Method for actuating a heating device of a hob, and hob

Patent metadata

Field	Value
Publication number	US-11570853-B2
Application number	US-202117248624-A
Country	US
Kind code	B2
Filing date	Feb 1, 2021
Priority date	Feb 1, 2021
Publication date	Jan 31, 2023
Grant date	Jan 31, 2023

Abstract

A hob plate above a radiant heating device and a safety temperature limiter between said radiant heating device and hob plate, which safety temperature limiter is designed to deactivate the radiant heating device when a switch-off temperature is reached. To actuate the radiant heating device, a cooking vessel is first placed on the hob plate above the radiant heating device and then the radiant heating device is activated and at the same time detection of a first switch-on time starts. When a switch-off temperature is reached at the safety temperature limiter, the radiant heating device is deactivated by said safety temperature limiter. The first switch-on time that has elapsed up to that point between activation and deactivation of the radiant heating device is detected and compared with a predefined limit switch-on time. If the first switch-on time lies below the limit switch-on time the radiant heating device is switched off.

First claim

The invention claimed is:

1. A method for actuating a heating device of a hob, wherein said hob has:
at least one radiant heating device as said heating device,
a hob plate, wherein said radiant heating device is arranged beneath said hob plate,
a safety temperature limiter being designed as a thermomechanical functional device and being arranged between said radiant heating device and said hob plate, wherein said safety temperature limiter is designed to deactivate said radiant heating device when a switch-off temperature is reached,
comprising the steps of:
placing a cooking vessel on said hob plate above said radiant heating device,
activating said radiant heating device and at the same time starting recording of a first switch-on time,
detecting a deactivation of said radiant heating device by said safety temperature limiter when a switch-off temperature is reached at said safety temperature limiter and monitoring said first switch-on time having elapsed up to a point of time between said activating and said deactivation of said radiant heating device,
comparing said monitored first switch-on time with a predefined limit switch-on time, where, if said first switch-on time lies below said limit switch-on time, a power is reduced, wherein said radiant heating device is activated and is operated with said power.

2. The method as claimed in claim 1 , wherein, if said first switch-on time lies below said limit switch-on time, said radiant heating device is deactivated.

3. The method as claimed in claim 2 , wherein said entire hob is not switched off when said radiant heating device is deactivated.

4. The method as claimed in claim 1 , wherein said reducing of said power of said radiant heating device, because said first switch-on time lies below said limit switch-on time, is optically or acoustically indicated to an operator.

5. The method as claimed in claim 1 , wherein said safety temperature limiter is arranged on said radiant heating device, where said safety temperature limiter has a temperature detection device acting on a switch of said hob or of said safety temperature limiter for deactivating said radiant heating device for switching purposes.

6. The method as claimed in claim 1 , wherein said safety temperature limiter is designed as a rod-type thermostat.

7. The method as claimed in claim 1 , wherein said radiant heating device is deactivated or its power is reduced only when a power with which said radiant heating device is intended to be activated lies above a predefined limit power.

8. The method as claimed in claim 7 , wherein said predefined limit power is at a power per unit area of more than 5 W/cm 2 .

9. The method as claimed in claim 1 , wherein said predefined limit switch-on time is settable by an operator in a separate setting mode.

10. The method as claimed in claim 1 , wherein, after a specific cool-down time after said reducing of said power at said radiant heating device or said deactivating of said radiant heating device, said previously set power is at least partially re-established.

11. The method as claimed in claim 10 , wherein said specific cool-down time is predefined.

12. The method as claimed in claim 10 , wherein a ratio of an active time to a sum of said active time and a non-active time for said radiant heating device is stored in a control device of said hob.

13. The method as claimed in claim 12 , wherein said control device also monitors and stores said power being generated by said radiant heating device over time.

14. The method as claimed in in claim 10 , wherein said ratio of an active time to a sum of said active time and a non-active time of an energy controller for supplying power to said radiant heating device is greater than a ratio of an active time to a sum of said active time and a non-active time for said safety temperature limiter.

15. The method as claimed in claim 1 , wherein a switching behavior of said safety temperature limiter is monitored throughout an operation of said radiant heating device, where, if a time of less than 90 sec elapses between two responses of said safety temperature limiter one after the other, it is concluded that said cooking vessel being heated by said radiant heating device has boiled-dry and then said power for said radiant heating device is reduced.

16. The method as claimed in claim 15 , wherein said radiant heating device is deactivated.

17. The method as claimed in claim 1 , wherein detection of a switching state and of a current flow takes place only at an energy controller for supplying power to said radiant heating device.

18. The method as claimed in claim 1 , wherein detection of a switching state takes place at an energy controller for supplying power to said radiant heating device and additionally takes place at said safety temperature limiter.

19. The method as claimed in claim 1 , wherein a switching state of said safety temperature limiter is detected by at least one of the following possibilities:
measuring a voltage across said radiant heating device,
measuring a current flowing through said radiant heating device,
measuring a current flowing parallel to a series circuit in said hob, said series circuit comprising said safety temperature limiter and said radiant heating device.

20. The method as claimed in claim 1 , wherein said time at which said safety temperature limiter activates and deactivates said radiant heating device is monitored throughout a cooking process with said cooking vessel on said hob plate above said radiant heating device by, after a time of more than 5 min and/or after more than ten deactivations of said radiant heating device by said safety temperature limiter, shortening a duration of activation of said radiant heating device being evaluated as said cooking vessel having boiled-dry and then said power with which said radiant heating device is activated and is operated being reduced or said radiant heating device being deactivated.

21. A hob for carrying out said method as claimed in claim 1 , wherein said hob has:
wherein said radiant heating device comprises said safety temperature limiter in its upper region or between a heating conductor of said radiant heating device and said hob plate.

22. The hob as claimed in claim 21 , having an electronic control device, wherein said control device activates or deactivates said radiant heating device via switching elements.

23. The hob as claimed in claim 22 , having an electronic control device activating or deactivating said radiant heating device via switching elements by way of connection to a mains voltage or complete disconnection from said mains voltage.

24. The hob as claimed in claim 21 , wherein said power for said radiant heating device is set by means of an electromechanical control device, where said hob has an additional controller for detecting a switching state of said safety temperature limiter.

25. The hob as claimed in claim 21 , wherein only one single additional controller is provided for all cooking points or all said radiant heating devices of said hob.

26. The hob as claimed in claim 21 , wherein it has a mains power supply with a connection to a neutral conductor, wherein either a single common disconnector relay is provided in said connection to a neutral conductor for all said radiant heating devices, or where a dedicated disconnector relay is provided in a connection to a neutral conductor for each

Assignees

• Ego Elektro Geraetebau Gmbh

Inventors

• Egenter Christian
• Frank Marcus
• Mangler Matthias
• Rickert Jochen

Classifications

• F24C7/087

  of electric circuits regulating heat · CPC title

• H05B1/0258 Primary

  For cooking · CPC title

• H05B3/746 Primary

  Protection, e.g. overheat cutoff, hot plate indicator · CPC title