JP5851362B2 - Induction heating cooker - Google Patents

Description

  The present invention relates to an induction heating cooker that can accurately detect the temperature of a pan on a top plate.

  As shown in FIGS. 2 and 5 of Patent Document 1, the conventional induction heating cooker includes a coil base that constitutes a heating coil and holds the heating coil, and is provided at a distance of 45 to 55 mm from the coil center. There is an induction heating cooker in which a waveguide defining a detection area of an infrared sensor is provided on a coil base and detects the temperature of an object to be heated placed on a top plate.

JP 2011-258482 A

  In patent document 1, in order to suppress the temperature rise of the waveguide (light guide tube) due to heat transfer from the heating coil or the top plate, the inside of the waveguide (light guide tube) is forcibly cooled with cooling air. However, the waveguide (light guide tube) integrated with the coil base configured to hold the heating coil and the ferrite is guided from the ferrite that rises in temperature as the heating coil temperature rises and the heating coil temperature rises. There is a problem that the temperature of the waveguide rises due to heat transfer to the side surface of the optical tube and the temperature of the pan bottom cannot be detected with high accuracy.

The above-described problems include a top plate on which a pan is placed, a heating coil unit that is provided below the top plate and induction-heats the pan, and an infrared ray that is provided below the heating coil unit and is emitted from the pan. An infrared sensor module that receives light through a window member, a light guide tube that guides infrared rays emitted from the pan to the infrared sensor module, an attachment member to which the infrared sensor module is attached, and the infrared sensor module; An induction heating cooker comprising: a cooling fan that supplies cooling air to the light guide tube , wherein the heating coil unit includes a heating coil that induction-heats the pan, and a coil base that supports the heating coil; A plurality of ferrites for adjusting the magnetic flux generated from the heating coil, and a ferrite for holding the plurality of ferrites radially. And the heating coil is divided into an inner peripheral heating coil and an outer peripheral heating coil, the light guide tube is between the inner peripheral heating coil and the outer peripheral heating coil, and wherein provided between the ferrite holding unit, the light guide tube is a side facing the inner circumference side heating coil, or provided substantially vertical ribs on the side facing the outer peripheral side heating coil Rutotomoni, The cooling air is provided with an opening that guides the cooling air to the inside of the cylinder, and the cooling air is flowed to cool the outside of the cylinder provided with the rib, and the inside of the cylinder after cooling the window material guided from the opening. The light guide tube is cooled by a flow of cooling the light guide, and the ferrite holding portion is solved by an induction heating cooker provided with a substantially vertical rib at a position facing the light guide tube.

Further, a top plate for placing the pan, disposed below the said top plate, and the heating coil units to inductively heat the pan provided below the heating coil unit, a window of infrared rays radiated from the pan An infrared sensor module that receives light through a material, a light guide tube that guides infrared rays emitted from the pan to the infrared sensor module, an attachment member to which the infrared sensor module is attached, the infrared sensor module, and the guide An induction heating cooker comprising a cooling fan for supplying cooling air to the light tube , wherein the heating coil unit includes a heating coil for induction heating the pan, a coil base for supporting the heating coil, A plurality of ferrites for adjusting the magnetic flux generated from the heating coil and a ferrite for holding the plurality of ferrites radially The heating coil is divided into an inner peripheral heating coil and an outer peripheral heating coil, and the light guide tube is between the inner peripheral heating coil and the outer peripheral heating coil, and provided between the ferrite holding unit, the light guide tube is Rutotomoni provided substantially vertical ribs on the side facing the ferrite holding portion, provided with an opening for guiding the cooling air to the cylinder inside, The cooling air cools the light guide tube by a flow of cooling the outside of the tube provided with the ribs and a flow of cooling the inside of the tube after being cooled from the window member guided from the opening. In addition, the coil base is solved by an induction heating cooker provided with a substantially vertical rib at a position facing the light guide tube.

  According to the present invention, the temperature of the pan bottom can be detected with high accuracy.

The external appearance perspective view of the induction heating cooking appliance of one Example. Explanatory drawing of the heating coil unit of the induction heating cooking appliance of one Example. Sectional drawing (AA sectional drawing of FIG. 1) of the induction heating cooking appliance of one Example. The functional block diagram of the temperature detection of the induction heating cooking appliance of one Example, and a heating control system. Explanatory drawing of the coil base of the induction heating cooking appliance of one Example. Explanatory drawing of the infrared sensor module of the induction heating cooking appliance of one Example. The top view of the infrared sensor module of the induction heating cooking appliance of one Example. Explanatory drawing explaining the cooling air of the coil base of the induction heating cooking appliance of one Example, and an infrared sensor module.

  Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

  1 and 2, reference numeral 1 denotes a main body of the induction heating cooker. Reference numeral 2 denotes a top plate made of crystallized glass having high heat resistance, which is horizontally arranged on the upper surface of the main body 1 and on which a pan 501 (FIG. 4) made of a magnetic material such as iron or a non-magnetic material such as aluminum is placed. Is. The top plate 2 has an optical characteristic of transmitting infrared light having a wavelength of 4 μm or less and cutting infrared light having a longer wavelength. Reference numerals 3a to 3c denote three heating units arranged below the top plate 2, and a heating coil unit 200 having a heating coil 201 described later for induction heating the pan 501 placed on the top plate 2 (FIG. 2). Is provided. Reference numerals 31 a to 31 c denote infrared transmission regions that transmit infrared rays radiated from the bottom of the pan to the lower side of the top plate 2. Here, the number of heating units is three, but the number of heating units may be one or two. Reference numeral 4 denotes an air intake opening which opens upward at the rear portion of the main body 1 and takes cooling air 406 into the main body 1. Reference numeral 5 denotes an exhaust port which opens upward at the rear portion of the main body 1 and discharges exhaust heat that has cooled the inside of the main body 1. In this embodiment, the intake port 4 is disposed on the right side of the rear portion of the main body 1 and the exhaust port 5 is disposed on the left side. Reference numeral 6 denotes a grill heating unit provided at the left front portion of the main body 1. Reference numerals 7a to 7c denote operation units provided on the upper surface side of the main body 1 for setting and operating the heating units 3a to 3c. Reference numerals 8a to 8c are display units that are provided at the upper part on the front side of the top plate 2 and display the setting states of the operation units 7a to 7c and the energization states of the heating units 3a to 3c.

  FIG. 2 is an explanatory diagram of the heating coil unit 200.

  The heating coil 201 is composed of a double coil of an inner peripheral side heating coil 201a and an outer peripheral side heating coil 201b provided on the same concentric plane, and an outer end and an outer peripheral side heating coil of the inner peripheral side heating coil 201a. The inner end of 201b is electrically connected. In this embodiment, the inner peripheral heating coil 201a is provided at a distance of about 30 to 45 mm from the coil center, and the outer peripheral heating coil 201b is provided at a distance of about 55 to 90 mm from the coil center.

  Reference numeral 203 denotes a coil base for holding the heating coil 201, and 202 denotes a gap spacer for providing a gap between the top plate 2 and the heating coil 201. The gap spacer 202 abuts on the top plate 2 to provide a gap between the heating coil 201 and the top plate 2, and allows cooling air 406 to cool the heating coil 201 to pass through the gap.

  Reference numeral 203a denotes a ferrite holding portion that is provided almost uniformly radially below the heating coil 201 of the coil base 203. The lower side of the coil base 203 is directed toward the pan 501 on which the magnetic flux of the heating coil 201 is placed on the top surface of the top plate 2. It holds the ferrite 209 that prevents it from flowing into.

  Reference numeral 508 denotes a light guide tube provided integrally with the mounting member 40 (FIG. 6) to which the infrared sensor module 407 (FIG. 3) is attached. The light guide tube 508 is provided at a distance of 45 to 55 mm from the center of the coil of the infrared sensor 12 (FIG. 8) of the infrared sensor module 407, defines the detection area of the infrared sensor 12 (FIG. 8), and is emitted from the bottom of the pan. Infrared rays are guided to an infrared sensor 12 (FIG. 8) to be described later. In this embodiment, the size of the detection area of the infrared sensor 12 is about 10 mm in diameter using the light guide tube 508. The upper end portion 508 a of the light guide tube 508 is substantially the same height as the heating coil 201.

  Reference numerals 205 to 208 denote thermistors (contact temperature sensors) for measuring the temperature of the lower surface of the top plate 2.

  3 is a cross-sectional view of the main body 1 taken along the plane AA ′ of FIG. In FIG. 3, 401 is a cooling fan, 402 is a motor that drives the cooling fan 401, 403 to 405 are high-frequency power supply circuits that supply high-frequency power to the heating coil 201, and 406 is an infrared sensor module that is sucked by the cooling fan 401 and described later. Reference numeral 407 denotes an arrow representing the flow of cooling air blown to the light guide tube 508. Note that the cooling air 406 displayed here is a simplified representation of the flow of the cooling air 406 of this embodiment in an easy-to-understand manner. Actually, the coil base 203, the infrared sensor module 407 and the light guide are guided using a duct or the like. Air is sent to the tube 508.

  The heating coil unit 200 is supported by a spring (not shown) so as to be in close contact with the lower surface of the top plate 2 (the gap spacer 202 of the heating coil unit 200 is in contact with the top plate 2).

  FIG. 4 is a functional block diagram of the temperature detection and heating control system. In FIG. 4, reference numeral 501 denotes a pan that is an object to be heated, 502 a temperature detection circuit that calculates the temperature of the pan 501 based on the outputs of the infrared sensor module 407 and the thermistors 205 to 208, and 26 is based on the output of the infrared sensor module 407. An emissivity calculation circuit for calculating the emissivity of the pan 501, 503 corrects the temperature calculated by the temperature detection circuit 502 based on the output of the emissivity calculation circuit 26, and sets the high frequency power supply circuit 405 according to the corrected temperature. It is a control circuit that controls and controls the power supplied to the heating coil 201.

  Next, the coil base 203 that fixes the infrared sensor module 407 with the mounting member 40 integrally provided with the light guide tube 508 will be described with reference to FIG.

  The light guide tube 508 is disposed between the inner peripheral heating coil 201a and the outer peripheral heating coil 201b between the ferrite holding portions 203a of the coil base 203. A pair of ribs 203d protruding in the circumferential direction is provided on the adjacent ferrite holding portion 203a between the inner peripheral heating coil 201a and the outer peripheral heating coil 201b. The rib 203d is provided in the vertical direction from the upper end 203a1 to the lower end 203a2 of the ferrite holding portion 203a. Here, an example in which the rib 203d is provided on the ferrite holding portion 203a is shown, but a configuration in which a rib is provided on the side surface of the light guide tube 508 facing the ferrite holding portion 203a may be adopted.

  Next, details of the infrared sensor module 407 and the light guide tube 508 provided integrally with the mounting member 40 will be described with reference to FIGS.

  As shown in the figure, the infrared sensor module 407 includes a resin case 16, a window portion 14 provided above the resin case 16, and a magnetic shielding case 13 that covers the outer shell of the resin case 16 except for the window portion 14, A window member 15 provided in the window portion 14, a thermal infrared detection circuit 131 provided in the resin case 16, a reflectance detection circuit 132, and a printed wiring board 27 are provided.

  An attachment member 40 is provided to be sandwiched between the upper and lower sides of the magnetic shielding case 13 and attached to the coil base 203. A light guide tube 508 is integrally provided on the upper surface 40 a of the mounting member 40. The light guide tube 508 is a substantially trapezoidal tube as viewed from above, and is formed by a pair of side surfaces 508d and 508e that are concentrically curved and a pair of side surfaces 508f that are paired in a C shape. The side surfaces 508d and 508e are provided with vertical ribs 508g below the upper end 508a. The other pair of side surfaces 508f form a plane. Here, an example in which the ribs 508g are provided on both of the side surfaces 508d and 508e is shown, but the rib 508g may be provided on only one of them, or the side surfaces 508d and 508e of the side surface of the coil base 203 are opposed to each other. It is good also as a structure which provides a rib in a position.

  The mounting member 40 is fixed to the coil base 203 with screws or the like by fixing portions 40c and 40d provided with mounting holes in a ring shape.

  FIG. 7 is a view in which the window portion 14 of the resin case 16 is transmitted through the window material 15. Since the window portion 14 of the resin case 16 is sealed by the window material 15, the heat inside the infrared sensor module 407 shown in FIG. The cooling air 406 does not directly hit the mold infrared detection circuit 131 and the reflectance detection circuit 132. That is, with this configuration, the influence of the cooling air 406 on the thermal infrared detection circuit 131 and the reflectance detection circuit 132 is reduced.

  Next, signal detection in the infrared sensor module 407 will be described. Infrared rays radiated from the bottom surface of the pan 501 reach the thermal infrared detection circuit 131 via the path 30 (the top plate 2, the waveguide 508, and the window material 15) that is the radiant infrared visual field range. The infrared light emitted from the reflectance detection circuit 132 reaches the pan 501 via the forward path (window material 15, waveguide 508, top plate 2) of the path 29, and the infrared light reflected by the pan 501 passes through the path 29. It returns to the reflectance detection circuit 132 through the return path (top plate 2, waveguide 508, window material 15). That is, both the thermal infrared detection circuit 131 and the reflectance detection circuit 132 reach the infrared rays that pass through both the top plate 2 and the window material 15.

  Further, the mounting member 40 and the resin case 16 are made of a resin having low thermal conductivity, thereby preventing the temperature inside the infrared sensor module 407 from changing rapidly. That is, this configuration prevents the temperatures of the thermal infrared detection circuit 131 and the reflectance detection circuit 132 from changing suddenly due to heat transfer.

  Further, the window member 15 has an optical characteristic that cuts infrared rays (4 μm or more) having a high temperature rising effect emitted from the top plate 2, the light guide tube 508, the heating coil 201, and the like that have become hot. , Infrared rays having a high temperature-raising effect are prevented from entering the infrared sensor module 407. That is, with this configuration, the temperature of the thermal infrared detection circuit 131 and the reflectance detection circuit 132 is prevented from suddenly changing due to infrared rays having a high temperature-raising effect. In the present embodiment, the infrared transmission characteristics of the top plate 2 and the infrared transmission characteristics of the window member 15 are the same.

  Furthermore, the magnetic shielding case 13 is made of non-magnetic aluminum, so that the electromagnetic noise entering the infrared sensor module 407 is reduced, and the radiation heat received by the magnetic shielding case 13 is easily radiated.

  By adopting such a configuration, the thermal type infrared detection circuit 131 and the reflectance detection circuit 132 have a cooling air, a sudden change in the ambient temperature, an influence of infrared rays having a high temperature rising effect, and an adverse effect of electrical noise. In the wide temperature range from 140 ° C. to 300 ° C., a highly accurate signal can be output, and the temperature of the pan 501 can be measured accurately.

  The light guide tube 508 is provided substantially perpendicular to the top plate 2, narrows the field of view of the infrared sensor 12, and defines the detection area of the pan 501 that emits infrared light. Further, infrared rays from the heating coil 201 are prevented from entering the visual field of the infrared sensor 12.

  The lower end of the light guide tube 508 is disposed immediately above the magnetic shield case 13 of the infrared sensor module 407, and the cooling air 406 blown by the cooling fan 401 can cool the surface of the window member 15 and the inside of the light guide tube 508. As described above, the upper surface 40a of the attachment member 40 at the lower end of the light guide tube 508 is provided with a guide portion 40b facing the windward side and an opening 510 is provided.

  Since the upper end of the light guide tube 508 is provided at substantially the same height as the upper end portion of the heating coil 201, the cooling air 406 that has passed through the light guide tube 508 is formed between the top plate 2 and the heating coil 201. When passing through the gap, the top plate 2 and the heating coil 201 are also cooled. In particular, the cooling air 406 passes through the light guide tube 508 and then strikes the top plate 2 so that the direction of the air is bent at right angles and dispersed in all directions, so that the portion that hits the top plate 2 can be efficiently cooled and temperature measurement accuracy is further improved. To improve.

  The rib 203d provided on the ferrite holding portion 203a of the coil base 203 is in contact with the outside of the side surface 508f of the light guide tube 508 formed integrally with the mounting member 40. Further, the rib 508g on the side surface 508d of the light guide tube 508 contacts the outer periphery of the inner peripheral heating coil 201a, and the rib 508g on the side surface 508e contacts the inner periphery of the outer peripheral heating coil 201b. A space portion through which the cooling air 406 passes is formed between the light guide tube 508 and the ferrite holding portion 203a of the coil base 203 outside the side surface 508f. In addition, the upper surface 40a of the mounting member 40 and the side surface 508f of the light guide tube 508 are integrally connected to guide the cooling air 406 from the upper surface 40a of the mounting member 40 to the upper end portion 508a of the light guide tube 508. . Further, on the side surface 508d and the side surface 508e of the light guide tube 508, the contact area to the heating coil 201 is reduced as much as possible by the rib 508g to prevent heat transfer from the heating coil 201. Further, the rib 508g forms a space between the side surface 508d and the outer periphery of the inner peripheral side heating coil 201a, and between the rib 508g of the side surface 508e and the inner periphery of the outer peripheral side heating coil 201b, and allows the cooling air 406 to pass therethrough. .

  By passing the cooling air 406 also outside the light guide tube 508, the temperature rise of the light guide tube 508 is suppressed and the temperature detection accuracy in the infrared sensor module 407 is improved.

  Next, the operation of this embodiment will be described.

  When the user places the pan 501 on the top plate 2 and operates the operation unit 7a to start heating, the control circuit 503 controls the high-frequency power supply circuit 405 to supply predetermined power to the heating coil 201. . When a high frequency current is supplied to the heating coil 201, an induction magnetic field is generated from the heating coil 201, and an eddy current is generated in the pan 501 to be induction heated. By this induction heating, the temperature of the pan 501 rises and the food in the pan 501 is cooked. At the same time, power is supplied to the motor 402 and the cooling fan 401 rotates to suck the cooling air 406, thereby cooling the high-frequency power supply circuits 403 to 405, the heating coil unit 200, the infrared sensor module 407, and the like.

  As cooking progresses, the temperature rise of the pan 501 and the self-heating of the heating coil 201 cause the top plate 2, the light guide tube 508, and the infrared sensor module 407 (particularly the window material 15) to start to rise in temperature.

The cooling air 406 blown from the cooling fan 401 enters the guide portion 40b from the opening 510 provided in the light guide tube 508 and the infrared sensor module 407, cools the window member 15, and then the inside of the light guide tube 508. It is cooled and discharged from the top.
Furthermore, the cooling air 406 flows along the outer side surfaces 508d and 508e of the light guide tube 508 through the space between the coil base 203 and the ferrite holding portion 203a, cools the outside of the tube, and is discharged toward the upper end portion 508a. The At the time of these discharges, the top plate 2 is cooled by hitting the top plate 2, passing through the gap between the heating coil 201 and the top plate 2 while being dispersed and cooling the heating coil 201 and the top plate 2, and then exhausting It is discharged from the mouth 5.

  The reason why the window material 15 is cooled first is that the temperature rise of the window material 15 has the most adverse effect on the error of the infrared rays received by the infrared sensor 12, and in order to minimize the temperature change of the window material 15. The window material 15 is first cooled using the cooling air 406 having a low temperature, and then the inside of the tube of the waveguide 508 is cooled.

  The light guide tube 508 is actively cooled by the cooling air 406 by flowing the tube outside separately from the flow inside the tube.

  A rib 203d is provided on the coil base 203 and spaces are provided between the side surfaces 508d and 508e of the light guide tube 508. However, a recess is provided on the coil base 203 and between the side surfaces 508d and 508e of the light guide tube 508. You may provide a space part in.

  According to the induction heating cooker of the present embodiment described above, the temperature of the pan bottom can be detected with high accuracy.

In the above embodiment,

DESCRIPTION OF SYMBOLS 1 Main body 2 Top plate 12 Infrared sensor 13 Magnetic-shield case 14 Window part 15 Window material 16 Resin case 40 Attachment member 40a Upper surface 200 of attachment member Heating coil unit 201 Heating coil 203 Coil base 203a Ferrite holding part 209 Ferrite 401 Cooling fan 406 Cooling air 407 Infrared sensor module 501 Pan 508 Light guide tube 508a Light guide tube upper end portions 508d, 508e, 508f Light guide tube side surface 508g Light guide tube rib 510 Opening portion

Claims (3)

A top plate on which the pan is placed;
A heating coil unit provided below the top plate for inductively heating the pan;
An infrared sensor module that is provided below the heating coil unit and receives infrared rays emitted from the pan through a window member ;
While having a light guide tube that guides infrared rays radiated from the pan to the infrared sensor module, an attachment member to which the infrared sensor module is attached,
A cooling fan for supplying cooling air to the infrared sensor module and the light guide tube;
An induction heating cooker comprising:
The heating coil unit includes a heating coil for inductively heating the pan, a coil base for supporting the heating coil, a plurality of ferrites for adjusting a magnetic flux generated from the heating coil, and a ferrite for holding the plurality of ferrites radially. A holding part,
The heating coil is divided into an inner peripheral heating coil and an outer peripheral heating coil,
The light guide tube is provided between the inner peripheral side heating coil and the outer peripheral side heating coil, and between the ferrite holding portions,
The light guide tube is a side facing the inner side heating coils, or the outer peripheral side on the side facing the heating coil provided substantially vertical ribs Rutotomoni, the opening for guiding cooling air to the cylinder inner And the cooling air flows through the light guide tube by a flow for cooling the outside of the tube provided with the ribs and a flow for cooling the inside of the tube after cooling the window material after being guided from the opening. Is to cool,
The induction heating cooker, wherein the ferrite holding portion is provided with a substantially vertical rib at a position facing the light guide tube. A top plate on which the pan is placed;
A heating coil unit provided below the top plate for inductively heating the pan;
An infrared sensor module that is provided below the heating coil unit and receives infrared rays emitted from the pan through a window member ;
While having a light guide tube that guides infrared rays radiated from the pan to the infrared sensor module, an attachment member to which the infrared sensor module is attached,
A cooling fan for supplying cooling air to the infrared sensor module and the light guide tube;
An induction heating cooker comprising:
The heating coil unit includes a heating coil for inductively heating the pan, a coil base for supporting the heating coil, a plurality of ferrites for adjusting a magnetic flux generated from the heating coil, and a ferrite for holding the plurality of ferrites radially. A holding part,
The heating coil is divided into an inner peripheral heating coil and an outer peripheral heating coil,
The light guide tube is provided between the inner peripheral side heating coil and the outer peripheral side heating coil, and between the ferrite holding portions,
The light guide tube, the ferrite holding portion provided substantially vertical ribs on the side facing the Rutotomoni provided with an opening for guiding the cooling air to the cylinder inside, the cooling air, the rib is provided The light guide tube is cooled by a flow for cooling the outer side of the tube and a flow for cooling the inner side of the tube after cooling the window material guided from the opening,
The induction heating cooker, wherein the coil base is provided with a substantially vertical rib at a position facing the light guide tube. In the induction heating cooker according to claim 1 or 2,
An induction heating cooker characterized in that, when the attachment member is attached to the coil base, the upper end portion of the light guide tube is substantially the same height as the heating coil.