Liquid heater capable of detecting liquid level across air

Abstract

The utility model discloses a liquid heater capable of detecting liquid level across the air, which belongs to the field of life electric appliances, solves the problem that the detection stability is influenced by too fast change of foam liquid level, and adopts the technical scheme that a detection component for detecting the liquid level across the air is hidden between a shell and a glass cup body; the detection assembly comprises a detection plate provided with induction metal sheets, the detection plate longitudinally extends along the outer wall of the glass cup body, the induction metal sheets are longitudinally distributed on the detection plate, the projection of the induction metal sheets on the heating disc is located between the two ends of the heating pipe, and the detection width of the induction metal sheets is smaller than the width of the opening. The foam liquid level detection device is mainly used for improving the stability of foam liquid level detection, reducing the frequency of controlling the power change of the heating pipe, and being beneficial to guaranteeing the stewing efficiency and effect.

Description

Technical Field

[0001] The utility model relates to a household electrical appliance, in particular to a liquid heater capable of detecting liquid level in the air. Background Art

[0002] Liquid heaters are common electrical appliances in daily life, such as kettles, electric kettles, health kettles, etc. They generally include a glass cup body and a heating plate. The heating plate and the glass cup body cooperate to form a container for holding liquid. A heating tube is arranged around the center of the heating plate on one side of the heating plate. The heating tube generally adopts a structure with an opening between the two ends, such as the heating tube disclosed in the prior art CN208658830U. Due to the structure of the heating tube, the temperature change speed of the heating plate will be uneven. At the opening position, since there is no heat source, heat can only be obtained by conduction, so the temperature change will be relatively slow. The temperature change will be relatively fast at the position with the heating tube.

[0003] Some liquid heaters, such as health kettles, can be used to stew some ingredients, such as tremella. During actual use, a large amount of foam will be generated. In order to prevent the foam from overflowing, an anti-overflow structure will be set. For example, the prior art CN108451360A discloses a health kettle, which includes a kettle body, a kettle lid covering the kettle body, a base located below the kettle body, a heating component for heating the kettle body, and a controller electrically connected to the heating component. At least one induction metal sheet electrically connected to the controller is provided on the outer side wall of the kettle body, and each induction metal sheet is electrically connected to the bottom wall of the kettle body to form a capacitive sensor; the controller controls the heating power of the heating component according to the electrical signal fed back by the induction metal sheet. In the area where the temperature change of the heating plate is relatively slow, the rising speed of the foam is relatively slow. In the area where the temperature change of the heating plate is relatively fast, the generation speed of the foam is relatively fast and the rising speed of the foam is relatively fast, and relatively large foam is more likely to be generated, and the foam is always continuously generated and broken. After the induction metal sheet senses that the foam liquid level exceeds the predetermined height, the heating tube will stop heating or reduce the heating power. If the induction metal sheet is arranged above the area where the temperature change of the heating plate is relatively fast, there will be the following two situations: one is that there is relatively large foam. The induction metal sheet detects that the foam liquid level reaches the height where anti-overflow action is required, and then the large foam immediately breaks, and the foam liquid level drops to the actual liquid level where it does not reach the height where anti-overflow action is required, which will affect the stability of detection; the other is that when the heating tube is heating at full power, the foam liquid level in this area rises relatively fast, and the induction metal sheet will detect in advance that the foam liquid level reaches the height where anti-overflow action is required, resulting in the heating tube stopping heating or reducing the heating power in advance. The foam liquid level will quickly drop, and then the heating tube will start heating again, and the foam liquid level will quickly rise again. The induction metal sheet will detect in advance that the foam liquid level reaches the height where anti-overflow action is required. The time interval between two anti-overflow actions is relatively short, resulting in the action of controlling the change of the heating power of the heating tube becoming more frequent, which affects the stewing efficiency and effect. Summary of the Invention

[0004] The purpose to be achieved by the present invention is to provide a liquid heater for remotely detecting the liquid level, solve the problem of unstable detection of the foam liquid level, improve the stability of the foam liquid level detection, reduce the frequency of controlling the change of the heating power of the heating tube, and is beneficial to ensuring the stewing efficiency and effect.

[0005] In order to achieve the above-mentioned purpose, the utility model adopts the following technical scheme: a liquid heater for detecting liquid level in the air, comprising a glass cup body and a heating plate, the heating plate and the glass cup body cooperate to form a container for holding liquid, a heating tube arranged around the center of the heating plate is provided on one side of the heating plate, an opening is formed between the two ends of the heating tube, a shell is provided on the outside of the glass cup body, a detection component for detecting liquid level in the air is hidden between the shell and the glass cup body, the detection component comprises a detection plate provided with a sensing metal sheet, the detection plate extends longitudinally along the outer wall of the glass cup body, the sensing metal sheets are longitudinally distributed on the detection plate, the projection of the sensing metal sheet on the heating plate is located between the two ends of the heating tube, and the detection width of the sensing metal sheet is smaller than the width of the opening.

[0006] After adopting the above technical scheme, the utility model has the following advantages: since the temperature change speed between the two ends of the heating tube is slow, the foam generation speed is slow, and the time interval for the foam liquid level to rise to the point where anti-overflow action is required is long, the projection of the induction metal sheet on the heating plate is designed to be located between the two ends of the heating tube, and the detection width of the induction metal sheet is smaller than the width of the opening, which can weaken the impact of rapid temperature changes on the induction metal sheet, reduce the frequency of anti-overflow action, and at the same time, it is not easy to generate large foam above the opening, effectively avoiding the situation where the actual foam liquid level has not risen to the height required for anti-overflow action due to the generation and rupture of large bubbles, but the anti-overflow action is taken, improving the stability of foam level detection, and reducing the frequency of controlling the power change of the heating tube, which is beneficial to ensuring the stewing efficiency and effect.

[0007] Furthermore, a projection of a center line of the induction metal sheet in the width direction on the heating plate overlaps with a center line of the opening.

[0008] By adopting the above technical solution, the distance between the induction metal sheet and the two ends of the heating tube is relatively balanced, further reducing the impact of rapid temperature changes on the induction metal sheet.

[0009] Furthermore, the distance between the projections of the top center and the bottom center of the induction metal sheet on the heating plate and the two ends of the heating tube does not exceed 5 mm.

[0010] By adopting the above-mentioned technical solution, the distance between the entire sensing metal sheet and the heating tube is kept in a relatively uniform state, further reducing the impact of rapid temperature changes on the sensing metal sheet, and meeting the requirements of stable detection when making drinks of different amounts.

[0011] Furthermore, the projection of the detection plate on the heating plate is located between the two ends of the heating tube.

[0012] Adopting the foregoing technical solution, the detection board conducts heat. By limiting the position of the detection board, the temperature change rate of the detection board is reduced, further reducing the impact of rapid temperature change on the induction metal sheet, and ensuring the stability and reliability of the foam liquid level detection.

[0013] Furthermore, the induction metal sheet includes a plurality of second capacitor sheets, which are longitudinally arranged at intervals, and the plurality of second capacitor sheets form an anti-overflow detection area on the detection board.

[0014] Adopting the foregoing technical solution, the second capacitor sheets at different height positions can generate different signals, which is beneficial to providing anti-overflow requirements at different heights when making different beverages, and at the same time ensuring the timeliness of anti-overflow detection and reducing the risk of anti-overflow delay.

[0015] Furthermore, the anti-overflow detection area is located above half of the height of the glass cup body; and / or, the projection of the second capacitor sheet on the heating plate is located between the two ends of the heating tube.

[0016] Adopting the foregoing technical solution, if the anti-overflow detection area is set too low, the anti-overflow action will be executed when the foam liquid level is far from reaching the height at which it will overflow, resulting in frequent execution of the anti-overflow action, losing the meaning of anti-overflow, and affecting the normal use of the product. Therefore, it is designed that the anti-overflow detection area is located above half of the height of the glass cup body to ensure the effectiveness of the anti-overflow action; the projection of the second capacitor sheet on the heating plate is located between the two ends of the heating tube, which can ensure the stability and reliability of the foam liquid level detection.

[0017] Furthermore, the induction metal sheet includes a plurality of first capacitor sheets arranged longitudinally at intervals, and the plurality of first capacitor sheets form a water level detection area on the detection board, and the water level detection area is located below the anti-overflow detection area.

[0018] Adopting the foregoing technical solution, since the height space below the anti-overflow detection area does not require anti-overflow detection, a water level detection area is added on the basis of the anti-overflow detection area to expand the function of the detection component.

[0019] Furthermore, along the height direction of the detection board, the detection height of a single second capacitor sheet is greater than the detection height of a single first capacitor sheet.

[0020] Adopting the foregoing technical solution, the generation and rupture of foam can occur within the height range of a single second capacitor sheet, and the detection signal does not change during this process, which can effectively reduce the frequency of taking the anti-overflow action when the actual foam liquid level does not rise to the height at which the anti-overflow action needs to be taken due to the generation and rupture of foam, further improving the stability of anti-overflow detection. And the small detection height of a single first capacitor sheet can more quickly detect the water level change and improve the sensitivity of water level detection.

[0021] Further, the detection component is adhesively attached to the outer sidewall of the glass cup body by glue; alternatively, the detection component further includes a mounting bracket, the mounting bracket is fixed to the outer sidewall of the glass cup body and presses the detection plate tightly against the outer sidewall of the glass cup body.

[0022] Further, a bottom cover is provided below the container, and the bottom cover and the container cooperate to form a mounting cavity for accommodating the upper coupler. The detection plate extends into the mounting cavity through a wire and is electrically connected to the upper coupler;

[0023] Alternatively, the detection plate is electrically connected to a signal transmitter, the liquid heater includes a power supply base, a signal receiver is provided inside the power supply base, and the signal receiver and the signal transmitter are matched to form signal transmission;

[0024] Alternatively, the glass cup body includes an arc-shaped outer wall that extends upward and inward in the height direction, and the detection plate extends along the arc-shaped outer wall;

[0025] Alternatively, the glass cup body includes a straight cylindrical outer wall that extends vertically in the height direction, and the detection plate extends vertically along the straight cylindrical outer wall;

[0026] Alternatively, the glass cup body includes a tapered cylindrical outer wall that extends upward and inwardly inclined in the height direction, and the detection plate extends along the tapered cylindrical outer wall. Description of the Drawings

[0027] The present invention will be further described below with reference to the accompanying drawings:

[0028] Figure 1 Schematic diagram of a liquid heater for remotely detecting the liquid level of the present invention (without a heating plate);

[0029] Figure 2 Bottom view of the container in the present invention;

[0030] Figure 3 Schematic diagram of the positional relationship between the induction metal sheet and the heating tube in the present invention;

[0031] Figure 4 Schematic diagram of the detection plate in the present invention;

[0032] Figure 5 Schematic diagram of the projection of the induction metal sheet on the heating plate in the present invention (the outer sidewall of the glass cup body is a tapered cylindrical outer wall that extends upward and inwardly inclined);

[0033] Figure 6 Schematic diagram of the projection of the induction metal sheet on the heating plate in the present invention (the outer sidewall of the glass cup body is a straight cylindrical outer wall that extends vertically in the height direction);

[0034] Figure 7Schematic diagram of the projection of the induction metal sheet on the heating plate in the present utility model (the outer side wall of the glass cup body is an arc-shaped outer wall extending upward and inward along an arc);

[0035] Figure 8 Schematic diagram of the projection of the induction metal sheet on the heating plate in the present utility model (the outer side wall of the glass cup body is entirely located on the outer peripheral side of the heating tube);

[0036] Figure 9 Schematic diagram of the container and the power supply base in the present utility model. Specific embodiments

[0037] To make the objectives, technical solutions, and advantages of the embodiments of the present utility model clearer, the technical solutions in the embodiments of the present utility model will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are only some of the embodiments of the present utility model, rather than all of the embodiments.

[0038] The terms "first", "second", etc. (if any) in the description and claims of the present utility model are used to distinguish similar objects, rather than to describe a specific order or sequence. Even if "second" is used to distinguish a certain technical feature, it does not necessarily imply the existence of "first". It should be understood that in the present utility model, "including" and "having" and any of their variations are intended to cover non-exclusive inclusion. It should be understood that in the present utility model, "a plurality of" means two or more. "And / or" is merely a description of the association relationship between associated objects, indicating that three relationships may exist. For example, X and / or Y may represent: X exists alone, X and Y exist simultaneously, and Y exists alone. The character " / " generally represents an "or" relationship between the associated objects before and after. "Including X, Y, and Z", "including X, Y, Z" means that all of X, Y, and Z are included, "including X, Y, or Z" means that one of X, Y, and Z is included, and "including X, Y, and / or Z" means that any one or any two or all three of X, Y, and Z are included.

[0039] The technical solutions of the present utility model will be described in detail below with specific embodiments. These specific embodiments can be combined or replaced according to the actual situation. For the same or similar concepts or processes, they may not be repeated in some embodiments.

[0040] Such as Figure 1As shown, the utility model provides a liquid heater for detecting liquid level in the air, including a glass cup body 100 and a heating plate 200. The heating plate 200 cooperates with the glass cup body 100 to form a container for holding liquid. A heating tube 21 arranged around the center of the heating plate 200 is provided on one side of the heating plate 200. An opening is formed between the two ends of the heating tube 21. A shell 300 is provided on the outside of the glass cup body 100. A detection component 400 for detecting liquid level in the air is hidden between the shell 300 and the glass cup body 100. The detection component includes a detection plate 41 provided with a sensing metal sheet 411. The detection plate 41 extends longitudinally along the outer wall of the glass cup body 100. The sensing metal sheets 411 are longitudinally distributed on the detection plate 41. Figure 2 It can be seen that the projection of the induction metal sheet 411 on the heating plate 200 is located between the two ends of the heating tube 21 , and the detection width W1 of the induction metal sheet 411 is smaller than the width W2 of the opening.

[0041] The shell 300 may only cover a portion of the outer wall of the glass body 100, for example Figure 1 The middle shell 300 is designed with a handle 31, which can cover the detection assembly 400, so that the user can observe the working conditions inside the container through the glass cup body 100, thereby improving the user experience. The shell 300 can also completely cover the outer wall of the glass cup body 100 to protect the glass cup body 100, and accordingly, an observation window can be opened on the shell 300 for conveniently observing the working conditions inside the container. The detection board 41 realizes the function of liquid level detection, which is a prior art. For details, please refer to the signal PCB board mentioned in the prior art CN106108646A, which will not be repeated here.

[0042] The glass cup body 100 can generally be a simple glass product, and the detection component 400 is in direct contact with the glass material. The glass cup body 100 can also include a glass substrate and a film. The film is arranged on the outer side of the glass substrate and can cover part or all of the outer side of the glass substrate. Some marks, such as water level marks, prompt marks, etc., are set on the film. At this time, the outer wall of the glass cup body 100 is the outer side of the film, and the detection component 400 is in contact with the film. In addition, a silk-screen shielding layer, such as ink or film, can be set on the outer wall of the glass cup body 100 to prevent the user from directly observing the detection component through the glass cup body 100 from the inside of the glass cup body 100, thereby improving the aesthetics. The silk-screen shielding layer is considered to be a part of the glass cup body 100, and the outer wall of the glass cup body 100 is the outer side of the silk-screen shielding layer, and the detection component 400 is in contact with the silk-screen shielding layer.

[0043] Since there is no heat source in the opening area between the two ends of the heating tube, the temperature change rate is slow, the foam generation rate is slow, and the time interval for the foam liquid level to rise to the level where anti-overflow action is required is long. It is designed that the projection of the induction metal sheet on the heating plate is located between the two ends of the heating tube, and the detection width of the induction metal sheet is smaller than the width of the opening, which can weaken the influence of rapid temperature change on the induction metal sheet, reduce the frequency of anti-overflow action, and at the same time, large bubbles are not easily generated above the opening, effectively avoiding the situation where anti-overflow action is taken when the actual foam liquid level does not rise to the height where anti-overflow action is required due to the generation and rupture of large bubbles, improving the stability of foam liquid level detection, reducing the frequency of controlling the power change of the heating tube, and being beneficial to ensuring the stewing efficiency and effect.

[0044] In some liquid heaters, the outer side wall of the glass cup body is a conical outer wall that extends upward and inward. After the outer side wall of the glass cup body 100 is projected downward, it will partially cover the heating tube 21. Although the projection 4110 of the induction metal sheet 411 on the heating plate 200 is located between the two ends of the heating tube 21, the projected area is large. As Figure 5 shown, there will be a situation where part of the projection is inside the opening and part is outside the opening. In some liquid heaters, the outer side wall of the glass cup body 100 is a straight outer wall that extends vertically in the height direction or an arc-shaped outer wall that extends upward and inward along an arc. The projected area of the induction metal sheet 411 on the heating plate 200 is small. For example, Figure 6 and Figure 7 shown, there will be a situation where the projection 4110 of the induction metal sheet 411 on the heating plate 200 is entirely inside the opening. In some liquid heaters, the outer side wall of the glass cup body is entirely on the outer peripheral side of the heating tube, then there will be a situation where the projection 4110 of the induction metal sheet 411 on the heating plate 200 is entirely outside the opening, as Figure 8 shown.

[0045] The detection plate 41 generally adopts a rectangular structure. In order to make the distances from both sides of the induction metal sheet 411 in the width direction to the two ends of the heating tube 21 close, it can be designed that the projection of the center line of the induction metal sheet 411 in the width direction on the heating plate 200 overlaps with the center line of the opening. The overlapping center line is the Figure 3 dotted line L in, further reducing the influence of rapid temperature change on the induction metal sheet.

[0046] And in order to further reduce the influence of rapid temperature change on the induction metal sheet 411, it is also possible to control the distances S1 and S2 from the projection of the top center and bottom center of the induction metal sheet 411 on the heating plate to the two ends of the heating tube 21 not to exceed 5 mm ( Figure 3The middle arc-shaped dotted line is a simplified schematic diagram of the heating tube 21). Make the distance from the entire induction metal sheet 411 to the heating tube in a relatively uniform state, further reducing the impact of rapid temperature changes on the induction metal sheet 411, and meeting the requirements of stable detection when making different portions of beverages. In some embodiments, the induction metal sheet 411 includes a plurality of separately arranged capacitor sheets. The top center and bottom center of the induction metal sheet 411 respectively refer to the top center of the capacitor sheet located at the highest position and the bottom center of the capacitor sheet located at the lowest position.

[0047] Since the detection plate 41 conducts heat, to further reduce the impact of rapid temperature changes on the induction metal sheet 411, the position of the detection plate 41 can be limited so that the projection of the detection plate on the heating plate is located between the two ends of the heating tube, reducing the temperature change speed of the detection plate and further reducing the impact of rapid temperature changes on the induction metal sheet, ensuring the stability and reliability of the foam liquid level detection.

[0048] Reference Figure 4 , in order to achieve anti-overflow detection, the induction metal sheet 411 includes a plurality of second capacitor sheets 411B. The plurality of second capacitor sheets 411B are longitudinally arranged at intervals, and the plurality of second capacitor sheets 411B form an anti-overflow detection area 401 on the detection plate 41. The second capacitor sheets 411B at different height positions can generate different signals, which is beneficial to providing anti-overflow requirements at different heights when making different beverages. For example, for beverages with very fast foam generation and not easy to break, the second capacitor sheet 411B at a lower position can be used for anti-overflow detection, while for beverages with slower foam generation and easy to break, the second capacitor sheet 411B at a higher position can be used for anti-overflow detection. If the anti-overflow detection area 401 is set too low, it will cause frequent anti-overflow actions, and there will be a situation where the anti-overflow action is executed when the foam liquid level is far from reaching the height that will overflow, losing the meaning of anti-overflow and affecting the normal use of the product. Therefore, generally, the anti-overflow detection area 401 is designed to be above half of the height of the glass body 100. And to reduce the impact of rapid temperature changes on the second capacitor sheet, it can be required that the projection of the second capacitor sheet 411B on the heating plate 200 is located between the two ends of the heating tube 21.

[0049] Since there is no need to perform anti-overflow detection in the height space below the anti-overflow detection area 401, on the basis of the anti-overflow detection area 401, a water level detection area can be added. It can be designed that the induction metal sheet 411 includes a plurality of first capacitor sheets 411A arranged at longitudinal intervals. The plurality of first capacitor sheets 411A form a water level detection area 402 on the detection plate 41. The water level detection area 402 is located below the anti-overflow detection area 401, expanding the function of the detection component.

[0050] The foam itself has a certain height dimension. To increase the fault tolerance rate of anti-overflow detection, in one embodiment, along the height direction of the detection board 41, the detection height H2 of a single second capacitor plate 411B is greater than the detection height H1 of a single first capacitor plate 411A. The generation and rupture of the foam can occur within the height range of a single second capacitor plate 411B, and the detection signal will not change during this process, which can reduce the situation where anti-overflow actions are taken when the actual foam liquid level has not risen to the height required for anti-overflow actions due to the generation and rupture of the foam, further improving the stability of anti-overflow detection. And the small detection height H1 of a single first capacitor plate can more quickly reflect the change in the water level.

[0051] In one embodiment, the detection component 400 is adhesively connected to the outer side wall of the glass cup body 100 with glue, and other common methods such as riveting and screwing can also be used to fix the detection component 400. The detection board 41 can also be fixed by pressing it against the outer side wall of the glass cup body through the mounting bracket 42, and the mounting bracket 42 can be fixed to the outer side wall of the glass cup body 100 by means of glue or screw clamps.

[0052] Reference Figure 9 , the liquid heater of the present utility model further includes a power supply base 500. The power supply base 500 is provided with a lower coupler 51. When the container is placed on the power supply base 500, it obtains the working power supply. Specifically, in one embodiment, a bottom cover 600 is provided below the container. The bottom cover 600 and the container cooperate to form an installation cavity for accommodating the upper coupler 61. The upper coupler 61 is plugged and electrically coupled with the lower coupler 51 to obtain the power supply. The detection board 41 extends into the installation cavity through a wire and is electrically connected to the upper coupler 61. The information transmission through the wire is relatively stable. In addition to realizing signal transmission through wired connection, wireless connection can also be used to realize signal transmission. For example, in another embodiment, the detection board 41 is electrically connected to a signal transmitter, and a signal receiver is provided in the power supply base 500. The signal receiver and the signal transmitter are matched to form signal transmission.

[0053] In some models, the glass cup body 100 includes an arc-shaped outer wall that extends upward and inward along the height direction, and the detection board 41 extends along the arc-shaped outer wall. In other models, the glass cup body 100 includes a straight cylindrical outer wall that extends vertically along the height direction. For example Figure 5 shown, the detection board 41 extends vertically along the straight cylindrical outer wall. In still other models, the glass cup body 100 includes a conical cylindrical outer wall that extends obliquely along the height direction. For example Figure 8 shown, the detection board 41 extends along the conical cylindrical outer wall. No matter how the outer wall of the glass cup body 100 extends, as long as the detection board 41 fits against the outer wall of the glass cup body 100 and reduces the air between the two, the influence of air on the detection of the induction metal sheet 411 can be reduced.

[0054] In one embodiment, a water outlet nozzle 11 is provided at the top of the glass body 100. In order to reduce the risk of anti-overflow delay that may be caused by the induction metal sheet 411 being provided above the opening, the water outlet nozzle can be designed to be located above the opening.

[0055] In addition to the above preferred embodiments, the present utility model has other implementation manners. Based on the embodiments in the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the scope of protection claimed by the present utility model.

Claims

1. A liquid heater for detecting liquid level in the air, comprising a glass cup body and a heating plate, wherein the heating plate and the glass cup body cooperate to form a container for holding liquid, a heating tube arranged around the center of the heating plate is provided on one side of the heating plate, an opening is formed between the two ends of the heating tube, and a shell is provided on the outer side of the glass cup body, wherein: A detection component for detecting the liquid level in the air is hidden between the shell and the glass cup body. The detection component includes a detection plate provided with a sensing metal sheet. The detection plate extends longitudinally along the outer wall of the glass cup body. The sensing metal sheet is longitudinally distributed on the detection plate. The projection of the sensing metal sheet on the heating plate is located between the two ends of the heating tube. The detection width of the sensing metal sheet is smaller than the width of the opening.

2. The liquid heater according to claim 1, characterized in that: The projection of the center line of the induction metal sheet in the width direction on the heating plate overlaps with the center line of the opening.

3. The liquid heater according to claim 2, characterized in that: The distance between the projection of the top center and the bottom center of the induction metal sheet on the heating plate and the two ends of the heating tube does not exceed 5 mm.

4. The liquid heater according to claim 1, characterized in that: The projection of the detection plate on the heating plate is located between the two ends of the heating tube.

5. The liquid heater according to claim 1, characterized in that: The inductive metal sheet includes a plurality of second capacitor sheets, the plurality of second capacitor sheets are arranged at intervals in the longitudinal direction, and the plurality of second capacitor sheets form an anti-overflow detection area on the detection plate.

6. The liquid heater according to claim 5, characterized in that: The anti-overflow detection area is located at more than one-half of the height of the glass body; and / or the projection of the second capacitor sheet on the heating plate is located between the two ends of the heating tube.

7. The liquid heater according to claim 5, characterized in that: The inductive metal sheet comprises a plurality of first capacitor sheets arranged at intervals in the longitudinal direction. The plurality of first capacitor sheets form a water level detection area on the detection plate. The water level detection area is located below the anti-overflow detection area.

8. The liquid heater according to claim 7, characterized in that: Along the height direction of the detection board, the detection height of a single second capacitor sheet is greater than the detection height of a single first capacitor sheet.

9. The liquid heater according to claim 1, characterized in that: The detection component is adhered to the outer wall of the glass body by glue; or, the detection component also includes a mounting bracket, which is fixed to the outer wall of the glass body and presses the detection plate tightly against the outer wall of the glass body.

10. The liquid heater according to claim 1, characterized in that: A bottom cover is provided below the container, and the bottom cover cooperates with the container to form a mounting cavity for accommodating the upper coupler, and the detection board extends into the mounting cavity through a wire and is electrically connected to the upper coupler; Alternatively, the detection board is electrically connected to a signal transmitter, the liquid heater comprises a power base, a signal receiver is arranged in the power base, and the signal receiver and the signal transmitter are matched to form signal transmission; Alternatively, the glass body comprises an arc-shaped outer wall extending upward and inward in the height direction, and the detection plate extends along the arc-shaped outer wall; Alternatively, the glass body comprises a straight outer wall extending vertically in the height direction, and the detection plate extends vertically along the straight outer wall; Alternatively, the glass body comprises a conical outer wall extending upward and inwardly in a height direction, and the detection plate extends along the conical outer wall.

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