JP4989265B2 - Temperature detection device for cooking device - Google Patents

Description

  The present invention is detected by a heating means for heating a cooking container, an infrared intensity detection means for detecting the infrared intensity for each of a plurality of wavelength ranges in the infrared rays emitted from the cooking container, and the infrared intensity detection means. The present invention relates to a temperature detection device for a heating cooker comprising temperature detection means for detecting the temperature of the cooking container based on infrared intensity for each of the plurality of wavelength ranges.

In the above-described temperature detection device for a heating cooker, conventionally, there has been one configured as follows as applied to a stove provided with heating means such as a gas burner or an electromagnetic heater as a heating cooker.
That is, the infrared intensity detection means has two different wavelength ranges in the infrared wavelength region, specifically, a wavelength range in the range of 3.5 μm to 4.0 μm, and a range of 8 μm to 10 μm. The temperature detecting means obtains a ratio of the infrared intensities in the two wavelength ranges, and the ratio of the infrared intensities and the stored infrared intensities in advance. The temperature of the cooking container is detected from the relationship between the ratio and the temperature, and the temperature of the cooking container is controlled based on the detected temperature of the cooking container, or the cooking container is excessively heated. In order to avoid an increase in the temperature, there has been a method that can perform a process such as an emergency stop of the heating operation of the heating means (see, for example, Patent Document 1).

  When the explanation is added, the change characteristic between the ratio of the infrared intensity in the two different wavelength ranges as described above and the temperature of the cooking container emitting infrared rays is within a temperature range from room temperature to about 300 ° C. The temperature of the cooking container is detected using such a relationship between the temperature and the infrared intensity on the premise that the characteristics are substantially the same regardless of the difference in the material of the cooking container.

JP 2002-340339 A

  However, as a result of intensive studies by the present applicant, many of the materials used as cooking containers have the characteristics described above, but some of the materials are preliminarily used as described above. When measuring the temperature of the cooking container using the data indicating the ratio between the infrared intensity ratio and the temperature stored, it is found through experiments that the measurement result is significantly different from the actual temperature. It came to.

The experimental results by the applicant will be described. FIG. 2 shows the change in emissivity with respect to the change in wavelength for various materials in the infrared wavelength region of the object whose object surface temperature measured by the applicant is 200 ° C. The radiation characteristic showing is shown. And it became clear from this measurement result that it explained below.
That is, the emissivity changes regardless of the change in wavelength in black bodies, cooking containers with a black coating on the metal surface, cooking containers with a silver coating on the metal surface, and cooking containers using a stainless steel plate. In a cooking container in which a silicon-based organic heat-resistant paint is applied to the surface of a metal or a cooking container in which the surface of an aluminum plate is anodized, if the wavelength changes, the emissivity increases. In other words, there is no or little change in emissivity in the longer wavelength region, whereas in the shorter wavelength region, the change in emissivity with respect to the change in wavelength becomes a state that changes greatly. The radiation characteristics have an emissivity leveling range in which the change in emissivity with respect to a change in wavelength is small and an emissivity fluctuation range in which the change in emissivity with a change in wavelength is large. It was.

  As described above, the change characteristics of the ratio of the infrared intensity in the two wavelength ranges and the temperature of the cooking container that emits infrared light are substantially the same regardless of the material of the cooking container. In the temperature detection configuration according to the above-described conventional configuration that detects the temperature on the premise of emissivity, the emissivity leveling range in which the change in emissivity with respect to the change in wavelength is small and the emissivity fluctuation range in which the change in emissivity with respect to the change in wavelength is large If the measurement target is an emissivity variation type cooking container having a radiation characteristic, the detected temperature is greatly deviated from the actual temperature of the cooking container, and the temperature of the cooking container There is a possibility that it cannot be detected, and there is a disadvantage that control based on the temperature of the cooking container cannot be performed satisfactorily.

  An object of the present invention is for a heating cooker that can detect the temperature of a cooking container with as little error as possible even when an emissivity-variable cooking container is used as the cooking container. The object is to provide a temperature detection device.

A temperature detecting device for a heating cooker according to the present invention includes a heating means for heating a cooking container, and an infrared intensity detecting means for detecting infrared intensity for each of a plurality of wavelength ranges in infrared rays emitted from the cooking container. And a temperature detecting means for detecting the temperature of the cooking container based on the infrared intensity for each of the plurality of wavelength ranges detected by the infrared intensity detecting means. Is
The infrared intensity detecting means is
As the infrared intensity for the plurality of wavelength ranges,
The radiation corresponding to an emissivity variation type cooking container having an emissivity characteristic having an emissivity leveling range with a small change in emissivity with respect to a change in wavelength and an emissivity variation range with a large change in emissivity with respect to a change in wavelength. Infrared intensity for the first temperature measurement wavelength range set in the rate variation range, Infrared intensity for the first temperature measurement wavelength range set in the emissivity level range, and a wavelength that is different from the emissivity level range It is configured to detect each of the infrared intensity for the two types of wavelength ranges for measuring the second temperature set as the area and the infrared intensity for the wavelength range for temperature determination set in the emissivity average range. ,
The temperature detecting means is
A first predicted temperature is obtained based on a ratio of a pair of infrared intensities detected for each of the two types of wavelength regions for the first temperature measurement, and each of the two types of wavelength regions for the second temperature measurement is used. The second predicted temperature is obtained based on the ratio of the pair of infrared intensities detected for the first predicted temperature and when the difference between the first predicted temperature and the second predicted temperature is within an allowable range, the first predicted temperature and When the temperature of the cooking container is determined based on the second predicted temperature, and the difference between the first predicted temperature and the second predicted temperature is outside the allowable range, the wavelength region for temperature determination It is in the point comprised so that the temperature of the said container for cooking may be determined based on the infrared intensity detected about.

  According to the first characteristic configuration, the infrared intensity detection means has an emissivity level range in which the change in emissivity with respect to the change in wavelength is small and an emissivity fluctuation range in which the change in emissivity with respect to the change in wavelength is large. Corresponding to the emissivity variation type cooking container, the infrared intensity for the first temperature measurement wavelength range set in the emissivity variation range, the first temperature measurement wavelength set in the emissivity average range Infrared intensity for the region, infrared intensity for the two wavelength ranges for the second temperature measurement set as different wavelength ranges in the emissivity average range, and for temperature determination set in the emissivity average range Each of the infrared intensities in the wavelength range is detected.

  In addition, as shown in FIG. 2, in a cooking container in which a silicon-based organic heat-resistant paint is applied to the surface of a metal or a cooking container in which the surface of an aluminum plate is anodized, However, there is no or little change in the emissivity in the longer wavelength region, whereas in the shorter wavelength region, the radiation characteristic is such that the change in emissivity with respect to the change in wavelength is greatly changed. However, if the emissivity variation type cooking container is used, the longer wavelength region corresponds to an emissivity average range in which the change in emissivity with respect to the change in wavelength is small, and The kame wavelength range corresponds to an emissivity fluctuation range in which the change in emissivity with respect to the change in wavelength is large, and the wavelength range for the first temperature measurement is set in the emissivity fluctuation range in correspondence with each wavelength range. Then, a wavelength range for the first temperature measurement is set in the emissivity average range, and two types of wavelength ranges for the second temperature measurement are set as different wavelength ranges in the emissivity average range. Infrared intensity is detected in each region.

  Then, the ratio of the pair of infrared intensities detected for each of the two types of wavelength ranges for the first temperature measurement separately set in the emissivity fluctuation range and the emissivity flattening range and the temperature of the cooking container A change characteristic, a ratio of a pair of infrared intensities detected for each of the two wavelength ranges for the second temperature measurement set as different wavelength ranges in the emissivity level range, and a temperature of the cooking container The change characteristics are different from each other.

  Incidentally, FIG. 7 shows the measurement results of the applicant of the change characteristics between the ratio of the pair of infrared intensity detected for each of the two types of wavelength ranges for the first temperature measurement and the temperature of the cooking container. FIG. 8 shows the measurement results of the applicant of the change characteristics between the ratio of the pair of infrared intensities detected for each of the two types of wavelength ranges for the second temperature measurement and the temperature of the cooking container.

  On the other hand, as the cooking container, in addition to the emissivity variation type cooking container, there is also an emissivity flat type cooking container having a radiation characteristic with no or little change in the emissivity with respect to the change in wavelength, In this emissivity flat type cooking container, there is no change in emissivity or little change in each of the emissivity fluctuation range and the emissivity flat range, and therefore, the two types of first temperature measurement containers are used. A ratio of a pair of infrared intensities detected for each wavelength region and a pair of infrared rays detected for each of the two types of wavelength regions for the second temperature measurement set as different wavelength regions in the emissivity average range The intensity ratio will be the same or substantially the same characteristics with respect to changes in the temperature of the cooking container.

  Therefore, for example, the change characteristic between the ratio of the infrared intensity in different wavelength ranges and the temperature is set based on the characteristics of either the emissivity fluctuation type cooking container or the emissivity flat type cooking container. The first predicted temperature is determined based on the ratio of the pair of infrared intensities detected for each of the two types of wavelength regions for the first temperature measurement using the infrared intensity ratio and the change characteristic of the temperature, A second predicted temperature is obtained based on a ratio of a pair of infrared intensities detected for each of the two types of wavelength ranges for the second temperature measurement, and the first predicted temperature and the second predicted temperature are obtained. By comparison, it is possible to determine whether it is an emissivity variation type cooking container or an emissivity flat type cooking container.

  That is, when the first predicted temperature and the second predicted temperature are within a preset allowable range, the cooking container is an emissivity-uniform cooking container, and when it exceeds the allowable range, radiation is performed. It turns out that it is a rate-variable cooking container. And, if the cooking container is the emissivity flat type cooking container, radiation characteristics such as a change in infrared intensity for each wavelength with respect to a change in the temperature of the cooking container can be measured in advance. The temperature of the cooking container can be determined from the first predicted temperature and the second predicted temperature.

On the other hand, when the first predicted temperature and the second predicted temperature exceed the allowable range, the cooking container is an emissivity fluctuation type cooking container, but in this case, the temperature determination wavelength region The temperature of the cooking container is determined on the basis of the infrared intensity detected.
In addition, as shown in FIG. 2, the applicant has shown that, in an emissivity-variable cooking container such as a cooking container in which a silicon-based organic heat-resistant paint is applied to a metal surface, as shown in FIG. In the rate flat range, it was found that the emissivity is a high value of about 0.9, and the value is substantially the same even if the wavelength is changed. Thus, when the emissivity is substantially constant and high value, as a result of measuring the actual temperature and infrared intensity of the cooking container in the wavelength region for temperature determination, their correlation is substantially constant, Store those correlations, measure the infrared intensity in the same wavelength range for another cooking container, and obtain the temperature from the stored infrared correlation and the correlation, for example, within the allowable temperature It turned out to be a small error.
Therefore, for example, the temperature of the cooking container can be determined from the infrared intensity in the wavelength region for temperature determination by using the correlation as described above.

  Therefore, a temperature detection device for a heating cooker that can detect the temperature of a cooking container with as little error as possible even when an emissivity variable cooking container is used as the cooking container. I was able to provide it.

In the second feature configuration of the present invention, in addition to the first feature configuration, the wavelength range for the first temperature measurement set in the emissivity variation range is a radiation with no or little change in emissivity with respect to a change in wavelength. For the emissivity flat type cooking container of the characteristic, the change with respect to the temperature change of the radiated infrared intensity corresponds to a wavelength range larger than the wavelength range for the two types of the second temperature measurement,
The temperature detecting means is
When the difference between the first predicted temperature and the second predicted temperature is within the allowable range, the first predicted temperature is determined as the temperature of the cooking container.

  According to the second feature configuration, when the difference between the first predicted temperature and the second predicted temperature is within an allowable range, there is no change in emissivity in each of a plurality of wavelength ranges as a cooking container. Or since it is assumed that it is an emissivity flat type cooking container with little change, in that case, the first predicted temperature is determined as the temperature of the cooking container.

  And in the wavelength range for the first temperature measurement set in the emissivity fluctuation range, the change of the infrared intensity radiated by the emissivity flat type cooking container with respect to the temperature change is the two types of the second temperature measurement. The ratio of the pair of infrared intensities for determining the first predicted temperature is larger than the ratio of the pair of infrared intensities for determining the second predicted temperature. The rate of change with respect to changes in temperature increases. That is, as the temperature of the cooking container, the first predicted temperature can be used as a more appropriate temperature than the second predicted temperature. Therefore, when the difference between the first predicted temperature and the second predicted temperature is within an allowable range, the first predicted temperature is determined as the temperature of the cooking container.

  Therefore, it becomes possible to detect the temperature of the cooking container as accurately as possible for the emissivity-flat cooking container.

  According to a third feature configuration of the present invention, in addition to the first feature configuration or the second feature configuration, the infrared intensity detection means has a wavelength range for the first temperature measurement set in the emissivity fluctuation range as 3 A wavelength range selected from a range of not less than 1 μm and not more than 4.2 μm is set, and the two wavelength ranges for the second temperature measurement set in the emissivity level range and the temperature determination As a wavelength range, a wavelength range selected from a range of 8.0 μm or more and 20.0 μm or less is set, and the infrared intensity of each of the plurality of wavelength ranges is detected.

  According to the third characteristic configuration, the wavelength range for the first temperature measurement is selected from a range of 3.1 μm or more and 4.2 μm or less, and the two types of the second temperature measurement wavelength range and the temperature are selected. The wavelength range for determination is selected and set from the range of 8.0 μm or more and 20.0 μm or less.

That is, if the cooking container is a heating cooker that is heated by, for example, a flame formed of a burner, when the infrared intensity of infrared rays emitted from the cooking container is detected via the flame by the infrared intensity detection means, the flame CO ₂ and H ₂ O exist in a gas state. And since the actual flame in the stove emits high-intensity infrared rays due to the emission of CO ₂ and H ₂ O, the emission is caused by noise generation in the infrared intensity detection means of infrared rays emitted from the cooking container. Cause. CO ₂ and H ₂ O emit infrared rays in the range of 2.4 μm to 3.1 μm and in the range of 4.2 μm to 8.0 μm, so if they are out of these ranges In this case, it is possible to detect the temperature as accurately as possible because the influence of noise accompanying the infrared emission of the flame can be removed.

  According to a fourth feature configuration of the present invention, in addition to any one of the first feature configuration to the third feature configuration, the infrared intensity detection unit is configured to perform the temperature determination wavelength range set in the emissivity level range. The infrared intensity is configured to detect the infrared intensity in any one of the two wavelength ranges for the second temperature measurement.

  According to the fourth feature configuration, the infrared intensity detecting means is configured to detect either one of the two wavelength ranges for the second temperature measurement as the infrared intensity for the temperature determination wavelength range. Compared to those that are set separately for different wavelength ranges, such as a light receiving means for receiving infrared rays and an optical filter for passing infrared rays of a specific wavelength range, etc. The number can be reduced and a simple configuration can be achieved.

DESCRIPTION OF EMBODIMENTS Hereinafter, an embodiment in which a temperature detection device for a heating cooker according to the present invention is applied to a stove as a heating cooker will be described with reference to the drawings.
As shown in FIG. 1, the stove as a heating cooker is used for cooking a flat top plate 1 having a circular heating opening 1a, a cooking pot such as a cooking pot for cooking an object to be heated above the opening 1a. Gotoku 2 on which container N can be placed, gas combustion burner 30 as a heating means for heating cooking container N placed on Gotoku 2, combustion control unit 3 for controlling the operation of burner 30, and the like It is configured with.

  The burner 30 is a Bunsen combustion type internal flame type burner. The gas nozzle 31 ejects the fuel gas G supplied through the fuel supply passage 5, the fuel gas G is ejected from the gas nozzle 31, and the fuel gas G An annular gas pipe is provided with a mixture tube 32 to which combustion air is supplied by the suction action associated with the jetting of the gas and a plurality of flame ports 33 for jetting the gas mixture to the inner periphery, and the gas mixture is supplied from the mixture tube 32. The burner body 34 is provided, and the burner 30 is provided below the opening 1a.

  In the burner 30, the mixture of the fuel gas G and air supplied from the mixing pipe 32 into the burner body 34 is ejected in a substantially horizontal direction from the flame port 33 toward the center of the burner body 34, and is ejected. The mixture of the fuel gas G and air burns, and a flame F is formed upward through the opening 1a.

  The fuel supply path 5 is provided with a fuel supply intermittent valve 6 for intermittently supplying the fuel gas G to the gas nozzle 31 and a fuel supply amount adjusting valve 7 for adjusting the supply amount of the fuel gas G to the gas nozzle 31. In the lower part of the burner body 34 of the burner 30, there is provided a juice receiving tray 8 for receiving boiled food that has fallen through the opening 1 a.

  Further, the stove has an infrared intensity detecting unit 40 as an infrared intensity detecting means that is located below the top plate and is located in the center of the soup pan 8 and detects the intensity of infrared rays emitted from the cooking container. And a temperature detecting unit 50 as temperature detecting means for detecting the temperature of the cooking container based on the intensity of infrared rays detected by the infrared intensity detecting unit 40 is provided.

  And the said infrared intensity detection part 40 is comprised so that the infrared intensity about each of the several different wavelength range in the infrared rays radiated | emitted from the cooking container may be detected, and the said temperature detection part 50 is the infrared intensity detection part 40. The temperature of the cooking container is detected based on the relationship of the infrared intensity for each of the plurality of wavelength ranges detected in this manner. Furthermore, the infrared intensity detection part 40 is comprised so that the infrared intensity of the wavelength range set out of the range with the strong radiation intensity from the flame of the burner 30 among the infrared wavelength ranges may be detected.

  As a cooking container heated by the burner 30, an emissivity variation type radiation characteristic having an emissivity leveling range in which the change in emissivity is small with respect to a change in wavelength and an emissivity variation range in which the change in emissivity is large with respect to a change in wavelength And a uniform emissivity-type cooking container with little or no change in the emissivity with respect to the change in wavelength, but the infrared intensity detector 40 has the plurality of wavelength ranges. Infrared intensity of the emissivity fluctuation type cooking container with emissivity characteristics having an emissivity leveling range where the emissivity change is small with respect to the wavelength change and an emissivity fluctuation range where the emissivity change is large with respect to the wavelength change Correspondingly, the infrared intensity for the wavelength range K1 for the first temperature measurement set in the emissivity fluctuation range, and the wavelength range K1 for the first temperature measurement set in the emissivity leveling range. Infrared light intensity, infrared intensity for two types of wavelength ranges K2 for second temperature measurement set as different wavelength ranges in the emissivity average range, and temperature determination set in the emissivity average range Each of the infrared intensities for the wavelength band K3 is detected.

  The temperature detection unit 50 obtains a first predicted temperature based on a ratio of a pair of infrared intensities detected for each of the two types of wavelength regions K1 for the first temperature measurement, and the two types of the temperature A second predicted temperature is obtained based on a ratio of a pair of infrared intensities detected for each of the wavelength ranges K2 for measuring the second temperature, and a difference between the first predicted temperature and the second predicted temperature is within an allowable range. The temperature of the cooking container is determined based on the first predicted temperature and the second predicted temperature, and a difference between the first predicted temperature and the second predicted temperature is out of the allowable range. The temperature of the cooking container is determined based on the infrared intensity detected for the temperature determination wavelength region K3.

  Hereinafter, various measurement data performed by the present applicant using a plurality of types of cooking containers in order to set a plurality of wavelength ranges to be measured by the infrared intensity detector 40 will be specifically described. To do. Here, as a plurality of types of cooking containers, a cooking container with a black coating on a metal surface, a cooking container with a silver coating on a metal surface, a cooking container using a stainless steel plate, a silicon-based coating on a metal surface The result measured using each of the cooking container which apply | coated the organic heat-resistant coating material, and the cooking container which carried out the anodizing of the surface of the aluminum plate is shown.

  FIG. 2 shows radiation characteristics of various materials in the infrared wavelength region of an object having an object surface temperature of 200 ° C. measured by the present applicant. To explain this, the emissivity of a black body is constant at 1.0 regardless of the change in wavelength. Also, a cooking container with a black coating on a metal surface and a cooking container with a silver coating on a metal surface. In a container, a cooking container using a stainless steel plate, and the like, the emissivity is substantially constant at about 0.9, about 0.4, and about 0.2 regardless of the change in wavelength.

  However, in a cooking container in which a silicon-based organic heat-resistant paint is applied to the surface of a metal or a cooking container in which the surface of an aluminum plate is anodized, if the wavelength changes, the emissivity is about 0.9 in the longer wavelength region. Although it is substantially constant, the emissivity is small in the shorter wavelength region, and it has been found from the experimental results that the emissivity changes greatly with respect to the change in wavelength. In other words, a cooking container in which a silicon-based organic heat-resistant paint is applied to the surface of a metal or a cooking container in which the surface of an aluminum plate is anodized corresponds to an emissivity variation type cooking container, and the longer wavelength region is A change in emissivity with respect to a change in wavelength corresponds to an emissivity average range, and the shorter wavelength region corresponds to an emissivity fluctuation range in which an emissivity change with respect to a change in wavelength is large.

  3 to 5 show spectral data of infrared radiation intensity for cooking containers (pots) made of various materials. That is, FIG. 3 shows a cooking container black-coated on the metal surface, FIG. 4 shows a cooking container silver-coated on the metal surface, and FIG. 5 shows a cooking container in which the surface of the aluminum plate is anodized. The spectral spectrum data of the infrared radiation intensity when the temperature is changed when heated in a range from room temperature (25 ° C.) to about 300 ° C. is shown. As is apparent from these figures, infrared rays are radiated in the wavelength range of 1.5 μm or more and several tens of μm or less at the temperature of the cooking container during cooking, for example, from room temperature to about 300 ° C. For example, it has sufficient radiation intensity that can be detected by various infrared sensors within a range of 3.5 μm or more and 15 μm or less.

  In addition, FIG. 6 shows spectral spectrum data of the infrared radiation intensity emitted from the flame formed by the gas combustion type burner 30, and as is clear from this figure, out of the infrared wavelength range, In the range of 2.4 μm or more and 3.1 μm or less, and in the range of 4.2 μm or more and 8.0 μm or less, radiation from the flame is strong. Therefore, it is desirable to set the detection target wavelength range in which the infrared intensity is detected by the infrared intensity detector 40 outside the wavelength range where the radiation from such a flame is strong.

  In consideration of the effect of the infrared radiation region from the cooking container and the flame as described above, cooking is performed with as little error as possible even when using a variable emissivity cooking container. The wavelength range by the infrared intensity detection unit 40 is set so that the temperature of the container can be detected.

  That is, as a wavelength region for infrared detection by the infrared intensity detector 40, a region of 3.5 μm or more and 4 μm or less is set as the first wavelength region α1, and a region of 8 μm or more and 11 μm or less is set as the second wavelength region α2. In addition, the region of 13 μm or more and 15 μm or less is set as the third wavelength region α3, and the infrared intensity in each of these three wavelength regions is detected. In addition, as can be seen from FIG. 3 and FIG. 4, the first wavelength region α1 has an emissivity flat type cooking container. It is determined so as to correspond to a wavelength region larger than the three wavelength regions α3. In other words, in the first wavelength range α1, the resolution with respect to the change in infrared intensity with respect to the change in temperature is larger than the resolution in the second wavelength range α2 and the third wavelength range α.

  The first wavelength region α1 corresponds to the first temperature measurement wavelength region K1 set in the emissivity variation range in the emissivity variation type cooking container, and the second wavelength region α2 is the emissivity uniformity. This corresponds to the first temperature measurement wavelength region K1 set in the range. And 2nd wavelength range (alpha) 2 and 3rd wavelength range (alpha) 3 respond | correspond to the wavelength range K2 for 2 types of 2nd temperature measurement set as a wavelength range different in the said emissivity average range. Therefore, in this embodiment, the second wavelength range α2 is configured to serve as both the first temperature measurement wavelength range K1 and the second temperature measurement wavelength range K2. Furthermore, in this embodiment, the second wavelength region α2 is configured to also serve as the temperature determination wavelength region K3.

  FIG. 7 shows the ratio of the infrared intensity (A) in the first wavelength range α1 and the infrared intensity (B) in the second wavelength range α2 detected by the infrared intensity detection unit 40, that is, the first infrared intensity ratio (B / A). FIG. 8 shows the relationship between the infrared intensity (B) in the second wavelength range α2 and the infrared intensity (in the third wavelength range α3) detected by the infrared intensity detection unit 40. The relationship between the ratio of C), that is, the temperature of the cooking container with respect to the second infrared intensity ratio (C / B) is shown.

  As shown in FIG. 7, in relation to the temperature of the cooking container with respect to the first infrared intensity ratio (B / A), the surface of the cooking container or aluminum plate in which the organosilicon coating is applied to the metal surface is anodized. The treated cooking container shows characteristics that are significantly different from those of a cooking container with a black coating on a metal surface and a cooking container with a silver coating on a metal surface, and the first infrared intensity ratio (B / A) is Even if they are the same, the corresponding temperatures are greatly different.

  On the other hand, the cooking container with black coating on the metal surface and the cooking container with silver coating on the metal surface both depend on the temperature in a temperature range from room temperature (25 ° C.) to about 300 ° C. in the same state. They are changing and both have almost the same characteristics. That is, if the first infrared intensity ratio (B / A) is the same, the temperature of the cooking container with respect to the first infrared intensity ratio (B / A) is substantially the same.

  Therefore, for a cooking container with a black coating on the metal surface and a cooking container with a silver coating on the metal surface, typical changes in the characteristics of the first infrared intensity ratio (B / A) and the temperature of the cooking container. Is stored in advance, and the ratio of the infrared intensity in the first wavelength range α1 and the infrared intensity in the second wavelength range α2 detected by the infrared intensity detection unit 40, that is, the first infrared intensity for the cooking container to be heated The ratio (B / A) is obtained, and the temperature of the cooking container can be detected from the actually measured first infrared intensity ratio (B / A) and the change characteristic stored in advance.

  As shown in FIG. 8, the relationship between the temperature of the cooking container and the second infrared intensity ratio (C / B) shows that the silicon-based organic heat resistant metal surface has a temperature range from room temperature (25 ° C.) to about 300 ° C. A cooking container with paint or an anodized aluminum container surface has almost the same characteristics as a cooking container with a black coating on a metal surface or a cooking container with a silver coating on a metal surface. If the second infrared intensity ratio (C / B) is the same, the temperature of the cooking container relative to the second infrared intensity ratio is substantially the same.

  However, according to the experimental results shown in FIG. 8, for example, in a temperature range of 200 ° C. or lower, not only the change rate of the infrared intensity ratio, which is the vertical axis, but also the temperature change, which is the horizontal axis, is not only small. It can be seen that the variation due to the different materials is slightly larger. Therefore, when the temperature of the cooking container is measured based on the relationship of the temperature of the cooking container with respect to the second infrared intensity ratio (C / B), the variation due to the difference in the material of the cooking container is a cause. The result accuracy may be reduced.

  Therefore, as shown in FIG. 2, for a cooking container in which a silicon-based organic heat-resistant paint is applied to the surface of a metal or a cooking container in which the surface of an aluminum plate is anodized, that is, an emissivity variation type cooking container, In the wavelength range of 8.0 μm or more, it can be seen that the emissivity is about 0.9 for any of these, but as a result of further investigation by the applicant, the emissivity is 0.80 to 0.98. I found it to be in range.

  Therefore, the present applicant uses a cooking container of 0.89 which is an average value when the emissivity is changed from 0.80 to 0.98 or a cooking container close to the second wavelength when the temperature is changed. The change characteristic of the infrared intensity in the region α2 is measured and stored in advance, and the stored change characteristic and the second measured by the infrared intensity detection unit 40 for the cooking container having a different material as the temperature measurement object. When an experiment was performed to measure the temperature of the cooking container from the actually measured value of the infrared intensity in the wavelength region α2, the actual emissivity of the object to be measured changed from 0.80 to 0.98. When the temperature was 200 ° C., it was experimentally confirmed that the measurement result was within a range of ± 15 ° C. In this way, by using the infrared intensity in the second wavelength region α2, the temperature can be measured as accurately as possible even in an emissivity variation type cooking container.

  Therefore, the temperature detection unit 50 has a change characteristic between the first infrared intensity ratio (B / A) and the temperature of the cooking container as described above, and the second infrared intensity ratio (C / B) and the temperature of the cooking container. And a change characteristic of the infrared intensity in the second wavelength region α2 with respect to a change in the temperature of the cooking container measured using a cooking container having an emissivity of 0.89 or close thereto are illustrated in advance. The temperature of the cooking container is determined from the detection results actually detected by the infrared intensity detection unit 40 and the stored change characteristics of the cooking container heated in the burner 30 and stored in the memory. Is configured to detect.

In other words, the temperature detector 50 includes a first infrared intensity ratio (B) that is a ratio of the infrared intensity in the first wavelength region α1 and the infrared intensity in the second wavelength region α2 detected by the infrared intensity detector 40. / A) measured value and the stored first infrared intensity ratio (B / A)
The first predicted temperature T1 of the cooking container is obtained from the change characteristic of the temperature and the temperature, and further, the infrared intensity in the second wavelength range α2 and the infrared intensity in the third wavelength range α3 detected by the infrared intensity detection unit 40 A second predicted temperature T2 of the cooking container is obtained from the actual measurement value of the ratio and the stored change characteristic of the second infrared intensity ratio (C / B) and the temperature, and the first predicted temperature T1 and the first 2 When the difference between the predicted temperature T2 is within an allowable range, the first predicted temperature T1 is set as the temperature of the cooking container, and the difference between the first predicted temperature T1 and the second predicted temperature T2 is When the allowable range is exceeded, the second wavelength band α2 is set as the temperature determination wavelength band K3, and the temperature of the cooking container is determined based on the infrared intensity in the second wavelength band α2. Has been.

Next, the configuration of the infrared intensity detection unit 40 will be specifically described.
As shown in FIG. 1, the infrared intensity detection unit 40 is disposed in a state of being inserted from below into an opening formed in the central part of the soup pan 8. It is configured to detect the infrared intensity of the infrared rays radiated and introduced from the bottom of the placed cooking container N. As shown in FIG. 1, the infrared intensity detector 40 includes three bandpass filters 41a, 41b, and 41c having different wavelength ranges of infrared rays to pass through, and the three bandpass filters 41a, 41b, and 41c. Three infrared detecting elements 42a, 42b, 42c for detecting the infrared rays that have passed through each of the three different wavelength ranges in the infrared rays emitted from the cooking container N, that is, the first wavelength. The infrared intensity is detected for each of the area α1, the second wavelength area α2, and the third wavelength area α3. Incidentally, the band pass filters 41a, 41b and 41c are configured to selectively transmit only infrared rays in the corresponding wavelength region.

  As the three infrared detecting elements 42a, 42b and 42c for detecting the infrared intensity in the wavelength range as described above, Ge or InGaAs is used as an infrared cell, PbS or PbSe is used as an infrared cell, Various things, such as what used HgCdTe as an infrared cell, can be utilized. In addition to the above materials, a power raising element, a thermopile, or the like can be used.

Next, a process for obtaining the temperature of the cooking container N by the temperature detection unit 50 will be described.
The temperature detector 50 includes a change characteristic between the first infrared intensity ratio (B / A) and the temperature of the cooking container as described above, and the second infrared intensity ratio (C / B) and the temperature of the cooking container. The change characteristic and the change characteristic of the infrared intensity in the second wavelength region α2 with respect to the change in the temperature of the cooking container measured using a cooking container whose emissivity is 0.89 or close to it are stored in the memory in advance. Yes. Incidentally, these change characteristics can be stored in various forms, for example, by obtaining an approximate expression for each correlation, or by storing it as map data.

  The temperature detection unit 50 obtains the infrared intensity corresponding to the first wavelength range α1 detected by the infrared intensity detection unit 40 and the first infrared intensity (B / A) corresponding to the second wavelength range α2. The first predicted temperature T1 is obtained from the actually measured first infrared intensity ratio (B / A) and the change characteristics of the first infrared intensity ratio (B / A) stored in advance and the temperature of the cooking container. Further, a ratio between the infrared intensity corresponding to the second wavelength range α2 detected by the infrared intensity detection unit 40 and the infrared intensity corresponding to the third wavelength range α3, that is, the second infrared intensity ratio (C / B) is obtained. A second predicted temperature T2 is obtained from the actually measured second infrared intensity ratio (C / B), and the change characteristics between the previously stored second infrared intensity ratio (C / B) and the temperature of the cooking container.

If the difference between the first predicted temperature T1 and the second predicted temperature T2 is within an allowable range (for example, a range of ± 15 ° C.), the first predicted temperature T1 is determined as the temperature of the cooking container.
On the other hand, if the difference between the first predicted temperature T1 and the second predicted temperature T2 exceeds the allowable range, the detected value of the infrared intensity in the second wavelength region α2 and the second wavelength region α2 stored in advance. The temperature of the cooking container is determined from the change characteristic between the infrared intensity at and the temperature of the cooking container.

  The temperature obtained by the temperature detection unit 50 is output to the combustion control unit 3, and the combustion control unit 3 controls the fuel supply amount adjustment valve 6 and the like based on the temperature obtained by the temperature detection unit 50. Thus, the automatic temperature control of the cooking container N, the emergency stop control when the cooking container N is excessively heated, and the like are performed.

[Another embodiment]
Next, another embodiment will be described.

(1) In the above-described embodiment, the second wavelength range α2 is also used as the temperature determination wavelength range K3. However, instead of such a configuration, the temperature determination wavelength range K3 is described above. The third wavelength band α3 may also be used. Alternatively, a wavelength band different from the second wavelength band α2 and the third wavelength band α3 may be set in the emissivity leveling range.

(2) In the above embodiment, the second wavelength region α2 is configured to serve as both the first temperature measurement wavelength region K1 and the second temperature measurement wavelength region K2. Instead, the wavelength range K1 for the first temperature measurement set in the emissivity average range and the two types of wavelength ranges K2 for the second temperature measurement set as different wavelength ranges in the emissivity average range, respectively. May be set in different wavelength ranges. That is, four different wavelength ranges may be set as the two types of wavelength ranges K1 for first temperature measurement and the two types of wavelength ranges K2 for second temperature measurement.

(3) In the above embodiment, the temperature detecting means determines the first predicted temperature T1 as the temperature of the cooking container if the difference between the first predicted temperature T1 and the second predicted temperature T2 is within an allowable range. However, instead of such a configuration, if the difference between the first predicted temperature T1 and the second predicted temperature T2 is within an allowable range, the average value of the first predicted temperature T1 and the second predicted temperature T2 is cooked. It can be implemented in various forms such as determining the temperature of the container for use.

(4) In the above embodiment, the stove provided with the internal flame type burner for injecting and burning the air-fuel mixture inward from the annular burner body as the heating cooker has been shown. A stove provided with a Bunsen combustion type burner to be used may be used.
In other words, as shown in FIG. 9, the burner 30 is exposed to the upper side through the opening formed in the top plate 1, and is an external flame type burner provided with a flame port 33 that ejects the air-fuel mixture upward and burns it. In this configuration, the burner body 35 forming the flame opening 33 is provided in a cylindrical shape, and a through hole 36 penetrating in the vertical direction is formed at the center thereof. The infrared intensity through the through hole 36 is detected. The upper end portion of the through hole 36 is covered with a translucent window portion 37.

(5) In the above embodiment, the infrared intensity detecting means includes three infrared detecting elements 42a, 42b, and 42c that individually detect the infrared rays that have passed through the three band pass filters 41a, 41b, and 41c. The infrared rays emitted from the container N are configured to detect the infrared intensity for each of the three different wavelength ranges, but instead of such a configuration, three bandpasses for one infrared detection element The positions may be switched so that the filters act alternately, and the infrared intensity in different wavelength ranges may be detected using the detection value of the infrared detection element in each of the switched states.

(6) In the above embodiment, the infrared intensity detecting means is exemplified to detect the intensity of the infrared ray that is located along the vertical direction and is located on the lower side of the center portion of the burner. The present invention is not limited to this, and it is possible to detect the intensity of infrared rays incident in the oblique direction by shifting the position in the horizontal direction from the center of the burner.

(7) In the above embodiment, a gas combustion type burner is used as the heating means. However, the heating means is not limited to the burner, for example, a halogen lamp is used, and an electric resistance wire is incorporated. You may comprise by an electric heating part, such as what uses a sheathed heater, or the thing using the magnetic field generation coil which performs electromagnetic induction heating (usually called "IH").

Schematic configuration diagram of the cooking device Diagram showing radiation characteristics The figure which shows the spectrum data of the infrared radiation intensity radiated | emitted from the container for cooking The figure which shows the spectrum data of the infrared radiation intensity radiated | emitted from the container for cooking The figure which shows the spectrum data of the infrared radiation intensity radiated | emitted from the container for cooking Figure showing the spectral data of the infrared radiation intensity emitted from the flame The figure which shows the relationship between the temperature of the container for cooking, and infrared rays intensity ratio The figure which shows the relationship between the temperature of the container for cooking, and infrared rays intensity ratio The schematic block diagram of the heating cooker of another embodiment

Explanation of symbols

30 Heating means 40 Infrared intensity detecting means 50 Temperature detecting means K1 Wavelength range for first temperature measurement K2 Wavelength range for second temperature measurement K3 Wavelength range for temperature determination T1 First predicted temperature T2 Second predicted temperature

Claims (4)

A heating means for heating the cooking container, an infrared intensity detection means for detecting an infrared intensity for each of a plurality of wavelength ranges in the infrared rays radiated from the cooking container, and the plurality detected by the infrared intensity detection means A temperature detection device for a heating cooker, comprising temperature detection means for detecting the temperature of the cooking container based on the infrared intensity for each of the wavelength ranges of
The infrared intensity detecting means is
As the infrared intensity for the plurality of wavelength ranges,
The radiation corresponding to an emissivity variation type cooking container having an emissivity characteristic having an emissivity leveling range with a small change in emissivity with respect to a change in wavelength and an emissivity variation range with a large change in emissivity with respect to a change in wavelength. Infrared intensity for the first temperature measurement wavelength range set in the rate variation range, Infrared intensity for the first temperature measurement wavelength range set in the emissivity level range, and a wavelength that is different from the emissivity level range It is configured to detect each of the infrared intensity for the two types of wavelength ranges for measuring the second temperature set as the area and the infrared intensity for the wavelength range for temperature determination set in the emissivity average range. ,
The temperature detecting means is
A first predicted temperature is obtained based on a ratio of a pair of infrared intensities detected for each of the two types of wavelength regions for the first temperature measurement, and each of the two types of wavelength regions for the second temperature measurement is used. The second predicted temperature is obtained based on the ratio of the pair of infrared intensities detected for the first predicted temperature and when the difference between the first predicted temperature and the second predicted temperature is within an allowable range, the first predicted temperature and When the temperature of the cooking container is determined based on the second predicted temperature, and the difference between the first predicted temperature and the second predicted temperature is outside the allowable range, the wavelength region for temperature determination A temperature detection device for a heating cooker configured to determine the temperature of the cooking container based on the infrared intensity detected for. Infrared intensity radiated for an emissivity-equalized cooking container having a radiation characteristic in which the wavelength range for first temperature measurement set in the emissivity fluctuation range has no or little change in emissivity with respect to wavelength change. Corresponding to a wavelength range larger than the two types of wavelength ranges for the second temperature measurement,
The temperature detecting means is
The configuration according to claim 1, wherein when the difference between the first predicted temperature and the second predicted temperature is within the allowable range, the first predicted temperature is determined as the temperature of the cooking container. Temperature detection device for cooking appliances. The infrared intensity detecting means is
A wavelength range selected from a range of 3.1 μm or more and 4.2 μm or less is set as the first temperature measurement wavelength range set in the emissivity variation range, and the emissivity average range is set. A wavelength range selected from the range of 8.0 μm or more and 20.0 μm or less is set as the two types of wavelength ranges for the second temperature measurement and the wavelength range for the temperature determination, and a plurality of them are set. The temperature detection apparatus for cooking-by-heating machines of Claim 1 or 2 comprised so that the infrared intensity of each wavelength range may be detected. The infrared intensity detecting means is
The infrared intensity for any one of the two types of wavelength ranges for the second temperature measurement is detected as the infrared intensity for the wavelength range for temperature determination set in the emissivity level range. The temperature detection device for a heating cooker according to any one of claims 1 to 3, which is configured as described above.

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