JP2011060781A - Induction heating device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an induction heating device having proper usability, capable of accurately sensing the temperature of a heated object. <P>SOLUTION: A top plate 13 is provided with a position display means 19, which allows a user to recognize a position of a sensor 15; and since the display range of the position display means 19 is wider than the temperature-sensing range of the sensor 15, the position of the sensor 15 can be recognized by a user, by placing a heated object 12 in such condition as to hide the entire display range of the position display means 19 which is wider than the temperature sensing range of the sensor 15, the heated object 12 can be positioned over the sensor 15 with sure. Since temperature sensing becomes more accurate, abnormal heating of the heated object 12, such as, pan or the deformations caused by abnormal heating are suppressed. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an induction heating apparatus capable of heating only when it is determined that there is an object to be heated above a sensor.

  Conventionally, in this type of induction heating apparatus, as shown in FIG. 2, a top plate 3 on which an object to be heated 2 is placed is disposed on the upper surface of the main body 1, and the object to be heated 2 is disposed below the top plate 3. A heating coil 4 is provided for induction heating. The heating coil 4 is divided into an inner coil 4a and an outer coil 4b, and the inner coil 4a and the outer coil 4b are electrically connected. The sensor 5 is a thermosensitive element such as a thermistor, and is disposed between the central portion of the heating coil 4 and between the inner coil 4a and the outer coil 4b, and on the back surface of the top plate 3 corresponding to the lower portion of the article 2 to be heated. A signal corresponding to the detected temperature is output. The reason for using such a configuration is that the heating coil 4 is divided so that the uniform heating property is improved and the temperature of the article to be heated 2 is prevented from being excessively high. It is effective to dispose the sensor 5 at a position corresponding to (the strongest place). The temperature calculation means 6 of the object to be heated 2 calculates the temperature state from the output of the thermal element 5, and the control means 7 controls the power supply to the heating coil 4 based on the information obtained from the temperature calculation means 6 (for example, , See Patent Document 1).

JP 2003-234168 A

  However, in the conventional configuration, when the object to be heated 2 is not above the sensor 5, compared to the case where the object to be heated is above the sensor 5, the thermal response and the temperature detection accuracy are inferior. When the object to be heated 2 such as a pan was baked, there was a problem that the pan was heated too much and easily deformed.

  An object of the present invention is to solve the above-described conventional problems, and to provide an induction heating apparatus that can accurately detect the temperature of an object to be heated and is easy to use.

  In order to solve the above-described conventional problems, the induction heating apparatus of the present invention includes a heated object determination unit that determines the presence or absence of an object to be heated above the sensor, and determines that there is an object to be heated above the sensor. In the induction heating apparatus capable of heating only in the case, a position display means for allowing the user to recognize the position of the sensor is provided on the top plate, and the display range of the position display means is wider than the temperature detection range of the sensor.

  Accordingly, the user can recognize the position of the sensor, and by placing the object to be heated so that the entire display range of the position display means that is wider than the temperature detection range of the sensor is hidden, the object to be heated is surely placed above the sensor. Since the temperature can be more accurately detected, abnormal heating of the heated object such as a pan or deformation due to abnormal heating can be suppressed.

  The induction heating device of the present invention can accurately detect the temperature of an object to be heated, and can improve the usability of the user.

(A) Sectional view of induction heating apparatus in Embodiment 1 of the present invention (b) Plan view of top plate in Embodiment 1 of the present invention Sectional view of a conventional induction heating device

  According to a first aspect of the present invention, there is provided a top plate disposed on the upper surface of the main body for placing an object to be heated, a heating coil disposed under the top plate for heating the object to be heated, and a lower portion of the top plate. A sensor disposed to detect the temperature of the object to be heated; temperature calculating means for calculating a bottom surface temperature of the object to be heated from an output of the sensor; and input control of the heating coil in accordance with an output of the temperature calculating means And an induction heating apparatus capable of heating only when it is determined that the object to be heated is above the sensor. In this embodiment, a position display means for allowing the user to recognize the position of the sensor is provided on the top plate, and the display range of the position display means is made wider than the temperature detection range of the sensor. By placing the heated object so that the entire display range of the position display means that is wider than the temperature detection range of the sensor is hidden, the heated object can be reliably positioned above the sensor. In addition, since temperature detection becomes more accurate, abnormal heating of a heated object such as a pan or deformation due to abnormal heating can be suppressed.

  In the second invention, in particular, the sensor of the first invention is arranged at a position eccentric from the center of the heating coil to the front side of the main body, and is eccentric from the center of the display range of the position display means to the coil center side. Since the sensor position displayed on the top plate is located closer to the user side than the coil center, the sensor position is easy to see (difficult to see if it is at the back), and it is behind the center of the display range. That is, since the sensor is located on the coil center side, if the user pays attention only to the front side of the display range when placing the object to be heated, the object to be heated is naturally hidden so that the entire display range of the position display means is hidden. Since the object to be heated can be surely positioned above the sensor, the usability is improved.

  According to the third aspect of the invention, in particular, by setting the outer shape of the display range of the position display means of the second aspect of the invention to a substantially elliptical shape, the restriction range when the user places the object to be heated can be minimized. And the object to be heated can be reliably positioned above the sensor.

  In the fourth aspect of the invention, in particular, by using the sensor of any one of the first to third aspects as an infrared sensor that detects infrared rays emitted from the heated object, the determination accuracy of the presence or absence of the heated object is improved. Therefore, detection with higher accuracy becomes possible.

  In the fifth invention, in particular, by providing a light emitting means for illuminating a part or the whole of the display range of the position display means of any one of the first to fourth inventions in the vicinity of the display means on the back side of the top plate, When the user places the object to be heated, the sensor position can be easily visually recognized, and the usability is further improved.

  According to the sixth aspect of the invention, the boundary of the display range of the position display means is further increased because the position display means of the fifth invention is formed by the punched portion of the printing applied to the top plate, so that light is transmitted only through the extracted portion. Clear and easy to understand.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the embodiments.

(Embodiment 1)
FIG. 1 shows a cross-sectional view of the induction heating apparatus in the first embodiment of the present invention.

  In FIG. 1, a top plate 13 for placing the article to be heated 12 is disposed on the upper surface of the main body 11, and a heating coil 14 for inductively heating the article to be heated 12 is disposed below the top plate 13. . The heating coil 14 is divided into an inner coil 14a and an outer coil 14b, and the inner coil 14a and the outer coil 14b are electrically connected. The sensor 15 is a thermosensitive element such as a thermistor, and is disposed between the central portion of the heating coil 14 and the inner coil 14a and the outer coil 14b. A signal corresponding to the detected temperature is output. The temperature calculation means 16 of the article to be heated 12 calculates the temperature state from the output of the sensor 15, and the control means 17 controls the power supply to the heating coil 14 based on the information obtained from the temperature calculation means 16. Further, a heated object determining means 18 for determining the presence or absence of the heated object 12 above the sensor 15 is provided, and heating can be performed only when it is determined that there are 12 heated objects above the sensor 15. ing. For example, in the case of a contact type such as a thermistor, the object to be heated determination means 18 is determined based on the initial temperature and the gradient of the temperature rise, or in the case of a non-contact type such as an infrared sensor, the object to be heated 12 is What is necessary is just to set the reference | standard output voltage when it exists on the sensor 15, and in short, if the presence or absence of the to-be-heated material 12 can be determined, the means may take what kind of method. In the present embodiment, only the sensor 15 between the inner coil 14a and the outer coil 14b has the function. This is because it is more effective to give the function to the sensor at the location where the heating coil 14 has the strongest magnetic flux and the temperature of the article to be heated 12 is likely to rise. Of course, the central sensor 15 may have the function. The unit constituting the sensor 15 between the inner coil 14a and the outer coil 14b is provided with a light emitting means 21 made of a light emitter such as an LED element, and the induction heating device is turned on for use by the user. And light is irradiated in the direction of the top plate 13 for a certain time. The top plate 13 is provided with a substantially elliptical position display means 19 so that the user can recognize the position of the sensor 15, and the display range is wider than the temperature detection range of the sensor 15. The sensor 15 between the inner coil 14a and the outer coil 14b is disposed at a position eccentric from the center O of the heating coil 14 to the front side of the main body 11, and is the center P of the display range of the position display means 19. To the coil center O side. In the present embodiment, the position display means 19 is formed by a punched portion of the top plate 13.

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

  A position display means 19 that allows the user to recognize the position of the sensor 15 is provided on the top plate 13, and the display range of the position display means 19 is made wider than the temperature detection range of the sensor 15, so that the user can determine the position of the sensor 15. The object to be heated 12 can be reliably positioned above the sensor 15 by placing the object to be heated 12 so that the entire display range of the position display means 19 is hidden. In addition, since temperature detection becomes more accurate, abnormal heating of the heated object 12 such as a pan or deformation due to abnormal heating can be suppressed.

  Further, the sensor 15 is arranged at a position eccentric from the center O of the heating coil 14 toward the front side of the main body 11, and is arranged at a position eccentric from the center of the display range of the position display means 19 toward the coil center O side. Therefore, the position of the sensor 15 displayed on the top plate 13 is located on the user side with respect to the coil center O, so that the sensor position is easy to see (difficult to see if it is in the back), and the back side with respect to the center P of the display range. That is, since the sensor 15 is located on the coil center O side, when the user places the object 12 to be heated, if the user pays attention only to the front side of the display range, the entire display range of the position display means 19 is naturally hidden. Since the heated object 12 can be placed and the heated object 12 can be reliably positioned above the sensor, the usability is improved.

  Further, when the user places the object to be heated 12, it is usually placed from the front of the main body 11, so that alignment in the left-right direction is relatively easy, and alignment in the front-rear direction is more difficult. Therefore, by making the outer shape of the display range of the position display means 19 into a substantially elliptical shape that is long in the front and back direction, the restriction range when the user places the object to be heated 12 can be minimized, and the sensor The object to be heated 12 can be reliably positioned above 15. The same effect can be obtained if the outer shape is a shape close to an elliptical shape (for example, an oval shape).

  Further, the sensor 15 that determines the presence or absence of the object to be heated 12 may be an infrared sensor that detects infrared rays emitted from the object to be heated 12. By using the sensor 15 as an infrared sensor, the accuracy of determining the presence / absence of the object to be heated 12 is improved, thereby enabling detection with higher accuracy. However, in the case of an infrared sensor, it is not brought into contact with the top plate 13 but is separated to the lower surface of the heating coil 14 to be detected in a non-contact manner. In particular, in the case of an infrared sensor, since the transmission performance of the top plate 13 affects, it is necessary to print the inside of the circular position display means 19 with good transmission performance. In addition, since the temperature detection of an infrared sensor may be disturbed by infrared rays such as illumination, it is necessary to reliably place an object to be heated on the sensor 15, and a margin of about 20 mm is required for the temperature detection range. It is known from experiments. Therefore, if the length in the longitudinal direction of the substantially elliptical shape in the present embodiment is set to a length obtained by adding about 20 mm to the diameter of the temperature detection range, ambient light can be reliably prevented, and the temperature detection reliability is improved. improves.

  In the present embodiment, since the light emitting means 21 for illuminating the display range of the position display means 19 is provided, it is easy for the user to visually recognize the position of the sensor 15 when placing the article 12 to be heated. Yes, it improves usability.

  Further, by forming the position display means 19 by a printing cut-out portion applied to the top plate 13, light is transmitted only through the drawing portion, so that the boundary of the display range of the position display means can be clearly understood.

  As described above, the induction heating device according to the present invention can accurately detect the temperature of an object to be heated and can improve the usability of the user. Therefore, the induction heating device can be applied to all uses having a similar configuration using a sensor. it can.

DESCRIPTION OF SYMBOLS 11 Main body 12 To-be-heated object 13 Top plate 14 Heating coil 15 Sensor 16 Temperature calculation means 17 Control means 18 To-be-heated object determination means 19 Position display means (printing-out part)
21 Light emitting means

Claims (6)

A top plate disposed on the upper surface of the main body for placing the object to be heated, a heating coil disposed below the top plate for heating the object to be heated, and disposed below the top plate, A sensor for detecting the temperature of the object, a temperature calculating means for calculating the bottom surface temperature of the object to be heated from the output of the sensor, a control means for performing input control of the heating coil in accordance with the output of the temperature calculating means, In an induction heating apparatus comprising a heated object determining means for determining the presence or absence of an heated object above the sensor and capable of heating only when it is determined that the heated object is above the sensor, the position of the sensor An induction heating apparatus in which a position display means that can be recognized by the user is provided on the top plate, and the display range of the position display means is wider than the temperature detection range of the sensor. 2. The induction heating according to claim 1, wherein the sensor is arranged at a position eccentric from the center of the heating coil toward the front side of the main body, and is arranged at a position eccentric from the center of the display range of the position display means toward the coil center. apparatus. The induction heating apparatus according to claim 2, wherein an outer shape of a display range of the position display means is substantially elliptical. The induction heating apparatus according to any one of claims 1 to 3, wherein the sensor is an infrared sensor that detects infrared rays emitted from an object to be heated. The induction heating apparatus according to any one of claims 1 to 4, wherein a light emitting means for illuminating a part or the whole of the display range of the position display means is provided in the vicinity of the display means on the back side of the top plate. 6. The induction heating apparatus according to claim 5, wherein the position display means is formed by a printing punched portion applied to the top plate.