JP4497225B2 - Induction heating cooker - Google Patents

Description

  The present invention relates to an induction heating cooker that heats a pan placed on a top plate by induction heating to cook food in the pan.

  In an induction heating cooker that heats an object to be heated such as a pot, as a method of detecting the temperature of the pot of the object to be heated, there is a method of detecting the temperature with a thermistor through a top plate on which the pot is placed. In addition, there is an apparatus for detecting the temperature by detecting the infrared ray radiated from the side surface of the pan with an infrared sensor behind the top surface of the top plate. Furthermore, an infrared sensor is arranged on the lower surface of the top plate to detect infrared rays from the pan through the top plate (for example, see Patent Document 1).

  In the induction heating cooker having the conventional configuration shown in FIG. 6, the temperature of the pan 1 is received by the thermistor 50 through the top plate 2 to detect the temperature, and the pan is detected according to the temperature detection output of the thermistor 50. The electric power supplied to the heating coil 3 for induction heating 1 is controlled by the control means 51 for cooking. Here, the top plate 2 made of ceramics has a low heat transfer coefficient, and due to a delay in the thermal response of the top plate 2, an actual pan temperature and error occur, and the temperature of the object to be heated cannot be detected with high accuracy. And in the case of a pan with a warped bottom, it is even more susceptible.

In addition, the infrared sensor 53 behind the top plate 2 is affected by ambient light such as sunlight or illumination, and cannot accurately detect temperature. Furthermore, if the infrared sensor is simply disposed on the lower surface of the top plate 2, it may be affected when there is ambient light incident from an oblique direction.
Japanese Patent Laid-Open No. 03-184295

  In view of the above-described problems of the conventional technology, the problem to be solved by the present invention is to provide an induction heating cooker that can accurately detect the temperature of a pan while avoiding the influence of ambient light.

In order to solve the above-mentioned problems, the present invention provides a heating coil for induction heating of a pan, a glass ceramic top plate that places a pan on the top of the heating coil and transmits infrared rays, and is placed under the top plate. Infrared detection means for detecting infrared radiation radiated from the bottom of the pan, temperature detection means for detecting the pan bottom temperature from the output of the infrared detection means, and power supplied to the heating coil in accordance with the output of the temperature detection means Control means for controlling, the infrared detection means is 2.5 μm
The infrared ray that is composed of a photodiode capable of detecting the following wavelengths and is attached to the coil substrate, and the control means suddenly changes greatly when infrared rays from other than the bottom of the pan enter the infrared detection means. When an abnormal temperature drift in the output of the detection means is detected for a certain period of time, the induction heating cooker is configured to stop the operation of the heating coil. This is to prevent malfunction of the equipment.

  The induction heating cooker of the present invention is intended to prevent malfunction of equipment when infrared rays from other than the pan enter.

The first invention is a heating coil for inductively heating a pan, a glass ceramic top plate that places a pan on the top of the heating coil and transmits infrared rays, and is radiated from the bottom of the pan placed under the top plate. Infrared detecting means for detecting infrared rays, temperature detecting means for detecting the pan bottom temperature from the output of the infrared detecting means, and control means for controlling the power supplied to the heating coil in accordance with the output of the temperature detecting means; And the infrared detecting means is composed of a photodiode capable of detecting a wavelength of 2.5 μm or less and is attached to the coil substrate, and the control means is configured to detect infrared rays from other than the bottom of the pan. of the heating coil when the abnormal temperature drift of the output of said infrared detection means for varying abruptly increased when the incident is detected continuously a predetermined time to In the induction heating cooker which is configured to stop the work, if the infrared rays from other than the pan is incident it is intended to prevent malfunction of the equipment.

The second invention is a heating coil for inductively heating a pan, a glass ceramic top plate that places a pan on the top of the heating coil and transmits infrared rays, and is placed under the top plate and radiated from the bottom of the pan. Infrared detecting means for detecting infrared rays, temperature detecting means for detecting the pan bottom temperature from the output of the infrared detecting means, and control means for controlling the power supplied to the heating coil in accordance with the output of the temperature detecting means. The infrared detecting means is configured with a photodiode capable of detecting a wavelength of 2.5 μm or less and is attached to the coil substrate, and the control means is configured such that infrared light from other than the pan is incident on the infrared detecting means. do not change the supply of a predetermined time power when abnormal temperature drift of the output of said infrared detection means which changes abruptly increases when is detected continuously a predetermined time In the induction heating cooker comprising a structure to perform control, it can be further prevented that the cooking is terminated prematurely.

In a third aspect of the invention, a heating coil for induction heating the pan, a glass ceramic top plate for placing the pan on the top of the heating coil and transmitting infrared rays, and a bottom plate radiated from the bottom of the pan. Infrared detecting means for detecting infrared rays, temperature detecting means for detecting the pan bottom temperature from the output of the infrared detecting means, and control means for controlling the power supplied to the heating coil in accordance with the output of the temperature detecting means. The infrared detecting means is configured with a photodiode capable of detecting a wavelength of 2.5 μm or less and is attached to the coil substrate, and the control means is configured such that infrared light from other than the pan is incident on the infrared detecting means. effects of infrared radiation is incident from outside the pan when the abnormal temperature drift of the output of said infrared detection means which changes abruptly increases when is detected continuously a predetermined time Avoiding certain time for a cooking device comprising a structure for increasing the power, but which can avoid the influence of infrared radiation is incident from outside the pan in a short time.

  According to a fourth aspect of the present invention, in any one of the first to third aspects, the temperature detecting means has undergone a temperature change greater than or equal to a predetermined value that is detected when infrared rays from other than the pan enter the infrared detecting means. In the case of the induction heating cooker configured to be notified by the notification means, when infrared rays from other than the pan enter, not only the malfunction of the device can be prevented but also the user can be notified.

  A fifth aspect of the invention is the induction heating cooker according to any one of the first to fourth aspects of the invention, wherein the temperature detecting means is configured to display the display means of the operation unit when a temperature change of a predetermined value or more occurs. Thus, when infrared rays from other than the pan enter, not only prevents malfunction of the device, but also makes it easy for the user to understand and continuously inform the user.

  Since the induction heating cooker of the present invention can achieve the object of the present invention by using the above-described configurations of the first to fifth inventions as the main part of the embodiment, each of the claims corresponding to each claim will be described below. Details of the embodiment will be described with reference to the drawings to explain the embodiment. Note that the present invention is not limited to the embodiments.

( Reference Example 1)
FIG. 1 is a block diagram showing an induction heating cooker according to Reference Example 1 of the present invention. The induction heating cooker in the present reference example includes a heating coil 3 that induction-heats a pan 1 that is to be heated and cooked, a top plate 2 on which the pan 1 is placed above the heating coil 3, and a top plate 2 In response to the output of the infrared detecting means 5 for detecting the infrared rays emitted from the bottom of the pan, the temperature detecting means 9 for detecting the temperature of the bottom of the pot from the output of the infrared detecting means 5, and the output of the temperature detecting means 9 A control means 10 for controlling the high-frequency current, which is the power supplied to the heating coil 3, and a ring located below the top plate 2 so that infrared rays from other than the pan 1 are not incident on the infrared detection means 5. The light shielding means 6 is provided. In the figure, reference numeral 4 denotes an inverter that supplies a high-frequency current to the heating coil 3 and heats the pan 1 by electromagnetic induction, 7 is a reflecting means, 8 is an amplifying means, and 11 is a casing.

In the above reference example , when a power supply (not shown) is turned on and a predetermined temperature is set with the operation switch, electric power is supplied from the inverter 4 to the heating coil 3 under the control of the control means 10. When electric power is supplied to the heating coil 3, an induction magnetic field is generated in the heating coil 3, and the pan 1 on the top plate 2 is induction-heated. Due to this induction heating, the temperature of the pan 1 rises and the object to be heated in the pan 1 is cooked. Here, the operation of the infrared detecting means 5 will be described. When the temperature of the pan 1 rises, infrared rays corresponding to the temperature are emitted from the pan 1.

  Since the glass ceramics used for the top plate 2 can efficiently transmit infrared rays having a wavelength range of 2.5 μm or less, the infrared detection means 5 is, for example, a photodiode that can detect wavelengths of 2.5 μm or less. The infrared ray of this wavelength range which passed through the top plate 2 is incident on the photodiode. Further, the reflecting means 7 is formed in a cylindrical shape, and the inner surface is formed in a mirror surface having a high reflectance so that more infrared rays can be collected and made incident on the photodiode disposed in the center of the bottom. .

Moreover, disturbance light, such as sunlight and illumination, may enter other than the infrared rays from the pan 1. Moreover, when the bottom of the pan 1 warps, it becomes more susceptible to disturbance light. For this reason, the infrared rays incident on the infrared detection means 5 from other than the pan 1 are blocked by the light shielding means 6. With these configurations, in this reference example , only the infrared rays from the pan 1 are incident on the infrared detection means 5, and the diode current corresponding to the amount of infrared rays is converted from current to voltage by the amplification means 8 and amplified. This information is input to the temperature detection means 9, and the temperature of the pan can be detected accurately. Thereby, the inverter 4 is controlled from the control means 10 to accurately control the pan 1 so as to reach a predetermined temperature, and the object to be heated can be cooked deliciously.

Further, in this reference example , the light shielding means 6 is integrated with the coil substrate 3a as a holding means made of resin or the like for holding the heating coil 3, so that the position accuracy of the infrared detecting means 5 and the reflecting means 7 is accurate. Therefore, only the disturbance infrared rays can be blocked without blocking the visual field of the infrared detection means 5, and the temperature of the pan can be detected stably and accurately.

Further, in the present reference example , if the light shielding means 6 is provided so as to cover the lower surface of the top surface 2 other than the upper part of the infrared detecting means 5, it is possible to eliminate the influence of the infrared rays of the turbulent incident. Yes, the temperature of the pan can be detected accurately and stably.

( Reference Example 2)
FIG. 2 is a block diagram showing a configuration of an induction heating cooker according to Reference Example 2 of the present invention. The induction heating cooker according to this reference example is different from the light shielding means of the invention according to Reference Example 1 only in that the function of the light shielding means is added to the top plate. Are denoted by the same reference numerals, detailed description thereof is omitted, and different points will be mainly described.

  As with the top plate shown in FIG. 1, the top plate 12 is for placing the pan 1 on the top of the heating coil 3, and other than the range through which the infrared rays from the pan 1 pass when entering the infrared detection means 5. A portion 12a having a high reflectivity is formed so as to block the incidence of disturbance light. That is, the top plate 12 is printed with high reflectivity on the back surface of the top plate 12 outside the visual field range of the infrared detecting means 5 to form a highly reflective portion 12a. The printing material is, for example, a paste with a high gloss of silver.

The top plate 12 has a mirror surface at the top, and has a light reflectance of 90% or more. For this reason, the infrared rays of disturbances such as the sun and illumination that are incident at an angle with no angle are reflected by the highly reflective portion 12 a on the back surface of the top plate 11, and therefore hardly enter the infrared detection means 5. With these configurations, in this reference example , only the infrared light from the pan 1 is incident on the infrared detection means 5, and the diode current corresponding to the amount of infrared light is converted from current to voltage by the amplification means 8 and amplified. This information is input to the temperature detection means 9, and the temperature of the pan can be detected accurately. Thereby, the inverter 4 is controlled from the control means 10, and the pan 1 is accurately controlled so as to reach a predetermined temperature, so that the object to be heated can be cooked deliciously.

Moreover, in this reference example , the silver-printed portion 12a having a high reflectance may be applied to the surface of the top plate 12 outside the range of the minimum pot diameter that can be cooked. That is, even when a pan having the smallest diameter is placed on the top plate, the disturbance infrared rays are reflected on the surface of the top plate. Thereby, the reflection on the back surface of the top plate and the reflection on the pan are not repeated and incident on the infrared detecting means 5. With this configuration, it is possible to provide an induction heating cooker that can accurately detect the temperature of the pan without incident disturbance infrared rays.

Further, in this reference example , by using a material having a low reflectance on the inner surface of the housing 11 or painting it with a low reflectance, the infrared rays of disturbances that are partially reflected from the bottom surface of the housing are further reduced. Without being incident, it can be an induction heating cooker that can detect the temperature of the pan more accurately.

(Embodiment 1 )
FIG. 3 is a diagram showing a control mode corresponding to the output of the temperature detecting means 9 in the induction heating cooker according to the first embodiment of the present invention. The induction heating cooker in the present embodiment is different from the invention of Reference Example 1 only in the control method of the control means 10, and other parts having the same configuration and operational effects are denoted by the same reference numerals using FIG. 1. Detailed description will be omitted, and different points will be mainly described.

  The control means 10 is placed under the top plate 2 and supplied to the heating coil 3 according to the output of the temperature detecting means 9 for detecting the temperature of the bottom of the pan from the output of the infrared detecting means 5 for detecting the infrared rays emitted from the bottom of the pan. A configuration for stopping the operation of the heating coil 3 when infrared rays from other than the pan 1 are incident on the infrared detection means 5 and a temperature change of a predetermined value or more occurs in the temperature detection means 8. In other words, the malfunction of the device is prevented when the power supply is stopped for a certain period of time and infrared rays from other than the pan are incident.

  In the said embodiment, the control means 10 controls the electric power supplied to the heating coil 3, as shown in FIG. 3, when the infrared rays from other than a pan enter. That is, the vertical axis indicates temperature, power, and output voltage, and the horizontal axis indicates time, and the temperature change in the pot 1 and the pot water, the change in the output voltage of the temperature detection means 9, and the heating coil 3 are supplied. As shown in FIG. 3, the infrared detection means 5 detects infrared rays corresponding to the temperature of the pot bottom, and the temperature detection means 9 sets the temperature of the pot bottom. Here, when the pan 1 has a warped bottom, or when a foreign object is caught and a gap is generated between the pan 1 and the top plate 2 and a disturbance infrared ray is suddenly incident, the infrared detecting means 5 that detects this. The output of the temperature detecting means 9 due to drifts as in mode 2 and remains at the same temperature for a certain time. When this abnormal temperature drift continues for a certain period of time, the control means 10 that has taken in this stops the supply of power to the heating coil 3 for a certain period of time and stops the heating. With this configuration, it is possible to realize an induction heating cooker that can prevent malfunction of the device and perform stable temperature control when infrared rays from other than the pan enter.

  In the above embodiment, in order to prevent malfunction of the device when infrared rays from other than the pan enter, and to enable stable temperature control, the output of the temperature detecting means 9 changes suddenly, and the abnormal temperature The control unit 10 is configured to stop the heating by the heating coil 3 when the drift continues for a certain time. However, the same effect as in the present embodiment can be expected even in the following control mode. .

  That is, for example, in cooking such as automatic water heating, since the pan bottom temperature rises only to a maximum of about 100 ° C. even if heating is continued, there is little risk of continuing heating, so as shown in FIG. When the infrared rays suddenly entered and the output of the temperature detecting means 9 by the infrared detecting means 5 that detected this was drifted as in the mode 2 and this abnormal temperature drift continued for a certain period of time, it was captured. The control means 10 performs control that does not change the supply of power to the heating coil 3 for a certain period of time. As a result, the temperature of the pan rises after a certain period of time, and the situation is not affected by disturbance as in mode 3 of FIG. Thereby, the induction heating cooking appliance which can avoid that cooking is complete | finished in the middle and can perform stable temperature control is realizable.

  Further, for example, during cooking such as automatic water heating, since the pan bottom temperature only rises to about 100 ° C. at the maximum even if heating is continued, there is little risk of continuing heating, as shown in FIG. When the infrared rays from other than the pan enter the infrared detection means 5 and the temperature detection means 9 undergoes a temperature change more than a predetermined value, the control means 10 that has taken in the power for a certain period of time as in mode 4 Control to increase. By this structure, the induction heating cooking appliance which can avoid the influence which the infrared rays from other than a pan entered early and can perform stable temperature control is realizable.

    In each of the above-described embodiments, when a temperature change of a predetermined value or more occurs in the temperature detection means 9, the notification means notifies the user, and similarly, the temperature detection means 9 has a predetermined value or more. When the temperature change occurs, if the display means of the operation unit is used, the cooking status of the induction heating cooker can be easily understood and continuously notified to the user.

  As described above, the induction heating cooker of the present invention can accurately detect the temperature of the pan bottom without being affected by ambient light, and can accurately perform temperature control in accordance with the temperature of the pan bottom. It can be applied to a container and its control method.

The block diagram which shows the induction heating cooking appliance in the reference example 1 of this invention The block diagram which shows the induction heating cooking appliance in the reference example 2 of this invention The figure which shows the control form in the induction heating cooking appliance in Embodiment 1 of this invention The figure which shows the other example of the control form with the induction heating cooking appliance in the same Embodiment 1 . The figure which shows the other example of the control form with the induction heating cooking appliance in the same Embodiment 1 . The block diagram which shows the induction heating cooking appliance in a prior art example

1 Pan 2, 12 Top plate 3 Heating coil 3a Coil substrate (holding means)
5 Infrared detecting means 6 Shading means 9 Temperature detecting means 10 Control means 12a High reflectance portion

Claims (5)

A heating coil that induction-heats the pan, a glass ceramic top plate that transmits the infrared rays by placing the pan above the heating coil, and an infrared ray that is placed under the top plate and detects infrared rays emitted from the bottom of the pan A detector for detecting the temperature of the bottom of the pan from the output of the infrared detector; and a controller for controlling the power supplied to the heating coil in accordance with the output of the temperature detector. The means is composed of a photodiode capable of detecting a wavelength of 2.5 μm or less and is attached to the coil substrate, and the control means suddenly receives an infrared ray from a portion other than the bottom of the pan when incident on the infrared detection means. stopping the operation of the heating coil when the abnormal temperature drift of the output's dynamic said infrared detection means is detected continuously a predetermined time Induction heating cooker made as a formation. A heating coil that induction-heats the pan, a glass ceramic top plate that transmits the infrared rays by placing the pan above the heating coil, and an infrared ray that is placed under the top plate and detects infrared rays emitted from the bottom of the pan Detecting means; temperature detecting means for detecting a pan bottom temperature from an output of the infrared detecting means; and control means for controlling electric power supplied to a heating coil in accordance with an output of the temperature detecting means, the infrared detecting means Is composed of a photodiode capable of detecting a wavelength of 2.5 μm or less and is attached to the coil substrate, and the control means suddenly changes greatly when infrared light from other than the pan enters the infrared detection means. arrangement for controlling not to change the supply of a predetermined time power when abnormal temperature drift of the output of said infrared detection means is continuously detected a predetermined time Induction heating cooker which was formed by. A heating coil for inductively heating the pan, a glass ceramic top plate through which infrared rays are transmitted by placing the pan on the top of the heating coil, and an infrared ray that is placed under the top plate and detects infrared rays emitted from the bottom of the pan Detecting means; temperature detecting means for detecting a pan bottom temperature from an output of the infrared detecting means; and control means for controlling electric power supplied to a heating coil in accordance with an output of the temperature detecting means, the infrared detecting means Is composed of a photodiode capable of detecting a wavelength of 2.5 μm or less and is attached to the coil substrate, and the control means suddenly changes greatly when infrared light from other than the pan enters the infrared detection means. since the infrared radiation from other than the pot when the abnormal temperature drift of the output of said infrared detection means is detected continuously a predetermined time to avoid the effect of the incident Induction heating cooker constant time comprising a configuration for increasing the power. The temperature detection means is configured to notify the notification means when a temperature change of a predetermined level or more detected when infrared rays from other than the pan enter the infrared detection means. The induction heating cooker according to crab. The induction heating cooker according to any one of claims 1 to 4, wherein the temperature detection unit is configured to display the temperature change by a display unit of an operation unit when a predetermined temperature change or more occurs.

Images