CN221172328U - Electromagnetic stove - Google Patents

Abstract

The utility model belongs to the technical field of household appliances and discloses an electromagnetic stove which comprises a shell, a panel, a control circuit board and a heating furnace, wherein the heating furnace comprises a heating coil and a capacitance sensing device for detecting capacitance change on the panel, the capacitance sensing device is tightly attached to the lower surface of the panel and comprises a plurality of arc-shaped capacitance sensing pieces, the plurality of capacitance sensing pieces are circumferentially arranged at the outer side of the heating coil at intervals, and the plurality of capacitance sensing pieces are respectively and electrically connected with the control circuit board. And detecting whether the cookware is biased or not through the capacitance sensing device, and informing the cookware of the bias state of the cookware and the in-place state of the cookware when detecting that the capacitance value of the capacitance sensing device is different from a set value or the difference of all capacitance values exceeds the set value.

Description

Electromagnetic stove

Technical Field

The utility model relates to the technical field of household appliances, in particular to an electromagnetic oven.

Background

In the prior art, the electromagnetic oven is heated through the heating coil, and the ideal heating state is that the cooker is positioned at the center of the heating coil, so that the cooker is heated uniformly. But in actual use, the cookware is easy to deviate, so that the cookware is heated unevenly, further food heating is affected, and meanwhile, the cookware is deformed easily due to uneven heating of the bottom of the cookware, and the service life of the cookware is shortened. Some induction cookers are improved, the cookers are not biased by limiting the cookers, for example, chinese patent with the patent number of CN 208170456U and the name of an induction cooker capable of limiting the cookers comprises a stove body and a protection component, wherein a limiting ring and a fixing component are arranged at the top of the stove body, the fixing component comprises a fixing plate, a fixing rod, an arc-shaped plate and a connecting piece, the fixing rod is arranged at one end of the fixing plate, and the arc-shaped plate is arranged at one side of the fixing rod. However, the prior art is limited by the limiting mechanism, so that the device is only applicable to specific cookers and cannot truly detect cookers bias.

Disclosure of utility model

The utility model provides an electromagnetic oven capable of detecting the offset position of a cooker, which aims to overcome the defect that the electromagnetic oven in the prior art can not detect the offset of the cooker.

In order to achieve the above purpose, the present utility model adopts the following technical scheme: the utility model provides an electromagnetic oven, includes casing, panel, control circuit board and heating furnace, the heating furnace includes heating coil and is used for detecting the electric capacity induction system that the electric capacity changes on the panel, electric capacity induction system hug closely in the lower surface of panel, electric capacity induction system includes circular-arc a plurality of electric capacity induction piece, and a plurality of electric capacity induction piece circumference interval sets up in the heating coil outside, a plurality of electric capacity induction piece respectively with the control circuit board electricity is connected, a plurality of electric capacity induction piece distributes on same benchmark circle, a plurality of electric capacity induction piece total arc length with the perimeter ratio of benchmark circle is not less than 0.5.

In the technical scheme, the bottom of the pot can be covered with the capacitance sensing device, and the pot can also be positioned near the capacitance sensing device, and the capacitance sensing device can detect the change of the capacitance value. The heating coil is electrically connected with the control circuit board, and the control circuit board can be used for controlling the heating coil to reduce power or stop the electromagnetic stove. The heating coil is generally circular, the bottom of the cooker is also generally circular, the capacitive induction pieces are circumferentially arranged at intervals on the outer side of the heating coil, and the capacitive induction pieces can be better matched with the heating coil and fully cover the detection range, so that the identification stability and accuracy are ensured; meanwhile, the capacitive sensing parts are circumferentially arranged, so that the deflection of the angle of the cooker can not cause the change of the capacitance of the capacitive sensing parts in a proper state of the cooker, and the possibility of false detection is reduced. Specifically, the capacitive sensing piece is arc-shaped, so that the detection range can be better covered in the circumferential direction, and the identification stability and accuracy are further improved. In addition, the capacitance sensing device is positioned on the lower surface of the panel and is not in direct contact with the cooker, and the capacitance sensing device cannot generate abrasion problem. According to the technical scheme, whether the cooker is biased is detected through the capacitance sensing device, and when the difference between the capacitance value of the capacitance sensing device and a set value or the difference between the capacitance values of the capacitance sensing device and the set value exceeds the set value is detected, the bias of the cooker is notified. The capacitance sensing devices are a plurality of capacitance sensing pieces, and the offset positions of the cookers can be reported through capacitance changes of the capacitance sensing pieces at different positions and comparison with set values. In addition, whether overflow exists on the panel can be detected through the capacitance sensing device, the capacitance value of the capacitance sensing device in the cooking process can be detected and recorded by the capacitance difference between the capacitance sensing device and the capacitance generated by the panel which is clung to the capacitance sensing device when the overflow exists on the panel, and then the power of the heating coil is adjusted. In the cooking process, when the capacitance value measured at intervals is continuously larger than a set value for a certain number of times or when the capacitance value measured in real time is continuously larger than the set value for a certain period of time, water overflow is reported, and the heating coil is controlled to reduce power or stop the electromagnetic cooker. In addition, the capacitive sensing device can also prevent misoperation problem generated when overflowed liquid flows to the touch keys, and improves the working safety of the electromagnetic oven when no one looks at the watch. The reference circle refers to that a plurality of capacitance sensing elements are distributed on the same circular outline, and the circular outline is the reference circle. The ratio of the total arc length of the plurality of capacitance sensing pieces to the circumference of the reference circle is not less than 0.5, so that the coverage area of the capacitance sensing pieces is ensured, the phenomenon that a pot cannot be detected due to overlarge gaps on the circumference of the reference circle is avoided, and the possibility of false detection is reduced; the ratio of the total arc length of the plurality of capacitance sensing pieces to the circumference of the reference circle is larger than 0.5, the coverage area of the capacitance sensing pieces is insufficient, the capacitance sensing pieces can not detect the change of the capacitance, and the bias of the cooker can not be detected. Secondly, when guaranteeing also whether there is the overflow thing on the panel, the total arc length of a plurality of capacitive sensing piece with the girth ratio of reference circle is not less than 0.5, guarantees capacitive sensing piece's coverage area, avoids appearing too big breach on the reference circle circumference, leads to unable detection overflow thing.

The utility model is further arranged to: the reference circle is arranged coaxially with the heating coil.

According to the technical scheme, the reference circle and the heating coil are coaxially arranged, so that the distance from each capacitive sensing piece to the center of the heating coil is consistent, the detection range can be uniformly covered, and the false detection possibility is further reduced. In addition, under the condition of the same perimeter, the circular area is the largest, and a plurality of capacitance sensing pieces are distributed on the same reference circle, so that a larger detection range can be covered, the identification stability and accuracy are ensured, and the false detection possibility is reduced. It should be noted that the number of the substrates,

The utility model is further arranged to: the diameter of the reference circle is at least 10mm larger than the outer diameter of the heating coil.

In the above technical scheme, the heating coil can produce stronger electromagnetic field at the during operation, probably causes the interference to the signal detection of electric capacity induction spare, and the diameter of reference circle is bigger than the external diameter of heating coil, reduces the possibility that heating coil disturbed electric capacity induction spare, guarantees the stability of discernment. If the diameter of the reference circle is smaller than 10mm than the outer diameter of the heating coil, the risk of the thermal coil interfering with the capacitive sensing member increases and the recognition stability decreases.

The utility model is further arranged to: the distance between two adjacent capacitance sensing pieces in the circumferential direction is smaller than 10mm.

In the above technical scheme, the interval between two adjacent capacitive sensing pieces in the circumferential direction is less than 10mm, avoids the too big distance between two adjacent capacitive sensing pieces, and the pan is in between two adjacent capacitive sensing piece clearances, leads to unable detection pan, reduces the possibility of reducing the false detection. Secondly, the distance between two adjacent capacitive sensing pieces in the circumferential direction is smaller than 10mm, and the situation that overflow cannot be detected due to overlarge distance between the two adjacent capacitive sensing pieces is avoided.

The utility model is further arranged to: the number of the capacitive sensing pieces is four, and the four capacitive sensing pieces are circumferentially and uniformly distributed on the outer side of the heating coil.

Among the above-mentioned technical scheme, through four electric capacity induction piece circumference equipartitions in the heating coil outside, cover four directions about to the heating coil, position and the biasing condition of detection pan that can be more comprehensive also can more comprehensive detect overflow thing whether overflow simultaneously.

The utility model is further arranged to: the effective contact width of the capacitance sensing piece and the lower surface of the panel is not less than 1.5mm.

In the technical scheme, the effective contact area of the capacitive sensing piece and the panel is ensured, the capacitance value generated by the capacitive sensing device and the panel clung to the capacitive sensing device is conveniently measured, the capacitance value of the detection reference circle is more accurate, and the identification stability is ensured.

The utility model is further arranged to: the plurality of capacitive sensing pieces are at least divided into two groups of capacitive sensing groups, a plurality of capacitive sensing pieces in the first group of capacitive sensing groups are distributed on a first reference circle, a plurality of capacitive sensing pieces in the second group of capacitive sensing groups are distributed on a second reference circle, the first reference circle, the second reference circle and the heating coil are coaxially arranged, and the second reference circle is sleeved outside the first reference circle.

In the technical scheme, the second group of capacitance induction groups are sleeved on the first group of capacitance induction groups, and the first reference circle, the second reference circle and the heating coil are coaxially arranged, so that the detection range is enlarged, the identification stability and accuracy are ensured, and the false detection possibility is reduced. In addition, the first group of capacitance induction groups is covered by the cookers, the second group of capacitance induction groups can also detect capacitance changes, the cookers with different sizes are adapted, and the practicability of the electromagnetic cooker is improved.

The utility model is further arranged to: the capacitive sensing pieces in the two capacitive sensing groups are staggered in the circumferential direction.

In the above technical scheme, through two sets of electric capacity induction sets at circumference crisscross setting, the clearance outside of two arbitrary adjacent electric capacity induction pieces of first group electric capacity induction set all corresponds one of them electric capacity induction piece of second group electric capacity induction set for all distribute electric capacity induction piece in whole circumference, avoid the too big distance between two adjacent electric capacity induction pieces, the pan is in between two adjacent electric capacity induction piece clearances, leads to unable detection pan, reduces the possibility of false detection. The other two groups of capacitance induction groups are arranged in a staggered mode in the circumferential direction, the same detection range is covered, meanwhile, the number of capacitance induction pieces is reduced, and the manufacturing cost of products is reduced.

The utility model is further arranged to: the number of the heating furnaces is two, and the two heating furnaces are arranged side by side.

In the technical scheme, the double-port electromagnetic oven is provided with two heating ovens, two cookers can be placed, the heating ovens on two sides are respectively and independently controlled, and cooking of two threads can be simultaneously carried out without mutual influence.

The beneficial effects of the utility model are as follows: and detecting whether the cookware is biased or not through the capacitance sensing device, wherein the capacitance generated by the capacitance sensing device is different from the capacitance generated by the cookware in a cookware biasing state and a cookware in-place state, and when the capacitance change is detected, notifying the cookware of the biasing. The capacitance induction devices in each heating furnace are respectively and electrically connected with the control circuit board, and when any one heating furnace is started, the capacitance induction devices in the rest heating furnaces are in a detection state. In addition, the capacitance sensing devices in each heating furnace respectively detect capacitance values. When the size of the pan is smaller than the inner diameter of the reference circle, water overflowed from the pan falls in the sensing range of the reference circle, so that the identification stability is ensured; when the size of pan is greater than the internal diameter of reference circle, from the water that one of them pan overflowed, falls outside the perception scope of corresponding reference circle, if other electric capacity induction system is inoperative this moment, can't detect whether there is the overflow thing, and when the electric capacity induction system in other heating furnaces still is in the detection state, from the water that corresponds the pan overflowed fall in the perception scope of other reference circle, still can detect whether there is the overflow thing, enlarges application scope, can not restrict the bottom diameter of pan, guarantees identification stability.

Drawings

FIG. 1 is a schematic diagram of the structure of the present utility model;

FIG. 2 is a schematic view of a pan bias of the present utility model;

FIG. 3 is a schematic view of the pan of the present utility model in place;

FIG. 4 is a schematic diagram of two capacitive sensing groups according to the present utility model;

Fig. 5 is a schematic diagram of two capacitive sensing groups in accordance with the present utility model.

In the figure: 100. a housing; 200. a panel; 300. a control circuit board; 400. a heating furnace; 410. a heating coil; 420. a capacitance sensing device; 421. a capacitive sensing member; 500. a pot.

Detailed Description

In the description of the present embodiment, it should be noted that, if the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside", "front", "rear", etc. appear, the indicated orientation or positional relationship is based on that shown in the drawings, only for convenience of description and simplification of the description, and does not indicate or imply that the indicated apparatus or element must have a specific orientation, be configured and operated in a specific orientation, and therefore, it should not be construed as limiting the present utility model. Furthermore, the terms "first," "second," "third," and the like, as presented herein, are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

The utility model is further described below with reference to the drawings and specific embodiments.

Example 1:

As shown in fig. 1 to 3, an induction cooker comprises a housing 100, a panel 200, a control circuit board 300 and a heating furnace 400, wherein the heating furnace 400 comprises a heating coil 410 and a capacitance sensing device 420 for detecting capacitance change on the panel 200, the capacitance sensing device 420 is tightly attached to the lower surface of the panel 200, the capacitance sensing device 420 comprises a plurality of arc-shaped capacitance sensing pieces 421, the plurality of capacitance sensing pieces 421 are circumferentially arranged outside the heating coil 410 at intervals, and the plurality of capacitance sensing pieces 421 are respectively electrically connected with the control circuit board 300.

In this embodiment, the bottom of the pan 500 may cover the capacitive sensing device 420, or may be located near the capacitive sensing device 420, and the capacitive sensing device 420 can detect the change of the capacitance value. The heating coil 410 is electrically connected with the control circuit board 300, and the control circuit board 300 can be used for controlling the heating coil 410 to reduce power or stop the electromagnetic oven. The heating coil 410 is generally circular, the bottom of the cooker 500 is also generally circular, the capacitive sensing pieces 421 are circumferentially arranged at intervals outside the heating coil 410, and the capacitive sensing pieces 421 can be better matched with the heating coil 410 and fully cover the detection range, so that the identification stability and accuracy are ensured; meanwhile, the capacitive sensing pieces 421 are circumferentially arranged, so that the capacitive sensing pieces 421 cannot be changed due to deflection of the cookware 500 in angle in the in-place state, and the possibility of false detection is reduced. Specifically, the capacitive sensing member 421 is arc-shaped, so that the detection range can be better covered in the circumferential direction, and the identification stability and accuracy are further improved. In addition, the capacitive sensing device 420 is located on the lower surface of the panel 200 and is not in direct contact with the pan 500, and the capacitive sensing device 420 does not generate abrasion problem. In this embodiment, whether the pan 500 is biased is detected by the capacitance sensing device 420, and when detecting that the capacitance value of the capacitance sensing device 420 is different from the set value or the difference between the capacitance values exceeds the set value, the pan 500 is notified of the bias. The capacitance sensing device 420 is a plurality of capacitance sensing elements 421, and the offset position of the pan 500 can be reported by the capacitance change of the capacitance sensing elements 421 at different positions and comparing with a set value. In addition, whether the panel 200 has overflows or not can be detected by the capacitance sensing device 420, and the capacitance value of the capacitance sensing device 420 in the cooking process can be detected and recorded by the capacitance difference between the capacitance sensing device 420 and the panel 200 which is closely attached to the capacitance sensing device 420 in the state that the panel 200 has no overflows and the state that the panel 200 has overflows, so that the power of the heating coil 410 is adjusted. During the cooking process, when the capacitance value measured at intervals is continuously larger than the set value for a certain number of times or when the capacitance value measured in real time is continuously larger than the set value for a certain period of time, water overflow is notified, and the heating coil 410 is controlled to reduce power or stop the electromagnetic range. In addition, the capacitive sensing device 420 can also prevent misoperation caused by overflowing liquid flowing to the touch keys, and improve the working safety of the unmanned electromagnetic oven.

It will be appreciated that capacitive sensing element 421 may be 2, 3, 4, etc. in any suitable number.

Specifically, as shown in fig. 1 to 3, several capacitive sensing members 421 are distributed on the same reference circle, and the reference circle is disposed coaxially with the heating coil 410. Under the condition that the circumferences are the same, the circular area is the largest, and the plurality of capacitance sensing pieces 421 are distributed on the same reference circle, so that a larger detection range can be covered, the identification stability and accuracy are ensured, and the false detection possibility is reduced. In addition, the reference circle and the heating coil 410 are coaxially arranged, so that the distance from each capacitive sensing element 421 to the center of the heating coil 410 is consistent, the detection range can be uniformly covered, and the false detection possibility is further reduced. The reference circle refers to a plurality of capacitive sensing elements 421 distributed on the same circular contour, i.e., the reference circle.

In order to ensure the detection range, the ratio of the total arc length of the plurality of capacitive sensing pieces 421 to the circumference of the reference circle is not less than 0.8. The coverage area of the capacitance sensing piece 421 is ensured, the phenomenon that the pot 500 cannot be detected due to an overlarge gap on the circumference of the reference circle is avoided, and the possibility of false detection is reduced; if the ratio of the total arc length of the plurality of capacitive sensing members 421 to the circumference of the reference circle is greater than 0.8, the capacitive sensing members 421 may not cover enough area, and thus the capacitive sensing members 421 may not detect the change of capacitance, and thus may not detect the bias of the pot 500. Secondly, it is also ensured that when there is an overflow on the panel 200, the ratio of the total arc length of the plurality of capacitive sensing pieces 421 to the circumference of the reference circle is not less than 0.8, the coverage area of the capacitive sensing pieces 421 is ensured, and an oversized gap on the circumference of the reference circle is avoided, so that the overflow cannot be detected.

Likewise, in order to secure a detection range, the interval between two capacitance sensing pieces 421 adjacent in the circumferential direction is less than 10mm. The distance between two adjacent capacitive sensing pieces 421 is prevented from being too large, the cooker 500 is positioned between gaps of the two adjacent capacitive sensing pieces 421, so that the cooker 500 cannot be detected, and the possibility of false detection is reduced. Second, the distance between two adjacent capacitive sensing pieces 421 in the circumferential direction is smaller than 10mm, so that the excessive distance between two adjacent capacitive sensing pieces 421 is avoided, and overflow cannot be detected.

To reduce interference, the diameter of the reference circle is at least 10mm larger than the outer diameter of the heating coil 410. The heating coil 410 can produce stronger electromagnetic field when working, probably causes the interference to the signal detection of electric capacity induction piece 421, and the diameter of reference circle is bigger than the external diameter of heating coil 410, reduces the possibility that heating coil 410 disturbed electric capacity induction piece 421, guarantees the stability of discernment. If the diameter of the reference circle is smaller than 10mm than the outer diameter of the heating coil 410, the risk of the heat coil interfering with the capacitive sensing member 421 increases and the recognition stability decreases.

To ensure recognition stability, the effective contact width of the capacitive sensing member 421 with the lower surface of the panel 200 is not less than 1.5mm. The effective contact area between the capacitive sensing piece 421 and the panel 200 is ensured, the capacitance value generated by the capacitive sensing device 420 and the panel 200 clung to the capacitive sensing piece is conveniently measured, the capacitance value of the capacitive sensing piece 421 is detected more accurately, and the identification stability is ensured.

Preferably, as shown in fig. 1 to 3, the number of the capacitive sensing pieces 421 is four, and the four capacitive sensing pieces 421 are circumferentially uniformly distributed outside the heating coil 410. Four capacitive sensing pieces 421 are circumferentially and uniformly distributed on the outer side of the heating coil 410, and cover the heating coil 410 in four directions, namely front, back, left and right, so that the position and the bias condition of the cooker 500 can be more comprehensively detected. Meanwhile, whether overflows overflow can be detected more comprehensively.

In order to perform cooking in two lines simultaneously without affecting each other, as shown in fig. 1, the number of heating furnaces 400 is two, and two heating furnaces 400 are arranged side by side. The double-port electromagnetic oven is provided with two heating ovens 400, two cookers 500 can be placed, the heating ovens 400 on two sides are respectively and independently controlled, and cooking of two threads can be simultaneously carried out without mutual influence. In addition, the capacitance sensing devices 420 in each heating furnace 400 respectively detect capacitance values. When the size of the pan 500 is smaller than the inner diameter of the reference circle, water overflowed from the pan falls into the sensing range of the capacitance sensing piece 421, so that the identification stability is ensured; when the size of the cookware is greater than the inner diameter of the reference circle, the water overflowed from one cookware falls outside the sensing range of the corresponding capacitance sensing piece 421, if other capacitance sensing devices 420 do not work at this time, whether overflows can not be detected, and when the capacitance sensing devices 420 in other heating furnaces are still in a detection state, the water overflowed from the corresponding cookware 500 falls in the sensing range of other reference circles, whether overflows can still be detected, the application range is enlarged, the bottom diameter of the cookware 500 can not be limited, and the identification stability is ensured.

The method for detecting the offset of the cooker 500 comprises the following steps: at start-up, the capacitance value of the capacitance sensing element 421 is recorded as a 11..a1n; the recording capacitance value is smaller than the set value B1, and the deviation of the cooker 500 is reported.

Whether there is an overflow method on the panel 200: starting the electromagnetic oven, and recording the capacitance value of the capacitance sensing piece 421, which is recorded as a 21..a2n; when the absolute value of A2n-A1n is larger than the program set value B2, the product stops working, and the overflow is reported. It can be understood that in order to prevent interference such as false touch, when the capacitance value exceeds B1, the power is reduced to the next low gear of the current setting power, the capacitance value is not continuously deteriorated in the setting time, and the setting power is restored, so that false detection caused by food falling and oil drop splashing can be effectively avoided.

Example 2:

As shown in fig. 4, the plurality of capacitive sensing elements 421 are at least divided into two groups of capacitive sensing elements, wherein the plurality of capacitive sensing elements 421 in the first group of capacitive sensing elements are distributed on a first reference circle, the plurality of capacitive sensing elements 421 in the second group of capacitive sensing elements are distributed on a second reference circle, the first reference circle, the second reference circle and the heating coil 410 are coaxially arranged, and the second reference circle is sleeved outside the first reference circle. The second capacitive sensing group is sleeved on the first capacitive sensing group, and the first reference circle, the second reference circle and the heating coil 410 are coaxially arranged, so that the detection range is enlarged, the identification stability and accuracy are ensured, and the false detection possibility is reduced. In addition, the detection range is enlarged, in addition, the first group of capacitance induction groups is covered by the cookware, the second group of capacitance induction groups can also detect capacitance changes, cookware 500 with different sizes is adapted, the bottom diameter limit of the cookware 500 can be reduced, the application range is further enlarged, and the practicability of the electromagnetic cooker is improved.

Specifically, as shown in fig. 4, the capacitive sensing elements 421 in the two capacitive sensing groups are staggered in the circumferential direction. Through two sets of electric capacity induction sets at circumference crisscross setting, the clearance outside of two arbitrary adjacent electric capacity induction pieces 421 of first group electric capacity induction set all corresponds one of them electric capacity induction piece 421 of second group electric capacity induction set for all distribute electric capacity induction piece 421 in whole circumference, avoid the too big distance between two adjacent electric capacity induction pieces 421, pan 500 is in between two adjacent electric capacity induction piece 421 clearance, leads to unable detection pan 500, reduces the possibility of false detection. The other two groups of capacitance sensing groups are arranged in a staggered mode in the circumferential direction, the number of capacitance sensing pieces 421 is reduced while the same detection range is covered, and the manufacturing cost of products is reduced.

Preferably, as shown in fig. 5, the capacitive sensing elements 421 in the two capacitive sensing groups are staggered in the circumferential direction, one capacitive sensing element 421 in the second capacitive sensing group is corresponding to the outside of the gap between any two adjacent capacitive sensing elements 421 in the first capacitive sensing group, and the capacitive sensing elements in the second capacitive sensing group just block the gap between two adjacent capacitive sensing elements 421 corresponding to the first capacitive sensing group, so that the perimeter of the arc-shaped capacitive sensing element 421 is reduced while the same detection range is covered, the manufacturing cost of the product is reduced, and the manufacturing difficulty of the arc-shaped capacitive sensing element 421 is also reduced.

It will be appreciated that the number of capacitive sensing groups may be 3 groups, 4 groups, etc. as well as other suitable numbers.

Other matters not described in this embodiment can refer to embodiment one.

The foregoing embodiments are provided for further explanation of the present utility model and are not to be construed as limiting the scope of the present utility model, and some insubstantial modifications and variations of the present utility model, which are within the scope of the utility model, will be suggested to those skilled in the art in light of the foregoing teachings.

Claims (9)

1. The utility model provides an electromagnetic oven, includes casing, panel, control circuit board and heating furnace, the heating furnace includes heating coil and is used for detecting the electric capacity induction system that the electric capacity changes on the panel, electric capacity induction system hug closely in the lower surface of panel, characterized by, electric capacity induction system includes circular-arc a plurality of electric capacity induction piece, a plurality of electric capacity induction piece respectively with the control circuit board electricity is connected, a plurality of electric capacity induction piece circumference interval sets up in the heating coil outside, and a plurality of electric capacity induction piece distributes on same reference circle, the total arc length of a plurality of electric capacity induction piece is not less than 0.5 with the girth ratio of its place reference circle.

2. An induction cooker according to claim 1, characterized in that said reference circle is arranged coaxially with said heating coil.

3. An induction hob according to claim 2, characterized in, that the diameter of the reference circle is at least 10mm larger than the outer diameter of the heating coil.

4. An induction hob according to claim 1, characterized in, that the distance between two adjacent capacitive induction elements in the circumferential direction is smaller than 10mm.

5. The induction cooker of claim 1, wherein the number of the capacitive induction pieces is four, and the four capacitive induction pieces are circumferentially and uniformly distributed outside the heating coil.

6. An induction cooker according to claim 1, wherein the effective contact width of said capacitive sensing member with the lower surface of said panel is not less than 1.5mm.

7. The induction cooker of claim 1, wherein the plurality of capacitive sensing elements is divided into at least two groups of capacitive sensing elements, wherein the plurality of capacitive sensing elements in the first group of capacitive sensing elements are distributed on a first reference circle, the plurality of capacitive sensing elements in the second group of capacitive sensing elements are distributed on a second reference circle, the first reference circle, the second reference circle and the heating coil are coaxially arranged, and the second reference circle is sleeved outside the first reference circle.

8. The induction cooker of claim 7, wherein the capacitive sensing elements of said two capacitive sensing groups are staggered circumferentially.

9. An induction cooker according to claim 1, wherein the number of said heating furnaces is two, and the two heating furnaces are arranged side by side.