JP2009123603A - Induction heating cooker - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an induction heating cooker having high heating efficiency regardless of the material of a heating cookware. <P>SOLUTION: The ribbon heater 42 of a plate-shape heating body 22 generates heat by flowing current. A heating cookware such as a pan 17 mounted on a top plate 13 is heated directly by the plate-shape heating body 22 generating heat. The ribbon heater 42 wound on an insulating substrate 41 is not in contact with the insulating substrate 41 in large portions except for the heater wound portions 47. Thereby, even if dimension changes occur in the ribbon heater 42 by heat generation of flowing current, there arises no interaction between the insulating substrate 41 and the ribbon heater 42 having different thermal expansion coefficient. That is, even if dimensions of the ribbon heater 42 change due to heat generation, a stress caused in the insulating substrate 41 is reduced. As a result, even when the difference of the thermal expansion coefficient between the insulating substrate 41 and the ribbon heater 42 is large, a damage such as cracks does not occur in the insulating substrate 41 due to heat generation of the ribbon heater 42. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an induction heating cooker, and more particularly to an induction heating cooker including a plate-shaped heating body between a top plate and an induction heating coil.

In an induction heating cooker, for example, when using a cooked appliance made of a material having a low dielectric constant and high electrical conductivity, such as aluminum or copper, the so-called “pot float” in which the cooked appliance moves repulsively with respect to the top plate. A phenomenon may occur. Therefore, it has been proposed to provide a heating element between the top plate and the induction heating coil in order to heat the cooked utensil made of a material having a low dielectric constant and high electrical conductivity. However, in this case, the heating element is induction-heated by the induction heating coil, and the cooked utensil is heated via the heating element heated by the induction heating coil. Therefore, there is a problem that the cooked utensil is indirectly heated by the induction heating coil via the heating element, and the heating efficiency is low. Therefore, an induction heating cooker has been proposed in which a heating element that generates heat when energized is provided between the top plate and the induction heating coil, and the cooked utensil placed on the top plate is heated by the heating element. (See Patent Document 1).
JP 2007-123159 A

  However, in the case of Patent Document 1, the heating element is supported by a ceramic reinforcing plate opposite to the top plate. A stainless steel heating element differs in thermal expansion coefficient from a ceramic reinforcing plate. Therefore, when the heating element expands due to heat generated by energization, the difference in dimensional change with the reinforcing plate increases. As a result, there is a problem that the reinforcing plate is damaged.

  Then, this invention is made | formed in view of said subject, and the objective is to reduce the influence by thermal expansion and to be an induction heating cooking appliance with high heating efficiency irrespective of the material of a to-be-heated cooking utensil. It is to provide.

  In order to achieve the above object, according to the induction heating cooker of the present invention, a top plate on which a cooked appliance to be heated is placed, a lower plate provided on the top plate, and placed on the top plate. An induction heating coil that induction-heats the heated cooking utensil, and a plate-like heating body that is disposed between the top plate and the induction heating coil and that heats the cooking utensil placed on the top plate; , The plate-like heating body includes a plate-like insulating substrate and a belt-like heater that is wound around the insulating substrate and generates heat when energized.

  According to the induction heating cooker having the above-described configuration, the plate-like heating body having the belt-like heater and the insulating substrate around which the heater is wound is provided. The heater generates heat when energized, and the heat heats the cooked utensil on the top plate. Thereby, a to-be-heated cooking appliance is directly heated by the heater of a plate-shaped heating body. Therefore, the cooked utensil can be heated regardless of the material, and the heating efficiency can be increased.

  Moreover, in the induction heating cooking appliance of Claim 1, the strip | belt-shaped heater is wound by the insulated substrate. As a result, since the insulating substrate and the heater are not in close contact with each other, even if a dimensional change occurs in the heater due to heat generation due to energization, no interaction occurs between the heater and the insulating substrate. That is, even if the heater dimensions change, the stress generated in the insulating substrate is reduced. For this reason, even when the difference in the coefficient of thermal expansion between the insulating substrate and the heater is large, the insulating substrate does not break or break due to the heat generated by the heater. Therefore, the durability of the plate-like heating body can be increased.

Hereinafter, a plurality of embodiments of an induction heating cooker according to the present invention will be described with reference to the drawings. In addition, in each Example, the same code | symbol is attached | subjected to the substantially same component, and description is abbreviate | omitted.
(First embodiment)
The induction heating cooker according to the first embodiment of the present invention is shown in FIG. The induction heating cooker 10 includes a body case 12 and a top plate 13 that constitute a cooker body 11. The induction heating cooker 10 is provided so that the top plate 13 is on the upper side in the direction of gravity. In FIG. 2, the left side is the front side of the induction heating cooker 10, and the right side is the rear side of the induction heating cooker 10. The induction heating cooker 10 includes a heating unit 14 and a cooling fan unit 15 in a cooking appliance body 11.

  The main body case 12 forms the main outline of the induction heating cooker 10. The top plate 13 covers the upper part of the main body case 12. The cooker body 11 is incorporated into a countertop 16 of a system kitchen, for example. Thereby, the top plate 13 of the cooker body 11 is exposed to the counter top 16. On the top surface of the top plate 13, a pan 17 indicated by a two-dot chain line is placed as a cooking utensil to be heated. The pan 17 placed on the top plate 13 is heated by heating means accommodated in the main body case 12. The top plate 13 is formed in a rectangular flat plate shape using, for example, tempered heat resistant glass. The top plate 13 has openings 18 for intake and exhaust at the rear. In the case of the present embodiment, the opening 18 is provided for exhaust on the left side behind the top plate 13 and for intake on the right side. A heating control unit 19 is accommodated in the main body case 12 of the cooker main body 11.

  As shown in FIG. 3, the induction heating cooker 10 includes an induction heating coil 21 and a plate-like heating body 22 as a heating unit 14 that constitutes a heating unit. The induction heating cooker 10 generally includes a plurality of heating means such as a roaster function including a plurality of induction heating coils 21 and a sheathed heater as another heating means. Moreover, the induction heating cooking appliance 10 may be equipped with the heating means other than the above illustrated. Illustration and description of these other heating means are omitted.

  In the case of the present embodiment, the induction heating coil 21 and the plate heater 22 constitute the heating unit 14 and are provided at the same position in the plan view of the induction heating cooker 10. That is, the induction heating coil 21 and the plate-like heating body 22 constituting the heating unit 14 are integrally supported at a predetermined position of the main body case 12. The heating unit 14 is pressed against the lower surface of the top plate 13 by an elastic body 23 having, for example, a compression coil spring. Thereby, the heating unit 14 is in close contact with the lower surface of the top plate 13.

  As shown in FIGS. 3 and 4, the heating unit 14 includes a support member 24 and a heat insulating material 25 in addition to the induction heating coil 21 and the plate-like heating body 22. The support member 24 supports the plate-like heating body 22 on the top plate 13 side of the induction heating coil 21. The support member 24 is provided so as to form a predetermined gap with the induction heating coil 21. Thereby, a passage 26 through which air flows is formed between the plate-like heating body 22 of the heating unit 14 and the induction heating coil 21. The support member 24 has a hole 241 as shown in FIG. The heat insulating material 25 is provided between the plate heater 22 and the induction heating coil 21. The heat insulating material 25 blocks heat generated from the plate-like heating body 22 from being transmitted from the plate-like heating body 22 to the induction heating coil 21 side. The heat insulating material 25 has a hole 251 in part. The hole 251 of the heat insulating material 25 is connected to a hole 241 provided in the support member 24.

The cooling fan unit 15 is provided inside the main body case 12 as shown in FIG. The cooling fan unit 15 includes a fan 27 and a fan motor 28. As the fan 27 rotates, the air drawn from the intake opening 18 is discharged from the exhaust opening 18 via the heating unit 14 and the heating control unit 19. Thereby, the cooling fan unit 15 forms a flow of cooling air and cools the heating unit 14 and the heating control unit 19.
The heating control unit 19 is connected to an inverter 29 that constitutes a high-frequency current supply unit as shown in FIG. That is, the heating control unit 19 has a circuit board on which a heat-generating switching element such as an IGBT that constitutes the main circuit of the inverter 29 is mounted. The exothermic element of the heating control unit 19 is cooled by the wind generated by the cooling fan unit 15.

Next, the heating unit 14 will be described in detail.
The induction heating coil 21 constituting the heating unit 14 is formed in a hollow disk shape as shown in FIG. The induction heating coil 21 is supported at a position away from the top plate 13 by a predetermined distance. The induction heating coil 21 is supported by a base plate 31 made of heat resistant resin as shown in FIG. The base plate 31 has cylindrical leg portions 32 that protrude downward at a plurality of positions on the outer peripheral portion. As shown in FIG. 2, an elastic body 23 is attached between the leg portion 32 and the inner frame member 33 of the main body case 12. Thereby, the induction heating coil 21 supported by the base plate 31 is pressed against the top plate 13 side. By supplying a high frequency current to the induction heating coil 21, an eddy current is generated in the pan 17 placed on the top plate 13. Due to this eddy current, Joule heat is generated in the pan 17 and the pan 17 is heated.

  On the other hand, the plate-like heating body 22 constituting the heating unit 14 has an insulating substrate 41 and a ribbon heater 42 as shown in FIG. The insulating substrate 41 is formed from an insulator. In this embodiment, the insulating substrate 41 is made of ceramics. The insulating substrate 41 is preferably formed from ceramics having high thermal conductivity. The ribbon heater 42 is formed in a belt shape and constitutes a heater in the claims. Most of the ribbon heater 42 formed in a belt shape is wound around the insulating substrate 41, and the end portion is taken out of the insulating substrate 41 as a terminal 43. As the ceramic forming the insulating substrate 41, for example, aluminum nitride, silicon nitride, or alumina can be applied. Aluminum nitride has a high thermal conductivity, and uniformly transfers the heat of the ribbon heater 42 to the top plate 13 side. On the other hand, aluminum nitride has a weak point that it is vulnerable to impact. Therefore, by forming the insulating substrate 41 with silicon nitride, the strength against impact can be improved as compared with aluminum nitride. Moreover, the insulating substrate 41 can be formed at low cost by forming the insulating substrate 41 from alumina. The material of these ceramics is not limited to the above example, but can be arbitrarily changed according to the requirements according to the specifications of the induction heating cooker 10 to which the insulating substrate 41 is applied.

  The insulating substrate 41 is formed in a substantially disc shape. The insulating substrate 41 has holes 431, 432, 433, and 434 and slits 441, 442, 443, and 444 at substantially equal intervals in the circumferential direction. The holes 431, 432, 433, 434 and the slits 441, 442, 443, 444 penetrate the insulating substrate 41 in the plate thickness direction. Both ends of the holes 431, 432, 433, and 444 are closed by the insulating substrate 41 in the radial direction of the insulating substrate 41. On the other hand, the slits 441, 442, 443, 444 are open at the outer peripheral ends in the radial direction of the insulating substrate 41. In this embodiment, the insulating substrate 41 has holes 431, 432, 433, 434 and slits 441, 442, 443, 444 alternately at intervals of 45 ° in the circumferential direction. The insulating substrate 41 has a sensor hole 45 at the center. The sensor hole 45 penetrates the insulating substrate 41 in the plate thickness direction.

  The insulating substrate 41 has concavo-convex portions 46 in holes 431, 432, 433, 434 and slits 441, 442, 443, 444, respectively. The concavo-convex part 46 is provided on the opposing wall part forming the holes 431, 432, 433, 434 and the slits 441, 442, 443, 444 in the insulating substrate 41. The uneven portion 46 protrudes or is recessed in the circumferential direction of the insulating substrate 41. The uneven portion 46 has a plurality of unevenness in the radial direction of the insulating substrate 41. The number and interval of the holes 431, 432, 433, 434 and the slits 441, 442, 443, 444, the shape of the concavo-convex portion 46, and the like can be arbitrarily changed.

  The ribbon heater 42 is wound around the insulating substrate 41. Specifically, in the ribbon heater 42, the uneven portion 46 of the holes 431, 432, 433, 434 and the uneven portion 46 of the slits 441, 442, 443, 444 adjacent to each other in the circumferential direction of the insulating substrate 41 are heated by the heater winding portion 47. The heater winding portion 47 is folded back. That is, the ribbon heater 42 forms a heater winding portion 47 in the uneven portions 46 of the holes 431, 432, 433, 434 and the uneven portions 46 of the slits 441, 442, 443, 444. The ribbon heater 42 is insulated by being sandwiched between the holes 431, 432, 433, 434 adjacent to each other in the circumferential direction of the insulating substrate 41 and the slits 441, 442, 443, 444 while being folded back by the heater winding part 47. It is wound around the substrate 41. Therefore, the ribbon heater 42 is wound not only on the upper surface side on the top plate 13 side of the insulating substrate 41 shown in FIG. 1 but also on the lower surface side on the induction heating coil 21 side. Since a plurality of holes 431, 432, 433, 434 and slits 441, 442, 443, 444 are provided as described above, a plurality of heater winding portions 47 are also provided in the circumferential direction of the insulating substrate 41.

  In the case of the present embodiment, the ribbon heater 42 wound around the plate-like heating body 22 has two ribbon heater elements 51 and 52 as heater wires. One ribbon heater element 51 is provided on the insulating substrate 41 while winding the insulating substrate 41 from the terminal 511 to the terminal 512. Here, the path of the ribbon heater element 51 wound around the insulating substrate 41 will be described in detail. The ribbon heater element 51 extends from the terminal 511 to the slit 443 through the transfer portion 513 on the back surface side of the insulating substrate 41. The ribbon heater element 51 that has reached the slit 443 is wound between the slit 443 and the hole 434. The ribbon heater element 51 that has reached the end portion on the inner peripheral side of the hole 434 by being wound around the insulating substrate 41 passes through the transfer portion 514 located on the back surface of the insulating substrate 41 on the inner peripheral side of the slit 443. It reaches the inner peripheral end of the hole 433 located across the slit 443. The ribbon heater element 51 that has reached the hole 433 is wound between the hole 433 and the slit 443 and reaches the outer peripheral end of the slit 443. The ribbon heater element 51 that has reached the outer peripheral side of the slit 443 passes through the transfer portion 515 on the back surface side of the insulating substrate 41, the connection portion 516 on the front surface side, and the transfer portion 517 on the back surface side. Reach the department. The ribbon heater element 51 includes a transfer portion 518 positioned between the slit 442 and the hole 433, the back surface of the insulating substrate 41, a transfer portion 519 positioned between the hole 432 and the slit 442, and the back surface of the insulating substrate 41. To the terminal 512.

  The other ribbon heater element 52 has the insulating substrate 41 wound around from the terminal 521 to the terminal 522 in the same manner as the ribbon heater element 51. Specifically, the ribbon heater element 52 is formed between the transfer portion 523 and the slit 444 on the back surface side of the insulating substrate 41 and the hole 434, and between the transfer portion 524 and the hole 431 and the slit 444 on the back surface side of the insulating substrate 41. , The back surface side transfer portion 525, the front surface side connection portion 526, the back surface side transfer portion 527, between the slit 441 and the hole 431, the back surface side transfer portion 528, between the hole 432 and the slit 441, And it reaches the terminal 522 via the transfer part 529 on the back surface side. Thus, in the first embodiment, the two ribbon heater elements 51 and 52 are wound around the insulating substrate 41 symmetrically in the vertical direction in FIG. 1 with the axis passing through the hole 432 and the hole 434 as the axis of symmetry.

  In the first embodiment, the connecting portion 516 is disposed outside the hole 433 in the radial direction of the insulating substrate 41, and the connecting portion 526 is disposed on the outer peripheral side of the hole 431. As a result, the ribbon heater element 51 passes through the outer peripheral side of the hole 433, and the ribbon heater element 52 passes through the outer peripheral side of the hole 431. For example, when the ribbon heater elements 51 and 52 are wound via the outer peripheral side of the slit, stress is applied to the insulating substrate 41 that forms slits whose ends are opened by the expansion and contraction of the ribbon heater elements 51 and 52, and the insulating substrate 41 may be damaged.

  On the other hand, the ribbon heater elements 51 and 52 do not cross the hole 433 and the hole 431 by arranging the connecting portions 516 and 526 on the outer periphery of the holes 433 and 431 as in the present embodiment. Therefore, the stress applied to the insulating substrate 41 is reduced, and damage to the insulating substrate 41 is avoided. The ribbon heater elements 51 and 52 pass through the transfer portions 528, 518, 514, and 524 located on the inner peripheral side of the slits 441, 442, 443, and 444, respectively. Therefore, the ribbon heater elements 51 and 52 do not cross the slits 441, 442, 443, and 444. As a result, the stress applied to the insulating substrate 41 is reduced, and damage to the insulating substrate 41 is avoided.

  Further, the connection portions 516 and 526 of the ribbon heater elements 51 and 52 are arranged so as not to cross any of the slits 441, 442, 443 and 444. Therefore, the ribbon heater elements 51 and 52 are supported at any portion with respect to the insulating substrate 41 and are not exposed. In other words, the ribbon heater elements 51 and 52 do not hang down from the insulating substrate 41 and are not suspended or passed between the insulating substrates 41. As a result, the stress generated in the ribbon heater elements 51 and 52 due to the displacement of the insulating substrate 41 is reduced. Therefore, disconnection of the ribbon heater elements 51 and 52 can be prevented.

Next, control of the induction heating cooker 10 will be described.
The heating control unit 19 is provided inside the cooker body 11 and is configured by a microcomputer (not shown). As shown in FIG. 5, an operation unit 61 and a temperature sensor 62 are connected to the heating control unit 19. The operation unit 61 is provided outside the cooker body 11. The operation unit 61 is disposed in front of the top plate 13. The operation unit 61 outputs the input information as an operation signal to the heating control unit 19. The temperature sensor 62 detects the temperature of the top plate 13. The temperature sensor 62 outputs the detected temperature of the top plate 13 to the heating control unit 19 as an electrical signal. The heating control unit 19 also functions as a material determination unit that determines the material of the cooked utensil such as the pan 17 placed on the top plate 13. The heating control unit 19 controls the inverter 29 based on a control signal input from the operation unit 61 and the temperature sensor 62 and a control program stored in advance. Thereby, the heating control unit 19 supplies the high-frequency current to the induction heating coil 21 via the inverter 29 and controls the induction heating coil 21. A resonance capacitor 63 is connected in series to the induction heating coil 21. It is desirable that the induction heating coil 21 and the resonance capacitor 63 have a configuration in which the number of turns of the coil and the capacity of the capacitor are variable in order to adjust the output according to the material of the pot 17.

  The inverter 29 is supplied with driving power converted from direct current AC power 64 into direct current by the rectifier circuit 65. Similarly, the energization control unit 66 controls the power supplied from the commercial AC power supply 64 to the plate heater 22. The energization control unit 66 supplies AC power to the plate-like heating body 22. The electric power supplied from the energization control unit 66 to the plate-like heating body 22 is comprehensively controlled by the heating control unit 19. Current transformers 67 and 68 are arranged on the input side of the rectifier circuit 65 and the output side of the inverter 29, respectively. The current values detected by the current transformers 67 and 68 are all input to the heating control unit 19. Thereby, the heating control unit 19 detects the input current value input from the commercial AC power supply 64 and the output current value of the inverter 29.

  The heating control part 19 determines the material of this pan 17 by determining whether the pan 17 which is a to-be-heated cooking appliance is a metal material with big resistance. For example, the heating control unit 19 supplies a constant high-frequency current to the induction heating coil 21, and determines the material of the pan 17 based on the relationship between the input current and the coil current that is the output current of the inverter 29. For example, when the pan 17 is formed of a ferromagnetic material such as iron, the magnetic flux generated by the induction heating coil 21 easily flows through the pan 17. And the skin effect which an eddy current concentrates on the induction heating coil 21 side in the bottom part of the pan 17 also becomes high. Therefore, the equivalent resistance of the induction heating coil 21 increases. On the other hand, when the material of the pan 17 is nonmagnetic or weakly magnetic such as aluminum or copper and the specific resistance is small, the magnetic flux generated by the induction heating coil 21 is difficult to reach the pan 17 and the leakage magnetic flux increases. . Since the specific resistance is small and the skin effect is difficult to obtain, the equivalent resistance decreases. As a result, the heating control unit 19 can determine the material of the pan 17 based on the magnitude change between the input current and the output current. Therefore, the heating control unit 19 determines the material of the pan 17 and selects heating by the induction heating coil 21 of the pan 17 or heater heating by the plate heater 22 based on the preset input power setting value. Can be executed.

Next, the operation of the induction heating cooker 10 having the above configuration will be described.
When the pan 17 containing the object to be cooked is placed at a predetermined position on the top plate 13 and a necessary input operation is performed by the operation unit 61, the heating control unit 19 starts heating the pan 17. If the heating control part 19 determines with the material determination process that the material of the pan 17 is a high resistance metal, the heating control part 19 will perform the induction heating cooking by the induction heating coil 21 based on normal input electric power. On the other hand, when it is determined that the material of the pot 17 is not a high resistance metal, the heating control unit 19 determines whether the material of the pot 17 is a low resistance nonmagnetic metal such as aluminum, copper or nonmagnetic stainless steel, Determine whether it is non-metallic or unloaded. And if it determines with the pan 17 being a low resistance metal, the heating control part 19 will preset the heat-power adjustment so that the bottom of the pan 17 may repel and move by the top plate 13 may not be produced. Based on the above, induction heating cooking is executed.

  Here, when the heating power becomes smaller than the normal input power set value due to the thermal power adjustment, the heating control unit 19 supplies the difference power to the plate-like heating body 22 via the energization control unit 66. Thereby, the heating control unit 19 heats the pan 17 placed on the top plate 13 with the plate-like heating body 22. Further, when the pan 17 is made of a low-resistance nonmagnetic metal, the equivalent resistance of the induction heating coil 21 is reduced. Therefore, the heating control unit 19 lowers the voltage output to the induction heating coil 21 via the inverter 29 or raises the frequency of the voltage as compared with the case of a high-resistance magnetic metal. Thereby, the heating control part 19 aims at the improvement of heating efficiency.

  In addition, when the pan 17 is formed of a non-metal or when there is no load, the heating control unit 19 does not perform induction heating by the induction heating coil 21. Therefore, the heating control unit 19 supplies power equal to the normal input power setting value from the energization control unit 66 to the plate-like heating body 22 and performs heating only by the plate-like heating body 22. In this case, the heating control unit 19 needs to determine whether the pan 17 is non-metallic or unloaded. Therefore, the heating control unit 19 detects a temperature change of the top plate 13 after the temperature sensor 62 starts energizing the plate-like heating body 22. At this time, the heating control unit 19 determines that a clay pot or the like is placed if the change in the temperature of the top plate 13 is gentle, and determines that there is no load if the change in temperature is rapid.

  When it determines with the to-be-heated cooking utensils, such as the pan 17, being a nonmetallic material, the heating control part 19 performs the heating of the pan 17 with the plate-shaped heating body 22. FIG. At this time, the heat generated by the ribbon heater 42 of the plate heater 22 is transmitted from the upper surface to the pan 17 via the top plate 13. On the other hand, after the heating is finished, heat remains in the top plate 13 and the plate-like heating body 22. Therefore, the heating control unit 19 rotationally drives the fan 27 of the cooling fan unit 15 when the heating by the plate heater 22 is completed. The air flow formed by the rotation of the fan 27 is directed from the lower side to the upper side of the heating unit 14. Then, the air flow passes upward from the central portion of the heating unit 14 and travels toward a passage 26 formed between the induction heating coil 21 and the support member 24. In the passage 26, an air flow is formed from the center side of the heating unit 14 to the outer peripheral side.

  At this time, a part of the air flowing between the induction heating coil 21 and the support member 24 passes through the hole 251 of the heat insulating material 25 and the hole 241 of the support member 24 as shown in FIG. It flows to the back side. FIG. 6 is a cross-sectional view schematically showing a part of the configuration of the heating unit 14. The air flow is in contact with the ribbon heater 42 located on the back side of the plate heater 22. Therefore, the ribbon heater 42 located on the back side of the plate-like heating body 22 is cooled by the air flowing in through the holes 241 and 251. Further, the ribbon heater 42 is cooled on the back side of the plate-like heating body 22, whereby the portion located on the surface side of the plate-like heating body 22 is also cooled. That is, the ribbon heater 42 radiates heat at a portion located on the back surface side of the plate-like heating body 22, and a portion located on the front surface side is also cooled. As a result, the top plate 13 whose temperature has been increased by the heating of the pan 17 is rapidly cooled by the air flow by the cooling fan unit 15.

  For example, when the pan 17 is heated by the plate-like heating body 22, when cooking is completed, the user removes the pan 17 from the top plate 13. When the pan 17 is removed from the top plate 13, the heat transmitted from the plate-like heating body 22 to the pan 17 serving as a heat dissipation or heat absorption body is reduced. As a result, the heat transmitted from the plate-like heating body 22 is stored on the surface of the top plate 13, and there is a possibility that the temperature of the top plate 13 is further increased.

  In the case of the first embodiment, when the heating by the plate-like heating body 22 is completed, the heating control unit 19 immediately drives the cooling fan unit 15. Thereby, while the flow of air is formed in the inside of the cooking appliance main body 11, the ribbon heater 42 located in the back surface side of the plate-shaped heating body 22 is cooled. Therefore, the heat remaining on the top plate 13 and the front surface side of the plate heater 22 is radiated from the ribbon heater 42 located on the back surface side of the plate heater 22. As a result, the transfer of heat from the plate-like heating body 22 to the top plate 13 side is reduced, and the temperature rise of the top plate 13 at the end of heating is suppressed.

  In this case, it is desirable that the hole 241 of the support member 24 and the hole 251 of the heat insulating material 25 are arranged to overlap with the positions corresponding to the holes 431, 432, 433, 434 or the slits 441, 442, 443, 444 of the insulating substrate 41. . By making the hole 241 of the support member 24 and the hole 251 of the heat insulating material 25 correspond to the holes 431, 432, 433, 434 or the slits 441, 442, 443, 444 of the insulating substrate 41, the air flowing through the holes 241 and 251 is It flows into the top plate 13 side from the holes 431, 432, 433, 434 or the slits 441, 442, 443, 444 of the insulating substrate 41. The ribbon heater 42 is wound around the insulating substrate 41 as described above. Therefore, a gap 53 corresponding to the thickness of the ribbon heater 42 is formed between the ribbon heater 42 wound between the top plate 13 and the plate-like heating body 22 as shown in FIG. As a result, the air flowing into the top plate 13 from the holes 431, 432, 433, 434 or the slits 441, 442, 443, 444 passes through the gap 53 and is adjacent to the holes 431, 432, 433, 434 or slits. Move to 441, 442, 443, 444. As a result, cooling of the ribbon heater 42 and the top plate 13 on the upper surface side of the plate-like heating body 22 is promoted.

  As described above, the heating control unit 19 performs heating cooking by the induction heating coil 21, heating cooking by the plate-like heating body 22, or heating cooking by a combination thereof according to the material of the cooking utensil such as the pan 17. To do. And the heating control part 19 promotes cooling of the top plate 13 and the plate-shaped heating body 22 by driving the cooling fan part 15 after cooking is completed.

As described above, the first embodiment provides the following effects.
The ribbon heater 42 of the plate heater 22 generates heat when energized. The cooked utensils such as the pan 17 placed on the top plate 13 are directly heated by the plate-like heating body 22 that generates heat. Therefore, the cooked utensils such as the pan 17 can be heated regardless of the material, and the heating efficiency can be increased.

  In the first embodiment, the ribbon heater 42 is wound around the insulating substrate 41. Thereby, most of the insulating substrate 41 and the ribbon heater 42 are not in contact with each other except the heater winding portion 47. That is, the relative movement of the insulating substrate 41 and the ribbon heater 42 with the dimensional change is allowed. Therefore, even if a dimensional change occurs in the ribbon heater 42 due to heat generated by energization, no interaction occurs between the insulating substrate 41 and the ribbon heater 42 having different coefficients of thermal expansion. That is, even if the dimension of the ribbon heater 42 changes due to heat generation, the stress generated in the insulating substrate 41 is reduced. For this reason, even if the difference in thermal expansion coefficient between the insulating substrate 41 and the ribbon heater 42 is large, the insulating substrate 41 is not broken or broken by the heat generated by the ribbon heater 42. Therefore, the durability of the plate-like heating body 22 can be increased.

  Furthermore, in the first embodiment, the heat of the ribbon heater 42 is uniformly propagated to the insulating substrate 41 by forming the insulating substrate 41 with a material having high thermal conductivity such as ceramics. That is, the plate-like heating body 22 is heated uniformly and the temperature distribution is reduced. Therefore, uniform heat generation of the entire plate-like heating body 22 is promoted, and the upper surface of the top plate 13 can be heated uniformly. Further, when ceramics is applied to the insulating substrate 41, the coefficient of thermal expansion is smaller than that of other insulating materials such as mica. Therefore, the ceramic insulating substrate 41 is less deformed when the ribbon heater 42 generates heat. As a result, the plate-like heating body 22 can easily secure the degree of adhesion with the top plate 13. Therefore, a contact area between the plate-like heating body 22 and the top plate 13, that is, a heat transfer area can be secured, and heat generated by the plate-like heating body 22 can be efficiently transmitted to the top plate 13.

  In the first embodiment, the ribbon heater 42 forms a plurality of heater winding portions 47 in the holes 431, 432, 433, 434 or the slits 441, 442, 443, 444 of the insulating substrate 41. By winding the ribbon heater 42 around the insulating substrate 41 at the plurality of heater winding portions 47, local heat generation of the ribbon heater 42 is reduced. Therefore, red heat or scorching of the ribbon heater 42 during energization is reduced. In addition, by winding the ribbon heater 42 around the insulating substrate 41 at the plurality of heater winding portions 47, even if the dimensions of the ribbon heater 42 change due to heat generation during energization, the change in the dimensions is not affected by the heater winding portion 47. Absorbed in. For example, when the ribbon heater 42 expands due to heat generation and the entire length of the ribbon heater 42 increases, the dimensional change is absorbed by the ribbon heater 42 wound in the heater winding portion 47 being slightly loosened. Therefore, the force applied from the ribbon heater 42 to the insulating substrate 41 due to dimensional changes accompanying heat generation is reduced. Therefore, the durability of the plate-like heating body 22 can be increased.

  In the first embodiment, a plurality of heater winding portions 47 are provided in the circumferential direction. That is, the heater winding part 47 is provided substantially radially from the center of the insulating substrate 41. Therefore, a portion where the ribbon heater 42 is not wound can be secured at the center of the insulating substrate 41. Thereby, the sensor hole 45 for arrange | positioning the temperature sensor 62 can be arrange | positioned in the part where this ribbon heater 42 is not wound. Therefore, the temperature sensor 62 can be disposed without causing an increase in size and design restrictions, and the temperature of the top plate 13 can be easily detected.

In the first embodiment, the ribbon heater 42 wound around the insulating substrate 41 is composed of two ribbon heater elements 51 and 52. That is, the plate-like heating body 22 includes a ribbon heater element 51 that extends from the terminal 511 to the terminal 512 and a ribbon heater element 52 that extends from the terminal 521 to the terminal 522. These ribbon heater elements 51 and 52 are each wound around an insulating substrate as one continuous ribbon heater. As a result, the terminals of the ribbon heater elements 51 and 52 are collected, and the space area to be secured around the plate-like heating body 22 is reduced. Therefore, the influence on the design of the induction heating coil 21 provided below the plate-like heating body 22 can be reduced, and the degree of freedom in design can be increased.
In the first embodiment, a cooling fan unit 15 is provided. When the cooking by the plate-like heating body 22 is completed, air for cooling is blown to the plate-like heating body 22 and the top plate 13 side. Therefore, the top plate 13 is quickly cooled using the heat radiation of the plate-like heating body 22 after the cooking is finished. Therefore, safety can be improved.

  In the present embodiment, an example in which the ribbon heater elements 51 and 52 are wound evenly around the insulating substrate 41 has been described. However, the ribbon heater elements 51 and 52 may be wound around the insulating substrate 41 unevenly. For example, when the operation unit 61 such as a touch panel is disposed on the front side of the top plate 13, an area where the ribbon heater elements 51 and 52 are not wound may be secured in the vicinity of the operation unit 61. Thereby, when a user operates the operation part 61, it can make it difficult to receive the influence of the heat_generation | fever of the ribbon heater elements 51 and 52. FIG.

(Second embodiment)
The plate-shaped heating body of the induction heating cooking device by 2nd Example of this invention is shown in FIG.
In the second embodiment, the plate-like heating body 122 includes an insulating substrate 141 and a ribbon heater 142 as shown in FIG. FIG. 7 is a schematic view of the plate-like heating body 122 viewed from the top plate 13 side, that is, a schematic view on the upper surface side. In the case of the second embodiment, the insulating substrate 141 is formed in an annular shape. The insulating substrate 141 has uneven portions 146 on the inner peripheral side and the outer peripheral side in the radial direction. The uneven portion 146 forms unevenness in the radial direction of the insulating substrate 141. The ribbon heater 142 is wound around the insulating substrate 141 while being folded back by the uneven portion 146 on the inner peripheral side and the uneven portion 146 on the outer peripheral side. In the case of the second embodiment, the plate-shaped heating body 122 has two ribbon heater elements 151 and 152 connected in parallel. In the two ribbon heater elements 151 and 152, the starting point of the concave and convex portion 146 on the inner peripheral side is shifted by one in the circumferential direction. Each of the ribbon heater elements 151 and 152 is wound around the insulating substrate 141 while connecting every other concavo-convex portion 146 on the inner peripheral side and concavo-convex portion 146 on the outer peripheral side. As a result, the ribbon heater elements 151 and 152 are wound while zigzagging between the uneven portion 146 on the inner peripheral side and the uneven portion 146 on the outer peripheral side of the insulating substrate 141. As a result, the ribbon heater elements 151 and 152 that are folded back by the concavo-convex portion 146 and pass through the upper surface side intersect with the ribbon heater elements 152 and 151 that pass through the lower surface side across the insulating substrate 141.

  In the second embodiment, the plate-shaped heating element 122 has two ribbon heater elements 151 and 152, which are wound around the insulating substrate 141 in a zigzag manner. Therefore, the number of turns of the ribbon heater 142 in the plate-like heating body 122 increases. Therefore, the top plate 13 can be uniformly heated by the plate-like heating body 122.

  In the second embodiment, the two ribbon heater elements 151 and 152 are wound around the insulating substrate 141 substantially uniformly. Therefore, even if energization of one of the two ribbon heater elements 151 and 152 is stopped, the top plate 13 is heated uniformly. That is, only one of the two ribbon heater elements 151 and 152 can be used as a heat source. Therefore, it is possible to energize only one of the two ribbon heater elements 151 and 152 according to the output, and the output of the plate heater 122 can be flexibly changed.

(Other examples)
In the first embodiment described above, the example in which the ribbon heater 42 is wound around the insulating substrate 41 having the radial holes 431, 432, 433, 434 or the slits 441, 442, 443, 444 in the circumferential direction has been described. In the second embodiment, the example in which the ribbon heater 142 is wound around the annular insulating substrate 141 in a zigzag manner has been described. However, the shape of the ribbon heater wound around the insulating substrate is not limited to the above example.

For example, as shown in FIG. 8A, the plate-like heating body 322 may be provided with holes 342 at arbitrary positions on the insulating substrate 341, and the ribbon heater 343 may be wound so as to connect the holes 342. . For example, as shown in FIGS. 8B and 8C, the plate-like heating body 322 can be arbitrarily changed in the position and number of holes 342 and slits provided in the insulating substrate 341 or the winding shape of the ribbon heater 343. can do.
In the first embodiment, the example in which the two ribbon heater elements 51 and 52 are wound around the insulating substrate 41 has been described. However, the number of ribbon heater elements wound around the insulating substrate 41 may be one, or three or more as long as a sufficient space for drawing out the terminals is secured.

  Furthermore, in the first embodiment and the second embodiment, an example in which a pair of insulating substrates 41 and 141 and ribbon heaters 42 and 142 are applied as the plate-like heating bodies 22 and 122 has been described. However, as shown in FIG. 9, a plate-like heating unit 622 may be configured from the insulating substrate 641 and the ribbon heater 642, and the plate-like heating unit 622 may be arranged in a double ring shape or a triple or more ring shape. . When the plate-shaped heating element units 622 are arranged in a double ring shape, the energization can be controlled independently for the plate-shaped heating element units 622 on the inner peripheral side and the plate-shaped heating element units 622 on the outer peripheral side. Thereby, an appropriate area | region can be heated according to the diameter etc. of a to-be-heated cooking appliance, for example.

It is the schematic which shows the plate-shaped heating body of the heating cooker by 1st Example of this invention, Comprising: The top view seen from the top plate side Sectional drawing which shows schematic structure of the heating cooker by 1st Example of this invention. 2 is an enlarged cross-sectional view of the main part of FIG. The disassembled perspective view which shows the structure of the heating unit of the heating cooker by 1st Example of this invention. The block diagram which shows the heating cooker by 1st Example of this invention. The schematic diagram which expanded further the principal part of the heating unit shown in FIG. It is the schematic which shows the plate-shaped heating body of the heating cooker by 2nd Example of this invention, Comprising: The top view seen from the top plate side The schematic diagram which shows the other Example of the heating cooker of this invention. The schematic diagram which shows the other Example of the heating cooker of this invention.

Explanation of symbols

  In the drawings, 10 is an induction heating cooker, 13 is a top plate, 15 is a cooling fan unit (fan), 17 is a pan (cooking utensil), 21 is an induction heating coil, 22, 122, and 322 are plate-like heating bodies. , 41, 141, 341 and 641 are insulating substrates, 42, 142, 343 and 642 are ribbon heaters (heaters), 45 is a sensor hole, 47 is a heater winding portion, 51, 52, 151 and 152 are ribbon heater elements ( Heater wire), 62 is a temperature sensor, 431, 432, 433 and 434 are holes, 441, 442, 443 and 444 are slits, and 622 is a plate-like heating unit.

Claims (11)

A top plate on which the cooker to be heated is placed;
An induction heating coil that is provided below the top plate and that induction-heats the cooked utensil placed on the top plate;
In an induction heating cooker comprising: a plate-like heating body that is disposed between the top plate and the induction heating coil and heats the cooked utensil placed on the top plate,
The said plate-shaped heating body has a plate-shaped insulated substrate and the strip | belt-shaped heater which heats by being wound around the said insulated substrate and energizing, The induction heating cooking appliance characterized by the above-mentioned. The insulating substrate has a plurality of holes or slits penetrating in the thickness direction,
The induction heating cooker according to claim 1, wherein the heater forms a plurality of heater winding portions that are hooked in the hole or the slit and wind the insulating substrate.   The induction heating cooker according to claim 2, wherein a plurality of the heater winding portions are provided in a circumferential direction of the insulating substrate. A temperature sensor for detecting the temperature of the top plate;
The induction heating cooker according to claim 3, wherein the insulating substrate has a sensor hole through which a temperature sensor is disposed so as to penetrate the central portion in a plate thickness direction.   The induction heating cooker according to any one of claims 1 to 4, wherein the plurality of heater winding portions are formed by a single continuous heater.   6. The heater according to claim 1, wherein the heater is spirally wound substantially symmetrically on a surface on the top plate side and a surface on the induction heating coil side of the insulating substrate. Induction heating cooker. The heater has a plurality of heater wires wound around the insulating substrate,
The plurality of heater wires are wound such that a portion located on the surface on the top plate side and a portion located on the surface on the induction heating coil side cross each other across the insulating substrate. The induction heating cooker according to any one of claims 1 to 5.   The induction heating cooker according to claim 7, wherein energization of the plurality of heater wires is independently interrupted.   The induction heating cooking according to any one of claims 1 to 8, wherein the plate-like heating body is provided in a plurality of annular shapes in a radial direction, and energization is independently interrupted for each ring. vessel.   The induction heating cooker according to any one of claims 1 to 9, wherein the insulating substrate is made of ceramics.   The induction heating cooker according to any one of claims 1 to 10, further comprising a fan that forms a gap between the plate heater and the induction heating coil and blows air into the gap. .

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