JPH0711432Y2 - Magnetic field generator for electromagnetic induction cooker - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of use] The present invention relates to a magnetic field generator used in an electromagnetic induction cooker.

[Prior Art] Conventionally, in this type of magnetic field generator, one spiral work coil 101 is used as shown in FIGS. 3 (a) and 3 (b). In addition, a work coil having two layers stacked in a direction along the axis of the spiral may be used.

To make an electromagnetic induction cooker, a top plate 102 is placed on a work coil 101, as shown in FIG. Then, an object to be heated (pot or the like) 103 is placed on the top plate 102, and the object to be heated 103 is heated. The object 103 to be heated can be heated most efficiently when the size of its bottom surface is substantially the same as the size of the work coil 101.

[Problems to be solved by the invention] However, when an object to be heated of a non-magnetic material such as an aluminum pot is heated in an electromagnetic cooker using a conventional single work coil, the magnetic energy density becomes large. There is a problem that a repulsive force is generated between the coil and the object to be heated and the object to be heated moves.

Therefore, it is an object of the present invention to provide a magnetic field generator with reduced electromagnetic energy density.

[Means for Solving the Problems] The present invention provides a plurality of spiral coil elements arranged on the same plane and a plurality of spiral coil elements in a magnetic field generator used for an electromagnetic induction cooker. And a selection device for selecting the direction of the current flowing through.

[Operation] When the directions of the currents flowing through the plurality of coil elements are individually controlled to change the directions of the magnetic fields of some of the coil elements, the magnetic energy density decreases.

[Embodiment] An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows a main part of a magnetic field generator according to an embodiment of the present invention. This magnetic field generator consists of seven spiral coil elements C1 to C7.
(Hereinafter, referred to as a coil element). As is apparent from FIG. 1 (a), the coil element C1 is centered, and the remaining coil elements C2 to C7 are arranged so as to surround the coil element C1.

When this magnetic field generator is used as an electromagnetic cooker, the top plate 102 is arranged on the upper surfaces of these coil elements C1 to C7 as in the conventional case. The object 103 to be heated is placed on the top plate 102 to perform heating.

FIG. 2 shows a circuit diagram of this embodiment. Referring to FIG. 2, the magnetic field generator of this embodiment has a plurality of coil elements C1 to C7.
And a resonance capacitor 2 and phase changeover switches S1 to S7. Each of the coil elements C1 to C7 and the resonance capacitor 2 are connected in series. Then, the switches S1 to S7
Are coil elements C1 to C so that the phases of the currents flowing in the coils C1 to C7 can be independently and selectively converted by 180 degrees by switching to the broken line state or the alternate long and short dash line state.
Connected to each of the seven. In addition, coil elements C1 to C7
Are connected in parallel to the inverter 3.

When the top plate is placed on the coil elements C1 to C7 of this magnetic field generator to heat the non-magnetic material to be heated, the phase shift of the current flowing through some of the coil elements C1 to C7 is 180 ° Conversion reduces magnetic energy density.

The number of spiral coil elements is not limited to seven and may be any number. Further, the shape is not limited to the above embodiment, but may be a hexagon, a quadrangle or the like, and the arrangement shape may be a rectangle or the like.

Further, although the series resonance type magnetic field generator is described in the above-mentioned embodiment, a parallel resonance type magnetic field generator may be used.

[Effects] According to the present invention, by connecting a plurality of spiral coils and a selection device for selecting the direction of the current to each of the plurality of spiral coils, the magnetic energy density is reduced and the non-magnetic material is reduced. It is possible to prevent the movement of the object to be heated.

[Brief description of drawings]

FIG. 1 shows a main part of a magnetic field generator according to an embodiment of the present invention. (A) is a front view, (b) is a side view, and FIG. 2 is a first view.
3 is a circuit diagram showing the wiring of the magnetic field generator shown in the figure, FIG. 3 shows a conventional work coil, (a) is a plan view, (b) is a side view, and FIG. 4 uses the work coil shown in FIG. It is a side view which shows an electromagnetic cooker. DESCRIPTION OF SYMBOLS 1 ... Magnetic field generator, 2 ... Resonance capacitor, 3 ... Inverter, C1-C7 ... Spiral coil element, S1-S7 ... Switch,
101 ... Work coil, 102 ... Top plate, 103 ... Heating object.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Choji Chiba 21-1 Taishi-do, Sendai-shi, Miyagi Tokin Co., Ltd. (72) Inventor Sada Watanabe 7-8-22 Nakayama, Sendai-shi, Miyagi (72) Creator Takuya Nozaki 8-33-2 Nakayama, Sendai-shi, Miyagi Prefecture (72) Creator Toshio Watanabe 7-48-301 Nakayama, Sendai City, Miyagi Prefecture (56) References JP-A-52-143534 (JP, SHO) A) JP-A-49-86927 (JP, A)

Claims (1)

[Scope of utility model registration request] 1. A magnetic field generator used in an electromagnetic induction cooker, for selecting a plurality of spiral coil elements arranged on the same plane and a current direction flowing through each of the plurality of spiral coil elements. Magnetic field generating device for an electromagnetic induction cooker, comprising: