JP2011138799A - Induction heating cooker - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an induction heating cooker carrying out proper temperature measurement while removing effects from adjacent heating coils or outside light, in the induction heating cooker carrying out temperature control by detecting infrared rays emitted from a cooking utensil with an infrared sensor and finding temperature of the cooking utensil based on an infrared volume. <P>SOLUTION: The cooker includes a top plate on which a cooking utensil is loaded for heating an object to be cooked, a plurality of heating coils generating induction magnetic fields for heating the cooking utensil, an infrared sensor detecting infrared rays emitted from the cooking utensil heated by the heating coils, a means for determining existence of a cooking utensil at start of heating, a temperature detecting means converting temperature of the cooking utensil from energy received from the infrared sensor only when the cooking utensil is loaded on the top plate, and an inputting means inputting conditions for carrying out heating in the heating control means. The infrared sensor, prepared for all the heating coils, is placed outside and toward a rear side of the center of each heating coil. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an induction heating cooker that detects infrared rays emitted from a cooking vessel with an infrared sensor, obtains the temperature of the cooking vessel based on the amount of infrared rays, and performs temperature control.

Conventional induction heating devices include the following configurations.
A top plate on which a cooking vessel for heating the food is placed, an infrared sensor for detecting infrared rays emitted from the cooking vessel through the top plate, and temperature detection for converting the temperature of the cooking vessel from the energy received by the infrared sensor Heating means for generating an induction magnetic field to heat the cooking container, heating control means for controlling the heating power amount of the cooking container by controlling the high-frequency current of the heating coil according to temperature information of the temperature detection means, The heating control means is provided with an input means for inputting conditions for heating, and the infrared sensor is an induction heating device disposed in the vicinity of the heating coil on the input means side from the center of the heating coil (see, for example, Patent Document 1).

JP 2008-262719 (page 14, FIG. 6)

In the conventional technology, the vicinity of the heating coil on the input means side from the center of the heating coil or the vicinity of the heating coil in the center direction of the top plate from the center of the heating coil is not easily affected by external light such as sunlight. It is said to be the most suitable position for placing the sensor.
However, in a state where the cooking container is mounted on the top plate, the outside light does not reach the infrared sensor because the outside light is blocked by the cooking container. Rather, in the case of a one-handed pan, in order to prevent the handle from sticking out of the induction heating cooker, it is often placed behind the center of the heating coil. In this case, the input means starts from the center of the heating coil. If an infrared sensor is arranged in the vicinity of the heating coil on the side, there may be no pan directly above the infrared sensor, and there is a disadvantage that the temperature cannot be measured correctly.
In addition, when an infrared sensor is arranged near the heating coil in the center direction of the top plate from the center of the heating coil, the top plate is heated by the heat from the adjacent heating coil, and receives infrared rays from the heated top plate. There is a drawback that the temperature cannot be measured correctly.

  This invention is made in order to solve the above subjects, and obtains the induction heating apparatus which can measure the temperature of a cooking container correctly and can perform suitable cooking.

  In the induction heating device according to the present invention, a top plate on which a cooking container for heating the food is placed, an operation unit that is provided on the front side of the top plate and performs various operations for heating the heating coil, A plurality of heating coils provided on the left and right sides of the top plate for generating an induction magnetic field to heat the cooking container, and provided for each heating coil, emitted from the cooking container heated by the heating coil An infrared sensor that detects infrared rays, and a contact-type temperature sensor that is provided for each heating coil and indirectly detects the heat of the cooking container via the top plate. It is installed in the infrared sensor mounting area provided on the end side of the top plate outside the center and on the back side of the center of the heating coil. That.

  In this invention, the infrared sensor is provided for each heating coil, and is installed outside and behind the center of each heating coil. Therefore, even when a plurality of heating coils are operated simultaneously, they are adjacent to each other. By operating the heating coil, it is not affected by the infrared rays radiated from the adjacent heating coils themselves, or the infrared rays radiated from the top plate heated by the heat from the cooking container placed immediately above the adjacent heating coils. And even when the one-handed pan is placed out of position, there is always a cooking container immediately above the infrared sensor, so that the temperature can be detected correctly.

It is a top view of the induction heating cooking appliance which shows Embodiment 1 of this invention. It is a side view of the induction heating cooking appliance which shows Embodiment 1 of this invention. It is a figure which shows the infrared sensor installation position of the induction heating cooking appliance which shows Embodiment 1 of this invention. It is a top view of the induction heating cooking appliance which shows Embodiment 2 of this invention. It is a side view of the induction heating cooking appliance which shows Embodiment 2 of this invention.

Embodiment 1 FIG.
FIG. 1 is a top view of an induction heating cooker according to Embodiment 1 for carrying out the present invention, and is a view of an induction heating cooker equipped with three heating coils as viewed from above, and an infrared sensor. This indicates the mounting position. In the figure, the shaded area indicates the area where the infrared sensor is mounted. As viewed from the operation unit, the mounting area is on the outer side and the rear side from the center of each heating coil. FIG. 2: shows the side view of the induction heating cooking appliance in Embodiment 1 for implementing this invention, and shows the structure at the time of seeing one heating coil from the side among several heating coils. 1 is a cooking container, 2 is a top plate, 3 is a light shielding means printed on the back surface of the top plate, 4 is a heating coil, 5 is a ferrite provided on the heating coil, 6 is a light guiding means, and 7 is an infrared sensor. , 8 is a substrate, 9 is a case, 10 is a control circuit, and 11 is a heating coil support on which a coil and ferrite are mounted. FIG. 3 shows the infrared sensor installation position of the induction heating cooker according to Embodiment 1 for carrying out the present invention. The positional relationship among the heating coil 4, the ferrite 5, and the infrared sensor 7 when viewed from above is shown. Show. The operation will be described with reference to FIGS.

  Although not shown, when the user sets the temperature and presses the heating start button, the control circuit 10 drives the heating coil 4 at a predetermined frequency and measures the electric power at this time. Since the impedance viewed from the heating coil changes depending on the presence or absence of the cooking container 1, the presence or absence of the cooking container 1 is determined based on the magnitude of the electric power. On the back of the top plate 2, light-shielding printing 3 is applied except for the portion directly above the infrared sensor 7. And only when the cooking container 1 is mounted on the top plate 2, the data converted from the infrared rays received by the infrared sensor 7 into the temperature is used for control. That is, only when it is determined that there is a cooker due to the magnitude of electric power, it is determined that the cooking container 1 is directly above the infrared sensor 7 and is shielded from light by the cooking container 1, and the output of the infrared sensor is used for control. Therefore, the influence of external light can be eliminated.

  As shown in FIG. 1, the infrared sensor 7 is located outside and behind the center of each heating coil 4, so that it is adjacent even when a plurality of heating coils 4 are operated simultaneously. When the heating coil 4 is operated, the influence of the infrared rays radiated from the adjacent heating coils 4 themselves and the infrared rays emitted from the top plate 2 heated by the heat from the cooking container 1 placed immediately above the adjacent heating coils 4 are affected. Even if the cooking container 1 is a one-handed pan without being received, and the handle part is placed on the far side so that it does not get out of the way of the induction heating cooker, it must be placed directly above the infrared sensor 4. Since the cooking container 1 exists, temperature detection can be performed correctly.

  The infrared sensor 4 is installed below the ferrite 5 for inducing the magnetic flux generated on the back surface of the heating coil 2 to the coil surface, and is located between the ferrites 5 installed in a radial manner. The magnetic flux from the coil 4 is blocked, and the temperature can be measured correctly without malfunction due to the magnetic flux. Furthermore, the influence of magnetic flux can be further eliminated by making the case 9 a metal case. Further, the case 9 is attached to the heating coil support 11 so that the positional relationship with the portion not provided with the light-shielding printing provided on the top plate 2 can be accurately maintained.

  A cylindrical light guide 6 made of metal or resin is provided between the infrared sensor 7 and the top plate 2. Thereby, the infrared rays radiated from the heating coil 4 and the back surface of the top plate 2 are blocked, and only the infrared rays from the cooking container 1 can be guided to the infrared sensor 7 and the temperature can be measured correctly.

Embodiment 2. FIG.
FIG. 4 shows a top view of the induction heating cooker according to Embodiment 2 for carrying out the present invention, and is a view when an induction heating cooker equipped with three heating coils is viewed from above. It shows the mounting position of the infrared sensor and the position of the contact-type temperature sensor. In FIG. 4, the shaded area indicates the mounting area (area) of the infrared sensor, and the shaded area indicates the mounting area (area) of the contact temperature sensor. When viewed from the operation unit, the area where the infrared sensor is mounted is outside the center of each heating coil and on the back side. FIG. 5: shows the side view of the induction heating cooking appliance in Embodiment 2 for implementing this invention, and shows the structure at the time of seeing one heating coil from the side among several heating coils. .
1 is a cooking container, 2 is a top plate, 3 is a light shielding means printed on the back surface of the top plate, 4 is a heating coil, 5 is a ferrite provided on the heating coil 4, 6 is a light guiding means, 7 is an infrared sensor, 8 Is a substrate, 9 is a case, 10 is a control circuit, 11 is a heating coil support on which the heating coil 4 and ferrite 5 are mounted, 12 is a contact temperature sensor such as a thermistor, and 13 is provided on the front side of the top plate 2. The operation part which performs various operation for heating the heating coil 4 is represented. The operation will be described with reference to FIGS.

  As described in the first embodiment, the cooking container 1 can be held in one hand by installing the infrared sensor 4 in the hatched area in FIG. 4 (the back side from the center of the heating coil 4 and the end side of the top plate 2). Even if the pan is placed on the back so that the handle does not get out of the way of the induction heating cooker, the cooking container 1 always exists immediately above the infrared sensor 4, so the temperature is detected correctly. It can be performed. Moreover, there is little error without being affected by the infrared rays emitted from the adjacent heating coil 4 itself. On the other hand, the contact-type temperature sensor 12 is provided closer to the operation unit 13 than the center of the heating coil 4 and closer to the center of the top plate 2, and comes into contact with the top plate 2 to transfer the heat of the cooking container 1 to the top plate 2. It is detected indirectly via. For this reason, temperature detection is always possible even if the cooking container 1 is not directly above the contact-type temperature sensor 12. Further, even if infrared rays from adjacent heating coils 4 are emitted, they are not influenced by temperature detection errors in principle.

  The temperature distribution at the bottom of the cooking vessel 1 shows a concentric distribution as shown in FIG. By arranging the infrared sensor 7 and the contact-type temperature sensor 12 on a concentric circle, the same temperature distribution band is measured. When the two are switched and used, the temperature difference can be reduced. It is possible to prevent the cooking finish from being different.

  The control circuit 10 compares the temperature detected by the infrared sensor 7 with the temperature detected by the contact-type temperature sensor 12, adopts the higher one, and controls the current to the heating coil 4 although not shown. Set the target temperature.

  By including the two sensors of the infrared sensor 7 and the contact temperature sensor 12 and adopting the higher temperature, an induction heating cooker with high safety can be provided. Since the infrared sensor 7 is installed at a position away from the adjacent heating coil 4, the error is small without being affected by the infrared rays from the adjacent heating coil 4. Further, the loading position of the cooking container 1 tends to shift to the back side, but even in this case, the cooking container 1 is directly above the infrared sensor 7 and can reliably receive infrared rays from the cooking container 1. By placing the contact-type temperature sensor 12 at a position diagonal to the infrared sensor 7, the temperature can be detected by the contact-type temperature sensor 12 even when the cooking container 1 is placed on the operation unit side. In addition, since the higher detection temperature is used, the position of the cooking container 1 can be obtained even when the cooking container 1 is not directly above one of the infrared sensor 7 or the contact temperature sensor 12 and the cooking container 1 is just above the other. The optimum sensor is automatically selected.

  DESCRIPTION OF SYMBOLS 1 Cooking container, 2 Top plate, 3 Shading printing, 4 Heating coil, 5 Ferrite, 6 Light guide means, 7 Infrared sensor, 8 Substrate, 9 Case, 10 Control circuit, 11 Heating coil support stand, 12 Contact type temperature sensor, 13 Operation unit.

Claims (4)

A top plate on which a cooking container for heating the food is placed;
An operation unit that is provided on the near side of the top plate and that performs various operations for heating the heating coil;
A plurality of heating coils provided on the front left and right of the top plate and generating an induction magnetic field to heat the cooking vessel;
An infrared sensor that is provided for each of the heating coils and detects infrared rays emitted from the cooking vessel heated by the heating coils;
A contact temperature sensor that is provided for each of the heating coils and indirectly detects the heat of the cooking vessel via the top plate;
The infrared sensor is installed in an infrared sensor mounting area provided on the end side of the top plate outside the center of each heating coil and on the back side from the center of the heating coil. Induction heating cooker.   The induction heating cooker according to claim 1, wherein the temperature detected by the infrared sensor and the contact-type temperature sensor is compared and control is performed by adopting a higher temperature.   The induction heating cooker according to claim 1 or 2, wherein the infrared sensor and the contact sensor are provided on substantially concentric circles.   The induction heating cooker according to any one of claims 1 to 3, wherein the heating coils are installed on the front left and right sides of the top plate and on the back side of the center of the top plate.

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