JP2006207874A - Heating cooker - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To heighten the efficiency of induction heating, to secure high durability, and further to facilitate repairing in a heating cooker jointly using induction heating and high-frequency heating. <P>SOLUTION: In the base part 3b of a cooking chamber 3, the main base plate 200 provided with a recessed part 201 whose base is an opening part 202 in the substantially center and a punched plate 203 provided with a number of small holes 204 having a predetermined diameter are integrated with each other. The punched plate 203 allows a magnetic flux to pass therethrough and inhibits passing of microwaves supplied into the cooking chamber 3. A placing table 21 made of crystal glass is housed in the recessed part 201, and an induction heating coil 24 is disposed under the punched plate 203 through a heat insulating material 22 and an insulating plate 23. The heat of heated material stored in the cooking chamber 4 is intercepted by the heat insulating material 22 so that the coil 24 is not heated, and the distance between the coil 24 and the heated material can be reduced to achieve high heating efficiency. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a combined cooking device having both a high-frequency heating unit and an induction heating unit in order to cook food stored in a cooking cabinet.

  Microwave ovens directly heat high-frequency foods using microwaves, so they are very effective for high-speed cooking such as warming, but they cannot burn foods and are not suitable for scorched cooking. On the other hand, induction heating (IH) cookers, which have been popularized in recent years, are ideal for cooking by cooking or cooking for cooking by heating a magnetic metal pan or the like by induction heating. Therefore, in order to compensate for the drawbacks of cooking by high frequency heating as described above, a composite cooking device using induction heating cooking has been conventionally known.

  For example, in the heating cooker described in Patent Document 1, an induction heating coil is disposed below the bottom surface of the substantially box-shaped cooking chamber, and the cooking dish placed on the cooking chamber bottom surface is guided by the magnetic flux generated from the coil. It can be heated. On the other hand, a magnetron is arranged outside the side surface of the cooking chamber, and the microwave generated from the magnetron is supplied into the cooking chamber through a power supply port formed on the side surface of the cooking chamber, and is thereby placed on the cooking pan. The food can be heated at high frequency. This type of cooking device is suitable for performing burnt-eye cooking or stew cooking on food stored in a container such as a pan or frying pan having a structure capable of induction heating.

  In order to efficiently heat the object to be heated stored in the cooking chamber in the heating cooker as described above, the alternating magnetic flux generated from the induction heating coil disposed below the cooking chamber is suppressed as much as possible. While being introduced into the cooking chamber, it is desirable to prevent microwaves radiated from the feeding port into the cooking chamber from leaking out of the cooking chamber and prevent the structure other than the object to be heated from being heated. Therefore, in the apparatus described in Patent Document 1, the bottom surface of the cooking chamber is formed of a non-magnetic mounting plate that is a dielectric material and has heat resistance, and the magnetic flux passes through the lower side of the mounting plate. A thin plate-like member that reflects microwaves is provided, and an induction heating coil is provided therebelow.

  However, the above configuration has the following problems. That is, since the alternating magnetic flux generated from the induction heating coil decreases as the distance from the coil decreases, the induction heating coil is preferably placed as close to the object to be heated as possible. However, if the induction heating coil and the conductive plate-like member are too close to each other, a short circuit or the like may occur when the coil coating is damaged. Therefore, it is necessary to arrange the induction heating coil at a certain distance from the plate-like member in consideration of positional deviation or thermal expansion due to vibration or the like, and the distance from the object to be heated inside the cooking chamber is Heating efficiency deteriorates at a distance.

  Moreover, in the case of induction heating, the container itself accommodated in the cooking chamber is heated, and when the content is rich in oil, the temperature of the content may be 200 to 300 ° C. Therefore, if the heat of the container that has become high temperature is conducted through the bottom wall of the cooking chamber and transmitted to the induction heating coil, the heat resistance temperature of the induction heating coil (about 150 to 170 ° C.) may be exceeded. Prone to failure.

  In the above configuration, ceramic is the most useful as the mounting plate. However, when trying to have the same level of strength, the ceramic plate is more expensive than a metal plate such as stainless steel, so the entire bottom surface of the cooking chamber. If it is made of a ceramic plate, the manufacturing cost will be greatly increased. Even if the thickness of the ceramic plate is designed to give sufficient strength, if a heavy container containing a large amount of contents is placed violently, it will crack if it receives a large impact. May occur or be damaged. In that case, it is not easy to replace only the damaged ceramic bottom plate, and the repair becomes substantially difficult.

JP 2004-327260 A

  The present invention was made in order to solve the problems peculiar to a cooking device using both high-frequency heating and induction heating as described above. The object of the present invention is to efficiently heat an object to be heated. Another object of the present invention is to provide a cooking device that can be used, has improved durability, and can be easily repaired even when a failure or breakage occurs.

In order to solve the above-mentioned problems, the present invention generates a substantially hermetic box-shaped cooking chamber for accommodating an object to be heated and a microwave for heating the object to be heated at high frequency. A high frequency heating means including a magnetron and a waveguide for guiding the microwave into the cooking chamber; and an induction heating means including an induction heating coil for generating an alternating magnetic flux for induction heating the object to be heated. In the heating cooker
A part of the bottom plate of the cooking chamber is provided with a magnetic flux passage part that prevents the passage of microwaves while allowing the magnetic flux to pass therethrough, and a heat insulating member that cuts off heat conduction and an electrical insulation characteristic below the magnetic flux passage part. The induction heating coil is arranged with an insulating member having a gap therebetween.

  It is preferable that each of the heat insulating member and the insulating member is made of a material that allows magnetic flux to pass through and is as thin as possible within a range where necessary characteristics can be obtained. For example, glass wool or the like molded into a plate shape may be used as the heat insulating member, and a mica sheet or the like may be used as the insulating member.

  In the cooking device according to the present invention, when a current is supplied to the induction heating coil, the alternating magnetic flux generated by the induction heating coil passes through the insulating member, the heat insulating member, and the magnetic flux passage part of the bottom plate and enters the cooking chamber. Then, an eddy current is induced on the bottom surface of, for example, a magnetic metal pan housed in the cooking cabinet. The pot is heated by the Joule heat, and the contents of the pot are cooked. Although the heat of the hot pot is conducted to the magnetic flux passage part, it is blocked by the heat insulating member below it and does not reach the induction heating coil. Therefore, it is possible to prevent the induction heating coil itself from being heated by heat conduction during induction heating. In addition, the insulating member is completely electrically disconnected from the magnetic flux passage portion (bottom plate of the cooking cabinet) having conductivity and the induction heating coil. For example, vibration is applied or the magnetic flux passage portion is deformed by thermal expansion. Even if it is, sufficient insulation is ensured. In particular, when a mica sheet or the like is used as the insulating member, the insulating member is very thin, so that high insulation can be achieved without increasing the distance between the induction heating coil and the magnetic flux passage portion. Thereby, the to-be-heated object and induction heating coil in a cooking chamber can be made to adjoin, and induction heating can be performed with high efficiency.

  As one aspect of the heating cooker according to the present invention, the bottom plate of the cooking chamber is made of metal and has a recess formed in the approximate center thereof, and the magnetic flux passage is formed on the bottom surface of the recess. Accommodates a plate-like mounting table made of a heat-resistant material that is a low-loss dielectric material while allowing magnetic flux to pass, and the upper surface of the mounting table is substantially the same as the upper surface of the bottom plate surrounding the recess It can be set as the structure formed in one. Here, for example, a heat-resistant ceramic can be used as the mounting table.

  According to this configuration, in the bottom surface of the cooking chamber, the mounting area using a relatively high cost material is used in the predetermined area directly above and around the induction heating coil, and the other area is an inexpensive metal plate. Etc. can be formed. Thereby, the manufacturing cost can be suppressed. In addition, the magnetic flux passage portion needs to have a large number of small holes perforated to allow the magnetic flux to pass therethrough or to be considerably thin, so that the strength is inferior, but the upper surface is sandwiched between the mounting table and the lower surface is sandwiched between heat insulating members As a result, reinforcement can be applied. Furthermore, although the mounting table made of heat-resistant ceramics may crack or break depending on the state of use, it is only necessary to remove and replace the mounting table in the cooking chamber without changing the bottom plate. It is easy and the repair cost is low.

  In this case, since a gap is generated between the peripheral edge of the mounting table and the inner peripheral wall of the recess, the gap may be filled with a heat-resistant filler such as a silicone resin. Thereby, even when food is spilled in the cooking cabinet, the food does not enter the gap, the cooking cabinet can be kept clean, and the cooking cabinet is easily cleaned.

  In the cooking device according to the present invention, for example, the magnetic flux passage portion may be formed by a large number of small holes having a predetermined diameter. In this case, the diameter of the small holes and the interval between them are appropriately determined in consideration of the microwave blocking characteristics and the alternating magnetic flux passing characteristics.

  Further, the magnetic flux passage portion may be thinner than the bottom plate surrounding the recess. Even when an appropriate number of small holes are formed as described above, if the plate thickness is large, the eddy current loss of the plate itself increases, so that the plate thickness should be as thin as possible. Conversely, if the plate thickness is very thin, it is not always necessary to provide openings such as small holes.

  In addition, as described above, even if the magnetic flux passage part and the bottom plate surrounding the recess are made of the same material, the thickness and presence / absence of small holes are different, so it is difficult and possible to mold the bottom plate from a single plate member. Even so, the cost is likely to be high. Therefore, preferably, the bottom plate of the cooking chamber has a first member having the recess formed substantially in the center and having an opening on the bottom surface of the recess, and a second member serving as the magnetic flux passage having a size for closing the opening. It is good to set it as the structure which consists of a member and is integrated by adhering the 1st and 2nd member. As a fixing method, for example, welding such as spot welding is appropriate. According to this configuration, the bottom plate can be formed at a relatively low cost.

  Moreover, as one aspect | mode of the heating cooker which concerns on this invention, the said heat insulation member, the said insulation member, and the said induction heating coil are the holding members fixed to the lower surface of the said baseplate, holding the lower surface of this induction heating coil. , And can be configured to be held so as to be pressed against the magnetic flux passage portion.

  According to this configuration, since the position of the induction heating coil in the height direction is determined by the holding member with respect to the bottom plate, the distance between the object to be heated and the induction heating coil stored in the cooking cabinet is stabilized, and assembly accuracy is improved. It is possible to suppress distance fluctuations caused by variations and thermal expansion. Thereby, the object to be heated can be induction-heated constantly and efficiently. In addition, since the heat insulating member is pressed against the lower surface of the magnetic flux passage part by the holding member, in the configuration in which the mounting table is arranged on the upper surface of the magnetic flux passage part as described above, the relatively weak magnetic flux passing part is composed of the heat insulating member and the mounting base It can be sandwiched between the two and more robust reinforcement can be applied.

  Hereinafter, a cooking device according to an embodiment of the present invention will be described with reference to the drawings.

  FIG. 1 is an external perspective view in a state in which a door is closed in the heating cooker of the present embodiment, and FIG. 2 is an external perspective view in a state in which the door is fully opened (there is a container containing food) in the heating cooker in the present embodiment. FIG. 3 is a front view (a) and a right side view (b) with the door fully opened (without a container containing food), and FIG. 4 is an external view with the exterior cover as a part of the housing removed. FIG. 5 is a top perspective view of the main part showing the inside of the cooking chamber with the door fully open, FIG. 6 is a right side longitudinal sectional view of the main part with the door closed, and FIG. It is a right side longitudinal cross-sectional view of the main part for explaining the protruding operation of the tray.

  As shown in FIGS. 1 to 3, the heating cooker 1 includes a box-shaped housing 2 having an inclined front surface forming an outer shape, and a cooking chamber 3 having a front surface opened inside the housing 2. Is formed. That is, the front opening of the cooking cabinet 3 is inclined such that the upper end of the cooking cabinet 3 recedes from the lower end, and the front opening of the cooking cabinet 3 rotates about a horizontal axis extending in the left-right direction at the front lower part. It is opened and closed by a freely openable vertical door 4. At the center of the door 4, a heat-resistant glass window 4a through which the inside of the cooking cabinet 3 can be seen is provided. An operation panel 5 having a key input unit 5a on which a plurality of operation keys are arranged and a display unit 5b using a segment LCD or the like is located on the left and right sides of the front surface of the housing 2 so as not to be hidden when the door 4 is closed. The cook is instructed by the key input unit 5a to indicate various cooking conditions and start / stop of operation, and the display unit 5b displays such cooking conditions and remaining operation time. It has become.

  Note that part or all of the operation panel 5 may be arranged on the front surface of the door 4. However, when the door 4 is opened, the front surface of the door 4 becomes invisible to the cook. Therefore, functions that may be required when the door 4 is opened are provided at the upper front of the housing 2 and are unnecessary or important when the door 4 is opened. For functions that are not, it may be provided on the front surface of the door 4. For example, the display unit 5b may be disposed on the front upper portion of the housing 2 so that the display can be seen even when the door 4 is opened, and an operation key for induction heating described below is disposed on the front upper portion of the housing 2 instead of the door 4. . On the other hand, operation keys for high-frequency heating or heater heating may be provided on the door 4 so as to be operated with the door 4 closed.

  As shown in FIG. 4, a cooking chamber 3 comprising a top surface portion 3a, a bottom surface portion 3b, a left side surface portion 3c, a right side surface portion 3d, a front surface portion 3e, and a rear surface portion 3f is installed in the exterior cover constituting the housing 2. Each heating unit and an electric circuit, which will be described later, for cooking the object to be heated accommodated in the cooking cabinet 3 are the outside of the cooking cabinet 3, that is, the above components constituting the cooking cabinet 3 and the housing 2. It is arranged in the space between.

  A pair of left and right tray guides 11 projecting inward of the cooking chamber 3 are formed at the lower side of the left side surface portion 3c and the right side surface portion 3d, and a pair of left and right rails 12 and 13 are similarly formed on the left and right sides. It is formed in a pair. The tray guide 11 is a container 90 that is formed of a magnetic metal such as iron or stainless steel in which food to be heated is accommodated, and at least the bottom is induction-heatable, mainly for cooking by a combination of high-frequency heating and induction heating. Is used to slidably hold the square-plate-like tray 7 placed on the top and bottom, and in order to make the tray 7 slide well, polyphenylene sulfide (PPS) or Teflon (registered) And other resins are used. The tray 7 is a material that allows magnetic flux to pass therethrough for induction heating described later, and is made of a low-loss dielectric material so as not to be heated by microwaves. The rails 12 and 13 are mainly used for installing a baking dish or grill dish for cooking in the cooking cabinet 3.

  As shown in FIG. 5, in a state where the tray 7 is properly accommodated in the cooking chamber 3, the flanges 7 a extending on the left and right edges of the tray 7 are placed on the tray guide 11. 11 can move smoothly back and forth. In order to make it easy to place a heavy container 90 on the tray 7, heating is temporarily interrupted during cooking to check the state of food in the container 90, add seasonings or the like, or stir. For ease of explanation, a tray transport mechanism 50 for automatically protruding the tray 7 forward is provided at the lower rear of the rear surface portion 3f of the cooking cabinet 3, which will be described in detail later. In FIG. 5, although hidden behind the container 90 and not visible, a circular marking 7b is provided on the upper surface of the tray 7 as a mark indicating an appropriate position for placing a container such as a pan. When the container is placed, the most appropriate induction heating is performed. Therefore, in the following description, it is assumed that the container 90 is placed on the tray 7 according to the marking 7b in principle.

  As shown in FIG.3 and FIG.5, the dimension of the bottom face part 3b of the cooking chamber 3 is depth: Ld, horizontal width: Lw, and height is Lh. In particular, the lateral width Lw of the bottom surface portion 3b is formed larger than the depth Ld. This is considered so that when a two-handed pan is used as the container 90 as shown in FIG. 5, the handles 90a, 90b of the two-handed pan have sufficient gaps La, Lb between the side surfaces 3c, 3d. As a result, when the two-handed pan is placed on the tray 7 or when the two-sided pan is taken out, the cook can hold the two handles 90a, 90b of the pan with a margin. Of course, the marking 7b formed on the upper surface of the tray 7 is also provided at a position where the gaps La and Lb on both sides of the handles 90a and 90b of the container 90 can be sufficiently secured as described above. Specifically, the position is near the center of the tray 7.

  Moreover, one of the reasons why the front opening of the cooking cabinet 3 is formed in an inclined shape is the same reason as described above. That is, by tilting the front surface portion 3e in this way, as shown in FIG. 7A, the position Pb of the upper edge of the front opening of the cooking chamber 3 (the front edge portion of the top surface portion 3a) is the cooking chamber. 3 is retracted by a distance D from the position Pa of the lower edge of the front opening 3 (the front edge of the bottom surface 3b). This position Pb is a position that substantially coincides with the substantially central portion of the container 90 in the front-rear direction in the state in which the tray 7 on which the container 90 is placed protrudes to the forefront part of the conveyance range, or is located on the rear side of the position. The distance D is such that the position Pb and the container 90 satisfy the above positional relationship. With such a configuration, even when the door 4 is not opened, the upper surface of the container 90 placed on the tray 7 can be easily viewed through the window 4a from the diagonally upper front. In addition, even when the tray 7 is stored in the cooking chamber 3 as shown in FIG. 7A, it becomes easy for the cook to stir the food in the container 90 and add the seasoning. ing.

  Furthermore, when the tray 7 protrudes forward as shown in FIG. 7B, about half or more of the upper surface of the container 90 can be seen from above. Thereby, it is easier for the cook to confirm the cooking state of the food in the container 90, and it is easier to perform operations such as stirring and adding seasonings. Further, in this state, the handles 90a and 90b of the container 90 are located in the vicinity of the front opening, or in some cases, part or all of the handles 90a and 90b protrudes outward from the front opening. The operation of putting the container 90 in and out of the cooking cabinet 3 with the two-handed pan handles 90a and 90b is very easy.

  In the heating cooker 1, in order to perform cooking by three different methods of induction heating, high-frequency heating, and heater heating (sometimes referred to as oven heating or grill heating, but referred to as heater heating in this specification). In addition, independent heating units are provided for each. That is, as shown in FIG. 6, an induction heating unit 20 for induction heating the container 90 placed on the tray 7 is provided below the bottom surface portion 3 b of the cooking cabinet 3 and at substantially the center thereof. ing. Further, a heater heating unit 40 for heating the food stored in the cooking cabinet 3 is provided behind the rear surface portion 3 f of the cooking cabinet 3. In addition, a high-frequency heating unit 30 for cooking the food stored in the cooking chamber 3 (for example, in the container 90) is provided on the upper left portion behind the rear surface portion 3f of the cooking chamber 3 and above the top surface portion 3a. It has been.

  FIG. 14 is a block configuration diagram of an electric system of the heating cooker 1 of the present embodiment. The control unit 70 is mainly configured of a microcomputer, and drives the inverter circuit 73 included in the induction heating unit 20 via the inverter driving unit 71 to be a part of the configuration of the inverter circuit 73. In addition, a high-frequency current is caused to flow, and the inverter circuit 74 is driven to supply driving power to the magnetron 31 included in the high-frequency heating unit 30 for driving. Further, the control unit 70 is connected to the antenna driving motor 35 included in the high-frequency heating unit 30, the heater 43 and fan motor 45 included in the heater heating unit 40, and the tray included in the tray transport mechanism 50 via the load driving unit 72. In addition to the conveyance motor 57, the operation of a cooling blower motor 77 for sending air into an intake duct 9 described later is controlled.

  Further, the controller 70 receives a key input signal from the key input unit 5 a, a door open detection signal for recognizing the open / closed state of the door 4 from the door switch 75, and a temperature detection signal in the cooking chamber 3 from the temperature sensor 76. Position detection signals are respectively input from a tray transfer position detection switch (micro switch) 60 included in the tray transfer mechanism 50, and further, display control signals for setting information of driving courses, driving conditions, and the like are output to the display unit 5b. To display. The control unit 70 includes a ROM in which an operation program is stored. In the process of executing the operation program on the CPU, the controller 70 monitors the operation of the cooker and the operation state of the appliance by using various input signals as described above. The operation of each unit is controlled.

  Next, among the above three heating units, first, the configuration and operation of the induction heating unit 20 will be described in detail with reference to FIGS. 8A is a front longitudinal sectional view of the heating cooker 1 of the present embodiment, FIG. 8B is an enlarged view of portion A in FIG. 8A, and FIG. 9 is a main portion of the induction heating unit 20. FIG.

  As shown in FIG. 9, the bottom surface portion 3b of the cooking cabinet 3 is formed of a stainless steel (SUS304) having a recess 201 formed by drawing into an octagonal shape at a substantially central portion, and an opening 202 having a large circular opening at the center. ) Made main bottom plate (first member in the present invention) 200 and a stainless steel (SUS304) punching plate in which many small holes 204 having a predetermined diameter are formed (the magnetic flux passage portion in the present invention and the second member) 203), which are integrated by welding such as spot welding. The punching plate 203 is sandwiched between a mounting table 21 fitted in the recess 201 and a disk-shaped heat insulating material (heat insulating member in the present invention) 22 made of glass wool provided at the lower portion. Similar to the tray 7, the mounting table 21 needs to allow magnetic flux to pass therethrough for induction heating, and needs to be a low-loss dielectric material so that high-frequency heating is difficult. Moreover, heat resistance is also required. Therefore, here, the mounting table 21 is made of crystal glass.

  There is a gap between the peripheral edge of the mounting table 21 and the inner wall of the recess 201, but this gap is filled with the silicone resin 26 as a filler in the present invention, whereby the bottom surface of the cooking cabinet 3 is substantially flat. It has become. Further, by tightly closing this gap, it is possible to prevent food residues and dust from entering the gap.

  Below the heat insulating material 22, an induction heating coil 24 is provided that is wound in a flat plate shape with an insulating plate 23 (insulating member in the present invention) such as a thin mica sheet interposed therebetween. The heat insulating material 22, the insulating plate 23, and the induction heating coil 24 are made of polypropylene (PP) resin, acrylonitrile butadiene styrene (ABS) resin, polycarbonate acrylonitrile butadiene styrene (polycarbonate ABS, PC) fixed to the lower surface of the main bottom plate 200 with screws or the like. / ABS), a polyethylene resin terephthalate (PET) resin, and a synthetic resin holder (a holding member in the present invention) 25 such as a phenol resin, so as to be pressed against the lower surface of the main bottom plate 200 from below.

  In this embodiment, the main bottom plate 200 has a thickness of 0.5 mm, and has a sufficient strength even when a heavy container is placed. On the other hand, the thickness of the punching plate 203 is 0.1 mm which is thinner than the thickness of the main bottom plate 200 and is inferior in strength compared to the main bottom plate 200. However, since the punching plate 203 is held by the holder 25 so as to be pressed from below via the induction heating coil 24 and the heat insulating material 22, it is sandwiched between the mounting table 21 and the heat insulating material 22. Reinforcement is made. In addition, by fixing the induction heating coil 24 in this way, individual differences in the separation distance in the height direction between the bottom surface portion 3b and the induction heating coil 24 can be reduced.

  The punching plate 203 has a function of blocking the microwave supplied into the cooking chamber 3 as described later while allowing the magnetic flux generated from the induction heating coil 24 below the punching plate 203 to pass therethrough. The condition of such magnetic flux passage efficiency is mainly determined by the aperture ratio and thickness of the punching plate 203, while the microwave passage prevention condition is mainly determined by the diameter and thickness of the small hole 204 of the punching plate 203. Determined. Therefore, these elements need to be set appropriately. Here, a small hole having a diameter of 1.4 mm provided at intervals of 1.7 mm is used. However, the magnetic flux can pass under the condition that the plate thickness is thin even if the small hole is not necessarily formed.

  FIG. 13 shows the case where induction heating is performed through a thin metal plate, induction heating through the thin metal plate against the electric power when induction heating is performed without the thickness of the thin plate, the aperture ratio of the small holes, and the thin metal plate. It is a graph which shows the result of having simulated the ratio of the electric power when performing, ie, the relationship of electric power ratio. In this figure, the power ratio is 1.0 and there is no loss. Specifically, for example, when the plate thickness is 0.1 mm as in the present embodiment, the power loss is only 10% when the aperture ratio is 50%, and the power loss is 18% even when there is no opening. Degree. If the plate thickness can be reduced to 0.05 mm, the power loss can be suppressed to about 10% even if there is no opening. Of course, the strength decreases as the plate thickness is reduced. Therefore, an appropriate plate thickness and aperture ratio (small hole size and interval) may be determined in consideration of these conditions.

  In the induction heating unit 20 having the above configuration, when a high frequency current is caused to flow from the inverter circuit 73 to the induction heating coil 24 by the inverter driving unit 71 operating under the control of the control unit 70, an alternating magnetic flux is generated. It passes through 203 and the mounting table 21 and enters the cooking chamber 3, and further passes through the tray 7 and crosses the bottom of the container 90 having at least a bottom made of magnetic metal. An eddy current is induced at the bottom of the container 90 by the induction action, the container 90 is heated by Joule heat, and the food to be cooked contained in the container 90 is heated. At this time, the heat of the container 90 is transmitted to the mounting table 21 and the punching plate 203, but is blocked by the heat insulating material 22 below the container 90. Therefore, the induction heating coil 24 can be prevented from being heated to a high temperature by the conducted heat. . Moreover, although the heating output of the container 90 depends on the distance between the bottom surface of the container 90 and the induction heating coil 24, the induction heating coil 24 is fixed to the bottom surface portion 3b by the holder 25 as described above. Since the individual difference in distance is small and does not fluctuate due to vibration or the like, stable induction heating can be performed.

  In this way, the food in the container 90 placed on the tray 7 can be cooked by induction heating. At this time, the object of induction heating is the container 90, and strictly speaking, the object to be heated is the container 90. However, since the food contained in the container 90 is indirectly heated, this food is the object to be heated. Can be considered. In this induction heating, since the container 90 itself becomes high temperature, for example, it is possible to perform burnt cooking in which food such as meat and fish that has contacted the container 90 is burnt.

  In addition, the above-mentioned induction heating coil 24 cooks so that it may be located under the marking 7b provided in the tray 7 in the state which the tray 7 was accommodated in the cooking chamber 3, as shown to Fig.7 (a). It arrange | positions as a part of induction heating unit 20 below the bottom face part 3b of a store | warehouse | chamber. That is, the circular marking 7b is an index for the cook to place the container 90 on the tray 7, and at the same time indicates the position of the induction heating coil 24 when the tray 7 is stored in the cooking cabinet 3. It becomes concentric with the induction heating coil 24. Further, as described above, since the marking 7b is provided at the center of the width of the tray 7, that is, the width of the bottom surface portion 3b, the induction heating coil 24 is also positioned at the approximate center of the width of the bottom surface portion 3b. The distances La and Lb between the both ends of the handles 90a and 90b of the container 90 placed so as to be best induction-heated by the coil 24 and the side surfaces 3c and 3d are sufficiently secured.

  Next, the configuration and operation of the high-frequency heating unit 30 will be described in detail with reference to FIGS. A magnetron 31 is attached to the space in the upper left rear part of the rear surface portion 3f of the cooking cabinet 3, and the top surface portion 3a is bent to the right from the magnetron 31 to the front in the upper part of the top surface portion 3a of the cooking chamber 3. A waveguide 32 extending to substantially the center of the is disposed. A microwave diffusion chamber 33 is formed in the top surface portion 3 a of the cooking chamber 3, and the end of the waveguide 32 extends to the upper portion of the microwave diffusion chamber 33. A through hole 32a as a power feeding port is formed in the upper wall surface of the microwave diffusion chamber 33 that separates the chamber 33 from the inside. In the microwave diffusion chamber 33, a metal plate-shaped radiation antenna 34 extending in the horizontal direction and fixed to a lower portion of a metal cylindrical antenna shaft 34a extending in the vertical direction is disposed. A bearing 32b having a through hole at the center is attached to the through hole 32a, and the antenna shaft 34a of the radiation antenna 34 is rotatably inserted into the through hole of the bearing 32b. With such a configuration, the radiating antenna 34 is rotatable in the microwave diffusion chamber 33 around the antenna shaft 34a.

  An antenna drive motor 35 having a motor shaft 35 a is installed near the through hole 32 a and above the waveguide 32. The motor shaft 35 a penetrates the upper wall surface of the waveguide 32 downward from above and is connected to the antenna shaft 34 a of the radiation antenna 34 in the waveguide 32. Thereby, the rotational driving force of the antenna drive motor 35 is transmitted to the radiation antenna 34 through the motor shaft 35a and the antenna shaft 34a. Further, the microwave guided from the magnetron 31 through the waveguide 32 passes through the through hole 32 a through the antenna shaft 34 a exposed in the waveguide 32 and propagates to the radiation antenna 34. And is radiated from the radiation antenna 34 into the cooking cabinet 3. At this time, since the radiation antenna 34 is rotated by the antenna driving motor 35, the radiation antenna 34 radiates the microwaves in various directions while diffusing the microwaves.

  During high-frequency heating, the inverter driving unit 71 drives the inverter circuit 74 under the control of the control unit 70 to supply driving power to the magnetron 31 and the antenna driving motor 35 is operated via the load driving unit 72. The When the magnetron 31 is driven, the microwave generated from the magnetron 31 passes through the waveguide 32 to the microwave diffusion chamber 33 as described above, and is diffused by the radiation antenna 34 that is rotationally driven by the antenna drive motor 35. It is discharged into the cooking chamber 3 while being done. That is, the microwave is emitted in various directions so as to pour down from the microwave diffusion chamber 33 on the top surface of the cooking chamber 3, and further reflects on the side surface or rear surface of the cooking chamber 3 or the inner surface of the door 4. Therefore, the food stored in the cooking chamber 3 can be heated evenly.

  In particular, as shown in FIG. 6, even when food contained in a deep container 90 is heated at high frequency, the microwave is obstructed by the container 90 because the microwave feeding port is formed on the top surface portion 3a. The food that is the object to be heated when hitting the food in the container 90 can be efficiently heated. At this time, since the microwave does not pass through the punching plate 203 of the bottom surface portion 3b as described above, the microwave can be prevented from leaking from the cooking chamber 3.

  Next, the configuration and operation of the heater heating unit 40 will be described in detail with reference to FIGS. A heater chamber 41 recessed in a deep dish shape is formed on the back side of the rear surface portion 3 f of the cooking cabinet 3, and a fan motor 45 is installed behind the heater chamber 41. A rotating shaft extending in the front-rear direction of the fan motor 45 passes through the rear wall of the heater chamber 41, and a fan 42 is fixed to the front end thereof. A heater 43, which is a sheathed heater, is provided on the outer periphery side of the fan 42 so as to surround the fan 42, and is heated by supplying drive current to the heater 43. The fan 42 has a structure in which a large number of blade bodies are attached to a disk body at predetermined angular intervals, and when rotated in a predetermined direction, the air sucked from the center front is sent to the outer peripheral side of the blade bodies. . In the rear surface portion 3 f in front of the heater chamber 41, a number of intake holes 14 are formed on the inner peripheral side of the fan 42, and a number of hot air supply holes 15 are formed in front of the heater 43. Of course, the intake holes 14 and the hot air supply holes 15 are also set to dimensions that prevent the passage of microwaves.

  When heating the heater, a heating current is supplied to the heater 43 via the load driving unit 72 under the control of the control unit 70 and the fan motor 45 is operated. When the fan 42 is rotationally driven by the fan motor 45, the air in the cooking chamber 3 is sucked into the heater chamber 41 through the intake hole 14 and sent out to the outer peripheral side. Since the heated heater 43 exists on the outer peripheral side, the sent air is heated by heat exchange with the heater 43 and returns to the cooking chamber 3 through the hot air feed hole 15. As described above, the air is circulated between the cooking chamber 3 and the heater chamber 41 by the action of the fan 42, whereby the temperature of the air in the cooking chamber 3 is increased to a high temperature of 200 ° C. or more. The food that is the object to be heated contained in the oven can be cooked in an oven and grill.

  In addition, steam is generated from the food during the cooking as described above, and the window 4a of the door 4 is clouded by the steam, making it difficult to see through the cooking chamber 3 during cooking. It is necessary to discharge from the inside of the storage 3 to the outside. For this purpose, a large number of air intake holes 8 are formed in the upper part of the left side surface portion 3c of the cooking chamber 3, and the air introduced from the rear portion of the cooking chamber 3 through the intake duct 9 disposed outside the left side surface portion 3c. Is fed into the cooking chamber 3 through the air intake hole 8. Although not shown in FIGS. 5 and 6, a blower driven by a cooling blower motor 77 is provided behind the rear surface portion 3f, and the outside air sucked from the rear of the housing 2 cools the electric circuit and the magnetron 31. After being used, it is configured to be collected and fed into the intake duct 9. On the other hand, a large number of exhaust holes 10 are formed in the right side surface portion 3d of the cooking chamber 3, and the air in the cooking chamber 3 passes through the exhaust holes 10 and passes through an exhaust duct (not shown) disposed outside the right side surface portion 3d. It is discharged outside the machine.

  In the cooking device 1 of the present embodiment, in particular, since cooking is performed by induction heating, there are many opportunities for the user to work on the food during cooking, such as stirring the food stored in the container 90. When the cooker performs a predetermined key operation with the key input part 5a with the door 4 fully opened in order to make it possible to easily perform such operations and to easily take in and out the container 90, the tray is The tray 7 automatically protrudes forward by the operation of the transport mechanism 50. The configuration and operation of the tray transport mechanism 50 will be described with reference to FIGS. 10, 11 and 12 in addition to FIG. FIG. 10 is a top view of the main part showing the door 4, the tray 7, and the tray transport mechanism 50 with the tray 7 protruding to the maximum extent, and FIG. 11 is a development view when the state of FIG. FIG. 12 is an external perspective view of the tray transport mechanism 50.

  The tray transport mechanism 50 has a U-shaped sliding body 52 having a metal base 51, a contact piece 53 that contacts the rear portion of the tray 7 and pushes it forward, and the sliding body 52 can be moved in the front-rear direction. , A guide 54 held at one end, an arm 56 having one end rotatably connected to the vertical shaft 55 and the other end connected to the rear end of the guide 54 so as to be movable within a predetermined range in the horizontal direction, and a tray transport as a drive source A motor 57, a rotating body 58 that is rotationally driven in one direction by the tray transport motor 57, a connecting body 59 that transmits the driving force of the rotating body 58 to the arm 56, and a micro for detecting the position of the sliding body 52. A tray transfer position detection switch 60 which is a switch.

  When the tray transport motor 57 is driven via the load driving unit 72 under the control of the control unit 70 with the tray 7 being maximally pushed into the cooking chamber 3 as shown in FIG. The rotating body 58 starts to rotate in a predetermined direction, and the sliding body 52 is pulled forward via the connecting body 59. Since the moving direction of the sliding body 52 is restricted only in the front-rear direction by the guide 54, the sliding body 52 goes straight forward, and along with the movement, the contact piece 53 at the front end pushes the rear part of the tray 7, and the tray 7 Is slid out of the cooking chamber 3 by sliding forward in the horizontal direction. When the rotating body 58 makes about 1/2 turn, the sliding body 52 is now pushed backward via the connecting body 59. Therefore, the sliding body 52 moves backward while leaving the tray 7 at the position where it is pushed out to the maximum. The state where the tray 7 is pushed out to the maximum is the state shown in FIG. 7B, and the front portion of the tray 7 protrudes forward from the cooking chamber 3. At this time, since the inner surface of the door 4 facing vertically upward and the upper surface of the bottom surface portion 3b of the cooking cabinet 3 form a substantially flush horizontal surface, the tray 7 protruding forward is placed on the inner surface of the door 4. , Can maintain a stable horizontal state.

  Then, when the rotating body 58 rotates approximately once, the projecting piece of the rotating body 58 presses the movable piece of the tray transport position detection switch 60, and the control unit 70 that detects that the switch 60 is turned on passes the load driving unit 72. Then, the power supply to the tray transport motor 57 is cut off. Thereby, the sliding body 52 stops in the state accommodated in the original position, that is, the predetermined position in the cooking chamber 3. The tray transport mechanism 50 has a function of sliding the tray 7 forward and does not have a function of pulling the tray 7 rearward. Therefore, the tray transport mechanism 50 is in a state of protruding forward as shown in FIG. The operation of pushing the tray 7 into the cooking cabinet 3 is manually performed by the cook. Of course, such a backward sliding movement operation may be automatically performed.

  Since the tray transport mechanism 50 as described above is small and particularly thin, it is properly stored in the lower space between the rear surface portion 3f of the cooking cabinet 3 and the rear surface of the housing 2. In addition, since the structure is simple, there are few failures and high reliability.

  If the tray 7 protrudes forward when the door 4 is not fully opened, the tray 7 comes into contact with the door 4 and an excessive load is applied to the tray transport motor 57, or the door 4 or the tray 7 is damaged. There is a risk of doing so. Therefore, in the heating cooker 1 of the present embodiment, the control unit 70 monitors the open / closed state of the door 4 by the door switch 75 and only when it is determined that the door 4 is fully opened by the detection signal from the door switch 75. The input key for projecting the tray 7 forward is permitted, and the tray transport motor 57 is actually operated. As a result, even if the cook mistakenly gives an instruction to slide the tray 7 forward when the door 4 is closed or in a half-open state, the tray 7 does not move at all. Can be prevented.

  It should be noted that any of the above embodiments is merely an example of the present invention, and it is apparent that the present invention is encompassed by the present invention even if appropriate modifications, corrections or additions are made within the scope of the present invention.

The external appearance perspective view of the state where the door was closed in the cooking-by-heating machine by one example of the present invention. The external appearance perspective view in the state (with the container which accommodated the foodstuff) which opened the door fully in the heating cooker of a present Example. The front view (a) in the state which opened the door fully (the container which accommodated the foodstuff) in the heating cooker of a present Example, and the right view (b). The external appearance perspective view of the state which removed the exterior cover which is a part of housing | casing in the heating cooker of a present Example. The upper surface perspective view of the principal part in the state which opened the door fully in the cooking-by-heating machine of a present Example. The right side surface longitudinal cross-sectional view of the principal part in the state which closed the door in the cooking-by-heating machine of a present Example. The right side longitudinal cross-sectional view of the principal part for demonstrating the protrusion operation | movement of a tray in the heating cooker of a present Example. The front longitudinal cross-sectional view (a) of the heating cooker of a present Example, and the enlarged view (b) of the A section in (a). The exploded structure figure of the principal part of the induction heating unit in the cooking-by-heating machine of a present Example. The top view of the principal part which shows the door, tray, and tray conveyance mechanism in the state which the tray protruded to the maximum in the heating cooker of a present Example. FIG. 11 is a development view when the state of FIG. The external appearance perspective view of the tray conveyance mechanism in the heating cooker of a present Example. The graph which shows the result of having simulated the relationship between the plate | board thickness of a thin plate, the aperture ratio of a small hole, and a power ratio about the case where induction heating is performed through a metal thin plate. The block block diagram of the electric system of the heating cooker of a present Example.

Explanation of symbols

2 ... Case 3 ... Cooking chamber 3a ... Top surface portion 3b ... Bottom surface portion 3c ... Left side surface portion 3d ... Right side surface portion 3e ... Front surface portion 3f ... Rear surface portion 4 ... Door 4a ... Window 5 ... Operation panel 5a ... Key input portion 5b ... Display Part 7 ... Tray 7a ... Flange 7b ... Marking 8 ... Intake hole 9 ... Intake duct 10 ... Exhaust hole 11 ... Tray guides 12, 13 ... Rail 14 ... Intake hole 15 ... Hot air feed hole 20 ... Induction heating unit 21 ... Place 22 ... Insulating material 23 ... Insulating plate 24 ... Induction heating coil 25 ... Holder 26 ... Silicone resin 200 ... Main bottom plate 201 ... Concave portion 202 ... Opening 203 ... Punching plate 204 ... Small hole 30 ... High frequency heating unit 31 ... Magnetron 32 ... Induction Wave tube 32a ... through hole 32b ... bearing 33 ... microwave diffusion chamber 34 ... radiating antenna 34a ... antenna shaft 35 ... antenna drive motor 35a ... motor shaft 40 ... heater Heat unit 41 ... heater chamber 42 ... fan 43 ... sheath wire heater 45 ... fan motor 50 ... tray transport mechanism 51 ... base 52 ... sliding body 53 ... contacting piece 54 ... guide 55 ... vertical shaft 56 ... arm 57 ... tray transport motor 58 ... rotating body 59 ... coupling body 60 ... tray transport position detection switch 70 ... control unit 71 ... inverter driving unit 72 ... load driving unit 73, 74 ... inverter circuit 75 ... door switch 76 ... temperature sensor 77 ... cooling blower motor 90 ... Container (container with food)
90a, 90b ... handle

Claims (7)

A box-shaped cooking chamber capable of containing a heated object inside, a magnetron for generating microwaves for high-frequency heating of the heated object, and a waveguide for guiding the microwave into the cooking chamber. In a heating cooker comprising: high-frequency heating means including a tube; and induction heating means including an induction heating coil that generates an alternating magnetic flux for induction heating the object to be heated.
A part of the bottom plate of the cooking chamber is provided with a magnetic flux passage part that prevents the passage of microwaves while allowing the magnetic flux to pass therethrough, and a heat insulating member that cuts off heat conduction and an electrical insulation characteristic below the magnetic flux passage part. A heating cooker, wherein the induction heating coil is arranged with an insulating member having a gap therebetween.   The bottom plate of the cooking chamber is made of metal and has a recess formed substantially in the center, and the magnetic flux passage is formed at the bottom of the recess. A flat plate-shaped mounting table made of a heat-resistant material is housed, and the upper surface of the mounting table is formed substantially flush with the upper surface of the bottom plate surrounding the recess. Item 10. The heating cooker according to item 1.   The heating cooker according to claim 2, wherein a gap between the peripheral edge of the mounting table and the inner peripheral wall of the recess is filled with a heat-resistant filler.   The cooking device according to claim 2 or 3, wherein the magnetic flux passage section is formed by a large number of small holes having a predetermined diameter.   The heating cooker according to any one of claims 2 to 4, wherein the magnetic flux passage part has a thinner plate thickness than a bottom plate surrounding the recess.   The bottom plate of the cooking chamber is composed of a first member having the recess formed substantially in the center and having an opening on the bottom surface of the recess, and a second member serving as the magnetic flux passage having a size for closing the opening, The cooking device according to claim 4 or 5, wherein the cooking device is integrated by fixing the first and second members. The heat insulating member, the insulating member, and the induction heating coil are held so as to be pressed against the magnetic flux passage portion by a holding member fixed to the lower surface of the bottom plate while holding the lower surface of the induction heating coil. The cooking device according to any one of claims 1 to 6, characterized in that.

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