JP2009284928A - Induction heating apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent destruction of an inverter by stopping the heating operation before the inverter is destroyed if interlayer short-circuit occurs in a coil in an induction heating apparatus for the induction heating with an alternating current fed to the coil. <P>SOLUTION: A pot 1 is induction-heated by the coil 2 to which the alternating current is fed by the inverter 3, and a driving signal is output to the inverter 3 according to the previously stored rice boiling sequence by a control means 4 to heat the pot 1 for the rice boiling. A comparing means 7 compares the temperature detected by a temperature sensor 6 for detecting the temperature of the coil 2 and the threshold temperature set by a threshold temperature setting means 8 for setting the threshold temperature. A heating stopping means 9 for stopping the operation of the inverter 3 is configured to stop the operation of the inverter 3 if the temperature detected by the temperature sensor 6 exceeds the threshold temperature set by the threshold temperature setting means 8. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an induction heating apparatus that supplies an alternating current to a coil to perform induction heating.

  Conventionally, this type of induction heating apparatus is configured as shown in FIG. 3 (see, for example, Patent Document 1). Hereinafter, the configuration will be described.

  As shown in FIG. 3, the pan 21 is detachably accommodated in an induction heating device main body (not shown), and the pan 21 is heated by induction heating with a coil 22. The inverter 23 supplies an alternating current for inductively heating the pan 21 to the coil 22.

  The control means 24 displays the operation state on the operation / display means 25 and, according to the user's operation input input to the operation / display means 25, refers to the rice cooking sequence stored in the control means 24 while referring to the inverter 23. The inverter 23 supplies an alternating current to the coil 22, and the alternating current flowing through the coil 22 causes an induced current to flow to the bottom surface of the pot 21. The induced current causes the pot 21 to generate heat, and the pot 21. The rice in is heated.

The coil 22 is obtained by twisting a thin copper wire whose outer periphery is coated with an insulating material and winding it for about 20 turns.
JP-A-6-90849

  However, in such a conventional configuration, an interlayer short circuit may occur in the coil 22 very rarely. This interlayer short-circuiting means that the outer peripheral insulating film is damaged and short-circuited at the same adjacent location of the fine copper wire constituting the coil 22.

  At this time, the short circuit is not only caused by one turn of the same thin copper wire, but also by one turn of another thin copper wire, the place where there is a potential difference must have been short-circuited. , Behave as an interlayer short.

  When an interlayer short circuit occurs, a one-turn loop is formed through the short part, and a large induced current due to the magnetic field of the current flowing through the coil 22 flows through the loop. Abnormal fever will occur. This abnormal heat generation also damages the insulating film of the surrounding fine copper wire, and a new interlayer short circuit occurs at the damaged portion.

  In this way, the interlayer short circuit is expanded in the coil 2, the inductance value of the coil 22 is decreased, the peak value of the alternating current supplied from the inverter 23 is increased, and eventually the inverter 23 is destroyed. Inverter 23 is expensive and has a problem that it places a heavy burden on the user during replacement.

  An object of the present invention is to solve the above-described conventional problems, and in the case where an interlayer short circuit occurs in a coil, an object of the present invention is to stop the heating operation until the inverter is destroyed and prevent the inverter from being destroyed.

  In order to achieve the above-mentioned object, the present invention detachably stores a pan in the induction heating apparatus body, induction-heats the pan with a coil supplied with an alternating current by an inverter, and cooks the rice stored in advance by the control means. According to the sequence, a drive signal is output to the inverter to heat the pot to realize the rice cooking operation, and the comparison temperature is detected by the temperature sensor that detects the coil temperature and the threshold temperature set by the threshold temperature setting means that sets the threshold temperature. The heating stop means for stopping the operation of the inverter by comparing with each other stops the operation of the inverter when the temperature detected by the temperature sensor exceeds the threshold temperature set by the threshold temperature setting means as a result of the comparison by the comparing means. It is comprised as follows.

  Accordingly, when an interlayer short circuit occurs in the coil, the operation of the inverter can be stopped and the heating operation can be stopped before the inverter is destroyed, and the inverter can be prevented from being destroyed.

  The induction heating device of the present invention can prevent the inverter from being destroyed by stopping the operation of the inverter and stopping the inverter operation until the inverter is destroyed when an interlayer short circuit occurs in the coil. Can do.

  1st invention is the said pot according to the rice cooking sequence memorize | stored in the pot which is detachably accommodated in the induction heating apparatus main body, the coil which induction-heats this pan, the inverter which supplies an alternating current to this coil, and is stored beforehand A control means for outputting a drive signal to heat the pan to realize a rice cooking operation, a temperature sensor for detecting the temperature of the coil, a threshold temperature setting means for setting a threshold temperature, a detected temperature of the temperature sensor, and the Comparing means for comparing the threshold temperature set by the threshold temperature setting means, and heating stopping means for stopping the operation of the inverter, the heating stopping means, as a result of the comparison by the comparing means, When the detected temperature is higher than the threshold temperature set by the threshold temperature setting means, the operation of the inverter is stopped. When an interlayer short circuit occurs in the coil, it can detect that the coil temperature has risen abnormally and stop the inverter operation until the inverter breaks down. It is possible to prevent the inverter from being destroyed as the interlayer short-circuit progresses, and the burden on the user during repair can be greatly reduced.

  2nd invention is the said 1st invention, The memory | storage means which memorize | stored that the heating stop signal was output from the heating stop means, The rice cooking prohibition means which prohibits the rice cooking operation | movement of a control means, The said control means Is configured to prohibit the rice cooking operation when the storage means stores that the heating stop signal has been output, an interlayer short circuit has occurred in the coil, and the coil temperature has risen abnormally By detecting this, the inverter operation can be stopped and the heating operation can be stopped before the inverter breaks down, and it is possible to prevent the inverter from breaking down and an interlayer short circuit has occurred In this case, by prohibiting the rice cooking operation, it is possible to notify the user of the occurrence of an interlayer short circuit.

  According to a third aspect of the present invention, in the first or second aspect of the present invention, a plurality of temperature sensors for detecting the temperature of the coil are installed, and the comparing means is a detection temperature and a threshold setting means for each of the plurality of temperature sensors. Compared with the set threshold temperature, any part of the coil where an interlayer short-circuit occurs and the coil temperature rises abnormally can be detected and the operation of the inverter can be controlled. It is possible to prevent the inverter from being stopped and being destroyed.

  A fourth invention is the above-mentioned third invention, wherein the plurality of temperature sensors are respectively installed at different distances from the center of the coil, an interlayer short circuit occurs in the coil, and the coil temperature becomes abnormal. The rise can be detected efficiently, and the operation of the inverter can be stopped to prevent the inverter from being destroyed.

  5th invention is provided with the inverter operation | movement detection means which detects whether an inverter is operating in invention of any one of said 1st-4th, The temperature sensor has the said inverter operation | movement detection means to perform operation | movement of an inverter. When the temperature is not detected, temperature detection is performed. An error in the temperature sensor detection temperature due to inverter noise can be eliminated, and the coil temperature can be detected with high accuracy.

  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)
FIG. 1 is a partial block circuit diagram of the induction heating apparatus according to Embodiment 1 of the present invention.

  As shown in FIG. 1, the pan 1 is detachably accommodated in an induction heating apparatus main body (not shown), and the pan 1 is heated by induction heating with a coil 2. The inverter 3 supplies an alternating current for inductively heating the pan 1 to the coil 2. The control means 4 displays the operation state on the operation / display means 5 and drives the inverter 3 according to the rice cooking sequence stored in advance in the control means 4 in accordance with the user's operation input input to the operation / display means 5. A signal is output and the pot 1 is induction-heated to realize the rice cooking operation.

  The temperature sensor 6 is installed so as to detect the temperature of the coil 2. The threshold temperature setting means 8 is for setting a threshold temperature. The comparison means 7 compares the threshold temperature set by the threshold temperature setting means 8 with the detected temperature of the temperature sensor 6. As a result of comparison by the comparison means 7, the detected temperature of the temperature sensor 6 exceeds the threshold temperature. In this case, the operation of the inverter 3 is stopped by the heating stop means 8 and the supply of the alternating current to the coil 2 is stopped.

  The operation and action of the above configuration will be described. When the user operates the operation / display means 5 to input rice cooking start, the control means 4 outputs a drive signal to the inverter 3, and the inverter 3 supplies an alternating current to the coil 2. An induction current of an alternating current flowing through the coil 2 flows through the pan 1 and the pan 1 generates heat.

  The control means 4 cooks rice by adjusting the amount of alternating current supplied to the coil 2 by the inverter 3 and adjusting the amount of induction heating of the pan 1 according to the rice cooking sequence stored in advance.

  It is assumed that an interlayer short circuit has occurred in the coil 2 during the cooking of rice. When an interlayer short circuit occurs, a one-turn loop is formed through the short part, and a large induced current due to the magnetic field of the current flowing through the coil 2 flows in the loop, and the fine copper wire constituting the loop Causes abnormal heat generation. This abnormal heat generation also damages the insulating film of the surrounding fine copper wire, and a new interlayer short circuit occurs at the damaged portion.

  In this process, the heat generated by the interlayer short circuit propagates through the copper wire constituting the coil 2 and diffuses throughout the coil 2, and the temperature of the entire coil 2 rises.

The comparison means 7 compares the temperature detected by the temperature sensor 6 with the threshold temperature set by the threshold temperature setting means 8. When the temperature detected by the temperature sensor 6 exceeds the threshold temperature, the heating stop means 9 operates on the inverter 3. A stop signal is output, the inverter 3 stops operating, and the supply of alternating current to the coil 2 is stopped. Thereby, destruction of the inverter 3 is also prevented.

  When a specific numerical value is raised, the threshold temperature set by the threshold temperature setting means 8 is a temperature around 150 ° C. to 200 ° C. Usually, the temperature of the coil 2 when the interlayer short-circuit does not occur is up to 130 ° C., and the occurrence of the interlayer short-circuit can be clearly distinguished by the above threshold temperature.

  As described above, in the present embodiment, as a result of the comparison by the comparison unit 7, the heating stop unit 9 has a temperature detected by the temperature sensor 6 exceeding the threshold temperature set by the threshold temperature setting unit 8. Since the operation of the inverter 3 is stopped, when an interlayer short circuit occurs in the coil 2, it is detected that the temperature of the coil 2 is abnormally increased and the inverter 3 is destroyed until the inverter 3 is destroyed. The operation can be stopped and the heating operation can be stopped, the inverter 3 can be prevented from being destroyed with the progress of the interlayer short circuit, and the burden on the user at the time of repair can be greatly reduced.

(Embodiment 2)
FIG. 2 is a partial block circuit diagram of the induction heating apparatus according to Embodiment 2 of the present invention.

  As shown in FIG. 2, the plurality of temperature sensors 601, 602, and 603 each detect the temperature of the coil 2, and change the distance from the center of the coil 2 to change the inner circumference, middle, It is attached to the outer periphery. The comparison unit 7 compares the detected temperatures of the temperature sensors 601, 602, and 603 with the threshold temperature set by the threshold temperature setting unit 8.

  The inverter operation detection means 10 detects whether or not the inverter 3 is in operation. During the operation of the inverter 3, the output of the temperature detection values of the temperature sensors 601, 602, and 603 to the comparison means 7 is blocked. When temperature sensor 3 is not operating, temperature is detected by temperature sensors 601, 602, and 603, and a temperature detection value is output to comparison means 7.

  The storage unit 11 is constituted by a storage element such as a flash memory, for example, and stores that the heating stop unit 9 has output a heating stop signal to the inverter 3. The rice cooking prohibition means 12 outputs a rice cooking operation prohibition signal to the control means 4 when the storage means 11 stores that the heating stop means 9 has output a heating stop signal, thereby prohibiting the rice cooking operation. ing. Other configurations are the same as those of the first embodiment, and the same reference numerals are given and description thereof is omitted.

  The operation and action of the above configuration will be described. In addition, the operation | movement until the pot 1 is heated with the control means 4 from the start of rice cooking, and the rice cooking operation advances and the interlayer short circuit generate | occur | produces is the same as the operation | movement of the said Embodiment 1, and abbreviate | omits description.

  The interlayer short circuit may occur at any position where the interlayer coil wires are in contact with each other. However, in this embodiment, the temperature sensors 601, 602, and 603 are respectively connected to the inner circumference, middle, It is installed on the outer periphery, and even if it occurs at any position of the coil 2, the temperature sensor in the vicinity can detect the temperature rise and can be compared with the threshold temperature set by the threshold temperature setting means 8 in the comparison means 7. Compared with the case where there is one temperature sensor, a quick interlayer short-circuit can be detected.

If the detection of the short-circuit between layers is quick, the decrease in the inductance of the coil 2 can be suppressed to a small extent, and the increase in the peak value of the alternating current of the inverter 3 is small, so that the possibility of destruction of the inverter 3 can be further reduced.

  During the operation of the inverter 3, the inverter operation detection means 10 does not output the temperature detection values of the temperature sensors 601, 602, 603 to the comparison means 7, and does not compare with the threshold temperature set by the threshold temperature setting means 8. I will not. On the other hand, while the inverter 3 is stopped, the temperature detection values of the temperature sensors 601, 602, 603 are output to the comparison means 7 and compared with the threshold temperature set by the threshold temperature setting means 8. Thereby, during the operation of the inverter 3, it is possible to eliminate the influence of noise induced in the temperature sensors 601, 602, 603 by the alternating current flowing through the coil 2.

  The storage unit 11 stores that the heating stop unit 9 has output a heating stop signal to the inverter 3. When the storage means 11 stores that the heating stop means 9 has output a heating stop signal, the rice cooking prohibition means 12 outputs a rice cooking prohibition signal to the control means 4 and then does not perform any rice cooking operation. Like that. Thereby, once an interlayer short-circuit is detected, no alternating current is supplied to the coil 2, and the inverter 3 can be prevented from being destroyed.

  As described above, in the present embodiment, the control unit 4 is configured to prohibit the rice cooking operation when the storage unit 11 stores that the heating stop signal has been output. By detecting that a short circuit has occurred and the temperature of the coil 2 has risen abnormally and the inverter 3 is destroyed, the operation of the inverter 3 can be stopped to stop the heating operation. It is possible to prevent destruction, and when the interlayer short circuit occurs, the user can be notified of the occurrence of the interlayer short circuit by prohibiting the rice cooking operation.

  Also, a plurality of temperature sensors 601, 602, 603 for detecting the temperature of the coil 2 are installed, and the comparison means 7 is set by the detected temperature and threshold value setting means 8 for each of the plurality of temperature sensors 601, 602, 603. Since the interlayer short circuit occurs in any part of the coil 2 and the temperature of the coil 2 rises abnormally, it can be detected and the operation of the inverter 3 can be performed. It is possible to prevent the inverter 3 from being stopped and being destroyed.

  In addition, since the plurality of temperature sensors 601, 602, and 603 are installed at different distances from the center of the coil 2, an interlayer short-circuit occurs in the coil 2, and the temperature of the coil 2 is abnormally increased. It can be detected well, and the operation of the inverter 3 can be stopped to prevent the inverter 3 from being destroyed.

  Further, since the temperature sensors 601, 602, and 603 perform temperature detection when the inverter operation detection unit 10 does not detect the operation of the inverter 3, the temperature sensors 601, 602, and 603 are detected by inverter noise. The temperature error can be eliminated, and the temperature of the coil 2 can be detected with high accuracy.

  As described above, the induction heating device according to the present invention can stop the heating operation by stopping the operation of the inverter before the destruction of the inverter when an interlayer short circuit occurs in the coil. Therefore, it is useful as an induction heating apparatus that supplies an alternating current to the coil to perform induction heating.

Circuit diagram in which the induction heating apparatus according to Embodiment 1 of the present invention is partially blocked Circuit diagram in which the induction heating apparatus according to Embodiment 2 of the present invention is partially blocked A partial block diagram of a conventional induction heating device

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Pan 2 Coil 3 Inverter 4 Control means 6 Temperature sensor 7 Comparison means 8 Threshold temperature setting means 9 Heating stop means

Claims (5)

A pot that is detachably stored in the induction heating apparatus main body, a coil that induction-heats the pot, an inverter that supplies an alternating current to the coil, and a drive signal that is output to the inverter according to a pre-stored rice cooking sequence. Set by control means for heating the pot to realize rice cooking operation, temperature sensor for detecting the temperature of the coil, threshold temperature setting means for setting a threshold temperature, detection temperature of the temperature sensor and threshold temperature setting means And a heating stop means for stopping the operation of the inverter. As a result of the comparison by the comparison means, the heating stop means detects the temperature detected by the temperature sensor as the threshold temperature. An induction heating apparatus configured to stop the operation of the inverter when the temperature exceeds a threshold temperature set by the setting means. A storage means for storing that the heating stop signal is output from the heating stop means; and a rice cooking prohibiting means for prohibiting the rice cooking operation of the control means; and the control means outputs a heating stop signal to the storage means. The induction heating device according to claim 1, wherein the rice cooking operation is prohibited when this is stored. A plurality of temperature sensors for detecting the temperature of the coil are installed, and the comparison means compares the detected temperature of each of the plurality of temperature sensors with the threshold temperature set by the threshold setting means. 2. The induction heating apparatus according to 2. The induction heating device according to claim 3, wherein the plurality of temperature sensors are installed at different distances from the center of the coil. The inverter operation detection means for detecting whether or not the inverter is operating is provided, and the temperature sensor performs temperature detection when the inverter operation detection means does not detect the operation of the inverter. The induction heating apparatus according to any one of the above.

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