JP4933989B2 - Induction heating cooker - Google Patents

Description

  The present invention relates to an induction heating cooker used by being incorporated in a system kitchen or the like.

  Conventionally, in this type of induction heating cooker, a top plate on which an object to be heated is placed is disposed on the upper surface of the main body, and a heating coil for inductively heating the object to be heated is disposed below the top plate. Yes. The heating coil is divided into an inner coil and an outer coil, and the inner coil and the outer coil are electrically connected. Further, a thermal element such as a thermistor pressed against the back surface of the top plate is provided between the central portion of the heating coil and the inner coil and the outer coil, and outputs a signal corresponding to the detected temperature. The reason for using such a configuration is that the heating coil is divided substantially in the center in the radial direction (generally, the most of the magnetic flux) from the viewpoint of improving the uniform heating property by dividing the heating coil and preventing the temperature rise of the object to be heated. It is effective to arrange a temperature sensor at a position corresponding to (strong place).

The induction heating cooker is provided with temperature detection means for detecting the temperature of the object to be heated. The temperature detection means detects, for example, the temperature state from the output of the thermal element, and the control means is from the temperature detection means. Based on the obtained information, the power supply to the heating coil is controlled (for example, see Patent Document 1).
JP 2003-234168 A

  Recently, it has been proposed that a third heating coil is provided instead of the radial heater provided behind the heating coil. However, in the case of a three-neck induction heating cooker having a third heating coil, the front heating is performed. If there is an object to be heated above the coil, there is a problem that it is difficult to accurately recognize the mounting position above the third heating coil arranged behind the coil.

  The present invention has been made in view of such problems of the prior art, and even when a heating coil is provided behind the main body, an object to be heated is appropriately disposed above the heating coil. An object of the present invention is to provide an induction heating cooker capable of accurately detecting the temperature of an object.

To achieve the above object, the invention according to claim 1 of the present invention includes a main body, a top plate that covers an upper surface of the main body and on which an object to be heated is placed, and covers the periphery of the top plate. An induction heating cooker provided with a plate frame and a plurality of heating coils disposed under the top plate for heating an object to be heated, wherein the plurality of heating coils are disposed in front of the main body. The first and second heating coils and a third heating coil disposed behind the main body, and the temperature of the object to be heated heated by the third heating coil is the third heating coil. First and second temperature sensors for detecting the inner side of the outer periphery of the coil, first and second temperature detecting means for detecting the temperature of the object to be heated from the outputs of the first and second temperature sensors, According to the outputs of the first and second temperature detecting means, the third addition Further comprising a control means for performing input control of the coil, while placing the first temperature sensor in front of the center of the third heating coil, the second temperature sensor of said third heating coil The second temperature sensor and the first temperature sensor are arranged on the inner side of the peripheral edge and the distance between the outer edge of the heating display portion indicating the heating area of the third heating coil and the front edge of the plate frame located behind the outer edge. The distance in the front-rear direction of the temperature sensor 1 is increased.

Furthermore, the invention described in claim 2 is characterized in that the first temperature sensor is an infrared sensor, and the second temperature sensor is a thermal element.

  According to the present invention, the first and second heating coils are disposed in front of the main body, the third heating coil is disposed in the rear of the main body, and the object to be heated heated by the third heating coil is arranged. The first and second temperature sensors for detecting the temperature are arranged in front of and substantially in the center of the third heating coil, respectively, and are positioned on the outer edge of the heating display portion indicating the heating area of the third heating coil and the rear thereof. Since the distance in the front-rear direction of the second temperature sensor and the first temperature sensor is made larger than the distance in the front-rear direction of the front edge of the plate frame to be moved, the object to be heated is shifted rearward from the center of the third heating coil. However, since the object to be heated is regulated by the plate frame and the object to be heated can cover at least the second temperature sensor, the temperature of the object to be heated can be accurately detected by the second temperature sensor. , Stable temperature control of heated object It can be carried out.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 shows an induction heating cooker according to the present invention, and a cooker body 2 is assembled by being dropped from above into an opening provided on the top surface of a kitchen cabinet. The upper surface of the main body 2 is covered with a plate frame 6 surrounding the top plate 4 made of crystallized ceramic. A plurality of (three in the present embodiment) heating units 8, 10, and 12 are displayed on the top plate 4 by printing. In the rear part of the main body 2 behind the top plate 4, an intake port 14 for taking outside air into the main body 2 and an exhaust port 16 for discharging the heated air inside the main body 2 to the outside are formed. ing.

  Inside the main body 2 corresponding to the heating units 8, 10, 12, first and second heating coils 18, 20 constituting induction heating means are disposed in front, and behind these two heating coils 18, 20. A third heating coil 22 is provided. These three heating coils 18, 20, and 22 are mounted on coil bases 24, 26, and 28, respectively.

  Below the first heating coil (the heating coil on the left side of FIG. 1) 18, a roaster 30 having an opening on the front surface of the main body is formed as shown by a broken line as a heating chamber for heating fish and the like, A roaster cover 32 as a partition plate that shields heat from the roaster 30 is interposed between the first heating coil 18 and the roaster 30. A gap for heat insulation is provided on the upper surfaces of the roaster cover 32 and the roaster 30.

  Moreover, the operation part 35 operated when cooking using an induction heating cooking appliance is provided in the front surface of the main body at the side of the roaster 30. Further, on the side of the roaster 30, below the second heating coil 20, three control boards 34, 36, equipped with electronic components for controlling the first to third heating coils 18, 20, 22, A plurality of (for example, two) centrifugal intake fans 40 and 42 for sucking air outside the main body 2 are arranged above and below. .

  A plurality of springs 44, 46, 48 are attached below each of the coil bases 24, 26, 28, and the coil bases 24, 26, 28 are attached to the top plate 4 by these springs 44, 46, 48. The bosses 24 a, 26 a, 28 a that are urged toward the back surface (lower surface) and are provided in the vertical direction on the outer peripheral portions of the coil bases 24, 26, 28 are pressed against the back surface of the top plate 4, thereby A predetermined gap is provided between the upper surface of the third heating coils 18, 20, and 22 and the back surface of the top plate 4.

  Next, the control system for the first to third heating coils 18, 20, 22 among the control systems for the induction heating cooker will be described by taking the third heating coil 22 as an example.

  As shown in FIG. 2, the third heating coil 22 has a split winding configuration of an inner coil 22 a and an outer coil 22 b that are electrically connected to each other, and is held on the coil base 28 as described above. Yes. Further, a ferrite 50 for concentrating the magnetic flux from the heating coil 22 to the object to be heated P is attached to the lower surface of the coil base 28. Furthermore, an infrared sensor 52 as a first temperature sensor for detecting the temperature of the object to be heated P is attached below the gap between the inner coil 22a and the outer coil 22b. A heat sensitive element 54 such as a thermistor as a second temperature sensor for detecting the temperature of the object to be heated P is attached in close contact with the top plate 4.

  The infrared sensor 52 is disposed below the ferrite 50 that forms a closed magnetic path of the magnetic flux below the heating coil 22 so as not to be affected by the magnetic flux from the heating coil 22. Detecting infrared rays. The infrared light emitted from the object to be heated P passes through the top plate 4, enters the main body 2 from the infrared incident region 4 b formed on the back surface of the top plate 4, and has a cylindrical light guide 29 formed on the coil base 28. Is incident on the upper opening 29 a of the light source, is condensed by the condensing lens 52 a disposed opposite to the lower opening 29 b, and is received by the infrared sensor 52.

  The infrared incident area 4b is formed as a window obtained by removing a part of the colored printing film 4a printed on the back surface of the top plate 4 into a circle or a rectangle, but the shape is not limited to a circle or a rectangle. Absent. The printed film 4a has a light shielding property, blocks disturbance light together with the cylindrical light guide 29, and makes the infrared rays from the opposed portions of the bottom of the heated object P dominantly enter, so that the high temperature of the heated object P is increased. Accurately measure the temperature of the part. The output of the infrared sensor 52 is input to the temperature detection unit 56, and the temperature detection unit 56 detects the temperature of the object P to be heated. The output of the temperature detection means 56 is input to the heated object determination means 58 and the control means 60, and the control means 60 outputs the high frequency current to the heating coil 22 according to the signal from the temperature detection means 56. To control.

  Further, the output of the thermal element 54 is input to the temperature detection means 64, and the temperature detection means 64 detects the temperature of the object P to be heated. The output of the temperature detection means 64 is input to the control means 60, and the control means 60 controls the output of the inverter circuit 62 that supplies a high frequency current to the heating coil 22 in accordance with a signal from the temperature detection means 64.

  In addition, since the infrared sensor 52 is more excellent in temperature responsiveness than the thermal element 54 such as a thermistor, in the present embodiment, the heated object P is heated when the heated object P is at a high temperature, such as fried food cooking. The thermal element 54 is used for temperature control of the object P, and the temperature of the object P to be heated is controlled by the infrared sensor 52 when the infrared sensor 52 is out of order or when the object P to be heated is placed out of the center of the heating unit 12. In addition to backup when it cannot be detected properly, it is provided for automatic temperature adjustment of rice cooking and fried foods, etc. The output control of the inverter circuit 62 by the control means 60 is either the output of the infrared sensor 52 or the signal of the thermal element Is set so as to control the temperature of the object P to be heated.

The operation of the heating coil 22 configured as described above will be described below.
When heating is started, the inverter circuit 62 supplies a high-frequency current to the heating coil 22, and the article P to be heated self-heats with the magnetic flux (magnetic field) from the heating coil 22. The bottom temperature of the object to be heated P after the start of heating is the highest in the vicinity of the inner edge of the outer coil 22b and the lowest in the approximate center of the heating coil 22 due to the influence of the magnetic flux density distribution from the heating coil 22. Therefore, in order to detect the temperature at the high temperature portion of the article P to be heated, the infrared sensor 52 is disposed inside the outer periphery of the heating coil 22 and below the inner coil 22a and the outer coil 22b of the heating coil 22, and the infrared sensor. The output from 52 is converted into a temperature by the temperature detecting means 56, and the detected temperature exceeds a predetermined temperature, or the output voltage of the infrared sensor 52 is calculated to determine that the temperature of the object P to be heated is equal to or higher than the predetermined temperature. Then, the inverter circuit 62 is controlled by the control means 60 so that its output decreases.

  The heated object determination means 58 is for determining the presence or absence of the heated object P above the infrared sensor 52, and when it is determined that there is no heated object P above the infrared sensor 52, It is configured not to stop heating or start heating. In the case of a non-contact temperature sensor such as the infrared sensor 52, the object to be heated determination means 58 is a current value relative to the output voltage of the infrared sensor 52 immediately after the start of heating when the object to be heated P is on the infrared sensor 52. Output voltage increase amount, that is, the reference output voltage increase amount is set, and when the detected temperature of the temperature detecting means 64 is equal to or higher than a predetermined temperature, the reference output voltage increase amount of the voltage output from the temperature detecting means 56 and When the reference output voltage set in advance is compared and the reference output voltage increase amount is less than the predetermined value, the object to be heated P is placed at a position where the temperature control is normally performed by the infrared sensor 52. Judge that there is no. The heated object determining means 58 irradiates the heated object P from below the top plate 4 with light from a light emitting element (not shown) such as an LED instead of the above method, and the infrared sensor 52 causes the heated object to be heated. The presence or absence of the object to be heated P may be determined depending on whether or not the reflected light from the light emitting element reflected by P is received.

  As shown in FIG. 3, sensor marks 66 and 68 having predetermined shapes (for example, circular shapes) are provided on the top plate 4 so that the user can recognize the positions of the infrared sensor 52 and the temperature sensing element 54. Printed around the center of each. The position of the infrared sensor 52 on the top plate 4 refers to an infrared incident area measured by the infrared sensor 52. For example, in FIG. 2, the position of the infrared sensor 52 refers to the position of the infrared incident region 4 b, and the position of the temperature sensitive element 54 on the top plate 4 refers to the portion where the temperature sensitive element 54 is in contact. The sensor marks 66 and 68 only need to have all or part of the infrared incident region measured by the infrared sensor 52 in at least the portion to be displayed. Further, a character display is also provided in the vicinity so that the user can recognize that the infrared sensor 52 and the temperature sensing element 54 are present. The inside of the sensor marks 66 and 68 may be distinguished from the color of the surrounding top plate 4.

  As described above, in the present embodiment, the sensor marks 66 and 68 that allow the user to recognize the positions of the infrared sensor 52 and the temperature sensitive element 54 are displayed on the top plate 4. The object P to be heated can be reliably placed at an appropriate upper position. As a result, temperature detection becomes more accurate, and abnormal heating of the heated object P such as a pan or deformation due to abnormal heating can be suppressed.

  2 is applicable to the first and second heating coils 18 and 20, but the sensor mark 66 for recognizing the positions of the infrared sensor 52 and the temperature sensing element 54 of the third heating coil 22. , 68 is most preferably arranged before and after the center of the third heating coil 22 as described above. In other words, the third heating coil 22 is arranged behind the first and second heating coils 18 and 20 between them, and is attached to at least one of the first and second heating coils 18 and 20. If the article P to be heated is placed on the corresponding heating units 8 and 10, the sensor marks 66 and 68 of the heating unit 12 corresponding to the third heating coil 22 may be difficult to see.

  Therefore, in the present embodiment, as shown in FIG. 3, if the line connecting the centers of the first and second heating coils 18 and 20 is the X axis, the X axis is parallel to the front of the main body 2. It has become. Two sensor marks 66 and 68 are arranged on a line (Y axis) orthogonal to the X axis and passing through the center of the third heating coil 22, and the sensor mark 66 above the infrared sensor 52 is third heated. While decentering forward from the center of the coil 22, the sensor mark 68 above the temperature sensing element 54 is decentered rearward from the center of the third heating coil 22. In addition, if the distance from the center of the 3rd heating coil 22 of the sensor marks 66 and 68 is set substantially equal, the infrared sensor 52 and the thermal element 54 will measure the location where the bottom face temperature of the to-be-heated material P is substantially equal. , Both can measure a portion having a temperature higher than the temperature of the object to be heated P facing the center of the heating coil 22, so that the temperature of the object to be heated can be measured with high responsiveness.

  As shown in FIG. 2, the temperature sensing element 54 as the second temperature sensor is provided outside the outer periphery of the inner coil 22a and disposed rearward from the center of the third heating coil 22. It is good also as a structure which is provided in the approximate center of the 3rd heating coil 22 inside the inner periphery of the coil 22a, and provides the corresponding sensor mark 70 as FIG. 4 shows as needed. With this configuration, the probability that the bottom surface of the object to be heated P exists on the temperature sensing element 54 becomes equal to the positional deviation of the object to be heated P in all directions from the center of the third heating coil 22. The temperature of the heated object P can be measured relatively stably.

  Further, as shown in FIG. 4, the outer edge of the heating section 12 (a heating display section indicating a heating area, which is a circle in the present embodiment) of the third heating coil 22 and the front of the plate frame 6 positioned behind the outer edge. The distance B in the front-rear direction of the first and second temperature sensors than the distance A in the front-rear direction of the edge (the center of the thermosensitive element that is the second temperature sensor and the center of the measurement region of the infrared sensor that is the first temperature sensor) If the center position of the standard-size heated object P (heated object having a diameter substantially equal to that of the heating display unit 12) is shifted backward from the center of the heating display unit 12, the distance to be heated is increased. Since the object P is regulated by the plate frame 6 and the object to be heated P can cover at least the thermal element, it is possible to avoid a situation in which neither the infrared sensor nor the thermal element can detect the temperature of the object to be heated P. Therefore, in this case, the sensor marks 66 and 70 are not necessarily provided.

  In the case of the first and second heating coils 18 and 20, sensor marks similar to the sensor marks 66 and 68 of the third heating coil 22 are provided on the heating units 8 and 10 corresponding to the heating coils 18 and 20. Although provided, these sensor marks are not necessarily arranged before and after the centers of the heating coils 18 and 20.

  Further, the light emitting unit 69 may be formed inside or outside the sensor mark 66, and the user may be instructed to cover the light emitting unit 69. By doing so, the visibility of the sensor mark 66 can be improved, and the infrared sensor 52 inside the sensor mark 66 and the infrared incident port for infrared measurement can be covered more reliably.

  The light emitting unit 69 emits light by, for example, providing a light emitter such as an LED adjacent to the infrared sensor 52 and another light guide unit (hereinafter referred to as a second light guide unit) similar to the light guide unit 29 shown in FIG. A light portion) is provided adjacent to the light guide portion 29 so that light from the light emitter enters the lower opening of the second light guide portion and is emitted from the upper opening so that the light can be seen from above the top plate 4. You can do it.

  Moreover, in the said embodiment, the 3rd heating coil 22 is infrared rays between the coil | windings of the 3rd heating coil 22 as a division | segmentation winding structure of the inner coil 22a and the outer coil 22b which were electrically connected mutually. Although the infrared incident area 4b of the sensor 52 is provided, the present invention is not limited to this, and the infrared incident area is provided inside the heating coil 22 and the temperature of the article P to be heated faces the third heating coil 22. What is necessary is just to detect the temperature inside. For example, as shown in FIG. 5, the third heating coil 71 is not divided and the infrared sensor (not shown) is guided in the vicinity of the inner peripheral edge forming the central opening 74 of the third heating coil 71. You may arrange | position the temperature sensing elements 73, such as a light part 72 and a thermistor. In this case, since the light guide portion 72 of the infrared sensor is provided at a position eccentric from the center of the heating coil 71, the temperature of the object P to be heated is higher than the center of the heating coil 71 during heating. Can do.

  As described above, the heating cooker according to the present invention can accurately detect the temperature of the object to be heated by appropriately arranging the object to be heated above the heating coil disposed at the rear, so at least forward It is useful as an induction heating cooker having three or more openings provided with two heating coils and one heating coil behind.

The exploded perspective view of the induction heating cooking appliance concerning this invention Block diagram showing heating coil control circuit The top view of the top plate provided in the induction heating cooking appliance of FIG. The top view of the induction heating cooking appliance at the time of making the position of the temperature sensing element provided in the 3rd heating coil into the heating coil center The perspective view of the 3rd heating coil at the time of making the position of the temperature sensing element provided in the 3rd heating coil into the heating coil center

Explanation of symbols

2 cooker body, 4 top plate, 4a printed film, 4b infrared incident area,
6 plate frame, 8, 10, 12 heating section, 14 air inlet, 16 air outlet,
18, 20, 22 heating coil, 22a inner coil, 22b outer coil,
24, 26, 28 coil base, 24a, 26a, 28a boss, 29 light guide,
29a upper opening, 29b lower opening, 30 roaster,
32 Roaster cover, 34, 36, 38 Control board, 35 Operation unit,
40,42 Intake fan, 44,46,48 Spring, 50 Ferrite,
52 infrared sensor, 54 temperature sensing element, 56 temperature detecting means,
58 heated object judgment means, 60 control means, 62 inverter circuit,
64 temperature detection means, 66, 68 sensor mark, 69 light emitting part,
70 sensor mark, 71 heating coil, 72 light guide, 73 temperature sensing element,
P Object to be heated.

Claims (2)

A main body, a top plate that covers the upper surface of the main body and on which the object to be heated is placed, a plate frame that covers the periphery of the top plate, and a plurality of heating units that are disposed below the top plate and heat the object to be heated An induction heating cooker comprising a coil,
The plurality of heating coils include first and second heating coils disposed in front of the main body, and a third heating coil disposed in the rear of the main body, the third heating coil. First and second temperature sensors for detecting the temperature of the heated object heated by the inner side of the outer periphery of the third heating coil, and the temperature of the heated object from the outputs of the first and second temperature sensors The first and second temperature detecting means for detecting the first and second temperature detecting means, and the control means for performing input control of the third heating coil in accordance with the outputs of the first and second temperature detecting means, The temperature sensor is arranged in front of the center of the third heating coil, while the second temperature sensor is arranged inside the inner periphery of the third heating coil, and the heating area of the third heating coil The outer edge of the heating display part showing the above and the plate located behind it Induction cooking device being characterized in that to increase the longitudinal length of the second temperature sensor and the first temperature sensor than longitudinal length of the front edge. The induction heating cooker according to claim 1 , wherein the first temperature sensor is an infrared sensor, and the second temperature sensor is a thermal element.

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