Generally, electric rangers are cooking devices which cook by using an electric heater or a heating element as a heating source.
FIG. 1 and FIG. 2 illustrate a structure of a conventional electric range. Referring to them, the structure of the conventional electric range will be described.
In FIG. 1, the conventional electric range comprises a body 10 for forming an exterior, one or more heater assemblies 20 for generating a heating source, a power supply part (not shown) for supplying power to each heater assembly 20, a control assembly 30 for controlling an entire operation of the electric range, and an upper plate 40 defining a top of the electric range for having a food container thereon.
The heater assembly 20 mounted in the body 10 is of an induction heating structure in which a food container itself generates heat once applying an electromagnetic force to the container in an induction heating way.
The heater assembly 20 comprises a working coil 21, a circuit board 22, a heater base 23, and an insulating sheet 24.
The working coil 21 is employed for transmitting the electromagnetic force to the food container, and the circuit board 22 is for controlling an induction current supplied to the working coil 21.
The heater base 23 is provided between the working coil 21 and the circuit board 22 for forming a body of the heater assembly 20.
Between the heater base 23 and the working coil 21 is provided a magnet 21a for preventing a magnetic field (not shown) formed by the working coil 21 in a downside of the working coil 21.
Furthermore, the insulating sheet 24 of asbestos material is provided to cover a top of the working coil 21.
The insulating sheet 24 is employed for preventing the heat radiated from the upper plate 40 from being transmitted to the working coil 21.
Still further, a temperature sensor 25 is mounted on the insulating sheet 24 for sensing a cooking temperature heated by the working coil 21.
A wire 25a passes through a downside of the insulating sheet 24 to be drawn outside for applying power to the temperature sensor 25.
Thus, after driving the electric range, power is applied to the working coil 21 of the heater assembly 20. Hence, the induction current is generated, after that the food container is heated and cooking is performed.
However, as described hereinabove, the heater assembly 20 of the conventional electric rage has the following problems.
First, since it is mounted on the top of the insulating sheet 24 without any additional supporting structure or securing structure, the temperature sensor 25 of the heater assembly 20 may be going out of its position in a process of placing the upper plate 40.
Second, preferably the temperature sensor 25 may be in a close contact with a downside of the upper plate 40 for a high sensing efficiency. Commonly, considering that the insulating sheet 24 is made of asbestos material with good thermo stability, the temperature sensor 25 may be embedded in the insulating sheet 24. Therefore, it may cause a problem that the close contact between the temperature sensor 25 and the upper plate 40 may not be made smoothly, thereby deteriorating a reliability of the sensed temperature.
Third, since it, as described above, is made of the asbestos material, the insulating sheet 24 may cause problems of a high production cost as well as of the bad influence on the workers health.
Accordingly, the above problems necessitate a replacement of the asbestos.