JPH065637B2 - Heating cooker - Google Patents

Description

TECHNICAL FIELD The present invention relates to a heating cooker such as an induction heating cooker that adjusts a heating state of a cooked food using a temperature probe.

(B) Conventional technology In an induction heating cooker, a power supply from a power source generates high-frequency current in an inverter device, and a heating coil included in the inverter device generates a high-frequency alternating magnetic field, and a ceramic coil is placed on the heating coil. Iron, placed in close proximity through a plate,
Induction heating of a cooking pot made of iron-based metal such as 18-8 stainless steel. In such an induction heating cooker, a heat sensitive element such as an induction heating coil and a thermistor is provided on the back surface of the pot mounting surface of the top plate. While the induction heating coil is used to generate a high-frequency alternating magnetic field to induction-heat a cooking pot made of an iron-based metal provided on a top plate, the temperature of the cooking pot is detected by the thermosensitive element. However, if an attempt is made to detect the temperature by such a method and adjust the temperature of the cooked food in the cooking device, the temperature of the cooked food cannot be detected directly because the temperature of the cooked food cannot be detected directly. There was a flaw. For this reason, a temperature probe having a thermistor at the tip is provided, and a mounting portion for electrically and mechanically attaching the temperature probe to the surface of the induction heating cooker is provided to detect the temperature of the food. It is considered that the temperature probe is attached to the attachment part of the cooker, the probe tip is inserted into the cooking object, and the resistance change of the thermistor at the probe tip is electrically transmitted into the cooker through the attachment part. Has been.

However, in such a cooker, moisture penetrates into the temperature probe attachment part due to spillage from the cooking pot, etc., and the electrical contact between the temperature probe and the cooker is deteriorated, and high frequency alternating current from the heating coil is used. Due to the influence of the magnetic field, high-frequency noise may be superimposed on the signal transmitted from the temperature probe to the inside of the cooker body.

(C) Problem to be Solved by the Invention The present invention has been made in view of the above circumstances, and an object thereof is to improve the reliability of temperature detection of cooked food.

(D) Means for Solving the Problems The present invention is directed to a heating means for heating a cooked food placed on a cooker body, a temperature setting means for setting a heating temperature of the cooked food, and the heating means. An output control knob for manually adjusting the output, a probe provided with a temperature detecting element for detecting the temperature of the cooked product by inserting the tip of the cooked product into the cooked product, and the probe connected to the probe and the cooker body. A connector that is detachably attached, a light emitting unit that is provided in the connector and converts the temperature detected by the temperature detecting element into an optical signal, and an optical signal that is provided in the cooker body and transmitted from the light emitting unit. Of a photoelectric conversion unit for converting the electric signal into an electric signal, and a drive control unit for controlling the heating means by a signal from the photoelectric conversion unit, for detecting the attachment state of the connector to the cooker body. When the attachment detection unit detects the attachment of the connector, the optical signal to the photoelectric conversion unit is validated, and when the detachment of the connector from the cooker body is detected, the photoelectric conversion unit is detected. Switching means for invalidating the optical signal, and when the switching means validates the optical signal, it responds to the optical signal for the temperature set by the temperature setting means transmitted from the temperature probe to the cooker body. To operate the drive control unit to control the heating means,
When the switching means invalidates the optical signal, the output of the heating means can be adjusted by the output adjusting knob.

(E) Action Since the temperature detected by the temperature probe is transmitted to the cooker body as an optical signal, there is no electrical contact portion between the cooker body and the temperature probe. Furthermore, since the signal transmitted by the temperature probe is due to light, even if there is a magnetic field in the vicinity where the heating means is the heating coil and the signal is transmitted from the temperature probe to the cooker body, this signal is affected by the magnetic field. High frequency noise does not overlap. Further, when the temperature probe is removed, the external light is invalidated, and malfunction due to the external light is prevented.

(F) Embodiment FIG. 1 is a cutaway perspective view of an essential part showing an embodiment of the induction heating cooker of the present invention. In FIG. 1, reference numeral 1 is a main body of an induction heating cooker in which an inverter device (not shown) that generates high-frequency alternating current is installed, and 2 is a ceramic top plate on which the cooking pot 3 is placed on the top of the cooker main body 1. A heating coil (not shown) that forms a part of the inverter device and that generates a high frequency alternating magnetic field is provided directly below the top plate 2. Reference numeral 4 denotes an operation unit provided on one end side of the upper surface of the cooker body 1, which is an output adjustment knob 5 for setting the output state of the inverter device, and power supply to the inverter device,
A display unit 6 for displaying the output state of the inverter device and the like is provided. Reference numeral 7 denotes a temperature probe provided with a thermosensitive element such as a thermistor (not shown) at its tip, and the thermosensitive element is connected to a signal line 8 for transmitting an electric signal. 9
Is a connector which is provided at the other end of the signal line 8 and which can be attached to and detached from the operation section 4, and the bottom surface section 10 is provided with a magnet 11 having strong magnetic force and a light emitting element 12 such as an LED. 1
Reference numeral 3 denotes a photoelectric conversion element such as a phototransistor provided in the mounting portion of the connector 9 of the cooker main body 1 so as to face the light emitting element 12, and an optical signal from the light emitting element 12 is photoelectrically converted into an inverter circuit. (Not shown)
Reference numeral 14 denotes a light-shielding plate made of a magnetized disc-shaped iron plate having a cutout portion 15 and serving as attachment detecting means or switching means of the temperature probe, which is provided close to the light-shielding plate 14 when the temperature probe is removed. As shown in FIG. 2, the magnetic force of the magnet 16 causes the cutout portion 15 to be displaced from the position directly above the photoelectric conversion element 13 to block the incidence of light from the outside.
The optical signal to the photoelectric conversion element 13 is invalidated, and when the connector 9 of the temperature probe 7 is attached, as shown in FIG.
The light shielding plate 14 rotates due to the influence of the magnetic field from the magnet 11 on the bottom surface portion 10 of the connector 9 to rotate the light emitting element 12 and the photoelectric conversion element 1.
By arranging the cutout portion 15 between the light emitting element 3 and the light source 3, the mechanism for enabling the optical transmission during this time and validating the optical signal to the photoelectric conversion element 13 is provided. In this case, by making the magnetic force of the magnet 11 on the connector 9 side stronger than that of the magnet 16 on the main body side, the rotation of the light shielding plate 14 becomes more complete. Further, a photodetector (not shown) or the like is provided in parallel with the photoelectric conversion element 13 so as to sandwich the light shielding plate 16, so that the rotation state of the light shielding plate 14 is detected and the mounting state of the temperature probe 7 is detected. When the temperature probe 7 is not attached, heating operation is enabled by the output set by the output control knob 5, and when the temperature probe 7 is attached, the heating operation is controlled by a signal from the temperature probe 7. A mechanism should be adopted.

4 and 5 are a perspective view and an internal circuit diagram of a main part showing a temperature detecting mechanism formed on the temperature probe 7 and the connector 9, and the same parts as those in FIGS. 1 to 3 are designated by the same reference numerals. Is attached. In these drawings, reference numeral 17 denotes a DC power source such as a battery provided on the connector 9 side, which can be replaced. Reference numeral 18 is a switch for starting the voltage supply of the DC power supply 17 to the temperature detecting mechanism. Reference numeral 19 denotes a first voltage dividing circuit to which the voltage of the DC power source 17 is supplied, and a thermosensitive element 20 such as a thermistor provided at the tip of the temperature probe 12 is connected to the thermoelectric element 20. The voltage changes. Reference numeral 21 is a second voltage dividing circuit to which the voltage of the DC power supply 17 is supplied, and the voltage dividing voltage is adjusted by the temperature setting means 22 composed of a variable resistor. 23 is a comparator to which the divided voltage of the first voltage dividing circuit 19 is input to the-input terminal and the divided voltage of the second voltage dividing circuit 21 is input to the + input terminal, and 24 is the DC power supply 17
The output of the comparator 23 is applied to the base of the transistor 25, which is a series circuit including the light emitting element 12 and the transistor 25 connected to each other. It should be noted that electric components other than the light emitting element 12, the heat sensitive element 20, and the DC power source 17 are attached to a substrate 26 that is erected from the connector bottom 10.

In the induction heating cooker having such a structure, when the connector 9 of the temperature probe 7 is attached to the cooker main body 1, the light shielding plate 14 is cooked with the light emitting element 12 of the connector 9 due to the influence of the magnet 11 of the bottom portion 10 of the connector 9. It rotates so that the optical path between the photoelectric conversion elements 13 on the container body 1 side may be opened. At the same time, the above-mentioned temperature probe detection mechanism (not shown) detects attachment of the temperature probe 7, and the cooking operation of the cooking device is controlled by a signal from the temperature probe 7. In this state, the temperature setting means 22 is operated to set the voltage input to the + input end of the comparator 23, and the probe tip is inserted into the cooking product in the cooking pot 3 on the top plate 2 to start the heating operation. First, since the divided voltage of the second voltage dividing circuit 21 input to the + input terminal of the comparator 23 is higher than the divided voltage of the first voltage dividing circuit 19 input to the − input terminal, 23 output goes to "H" and transistor 2
5 is turned on, and the light emitting element 12 emits light. The photoelectric conversion element 13 on the cooker main body 1 side receives this light, and the inverter continues the oscillating operation. Heat-sensitive element 20 due to temperature rise of cooked food
Reduces its resistance value and increases the divided voltage of the first voltage dividing circuit 19. The temperature of the cooked food has risen sufficiently and comparator 2
When the voltage at the-input terminal of 3 becomes higher than the voltage at the + input terminal,
The output of the comparator 23 becomes "L" and the transistor 25
Is turned off and the light emitting element 12 is turned off. As a result, the photoelectric conversion element 13 on the cooker body 1 side does not detect light and the inverter operation is stopped. When the inverter is stopped, the temperature of the cooked food is lowered, the resistance value of the heat sensitive element 20 is increased, and when the-input terminal voltage of the comparator 23 is lower than the + input terminal voltage, the output of the comparator 23 becomes "H" again. Then, the transistor 25 is turned on and the light emitting element 12 emits light. When the photoelectric conversion element 13 detects this light, the inverter oscillation is restarted. Thus
The food is kept at a constant temperature. The cooking temperature can be arbitrarily set by operating the temperature setting means 22 and adjusting the voltage input to the + input terminal of the comparator 23.

When the temperature probe 7 is removed from the cooker main body 1, the shading plate 14 is rotated by the magnet 16 on the cooker main body 1 side so as to cover the upper surface of the photoelectric conversion element 14, and blocks external light. At the same time, the removal of the probe is detected by the probe detection mechanism, and the heating control of the cooking device is performed by operating the output adjustment knob 5.

FIG. 6 is a cross-sectional view showing another embodiment of the temperature probe used in the induction heating cooker of the present invention, in which the same parts as those in FIG. 1 are designated by the same reference numerals. In the figure, all the electric components such as the heat sensitive element 20 and the light emitting element 12 are connected to the temperature probe 7.
The optical signal from the light emitting element 12 is guided to the connector 9 by using the optical fiber 26 provided on the main body side.
Further, the tip of the temperature probe is provided with a heat insulating member 27 such as ceramic so that the temperature of the bottom of the cooking pot 3 is prevented from being detected when the tip comes into contact with the bottom of the cooking pot 3. ing.

(G) Effect of the Invention According to the heating cooker of the present invention, the temperature detected by the temperature probe is transmitted to the cooker main body side by an optical signal, so that there is an electrical connection between the cooker main body and the temperature probe. Since there is no problem even if food is spilled, and the signal transmitted from the temperature probe is due to light, the heating means is a heating coil and the temperature probe is connected to the cooker body. Even if a magnetic field exists in the vicinity of transmitting the signal, high-frequency noise due to the influence of the magnetic field is not superimposed on this signal, so that highly reliable temperature detection can be performed.

Furthermore, when the temperature probe is removed, even if light is introduced from the outside to the temperature probe attachment part of the cooker body, it is invalidated, so there is no risk of malfunction of the cooker due to outside light, and high safety A cooker can be provided.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a cutaway perspective view of a main part of an induction heating cooker according to the present invention.
3 and 4 are perspective views showing the rotating state of the light shielding plate, FIG.
FIG. 5 is a perspective view and a circuit diagram showing a main part of the temperature detecting mechanism, and FIG. 6 is a sectional view showing another embodiment of the temperature probe used in the induction heating cooker of the present invention. 1 ... Cooker main body, 2 ... Ceramic top plate, 7 ... Temperature probe, 8 ... Signal line, 9 ... Connector, 12 ... Light emitting element, 13
... Photoelectric conversion element, 17 ... DC power source, 20 ... Thermal element, 2
2 ... Temperature setting means.

Claims (1)

[Claims] Claim: What is claimed is: 1. A heating means for heating a cooked food placed on a cooker body, a temperature setting means for setting a heating temperature of the cooked food, and an output control knob for manually adjusting the output of the heating means. A probe having a temperature detecting element for detecting the temperature of the food by inserting the tip of the food into the food, a connector connected to the probe and detachably attached to the cooker body, Provided in the connector,
A light emitting unit that converts the temperature detected by the temperature detecting element into an optical signal, a photoelectric conversion unit that is provided in the cooker body and converts the optical signal transmitted from the light emitting unit into an electric signal, and the photoelectric conversion unit. A drive control section for controlling the heating means by a signal from the section, an attachment detecting section for detecting the attachment state of the connector to the cooker body, and the attachment detecting section for attaching the connector. Switching means for validating the optical signal to the photoelectric conversion unit when detected, and invalidating the optical signal to the photoelectric conversion unit when detection of removal of the connector from the cooker body is detected. When the means validates the optical signal, the drive control unit is activated in accordance with the optical signal for the temperature set by the temperature setting means transmitted from the temperature probe to the cooker body. By moving controls the heating means,
A heating cooker characterized in that when the switching means invalidates an optical signal, the output of the heating means can be adjusted by the output adjusting knob.