JPH01235187A - Composite cooking utensil - Google Patents

Abstract

PURPOSE:To normally obtain functions of a microwave oven and an induction- heated cooking utensil without affecting each other by connecting the first switch in parallel with a dielectric heating safety switch and connecting the second switch in parallel with an induction heating safety switch. CONSTITUTION:When a selector switch 6 or 7 is operated and a start switch 9 is operated to operate a dielectric heating circuit 27, a transfer switch 81 is switched to close the contacts (c) and (b) by a control circuit 32, the second switch 34 is also closed. During the induction heating operation, both ends of a dielectric heating safety switch 16 are short-circuited by the first switch 33 in the closed state, the second switch 34 in parallel with an induction heating safety switch 17 is opened, the operation is controlled only by the opening or closing of the induction heating safety switch 17. The function as a microwave oven and the function as an induction-heated cooking utensil can be normally obtained without affecting each other.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a composite cooking device that has the functions of a microwave oven and an induction heating cooking device.

(Prior art) In a microwave oven, a high-frequency current is passed through the primary coil of a step-up transformer, and the high-voltage, high-frequency voltage output to the secondary coil is applied to a magnetron, which is a microwave tube, to generate microwaves. Dielectrically heats foods, etc. Further, an induction heating cooker inductively heats a cooking container (such as a pot) by passing a high frequency current through a heating coil.

Recently, the inverter main circuit used in microwave ovens to send high-frequency current to the primary coil of a step-up transformer and the inverter main circuit used to send high-frequency current to the heating coil in induction heating cookers have been developed. Since they can be used in common and the main components such as inverter control circuits can be used in common, a composite 1"f!J heating device is provided that has the functions of both a microwave oven device and an induction heating device.This item In this case, a microwave chamber is formed inside the box-shaped container body for storing food to be heated by induction, and a top plate is provided on the top surface of the container body for placing a cooking container to be heated by induction. Furthermore, a dielectric heating circuit equipped with a magnetron is provided in the main body of the vessel, as well as a dielectric heating circuit equipped with a heating coil.In this case, the inverter main circuit is shared between the dielectric heating circuit and the induction heating circuit. This type of composite cooker is equipped with a selection switch that is operated by the user, and depending on the operation of this switch, the microwave oven mode (dielectric heating) and heating cooking mode are selected. It is possible to select whether to use a heating device (induction heating).

Further, in this type of composite cooker, a safety switch for dielectric heating and a safety switch for induction heating are interposed in series connection in a common power supply line for the dielectric heating circuit and the induction heating circuit. These safety switches consist of normally closed thermal switches.

The safety switch for dielectric heating is opened when the temperature of the magnetron section becomes abnormally high during operation of the dielectric heating circuit. ! ! The safety switch for induction heating is opened to cut off the power when the temperature of the top plate and thus the cooking vessel becomes abnormally high during operation of the induction heating circuit.

(Problem to be Solved by the Invention) However, in the above-mentioned method, if the safety switch for induction heating malfunctions when the microwave oven is used (during operation of the dielectric heating circuit), even though the magnetron is not in an abnormally high temperature state, In other words, even though the microwave oven is functioning normally, the induction heating safety switch stops the operation in the microwave oven usage mode.

Conversely, when the induction heating cooker is used (when the induction heating circuit is in operation), if the safety switch for dielectric heating malfunctions, induction heating cooking will occur even though the cooking container is not in an abnormally high temperature state. Although the dielectric heating safety switch is functioning normally,
The operation of the induction heating cooker will be stopped.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a dielectric heating circuit and an induction heating circuit to function as a microwave oven and an induction heating cooker, and to provide a dielectric heating safety switch and a dielectric heating safety switch. In a device equipped with a safety switch for induction heating, the safety switch for induction heating does not affect dielectric heating, and the safety switch for dielectric heating does not affect induction heating. Therefore, it is an object of the present invention to provide a composite cooking device which can normally perform the functions of a microwave oven and an induction heating cooking device without mutually affecting each other.

[Structure of the Invention] (Means for Solving the Problems) The present invention provides a main body having a microwave chamber and a top plate, and a microwave tube that generates microwaves for food stored in the microwave chamber. a dielectric heating circuit that dielectrically heats the cooking container placed on the top plate by passing a high frequency current through a heating coil, and a power supply line common to the dielectric heating circuit and the induction heating circuit. In a device comprising a dielectric heating safety switch and an induction heating safety switch each consisting of a thermal switch interposed in series connection, the first switch is connected in parallel to the dielectric heating safety switch, and A second switch is connected in parallel to the safety switch for induction heating, and when the dielectric heating circuit is in operation, the first switch is opened and the second switch is closed, and when the induction heating circuit is in operation, the first switch is closed. The feature is that the switch is closed and the second switch is closed.

(Function) When the dielectric heating circuit is in operation, both ends of the safety switch for induction heating are short-circuited by opening a second switch in parallel with the safety switch. At the same time, the first switch in parallel with the safety switch for dielectric heating is opened, so that the power supply to the dielectric heating circuit is completely unrelated to the opening and closing of the safety switch for induction heating, and only the safety switch for dielectric heating is supplied. It will be controlled according to opening and closing.

Further, when the induction heating circuit is in operation, both ends of the dielectric heating safety switch are short-circuited by opening a first switch in parallel with the safety switch. At the same time, the second switch in parallel with the safety switch for induction heating is opened, so the power supply to the dielectric heating circuit is completely unrelated to the opening and closing of the safety switch for induction heating, and only the safety switch for induction heating is supplied. It will be controlled according to opening and closing.

(Example) An embodiment of the present invention will be described below with reference to the drawings.

First, in Fig. 2, 1 is a box-shaped container body, and inside it is a microwave chamber 3 whose front can be opened and closed by a door 2.
is formed. Further, a top plate 4 is arranged on the upper surface of this vessel body 1. Reference numeral 5 denotes an operation panel section provided on the upper front side of the main body 1. As shown in FIG. 3, the operation panel section 5 includes a range selection switch 6.7, a dielectric heating selection switch 8, and a start switch 9. Cancel switch 10. Output adjustment switches 11.12 are provided. Selection switch 6
is for selecting the operation of the dielectric heating circuit (described later) and setting the range operation mode to the normal mode (output mode suitable for cooking food), and the selection switch 7 is for selecting the operation of the dielectric heating circuit (described later). This is for selecting the operation and setting the thawing mode (output mode suitable for thawing frozen foods) as the range operation mode.

The selection switch 8 is for selecting the operation of the induction heating circuit 21 (described later). 9 is for starting the selected operation. A cancel switch 10 is used to cancel the settings made by each of the switches 6 to 10. The output adjustment switches 11 and 12 are used to adjust and set the induction heating output in the up direction and down direction, respectively. Note that 13 is a knob for setting the operating time, and 14 is a display that displays the output setting level and the like.

Next, in FIG. 1 showing the electrical configuration, 15 is a plug connected to an AC power source, and its power lines 15a, 1
A dielectric heating safety switch 16 and an induction heating safety switch 17 are interposed in series in one power supply line 15a of the power supply lines 5b. Each of these safety switches 16.1
The dielectric heating safety switch 16 is provided to sense the temperature of a magnetron 29 portion of a dielectric heating circuit 27, which will be described later, and opens when abnormally high temperature is detected. Further, an induction heating safety switch 17 is provided to sense the temperature of the back surface of the top plate 4, and opens when an abnormally high temperature is detected. A DC power supply circuit 18 is connected to the power supply lines 15a and 15b, and is composed of a rectifier 19 consisting of a diode bridge and a smoothing capacitor 20. Reference numeral 21 denotes an induction heating circuit, which is composed of an inverter main circuit 25 having a resonant capacitor 22, a switching transistor 23, and a flywheel diode 24, and a heating coil 26. 27 is a dielectric heating circuit, which includes a step-up transformer 28 and a magnetron 29 which is a microwave tube provided on the side of the secondary coil 28b.
The inverter main circuit 25 is comprised of a microwave generating circuit 30 having a microwave generating circuit 30, etc., and the inverter main circuit 25. Therefore, the inverter main circuit 25 is common to the induction heating circuit 21 and the dielectric heating circuit 27. Reference numeral 31 denotes a changeover switch consisting of a relay switch, which is operated by an excitation coil 31a that is turned on and off by a control circuit 32, which will be described below. (c-a) When the heating coil 17 side (induction heating circuit 21 side) is made conductive by opening the contact point (c-b
) by opening the primary coil 2B of the step-up transformer 28.
a (ill (dielectric heating circuit 27 side)).
-a) It closes the space between.

32 is a control circuit, which includes a microcomputer, and when the selection switch 8 is operated, the output is set by the output adjustment switches 11 and 12, and the start switch 9 is operated. When it is done,
With the changeover switch 31 left open between contacts (c and a), a pulse drive signal shaped by PWM control is output from the output terminal 01 to the switching transistor 23 according to the output setting level, and thus, By turning on and off this transistor 23, the heating coil 26
A high frequency current is passed through the top plate 4, and as a result, the cooking container placed on the top plate 4 is heated by induction. Also, selection switch 6
or 7 is operated, the time is set by the time setting knob 13, and the start switch 9 is operated, the selector switch 31 is switched to (c-b) open/close, and the output terminal o1 is Normal mode (when selection switch 6 is operated) or thawing mode (selection switch 7
is operated), a high voltage, high frequency voltage is applied to the magnetron 29 to generate microwaves, and the food placed in the microwave chamber 3 is dielectrically heated. do.

Now, 33 is a first switch, and 34 is a second switch, both of which are normally open relay switches. The first switch 33 is connected in parallel with the safety switch 16 for dielectric heating, and the second switch 34 is connected in parallel with the safety switch 17 for induction heating. The first switch 33 and the second switch 34 are closed by exciting coils 33a and 34a, respectively. The excitation coils 33a and 34a are connected to the control circuit 32.
The power is turned on and off by a drive circuit (not shown) included in the power source. Specifically, when operating the dielectric heating circuit 27 based on human power from the various switches 8 to 12 described above, the control circuit 32 closes the second switch 34 while keeping the first switch 33 open. Also, when operating the induction heating circuit 21 based on the inputs from the various switches 8 to 12 described above, the first switch 33 is closed and the second switch 33 is closed.
The switch 34 is kept open.

The operation of the above configuration will be described. Now, in order to operate the dielectric heating circuit 27 (to function as a microwave oven), when the selection switch 6 or 7 is operated and the start switch 9 is operated, the control circuit 32 causes the changeover switch 31 to switch to the contact (c). -b) is switched to open bottom, and the second switch 34 is closed. Then, a drive signal is outputted from the output terminal O1, thereby operating the dielectric heating circuit 27, thereby causing the food in the range chamber 3 to be dielectrically heated.

During this dielectric heating operation, both ends of the induction heating safety switch 17 are connected to the second switch 34 which is in an open state.
The safety switch 16 for dielectric heating is short-circuited by
Since the first switch 33 in parallel with is in the open state, the power supply to the dielectric heating circuit 27 is completely unrelated to the opening and closing of the safety switch 17 for induction heating, and the power supply to the dielectric heating circuit 27 is completely independent of the opening and closing of the safety switch 16 for induction heating. become controlled. As a result, even if the induction heating safety switch 17 opens due to malfunction, the power supply to the dielectric heating circuit 27 will not be stopped, and the dielectric heating circuit 27 will not be stopped.
7 is operated normally.

Further, in order to operate the induction heating circuit 21 (to function as an induction heating cooker), the selection switch 8 is operated, the output is set by the output setting switch 11 or 12, and the start switch 9 is operated. Control circuit 32
In this case, the changeover switch 31 is left in the open/closed state at the contact point (ca), the second switch 34 is left in the open state, and the first switch 33 is closed. and,
A drive signal is output from the output terminal O1, and the induction heating circuit 21 is operated, thereby causing the cooking container on the top plate 4 to be heated by induction. During this induction heating operation, both ends of the dielectric heating safety switch 16 are short-circuited by the first switch 33 which is in the open state, and the second switch 34 in parallel with the induction heating safety switch 17 is in the open state. As a result, the power supply to the induction heating circuit 21 becomes completely unrelated to the opening and closing of the dielectric heating safety switch 16, and is controlled according to only the opening and closing of the induction heating safety switch 17. As a result, even if the dielectric heating safety switch 16 opens due to malfunction, the power supply to the induction heating circuit 21 will not be stopped and the induction heating circuit 21 will operate normally.

[Effects of the Invention] As is clear from the above description, the present invention includes a main body having a microwave chamber and a top plate, and a microwave tube that generates microwaves and is housed in the microwave chamber. A dielectric heating circuit that dielectrically heats food etc., an induction heating circuit that inductively heats a cooking container placed on the top plate by passing a high frequency current through a heating coil, and a power supply line common to the dielectric heating circuit and the induction heating circuit. A dielectric heating safety switch and an induction heating safety switch each comprising a thermal switch are connected in series to the dielectric heating safety switch, and the first switch is connected in parallel to the dielectric heating safety switch, and the first switch is connected in parallel to the dielectric heating safety switch. , a second switch is connected in parallel to the safety switch for induction heating, the first switch is opened and the second switch is closed when the dielectric heating circuit is in operation, and the first switch is closed when the induction heating circuit is in operation. It is characterized by having a structure in which the first switch is closed and the second switch is closed, so that the induction heating safety switch does not affect the dielectric heating operation, and The safety switch for dielectric heating does not affect induction heating operation, and thus the functions of a microwave oven and an induction heating cooker can be normally obtained without affecting each other. .

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention, and FIG. 1 is an electric circuit diagram including some blocks, FIG. 2 is an overall perspective view, and FIG.
The figure is a front view of the operation panel section. In the figure, 1 is the main body, 3 is the microwave chamber, 4 is the top plate, 6 to 8 are selection switches, 15 is the plug, 15a, 1
5b is a power line, 16 is a safety switch for dielectric heating, 1
7 is a safety switch for induction heating, 18 is a DC power supply circuit, 2
1 is an induction heating circuit, 25 is an inverter main circuit, 26 is a heating coil, 27 is a dielectric heating circuit, 29 is a magnetron (
32 is a control circuit, 33 is a first switch, and 34 is a second switch. Applicant Toshiba Corporation Toshiba Audio/Video Figure 2 Figure 3 436-1

Claims (1)

[Claims] 1. A main body having a microwave chamber and a top plate, a dielectric heating circuit that dielectrically heats food stored in the microwave chamber by generating microwaves from a microwave tube, and a high-frequency current applied to a heating coil. A dielectric heating safety device comprising an induction heating circuit for inductively heating a cooking container placed on the top plate by flowing water, and a dielectric heating circuit and a thermal switch connected in series to a power supply line common to the induction heating circuit. In the device comprising a switch and a safety switch for induction heating, the first switch is connected in parallel to the safety switch for dielectric heating, and the second switch is connected in parallel to the safety switch for induction heating. The first switch is opened and the second switch is closed when the dielectric heating circuit is in operation, and the first switch is closed and the second switch is closed when the induction heating circuit is in operation. A composite cooker that is characterized by: