KR-20260062918-A - INDUCTION HEATING TYPE COOKTOP

KR20260062918AKR 20260062918 AKR20260062918 AKR 20260062918AKR-20260062918-A

Abstract

The present disclosure relates to an induction heating type cooktop, comprising: a case; a cover plate coupled to the top of the case and having a top plate portion on which an object to be heated is placed on the top surface; a working coil provided inside the case; a thin film coated on the top plate portion; an insulating material that blocks heat transfer from the thin film to the working coil; and a temperature sensor that detects the temperature of the thin film, wherein at least one sensing hole may be formed in the insulating material for the temperature sensor to detect the temperature of the thin film.

Inventors

황성훈
김원태
김성준

Assignees

엘지전자 주식회사

Dates

Publication Date: 20260507
Application Date: 20260423

Claims (14)

In an induction heating cooktop, case; A cover plate coupled to the top of the above case, on which an object to be heated is placed on the upper surface; A thin film formed on the upper portion of the above cover plate; A working coil provided inside the above case for inductively heating at least one of the thin film or the object to be heated; An insulating material disposed between the thin film and the working coil to block heat transfer from the thin film to the working coil; and It includes a temperature sensor that detects the temperature of the above-mentioned thin film, At least one sensing hole is formed in the above insulating material for the temperature sensor to be positioned to detect the temperature of the thin film, and The above temperature sensor is positioned to detect the temperature of the thin film through the sensing hole. Induction heating cooktop.
In paragraph 1, The thickness of the above thin film is thinner than the skin depth of the above thin film Induction heating cooktop.
In paragraph 2, The thickness of the above thin film is within the range of 0.1 µm to 1,000 µm. Induction heating cooktop.
In paragraph 1, The above thin film is made of a conductive material having a surface resistance value inversely proportional to the thickness of the said thin film. Induction heating cooktop.
In paragraph 1, The above thin film is coated on the upper plate in a repeating pattern of multiple ring shapes having different diameters. Induction heating cooktop.
In paragraph 1, When a magnetic object to be heated is placed on the cover plate, the impedance of the object to be heated is formed to be smaller than the impedance of the thin film, so that most of the eddy current generated by the working coil is applied to the object to be heated. Induction heating cooktop.
In paragraph 1, When a non-magnetic object to be heated that does not possess magnetism is placed on the cover plate, an eddy current generated by the working coil is applied to the thin film, thereby directly heating the thin film. Induction heating cooktop.
In paragraph 1, It further includes an air guide disposed inside the above case to guide cooling air toward the working coil. Induction heating cooktop.
In paragraph 1, It further includes a bracket disposed between the insulation material and the working coil, A cooling channel is formed in the above bracket through which air flows to cool the above working coil. Induction heating cooktop.
In paragraph 1, The above working coil includes a plurality of windings wound spirally, and The sensing hole is positioned to overlap in the vertical direction with the spacing between two adjacent windings among the plurality of windings. Induction heating cooktop.
In paragraph 1, The above sensing holes are provided in multiple numbers so as to be spaced apart and distributed along the circumferential direction of the thin film with respect to the center of the working coil. Induction heating cooktop.
In Paragraph 11, The plurality of sensing holes are formed at different distances from the center of the working coil and are arranged to detect the temperature distribution along the radial direction of the thin film. Induction heating cooktop.
In paragraph 1, In the above insulation material, another sensing hole is further formed in which a temperature sensor for detecting the temperature of the upper plate is disposed. Induction heating cooktop.
In Paragraph 13, The sensing hole for detecting the temperature of the thin film overlaps the thin film in a vertical direction, and The other sensing hole for detecting the temperature of the upper plate is vertically overlapping with the area of the upper plate where the thin film is not formed. Induction heating cooktop.

Description

Induction Heating Type Cooktop The present disclosure relates to an induction heating type cooktop. Various types of cooking appliances are used to heat food in homes and restaurants. Traditionally, gas ranges using gas as fuel have been widely used; however, recently, devices that heat objects using electricity instead of gas—such as cooking vessels like pots—are becoming more popular. Methods of heating an object using electricity are broadly divided into resistance heating and induction heating. The electric resistance method heats an object by transferring heat generated when an electric current is passed through a metal resistance wire or a non-metallic heating element, such as silicon carbide, to the object (e.g., a cooking vessel) through radiation or conduction. The induction heating method, on the other hand, is a method in which an eddy current is generated in an object made of metal components by utilizing the magnetic field generated around a coil when high-frequency power of a predetermined magnitude is applied to the coil, thereby heating the object itself. Recently, induction heating methods are mostly applied to cooktops. However, in the case of a cooktop with an induction heating method, there is a limitation that it can only heat magnetic materials. That is, if a non-magnetic material (e.g., heat-resistant glass, ceramics, etc.) is placed on the cooktop, there is a problem that the cooktop with an induction heating method cannot heat the object to be heated. Accordingly, as an example of a method to overcome the limitations of conventional induction heating cooktops, a method was devised to add a heating plate capable of heating by induction between a cooktop and a non-magnetic material. Referring to Japanese Registered Patent Publication No. 5630495 (Oct. 17, 2014), a method of induction heating by adding a heating plate is disclosed. However, in the case of that method, since the heating plate does not heat up above a set temperature, there was a problem in that not only was the heating efficiency reduced, but the time required to heat the material contained in the object to be heated also increased significantly compared to the conventional method. As another example, referring to Japanese Registered Patent Publication No. 0644191 (November 10, 2006), a method is disclosed in which an electric conductor is installed to heat a workpiece made of a material having low permeability. However, in the case of this method, since the thickness of the electric conductor is formed to be greater than the skin depth of the electric conductor, the magnetic field generated by the coil does not reach the object being heated, and thus the magnetic object being heated cannot be directly inductively heated, which causes a problem of significantly reduced heating efficiency. Accordingly, there is a growing need to develop new technologies that can overcome the limitations of induction heating cooktops. Furthermore, the heating method implemented in the induction heating cooktop of the prior art has been implemented such that the heating plate and electric conductor are not heated above a certain temperature, or only in a manner where the container is directly induction heated, so due to its characteristics, there was no need to heat the object to be heated above any temperature (e.g., 300°C or higher). Meanwhile, to improve the aforementioned problem, if a thin film heated to a certain temperature or higher (e.g., about 600°C or higher) is provided on the top plate, the high temperature heat generated from the thin film may be transferred to other parts within the cooktop, such as the top plate on which the object to be heated is placed and the working coil, and the parts receiving this heat may malfunction or be damaged. In particular, in order to reduce the risk of damage to the top plate due to such high heat, temperature monitoring of the thin film installed on the top plate is required; however, the device described in the aforementioned Japanese Registered Patent Publication No. 0644191 (November 10, 2006) only presents a temperature sensor that detects the temperature of the top plate and a temperature sensing unit that detects the temperature of the inner circumference of the electrical conductor. That is, conventional devices have a problem in that they cannot directly detect the temperature of the thin film, which is heated to nearly 600°C. Furthermore, due to such high temperatures, if temperature sensors are installed around the top plate, the risk of damage to the sensors increases. Additionally, since insulation is provided beneath the top plate to minimize the transfer of heat generated from the thin film to the working coil, there is a problem of insufficient space to place additional temperature sensors. FIG. 1 is a perspective view showing an induction heating type cooktop according to one embodiment of the present disclosure. Figure 2 is a drawing showing the lower surface of the cover p