermore, the water purifier according to the present disclosure may prevent electricity and water from being conducted at the time of an abnormal operation or insulation breakdown of the power semiconductor element, thereby preventing an electric shock accident.

In addition to the above-described effects, the specific effects of the present disclosure will be described, together with details for carrying out the invention.

FIG. 1 is a perspective view illustrating a water purifier according to an embodiment of the present disclosure.

FIG. 2 is an exploded perspective view illustrating an internal configuration of the water purifier of FIG. 1.

FIG. 3 is an exploded perspective view illustrating an induction heating module and a control module of the water purifier of FIG. 2.

FIG. 4 is a schematic view illustrating a flow channel configuration of the water purifier of FIG. 1.

FIG. 5 is a schematic view for explaining a partial configuration of the water purifier of FIG. 1.

FIG. 6 is a plan view illustrating the induction heating printed circuit board of FIG. 5.

FIG. 7 is a perspective view illustrating a fixing structure of the power semiconductor element of FIG. 6.

FIG. 8 is an exploded perspective view of FIG. 7.

The aforementioned aspects, features and advantages will be described in detail with reference to the accompanying drawings, such that those skilled in the art can easily carry out a technical idea of the present disclosure. In the description of the embodiments, the detailed description of well-known related configurations or functions will be omitted when it is deemed that such description will cause ambiguous interpretation of the present disclosure. Hereinafter, preferred embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. The same reference numerals designate same or like elements through the drawings.

Hereinafter, an arbitrary component disposed on a "upper portion (or lower portion)" of a component or "on (or under)" the component may mean that not only the arbitrary component may be disposed in contact with an upper surface (or lower surface) of the component, but also another component may be interposed between the component and the arbitrary component disposed on (or under) the component.

It should be understood that, when an component is referred to as being "connected", "coupled", or "attached" to another component, the components may be directly connected to each other or attached to each other, or other components may be "interposed" between the components, or the components may be "connected", "coupled" or "attached" through other components.

Hereinafter, a water purifier according to an embodiment of the present disclosure will be described.

Referring to FIG. 1, a water purifier 1000 according to an embodiment of the present disclosure includes a cover 1010, a water dispensing unit 1020, a base 1030, and a tray 1040.

The cover 1010 forms an exterior of the water purifier 1000. The exterior of the water purifier 1000 formed by the cover 1010 may be referred to as a main body of the water purifier 1000. Components for filtering raw water are installed within the main body of the water purifier 1000. The cover 1010 surrounds the components to protect the components. The cover 1010 may be called a case, a housing, or the like. Whatever it is called, a component configured to form the exterior of the water purifier 1000 and surround the components for filtering the raw water corresponds to the cover 1010 described in the present disclosure.

The cover 1010 may be formed of a single component, but may be formed by combining several components. For example, as illustrated in FIG. 1, the cover 1010 may include a front cover 1011, a rear cover 1014, a side panel 1013a, an upper cover 1012, and a top cover 1015.

The front cover 1011 is disposed on a front side of the water purifier 1000. The rear cover 1014 is disposed on a rear side of the water purifier 1000. Here, the front side and the rear side of the water purifier 1000 each are set based on a direction facing the water dispensing unit 1020 in a vision of a user. However, since the concept of the front side and the rear side of the water purifier 1000 is not absolute, and may vary depending on how the water purifier 1000 is described.

The side panel 1013a is disposed on a left side and a right side of the water purifier 1000. The side panel 1013a is disposed between the front cover 1011 and the rear cover 1014. The side panel 1013a may be coupled to the front cover 1011 and the rear cover 1014. The side panel 1013a substantially forms a side surface of the water purifier 1000.

The upper cover 1012 is disposed on the front side of the water purifier 1000. The upper cover 1012 is installed at a position higher than the front cover 1011. The water dispensing unit 1020 is exposed to a space between the upper cover 1012 and the front cover 1011. The upper cover 1012 forms an exterior of a front surface of the water purifier 1000, together with the front cover 1011.

The top cover 1015 forms an upper surface of the water purifier 1000. A front side of the top cover 1015 may be provided with an input/output unit 1016. The input/output unit 1016 is based on a concept that includes an input unit and an output unit. The input unit is configured to receive a user's control command. A way in which the input unit receives the user's control command may include all of a touch input, physical pressing, and the like, or selectively include any one of the touch input, the physical pressing, and the like. The output unit is configured to audiovisually provide information about a status of the water purifier 1000 to the user.

The water dispensing unit (outlet unit or cork assembly) 1020 serves to provide purified water to a user according to the user's control command. At least a portion of the water dispensing unit 1020 is exposed to the outside of the main body of the water purifier 1000 to provide water. In particular, the water purifier　1000 is configured to provide purified water that is at a room temperature, cold water that is at a temperature lower than a room temperature, and hot water that is at a temperature higher than a room temperature, and at least one among purified water that is at a room temperature, cold water, and hot water may be dispensed to the user through the water dispensing unit　1020　according to a control command entered by the user.

The water dispensing unit　1020　may be configured to rotate according to a user's manipulation. The front cover　1011　and the upper cover　1012　may form a rotation region of the water dispensing unit　1020　therebetween, and the water dispensing unit　1020　may rotate horizontally in the rotation region. The water dispensing unit　1020　may rotate by means of a force physically applied to the water dispensing unit　1020　by the user. Further, the water dispensing unit　102　may rotate on the basis of a control command entered by the user to the input/output unit　1016. A component that implements rotation of the water dispensing unit　1020　may be installed within the water purifier　1000, and specifically, may be installed in a region covered by the upper cover　1020. The input/output unit　1016　may be also implemented to rotate together with the water dispensing unit　1020　when the water dispensing unit　1020　rotates.

A base　1030 forms a bottom of the water purifier　1000. Internal components of the water purifier　1000　is supported by the base　1030. When the water purifier　1000　is placed on a floor, a shelf, or the like, the base　1030　may face the floor, the shelf, or the like. Thus, when the water purifier　1000　is placed on the floor, the shelf, or the like, a structure of the base　1030　is not exposed to the outside.

A tray　1040　is disposed to face the water dispensing unit　1020. When the water purifier　1000　is installed as illustrated in　FIG. 1, the tray　1040 faces the water dispensing unit　1020　in a vertical direction. The tray　1040　is configured to support a container for receiving purified water, or the like, dispensed through the water dispensing unit　1020. Further, the tray　1040　is configured to accommodate residual water dropped from the water dispensing unit　1020. When the tray　1040　receives and accommodates residual water dropped from the water dispensing unit　1020, contamination around the water purifier　1000 occurring due to residual water may be prevented.

Since the tray　1040　is required to receive residual water dropped from the water dispensing unit　1020, the tray　1040　may also be implemented to rotate together with the water dispensing unit　1020. Preferably, the input/output unit　1016　and the tray　1040　may be implemented to rotate together with the water dispensing unit　1020　in the same direction.

Next, an internal configuration of the water purifier 1000 of FIG. 1 will be described with reference to FIG. 2.

FIG. 2　is an exploded perspective view illustrating an internal configuration of the water purifier　1000　of　FIG. 1.

Specifically, a filter unit　1060　is installed on an inner side of the front cover　1011. The filter unit　1060　is configured to filter raw water supplied from a raw water supply to produce purified water. Only with a single filter, it may be difficult to produce purified water suitable for a user to drink, and thus, the filter unit　1060　may include a plurality of

unit filters

　1061　and　1062. The unit filters　1061　and　1062　include, for example, a pre-filter such as a carbon block, an adsorption filter, or the like and a highly efficient filter such as a high efficiency particulate air (HEPA) filter, an ultra filtration (UF) filter. In　FIG. 2, the two

unit filters

　1061　and　1062　are installed, but the number of the unit filters　1061　and　1062　may be increased or decreased as necessary.

The plurality of

unit filters

　1061　and　1062　is connected according to a preset order. The preset order refers to an order appropriate for the filter unit　1060　to filter raw water. Raw water may include various foreign materials. Particles such as hair, dust, and the like, degrade filtering performance of the highly efficient filters such as the HEPA filter or the UF filter, and thus, it is required to protect the highly efficient filters from large particles such as hair or dust. Thus, in order to protect the highly efficient filters, it is required to install the pre-filter on an upstream side of the highly efficient filters.

The pre-filter is configured to remove large particles from water. When the pre-filter is disposed on the upstream side of the highly efficient filters, it is possible to remove the large particles included in raw water. Then, raw water that does not include the large particles is supplied to the highly efficient filters, and thus, the highly efficient filters may be protected. Raw water that has passed through the pre-filter is subsequently filtered by the HEPA filter, the UF filter, or the like.

Purified water produced by the filter unit　1060　may be directly provided to a user through the water dispending unit　1020. In this case, a temperature of purified water provided to the user is equal to a room temperature. Alternatively, purified water produced by the filter unit　1060　may be heated by an induction heating module　1100　or may be cooled by a cold water tank assembly　1200.

A filter bracket assembly　1070 is a structure for fixing the unit filters　1061　and　1062　of the filter unit　1060　and fixing components such as a water dispensing flow channel of purified water or cold water, a valve, a sensor, and the like.

A lower portion　1071　of the filter bracket assembly　1070　is coupled to the tray　1040. The lower portion　1071　of the filter bracket assembly　1070 is formed to accommodate a protrusion coupling portion　1041　of the tray　1040. As the protrusion coupling portion　1041　of the tray　1040　is inserted into the lower portion　1071　of the filter bracket assembly　1070, the filter bracket assembly　1070　and the tray　1040　may be coupled to each other.

The lower portion　1071　of the filter bracket assembly　1070　and the tray　1040　have curved surfaces corresponding to each other. The lower portion　1071　of the filter bracket assembly　1070　may rotate independently with respect to the other remaining portions of the filter bracket assembly　1070.

An upper portion　1072　of the filter bracket assembly　1070　is configured to support the water dispensing unit　1020. The upper portion　1072　of the filter bracket assembly　1070 forms a rotation path of the water dispensing unit　1020. The water dispensing unit　1020 may be divided into an outlet cork unit　1021　protruding outward from the water purifier　1000　and a rotating unit　1022　disposed within the water purifier　1000. The rotating unit 1022　may have a circular shape as illustrated in　FIG. 2　for the purpose of rotation. The rotation unit　1022　may be mounted on the upper portion　1072　of the filter bracket assembly　1070. The water dispensing unit 1020 mounted on the upper portion　1072　of the filter bracket assembly　1070　may rotate relative to the filter bracket assembly　1070.

The lower portion　1071　and the upper portion　1072　of the filter bracket assembly　1070　may be connected to each other by a vertical connecting portion　1073. The lower portion　1071　and the upper portion　1072　of the filter bracket assembly　1070 connected to each other by the vertical connecting portion 1073　may rotate in the same direction. When a user rotates the water dispensing unit　1020, the upper portion　1072, the vertical connecting portion　1073, the lower portion　1071　of the filter bracket assembly　1070　connected to the water dispensing unit　1020,　and tray 1040 may be rotated together with the water dispensing unit 1020.

A filter installation region　1074　configured to accommodate the unit filters　1061 and　1062　of the filter unit　1060　is formed between the lower portion　1071 and the upper portion　1072　of the filter bracket assembly　1070. The filter installation region　1074 provides an installation space of the unit filters　1061　and　1062.

A support　1075　protruding toward the rear side of the water purifier　1000　is formed on an opposite side of the filter installation region　1074. The support　1075 is configured to support a control module　1080　and the induction heating module 1100. The control module　1080　and the induction heating module 1100　are mounted on the support　1075. The support　1075　is disposed between the induction heating module 1100　and a compressor　1051 to block heat generated by the induction heating module 1100　from being transferred to the compressor　1051, or the like.

The control module　1080　is configured to generally control the water purifier　1000. Various printed circuit boards for controlling the operation of the water purifier　1000　may be installed in the control module　1080.

An induction heating module 1100　is configured to heat purified water produced by the filter unit　1060　to produce hot water. The induction heating module 1100 are provided with components configured to heat purified water. The induction heating module 1100 receives purified water from the filter unit　1060,　and hot water produced by the induction heating module 1100 is dispensed through the water dispensing unit　1020.

The induction heating module 1100 may include a printed circuit board for controlling the production of hot water. A protective cover 1161 may be coupled to one side of the induction heating module 1100 to prevent water from penetrating into the printed circuit board and to protect the printed circuit board in the event of a fire.

A refrigerating cycle device 1050 is configured to produce cold water. The refrigerating cycle device 1050 refers to an aggregation of devices that continuously perform compression, condensation, expansion, and evaporation of a refrigerant. In order to allow a cold water tank assembly　1200 to produce cold water, it is required to operate the refrigerating cycle device 1050 such that cooling water filled in the cold water tank assembly　1200 is at a low temperature.

The refrigerating cycle device 1050 includes a compressor　1051, a condenser　1052, a capillary 1053, an evaporator　(not illustrated; disposed on an inner side of the cold water tank assembly), a dryer 1055, and a refrigerant flow channel connecting these components. The refrigerant flow channel may be formed by a pipe, or the like, and may connect the compressor　1051, the condenser　1052, the capillary 1053, and the evaporator　to form a circulation flow channel of a refrigerant.

The compressor　1051　is configured to compress a refrigerant. The compressor　1051　is connected to the condenser　1052　by the refrigerant flow channel, and the refrigerant compressed by the compressor　1051 flows to the condenser　1052　through the refrigerant flow channel. The compressor　1051　may be disposed below the support　1075, and may be installed to be supported by the base　1030.

The condenser　1052　is configured to condense a refrigerant. The refrigerant compressed by the compressor　1051 flows to the condenser　1052　through the refrigerant flow channel, and is condensed by the condenser　1052. The refrigerant condensed by the condenser　1052 flows to the dryer　1055　through the refrigerant flow channel.

The dryer 1055 is configured to remove moisture from a refrigerant. In order to improve the efficiency of the refrigeration cycle device 1050, it is required to remove moisture from a refrigerant to be introduced into the capillary 1053 and the evaporator in advance. The dryer 1055 is installed between the condenser 1052 and the capillary 1053, and removes moisture from the refrigerant to improve the efficiency of the refrigeration cycle device 1050.

The expansion of a refrigerant is implemented by the capillary 1053. The capillary 1053　is configured to expand a refrigerant, and a throttling valve or the like may form an expansion device instead of the capillary 1053 depending on the design. The capillary 1053 may be rolled in a coil form to secure a sufficient length in a narrow space.

The evaporator　is configured to evaporate a refrigerant, and is installed on an inner side of the cold water tank assembly　1200.　Cooling water filled in an inner side of the cold water tank assembly　1200　and a refrigerant of the refrigerating cycle device　1050　exchange heat with each other by means of the evaporator, and the cooling water may be maintained at a low temperature by heat exchange. In addition, purified water may be cooled by the cooling water maintained at a low temperature.

A refrigerant heated by heat exchange with cooling water in the evaporator is returned back to the compressor 1051 along the refrigerant flow channel, and continuously circulates through the refrigeration cycle device 1050.

The base　1030　is configured to support the front cover　1011, the rear cover　1014, the

opposite side panels

　1013a　and　1013b, the　 filter bracket assembly　1070, the condenser　1052, fan　1033, and the like. The base　1030　may preferably have high rigidity so as to support these components.

The condenser　1052　and the fan　1033　may be installed on the rear side of the water purifier　1000, and it is required to continuously circulate air for heat radiation of the condenser　1052. For air circulation, an intake　1034　may be provided on a bottom of the base　1030. Air sucked through the intake　1034　is moved by the fan　1033. While air is moving toward the condenser　1052, air realizes air-cooling type cooling. In order to increase heat radiation efficiency of the condenser　1052, a duct structure 1032 for surrounding the fan　1033　and the condenser　1052　may be fixed to the base　1030.

A drain 1035 is installed on a rear side of the duct structure 1032. The drain 1035 is exposed to an outer side of the water purifier 1000 to form a drain flow channel. The internal flow channels of the water purifier 1000 pass through all components,　and fluids present in the internal flow channels may be all discharged through the drain　1035　even when the drain　1035　is connected to any one internal flow channel.

A holder　1031　for supporting the cold water tank assembly　1200　may be installed on an upper portion of the condenser　1052. The holder　1031　may be provided with a first hole　1031a　on a rear side thereof, and the rear cover　1014　may be provided with a second hole　1014a. The　first hole　1031a　and the second hole　1014a　may be formed at positions corresponding to each other. The first hole　1031a　and the second hole　1014a allow a drain valve for draining cooling water filled in the cold water tank assembly　1200　to be disposed.

The cold water tank assembly　1200　is formed to accommodate cooling water therein. The cold water tank assembly　1200　receives purified water produced by the filter unit　1060. In the case of the direct type water purifier 1000, the cold water tank assembly　1200　may directly receive purified water from the filter unit　1060.

A temperature of cooling water filled in the cold water tank assembly　1200　is decreased by the operation of the refrigerating cycle device　1050. The cold water tank assembly　1200　is configured to cool purified water with cooling water to form cold water.

Since the cooling water is stored in the cold water tank assembly　1200　but not circulated, a contamination level of the cooling water is increased when a long period of time has passed. For sanitary reasons, it is required to periodically discharge cooling water stored in the cold water tank assembly　1200 to the outside, and to fill new cooling water in the cold water tank assembly　1200.

Here, the induction heating module 1100 and the control module 1080 of the water purifier 1000 of FIG. 2 will be described in more detail with reference to FIG. 3.

Specifically, the induction heating module 1100 refers to an aggregation of components that receive purified water produced by the filter unit 1060 (see FIG. 2) to produce hot water. In the case of the direct type water purifier 1000 (see FIG. 1), purified water may be supplied to the induction heating module 1100 directly from the filter unit 1060 (see FIG. 2).

The induction heating module 1100 includes an induction heating printed circuit board 1110, induction heating printed circuit board covers 1121 and 1122, a hot water tank 1130, a working coil 1140, a bracket 1160, and a shield plate 1190.

The induction heating printed circuit board 1110 controls an operation of induction heating of the working coil 1140. Opposite ends of the working coil 1140 are connected to the induction heating printed circuit board 1110, and controlled by the induction heating printed circuit board 1110. For example, when a user enters a control command through the input/output unit 1016 of the water purifier 1000 (see FIGS. 1 and 2) so as to extract hot water, purified water produced by the filter unit 1060 (see FIG. 2) is supplied to the hot water tank 1130. The induction heating printed circuit board 1110 controls the current so that the current flows through the working coil 1140. The hot water tank 1130 is induction-heated by the current supplied to the working coil 1140. The purified water is heated instantaneously while passing through the hot water tank 1130 to become hot water.

The induction heating printed circuit board covers　1121 and　1122　are configured to surround the induction heating printed circuit board　1110. The induction heating printed circuit board covers includes a first induction heating cover　1121　and a second induction heating cover　1122.

The induction heating printed circuit board　1110　is installed in an inner space formed by the first induction heating cover　1121　and the second induction heating cover　1122. The first induction heating cover　1121　and the second induction heating cover　1122　are coupled to each other by edges thereof to prevent the infiltration of water. Further, a sealing member (not illustrated) may be coupled to the edges of first induction heating cover　1121　and second induction heating cover　1122 so as to prevent the infiltration of water. The first induction heating cover　1121　and second induction heating cover　1122　may be preferably formed of a flame retardant material so as to prevent the damage of the induction heating printed circuit board　1110　due to fire.

The hot water tank　1130 heats purified water to produce hot water. The hot water tank 1130 is provided with an inner space for heating liquid. The hot water tank　1130　is induction-heated by the effect of magnetic field lines formed by the working coil　1140. The liquid becomes hot while passing through the inner space of the hot water tank　1130. 　The hot water tank　1130　is configured to maintain airtight sealing.

The working coil　1140　forms magnetic field lines for induction heating of the hot water tank　1130. The working coil　1140　is disposed on one side of the hot water tank　1130　to face the hot water tank　1130. When a current is supplied to the working coil　1140, magnetic field lines are formed by the working coil　1140. The magnetic field lines gives an effect on the hot water tank　1130, and the hot water tank　1130 is induction-heated by the effect of the magnetic field lines.

The shield plate 1190　is disposed on one side of the working coil　1140. The shield plate 1190　is disposed on an opposite side of the hot water tank　1130　based on the working coil　1140. The shield plate 1190　is to prevent magnetic field lines generated by the working coil　1140　from being radiated into the remaining region except the hot water tank　1130. The shield plate 1190　may be made of aluminium or other materials for changing the flow of magnetic field lines.

Meanwhile, the control module　1080　includes a control printed circuit board　1082, a noise printed circuit board　1083, a near field communication (NFC) printed circuit board　1084, a buzzer　1085, a main printed circuit board　1086, and main printed circuit board covers　1087 and　1088.

The control printed circuit board　1082　is a sub-component of a display printed circuit board (not illustrated). The control printed circuit board　1082　is not an essential component for driving a water supply apparatus such as the water purifier　1000, but performs a secondary role of the display printed circuit board (not illustrated).

The noise printed circuit board　1083　is to supply power to the induction heating printed circuit board　1110. That is, the noise printed circuit board 1083 reduces noise of alternating current power (that is, AC power) outputted from an input power supply 100 (see FIG. 5) to supply AC power with reduced noise to the induction heating printed circuit board 1110. In addition, the noise printed circuit board 1083 may serve to supply power not only to the induction heating printed circuit board 1110 but also to other components (for example, the main printed circuit board 1086).

For reference, induction heating requires a very high output voltage, and thus it is required to supply sufficient power. Accordingly, the input power supply 100 (see FIG. 5) may be provided in case power required for induction heating is not sufficiently supplied. The input power supply 100 (see FIG. 5) may supply additional power to the induction heating printed circuit board 1110 to fulfill an output voltage for induction heating. In addition, the input power supply 100 (see FIG. 5) may serve to provide auxiliary power to not only the induction heating printed circuit board 1110 but also other components (for example, the main printed circuit board 1086).

Meanwhile, the buzzer　1085　outputs an audio sound to provide accurate failure information to a user when a failure has occurred on a water supply apparatus such as the water purifier　1000 (see FIG. 1). The buzzer　1085　may output a specific audio sound of a preset code according to the failure.

The NFC printed circuit board　1084　is to send and receive data to and from a communication device. In recent years, personal communication devices such as a smart phone, and the like have been widely used. Accordingly, when a consumer is able to check a status of a water purifier or enter a control command using a personal communication device, it is possible to enhance the convenience of the consumer. The NFC printed circuit board　1084　may provide status information of a water supply apparatus to a personal communication device paired therewith, and receive a user's control command from the personal communication device.

The main printed circuit board　1086　controls the overall operation of a water supply apparatus such as the water purifier　1000 (see FIG. 1). The operation of the input/output unit　1016 illustrated in　FIG. 1　(see FIG. 1)　or the compressor　1051　illustrated in　FIG. 2　(see FIG. 2)　may be also controlled by the main printed circuit board　1086. When power is insufficient, the main printed circuit board　1086　may receive insufficient power through the noise printed circuit board　1083.

The main printed circuit board covers　1087 and　1088　are configured to surround the main printed circuit board　1086. The main printed circuit board covers　1087 and　1088　includes a first main cover　1087　and a second main cover　1088.

The main printed circuit board　1086　is installed in an inner space formed by the first main cover　1087　and the second main cover　1088.

The first main cover　1087　and the second main cover　1088　are coupled to each other by edges thereof to prevent the infiltration of water. The first main cover　1087　and the second main cover　1088　may be provided with a sealing member (not illustrated) to prevent the infiltration of water. Further, the first main cover　1087　and second main cover　1088　may be preferably formed of a flame retardant material to prevent the damage of the main printed circuit board　1086　due to fire.

As described above, the water purifier 1000 may supply hot water by using the induction heating module 1100 and the control module 1080. Hereinafter, a flow channel configuration of the water purifier 1000 of FIG. 1 will be described with reference to FIG. 4.

FIG. 4 is a schematic view illustrating a flow channel configuration of the water purifier of FIG. 1. For reference, a solid line in FIG. 4 represents a flow channel of water.

Specifically, for the flow channel of water, an upstream side of the filter unit　1060　and a downstream side of the filter unit　1060　may be divided into a prified water line　1400　and a purified water line　1500, respectively, based on the filter unit　1060. Here, the upstream side or the downstream side is divided based on the flow of water.

A water supply valve　1312　is opened or closed based on a control command received through the input/output unit　1016　(see FIG. 1). When a control command for dispensing purified water, hot water or cold water is received through the input/output unit　1016, the water supply valve　1312　is opened, and the supply of raw water is carried out from a raw water supply　10　to the filter unit　1060.

Raw water passes through a pressure reducing valve　1311　during the process of being supplied to the filter unit　1060. The pressure reducing valve　1311　is installed between the raw water supply　10　and the filter unit　1060. The pressure reducing valve　1311　is configured to reduce a pressure of raw water supplied from the raw water supply　10.

The direct type water purifier　1000　is provided with a water tank, and thus a pressure of purified water dispensed through the water dispensing unit　1020　is determined by the pressure of raw water supplied from the raw water supply　10. In general, the pressure of raw water supplied from the raw water supply　10　is high, and thus water is dispensed from the water dispensing unit　1020 at a high pressure　when there is no pressure reducing valve　1311. There may exist a danger in which the unit filters　1061 and　1062　of the filter unit　1060　are physically damaged by the pressure of raw water. Accordingly, it is required to reduce the pressure of raw water.

The pressure reducing valve　1311　reduces the pressure of raw water supplied from the raw water supply　10　to the filter unit 1060. As a result, the filter unit 1060　may be protected, and water may be dispensed at an appropriate pressure from the water dispensing unit 1020.

Raw water is sequentially filtered while passing through the unit filters　1061 and　1062 of the filter unit 1060. Water that is present at an upstream side of the filter unit 1060 may be referred to as raw water, and water that is present at a downstream side of the filter unit 1060 may be referred to as purified water.

Purified water produced by the filter unit　1060　passes through the water supply valve　1312　and a flow sensor　1313. The flow sensor　1313　is configured to measure a flow rate of water supplied from the filter unit 1060. The flow rate measured by the flow sensor　1313　is used to control the water purifier.

For example, when a control command for dispensing a predetermined amount of purified water is received through the input/output unit 1016, a pulse value corresponding to the predetermined amount is received to the flow sensor　1313　by the control module　1080, and the water supply valve　1312　is opened by the control of the control module　1080. When purified water having a flow rate corresponding to the pulse value passes through the flow sensor　1313, the control module　1080 receives a feedback from the flow sensor　1313　to control the water supply valve　1312, and the water supply valve　1312　is closed by the control of the control module　1080. A flow rate measured by the flow sensor　1313　through the foregoing process or the like may be used to control the water purifier　1000.

The purified water line　1500　connected to the flow sensor　1313　is branched into two

sections

　1600 and　1700, and one section is sequentially connected to a flow control valve　1351　and the induction heating module　1100. This section sequentially connected to the flow control valve　1351　and the induction heating module　1100　may be referred to as a hot water line　1700. The other section 1600 is provided with a check valve 1321, and this section is branched again into a purified water line　1601　and a cold water line　1602　at a downstream side of the check valve　1321. The purified water line　1601 is provided with a purified water dispensing valve　1330, and the cold water line　1602 is provided with a cold water dispensing valve 1340. The purified water line　1601　and the cold water line　1602　are merged back into one to be connected to the water dispensing unit　1020, and a merged flow channel　1603 is provided with a check valve　1322.

Two

check valves

　1321 and　1322　installed at an upstream side and a downstream side of the purified water dispensing valve　1330　and the cold water dispensing valve　1340　may be referred to as a first check valve　1321　and a second check valve　1322　to be distinguished from each other. The first check valve　1321　and the second check valve　1322　are provided to prevent residual water from be generated.

When a control command for supplying hot water is received to the water purifier, the water supply valve　1312, the flow control valve　1351,　and a hot water dispensing valve　1353　are opened, and hot water is dispensed through the hot water line　1700. During the process, internal pressures of the purified water line　1601　and the cold water line　1602　may decrease to cause a phenomenon in which the purified water dispensing valve　1330　or cold water dispensing valve　1340　are instantaneously opened and then closed. There is no problem of residual water in a structure in which the water dispensing unit　1020　is provided with only one outlet cork, and both cold water and hot water are dispensed through the outlet cork. However, in a structure in which both cold water and hot water are dispensed through different outlet corks, a small amount of residual water may be dispensed from one outlet cork while water is dispensed from the other outlet cork.

However, when the first check valve　1321　is installed at an upstream side of a branch point between the purified water line　1500　and the cold water line　1602, it is possible to block a pressure change formed during the process of dispensing hot water through the hot water line　1700　from being transferred to the purified water line　1601　and cold water line　1602. As a result, it is possible to prevent the occurrence of a phenomenon in which the purified water dispensing valve　1330　or the cold water dispensing valve　1340　from being instantaneously opened and then closed.

When comparing a configuration in which the cold water dispensing valve　1340　is installed at an upstream side of the cold water tank assembly　1200　and a configuration in which the cold water dispensing valve　1340　is installed at a downstream side of the cold water tank assembly　1200 to each other, the former configuration may obtain even a little more cold water in comparison to the latter configuration. It is because an amount of cold water corresponding to a length of a flow channel provided between the cold water tank assembly　1200　and the cold water dispensing valve　1340　can be further supplied. Accordingly, the cold water dispensing valve　1340　may be preferably installed at the upstream side of the cold water tank assembly　1200,　as illustrated. However, in a structure in which the cold water dispensing valve　1340　is installed at the upstream side of the cold water tank assembly　1200, residual water may be generated by an internal pressure change of the cold water line　1602, and a small amount of residual water may be dispensed through the water dispensing unit　1020 even when the dispensing of water is stopped.

However, when the merged flow channel　1603 provided between the purified water line　1601　and the cold water line　1602 is provided with the second check valve　1322, it is possible　to block a pressure change of the cold water line　1602　from being transferred to the water dispensing unit　1020. Accordingly, when the dispensing of water is stopped, it is possible to prevent a phenomenon in which a small amount of residual water is dispensed through the water dispensing unit 1020.

Purified water that has passed through the flow sensor　1313　may be immediately supplied to a user in a room temperature state or supplied to a user subsequent to becoming hot water or cold water.

The purified water dispensing valve　1330　and the cold water dispensing valve　1340　are configured to be opened or closed based on a control command received through the input/output unit　1016. When a control command for dispensing purified water is received through the input/output unit　1016, the water supply valve　1312　and the purified water dispensing valve　1330　are opened. Purified water produced by the filter unit　1060　is dispensed to the water dispensing unit　1020　through the purified water line　1601. Similarly, when a control command for dispensing cold water is received through the input/output unit　1016, the water supply valve　1312　and the cold water dispensing valve　1340　are opened. Purified water produced by the filter unit　1060　is introduced into the cold water tank assembly　1200　along the cold water line　1602, and is cooled while passing through the cold water tank assembly　1200. Cold water produced by the cold water tank assembly　1200　is dispensed through the water dispensing unit　1020.

The cold water tank assembly　1200 is provided with the drain valve　1280, cooling water filled in the cold water tank assembly　1200　may be discharged to the outside through the drain valve　1280.

The hot water line　1700 may be provided with the flow control valve　1351. When a flow rate above an appropriate amount is introduced into the hot water tank　1130 (see FIG. 3), sufficient heating may not be carried out, and thus it is required to control the flow rate at all times so as to introduce only a flow rate with an appropriate amount. The flow control valve　1351　is installed at an upstream side of the induction heating module　1100,　and is configured to adjust a flow rate of purified water introduced into the hot water tank　1130 (see FIG. 3).

For reference, before purified water is introduced into the hot water tank 1130 (see FIG. 3), purified water may be introduced into the liquid-cooled heat sink 1118 (see FIG. 5) provided in the induction heating printed circuit board 1110 (see FIG. 3).

That is, purified water introduced into the liquid-cooled heat sink 1118 (see FIG. 5) is preheated by the heat radiating operation of the liquid-cooled heat sink 1118 (see FIG. 5), and accordingly a temperature of purified water introduced into the hot water tank 1130 (see FIG. 3) through the liquid-cooled heat sink 1118 (see FIG. 5) may be higher than when the air-cooled heat sink is used, thereby reducing the output of the induction heating module 1100 required to reach a target temperature.　

The flow control valve　1351 may be also provided with a thermistor　1352. A temperature of purified water measured by the thermistor　1352　is used to control the induction heating module　1100. For example, when the temperature of purified water measured by the thermistor　1352　is relatively low, the induction heating module　1100　may be operated at high power. Conversely, when the temperature of purified water measured by the thermistor　1352　is relatively low, the induction heating module　1100　may be operated at low power.

The hot water dispensing valve　1353　is installed at a downstream side of the hot water tank　1130. When a control command for dispensing hot water is received through the input/output unit 1016, the water supply valve　1312　and hot water dispensing valve　1353　are opened to dispense hot water along the hot water line　1700.

A flow channel branched from the hot water line 1700 may be provided with a safety valve　1360. The safety valve　1360　is formed to operate due to a pressure change formed in a flow channel of water. When a flow channel of the water purifier　1000　is excessively pressurized such as a case where the induction heating module　1100 abnormally operates, the safety valve　1360　is opened, and purified water is discharged through the drain　1035.

The flow channel of the water purifier 1000 is configured as described above. Hereinafter, a partial configuration of the water purifier 1000 of FIG. 1 will be described with reference to FIGS. 5 and 6.

FIG. 5 is a schematic view for explaining a partial configuration of the water purifier of FIG. 1. FIG. 6 is a plan view illustrating the induction heating printed circuit board of FIG. 5.

First, FIG. 5 illustrates the input power supply 100, the noise printed circuit board 1083, the induction heating printed circuit board 1110, the hot water tank 1130, a temperature fuse 1182, and the working coil 1140. The following is a configuration of each component.

Specifically, the input power supply 100 is a power supply unit for outputting AC power to fulfill a high output voltage for induction heating. AC power outputted from the input power supply 100 may be supplied to the noise printed circuit board 1083. In addition, one end of the input power supply 100 may be connected to the noise printed circuit board 1083, the other end of the input power supply 100 may be connected to one end of the temperature fuse 1182, and the other end of the temperature fuse 1182 may be connected to the noise printed circuit. As a result, when the temperature fuse 1182 operates to block a circuit, the AC power outputted from the input power supply 100 may not be supplied to the noise printed circuit board 1083, and thus the operation of the induction heating printed circuit board 1110 is also stopped.

For reference, the temperature fuse　1182　operates when liquid present within the hot water tank　1130　is overheated.

The noise printed circuit board 1083 is a board for reducing noise of AC power outputted from the input power supply 100 and supplying power with reduced noise to the induction heating printed circuit board 1110. In addition, one end of the noise printed circuit board 1083 may be connected to one end of the input power supply 100 and the other end of the temperature fuse 1182, and the other end of the noise printed circuit board 1083 may be connected to an input terminal INPT (that is, SINPT1 and SINPT2) of the induction heating printed circuit board 1110. That is, the noise printed circuit board 1083 may supply the AC power with reduced noise to the induction heating printed circuit board 1110 through the input terminal INPT.

For reference, the noise printed circuit board 1083 may be provided with an electric fuse (not illustrated) that operates when an overcurrent with a predetermined magnitude or more flows. Accordingly, when an overcurrent flows through the induction heating printed circuit board 1110 and the noise printed circuit board 1083 due to a short circuit of a switch of an induction heating driver 1113, the electric fuse may operate to block the circuit. As a result, the operation of the induction heating printed circuit board 1110 and the noise printed circuit board 1083 may be stopped.

The working coil　1140　is formed by a conducting wire wound in an annular shape. In addition, opposite ends of the working coil 1140 may be connected to output terminals OUPT (that is, SOUPT1 and SOUPT2) of the induction heating printed circuit board 1110, and the operation of induction heating of the working coil 1140 may be controlled by the induction heating printed circuit board 1110 (in particular, the induction heating driver 1113).

The hot water tank 1130 may be disposed to face the working coil 1140 at a position spaced apart from the working coil 1140, and may be induction-heated by the working coil 1140 to heat liquid passing through an inner space thereof. In addition, the hot water tank 1130 may be induction-heated by the working coil 1140, and thereby the liquid (that is, purified water) passing through the inner space thereof may be heated. In addition, the hot water tank 1130 may be coupled to a bracket 1160 (see FIG. 3) with the working coil 1140 interposed therebetween, and the bracket 1160 (see FIG. 3) may be provided with the temperature fuse 1182 that operates when the hot water tank 1130 is overheated above a preset temperature (for example, 450°C). As described above, one end of the temperature fuse 1182 may be connected to the other end of the input power supply 100, and the other end of the temperature fuse 1182 may be connected to one end of the noise printed circuit board 1083.

The induction heating printed circuit board 1110 may control the operation of induction heating of the working coil 1140 by receiving the AC power with reduced noise from the noise printed circuit board 1083.

Specifically, the induction heating printed circuit board 1110 may include a rectifier 1111, a DC link capacitor 1112, an induction heating driver 1113, an induction heating controller 1114, a gate driver 1115, a resonant capacitor 1116, insulating

members

1117a and 1117b, the liquid-cooled heat sink 1118, and a fixing member 1184.

The rectifier 1111 may convert AC power supplied from the input terminal INPT into DC power, and supply the DC power to the induction heating driver 1113.

Specifically, the rectifier 1111 may rectify and convert AC power supplied from the input terminal INPT into DC power, and supply the DC power to the induction heating driver 1113. In addition, the liquid-cooled heat sink 1118 may be mounted on a rear surface of the rectifier 1111, and accordingly heat generated when the rectifier 1111 is driven may be radiated through the liquid-cooled heat sink 1118. The rectifier 1111 may be fixed to liquid-cooled heat sink 1118 through the fixing member 1184. In addition, the rectifier 1111 may include, for example, a bridge diode, but is not limited thereto.

For reference, DC power rectified by the rectifier 1111 may be supplied to the DC link capacitor 1112, and the DC link capacitor 1112 may reduce ripple of the DC power.

As described above, the DC power which is rectified by the rectifier 150 and has ripple reduced by the DC link capacitor 1112 may be supplied to the induction heating driver 1113.

The induction heating driver 1113 may receive the DC power from the rectifier 1111 to perform a switching operation. That is, the induction heating driver 1113 may receive the DC power which is rectified by the rectifier 1111 and has ripple reduced by the DC link capacitor 1112. In addition, the switching operation of the induction heating driver 1113 may be controlled by the induction heating controller 1113, and the induction heating driver 1113 may apply a resonant current to the working coil 1140 through the switching operation. That is, the induction heating driver 1113 may drive the working coil 1140 by applying the resonant current to the working coil 1140, and accordingly, the working coil 1140 may perform an operation of induction heating. In addition, the liquid-cooled heat sink 1118 may be mounted on a rear surface of the induction heating driver 1113, and accordingly heat generated when the induction heating driver 1113 is driven may be radiated by the liquid-cooled heat sink 1118. In addition, the induction heating driver 1113 may be fixed to the liquid-cooled heat sink 1118 through the fixing member 1184. In addition, the induction heating driver 1113 may include a plurality of switchs (for example, even number of switchs) for performing a switching operation, and each of the plurality of switchs may include, for example, an insulated gate bipolar mode transistor (IGBT), but are not limited thereto.

For reference, the plurality of switchs may be alternately turned on and off by a switching signal supplied from the gate driver 1115. In addition, a high-frequency AC (that is, a resonant current) may be generated by the switching operation of the plurality of switchs, and the generated high-frequency AC may be applied to the working coil 1140.

The induction heating controller 1114 may control the switching operation of the induction heating driver 1113. That is, the induction heating controller 1114 may control the switching operation of the induction heating driver 1113 by controlling the gate driver 1115 that turns on or off the switchs provided in the induction heating driver 1113.

The gate driver 1115 may be controlled by the induction heating controller 1114, and may turn on or off the switchs provided in the induction heating driver 1113. That is, the switching operation of the switchs provided in the induction heating driver 1113 may be controlled according to the switching signal of the gate driver 1115.

For reference, the gate driver 1115 may generate various switching signals through a pulse width modulation (PWM) function.

The resonant capacitor 1116 may be connected to the working coil 1140 through the output terminal OUPT. When the switching operation of the induction heating driver 1113 starts (that is, when a voltage is applied by the switching operation), the resonant capacitor 1116 starts to resonate. In addition, when the resonant capacitor 1116 resonates, a current flowing through the working coil 1140 connected to the resonant capacitor 1116 increases.

Through the above-described process, an eddy current is induced to the hot water tank 1130 disposed adjacent to the working coil 1140 connected to the resonant capacitor 1116.

A first insulating member 1117a may be attached between the rectifier 1111 and the liquid-cooled heat sink 1118. That is, the first insulating member 1117a may be attached between the rear surface of the rectifier 1111 and the liquid-cooled heat sink 1118, thereby insulating between the rectifier 1111 the liquid-cooled heat sink 1118. As a result, even when the rectifier 1111 abnormally operates or is destroyed, conduction between electricity of the rectifier 1111 and water of the liquid-cooled heat sink 1118 may be prevented.

For reference, the first insulating member 1117a may include, for example, a ceramic heat radiating plate made of insulating paper or alumina. In addition, when the first insulating member 1117a includes a ceramic heat radiating plate made of alumina, it is possible to secure an insulation distance between the rectifier 1111 and the liquid-cooled heat sink 1118 (for example, 2 mm) and to improve thermal conductivity (for example, 20 W/mk or more; W: Watt, m: meter, K: Kelvin).

A second insulating member 1117b may be attached between the induction heating driver 1113 and the liquid-cooled heat sink 1118. That is, the second insulating member 1117b may be attached between the rear surface of the induction heating driver 1113 and the liquid-cooled heat sink 1118, thereby insulating between the induction heating driver 1113 and the liquid-cooled heat sink 1118. As a result, even when the induction heating driver 1113 abnormally operates or is destroyed, conduction between electricity of the induction heating driver 1113 and water of the liquid-cooled heat sink 1118 may be prevented.

For reference, the second insulating member 1117b may include, for example, a ceramic heat radiating plate made of insulating paper or alumina. In addition, when the second insulating member 1117b includes a ceramic heat radiating plate made of alumina, it is possible to secure an insulation distance between the induction heating driver 1113 and the liquid-cooled heat sink 1118 (for example, 2 mm) and to improve thermal conductivity (for example, 20 W/mk or more; W: Watt, m: meter, K: Kelvin).

The liquid-cooled heat sink 1118 may perform a heat radiating operation on the rectifier 1111 and the induction heating driver 1113. As illustrated in FIGS. 5 and 6, the liquid-cooled heat sink 1118 may be mounted on the rear surfaces of the rectifier 1111 and the induction heating driver 1113, and the first insulating member 1117a may be attached between the liquid-cooled heat sink 1118 and the rectifier1111, and the second insulating member 1117b may be attached between the liquid-cooled heat sink 1118 and the induction heating driver 1113.

In addition, a material of the liquid-cooled heat sink may be, for example, aluminum, but is not limited thereto.

For reference, the liquid-cooled heat sink 1118 may perform a heat radiating operation by using water, and accordingly purified water may be introduced into the liquid-cooled heat sink 1118 through the flow channel of the water purifier described above. In addition, purified water introduced into the liquid-cooled heat sink 1118 may be preheated by the heat radiating operation of the liquid-cooled heat sink 1118. Accordingly, a temperature of purified water introduced into the hot water tank 1130 through the liquid-cooled heat sink 1118 may be higher than when the air-cooled heat sink is used. As a result, it is possible to reduce the output of the working coil 1140 (that is, the output of the induction heating driver 1113) required to reach a target temperature.

However, when power semiconductor element (that is, the rectifier 1111 and the induction heating driver 1113) are fixed to the liquid-cooled heat sink 1118 through screws, electricity may be conducted to water that is present within the liquid-cooled heat sink 1118 through the screws at the time of an abnormal operation or insulation breakdown of the power semiconductor element, resulting in an electric shock accident.

Accordingly, as illustrated in FIG. 6, the power semiconductor element (that is, the rectifier 1111 and the induction heating driver 1113) may be fixed to the liquid-cooled heat sink 1118 through the fixing member 1184. Hereinafter, a fixing structure of a power semiconductor element will be described with reference to FIGS. 7 and 8.

FIG. 7 is a perspective view illustrating a fixing structure of the power semiconductor element of FIG. 6. FIG. 8 is an exploded perspective view of FIG. 7.

Referring to FIGS. 7 and 8, the rectifier 1111 and the induction heating driver 1113 may be fixed to the liquid-cooled heat sink 1118 through the fixing member 1184.

Specifically, the liquid-cooled heat sink 1118 may be mounted on the rear surface of each of the rectifier 1111 and the induction heating driver 1113, and the fixing member 1184 may be formed to surround front and side surfaces of each of the rectifier 1111 and the induction heating driver 1113, thereby fixing the rectifier 1111 and the induction heating driver 1113 to the liquid-cooled heat sink 1118.

That is, the rectifier 1111 may be fixed to a first portion P1 of the rear surface of the fixing member 1184, and the induction heating driver may be fixed to a second portion P2 of the rear surface of the fixing member 1184 spaced apart from the first portion P1. In addition, holes H1, H2, and H3 passing through the fixing member 1184 in forward and backward directions FB may be formed in a third portion P3 of the rear surface of the fixing member 1184 which does not overlap the first portion P1 and the second portion P2, and fixing screws FS1, FS2, and FS3 for fixing the fixing member 1184 to the liquid-cooled heat sink 1118 may be inserted into the holes H1, H2, and H3.

Here, the first portion P1 may be provided with a first protrusion PR1 formed to protrude backward so as to pass through the rectifier 1111, and coupled to the liquid-cooled heat sink 1118.

Accordingly, the rectifier 1111 may be fixed between the fixing member 1184 and the liquid-cooled heat sink 1118 through the first protrusion PR1 (made of an insulating material) instead of a screw, and thus electricity may not be conducted to water that is present within the liquid-cooled heat sink 1118 even at the time of an abnormal operation or insulation breakdown of the rectifier 1111.

For reference, the first protrusion PR1 may also pass through the first insulating member 1117a.

Meanwhile, the second portion P2 may be provided with a second protrusion PR2 formed to protrude backward so as to pass through the induction heating driver 1113, and coupled to the liquid-cooled heat sink 1118.

Accordingly, the induction heating driver 1113 may be fixed between the fixing member 1184 and the liquid-cooled heat sink 1118 through the second protrusion PR2 (made of an insulating material) instead of a screw, and thus electricity may not be conducted to water that is present within the liquid-cooled heat sink 1118 even at the time of an abnormal operation or insulation breakdown of the induction heating driver 1113.

For reference, the second protrusion PR2 may also pass through the second insulating member 1117b.

In addition, the third portion P3 may include a first sub-portion SP1 located on one side of the rectifier 1111, a second sub-portion SP2 located between the other side of the rectifier 1111 and one side of the induction heating driver 1113, and a third sub-portion SP3 located on the other side of the induction heating driver 1113.

In addition, a hole may include the first hole H1 formed in the first sub-portion SP1 to pass through the fixing member 1184 in the forward and backward directions FB, the second hole H2 formed in the second sub-portion SP2 to pass through the fixing member 1184 in the forward and backward directions FB, and a third hole H3 formed in the third sub-portion SP3 to pass through the fixing member 1184 in the forward and backward directions FB.

The fixing screws FS1 to FS3 may be inserted into the holes H1 to H3, and the fixing member 1184 may be fixed to the liquid-cooled heat sink 1118 through the fixing screws FS1 to FS3. A fixing screw may include the first fixing screw FS1 inserted into the first hole H1 and coupled to the liquid-cooled heat sink 1118, a second fixing screw FS2 inserted into the second hole H2 and coupled to the liquid-cooled heat sink 1118, and the third fixing screw FS3 inserted into the third hole H3 and coupled to the liquid-cooled heat sink 1118.

For reference, the fixing member 1184 may be made of at least one material among, for example, poly phenyl sulphide (PPS) and polycarbonate (PC).

Specifically, PPS, which is an engineering plastic having excellent strength, heat resistance, chemical resistance, dimensional stability, and the like, has advantages of allowing easy formation because it is a thermoplastic resin, and being inexpensive in terms of cost.

In addition, PC has advantages of excellent toughness, impact strength, heat resistance, low temperature properties, electrical properties, dimensional stability, weather resistance, light stability, low oxidation during processing, being resistant to water and strong acids, and no toxicity.

That is, the fixing member 1184 made of the above-described material may serve as an insulating injection molding. In particular, even at the time of an abnormal operation or insulation breakdown of the power semiconductor element (that is, the rectifier 1111 or the induction heating driver 1113), electricity may not pass through the first protrusion PR1 and the second protrusion PR2 made of an insulating material, thereby preventing an electric shock accident.

As a result, in the embodiments of the present disclosure, a double insulating structure (that is, the first insulating member 1117a and the second insulating member 1117b) may be applied to the liquid-cooled heat sink 1118 and the power semiconductor element (that is, the rectifier 1111 and the induction heating driver 1113), thereby preventing an electric shock accident.

As described above, the water purifier 1000 according to an embodiment of the present disclosure may improve heat radiation performance of a power semiconductor element and an amount of continuously dispensing hot water through a liquid-cooled heat sink. In addition, a size of the liquid-cooled heat sink is smaller than that of a conventional air-cooled heat sink, thereby reducing a volume of an induction heating printed circuit board. Furthermore, water is preheated through the liquid-cooled heat sink, and accordingly it is possible to reduce the output of an induction heating driver (or a working coil) required to reach a target temperature, thereby saving power.

In addition, in the water purifier 1000 according to an embodiment of the present disclosure, the power semiconductor element may be stably fixed to the liquid-cooled heat sink. Furthermore, the water purifier according to the present disclosure may prevent electricity and water from being conducted at the time of an abnormal operation or insulation breakdown of the power semiconductor element, thereby preventing an electric shock accident.

The present disclosure has been described with reference to the illustrated drawings, but the present disclosure is not limited to the disclosed embodiments and the drawings. It should be obvious to those skilled in the art that various modifications may be made within the scope of the present disclosure. In addition, even though operational effects according to a configuration of the present disclosure have not been explicitly described while describing the embodiments of the present disclosure, it should be appreciated that effects predictable from the configuration can also obtained.

Claims

A water purifier, comprising:

a noise printed circuit board configured to reduce noise of alternating current (AC) power outputted from an input power supply; and

an induction heating printed circuit board configured to receive AC power with reduced noise from the noise printed circuit board, and to control an operation of induction heating of a working coil based on the received AC power,

wherein the induction heating printed circuit board comprises:

a rectifier configured to rectify AC power received from the noise printed circuit board into direct current (DC) power;

an induction heating driver configured to perform a switching operation by receiving the DC power from the rectifier;

a liquid-cooled heat sink configured to perform a heat radiating operation on the rectifier and the induction heating driver; and

a fixing member configured to fix the rectifier and the induction heating driver to the liquid-cooled heat sink.
The water purifier according to claim 1, wherein

the liquid-cooled heat sink is mounted on a rear surface of each of the rectifier and the induction heating driver, and

the fixing member is formed to surround a front surface and a side surface of each of rectifier and the induction heating driver so as to fix the rectifier and the induction heating driver to the liquid-cooled heat sink.
The water purifier according to claim 1, wherein

the rectifier is fixed to a first portion of a rear surface of the fixing member,

the induction heating driver is fixed to a second portion of the rear surface of the fixing member spaced apart from the first portion,

a hole passing through the fixing member in forward and backward directions is formed in a third portion of the rear surface of the fixing member which does not overlap the first portion and the second portion, and

a fixing screw for fix the fixing member to the liquid-cooled heat sink is inserted into the hole.
The water purifier according to claim 3, wherein

the third portion comprises:

a first sub-portion located at one side of the rectifier;

a second sub-portion located between the other side of the rectifier and one side of the induction heating driver; and

a third portion located at the other side of the induction heating driver.
The water purifier according to claim 4, wherein

the hole comprises:

a first hole formed in the first sub-portion to pass through the fixing member in the forward and backward directions;

a second hole formed in the second sub-portion to pass through the fixing member in the forward and backward directions; and

a third hole formed in the third sub-portion to pass through the fixing member in the forward and backward directions, and

the fixing screw comprises:

a first fixing screw inserted into the first hole and coupled to the liquid-cooled heat sink;

a second fixing screw inserted into the second hole and coupled to the liquid-cooled heat sink; and

a third fixing screw inserted into the third hole and coupled to the liquid-cooled heat sink.
The water purifier according to claim 3, wherein

the fixing member comprises:

a first protrusion formed to protrude from the first portion so as to pass through the rectifier, and coupled to the liquid-cooled heat sink; and

a second protrusion formed to protrude from the second portion so as to pass through the induction heating driver, and coupled to the liquid-cooled heat sink.
The water purifier according to claim 6, wherein

the rectifier is fixed between the fixing member and the liquid-cooled heat sink through the first protrusion, and

the induction heating driver is fixed between the fixing member and the liquid-cooled heat sink through the second protrusion.
The water purifier according to claim 1, wherein

the fixing member is made of at least one material among poly phenylene sulfide (PPS) and polycarbonate (PC).
The water purifier according to claim 1, wherein

the rectifier includes a bridge diode, and

the induction heating driver includes a plurality of switchs configured to perform the switching operation.
The water purifier according to claim 9, wherein

the plurality of switchs each include an insulated gate bipolar mode transistor (IGBT).
The water purifier according to claim 1, wherein

the induction heating printed circuit board further comprises:

a DC link capacitor configured to reduce ripple of DC power rectified by the rectifier, and to supply the DC power with reduced ripple to the induction heating driver;

an induction heating controller configured to control the switching operation of the induction heating driver;

a gate driver controlled by the induction heating controller, and configured to turn on or off a switch provided in the induction heating driver;

a resonant capacitor configured to start to resonate when the switching operation of the induction heating driver starts;

a first insulating member attached between the rectifier and the liquid-cooled heat sink; and

a second insulating member attached between the induction heating driver and the liquid-cooled heat sink.