JP4170877B2 - Cooker - Google Patents

Description

  The present invention relates to a cooking device having an induction heating coil and an electric heater such as a radiant heater as heat sources.

  Conventionally, this type of cooking device includes a top plate on which the cooking container is placed, a plurality of heating means for heating the cooking container, a vibration sensor for detecting the vibration of the cooking container through the top plate, and this vibration. The boiling detection means for detecting the boiling state of the object to be heated by the output of the sensor, and the output of the boiling detection means and the control information of the heating coil indicate which heating means is heated by the heating means. What is provided with the boiling position detection means to discriminate | determine is known. There is also known a cooking device that includes a temperature sensor on the lower surface of the top plate and detects the boiling state of the object to be heated by using the temperature sensor and the vibration sensor (see, for example, Patent Document 1).

  In the cooking device, the vibration sensor is provided in close contact with the back surface of the top plate, detects the boiling state of the object to be heated, and the boiling position detection means detects the heating amount of the heating coil when control information of the heating coil is detected. Is temporarily stopped or reduced, and it is determined which heating means is heated by the heating means. The temperature sensor determines boiling when the output of the vibration sensor is present when the temperature signal is rising.

Japanese Patent Application Laid-Open No. 2003-77644 (Page 2, FIGS. 3 and 5)

  However, in the conventional cooking device having a plurality of heating means, in order to determine which heating means the object to be heated is boiling, it is performed by the output information of the vibration sensor and the control information of the energizing coil, There is a problem that the determination operation becomes complicated and requires time and effort.

  The present invention has been made in view of the above-described problems. In a heating cooker including an induction heating coil and an electric heater using a heating element such as a radiant heater as a plurality of heating means, each of the heating means An object of the present invention is to obtain a heating cooker that can easily specify which heating means boiled when any of the containers placed on the boiled.

The present invention includes a top plate on which a container containing an object to be heated can be placed, and a plurality of heating means each including at least one induction heating coil and an electric heater respectively disposed below the top plate. In the heating cooker, vibration detection means for detecting vibration of the container via the top plate, boiling detection means for detecting the boiling state of the object to be heated based on an output from the vibration detection means, and the boiling detection If the unit detects the boiling, the induction heating coil and the power supply to the electric heater is stopped, and the heating means to boil the vibration damping factor of the container corresponding to respective heating means the induction heating coil Boiling determination means for specifying any one of the electric heaters .

  A heating cooker according to the present invention includes a top plate on which a container containing an object to be heated can be placed, a plurality of heating units each including at least one induction heating coil and an electric heater respectively disposed below the top plate. Means for detecting vibration of the container via the top plate, and boiling detection means for detecting the boiling state of the object to be heated by the output from the vibration detection means. And a boiling judgment means for identifying the heating means that has boiled from the vibration damping rate of the container corresponding to each heating means after the heating is stopped due to the boiling of the object to be heated. In combination with a heater, it is possible to easily determine which heating means boiled, and reliably detect boiling in a device equipped with a plurality of heating means. Door can be.

Embodiment 1 FIG.
1 is a plan view of a heating cooker according to Embodiment 1 of the present invention, FIG. 2 is a cross-sectional view taken along the line A-A in FIG. 1, and FIG. 3 is a front view of an operation panel.
1 to 3, the same or corresponding parts are denoted by the same reference numerals.
1 to 3, a flat top plate 2 made of a heat-resistant insulating material such as crystallized glass is provided on the upper surface of the housing 1. Below the top plate 2, an electric heater comprising two induction heating coils 3, 4 formed in, for example, a spiral shape and one radiant heater 5 as heating means is provided on the back surface of the top plate 2. Proximity is arranged. The induction heating coils 3 and 4 are arranged side by side in front of the top plate 2 in the left-right direction, and the radiant heater 5 is arranged behind the induction heating coils 3 and 4. The arrangement positions and the number of the induction heating coils 3 and 4 and the radiant heater 5 are not limited to this.

  A vibration sensor 6 is attached to the back surface of the top plate 2 at approximately the middle of the two induction heating coils 3, 4 and the radiant heater 5, that is, at a position approximately equidistant from them. The vibration sensor 6 detects vibration caused by bubbles generated when a heated object in a container 8 made of a metal material such as iron placed on the top plate 2 is boiled as vibration of the top plate 2. . Further, temperature sensors 10 a to 10 c are disposed in contact with the back surface of the top plate 2 at portions facing the induction heating coils 3 and 4 and the radiant heater 5, and the bottom surface of the container 8 is interposed via the top plate 2. Detect temperature.

  As shown in FIG. 3, the operation panel 11 provided on the front surface of the housing 1 sets a heating switch 11 a that starts / stops heating the induction heating coils 3, 4 and the radiant heater 5, and sets each heating power. The heating power setting switch 11b, the boiling detection setting switch 11c for setting the boiling detection mode (the mode for which boiling detection is to be performed), and the vessel 8 corresponding to the induction heating coils 3 and 4 and the radial heater 5 are boiling. For example, visual notifying means for notifying by lighting or blinking by the LED 11d in the state, and sound notifying means by, for example, a speaker 11e for notifying that the container 8 is in a boiling state are provided.

  In addition, a signal processing means 12 that performs waveform processing on a detection signal output from the vibration sensor 6 is input to the housing 1, and a detection signal subjected to waveform processing is input to detect the boiling state of the object to be heated in the container 8. A boiling determination means 13 for specifying the heating means that has boiled from the detection signal, and a heating control means 14 for controlling the heating output of each of the heating means are arranged.

  FIG. 4 is a diagram showing the relationship between the temperature change (a) of the object to be heated as the heating time elapses and the change (b) in the magnitude of the detection signal from the vibration sensor. According to this, the detection signal of the vibration sensor smoothed by the signal processing means 12 shows a relatively small and substantially constant value up to about 80 ° C. as the temperature of the object to be heated increases, but about 80 ° C. In the vicinity, it rises abruptly, reaches a maximum value in a boiling state, that is, a temperature slightly before 100 ° C., and then decreases until reaching 100 ° C. Therefore, a signal resulting from such vibration is output to the boiling detection means 15, the boiling determination means 13, and the heating control means 14.

The substantially constant detection signal waveform generated in the region where the object to be heated is about 80 ° C. or less may include disturbances such as a cooling fan. The detection signal waveform in the region is removed.

Next, in the heating cooker configured as described above, one induction heating coil 3 and the radiant heater 5 perform the heating operation at the same time, and the boiling detection operation when the boiling detection mode is set for each of them, This will be described with reference to the flowchart of FIG.
A container 8 containing an object to be heated is placed on the top plate 2 at a position facing the respective heating means, and the heating power setting of each induction heating coil 3 and the radiant heater 5 from the operation panel 11 is performed by a heating power setting switch 11b. In addition, when the boiling detection mode setting is performed by the boiling detection setting switch 11c and the heating operation is started by the heating switch 11a, the heating control means 14 supplies predetermined power to the induction heating coil 3 and the radial heater 5, The object to be heated in each container 8 is heated (S1).

That is, the induction heating coil 3 generates an alternating magnetic field in the induction heating coil 3 when the heating control means 14 supplies the induction heating coil 3 with a high frequency current in accordance with the heating power setting. Then, an eddy current flows to the bottom of the placed container 8, the container 8 itself is induction-heated by Joule heat due to the eddy current, and the object to be heated is heated. On the other hand, the radial heater 5 is supplied with AC power having a normal commercial frequency, and the heater itself generates heat, whereby the container 8 is heated by the radiant heat.

At the same time, upon receipt of the heating operation, the vibration sensor 6 starts detecting the vibration of the container 8 (S2). As the heated object is heated, fine bubbles are generated in the container 8 when the temperature of the heated object exceeds about 80 ° C. The container is vibrated by the pressure wave caused by the bubbles, and the vibration due to the exciting force is transmitted to the top plate 2, and as shown in FIG. 4, the vibration sensor 6 catches this and the output starts to rise rapidly. Then, the vibration level becomes maximum when the object to be heated is about 95 ° C., and the bubbles in the container 8 increase in the vicinity of 100 ° C. where it boils. Therefore, the vibration level becomes weaker and the output of the vibration sensor 6 tends to decrease. Indicates.

The detection signal from the vibration sensor 6 is an alternating half-wave waveform, and the signal waveform of the vibration sensor 6 is smoothed by the signal processing means 12 to be processed into a smooth waveform signal shown in FIG. S3).

The vibration output of the smoothed waveform signal smoothed by the signal processing means 12 is input to the boiling detection means 15, and the object to be heated is detected by detecting the magnitude of the vibration with the vibration waveform showing the change as shown in FIG. It is determined whether or not is in a boiling state (S4). When the boiling detection means 15 detects a vibration having a predetermined magnitude, it is determined that the object to be heated in any of the containers 8 has reached a boiling state, and power is supplied to the induction heating coil 3 and the radiant heater 5. Is stopped (S5).

As a result of the power supply to the induction heating coil 3 and the radiant heater 5 being stopped, the temperature of the containers 8 placed opposite to the heating sources, that is, the objects to be heated in the containers, is decreased. Vibration caused by the temperature of the heated object is attenuated. Therefore, this vibration change is captured by the vibration sensor 6, and the rate of change, that is, the vibration attenuation rate, is stored in the storage area of the boiling determination means 13 in advance when boiling by the induction heating coil and the radiant heater. By comparing with the vibration damping rate of the container after the heating is turned off, it is determined whether the heating source of the boiled container is an induction heating coil or a radiant heater (S6).

A curve (IH) in FIG. 6 shows a change in vibration from the start of heating to after heating off when 2000 cc of water is heated with an induction heating coil (output 1.5 kW ) in a stainless pan, for example. There is a slight difference in the change in vibration depending on the material of the container and the amount of water, but the container itself is induction-heated during heating, so the temperature of the object to be heated rises rapidly, and the rise of the change in vibration is rapid. After the heating is turned off, the induction heating coil itself does not generate heat, so that the temperature of the container decreases within a relatively short time, and the damping of vibration increases. On the other hand, a curve (RH) in FIG. 6 shows a change in vibration from the start of heating to after heating off when 2000 cc of water is heated with a radiant heater (output 1 kW ) in a stainless pan, for example. As described above, there is a slight difference in the change in vibration depending on the material of the container and the amount of water, but due to heating by radiant heat, the temperature of the container gradually rises and the change in vibration also rises gently. After the heating is turned off, the heat capacity of the radiant heater itself is large, and the container 8 is affected by this heat for a while, so that the temperature drop is delayed and the vibration attenuation is naturally reduced. Therefore, the attenuation rate, which is a change in the vibration of the container corresponding to the induction heating coil and the radiant heater after the heating is turned off, may be stored in advance in the storage area of the boiling determination means 13. In addition, about the change of the vibration after the heating-off corresponding to each heating means, you may make it memorize | store several types of data, changing the container material, the quantity of to-be-heated objects, etc., and memorize | store the average value.

Therefore, when the object to be heated heated by the induction heating coil 3 reaches the boiling state, the vibration sensor 6 detects the vibration of the container 8 heated by the induction heating coil 3 and outputs a detection signal. 13 stops the supply of electric power to each heating means via the heating control means 14. After that, the vibration sensor 6 continues to detect the vibration of the container corresponding to the induction heating coil 3 and outputs a detection signal. However, in the case of heating by the induction heating coil, as shown in FIG. Since the attenuation is attenuated, the boiling determination means 13 compares the attenuation rate of the detection signal with the previously stored attenuation rate. If the attenuation rate in the induction heating coil is close, the induction heating coil side has reached the boiling state. determines that (S8). Based on the determination information, lighting or blinking by the LED 11d of the visual notification means of the operation panel 11 and notification that the user is in a boiling state by the speaker 11e of the sound notification means (S11). Exit.

On the other hand, the same applies to the case where the heated object heated by the radiant heater 5 boils. In this case, the vibration of the container 8 attenuates relatively slowly after the heating is turned off as shown in FIG. The vibration sensor 6 outputs a detection signal corresponding to the vibration, and the boiling judgment means 13 is compared with the attenuation rate stored in advance based on the detection signal, thereby approaching the attenuation rate of the radiant heater. If so, it is determined that the radiant heater side has reached a boiling state (S7). Then, the notification means provided on the operation panel 11 notifies the user that the user is in a boiling state. In this embodiment, the induction heating coil 3 and the radiant heater 5 are described to start the heating operation at the same time, but the same applies to the case where each of them starts the heating operation after a certain time. It is possible to determine.
Note that steps (S8) to (S10) in the flowchart in FIG. 5 are such that when the two induction heating coils 3 and 4 are simultaneously supplied with power, any of the induction heating coils 3 and 4 reaches a boiling state. This shows the action to identify what was happening. That is, when power is separately supplied to the induction heating coils 3 and 4, it is specified that the induction heating coil side on which a predetermined signal output is detected from the vibration sensor 6 when the power is supplied has reached a boiling state ( S9). Thereafter, heating of the specified induction heating coil 3 or 4 is stopped by the heating control means 14 (S10). Based on the information, the LED 11d provided for each heating means of the operation panel 11 is turned on or blinked, and the speaker 11e informs the user that it is in a boiling state (S11) to detect boiling. finish.

  As described above, the vibration attenuation rate of the container after heating off at the time of boiling by the induction heating coil and the radiant heater stored in advance in the storage area of the boiling determination means and the vibration attenuation rate of the detection signal by the vibration sensor By comparison, it is possible to easily determine which boiling means is caused by boiling. Further, since the warning is given by the LED of the visual notification means and the speaker of the sound notification means that it is in a boiling state, the user can surely visually or auditorily understand that the heated object in the container has boiled. And subsequent cooking can be carried out without delay.

In the present embodiment, the induction heating coil and the radiant heater each have a plurality of vibration damping rates in the boiling-off determination means 13 in the heating-off state after boiling under different conditions of the container material and the amount of water, for example. The induction heating coil and the radiant heater are compared by comparing the vibration attenuation rate of the induction heating coil and the radiant heater stored in advance and the vibration attenuation rate of the detection signal obtained from the vibration sensor after heating off. You may make it perform boiling determination of.

  In this embodiment, an example of a combination of an induction heating coil and a radiant heater has been described. However, the present invention can also be applied to a combination of an induction heating coil and a halogen heater, or an induction heating coil and a sheathed heater. In this case, in the same way as described above, the vibration attenuation rate of the container after the boiling heating off of the induction heating coil and the halogen heater or the induction heating coil and the sheathed heater is set in the storage area of the boiling determination unit as a predetermined value in advance. Of course, it should be remembered.

  In addition, the time until the vibration level after heating off when boiled by the induction heating coil returns to the vibration level immediately after the start of heating (inclination gradient portion after heating off in FIG. 6) is the time required for the material of the container and the coating. Although there is a slight difference depending on the amount of water in the heated object, it is about 10 seconds or less. Therefore, in the boiling determination, the vibration level of the detection signal obtained from the vibration sensor after heating off returns to the level immediately after the start of heating. For example, if the time is about 10 seconds or less, it may be determined that the induction heating coil side is in a boiling state, and if the time is about 10 seconds or more, it may be determined that the radiant heater side is in a boiling state.

  In addition, the vibration level after heating off in the induction heating coil returns to the vibration level immediately after the start of heating (inclination gradient portion after heating off in FIG. 6), and the time is about one-half of the inclination gradient, assuming about 10 seconds. It may be determined which of the induction heating coil and the radiant heater is in a boiling state at the time until this time, that is, about 5 seconds.

  Further, in the present embodiment, the configuration in which the vibration sensor is used to detect boiling at the vibration level from the vibration sensor has been described. However, for example, a sound sensor (microphone) or a strain sensor may be used instead of the vibration sensor. Of course, a combination of these sensors may be used. The sound sensor is disposed, for example, on the upper surface of the top plate or in the housing, and can detect vibration caused by bubbles generated in the container as sound waves. The strain sensor is disposed on, for example, the back surface or the casing of the top plate, and can detect the pressure due to bubbles generated in the container as the strain of the top plate.

  Further, in the present embodiment, the configuration for detecting the boiling using the vibration sensor has been described. However, the temperature sensor provided in each heating unit is used as an auxiliary to detect the boiling with the vibration sensor and the temperature sensor. It is good also as composition to do. For example, when vibration is detected by the vibration sensor, the container of the vibration source is extracted based on the rate of change in temperature of each temperature sensor, and the boiling of the heating means corresponding to the extracted container is specified. Also good.

It is a top view of the heating cooker in Embodiment 1 of this invention. It is sectional drawing in AA of the said FIG. 1 which concerns on Embodiment 1 of this invention. It is a front view of the heating cooker operation part which concerns on Embodiment 1 of this invention. It is a figure which shows the relationship between the temperature change (a) of the to-be-heated object accompanying progress of the heating time which concerns on Embodiment 1 of this invention, and the change (b) of the magnitude | size of the detection signal by a vibration sensor. It is a flowchart figure which shows an example of the boiling detection operation | movement which concerns on Embodiment 1 of this invention. It is the figure which showed an example of the change of the vibration from the time of the heating start in the induction heating coil and radiant heater which concerns on Embodiment 1 of this invention after heating off.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Case, 2 Top plate, 3, 4 Induction heating coil, 5 Radiant heater, 6 Vibration sensor, 8 Container, 10a, 10b, 10c Temperature sensor, 11 Operation panel, 11a Heat switch, 11b Thermal power setting switch, 11c Boiling detection Setting switch, 11d LED, 11e speaker, 12 signal processing means, 13 boiling determination means, 14 heating control means, 15 boiling detection means.

Claims (5)

A top plate on which a container containing an object to be heated can be placed;
In a heating cooker provided with a plurality of heating means comprising at least one induction heating coil and an electric heater respectively disposed below the top plate,
Vibration detecting means for detecting vibration of the container via the top plate;
Boiling detection means for detecting a boiling state of the object to be heated by an output from the vibration detection means;
When the boiling detection means detects a boiling state, the power supply to the induction heating coil and the electric heater is stopped, and the heating means that has boiled from the vibration attenuation rate of the container corresponding to each heating means A cooking device comprising a heating coil and a boiling determination means for specifying any one of the electric heaters . A top plate on which a container containing an object to be heated can be placed;
In a heating cooker provided with a plurality of heating means comprising at least one induction heating coil and an electric heater respectively disposed below the top plate,
Vibration detecting means for detecting vibration of the container via the top plate;
Boiling detection means for detecting the boiling state of the object to be heated by the output from the vibration detection means;
The vibration attenuation rate of the container corresponding to each heating means after the heating stop due to boiling of the object to be heated is stored in advance, and when the boiling detection means detects a boiling state, the induction heating coil and the electric heater are supplied to The power supply is stopped, and the heating means boiled from the vibration attenuation rate by the output from the vibration detection means and the vibration attenuation rate stored in advance identifies either the induction heating coil or the electric heater. A cooking device characterized by comprising a boiling judgment means. The cooking device according to claim 1 or 2 , wherein the electric heater is a radiant heater . The cooking device according to claim 1 or 2 , wherein the electric heater is a halogen heater . The cooking device according to claim 1 or 2 , wherein the electric heater is a sheathed heater .

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