A radiant HOB with a thermocouple unit

Abstract

The invention relates to an electric hob comprising a radiant heater plate (20) provided under a base plate (10); a thermocouple unit (40) operatively connected to the radiant heater plate (20); and a controller (52) configured to receive temperature data from the thermocouple unit (40). The electric hob comprises a heat sensor (42) positioned such that the thermocouple unit (40) supplies instantaneous temperature measurements of the radiant heater plate (20) to the controller (52), and the controller (52) is configured to drive the radiant heater plate (20) according to a predetermined cooking program based on the temperature measurements provided by the heat sensor (42).

Description

[0001] A RADIANT HOB WITH A THERMOCOUPLE UNIT

[0002] TECHNICAL FIELD

[0003] The present invention relates to a hob with a radiant burner plate, and more particularly, to a radiant hob equipped with a control apparatus having a thermocouple.

[0004] BACKGROUND ART

[0005] A radiant hob has sequential radiant burner plates located under a glass cooktop, forming a cooking zone. A bimetallic thermostat is placed on each radiant burner for safety purposes. An electronic control unit located under the base plate energizes a radiant burner plate selected by the user from a control panel with the help of a controller it possesses.

[0006] The hob has various predetermined power levels. For example, at the maximum power level, the selected radiant burner plate is continuously energized. On the other hand, at lower power levels, intermittent energization is performed at predetermined durations, which are located in the memory module accessed by the controller, in accordance with the value of the selected power level.

[0007] ES1272019 describes a system for automatically cooking food in a pot on a base plate. The system includes an interface configured to receive an instruction from the user for preparing the food; a control unit configured to be connected to a sensor for measuring temperature in a region on a surface, wherein the cooking surface includes a heating element and an actuator for changing the heat power supplied by the heating element to the pot. The control unit is configured to determine multiple cooking phases according to the instruction received from the user, where each phase has a predetermined target temperature in the pot, to calculate the estimated temperature in the pot from the electrical parameters obtained from the actuator and / or the heating element, and to generate a sequence of control instructions for controlling the actuator connected to the heating element within a specific time interval according to the target temperature and the estimated temperature.

[0008] BRIEF DESCRIPTION OF THE INVENTION

[0009] The object of the invention is to provide precise heat-controlled cooking in an electric hob with a radiant heater. In order to achieve the above objective, the invention relates to an electric hob comprising a radiant heater plate provided under a base plate; a thermocouple unit operatively connected to the radiant heater plate, and a controller configured to receive temperature data from the thermocouple unit. The electric hob includes a heat sensor positioned such that the thermocouple unit supplies instantaneous temperature measurements of the radiant heater plate to the controller, and the controller is configured to drive the radiant heater plate according to a predetermined cooking program based on the temperature measurements provided by the heat sensor. Since the heat sensor of the thermocouple unit provides instantaneous temperature information to the controller, the cooking program can be precisely controlled according to the instantaneous temperature values of each radiant heater plate. This allows the cooking program to execute a heat-dependent cooking program by being programmed in terms of the desired temperatures for the radiant heater plate to reach and maintain, rather than just an estimated time table obtained by trial and error.

[0010] In a preferred embodiment, the heat sensor is fixed to extend to the center of the radiant heater plate. In this case, the average temperature of the radiant heater plate is precisely measured from the center, and measurement errors are minimized.

[0011] A preferred embodiment includes at least one auxiliary heater plate of similar structure and different power, positioned at a distance from the radiant heater plate to support the cooking process. Auxiliary heater plates allow multiple cooking programs to be run simultaneously on the base plate.

[0012] A preferred embodiment includes a cable connecting the thermocouple unit to the controller to provide electrical signal transmission. The cable safely carries temperature data transmitted as electrical voltage from the heat sensors of the high-temperature generating radiant heater plates to the controller. In a possible embodiment, signals can also operate without a cable through alternative signal transmission systems such as wireless RF modules or optical modules.

[0013] In a preferred embodiment, it includes a control panel to which the controller is connected for signal transmission and which has a visually accessible indicator element. The control panel forms the user interface and enables the transmission of operation commands such as start, stop, and operate to the controller and the execution of the results on the indicator element (e.g., a display or an audible alarm device). In a preferred embodiment, the controller is configured to periodically check the signal data carrying instantaneous temperature measurement information from the heat sensor and, upon processing the signal, if it detects an anomaly matching a predetermined error pattern, to display an error code corresponding to the detected error pattern on the indicator element of the control panel to which it is connected for signal transmission. In this way, the electric hob is made safe by a quick response in case of instantaneous anomaly detection.

[0014] In a preferred embodiment, the controller is configured to cancel the cooking program and display error information on the indicator element if the error pattern stored in the memory unit indicates no temperature change within a predetermined temperature range. If the temperature does not change while power is supplied to the radiant heater plate, it indicates a malfunction in the radiant heater plate or the thermocouple unit. This way, i.e., the temperature not changing over time, is a condition requiring maintenance and is communicated to the user via the indicator element.

[0015] In a preferred embodiment, the controller is configured to cancel the cooking program and display error information on the indicator element if it fails to detect a signal from the heat sensor for a predetermined time interval set wider than a control period. This means that the thermocouple unit has become dislodged or its terminals have oxidized and requires maintenance. It is communicated to the user via the indicator element.

[0016] In a preferred embodiment, if the cooking program includes preheating, the controller is configured to supply power to the radiant heater plate until the predetermined preheating temperature is reached and, if the targeted preheating temperature is measured via the heat sensor from the radiant heater plate, to display "preheating completed" information on the indicator element. Thus, a time-independent programmable preheating function is provided in the radiant electric hob. It becomes possible to operate the preheating function on a plug- and-play basis without performing pre-tests to determine durations for different radiant heater plates.

[0017] In a preferred embodiment, the controller is configured to periodically check the signal data carrying instantaneous temperature measurement information from the heat sensor and, upon processing the signal, if it detects a temperature above a predetermined threshold, to cut off the power supplied to the radiant heater plate. In this way, overheating safety is provided in the electric hob without the need for an additional safety circuit. In a preferred embodiment, if the cooking program is a yogurt program, the controller is configured to energize the radiant heater plate at the highest energy level with preheating until T >= 130°C is detected by the signal supplied from the heat sensor, and then intermittently energize the heater plate at the lowest energy level between 160°C > T >= 130°C in periods for a predetermined duration. In this way, temperature changes are detected by the controller with instantaneous data provided by the heat sensor, and the yogurt program can be successfully executed regardless of the model and structure of the radiant heater plate.

[0018] In a preferred embodiment, if the cooking program is a rice program, the controller is configured to energize the radiant heater plate at the highest power level for a predetermined first duration, and then, sequentially, with the signal supplied from the heat sensor, energize the heater plate at a medium power level for a second duration, which is twice or more than the first duration, and then above the medium power level, and finally, by cutting off the energization, if residual heat of the radiant heater plate is detected from the heat sensor, wait for a predetermined duration and at the end of the duration, trigger a cooking completion signal on the indicator element. Again, in this way, temperature changes are detected by the controller with instantaneous data provided by the heat sensor, and the rice, for example, paella program can be successfully executed regardless of the model and structure of the radiant heater plate.

[0019] In a preferred embodiment, the radiant heater plate includes a flat insulation housing and a metallic strip functioning as a resistor mounted on the insulation housing, and the heat sensor is vertically positioned to extend between the base of the insulation housing at one end and the center of the metallic strip at the other end. Thus, the heat sensor is safely placed in the radiant heater plate, and the accuracy of temperature data is increased.

[0020] BRIEF DESCRIPTION OF THE FIGURES

[0021] Figure 1 is a schematic top view of a representative embodiment of an electric radiant hob according to the invention, with the base plate in a transparent state.

[0022] Figure 2 is a schematic top view of the electric radiant hob shown in Figure 1 .

[0023] Figure 3 is a cross-sectional view of a radiant heater plate with the thermocouple unit adapted thereto. DETAILED DESCRIPTION OF THE INVENTION

[0024] In this detailed description, the development according to the invention is explained with references to examples without any limitation and only for a better understanding of the subject matter.

[0025] Figure 1 shows an electric hob from above, comprising a ceramic flat base plate (10), radiant heater plates (20) and auxiliary heater plates (30) arranged thereunder, each equipped with a corresponding thermocouple unit (40), and a control panel (50) to which they are connected for signal transmission. The part of the base plate (10) where each radiant heater plate (20, 30) is aligned defines a cooking zone, as shown in Figure 2 with a circular boundary. A cooking pot (not shown) is placed in a corresponding cooking zone.

[0026] The radiant heater plate (20) is as described in utility model document CN204901869U, which is incorporated herein by reference. Each radiant heater plate (20, 30) is in the form of a circular disc, and a cylindrical heat sensor (42) of the thermocouple unit (40) is vertically located at the circular center of a metallic strip (22) composed of concentric tapering circular structures. A control panel (50) is provided under the base plate (10), close to its bottom edge. The control panel (50) is in the form of a touch panel structure in PCB form. A controller (52) with a processor and a memory unit is placed on the control panel (50). Numerous electrical signal transmission cables are connected at one end to a connector (54) at the edge of the control panel (50) and at the other end directly to the heat sensor (42) of the thermocouple unit (40) at the edge of the corresponding radiant heater plate (20). Thus, each radiant heater plate (20) is connected via a cable (46) through the control panel (50) to the controller (52) to transmit temperature data with voltage. An indicator element (55) in the form of an LCD screen, visually accessible from the base plate (10), is located on the control panel (50).

[0027] As shown in Figure 2, the control panel (50) includes a touch adjustment knob (57) electrically connected to the controller (52) for signal transmission, and an indicator area (53) bounded by marking areas (59) formed by icons marked with LEDs. Important steps related to the cooking program are added to the upper part (12) of the base plate (10) in the indicator area (53) by silkscreen printing.

[0028] Figure 3 provides a representative cross-sectional view of the radiant heater plate (20). A cylindrical heat sensor (42) is passed through a hole drilled through the middle of an insulation housing (21 ) made of a ceramic material with high electrical and heat insulation, in the form of a circular disc. An edge protrusion (23) is formed by raising the upper part of the insulation housing (21 ) from its outer periphery. The metallic strip (22) rests on the insulation housing (21) from its upper surface bounded by the edge protrusion (23).

[0029] When the control panel (50) is not activated, it operates in stand-by mode. The user activates the control panel (50) by touching the adjustment knob (57). From here, the radiant heater plate (20) and the cooking program to be operated are selected using the adjustment knob (57). For example, when the yogurt making program is selected, the controller (52) calls the command from the program in its memory to operate the radiant heater plate (20) at full power level for 60 seconds and energizes the radiant heater plate (20). Full power level is the continuous energization of the radiant heater plate (20) without interruption. With the initial energization, the controller (52) periodically checks whether the radiant heater plate (20) forms an error pattern by interpreting the low-voltage heat measurement information signal transmitted by the heat sensor (42) via cable (46) throughout the cooking program. To continue cooking, the controller (52) switches to intermittent energization at the interval determined for the lowest power level for the radiant heater plate (20). The controller performs this process for approximately 2 hours. Then, the controller (52) completely cuts off the heat and counts for approximately 20 minutes, and then creates an operating cycle by energizing the radiant heater plate (20) for one minute at the lowest power level and keeping it off for 2 minutes, repeating this at least 3 times. Then, it runs a timer without energization and gives an audible or visual warning via the indicator element (55) after 6-10 hours.

[0030] During the cooking program, if the controller (52) detects a predetermined error pattern based on the temperature information of the radiant heater plate (20) periodically collected from the heat sensor (42), it gives the corresponding warning via the indicator element (55). One of these is the error of inability to detect temperature change. If the user activates the radiant heater plate (20) for the cooking program using the adjustment knob (57), but the controller (52) cannot detect a temperature increase in the temperature information coming from the heat sensor (42) over time, it stops the cooking program and cuts off the power to the radiant heater plate (20) by showing the code corresponding to the error in the memory unit on the indicator element (55).

[0031] Another error pattern is the inability to detect a thermocouple connection. If the controller (52) does not receive temperature information from the heat sensor (42) within 30 seconds despite the cooking program being started, it stops the cooking program and cuts off the power to the radiant heater plate (20) by showing the code corresponding to the error in the memory unit on the indicator element (55). Another error pattern is uncontrolled heating. If the controller (52) receives suddenly increasing temperature information from the temperature sensor (42) when the hob is off or when no power is detected going to the radiant heater plate (20), it prevents this by opening the power cut-off circuit to the radiant heater plate (20) by showing the code corresponding to the error in the memory unit on the indicator element (55).

[0032] Another error pattern is overheating. If the controller (52) receives a temperature far above the temperature value foreseen in the cooking program from the temperature sensor (42) while the cooking program is running, it prevents this by opening the power cut-off circuit to the radiant heater plate (20) by showing the code corresponding to the error in the memory unit on the indicator element (55).

[0033] When the cooking program is completed, the controller (52) gives a residual heat warning on the indicator element (55) until the temperature information from the temperature sensor (42) drops below 55 degrees Celsius. In this way, if the cooking zone on the upper part (12) of the base plate (10) corresponding to the radiant heater plate (20) is still hot, it warns the user not to touch the area.

[0034] Another cooking mode activated with the electric hob is the rice (especially paella) cooking mode. The user is guided step by step by illuminating the marking areas (59) in the indicator area (52) with the corresponding LED circuit on the control panel (50).

[0035] The controller (52) operates the radiant heater plate (20) at full power level for approximately 2 minutes. During this time, oil heating is provided, and the relevant marking area (59) indicates this situation. Then, the marking area (59) switches to another mode, indicating the browning of meats. The controller (52) drives the radiant heater plate (20) for 5 minutes by intermittent energization to create a medium power level. The browning of meats occurs at this stage. Then, without changing the power level, the controller (52) changes the marking area (59). For this stage, the controller (52) counts at least 10 minutes, and vegetables are added and sauteed. For the next stage, the controller (52) changes the marking area (59), increases the power level by one step, and performs boiling for approximately half an hour. Then, without changing the power level, it changes the marking area (59) and directs the user to add rice. Finally, to ensure controlled sticking to the bottom, it cuts off the heat to the radiant heater plate (20) and runs a timer for 5 minutes, and at the end of the process, it informs the user via a signal on the indicator element (55) that the program has been completed. In this cooking program, too, the controller (52) monitors the temperature data coming from the heat sensor (42) and, if an error pattern is detected as described above, cuts off the cooking program and informs the user via the indicator element (55).

[0036] REFERENCE NUMERALS

[0037] 10 Base plate

[0038] 12 Upper part

[0039] 20 Radiant heater plate

[0040] 21 Insulation housing

[0041] 22 Metallic strip

[0042] 23 Edge protrusion

[0043] 30 Auxiliary heater plate

[0044] 40 Thermocouple unit

[0045] 42 Heat sensor

[0046] 44 Terminal element

[0047] 46 Cable

[0048] 50 Control panel

[0049] 52 Controller

[0050] 53 Indicator area

[0051] 54 Connector

[0052] 55 Indicator element

[0053] 57 Adjustment knob

[0054] 59 Marking area

Claims

CLAIMS1. An electric hob comprising a radiant heater plate (20) provided under a base plate (10); a thermocouple unit (40) operatively connected to the radiant heater plate (20); and a controller (52) configured to receive temperature data from the thermocouple unit (40), characterized in that the thermocouple unit (40) includes a heat sensor (42) positioned to supply instantaneous temperature measurements of the radiant heater plate (20) to the controller (52), and the controller (52) is configured to drive the radiant heater plate (20) according to a predetermined cooking program based on the temperature measurements provided by the heat sensor (42).

2. An electric hob according to Claim 1 , wherein the heat sensor (42) is fixed to extend to the center of the radiant heater plate (20).

3. An electric hob according to any of the preceding claims, wherein it comprises at least one auxiliary heater plate (30) of similar structure and different power, positioned at a distance from the radiant heater plate (20) to support the cooking process.

4. An electric hob according to any of the preceding claims, wherein it comprises a cable (46) connecting the thermocouple unit (40) to the controller (52) for electrical signal transmission.

5. An electric hob according to any of the preceding claims, wherein it comprises a control panel (50) to which the controller (52) is connected for signal transmission and which has a visually accessible indicator element (55).

6. An electric hob according to Claim 5, wherein the controller (52) is configured to periodically check the signal data carrying instantaneous temperature measurement information from the heat sensor (42) and, upon processing the signal, if it detects an anomaly matching a predetermined error pattern, to display an error code corresponding to the detected error pattern on the indicator element (55) of the control panel (50) to which it is connected for signal transmission.

7. An electric hob according to Claim 6, wherein the controller (52) is configured to cancel the cooking program and display error information on the indicator element (55) if the error pattern stored in the memory unit indicates no temperature change within a predetermined temperature range.

8. An electric hob according to Claims 6-7, wherein the controller (52) is configured to cancel the cooking program and display error information on the indicator element (55) if it fails to detect a signal from the heat sensor (42) for a predetermined time interval set wider than a control period.

9. An electric hob according to Claims 5-8, wherein, if the cooking program includes preheating, the controller (52) is configured to supply power to the radiant heater plate (20) until the predetermined preheating temperature is reached and, if the targeted preheating temperature is measured via the heat sensor (42) from the radiant heater plate (20), to display "preheating completed" information on the indicator element (55).

10. An electric hob according to any of the preceding claims, wherein the controller (52) is configured to periodically check the signal data carrying instantaneous temperature measurement information from the heat sensor (42) and, upon processing the signal, if it detects a temperature above a predetermined threshold, to cut off the power supplied to the radiant heater plate.11 . An electric hob according to any of the preceding claims, wherein, if the cooking program is a yogurt program, the controller (52) is configured to energize the radiant heater plate (20) at the highest energy level with preheating until T >= 130°C is detected by the signal supplied from the heat sensor (42), and then intermittently energize the heater plate (20) at the lowest energy level between 160°C > T >= 130°C in periods for a predetermined duration.

12. An electric hob according to any of the preceding claims, wherein, if the cooking program is a rice program, the controller (52) is configured to energize the radiant heater plate (20) at the highest power level for a predetermined first duration, and then, sequentially, with the signal supplied from the heat sensor (42), energize the heater plate (20) at a medium power level for a second duration, which is twice or more than the first duration, and then above the medium power level, and finally, by cutting off the energization, if residual heat of the radiant heater plate (20) is detected from the heat sensor (42), wait for a predetermined duration and at the end of the duration, trigger a cooking completion signal on the indicator element (55).

13. An electric hob according to any of the preceding claims, wherein the radiant heater plate (20) is having a flat insulation housing (21 ) and a metallic strip (22) functioning as a resistor mounted on the insulation housing (21), and the heat sensor (42) is vertically positioned to extend between the base of the insulation housing (21 ) at one end and the center of the metallic strip (22) at the other end.

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