Heating film assembly, pot cover and cooking utensil

Abstract

The utility model discloses a heating film assembly, a pot cover and a cooking utensil, and relates to the technical field of household appliances, the heating film assembly is arranged on the pot cover of the cooking utensil and is used for heating the pot cover, the heating film assembly comprises a heating piece and a conductive structure, the heating piece is provided with an external connection part, the conductive structure is arranged on the external connection part and is electrically connected with the external connection part, and the conductive structure is electrically connected with the external connection part. The resistivity of the conductive structure is smaller than that of the external connection part. According to the heating film assembly, heating generated when the external connection part is powered on is reduced, the heat uniformity of the heating film assembly in the heating process is improved, and the safety and stability of the whole cooking utensil are improved.

Description

Technical Field

[0001] The utility model relates to the technical field of household appliances, in particular to a heating film component, a pot cover and a cooking utensil. Background Art

[0002] During the cooking process, the steam generated in the cooking utensils, such as rice cookers, will encounter the lower temperature area on the upper cover, which will inevitably produce condensation water. On the one hand, the condensation water will affect the electronic components in the rice cooker. On the other hand, the condensation water is also easy to fall into the pot when the rice cooker is opened, affecting the taste of the food.

[0003] The electric rice cooker in the related art provides a cover heating technology, such as setting a heating element on the cover to keep the temperature of the cover consistent with the temperature of the cooker body, thereby reducing condensation water. The use of the heating element requires input of an external power supply to achieve electrical heating, and the external parts have different resistivities due to different materials. Under the action of the external AC power supply, spark discharge and heat accumulation effects will occur in the external parts, posing a safety hazard. Utility Model Content

[0004] The main purpose of the utility model is to provide a heating film assembly, a pot cover and a cooking utensil, aiming to reduce the heat generated when the external parts are energized through the heating film assembly, improve the thermal uniformity when the heating film is heated, and enhance the safety and stability of the overall cooking utensil.

[0005] To achieve the above object, the utility model proposes a heating film assembly, which is arranged on a pot cover of a cooking utensil and is used to heat the pot cover. The heating film assembly comprises:

[0006] A heating element, wherein the heating element is provided with an external connection portion; and

[0007] A conductive structure is provided at the external connection portion and electrically connected to the external connection portion, and the resistivity of the conductive structure is lower than the resistivity of the external connection portion.

[0008] In one embodiment, the conductive structure includes at least two conductive layers stacked together, wherein one of the conductive layers is disposed at the external connection portion;

[0009] The resistivity of the conductive layer far from the external connection portion is smaller than the resistivity of the conductive layer disposed at the external connection portion, and the resistivity of the conductive layer disposed at the external connection portion is smaller than the resistivity of the external connection portion.

[0010] In one embodiment, the at least two stacked conductive layers include a first conductive layer and a second conductive layer, the first conductive layer is disposed on the external connection portion, and the second conductive layer is located on a surface of the first conductive layer away from the external connection portion;

[0011] The material of the first conductive layer is conductive silver paste, and the material of the second conductive layer is copper or aluminum.

[0012] In one embodiment, the stacking direction of the external connection part, the first conductive layer, and the second conductive layer is defined as the height direction;

[0013] Along the height direction, the thickness of the second conductive layer is less than the thickness of the first conductive layer, and the thickness of the first conductive layer is less than the thickness of the heating element.

[0014] In one embodiment, in the projection on the plane where the heating element is located, the projected area of the external connection part is larger than the projected area of the first conductive layer, and the projected area of the first conductive layer is larger than the projected area of the second conductive layer.

[0015] In one embodiment, the heating element includes a heating strip and two external connection parts. The two external connection parts are arranged at both ends of the heating strip. The heating film assembly includes two conductive structures, and one conductive structure is correspondingly arranged at one external connection part.

[0016] In one embodiment, a part of the heating strip connected to the external connection part extends linearly. The extending direction of the heating strip extending linearly is defined as the first direction, and the direction perpendicular to the first direction is defined as the second direction. In the first direction, the length of the external connection part is 1.7 times to 2 times the length of the first conductive layer. In the second direction, the lengths of the first conductive layer, the second conductive layer, and the external connection part are the same.

[0017] In one embodiment, the length of each external connection part along the second direction is 1 time to 3 times the width of the heating strip;

[0018] And / or, in the first direction, the length of the first conductive layer is 1.2 times to 1.5 times the length of the second conductive layer.

[0019] The present invention also provides a pot lid, which includes:

[0020] A lid body;

[0021] A heat-conducting substrate, which is arranged on the lid body; and

[0022] The heating film assembly as described above, and the heating film assembly is coated or attached to the surface of the heat-conducting substrate.

[0023] In one embodiment, the heat-conducting substrate is microcrystalline glass or borosilicate glass.

[0024] The present invention also provides a cooking appliance, which includes:

[0025] A pot body; and

[0026] As described above, the pot lid is connected to the pot body.

[0027] In the technical solution of the present utility model, the heating film assembly is provided on the pot lid of the cooking appliance and is used to heat the pot lid. By heating the pot lid through the heating film assembly, the temperature of the pot lid of the cooking appliance can be maintained, and the condensed water generated due to the temperature difference can be reduced. The heating film assembly includes a heating element and a conductive structure. The heating element is provided with an external connection part, and the conductive structure is arranged on the external connection part. Moreover, the conductive structure is electrically connected to both the external connection part and an external power supply at the same time, so as to transmit the current of the external power supply to the heating element through the conductive structure, realizing the energization and heating of the heating element. Among them, the resistivity of the conductive structure is less than that of the external connection part, making the resistance change smooth from the external power supply to the conductive structure and then to the external connection part, reducing the heat generated when the current flows due to too large a resistance difference, improving the thermal uniformity when the heating film assembly heats, and enhancing the safety and stability of the overall cooking appliance. Description of the Drawings

[0028] In order to more clearly illustrate the technical solutions in the embodiments of the present utility model or the prior art, the following will briefly introduce the drawings required to be used in the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present utility model. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on the structures shown in these drawings.

[0029] Figure 1 It is a schematic structural diagram of the heating film assembly in an embodiment of the present utility model;

[0030] Figure 2 It is a schematic structural diagram of the heating element and the conductive structure in an embodiment of the present utility model;

[0031] Figure 3 It is a schematic structural diagram of the heating film assembly from another perspective in an embodiment provided by the present utility model;

[0032] Figure 4 It is a schematic structural diagram of the cooking appliance in an embodiment of the present utility model.

[0033] Explanation of the Reference Numerals in the Drawings:

[0034] 100, heating film assembly; 1, heating element; 11, heating strip; 111, bending section; 112, joint section; 12, external connection part; 2, conductive structure; 21, first conductive layer; 22, second conductive layer; 3, heat-conducting substrate; 400, pot lid; 401, lid body; 500, cooking appliance; 501, pot body.

[0035] The realization, functional features and advantages of the present utility model will be further described in conjunction with the embodiments with reference to the accompanying drawings. Specific embodiments

[0036] Next, the technical solutions in the embodiments of the present utility model will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all embodiments. Based on the embodiments in the present utility model, all other embodiments obtained by those of ordinary skill in the art without making creative efforts belong to the scope of protection of the present utility model.

[0037] It should be noted that if there are directional indications (such as up, down, left, right, front, back...) involved in the embodiments of the present utility model, the directional indications are only used to explain the relative positional relationship and movement conditions between components in a specific posture. If the specific posture changes, the directional indications will also change accordingly.

[0038] In addition, if there are descriptions such as "first", "second", etc. involved in the embodiments of the present utility model, the descriptions of "first", "second", etc. are only for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one of such features. In addition, if "and / or" or "and / or" appears throughout the text, its meaning includes three parallel solutions. Taking "A and / or B" as an example, it includes solution A, solution B, or a solution where A and B are satisfied simultaneously. In addition, the technical solutions between the embodiments can be combined with each other, but it must be based on the fact that those of ordinary skill in the art can implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection required by the present utility model.

[0039] During the cooking process of the rice cooker, the steam generated in the pot body encounters the area with a lower temperature on the upper cover, and inevitably generates condensed water. On the one hand, the generated condensed water will affect the electronic components in the rice cooker. On the other hand, part of the condensed water will also remain attached to the cover body and is likely to fall into the pot when the rice cooker is opened, affecting the dining taste.

[0040] The rice cooker in the related art provides upper cover heating technology. For example, by setting a heating element on the upper cover to keep the temperature of the upper cover consistent with the temperature in the pot body, thereby reducing condensed water. However, the use of the heating element requires an external power supply to achieve electric heating. Due to the different resistivity of different materials in the external connection part, under the action of the external AC power supply, spark discharge and heat aggregation effects will occur in the external connection part, posing a safety hazard.

[0041] Based on this, please refer to Figures 1 to 4 To achieve the above object, the present utility model provides a heating film assembly 100, which is provided on the lid of a cooking appliance and is used to heat the lid. The heating film assembly 100 includes a heating element 1 and a conductive structure 2. The heating element 1 is provided with an external connection portion 12. The conductive structure 2 is provided on the external connection portion 12 and is electrically connected to the external connection portion 12. The resistivity of the conductive structure 2 is less than that of the external connection portion 12.

[0042] In this embodiment, as Figure 1 shown, the heating film assembly 100 is provided in the upper cover (lid 400) of a cooking appliance 500, such as the lid or upper cover of an electric rice cooker, an electric pressure cooker, a steaming pot, an electric kettle, etc. The heating film assembly 100 is a film structure, which is coated or adhered to a heat-conducting substrate 3 made of a glass substrate. The material of the heating element 1 can be made of a heat-generating material such as graphene or metal. The lid 400 is provided with the heat-conducting substrate 3. The heating element 1 is usually attached to the surface of the heat-conducting substrate 3. When the upper cover covers the cooking cavity of the cooking appliance 500, the heat-conducting substrate 3 is in direct contact with the cooking cavity. The heating element 1 is provided on the side of the heat-conducting substrate 3 facing away from the cooking cavity. During the cooking process, the cooking appliance 500 can control the heating element 1 on the upper cover (lid 400) to be powered on and generate heat. At this time, the heat generated by the heating element 1 can be conducted to the heat-conducting substrate 3. By controlling the operating power of the heating element 1, the temperature of the heat-conducting substrate 3 can be kept consistent with the temperature of the cooking cavity of the pot body, which can prevent the water vapor in the pot body from spreading to the lid 400 and forming condensed water on the lid 400, and avoid condensed water droplets falling into the cooking cavity when the lid 400 is opened, so that the cooked food can have a better taste.

[0043] In this embodiment, as Figures 1 to 3 shown, the heating element 1 is provided with an external connection portion 12. The external connection portion 12 is used to connect to the conductive structure 2 and electrically connect the conductive structure 2 to the heating element 1. At the same time, the conductive structure 2 is also electrically connected to an external power source, so that the external power source inputs current to the external connection portion 12 through the conductive structure 2, and the heating element 1 is powered on and generates heat. The conductive structure 2 can be one or more of a conductive contact piece, a conductive coating, a conductive wiring terminal, a conductive connector, and a conductive solder. The conductive structure 2 can be a layered conductive structure 2 formed by including at least one layer of conductive coating and / or at least one layer of conductive contact piece, or a connector structure soldered to the heating element 1 and further electrically connected to the external power source through the connector, which is not limited herein.

[0044] It can be understood that the material of the heat-conducting substrate 3 is usually high-borosilicate glass. The heating film assembly 100 is integrally disposed on the surface of the heat-conducting substrate 3 by means of coating or laminating. For the glass of high-borosilicate material, its high-temperature resistance is poor. When the heating film assembly 100 is heated and the heat is transferred to the surface of the heat-conducting substrate 3, due to the different resistivity at the joint with the external circuit, local heat accumulation effect may occur, which is extremely likely to cause the local part of the high-borosilicate glass heat-conducting substrate 3 to crack due to high temperature. Based on this, the present application provides the above-mentioned conductive structure 2.

[0045] It can be understood that the conductive structure 2 is used to connect the external power supply and the heating element 1. The conductive structure 2 makes the resistance values between the external connection part 12, the conductive structure 2, and the wire of the external power supply lead form a stepped distribution and gradually decrease. Therefore, when the current flows from the external power supply lead through the conductive structure 2 to the external connection part 12, it will not generate excessive heat and temperature rise due to the too large resistance difference between the two connected circuit connection structures, effectively reducing the heat generation when the connection is energized, and avoiding the possible micro-spark discharge phenomenon, improving the safety and stability of the heating film assembly 100 and the overall cooking appliance 500.

[0046] In the technical solution of the present application, the heating film assembly 100 includes a heating element 1 and a conductive structure 2. The heating element 1 is provided with an external connection part 12. The conductive structure 2 is disposed on the external connection part 12, and the conductive structure 2 is electrically connected to the external connection part 12 and the external power supply at the same time, so as to transmit the current of the external power supply to the heating element 1 through the conductive structure 2 to realize the energization and heating of the heating element 1. Among them, the resistivity of the conductive structure 2 is less than the resistivity of the external connection part 12, so that the resistance change from the external power supply to the conductive structure 2 and then to the external connection part 12 is gentle, reducing the heat generation caused by the excessive resistance difference during the current flow, improving the thermal uniformity when the heating film assembly 100 is heated, and improving the safety and stability of the overall cooking appliance 500.

[0047] In an embodiment, the conductive structure 2 includes at least two conductive layers stacked. One of the conductive layers is disposed on the external connection part 12; among them, the resistivity of the conductive layer far from the external connection part 12 is less than the resistivity of the conductive layer disposed on the external connection part 12, and the resistivity of the conductive layer disposed on the external connection part 12 is less than the resistivity of the external connection part 12.

[0048] In this embodiment, as Figures 1 to 3As shown, the conductive structure 2 is a layered structure, which includes at least two conductive layers, such as two, three or more than three layers. The at least two conductive layers are sequentially stacked from the side connected to the external connection part 12 to the direction away from the external connection part 12, that is, the at least two conductive layers are arranged in parallel. Of course, the at least two conductive layers can also be stacked at a certain angle to each other, which is not limited herein. The conductive layer away from the external connection part 12 is used for electrically connecting to an external power source, so as to input the current of the external power source into the heating element 1 through the conductive structure 2, so that the heating element 1 is energized and generates heat.

[0049] Among them, each conductive layer has conductivity. Each conductive layer can be a conductive sheet (layer) structure formed by a single metal, or a conductive sheet (layer) structure formed by a composite metal, or a conductive paste formed by metal particles with a certain ratio. The conductive layer is formed by layer-by-layer printing or coating to achieve conductivity. Adjacent two conductive layers are electrically connected, such as by welding connection, wire connection, insertion connection and other methods, which are not limited herein.

[0050] In this embodiment, the resistivity of the conductive layer away from the external connection part 12 is less than the resistivity of the conductive layer provided at the external connection part 12, and the resistivity of the conductive layer provided at the external connection part 12 is less than the resistivity of the external connection part 12. Since the resistivity of the material is reciprocal to the conductivity of the material, the resistivity relationship between the above-mentioned external connection part 12 and the conductive structure 2 can also be expressed as that the conductivity of the conductive layer away from the external connection part 12 is greater than the conductivity of the conductive layer provided at the external connection part 12, and the conductivity of the conductive layer provided at the external connection part 12 is greater than the conductivity of the external connection part 12. That is to say, starting from the conductive layer connecting the external connection part 12, to the at least two conductive layers stacked layer by layer, its resistivity gradually decreases in a stepwise manner, or its conductivity gradually increases in a stepwise manner. For example, the material of the heating element 1 is usually graphene, that is, the material of the external connection part 12 is also graphene. The resistivity of high-purity graphene is usually 5×10^-7 (Ω·m). The material of the conductive layer connected to the external connection part 12 can be aluminum or copper with a resistivity less than that of graphene. Among them, the resistivity of aluminum is 2.8×10^-8 (Ω·m), and the resistivity of copper is 1.7×10^-8 (Ω·m). Further, the material of another conductive layer provided on the conductive layer connected to the external connection part 12 can be silver, and the resistivity of silver is 1.5×10^-8 (Ω·m). And the material of the conductive layer connected to the external connection part 12 can also be an alloy material with a resistivity between graphene and aluminum, such as brass alloy, copper-nickel alloy, etc., which is not limited herein.

[0051] It can be understood that by setting the conductive structure 2 as a layered structure, the electrical properties of each conductive layer, such as resistivity or conductivity, can be flexibly adjusted, so that the resistivity or conductivity of the entire conductive structure 2 can be flexibly adjusted. Specifically, the resistivity of each conductive layer in the conductive structure 2 can be changed by adjusting the structure and / or material of each conductive layer. The resistivity of the conductive layer connected to the external part 12 is greater than the resistivity of the external part 12, and the resistivity of other conductive layers arranged away from the conductive layer connected to the external part 12 is greater than the resistivity of the conductive layer connected to the external part 12. Such a setting avoids the excessive difference in resistivity of two adjacent conductive connection structures in the traditional structure due to excessive material differences, thereby effectively reducing the temperature rise and heat at the connection between the conductive structure 2 and the external part 12, and reducing the spark discharge phenomenon at the joint, thereby improving the safety performance of the heating film assembly 100 and the overall cooking utensil 500.

[0052] In one embodiment, at least two stacked conductive layers include a first conductive layer 21 and a second conductive layer 22, wherein the first conductive layer 21 is disposed on the external connection portion 12, and the second conductive layer 22 is located on the surface of the first conductive layer 21 away from the external connection portion 12; the material of the first conductive layer 21 is conductive silver paste, and the material of the second conductive layer 22 is copper or aluminum.

[0053] In this embodiment, if Figures 1 to 3 As shown, the conductive structure 2 includes two conductive layers, and the two conductive layers include a first conductive layer 21 and a second conductive layer 22. The first conductive layer 21 is arranged at the external connection portion 12, and the first conductive layer 21 and the external connection portion 12 are electrically connected. The second conductive layer 22 is arranged on the surface of the first conductive layer 21 away from the external connection portion 12, and the second conductive layer 22 is electrically connected to the first conductive layer 21. At the same time, the second conductive layer 22 is electrically connected to an external power supply so that the external power supply is connected to the heating element 1 circuit, so that the heating element 1 is powered on and generates heat.

[0054] It can be understood that the resistivity of the first conductive layer 21 is smaller than that of the external connection part 12, and the resistivity of the second conductive layer 22 is smaller than that of the first conductive layer 21, so that the resistivity decreases gradually from the external connection part 12 to the first conductive layer 21 and then to the second conductive layer 22 in a step-like manner, so that when the current flows from the external power supply into the conductive structure 2 and then from the conductive structure 2 into the external connection part 12, the overall resistivity difference is reduced, and the resistivity change is also smoother, and a large temperature rise and heat generation will not be generated due to the excessive resistivity difference, so as to reduce the spark discharge phenomenon at the joint and improve the safety performance of the heating film assembly 100 and the overall cooking utensil 500.

[0055] It can be understood that the material of the first conductive layer 21 can be conductive silver paste. The conductive silver paste is composed of a matrix epoxy resin and conductive fillers, namely conductive silver particles, etc. Through the bonding action of the matrix resin, the conductive particles are combined together to form a conductive path, realizing the conductive connection of the adhered materials. The conductive silver paste also includes materials such as curing agents and diluents. The resistivity of the conductive silver paste is usually less than the resistivity of the external connection part 12, that is, the conductivity of the conductive silver paste is higher than the conductivity of the external connection part 12, so as to form a step - changed resistance between the first conductive layer 21 and the external connection part 12. Further, the material of the second conductive layer 22 can be copper or aluminum. Copper or aluminum can be well welded to the conductive silver paste, and the resistivity of copper or aluminum is less than the conductivity of the conductive silver paste, so as to form a step - changed resistance between the second conductive layer 22 and the first conductive layer 21. At the same time, conductive silver paste is used between the second conductive layer 22 and the external connection part 12. Microscopically, the conductive particles in the conductive silver paste, namely silver particles, can better contact the conductive particles in the underlying external connection part 12 and the metal layer in the upper layer, effectively increasing the contact area, ensuring the smooth transmission of current, thus effectively reducing current loss, lowering temperature rise and heat generation, and effectively avoiding the problem of micro - spark discharge.

[0056] In one embodiment, the stacking direction of the external connection part 12, the first conductive layer 21 and the second conductive layer 22 is defined as the height direction; along the height direction, the thickness of the second conductive layer 22 is less than the thickness of the first conductive layer 21, and the thickness of the first conductive layer 21 is less than the thickness of the heating element 1.

[0057] In this embodiment, as Figure 3 shown, the heating element 1 and the external connection part 12 are both arranged on the heat - conducting substrate 3. The heat - conducting substrate 3 can be a glass substrate, a ceramic substrate or a metal substrate, and the first conductive layer 21 and the second conductive layer 22 are stacked layer by layer along the direction perpendicular to the heat - conducting substrate 3. The direction perpendicular to the heat - conducting substrate 3 is also the height direction. In the height direction, the thickness of the first conductive layer 21 is less than the thickness of the heating element 1. Specifically, that is, the thickness of the first conductive layer 21 is less than the thickness of the external connection part 12, and the thickness of the second conductive layer 22 is less than the thickness of the first conductive layer 21.

[0058] In another embodiment of the present utility model, it can also be that the thicknesses of the first conductive layer 21 and the second conductive layer 22 are gradually changed along the direction of the heat - conducting substrate 3, such as gradually increasing along a fixed direction. Among them, the thickness of the region where the first conductive layer 21 is the thickest is less than the thickness of the external connection part 12, and the thickness of the region where the second conductive layer 22 is the thickest is less than the thickness of the thinnest region of the first conductive layer 21, so as to form a layered conductive structure 2 with a step - decreasing resistance for the external connection part 12, the first conductive layer 21 and the second conductive layer 22.

[0059] It can be understood that using partial materials will result in a relatively small difference in resistivity among the three layers of materials of the external connection part 12, the first conductive layer 21, and the second conductive layer 22. In this way, the resistivity difference between the external power supply and the external connection part 12 will be relatively large, still causing the problem of more heat generation. By setting the thicknesses of the three-layer structure of the external connection part 12, the first conductive layer 21, and the second conductive layer 22 to gradually decrease, when the cross-sectional area in the direction perpendicular to the height is constant, the larger the thickness, the larger the cross-sectional area through which the overall current passes, resulting in a larger resistance. With such a setting, the resistivity differences between the external connection part 12 and the first conductive layer 21, and between the first conductive layer 21 and the second conductive layer 22 can be increased, thereby reducing the resistivity difference between the external power supply and the external connection part 12, forming a layered conductive structure 2 with an obvious stepped change in resistance, effectively reducing the temperature rise and heat generation. Moreover, the resistivity difference degrees between the first conductive layer 21 and the external connection part 12, and between the second conductive layer 22 and the first conductive layer 21 can be accurately adjusted by adjusting the thicknesses of the first conductive layer 21 and the second conductive layer 22, so as to accurately match conductive layers of different materials and achieve precise control of the temperature rise.

[0060] In an embodiment, in the projection on the plane where the heating element 1 is located, the projected area of the external connection part 12 is larger than the projected area of the first conductive layer 21, and the projected area of the first conductive layer 21 is larger than the projected area of the second conductive layer 22.

[0061] In this embodiment, as Figures 1 to 3 shown, the heating element 1 is usually disposed on a glass substrate or a ceramic substrate by means of pasting or printing, etc., so that the heating element 1 forms a heating film assembly. When projecting onto the plane where the heating film assembly is located, the projected area of the external connection part 12 should be larger than the projected area of the first conductive layer 21, and the projected area of the first conductive layer 21 should be larger than the projected area of the second conductive layer 22.

[0062] It can be understood that when using different materials and adjusting the thicknesses of different conductive layers cannot significantly improve the resistivity differences between the external connection portion 12 and the first conductive layer 21, and between the first conductive layer 21 and the second conductive layer 22, the projected areas of the first conductive layer 21 and the second conductive layer 22 onto the plane where the heating element 1 is located can be adjusted to cause a significant stepped change in area among the external connection portion 12, the first conductive layer 21, and the second conductive layer 22. Among them, on the basis that the thicknesses of the external connection portion 12, the first conductive layer 21, and the second conductive layer 22 are kept constant, the larger the projected area onto the plane where the heating element 1 is located, the larger the cross-sectional area through which the overall current passes, resulting in a larger resistance. With such a setting, the resistivity differences between the external connection portion 12 and the first conductive layer 21, and between the first conductive layer 21 and the second conductive layer 22 can be increased, thereby reducing the resistivity difference between the external power supply and the external connection portion 12, forming a layered conductive structure 2 with an obvious stepped change in resistance, and effectively reducing temperature rise and heat generation.

[0063] In one embodiment, the heating element 1 includes a heating strip 11 and two external connection portions 12. The two external connection portions 12 are provided at both ends of the heating strip 11. The heating film assembly 100 includes two conductive structures 2, and one conductive structure 2 is correspondingly provided for one external connection portion 12.

[0064] It can be understood that as Figure 1 shown, the heating strip 11 extends as a strip as a whole. The heating strip 11 includes a bent section 111 and two joint sections 112. The two joint sections 112 are provided at both ends of the entire heating strip 11. The two joint sections 112 are arranged in a straight line and are arranged in parallel at intervals. The bent section 111 is connected to the two joint sections 112 and is located between the two joint sections 112. Each external connection portion 12 is connected to one end of a joint section 112 away from the bent section 111. Among them, the bent section 111 bends and extends away from the joint section 112, and the bent sections 111 are also arranged in parallel at intervals, so that the heating strip 11 is coiled into a heating film assembly similar to the outer peripheral shape of the heat-conducting substrate 3. At the same time, each joint section 112 is electrically connected to a conductive structure 2. One of the two conductive structures 2 is used to be electrically connected to the positive pole of the external power supply, and the other of the two conductive structures 2 is used to be electrically connected to the negative pole of the external power supply, so that the external power supply can form a closed loop with the bent section 111 through the two conductive structures 2 and the two joint sections 112, and input current to the entire heating strip 11 to make the heating strip 11 generate heat when powered on.

[0065] In one embodiment, the partial heating strip 11 connected to the external connection part 12 extends linearly. The extension direction of the linearly extending heating strip 11 is defined as the first direction, and the direction perpendicular to the first direction is defined as the second direction. In the first direction, the length of the external connection part 12 is 1.7 to 2 times the length of the first conductive layer 21. In the second direction, the lengths of the first conductive layer 21, the second conductive layer 22, and the external connection part 12 are the same.

[0066] In this embodiment, as Figure 1 and Figure 2 shown, the partial heating strip 11 connected to the external connection part 12, that is, the above-mentioned joint section 112, extends linearly. The extension direction of the joint section 112 is defined as the first direction. The extension directions of the two joint sections 112 are the same, and the two joint sections 112 are arranged at intervals. The direction perpendicular to the first direction is defined as the second direction, that is, the direction in which the two joint sections 112 are arranged at intervals is the second direction. The external connection part 12 itself also extends in the first direction and the second direction. To avoid interference between the two external connection parts 12 provided on the two joint sections 112, the external connection part 12 extends in the direction away from the joint section 112 in the first direction and in the direction away from the other external connection part 12 in the second direction.

[0067] It can be understood that in the first direction, the length of the external connection part 12 is greater than the length of the first conductive layer 21, and in the second direction, the lengths of the first conductive layer 21, the second conductive layer 22, and the external connection part 12 are the same. By changing the length of the first conductive layer 21 relative to the external connection part 12 and keeping the lengths of the first conductive layer 21 and the second conductive layer 22 the same in the second direction, the projected area of the first conductive layer 21 on the plane where the heating element 1 is located is made smaller than the projected area of the external connection part 12 on the plane where the heating element 1 is located. In the second direction, making the lengths of the first conductive layer 21, the second conductive layer 22, and the external connection part 12 the same is used, on the one hand, to control the length of the first conductive layer 21 relative to the external connection part 12 in the second direction, so that only by adjusting the length of the first conductive layer 21 in the first direction can the projected area of the first conductive layer 21 relative to the external connection part 12 on the plane where the heating element 1 is located be changed. On the other hand, it can also ensure that the first conductive layer 21 and the second conductive layer 22 do not extend beyond the edge of the external connection part 12, so as to maintain the appearance of the external connection part 12 and the conductive structure 2 and reduce the risk of short circuit that may occur due to the exposure of the conductive structure 2. Similarly, the second conductive layer 22 has the same length as the first conductive layer 21 in the second direction, and the length of the second conductive layer 22 in the first direction is also smaller than the length of the first conductive layer 21 in the first direction, so that the projected area of the second conductive layer 22 on the plane where the heating element 1 is located is smaller than the projected area of the first conductive layer 21 on the plane where the heating element 1 is located, which will not be elaborated here.

[0068] It can be understood that in the first direction, the length of the external connection portion 12 is 1.7 to 2 times the length of the first conductive layer 21. On the basis that the thickness and width of the first conductive layer 21 and the external connection portion 12 are the same, that is, on the basis that the cross-sectional areas through which the current passes through the external connection portion 12 and the first conductive layer 21 are the same, assuming that the external connection portion 12 and the first conductive layer 21 are made of the same material and have the same resistivity, the projected area of the external connection portion 12 on the plane where the heating element 1 is located is 1.7 to 2 times the projected area of the first conductive layer 21 on the plane where the heating element 1 is located, and the resistance of the external connection portion 12 is 1.7 to 2 times the resistance of the first conductive layer 21. Thus, a changing resistance is formed from the external connection portion 12 to the first conductive layer 21. Moreover, the length of the first conductive layer 21 relative to the external connection portion 12 in the first direction can be adjusted, such as the length of the external connection portion 12 in the first direction being 1.8 times, 1.9 times or 2 times that of the first conductive layer 21, etc., so as to accurately adjust the multiple of the resistance difference between the external connection portion 12 and the first conductive layer 21, and accurately control the temperature rise and heat generation between the conductive structure 2 and the heating element 1.

[0069] Furthermore, in another embodiment of the present utility model, the lengths of the first conductive layer 21 and the second conductive layer 22 in the second direction can also be less than the length of the external connection portion 12 in the second direction, and by adjusting the lengths of the first conductive layer 21 and the second conductive layer 22 in the first direction, the projected area of the external connection portion 12 is made larger than the projected area of the first conductive layer 21, and the projected area of the first conductive layer 21 is larger than the projected area of the second conductive layer 22, which will not be elaborated here.

[0070] In one embodiment, the length of each external connection portion 12 in the second direction is 1 to 3 times the width of the heating strip 11; it can be understood that as Figure 1 and Figure 2 shown, to increase the connection area between the external connection portion 12 and the conductive structure 2, one side of the external connection portion 12 facing another external connection portion 12 in the second direction is flush with the side of the joint section 112, and the side of the external connection portion 12 facing away from another external connection portion 12 in the second direction extends away from the joint section 112, so that the length of the external connection portion 12 in the second direction is greater than the width of the heating strip 11 and is 1 to 3 times the width of the heating strip 11, so as to flexibly adjust the area of the external connection portion 12, thereby adapting to different magnitudes of external current.

[0071] Optionally, in the first direction, the length of the first conductive layer 21 is 1.2 to 1.5 times the length of the second conductive layer 22. It can be understood that as Figures 1 to 3As shown, in the first direction, the length of the first conductive layer 21 is 1.2 to 1.5 times the length of the second conductive layer 22. On the basis that the thickness and width of the second conductive layer 22 and the first conductive layer 21 are the same, that is, on the basis that the cross-sectional areas through which the current passes through the first conductive layer 21 and the second conductive layer 22 are the same, assuming that the first conductive layer 21 and the second conductive layer 22 are made of the same material and have the same resistivity, the projected area of the first conductive layer 21 on the plane where the heating element 1 is located is 1.2 to 1.5 times the projected area of the second conductive layer 22 on the plane where the heating element 1 is located, and the resistance of the first conductive layer 21 is 1.2 to 1.5 times the resistance of the second conductive layer 22. Thus, a varying resistance is formed from the first conductive layer 21 to the second conductive layer 22. Moreover, the length of the second conductive layer 22 relative to the first conductive layer 21 in the first direction can be adjusted. For example, the length of the first conductive layer 21 in the first direction is 1.3 times, 1.4 times, or 1.5 times that of the second conductive layer 22, etc., so as to precisely adjust the resistance difference multiple between the first conductive layer 21 and the second conductive layer 22 and precisely control the temperature rise and heat generation between the conductive structure 2 and the heating element 1.

[0072] The present utility model also provides a pot lid 400, as Figure 4 shown. The pot lid 400 includes a lid body 401, a heat-conducting substrate 3, and the above-mentioned heating film assembly 100. The heat-conducting substrate 3 is disposed on the lid body 401, and the heating film assembly 100 is coated or attached to the surface of the heat-conducting substrate 3. For the specific structure of the heating film assembly 100, reference may be made to the foregoing embodiments. Since this pot lid 400 adopts all the technical solutions of all the foregoing embodiments, it at least has all the beneficial effects brought by the technical solutions of the foregoing embodiments, which will not be elaborated herein one by one.

[0073] It can be understood that the material of the heat-conducting substrate 3 is microcrystalline glass or borosilicate glass, and the heating film assembly 100 can be disposed on the surface of the borosilicate glass by coating or attaching. Through the heating of the heating film assembly 100, the heat-conducting substrate 3 can also generate heat, so as to keep the temperature inside the lid body 401 consistent with that inside the cooking appliance, reduce the temperature difference, and thus reduce the condensation water.

[0074] The present utility model also provides a cooking appliance 500, as Figure 4 shown. The cooking appliance 500 includes a pot body 501 and the above-mentioned pot lid 400. The pot lid 400 is connected to the pot body 501. For the specific structure of the pot lid 400, reference may be made to the foregoing embodiments. Since this cooking appliance 500 adopts all the technical solutions of all the foregoing embodiments, it at least has all the beneficial effects brought by the technical solutions of the foregoing embodiments, which will not be elaborated herein one by one.

[0075] It can be understood that the cooking appliance 500 can be an electric rice cooker, a pressure electric rice cooker, a steaming pot, an electric kettle, an electric soup pot, an electric Chinese medicine pot, an electric clay pot rice cooker, etc. The pot body 501 includes a base, an electric heater provided on the base, and a rice cooking container provided in the base and sitting on the electric heater. Among them, one end of the lid body 401 of the lid 400 is rotatably hinged to the base, and the other end is snap-connected to the base, so that by opening the snap, the lid 400 can be opened.

[0076] The above are only exemplary embodiments of the present invention, and do not limit the patent scope of the present invention. Any equivalent structural transformation made under the technical concept of the present invention by using the content of the specification and drawings of the present invention, or direct / indirect application in other related technical fields are all included in the patent protection scope of the present invention.

Claims

1. A heating film assembly, characterized in that: The heating film assembly comprises: A heating element, wherein the heating element is provided with an external connection portion; and A conductive structure is provided at the external connection portion and electrically connected to the external connection portion, and the resistivity of the conductive structure is lower than the resistivity of the external connection portion.

2. The heating film assembly according to claim 1, characterized in that: The conductive structure comprises at least two conductive layers stacked together, wherein one of the conductive layers is disposed at the external connection portion; The resistivity of the conductive layer far from the external connection portion is smaller than the resistivity of the conductive layer disposed at the external connection portion, and the resistivity of the conductive layer disposed at the external connection portion is smaller than the resistivity of the external connection portion.

3. The heating film assembly according to claim 2, characterized in that: The at least two stacked conductive layers include a first conductive layer and a second conductive layer, wherein the first conductive layer is disposed on the external connection portion, and the second conductive layer is located on a surface of the first conductive layer away from the external connection portion; The material of the first conductive layer is conductive silver paste, and the material of the second conductive layer is copper or aluminum.

4. The heating film assembly according to claim 3, characterized in that: defining a stacking direction of the external connection portion, the first conductive layer, and the second conductive layer as a height direction; The thickness of the second conductive layer along the height direction is smaller than the thickness of the first conductive layer, and the thickness of the first conductive layer is smaller than the thickness of the heating element.

5. The heating film assembly according to claim 3, characterized in that: As projected on the plane where the heating element is located, the projection area of ​​the externally connected portion is larger than the projection area of ​​the first conductive layer, and the projection area of ​​the first conductive layer is larger than the projection area of ​​the second conductive layer.

6. The heating film assembly according to claim 3, characterized in that: The heating element comprises a heating strip and two external connection parts, the two external connection parts are arranged at two ends of the heating strip, and the heating film assembly comprises two conductive structures, one conductive structure is correspondingly arranged at one external connection part.

7. The heating film assembly according to claim 6, characterized in that: The portion of the heating strip connected to the external portion extends in a straight line, and the extending direction of the heating strip extending along the straight line is defined as a first direction, and a direction perpendicular to the first direction is defined as a second direction; In the first direction, the length of the external connection portion is 1.7 to 2 times the length of the first conductive layer. In the second direction, the lengths of the first conductive layer, the second conductive layer, and the external connection portion are consistent.

8. The heating film assembly according to claim 7, characterized in that: The length of each of the externally connected portions along the second direction is 1 to 3 times the width of the heating strip; And / or, in the first direction, the length of the first conductive layer is 1.2 to 1.5 times the length of the second conductive layer.

9. A pot cover, characterized in that: The pot cover comprises: Cover body; a heat-conducting substrate, the heat-conducting substrate being disposed on the cover; and The heating film assembly according to any one of claims 1 to 8, wherein the heating film assembly is coated or adhered to the surface of the thermally conductive substrate.

10. The pot cover according to claim 9, characterized in that: The thermally conductive substrate is microcrystalline glass or high borosilicate glass.

11. A cooking utensil, characterized in that: The cooking appliance comprises: pot body; and The pot cover as claimed in claim 10, wherein the pot cover is connected to the pot body.

Images