Liquid heating device

Abstract

The electric water heater (1) of the present invention comprises: a heating coil (320) through which a high-frequency current flows; a frame (310) that accommodates the heating coil (320); a container (100) that can be set in the frame (310) and stores liquid; and a heating body (110) that is set at the bottom of the container (100) and heats the liquid in the container (100). Here, when the container (100) is set in the frame (310), the heating body (110) generates heat by electromagnetic induction from the heating coil (320).

Description

Technical Field

[0001] The present invention relates to liquid heating devices such as electric water heaters. Background Art

[0002] For example, Patent Document 1 describes a kettle comprising a main body having a heating resistor and capable of boiling water, and a base coupled to the main body. A female electrical connector is provided at the bottom of the main body, and a male electrical connector is provided at the base. By electrically coupling these electrical connectors, power for energizing the heating resistor is supplied from the base side to the main body side.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Laid-Open No. 2014-226555 Summary of the Invention

[0006] Problems to be solved by the invention

[0007] In the kettle of patent document 1, although the female electrical connector on the main body side is set to be waterproof, considering the risk of connecting to the male electrical connector when moisture remains in part of the female electrical connector, it is difficult to thoroughly clean the main body from the main body to the outside by washing it with a large amount of water or immersing it in water.

[0008] In view of the above problems, an object of the present invention is to provide a liquid heating device capable of thoroughly cleaning the entire container.

[0009] Technical means to solve the problem

[0010] The main embodiment of the present invention comprises a liquid heating device comprising: a heating coil through which a high-frequency current flows; a housing that houses the heating coil; a container that can be mounted within the housing and stores liquid; and a heater mounted at the bottom of the container to heat the liquid within the container. When the container is mounted within the housing, the heater generates heat using electromagnetic induction from the heating coil.

[0011] According to the above configuration, since there is no portion electrically connected to the frame on the outside of the container, the entire container can be thoroughly washed with water.

[0012] In the liquid heating device of this embodiment, a structure in which the heating element is in contact with the liquid in the container can be adopted.

[0013] According to the above configuration, since the heat of the heating element is directly transferred to the water, the heating efficiency of the water is improved.

[0014] In the case of the above structure, the heating element may further include a first surface and a second surface parallel to the first surface. In this case, both the first surface and the second surface are in contact with the liquid in the container.

[0015] According to such a structure, since the heat of the heating element is efficiently transferred to the water, the heating efficiency of the water by the heating element is further improved.

[0016] In the liquid heating device of this embodiment, the container can be configured to have a double-wall structure consisting of an inner wall portion and an outer wall portion.

[0017] According to the above configuration, when the water in the container is heated, the heat is less likely to be transferred to the outer surface of the container, and the outer surface of the container is less likely to be heated.

[0018] It should be noted that "disposed on a frame" means placed on the frame, for example, above or to the side of the frame, in contact with or close to the frame, as long as electromagnetic induction occurs. Furthermore, "a heater disposed on the bottom of the container" includes not only structures in which the heater is separate from the bottom of the container, but also structures in which the heater also serves as the bottom of the container.

[0019] Effects of the Invention

[0020] As described above, according to the present invention, it is possible to provide a liquid heating device capable of thoroughly cleaning the entire container.

[0021] The effects and significance of the present invention will become more apparent from the following description of the embodiments. However, the embodiments described below are merely examples of implementing the present invention, and the present invention is not limited to the contents described in the following embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 (a) is a perspective view of the electric water heater of the first embodiment, Figure 1 (b) is a plan view of the container of the first embodiment.

[0023] Figure 2 It is a cross-sectional view of the electric water heater according to the first embodiment.

[0024] Figure 3 This is a block diagram showing the structure of the base according to the first embodiment.

[0025] Figure 4 (a) is a perspective view of an electric water heater according to a second embodiment. Figure 4 (b) is a plan view of the container of the second embodiment.

[0026] Figure 5 It is a cross-sectional view of the electric water heater according to the second embodiment.

[0027] Figure 6 (a) and Figure 6 (b) are a cross-sectional view of a container with a lid and a top view of the container, respectively, showing a threaded fixing structure according to a modified example.

[0028] Figure 7 (a) and Figure 7 (b) are a cross-sectional view and a top view of a container with a lid showing a modified example of an embedded fixing structure.

[0029] Figure 8 (a) and Figure 8 (b) is a cross-sectional view of a container with a lid according to a modified example.

[0030] Figure 9 (a) and Figure 9 (b) is a cross-sectional view of a container with a lid according to a modified example.

[0031] Figure 10 (a) is a cross-sectional view of the bottom of a container according to a modified example. Figure 10 (b) to Figure 10 (d) is a top view of a heating element according to a modified example.

[0032] Figure 11 (a) and (b) are respectively a perspective view and a cross-sectional view of a container with a lid according to a modified example.

[0033] However, the drawings are only used to illustrate the present invention and are not intended to limit the scope of the present invention. DETAILED DESCRIPTION

[0034] Hereinafter, an electric water heater according to an embodiment of the liquid heating device of the present invention will be described with reference to the drawings.

[0035] <First embodiment>

[0036] Figure 1 (a) is a perspective view of the electric water heater 1 according to the first embodiment. Figure 1 (b) is a plan view of the container 100 according to the first embodiment. Figure 2 It is a cross-sectional view of the electric water heater 1 according to the first embodiment. Figure 3 3 is a block diagram showing the structure of the base 300 of the first embodiment. Figure 2 , for convenience, the temperature detector 330 is not drawn in cross section.

[0037] The electric water heater 1 includes a container 100 storing water (liquid to be heated), a cover 200 for closing a water supply port 103 of the container 100 , and a base 300 for placing the container 100 .

[0038] Container 100 is formed, for example, from glass, particularly heat-resistant glass, and includes a circular bottom portion 101 and a cylindrical peripheral portion 102, the top surface of which is open to form a water supply port 103. Peripheral portion 102 has a tapered shape and gradually widens upward. A ring-shaped handle 104 is formed on the rear side of peripheral portion 102, and a water inlet 105 for pouring water from container 100 is formed at the front upper end. It should be noted that container 100 can be formed from materials other than glass, such as ceramics or resin, preferably heat-resistant materials.

[0039] A heater 110 is provided at the bottom of container 100 for heating the water within container 100. Heater 110 is formed, for example, of stainless steel and has a disc-like shape, including an upper surface 111 and a lower surface 112 parallel to (facing away from) upper surface 111. Heater 110 is supported slightly away from bottom portion 101 of container 100 by cylindrical supports 120 integrally formed with heater 110. Thus, when water is stored within container 100, both upper surface 111 and lower surface 112 of heater 110 are in contact with the water.

[0040] The center of the heating body 110 coincides with the center of the bottom portion 101. The diameter of the heating body 110 is smaller than the inner diameter of the container 100, and a gap is provided between the heating body 110 and the peripheral portion 102. When water is added to the container 100, the water flows into the lower side of the heating body 110 through this gap.

[0041] The heating element 110 is fixed to the bottom portion 101 of the container 100 in a manner that allows the user to remove it without using tools such as a screwdriver, that is, to attach and detach it by the user. In this embodiment, a fixing structure using a magnet 130 is adopted. Specifically, a flat cylindrical magnet 130 is mounted in the center of the bottom portion 101. The upper side of the magnet 130 protrudes from the bottom portion 101, and the protruding portion of the magnet 130 is embedded in a recess 121 formed on the lower surface of the support 120. Due to the magnetic force of the magnet 130, the heating element 110 is fixed so that it does not detach upward from the bottom portion 101. A cylindrical grip 140 is formed in the center of the upper surface of the heating element 110. The user can pinch this grip 140 to lift the heating element 110 with a force greater than the magnetic force of the magnet 130, thereby removing the heating element 110 from the container 100. This makes it easy to clean the lower surface 112 of the heating element 110 and the inner surface of the bottom portion 101 of the container 100 .

[0042] When the fixing structure using the magnet 130 is adopted as described above, the heating body 110 is made of ferritic or martensitic stainless steel that can attract the magnet 130 .

[0043] It should be noted that the heating body 110 may be formed of a metal material other than stainless steel that is excellent in electrical conductivity and corrosion resistance.

[0044] The lid 200 is formed, for example, from glass, particularly heat-resistant glass, and has a disc-like shape. Its circumferential surface has a tapered shape corresponding to the tapered shape of the circumferential surface portion 102 of the container 100. The upper surface of the lid 200, except for the outer periphery, is curved and concave. A handle 202 is formed in the center of the concave portion 201. It should be noted that the lid 200 can also be formed from materials other than glass, such as resin, particularly heat-resistant resin. The lid 200 can be removed upward from the water supply port 103 of the container 100, thereby opening the water supply port 103.

[0045] The base 300 includes a housing 310 , a heating coil 320 housed in the housing 310 , and a temperature detector 330 .

[0046] The frame 310 is composed of a shell 311 that is flat in the vertical direction and has a roughly rectangular parallelepiped shape with an open upper surface, and a top plate, i.e., a cover 312, that covers the upper surface of the shell 311. The frame 310, i.e., the shell 311 and the cover 312, are formed of, for example, glass. A circular mark 313 is depicted on the upper surface of the frame 310, which serves as the loading surface. This mark 313 serves as a marking portion to indicate the position of the container 100 when it is placed on the base 300, i.e., on the frame 310. The diameter of the mark 313 is roughly the same as (slightly larger than) the diameter of the bottom portion 101 of the container 100. The container 100 is placed corresponding to the mark 313. In addition, a circular recess that is slightly recessed from the upper surface can be formed on the upper surface of the frame 310 as a marking portion instead of the mark 313. It should be noted that the frame 310 does not have to be roughly rectangular, for example, it can also be roughly cylindrical.

[0047] The heating coil 320 is formed into a circular plate shape by a spirally wound coil. The heating coil 320 is arranged in the housing 310 close to the cover 312 so that its center is at the center of the cover 312. The heating coil 320 is attached to the back of the cover 312 via, for example, an unillustrated mounting member.

[0048] The center of the heating coil 320 coincides with the center of the mark 313, that is, the center of the upper surface of the frame 310. Therefore, when the container 100 is placed at the center of the upper surface of the frame 310 so as to correspond to the mark 313, the center of the heating coil 320 coincides with the center of the heating element 110. Here, the diameter of the heating element 110 is set larger than the diameter of the heating coil 320. Therefore, even if the container 100 is placed slightly off-center from the center of the upper surface of the frame 310, the heating coil 320 can be positioned within the area of ​​the heating element 110, thereby achieving stable induction heating efficiency.

[0049] In addition, when the container 100 is placed on the base 300, the heating body 110 and the heating coil 320 are in a parallel state. That is, when the heating body 110 and the heating coil 320 are viewed from the direction in which they are arranged (the up and down direction), the distance at any position is constant. As a result, the heating efficiency of the heating body 110 as a whole can be stabilized. It should be noted that, for example, when the inner surface of the bottom portion 101 of the container 100 is concavely curved and the heating plate 110 is set to a concave plate shape corresponding thereto, the heating coil 320 is also set to a concave annular plate shape in such a way that the distance at any position when viewed from the up and down direction is constant. That is, no matter what shape the heating plate 110 has, it is preferred that the heating coil 320 has a shape in which the distance at any position when viewed from the direction in which the heating plate 110 and the heating coil 320 are arranged is constant.

[0050] The temperature detector 330 is mounted at the center of the back surface of the cover 312. The temperature detector 330 includes a thermistor, and indirectly detects the temperature of the water (hot water) stored in the container 100 via the bottom portion 101 of the container 100 and the cover 312, and outputs a detection signal (voltage signal) corresponding to the temperature of the water in the container 100.

[0051] like Figure 3 As shown, the base 300 includes an operation switch 340 , a control unit 350 , and an inverter 360 in addition to the heating coil 320 and the temperature detector 330 .

[0052] The operating switch 340 is located, for example, on the side of the housing 310 and is operated to start the water heating operation. The control unit 350, which includes a microcomputer, controls the power supply to the heating coil 320 based on the operating signal from the operating switch 340 and the detection signal from the temperature detector 330. The inverter 360 supplies a high-frequency current (high-frequency alternating current) to the heating coil 320 in response to the control signal from the control unit 350. For example, the frequency of the alternating current can be selected from a range of 20 kHz to 90 kHz.

[0053] Next, the operation of the electric water heater 1 will be described based on the above-described configuration.

[0054] The user places the container 100 containing water on the base 300, i.e., the upper surface of the frame 310, and operates the operation switch 340. Upon receiving the operation signal from the operation switch 340, the control unit 350 starts the water boiling operation. That is, the control unit 350 drives the inverter 360, and supplies high-frequency current from the inverter 360 to the heating coil 320. Through the electromagnetic induction from the heating coil 320, eddy currents are generated in the heating body 110 in the container 100, and the heating body 110 generates heat. As a result, the water in the container 100 is heated. At this time, since the heating body 110 is in contact with the water, the heat of the heating body 110 is directly transferred to the water, and the heating efficiency of the water is improved. In particular, since both the upper surface 111 and the lower surface 112 of the heating body 110 are in contact with the water, the heat of the heating body 110 is effectively transferred to the water. Therefore, the heating efficiency of the water is further improved.

[0055] When the temperature of the water in container 100 rises, bubbles form locally on upper surface 111 and lower surface 112 of heater 110 due to the evaporation of the water. In heater 110, lower surface 112 generates more heat than upper surface 111, so bubbles are more likely to form on lower surface 112. Bubbles formed on upper surface 111 of heater 110 rise directly. Meanwhile, bubbles formed on lower surface 112 of heater 110 rise through the gap between heater 110 and peripheral surface 102 of container 100, escaping from between heater 110 and bottom surface 101 of container 100.

[0056] When the water in container 100 boils, i.e., the hot water boils, and the temperature of the water in container 100 reaches the boiling temperature, temperature detector 330 detects the temperature of cover 312, which is related to the boiling temperature, and outputs a detection signal corresponding to the temperature of cover 312, i.e., the boiling temperature, to control unit 350. Upon receiving this detection signal, control unit 350 stops driving inverter 360, thereby stopping the power supply to heating coil 320. This stops heating the water by heater 110.

[0057] In this way, the water boiling operation is completed. The user separates the container 100 from the base 300 and uses the hot water in the container 100.

[0058] <Effects of the First Embodiment>

[0059] According to this embodiment, the following effects can be achieved.

[0060] The electric water heater 1 utilizes electromagnetic induction from a heating coil 320 housed in a frame 310 to generate heat from a heating element 110 disposed at the bottom of a container 100, thereby heating the water within the container 100. Therefore, there is no portion outside the container 100 electrically connected to the frame 310, allowing the entire container 100 to be thoroughly rinsed.

[0061] Furthermore, since the heater 110 is configured to be in contact with the water stored in the container 100 , the heat of the heater 110 is directly transferred to the water, thereby improving the heating efficiency of the water.

[0062] Furthermore, since the heater 110 is configured so that both the upper surface 111 and the lower surface 112 are in contact with the water, the heat of the heater 110 is efficiently transferred to the water. Therefore, the heating efficiency of the water by the heater 110 is further improved.

[0063] <Second embodiment>

[0064] Figure 4 (a) is a perspective view of an electric water heater 2 according to a second embodiment. Figure 4 (b) is a plan view of the container 500 according to the second embodiment. Figure 5 It is a cross-sectional view of the electric water heater 2 of the second embodiment. Figure 5 , for convenience, the temperature detector 730 is not drawn in cross section.

[0065] The electric water heater 2 includes a container 500 storing water (liquid to be heated), a cover 600 closing a water supply port 503 of the container 500 , and a base 700 for placing the container 500 .

[0066] Container 500 is formed of, for example, glass, particularly heat-resistant glass, and includes a circular bottom portion 501 and a cylindrical peripheral portion 502. The top surface is open to form a water supply port 503. Container 500 may also be formed of materials other than glass, such as ceramics or resin, preferably having heat resistance.

[0067] A heater 510 is provided at the bottom of the container 500 for heating the water in the container 500. The heater 510 is formed, for example, of stainless steel and has a cylindrical shape, including an inner peripheral surface 511 and an outer peripheral surface 512 parallel to the inner peripheral surface 511. The outer peripheral surface 512 faces the peripheral surface 502 of the container 500. The heater 510 is so high that its upper end reaches the center of the container 500.

[0068] The heater 510 can be fixed to the container 500 by screwing, bonding, or other fixing methods. Like the heater 110 of the first embodiment, the heater 510 is detachably configured so that the user can remove it without using tools such as a screwdriver.

[0069] The outer diameter of the heater 510 is smaller than the inner diameter of the container 500, and a gap is formed between the outer peripheral surface 512 of the heater 510 and the peripheral surface 502 of the container 500. Therefore, when water is stored in the container 500, both the inner peripheral surface 511 and the outer peripheral surface 512 of the heater 510 are in contact with the water.

[0070] It should be noted that the heating body 510 may be formed of a metal material other than stainless steel that has excellent electrical conductivity and corrosion resistance.

[0071] The cover 600 is formed of glass, especially heat-resistant glass, and has a disc shape. The upper surface of the cover 600 is concave in a curved shape except for the outer periphery, and a handle 602 is formed in the center of the concave portion 601. It should be noted that the cover 600 can also be formed of materials other than glass, such as resin, especially heat-resistant resin. Figure 8 Although not shown in the figure, in order to keep the cover 600 on the upper end of the container 500 , an annular bulging portion that slightly bulges inward to support the cover 600 is provided on the peripheral surface portion 502 of the container 500 .

[0072] The base 700 includes a housing 710 , a heating coil 720 housed in the housing 710 , and a temperature detector 730 .

[0073] The housing 710 is formed of, for example, resin and has a hollow cylindrical shape with a bottom. The container 500 is housed in a recess 711 of the housing 710 and is placed on the bottom surface of the recess 711 .

[0074] The heating coil 720 is composed of a coil wound into a cylindrical shape and is arranged within the frame 710 so as to surround the recess 711. When the container 500 is placed on the base 700, that is, on the frame 710, the heater 510 and the heating coil 720 face each other with the peripheral surface 502 of the container 500 interposed therebetween. It should be noted that the length (the vertical dimension) of the heater 510 is greater than the length (the vertical dimension) of the heating coil 720.

[0075] The temperature detector 730 is located in the storage space at the bottom of the housing 710 and is mounted at the center of the surface opposite to the bottom surface of the recess 711. The temperature detector 730 is the same as the temperature detector 330 of the first embodiment.

[0076] Furthermore, if Figure 3 As shown, the base 700 has an operating switch 340, a control unit 350, and an inverter 360, similar to the base 300 of the first embodiment. The operating switch 340 can be provided on the outer peripheral surface of the housing 710, and the control unit 350 and the inverter 360 can be arranged in the storage space at the bottom of the housing 710, similar to the temperature detector 730.

[0077] The electric water heater 2 of this embodiment can also perform the same water boiling operation as the electric water heater 1 of the first embodiment.

[0078] During the water heating operation, when high-frequency current is supplied to the heating coil 720, electromagnetic induction from the heating coil 720 generates heat in the heating element 510 within the container 500. This heats the water within the container 500. Since the heating element 510 is in contact with the water, heat from the heating element 510 is directly transferred to the water, improving water heating efficiency. In particular, since both the inner circumferential surface 511 and the outer circumferential surface 512 of the heating element 510 are in contact with the water, heat from the heating element 510 is efficiently transferred to the water, further improving water heating efficiency.

[0079] <Effects of the Second Embodiment>

[0080] According to this embodiment, the same effects as those of the above-mentioned first embodiment can be achieved.

[0081] Modifications

[0082] Although the embodiments of the present invention have been described above, the present invention is not limited to the first and second embodiments described above, and various modifications can be made to application examples of the present invention in addition to the above embodiments.

[0083] For example, in the first embodiment, a fixing structure using magnets 130 is used to detachably fix the heating element 110 to the bottom portion 101 of the container 100. However, the fixing structure of the heating element 110 is not limited to the above structure. For example, the following structure may be used. Figure 6 (a) Figure 6 (b) and Figure 7 (a) Figure 7 (b) shows the fixing structure of the heating body 110.

[0084] Figure 6 (a) and Figure 6 (b) are a cross-sectional view of the container 100 with the cap 200 and a top view of the container 100, respectively, showing a threaded fixing structure according to a modification example.

[0085] In this variation, container 100 includes a fixture 150 for securing heating element 110. Fixing 150 is made of metal, resin, or the like and comprises a cylindrical grip 151 and a threaded portion 152 provided at the center of the lower surface of grip 151. Threaded portion 152 is formed as an external thread.

[0086] The support column 120 supporting the heater 110 is formed integrally with the bottom portion 101 of the container 100. A screw hole 122 having an internal thread is provided on the upper surface of the support column 120. A through hole 113 is formed in the center of the heater 110.

[0087] The threaded portion 152 of the fixing member 150 passing through the through hole 113 is fastened to the threaded hole 122 of the support 120, thereby fixing the heating element 110 to the support 120, that is, fixing the heating element 110 to the container 100. When attaching or detaching the heating element 110 to or from the container 100, the user can tighten or loosen the threaded portion 152 by pinching the gripping portion 151 of the fixing member 150, making it easy to attach or detach the heating element 110 without using tools such as a screwdriver.

[0088] Figure 7 (a) and Figure 7 (b) is a cross-sectional view of the container 100 with the lid 200 and a top view of the container 100, respectively showing a modified example of the embedded fixing structure.

[0089] In this variation, a fixing member 160 is attached to the center of the heater 110. Fixing member 160 comprises a cylindrical gripping portion 161 and an inserting portion 162 disposed below gripping portion 161. The heater 110 is held and fixed between gripping portion 161 and inserting portion 162. Inserting portion 162 has a circular, T-shaped inserting recess 163 with a smaller diameter at the entrance than at the interior.

[0090] The support column 120 that supports the heating element 110 is formed integrally with the bottom portion 101 of the container 100 . The support column 120 has a cylindrical shape with a T-shaped cross section so as to correspond to the fitting recess 163 of the fitting portion 162 .

[0091] By fitting the support 120 into the recessed portion 163 of the inserting portion 162 of the fixing member 160, the heater 110 is secured to the support 120, that is, to the container 100. The inserting portion 162 is formed from an elastic material such as rubber, and the entrance of the recessed portion 163 expands due to elasticity during installation or removal from the support 120. Therefore, the user can attach or detach the inserting portion 162 to or from the support 120 by gripping the gripping portion 161 of the fixing member 160, making it easy to attach and detach the heater 110 without using tools such as screwdrivers.

[0092] Furthermore, in the first embodiment described above, the heater 110 is arranged so as to float from the bottom portion 101 of the container 100, with both the upper surface 111 and the lower surface 112 of the heater 110 in contact with the water stored in the container 100. However, the arrangement of the heater 110 in the bottom portion of the container 100 is not limited to the above-described configuration.

[0093] For example, Figure 8 (a) and Figure 8 As shown in (b), a structure may be adopted in which only the upper surface 111 of the two surfaces of the heating element 110 is in contact with the water in the container 100.

[0094] exist Figure 8 In the modified example (a), the heater 110 is insert-molded inside the bottom portion 101 of the container 100. A circular opening 106 is formed in the bottom portion 101. This opening 106 exposes the upper surface 111 of the heater 110, excluding its outer peripheral edge, to the interior of the container 100. As a result, most of the upper surface of the heater 110 is in contact with the water stored in the container 100.

[0095] The electric water heater 1 has a structure in which heating element 110 generates heat downward through induction heating by heating coil 320. Since no heater is mounted on lower surface 112 of heating element 110, there is no opening or the like on bottom portion 101 that exposes lower surface 112 to the outside of heating element 110. Therefore, bottom portion 101 is completely closed. Therefore, there is no need for a water seal between heating element 110 and bottom portion 101, and the structure of container 100 is less complicated.

[0096] exist Figure 8 In the modified example (b), in the container 100, the heater 110 is arranged on the bottom portion 101 so that its lower surface 112 contacts the bottom portion 101. For example, the container 100 is provided with an annular claw 107 on the bottom, and the heater 110 is fixed to the bottom portion 101 by being pressed by the claw 107. Almost the entire upper surface 111 of the heater 110, excluding the portion that engages with the claw 107, contacts the water stored in the container 100. In this structure, the container 100 is preferably formed of a resin so that the claw 107 can easily elastically deform when the heater 110 is attached to the bottom portion 101 of the container 100.

[0097] Alternatively, you can use Figure 9 (a) shows the arrangement structure of the heating element 110 as Figure 8 (a) and Figure 8 The modification example (b) is similarly configured such that one surface of the heating element 110 is in contact with water.

[0098] exist Figure 9 In the modified example (a), the bottom of the container 100 is formed of a metal material capable of induction heating, such as stainless steel, and serves as the heating body 110. That is, the heating body 110 is not provided separately from the bottom of the container 100, but serves as the bottom of the container 100. For example, Figure 9As shown in (a), the heater 110 includes a bottom portion 110a and a peripheral portion 110b that rises from the bottom portion 110a and is joined to the peripheral portion 102 of the container 100. The upper surface of the bottom portion 110a and the inner peripheral surface of the peripheral portion 110b of the heater 110 are in contact with the water stored in the container 100. It should be noted that the heater 110 may also be constructed with only the bottom portion.

[0099] Even in the above Figure 8 (a) Figure 8 (b) and Figure 9 In the structure of (a), since the heat of the heating body 110 is directly transferred to the water, the heating efficiency of the water is improved.

[0100] Furthermore, as described above, instead of adopting a structure in which at least one surface of the heating body 110 contacts the water in the container 100, a structure in which Figure 9 In the structure shown in (b), the heater 110 is completely embedded in the bottom portion 101 of the container 100 by insert molding, and the heater 110 is not exposed in the container 100 and does not come into contact with water.

[0101] Furthermore, in the container 500 of the second embodiment, the following structure may be adopted: Figure 8 (a) and Figure 8 (b) is a structure similar to that of the structure in which the heating element 510 is arranged so that only the inner peripheral surface 511 is exposed inside the container 500 so that the outer peripheral surface 512 contacts the peripheral surface 502, or the outer peripheral surface 512 is buried in the peripheral surface 502; Figure 9 (a) is the same structure as that shown, in which the heating element 510 is also used as the bottom of the container 500; and Figure 9 The structure shown in (b) is similar to the structure in that the heater 510 is embedded in the peripheral surface portion 502 of the container 500 and is not exposed inside the container 500.

[0102] Furthermore, in the first embodiment, when the water in the container 100 is heated, the bubbles generated on the lower surface 112 of the heating body 110 escape upward from the heating body 110 through the gap between the heating body 110 and the peripheral surface 102 of the container 100. However, a method such as Figure 10 (a) to Figure 10 As shown in (d), bubbles generated on the lower surface 112 side of the heater 110 are easily released from between the bottom surface 101 and the heater 110 .

[0103] Figure 10 (a) is a cross-sectional view of the bottom of a container 100 according to a modified example. Figure 10 (b) is a top view of the heating element 110 of the modified example. Figure 10 In (b), for convenience, the position of the heating coil 320 is indicated by a single-dot chain line.

[0104] In this modification, a plurality of circular holes 114 are formed along the circumferential direction in the central portion of the heating body 110. There is no heating coil 320 directly below the center of the plurality of holes 114. In this structure, as shown in FIG. Figure 10 As shown in (a), the bubbles generated on the lower surface 112 side of the heating body 110 not only pass through the gap between the heating body 110 and the peripheral surface 102 of the container 100, but also pass through the multiple holes 114, thereby escaping from between the bottom surface 101 and the heating body 110 to the top of the heating body 110. Therefore, since bubbles are not easily retained between the bottom surface 101 and the heating body 110, it is difficult for bubbles to hinder the contact between the heating body 110 and the water, and the heating efficiency of the water by the heating body 110 is improved. Moreover, the multiple holes 114 are formed in the central part of the heating body 110. Since the heating coil 320 is in the shape of an annular plate, the central part is not easy to generate eddy current due to electromagnetic induction from the heating coil 320. Therefore, the reduction in the heating efficiency of the heating body 110 caused by the formation of the multiple holes 114 can be suppressed.

[0105] Figure 10 (c) and Figure 10 (d) is a top view showing another structure of the heating element 110 of the modified example. Figure 10 (c) and Figure 10 In (d), for convenience, the position of the heating coil 320 is indicated by a single-dot chain line.

[0106] The outer periphery of the heating element 110 is less likely to generate eddy current due to electromagnetic induction from the heating coil 320, and is less likely to generate heat. Figure 10 As shown in (c), a plurality of circular holes 115 may be formed along the circumferential direction on the outer periphery of the heating body 110. Figure 10 As shown in (d), a plurality of circular holes 114 and 115 may be formed in both the central portion and the outer periphery of the heater 110. This structure makes it difficult for bubbles to remain between the bottom portion 101 and the heater 110, thereby improving the heating efficiency of the heater 110 for water.

[0107] It should be noted that, in the above example, the plurality of holes 114, 115 are formed in one row in the radial direction, but may be formed in two or more rows in the radial direction. In this case, the diameter of the holes 114, 115 is smaller than in the above example.

[0108] Furthermore, you can also use Figure 11 The container 100A shown here replaces the container 100 of the first embodiment described above.

[0109] Figure 11 (a) and Figure 11 (b) are a perspective view and a cross-sectional view of a container 100A with a lid 200 according to a modified example.

[0110] Container 100A has a double-wall structure. Bottom portion 101 is composed of an inner wall portion 101a (hereinafter referred to as inner bottom wall 101a) and an outer wall portion 101b (hereinafter referred to as outer bottom wall 101b). Peripheral portion 102 is composed of an inner wall portion 102a (hereinafter referred to as inner peripheral wall 102a) and an outer wall portion 102b (hereinafter referred to as outer peripheral wall 102b). Gaps are formed between inner bottom wall 101a and outer bottom wall 101b, and between inner peripheral wall 102a and outer peripheral wall 102b, enclosing an air layer. The remaining structure of container 100A is the same as that of container 100 of the first embodiment. It should be noted that in container 100A, a heat insulating material may be added to the gaps between inner bottom wall 101a and outer bottom wall 101b, and between inner peripheral wall 102a and outer peripheral wall 102b, to form a heat insulating layer to enhance the heat insulation effect between these walls. Alternatively, the heat insulating layer may be formed by evacuating the gaps between inner bottom wall 101a and outer bottom wall 101b, and between inner peripheral wall 102a and outer peripheral wall 102b, or by forming an air layer having a pressure lower than atmospheric pressure in the gaps.

[0111] When the container 100A is used, when the water in the container 100A is heated, the heat is less likely to be transferred to the outer surface of the container 100A, and the outer surface is less likely to be heated.

[0112] It should be noted that since heat is less likely to be transferred to the outer bottom surface of container 100A, cover 312 of frame 310 is less likely to reach a high temperature. Therefore, cover 312 can be formed from a resin, which is generally less heat-resistant than glass. When cover 312 is made of resin, costs can be reduced, weight can be reduced, and shapes can be diversified.

[0113] Furthermore, in the second embodiment described above, the base 700 is formed into a hollow, bottomed cylindrical shape, with the temperature detector 730, the control unit 350, and the inverter 360 disposed in the storage space at the bottom. However, a configuration may also be employed in which the base 700 comprises a bottomless, hollow cylindrical portion and a storage portion disposed adjacent to the cylindrical portion, the heating coil 720 being disposed in the cylindrical portion, and the control unit 350 and the inverter 360 being disposed in the storage portion. In this case, when the electric water heater 2 is placed in a kitchen or the like, the container 500 is not placed on the base 700 but is disposed inside the cylindrical portion of the base 700.

[0114] Furthermore, in the first and second embodiments, the electric water heaters 1 and 2 have the function of boiling water. However, the electric water heaters 1 and 2 may have the function of keeping the boiled water warm in addition to boiling water.

[0115] Furthermore, in the first and second embodiments described above, the liquid heating device of the present invention is applied to electric water heaters 1 and 2. However, the present invention can be applied to liquid heating devices that heat liquid stored in a container, in addition to electric water heaters that heat liquid stored in a container. For example, it can be applied to a coffee machine that can keep coffee in a container warm after it is brewed. Furthermore, the liquid heating device to which the present invention is applied can also have a heat-keeping function without a hot water function.

[0116] In addition, various modifications can be made to the embodiments of the present invention as appropriate within the scope of the claims.

[0117] Description of Reference Numerals

[0118] 1 Electric water heater (liquid heating device)

[0119] 2 Electric water heaters (liquid heating devices)

[0120] 100 containers

[0121] 100A container

[0122] 101a inner wall

[0123] 101b outer wall

[0124] 102a inner wall

[0125] 102b outer wall

[0126] 110 heating element

[0127] 111 upper surface (first surface)

[0128] 112 lower surface (second surface)

[0129] 310 frame

[0130] 320 heating coil

[0131] 350 Control Department

Claims

1. A liquid heating device, characterized in that: have: The heating coil is passed through with a high-frequency current; A frame body, accommodating the heating coil; a container, which can be disposed on the frame and store liquid; and A heating body is arranged at the bottom of the container and heats the liquid in the container. The heating coil has a circular plate shape with an opening in the center of the heating coil. The heating body has a disk shape and includes an upper surface and a lower surface parallel to the upper surface. The heating body is arranged away from the bottom portion of the container so that both the upper surface and the lower surface are in contact with the liquid in the container. When the container is placed in the frame, the heating element generates heat by electromagnetic induction from the heating coil. The heating body is formed with a plurality of holes for the bubbles generated on the lower surface side to pass through, The plurality of holes are formed only in the central portion of the heating body which overlaps with the central portion of the heating coil when viewed from the top and bottom directions. The heating coil does not exist directly below the center of each of the plurality of holes.

2. A liquid heating device, characterized in that: have: The heating coil is passed through with a high-frequency current; A frame body, accommodating the heating coil; a container, which can be disposed on the frame and store liquid; and A heating body is arranged at the bottom of the container and heats the liquid in the container. The heating coil has a circular plate shape with an opening in the center of the heating coil. The heating body has a disk shape and includes an upper surface and a lower surface parallel to the upper surface. The heating body is arranged away from the bottom portion of the container so that both the upper surface and the lower surface are in contact with the liquid in the container. When the container is placed in the frame, the heating element generates heat by electromagnetic induction from the heating coil. The heating body is formed with a plurality of holes for the bubbles generated on the lower surface side to pass through, The plurality of holes are formed only in the outer peripheral portion of the heating body that overlaps with the outer peripheral portion of the heating coil when viewed from the top and bottom directions.

3. A liquid heating device, characterized in that: have: The heating coil is passed through with a high-frequency current; A frame body, accommodating the heating coil; a container, which can be disposed on the frame and store liquid; and A heating body is arranged at the bottom of the container and heats the liquid in the container. The heating coil has a circular plate shape with an opening in the center of the heating coil. The heating body has a disk shape and includes an upper surface and a lower surface parallel to the upper surface. The heating body is arranged away from the bottom portion of the container so that both the upper surface and the lower surface are in contact with the liquid in the container. When the container is placed in the frame, the heating element generates heat by electromagnetic induction from the heating coil. The heating body is formed with a plurality of holes for the bubbles generated on the lower surface side to pass through, The plurality of holes are formed only in the central portion and the outer peripheral portion of the heating body which overlap with the central portion and the outer peripheral portion of the heating coil respectively when viewed from the top and bottom directions. The heating coil does not exist directly below the center of each of the plurality of holes in the central portion of the heating body.

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