JPH02162679A - Dielectric heating cooking appliance - Google Patents

Abstract

PURPOSE:To make a filter coil occupying surface area small and lower leakage noize and reduce the size of the title appliance by placing a plurality of filter coils up and down closely against a high frequency electric power transforming device and a commercial electric power source. CONSTITUTION:A commercial electric power source 1 is rectified 6, transformed into a high frequency by a high frequency electric power source transforming apparatus 10, and supplied to a heating coil 12. As the same way, a commercial electric power source 2 is rectified 7, transformed into high frequency, and supplied to a heating coil 13. Terminal noize of high frequency leaking from an apparatus 10 is filtered by a filter coil 8 and further filtered by filter coils 3, 4. As the same way, terminal noize of high frequency leaking from an apparatus 11 is filtered by a filter coil 9 and further filtered by filter coils 4, 5. The coils 5 and 9 and the coils 3 and 8 are closely placed up and down and contained in a space between a printed circuit board 15 where the apparatus 10 and 11 are mounted and controlling substrate 19.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an induction heating cooker equipped with a fill coil.

Conventional technology Conventional induction heating cookers of this type are generally equipped with a high-frequency power converter, which converts commercial power into a high-frequency power of approximately 2 sK+, energizes the heating coil, and generates a high-frequency magnetic field. The structure is such that the steel to be heated is heated and cooked. On the other hand, a filter coil that leaks from this high-frequency power supply to the commercial power supply is required, and if multiple filter coils are required, they should be placed one by one on the chassis or the bottom of the housing with a distance between them. It was arranged in a row.

Problems to be Solved by the Invention The power consumption of induction heating cookers is generally large, and the current flowing through the filter coil windings is also large.In order to prevent heat generation, the diameter of the strands of the filter coil windings must be increased. On the other hand, in order to obtain a predetermined noise removal ability, a predetermined number of windings and a core volume are required, so the shape of the filter coil becomes large. Therefore, if the coils are placed one at a time on the chassis or the bottom of the casing, as in the conventional configuration, the total area occupied by these multiple coils becomes larger, and induction heating cooking becomes more efficient. The problem was that it was difficult to miniaturize the device.

The present invention solves such problems, and a first object thereof is to reduce the area occupied by the plurality of filter coils P in the housing, and to obtain a small induction heating cooker with less leakage noise.

The second purpose is to prevent high frequency noise from leaking into the commercial power supply by magnetically coupling a plurality of adjacent filter coils by their respective leakage magnetic fluxes.

Means for Solving the Problems In order to achieve the above-mentioned first object, the first technical means of the present invention is to arrange at least two or more filter coils close to each other above and below, and to connect the high frequency power converter with electricity. The coil that is electrically closer to the commercial power supply is placed at the top, and the coil that is electrically closer to the commercial power source is placed at the bottom.

In addition, in order to achieve the second object, the second technical means of the present invention is to arrange at least two or more filter coils vertically close to each other, and to support the lower part of the upper filter coil with a conductive metal plate. It is something.

Effect: According to the first technical means of the present invention, at least two or more filter coils are arranged close to each other vertically, so the installation area occupied by the filter coils can be reduced, and therefore the bottom area of the casing can be reduced. can.

In addition, the filter coils that are arranged close to each other vertically are arranged above the filter coils because the coils that are electrically closer to the high-frequency power converter are placed at the top and the coils that are closer to the commercial power source are placed at the bottom. The filter coil located at the bottom near the commercial power supply is not affected by the high frequency magnetic field emitted from the heating coil because it is far away from the heating coil, and the high frequency magnetic field of the heating coil is transmitted to the filter coil located at the bottom of the commercial power supply. The amount leaked to the commercial power supply will be extremely small. In addition, the coil that is electrically close to the high-frequency power converter located at the top is close to the heating coil above, and is naturally affected by the high-frequency magnetic field of the heating coil, causing high-frequency noise in the current flowing through this filter coil. Although this is superimposed, the current flowing through this coil is electrically high-frequency components of the high-frequency power converter are not sufficiently filtered (filtered), so due to the noise level and the influence of the heating coil magnetic field, the weight of this filter coil increases. There is not much difference when compared with the level of F), and since these waves are F) F waves by the filter capacitor added in the next stage or the filter coil on the commercial power supply side, the high frequency noise leaking to the commercial power supply can be sufficiently reduced. As a result, the area occupied by the filter coil is reduced,
A small-sized induction heating cooker with less leakage noise can be obtained.

According to the second technical means, at least two or more filter coils μ are arranged close to each other vertically, so that the installation area occupied by the filter coils can be reduced, and the bottom area of the casing can be reduced. Furthermore, since the lower part of the upper filter coil is supported by a conductive metal plate, magnetic coupling due to magnetic flux leaking from the upper and lower filter coils can be prevented. Therefore, when a filter coil close to a high-frequency power converter through which a noisy current flows and a filter coil with low noise are placed close to each other vertically, the noise of the former is transmitted to the latter by the magnetic foundation, causing noise in the commercial power supply. It can prevent it from flowing.

EXAMPLE An example of the present invention will be described below with reference to the drawings.

In FIG. 1, 1 and 2 are commercial power sources, which are single-phase three-wire power sources. A commercial power source 1 is rectified by a rectifier 6, converted to a high frequency power source by a high frequency power converter 10, and a high frequency current is supplied to a heating coil 12 with an output of 2 KW. The commercial power source 2 is rectified by a rectifier 7, converted into a high frequency power source by a high frequency power converter 11, and is converted into a high frequency power source by a heating coil/L' with an output of 1.2 KW.
A high frequency current is supplied to 13. High frequency power converter 10
The high-frequency terminal noise that leaks through the terminal is transmitted by the filter coil and further filtered by the filter coils/L/3 and 4. Similarly, high frequency terminal noise leaking from the high frequency power converter 11 is filtered by the filter coil 9 and filtered by the filter coils μ4 and 5.

The parts of the induction heating cooker shown in Figure 1 are shown in Figure 2.
4.It is stored on the bottom surface and constitutes a two-burner cabinet-built induction heating cooker. In the same figure, reference numeral 15 mounts and fixes components such as the high-frequency power converter 1o for a burner with a heating output of 2 kW and the rectifier 6 shown in FIG. 16 and 17 are printed circuit boards, 16 and 17 are cooling fins for switching semiconductors of the high frequency power converters of each of the burners, 18 and 19 are printed circuit boards on which control circuit components of the high frequency power converters of each of the burners are mounted, and 20 is a printed circuit board on which control circuit components of the high frequency power converters of each burner are mounted. An intake fan disposed near the intake port 21; 22 is an intake port that sucks outside air from the intake port at the top of the housing into the cabinet in which the housing 14 is installed; This is an exhaust port that sucks air into the casing 14 and releases waste heat after cooling each component to the outside from an exhaust port provided at the top of the casing. Also,
The filter coils 6 and 9 and the filter coil I/3 shown in FIG. 1 are, as shown in FIG. 8 are located at the top and are arranged close to each other. Note that 24 in FIG. 3 is a support made of a hollow cylinder for fixing the upper filter coil, and the upper filter coil is fixed to the bottom surface of the housing 14 with screws through this support. Heating carp /l/12 and 13 in Figure 1 are the second
It is placed at the position indicated by the dotted circle in the figure.

In the above configuration, since the filter coils/l/6 and 9 and the filter coils/L/3 and 8 are arranged close to each other vertically, the printed circuit board on which the components of the high-frequency power converter are mounted, as shown in FIG. 15 and control board '-1
It can be stored in a narrow space between 9 and 9. In addition, a heating coil/L'13 is placed close to the top of the filter coil group, and the magnetic field generated from this heating coil interlinks with the filter group, inducing high frequency noise in the filter coil. Although there is a possibility that the filter coil/L/9 Oyohi 8 located at the top and close to the heating coil 13,
As shown in Figure 1, these coils are electrically close to the high-frequency power conversion circuit, so even if high-frequency noise is induced in these filter coils due to the influence of the magnetic field of the heating coil, this filter Since the high frequency noise induced by the filter capacitor and filter coil on the side of the commercial power supply 2 and 1 can be removed from the coil, high frequency noise can be prevented from leaking to the commercial power supply. In addition, heating carp/
If high frequency noise is induced due to the influence of the magnetic field of L/13, the filter coil 13 on the side near the commercial power supply may leak into the commercial power supply as there is no component to transmit the high frequency noise in the subsequent stage. .5 is disposed at the bottom and is located at a distance from the heating coil 13, and the strength of the magnetic field from the heating coil is approximately inversely proportional to the cube of the distance from the heating coil, so the magnetic field of the heating coil is The influence of high-frequency noise is extremely small, and leakage of high-frequency noise to the commercial power supply can be suppressed to a low level.

Next, another embodiment of the present invention will be described with reference to FIGS. 4 and 6.

Note that the filter coils/115 and 9 shown in FIG. 1 and the filter coils lv3 and 8 are arranged close to each other vertically as shown in FIGS. 5 a and b, and are indicated by the same reference numerals in FIG. Parts are stored in position. FIG. 6C shows the remaining filter coil /L'4.

As shown in FIG. 4, the filter coils lv9 and lv8 located at the top are fixed to a conductive metal plate 25 made of aluminum or copper, and the conductive metal plate 26 is fixed to the bottom surface of the casing with screws.

The operation of this embodiment will be described. In the above configuration, since the two sets of filter coils /l/9, 8 and 5.3 are arranged close to each other vertically, they can be stored in a narrow space in terms of plane. In addition, filter coil /l/9 (or 8) is the first stage short wave circuit of the high frequency power converter 11 (or 10),
The current flowing through this filter coil contains many high-frequency current components that have not been completely converted into short waves. Therefore, if the filter coil L/9 (or 8) and the filter coil A15 (or 3) are placed close to each other vertically, the current leaking from the filter coil A/9 (or 8) and containing a large amount of the high frequency current component Since the magnetic field reaches the winding of filler coil 6 (or 3), the high frequency current component of filter coil A/9 (or 8) is transmitted to filter coil V5 (or 3). This transmitted high-frequency current component leaks to the commercial power supply as terminal noise because the filter coil v5 (or 3) is located close to the commercial power supply 2 (or 1). Since the support plate 26 is interposed between both coils as a magnetic shielding member,
The magnetic coupling between the two coils as described above is prevented, and there is no possibility that the high frequency noise component of the filter coil 9 (or 8) will enter the filter coil. In addition, the filter coil /L/9 (or 8) placed at the top is supported by a conductive metal member such as an aluminum plate or copper.
By transmitting the heat generated from the filter coil 9 (or 8) and discharging it into the lower casing or into the air, there is also the effect of reducing the temperature rise of the filter coil 9 (or 8). Note that iron or the like may be used as the conductive member 26, but in order to magnetically separate the upper coil and the lower coil, it is best to use a highly conductive non-magnetic material such as copper or aluminum. Effective.

Effects of the Invention As is clear from the description of the embodiments, the present invention provides the following effects.

(1) At least two or more filter coils are arranged close to each other vertically, with the filter coil electrically closer to the high-frequency power converter at the top and the filter coil closer to the commercial power source at the bottom. Because of this configuration, the area occupied by the filter coil can be reduced, and the noise leaked to the commercial power supply due to the magnetic field of the heating coil being transmitted to the filter coil can be reduced, making it possible to downsize the induction heating cooker. .

(2) At least two or more filter coils are arranged close to each other vertically, and the lower part of the upper filter coil is supported by a conductive metal plate, so the area occupied by the filter coils can be reduced, and The filter coils magnetically coupled to each other can prevent high-frequency noise from the filter coil on the high-frequency power converter side from leaking into the commercial power supply, and can also radiate heat from the upper heating coil from the conductive metal member. So the upper filter can be coiled. Therefore, since the area occupied by the filter coil can be reduced without increasing the leakage noise level, the induction heating cooker can be made smaller.

[Brief explanation of the drawing]

Fig. 1 is an electric circuit diagram of an induction heating cooker showing an embodiment of the present invention, Fig. 2 is a plan view thereof, Fig. 3 is a perspective view thereof, and Fig. 4 is a diagram showing a second embodiment of the invention. FIG. 6 is an exploded perspective view of the filter coil shown in FIG. 1, 2... Commercial power supply, 3, 4, 5.・
...Filter coil on the side electrically closer to the commercial power supply Kti, 8, 9, mountain...Filter coil on the side electrically closer to the high frequency power converter, 10, 11...High frequency power converter , 26... Conductive metal plate. Name of agent: Patent attorney Shigetaka Awano Is there one person? , 'l... - fable d' jig 1j ka'I! Exchange worker 1st lfuk?) detective (1■) (IL tile Io41---411
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Claims (2)

[Claims] (1) comprising a high-frequency power converter that converts commercial power to high-frequency power; and a plurality of filter coils that reduce high-frequency noise leaking from the high-frequency power converter to the commercial power;
At least two or more filter coils of the plurality of filter coils are arranged close to each other vertically, and the filter coils electrically closer to the high frequency power converter are placed above the filter coils that are arranged close to each other vertically. , an induction heating cooker having a configuration in which a filter coil on the side electrically closer to the commercial power source is disposed at the bottom. (2) comprising a high-frequency power converter that converts commercial power to high-frequency power; and a plurality of filter coils that reduce high-frequency noise leaking from the high-frequency power converter to the commercial power;
At least two or more filter coils of the plurality of filter coils are vertically arranged close to each other, and the upper filter coil has a lower portion supported by a conductive metal plate.