JP4207786B2 - Induction heating cooker - Google Patents

Description

  The present invention relates to an induction heating cooker used in general homes, offices, restaurants and the like.

  Conventionally, this type of induction heating cooker is known in which an infrared sensor is provided on the side surface of a cooking vessel, and the amount of heating is controlled by detecting the side surface temperature of the cooking vessel (for example, Patent Document 1). reference).

  As shown in FIG. 7, the top plate 2 on which the cooking container 1 is placed, the heating coil 3 disposed below the top plate 2, and the side surface of the cooking container 1 are disposed. Infrared sensor 4, operating means 5 for operating heating on or off, control means 6 for inductively heating cooking container 1 by applying a high-frequency current to heating coil 3, and the material of cooking container 1 according to inverter characteristics A load detecting means 7 to be specified, and a database 8 for correcting the emissivity of the cooking container 1 based on the temperature signal of the infrared sensor 4 and the signal of the load detecting means 7 are provided.

  When the power source of the operation means 5 or the operation switch is pressed and heating is started, a high frequency magnetic field is generated from the heating coil 3 by a signal from the control means 6. The cooking vessel 1 is heated by this high frequency magnetic field and the temperature rises. The load detection means 7 detects whether the cooking container 1 is an iron-based pan, a non-magnetic stainless steel pan, or a pan that cannot be heated based on the inverter characteristic information. Since the emissivity of the cooking container 1 is as high as 0.8 for iron-based materials and as low as 0.1 for non-magnetic stainless steel, there is an error in the temperature value of the infrared sensor 4. In order to eliminate this error, the emissivity of the cooking container 1 is corrected using the database 8. Here, the emissivity of the cooking container 1 is obtained by the load detection means 7, the temperature of the infrared sensor 4 is corrected, and the temperature of the cooking container 1 is detected.

  Moreover, what has provided the infrared sensor under the cooking container, has detected the bottom face temperature of a cooking container, and controlled the heating amount (for example, refer patent document 2).

This induction heating cooker includes infrared sensors that detect infrared intensities in different wavelength ranges, and detects the emissivity of the cooking vessel from the infrared intensities in different wavelength ranges to detect the temperature of the cooking vessel. It is.
JP 2003-264055 A JP 2003-109736 A

  However, in the said conventional structure, the infrared sensor is provided in the side surface of the cooking container, and the side surface temperature of a cooking container is detected, and the difference arises in the bottom face temperature and side surface temperature of a cooking container depending on the quantity of a foodstuff. It was a thing. Moreover, in the thing which detects the infrared rays of a different wavelength, in order to provide in the center part of a heating coil, it had the subject that size reduction of an infrared sensor was needed.

  The present invention solves the above-described conventional problems, and an object thereof is to provide an induction heating cooker that can stably detect the bottom surface temperature of a cooking container at the center of a heating coil.

  In order to solve the above-mentioned conventional problems, in the induction heating cooker of the present invention, the infrared sensor has a planar shape of a cutout circle partly having a cutout part, and the plate temperature detection means is infrared in plan view. The infrared sensor and the plate temperature detecting means are arranged at the center of the heating coil, and are positioned at the notch of the sensor.

  Thereby, an infrared sensor and a plate temperature detection means can be arrange | positioned in the center part of a heating coil, and the bottom face temperature of the center part of a cooking vessel can be detected stably.

  The induction heating cooker of this invention can detect stably the bottom face temperature of the center part of a cooking container.

  1st invention is the plate temperature detection which detects the temperature of the top plate which mounts a cooking vessel, the heating coil which generate | occur | produces an induction magnetic field in order to heat the said cooking vessel, and the said top plate Means, an infrared sensor for detecting the temperature of the cooking container via the top plate, and a heating control for controlling the heating power by controlling the high frequency current of the heating coil according to the temperature information of the infrared sensor and the plate temperature detecting means The infrared sensor has a planar shape of a circular cutout having a cutout part, and the plate temperature detection means is positioned in the cutout portion of the infrared sensor in plan view. By making the plate temperature detection means an induction heating cooker arranged at the center of the heating coil, the center of the heating coil is infrared. It is possible to place the sensor and the plate temperature detection means, the bottom surface temperature of the central portion of the cooking container can be detected stably.

  In particular, according to a second aspect of the present invention, in the first aspect, the infrared sensor includes a magnetic shield that reduces an induced magnetic field or an electric field radiated from the heating coil, and an infrared condensing unit that is connected to the magnetic shield and located inside the magnetic shield. The temperature detection error by the infrared sensor can be prevented from occurring.

  According to a third aspect of the invention, in particular, in the second aspect of the invention, the magnetic shield tube and the lens barrel are connected at a lower position than the heating coil, so that the infrared sensor is influenced by the induction magnetic field or electric field radiated from the heating coil. The temperature of the cooking container can be detected stably.

  According to a fourth aspect of the invention, in particular, in the second or third aspect of the invention, the magnetic-shielding cylinder is provided with a concave portion for ventilation in the vertical direction, thereby improving air permeability by the action of the concave portion and reducing temperature rise. It is possible to prevent temperature detection errors caused by the infrared sensor.

  According to a fifth aspect of the invention, in particular, in any one of the first to fourth aspects of the invention, the positioning sensor is provided on at least one of the heating coil and the infrared sensor, so that the infrared sensor is reliably attached to the heating coil. Can be positioned and mounted.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In addition, this invention is not limited by this embodiment.

(Embodiment 1)
1 and 2 show an induction heating cooker according to Embodiment 1 of the present invention.

  As shown in FIG. 1, the induction heating cooker according to the present embodiment includes a cooking container 21 that accommodates and heats food, a top plate 22 on which the cooking container 21 is placed, and the cooking container 21. A heating coil 23 comprising a heating coil for generating an induction magnetic field, plate temperature detecting means 24 comprising a thermistor for detecting the temperature of the cooking vessel 21 in contact with the top plate 22, and the cooking vessel 21 via the top plate 22 An infrared sensor 25 comprising a photodiode for detecting the temperature of the heater, and a heating control means 26 for controlling the heating power by controlling the high-frequency current of the heating coil 23 based on the temperature information of the infrared sensor 25 and the plate temperature detecting means 24; It has.

  As shown in FIG. 2, the infrared sensor 25 is configured such that the entire planar shape thereof is a cutout circular shape having a cutout portion 25 a in a part thereof, and a sensor element 25 b is arranged at the center portion thereof. It is a sensor unit. The plate temperature detecting means 24 is positioned in the notch 25a of the infrared sensor 25 in plan view. The infrared sensor 25 and the plate temperature detection means 24 are arranged at the center of the heating coil 23 in the arrangement configuration. Thereby, the temperature of the center part of the cooking vessel 21 is detected by the infrared sensor 25 and the plate temperature detection means 24. In the present embodiment, the cutout portion 25a of the infrared sensor 25 is formed linearly, but the present invention is not limited to this.

  The top plate 22 is formed of a lithia ceramic material. As for the infrared transmittance of the top plate 22, a wavelength of 2.5 μm or less is transmitted well, and a wavelength of 2.5 μm to 4 μm or less is transmitted by several tens of percent. Moreover, 4 μm or more is hardly transmitted.

  The sensor element 25b of the infrared sensor 25 is made of an InGaAs (indium gallium arsenide) photodiode, and has a light receiving sensitivity wavelength of about 0.7 μm to about 2.7 μm. The sensor element 25b uses a photodiode, but a PIN photodiode, PbS (lead sulfide), PbSe (lead selenide), or Ge (germanium) can perform the same operation. The infrared sensor 25 may use a thermal infrared detection element such as a thermopile or a pyroelectric element, and the same effect can be obtained by using a transmission window through which infrared light passes through the top plate 22.

  Furthermore, although the infrared sensor 25 is provided at the center where the cooking vessel 21 is placed on the top plate 22, it is only necessary to detect the temperature of the cooking vessel 21 and is not limited to the present embodiment. Further, if a plurality of infrared sensors 25 are provided to detect the temperature of the cooking vessel 21, the temperature distribution of the cooking vessel 21 can be detected and the temperature of the cooking vessel 21 can be controlled with higher accuracy. .

  About the induction heating cooking appliance comprised as mentioned above, the operation | movement and an effect | action are demonstrated below.

  First, when a power supply (not shown) is turned on and heating is started by a switch, the heating control means 26 supplies a high-frequency current to the heating coil 23. When a high frequency current is supplied to the heating coil 23, an induction magnetic field is generated from the heating coil 23, and the cooking vessel 21 placed on the top plate 22 is induction heated. Due to this induction heating, the temperature of the cooking vessel 21 rises, and the food in the cooking vessel 21 is cooked. At this time, the heating control means 26 can grasp the cooking progress of the cooked food based on the temperature information from the infrared sensor 25, and adjusts the power supplied to the heating coil 23 according to the cooking progress. Thus, the food in the cooking container 21 is cooked by heating.

  The infrared sensor 25 includes a sensor element 25 b made of a photodiode, and detects thermal energy radiated from the bottom surface of the cooking vessel 21 through the top plate 22. The infrared sensor 25 calculates the temperature of the cooking vessel 21 by changing the amount of light, which is the thermal energy, into current or voltage. Thus, since the infrared sensor 25 detects the bottom surface of the cooking container 21 in a non-contact manner and calculates the cooking container 21 temperature, the responsiveness is fast and the temperature of the cooking container 21 can be accurately detected. It can be done. For this reason, the electric power control for the heating coil 23 of the heating control means 26 is also adapted to the temperature change of the cooking vessel 21. The light receiving sensitivity of the infrared sensor 25 overlaps with the transmittance of the top plate 22, and the light energy emitted from the cooking container 21 can be detected to detect the bottom temperature of the cooking container 21.

  The plate temperature detection means 24 is provided so as to be in close contact with the top plate 22 and detects the bottom surface temperature of the cooking vessel 21 via the top plate 22. The temperature signal of the plate temperature detecting means 24 is sent to the heating control means 26, and the electric energy of the heating coil 23 is controlled based on the temperature signal. That is, the plate temperature detection means 24 and the infrared sensor 25 are disposed at the center of the heating coil 23 and can detect the temperature of the center heated by the cooking vessel 21. The center temperature of the cooking vessel 21 that is the center of the heating coil 23 is a temperature that is less affected by induction heating and that is close to the temperature of the food in the cooking vessel 21, and is detected by the plate temperature detection means 24 and the infrared sensor 25. By detecting the temperature at the center, the temperature of the food can be controlled appropriately.

  As described above, in the present embodiment, the plate temperature detecting means 25 and the infrared sensor 25 are arranged at the center of the heating coil 23, and the bottom surface temperature of the center of the cooking vessel 21 is accurately detected stably. An induction heating cooker that can be used is realized.

(Embodiment 2)
FIG. 3 shows an infrared sensor of the induction heating cooker in the second embodiment of the present invention. The same elements as those of the first embodiment are denoted by the same reference numerals and the description thereof is omitted.

  The difference between the present embodiment and the first embodiment is that the infrared sensor 25 is connected by a magnetic shield cylinder 27 for reducing the induction magnetic field or electric field radiated from the heating coil 23, and the magnetic shield cylinder 27 and the member 27a. This includes an infrared condensing lens barrel 28 located inside the tube 27, which reduces the thermal effect of the magnetic shield tube 27 and prevents temperature detection errors caused by the infrared sensor 25.

  The magnetic shield cylinder 27 is made of an aluminum material to reduce the induction magnetic field and electric field from the heating coil 23. The magnetic shield 27 can be formed of a magnetic material such as ferrite or combined with a magnetic material to reduce the induction magnetic field and electric field.

  About the induction heating cooking appliance comprised as mentioned above, the operation | movement and an effect | action are demonstrated below.

  The magnetic shield cylinder 27 generates heat by an induction magnetic field or an electric field generated from the heating coil 23. It is necessary to reduce that the temperature of the magnetic shield cylinder 27 is transmitted to the lens barrel 28. The lens barrel 28 has a mirror-finished inner surface for condensing infrared rays on the internal sensor element 25 b, and the temperature change of the lens barrel 28 becomes a temperature detection error of the infrared sensor 25. In order to reduce the temperature change of the lens barrel 28, the connecting portion with the magnetic-shielding tube 27 is connected with a member 27a having a relatively small cross section in order to increase the thermal resistance. With this configuration, the infrared sensor 25 can detect the bottom surface temperature of the cooking vessel 21 stably by reducing the influence of the temperature of the magnetic shield cylinder 27.

  As described above, in the present embodiment, by providing the magnetic shield cylinder 27 and the lens barrel 28 connected thereto, the thermal effect from the magnetic shield cylinder 27 is reduced, and the infrared sensor 25 is stabilized. The temperature of the cooking vessel 21 can be detected.

(Embodiment 3)
FIG. 4 shows an infrared sensor of the induction heating cooker in Embodiment 3 of the present invention. The same elements as those in the first and second embodiments are denoted by the same reference numerals and description thereof is omitted.

  The difference between the second embodiment and the second embodiment is that the magnetic-shielding cylinder 27 and the lens barrel 28 are connected by a member 27 a at a position below the lower surface of the heating coil 23. Thereby, the infrared sensor 25 can reduce the influence of the induction magnetic field or electric field radiated from the heating coil 23, and can stably detect the temperature of the cooking vessel 21.

  About the induction heating cooking appliance comprised as mentioned above, the operation | movement and an effect | action are demonstrated below.

  The lens barrel 28 is connected to the magnetic-shielding cylinder 27 for mechanical holding, and generates heat by receiving an induction magnetic field or an electric field radiated from the heating coil 23 in the same manner as the magnetic-shielding cylinder 27. The magnetic shield tube 27 is connected to the lens barrel 28 at a position below the heating coil 23 by the member 27a, thereby reducing heat generation due to the induction magnetic field and electric field of the heating coil 23. The influence of the induction magnetic field is reduced by separating the distance from the heating coil 23, and the influence is reduced. Taking advantage of this characteristic, the infrared sensor 25 can reduce the influence of the induction magnetic field by connecting the magnetic shield cylinder 27 and the lens barrel 28 at a position below the heating coil 23.

  As described above, in the present embodiment, the magnetic shield cylinder 27 and the lens barrel 28 are connected at a position below the heating coil 23 to reduce the induction magnetic field or electric field radiated from the heating coil 23. Thus, the infrared sensor 25 can stably detect the temperature of the cooking vessel 21.

(Embodiment 4)
FIG. 5 shows an infrared sensor of an induction heating cooker in Embodiment 4 of the present invention. The same elements as those in the first to third embodiments are denoted by the same reference numerals and description thereof is omitted.

  The difference between the third embodiment and the third embodiment is that the magnetic-shielding tube 27 is provided with a ventilation recess 27b in the vertical direction at the connection portion with the lens barrel 28, thereby providing air permeability by the action of the recess 27b. It was improved and the temperature rise was reduced. Thereby, it can prevent that the temperature detection error by the infrared sensor 25 arises. In the present embodiment, as shown in the figure, both the magnetic shield cylinder 27 and the lens barrel 28 are directly connected without using a connection member.

  In the present embodiment, the concave portion 27b of the magnetic shielding cylinder 27 is provided on the plate temperature detecting means 24 side, but it is only necessary to improve the air permeability, and is not limited to this. Further, for example, the performance can be improved by providing a plurality of recesses 27b.

  As described above, in the present embodiment, by providing the magnetically shielded cylinder 27 with the concave portions 27b for ventilation in the vertical direction, the air permeability can be improved and the temperature rise can be reduced. Thereby, the infrared sensor 25 can detect the temperature of the cooking container 21 stably by doing.

(Embodiment 5)
FIG. 6 shows an induction heating cooker according to the fifth embodiment of the present invention. The same elements as those in the first to fourth embodiments are denoted by the same reference numerals and description thereof is omitted.

  The difference between the present embodiment and the first to fourth embodiments is that a positioning rib 23 a is provided on at least one of the heating coil 23 and the infrared sensor 25. Thereby, the infrared sensor 25 can be reliably positioned and attached to the heating coil 23.

  In the present embodiment, a convex rib 23a is provided on the lower surface of the coil base that holds the heating coil 23, and the infrared sensor 25 is positioned when the unit of the infrared sensor 25 is mounted. As described above, the infrared sensor 25 is mechanically fixed to the heating coil 23 so that the temperature detection error of the infrared sensor 25 due to the attachment can be reduced.

  The convex rib 23a of the heating coil 23 only needs to be able to regulate the position of the combination with the infrared sensor 25. For example, a configuration in which a concave portion is provided on the coil base and the convex portion of the infrared sensor 25 is combined, or both are ribs. It is also possible to consider a configuration in which

  As described above, in the present embodiment, since the infrared sensor 25 is positioned by the rib, the temperature detection error due to the attachment of the infrared sensor 25 can be reduced.

  As described above, the induction heating cooker according to the present invention prevents the influence of infrared rays radiated from the electric heater even in a heating cooker in which an electric heater such as a radial heater is combined in addition to the induction heating. In addition, since the temperature of the cooking container can be stably detected by the infrared sensor, it can be applied to general induction heating cookers used in general homes, offices, restaurants and the like.

Sectional drawing which shows the structure of the induction heating cooking appliance in Embodiment 1 of this invention. Sectional drawing which shows the structure of the infrared sensor of the induction heating cooking appliance Sectional drawing which shows the structure of the infrared sensor in Embodiment 2 of this invention. A longitudinal sectional view showing a configuration of an infrared sensor according to Embodiment 3 of the present invention. Sectional drawing which shows the structure of the infrared sensor in Embodiment 4 of this invention. Sectional drawing which shows the structure of the induction heating cooking appliance in Embodiment 5 of this invention. Sectional drawing which shows the structure of the induction heating cooking appliance of a prior art example

Explanation of symbols

DESCRIPTION OF SYMBOLS 21 Cooking container 22 Top plate 23 Heating coil 24 Plate temperature detection means 25 Infrared sensor 25a Notch 25b Sensor element 26 Heating control means 27 Magnetic-shielding cylinder 28 Lens barrel

Claims (5)

A top plate on which the cooking container is placed; a heating coil for generating an induction magnetic field to heat the cooking container; plate temperature detecting means for detecting the temperature of the cooking container in contact with the top plate; and the top plate An infrared sensor for detecting the temperature of the cooking container via the heating means, and a heating control means for controlling the heating power by controlling the high-frequency current of the heating coil according to the temperature information of the infrared sensor and the plate temperature detection means, The infrared sensor has a planar shape with a cutout circle partly having a cutout portion, and the plate temperature detection means is positioned in the cutout portion of the infrared sensor in plan view, and the infrared sensor and the plate temperature detection means are An induction heating cooker placed in the center of the heating coil. 2. The induction according to claim 1, wherein the infrared sensor includes a magnetic shield that reduces an induced magnetic field or an electric field radiated from the heating coil, and an infrared condensing barrel that is connected to the magnetic shield and located inside the magnetic shield. Cooking cooker. The induction heating cooker according to claim 2, wherein the magnetic-shielding cylinder and the lens barrel are connected at a position below the heating coil. The induction heating cooker according to claim 2 or 3, wherein the magnetic-shielding cylinder is provided with a recess for ventilation in the vertical direction. The induction heating cooker according to any one of claims 1 to 4, wherein a positioning rib is provided on at least one of the heating coil and the infrared sensor.

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