JPS61243690A - Induction heating cooker - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an induction heating cooking device that heats a cooking container by induction and cooks a food to be cooked in the container.

[Conventional technology]

Generally, in an induction heating cooking device, the top surface of the main body of the device is closed with a heat-resistant and insulating top plate made of ceramics or the like to prevent moisture from entering the main body, and the top plate with a smooth surface is used as a large surface. This makes it easy to wipe off stains caused by boiling over the food to be cooked, thereby improving the sense of cleanliness given to the user.

However, since dirt can be easily wiped off, cooking is often continued without wiping off the dirt on the spot.
Moreover, since the boiling over of the food is not notified, the user may continue cooking without noticing the boiling over, and if you continue cooking even after the boiling over occurs, the boiling over will stick to the top plate. This causes the inconvenience of being unhygienic and impairing the sense of cleanliness.

By the way, in a conventional induction heating cooking apparatus, as described in Japanese Utility Model Publication No. 58-3267, for example, two closed conductive paths are formed close to each other and separated from each other on the back surface of the top plate, and the closed conductive paths are short-circuited. A control circuit is provided to detect the power supply to the high-frequency oscillation circuit that supplies high-frequency current to the spiral heating coil. A device that detects a short circuit in the closed conductive path due to moisture from the food to be cooked and shuts off the power supply using a control circuit to prevent electrical leakage, damage to electrical parts, electric shock, etc. due to moisture that has entered. be.

[Problem that the invention seeks to solve]

However, the induction heating cooking device IT described in the above-mentioned publication attempts to detect cracks in the top plate due to heat transfer from the heating container to prevent electrical leakage caused by moisture intrusion. The problem is that it is not possible to detect and notify boiling over of food to be cooked, and it is not possible to prevent dirt from sticking to the top plate due to continued heating adjustment with boiling over left unattended. There is.

[Means for Solving the Problems] The present invention has been made with the above-mentioned points in mind, and is intended to prevent stains caused by boiling over the food to be cooked from sticking to the top plate 1. a high-frequency power source housed in the main body; an induction heating coil housed in the main body through which a high-frequency current from the power source flows; and an induction heating coil provided by closing the top surface of the main body by the magnetic field generated by the coil. a heat-resistant insulating top plate on which a cooking container to be cooked is placed; a detection means for detecting boiling over of the food on the top plate and outputting a detection signal; This is an induction heating cooking device characterized by comprising a notification means for notifying.

[For production]

Therefore, in this invention, the detection means detects boiling over of the food on the top plate 1 and outputs a detection signal, and the detection signal activates the notification means to notify the user of the occurrence of boiling over. It is possible to prevent the boiling-over vitality 5 from sticking to the top plate due to continued cooking without noticing the boil-over.

〔Example〕

Next, the present invention will be described in detail with reference to drawings showing embodiments thereof.

(Example 1) Figures 1 to 4, which show Example 1, will now be described.

In Figures 1 and 2 showing the external appearance, (1) is the main body of the device that houses the high-frequency power source, induction heating coil, etc., and (2)
is provided by closing the top surface of the main body (1), on which is placed a cooking container made of a predetermined material such as iron, which is heated by induction by the magnetic field generated by the coil; 1-1 (3) is a through hole in the left and right direction provided in the inclined part (4) at the front end of the main body (1), and (5) is a through hole (3).
) is closed from the inside, and (6) is a light emitting diode (hereinafter referred to as L E D) display section provided approximately in the center of the spring / I / (5), and at least when the power is turned on. A first T and ED that light up, and a second LED that lights up or flashes when boiling over of the food to be cooked is detected and that emit light in a different color from the first LED are provided.

(7) and (8) are the output adjustment knob and spillover detection electrode changeover switch provided on the spring/l/ (5) so as to be slidable in the left and right direction, and (9) is the top play 1.
- No. +ti, 00 is a circular conductive film attached to the center of the top plate 2), and 00 is the first electrode (9) attached to the outside of the first electrode (9) in the center of the top plate 2). ) a second electrode made of a circular conductive film with a larger diameter, (1
]) is the third electrode made of a rectangular conductive film attached to the periphery of the top plate (2), α is the third electrode attached to the outside of the third electrode Oυ on the periphery of the top plate [21] The fourth electrode is made of a rectangular conductive film with a larger diameter than the third electrode (1]), and 0■ to 0· are the top play 1- (2
) and one end is attached to each electrode (9) to O
It is a connection piece made of conductive film that is connected to P and the other end is connected to the contact of the boiling-over detection electrode changeover switch 〇71. 1st ° 2nd electrode (9), QQ or 3rd, 4th electrode 0η
, a are connected to the boiling over detection section described later, and each electrode (9) to 04. The detection means is constituted by the changeover switch 0η and the spillage detection section described above.

08) is the fourth electrode 0 on the periphery of the 1-tube plate (2)
Top play 1 with a U-shaped cross section cut out to the outside of the wall.
- (This is a metal sash for preventing spillage to the outside of 21, this sash 08) and each connection piece (13 to (16+) is a metal sash for electrical insulation, as shown in Figure 2, sash 08)
An insulating film portion is interposed between the connection pieces 1 and 0O.

Next, FIG. 3 showing the circuit configuration will be explained.

In the figure, (A) is a commercial AC power supply, (21) is a power switch whose one end is connected to one end of the power supply (A), and (22) is a power switch whose one end is connected to one end of the power supply (A).
) has both ends connected to the other end of the switch 121) and the power supply (the other end of the key), and (23) has the sub input terminal connected to the other end of the switch (21) and the other end of the power supply (a). The connected first rectifier circuit (24) is the switch (2
1) A current transformer that is installed between the other end and one input terminal of the first rectifier circuit (23) and detects the input current to the first rectifier circuit (see the diagram of the first rectifier circuit); The first rectifier circuit (2
3) an input power detection circuit that detects the input power and outputs a power detection signal proportional to the input power; (26) is 1;
The next winding (26&) and the first and second windings (26 &) as secondary windings (
26+1), (260), and the primary winding (26a
) is the transformer connected to the other end of the switch (21+ and the other end of the power supply wire), both ends of the switch (271 and (28+) have the sub input terminals of the first winding (26+), respectively), and the second winding ( 2
6C) connected to both ends of the second. Third rectifier circuit, (29
) is a smoothing reactor whose one end is connected to the positive output terminal (+) of the first rectifier circuit (23), and (30) is a smoothing reactor whose both ends are connected to the other end of the reactor (29) and the negative output terminal of the first rectifier circuit (23). A smoothing capacitor (31) has one end connected to the axle (29) and is disposed directly under the top plate (2).
) A spiral induction heating coil that conductively heats a cooking container 132) made of a predetermined material such as iron, +33), +
341 has sub-input terminals of %2. Third rectifier circuit (2
The first and second constant voltage circuits are connected to the positive and negative output terminals (+) of (211+, ←), and the first constant voltage circuit (
33) to supply power to each part except the input part of the detection circuit (described later), and the second constant voltage circuit (33) has a lower IB voltage than the first constant voltage circuit (33).
A constant voltage circuit (34) supplies power to the input section.

13(5) is an initial/l/F path whose sub-input terminals are connected to both ends of the primary winding (26a) and which outputs an initial signal when the input voltage to the transformer (firefly) is stabilized; 136:
(
37) is an input power setting circuit that outputs a first setting signal for setting the input power to the first rectifier circuit (23) according to the set scale of the knob (7); 1 setting signal and outputs a first comparison signal so that the former matches the latter, the first comparator (39) is activated by the activation signal and continuously activated by the on-trigger signal described later to perform pulse width modulation ( A PWM control circuit (40) that outputs a control signal (hereinafter referred to as PWM) is a base control circuit that outputs a base control signal based on the PWM control signal. 8 circuits, (41) has collector, base, and emitter as carp) The other end of lzz31, base control circuit (40)
output terminal of the first rectifier circuit (negative output terminal (-) of 23j)
It is an NPN type switching transistor connected to the base control signal, and is designed to supply a high frequency current to the coil (31) by switching based on the base control signal.
WM control circuit f39), base control circuit t4n+,
A flywheel diode (42) and a resonant capacitor (43) provided in parallel with the transistor (411), the collector and emitter of the transistor (41), respectively.
A high frequency power source (44) is configured.

(45) is a trigger generation circuit that detects the voltage across the coil (31) and continuously outputs an on-trigger signal to continue the output of the PWM control circuit (39), (4G) is a coil lv4
'31, detects an overcurrent exceeding a predetermined value, outputs an overcurrent detection signal to the PWM control circuit (39), and outputs an overcurrent detection signal to the coil (39).
1) an overcurrent protection circuit that controls the output of the PWM control circuit (39) so that the current flowing through the circuit is smaller than the predetermined value;
The small object detection 1 novel setting circuit (148) which receives the WM control signal and outputs a second setting signal proportional to the Hals width of the signal (T), that is, the ON period of the transistor (41), is connected to the input power detection circuit (25). ) a second comparator that outputs a second comparison signal as a stop 1-command signal to the oscillation control circuit 13G1 etc. when the power detection signal and the second setting signal are inputted and the former is smaller than the latter; (5
[j) are provided in the vicinity of the fl-transistor (411) and in the center inside of the top plate 1 and (2), respectively, and detect the temperature of the transistor (41) and the capacitor g?x'f321. 1st and 2nd for outputting temperature detection signal
Temperature sensing element <51), 652 is the first. a second overheating prevention circuit, when the first and second temperature detection signals are respectively input and the temperature of the transistor (41) and the temperature of the container (32) based on both the signals are respectively different predetermined temperatures or higher; , the oscillation control circuit 136) as a stop command signal. A second overheat prevention signal is output, and the container 132 is caused by overheating of the transistor (41), dry cooking, etc.
) is designed to prevent overheating.

G is a blowout detection circuit consisting of the changeover switch θ and a boilover detection section, and the power supply terminal is the first one.
The second constant voltage circuit +33) is connected to the positive and negative output terminals (+), ←) of F341, and the 1st, 2nd electrodes (9), (IQ or 3rd and 4th electrodes (11) , (12 short-circuit causes the oscillation control circuit (3
6) etc., outputs a boilover detection signal as a stop command signal.

(Foundation) is a buzzer that is activated by the second comparison signal and the boilover detection signal to emit an alarm sound;
A drive circuit that outputs a drive signal based on the comparison signal, the second overheating prevention signal, and the boiling over detection signal; (a) is a light emitting diode (hereinafter referred to as LED) display section, which lights up in response to the drive signal to notify of boiling over, etc. L E
D, and constitutes a notification means together with a buzzer.

Next, FIG. 4, which shows the detailed configuration of the detection means for detecting boiling over on the top plate (2), will be described.

In the figure, 671 is the first. second contact (57a,),
(57h) are the first. Third electrode (9), (1
The first switch connected to the connecting piece 03,0■ of 1), the ring is connected to the first switch. The second contacts C5ga) and (5gl)) are respectively connected to the second contact points C5ga) and (5gl)). 4th electric 1 oco, oa connection piece (14), Q
It is the second switch connected to Q, and both switches have 6 switches,
The switching pieces (57C) and (58C) of (2) are configured to switch in conjunction with each other, and both switches 67) and (c) constitute a boil-over detection electrode changeover switch (+71).

One end of the G is connected to the second constant voltage circuit (34
) is connected to the positive output terminal (+) of the first resistor for voltage division, (
6]) has one end connected to the other end on the first resistance side and the second switch (
C) is connected to the switching piece (58G) and the other end is grounded,
In other words, the second resistor for voltage division is connected to the negative output terminal ←) of the second constant voltage circuit (34), O→ is the collector, and the base is the connection terminal, respectively... and the switching piece of the first switch 67) (
570), the anode of the ring is a transistor (connected to six emitters, the cathode is grounded, and is a signal transmission LED, each resistor 69), (61) , (
A transistor (6) and an LED (33) constitute an input section of the boiling over detection section.

− indicates that the cathode is connected to the first constant voltage circuit (
The anode is connected to the positive output terminal (+) of the first constant voltage circuit (33), and the anode is grounded via the fourth resistance ring.
3) is a photodiode connected to the negative output terminal (-) of the photodiode, and the light from LED $3 causes a photocurrent to flow to the fourth resistor branch of the connection terminal 671° photodiode-1, and the input terminal is connected to the photodiode's negative output terminal. The oscillation control circuit connected to the anode side is connected to the buzzer, the drive circuit (to), and the boil-over detection based on the voltage across the fourth resistor (to).
03 The detection signal is now input, and the photodiode □ and the fourth resistor branch constitute the output section of the boiling-over detection section, which is electrically insulated from the input section, and the changeover switch 07 ), six input sections, an output section O and a boil-over detection circuit (to), and each electrode (9) to zero output and the detection circuit Q constitute a boil-over detection means.

Next, the operation of the first embodiment described above will be explained.

Now, when cooking food by placing a container (32) made of a predetermined material such as iron on the top plate (2), set the knob (7) to the predetermined scale and turn the switch (2).
1), each rectifier circuit (23+, □
□□.

AC is input to (28) and rectified, power supply to each part is started, and the initial signal is output when the stability of the input voltage to the transformer (A) is detected by the initial circuit (3 (F)). A start signal is output from the oscillation control circuit (36) to the PVI7M control circuit (39), and the interface control circuit (
39) is activated and a PWM control signal is output, a base control signal is output from the base control circuit (40), the transistor (41) is turned on, and the current from the first rectifier circuit (23) flows into the coil (3I). is conducted, a voltage is generated across the coil (31), the voltage is detected by the 1-trigger generation circuit (29), and the PWM control circuit (39) is turned on.
-, lJ signal is output, and the PWM control circuit (39) continues to drive by the on l-IJ signal.
The PWM control circuit (39) generates a control signal such that the input power to the first rectifier circuit (23) is equal to the set value by the setting circuit (Jun) according to the first comparison signal from the comparator (J38).
The transistor (41) continues to output from the P
The coil 1 is repeatedly turned on and off by the base control signal from the base control circuit (40) based on the WM control signal.
A high frequency current is passed through 3+1 to generate a high frequency magnetic field in the coil (31), and the magnetic field generated by the coil (31) inductively heats the container 1321 to cook the food in the container (3+1).

In addition, when the outer diameter of the container (32) is smaller than the diameter of the first electrode (9), both the changeover switch α power switch e71
Both switching pieces (570) and (580) of the first contact point t'57a).

(58a), the outer diameter of the container 132) is changed to the second
If it is larger than the diameter of electrode 00 and smaller than the short side of third electrode 01), both switches of changeover switch a''h are
Both switching pieces (57C) and (580) of (to) are switched to the second contact (571)) and (581), respectively, and the container (32) connects the first and second electrodes (9), zero or the second contact. 3. It is assumed that the switch α force is switched and the container (32) is placed on the play 4 (2) so that the fourth electrode Ql), 02 is not short-circuited. However, a container with an outer diameter larger than the short side of the fourth electrode θ (32
) of course cannot be used.

At this time, when the transistor (4]1 and the container (32) are overheated, both the temperature sensing elements (49), (50) and both the overheating prevention circuits (5]) and @Z cause the transistor (4]1 and the container to be overheated. 1) of both overheat prevention circuits.

G2 to the oscillation control circuit 136). The second overheating prevention signal is output, a stop signal is output from the oscillation control circuit (36) to the PWM control circuit (39), and the PWM control circuit [3
The output of the PWM control signal from the transistor (411) is stopped, the transistor (41) is turned off, and the flow of high frequency current to the coil (31) is stopped.
1 excess p( is prevented.

If the food to be cooked contains water, such as soup, the water in the food may boil due to the heating of the container (32), causing some of the food to boil over onto the top plate (2). If boiling over occurs during cooking, both switches 67) of selector switch Qη,
The switching pieces (57C) and (588) in (c) are the first contacts (5
7a), (5ga), the top play [2+1] will be connected to the 1st. The second electric terminal 1i (9), Qcl is short-circuited, the connection terminal -, six resistors, the switching piece (58C) of the switch, the first contact (58a), the second. First electrode GO, (9), y,
Itchi l! 5η first contact (57a), switching piece (57
0), the base potential of the transistor is l-M.

Then, the transistor (6) turns on and the second constant voltage circuit (3
4) energizes LET)l■, and L E D QJ
lights up, the photodiode branch receives the light of LED -, and a photocurrent flows through the connection terminal - and the photodiode 1 resistor.

Furthermore, by passing the photocurrent, the oscillation control circuit tse
r), a boil-over detection signal proportional to the voltage across the resistor is output to the buzzer 9 drive circuit, and the oscillation control circuit (
A stop signal is output from the PWM control circuit (39).
) is stopped, the transistor (41) is turned off, the flow of high frequency current to the coil 31) is stopped, heating of the container (321) is forcibly stopped, and the buzzer ( The battery) activates and emits an alarm sound, a drive signal is output from the drive circuit (c), the LED in the L1 display (a) lights up, and a buzzer sounds to indicate the occurrence of boiling over.
The user is notified by an alarm sound and lighting of the LED on the display section (4).

Therefore, in order to continue cooking after being notified of the occurrence of boiling over, it is necessary to remove the boiling over on the top plate (2) and remove the boiling over from the top plate (2). Second electrode (9).

By repeating the above-described operations, the container 134 When the food is heated again and the food to be cooked is cooked again, and there is no need to continue cooking after the occurrence of boiling over is reported, remove the boiling over on top play 1- (2) and proceed to the next step. Just prepare for cooking.

By the way, I accidentally put a knife on the top plate (2).

If switch t2]1 is turned on with a small load such as a fork placed on it, or a cooking container made of a material other than the specified material such as aluminum or Since the output current of the first rectifier circuit (23) is significantly reduced compared to the normal case in which the container (32) made of material is mounted, the current detected by the current transformer (24) is significantly reduced. Since the second comparator (
48), the power detection signal from the detection circuit (25) is smaller than the second setting signal from the setting circuit (47).
From the comparator (48) to the oscillation control circuit f361 and the buzzer (
), the second comparison signal is output to the drive circuit 60, a stop signal is output from the oscillation control circuit 130, the output of the PWM control signal from the PWM control circuit (39) is stopped, and the transistor (41) is turned off. The flow of high-frequency current to the coil (31) is then stopped, and the heating of the small load and cooking container such as aluminum is stopped, and the buzzer is activated to emit an alarm sound and the drive circuit Go The drive signal is output, T and E D on the LED display section light up, and the buzzer sounds an alarm and the display section (1 and ET) on the display section (4) lights up, just like when a blow-off occurs. By turning on the light, it is notified that an abnormal load such as a load of small items has been placed on the person.

(Embodiment 2) Next, embodiment 2 will be explained with reference to FIGS. 5 to 8, which show the embodiment.

1 and 2 in Figures 5 to 7.
The same symbols as those in the figure indicate the same or equivalent items (70 is a heat-resistant insulating base made of ceramics, etc.;
(71) is a stepped portion formed at one end of the base body <701;
72, (73 is the two electrodes hanging down and implanted in the step part (71), I7→ is the connection plug, and the cord (73) is the connecting plug.
The connection pin (70, (c) connected to both electrodes (7) and (73) is attached to the other end of the base body (σ0) through the wire, and the lead wire in the cord (7F) connects the connection pin (70, (c)) of the main body (1). It is designed to be connected to the connector section on the left end of the front.

Q→ is a fixture provided at the end of the cord (70) on the base body (70) side, and the fixture (7→ is a fixture provided at the end of the cord (70) on the base (70) side.
) is fixed to the sash 08) around the electrodes 172,
(73 is arranged near the container (32) on the top play 1-+21 together with the base QO.

(7 Samurai is a knob h for the detection set switch, which is slidably provided on the left end of the spring / l / (5), and is a knob for the detection set switch, and the switch to the ON side of the sweetness (8)' and the 0FTi'' side. The sliding action turns on the boilover detection cell 1 switch described later.

Turn off.

Next, in FIG. 8 showing the detailed configuration of the detection means,
The same symbols as in FIG.
e, connected to the electrode (7, Q■) via (77).

The interlocking switch 01), which is turned on in conjunction with the connection to the connector part of the book (74), is a boil-over detection set switch with one end connected to the other end of the switch handle, and the operation of the handle (8)' The contact piece is turned on.

Turn off.

@z, (c) are the 5th and 6th resistors for voltage division, each of which has one end connected to the positive output terminal (34) of the second constant voltage circuit (34) through the connection terminal (material); The other end of the resistor G'2 is connected to the other end of the switch G1). The cans (c) each have one end with the 5th. The other end of the sixth resistor i) 3 is connected to the other end of the ground wire 1. That is, the seventh voltage dividing circuit connected to the negative output terminal (-) of the second constant voltage circuit (34)
．． It is the 8th resistor, and the 7th resistor (C) is connected through the electrode (79, (switch 翺~en that is on when 7□□□ is short-circuited)
Connect each resistor (9, 6) so that the voltage across it is greater than the voltage across the eighth resistor (c). , hs, (to) is selected.

For 6, both input terminals are connected to the other end of the switch handle and the resistor (c)
When the electrodes (72, (73) are short-circuited, the seventh
゜A third comparator that compares the voltages across the eighth resistors (c) and (c) and outputs a high-level third comparison signal. 3 Signal transmission L connected to the output terminal of the comparator and its cathode grounded.
ED, and the light of LED (c) is received by the photodiode ring constituting the output section 6 [phase] similar to that in FIG. 4, and each resistor (a), e3. (c)
,(c).

The input section (G) of the boiling-over detection section is configured by the third comparator G'7) and the LED (C), and the boil-over detection circuit 6 is constituted by the switch button), the input section (G), and the output section O0. ') 1) is configured, and further electric t
lffl (7, Q[present].

The pin (7Q, f7), the interlocking switch wire, and the detection circuit H constitute the detection means.

Next, the operation of the second embodiment will be explained.

However, the circuit configuration of the second embodiment is the detection circuit 1 shown in FIG.
! The components other than 11) are the same as those in FIG. 3, and the same operations as in the first embodiment described above are performed for preparing ordinary food.

In addition, as shown in FIGS. 5 and 7, electrodes (7,
(7:'! is in contact with the top plate (2) near the k f321, the fixing position to Saran 08 of the fixing tool pass) is determined, and the electric bCI'a, v■ is arranged. It is assumed that

Then, the food containing water boils and tops up.
1-(21 has a boiling point, and the electrodes (72, (73)
When the third comparator G is short-circuited due to boiling water, the third comparator G
7th to both power input terminals. The voltage across the 8th resistors (c) and (c) is applied, and the former is larger than the latter, so the 3rd
A high-level third comparison signal is output from the comparator l871, T and E D (c) light up, and the light from the LED (c) is received by the photodiode (a) and connected to the connection terminal e71.
．． A photocurrent flows through the photodiode (7) and the resistor, and the passage of the photocurrent causes an oscillation control circuit system) and a buzzer.

A boil-over detection signal proportional to the voltage across the resistor (to) is output to the drive circuit (g), a stop signal is output from the oscillation control circuit (36), and the P from the PWM control circuit (39) is output.
The output of the WM control signal is stopped, and the transistor (41)
is turned off, the flow of high frequency current to Koi/1/(31) is stopped, heating of the container (32) is forcibly stopped, and the buzzer is activated to emit an alarm sound. A drive signal is output from the drive circuit (to the drive circuit), and the LED display section (a)
The LED lights up, and the user is notified of the occurrence of boiling over by the buzzer sound and the LED light on the display.

(Example 3) Next, FIG. 9 showing the third embodiment will be explained.

In the same figure, the same symbols as in Figure 3 indicate the same or equivalent things, and the difference from Figure 3 is that the strainer (7
) In place of the input power setting circuit 1M using the scale setting, the switching input signals to the three input terminals (92a) to (920) by the three-stage sliding switching of the dial (7) are used to set the low humidity. Two input power setting circuits tb are provided to output mode power setting signals corresponding to each mode of heating, high-temperature tempura, and keeping warm. A temperature setting circuit is provided to output a temperature setting signal of 32'+, and when the temperature setting signal and the temperature detection signal from the second temperature sensing element (50) are compared and the latter is larger than the former, @44 A fourth comparator 0 is provided to output a comparison signal, and three command input terminals are provided to which drive command signals are input in accordance with the switching input signals to each of the input terminals (92a) to (92C) of the setting circuit O. (9
5a) to (958) are provided in the drive circuit (to), and drive signals for mode display according to signals from the drive circuit to each terminal (95a) to (95C) are outputted to the panel (5). Heating is provided by the LED on the display section.

In addition to displaying each mode of tempura and keeping warm, the second overheating prevention signal and the second. The fourth comparison signal causes the oscillation control circuit 136) to output a stop signal, and the six drive circuits output the abnormality display drive signal a3, and the LEDs on the display section 6Q indicate whether the container 13 is empty, loaded with small items, or temperature rise. Each abnormality display is performed, and the detection circuit (
The point is that the output signals of the setting circuit () and the drive circuit (-) are forcibly switched to the heat retention mode power setting signal and the heat retention mode display drive signal, respectively, in response to the boil-over detection signal from (g).

Therefore, during the cooking of food containing moisture, cracking occurs, causing the first problem. When a boiling over detection signal is output from the detection circuit 0 due to a short circuit between the second electrode (9), QO or the third and fourth electrodes (11), the input terminal (
92a) to (920), the setting circuit (!
12 is switched from the heating or tempura mode power setting signal to the moisturizing mode power setting signal, and the first rectifier circuit (2
3) The PWM control signal is set such that the input power to the PWM control signal is lowered with a setting speed based on the keep warm mode power setting signal.
The high frequency current output from the control circuit (39) is reduced to the coil (31) to maintain the temperature of the container (321) at a predetermined temperature retention flow rate, and the boiling over detection signal activates the buzzer. The output of the drive circuit (a) is switched from the drive signal for displaying the heating or tempura mode to the drive signal for displaying the keep warm mode.
-L of the display section that was lighting up the tempura mode
ED goes out and the LED indicating the keep warm mode lights up, notifying you that boiling over has occurred.

On the other hand, if the temperature of the container [32] exceeds the temperature set in the temperature setting circuit O during cooking in the heating mode, the temperature in the heating mode or the tempura mode is If you cook incorrectly, or if you place small items such as knives and forks on the top plate (2) and turn on the switch 21+, the fourth
Comparator 0→, second overheating prevention circuit 6 and second comparator (
The fourth comparison signal, second overheating prevention signal, and second comparison signal from 48) cause the oscillation control circuit (361) to output a stop 1- signal and stop outputting the PWM control signal from the PWM control circuit (39). At the same time, a drive signal for indicating abnormalities such as temperature rise, dry cooking, and small load is output from the drive circuit (1) to the drive circuit, and the LED on the display section (4) lights up to indicate that the temperature is high.
Abnormality is displayed for dry cooking and loading of small items.

(Example 4 to Example 6) Note that in place of each electrode (9) to 0 in Example 1, Example 4
As shown in FIG. 10, a plurality of pairs of small rectangular film electrodes may be provided at the front end of the top plate (2), and as shown in FIG. 11, which is Embodiment 5, Alternatively, a circular fifth electrode (6) with a larger diameter than the second electrode 00 and a sixth electrode O→ with a larger diameter than the second electrode 00 may be provided instead of the 1st to 4th electrodes (9) to 0. The first example is Example 6.
As shown in Figure 2, the third. 4th electrode (1υ, 1st, 2nd, 5th, 6th electrode (9) instead of 0).

ao, 'h, o→ may also be provided.

Furthermore, it goes without saying that the present invention can be implemented in the same manner even if film electrodes having patterns other than those described above are provided on the top plate (2).

Furthermore, the output of the PWM control circuit (39) is stopped by the boiling over detection signal from the detection circuit (63, 611).

The buzzer (foundation) often switches the operating mode to keep warm.
It is also possible to simply turn on the LED on the display section (g) at the same time as the activating the button to notify the occurrence of boiling over.

Alternatively, a suction cup or a magnet may be provided on the base (70) so that the base (70) can be attracted to the top play [2] and the container j32).

〔Effect of the invention〕

As described above, according to the induction heating cooking device of the present invention,
Detects boiling of food on the top plate (2) and sounds an alarm with a buzzer and displays T, E.
This can be notified by lighting D, and it can prevent dirt from sticking to the top plate (2) due to continued cooking for a period of time when boiling over has been left unattended, helping to maintain a sense of cleanliness. The effect is very noticeable.

In addition, in the first embodiment, when a boiling over occurs, the oscillation control circuit (3 (support)
Since the output of the PWM control signal from the PWM control circuit (39) is stopped by outputting a stop signal from the PWM control circuit (39),
It is possible to forcibly stop cooking from continuing if boiling over is left unattended.

Furthermore, in Example 3, when boiling over occurs, the output of the setting circuit is switched to the warming mode power setting signal, and the container (
321 is maintained at a predetermined heat retention temperature, it is possible to prevent boiling over by more than 7 hours, and at the same time, it is possible to keep the food to be cooked warm.

In addition, in each embodiment, the input section of the detection circuit-90]),
(A) and 11"+force part O [phase] are electrically insulated by LED (63, (C) and photodiode (fJ),
Because the second constant voltage circuit (34) with a low output voltage was used as the power source for the input section-2 (a), the hand or finger accidentally touched the electrodes (9) to θ and was injured.

It is possible to prevent the occurrence of electric shock when touching (G) to 0→.

Furthermore, in the second embodiment, since the electrode (73) of the electrode Q is removable, the second position of the electrode (7) C!1 can be selected as appropriate.

[Brief explanation of drawings]

The drawings show an embodiment of the induction heating cooking device of the present invention,
Figures 1 to 4 each show Embodiment 1, with Figure 1 being a perspective view, Figure 2 being a partially cutaway right side view, Figure 3 being a block diagram, and Figure 4 being a partial wiring diagram. , FIGS. 5 to 8 each show Example 2, FIG. 5 is a perspective view, and FIG. 6 (a
) to (d) are partial perspective views, plan views, and front views, respectively.
The right side view, FIG. 7 is a sectional view, FIG. 8 is a partial wiring diagram, FIG. 9 is a block diagram of Embodiment 3, and FIGS. 10 to 12 are plan views of Embodiments 4 to 6, respectively. It is a diagram. (1)...Device main body, (2)...Top plate,
(9)~θ4゜@, (73, H~a11e...Electric (j, f44)-7% Frequency m m, N, I!'1
1)...Bubble-over detection circuit, (Foundation)...buzzer,
(g)...I/ED display section.

Claims (1)

[Claims] (1) A high-frequency power source housed in the main body of the device, an induction heating coil housed in the body and through which a high-frequency current from the power source flows, and a magnetic field generated by the coil provided by closing the top surface of the main body. a heat-resistant insulating top plate on which a cooking container to be heated by induction is placed; a detection means for detecting boiling over of the food on the top plate and outputting a detection signal; An induction heating cooking device comprising: a notification means for notifying the occurrence of boiling over.