Cooking device

Abstract

To provide a heating cooker capable of preventing overheating near a terminal part in a heater as much as possible.SOLUTION: A heating cooker according to the present invention includes a heating compartment configured to heat an object to be cooked, and a heater disposed on a ceiling wall of the heating compartment and serving as a heat source, wherein the heater includes a mica and a heater wire wound around the mica, the heater includes a terminal portion located outside the mica, the terminal portion is provided with a terminal connected to the heater wire, and another mica is disposed to overlap the mica at a position near the heater wire extending from the mica to the terminal portion.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The present invention relates to a cooking device that heats and cooks food in a heating chamber, and more particularly to a cooking device that heats food using a flat heater provided on the ceiling wall of the heating chamber. [Background technology]

[0002] The cooking means used in cooking appliances include an infrared heater unit that radiates heat rays to directly heat food, a microwave heating unit that radiates microwaves to heat food, a steam heating unit that heats food with water vapor, and a hot air circulation unit that circulates hot air inside the heating chamber to heat food.

[0003] In addition, as a heating cooking means in a heating cooker, there is a configuration in which a flat heater is provided on the ceiling wall of a rectangular parallelepiped heating chamber to heat the ceiling wall, and the interior of the heating chamber is indirectly heated by the ceiling wall (see Patent Documents 1 and 2).

[0004] There is also a configuration in which a flat heater is placed on the ceiling wall and used to increase the temperature inside the refrigerator (see Patent Document 3). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 3-103206 [Patent Document 2] Japanese Patent Application Laid-Open No. 2010-54124 [Patent Document 3] Japanese Patent Application Laid-Open No. 2017-161163 Summary of the Invention [Problem to be solved by the invention]

[0006] However, there is room for improvement in preventing local overheating of the heater.

[0007] An object of the present invention is to provide a cooking device that can prevent overheating near the terminals of a heater as much as possible. [Means for solving the problem]

[0008] One embodiment of the heating cooker according to the present invention is a heating cooker comprising a heating chamber for heating food to be cooked, and a heater constituting a heat source, the heater being arranged on the ceiling wall of the heating chamber, wherein the heater is configured by wrapping a heater wire around mica, the heater having a terminal portion located outside the mica, a terminal connected to the heater wire being provided on the terminal portion, and another piece of mica being placed on top of the heater wire extending from the mica to the terminal portion in the vicinity of the heater wire. [Effects of the Invention]

[0009] According to the present invention, it is possible to provide a cooking device that can prevent overheating near the terminal portion of the heater as much as possible. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a perspective view showing the appearance of a cooking device according to an embodiment of the present invention; [Figure 2] FIG. 1 is a perspective view showing a state in which the door of the cooking device according to the present embodiment is open; [Figure 3] FIG. 1 is a perspective view showing a state in which an outer cover of the cooking device according to the present embodiment is removed; [Figure 4] FIG. 1 is an exploded perspective view of a flat heater unit in a cooking device according to an embodiment of the present invention; [Figure 5] FIG. 1 is an exploded schematic diagram showing a top view of a heater (upper heater) in a cooking device according to an embodiment of the present invention. [Figure 6] FIG. 1 is an exploded schematic view showing a bottom view of a heater (upper heater) in a cooking device according to an embodiment of the present invention. [Figure 7] FIG. 1 is a perspective view of the cooking device of the present embodiment with the door and the bottom wall of the heating chamber removed; [Figure 8]A circuit diagram for controlling the cooking means in the cooking device of this embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0011] A first aspect of the cooking device according to the present invention is a cooking device comprising a heating chamber for heating food to be cooked, and a heater constituting a heat source, the heater being arranged on the ceiling wall of the heating chamber, wherein the heater is configured by wrapping a heater wire around mica, the heater has a terminal portion located outside the mica, the terminal portion is connected to the heater wire, and another mica is arranged on top of the mica in a position near the heater wire extending from the mica to the terminal portion. The cooking device of the first aspect configured in this way can prevent overheating near the terminal portion of the heater as much as possible.

[0012] A cooking device according to a second aspect of the present invention may be configured such that a heater wire extends from the surface of the mica in the first aspect to a terminal portion, and another mica is placed on top of the back surface of the mica.

[0013] In a third aspect of the cooking device according to the present invention, the heater wires may be extended from holes formed in the mica to the terminal portion in a state where a plurality of the heater wires are overlapped.

[0014] Hereinafter, as an embodiment of the cooking device of the present invention, a cooking device using at least a heater as cooking means will be described with reference to the accompanying drawings. Note that the cooking device of the present invention is not limited to the cooking device configuration described in the following embodiment, but includes cooking device configurations equivalent to the technical ideas described in the following embodiment.

[0015] The embodiments described below are examples of the present invention, and the configurations, functions, operations, etc. shown in the embodiments are merely examples and do not limit the present invention. Among the components in the following embodiments, components that are not described in the independent claims that represent the highest concepts are described as optional components.

[0016] (Embodiment 1) Hereinafter, a cooking device according to the present embodiment of the present invention will be described with reference to the accompanying drawings. Fig. 1 is a perspective view showing the appearance of the cooking device according to the present embodiment. Fig. 2 is a perspective view showing the cooking device according to the present embodiment of Fig. 1 with the door open.

[0017] As shown in Figures 1 and 2, the cooking appliance is configured so that the front opening of a heating chamber 4 provided inside a main body 1 can be opened and closed by a door 2. A handle 3 is provided at the upper end of the door 2, and a user grasps the handle 3 to rotate the door 2, thereby opening and closing the front opening of the heating chamber 4 in an up-and-down manner. The interior of the heating chamber 4 is substantially sealed when the door 2 is closed, and food to be heated, which is placed inside the heating chamber 4, is heated and cooked in a substantially sealed state.

[0018] As shown in Fig. 1, on the front of the cooking appliance, a setting unit 5 is provided on an upward-opening door 2, which has a dial-like knob and various setting buttons for setting various cooking conditions such as cooking temperature and cooking time. The setting unit 5 provided on the front of the cooking appliance also has a display unit that displays various cooking conditions and the heating state during cooking.

[0019] In addition to the heater (flat heater), the cooking device of this embodiment is provided with a microwave heating unit that irradiates microwaves to heat food as cooking means. Alternatively, a steam heating unit that heats food with steam, and a hot air circulation unit that circulates hot air inside the heating chamber 4 to heat food may also be used.

[0020] The microwave heating unit has an antenna that emits microwaves installed under the bottom wall of the heating chamber 4, and the directional antenna radiates microwaves in the desired direction into the heating chamber 4. When a steam heating unit is installed, a water tank is provided inside the main body 1, and water from the water tank is heated to a high temperature by a boiler steam heater, and the generated steam is sprayed in a concentrated manner into the heating chamber 4. When a hot air circulation unit is installed, a rear heater installed on the rear side of the heating chamber 4 heats the air drawn in from the heating chamber 4, and the hot air is supplied into the heating chamber 4.

[0021] The cooker of this embodiment is provided with multiple cooking means, and the appropriate cooking means is selected by the user selecting the desired cooking means or the cooking contents. The user places the food to be cooked in the heating chamber 4 of the cooker, closes the door 2, sets the cooking means and cooking contents in the setting unit 5, and presses the start button to start the cooking operation.

[0022] As shown in Fig. 2, the cooking device of this embodiment is configured so that a heating dish 6 on which an object to be heated is placed can be stored inside the heating chamber 4. The heating dish 6 can be placed on either the upper or lower level inside the heating chamber 4, and steps are formed on both side walls of the heating chamber 4 to allow the heating dish 6 to slide and support the heating dish 6. A heating element (not shown) is embedded in the placement surface of the heating dish 6. The heating element absorbs microwaves and generates heat, and ferrite or the like is used for the heating element.

[0023] In this embodiment, an example is described in which ferrite is embedded in the heating dish 6 as the heating element, but the heating element may be any element that absorbs microwaves and generates heat, and may be configured by applying the heating element to the back surface of the heating dish 6. Furthermore, the main material of the heating dish 6 may be any material that has excellent thermal conductivity, and may be configured from metal or ceramic.

[0024] In addition, in this embodiment, the heating dish 6 is described as being supported by a step on the side wall of the heating chamber 4, but it may also be suspended from the ceiling wall, or may be provided with feet that protrude downward on the heating dish 6 and placed on the bottom wall of the heating chamber 4.

[0025] An antenna (not shown) that radiates microwaves into the heating chamber 4 is disposed directly below the approximate center of the bottom wall of the heating chamber 4. The antenna in this embodiment has directionality in the radiating direction of the microwaves and is configured to radiate circularly polarized waves directly above the antenna. Therefore, the antenna in this embodiment is provided with a rotation mechanism and is configured to rotate the radiation port of the antenna so as to radiate microwaves uniformly inside the heating chamber 4, and is also configured to radiate circularly polarized waves to the heating element of the heating plate 6 placed directly above the antenna for dielectric heating.

[0026] The bottom wall of the heating chamber 4 is made of a material that transmits microwaves from the antenna, and the other walls of the heating chamber 4, namely the side walls, back wall, and ceiling wall, are made of steel or aluminum-plated stainless steel (SUS). Each wall surface may be coated with a non-stick coating layer made of, for example, fluororesin or silicone resin. By forming such a coating layer, it is possible to prevent adhesion of dirt such as oil and grease scattered during cooking and cooking residue, and even if dirt does adhere, it can be easily wiped off. This results in an easy-to-use configuration.

[0027] Furthermore, a coating layer with a self-cleaning function may be formed on each wall surface of the heating chamber 4, which decomposes and automatically cleans off grease scattered during cooking when heated during cooking. Methods for imparting a self-cleaning function to the coating layer include, for example, blending a manganese oxide-based catalyst species that promotes oxidative decomposition into the coating layer, or adding platinum, which has a significant effect on oxidative decomposition at low temperatures, or palladium, which is highly active in the medium to high temperature range. Furthermore, a method of adding cerium, which has an adsorption property, may also be used.

[0028] As described above, the object to be heated (food) placed on the heating plate 6 stored inside the heating chamber 4 is heated and cooked by the heating plate 6, which has reached a high temperature due to the heat of the heating element that is dielectrically heated by microwaves.In this embodiment, however, the top surface of the object to be heated (food) placed on the heating plate 6 is heated by a flat heater unit 8 provided on the upper part of the ceiling wall of the heating chamber 4.

[0029] Fig. 3 is a perspective view showing the state in which the outer cover is removed from the main body 1 of the cooking device of this embodiment. As shown in Fig. 3, a flat heater unit 8 is provided on the ceiling side of the main body 1 of the cooking device, i.e., in the part including the ceiling wall of the heating chamber 4. As shown in Fig. 3, the upper part of the heating chamber 4 in the cooking device is configured with the flat heater unit 8.

[0030] An internal temperature detection unit 9, such as a thermistor, is provided near the right rear corner of the heating chamber 4 as internal temperature detection means for detecting the internal temperature inside the heating chamber 4. Internal temperature information detected by the internal temperature detection unit 9 is transmitted to a control unit (control board) (see FIG. 8) described below and is used to control various heating cooking operations. Although the thermistor is provided near the right rear corner of the heating chamber 4, it may be provided anywhere in the heating chamber 4 where the internal temperature can be detected, such as the left rear corner, the right front corner, or the left front corner.

[0031] [Flat heater unit] Fig. 4 is an exploded perspective view showing the planar heater unit 8. As shown in Fig. 4, from the bottom of Fig. 4, the planar heater unit 8 has a heating chamber upper plate 10 that forms the ceiling wall of the heating chamber 4, a heater (planar heater) 11 that is in close contact with the upper surface of the heating chamber upper plate 10, and a first heat insulating material 13 that blocks heat conduction from the heater 11 upward. The planar heater unit 8 also has an insulating sheet 15 that electrically insulates the terminal portion 24 of the heater 11, and a heat shield plate 16 that blocks heat from the planar heater unit 8 from being transferred to the outer cover of the main body 1.

[0032] As described above, the planar heater unit 8 has a stacked assembly structure, and all of the parts can be replaced during maintenance, improving maintainability. Furthermore, the planar heater unit 8 is provided with a heater temperature detection section 18, which is a heater temperature detection means for detecting the temperature of the heating area directly heated by the heater 11. Each component of the planar heater unit 8 will be described in detail below.

[0033] [Heating chamber top plate] The heating chamber upper plate 10 constitutes the ceiling wall of the heating chamber 4, and the central portion of the heating chamber upper plate 10, excluding the outer periphery, has a heat generating area 10a that is approximately square in plan view. This square shape has a curved shape with the heating chamber side (bottom side) being concave, and forms the heat generating area 10a where the heater 11 is disposed in close contact. The heating chamber 4 of this embodiment has a rectangular parallelepiped shape in front view, with the width and depth directions being longer than the height direction, and the heat generating area 10a covers approximately the entire ceiling wall of the heating chamber 4. The heater 11, which has a rectangular shape corresponding to the shape of the heating chamber 4, is The heater 11 is disposed over the entire surface of the curved heat generating area 10a in close contact with the surface. Therefore, substantially the entire surface of the heating chamber upper plate 10 constituting the ceiling wall of the heating chamber 4 becomes a heat generating element to be heated by the heater 11.

[0034] The cross section of the heat generation area 10a in the horizontal direction (left and right direction in FIG. 4) of the heating chamber upper plate 10 is configured as a curve. Similarly, the cross section of the heat generation area 10a in the vertical direction (front and back direction in FIG. 4) of the heating chamber upper plate 10 is also configured as a curve. Therefore, the heat generation area 10a in the heating chamber upper plate 10 has a three-dimensional curved surface with a concave surface on the heating chamber side.

[0035] As shown in Figure 4, in the heating chamber upper plate 10, the heat generating region 10a to which the heater 11 is closely attached has a plurality of regular hexagonal (honeycomb-shaped) regions (honeycomb regions) 10b. In this embodiment, the boundaries of the honeycomb regions 10b in the heating chamber upper plate 10 are formed by grooves that protrude toward the heating chamber, and each honeycomb region 10b has substantially the same area. The heating chamber upper plate 10 configured in this manner is formed by press working.

[0036] As described above, the heat generating region 10a in the heating chamber upper plate 10 is formed with multiple honeycomb regions 10b. Therefore, the heat generating region 10a expands due to the heat of the heater 11, and contracts when the heater 11 is turned off, but the deformation force in all directions caused by this expansion / contraction can be absorbed within each honeycomb region 10b. The heat generating region 10a is heated by the heater 11 to which it is in close contact, but the entire surface of the heat generating region 10a is not heated uniformly by the heater 11, and the heat distribution in the heat generating region 10a is uneven.

[0037] For this reason, the deformation force of expansion / contraction in the heat generating region 10a may be of different magnitude in each region. If the upper plate of the heating chamber, which is the ceiling wall of the heating chamber 4, were flat and had no area that could absorb the deformation force of expansion / contraction, the ceiling wall would be heated locally, deforming and distorting unevenly, creating a gap between the upper plate of the heating chamber and the flat heater, making it difficult for heat from the flat heater to be transmitted.

[0038] In the cooking device of this embodiment, multiple regions (honeycomb regions) 10b separated by grooves are formed in the heat generation region 10a of the heating chamber upper plate 10. Therefore, the deformation force of expansion / contraction is dispersed and absorbed by each of these honeycomb regions, and the heat generation region 10a of the ceiling wall does not deform or distort locally significantly, and the curved shape that is concave on the heating chamber side becomes smoothly raised overall. As a result, the heat generation region 10a maintains close contact with the heater 11, and can receive heat from the heater 11 efficiently and reliably.

[0039] As described above, in this embodiment, the heat generating area 10a on the heating chamber upper plate 10 is prevented from deforming locally, and the heat generating area 10a is configured to maintain the same shape overall and rise overall, thereby ensuring that the heater 11 is maintained in close contact with the heat generating area 10a.

[0040] In this embodiment, the heating region 10a in the heating chamber upper plate 10 is described as being divided into a plurality of regular hexagonal (honeycomb) honeycomb regions 10b, but the honeycomb regions 10b are not limited to a honeycomb shape as long as they are composed of a plurality of regions that can distribute and absorb deformation forces due to local expansion / contraction in the heating region 10a. The plurality of regions that absorb deformation forces due to expansion / contraction can also be polygonal regions such as triangular or rectangular regions, or regions composed of curved lines.

[0041] In this embodiment, the heating chamber top plate 10 is made of steel or aluminum-plated stainless steel (SUS). A black film made of, for example, silicone resin is formed on both sides of the heating chamber top plate 10. By forming this black film on the heater-side surface, heat from the heater 11 can be efficiently absorbed. In this embodiment, a coating layer with a self-cleaning function is formed on the heating chamber-side surface of the heating chamber top plate 10, which breaks down and automatically cleans up oil and grease scattered during cooking when heated during cooking. The method for forming the coating layer with self-cleaning function has been described above, so it will not be repeated here. In this embodiment, a coating layer with self-cleaning function is also formed on both side walls and the back wall of the heating chamber 4.

[0042] [Heater] Fig. 5 is an exploded schematic view showing the heater 11 attached in close contact with the heat generating area 10a of the heating chamber upper plate 10, Fig. 5(a) shows a top view (top perspective view) of the upper insulating material 22, and Fig. 5(b) shows a top view (plan view) of the upper heater 20. The upper heater 20 is arranged under the upper insulating material 22.

[0043] Fig. 6 is an exploded schematic view showing the heater 11 attached in close contact with the heat generating area 10a of the heating chamber upper plate 10, Fig. 6(a) shows a bottom view (bottom perspective view) of the lower insulating material 23, and Fig. 6(b) shows a bottom view (bottom view) of the upper heater 20. The upper heater 20 is arranged on top of the lower insulating material 23.

[0044] That is, the upper heater 20 is sandwiched and secured between the upper insulating material 22 and the lower insulating material 23 .

[0045] Note that the areas surrounded by dotted lines in Figures 5(b) and 6(b) are areas that do not actually appear, and are the areas that appear in Figures 5(a) and 6(a), respectively, but are shown surrounded by dotted lines as invisible areas for ease of understanding.

[0046] The upper heater 20 may be configured to be steplessly variable controlled within a range of, for example, 300 W to 900 W, or may be configured to be on / off controlled at, for example, 700 W.

[0047] The upper heater 20 is formed by winding a heater wire 20b around an insulating plate of mica 20a. In this embodiment, for example, a strip-shaped heater wire having a thickness of 0.144 mm is used as the heater wire for the upper heater 20, but a strip-shaped heater wire having a thickness of about 0.10 mm may also be used. By winding the heater wire at a high density, the temperature rise of the heating chamber upper plate 10 can be made uniform.

[0048] As shown in Fig. 6(b), two heater wires 20b1 are laid in a substantially straight line at the left end of the upper heater 20. Also, as shown in Figs. 5(a) and 5(b), two heater wires 20b2 are laid at the right end of the upper heater 20 so as to connect to the terminal portions 24 at outer positions of the upper heater 20.

[0049] Furthermore, two mica holes 20a2 are formed in the vertical direction (front-to-back direction) near the center of the right end of the mica 20a, and two heater wires 20b pass through the mica holes 20a2. The two sets of heater wires 20b2 are extended and connected to the terminal portion 24 so that multiple heater wires overlap each other, and the two sets of heater wires 20b2 are connected to the terminals 24a of the terminal portion 24 with multiple heater wires overlapping each other.

[0050] With this configuration, the temperature at the left and right ends of the upper heater 20 can be prevented from dropping too much, so the temperature rise of the heating chamber upper plate 10 can be made as uniform as possible, and the heating chamber 4 In plan view, heating can be performed from the vicinity of the center of the heating chamber 4 to the edge of the heating chamber 4, so that, for example, when heating two slices of bread side by side in the heating chamber 4, the bread can be heated sufficiently all the way to the edge.

[0051] 6(b), another mica 20a1 is placed on the bottom layer of the upper heater 20 on the rear side (heating chamber 4 side) of the upper heater 20, near the mica holes 20a2 and the two sets of heater wires 20b2. This mica 20a1 prevents the temperature from rising too high near the two sets of heater wires 20b2, each of which has two heater wires overlapping each other. This makes it possible to ensure that the temperature rise in the heating chamber upper plate 10 is as uniform as possible.

[0052] As shown in Figures 5 and 6, the upper insulating material 22 and the lower insulating material 23 that sandwich the upper heater 20 each have openings 22b, 23b formed therein into which the pressure plate engaging portion 10c provided on the heating chamber upper plate 10 mentioned above is inserted.

[0053] [First insulation material] As shown in Figure 4, a first insulating material 13 is disposed so as to cover the heater 11. The first insulating material 13 has the function of blocking heat from the upper surface of the heater 11, and is formed of, for example, glass wool. The first insulating material 13 has a shape that can cover at least the entire heat generating region 10a of the heating chamber upper plate 10, has a substantially uniform thickness, and has elasticity (restoring force) at least in the thickness direction.

[0054] 4, multiple openings are formed in the first insulating material 13. The opening formed in the center of the first insulating material 13 is a locking portion opening 13a that houses the presser plate locking portion 10c that protrudes from the heating chamber upper plate 10. The first insulating material 13 also includes a terminal opening 13c through which the heater wire of the heater 11 passes.

[0055] [Pressure plate] As shown in Figure 4, the pressing plate 14 attached to the heating chamber upper plate 10 is formed with a curved area 14a having a curved surface similar to the heat generating area 10a formed with a curved surface on the heating chamber upper plate 10. The pressing plate 14 has the function of pressing the heater 11 against the heat generating area 10a of the heating chamber upper plate 10 via the first insulating material 13, and the entire surface of the heater 11 is tightly attached to the heat generating area 10a without any gaps.

[0056] Corresponding to the heating chamber upper plate 10 in FIG. 4, the horizontal cross section of the curved region 14a of the pressure plate 14 is substantially curved. Similarly, the vertical cross section of the curved region 14a of the pressure plate 14 is also substantially curved. Therefore, the curved region 14a of the pressure plate 14 has a three-dimensional curved surface with a concave surface on the heating chamber side (lower side). In this embodiment, the curvature of the horizontal curve of the curved region 14a is different from the curvature of the vertical curve of the curved region 14a, and the horizontal curvature is smaller than the vertical curvature. The curvatures of the horizontal and vertical curves may be approximately the same. As described above, the curved region 14a of the pressure plate 14 has a curve similar to that of the heat generation region 10a of the heating chamber upper plate 10.

[0057] As shown in Fig. 4, the presser plate 14 is provided with a terminal mounting portion 14e and a heater temperature detection portion 18. The heater temperature detection portion 18 is a portion that detects the temperature of an area that is directly heated by heat from the heater 11. A terminal portion 24 having terminals for the upper heater 20 of the heater 11 is mounted on the terminal mounting portion 14e. Each terminal 24a of the terminal portion 24 is connected to a power supply portion that is driven and controlled by a control portion of a control board in the cooking appliance.

[0058] The heater temperature detection unit 18 is disposed in a heating area (heating space) that is directly heated by the heater 11. In this embodiment, the heating area (heating space) is formed directly above the upper heater 20 of the heater 11, and is directly heated by the upper heater 20. The heater temperature detection unit 18 detects the temperature of the heating area that is directly heated by the upper heater 20, and therefore the control unit controls the driving of the heat sources of the various cooking means used in the cooking appliance, such as the heater 11, based on this heater temperature information and on internal temperature information from the internal temperature detection unit 9 that detects the temperature inside the heating chamber 4.

[0059] [Heating control] In the cooking device of this embodiment, a microwave heating unit is provided as another cooking means in addition to the planar heater unit 8 configured as described above. The microwave heating unit includes a magnetron that generates microwaves and radiates the microwaves generated by the magnetron from an antenna via a waveguide. The antenna that radiates microwaves to the heating chamber 4 is disposed below the bottom wall of the heating chamber 4 and is configured to radiate microwaves such as circularly polarized waves from below toward the heating chamber 4. The antenna is configured to radiate directional microwaves, and can be rotated to uniformly heat the interior of the heating chamber 4.

[0060] Other cooking means in the cooker of this embodiment may include a steam heating unit that intensively injects steam into the heating chamber to cook food, and a hot air circulation unit that circulates hot air inside the heating chamber 4 to cook food. The steam heating unit has a water tank inside the main body 1, and is configured to intensively inject steam generated by heating water from the water tank to a high temperature with a boiler steam heater into the heating chamber 4. The hot air circulation unit is configured to heat air sucked from the heating chamber 4 with a rear heater provided on the rear side of the heating chamber 4, and supply hot air into the heating chamber 4.

[0061] As described above, the cooking means in the cooker of this embodiment are the flat heater unit 8, microwave heating unit, steam heating unit, and hot air circulation unit, and each cooking means is selected according to the cooking contents, and in some cases, multiple cooking times are driven and controlled simultaneously or in combination. Note that in this embodiment, the heating control by the flat heater unit 8 will be mainly described.

[0062] The detection end of heater temperature detection unit 18 is disposed in the heating region (heating space) that is directly heated by upper heater 20 of heater 11. Heater temperature detection unit 18 detects the temperature of the space that is directly heated by upper heater 20 and transmits the detected temperature as heater temperature information to the control unit of the control board (see FIG. 8). The control unit controls the heat source and drive source for the heating cooking operation according to the cooking content set by the user, based on the heater temperature information as well as internal temperature information from internal temperature detection unit 9 that detects the internal temperature of heating chamber 4.

[0063] In this embodiment, the heater temperature detection unit 18 is configured to detect the temperature of the heating region (heating space) that is directly heated by the upper heater 20, and therefore the control unit can control the temperature in the heating cooking operation by the upper heater 20 based on highly accurate heater temperature information from the heater temperature detection unit 18. In this embodiment, as will be described later, a speed heating operation is performed in which the upper heater 20, which has a large heater output, rapidly raises the temperature of the heating chamber 4, and therefore the heater temperature information is effective in this speed heating operation.

[0064] In conventional cooking appliances, the flat heater is turned on and off based on the detected temperature inside the cooking cabinet so that the temperature inside the cooking cabinet reaches the set temperature. The heater was initially turned off, and then the on / off operation of the flat heater was repeated to gradually bring the temperature inside the cabinet closer to the set temperature. Therefore, it was difficult to accurately adjust the temperature inside the cabinet to the set temperature using the flat heater, and it took time to reach the set temperature.

[0065] In the cooking device of this embodiment, the control unit controls the temperature during cooking based on heater temperature information and chamber temperature information from the heater temperature detection unit 18. In particular, in a speed heating operation in which the temperature of the heating chamber 4 is rapidly increased to reach the set temperature in a short time, the control operation is performed based on heater temperature information indicating the temperature of the heating region heated by the upper heater 20. This allows the control unit to rapidly increase the temperature of the heating region heated by the upper heater 20 to the set temperature, making it possible to rapidly increase the chamber temperature of the heating chamber 4.

[0066] As will be described later, the upper heater 20 in this embodiment is configured to be able to control the input current to a desired value and set the heater output to a desired value. Therefore, after the internal temperature reaches the set temperature, the control unit controls the input current to the upper heater 20 based on the internal temperature information and the heater temperature information, thereby enabling the internal temperature to be maintained at the set temperature with high precision. As a result, the cooking appliance of this embodiment can significantly reduce the time it takes for the internal temperature to reach the set temperature and can accurately maintain the internal temperature at the set temperature for a predetermined period of time.

[0067] [Cooking operation] FIG. 7 is a perspective view of the cooking device of this embodiment with the door and the bottom wall of the heating chamber removed.

[0068] Fig. 8 is an example of a circuit diagram for controlling the cooking means in the cooker of this embodiment. The heat sources in the cooking means in the cooker of this embodiment include upper heater 20 in flat heater unit 8 and lower heater 21 installed in the lower part of heating chamber 4, and a magnetron in the microwave heating unit (see Fig. 8).

[0069] As shown in the circuit diagram of Fig. 8, the upper heater 20 and the lower heater 21 are connected to switching elements so that they can be controlled to be on or off. They are also connected to an inverter board (inverter circuit) as a driving power source for a magnetron, which is a microwave generating means in the microwave heating unit. In this embodiment, a triac may be used as a switching element to control the driving of the upper heater 20, and a configuration may be provided in which the current input to the upper heater 20 can be steplessly variably controlled to a desired value.

[0070] The lower heater 21 also uses a relay as a switching element that simply switches on and off. Note that, although the lower heater 21 in this embodiment is described as using a relay as a switching element that simply switches on and off, it may also be configured to be able to steplessly variably control the input power by using a triac as a switching element, as with the upper heater 20.

[0071] Cooking appliances have a predetermined rated power, and power above that rated power cannot be used. The cooking appliance of this embodiment is configured to be capable of cooking using multiple cooking means, and the control unit controls the power consumption of activated heat sources, etc. to always be within the rated power. In particular, the flat heater unit 8 in the cooking appliance of this embodiment is subjected to distinctive control.

[0072] In this embodiment, the maximum heater output of the upper heater 20 is, for example, 900 W. The maximum heater output of the lower heater 21 is, for example, 700 W. Therefore, the total maximum heater output of the upper heater 20 and the lower heater 21 exceeds the rated power (1500 W = 15 A (rated current) × 100 V) in a typical home. In the cooking device of this embodiment, as shown in FIG. 8, if the upper heater 20 has a configuration in which it is driven and controlled by a triac as a switching element, the upper heater 20 can be driven at a heater output that can be steplessly varied within a range of 300 to 900 W by a control signal input to the triac.

[0073] Hereinafter, a specific cooking operation using the cooking means in the cooking device of the present embodiment will be described with reference to examples.

[0074] When using only the flat heater unit 8 to heat and cook the heating chamber 4 with almost the entire ceiling wall as a heating element, for example, the upper heater 20 can be controlled to operate at a heater output of 700 W and the lower heater 21 can be turned on to provide a heater output of 700 W, thereby heating the heating chamber 4 with a total heater output of 1400 W.

[0075] When using the flat heater unit 8 and the microwave heating unit to heat and cook the heating chamber 4 with microwaves from the ceiling wall and the underside of the bottom wall, for example, the upper heater 20 is set to a maximum heater output of 900 W, the lower heater 21 is set to an off state (0 W), and the heating chamber 4 is heated from above with a total heater output of 900 W as heater 11. On the other hand, in a microwave heating unit used as another heating cooking means, the magnetron or the like can use a power consumption of, for example, 450 W to heat the heating plate 6 stored in the heating chamber 4, and food placed on the heating plate 6 can be cooked.

[0076] As another example, food placed on the heating tray 6 can be cooked with the lower heater 21 in the off state (0 W), the upper heater 20 at a heater output of 430 W, and 550 W consumed by the magnetron and other components of the microwave heating unit. As described above, even when cooking using the flat heater unit 8 and the microwave heating unit, the desired cooking operation can be performed with power consumption equal to or less than the rated power for a typical household (1500 W = 15 A (rated current) × 100 V).

[0077] On the other hand, in the configuration of this embodiment, microwaves (circularly polarized waves) can be radiated intensively from the antenna of the microwave heating unit from below the heating chamber 4 toward the center of the heating chamber 4. Inside the heating chamber 4, a heating plate 6 is stored on which food to be heated is placed, and a heating element that absorbs microwaves and generates heat is embedded in the placement surface 33 of this heating plate 6.

[0078] As a result, the food on the placing surface of the heating plate 6 is heated from below by the heating plate 6 heated by the heating element in the microwave heating unit, and the ceiling wall is heated by the flat heater unit 8, and this heat radiation is received from above and heated intensively. In other words, the heating cooker of this embodiment is configured to be able to rapidly heat the food on the heating plate 6 stored in the heating chamber 4 to high temperatures from above and below.

[0079] As described above, the cooking device of this embodiment is configured to be able to perform cooking efficiently within the rated power using at least a flat heater as a cooking means. The cooking device of this embodiment is configured to be able to rapidly heat the interior of the heating chamber to a desired high heat output by using multiple power devices whose total power consumption exceeds the rated power, thereby performing cooking quickly.

[0080] In addition, the cooking device of this embodiment can quickly raise the temperature inside the cooking chamber. At the same time, the cooking chamber temperature (the temperature of the upper plate of the heating chamber) can be maintained at a constant temperature. The cooking device of this embodiment can accurately set the cooking chamber temperature (the temperature of the upper plate of the heating chamber) to a set temperature, and can shorten the time it takes for the cooking chamber temperature to reach the set temperature, so it is configured to achieve a reduction in cooking time. [Industrial Applicability]

[0081] The cooking device of the present invention can prevent overheating near the terminals of the heater as much as possible and can ensure uniform temperature rise in the upper plate of the heating chamber as much as possible, making it a cooking appliance with high market value. [Explanation of symbols]

[0082] 1 Main unit 2 doors 3 handle 4 Heating cabinet 5. Settings 6 Heating Plate 8 Flat Heater Unit 9. Temperature detection unit inside the cabinet 10 Heating chamber top plate (ceiling wall) 10a Heat generation area 10b Honeycomb region 10c Presser plate locking part 11 Heater 13 First insulation material 14 Presser plate 15 Insulation sheet 16 Heat shield 18 Heater temperature detector (thermistor) 20 Upper heater 21 Lower heater 20a Mica 20a1 Another Mica 20a2 Mica hole 20b, 20b1, 20b2 heater wire 22 Upper insulation 23 Lower insulation 24 Terminal section 24a terminal

Claims

1. A cooking device comprising a heating chamber for heating food to be cooked and a heater configured as a heat source by a heater disposed on a ceiling wall of the heating chamber, The heater is made of mica with a heater wire wound around it. The heater has a terminal portion located outside the mica, and a terminal connected to the heater wire is provided on the terminal portion. A cooking device in which another mica is placed on top of the mica in a position adjacent to the heater wire extending from the mica to the terminal portion.

2. 2. The cooking device according to claim 1, wherein a heater wire extends from a surface of the mica to a terminal portion, and the other mica is disposed on a back surface of the mica so as to overlap the other mica.

3. 3. The cooking device according to claim 1, wherein the heater wires are extended from holes formed in the mica to the terminal portion in a state where a plurality of the heater wires are overlapped.

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