JP7304304B2 - Gas stove - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas stove that determines the temperature of the bottom of a cooking utensil by detecting infrared rays emitted from the bottom of the cooking utensil with an infrared sensor.

Conventionally, there has been proposed a gas stove that detects infrared rays radiated from cooking utensils with an infrared sensor and determines the temperature of the bottom of the cooking utensils in a non-contact manner based on the infrared intensity of the detected infrared rays (for example, Patent Document 1). .

Japanese Patent Application Laid-Open No. 2002-340339

By the way, since the burner itself that heats the cooking utensil during cooking is also a high-temperature heating element, infrared rays emitted from the burner are also detected by the infrared sensor. Therefore, an infrared sensor may be provided at a position where it is difficult to receive the infrared rays emitted from the burner, or a shielding means may be provided. As a result, infrared rays emitted from the bottom of the cooking utensil and infrared rays emitted from the burner and reflected from the bottom of the cooking utensil are superimposed and detected by the infrared sensor, resulting in misdetection of the temperature of the bottom of the cooking utensil. There is a problem.

SUMMARY OF THE INVENTION An object of the present invention is to provide a gas stove capable of accurately determining the bottom temperature of a cooking utensil heated by a burner.

According to the invention,
burner and
a burner temperature detecting means for detecting a burner temperature;
an infrared sensor for detecting infrared rays emitted from the bottom of the cooking utensil placed on the burner;
a control means for calculating the bottom temperature of the pan of the cooking utensil, wherein the control means comprises a reflective burner source infrared rays radiated from the burner and reflected by the pan bottom of the cooking utensil based on the burner temperature detected by the burner temperature detecting means; Calculate the source infrared intensity,
A gas stove is provided that calculates the pot bottom temperature of the cookware by subtracting the calculated reflected burner source infrared intensity from the infrared intensity of the infrared detected by the infrared sensor.

Once the burner temperature of the heated burner is obtained, it is possible to calculate the reflected burner source infrared intensity of the reflected burner source infrared radiation emitted from the burner and reflected by the bottom of the cooking utensil. Therefore, by subtracting the reflected burner source infrared intensity calculated based on the burner temperature from the infrared intensity detected by the infrared sensor, the pan bottom temperature of the cookware excluding the influence of the disturbance due to the infrared ray radiated from the burner is calculated. be able to.

Preferably, in the above gas stove,
The control means calculates the reflected burner source infrared intensity based on the burner temperature detected by the burner temperature detection means and the reflectance of the bottom of the cooking utensil.

The intensity of the reflected burner source infrared rays detected by the infrared sensor varies depending on the reflectance of the bottom of the cooking utensil due to the material, surface shape, and the like. Therefore, according to the above gas stove, the pan bottom temperature of the cooking utensil can be calculated more accurately based on the corrected reflected burner source infrared intensity calculated in consideration of the reflectance of the pan bottom of the cooking utensil.

Preferably, in the above gas stove,
An infrared sensor is provided in a space located in the center of the burner.

According to the above gas stove, it is possible to further reduce the influence of disturbance due to infrared rays radiated from the flame.

Preferably, the gas stove further includes:
A light emitting part for measuring the reflectance of the bottom of the cooking utensil is provided in the space, and the control means detects reflected infrared rays emitted from the light emitting part detected by the infrared sensor and reflected by the bottom of the cooking utensil. Based on the intensity, the reflectance of the bottom of the cookware is calculated.

When the infrared sensor detects the reflected infrared rays emitted from the light emitting part and reflected by the bottom of the cooking utensil, the anti-slant ratio of the bottom of the cooking utensil is calculated from the intensity of the reflected infrared rays and the infrared intensity of the infrared rays emitted by the light emitting part. be able to. Therefore, according to the above gas stove, it is possible to calculate the reflected burner source infrared intensity based on the reflectance according to the cooking utensil used.

INDUSTRIAL APPLICABILITY As described above, according to the present invention, it is possible to provide a gas stove capable of accurately determining the temperature of the bottom of a cooking utensil using an infrared sensor.

FIG. 1 is a schematic cross-sectional view of essential parts showing an example of a gas stove according to an embodiment of the present invention. FIG. 2 is a block diagram showing an example of a controller included in the gas stove according to the embodiment of the invention. FIG. 3 shows infrared rays radiated from the bottom of the cooking utensil, infrared rays radiated from the burner, infrared rays radiated from the burner reflected from the bottom of the cooking utensil, and infrared rays radiated from the burner reflecting from the utensil and the bottom of the cooking utensil. FIG. 2 is a characteristic diagram showing an example of each infrared spectrum. FIG. 4 shows infrared rays radiated from the bottom of the cooking utensil, infrared rays radiated from the burner, infrared rays radiated from the burner reflected from the bottom of the cooking utensil, and infrared rays radiated from the burner reflecting from the utensil and the bottom of the cooking utensil. FIG. 10 is a characteristic diagram showing another example of each infrared spectrum.

Hereinafter, gas stoves according to embodiments of the present invention will be specifically described with reference to the drawings.
As shown in FIG. 1, the gas stove according to the present embodiment includes a top plate 2 having a burner opening 21 through which a burner 1 faces. The burner 1 includes a burner body 12 extending upward from the downstream end of the mixing tube 11 and inserted into the burner opening 21 , and an annular burner cap 16 mounted on the burner body 12 .

The burner body 12 is provided with an inner cylinder 121 and an outer cylinder 122 and is formed in a hollow annular shape. An inwardly bent flange 122 a is formed at the upper end of the outer cylinder 122 . A burner ring 3 covering the burner opening 21 from above is fitted to the outer cylinder 122 . Further, the burner ring 3 is fitted with a trivet 9 for placing the cooking utensil P above the burner 1 at a predetermined interval. In addition, in FIG. 1, only the bottom surface of the cooking utensil P is illustrated.

A seal tube portion 161 that fits inside the upper end portion of the inner tube 121 is vertically provided on the inner peripheral portion located in the center of the burner cap 16 . Therefore, a space 163 that opens vertically is formed in the central portion of the burner cap 16 . Further, an annular wall 162 is protruded from the outer peripheral portion of the lower surface of the burner cap 16 so as to contact the upper surface of the inwardly bent flange 122a of the outer cylinder 122 forming the outer peripheral portion of the upper surface of the burner body 12 . The annular wall 162 is formed with a plurality of flame holes 19 formed of grooves spaced apart in the circumferential direction. Therefore, the air-fuel mixture (mixed gas of fuel gas and primary air) from the mixing tube 11 is ejected outward from the flame hole 19, and when the air-fuel mixture is ignited by an ignition electrode attached to the burner 1 (not shown), the flame An outwardly extending flame is formed in hole 19 . An annular wall that abuts against the outer periphery of the lower surface of the burner cap 16 may be protruded from the outer periphery of the upper surface of the burner body 12, and the flame hole may be formed in this annular wall.

The cylindrical seal portion 161 of the burner cap 16 forming the space 163 is provided with a thermistor 170 (a burner temperature detection unit), which is contact-type temperature detection means for detecting the temperature of the burner cap 16 by coming into contact with the cylindrical seal portion 161 . means) are provided. The thermistor 170 outputs a detection signal corresponding to the detected temperature to the controller 100, which will be described later. As a result, the temperature of the burner 1 can be directly detected without being affected by disturbance.

In the vicinity of the upper end open portion of the space portion 163, the infrared light receiving portion 5 and the reflectance measuring light emitting portion 6 are arranged in parallel in the radial direction. The infrared light receiving section 5 has an infrared sensor 51 and a light receiving cap 52 covering the infrared sensor 51 from above. The infrared sensor 51 receives infrared rays emitted from the bottom of the cooking utensil P. As the infrared sensor 51, conventionally known quantum sensors such as infrared photodiodes and infrared phototransistors, and thermal sensors such as thermopiles and pyroelectric elements can be used. The infrared sensor 51 outputs an output signal corresponding to the intensity of received infrared rays to the controller 100, which will be described later. By arranging the infrared sensor 51 in the space 163 provided in the central part of the burner 1, the infrared ray emitted from the burner 1 is difficult to be directly received by the infrared sensor 51, and is not emitted from sunlight and flame. It is possible to reduce the influence of disturbance due to infrared rays.

The light-receiving cap 52 has a hat-shaped cross section, and has a window in the central upper surface. Therefore, the infrared rays radiated from the bottom of the cooking utensil P enter the infrared sensor 51 through the window. When the infrared sensor 51 without wavelength selectivity is used, the window is provided with an optical filter 55 that selectively transmits infrared rays within a certain wavelength range. Alternatively, the infrared sensor 51 having wavelength selectivity may be used without the optical filter 55 .

The reflectance measurement light emitting unit 6 has a light source 61 for emitting infrared rays. A conventionally known infrared LED or the like can be used as the light source 61 . The light source 61 is connected to the controller 100 and emits infrared rays toward the bottom of the cooking appliance P when the burner 1 is extinguished, and the infrared sensor 51 detects the infrared rays reflected by the bottom of the cooking appliance P. do. The infrared intensity of the infrared rays emitted from the light source 61 and detected by the infrared sensor 51 is proportional to the reflectance of the pan bottom of the cookware P. In general, since the infrared transmittance of the cooking utensil P can be regarded as 0, the bottom of the cooking utensil P has a relationship of reflectance+emissivity=1.

As shown in FIG. 2, the controller 100 receives a detection signal corresponding to the burner temperature detected and output by the thermistor 170 and an output signal corresponding to the infrared intensity received and output by the infrared sensor 51 . The controller 100 is configured using a microcomputer, and configured to execute various controls by executing a predetermined computer program. In addition, the controller 100 includes, as functional components, a light emission control unit 101 that controls the irradiation of infrared rays from the light source 61, and the infrared rays emitted from the light source 61 are reflected by the bottom of the cooking utensil P and detected by the infrared sensor 51. A reflectance calculation unit 102 for calculating the reflectance of the bottom of the cooking utensil P based on the intensity of the reflected infrared rays reflected, and the emissivity of the bottom of the cooking utensil P from the calculated reflectance of the bottom of the cooking utensil P. Based on the temperature detected by the emissivity calculator 103 and the thermistor 170 and the calculated reflectance of the pan bottom of the cooking utensil P, the reflected burner source infrared rays radiated from the burner 1 and reflected by the pan bottom of the cooking utensil P a reflected burner source infrared intensity calculation unit 104 for calculating the reflected burner source infrared intensity, and a pot bottom temperature calculation unit for calculating the pot bottom temperature of the cooking utensil P by subtracting the reflected burner source infrared intensity from the infrared intensity of the infrared rays detected by the infrared sensor 51. 105 and the like. Therefore, in this embodiment, the controller 100 functions as control means. The storage unit 110 of the controller 100 stores a data table including emissivity of the burner 1, correlation data between the pot bottom temperature of the cooking utensil P and the infrared intensity, and correlation data between the burner temperature and the burner source infrared intensity corresponding to the temperature. stored. Since the emissivity of the burner 1 is a value specific to the appliance and is constant, the correlation data between the burner temperature and the burner source infrared intensity can be obtained in advance by experiment.

3 and 4 show the spectral spectrum (line (a)) of the cookware source infrared rays radiated from the cookware P (temperature: 150°C), from the burner 1 (temperature: 250°C, emissivity: 0.9) The spectral spectrum of the emitted burner source infrared radiation (line (b)), the spectral spectrum of the reflected burner source infrared radiation reflected by the pan bottom of the cooking utensil P (line (c)), and the cooking utensil source infrared radiation emitted from the cooking utensil P. and the reflected burner source infrared rays reflected by the bottom of the cooking utensil P are superimposed on each other and detected by the infrared sensor 51 (line (d)). 0.8, and FIG. 4 shows the case where the reflectance of the cooking utensil P is 0.2.

As shown in FIGS. 3 and 4, the intensity of the infrared rays received by the infrared sensor 51 (line (d)) is the intensity of the cookware source infrared rays (line (a)) of the cookware P and the intensity of the infrared rays radiated from the burner 1. The intensity of the reflected burner source infrared rays (line (c)) of the reflected burner source infrared rays reflected by the bottom of the pan of the cooking utensil P is superimposed. That is, the intensity of the infrared rays detected by the infrared sensor 51, the intensity of the cookware source infrared rays emitted from the pan bottom of the cooking appliance P, and the burner source infrared rays emitted from the burner 1 are as follows. The relationship of the formula (1) is established.
Ip·εp=I−(Ib·εb·rp) (1)
In the above formula, I is the infrared intensity of the infrared rays detected by the infrared sensor 51, Ip is the intensity of the cookware source infrared rays radiated from the pan bottom of the cookware P, and Ib is the intensity of the cookware source infrared rays radiated from the burner 1. εp is the emissivity of the pan bottom of the cookware P, εb is the emissivity of the burner 1, and rp is the reflectance of the pan bottom of the cookware P.

As described above, the emissivity of the burner 1 is a value unique to the appliance and is constant. Therefore, in the above equation, if the burner temperature of the heated burner 1 is directly detected by the thermistor 170, the burner temperature and the infrared rays The burner source infrared intensity corresponding to the burner temperature can be calculated from the intensity correlation data. In addition, the intensity of the reflected burner source infrared rays detected by the infrared sensor 51 varies depending on the reflectance of the bottom of the cooking utensil P caused by the material, surface shape, and the like. Therefore, by subtracting the reflected burner source infrared intensity calculated based on the burner temperature and the reflectance of the pan bottom of the cooking utensil P from the infrared intensity detected by the infrared sensor 51, the cooking power emitted from the pan bottom of the cooking utensil P is obtained. Instrument source infrared intensity can be calculated. Since there is a certain correlation between the pan bottom temperature and the infrared intensity, using the correlation data between the pan bottom temperature and the infrared intensity of the cooking utensil P, the cooking utensil P corresponding to the calculated cooking utensil source infrared intensity can be obtained. You can find the bottom temperature of the pan. In addition, the infrared rays detected by the infrared sensor 51 preferably have a wavelength range that is less affected by disturbance due to sunlight or infrared rays radiated from flames.

As described above, according to the present embodiment, it is possible to calculate the pan bottom temperature of the cookware P excluding the influence of the disturbance caused by the infrared rays emitted from the burner 1 . Further, according to the present embodiment, since the reflected burner source infrared ray intensity corrected in consideration of the reflectance of the bottom of the cooking utensil P is calculated, the temperature of the bottom of the cooking utensil P can be calculated more accurately. In addition, since infrared rays are emitted from the light source 61 of the reflectance measurement light emitting unit 6 to measure the reflectance and emissivity of the pan bottom of the cooking utensil P, the correct reflectance and emissivity according to the cooking utensil P to be used can be obtained. can be used to calculate the pan bottom temperature of the cookware P. Further, by calculating the reflected burner source infrared intensity using the correlation data between the burner temperature and the burner source infrared intensity obtained by actual measurement, the pan bottom temperature of the cookware P can be calculated more accurately.

(Other embodiments)
(1) In the above embodiment, the cookware is irradiated with infrared rays of a predetermined infrared intensity, and the reflectance and emissivity of the cookware are calculated based on the intensity of the reflected infrared rays reflected by the cookware. However, if the cookware to be used is fixed, the previously measured reflectance and emissivity of the cookware may be used without providing irradiation means. Alternatively, the reflectance of the cookware may be determined using infrared rays emitted by the flame of the burner without providing the light emitting portion.

(2) In the above embodiment, only the reflected burner source infrared intensity from the burner that greatly affects the infrared intensity detected by the infrared sensor is subtracted. Infrared rays from heating elements may also be considered.

(3) In the above embodiment, the infrared sensor is provided at the center of the burner, but it may be provided below the burner ring or the top plate as long as the infrared ray emitted from the bottom of the cooking utensil can be detected.

REFERENCE SIGNS LIST 1 burner 6 light-emitting unit for reflectance measurement 51 infrared sensor 100 controller 163 space 170 thermistor P cooking utensil

Claims (4)

burner and
a burner temperature detecting means for detecting a burner temperature;
an infrared sensor for detecting infrared rays emitted from the bottom of the cooking utensil placed on the burner;
and a control means for calculating the bottom temperature of the cooking utensil,
Based on the burner temperature detected by the burner temperature detection means, the control means calculates the intensity of the reflected burner source infrared rays emitted from the burner and reflected by the bottom of the pan of the cooking utensil,
A gas stove that calculates the bottom temperature of a cooking utensil by subtracting the infrared intensity of a reflected burner source calculated from the infrared intensity of infrared rays detected by an infrared sensor. In the gas stove according to claim 1,
The control means is a gas stove for calculating the reflected burner source infrared intensity based on the burner temperature detected by the burner temperature detection means and the reflectance of the bottom of the cooking utensil. In the gas stove according to claim 1 or 2,
The infrared sensor is a gas stove installed in the space located in the center of the burner. The gas stove according to claim 3 further comprises
A light emitting part for measuring the reflectance of the bottom of the cooking utensil is provided in the space, and the control means detects reflected infrared rays emitted from the light emitting part detected by the infrared sensor and reflected by the bottom of the cooking utensil. A gas stove that calculates the reflectance of the bottom of the cooking utensil based on the intensity.

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