JP3223554B2 - Induction heating cooker - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an induction heating cooker in which an eddy current is induced at the bottom of a load pan by a high-frequency magnetic field to heat the pot.

[0002]

2. Description of the Related Art In recent years, induction heating cookers for inducing eddy currents at the bottom of a load pan by using a high-frequency magnetic field for heating have attracted attention as clean, safe and highly heat-efficient cooking means. Types are gaining in popularity.

Conventionally, this type of induction heating cooker has been configured as shown in FIG. Hereinafter, the configuration will be described.

As shown in FIG. 1, an inverter 1 converts a commercial power supply into a high-frequency current, and a control circuit 2 controls the inverter 1 and the like. The operation unit 3 inputs and sets power and the like, and the display unit 4 displays power and the like. First
The temperature detecting element 5 is disposed near the load 1b to detect the temperature, and inputs the temperature to the first temperature detecting circuit 6. The first temperature detection circuit 6 reads a voltage obtained by dividing the power supply voltage VD by the first temperature detection element 5 and the resistor 7, and converts the voltage into temperature data. The second temperature detecting element 8 is arranged near the load 1b to detect a temperature, and inputs the temperature to the second temperature detecting circuit 9. Second
The temperature detection circuit 9 reads a voltage obtained by dividing the power supply voltage VD by the second temperature detection element 8 and the resistor 10 and converts the voltage into temperature data.

The operation of the above configuration will be described. When the automatic temperature control mode is input from the operation unit 3,
First, the control circuit 2 operates the inverter 1 to supply a high-frequency current to the heating coil 1a to generate a high-frequency magnetic field, start heating the load 1b, and display the set temperature on the display unit 4. If the temperature of the first temperature detecting element 5 detected by the first temperature detecting circuit 6 or the temperature of the second temperature detecting element 8 detected by the second temperature detecting circuit 9 exceeds the set temperature, The operation of the inverter 1 is stopped, and when the temperature falls below the set temperature, the inverter 1 is operated again to adjust the temperature of the load 1b. The first temperature detecting element 5 and the second temperature detecting element 8 are arranged near the load 1b,
And the second temperature detection circuits 6, 9 and the like
And is connected by a connector 12.

[0006]

In such a conventional induction heating cooker, when the lead wire 11 is inserted into the connector 12 and a wrong pin number is incorrectly wired, for example, as shown in FIG. If the first temperature detection element 5 and the second temperature detection element 8 are different from each other, the connection between the first temperature detection element 5 and the second temperature detection element 8 and the resistance 7 and the resistance 10 is different. 8 could not be detected correctly, and the temperature adjusted for the temperature could be different from the set value, resulting in poor cooking performance.

An object of the present invention is to solve the above-mentioned problems, and a first object of the present invention is to provide an induction heating cooker capable of displaying an abnormality when a lead wire is erroneously wired.

It is a second object of the present invention to provide an induction heating cooker which can easily confirm whether there is any abnormality in a lead wire, a temperature detecting element and the like.

It is a third object of the present invention to provide an easy-to-use induction heating cooker capable of displaying a load temperature with high accuracy.

A fourth object of the present invention is to provide an easy-to-use induction heating cooker capable of determining erroneous wiring of a lead wire and displaying a temperature of a load with high accuracy.

[0011]

In order to achieve the first object, the present invention provides an inverter for converting a commercial power supply into a high-frequency current, a control circuit for controlling the inverter and the like, and detecting a temperature of a load. And two or more temperature detecting elements and a temperature detecting circuit, a temperature difference detecting circuit for detecting a temperature difference detected by the two or more temperature detecting elements and the temperature detecting circuit, an operation unit, and a display unit. , The two or more
The first problem-solving means is that an abnormality display is performed when the temperature difference detected by the temperature difference detection circuit is equal to or more than a certain value in a state where the temperature detection elements are set to the same temperature .

In order to achieve the second object, an inverter for converting a commercial power supply to a high-frequency current, a control circuit for controlling the inverter and the like, and two or more temperature detecting elements for detecting the temperature of a load are provided. And a temperature detection circuit, an operation unit, and an element temperature display unit for displaying each temperature detected by the two or more temperature detection elements and the temperature detection circuit. Means.

In order to achieve the third object, an inverter for converting a commercial power supply to a high-frequency current, a control circuit for controlling the inverter and the like, and two or more temperature detecting elements for detecting the temperature of a load are provided. And a temperature detection circuit, an average temperature detection circuit that detects an average temperature detected by the two or more temperature detection elements and the temperature detection circuit, an operation unit,
A third means for solving the problem is that a display section is provided to display the temperature detected by the average temperature detection circuit.

Further, in order to achieve the fourth object, an inverter for converting a commercial power supply into a high-frequency current, a control circuit for controlling the inverter and the like, and two or more temperature detecting elements for detecting the temperature of the load And a temperature detection circuit, a temperature difference detection circuit for detecting the temperature difference detected by the two or more temperature detection elements and the temperature detection circuit, an average temperature detected by the two or more temperature detection elements and the temperature detection circuit An average temperature detection circuit, a switching unit, an operation unit, and a display unit, and a display of the temperature difference detected by the temperature difference detection circuit by the switching unit and detected by the average temperature detection circuit. A configuration for switching between the display of the average temperature and the display of the average temperature is a fourth problem solving means.

[0015]

According to the first aspect of the present invention, there is provided:
The temperature difference detection circuit for detecting a temperature difference between the sensed temperature in two or more temperature sensing element and a temperature sensing circuit is provided, wherein
When two or more temperature sensing elements are set to the same temperature and the temperature difference detected by the temperature difference detection circuit is a certain value or more, an error display is displayed. Since the temperature difference detected in step (1) becomes equal to or more than a certain value, an abnormality display can be performed.

According to a second aspect of the present invention, there is provided an element temperature display section for displaying a temperature detected by two or more temperature detecting elements and a temperature detecting circuit, so that two or more temperature detecting elements are provided at any time. The temperature of the element can be displayed.

According to a third aspect of the present invention, there is provided an average temperature detecting circuit for detecting an average temperature detected by two or more temperature detecting elements and a temperature detecting circuit, and displaying the temperature detected by the average temperature detecting circuit. With this configuration, an error between the displayed temperature and the load temperature can be reduced, and a temperature display close to the load temperature can be performed.

Further, according to a fourth aspect of the present invention, there is provided a temperature difference detecting circuit for detecting a temperature difference between temperatures detected by two or more temperature detecting elements and a temperature detecting circuit, and two or more temperature detecting elements and a temperature detecting means. An average temperature detection circuit for detecting the average temperature detected by the circuit and a switching unit are provided, and the switching unit displays the temperature difference detected by the temperature difference detection circuit and the average temperature detected by the average temperature detection circuit. In this configuration, erroneous wiring or the like of a lead wire can be determined by displaying the temperature difference, and a temperature display close to the load temperature can be displayed by displaying the average temperature.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described below with reference to FIG. The same components as those in the conventional example are denoted by the same reference numerals, and description thereof is omitted.

As shown in the figure, the temperature difference detecting circuit 13
The temperature difference between the temperature detected by the first temperature detection circuit 6 and the temperature detected by the second temperature detection circuit 9 is detected, and the output is input to the control circuit 14. Then, when the temperature difference detected by the temperature difference detection circuit 13 is equal to or more than a predetermined value, an abnormality display is performed by the temperature difference abnormality display section 4a provided on the display section 4. The operation unit 3 is provided with a temperature difference checker 3a.

In the above configuration, the operation will be described. When the automatic temperature control mode is input from the operation unit 3, first,
The control circuit 14 operates the inverter 1 to operate the heating coil 1
a to generate a high-frequency magnetic field,
The set temperature is displayed on the display unit 4 at the same time as the heating of b is started. If the temperature of the first temperature detecting element 5 detected by the first temperature detecting circuit 6 or the temperature of the second temperature detecting element 8 detected by the second temperature detecting circuit 9 exceeds the set temperature, The operation of the inverter 1 is stopped, and when the temperature falls below the set temperature, the inverter 1 is operated again to adjust the temperature of the load 1b. When the temperature difference check key 3 a in the operation unit 3 is pressed, the temperature of the first temperature detection element 5 detected by the first temperature detection circuit 6 and the temperature of the first temperature detection element 9 detected by the second temperature detection circuit 9 are changed. The temperature difference T with the temperature of the second temperature detection element 8 (hereinafter, the detected temperature difference is referred to as T) is referred to as a temperature difference detection circuit 1.
If the absolute value of the temperature difference T exceeds the fixed value T0, the temperature difference abnormality display section 4a in the display section 4 is turned on to indicate that the absolute value of the temperature difference T is large. If the wiring of the lead wire 11 is correct, the temperature difference T is the temperature difference between the actual temperature of the first temperature detecting element 5 and the actual temperature of the second temperature detecting element 8, but as shown in FIG. When wiring is performed, the absolute value of the temperature difference T increases because the actual temperature of the first temperature detecting element 5 and the actual temperature of the second temperature detecting element 8 cannot be detected. Therefore, the first temperature sensing element 5
When the temperature difference check key 3a is pressed in a state where the temperature of the second temperature detecting element 8 is the same as the temperature of the second temperature detecting element 8 (for example, a state where the device is left in a constant atmospheric temperature), the lead wire 11
If the wiring is correct, the temperature difference abnormality display section 4a does not light up,
If the wiring of the lead wire 11 is incorrect, the temperature difference abnormality display section 4a is turned on, so that an incorrect wiring or the like of the lead wire 11 can be detected.

As described above, according to this embodiment, the first temperature detecting circuit 6 detects the temperature of the first temperature detecting element 5 and the temperature of the second temperature detecting element 8 in the same state. The temperature difference T between the detected temperature of the first temperature detecting element 5 and the temperature of the second temperature detecting element 8 detected by the second temperature detecting circuit 9 is detected by the temperature difference detecting circuit 13, and the temperature difference T If the absolute value exceeds the fixed value T0, the temperature difference abnormality display section 4a in the display section 4 is turned on, whereby the incorrect wiring of the lead wire 11 can be displayed.

In this embodiment, the temperature difference check key 3
Although the a and the temperature difference abnormality display section 4a are provided, the operation display method may naturally be another method. For example, the temperature difference check key 3a can be replaced by simultaneously pressing a plurality of power setting keys or the like, and the temperature difference abnormality display portion 4a can be replaced by the blinking display of the power display portion. Function.

Next, a second embodiment of the present invention will be described with reference to FIG. The same components as those in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted.

As shown in the drawing, the display section 4 has an element temperature display section 4b. The element temperature display section 4b has a temperature detected by the first temperature detection circuit 6 and a second temperature detection section. The temperature detected by the circuit 9 is displayed through the control circuit 2.
The operation unit 3 is provided with an element temperature check key 3b .

The operation of the above configuration will be described. When the automatic temperature control mode is input from the operation unit 3, first, the control circuit 2 operates the inverter 1 to supply a high-frequency current to the heating coil 1a to generate a high-frequency magnetic field. Then, the heating of the load 1b is started, and the set temperature is displayed on the display unit 4.
If the temperature of the first temperature detecting element 5 detected by the first temperature detecting circuit 6 or the temperature of the second temperature detecting element 8 detected by the second temperature detecting circuit 9 exceeds the set temperature, The operation of the inverter 1 is stopped, and when the temperature falls below the set temperature, the inverter 1 is operated again to adjust the temperature of the load 1b. When the element temperature check key 3b in the operation section 3 is pressed, the temperature of the first temperature detection element 5 detected by the first temperature detection circuit 6 on the element temperature display section 4b and the second temperature detection circuit 9 and the temperature of the second temperature detecting element 8 detected. Therefore, the temperatures of the first and second temperature detecting elements 5 and 8 can be displayed at any time, and the presence or absence of an abnormality such as an incorrect wiring of the lead wire 11 or a defect of the first and second temperature detecting elements 5 and 8 can be determined at a glance. You can check.

As described above, according to the present embodiment, the temperature of the first temperature detecting element 5 detected by the first temperature detecting circuit 6 in the element temperature display section 4b and the temperature detected by the second temperature detecting circuit 9 are used. By displaying the performed temperature of the second temperature detection element 8,
It is possible to check at a glance whether there is an error such as an erroneous wiring of the lead wire 11 or a defect of the first and second temperature detecting elements 5 and 8. Further, the first and second temperature detecting elements 5,
Since the temperature of the load 8 can be displayed, the temperature of the load 1b can be easily understood by general users.

If the function is limited to a hidden function for product inspection which cannot be operated by a general user, the element temperature check key 3b can be replaced by simultaneously pressing a plurality of power setting keys or the like, and the element temperature display section 4b can display a timer. It is sufficient to substitute the numerical display for the application.

Next, a third embodiment of the present invention will be described with reference to FIG. The same components as those in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted.

As shown in FIG.
Detects an average temperature of the temperature detected by the first temperature detection circuit 6 and the temperature detected by the second temperature detection circuit 9, and outputs the output to the control circuit 16. And
The operator displays the load <br/> temperature display section 4c of the display unit 4 the temperature detected by the average temperature sensing circuit 15.

The operation in the above configuration will be described. When the automatic temperature control mode is input from the operation unit 3, first, the control circuit 16 operates the inverter 1 to supply a high-frequency current to the heating coil 1a to generate a high-frequency magnetic field. Then, the heating of the load 1b is started, and the set temperature is displayed on the display unit 4.
Then, the temperature of the first temperature detecting element 5 detected by the first temperature detecting circuit 6, the temperature of the second temperature detecting element 8 detected by the second temperature detecting circuit 9, or the average temperature detecting circuit If any one of the average temperatures of the temperature detected by the first temperature detection circuit 6 and the temperature detected by the second temperature detection circuit 9 exceeds the set temperature, the operation of the inverter 1 is stopped and the set temperature is set. In the following cases, the inverter 1 is operated again to adjust the temperature of the load 1b. Load 1b
A temperature gradient is generated at the bottom of the load 1b, and the temperature becomes highest around a substantially intermediate position between the center of the bottom of the load 1b and the outer periphery of the bottom. Therefore, the load 1b detected by the average temperature detection circuit 15
Temperature sensing element 5 arranged near the center of the bottom of the device
And the temperature of the second temperature detecting element 8 arranged near the middle position between the center of the bottom of the load 1b and the outer periphery of the bottom of the load 1b is substantially the average temperature of the load 1b. Therefore, if the average temperature detected by the average temperature detection circuit 15 is displayed, the temperature of the load 1b can be almost displayed. Further, by detecting the average temperature of the two temperature detecting elements 5 and 8, the detection variation of each of the temperature detecting elements 5 and 8 and the temperature detecting circuits 6 and 9 is added or subtracted by approximately half. Detection accuracy can be improved by the effect of canceling each variation.

As described above, according to the present embodiment, the temperature of the first temperature detection element 5 detected by the first temperature detection circuit 6 and the second temperature detected by the second temperature detection circuit 9 By detecting and displaying the average temperature with the temperature of the detection element 8 by the average temperature detection circuit 15, it is possible to perform temperature display with high detection accuracy close to the temperature of the load 1b.

Next, a fourth embodiment of the present invention will be described with reference to FIG. The same components as those in the first and third embodiments are denoted by the same reference numerals, and description thereof is omitted.

As shown in the figure, the temperature difference detection circuit 13
The temperature difference between the temperature detected by the first temperature detection circuit 6 and the temperature detected by the second temperature detection unit 9 is detected, and the average temperature detection circuit 15 detects the temperature difference between the temperature detected by the first temperature detection circuit 6 and The average temperature with the temperature detected by the second temperature detection circuit 9 is detected, and each output is input to the control circuit 17. The operation unit 3 is provided with switching means 3d for switching between a temperature difference check key 3a and a load temperature display key 3c. The switching means 3d displays the temperature difference detected by the temperature difference detection circuit 13 and the average temperature detection circuit 15 displays the temperature difference. The display of the detected average temperature is switched.

The operation of the above configuration will be described. When the automatic temperature control mode is input from the operation unit 3, first, the control circuit 17 operates the inverter 1 to activate the heating coil 1a.
A high-frequency current to generate a high-frequency magnetic field and load 1b
Is started and the set temperature is displayed on the display unit 4. Then, the temperature of the first temperature detecting element 5 detected by the first temperature detecting circuit 6, the temperature of the second temperature detecting element 8 detected by the second temperature detecting circuit 9, or the average temperature detecting circuit If one of the average temperatures of the temperature detected by the first temperature detection circuit 6 and the temperature detected by the second temperature detection circuit 9 exceeds the set temperature, the inverter 1
Is stopped, and when the temperature falls below the set temperature, the inverter 1 is operated again to adjust the temperature of the load 1b. A temperature gradient is generated at the bottom of the load 1b, and the temperature becomes highest around a substantially middle position between the center of the bottom of the load 1b and the outer periphery of the bottom.

Accordingly, the temperature of the first temperature detecting element 5 disposed near the center of the bottom of the load 1b detected by the average temperature detecting circuit 15 and the position substantially at the intermediate position between the center of the bottom of the load 1b and the outer periphery of the bottom. The average temperature with the temperature of the second temperature detecting element 8 disposed in the vicinity is almost the average temperature of the load 1b. In the temperature difference detection circuit 13, the temperature of the first temperature detection element 5 detected by the first temperature detection circuit 6 and the temperature of the second temperature detection element 8 detected by the second temperature detection circuit 9 are calculated. Temperature difference is detected. Here, when the load temperature display key 3c in the switching means 3d is pressed, the average temperature detected by the average temperature detection circuit 15 is displayed on the temperature difference and load temperature display section 4d as the load temperature, and the temperature difference is checked. When the key 3a is pressed, the temperature difference detected by the temperature difference detection circuit 13 is displayed on the temperature difference and load temperature display section 4d.

Therefore, by pressing the load temperature display key 3c while the device is in use and displaying the average temperature detected by the average temperature detection circuit 15, a highly accurate load temperature can be displayed. In a state where the temperature of the first temperature detecting element 5 and the temperature of the second temperature detecting element 8 are the same (for example, a state where the device is left in a constant atmospheric temperature), the temperature difference check key 3a is pressed and the temperature difference detecting circuit is pressed. By displaying the temperature difference detected at 13 on the temperature difference and load temperature display section 4d, if the temperature difference is large, erroneous wiring or the like of the lead wire 11 can be detected.

As described above, according to this embodiment, the temperature difference between the temperature detected by the first temperature detection circuit 6 detected by the temperature difference detection circuit 13 and the temperature detected by the second temperature detection unit 9 is calculated. The average temperature between the temperature detected by the first temperature detection circuit 6 detected by the average temperature detection circuit 15 and the temperature detected by the second temperature detection circuit 9 can be arbitrarily displayed by a key operation of the switching means 3d. Therefore, erroneous wiring of the lead wire 11 can be detected, and the temperature of the load can be displayed with high accuracy.

In this embodiment, the temperature difference check key 3
a and the load temperature display key 3c are provided. However, if only the load temperature is displayed during normal operation and the temperature difference is displayed only when a plurality of power setting keys or the like are simultaneously pressed, the temperature difference display can be performed. It can be a hidden function for product inspection that cannot be operated by general users.

[0040]

According the above embodiment, according to the present invention evident as the present invention, provided the temperature difference detecting circuit for detecting the temperature difference between the sensed temperature in two or more temperature sensing element and a temperature sensing circuit, wherein Two or more temperature sensing elements at the same temperature
When the temperature difference detected by the temperature difference detection circuit is higher than a certain value, an error is displayed.If the lead wire is miswired, the temperature difference detected by the temperature difference detection circuit is higher than a certain value. Therefore, an abnormality display can be performed, and a highly reliable induction heating cooker can be provided.

Further, since an element temperature display section for displaying the temperatures detected by the two or more temperature detecting elements and the temperature detecting circuit is provided, the temperatures of the two or more temperature detecting elements can be displayed at any time, and the lead wires and It is possible to provide a highly reliable induction heating cooker that can easily confirm whether there is any abnormality in the temperature detection element or the like.

Further, since an average temperature detecting circuit for detecting the average temperature detected by two or more temperature detecting elements and the temperature detecting circuit is provided and the temperature detected by the average temperature detecting circuit is displayed, the temperature is displayed. It is possible to provide an easy-to-use induction heating cooker that can reduce an error between the temperature and the load temperature and can display a temperature with high accuracy close to the load temperature.

Further, a temperature difference detecting circuit for detecting a temperature difference between the temperatures detected by the two or more temperature detecting elements and the temperature detecting circuit, and an average temperature detected by the two or more temperature detecting elements and the temperature detecting circuit. Since the average temperature detection circuit and the switching means for detecting are provided, and the switching means switches between the display of the temperature difference detected by the temperature difference detection circuit and the display of the average temperature detected by the average temperature detection circuit, By displaying the temperature difference, it is possible to determine the incorrect wiring of the lead wire, etc.
It is possible to provide a convenient induction heating cooker capable of displaying a temperature with high accuracy close to the load temperature by displaying the average temperature.

[Brief description of the drawings]

FIG. 1 is a circuit block diagram of an induction heating cooker according to a first embodiment of the present invention.

FIG. 2 is a circuit block diagram when a lead wire of the induction heating cooker is incorrectly wired.

FIG. 3 is a circuit block diagram of an induction heating cooker according to a second embodiment of the present invention.

FIG. 4 is a circuit block diagram of an induction heating cooker according to a third embodiment of the present invention.

FIG. 5 is a circuit block diagram of an induction heating cooker according to a fourth embodiment of the present invention.

FIG. 6 is a circuit block diagram of a conventional induction heating cooker.

FIG. 7 is a circuit block diagram when the lead wires of the induction heating cooker are incorrectly wired.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Inverter 3 Operation part 4 Display part 5 1st temperature detection element (temperature detection element) 6 1st temperature detection circuit (temperature detection circuit) 8 2nd temperature detection element (temperature detection element) 9 2nd temperature detection Circuit (Temperature detection circuit) 13 Temperature difference detection circuit 14 Control circuit

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-4-20308 (JP, A) JP-A-4-2090 (JP, A) JP-A-62-254389 (JP, A) JP-A-2- 249097 (JP, A) JP-A-58-133528 (JP, A) JP-A-62-188086 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) H05B 6/12

Claims (4)

(57) [Claims] An inverter for converting a commercial power supply to a high-frequency current; a control circuit for controlling the inverter and the like;
Two or more temperature detection elements and a temperature detection circuit for detecting the temperature of the load, a temperature difference detection circuit for detecting a temperature difference detected by the two or more temperature detection elements and the temperature detection circuit, an operation unit, A display unit, and the two or more temperature detectors
An induction heating cooker configured to display an abnormality when the temperature difference detected by the temperature difference detection circuit is equal to or more than a certain value in a state where the temperature of the sensing element is the same . 2. An inverter for converting a commercial power supply into a high-frequency current, a control circuit for controlling the inverter and the like,
Two or more temperature detecting elements and a temperature detecting circuit for detecting the temperature of the load, an operation unit, and an element temperature display unit for displaying each temperature detected by the two or more temperature detecting elements and the temperature detecting circuit; An induction heating cooker configured to include: 3. An inverter for converting a commercial power supply to a high-frequency current, a control circuit for controlling the inverter and the like,
Two or more temperature detection elements and a temperature detection circuit for detecting the temperature of the load, an average temperature detection circuit for detecting an average temperature detected by the two or more temperature detection elements and the temperature detection circuit, an operation unit, An induction heating cooker comprising a display unit and configured to display a temperature detected by the average temperature detection circuit. 4. An inverter for converting a commercial power supply to a high-frequency current, a control circuit for controlling the inverter and the like,
Two or more temperature detecting elements and a temperature detecting circuit for detecting the temperature of the load; a temperature difference detecting circuit for detecting a temperature difference detected by the two or more temperature detecting elements and the temperature detecting circuit; An average temperature detection circuit that detects an average temperature detected by the temperature detection element and the temperature detection circuit, a switching unit, an operation unit, and a display unit, and the switching unit detects the average temperature detected by the temperature difference detection circuit. An induction heating cooker configured to switch between display of a temperature difference and display of an average temperature detected by the average temperature detection circuit.