Liquid heater

Abstract

The utility model discloses a liquid heater which comprises a kettle body and a metal heating disc, the metal heating disc is fixed at the bottom of the kettle body, a hydrophobic coating is arranged on the upper surface of the metal heating disc, a detection probe is arranged on the outer bottom face of the metal heating disc, an exposed area for exposing metal is arranged on the upper surface of the metal heating disc, and the exposed area is in a closed ring shape. The hydrophobic coating on the inner side of the exposed area forms a temperature sensing area corresponding to the detection probe, the projection of the temperature sensing area on the upper surface of the metal heating disc is located in the inner side edge of the exposed area, and the conductive end of the detection probe is tightly attached to the temperature sensing area to achieve electric conduction. The problem that the anti-overflow function of a liquid heater with a hydrophobic coating is poor due to inaccurate temperature measurement is solved, the accuracy of monitoring the temperature of the temperature sensing area by the detection probe is optimized through electric conduction of the exposed area and the detection probe, and then the response speed between the detection electrode and the metal heating disc is increased; and the risk of foam overflow is reduced.

Description

Technical Field

[0001] This utility model relates to the field of household appliance technology, and in particular to a liquid heater. Background Technology

[0002] Currently, the inner tanks of small household appliances that come into contact with food and drinking water (including beverages, tea, etc.) are commonly made of materials such as aluminum and stainless steel. Especially in devices focused on healthy drinking water, such as health-preserving kettles, due to technological limitations, the heating plate of the inner tank is often made of stainless steel. However, when stainless steel comes into contact with certain acidic or alkaline substances, such as tea, fruit juice, and traditional Chinese medicine, especially during heating, some metals may slowly leach out, posing a potential threat to human health. Furthermore, stainless steel has poor non-stick properties, easily forming surface dirt and difficult-to-remove tea stains, making cleaning inconvenient.

[0003] Existing technology CN209058757U discloses an "electric health-preserving kettle," specifically disclosing that the bottom of the kettle body is equipped with a stainless steel heating plate, the surface of which is covered with a ceramic coating to isolate the stainless steel heating plate from the health-preserving ingredients. A heater is installed inside the stainless steel heating plate, and a temperature sensor is also connected to it. A controller and a power cord are installed on the base of the kettle body, and the heater is connected to a power source via the power cord. In the aforementioned application, the controller, temperature sensor, and power source are electrically connected, allowing the power supply to be reduced or cut off based on the temperature data measured by the temperature sensor, preventing the liquid inside the kettle from overheating. However, the temperature sensor is connected to the stainless steel heating plate and extends beyond the ceramic coating, causing direct contact between the temperature sensor and the liquid inside the kettle. During the heating process, water vapor molecules are generated on the bottom surface of the kettle body, forming bubbles. These bubbles also form near the temperature sensor. The bubbles isolate the liquid inside the kettle, causing the temperature to rise; when the bubbles burst, the temperature drops rapidly. This can cause the liquid temperature detected by the temperature sensor to fluctuate, leading to inaccurate temperature measurements. Consequently, the temperature data measured by the temperature sensor will also fluctuate, resulting in the temperature inside the pot being higher than the detected temperature. This can easily cause the liquid inside the pot to overflow. Utility Model Content

[0004] The objective of this invention is to provide a liquid heater that solves the problem of poor overflow prevention caused by inaccurate temperature measurement in liquid heaters with hydrophobic coatings. This is achieved by placing the conductive end of the detection probe in close contact with the temperature-sensing area on the lower surface of the heating plate, and by providing an exposed, uncoated metal area on the upper surface of the heating plate. The electrical conductivity between the exposed area and the detection probe optimizes the accuracy of temperature monitoring of the sensing area, thereby enhancing the response speed between the detection electrode and the metal heating plate and reducing the risk of foam overflow.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: a liquid heater, comprising a kettle body and a metal heating plate, the metal heating plate being fixed to the bottom of the kettle body, the upper surface of the metal heating plate being provided with a hydrophobic coating, the outer bottom surface of the metal heating plate being provided with a detection probe, the upper surface of the metal heating plate being provided with an exposed area of ​​exposed metal, the exposed area being a closed ring, the hydrophobic coating inside the exposed area corresponding to the detection probe forming a temperature sensing area, the projection of the temperature sensing area on the upper surface of the metal heating plate being located within the inner edge of the exposed area, and the conductive end of the detection probe being in close contact with the temperature sensing area to achieve electrical conduction.

[0006] After adopting the above technical solution, this utility model has the following advantages: The metal heating plate is located at the bottom of the kettle body, which can heat the liquid inside the kettle. The upper surface of the metal heating plate is provided with a hydrophobic coating to prevent food from sticking to the bottom. The hydrophobic coating can also reduce the difficulty of cleaning the upper surface of the metal heating plate after steaming or cooking food in the kettle. The upper surface of the metal heating plate has an exposed metal area, which is a closed ring. The liquid inside the kettle body comes into contact with the metal heating plate through this exposed area. Since the metal heating plate is in direct contact with the liquid inside the kettle body through the exposed area, the temperature detected by the detection probe located on the bottom surface of the metal heating plate is closer to the actual water temperature inside the kettle body. The lower surface of the metal heating plate is provided with a temperature sensing area. The conductive end of the detection probe is placed in close contact with the temperature sensing area. By setting the temperature sensing area within the inner edge of the exposed area, the accuracy of the detection probe in monitoring the temperature of the temperature sensing area is optimized, which can better detect the temperature of the liquid inside the kettle body, making the obtained signal more accurate and reliable.

[0007] Furthermore, the kettle body is equipped with a detection electrode that extends into the inner cavity of the kettle body. The detection electrode and the detection probe are electrically connected to the detection circuit. The liquid inside the kettle body comes into contact with the exposed area and then with the detection electrode to form a detection circuit.

[0008] Using the aforementioned technical solution, a detection electrode is provided at the top of the kettle body, extending into the inner cavity of the kettle body. It is electrically connected to the detection probe in the detection circuit. During the heating process of the liquid inside the kettle body, the liquid will generate foam. When the foam generated by the liquid rises to contact the detection electrode at the top of the kettle body, the detection electrode, the foam, the liquid, the exposed area, the detection probe, and the detection circuit form a closed detection loop. At this time, the liquid heater receives an anti-overflow signal, causing the heater to cut off the power or reduce the heating power to prevent the liquid from overflowing. Since the exposed area is made of metal, and the conductivity of metal is better than that of the hydrophobic coating, when the exposed area of ​​the metal forms a closed detection loop with it, the response speed between the detection electrode and the metal heating plate is enhanced compared to the non-metallic hydrophobic coating, reducing the risk of foam overflow.

[0009] Furthermore, the upper surface of the metal heating plate is provided with annular ribs, and the top surface of the annular ribs forms an exposed area.

[0010] Using the aforementioned technical solution, the top surface of the annular rib on the upper surface of the metal heating plate forms an annular exposed area. The annular rib allows the liquid inside the pot to directly contact the metal heating plate. The detection probe placed on the outer bottom surface of the metal heating plate can more accurately detect the temperature of the liquid inside the pot. When combined with the detection electrode, this further enhances the response flexibility of the heating plate and the detection electrode, significantly reducing the risk of liquid overflow from the pot. At the same time, the structure of the annular rib not only allows the structure itself to effectively disperse external forces, but also reduces stress concentration points in the hydrophobic coating around the annular rib, thereby improving the overall structural stability.

[0011] Furthermore, the longitudinal cross-sectional shape of the annular rib is an inverted trapezoidal structure.

[0012] Using the aforementioned technical solution, the structure of the annular rib is set as an inverted trapezoidal structure, so that the longitudinal section of the hydrophobic coating that cooperates with it is also a corresponding inclined surface. The inclined surface structure can reduce stress concentration when the hydrophobic coating is subjected to external force, compared with the vertical structure, and can better absorb and disperse external force, thereby reducing the risk of damage caused by stress concentration and extending the service life of the hydrophobic coating.

[0013] Furthermore, the upper surface of the metal heating plate has a hydrophobic coating on the inner ring side of the annular rib, and the two sides of the top surface of the annular rib are flush with the edge of the hydrophobic coating.

[0014] Using the aforementioned technical solution, a hydrophobic coating is provided on the inner side of the annular rib, ensuring that the width of the exposed area formed by the annular rib is not too wide. At this point, the width of the exposed area and the contact area formed by the liquid inside the pot are just right to ensure the accuracy of the detection probe in measuring the temperature of the liquid inside the pot. The top edge of the annular rib is flush with the hydrophobic coating, ensuring the flatness of the entire bottom surface of the pot. This structure makes the bottom surface of the pot easier to clean after steaming or cooking food, without leaving any hard-to-clean corners. At the same time, it also avoids the step-like span caused by unevenness, preventing the edge of the coating from being scratched or damaged during the cleaning of the bottom surface of the pot. This helps to maintain the integrity of the hydrophobic coating, improves its service life, and ensures the function of the pot.

[0015] Furthermore, the distance between the inner and outer edges of the exposed area is 2–6 mm.

[0016] Using the aforementioned technical solution, the distance between the inner and outer edges of the exposed area is limited to 2-6 mm. This avoids the exposed area being too wide or too narrow, ensuring the accuracy of the detection probe's measurement of the liquid temperature within this range. When the distance between the inner and outer edges of the exposed area is less than 2 mm, during the heating process, when the liquid foams and comes into contact with the detection electrode on the top of the pot, the narrow exposed area may cause poor contact, increasing the probability of liquid overflow. When the distance between the inner and outer edges of the exposed area is greater than 6 mm, the exposed area is too wide. Since the exposed area is made of metal, food may stick to the bottom of the pot during steaming, increasing the difficulty of cleaning after steaming.

[0017] Furthermore, the inner and outer edges of the exposed area are concentric rings.

[0018] By adopting the aforementioned technical solution, the exposed area is set as a concentric ring, making the structure of the exposed area more symmetrical and the heating more uniform. When the liquid in the pot comes into contact with the metal heating plate through the exposed area, the temperature detected by the detection probe can be more accurate, avoiding detection errors caused by rapid local temperature rise. At the same time, the concentric ring structure has good stability and can effectively disperse external forces. It also reduces stress concentration points in the hydrophobic coating around the exposed area of ​​the concentric ring, thereby improving the overall structural stability.

[0019] Furthermore, the inner and outer edges of the exposed area are circular.

[0020] By adopting the aforementioned technical solution, the exposed area is designed as a ring, making its structure more symmetrical and its heating more uniform. When the liquid inside the pot comes into contact with the metal heating plate through the exposed area, the temperature detected by the probe can be more accurate, avoiding detection errors caused by rapid local temperature rise. At the same time, the ring structure has good stability, effectively dispersing external forces. It also reduces stress concentration points for the hydrophobic coating around the concentric ring exposed area, thereby improving the overall structural stability. Furthermore, the ring is easier to process than other shapes, and its smooth curves minimize dead corners, making it easier to clean.

[0021] Furthermore, the metal heating plate includes a stainless steel plate body and a heating plate, with the heating plate fixed to the outer bottom surface of the stainless steel plate body and a hydrophobic coating applied to the upper surface of the stainless steel plate body.

[0022] Using the aforementioned technical solution, the heating plate is fixed to the outer bottom surface of the stainless steel plate. The stainless steel plate has the advantage of rapid heat conduction. Heat is transferred to the stainless steel plate through the heating plate, which improves the heating efficiency. Furthermore, a hydrophobic coating is applied to the stainless steel plate, which helps to clean the pot better after steaming or cooking food and prevents food from burning on the stainless steel plate.

[0023] Furthermore, the hydrophobic coating is a ceramic coating or a Teflon coating.

[0024] Using the aforementioned technical solution, the ceramic coating possesses stable and uniform thermal conductivity. Placed on the upper surface of the stainless steel pan, the ceramic coating enhances heat transfer between the two. Therefore, when the stainless steel pan is heated, heat can be rapidly transferred to the ceramic coating, resulting in a more uniform heat distribution and even heating of the liquid inside the kettle. This avoids localized overheating that occurs when directly heating the liquid through the stainless steel pan, thus improving heating efficiency. The Teflon coating exhibits excellent non-stick properties and chemical resistance, allowing for easy cleaning after cooking. It is also hydrophobic and oleophobic, making it easy to clean and less prone to leaving food stains. Attached Figure Description

[0025] The present invention will be further described below with reference to the accompanying drawings:

[0026] Figure 1 The present invention relates to the structure of a liquid heater. Figure 1 ;

[0027] Figure 2 This utility model Figure 1 Enlarged view of point A in the image;

[0028] Figure 3 This is a structural diagram of another embodiment of the liquid heater of this utility model;

[0029] Figure 4 This utility model Figure 3 Enlarged view of point B in the image;

[0030] Figure 5 This is a top view of a liquid heater according to the present invention;

[0031] Figure 6 This utility model Figure 1 Enlarged view of point C in the image. Detailed Implementation

[0032] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments.

[0033] The terms "first," "second," etc. (if present) in the specification and claims of this utility model are used to distinguish similar objects, not to describe a specific order or sequence. Even if "second" is used before a technical feature for distinction, it does not necessarily imply the presence of "first." It should be understood that in this utility model, "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion. It should be understood that in this utility model, "multiple" refers to two or more. "And / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, X and / or Y can represent: X alone, X and Y simultaneously, and Y alone. The character " / " generally indicates that the preceding and following related objects are in an "or" relationship. "Containing X, Y, and Z," "Containing X, Y, and Z" means that all three X, Y, and Z are included; "Containing X, Y, or Z" means that one of X, Y, and Z is included; "Containing X, Y, and / or Z" means that any one, two, or three of X, Y, and Z are included.

[0034] The technical solution of this utility model will be described in detail below with specific embodiments. The following specific embodiments can be selected to be combined or substituted with each other according to the actual situation, and the same or similar concepts or processes may not be described again in some embodiments.

[0035] like Figure 1 , Figure 2 and Figure 5 As shown, this utility model provides a liquid heater, including a kettle body 1 and a metal heating plate 2. The metal heating plate 2 is fixed to the bottom of the kettle body 1. The upper surface of the metal heating plate 2 (the direction described in the embodiment is consistent with the direction indicated in the attached drawings) is provided with a hydrophobic coating 21. A detection probe 22 is provided on the outer bottom surface of the metal heating plate 2. The upper surface of the metal heating plate 2 is provided with an exposed area 251 of exposed metal. The exposed area 251 is a closed ring. The hydrophobic coating 21 on the inner side of the exposed area 251 forms a temperature sensing area 26 corresponding to the detection probe 22. The temperature sensing area 26 ( Figure 5 The projection of the portion indicated by the dashed line on the upper surface of the metal heating plate 2 is located within the inner edge of the exposed area 251, and the conductive end of the detection probe 22 is in close contact with the temperature sensing area 26 to achieve electrical conduction.

[0036] Understandably, the metal heating plate 2 is located at the bottom of the kettle body 1 and can heat the liquid inside the kettle. The upper surface of the metal heating plate 2 is provided with a hydrophobic coating 21 to prevent food from sticking to the bottom. The hydrophobic coating 21 can also reduce the difficulty of cleaning the upper surface of the metal heating plate 2 after steaming or cooking food in the kettle. The upper surface of the metal heating plate 2 is provided with an exposed metal area 251, which is a closed ring. The liquid inside the kettle body 1 comes into contact with the metal heating plate 2 through the exposed area 251. Since the metal heating plate 2 is in direct contact with the liquid inside the kettle body 1 through the exposed area 251, the temperature detected by the detection probe 22 located on the outer bottom surface of the metal heating plate 2 is closer to the actual water temperature inside the kettle body 1. The lower surface of the metal heating plate 2 is provided with a temperature sensing area 26. The conductive end of the detection probe 22 is placed in close contact with the temperature sensing area 26. By setting the temperature sensing area 26 within the inner edge of the exposed area 251, the accuracy of the detection probe 22 in monitoring the temperature of the temperature sensing area 26 is optimized, and the temperature of the liquid inside the kettle body 1 can be better detected, making the obtained signal more accurate and reliable.

[0037] In addition, the kettle body 1 is equipped with a detection electrode 41 extending into the inner cavity of the kettle body 1. The detection electrode 41 and the detection probe 22 are electrically connected to the detection circuit. The liquid inside the kettle body 1 contacts the exposed area 251 and then contacts the detection electrode 41 to form a detection circuit. During the heating process of the liquid inside the kettle body 1, the liquid will produce foam. When the foam produced by the liquid rises to contact the detection electrode 41 at the top of the kettle body 1, the detection electrode 41, the foam, the liquid, the exposed area 251, the detection probe 22, and the detection circuit form a closed detection circuit. At this time, the metal heating plate 2 receives an electrical signal, which causes it to cut off the power or reduce the heating power to prevent the liquid from overflowing. Since the exposed area 251 is made of metal, and the conductivity of metal is better than that of the hydrophobic coating 21, when the exposed area 251 of the metal material forms a closed detection circuit with it, the response speed between the detection electrode 41 and the metal heating plate 2 is enhanced compared to the non-metallic hydrophobic coating 21, reducing the risk of foam overflow.

[0038] It should be noted that the liquid heater in this embodiment takes a health pot as an example, including a pot body 1 and a metal heating plate 2, with the metal heating plate 2 fixed to the bottom of the pot body 1.

[0039] The metal heating plate 2 includes a detection probe 22 and a control component. The control component is electrically connected to the detection probe 22. The control component is responsible for controlling the heating of the liquid in the health pot, while the detection probe 22 is responsible for monitoring the temperature of the liquid in the health pot in real time. When the liquid temperature reaches the set value or boils, the temperature detection probe 22 sends a signal to the control component. The control component controls the opening and closing of the circuit to stop heating or continue heating, thereby maintaining a stable liquid temperature in the health pot.

[0040] The metal heating plate 2 includes a stainless steel plate body 23 and a heating plate 24. The heating plate 24 is fixed to the outer bottom surface of the stainless steel plate body 23. A hydrophobic coating 21 is provided on the upper surface of the stainless steel plate body 23. The stainless steel plate body 23 has the advantage of rapid heat conduction. The heating plate 24 transfers heat to the stainless steel plate body 23, which improves the heating efficiency. Furthermore, the hydrophobic coating 21 on the stainless steel plate body 23 helps to clean the food better after steaming or cooking in the pot body 1, and prevents the food from burning on the stainless steel plate body 23.

[0041] The health pot includes a shell 3, a metal heating plate 2 placed in the shell 3 and connected to the pot body 1. The shell 3 is fixedly connected to the bottom of the pot body 1 and encloses the metal heating plate 2. The shell 3 and the pot body 1 can be fixedly connected by adhesive, bolts, or snap-fit, as long as the two can be fixedly connected.

[0042] The health-preserving kettle includes a lid (4) and a handle (5), such as... Figure 6 As shown, the top of the kettle body 1 is provided with a lid 4, and the lid 4 is provided with a detection electrode 41 and a detection electrode contact 42. The handle 5 is provided with an electrode connecting piece 51 that electrically connects the detection electrode 41 and the detection electrode contact 42, and a detection circuit that electrically connects the detection electrode 41 and the metal heating plate 2. When the foam generated by the liquid in the kettle during the heating process comes into contact with the detection electrode 41, the detection electrode 41 transmits an electrical signal to the detection electrode contact 42. The electrode connecting piece 51 transmits the electrical signal to the metal heating plate 2 through the detection circuit. At this time, the metal heating plate 2 receives the electrical signal to control the kettle body 1 to stop heating or reduce the heating rate, so as to achieve the effect of preventing overflow.

[0043] The health-preserving kettle includes a filter 6, which is placed at the top of the kettle body 1 and extends into the inner cavity of the kettle body 1. When the lid 4 is closed onto the kettle body 1, the filter 6 is also fixed to the kettle body 1. When in use, tea leaves or fruit can be placed in the filter 6 to filter out tea or fruit residue from the water, ensuring the taste of the beverage. When the filter 6 is not needed, it can be directly removed from the top of the kettle body 1, which is convenient and quick.

[0044] Generally speaking, the body 1 and lid 4 are made of high borosilicate glass; the filter 6 is made of stainless steel mesh or ceramic; and the handle 5 and shell 3 are made of plastic, such as PP.

[0045] The hydrophobic coating 21 mentioned above can preferably be a ceramic coating. The ceramic coating has stable and uniform thermal conductivity. The ceramic coating is placed on the upper surface of the stainless steel plate 23, which improves the heat transfer between the two. Therefore, when the stainless steel plate 23 is heated, the heat can be quickly transferred to the ceramic coating. The heat will be more evenly distributed on the ceramic coating, thereby heating the liquid in the kettle body 1 evenly. This avoids the local overheating caused by directly heating the liquid in the kettle through the stainless steel plate 23, thereby improving the heating efficiency.

[0046] When used for different purposes, a Teflon coating can also be selected. The Teflon coating has good non-stick and chemical resistance. After steaming or cooking food inside the pot, it can be easily cleaned. It is also hydrophobic and oleophobic, easy to clean, and does not easily leave food stains.

[0047] In this embodiment, the detection probe 22 is a temperature sensor; the detection electrode 41 can be an anti-overflow electrode.

[0048] In summary, the more specific functions of a health-preserving kettle include: boiling water, brewing tea, stewing, and keeping warm.

[0049] By setting an annular rib 25 on the upper surface of the metal heating plate 2, an exposed area 251 is formed on the top surface of the annular rib 25. In this way, the annular rib 25 allows the liquid in the pot to directly contact the metal heating plate 2. The detection probe 22 placed on the outer bottom surface of the metal heating plate 2 can more accurately detect the temperature of the liquid in the pot. Therefore, when it is used in conjunction with the detection electrode 41, the response flexibility of the heating plate 24 and the detection electrode 41 is enhanced, significantly reducing the risk of liquid overflow in the pot body 1. At the same time, the structure of the annular rib 25 not only enables its own structure to effectively disperse external forces, but also reduces the stress concentration points of the hydrophobic coating 21 around the annular rib 25, thereby improving the stability of the overall structure.

[0050] In this embodiment, the inner and outer edges of the exposed area 251 are annular.

[0051] The advantages of this design are that by making the exposed area 251 a ring, the structure of the exposed area 251 becomes more symmetrical and the heating is more uniform. When the liquid in the pot body 1 comes into contact with the metal heating plate 2 through the exposed area 251, the temperature detected by the detection probe 22 can be more accurate, avoiding detection errors caused by rapid local temperature rise. At the same time, the ring structure has good stability and can effectively disperse external forces. It also reduces stress concentration points for the hydrophobic coating 21 around the concentric ring exposed area 251, thereby improving the overall structural stability. Furthermore, the ring is easier to process than other shapes, and the edge of the ring is a smooth curve, which makes it less likely to have dead corners and easier to clean.

[0052] In another embodiment, the inner and outer edges of the exposed area 251 can also be concentric rings, and the shape of the concentric rings can be polygonal, elliptical, etc. Such a structural arrangement can also achieve the above-mentioned effect.

[0053] Considering the uniformity and accuracy of the temperature detection of the liquid inside the pot by the detection probe 22, the projection of the temperature sensing area 26 on the upper surface of the heating plate is located within the range of the inner edge of the exposed area 251.

[0054] Since the exposed area 251 is annular and the temperature sensing area 26 is located within the inner edge of the exposed area 251, the detection probe 22 can more evenly detect the temperature changes of the liquid inside the pot 1. Furthermore, because the exposed area 251 is made of metal, the temperature of the liquid at the exposed area 251 rises faster than that of the liquid in the inner ring of the exposed area 251. This structural design not only ensures that the temperature of the liquid at the exposed area 251 is closer to the temperature of the liquid inside the pot 1, but also prevents the temperature of the inner ring of the exposed area 251 from boiling and generating bubbles during the heating process of the liquid inside the pot 1. Therefore, the temperature sensing area 26, located within the inner edge of the exposed area 251, will not cause the liquid temperature detected by the detection probe 22 to fluctuate due to the generation and rupture of bubbles, thus ensuring the accuracy of temperature detection inside the pot 1.

[0055] In order to reduce stress concentration when the hydrophobic coating 21 is subjected to external force and to better absorb and disperse external force, this embodiment makes the longitudinal section shape of the annular rib 25 an inverted trapezoidal structure, and the longitudinal section of the hydrophobic coating 21 that matches it is also a corresponding inclined surface. Compared with the vertical structure, this structure reduces the risk of damage caused by stress concentration and extends the service life of the hydrophobic coating 21.

[0056] In addition, the upper surface of the metal heating plate 2 is provided with a hydrophobic coating 21 on the inner ring side of the annular rib 25, so that the width of the exposed area 251 formed by the annular rib 25 is not too wide. At this time, the width of the exposed area 251 and the contact area formed by the liquid in the pot are just right to ensure the accuracy of the detection probe 22 in measuring the temperature of the liquid in the pot.

[0057] The hydrophobic coating 21 is generally sprayed onto the upper surface of the metal heating plate 2. In this embodiment, the exposed area 251 is formed by the protrusion of the metal heating plate 2, and the two sides of the top surface of the annular rib 25 are flush with the edge of the hydrophobic coating 21, ensuring the flatness of the bottom surface of the entire pot body 1. This structure makes the bottom surface of the pot body 1 easier to clean after steaming or cooking food, without leaving any hard-to-clean corners. At the same time, it also avoids the step span caused by unevenness, so that the edge of the coating is not scratched or damaged during the cleaning of the bottom surface of the pot body 1. This helps to maintain the integrity of the hydrophobic coating 21, improves the service life, and ensures the function of the pot body 1.

[0058] Alternatively, the detection probe 22 can remain on the lower surface of the metal heating plate 2. By disrupting the integrity of the coating on the surface of the metal heating plate 2, the metal part of the metal heating plate 2 can be exposed and come into contact with the liquid inside the pot body 1, achieving the same effect.

[0059] Generally speaking, methods to damage the integrity of the hydrophobic coating 21 include masking the spray or removing part of the hydrophobic coating 21 by laser engraving after spraying.

[0060] Specifically, the distance L1 between the inner and outer edges of the exposed area 251 is limited to 2–6 mm to avoid the exposed area 251 being too wide or too narrow, ensuring the accuracy of the temperature measurement of the liquid inside the pot by the detection probe 22 within this range. When the distance L1 between the inner and outer edges of the exposed area 251 is less than 2 mm, it may cause poor contact between the liquid and the exposed area 251 during the heating process, when the liquid foams and comes into contact with the detection electrode 41 on the top of the pot 1, increasing the probability of liquid overflow. When the distance L1 between the inner and outer edges of the exposed area 251 is greater than 6 mm, the exposed area 251 is too wide. Since the exposed area 251 is made of metal, the food inside the pot 1 may stick to the bottom during steaming, increasing the difficulty of cleaning after steaming.

[0061] It should be noted that the specific values ​​mentioned above are only preferred examples in this implementation. In other usages, this means that the values ​​can be scaled up according to the specific size of the liquid heater.

[0062] In another embodiment, based on the above, such as Figure 3 and Figure 4 As shown, the protrusion on the upper surface of the metal heating plate 2 can also be a boss 27, the top surface of the boss 27 forms an exposed area 251, and the outer peripheral edge of the top surface of the boss 27 is flush with the hydrophobic coating 21.

[0063] As described above, the boss 27 is formed by protrusion from the upper surface of the metal heating plate 2. The top surface of the boss 27 forms an exposed area 251 that is flush with the hydrophobic coating 21. The top surface of the boss 27 directly contacts the liquid inside the pot, making the contact area between the exposed area 251 and the liquid inside the pot larger. This optimizes the accuracy of the detection probe 22 in detecting temperature changes inside the pot body 1. At the same time, the outer edge of the top surface of the boss 27 is flush with the hydrophobic coating 21, ensuring the flatness of the bottom surface of the entire pot body 1. This structure makes the bottom surface of the pot body 1 easier to clean after steaming or cooking food, without leaving any hard-to-clean corners. It also avoids the step-like span caused by unevenness, which could scratch or damage the edge of the coating during the cleaning process of the bottom surface of the pot body 1. This helps to maintain the integrity of the hydrophobic coating 21, improves its service life, and ensures the function of the pot body 1.

[0064] Specifically, the diameter L2 of the protrusion 27 is limited to 9mm ± 1mm ​​to avoid the protrusion 27 being too wide or too narrow, ensuring the accuracy of the detection probe 22 in measuring the temperature of the liquid inside the pot within this range. When the diameter L2 of the protrusion 27 is less than 8mm, during the heating process of the liquid inside the pot 1, when the liquid produces foam and comes into contact with the detection electrode 41 on the top of the pot 1, the exposed area 251 may be too small, resulting in poor contact between the liquid and the exposed area 251, increasing the probability of liquid overflowing from the pot 1. When the width L2 of the protrusion 27 is greater than 10mm, the diameter of the protrusion 27 is relatively large. Since the protrusion 27 is made of metal, the food inside the pot 1 may stick to the bottom during the steaming process, increasing the difficulty of cleaning after steaming.

[0065] It should be noted that the specific values ​​mentioned above are only preferred examples in this embodiment. In other usages, this specifically refers to scaling up according to the specific size of the liquid heater. Besides the preferred embodiments described above, this utility model has other implementations. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection claimed by this utility model.

Claims

1. A liquid heater, characterized in that, The device includes a kettle body and a metal heating plate. The metal heating plate is fixed to the bottom of the kettle body. The upper surface of the metal heating plate is coated with a hydrophobic coating. A detection probe is installed on the outer bottom surface of the metal heating plate. The upper surface of the metal heating plate has an exposed area of ​​bare metal, which is a closed ring. The hydrophobic coating inside the exposed area corresponds to the detection probe to form a temperature sensing area. The projection of the temperature sensing area on the upper surface of the metal heating plate is located inside the inner edge of the exposed area. The conductive end of the detection probe is in close contact with the temperature sensing area to achieve electrical conduction.

2. The liquid heater according to claim 1, characterized in that, The kettle body is equipped with a detection electrode that extends into the inner cavity of the kettle body. The detection electrode and the detection probe are electrically connected to the detection circuit. The liquid inside the kettle body comes into contact with the exposed area and then with the detection electrode to form a detection circuit.

3. The liquid heater according to claim 1, characterized in that, The upper surface of the metal heating plate is provided with annular ribs, and the top surface of the annular ribs forms an exposed area.

4. The liquid heater according to claim 3, characterized in that, The longitudinal cross-sectional shape of the annular rib is an inverted trapezoidal structure.

5. The liquid heater according to claim 3, characterized in that, The upper surface of the metal heating plate has a hydrophobic coating on the inner ring side of the annular rib, and the two sides of the top surface of the annular rib are flush with the edge of the hydrophobic coating.

6. The liquid heater according to claim 3, characterized in that, The distance between the inner and outer edges of the exposed area is 2 to 6 mm.

7. The liquid heater according to claim 1, characterized in that, The inner and outer edges of the exposed area are concentric rings.

8. The liquid heater according to claim 1, characterized in that, The inner and outer edges of the exposed area are circular.

9. The liquid heater according to claim 1, characterized in that, The metal heating plate includes a stainless steel plate body and a heating plate, with the heating plate fixed to the lower surface of the stainless steel plate body and a hydrophobic coating applied to the upper surface of the stainless steel plate body.

10. The liquid heater according to any one of claims 1 to 9, characterized in that, The hydrophobic coating is a ceramic coating or a Teflon coating.

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