JP6895809B2 - Induction cooker - Google Patents

Description

The present invention relates to an electromagnetic cooking device that heats a cooking container placed on a top plate by an induction heating (IH) type heating coil provided on the lower surface side of the top plate.

The electromagnetic cooking device includes a top plate and a heating coil provided on the lower surface side of the top plate. The heating coil generates a magnetic field by energization to induce and heat a cooking container such as a pan or a frying pan made of a ferromagnetic material on the top plate.

In this type of electromagnetic cooking device, the container mounting portion is set at a position corresponding to the heating coil of the top plate. By accurately placing the cooking container on the container mounting portion, the cooking container can be efficiently heated.

Further, a temperature detecting means for detecting the temperature of the cooking container is provided in the central portion of the lower surface of the container mounting portion. Then, the energization of the heating coil is controlled based on the temperature detected by the temperature detecting means.

By the way, in some cooking containers such as pots, the central portion of the bottom is warped away from the top plate. When a cooking container with a curved bottom is heated by an electromagnetic cooking device, the heat of the cooking container is located in the center of the container mounting part because the heat transfer is blocked by the air layer between the center of the bottom and the top plate. The temperature detected by the temperature detecting means is lower than the actual temperature of the cooking container because the temperature is not sufficiently transmitted to the temperature detecting means.

Therefore, an electromagnetic cooking apparatus has been proposed in which two temperature detecting means are provided in the central portion and the peripheral portion of the heating coil, respectively (see Patent Document 1 below).

The first temperature detecting means, which is one of the temperature detecting means, is arranged at the center of the heating coil described above, while the second temperature detecting means, which is the other temperature detecting means, is located from the peripheral edge of the heating coil. It is located inward and is located at a predetermined distance from the first temperature detecting means.

Then, when either one of the detection temperatures of the first temperature detecting means and the second temperature detecting means becomes equal to or higher than a preset upper limit temperature, the energization of the heating coil is stopped.

Further, when the cooking container is placed at a position away from the container mounting portion, the detection temperature of the second temperature detecting means is close to the detection temperature of the first temperature detecting means. Then, when the detection temperature difference between the first temperature detecting means and the second temperature detecting means becomes small and enters a predetermined temperature range, the detection temperature of the first temperature detecting means or the second temperature detecting means is applied to the heating coil. Since the energization cannot be controlled correctly, the energization of the heating coil is stopped.

Japanese Unexamined Patent Publication No. 2005-183055

However, even if the cooking container is placed at a position away from the container mounting portion, if the detection temperature of one of the first temperature detecting means and the second temperature detecting means is less than the upper limit temperature (that is, in an overheated state). If not), it may be preferable to continue cooking as it is. In this case, if the energization of the heating coil is stopped, cooking failure may occur, which is not convenient.

In view of the above points, the present invention provides an electromagnetic cooking apparatus capable of continuing cooking even when the cooking container is placed at a position away from the container mounting portion and improving usability. With the goal.

In order to achieve such an object, the present invention presents a top plate, a container mounting portion provided at a position where a cooking container of the top plate is placed, and a lower surface of the top plate corresponding to the container mounting portion. A heating coil arranged on the side to induce and heat the cooking container on the container mounting portion by energization, a first temperature detecting means arranged at the center of the heating coil, and an inner side from the peripheral edge of the heating coil. Based on the second temperature detecting means located at the position where the first temperature detecting means is located and at a predetermined distance from the first temperature detecting means, and the detection temperatures obtained from the first temperature detecting means and the second temperature detecting means. In an electromagnetic cooking apparatus including a control means for controlling energization of a heating coil, the control means has a preset upper limit of the detection temperature of either the first temperature detection means or the second temperature detection means. A high-cut stop processing unit that stops energization of the heating coil when the temperature exceeds the temperature, and a container mounting unit when the detection temperature of the second temperature detection means is equal to or lower than the detection temperature of the first temperature detection means. When the misalignment determination unit determines that the cooking container is misaligned and the misalignment determination unit does not determine that the cooking container is misaligned, the second temperature detecting means is detected. When it is determined by the normal operation control unit that controls the energization of the heating coil based on the temperature and the misalignment determination unit that the cooking container is misaligned, the first temperature detecting means and the second If the difference in the detection temperature from the temperature detecting means is within a predetermined range, the continuous operation control unit that controls the energization of the heating coil based on the detection temperature of the first temperature detecting means and the misalignment determination unit When it is determined that the cooking container is misaligned, the heating is performed when the difference between the detected temperatures of the first temperature detecting means and the second temperature detecting means exceeds a preset predetermined range. It is characterized by including an operation prohibition processing unit that prohibits energization of the coil.

According to the present invention, when the control means includes the continuous operation control unit, cooking can be continued even if the cooking container is slightly displaced from the container mounting portion, and the usability is improved.

The continuous operation process executed by the continuous operation control unit is based on the knowledge obtained by the present inventor from various tests. That is, when the cooking container is accurately placed on the container mounting portion, the increase in the detection temperature of the second temperature detecting means is larger than the increase in the detection temperature of the first temperature detecting means. This is because the temperature transmission from the cooking container to the first temperature detecting means is small due to the influence of the upward warp of the central part of the bottom of the cooking container, and the bottom of the cooking container is in contact with the container mounting part. This is because the temperature is largely transmitted to the second temperature detecting means.

Then, when the cooking container deviates from the container mounting portion, the portion in contact with the container mounting portion deviates from the second temperature detecting means, so that the temperature transmission from the cooking container to the second temperature detecting means becomes small. .. As a result, the detection temperature of the second temperature detecting means becomes lower than the detection temperature of the first temperature detecting means. Further, when the cooking container is displaced from the container mounting portion, the increase in the detection temperature of the second temperature detection means becomes smaller than the increase in the detection temperature of the first temperature detection means.

According to the findings of the present inventor, when the cooking container is displaced from the container mounting portion, the detection temperature of the second temperature detecting means becomes low, but the detection temperature of the first temperature detecting means changes extremely. Few.

Therefore, when the continuous operation control unit continues to energize the heating coil, the cooking container is controlled by controlling the energization of the heating coil based on the detection temperature of the first temperature detecting means, which is relatively stable. Even if the coil is displaced from the container mounting portion, cooking can be continued and usability can be improved.

The explanatory view which shows typically the structure of the electromagnetic cooking apparatus of embodiment of this invention. It is explanatory drawing which shows typically the position of the cooking container with respect to the container mounting part, FIG. 2A is the state which the cooking container is in the correct position of the container mounting part, and FIG. 2C shows a state in which the cooking container is displaced from the container mounting portion more than in FIG. 2B. 2A, 2B, and 2C are explanatory cross-sectional views showing the misalignment of the cooking container corresponding to each of FIGS. 2A, 3A in which the cooking container is in the correct position of the container mounting portion, and FIG. 3B is the cooking container in which the container is placed. A state in which the cooking container is displaced from the mounting portion, FIG. 3C shows a state in which the cooking container is displaced from the container mounting portion more than in FIG. 3B. The graph which shows the detected temperature change corresponding to each of FIG. 2A, FIG. 2B, and FIG. 2C. The flowchart which shows the operation of the electromagnetic cooking apparatus of this embodiment.

An embodiment of the present invention will be described with reference to the drawings. As shown in FIG. 1, the electromagnetic cooking device 1 of the present embodiment includes a top plate 2 on which a cooking container W such as a pan or a frying pan is placed. A heating coil 3 is provided below the mounting position of the cooking container W on the top plate 2.

A container mounting portion 4 which is the most suitable position for heating the cooking container W is set on the top plate 2 corresponding to the position of the heating coil 3. In the present embodiment, the diameter of the heating coil 3 is 155 mm, and the size of the container mounting portion 4 is substantially the same as the diameter of the heating coil 3.

The energization of the heating coil 3 is controlled by the controller 5 (control means). A heating coil 3, a middle thermistor 6 (first temperature detecting means), and a horizontal thermistor 7 (second temperature detecting means) are electrically connected to the controller 5, and power is supplied from a power source (not shown). Receives and operates. Further, the controller 5 is connected to an operation unit 8 for turning on / off the power supply / cooking operation and adjusting the output.

The middle thermistor 6 (first temperature detecting means) is arranged at the center of the container mounting portion 4 (the central portion of the heating coil 3). The lateral thermistor 7 (second temperature detecting means) is arranged inward from the outer peripheral edge of the heating coil 3 with a distance of about 50 mm in the lateral direction of the middle thermistor 6.

The controller 5 includes a normal operation control unit 9, a high-cut stop processing unit 10, a misalignment determination unit 11, a continuous operation control unit 12, an operation prohibition processing unit 13, and a storage unit 14. The storage unit 14 stores various data used by each control program, such as a control program corresponding to each of the plurality of cooking modes, and data for notifying an error or the like.

When the detection temperature of either the middle thermistor 6 or the horizontal thermistor 7 becomes equal to or higher than the upper limit temperature (preset for each cooking mode), the high-cut stop processing unit 10 describes the heating coil. Stop energizing to.

The misalignment determination unit 11 determines the misalignment of the cooking container W with respect to the container mounting portion 4, and there is a misalignment of the cooking container W when the detection temperature of the horizontal thermistor 7 is equal to or lower than the detection temperature of the medium thermistor 6. Is determined.

The normal operation control unit 9 is the horizontal thermistor 7 when the cooking container W is placed on the container mounting unit 4 without misalignment (when the misalignment determination unit does not determine that the cooking container is misaligned). The energization of the heating coil 3 is controlled based on the detected temperature of.

When the misalignment determination unit 11 determines that the cooking container W is misaligned, the continuous operation control unit 12 determines that the difference in the detection temperature between the middle thermistor 6 and the horizontal thermistor 7 is a predetermined range (predetermined). When the temperature is within the range of, for example, 30 ° C., which varies depending on the size and type of the cooking container W, the energization of the heating coil 3 is controlled based on the detection temperature of the middle thermistor 6.

When the misalignment determination unit 11 determines that the cooking container W is misaligned, the operation prohibition processing unit 13 sets a predetermined range in which the difference in the detection temperature between the middle thermistor 6 and the horizontal thermistor 7 is preset. If it exceeds the limit, energization of the heating coil 3 is prohibited. Further, the operation prohibition processing unit 13 is even when a cooking container having an extremely small diameter (for example, a diameter of 120 mm or less) with respect to the diameter of the heating coil 3 (155 mm in the present embodiment) is placed on the container mounting unit 4. It also has a function of detecting this and prohibiting energization of the heating coil 3.

Here, the relationship between the mounting position of the cooking container W with respect to the container mounting portion 4 and the temperature will be described. As shown in FIG. 2A, when the cooking container W is in the correct position of the container mounting portion 4, as shown in FIG. 3A, the heat generating portion P (the portion heated by the heating coil 3) at the bottom of the cooking container W is It is located directly above the lateral thermistor 7. Therefore, as shown in FIG. 4, the detection temperature of the horizontal thermistor 7 rises higher than the detection temperature of the middle thermistor 6 within a predetermined time range (about 60 to 300 seconds) after the heating of the cooking container W is started. Becomes larger.

That is, in a predetermined time range (about 60 to 300 seconds), the detection temperature of the horizontal thermistor 7 is higher than the detection temperature of the middle thermistor 6. In this case, by controlling the heating coil 3 based on the detection temperature of the horizontal thermistor 7, cooking can be performed at a relatively accurate temperature.

As shown in FIG. 2B, when the cooking container W is placed 20 mm to the left from the correct position of the container mounting portion 4, as shown in FIG. 3B, the heat generating portion P at the bottom of the cooking container W is placed. It shifts from directly above the horizontal thermistor 7. Therefore, as shown in FIG. 4, the degree of increase in the detection temperature of the lateral thermistor 7 slows down. On the other hand, the degree of increase in the detection temperature of the medium thermistor 6 does not change so much. However, also in this case, since the detection temperature of the horizontal thermistor 7 is higher than the detection temperature of the middle thermistor 6, the middle thermistor 6 is used by controlling the heating coil 3 based on the detection temperature of the horizontal thermistor 7. It is possible to cook at a more accurate temperature. At this point, it can be considered that there is no misalignment of the cooking container W with respect to the container mounting portion 4.

As shown in FIG. 2C, when the cooking container W is placed 40 mm to the left from the correct position of the container mounting portion 4, as shown in FIG. 3C, the cooking container W directly above the horizontal thermistor 7 The heat generating portion P at the bottom becomes smaller, and the heat transfer to the lateral thermistor 7 becomes smaller. On the other hand, the degree of increase in the detection temperature of the medium thermistor 6 does not change so much. Therefore, as shown in FIG. 4, the detection temperature of the middle thermistor 6 is higher than the detection temperature of the horizontal thermistor 7 in a predetermined time range (about 60 to 300 seconds). In this case, cooking can be performed at a relatively accurate temperature by controlling the heating coil 3 based on the detection temperature of the medium thermistor 6 with little change.

Next, the operation of the controller 5 in consideration of the above points will be described with reference to the flowchart of FIG. As shown in FIG. 5, when the detection temperature of either the middle thermistor 6 or the lateral thermistor 7 is lower than the upper limit temperature in STEP 1, the heating coil 3 does not overheat, so the controller 5 proceeds to STEP 2. When the controller 5 proceeds to STEP 2, it is determined whether or not the detection temperature of the horizontal thermistor 7 is equal to or higher than the detection temperature of the medium thermistor 6, and if the detection temperature of the horizontal thermistor 7 is equal to or higher than the detection temperature of the medium thermistor 6, the controller 5 determines. Proceeding to STEP3, the misalignment determination unit 11 determines that there is no misalignment of the cooking container W. Then, the process proceeds to STEP 4, and the normal operation control unit 9 controls the energization of the heating coil to perform the cooking operation based on the detected temperature of the horizontal thermistor 7.

After that, the controller 5 proceeds to STEP 5 and determines whether or not the operation unit 8 is turned off. If there is an OFF operation of the operation unit 8 in STEP 5, the process proceeds to STEP 6 to stop the energization of the heating coil to end the cooking operation, and if there is no OFF operation of the operation unit 8, the process returns to STEP 1.

In STEP 1, when the detection temperature of either the middle thermistor 6 or the horizontal thermistor 7 becomes equal to or higher than the upper limit temperature, the controller 5 proceeds to STEP 7 assuming that the heating coil 3 has overheated, and the high-cut stop processing unit 10 heats up. The energization of the coil 3 is stopped.

If the detection temperature of the horizontal thermistor 7 is lower than the detection temperature of the medium thermistor 6 in STEP 2, the process proceeds to STEP 8 and the misalignment determination unit 11 determines that the cooking container W is misaligned. Next, the controller 5 proceeds to STEP 9, and if the difference between the middle thermistor 6 and the horizontal thermistor 7 is 30 ° C. or less, the heating of the cooking container W by the heating coil 3 is not so adversely affected as described above, and thus proceeds to STEP 10. .. Proceeding to STEP 10, the continuous operation control unit 12 controls the energization of the heating coil to perform the cooking operation based on the detected temperature of the middle thermistor 6. As a result, even if the cooking container W is displaced from the container mounting portion 4, cooking can be continued, which is convenient.

On the other hand, in STEP 9, when the difference between the middle thermistor 6 and the lateral thermistor 7 exceeds 30 ° C., the controller 5 proceeds to STEP 11 and prohibits the heating coil 3 from being energized by the operation prohibition processing unit 13. As a result, when the cooking container W is extremely displaced from the container mounting portion 4, it is possible to prevent cooking from being performed in that state.

1 ... electromagnetic cooking device, 2 ... top plate, 3 ... heating coil, 4 ... container mounting part, 5 ... controller (control means), 6 ... medium thermistor (first temperature detecting means), 7 ... horizontal thermistor (second) Temperature detection means), 9 ... Normal operation control unit, 10 ... High cut stop processing unit, 11 ... Positional deviation determination unit, 12 ... Continuous operation control unit, 13 ... Operation prohibition processing unit, W ... Cooking container.

Claims (1)

The top plate, a container mounting portion provided at a position where the cooking container of the top plate is placed, and the container mounting portion arranged on the lower surface side of the top plate corresponding to the container mounting portion and energized. The heating coil that induces and heats the cooking container, the first temperature detecting means arranged at the center of the heating coil, and the first temperature detecting means that are located inward from the peripheral edge of the heating coil and are predetermined from the first temperature detecting means. A second temperature detecting means arranged at a position where a distance exists, and a control means for controlling energization of the heating coil based on the detected temperatures obtained from the first temperature detecting means and the second temperature detecting means. In the electromagnetic cooking device to be equipped
The control means stops energizing the heating coil when the detection temperature of either the first temperature detecting means or the second temperature detecting means becomes equal to or higher than a preset upper limit temperature. Positional deviation determination for determining that the cooking container is displaced with respect to the container mounting unit when the detection temperature of the processing unit and the second temperature detecting means is equal to or lower than the detection temperature of the first temperature detecting means. And a normal operation control unit that controls energization to the heating coil based on the detection temperature of the second temperature detecting means when it is not determined by the misalignment determination unit that the cooking container is misaligned. When the misalignment determination unit determines that the cooking container is misaligned, if the difference between the detected temperatures of the first temperature detecting means and the second temperature detecting means is within a predetermined range, the above. When it is determined by the continuous operation control unit that controls the energization of the heating coil based on the detection temperature of the first temperature detecting means and the misalignment determination unit that the cooking container is misaligned, the first It is characterized by including an operation prohibition processing unit that prohibits energization of the heating coil when the difference in detected temperature between the temperature detecting means and the second temperature detecting means exceeds a preset predetermined range. Electromagnetic cooking equipment.

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