JP6757889B2 - Induction heating cooker - Google Patents

Description

The present disclosure relates to induction cookers used for home and commercial use.

In general, an induction cooker has one or more heating coils just below the top plate on which a metal cooking container such as a pan is placed. In an induction heating cooker, an eddy current is generated in a cooking container placed by a high-frequency magnetic field generated by a heating coil, and cooking is performed by utilizing the heat generated by the cooking container.

In this field, Patent Document 1 states that in order to drive a plurality of heating coils with a single drive circuit, a high frequency current is not supplied to unnecessary heating coils by connecting and disconnecting an electric circuit to the heating coils using a relay. The induction heating cooker that controls the drive circuit is disclosed.

Patent Document 2 discloses an induction heating cooker in which a plurality of relays are integrated to improve assembling property.

Patent Document 3 discloses an induction heating cooker having a large number of heating coils arranged in a matrix and supplying a high frequency current from a single drive circuit to a plurality of heating coils located below the cooking container. There is.

Japanese Unexamined Patent Publication No. 09-140561 Japanese Unexamined Patent Publication No. 05-335073 European Patent Application Publication No. 2380399

However, in the above-mentioned prior art, it is necessary to connect each heating coil to the corresponding relay by wiring.

Usually, wiring to the heating coil is performed in a state where the driving circuit is incorporated inside the housing and then the heating coil is temporarily placed near the housing or on a special jig. Therefore, the wiring work becomes complicated in proportion to the number of heating coils. Further, since the wiring is temporarily placed, it is necessary to make various lead wires including the connecting wire of the heating coil longer than necessary.

Therefore, not only the cost is increased, but also the lead wire is damaged when the lead wire is stored in the installation work of the wired heating coil because the lead wire is stressed or the lead wire comes into contact with the internal parts. There is a possibility of causing it. Since the lead wire is longer than necessary, it is also necessary to consider the influence of noise from the heating coil on the drive circuit.

If the distance between the heating coil and the relay cannot be kept constant due to the configuration, the length of the connection wire may be changed for each heating coil, or the structure of the housing may be changed according to the installation position of the relay. There was a problem with the commonality of parts.

In order to solve the above-mentioned conventional problems, the induction heating cooker of one aspect of the present disclosure includes a drive circuit, a plurality of heating coils, and a relay circuit.

The drive circuit converts AC power to high frequency power. The plurality of heating coils are provided on a metal shield plate and generate a high-frequency magnetic field when high-frequency power flows. The relay circuit has a plurality of relays that switch the connection between the drive circuit and the plurality of heating coils in response to a signal from the drive circuit, and is connected to the heating coils via a connection line. The relay circuit is installed in a holder provided on the surface of the shield plate opposite to the surface on which the heating coil is provided. The drive circuit is not installed in the holder.

According to this aspect, particularly in an induction heating cooker that switches the connection between a plurality of heating coils and a drive circuit by using a relay, the heating coil and the relay circuit do not change the length of the connection line of the heating coil. The wiring between the relay circuit and the drive circuit can be facilitated. As a result, noise can be suppressed, and the assemblability of the device and the commonality of parts can be improved.

FIG. 1A is a perspective view of the induction cooking device according to the embodiment of the present disclosure. FIG. 1B is a top view of the induction heating cooker according to the embodiment of the present disclosure. FIG. 2 is an exploded perspective view of the induction cooking device according to the embodiment of the present disclosure. FIG. 3 is an exploded perspective view of the heating coil unit according to the embodiment of the present disclosure. FIG. 4 is an exploded perspective view of the heating coil unit according to the embodiment of the present disclosure when viewed from the back side. FIG. 5 is a perspective view of the holder according to the embodiment of the present disclosure when viewed from the back side. FIG. 6 is a cross-sectional view taken along the line 6-6 shown in FIG. 1B. FIG. 7 is a perspective view showing how the heating coil unit is wired to the drive circuit in the embodiment of the present disclosure.

The induction heating cooker of the first aspect of the present disclosure includes a drive circuit, a plurality of heating coils, and a relay circuit.

The drive circuit converts AC power to high frequency power. The plurality of heating coils are provided on a metal shield plate and generate a high-frequency magnetic field when high-frequency power flows. The relay circuit has a plurality of relays that switch the connection between the drive circuit and the plurality of heating coils in response to a signal from the drive circuit, and is connected to the heating coils via a connection line. The relay circuit is installed in a holder provided on the surface of the shield plate opposite to the surface on which the heating coil is provided.

According to this aspect, after wiring between the relay circuit and the heating coil, wiring between the relay circuit and the drive circuit can be performed. As a result, the assemblability of the induction heating cooker is improved.

According to this aspect, when the heating coil is connected to the relay circuit, the heating coil and the relay circuit can be brought close to each other. Therefore, it is not necessary to lengthen the connecting wire more than necessary, and it is possible to suppress the generation of noise from the heating coil.

According to this aspect, even if the heat generated by the heating coil causes the shield plate to become hot, the holder can protect the relay circuit from the heat of the shield plate.

According to this aspect, even if the installation position of the heating coil unit in the housing is changed, the distance between the heating coil and the relay circuit in the heating coil unit does not change. That is, the length of the connecting wire does not depend on the position of the heating coil unit. Therefore, a connection line having the same length can be shared between models having different installation positions of the heating coil unit.

According to the induction heating cooker of the second aspect of the present disclosure, in the first aspect, the connection line is wired through the opening provided in the shield plate to connect the heating coil and the relay circuit. ..

According to this aspect, a shorter connection line can be used as compared with a wiring method in which the connection line bypasses the outer circumference of the shield plate.

According to the induction heating cooker of the third aspect of the present disclosure, in the first aspect, the holder has a fixing portion for being mechanically bonded to the housing and is installed around the end portion of the shield plate. Will be done.

According to this aspect, the holder is used not only to hold the relay circuit but also to connect the shield plate and the housing. Since the housing is made of a relatively inexpensive steel plate, it is possible to inexpensively configure the electrical insulation between the housing and the heating coil by using a resin holder provided between the heating coil and the shield plate. it can.

In the third aspect of the induction heating cooker of the fourth aspect of the present disclosure, the relay circuit has a connection part for attaching a connection line, and the holder is higher than the relay and the connection part and is close to the housing. Has an outer wall provided.

According to this aspect, the outer wall provided on the holder can increase the creepage distance between the housing and the connecting portion, and can form stable electrical insulation. In the unlikely event that water enters the area around the shield plate, the outer wall protects the relay circuit.

Hereinafter, preferred embodiments of the induction cooking device according to the present disclosure will be described with reference to the accompanying drawings. In the following drawings, the same or equivalent parts may be designated by the same reference numerals, and duplicate description may be omitted.

FIG. 1A is a perspective view of the induction cooking device 1 according to the embodiment of the present disclosure. FIG. 1B is a top view of the induction cooking device 1 according to the present embodiment. FIG. 2 is an exploded perspective view of the induction cooking device 1 according to the present embodiment.

As shown in FIGS. 1A, 1B, and 2, the induction cooker 1 is installed in the kitchen cabinet 3. The induction heating cooker 1 has a top plate 4, a heating coil unit 5a, a heating coil unit 5b, a heating coil unit 6, a fan motor 8, a drive circuit 9, a housing 10, and an operation board 12.

The top plate 4 is made of heat-resistant tempered glass and has a plurality of heating regions 4b on the surface thereof.

The heating coil units 5a, 5b, and 6 are installed below the heating region so that one side is supported by the support plate 7. The fan motor 8 is installed below the support plate 7 to cool the drive circuit 9. The drive circuit 9 is installed below the support plate 7 and supplies high-frequency power to the heating coil units 5a, 5b, and 6.

The housing 10 for accommodating these is made of a plated steel plate having a thickness of about 0.6 mm, and has a mica sheet 11 provided inside for electrical insulation with the drive circuit 9. The operation board 12 is installed in front of the support plate 7 and below the operation area 4a.

The induction heating cooker 1 heats the pan 2 placed in the heating region 4b according to the heating power set in the operation region 4a installed on the front side of the top plate 4.

FIG. 3 is an exploded perspective view of the heating coil unit 6 in the induction heating cooker 1 according to the present embodiment. FIG. 4 is an exploded perspective view of the heating coil unit 6 when viewed from the back side.

As shown in FIGS. 3 and 4, the heating coil unit 6 has four heating coils 22, mica sheets 21, 23, a shield plate 24, and a coil ferrite 25.

The shield plate 24 is made of an aluminum plate having a thickness of about 1.0 mm. The heating coil 22 is installed on the upper surface of the shield plate 24. The coil ferrite 25 is installed on the upper surface of the shield plate 24 so as to surround the heating coil 22.

The mica sheet 21 is provided between the top plate 4 and the heating coil 22 for electrical insulation. The mica sheet 23 is provided between the heating coil 22 and the coil ferrite 25 for electrical insulation. The mica sheets 21 and 23 are bonded with silicon (not shown).

In the present embodiment, the heating coil 22 is coated with, for example, polyethylene, and is formed into an elliptical shape by winding a bundled and twisted copper wire. The connecting wire 27 is connected to both ends of the heating coil 22 via a round terminal 38 attached to the tip from which the resin coating has been removed by heat caulking.

The heating coil 22 can also be configured by using other wire rods such as a wire rod made of copper and aluminum layers. The shape of the heating coil 22 is not limited to an ellipse, and may be, for example, a circle, a triangle, or a quadrangle. The heating coil unit 6 may have three or less or five or more heating coils 22.

As shown in FIG. 4, two holders 26 are formed around the end of the surface (lower surface in the present embodiment) opposite to the surface (upper surface in the present embodiment) to which the heating coil 22 is attached of the shield plate 24. Is fixed by the screw 34. The holder 26 is a box-shaped container made of heat-resistant resin and having no lid (see FIG. 5). One relay circuit 31 is fixed to the inside of the holder 26 by a screw 39.

In the present embodiment, since one relay circuit 31 is provided for the two heating coils 22, the induction heating cooker 1 has two relay circuits 31 in which two relays 32 are installed, respectively.

The relay circuit 31 has one terminal block 35a for connecting the power line 33 from the drive circuit 9, and four terminal blocks 35b for connecting the connection line 27. The terminal blocks 35a and 35b are connection portions for connecting the connection line 27 and the power line 33 to the relay circuit 31, respectively.

The connection line 27 is wired via an opening 36 provided in the shield plate 24, and connects the heating coil 22 installed on the upper surface of the shield plate 24 and the relay 32 installed on the lower surface of the shield plate 24. ..

The relay 32 switches the connection according to the signal transmitted from the drive circuit 9 via the signal line 37. High-frequency power is supplied to either of the two heating coils 22 according to the switching of the connection by the relay 32.

FIG. 5 is a perspective view of the holder 26 when viewed from the back side. FIG. 6 is a cross-sectional view taken along the line 6-6 shown in FIG. 1B.

As shown in FIGS. 2, 5 and 6, the heating coil unit 6 is attached to a step portion provided in the housing 10. The heating coil unit 6 is positioned by a positioning pin 42 provided on the holder 26, and then the screw receiving portion 41, which is a fixing portion provided in the horizontal direction, and the housing 10 are screwed together. It is fixed to the housing 10.

The holder 26 has an outer wall 40 higher than the relay 32 and the terminal blocks 35a and 35b with the relay circuit 31 installed. When the holder 26 is fixed to the housing 10, the outer wall 40 approaches the housing 10.

Hereinafter, a method of installing and wiring the heating coil 22, the relay circuit 31, and the like in the present embodiment will be described.

First, the heating coil 22 is arranged on the upper surface of the shield plate 24, and the relay circuit 31 is installed on the lower surface of the shield plate 24 via the holder 26. The connection lines 27 are connected to the corresponding terminal blocks 35b. This completes the connection between the heating coil 22 and the relay circuit 31.

Next, the heating coil unit 6 is wired to the drive circuit 9. FIG. 7 is a perspective view showing the situation. However, the connecting line 27 is not shown in FIG. 7.

As shown in FIG. 7, the heating coil unit 6 is temporarily placed sideways in the vicinity of the drive circuit 9 so that the holder 26 side faces downward. When the power line 33 and the signal line 37 are connected in this state, the wiring between the heating coil unit 6 and the drive circuit 9 is completed.

That is, according to the present embodiment, after wiring between the relay circuit 31 and the heating coil 22, wiring between the relay circuit 31 and the drive circuit 9 can be performed. As a result, the assembling property of the induction cooking device 1 is improved.

According to this embodiment, when the heating coil 22 is connected to the relay circuit 31, the heating coil 22 and the relay 32 can be brought close to each other. Therefore, it is not necessary to lengthen the connecting wire 27 more than necessary, and it is possible to suppress the generation of noise from the heating coil.

According to the present embodiment, even if the shield plate 24 becomes hot due to the heat generated by the heating coil 22, the relay circuit 31 is protected from the heat of the shield plate 24 by the holder 26 made of a heat-resistant insulating material. Can be done.

According to the present embodiment, even if the installation position of the heating coil unit 6 in the housing 10 is changed, the distance between the heating coil 22 and the relay circuit 31 in the heating coil unit 6 does not change. That is, the length of the connecting wire 27 does not depend on the position of the heating coil unit 6. Therefore, the connection wire 27 having the same length can be shared between models having different installation positions of the heating coil unit 6.

According to the present embodiment, wiring is performed via an opening provided in the shield plate 24, and the connection line 27 can be connected to the relay 32. Therefore, a shorter connection line 27 can be used as compared with a wiring method in which the connection line 27 bypasses the outer circumference of the shield plate 24.

According to this embodiment, the holder 26 is used not only for holding the relay circuit 31, but also for connecting the shield plate 24 and the housing 10. Since the housing 10 is made of a relatively inexpensive steel plate, a resin holder 26 provided between the heating coil 22 and the shield plate 24 is used to electrically insulate the housing 10 from the heating coil 22. It can be configured inexpensively.

According to the present embodiment, the outer wall 40 provided on the holder 26 can increase the creepage distance between the housing 10 and the terminal blocks 35a and 35b which are the connection portions, and can form stable electrical insulation. .. In the unlikely event that water enters the periphery of the shield plate 24, the relay circuit 31 is protected by the outer wall 40.

As described above, the induction heating cooker according to the present disclosure suppresses noise, improves assemblability and commonality, and can be applied to cooking equipment other than the built-in type.

1 Induction heating cooker 2 Pot (cooking container)
3 Kitchen cabinet 4 Top plate 4a Operation area 4b Heating area 5a, 5b, 6 Heating coil unit 7 Support plate 8 Fan motor 9 Drive circuit 10 Housing 11, 1, 23 Mica sheet 12 Operation board 22 Heating coil 24 Shield plate 25 Coil Ferrite 26 Holder 27 Connection line 31 Relay circuit 32 Relay 33 Power line 34, 39 Screw 35a, 35b Terminal block 36 Opening 37 Signal line 40 Outer wall 41 Screw receiving part (fixed part)
42 pin

Claims (4)

A drive circuit that converts AC power to high-frequency power,
A plurality of heating coils provided on a metal shield plate to generate a high-frequency magnetic field when the high-frequency power flows,
It has a plurality of relays for switching the connection between the drive circuit and the plurality of heating coils in response to a signal from the drive circuit, and includes a relay circuit connected to the heating coils via a connection line.
The relay circuit is installed in an electrically insulating holder provided on a surface of the shield plate opposite to the surface on which the heating coil is provided .
An induction cooker in which the drive circuit is not installed in the holder . The induction heating cooker according to claim 1, wherein the connection line is wired through an opening provided in the shield plate to connect the heating coil and the relay circuit. The induction heating cooker according to claim 1, wherein the holder has a fixing portion for being mechanically coupled to the housing, and is installed around the end portion of the shield plate. The induction according to claim 3, wherein the relay circuit has a connection for attaching the connection line, and the holder has an outer wall that is higher than the relay and the connection and is provided close to the housing. Heating cooker.