Heating and heat-retaining device

Abstract

To provide a heat-retaining device that retains heat of a cooking container that is not compatible with IH more effectively than the prior art and that is further reduced in weight compared with the prior art.SOLUTION: A heating and heat-retaining device 10 includes a heat-generating member 20 corresponding to a plate-shaped portion having an upper surface 21 and a lower surface 22 and containing graphite as a main component, an outer heat-insulating layer 30 that covers an outer edge 23 of the heat-generating member 20, and a lower heat-insulating layer 40 that covers the lower surface 22, where a plate thickness from the lower surface 22 to the upper surface 21 is greater than a layer thickness of the outer heat-insulating layer 30 in an inward-outward direction and greater than a layer thickness of the lower heat-insulating layer 40 in an up-down direction, and the heating and heat-retaining device heats and / or retains heat of a cooking container such as an earthenware pot or an aluminum cooking container placed on the upper surface 21.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a heating and warming device that stores heat by receiving electromagnetic induction. [Background technology]

[0002] Known examples of electromagnetic induction heating appliances include the structures described in Japanese Patent No. 4827447 (Patent Document 1) and Japanese Patent No. 5964629 (Patent Document 2). The structures described in these patent documents include an iron plate on which food is placed and an iron heat storage member that contacts the underside of the bottom wall of the plate. The heat storage member is disk-shaped with a through-hole in the center when viewed vertically, exposing the bottom surface of the plate through this through-hole. As a result, magnetic field lines generated by an electromagnetic induction heating (IH) cooking device pass through the through-hole, causing the plate to be electromagnetically heated. The heat storage member is also electromagnetically heated. Furthermore, the heat storage member prevents the plate from cooling down after electromagnetic induction heating. This allows food on the plate to be kept warm without increasing the plate's thermal capacity, and allows the plate to be made lighter. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 4827447 [Patent Document 2] Patent No. 5964629 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the inventors have discovered that the above-described conventional structure requires further improvement. Specifically, the heat storage member is made of iron, leaving room for improvement in terms of weight reduction. Furthermore, because iron heat storage members block magnetic field lines, a large-diameter through-hole is formed in the center of the heat storage member to allow the magnetic field lines to reach the iron plate placed above the heat storage member. As a result, the heat storage member does not have sufficient thermal capacity, and the plate does not retain heat for long enough. Furthermore, if the plate placed above the heat storage member is made of a material other than iron, such as ceramic or aluminum, it is difficult to heat the food inside the plate.

[0005] In view of the above-mentioned circumstances, the present invention aims to provide a structure that has sufficient heat storage performance without sacrificing weight reduction, can heat pots and frying pans made of materials other than iron to the temperature required for cooking, and can keep plates and pots with food served on them warm for a longer period of time than conventional structures. [Means for solving the problem]

[0006] For this purpose, the heating and keeping warmer according to the present invention comprises a plate-shaped portion having upper and lower surfaces and made primarily of graphite (conductive graphite), an outer insulating layer covering the outer edge of the plate-shaped portion, and a lower insulating layer covering the lower surface of the plate-shaped portion, the thickness of the plate-shaped portion from the lower surface to the upper surface being greater than the thickness of the outer insulating layer in the inward and outward directions and the thickness of the lower insulating layer in the upward and downward directions, and heats and / or keeps warm a cooking container placed on the upper surface side of the plate-shaped portion.

[0007] According to the present invention, the plate-shaped portion is primarily composed of lightweight, high-heat-capacity graphite, allowing for greater heat storage than conventional methods while avoiding weight gain. The outer edge of the plate-shaped portion is covered with an outer insulating layer, and the underside of the plate-shaped portion is covered with a lower insulating layer. This allows for extended heating of cooking vessels, such as pots and steak plates, placed on the upper surface of the plate-shaped portion. The plate thickness from the lower surface to the upper surface need only be greater than the thickness of the outer insulating layer in the inward-outward direction and greater than the thickness of the lower insulating layer in the upward-downward direction. The thickness of the lower insulating layer in the upward-downward direction is designed so that the conductive plate-shaped portion is placed over the electromagnetic induction heating device. These insulating layers covering the plate-shaped portion may directly contact the surface of the plate-shaped portion, or a gap, such as a spacer, may be provided between the plate-shaped portion and the insulating layer. These insulating layers may cover the entire side and underside of the plate-shaped portion, or may leave portions of the side and underside of the plate-shaped portion uncovered. The plate-shaped portion may be made solely of a plate material primarily composed of graphite, or may be a combination of a thick plate material primarily composed of graphite and a thin plate material primarily composed of another material. The shape of the plate-shaped portion should correspond to the planar shape of the cooking vessel or the planar shape of the coil of the electromagnetic induction heating device. Since the planar shapes of the cooking vessel and the coil are generally perfect circles, the plate-shaped portion should also be perfect circles. Alternatively, the plate-shaped portion may be a shape other than a perfect circle, such as an ellipse like a steak plate or an approximately polygonal shape.

[0008] In a preferred aspect of the present invention, the heating and warming device further includes a support plate that supports the lower insulating layer from below. According to this aspect, by holding the support plate, the user can quickly and easily move the plate-shaped portion without touching the hot plate-shaped portion, thereby improving convenience.

[0009] The backing plate need only be generally plate-shaped, and the shape and thickness are not limited. In a preferred aspect of the present invention, the backing plate has a bottom wall portion that supports the lower insulation layer from below, and a side wall portion that stands on the outer edge of the bottom wall portion and contacts the outer insulation layer. According to this aspect, the outer insulation layer is covered by the side wall portion, and the lower insulation layer is covered by the bottom wall portion, thereby improving the insulation performance of the heating / heating device. The strength of the heating / heating device is also improved. The side wall portion of the backing plate preferably covers at least a portion of the outside of the outer insulation layer, and more preferably covers the entire outside of the outer insulation layer. The bottom wall portion of the backing plate preferably covers at least a portion of the underside of the lower insulation layer, and more preferably covers the entire underside of the lower insulation layer.

[0010] In a further preferred aspect of the present invention, the upper surface of the bottom wall portion is formed with a convex portion that contacts and supports the lower insulating layer, and a concave portion that is spaced apart from the lower insulating layer. According to this aspect, even if distortion occurs in the backing plate, such as when the bottom wall portion warps due to use of the heating insulator, the distortion can be absorbed by the concave portion. Therefore, the backing plate can stably support the lower insulating layer and the plate-shaped portion. The shape of the concave portion as viewed from above is not particularly limited. For example, the concave portion may be annular, concentric with the center of the backing plate 50.

[0011] In one aspect of the present invention, the heating warmer further includes a handle supporting the outer insulating layer or the lower insulating layer. According to this aspect, a user can hold the handle to move the cooking container together with the heating warmer without touching the cooking container. The shape and attachment location of the handle are not particularly limited. The handle is preferably provided on the backing plate. Alternatively, the handle is provided on the outer insulating layer or the lower insulating layer.

[0012] In one aspect of the present invention, the bottom wall has an annular flat surface formed in the outer peripheral region of its lower surface, and a ridge protruding downward from the flat surface in the central region of the lower surface of the bottom wall. According to this aspect, the flat surface recessed from the ridge and the ridge protruding from the flat surface on the lower surface of the backing plate form a two-planar step. Therefore, the backing plate can be stably supported from below by a tray having a protrusion of the same height as this step.

[0013] The material of the outer insulation layer and the material of the lower insulation layer are not particularly limited and may be the same or different. The outer insulation layer and the lower insulation layer may be one layer or two or more layers. In one aspect of the present invention, the lower insulation layer is a plate material containing mica as a main component. According to this aspect, the lower insulation layer can be made of a hard plate material, and the plate-shaped portion can be stably supported from below.

[0014] In one aspect of the present invention, the outer insulating layer is an insulating material made of silica (Si)-based fibers. According to this aspect, the outer insulating layer can be made of soft fibrous material, making it difficult for heat from the plate-shaped portion to be transmitted to the outside beyond the outer insulating layer. The silica (Si)-based fibers are not particularly limited as long as they are non-flammable. Examples of silica (Si)-based fibers include glass wool, rock wool, asbestos, and other mineral fibers.

[0015] In one aspect of the present invention, the backing plate further includes a protrusion projecting upward from the side wall. This configuration restricts the horizontal position of the cooking container to the inside of the protrusion, preventing the cooking container from sliding outward beyond the protrusion. The user's fingers are also restricted to the outside of the protrusion. Therefore, the protrusion separates the fingers from the hot cooking container, preventing burns to the fingers.

[0016] There are a wide variety of electromagnetic induction heating devices, including some that use a sensor to detect aluminum or copper cooking vessels and stop electromagnetic induction heating. In another aspect of the present invention, the plate-shaped portion includes a first circular plate primarily made of graphite and a second circular plate made of a ferromagnetic material that is thinner than the first circular plate and overlaps the first circular plate. According to this aspect, the sensor in the electromagnetic induction heating device detects the second circular plate and does not detect cooking vessels above the heating and warming device. This allows aluminum or copper cooking vessels to be heated or kept warm.

[0017] The material of the lower insulating layer is not particularly limited. In one aspect of the present invention, the lower insulating layer includes a plate material mainly composed of heat-resistant glass. According to this aspect, the durability of the lower insulating layer is improved.

[0018] The number of the lower insulation layers is not particularly limited. In a preferred aspect of the present invention, the lower insulation layer further includes a plate material containing mica as a main component. According to this aspect, the insulation performance is further improved.

[0019] In a further preferred aspect of the present invention, the mica-based plate is disposed in a recessed area formed in the bottom plate portion of the receiving plate, and the heat-resistant glass-based plate covers the recessed area and seals the mica-based plate. According to this aspect, the mica-based plate is covered with waterproof heat-resistant glass. This makes the present invention washable with water.

[0020] The structure of the lower insulation layer is not limited to a plate material. In one aspect of the present invention, the lower insulation layer further includes an air layer formed below the plate material. According to this aspect, the heat insulating properties of the air keep the plate-shaped portion warm, and the heat of the plate-shaped portion is less likely to be transmitted to the bottom wall portion of the support plate below.

[0021] In order to keep the plate-shaped portion warm and to make it difficult for the heat of the plate-shaped portion to be conducted to the bottom wall portion of the support plate below, it is preferable that the heat rays radiated downward from the plate-shaped portion be reflected upward. In a further preferred aspect of the present invention, a coating film containing a heat ray reflecting material is formed on the upper surface of the plate material included in the lower insulation layer. Note that the coating film is not heated by electromagnetic induction. The coating film is, for example, a layer containing aluminum particles and having a thickness of 10 μm or less. In another aspect of the present invention, the plate material does not have a coating film.

[0022] The backing plate has side walls surrounding the plate-shaped portion and the lower insulating layer, but does not necessarily have a bottom wall. In one aspect of the present invention, a frame-shaped backing plate is provided to support the plate-shaped portion, and the lower insulating layer is disposed within a central opening of the backing plate.

[0023] In a preferred aspect of the present invention, the lower insulating layer is separated from the plate-shaped portion and the backing plate, and the separated lower insulating layer can be used in an electromagnetic induction heating device while the plate-shaped portion and the backing plate are placed on a dining table.

[0024] The structure of the lower insulation layer is not particularly limited, but in a preferred aspect of the present invention, the lower insulation layer includes a rigid upper plate, a rigid lower plate, and a soft insulation material sandwiched between the upper plate and the lower plate, which can improve the structural strength and thermal insulation performance of the lower insulation layer.

[0025] In a more preferred aspect of the present invention, the lower plate is larger than the central opening of the backing plate, so that the lower plate protrudes from the backing plate, making it possible to confirm from the outside of the backing plate that the lower insulating layer is set in the central opening of the backing plate. [Effects of the Invention]

[0026] As described above, the present invention provides a plate-shaped portion that is lighter than conventional plates. It also allows a greater amount of heat to be stored in the plate-shaped portion than conventional plates to keep a cooking vessel warm. Furthermore, magnetic field lines for electromagnetic induction heating can penetrate the plate-shaped portion and reach an iron cooking vessel placed on top of the plate-shaped portion. Furthermore, the heating and warming device of the present invention can heat cooking vessels made of materials other than iron that are not susceptible to electromagnetic induction heating. Furthermore, the heating and warming device of the present invention can keep a cooking vessel placed on top of the plate-shaped portion warm for a while even when the cooking vessel is moved to a dining table that is not subject to electromagnetic induction heating, thereby maintaining the sizzle of the food served in the cooking vessel. [Brief explanation of the drawings]

[0027] [Figure 1] 1 is an overall schematic view showing a heating and warming device according to a first embodiment of the present invention. [Figure 2] FIG. [Figure 3] FIG. [Figure 4]FIG. [Figure 5] FIG. 4 is a plan view showing a heating warmer according to a second embodiment of the present invention. [Figure 6] FIG. 6 is a cross-sectional view showing the embodiment shown in FIG. [Figure 7] FIG. 10 is a plan view showing the second lower insulating layer. [Figure 8] FIG. 10 is a cross-sectional view showing a heating warmer according to a third embodiment of the present invention. [Figure 9] FIG. 10 is a cross-sectional view showing a heating warmer according to a fourth embodiment of the present invention. [Figure 10] FIG. 10 is a perspective view showing a heating warmer according to a fifth embodiment of the present invention. [Figure 11] FIG. 10 is a cross-sectional view showing a heating warmer according to a fifth embodiment of the present invention. [Figure 12] 11 is a perspective view showing a heating warmer which is a modified example of the embodiment shown in FIG. [Figure 13] 12 is a cross-sectional view showing a heating warmer according to a modified example of the embodiment shown in FIG. [Figure 14] FIG. 10 is a graph showing test results (time-temperature) for an example corresponding to the fifth embodiment of the present invention. [Figure 15] FIG. 10 is a perspective view showing a heating warmer according to a sixth embodiment of the present invention. [Figure 16] FIG. 10 is a plan view showing a heating warmer according to a sixth embodiment of the present invention. [Figure 17] FIG. 10 is a cross-sectional view showing a heating warmer according to a sixth embodiment of the present invention. [Figure 18] FIG. 10 is an exploded perspective view showing a heating warmer according to a sixth embodiment of the present invention. [Figure 19] FIG. 13 is a perspective view showing a state in which the backing plate of the sixth embodiment is lifted from the top plate of the electromagnetic induction heating device. DETAILED DESCRIPTION OF THE INVENTION

[0028] Embodiments of the present invention will be described in detail below with reference to the drawings. Fig. 1 is an overall schematic diagram showing a heating and warming device according to a first embodiment of the present invention. Fig. 2 is an exploded perspective view showing the same embodiment. Fig. 3 is a plan view showing the same embodiment. Fig. 4 is a cross-sectional view showing the same embodiment, taken along the cross section indicated by IV-IV in Fig. 3, and viewed in the direction of the arrow. The heating and warming device 10 of this embodiment comprises a heat-generating member 20, an outer insulating layer 30, a lower insulating layer 40, and a backing plate 50. The heat-generating member 20, the lower insulating layer 40, and the backing plate 50 are plate-shaped members, and are stacked vertically in the order shown.

[0029] The heat-generating member 20 is a plate-shaped portion primarily composed of graphite. It not only allows electricity to flow through it, but also allows magnetic lines of force to pass through it. Graphite differs from iron in that iron blocks magnetic lines of force (magnetic lines of force tend to follow the iron). In this embodiment, the heat-generating member 20 is a disk. However, as a modification (not shown), the heat-generating member 20 may be polygonal, such as a square or hexagon. The plate thickness of the heat-generating member 20 is greater than the plate thicknesses of the lower insulating layer 40 and the backing plate 50, for example, 3 mm or more, preferably 5 mm or more, more preferably 10 mm or more, and for example, 30 mm or less, preferably 25 mm or less, more preferably 20 mm or less. This allows the heat-generating member 20 to retain heat more slowly once it reaches a high temperature. A cooking vessel 100, such as a pot or frying pan, is placed on the upper surface 21 of the heat-generating member 20. The lower surface of the cooking vessel 100 is preferably flat, so that it comes into direct surface contact with the upper surface 21 .

[0030] The dimensions of the heat generating member 20 are not particularly limited, but it is preferable that the heat generating member 20 be the same size as or slightly smaller than the bottom surface of the cooking vessel 100. This allows the high-temperature heat generating member 20 to be covered by the cooking vessel 100 and not exposed, preventing burns due to user error.

[0031] The outer insulating layer 30 is, for example, ring-shaped and continuously covers the outer edge 23 of the heat-generating component 20. Alternatively, as a variant not shown, the outer insulating layer 30 discontinuously covers the outer edge 23 of the heat-generating component 20. As a variant not shown, the outer insulating layer 30 may have through-holes extending radially of the heat-generating component 20, or radial or vertical recesses or notches, exposing a portion of the outer edge 23. The outer insulating layer 30 is, for example, a felt-like non-combustible material made of silica (Si)-based (including glass-based) fibers, and has thermal insulation, elasticity, and deformability. The upper edge 31 of the outer insulating layer 30 is approximately flush with the upper surface 21 of the heat-generating component 20 or protrudes above the upper surface 21 of the heat-generating component 20. The lower edge 32 of the outer insulating layer 30 contacts the outer edge of the lower insulating layer 40. As a result, the outer edge 23 of the heat-generating component 20 is covered by the outer insulating layer 30 from the upper surface 21 to the lower surface 22.

[0032] The lower insulating layer 40 is a non-combustible plate material whose main component is mica and has insulating properties. The lower insulating layer 40 is harder than the fibrous outer insulating layer 30. In this embodiment, the lower insulating layer 40 is a circular plate that is larger than the heat-generating component 20 and covers the entire lower surface 22 of the heat-generating component 20 that is placed directly above the lower insulating layer 40. Alternatively, as a modified example not shown, the lower insulating layer 40 may have through holes extending in the plate thickness direction, or recesses or notches in the plate thickness direction, so that a portion of the lower surface 22 is exposed.

[0033] The outer edge of the lower insulation layer 40 supports the lower edge 32 of the outer insulation layer 30 from below. The thickness of the lower insulation layer 40 is smaller than the thickness of the heat-generating member 20 and the thickness of the bottom wall portion 51, and is preferably in the range of 2 to 9 mm, and more preferably in the range of 4 to 6 mm.

[0034] The backing plate 50 is a plate-shaped member that houses the heat-generating member 20, the outer insulating layer 30, and the lower insulating layer 40 in its center, and has a bottom wall 51, side walls 52, and a handle 53. The bottom wall 51 is a circular plate that occupies most of the backing plate 50 and covers the entire underside of the lower insulating layer 40. Although not shown, as a modification of this embodiment, a portion of the bottom wall 51 may be cut out, and the lower insulating layer 40 may be exposed through the cutout. A recess 55 is formed in the central region of the underside 54 of the bottom wall 51. The recess 55 separates the central region of the backing plate 50 from the top plate 201 (Figure 1) of the electromagnetic induction heating device 200, and the outer edge of the backing plate 50 is stably supported by the top plate 201.

[0035] The side wall portion 52 is integrally formed with the outer edge portion of the bottom wall portion 51 and protrudes upward from the bottom wall portion 51. The upper edge 52b of the side wall portion 52 protrudes upward above the upper surface 21 of the heat-generating member 20. The upper edge 52b is either at approximately the same height as the upper edge 31 of the outer insulating layer 30 or protrudes upward above the upper edge 31. In this embodiment, the side wall portion 52 is an annular wall erected on the bottom wall portion 51. The side wall portion 52 covers the entire outside of the outer insulating layer 30. Although not shown, as a modification of this embodiment, a portion of the side wall portion 52 may be cut out, and the outer insulating layer 30 may be exposed through the cutout. It should be noted here that the outer insulating layer 30 is packed more densely between the outer edge of the heat-generating member 20 and the side wall portion 52 than in its original state. Therefore, the horizontal movement of the heat-generating member 20 is restricted by the outer insulating layer 30.

[0036] The handles 53 are formed integrally with the side wall 52 and protrude radially outward from the side wall 52. In this embodiment, two handles 53 are provided as a pair, spaced 180° apart in the circumferential direction of the side wall 52. Alternatively, as a modified example not shown, the handles may be separate members that extend elongatedly in a semicircular arc shape or the like, and the ends of the handles are each connected to the receiving plate 50.

[0037] In this embodiment, the backing plate 50, i.e., the bottom wall portion 51 and the side wall portion 52, is made of wood. Wood has excellent heat insulating properties and is lightweight. Alternatively, the backing plate 50 may be made of heat-resistant ceramic or heat-resistant resin.

[0038] The method of use of this embodiment will now be described.

[0039] Referring to FIG. 1 , heating of the cooking container 100 will be described first. With the heating warmer 10 placed on the top plate 201 of the electromagnetic induction heating device 200, the power switch of the electromagnetic induction heating device 200 is turned on, and when the magnetic field lines of the electromagnetic induction heating device 200 penetrate the heat-generating member 20, the heat-generating member 20 is electromagnetically heated. The upper limit of this temperature (normal operating temperature) is usually 400°C, and 500°C to 600°C is temporarily acceptable. Because the heat-generating member 20 generates heat up to such a high temperature range, the cooking container 100 placed on top of the heat-generating member 20 is sufficiently heated, and the ingredients inside the cooking container 100 are cooked. According to this embodiment, the cooking container 100 can be heated even if it is made of a material that is not susceptible to electromagnetic induction heating, such as a clay pot or other ceramic material, aluminum, copper, or heat-resistant glass.

[0040] Unlike an iron plate, heat generating member 20, which is primarily made of graphite, does not prevent magnetic lines of force from penetrating. Therefore, when cooking vessel 100 is made of iron, electromagnetic induction heating device 200 can simultaneously electromagnetically heat both heat generating member 20 and cooking vessel 100 placed on top of heat generating member 20. This is because the magnetic lines of force from electromagnetic induction heating device 200 penetrate heat generating member 20 and reach cooking vessel 100.

[0041] Next, heat retention of the cooking vessel 100 will be described. As described above, the heat-generating member 20 stores heat and is surrounded by the entire outer edge 23 and the entire lower surface 22, making it difficult to cool down by the outer insulating layer 30 and the lower insulating layer 40. Therefore, even when the power switch of the electromagnetic induction heating device 200 is turned off, the magnetic field lines do not penetrate the heat-generating member 20, and the heat-generating member 20 stops generating heat, the heat-generating member 20 remains at a high temperature for a while. Therefore, the cooking vessel 100 placed on the upper surface 21 of the heat-generating member 20 is kept warm by the heat-generating member 20. The heat-retention effect of the heat-generating member 20 is significant because the heat-generating member 20 is solid and does not have any through holes. Furthermore, because the plate thickness of the heat-generating member 20 is greater than the thickness of the lower insulating layer 40 and the thickness of the bottom wall portion 51, the heat-retention effect of the heat-generating member 20 is further enhanced.

[0042] As such, the heat generating member 20 of this embodiment is a solid body without a through hole in the center, and has sufficient thickness, so it stores the amount of heat necessary to keep the food served in the cooking container 100 warm during mealtime.

[0043] Furthermore, since the heat generating member 20 of this embodiment is mainly composed of graphite, it emits far infrared rays defined as wavelengths in the range of 3 μm to 1000 μm at high temperatures, thereby accelerating the heating of the cooking vessel 100.

[0044] Furthermore, according to this embodiment, the support plate 50, which is more rigid than the lower insulating layer 40 and the heat-generating member 20, supports the lower insulating layer 40 and the heat-generating member 20 from below, not only improving the durability of the heating warmer 10, but also enabling the heating warmer 10 to be moved by holding the handle 53 shown in Figure 1, so that the cooking container 100, which has been cooked using the electromagnetic induction heating device 200, can be efficiently provided and served to the person eating the food.

[0045] The heating warmer 10 of this embodiment remains hot for a while even when it is moved from the electromagnetic induction heating device 200 to a dining table without heating equipment. Therefore, the food served in the cooking vessel 100 can maintain its sizzle for a while, providing a delightful experience to those eating the food.

[0046] Next, a second embodiment of the present invention will be described. Figure 5 is a plan view of the second embodiment, showing the device placed on a horizontal tray. Figure 6 is a cross-sectional view of the same embodiment, taken along the line VI-VI in Figure 5 and viewed in the direction of the arrow. In other embodiments, components common to the previously described embodiments are designated by the same reference numerals and will not be described again. The following describes the differences. In the second embodiment, a heating and warming device 60 has a backing plate 50 with a flat annular surface 56 and a pedestal 57 formed on the lower surface 54. A recess 59 is formed on the upper surface 58 of the backing plate 50. The recess 59 in this embodiment is a wide circumferential groove concentric with the center of the backing plate 50. Therefore, a convex portion 58c is formed in the center of the upper surface 58, which is not the recess 59. The convex portion 58c contacts the lower insulation layer 40 with its flat top surface (upper surface 58) and supports the center of the lower insulation layer 40 from below. Furthermore, the protrusion 58c bears the weight of the cooking vessel 100 (FIG. 1), which is a heavy object, via the heat generating member 20.

[0047] Additionally, the outer edge 58b of the upper surface 58 other than the recess 59 supports the outer edge of the lower insulating layer 40 from below and bears the weight of the cooking vessel 100 (FIG. 1), which is a heavy object, via the heat-generating member 20. The recess 59 separated from the lower insulating layer 40 is covered by the lower insulating layer 40 from above, forming a gap that inhibits heat conduction from the heat-generating member 20 to the bottom wall 51, improving the insulating performance and protecting the bottom wall 51 from the high-temperature heat-generating member 20.

[0048] According to this embodiment, even if slight distortion occurs in the backing plate 50 during use, the recesses 59 absorb the distortion, and the lower heat insulating layer 40 and the heat generating member 20 are stably supported by the backing plate 50 .

[0049] A flat surface 56 included in the underside of the backing plate 50 is disposed in the outer edge region of the backing plate 50. A platform 57 is disposed in the central region of the backing plate 50 and protrudes from the flat surface 56. When the platform 57 is placed on a horizontal tray 300 or a horizontal top plate 201 (FIG. 1), the flat surface 56 is placed in a horizontal position. The platform 57 may be leg-shaped, like the legs of a tripod.

[0050] The outer diameter Dc of the pedestal 57 is in the range of 1 / 3 to 2 / 3 of the outer diameter Db of the flat surface 56, and preferably in the range of 2 / 5 to 3 / 5. This allows the backing plate 50 to be stably placed on the horizontal tray surface 301 or the top plate 201 (FIG. 1). Furthermore, a necessary and sufficient flat surface 56 can be secured.

[0051] The tray 300 has a tray surface 301 and an edge 302. The edge 302 is a protrusion that protrudes from the tray surface 301. As shown in FIG. 1 , a kitchen worker can hold the handle 53 and move the heating warmer 60 from the top plate 201 to the tray surface 301 while the cooking container 100 is placed on the heating warmer 60. The cooking container 100 with the food served on it, together with the heating warmer 60, is carried on the tray 300 to the dining table where the person who will eat the food is waiting. According to the embodiment shown in FIGS. 5 and 6 , the cooking container 100 that has been cooked using the electromagnetic induction heating device 200 can be quickly and easily provided to the person who will eat the food.

[0052] 6, the amount of protrusion [mm] of platform 57 as viewed from flat surface 56 corresponds to the amount of protrusion [mm] of edge 302 of tray 300 from tray surface 301. This allows heating warmer 60 to be supported and stabilized not only by tray surface 301 but also by edge 302. Edge 302 can engage with platform 57, restricting heating warmer 60 from sliding horizontally.

[0053] Next, a modified example of the embodiment shown in Figure 6 will be described. In Figure 6, a second lower insulating layer 70 is provided in the recess 59. Figure 7(a) is a plan view showing the lower insulating layer 70. The lower insulating layer 70 has a shape corresponding to the recess 59 and has, for example, an opening 71 in the center. The protrusion 58c passes through the opening 71. The lower insulating layer 70 is made of the same material as the outer insulating layer 30 described above. According to this modified example, heat conduction from the heat-generating component 20 to the bottom wall 51 is inhibited, thereby further improving the insulating performance and making it possible to protect the bottom wall 51, in particular, from the high-temperature heat-generating component 20.

[0054] As a further modification of the embodiment shown in Fig. 6, the protrusion 58c may be eliminated, the opening 71 in the lower insulating layer 70 may be eliminated, and the lower insulating layer 70 may be formed into a circular shape as shown in Fig. 7(b). The felt-like lower insulating layer 70 is packed more densely between the concave bottom surface of the recess 59 and the lower insulating layer 40 than in its original state. As a result, the weight of the cooking vessel 100 (Fig. 1) is supported by the outer edge 58b, as well as by the concave bottom surface of the recess 59 via the heat-generating member 20 and the lower insulating layers 40, 70.

[0055] Next, a third embodiment of the present invention will be described. Figure 8 is a cross-sectional view showing the third embodiment. In the third embodiment, components common to the previously described embodiments will be assigned the same reference numerals and explanations will be omitted, and only different components will be described below. A heating and warming device 80 of the third embodiment includes a backing plate 81. In addition to having a basic configuration common to the previously described backing plate 50, the backing plate 81 further includes a protrusion 82 provided on the side wall portion 52 and protruding upward.

[0056] The protrusion 82 is disposed on the outer diameter side of the side wall 52. In the embodiment shown in FIG. 8, the protrusion 82 is, for example, ring-shaped and is concentric with the side wall 52. The inner circumferential surface 83 of the protrusion 82 defines a space S in the center of the heating insulator 80. The space S is an opening that is larger than the heat-generating member 20 and the outer insulating layer 30.

[0057] As in the above-described embodiment, the height position of the handle 53 is approximately the same as the height position of the heat-generating member 20, or overlaps with the height position of the heat-generating member 20. Therefore, the protrusion 82 protrudes upward on the inner diameter side of the handle 53.

[0058] Regarding the handle 53, the upper surface 53b of the handle 53 is connected to the protrusion 82, and the lower surface 53c of the handle 53 is connected to the side wall 52. The protrusion 82 is located on the outer diameter side of the side wall 52. Therefore, with regard to the radial dimension of the heating warmer 80, the upper surface 53b of the handle 53 is relatively narrow, and the lower surface 53c is relatively wide. According to this embodiment, the user can firmly support the lower surface 53c of the handle 53 with their fingers, allowing the heating warmer 80 to be moved stably.

[0059] Protrusion 82 protrudes upward on the inner diameter side of upper surface 21. Therefore, the horizontal position of cooking vessel 100 (FIG. 1) placed on upper surface 21 is restricted to the inner diameter side of protrusion 82.

[0060] The heating and warming device 80 further includes a lower insulating layer 34. The lower insulating layer 34 is made of the same material as the outer insulating layer 30, continues from the lower end of the outer insulating layer 30, and covers the lower surface of the heat-generating member 20. The lower insulating layer 40 covers the lower surface of the lower insulating layer 34. The lower insulating layer 70 covers the lower surface of the lower insulating layer 40. In this embodiment, the lower insulating layers 34, 40, and 70 are arranged in layers in this order.

[0061] 8, when a user holds the handle 53 with his or her fingers, the position of the fingers is restricted to the outer diameter side of the protrusion 82. Therefore, the protrusion 82 separates the fingers from the high-temperature cooking vessel 100 (FIG. 1), preventing the fingers from being burned.

[0062] Next, a fourth embodiment of the present invention will be described. Figure 9 is a cross-sectional view showing the fourth embodiment stacked up. In the fourth embodiment, components common to the previous embodiments are given the same reference numerals and will not be described again, and only the different components will be described below. The heating and warming device 90 of the fourth embodiment has a backing plate 91 with a different shape from the backing plate 81 of the third embodiment. The backing plate 91 has an arc-shaped protrusion 82.

[0063] As shown in Figure 9, multiple heating warmers 90 can be stacked one on top of the other in the vertical direction. When stacked in this manner, the protruding portion 82 of the lower heating warmer 90 comes into contact with the flat surface 56 of the upper heating warmer 90, supporting it from below. Furthermore, because the protruding portion 82 stably supports the flat surface 56 from below, multiple heating warmers 90 can be aligned in the vertical direction.

[0064] When the heating warmers 90 are stacked, the platform 57 of the upper heating warmer 90 is stored in the space S partitioned by the protruding portion 82 of the lower heating warmer 90. The platform 57 of the upper heating warmer 90 is spaced upward from the heat-generating member 20 of the lower heating warmer 90. The height position of the platform 57 described above overlaps or is approximately the same as the height position of the protruding portion 82 described above.

[0065] According to the embodiment shown in Fig. 9, multiple heating warmers 90 can be stocked in a small kitchen. Furthermore, according to the embodiment shown in Fig. 9, even if the heat-generating member 20 has not completely cooled down or is still hot when the heating warmers 90 are stacked, the heat-generating member 20 does not come into contact with the base 57, so the base 57 can be protected from high temperatures. Furthermore, according to the embodiment shown in Fig. 9, the flat surface 56 is sufficiently wide, so that when multiple heating warmers 90 are stacked, any horizontal misalignment between the upper and lower heating warmers 90 can be absorbed. Therefore, multiple heating warmers 90 can be stacked quickly and easily.

[0066] Next, a fifth embodiment of the present invention will be described. FIG. 10 is a perspective view showing the fifth embodiment, with a portion shown as a broken surface for ease of understanding. FIG. 11 is a cross-sectional view showing a heating / warming device according to the fifth embodiment. In the fifth embodiment, components common to the previous embodiments are designated by the same reference numerals and will not be described again. The following describes the differences. The heating / warming device 110 of the fifth embodiment includes, from top to bottom, a first plate-shaped portion 120 primarily composed of graphite, a second plate-shaped portion 123 made of a ferromagnetic material, a glass plate 42, and two mica plates 44 and 46. The first plate-shaped portion 120, the second plate-shaped portion 123, the glass plate 42, and the two mica plates 44 and 46 are solid disks, not ring-shaped. The bottom wall portion 51 also has no openings. The lower second plate-shaped portion 123 is thinner than the upper first plate-shaped portion 120 and is made of, for example, iron, steel, or ferritic stainless steel. The thickness of the first plate-shaped portion 120 is within the range of 5.0 to 20.0 mm. In the embodiment shown in Fig. 10 of this embodiment, the thickness of the first plate-shaped portion 120 is 9 mm. The thickness of the second plate-shaped portion 123 is within the range of 1.0 to 3.0 mm. In this embodiment, the thickness of the second plate-shaped portion 123 is 1.5 mm.

[0067] The upper first plate-shaped portion 120 and the lower second plate-shaped portion 123 are connected in an overlapping state by connecting means of a bolt 111 and a tap screw drilled in the second plate-shaped portion 123. The bolt 111 is, for example, a slim-head screw with a head thinner than usual, and is positioned with the head facing upward. An annular recess 121b for accommodating the head of the bolt 111 is formed in the upper surface 121 of the first plate-shaped portion 120. The shank of the bolt 111 is inserted from above into a through-hole that penetrates the first plate-shaped portion 120 in the plate thickness direction. A male thread formed on the outer periphery of the shank of the bolt 111 is threaded into a tap screw 124 of the second plate-shaped portion 123. As a result, the bolt 111 does not protrude upward from the first plate-shaped portion 120 beyond the upper surface 121. The shank of the bolt 111 also does not protrude downward from the second plate-shaped portion 123 beyond the second plate-shaped portion 123. 10, the connecting means for the bolt 111 and the tap screw 124 are provided at the center of these plate-shaped portions, but the position, number, and structure of the connecting means are not limited to this. Preferably, combinations of the bolt 111 and the tap screw 124 are also provided at several locations on the periphery of these plate-shaped portions. Alternatively, as a modified example not shown, the first plate-shaped portion 120 and the second plate-shaped portion 123 do not have to be connected to each other, in which case the first plate-shaped portion 120 is placed on the upper surface of the second plate-shaped portion 123.

[0068] The outer periphery of the second plate-shaped portion 123 is supported from below by a protrusion 61 erected on the bottom wall portion 51 of the receiving plate 50. The protrusion 61 further supports the glass plate 42 and the mica plates 44, 46 at intervals in the vertical direction. The protrusion 61 also supports the first plate-shaped portion 120 and the cooking vessel 100 placed on the upper surface of the first plate-shaped portion 120.

[0069] Specifically, the protrusion 61 includes a metal bolt 67 with a head on the upper side, a nut 68 that screws onto the tip of the lower shank of the bolt 67, and washers 63, 64, 65, and 66 that are threaded between the head of the bolt 67 and the nut 68. The washers 63, 64, 65, and 66 are arranged in series in this order. A plurality of protrusions 61 are arranged at intervals around the circumferential direction of the backing plate 50; in this embodiment, three protrusions are arranged at equal intervals around the circumferential direction. The protrusion 61 is adjacent to the side wall 52 that extends in an arc shape. In this embodiment, a half-cylindrical recess 49 with an inner diameter slightly larger than the outer diameter of the washer 63 is formed on the inner diameter side of the side wall 52. The recess 49 accommodates one side portion of the protrusion 61.

[0070] The outer periphery of the second plate-shaped portion 123 is placed on the upper surface of a washer 63, which is a large-diameter ring plate. A small-diameter ring portion 62 is formed on the upper surface of the washer 63. The ring portion 62 surrounds the head of the bolt 67 and restricts the second plate-shaped portion 123 from moving radially outward from the center of the backing plate 50. The second plate-shaped portion 123 is positioned at the center of the backing plate 50 by each of the washers 63 on multiple protrusions 61 that are arranged at intervals around the circumferential direction of the backing plate 50. The lower washer 63 and the upper ring portion 62 are integrally joined to form a single member.

[0071] The first plate-shaped portion 120, the second plate-shaped portion 123, and the glass plate 42 are all circular and arranged concentrically. The first plate-shaped portion 120 and the second plate-shaped portion 123 have the same outer diameter, but the outer diameter of the glass plate 42 is larger than that of the second plate-shaped portion 123. This forms a gap (air layer Sb) as an outer insulating layer between the side wall portion 52 and the first plate-shaped portion 120 (and the second plate-shaped portion 123). The upper edge 52b of the side wall portion 52 and the inner wall surface are connected by a chamfer 39. The chamfer 39 is formed around the entire periphery of the side wall portion 52 and faces the outer circumferential surface of the cooking vessel 100.

[0072] The glass plate 42 and the mica plates 44, 46 are all circular and have the same outer diameter, and are arranged concentrically. A washer 63 is interposed between the adjacent second plate-shaped portion 123 and glass plate 42, thereby forming an air layer S1 between them. A washer 64 is interposed between the adjacent glass plate 42 and mica plate 44, thereby forming an air layer S2 between them. A washer 65 is interposed between the adjacent mica plate 44 and mica plate 46, thereby forming an air layer S3 between them. A washer 66 is interposed between the adjacent mica plate 45 and the plate-shaped bottom wall portion 51, thereby forming an air layer S4 between them. Thus, the glass plate 42 and the mica plates 44, 46 are sandwiched in series between the washers 63 to 66 and are connected and fixed to the backing plate 50 by tightening a nut 68. A bolt 67 is fixed in an upright position to the bottom wall portion 51. The nut 68 is housed in a recess 47 formed in the lower surface 48 of the bottom wall portion 51. This prevents the nut 68 from protruding from the lower surface of the bottom wall portion 51. The nut 68 is, for example, a woodworking insert nut, and is embedded in the wooden bottom wall portion 51.

[0073] Next, a method of using the warming device 110 according to the embodiment shown in FIGS. 10 and 11 will be described.

[0074] A cooking vessel 100 (FIG. 1) is placed on the upper surface 121 of the first plate-shaped portion 120. When the heating and warming device 110 is placed on the electromagnetic induction heating device 200 as shown in FIG. 1, the second plate-shaped portion 123 is heated by electromagnetic induction, and the first plate-shaped portion 120 stores the heat of the second plate-shaped portion 123, and further heats or keeps the cooking vessel 100 warm.

[0075] There are a wide variety of electromagnetic induction heating devices 200, including an electromagnetic induction heating device 200 that detects an aluminum or copper cooking vessel 100 with a sensor provided in the electromagnetic induction heating device 200 and automatically stops electromagnetic induction heating.

[0076] The heating and warming device 110 of the fifth embodiment includes a second plate-shaped portion 123 made of a ferromagnetic material, and therefore the magnetic field of the electromagnetic induction heating device 200 extending from below to above the heating and warming device 110 is blocked by the second plate-shaped portion 123. Furthermore, the sensor provided in the electromagnetic induction heating device 200 detects the presence of the second plate-shaped portion 123, but does not detect the cooking vessel 100 above the heating and warming device 110. Therefore, the heating and warming device 110 of the fifth embodiment can heat or keep warm cooking vessels 100 made of aluminum or copper.

[0077] It should be noted that at least one of the upper surfaces of the glass plate 42 and the mica plates 44 and 46 may be coated with a coating made of a heat-reflecting material. This reflects far infrared rays upward, improving the heat retention performance of the cooking container 100. The coating also prevents thermal radiation, such as far infrared rays, emitted by the first plate-shaped portion 120 and the second plate-shaped portion 123 from reaching the bottom wall portion 51 below. This prevents deterioration of the wooden backing plate 50 even if the temperatures of the first plate-shaped portion 120 and the second plate-shaped portion 123 are increased. The coating is, for example, a 5-20 μm thick coating of a binder containing aluminum particles. The thin film in this embodiment is 10 μm thick. Because this coating is extremely thin, it is not subject to electromagnetic induction heating.

[0078] The glass plate 42 is made of heat-resistant glass, which has a significantly lower coefficient of thermal expansion than metal and is therefore less susceptible to moisture degradation. For example, by appropriately selecting the outer diameter of the glass plate 42 and the inner diameter of the sidewall 52 so that the outer edge of the glass plate 42 contacts the sidewall 52, or by sealing the gap between the outer diameter of the glass plate 42 and the inner surface of the sidewall 52 with resin, the mica plates 44, 46 are isolated from the internal space enclosed by the sidewall 52. Because the glass plate 42 is moisture-tight, the mica plates 44, 46 are not submerged in water. This improves the durability of the backing plate 50 against water washing. The mica plates 44, 46 are thin plates formed by bonding mica flakes together with a heat-resistant binder. Therefore, the mica plates 44, 46 should be protected from submersion in water.

[0079] A heating test, a heat retention test, and a heat resistance test were conducted on an example of the heating and warming device 110 according to the fifth embodiment. A heat-reflecting coating was formed on the upper surfaces of the mica plates 44 and 46. Referring to FIG. 10, a thermocouple (hereinafter referred to as H1) was attached between the first plate-shaped portion 120 and the second plate-shaped portion 123. A thermocouple (hereinafter referred to as H2) was attached to the underside of the glass plate 42. A thermocouple (hereinafter referred to as H3) was attached to the upper surface of the bottom wall portion 51. A thermometer (hereinafter referred to as H4) for measuring the water temperature was installed in the water stored in the cooking vessel 100. With water at 25°C contained in the cooking vessel 100, the heating and warming device 110 was electromagnetically heated by the electromagnetic induction heating device 200 (FIG. 1), and heating was continued until the water temperature stabilized at 100°C. The output of the electromagnetic induction heating device 200 (FIG. 1) was set to 2000W. The electromagnetic induction heating was stopped when the water temperature stabilized at 100° C. The temperature measurement values ​​of H1 to H4 over time are plotted and shown in FIG.

[0080] Referring to Figure 14, H1 rose to a maximum of 428°C, while H3 was a maximum of 200°C. When the backing plate 50 was made of cedar board, the flash point of cedar board was 240°C, so it was confirmed that the heating property and heat resistance of the heating and warming device 110 were effective.

[0081] Furthermore, even after the electromagnetic induction heating was stopped, H4 maintained 100°C for a while. This confirmed the effectiveness of the heat retention properties of the heating warmer 110. Because the heating warmer 110 has excellent heat storage and heat retention properties, even if the heating warmer 110 is heated by the electromagnetic induction heating device 200 in the same manner as above, and then the heating warmer 110 is removed from the electromagnetic induction heating device 200, and a cooking container 100 whose contents have not yet boiled is placed on the heating warmer 110 and served at the table (even if it is in a state where it is not heated but is only kept warm), the contents of the cooking container 100 can be boiled later, allowing for a sizzling sensation at the table.

[0082] Next, a modified example of the fifth embodiment will be described. Fig. 12 is a perspective view showing a heating warmer of the modified example, with some parts omitted to show the interior of the heating warmer, and is shown in cross section. Fig. 13 is a cross section showing a heating warmer of the modified example. Differences in the configuration of the modified example can be understood by comparing it with the embodiment shown in Figs. 10 and 11. In the heating warmer 130 of the modified example, the graphite heat-generating member 20 is supported from below by the washer 63 of the protrusion 61 described above. In addition, the glass plate 42 and the bottom wall portion 51 of the backing plate 50 are adjacent to each other, and a gap (air layer S2) is formed between them. A gap (air layer S2) is formed between the glass plate 42 and the lower bottom wall portion 51.

[0083] 12 and 13 has an air layer Sb as an outer insulating layer, and a glass plate 42 and an air layer S2 as a lower insulating layer, thereby keeping the heat-generating member 20 as a plate-shaped part warm. In addition, because the glass plate 42 is water-resistant, the heating warmer 130 can be washed with water.

[0084] Next, a sixth embodiment of the present invention will be described. FIG. 15 is a perspective view of a heating warmer according to the sixth embodiment. FIG. 16 is a plan view of the sixth embodiment. FIG. 17 is a cross-sectional view of a heating warmer according to the sixth embodiment. FIG. 18 is an exploded perspective view of a heating warmer according to the sixth embodiment. In the sixth embodiment, components common to the previous embodiments are designated by the same reference numerals and will not be described again. The following describes the differences. The heating warmer 140 of the sixth embodiment includes a frame-shaped backing plate 141 and, stacked from top to bottom, a first plate-shaped portion 120 primarily made of graphite, a second plate-shaped portion 123 made of a ferromagnetic material, a heat-resistant glass plate 42, and a lower insulating layer 150 (described later). These laminated components are housed in a central opening 142 of the backing plate 141. In other words, the outer peripheries of these laminated components are surrounded by the backing plate 141.

[0085] 18, support portions 143 that protrude toward the inner diameter side are formed on the inner peripheral surface of the backing plate 141. A plurality of support portions 143 are arranged at intervals in the circumferential direction of the backing plate 141. The backing plate 141 of this embodiment has three support portions 143 that are arranged at equal intervals in the circumferential direction. A through hole 144 that extends vertically is formed in the support portion 143. A bolt 67 is inserted into the through hole 144 from above, and the lower end of the bolt 67 is screwed into a nut 68 below the support portion 143. As a result, the bolt 67 is fixed in an upright position on the support portion 143.

[0086] 17, the support portion 143 supports the bolt 67, the first plate-shaped portion 120, the second plate-shaped portion 123, and the glass plate 42. The support portion 143 further supports the cooking vessel 100 placed on the upper surface 121 of the first plate-shaped portion 120. In this manner, the assembly of the first plate-shaped portion 120, the second plate-shaped portion 123, the glass plate 42, and the backing plate 141 is grouped together. When a user of the heating warmer 140 lifts the handle 53 of the backing plate 141, this assembly 149 is separated from the lower insulating layer 150, as shown in FIG. 19. In other words, the lower insulating layer 150 is always separated from the assembly 149.

[0087] Referring to Figure 17, a lower insulating layer 150 is disposed below the glass plate 42. The lower insulating layer 150 includes an upper plate 151 and a lower plate 152, and an insulating material 153 sandwiched between these plates. The upper plate 151 and the lower plate 152 are made of a non-flammable, heat-resistant, hard material, such as mica plate. The insulating material 153 is made of a non-flammable, heat-resistant, soft material, and is made by forming inorganic fiber, such as silica (Si)-based fiber, into a disk shape. Soft materials have particularly excellent insulating properties.

[0088] The upper plate 151 and the heat insulating material 153 have a smaller diameter than the central opening 142 of the receiving plate 141 and are housed within the central opening 142. In contrast, the lower plate 152 is larger than the upper plate 151 and the heat insulating material 153 and is larger than the receiving plate 141. Therefore, as shown in FIG. 15 , the lower plate 152 protrudes from the receiving plate 141. With the heating and warming device 140 of the sixth embodiment, it is possible to visually confirm from the outside that the lower heat insulating layer 150 is set in the heating and warming device 140. The lower plate 152 of the sixth embodiment is oval, but may have another shape as a modified example (not shown). When the heating and warming device 140 is used by placing it on the top plate of an electromagnetic induction heating device, the thickness of the lower heat insulating layer 150 is in the range of 8 mm to 20 mm to ensure an appropriate distance from the top plate to the second plate-shaped portion 123.

[0089] The upper plate 151 and the outer edge of the heat insulating material 153 are formed with notches 154 to avoid the support portion 143. This prevents the support portion 143 and the nut 68 from interfering with the lower heat insulating layer 150.

[0090] A method of using the heating warmer 140 of the sixth embodiment will be described. As shown in FIG. 17, the heating warmer 140 is electromagnetically heated while placed on the top plate 201. The cooking container 100 is heated or kept warm by the heating warmer 140. FIG. 19 is a perspective view showing the backing plate of the sixth embodiment lifted from the top plate of the electromagnetic induction heating device. When eating, the assembly 149 is lifted and served together with the cooking container 100. At this time, the lower insulating layer 150 is left on the top plate 201. Then, for the next cooking, another assembly 149 is set on top of this lower insulating layer 150.

[0091] According to the sixth embodiment, the lower insulating layer 150 is not fixed to the assembly 149, and therefore the assembly 149 and the lower insulating layer 150 can be washed separately with water, and cleaning water does not get on the lower insulating layer 150. Furthermore, when the heating warmer 140 is subjected to electromagnetic induction heating, only the lower insulating layer 150 can be used continuously on the top plate of the electromagnetic induction heating device, while the assembly 149, which has heat retention properties, can be transported and served from the electromagnetic induction heating device to the dining table.

[0092] Although the present invention has been described above with reference to the drawings, the present invention is not limited to the illustrated embodiments. Various modifications and variations can be made to the illustrated embodiments within the scope of the present invention or within an equivalent scope. For example, some components may be extracted from one embodiment described above, and other components may be extracted from another embodiment described above, and these extracted components may be combined. While the backing plate 50 is preferably made of wood for aesthetic reasons and portability, it may alternatively be made of laminated bamboo lumber. Laminated wood is resistant to water, heat, impact, and deformation, and does not easily deform even when repeatedly washed with water.

[0093] As a modification of the above-described embodiment, the glass plate 42 can be replaced with a heat-resistant ceramic plate. Ceramic plates contain fine bubbles, which provides better heat insulation than heat-resistant glass plates. Furthermore, ceramic plates can be molded, which allows for efficient mass production and low cost. Furthermore, ceramic plates are made from china clay and have heat storage properties, improving the heat retention performance of the above-described embodiment. [Industrial Applicability]

[0094] The present invention is advantageously utilized in the food service industry and in cooking appliances. [Explanation of symbols]

[0095] 10 heating insulator, 20 heat generating element, 30 outer heat insulating layer, 40 lower insulating layer, 42 glass plate, 44, 45, 46 mica plate, 50 receiving plate, 51 bottom wall portion, 52 side wall portion, 53 handle, 120 first plate-shaped portion, 123 second plate-shaped portion, 149 assembly.

Claims

1. a plate-like portion having an upper surface and a lower surface and made primarily of graphite; an outer heat insulating layer covering the outer edge of the plate-shaped portion and a lower heat insulating layer covering the lower surface, The plate thickness from the lower surface to the upper surface is greater than the thickness of the outer insulating layer in the inward / outward direction and the thickness of the lower insulating layer in the upward / downward direction, A heating and warming device that heats and / or keeps warm a cooking container placed on the upper surface side.

2. The heating warmer according to claim 1 , further comprising a backing plate for supporting the lower insulating layer.

3. 3. The heating and warming device according to claim 2, wherein the support plate has a bottom wall portion that supports the lower insulation layer from below, and a side wall portion that stands on the outer edge of the bottom wall portion and contacts the outer insulation layer.

4. 4. The heating warmer according to claim 3, wherein the upper surface of the bottom wall is formed with a convex portion that contacts and supports the lower insulating layer, and a concave portion that is spaced apart from the lower insulating layer.

5. The heating warmer of claim 1 , further comprising a handle for supporting the outer insulating layer or the lower insulating layer.

6. 4. The heating and warming device according to claim 3, wherein an annular flat surface is formed in the outer peripheral region of the lower surface of the bottom wall portion, and a pedestal protruding downward from the flat surface is formed in the central region of the lower surface of the bottom wall portion.

7. The heating and warming device according to claim 1 , wherein the lower insulating layer is a plate material containing mica as a main component.

8. 2. The heating and warming device according to claim 1, wherein the outer insulating layer is an insulating material made of silica (Si)-based fibers.

9. 7. The heating warmer according to claim 3, wherein the support plate further has a protrusion protruding upward from the side wall.

10. The heating and warming device according to any one of claims 1 to 3 and 5 to 8, wherein the plate-shaped portion includes a first circular plate portion mainly composed of graphite, and a second circular plate portion made of a ferromagnetic material and having a thickness thinner than the first circular plate portion and arranged so as to overlap the first circular plate portion.

11. The heating and warming device according to claim 2 , wherein the lower insulating layer includes a plate material mainly composed of heat-resistant glass or a ceramic plate.

12. The heating warmer according to claim 11, wherein the lower insulating layer further includes a plate material containing mica as a main component.

13. the plate material containing mica as a main component is disposed in a recessed region formed in a bottom plate portion of the support plate, The heating warmer according to claim 12, wherein the plate material mainly made of heat-resistant glass covers the recessed region and seals the plate material mainly made of mica.

14. The heating warmer according to claim 11, wherein the lower insulating layer further includes an air layer formed below the plate material.

15. The heating warmer according to claim 11 or 12, wherein a coating film containing a heat ray reflecting material is formed on an upper surface of the plate material.

16. a frame-shaped receiving plate for supporting the plate-shaped portion; The heating warmer according to claim 1 , wherein the lower insulating layer is disposed within a central opening of the backing plate.

17. The heating warmer according to claim 16, wherein the lower insulating layer is separated from the plate-shaped portion and the backing plate.

18. 17. The heating warmer of claim 16, wherein the lower insulating layer includes a rigid upper plate, a rigid lower plate, and a soft insulating material sandwiched between the upper and lower plates.

19. 19. The heating warmer of claim 18, wherein the bottom plate is larger than the central opening.

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