JP5047226B2 - Cooker - Google Patents

Description

  The present invention relates to a cooking device that cooks a cooking container (hereinafter referred to as an object to be heated) such as a pan or a pan placed on a top plate using electromagnetic induction.

In a conventional cooking device, a contact temperature detecting means (such as a thermistor) preliminarily arranged from below the top plate as a temperature detecting unit is most often used. However, with the contact-type temperature detection means installed under the top plate, the temperature of the object to be heated placed on the top plate is warped or the top plate is preheated from the beginning of heating. Reliability is remarkably reduced due to slow change following. Furthermore, since there is also a heat capacity of the top plate (glass), a time delay occurs in temperature detection.
Therefore, in order to solve such a problem of the contact-type temperature detection means, a method of detecting the temperature using the infrared temperature detection means is known. For example, the infrared temperature detection means is installed under the top plate from below. What measures the temperature of an upper to-be-heated material through a top plate is known. However, when the infrared temperature detection means is installed under the top plate in this way, since the top plate (glass) does not transmit electromagnetic waves in the wavelength band of 150 ° C. or lower, the temperature of the heated object is 150 ° C. or lower. However, there was a problem that temperature could not be detected.
Therefore, in order to solve the problem in the case where the infrared temperature detection means is installed under such a top plate, the heated object placed on the top plate using the infrared temperature detection means from the side and above the top plate. A device that directly detects a wide temperature range from the initial temperature of an object to the cooking temperature without using a top plate is known (see, for example, Patent Document 1).
In this case, the emissivity varies depending on whether the object to be heated, which is a measurement target, is mirror-finished or non-mirror-finished. For example, when the object to be heated is made of stainless steel and mirror-finished, the emissivity ε is about ε = 0.15, whereas in a container such as a hollow, the emissivity ε is about ε = 0.8. There is a big difference in the amount of infrared radiation energy.
Therefore, correction is required to solve this problem, but details of this correction processing are described in Patent Document 2, and thus detailed description thereof is omitted here.

Japanese Patent No. 3924720 Japanese Patent Application No. 2008-284081 (pages 3 to 6, FIGS. 4 to 8)

In addition, when the object to be heated is a mirror surface, the side surface of the object to be heated (hereinafter sometimes referred to as nabe skin), the boundary between the top plate (glass) and the bottom of the object to be heated, and the vicinity of the boundary The amount of radiation from the boundary of the top plate is the largest. In the case of a non-mirror surface, the side surface and the boundary portion of the object to be heated are the most. Therefore, if temperature detection is performed based on the amount of infrared rays detected by a detection element including this boundary portion in the visual field region (hereinafter also referred to simply as an element) in both cases of mirror and non-mirror surfaces, a highly accurate temperature can be obtained. Detection is possible.
However, the infrared temperature detection unit is a thermopile composed of a plurality of detection elements having, for example, a vertical visual field area of 1 ° and a horizontal visual field area of 3 ° / 1 element. Average the total amount of infrared rays obtained by area and return the value.
For this reason, when the distance from the boundary between the top plate (glass) and the bottom surface of the object to be heated is far away from the detection element, the ratio of the area occupied by the boundary to the total area of the detection region is Since it becomes small, the amount of infrared rays detected by the sensing element becomes small. Therefore, there is a problem in that the temperature detection accuracy decreases because the temperature of the element that detects the boundary between the object to be heated and the top plate becomes excessive or too low due to the size of the bottom diameter of the object to be heated. It was.

  The present invention has been made to solve the above-mentioned problems, and its purpose is to obtain a cooking device capable of accurately detecting the temperature of the object to be heated regardless of the size of the bottom diameter. is there.

A heating cooker according to the present invention supplies a top plate on which an object to be heated such as a pan is placed, a heating coil provided below the top plate for induction heating the object to be heated, and supplies alternating power to the heating coil. The heating coil drive unit that is driven and the side of the object to be heated and the upper side of the top panel, the side surface of the object to be heated, the boundary between the bottom surface of the object to be heated and the top panel, and the continuous area that reaches the top panel are divided into multiple parts A plurality of detection elements provided corresponding to each of the obtained divided regions, an infrared temperature detection unit that directly detects the amount of infrared radiation above the top plate, and an infrared amount detected by the infrared temperature detection unit Corresponding the calculation unit for converting to temperature, the control unit for controlling the heating coil driving unit based on the temperature output by the calculation unit, the distance to each detection element and the divided area detected by the detection element, and the correction coefficient comprising a storage unit for storing a correspondence table, and the arithmetic unit, a plurality Based on a comparison of the amount of infrared rays detected in the detection element, the detection of the boundary is specified, and the infrared amount detected from the object to be heated by the specified detection element is corrected by a preset correction coefficient. The temperature of the object to be heated is estimated based on the amount of infrared rays , and the correction coefficient is set in advance with the amount of infrared rays output by the detection element when the boundary area is included in the divided area detected by each detection element. It is calculated as a relative ratio to the infrared amount that is the reference value, and is a value set for each detection element according to the distance to the divided area detected by each detection element .

According to the present invention, when the boundary portion is included in the divided area detected by each detection element, the amount of infrared rays output from the detection element that detects infrared rays from the boundary portion between the bottom surface of the object to be heated and the top plate is detected. Calculated as a relative ratio between the amount of infrared light output by the sensing element and the amount of infrared radiation that is a preset reference value, and a correction set for each sensing element according to the distance to the divided area detected by each sensing element Since the temperature of the object to be heated is estimated based on the corrected amount of infrared rays, the temperature of the object to be heated can be accurately detected regardless of the size of the bottom diameter.

It is a perspective view which shows typically the external appearance of the heating cooker in Embodiment 1, 2 of this invention. It is front sectional drawing of FIG. It is side surface sectional drawing of FIG. It is a figure which shows the arrangement | sequence and its to-be-detected area | region of 8 rows in a vertical direction and 1 row in a horizontal direction of the detection element which comprises the infrared temperature detection part 7 in Embodiment 1 of this invention. It is a figure which shows the zigzag arrangement | sequence of 4 rows in the vertical direction of the detection element which comprises the infrared temperature detection part 7 in Embodiment 1, 2 of this invention, and 2 rows in a horizontal direction, and its to-be-detected area | region. FIG. 5 is a correspondence table in which identifiers of detection elements, correction coefficients, and distances from the boundary between the heated object and the top plate to corresponding detection elements are associated with each other. In FIG. 4B, the boundary portion is emphasized. It is a graph which shows the relationship between the output of each element, and time when a to-be-heated material is mounted in the position shown in FIG. 3 is a flowchart illustrating an operation of a calculation unit 15 according to the first embodiment. It is side surface sectional drawing and perspective view of the principal part which show the relationship between the 8-eye infrared temperature detection part and its to-be-detected area | region at the time of providing infrared LED for positioning in the specific detection area in Embodiment 3 of this invention. . It is a graph which shows the output of each element in the 8-eye infrared temperature detection part at the time of infrared LED lighting in FIG. It is a figure which shows the infrared temperature detection part and to-be-detected area | region of the heating cooker in Embodiment 3 of this invention. It is a figure which shows operation | movement of the calculating part 15 in Embodiment 3 of this invention. It is a side cross section and a perspective view at the time of comprising so that the radiation direction of infrared LED may face the infrared temperature detection part 7 via a reflecting plate. It is a graph which shows the output of each element in the 8-eye infrared temperature detection part at the time of infrared LED lighting in FIG. 14 is a flowchart illustrating an operation of a calculation unit 15 according to the fourth embodiment. 10 is a flowchart illustrating an operation of a calculation unit 15 according to the fifth embodiment. It is a schematic diagram which shows the front cross section of the heating cooker in Embodiment 6 of this invention. 14 is a flowchart illustrating an operation of a calculation unit 15 according to the sixth embodiment. It is side surface sectional drawing which shows the principal part structure of the heating cooker which has a monocular infrared temperature detection part. It is a flowchart which shows operation | movement of the calculating part 15 in Embodiment 7 of this invention.

Embodiment 1 FIG.
1 is a perspective view schematically showing the appearance of a heating cooker according to Embodiment 1 of the present invention, FIG. 2 is a front sectional view of FIG. 1, and FIG. 3 is a side sectional view of FIG.
The heating cooker is disposed on the upper surface of the main body 1 and the main body 1, and is disposed on one side of the upper surface of the main body 1 and the top plate 3 made of a heat resistant material such as ceramics for placing the object to be heated 2. The operation unit 4 provided with each operation switch (not shown) for setting on / off of the device and the heating temperature of the object 2 to be heated placed on the top board 3, and the on / off of the device and the set temperature Is displayed. Further, the top plate 3 is printed with a circle indicating the heating port 6 when the article 2 to be heated is placed. The main body 1 has a grill part 11, a heating part 12 that is arranged immediately below the top plate 3 and above the grill part 11, and is composed of a heating coil for heating the heated object 2 placed on the top plate 3. , A drive unit 13 that converts commercial power supplied from an AC power source (not shown) into high-frequency power and supplies it to the heating unit 12, and a control unit 14 that controls the drive unit 13. The control unit 14 includes a DSP and a microcomputer.

The heating cooker further includes one infrared temperature detection unit 7 for detecting the amount of infrared rays radiated from the object to be heated 2 corresponding to each of the two heating units. The infrared temperature detection unit 7 is attached using an intake port 8 formed on the top and side of the top plate 3, specifically on the back surface of the heating cooker body 1 so as to face the top surface of the top plate 3. The calculation unit 15 provided in the main body 1 converts the amount of infrared rays directly detected by the infrared temperature detection unit 7 without using the top plate 3 into temperature data, and outputs the temperature data to the control unit 14. Thus, by installing the infrared temperature detection part 7 above the top plate 3, since the temperature of the to-be-heated object 2 can be detected directly, high-speed responsiveness is securable. Further, in the main body 1, a contact-type temperature detection unit 17 that is disposed so as to be in thermal contact with the back surface of the top plate 3 and detects the temperature of the object to be heated 2 through the top plate 3 is provided. .
On the other hand, the control unit 14 acquires the operation condition set from the operation unit 4 via the input unit 10, controls the drive unit 13 based on the operation condition and the detected temperature of the infrared temperature detection unit 7, and performs heating. The heating operation of the unit 12 is driven.

Next, the configuration of the infrared temperature detection unit 7 will be described.
FIG. 4 is a diagram showing an array of eight rows in the vertical direction and one row in the horizontal direction of the detection elements constituting the infrared temperature detection unit 7 according to Embodiment 1 of the present invention, and the detected region. (A) is a figure which shows the arrangement | sequence of a sensing element, FIG.4 (b) is a figure which shows the to-be-detected area | region of a sensing element. As shown in FIG. 4 (a), a plurality of detection elements 7a to 7h constituting an infrared temperature detection unit 7 configured with a compound eye are provided, and here are arranged in 8 rows in the vertical direction and 1 row in the horizontal direction. It is shown that the detection elements 7a to 7h detect the respective detection areas a to h. FIG. 5 is a diagram showing a staggered arrangement of four rows in the vertical direction and two rows in the horizontal direction and the detection region thereof in the infrared temperature detection unit 7 according to Embodiment 1 of the present invention. FIG. 5A is a view showing the arrangement of the detection elements, FIG. 5B is a view showing the detection area of the detection elements, and FIG. 5C is an enlarged view of the boundary portion of the object to be heated. As shown in FIG. 5 (a), a plurality of detecting elements 7a to 7h constituting an infrared temperature detecting unit 7 configured with a compound eye are provided, and a solid line and an adjacent solid line as shown in FIG. 5 (b). The interval between the detection areas of one element is shown, and the detection area of another element adjacent between the broken line and the adjacent broken line is shown. Here, there are four rows in the vertical direction and two rows in the horizontal direction. It is shown that the detection elements 7a to 7h arranged in a zigzag form each of the detection areas a to h partially overlap each other, and as a result, the heating area is detected twice.
Accordingly, the side surface of the object to be heated 2 placed on the top plate 3, the boundary between the object to be heated 2 and the top plate 3, and the continuous detection area including the top plate 3 are divided into a plurality of parts. It becomes possible to more accurately detect the temperature of the obtained divided region.

Next, the operation of the first embodiment will be described.
In the explanation, the following preconditions are provided to simplify the explanation. This precondition is common to all the embodiments.
(A) The infrared temperature detection unit is a thermopile composed of eight eyes of eight rows of detection elements 7a to 7h in the vertical direction and one row in the vertical direction. As an example, the vertical visual field region is 1 ° and the horizontal visual field. An area of 3 ° / 1 element is taken, and the total amount of infrared rays obtained by the area of the detection area of one element is averaged by the area to return a value. The detected area is as shown in FIG.
(B) The calculation unit 15 provided in the main body 1 has a correspondence table in which the detection elements 7a to 7h are associated with the distances to the respective detection areas a to h and correction coefficients (infrared emissivity to be corrected). It is assumed that a storage unit (not shown) for storing is incorporated.
(C) When the user places the object to be heated 2 on the top plate 3, the user places the object 2 in a state where the center of the object to be heated 2 substantially matches the center of the heating coil 12.

The operation will be described under the above preconditions.
First, the following preparations are made.
(A) The object to be heated 2 serving as a reference is selected in advance, and the bottom diameter of the object to be heated is measured. In the heating experiment, the user places the object 2 to be heated in a state where the center position of the object to be heated 2 substantially matches the center of the heating port 6, that is, the center position of the heating coil 12, and operates the operation unit 4 to change the operating condition. Set. Thereby, the control part 14 controls the heating coil drive part 13 based on the driving | running condition set from the operation part, and the to-be-heated material 2 mounted in the heating port 6 of the top plate 3 is induction-heated. And when the temperature of the to-be-heated object 2 reaches the temperature set by the operating condition, each detection element 7a-7h divides | segments the continuous area | region which reaches the pot skin of the to-be-heated object 2, a boundary part, and the top plate 3 into eight. Then, the infrared amount of each of the obtained divided areas is acquired, and the largest one of the acquired infrared amounts is specified. Then, the specified infrared amount and the bottom diameter of the object to be heated 2 are associated with each other and stored in the storage unit as a reference value.
(A) Next, the correction coefficient is estimated as follows and set in a storage unit (not shown). The object to be heated 2 having a plurality of bottom diameters is selected in advance, and the bottom diameter of the object to be heated is measured. In the heating experiment, the user places the object 2 to be heated in a state where the center position of the object to be heated 2 substantially matches the center of the heating port 6, that is, the center position of the heating coil 12, and operates the operation unit 4 to change the operating condition. Set. Thereby, the control part 14 controls the heating coil drive part 13 based on the driving | running condition set from the operation part, and the to-be-heated material 2 mounted in the heating port 6 of the top plate 3 is induction-heated. And when the temperature of the to-be-heated object 2 reaches the temperature set by the operating condition, each detection element 7a-7h divides | segments the continuous area | region which reaches the pot skin of the to-be-heated object 2, a boundary part, and the top plate 3 into eight. Then, the infrared amount of each of the obtained divided areas is acquired, and the largest one of the acquired infrared amounts is specified. And while calculating the relative ratio of the specified amount of infrared rays and the amount of infrared rays obtained in (a) above, storing it in a storage unit (not shown) as a correction coefficient, and from the bottom diameter of the object to be heated 2, The distance to the detection element that detects the detection area corresponding to the boundary between the object to be heated 2 and the top plate 3 is calculated. Then, the obtained correction coefficient and the distance to the detection element that detects the detection area corresponding to the boundary portion are stored in a storage unit (not shown) as a correspondence table in association with the identifier of the detection element. Next, the position of the object to be heated is shifted, the boundary portion of the object to be heated is arranged in the adjacent detection area, and the above operation is performed again. Such an operation is repeated for the eight detected areas to create a correspondence table. The correspondence table obtained in this way is shown in FIG.

Next, a method for calculating the distance will be described in detail.
FIG. 7 is a diagram emphasizing the boundary portion which is the point of the present invention in FIG. In FIG. 7, the boundary portion is filled with black.
FIG. 8 is a graph showing the relationship between the output of each element and time when the object to be heated is placed at the position shown in FIG.
In FIG. 7, if the sensor angle / height of the infrared temperature detector 7 is determined, the position of the pan bottom of the article 2 to be heated is located on the top 3 from each element 7 a to 7 h to the detection area of each element. The distance can be determined by trigonometric function calculation. (FIG. 7 shows an area correspondence table of sensor viewing angle Y direction of 1 °, sensor center height of 13 mm, and center axis angle of 6 °.) When a mirror pan is installed, an element that returns the maximum output of the infrared temperature detector 7 is Since the edge of the pan bottom is viewed, the distance to the edge position can be calculated by calculation as described above.
The calculating part 15 estimates the distance to the edge part of the to-be-heated object of the infrared temperature detection part 7 by the output of the infrared temperature detection part 7 provided above and on the side of the top board (the to-be-heated object and the top board). And determine the distance of the boundary part.)
Thus, by determining the position where the pan is placed, it is possible to detect the pan bottom diameter, the positional relationship between the heating coil 12 and the pan bottom, and whether the pan is a large pan or a small pan.
In addition, the frequency of the detection temperature is improved by changing the coefficient of the output of the infrared sensor according to each condition (by repeatedly performing an experiment).
As shown in FIG. 4 (a), when a compound eye infrared temperature detection unit 7 composed of detection elements in a vertical arrangement of 1 horizontal row × 8 vertical rows is used, each of the detection elements 7a to 7h depends on the initial installation angle and height. The detection area is determined. For example, when the infrared temperature detector 7 having a height of 13 mm from the top plate 3, an angle level of 1 and a visual field area of 2 elements is used, the detection area of the element 7 h installed at the bottom is
“X _{1 to} X ₂ ”.
However, X ₁ = 13 mm * tan ⁻¹ (8 °),
X ₂ = 13 mm * tan ⁻¹ (6 °)
That is, the detection width is 92.5 to 123.7 mm from the tip of the infrared sensor. If the pan bottom is placed in this range, the sixth element 7f from the top returns the maximum value as shown in FIGS. 7 and 8, and the calculation unit 15 prepares in advance for this value. The correction coefficient corresponding to the element 7f is extracted from the correspondence table and the infrared ray amount is corrected.

Next, the operation will be described under the above conditions.
The user places an object to be heated 2 such as a pan on the heating port 6 on the top plate 3, turns on the power switch of the heating cooker body 1, and further operates the operation unit 4 to input and set operating conditions. Start cooking. The control unit 14 is activated by turning on the power switch, and controls the drive unit 13 based on the operating condition input and set from the operation unit 4 and the detected temperature output from the infrared temperature detection unit 7, thereby heating the heating unit 12. Drive action. Thereby, cooking of the to-be-cooked object 9 in the to-be-heated object 2 is performed, and the some detection elements 7a-7h which comprise the infrared temperature detection part 7 respectively detect the infrared rays amount of the to-be-detected area | region ah detected by itself. Is detected. On the other hand, the calculation unit 15 is also activated by turning on the power switch, and the calculation unit 15 amplifies and A / D-converts the amount of infrared rays detected by the detection elements 7a to 7h. And when the temperature of the to-be-heated material 2 reaches the temperature set on the driving | running condition, the calculating part 15 selects the largest thing among eight infrared rays amount acquired from the detection elements 7a-7h. In this case, since the boundary between the bottom of the object to be heated 2 and the top plate radiates the maximum amount of temperature information infrared rays, a detection element for detecting this boundary (detected region f in the example of FIG. 7) (FIG. 8). In the example, the element 7f) outputs the maximum temperature information. This is shown in FIG.
The computing unit 15 identifies the detection element 7f that has detected the maximum amount of infrared rays. Next, the calculation unit 15 searches the correspondence table shown in FIG. 4 stored in a storage unit (not shown) using the specified detection element 7f as a search key, and extends from the specified detection element 7f to the boundary portion of the object 2 to be heated. Get distance and correction factor. Next, the calculation unit 15 corrects the identified infrared ray amount detected from the heated object 2 by multiplying the infrared ray amount detected from the storage unit by the correction coefficient acquired from the storage unit, and corrects the corrected infrared ray amount to the actual value of the heated object 2. Estimated as the amount of infrared rays. And it converts into temperature data by substituting into the following formula | equation (1).

T = (P / k) ^1/4 ... (1)
However, P = detected infrared ray amount x correction coefficient ,
k = constants determined by the Stefan Boltzmann constant and sensor sensitivity

The temperature data obtained as described above is sent from the calculation unit 15 to the control unit 14, and the control unit 14 estimates that the temperature data acquired from the calculation unit 15 is the temperature of the object to be heated 2, and this temperature data. Controls the drive unit 13 so that the target temperature set by the operation unit 4 is reached.
Since feedback control is performed on the target temperature value as described above, accurate temperature control is possible.

FIG. 9 is a flowchart showing the operation of the calculation unit 15 in the first embodiment.
Next, the operation of the calculation unit 15 will be described with reference to FIGS.
When activated, the calculation unit 15 executes initial processing such as counter clearing, infrared ray clearing (step S901), and then selects the first sensing element (for example, the element 7a) (step S902). An infrared ray amount (assumed as A) is acquired as an output (step S903). Next, the computing unit 15 compares the acquired infrared ray amount A with the maximum infrared ray amount B (initially zero) stored in the storage unit (step S904), and the detected infrared ray amount A is more than B. If it is smaller, the process jumps to step S907, and if the detected infrared light amount A is larger than B, the current infrared light amount is written as B in the storage unit (step S905), and the detection element identifier at this time (for example, Number) is also written in the storage unit (step S906). Next, the calculation unit 15 checks whether or not all areas have been detected (step S907), and if not completed yet, selects the next detection element (for example, element 7b) (step S908). Returning to step S903, similar processing is executed again. This operation is sequentially repeated until the elements 7c, 7d, 7e,. Then, when the process of the element 7h is finished, the result of Step S907 is Yes, so that the process proceeds to Step S909. Here, the sensing element that has detected the maximum amount of infrared rays (the sensing element that has detected the boundary) is read from a storage unit (not shown), and the correspondence table stored in the storage unit is referred to by this detection element, so that the distance and the correction coefficient Is read (step S910). Next, the calculating part 15 corrects by multiplying the amount of infrared rays by a correction coefficient (step S911). Next, the calculation unit 15 converts the corrected infrared ray amount into temperature data (step S912).

According to the first embodiment, the calculation unit is divided into a plurality of areas obtained by dividing the side surface of the object to be heated, the boundary between the bottom surface of the object to be heated and the top plate, and the continuous region reaching the top plate into a plurality of parts. Based on a comparison of the magnitudes of infrared rays detected among a plurality of detection elements provided in correspondence, the detection of the boundary is specified, and the infrared quantity detected from the object to be heated by the specified detection element is preset. Since the temperature of the object to be heated is estimated based on the corrected infrared amount, the temperature of the object to be heated can be accurately detected regardless of the bottom diameter of the object to be heated. .
In addition, since the infrared sensor has a compound eye structure, the visual field range is wider than that of a single eye, so that the detection accuracy is high.

Embodiment 2. FIG.
In the first embodiment, the amount of infrared detected by the detection element to prevent the amount of infrared detected by the detection element from decreasing when the distance from the boundary of the object to be heated to the corresponding detection element is far away. However, depending on whether the object to be heated is inside the heating coil 12 or not, the temperature of the object to be heated varies abruptly. That is, if the object to be heated is inside the heating coil 12, not only the boundary portion but also the side surface (naked skin) of the object to be heated is strongly electromagnetically coupled to the heating coil 12, so the side surface temperature rises rapidly. As a result, the temperature of the entire object to be heated increases, and the temperature at the boundary portion also rises. However, since a sufficiently high infrared ray is emitted from the beginning, it is close to saturation and cannot follow the temperature increase of the entire object to be heated. On the other hand, if the object to be heated is outside the heating coil 12, the side surface temperature does not change greatly because the amount of the side surface (naked skin) of the object to be heated electromagnetically coupled to the heating coil 12 is small. Therefore, temperature measurement is possible in the same manner as in the first embodiment. Thus, if the bottom diameter of the object to be heated is smaller than the diameter of the heating coil 12, the temperature of the entire object to be heated is estimated based on the temperature rise at the boundary between the object to be heated and the top plate. There is a risk that the accuracy may decrease. In this embodiment, a mode for solving such a problem will be described.

1 to 8 are also used in the second embodiment. The configuration is the same as in the first embodiment.
Next, the operation of the second embodiment will be described.
Also in the second embodiment, a correspondence table that associates each detection element with the distance to the divided area detected by the detection element is stored in the storage unit in advance. In addition, the storage unit stores in the storage unit a second correction coefficient having different values depending on whether the boundary portion of the article to be heated 2 is located inside the heating coil 12 or the outside.
(A) In this case, the second correction coefficient is estimated as follows and set in a storage unit (not shown). The object to be heated 2 having a bottom diameter smaller than the heating coil 12 is selected in advance, and the bottom diameter of the object to be heated is measured. In the heating experiment, the user places the object 2 to be heated in a state where the center position of the object to be heated 2 substantially matches the center of the heating port 6, that is, the center position of the heating coil 12, and operates the operation unit 4 to change the operating condition. Set. Thereby, the control part 14 controls the heating coil drive part 13 based on the driving | running condition set from the operation part, and the to-be-heated material 2 mounted in the heating port 6 of the top plate 3 is induction-heated. When the temperature of the object to be heated reaches the temperature set in the operating conditions, each of the detection elements 7a to 7h divides the continuous area of the object 2 to reach the pot skin, the boundary, and the top plate 3 into eight. The obtained infrared amount of each of the divided areas is acquired, and the largest one of the acquired infrared amounts is specified. Then, the temperature obtained by substituting the specified amount of infrared rays into equation (1) is calculated, and the relative ratio between the calculated temperature and the set temperature (this temperature corresponds to the actual temperature) is calculated. The second correction coefficient for the inner side is stored in a storage unit (not shown), and the detection area corresponding to the boundary between the heated object 2 and the top plate 3 is detected from the bottom diameter of the heated object 2. The distance to the sensing element to be calculated is calculated. Then, the obtained second correction coefficient for the inside and the distance to the detection element that detects the detection area corresponding to the boundary are stored in a storage unit (not shown) as a correspondence table in association with the identifier of the detection element. Keep it. Next, the position of the object to be heated 2 is shifted so that the boundary of the object to be heated protrudes outside the heating coil 12, and the above operation is performed again. At this time, the amount of infrared rays obtained from the boundary portion decreases rapidly. Therefore, the identifier of the detection element that detects the boundary portion at this time, the distance from the boundary portion to the corresponding detection element, and the second correction coefficient for the outside are acquired in the same manner as described above and stored in the storage unit. deep.

Next, the operation will be described under the above conditions.
The user places an object to be heated 2 such as a pan on the heating port 6 on the top plate 3, turns on the power switch of the heating cooker body 1, and further operates the operation unit 4 to input and set operating conditions. Start cooking. The control unit 14 is activated by turning on the power switch, and controls the drive unit 13 based on the operating condition input and set from the operation unit 4 and the detected temperature output from the infrared temperature detection unit 7, thereby heating the heating unit 12. Drive action. Thereby, cooking of the to-be-cooked object 9 in the to-be-heated object 2 is performed, and the some detection elements 7a-7h which comprise the infrared temperature detection part 7 respectively detect the infrared rays amount of the to-be-detected area | region ah detected by itself. Is detected. On the other hand, the calculation unit 15 is also activated by turning on the power switch, and the calculation unit 15 amplifies and A / D-converts the amount of infrared rays detected by the detection elements 7a to 7h. And when the temperature of the to-be-heated material 2 reaches the temperature set on the driving | running condition, the calculating part 15 selects the largest thing among eight infrared rays amount acquired from the detection elements 7a-7h. In this case, since the boundary between the bottom of the object to be heated 2 and the top plate radiates the maximum amount of temperature information infrared rays, a detection element for detecting this boundary (detected region f in the example of FIG. 7) (FIG. 8). In the example, the element 7f) outputs the maximum temperature information. This state is shown in FIGS .
The computing unit 15 identifies the detection element 7f that has detected the maximum amount of infrared rays. Next, the calculation unit 15 searches the correspondence table shown in FIG. 6 stored in a storage unit (not shown) using the specified detection element 7f as a search key, and extends from the specified detection element 7f to the boundary portion of the object 2 to be heated. Get the distance. Next, the calculation unit 15 calculates the bottom diameter of the object to be heated 2 based on the acquired distance, and compares the bottom diameter of the object to be heated 2 with the diameter of the heating coil 12. If the bottom diameter of the object to be heated 2 is smaller than the diameter of the heating coil 12, the second correction coefficient for the inside is corrected by multiplying the detected infrared ray amount and applied, and the bottom diameter of the object to be heated 2 is corrected by the heating coil 12. If it is larger than the diameter, the second correction coefficient for the outside is multiplied by the detected infrared amount and applied to correct it. Thereafter, the correction described in the first embodiment is further performed. And it converts into temperature data by substituting into said Formula (1).
Thereby, accurate temperature control becomes possible regardless of the size of the bottom diameter of the article 2 to be heated.

According to the second embodiment, the calculation unit acquires the distance from the specified detection element to the boundary portion based on the specified detection element and the correspondence table, and calculates the bottom diameter of the object to be heated based on the acquired distance. It is determined whether or not the object to be heated is positioned inside the heating coil 12 based on a comparison between the calculated bottom diameter of the object to be heated and the diameter of the heating coil 12, and based on the determination result. It switches the second correction coefficients for stored in the storage unit inside and a second correction coefficient for the outer, corrected by a second correction coefficient specified sensing element switches the amount of infrared detected from the object to be heated Since it comprised so, exact temperature control is attained irrespective of the magnitude | size of the bottom diameter of the to-be-heated material 2. FIG.

  In the above description, the correction coefficient is not included in the correspondence table. However, it goes without saying that the correction coefficient may be included in the correspondence table.

Embodiment 3 FIG.
The first and second embodiments have been described on the assumption that the setting position of the infrared temperature detection unit 7 is normal. However, if the setting position is not normal, accurate detection may not be possible or detection itself may not be possible. There is. In the third embodiment, a correction method for such a case will be described.
FIG. 10 is a side cross-sectional view and a perspective view of a main part showing the relationship between an 8-eye infrared temperature detection unit and its detection region when a positioning infrared LED is provided in a specific detection region in Embodiment 3 of the present invention. FIG. 10A is a side cross-sectional view of the main part showing the relationship between the eight-eye infrared temperature detection unit and its detection region, and FIG. 10B is the eight-eye infrared temperature detection unit and its detection region. It is a perspective view of the principal part which shows the relationship.
10A, the same reference numerals as those in FIG. 7 denote the same or corresponding parts. Here, the configuration is the same as in FIG. 7 except that an infrared LED is added.

Next, the operation of the third embodiment will be described.
The main body 1 is provided with at least one infrared LED 16 at an arbitrary position on the top plate 3, and among the eight detection elements 7 a to 7 h constituting the infrared temperature detection unit 7, the element that always detects the infrared LED 16 is 1. Suppose that Here, the element for detecting the infrared LED 16 is 7h.
As shown in FIGS. 10 (a) and 10 (b), as an initial position correction, an infrared LED 16 is provided in the detection region h of the top plate 3 and directly under the top plate that is not affected by heating. Installed with the direction of infrared radiation. On the other hand, the infrared temperature detector 7 is also installed with its direction facing the infrared LED 16 so that infrared rays from the infrared LED 16 can be detected efficiently. With this configuration, the amount of infrared rays detected by the element 7h protrudes and becomes large as shown in FIG. 11 among the amount of infrared rays detected by each detection element before the start of heating.
Under such conditions, in order to determine whether or not each temperature detection element is normally installed at the initial stage of operation before the control unit 14 starts the induction heating control, the calculation unit 15 includes each temperature detection element. The element 7h that has acquired the amount of infrared rays from the infrared LED 16 is identified by comparing the amount of infrared rays detected by 7a to 7h, and this is used as an index point.
Next, the control unit 14 controls the heating coil driving unit 13 to cause the heating coil 12 to inductively heat the article 2 to be heated, and the calculation unit 15 compares the detected infrared light amounts to obtain a maximum value. By acquiring a detection element (in the example of FIG. 12, the element 7e that detects the area e painted in black) and referring to the correspondence table with the identifier of this detection element, the detected area (point) that radiates the maximum infrared ray ) (Distance e in FIG. 12) to the sensing element is calculated. Next, since the position of the detection element 7e that has detected the maximum value and the position of the detection element 7h are the same position, from the "distance from the detection region (point) that radiates the maximum infrared ray to the detection element 7h" By subtracting the “distance from the index point to the detection element 7h”, the relative distance from the index point to the detected region (point) that emits the maximum infrared ray is calculated. This relative distance does not change even if the initial position of the infrared temperature detector is shifted. Therefore, even if the initial position of the infrared temperature detection unit is shifted every time, correction can be performed by software processing based on this index point.

FIG. 13 is a diagram illustrating the operation of the calculation unit 15 according to the third embodiment of the present invention. Next, the operation of the calculation unit 15 in the third embodiment will be described with reference to FIG.
The operations from step S901 to S910 are the same as those in FIG. Next, the calculation unit 15 calculates a relative distance between the distance read from the storage unit and the position (index value) of the infrared LED (step S131). Next, the computing unit 15 estimates a correction coefficient from the relative distance (step S132). Next, it operates similarly to steps S911 to S912 of FIG.
With the above operation, the same effects as in the embodiment can be obtained.

  According to the third embodiment, the relative distance does not always change by providing the infrared LED as the index point and calculating the relative distance between the detected area where the maximum value of the infrared is detected and the index point. Therefore, even if the initial position of the infrared temperature detection unit is shifted every time, the correction can be performed based on this index point. Therefore, it becomes possible to accurately detect the temperature of the object to be heated.

In the above example, the infrared LED is disposed on the outermost side. However, the present invention is not limited to this. For example, the infrared LED may be installed at the center of the heating coil 12.
Further, in the above example, the case where the radiation direction of the direct infrared LED is directed directly to the infrared temperature detection unit 7 has been described, but the radiation direction of the infrared LED is configured to be directed to the infrared temperature detection unit 7 via the reflector. Also good.
FIG. 14 is a side cross-sectional view and a perspective view of the infrared LED configured such that the radiation direction of the infrared LED is directed to the infrared temperature detection unit 7 via the reflector, and FIG. 14A shows the radiation direction of the infrared LED as the reflector. FIG. 14B is a perspective view of a configuration in which the radiation direction of the infrared LED is directed toward the infrared temperature detection unit 7 via the reflector. FIG.
14A, the same reference numerals as those in FIG. 10 denote the same or corresponding parts. 10 is the same as FIG. 10 except that a reflector 18 is added.
Here, an infrared LED is arranged in the detection area d. Thereby, as shown in FIG. 15, the detection element 7d detects the protruding amount of infrared rays.

Embodiment 4 FIG.
In the third embodiment, there is no method for notifying the user of the positioning operation by the infrared LED 16. Therefore, for example, an infrared LED may be blinked to indicate that the positioning operation is being performed.
This case will be described in the fourth embodiment.
FIG. 16 shows the operation of the calculation unit 15 in the fourth embodiment. Next, the operation of the calculation unit 15 in the fourth embodiment will be described with reference to FIG.
In the initial operation before the control unit 14 starts the heating control, the calculation unit 15 performs the following operation. The calculation unit 15 performs initial processing such as counter clear (S1601), and then turns on the infrared LED for a predetermined time (step S1602). Next, the calculation unit 15 acquires an output A of a specific detection element (that is, a detection element corresponding to the infrared LED) that detects the maximum amount of infrared rays among the eight detection elements of the detection elements 7a to 7h (that is, the detection element corresponding to the infrared LED). Step S1603). Next, the calculation unit 15 turns off the infrared LED for a predetermined time (step S1604). Next, the counter value is checked (step S1605). While the counter value does not reach the predetermined number of times, the counter is incremented by one (step S1606), and then the process returns to step S1602 to repeat the blinking again. If the value of the counter reaches the predetermined number in the determination in step S1605, the process is terminated after transmitting the end of the blinking operation to the control unit 14.
In addition, although the case where the calculation part 15 performed said process was demonstrated, you may perform the control part 14. FIG.

  As described above, even when there is a disturbance such as noise, the infrared LED 16 blinks, so that the user's attention can be drawn. In addition, if a rule is determined in advance that “the positioning is being detected” while the infrared LED 16 is blinking, the infrared LED 16 can be blinked so that the user can recognize the fact. Thereby, it is possible to prompt the user not to perform an operation such as moving the pan during the positioning operation.

Embodiment 5 FIG.
If the output of the infrared LED 16 cannot be obtained, such as when the life of the infrared LED 16 comes to an age due to aging, or when an obstacle is placed on the infrared LED 16, the position cannot be determined. In that case, information indicating that can be output to the display unit 5 or an audio output unit such as a speaker to notify the user.
This case will be described in the fifth embodiment.
FIG. 17 is a flowchart showing the operation of the calculation unit 15 in the fifth embodiment. Next, the operation of the calculation unit 15 will be described with reference to FIG.
At the initial stage of operation before the control unit 14 starts induction heating control, the calculation unit 15 performs initial processing such as counter clearing (S1601), and then turns on the infrared LED for a predetermined time (step S1602). Next, the calculation unit 15 acquires an output A of a specific detection element (that is, a detection element corresponding to the infrared LED) that detects the maximum amount of infrared rays among the eight detection elements of the detection elements 7a to 7h (that is, the detection element corresponding to the infrared LED). Step S1603). Next, the calculation unit 15 turns off the infrared LED for a predetermined time (step S1604). Next, the counter value is checked (step S1605). While the counter value does not reach the predetermined number of times, the counter is incremented by one (step S1606), and then the process returns to step S1602 to repeat the blinking again. When the value of the counter reaches the predetermined number in the determination in step S1605, the average value of the infrared amount A detected by the detection element is calculated (step S1701). That is, the infrared amount A is accumulated a predetermined number of times, and the accumulated value is divided by the predetermined number of times to calculate an average value. Next, the calculation unit 15 compares the average value of A with a preset lower limit value (step S1702), and if the average value of A is equal to or greater than the lower limit value, the calculation unit 15 determines that it is normal and blinks. Exit. If it is determined in step S1702 that the average value of A is smaller than the lower limit value, the calculation unit 15 determines that it is abnormal, and outputs information indicating the abnormality to the display unit 5. Further, it is output to an audio output device such as a speaker (step S1703).

As described above, the position cannot be determined when the output of the infrared LED 16 cannot be obtained, for example, when the life of the infrared LED 16 is reached due to deterioration over time or when an obstacle is placed on the infrared LED 16. Is output to the display unit 5 or an audio output unit such as a speaker to notify the user, so that the user can deal with it quickly.
Even when there is a disturbance such as noise, there is no problem because the disturbance is dispersed and becomes almost zero by integrating the amount of infrared rays over time (time average). On the other hand, since the amount of infrared rays from the infrared LED 16 remains as it is without being dispersed, only this amount of infrared rays can be taken out. Therefore, the output component of the infrared LED 16 can be analyzed.

Embodiment 6 FIG.
In the fifth embodiment, when the infrared LED 16 has reached the end of its life due to aging, or when an obstacle is placed on the infrared LED 16, the output of the infrared LED 16 cannot be sufficiently obtained even after cooking. The information indicating that the position cannot be determined is output to the display unit 5 or an audio output unit such as a speaker to notify the user, but in place of the infrared temperature detection unit, You may comprise so that the temperature of a to-be-heated material may be detected based on the output of contact-type temperature detection parts, such as the thermistor pressed down.
This case will be described in the sixth embodiment.
FIG. 18 is a schematic diagram showing a front cross section of a heating cooker according to Embodiment 6 of the present invention. 18, the same reference numerals as those in FIG. 2 denote the same or corresponding parts. It is the same as FIG. 2 except that the contact temperature detector 17 is added. Although there is a heating coil driving unit 13, it is not shown.

Next, the operation of the sixth embodiment will be described.
FIG. 19 is a flowchart showing the operation of the calculation unit 15 in the sixth embodiment. 19 is the same as FIG. 17 except that step S1801 is replaced with step S1801 in FIG. Next, the operation of the calculation unit 15 will be described with reference to FIG.
Steps S160 to S1605 and S1701 to S1702 are the same as those in FIG. If it is determined in step S1702 that the average value of the infrared rays A is smaller than the lower limit value, the calculation unit 15 determines that it is abnormal and switches to the contact-type temperature detection unit 17. The temperature is detected (step S1901).

  As described above, when the infrared temperature detection unit 7 is abnormal, the infrared temperature detection unit 7 is replaced with the infrared temperature detection unit 7 based on the output of the contact type temperature detection unit such as a thermistor that is pressed and installed under the top plate 3. Since the temperature of the object 2 is detected, a decrease in the temperature detection capability of the object to be heated 2 can be minimized.

Embodiment 7 FIG.
Although the case where a compound eye infrared temperature detection unit is used has been described in the above embodiment, the detection may be performed while shaking the monocular infrared temperature detection unit up and down. In the present embodiment, such a case will be described.
FIG. 20 is a side cross-sectional view showing a main configuration of a heating cooker having a monocular infrared temperature detection unit. 20, the same reference numerals as those in FIG. 12 denote the same or corresponding parts. The monocular infrared temperature detector 70 is replaced with a semi-cylindrical rack 701 having gears on the outer periphery as a drive mechanism for rotating and moving the monocular infrared temperature detector 70 in the vertical direction (swinging). FIG. 12 is the same as FIG. 12 except that a pinion 702 configured to mesh with the gear is added. By driving a motor (not shown) according to a command from the calculation unit 15, the pinion 702 rotates, and the rotation of the pinion 702 rotates the angle of the rack 701, thereby causing the monocular infrared temperature detection unit 70 to swing. Do. Therefore, by controlling the rotation of the motor by the control unit 14, the operation of rotating and stopping the monocular infrared temperature detection unit 70 by a predetermined angle is repeated.

FIG. 21 is a flowchart showing the operation of the calculation unit 15 according to the seventh embodiment of the present invention. Next, the operation of the calculation unit 15 in the seventh embodiment will be described with reference to FIGS.
When activated, the calculation unit 15 executes initial processing such as counter clearing and infrared ray clearing (step S901), and then moves the viewing angle of the monocular infrared temperature detection unit 70 by a predetermined angle to detect the first detected object. A region (for example, region a) is selected (step S2101), and an infrared ray amount (A) is acquired as an output from the infrared temperature detection unit 70 (step S903). Next, the computing unit 15 compares the acquired infrared ray amount A with the maximum infrared ray amount B (initially zero) stored in the storage unit (step S904), and the detected infrared ray amount A is more than B. If it is smaller, the process jumps to step S907, and if the detected infrared ray amount A is larger than B, the present infrared ray amount is written as B in the storage unit (step S905), and the infrared temperature detector 70 at this time The angle (or an angle number is acceptable) is also written in the storage unit (step S2102). Next, the calculation unit 15 checks whether or not all the areas have been detected (step S907). If the calculation has not been completed, the calculation unit 15 moves the viewing angle of the monocular infrared temperature detection unit 70 by a predetermined angle and continues. After selecting the detected area (for example, the area b) (step S2103), the process returns to step S903 and the same process is executed again. This operation is further repeated sequentially until the detected areas c, d, e,. Then, when the process for the detected area h is finished, the process proceeds to step S2104 because the result of step S907 is Yes. Here, the angle of the infrared temperature detection unit 70 that detects the maximum amount of infrared rays (the angle at which the boundary portion is detected) is read from a storage unit (not shown), and the correspondence table stored in the storage unit is referred to by this detection element. The distance and the correction coefficient are read (step S910). Next, the calculating part 15 corrects by multiplying the amount of infrared rays by a correction coefficient (step S911). Next, the calculation unit 15 converts the corrected infrared ray amount into temperature data (step S912).

  According to the seventh embodiment, even if a deviation occurs in the installation of the monocular infrared temperature detection unit 70, the initial position can be determined very easily by adjusting the angle of the monocular infrared temperature detection unit 70 by swinging. Therefore, unlike the compound-eye infrared temperature detection unit, it is not necessary to perform correction by a software algorithm, and the same effects as those of the first embodiment can be achieved with a very simple configuration.

  In addition, you may arrange | position infrared LED16 in the center of the heating coil 12. FIG. In this case, the same effect is obtained.

  DESCRIPTION OF SYMBOLS 1 Main body, 2 To-be-heated object, 3 Top plate, 4 Operation part, 5 Display part, 6 Heating port, 6a The center of a heating port, 7 Infrared temperature detection part, 7a-7h Detection element (element), 8 Intake port, 9 To-be-cooked object, 10 input section, 11 grill section, 12 heating section (heating coil), 13 drive section, 14 control section, 15 calculation section, 16 infrared LED, 17 contact-type temperature detection section, 18 reflector, 70 monocular Infrared temperature detector, 701 rack, 702 pinion.

Claims (13)

A top plate on which a heated object such as a pan is placed;
A heating coil provided below the top plate for induction heating the object to be heated;
A heating coil driving section for supplying and driving alternating power to the heating coil;
It is provided at the side and above the top plate, and is obtained by dividing the side surface of the object to be heated, the boundary between the bottom surface of the object to be heated and the top plate, and the continuous region reaching the top plate into a plurality of parts. An infrared temperature detection unit that has a plurality of detection elements provided corresponding to each of the divided areas, and directly detects the amount of infrared radiation above the top plate;
A calculation unit that converts the amount of infrared rays detected by the infrared temperature detection unit into a temperature;
A control unit for controlling the heating coil driving unit based on the temperature output by the calculation unit;
A storage unit for storing a correspondence table in which each detection element is associated with a distance to a divided region detected by the detection element and a correction coefficient ;
Before SL calculating unit identifies a material obtained by detecting the boundary based on the amount of infrared rays compares detected by the plurality of sensing elements, the amount of infrared is specified sensing element detects from the object to be heated corrected by preset the correction coefficient, which estimates the temperature of the object to be heated based on the corrected amount of infrared rays,
The correction factor is
Calculated as a relative ratio between the amount of infrared light output by the detection element when the boundary portion is included in the divided area detected by each detection element and the amount of infrared light that is a preset reference value, The heating cooker, which is a value set for each of the detection elements in accordance with the distance to the divided region detected by . Wherein the storage unit is a second correction coefficient values in the case located outside the case located inside different front Kisakai boundary part said heating coil is stored,
In addition to correcting the amount of infrared rays using the correction coefficient, the calculation unit,
Based on the distance from the detection element that has detected the boundary portion to the divided region detected by the detection element, it is determined whether or not the boundary portion is located inside the heating coil, and based on the determination result The cooking device according to claim 1, wherein the infrared ray amount detected by the detection element is corrected using any one of the selected second correction coefficients . The arithmetic unit, according to claim 1 or claim 2, characterized in that by applying a predetermined arithmetic expression on the amount of infrared radiation obtained by correcting the output of the specified sensing element for calculating the temperature of the object to be heated heating cooking device according to. An infrared LED emitting infrared for at least one position detection region of the plurality of the sensing element of the infrared temperature detector,
In the initial stage of heating, the infrared LED emits infrared rays,
The calculation unit is a detection element that detects infrared rays from the infrared LEDs among the plurality of detection elements based on the amount of infrared rays detected by the plurality of detection elements when the infrared LEDs emit infrared rays. The cooking device according to any one of claims 1 to 3 , wherein the cooking device is determined to be normal if the identified sensing element is confirmed to be a predetermined sensing element. . 5. The cooking device according to claim 4 , wherein the calculation unit identifies the infrared ray detected in the plurality of detection elements having a maximum amount. A contact-type temperature detection unit that is provided under the top plate and detects the temperature of the object to be heated;
And a infrared LED for emitting infrared rays for at least one position detection region of the plurality of the sensing element of the infrared temperature detector,
In the initial stage of heating, when the infrared LED emits infrared rays and the amount of infrared rays detected by the detection element that should detect infrared rays emitted from the infrared LEDs is lower than a predetermined value,
The said control part controls the said heating coil drive part based on the output of the said contact-type temperature detection part instead of the temperature which the said calculating part output , The any one of Claims 1-3 characterized by the above-mentioned. heating cooker according to an item or. A notification unit;
And a infrared LED for emitting infrared rays for at least one position detection region of the plurality of the sensing element of the infrared temperature detector,
In the initial stage of heating, when the infrared LED emits infrared rays and the amount of infrared rays detected by the detection element that should detect infrared rays emitted from the infrared LEDs is lower than a predetermined value,
The notification unit, any of claims 1 to 3, characterized in that said infrared LED is broken, or obstacle alarm output information indicating that that have been placed on the IR LED heating cooker according to an item or. The cooking device according to claim 7 , wherein the notification unit is an audio output unit. The cooking device according to claim 7 , wherein the notification unit is a display unit. The cooking device according to any one of claims 4 to 9 , wherein an infrared radiation direction of the infrared LED is directed to any detection region of the plurality of detection elements . . In any one of claims 4 to claim 9, wherein the kite comprising a reflector to direct to one of the detection region of the plurality of sensing elements by reflecting infrared radiation emitted from the infrared LED The cooking device described. The infrared LED cooking device according to any one of Claims 4 to 11, characterized in that it is provided in the center of the heating coil. The cooking device according to any one of claims 4 to 12 , wherein the control unit causes the infrared LED to blink at a predetermined cycle in the initial stage of heating.

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