JP5859085B2 - Sensor case structure and cooking device provided with the sensor case structure - Google Patents

Description

  The present invention relates to a sensor case structure of a sensor that detects the temperature of an object to be heated placed on a top plate, and a heating cooker including the sensor case structure.

As a method of detecting the temperature of the pan, which is the object to be heated, placed on the top plate of the cooking device, a thermistor, which is a contact temperature sensor, is brought into contact with the top plate and transmitted from the pan through the top plate. There are a thermistor method for detecting the temperature to be detected and an infrared sensor method for detecting the infrared radiation energy radiated from the pan through the top plate.
In the infrared sensor system, an infrared sensor is disposed below the central space of the heating coil and the space between the inner coil and the outer coil, and infrared radiation energy radiated from a pan placed on the top plate is passed through the space. The temperature of the pan is detected by the amount of energy detected.

  In such an infrared sensor, the output of the infrared sensor becomes unstable due to the radiant heat radiated from the top plate or the like around the infrared sensor, the electromagnetic wave radiated from the heating coil, the cooling air for cooling the inside of the housing, etc. In order to prevent this, the infrared sensor is housed inside a resin case with a large heat capacity, and a case made of a non-magnetic metal is provided on the outside of the resin case. The sensor case is made of the same material as the top plate above the field of view of the infrared sensor. What seals using a glass filter is known (refer patent document 1).

JP 2013-97935 A

  However, such a conventional sensor case has a problem that the structure is complicated and the cost is high, and the sensor case itself is enlarged. In addition, the glass filter used as a sealing member for the sensor case absorbs the infrared radiation emitted from the top plate and the pan placed above, generating secondary radiant heat from the glass filter, resulting in variations in the output of the infrared sensor. There was a problem of giving.

  The present invention has been made to solve the above-described problems, and causes noise in order to accurately detect the temperature of an object to be heated placed above the top plate using an infrared sensor. Strong against various noises such as the effect of radiant heat from above (top plate, pan bottom), the effect of cooling air to cool the inside of the sensor case, and the effect of electromagnetic waves generated when high-frequency current is applied to the heating coil It aims at providing the sensor case structure provided with tolerance, and the cooking-by-heating machine provided with the sensor case structure.

The sensor case structure according to the present invention is a sensor case structure including an infrared detection unit that detects infrared rays, a hollow sensor case unit that houses the infrared detection unit, and a magnetic shield unit that is attached to the sensor case unit. The sensor case portion has an opening for the sensor case portion corresponding to the visual field range in which the infrared detection portion detects infrared rays, and the magnetic shield portion has an opening for the magnetic shield portion corresponding to the visual field range. The opening area of the opening is configured to be smaller than the opening area of the sensor case portion opening, and the magnetic shielding portion is disposed outside the sensor case portion .

  According to the sensor case structure of the present invention, it is possible to suppress the influence of radiant heat, electromagnetic waves, and cooling air on the infrared sensor with a simple structure. A highly resistant infrared sensor can be provided.

3 is a top view of the cooking device according to Embodiment 1. FIG. It is a block diagram explaining the structure and function of the principal part of the heating cooker which concerns on Embodiment 1. FIG. It is a figure explaining the operation part and thermal-power display part which were provided corresponding to the left heating coil of the heating cooker which concerns on Embodiment 1. FIG. 4 is a cross-sectional view of the sensor case according to Embodiment 1. FIG. 6 is an explanatory diagram of a viewing angle of a condensing lens in the infrared sensor according to Embodiment 1. FIG. 3 is a top view of the sensor case according to Embodiment 1. FIG. 2 is a top view of the magnetic shield according to Embodiment 1. FIG. 4 is a graph showing spectral transmission characteristics of a top plate of a heating cooker according to Embodiment 1. It is a graph which shows the relationship between the spectral transmission characteristic of the top plate of the heating cooker which concerns on Embodiment 1, and the spectral radiance curve in each temperature. It is the graph which showed the spectral radiance curve of the black body for every temperature. 6 is a cross-sectional view of a sensor case according to Embodiment 2. FIG. It is a block diagram which shows the electric power system of the heating cooker which concerns on Embodiment 3. FIG. It is a flowchart at the time of the earthquake response of the heating cooker which concerns on Embodiment 3. FIG.

Hereinafter, the cooking device according to the present invention will be described with reference to the drawings.
In addition, the structure, control content, etc. which are demonstrated below are examples, and the heating cooker which concerns on this invention is not limited to such a structure, control content, etc.
Further, the illustration of the fine structure is simplified or omitted as appropriate.
In addition, overlapping or similar descriptions are appropriately simplified or omitted.

Embodiment 1 FIG.
FIG. 1 is a top view of the heating cooker according to the first embodiment.
The induction heating cooker 100 includes a main body 1 and a top plate 2 that is disposed on the upper surface of the main body 1 and is formed of heat-resistant glass. The induction cooker 100 is a pan 10 or a pan that is placed on the top plate 2. The heated object is heated by induction heating means provided inside the main body 1. In the first embodiment, heating ports 6 are respectively provided on the left front side, the right front side, and the center side back of the top plate 2. In the following description, the object to be heated may be referred to as “pan 10”.

  On the upper surface of the main body 1, an operation unit 3 that receives an input operation of a heating condition or a heating instruction is arranged corresponding to each heating port 6. When a user places a pot 10 or a frying pan, which is an object to be heated, on the top plate 2 and performs an operation input on an operation key provided in the operation unit 3 corresponding to each heating port 6, guidance is performed according to the operation input. The object to be heated is heated by the heating means. Information relating to settings such as the progress of heating and cooking mode is displayed on the display unit 4 having liquid crystal or the like disposed on the upper surface of the top plate 2 corresponding to each heating port 6, and the thermal power of heating is the thermal power display unit 5. Is displayed.

  Behind the main body 1, there are intake ports 9 a and 9 b that take in air for cooling the inside of the main body 1 (hereinafter, may be collectively referred to as the intake port 9), and an exhaust port 8 that exhausts air in the main body 1. Provided. When the air blowing means (not shown) provided in the main body 1 operates, external air flows into the main body 1 from the intake port 9 as cooling air, and the cooling air is sent to the inside of the main body by a substrate (not shown), elements, and induction heating means. A certain heating coil 14, the lower surface of the top plate 2, and the like are cooled. The cooling air after cooling the inside of the main body 1 is discharged from the exhaust port 8 to the outside.

  The portion corresponding to the heating port 6 of the top plate 2 is provided with, for example, a circular display indicating the place where the pan 10 is placed by printing or the like, so that the user knows where the pan 10 should be placed. It has become.

  A heating coil 14 as a heating means is provided below the heating port 6 in the main body 1. In addition, in FIG. 1, arrangement | positioning of the heating coil 14 is illustrated with the broken line. An eddy current is generated in the pan 10 placed on the top plate 2 by flowing a high-frequency current through the heating coil 14, and the pan bottom itself generates heat due to the generated eddy current and the resistance of the pan 10 itself. Cooking with good heating efficiency can be realized. In addition, you may provide other heating means, such as an electric heater, as a heating means of the heating port 6 of the induction heating cooking appliance 100. FIG.

FIG. 2 is a block diagram illustrating the configuration and functions of the main part of the heating cooker according to the first embodiment. In FIG. 2, only the structure corresponding to one heating port 6 is illustrated, and the pan 10 as an object to be heated is also illustrated.
A heating coil 14 is disposed below the heating port 6 provided in the top plate 2. In the first embodiment, the heating coil 14 has a double ring shape including a substantially annular inner heating coil 14a and a substantially annular outer heating coil 14b provided outside thereof. A substantially annular gap is provided between the inner heating coil 14 a and the outer heating coil 14 b, and this gap is referred to as a gap 15. The heating coil 14 is held at a predetermined distance from the lower surface of the top plate 2 by a heating coil support 16 that accommodates the heating coil 14.

  An infrared sensor 12 is provided in the gap 15 between the inner heating coil 14a and the outer heating coil 14b and below the upper surface of the heating coil 14 to output an output corresponding to the detected amount of infrared when detecting infrared rays. Yes. The output from the infrared sensor 12 is input to an infrared temperature detection unit 24 provided in the main body 1. The infrared temperature detector 24 calculates the temperature based on the output from the infrared sensor 12. More specifically, the storage unit 21 stores in advance a temperature conversion table in which the output amount of the infrared sensor 12 is associated with the temperature data calculated based on the output amount and a predetermined emissivity. When receiving the output from the infrared sensor 12, the infrared temperature detecting unit 24 refers to the temperature conversion table and calculates the temperature.

  The infrared sensor 12 is covered with a sensor case 200 so that the cooling air flowing in the vicinity of the heating coil 14 is not directly applied. The infrared sensor 12 is held in the sensor case 200 while maintaining a spatial distance so that the ambient temperature around the infrared sensor 12 is uniform. The sensor case 200 is fixed to the heating coil support portion 16 with a tapping screw or the like, or partly formed integrally with the heating coil support portion 16, and the distance between the top plate 2 and the infrared sensor 12. Is kept constant. Further, a magnetic shield plate 220 is disposed on the upper surface side of the sensor case 200.

  In the first embodiment, in order to detect the infrared rays of the pan 10 that passes through the top plate 2, it is desirable that the transmission window portion 7 on the upper surface portion of the infrared sensor 12 does not have the coating 13. However, if the transmission window 7 is not coated, the internal heating coil 14 and wiring may be visible from the upper surface of the top plate 2, which is not desirable in design. For this reason, when the coating 13 is not applied to the transmission window portion 7, a cylinder or a plate is provided toward the top plate 2 in the heating coil support portion 16 that holds the heating coil 14 or the sensor case 200. What is necessary is just to make it difficult to see the heating coil 14, wiring, etc. from the outside by doing in this way. In addition, instead of covering the entire surface of the transmission window portion 7 with the coating 13, the coating 13 is applied to the transmission window portion 7 in the form of dots or stripes so as to manage the ratio of the unpainted openings. Well, it is possible to ensure design and functionality by doing so.

  In addition, two contact-type temperature sensors 17 that are contact-type temperature detecting means such as a thermistor are provided on the lower surface of the top plate 2 (FIG. 2 shows only one contact-type temperature sensor 17. ). The two contact temperature sensors 17 are provided at positions shifted by 180 degrees with respect to the center of the heating coil 14. The contact temperature sensor 17 is provided so as to be in close contact with the lower surface of the top plate 2 and outputs a signal corresponding to the temperature of the lower surface of the top plate 2. The output signal of the contact temperature sensor 17 is input to the top plate temperature detector 25 provided in the main body 1. The top plate temperature detector 25 detects the temperature of the top plate 2 based on the signal from the contact temperature sensor 17. In the first embodiment, the contact temperature sensor 17 and the top plate temperature detection unit 25 constitute the top plate temperature detection means of the present invention. As long as the temperature of the top plate 2 can be detected more accurately with less time delay, not only the contact-type temperature sensor 17 such as a thermistor, but any other one can be used as the top plate temperature detection means. .

  In the first embodiment, the contact temperature sensor 17 is provided in the gap 15 between the inner heating coil 14a and the outer heating coil 14b. However, the arrangement of the contact temperature sensor 17 is not limited to this. For example, the contact temperature sensor 17 may be disposed in the vicinity of the outer periphery of the outer heating coil 14 b or may be disposed in the center of the heating coil 14. Moreover, the number of the contact-type temperature sensors 17 is not limited to two, and may be one or two or more.

The output of the contact-type temperature sensor 17 is used when calculating the temperature of the pan 10 based on the amount of infrared rays detected by the infrared sensor 12. For this reason, in order to detect the temperature of the pan 10 with higher accuracy, the contact-type temperature sensor 17 is preferably installed in the vicinity of the infrared sensor 12.
It should be noted that it is uncertain where the pan 10 as the object to be heated is placed on the top plate 2, and since the shape of the pan 10 is also uncertain, it detects a wider range of temperatures, and The contact-type temperature sensor 17 and the infrared sensor 12 may be arranged apart from each other by giving priority to the realization at a low cost.

  If the number of the contact-type temperature sensors 17 is small, the acquisition temperature may vary due to the difference in the position and shape of the object to be heated placed on the top plate 2. For this reason, the average value of the detection values of the plurality of contact-type temperature sensors 17 and the detection value of the output of the highest temperature among the plurality of contact-type temperature sensors 17 are used for temperature detection of the pan 10. Also good. By doing in this way, even when the number of installation of the contact-type temperature sensor 17 is small, temperature detection resistant to variations can be performed.

Information set by the operation unit 3 and outputs from the infrared temperature detection unit 24 and the top plate temperature detection unit 25 are input and stored in the storage unit 21 provided in the main body 1.
The calculation part 22 is comprised, for example with a microcomputer etc., and performs the various calculation processing which calculates the temperature of the pan 10. FIG.

  The control unit 23 subtracts the influence of the top plate temperature from the detected temperature of the infrared sensor 12 based on the setting content of the operation unit 3 and the physical information detected by the infrared sensor 12 and the contact temperature sensor 17. The high frequency current flowing in the heating coil 14 is adjusted by controlling the high frequency inverter 26. By doing in this way, heating control of a to-be-heated material is performed.

Next, the structure of the operation part 3 and the thermal power display part 5 of the induction heating cooking appliance 100 is demonstrated.
FIG. 3 is a diagram illustrating an operation unit and a thermal power display unit provided corresponding to the left heating coil of the cooking device according to the first embodiment. The operation unit 3 and the thermal power display unit 5 respectively corresponding to the heating coil 14 provided on the left side, the right side, and the center of the induction heating cooker 100 have the same configuration. The operation unit 3 and the thermal power display unit 5 provided correspondingly will be described as an example.

The operation unit 3 includes a heating power setting key 31 for setting a heating power for heating the object to be heated, and a menu key 32 for setting a cooking menu.
The heat setting key 31 includes a “low heat” key, a “medium fire” key, a “high fire” key, and a “3 kW” key, and the user can use any of the four levels of fire power using these keys. Can be set. By providing keys individually according to the thermal power, the user can input the necessary thermal power settings with a single operation.

  The menu key 32 includes a “fried food” key, a “preheat” key, a “boiled” key, and a “timer” key. When these keys are pressed, the control unit 23 performs heating control according to a control sequence preset for each menu and stored in the storage unit 21.

  The thermal power display unit 5 displays thermal power in a plurality of stages based on the thermal power input by the thermal power setting key 31 and the menu set by the menu key 32, and the display mode is switched according to the thermal power. The display of the thermal power display unit 5 can indicate to the user that it is operating. The thermal power display unit 5 includes, for example, a plurality of LEDs, and expresses thermal power by switching the lighting states (lighting, extinguishing, blinking, etc.) of these LEDs or switching the lighting color. By doing in this way, the user can perform notification which is easy to understand intuitively.

  Although not shown in FIG. 3, the display unit 4 (see FIG. 1) configured with a liquid crystal screen or the like has, for example, a thermal power and progress status such as “during preheating” and “appropriate temperature reached”, a set menu Information on the contents of the is displayed.

  In the induction heating cooker 100 having such a configuration, for example, when cooking fried food, the user first puts oil for performing fried food in the pan 10 and places the pan 10 on the heating port 6 of the top plate 2. Put. Next, when the user performs an operation input for starting heating at the operation unit 3, the control unit 23 applies a high-frequency current to the heating coil 14 based on the signal from the operation unit 3 and the estimated temperature of the pan 10. The cooking is performed according to a control sequence set in advance and stored in the storage unit 21.

Here, a configuration example of the infrared sensor 12 and the sensor case 200 will be described.
FIG. 4 is a cross-sectional view of the sensor case according to the first embodiment.
As the infrared sensor 12, a sensor having sensitivity in a wide wavelength with respect to an infrared region, such as a thermopile sensor, is used.
The main body of the infrared sensor 12 shown in FIG. 4 is provided with a convex condensing lens 121 on the upper surface, for example, a cylindrical encapsulating member 122 enclosing a thermopile chip (not shown) and a self-temperature detecting thermistor (not shown). Is mounted on the printed circuit board 123 and packaged. By making the condensing lens 121 convex, the visual field range 12a of the infrared sensor 12 is narrowed to suppress the influence of ambient light. The shape of the enclosing member 122 is not limited to a cylindrical shape.

  Silicon can be used as the base material of the condenser lens 121. Silicon has a low wavelength dependency of about 50 to 60% in the infrared region, and has a high reflectance and a low heat absorption rate except for the transmission of light in the infrared region, so that the temperature hardly rises. In addition, since the thermal diffusivity is high, even if the condenser lens 121 absorbs infrared rays and the temperature rises, the thermal diffusion does not easily affect the detection of the amount of infrared rays.

  As described above, by using the silicon base material as the base material of the condensing lens 121, the temperature of the condensing lens 121 of the infrared sensor 12 rises even in a usage environment provided in the vicinity of the top plate 2. Insensitive to the detection of the amount of infrared rays. In addition, the base material of the condensing lens 121 is not limited to silicon, and any material having similar transmission characteristics and thermal diffusibility can be used. Further, the specific configuration of the infrared sensor 12 is not limited to that illustrated in FIG.

Here, the characteristic of the condensing lens 121 is demonstrated using FIG.
FIG. 5 is an explanatory diagram of the viewing angle of the condenser lens in the infrared sensor according to the first embodiment.
The infrared sensor 12 obtains the maximum value of the detected output value on the central axis (measurement viewing angle 0 °) of the condensing lens 121 when a point light source is disposed immediately above the condensing lens 121. FIG. 5 shows a distribution obtained by measuring the detection output value of the point light source when the measurement viewing angle is shifted in the front-rear and left-right directions with this maximum value being 100%.
In the infrared sensor 12 according to Embodiment 1, the measurement viewing angle (θ) at which the detection output value is 50% or more is defined as the measurement range.

  By defining the measurement viewing angle (θ) of the measurement range in this way, the cone-shaped viewing range 12a where the detection output of the infrared sensor 12 is strong is limited, the influence of disturbance is suppressed, and the infrared measurement accuracy is improved. Yes. Note that if the measurement viewing angle (θ) is wide, the measurement viewing angle (θ) is likely to be affected by disturbances, so that it is preferably 30 ° or less.

Next, the sensor case 200 that covers the infrared sensor 12 will be described with reference to FIGS. 4 and 6.
6 is a top view of the sensor case according to Embodiment 1. FIG.
The sensor case 200 is formed of a resin having a low thermal conductivity and a large heat capacity. The shape of the sensor case 200 is a hollow, substantially rectangular parallelepiped shape, and includes a rectangular side surface 201, a bottom surface 202, and an upper surface 204.
A pair of attachment pieces 203 having openings 203a are formed on the opposing side surfaces 201. Further, a bottom rib 207 that supports the printed circuit board 123 is partially provided on the upper surface of the bottom surface 202, and a gap is provided between the lower surface of the printed circuit board 123 and the upper surface of the bottom surface 202.

  For example, a circular case opening 210 is formed on the upper surface 204. The case opening 210 opens to the visual field range 12 a in the condenser lens 121 of the infrared sensor 12 housed in the sensor case 200. Moreover, the 1st upper surface rib 205 shown in FIG. 6 is protrudingly provided by the upper pan surface of the upper surface 204 so that the case opening 210 may be enclosed. Further, a second upper surface rib 206 having a height equal to that of the first upper surface rib 205 is linearly provided on the upper surface 204 facing the case opening 210. The case opening 210 is not limited to a circle.

Next, the configuration of the magnetic shield plate 220 disposed on the upper part of the sensor case 200 will be described.
FIG. 7 is a top view of the magnetic shield according to the first embodiment.
The magnetic shield 220 is bonded to the upper portions of the first upper surface rib 205 and the second upper surface rib 206 of the sensor case 200. The material is a conductor that has a high reflectance with respect to the radiant heat from above the infrared sensor 12 and suppresses the influence of electromagnetic waves generated when a high-frequency current is applied to the heating coil 14, such as aluminum or copper. It is made of a nonmagnetic metal.
The magnetic shield plate 220 is formed of a substantially rectangular flat plate, and has attachment pieces 222 having openings 222a at two opposing positions. Further, a magnetic shield plate opening 221 is opened in a circular shape at a position corresponding to the case opening 210 of the sensor case 200, for example. The magnetic shield plate opening 221 opens in the visual field range 12 a in the condenser lens 121 of the infrared sensor 12 housed in the sensor case 200. The magnetic shield opening 221 is not limited to a circle.

Here, the structure which assembled | attached the sensor case 200, the infrared sensor 12, and the magnetic-shield board 220 is demonstrated.
The central axis of the condensing lens 121 of the infrared sensor 12, the center of the case opening 210 of the sensor case 200, and the center of the magnetic shielding plate opening 221 of the magnetic shielding plate 220 are arranged coaxially as shown in the sectional view of FIG. Has been.
When the encapsulating member 122 of the infrared sensor 12 has a cylindrical shape, the outer diameter C of the encapsulating member 122 is substantially equal to (or may be the same as) the diameter B of the case opening 210 when viewed from above, or slightly smaller. In addition, when the enclosing member 122 is not a cylindrical shape but a rectangular parallelepiped shape, for example, the enclosing member 122 may have a rectangular shape so that the case opening 210 does not overlap the outer shape of the enclosing member 122 in a top view. That is, the shape of the case opening 210 can be made to be an opening shape that does not overlap the sealing member 122 in accordance with the shape of the sealing member 122 as viewed from above.

Further, when the magnetic shield plate opening 221 and the case opening 210 are circular, the diameter A of the magnetic shield plate opening 221 is smaller than the diameter B of the case opening 210. Alternatively, the opening area of the magnetic shield plate opening 221 is smaller than the opening area of the case opening 210.
When the magnetic shield opening 221 and the case opening 210 are circular, the diameter B of the case opening 210 and the diameter A of the magnetic shield opening 221 are measured viewing angles (θ) at which the detection output value of the infrared sensor 12 is 50% or more. Is set to a size that is in contact with the conical visual field range 12a defined by the above or a size that is slightly larger than the visual field range 12a so as not to correspond to the visual field range 12a. In addition, when the magnetic-shielding board opening 221 and the case opening 210 are other than circular, it is set as a dimension a little larger than the visual field range 12a so that each opening may not hit the visual field range 12a.

With such a configuration, the influence of radiant heat from the top plate 2 on the infrared sensor 12 and the influence of electromagnetic waves by the heating coil 14 are suppressed, and the inside of the main body 1 of the induction heating cooker 100 is cooled for cooling. The influence of the wind can be suppressed.
That is, the magnetic shield plate 220 having a high reflectivity with respect to the surface of the sensor case 200 made of resin reflects the radiant heat from the top plate 2 and suppresses the influence of electromagnetic waves by the heating coil 14. At this time, the diameter A of the magnetic shield plate opening 221 of the magnetic shield plate 220 is the minimum with the conical field range 12a defined by the measurement field angle (θ) at which the detection output value of the infrared sensor 12 is 50% or more as the lower limit dimension. Therefore, the influence on the infrared sensor 12 due to radiant heat and electromagnetic waves entering the sensor case 200 can be minimized. Further, since the visual field range 12a of the infrared sensor 12 is not shielded around the magnetic shield plate opening 221, the sensitivity of the infrared sensor 12 is not dulled.

  Further, since an air layer is formed by the upper surface ribs 205 and 206 between the upper surface 204 of the sensor case 200 and the magnetic shield plate 220, there is a heat insulation effect, and the propagation of radiant heat from the top plate 2 into the sensor case 200 is suppressed. can do. Note that the same effect can be obtained by forming a heat insulating layer with urethane or the like, instead of forming an air layer with the upper surface ribs 205 and 206.

When the encapsulating member 122 of the infrared sensor 12 is cylindrical, the outer diameter C of the encapsulating member 122 is substantially the same as (or may be the same as) the aperture B of the case opening 210, or is slightly smaller. Even if the temperature is high due to radiant heat, the upper surface of the encapsulating member 122 does not receive secondary radiation from the upper surface 204 of the sensor case 200.
In addition, by defining the aperture B of the case opening 210 in this way, the aperture B of the case opening 210 is too large and cooling air does not cool the upper surface of the enclosing member 122 of the infrared sensor 12 more than necessary. Since the diameter B of the case opening 210 is too small, heat does not accumulate in the sensor case 200, and the influence of heat on the infrared sensor 12 can be suppressed.

  Further, since the sensor case 200 has no opening other than the case opening 210, the cooling air does not blow around the infrared sensor 12. Further, since the first upper surface rib 205 is provided so as to surround the case opening 210, the cooling air does not flow into the case opening 210 from between the upper surface 204 of the sensor case 200 and the magnetic shield plate 220. Therefore, the influence of the cooling air on the infrared sensor 12 can be suppressed.

  When the encapsulating member 122 of the infrared sensor 12 has a cylindrical shape, the outer diameter C of the encapsulating member 122 is substantially equal to or slightly smaller than the diameter B of the case opening 210. You may arrange | position in the state inserted in case opening 210. FIG. In this case, in order to suppress the influence of the cooling air on the condensing lens 121 of the infrared sensor 12, it is necessary to dispose the upper surface of the enclosing member 122 below the upper surface 204 of the sensor case 200.

  Thus, since it is possible to suppress the effects of radiant heat, electromagnetic waves, and cooling air on the infrared sensor 12 with a simple structure, the infrared rays are highly resistant to various noises in the induction heating cooker 100. A sensor 12 can be provided. Therefore, by obtaining a stable output value from the infrared sensor 12, it is possible to accurately detect the temperature of the pan 10 that is a placement object placed on the top plate 2.

Next, the spectral transmission characteristics of the top plate 2 will be described.
FIG. 8 is a graph showing the spectral transmission characteristics of the top plate of the heating cooker according to the first embodiment.
The graph in FIG. 8 shows, as an example, the transmittance τ of the top plate 2 made of crystallized glass having a thickness of about 4 mm and high heat resistance.
FIG. 9 is a graph showing the relationship between the spectral transmission characteristic of the top plate of the cooking device according to Embodiment 1 and the spectral radiance curve at each temperature.
FIG. 9 shows the spectral radiance curve and the transmittance τ of the top plate 2 when the pan temperature is 150 ° C., 200 ° C., and 250 ° C.

  As can be seen from FIG. 8, the wavelength band with high transmittance in the top plate 2 is 0.6 μm to 2.6 μm, and then is 3.2 μm to 4.2 μm. In addition, referring to FIG. 9, the spectral radiance curves of the pan 10 at 150 ° C., 200 ° C., and 250 ° C. increase from around 2.0 μm. Accordingly, the value of the amount of infrared energy that reaches the infrared sensor 12 from the bottom of the pan 10, which is obtained by the product of the transmittance (%) and the spectral radiance, increases in the wavelength band of 3.2 μm to 4.2 μm. In order to detect temperature, it is necessary to detect infrared rays in this wavelength band. By detecting the wavelength band of 3.2 μm to 4.2 μm, it becomes possible to accurately measure the temperature range where the temperature of the pan bottom which is not easily affected by the attenuation by the top plate 2 is 140 ° C. or more.

The infrared sensor 12 detects infrared energy radiated from the bottom of the pan and infrared energy radiated from the lower surface of the top plate 2 when the top plate 2 is heated by heat conduction.
Infrared energy emitted from the top plate 2 is emitted at a high rate in a wavelength band longer than 4.5 μm, which is a region where the transmittance of the top plate 2 is low. The emissivity ε of glass is generally about 0.84 to 0.9, and has a high emissivity.
FIG. 10 is a graph showing a spectral radiance curve of a black body for each temperature.
As the temperature of the cooked food (pan 10) heated by the induction heating cooker 100, a temperature range lower than about 230 ° C. from boiling water to deep-fried food is used.

According to FIG. 10, the spectral radiance up to 250 ° C. is detected up to about 20 μm as the wavelength band.
For this reason, the amount of infrared energy emitted from the top plate 2 has a high influence as noise on the wavelength band of 3.2 μm to 4.2 μm that the infrared sensor 12 originally wants to detect.
By increasing the reflectivity of the magnetic shield plate 220 to such a long wavelength band, the infrared sensor 12 and the sensor case 200 are resistant to long-wavelength radiation emitted by the top plate 2.
Therefore, it is desirable that the magnetic shield plate 220 is surface-treated so as to have a high reflectance with respect to the reflectance of the sensor case 200, particularly in the infrared region of 0.1 μm to 20 μm. The surface treatment can be performed by plating or surface polishing to adjust the reflectance.

The radiation characteristic of the magnetic shield 220 is expressed by Kirchhoff's law [emissivity (ε) + transmittance (τ) + reflectivity (ρ) = 1]. For an object that does not transmit heat, such as a metal surface, transmittance (τ) = 0, and emissivity (ε) = 1−reflectance (ρ). That is, as the reflectance (ρ) increases, the emissivity (ε) decreases.
Therefore, it is possible to reflect the radiation from the top plate 2 by increasing the reflectance of both surfaces of the magnetic shielding plate 220 and to reduce the secondary radiation from the lower surface of the magnetic shielding plate 220.
In this way, it is desirable to increase the reflectivity of both sides of the magnetic shield plate 220 in terms of resistance to radiation from the top plate 2, but even if the reflectivity of either the upper surface or the lower surface is increased, the sensor case 200 and infrared rays are increased. There is a certain effect of suppressing radiation of radiation heat to the sensor 12.

Embodiment 2. FIG.
The sensor case 200 according to the second embodiment is characterized in that the optical filter 300 is disposed between the upper surface 204 of the sensor case 200 according to the first embodiment and the magnetic shielding plate 220.
FIG. 11 is a cross-sectional view of the sensor case according to the second embodiment.
As shown in FIG. 11, the optical filter 300 is disposed between the upper surface 204 of the sensor case 200 and the magnetic shield plate 220. Other configurations are the same as those of the sensor case 200 according to the first embodiment.

As described above, the infrared sensor 12 detects infrared energy emitted from the bottom of the pan and infrared energy emitted from the lower surface of the top plate 2 when the top plate 2 is heated by heat conduction.
In order to detect the temperature of the pan bottom, it is necessary to detect infrared rays having a wavelength band of 3.2 μm to 4.2 μm in which the value of the amount of infrared energy reaching the infrared sensor 12 from the pan bottom increases. Therefore, the optical filter 300 is a band pass filter having a high transmittance in the wavelength band of 3.2 μm to 4.2 μm.

Here, the optical filter 300 will be described.
The optical filter 300 uses silicon as a base material in at least one of the upper surface and the lower surface in the infrared region such as SiO, ZnS, Ge, and sapphire in order to particularly increase the transmittance in the range of 3.2 μm to 4.2 μm. Deposit thin films with materials with transmission, absorption, reflection, and different refractive indices, and up to 90% peak value in the range of 3.2 μm to 4.2 μm, or in the range of 0.6 μm to 2.6 μm The structure has a degree of transmission characteristics. In addition, the structure has a transmission characteristic that does not reach half the peak value outside these ranges. By configuring the optical filter 300 in this way, the wavelength band having a high value of the amount of infrared energy reaching from the pan bottom determined by the product of the transmittance (τ) of the top plate 2 and the spectral radiance is actively transmitted. By blocking other wavelength bands, it is possible to detect infrared rays with high noise resistance.

  Silicon, which is the base material of the optical filter 300, has a low wavelength dependency of about 50% to 60% in the infrared region as described above, and has a reflectance other than the transmission of light in the infrared region. The heat absorption rate is large and the temperature rise is difficult. In addition, since the thermal diffusivity is high, even if the optical filter 300 absorbs infrared rays and the temperature rises, the thermal diffusion hardly affects the detection of the amount of infrared rays.

  In this way, by using a silicon base material as the base material of the optical filter 300, even in a use environment provided in the vicinity of the top plate 2, it is possible to detect the amount of infrared rays due to an increase in the temperature of the optical filter 300. Impact is unlikely to occur. The base material of the optical filter 300 is not limited to silicon, and any material having similar transmission characteristics and thermal diffusibility can be used.

Embodiment 3 FIG.
The heating cooker according to the third embodiment includes the configuration of the heating cooker according to the first or second embodiment, and further, cooks in a disaster by coordinating with a home power system and an information device controller. It is provided with a control that can select whether to resume or stop.
A wireless communication receiver or the like provided in the induction heating cooker 100 is connected to a power system (energy management system) provided in the house or the Internet, and a control system for acquiring disaster information is constructed.

FIG. 12 is a configuration diagram showing an electric power system of the heating cooker according to the third embodiment.
The power source of the heating cooker according to Embodiment 3 is configured by drawing a system power source (commercial power source) 400 and an external power source (storage battery) 410 different from the system power source 400 into the house. This external power supply 410 converts a DC power charged in a lithium ion storage battery or the like into an AC power that can be used in the house and supplies it to the house.

  The switching distribution board 420 functions to select an AC power source to be supplied to each outlet (not shown) in the house from the system power source 400 and the external power source 410. The in-home controller 430 communicates with devices (not shown) such as the induction heating cooker 100, for example, by radio to perform energy management in the house.

FIG. 13: is a flowchart at the time of the earthquake response of the heating cooker which concerns on Embodiment 3. FIG.
The heating cooker according to Embodiment 3 receives, for example, an electric power system (energy management system), earthquake information on various places on the Internet, and the like. The earthquake information includes the seismic intensity at the place where the heating cooker is used, the arrival time of the earthquake, and the like.
Therefore, as an example, an operation when one earthquake information of disaster information is received when cooking at a high temperature such as a fried food automatic cooking function is performed will be described below.

First, in step S1, the user presses the “fried food” key of the menu key 32 of the operation unit 3, and the control unit 23 is set in advance in step S2 according to the control sequence stored in the storage unit 21. The heating operation is started so as to be (for example, about 140 ° C. to 200 ° C. in the case of fried food).
In step S3, the control unit 23 reads temperature sensor information (Ttp = output temperature of the infrared temperature detection unit 24, Tth = output temperature of the top plate temperature detection unit 25).
Proceeding to step S4, the pan temperature estimated value (Tobj) is calculated using the output values of Ttp and Tth.
In step S5, preheating control is performed so that the calculated pan temperature estimated value (Tobj) becomes the target temperature.
In step S6, the receiver mounted in the main body 1 receives the earthquake information from the home controller 430, and confirms the presence or absence of the earthquake information.

If there is no earthquake information in step S6, the normal fried food control flow is entered, and the process proceeds to step S7.
In step S7, it is determined whether or not the pot temperature estimated value (Tobj) has reached the first target temperature. When it reaches, it progresses to step S8, preheating control is complete | finished, and it transfers to temperature maintenance control so that the pan temperature estimated value (Tobj) may be maintained at 1st target temperature in step S9. If it has not reached, the process returns to step S6.
In step S <b> 10, normal fried food cooking control is performed, and the control unit 23 performs heating control according to the control sequence stored in the storage unit 21.
Then, in step S11, it is determined whether or not the maximum heating available time (for example, 45 minutes is set) has elapsed since the start of cooking. If not, the process returns to step S9.

Next, the case where there is earthquake information in step S6 will be described.
If there is earthquake information in step S6, it will progress to step S21 and will be in an earthquake notification mode. The control unit 23 notifies the user that earthquake information is contained by voice or display on the display unit 4.
In step S22, it is confirmed whether or not the pan temperature estimated value (Tobj) has reached the first target temperature. When it has reached, it progresses to step S23, and it is confirmed to a user by an audio | voice, the display on the display part 4, etc. whether heating is stopped. If the user instructs to stop heating, or if there is no input, the process proceeds to step S12 to forcibly stop heating. However, when there is no input, after the elapse of a predetermined time, re-notification may be performed before the heating is stopped. While the heating operation is stopped based on this earthquake information, for example, a display to that effect is displayed on the display unit 4.
In step S23, when the user instructs to continue heating, the process proceeds to step S24, temperature maintenance control is performed so that the estimated pan temperature value (Tobj) is maintained at the first target temperature, and the process proceeds to step S25. Control fried food cooking.

In step S22, when the pan temperature estimated value (Tobj) does not reach the first target temperature, the process proceeds to step S31, where the target temperature is lowered to the second target temperature lower than the first target temperature and is set to the safe side. Perform preheating control. The second target temperature is set to about 100 ° C., for example, and is set to a temperature that can return to the first target temperature without taking time during reheating.
In step S <b> 32, it is confirmed to the user by voice, display on the display unit 4, etc., whether or not heating is stopped. If the user instructs to stop heating, or if there is no input, the process proceeds to step S12 to forcibly stop heating. However, when there is no input, after the elapse of a predetermined time, re-notification may be performed before the heating is stopped. While the heating operation is stopped based on this earthquake information, for example, a display to that effect is displayed on the display unit 4.

In step S32, when the user instructs to continue heating, the process proceeds to step S33, and the preheating control is continued so that the estimated pan temperature value (Tobj) is maintained at the second target temperature.
In step S34, it is confirmed whether or not the pan temperature estimated value (Tobj) has reached the second target temperature. If it has not reached, the process returns to step S32, and if it has reached, the process proceeds to step S35 to confirm whether or not to return to normal fried food cooking control by voice or display on the display unit 4. If there is an input that does not return to the normal deep-fried food cooking control, the process returns to step S32. If there is an input that returns to the normal deep-fried food cooking control, the process proceeds to step S36 to perform the normal deep-fried food cooking control.

In addition, when the control part 23 receives the confirmation report without an earthquake prediction by earthquake information at the time of the said earthquake response flow, the control which returns to the normal heating control after displaying the notification to that effect on the audio | voice or the display part 4 is performed. .
In step S22, if the estimated pan temperature value (Tobj) does not reach the first target temperature, the process proceeds to step S31, where the target temperature is lowered to the second target temperature lower than the first target temperature and preheated. Although control is performed, for example, if the magnitude of the earthquake is determined from the earthquake information and the seismic intensity is large, control for reducing the target temperature of the preheating control may be employed.

As mentioned above, when performing earthquake response control of the heating cooker, it is important that the detected temperature of the object to be heated is accurate, and the resistance of the infrared sensor 12 to the noise in the induction heating cooker 100 is increased. is necessary. In the heating cooker according to the third embodiment, the infrared measurement accuracy is improved by adopting the configuration of the sensor case 200 of the infrared sensor 12 according to the first and second embodiments. For example, the frying food automatic cooking control is performed. It is possible to provide convenience to the user by performing control corresponding to a disaster when the object to be heated is heated in a high temperature range of 140 ° C. or higher.
In addition, in Embodiment 3, although the case where the heating operation by a fried food automatic cooking function was performed was demonstrated as an example, it is not limited to this function, and the heating at the time of receiving disaster information during various heating operation control It can be applied as a cooker.

  Although the first to third embodiments have been described above, the present invention is not limited to the description of each embodiment. For example, it is possible to combine all or some of the embodiments.

  DESCRIPTION OF SYMBOLS 1 Main body, 2 Top plate, 3 Operating part, 4 Display part, 5 Thermal power display part, 6 Heating port, 7 Transmission window part, 8 Exhaust port, 9 Intake port, 9a Intake port, 9b Intake port, 10 Pan, 12 Infrared Sensor (corresponding to the infrared detector of the present invention), 12a field of view, 13 coating, 14 heating coil, 14a inner heating coil, 14b outer heating coil, 15 gap, 16 heating coil support, 17 contact temperature sensor, 21 memory Part, 22 operation part, 23 control part, 24 infrared temperature detection part, 25 top plate temperature detection part, 26 high frequency inverter, 31 thermal power setting key, 32 menu key, 100 induction heating cooker, 121 condenser lens, 122 enclosing member , 123 Printed circuit board, 200 Sensor case (corresponding to the sensor case portion of the present invention), 201 side surface, 202 bottom surface 203 mounting piece, 203a opening, 204 upper surface, 205 first upper surface rib, 206 second upper surface rib, 207 bottom surface rib, 210 case opening (corresponding to the sensor case portion opening of the present invention), 220 magnetic shielding plate (of the present invention (Corresponding to the magnetic shield part), 221 magnetic shield plate opening (corresponding to the magnetic shield part opening of the present invention), 222 mounting piece part, 222a opening, 300 optical filter, 400 system power supply, 410 external power supply, 420 switching distribution board, 430 Controller, A aperture of the magnetic shield plate, B aperture of the case opening, C outer diameter of the enclosing member.

Claims (17)

A sensor case structure comprising: an infrared detector that detects infrared; a hollow sensor case that houses the infrared detector; and a magnetic shield attached to the sensor case;
In the sensor case part, an opening of the sensor case part corresponding to a visual field range in which the infrared detection part detects infrared rays,
The magnetic shield part has an opening of the magnetic shield part corresponding to the visual field range,
The opening area of the magnetic shield opening is configured with an area smaller than the opening area of the sensor case opening ,
The sensor case structure , wherein the magnetic shielding portion is disposed outside the sensor case portion . The sensor case part opening and the magnetic shield part opening have a circular shape,
The sensor case structure according to claim 1, wherein an inner diameter of the magnetic shield opening is smaller than an inner diameter of the sensor case opening. The infrared detection unit includes a condenser lens on an upper surface,
3. The sensor case structure according to claim 1, wherein the sensor case portion opening is configured to have a shape that does not overlap an outer shape of the infrared detection portion in a top view. The infrared detector is cylindrical,
The sensor case part opening, the magnetic-shielding part opening, and the central axis of the cylinder of the infrared detection part are arranged coaxially,
The inner diameter of the sensor case part opening is configured to have the same dimension as the outer diameter of the cylinder of the infrared detection part or larger than the outer diameter of the cylinder of the infrared detection part. The sensor case structure according to claim 3, which is dependent on item 2.   The said magnetic-shield part is formed in plate shape, The reflectance of the at least 1 surface of this magnetic-shield part is comprised so that it may become larger than the reflectance of the surface of the said sensor case part. The sensor case structure according to any one of the above.   The magnetic shield portion is formed in a plate shape, and the reflectance of at least one surface of the magnetic shield portion is configured to be larger than the reflectance of the surface of the sensor case portion in the light wavelength region of 0.1 μm or more and 20 μm or less. The sensor case structure according to claim 1, wherein the sensor case structure is formed.   The sensor case structure according to claim 1, wherein an upper surface of the infrared detection unit is disposed below an upper surface of the sensor case unit.   The visual field range in which the infrared detection unit detects infrared rays includes an optical filter having a maximum transmittance in a wavelength region of light of 0.9 μm to 2.6 μm, or 3.2 μm to 4.2 μm. The sensor case structure according to any one of claims 1 to 7.   9. The sensor case structure according to claim 8, wherein the optical filter is made of silicon. The condensing lens of the infrared detection unit has a measurement viewing angle that is 50% or more of the maximum detection output value,
10. The sensor case structure according to claim 1, wherein the measurement viewing angle is within 30 ° with respect to a central axis of the condenser lens.   The sensor case structure according to claim 1, wherein the sensor case portion is made of resin.   The sensor case structure according to claim 1, wherein the magnetic shielding portion is a conductor. A sensor case structure according to any one of claims 1 to 12, a top plate, heating means, and control means,
The infrared detection unit detects infrared rays emitted from an object to be heated on the top plate through the top plate,
The cooking device according to claim 1, wherein the control means performs heating control based on a value detected by the infrared detection unit. It has a receiving means to receive disaster information from outside,
The cooking device according to claim 13, wherein the control unit includes a notification unit that notifies the user that the disaster information has been received when the reception unit receives the disaster information during the heating operation. .   When the receiving means receives the disaster information, the control means performs a notification for selecting whether or not to continue the heating operation with the notification means, and when there is an input to continue the heating operation, The cooking device according to claim 14, wherein the heating operation is stopped when there is an input to continue the operation and stop the heating operation.   16. The control unit according to claim 15, wherein the control unit stops the heating operation when there is no input when the notification unit performs notification for selecting whether to continue the heating operation. The cooking device described.   The cooking device according to any one of claims 14 to 16, wherein when the disaster information is received, the control means lowers a heating target temperature of the object to be heated.

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