JPH0115101Y2 - - Google Patents

Description

[Detailed explanation of the idea] <Industrial application field> The present invention relates to an electromagnetic cooker.

<Prior Art> The induction heating coil used in a conventional electromagnetic cooker is made of a spirally punched metal plate with a constant width and equal intervals. For this reason, the magnetic flux density is not uniform in the core portion, the outer portion, and the intermediate portion of the spiral, and the magnetic flux density is uneven, resulting in uneven heating, and effective heat utilization cannot be achieved.

Therefore, as a means of eliminating such heating unevenness and increasing thermal efficiency, as shown in Fig. 1a, a coil of a constant width W is arranged such that the interval P ₂ at the middle part is smaller than the interval P ₁ between the core and the outer part. An induction heating coil formed to be wide was used.

However, even in this case, the temperature distribution characteristics at the bottom of the pot or pot are relatively uniform, as shown in Figure 1b, but the temperature distribution characteristics of the coil are not uniform, as shown in Figure 1c. Furthermore, the induction heating coil itself was partially subjected to concentrated heating, which was a factor in shortening the life of the induction heating coil.

<Purpose of the invention> The object of the invention is to provide an induction heating coil that can be used in an electromagnetic cooker without uneven heating.

<Construction of the invention> This is an induction heating coil in which the width of the conductor constituting the spiral is made wide at the middle part of the spiral, and gradually narrows in the direction of the winding core and in the centrifugal direction.

<Embodiment> The main point of the present invention is that the width of the conductor at the middle part of the spiral of the spiral coil is widened.

The present invention will be specifically explained with reference to the embodiments shown in FIG. 2 and below.

Metal induction heating coil 2 formed in a spiral shape
As shown in Figs. 3 and 4, the coil width W ₂ at the middle part is wider than the coil widths W ₁ and W ₃ at the core and outer parts, and the punching is performed at a constant interval P. The induction heating coil 2 is installed between the back surface of the top plate 1 and the shielding plate 4, and is attached to the upper part of the cooking device main body 5.

Note that the reference numeral 3 in the figure indicates a secondary coil, which is obtained by punching or pressing a spiral conductive tube.

<Operation> When electricity is applied to the induction heating coil 2 configured in spirals with different widths, the coil width becomes wider at the middle part between the core and the outer part of the coil, so the current density decreases and the amount of heat generated decreases. decreases, and the temperature distribution across the induction heating coil becomes uniform.

<Effect of the invention> The width of the coil constituting the induction heating coil was
As shown in Figure a, by making the temperature distribution wider in the middle part, as shown in Figure 2 b, there is a significant difference in temperature distribution at the bottom of the pot between the center position of the induction heating coil, the outer part, and the middle part. Furthermore, as above, the temperature distribution in the center, outer part, and intermediate part of the induction heating coil is as shown in Figure 2c, and the temperature distribution is average compared to the case in Figure 1c. It is true.

Therefore, the temperature distribution of the induction heating coil is average in both the coil winding core and the outer part, and the temperature distribution of the induction heating coil and the bottom of the pot match very well, which prevents the temperature distribution from reaching unnecessary parts. Since there is no heat leakage, there is no need to worry about overheating the built-in electronic components, and there is no peak value in the heat distribution of the heating coil itself (the same applies to other heat-receiving components), and it is uniform, so the peak value can be reduced as before. Since there is no need to select a metal material that can withstand high temperatures, it is possible to use low-cost materials, and it is also easy to manufacture by stamping, making it possible to provide an induction heating coil with good thermal efficiency at a low cost.

[Brief explanation of drawings]

Fig. 1a is a schematic cross-sectional view of a conventional induction heating coil, Fig. 1b is a temperature distribution characteristic diagram of the bottom of the pot due to the above induction heating coil, and Fig. 1c is a temperature distribution characteristic diagram of the same induction heating coil. FIG. 2a is a schematic cross-sectional view of the induction heating coil of the present invention, and FIG. 2b is a temperature distribution characteristic diagram of the bottom of the pot due to the induction heating coil of the present invention.
Fig. 2c is a temperature distribution characteristic diagram of the induction heating coil as described above, Fig. 3 is a schematic vertical cross-sectional view of an electromagnetic cooker using the induction heating coil of the invention, and Fig. 4 is the induction heating coil of the invention. Top view. 1...Top plate, 2...Induction heating coil, _W1 , _W2 , _W3 ...Coil width.

Claims (1)

[Scope of utility model registration request] Below the top plate that holds pots, pots, etc.
An electromagnetic cooking device characterized in that, in an induction heating coil arranged in a spiral manner, the width of the conductor constituting the coil in the middle part thereof is wider than that in the core part and the outer part.