JP5725985B2 - Cooking plate - Google Patents

Description

  The present invention relates to a cooking utensil provided with a lava plate and heated by a gas stove or an IH (Induction Heating) cooker.

  Meat, vegetables, etc. baked on the lava plate are heated while leaving moisture in the contents due to the effect of far infrared rays. For this reason, it is known that the umami component is not missed and is baked more deliciously than the one baked on the iron plate. As such a lava plate for cooking, for example, the one described in Japanese Utility Model Publication No. 63-147137 (Patent Document 1) is known. The lava plate described in Patent Document 1 is obtained by cutting porous lava into a plate having a predetermined shape suitable for a grilled meat plate. Then, food such as meat and vegetables is placed on the upper surface, and the lower surface is heated by a gas fire.

  In addition, when the lava plate is heated with an IH cooker that is becoming popular in general households in recent years, the lower surface of the lava plate cannot be directly heated like a gas fire. Japanese Unexamined Patent Publication No. 2009-189724 (Patent Document 2) describes forming a heat generation layer by plating on the lower surface of a stone-fired plate.

Japanese Utility Model Publication No. 63-147137 JP 2009-189724 A

  The lava plate of Patent Document 1 generally has a thickness of 20 to 30 mm, but cannot be formed thin by reducing the thickness further. The reason for this is that the lava plate contains communicating bubbles, and if the lower surface of the lava plate is exposed to a gas fire, the oil content of food accumulated in the bubbles may ignite.

  Furthermore, since the lava rock is a porous rock, its strength is weaker than that of the iron plate, and cracking and chipping occur upon impact. Since the lava plate of patent document 1 is carried independently and mounted on the gas stove, it is easy to receive an impact. For this reason, the lava plate of patent document 1 needs to ensure sufficient thickness so that it may not be easily cracked or chipped. If it does so, it will take time until the upper surface of a lava plate with a large thickness reaches the predetermined temperature suitable for yakiniku, and meat cannot be baked quickly.

  In addition, when the lava plate of Patent Document 1 is heated with an IH cooker, the lower surface of the lava plate cannot be directly heated like a gas fire, and a heating element (ferromagnetic material) such as an iron plate is placed on the top plate of the IH cooker. Body) and a lava plate must be placed on this heating element. And it is desirable to use the lava plate mounted on a base plate made of iron or the like for the purpose of solving the above-mentioned problems of cracking and chipping and making the lava plate thinner than before, even in a gas fire. .

  In the stone-fired plate described in Patent Document 2, since the heat generating layer is exposed by plating, the heat generating layer is worn and damaged. Further, since the porous stone-fired plate is carried and placed on the top plate of the IH cooker, it is necessary to increase the thickness so that the stone-fired plate does not break or chip. Then, it takes time to heat the upper surface of the stone grill plate. Furthermore, all the holes on the lower surface of the stone-fired plate are blocked by plating, which causes problems during cooking and cleaning. Furthermore, there is a concern that cracking or chipping may occur due to a temperature difference due to the difference in the coefficient of linear expansion between the plated heat generating layer and the stone plate portion of the stone baking plate.

  However, in the configuration in which a single lava plate is placed on the top surface of the iron plate and heated, the problems described below still occur. That is, the iron plate is warped and deformed by heating, and the central portion of the lava plate is lifted and the peripheral portion is lifted from the iron plate.

  This phenomenon will be described in detail. FIG. 11 is a cross-sectional view showing a state in which a flat iron plate B is laid on the top plate C of the IH cooker and a conventional flat lava plate A is placed on the iron plate B. At room temperature, the lower surface of the lava plate A is in surface contact with the upper surface of the iron plate B. 12 is a cross-sectional view showing a state where the iron plate of FIG. 11 is heated. It can be seen that the periphery of the lava plate A is lifted from the iron plate B by electromagnetic induction heating, and a gap D is generated. For this reason, lava plates were struck while cooking meat and vegetables with chopsticks, making it unusable.

  In addition, since a gap was formed between the peripheral edge of the lava plate and the iron plate during cooking, heat conduction from the iron plate to the lava plate was not successful. For this reason, there existed a problem that the temperature of the lava plate upper surface was insufficient, or it took too much time until the lava plate was heated. FIG. 13 shows a change in temperature of the conventional configuration shown in FIGS. 11 and 12, in which an iron plate (a disc having a thickness of 2 mm and a diameter of 200 mm) is placed on the top plate, and a lava plate (thickness) is placed on the upper surface of the iron plate. It is a graph which shows a temperature change when putting 12 mm and a square of length and width 250mm) and carrying out electromagnetic induction heating.

  The temperature of the lava plate upper surface central portion a was 30 ° C. at the start of heating. At this time, the center of the lower surface of the lava plate was in contact with the center of the upper surface of the iron plate (FIG. 11). The temperature reached 150 ° C. after about 10 minutes from the start of heating by electromagnetic induction heating, and reached 172 ° C. after about 15 minutes from the start of heating. At this time, the center part of the lower surface of the lava plate was in contact with the center part of the upper surface of the iron plate (FIG. 12).

  The temperature of the lava plate upper surface peripheral edge b was 30 ° C. at the start of heating. At this time, the peripheral part of the lower surface of the lava plate was in contact with the peripheral part of the iron plate (FIG. 11). Then, due to electromagnetic induction heating, the temperature reached 119 ° C. after about 10 minutes from the start of heating, and reached 125 ° C. after about 15 minutes from the start of heating. At this time, a gap was generated between the lower surface periphery of the lava plate and the upper surface periphery of the iron plate (FIG. 12). At this time, the gap between the lava plate periphery and the iron plate periphery was 3 mm at the maximum.

  As is clear from FIG. 13, in the configuration in which the lava plate is placed on the upper surface of the iron plate, the temperature on the upper surface of the lava plate is only 172 ° C., so the temperature required for cooking cannot be reached, the temperature rise is slow, and the thermal efficiency is poor. Moreover, the temperature difference between the lava plate upper surface central portion a and the lava plate upper surface peripheral edge b is 53 ° C. after about 15 minutes from the start of heating, and the temperature difference is large. For this reason, the temperature on the upper surface of the lava plate was uneven. Although the case of electromagnetic induction heating has been described so far, it is considered that the same problem occurs in a gas fire.

  In view of the above circumstances, a first object of the present invention is to provide a cooking plate for an IH cooker that can stably support a lava plate during heating. It is a second object of the present invention to provide a cooking plate for an IH cooker that can efficiently heat a lava plate from below during cooking. Moreover, a third object is to shorten the heating time until the upper surface of the lava plate rises to a predetermined temperature.

  For this purpose, the cooking plate according to the present invention comprises a base plate and a lava plate placed on the upper surface of the base plate and whose lower surface is in contact with the peripheral edge of the upper surface of the base plate. A gap is formed between the base plate, the base plate is deformed by heating, and the gap is closed at a predetermined temperature.

  According to the present invention, since the peripheral portion of the upper surface of the base plate supports the lava plate at room temperature, the lava plate can be stably supported at room temperature. And since a clearance gap closes during a heating, the peripheral part and center part of a baseplate upper surface support a lava plate. Therefore, the lava plate can be stably supported even during heating. This prevents lava plates from rattling during use. Further, since the gap is closed at a predetermined temperature, the heat of the base plate is directly conducted to the lava plate. Therefore, the base plate peripheral portion and the central portion can efficiently heat the lava plate from below as a whole. Moreover, since the lava plate is supported by the base plate from the bottom, even if the thickness is made thinner than that of the conventional lava plate, the problem of strength, cracking and chipping hardly occur. And since the whole lower surface of the lava plate thinned receives the heat of a baseplate, the heating time until the upper surface of a lava plate rises to predetermined temperature can be shortened.

  The gap between the lava plate and the base plate can be realized by various embodiments. As one embodiment, both the lower surface of the lava plate or the upper surface of the base plate are recessed to form a recess. In another embodiment, one of the upper surface of the base plate and the lower surface of the lava plate is a flat surface, and the other has a recess in the center. Also, the lava plate and base plate cross-sectional shapes are not particularly limited. As a preferred embodiment, a recess is formed in the central portion of the upper surface of the base plate, and the lower surface of the lava plate is flat. According to such an embodiment, it is easy to form lava stone into a flat surface, and the manufacturing and processing efficiency is improved. In addition, although the recessed part here may be the circular arc recessed downward like the concave lens in the cross-sectional shape of a recessed part, it is preferable that the recessed part bottom face is flat. As a result, the base plate can be easily thermally deformed so that the bottom surface of the concave portion is lifted.

  The cooking plate of the present invention can exhibit the above-described effects in both a gas stove and an IH cooker. In one embodiment, the base plate has a heat generating layer that generates heat by electromagnetic induction heating. According to this embodiment, since the base plate has the heat generating layer, it can be used in the IH cooker even if the main body of the base plate is not a magnetic body.

  In order to protect the IH cooker from the high-temperature heat generating part, a heat insulating layer may be provided on the lower surface of the base plate. The material of the heat insulation layer is not limited to one embodiment. The heat insulating layer may be affixed and fixed to the lower surface of the base plate, or may be applied to the lower surface of the base plate in a fluid state and then cured. As a preferred embodiment, the base plate further includes a heat insulating layer including a resin and an inorganic hollow body below the heat generating layer. According to this embodiment, heat conduction below the heat generating layer is suppressed by the heat insulating layer, and the lava plate above the heat generating layer can be efficiently heated. Moreover, since the heat insulating layer contains a resin and an inorganic hollow body, the permeability of the magnetic field lines is good. Furthermore, since the heat insulating layer contains a resin, it adheres firmly to the mating surface.

  The main body of the base plate is preferably made of metal. As a more preferred embodiment, the base plate further includes a main body plate formed of aluminum or an aluminum alloy, provided with a concave portion at the center of the upper surface, and provided with a protrusion extending over the entire circumference on the lower surface, The lower surface of the main body plate is made of a ferromagnetic material sprayed on the region surrounded by the ridges, and the heat insulating layer is attached to the region surrounded by the ridges to cover the heat generating layer. According to this embodiment, since it has a main body plate formed of aluminum or an aluminum alloy, thermal conductivity and strength are improved, and it contributes to weight reduction of the cooking plate.

  Although the lower surface of the base plate may be flat, as a preferred embodiment, radially extending ridges are formed on the peripheral surface of the lower surface of the main body plate. Since aluminum and aluminum alloy are excellent in heat conduction, according to this embodiment, heat of the heat generating layer can be quickly conducted to the peripheral edge of the base plate. The number of ridges extending radially is not particularly limited.

  Generally, the thickness of the lava plate is not particularly limited, although the thickness of the lava plate increases as the planar dimension of the lava plate increases. In a preferred embodiment, the lava plate is 12 mm to 20 mm thick. According to this embodiment, since it is made thinner than the conventional lava plate which was 20-30 mm in thickness, it becomes possible to raise the upper surface of a lava plate more rapidly than before.

  Thus, the present invention can stably hold a lava plate not only in a non-heated state but also in a heated state. Further, the lava plate can be heated with high thermal efficiency. Furthermore, the heating time of the lava plate is shortened, and meat and vegetables can be baked efficiently.

It is a top view which shows the plate for cooking which becomes one Example of this invention. It is a front view which shows the plate for cooking used as the Example. It is a bottom view which shows the plate for cooking used as the Example. It is a side view which shows the plate for cooking used as the Example. It is sectional drawing which shows the plate for cooking in room temperature. It is sectional drawing which shows the plate for cooking heated to predetermined temperature. It is a graph which shows the temperature change of the plate for cooking used as the Example. It is sectional drawing which shows the plate for cooking used as the other Example of this invention. It is sectional drawing which shows the plate for cooking of the other Example heated to predetermined temperature. It is a graph which shows the temperature change of the plate for cooking used as another Example. It is sectional drawing which shows the state which mounted the conventional lava plate on the iron plate. It is sectional drawing which shows the state which the conventional lava plate floated from the iron plate during cooking. It is a graph which shows the temperature change of the lava plate of a conventional product.

  Hereinafter, embodiments of the present invention will be described in detail based on examples shown in the drawings.

  FIG. 1 is a plan view showing a cooking plate according to an embodiment of the present invention, in which the left half in the figure has a lava plate placed on the base plate, and the right half in the figure has the lava plate removed from the base plate. It is in the state. FIG. 2 is a front view showing a cooking plate according to the embodiment. FIG. 3 is a bottom view showing the cooking plate according to the embodiment. FIG. 4 is a side view showing a cooking plate according to the embodiment. FIG. 5 is a cross-sectional view showing the cooking plate according to the embodiment, and shows a state taken along the line V-V in FIG.

  The cooking plate 10 includes a base plate 11 and a lava plate 21 placed on the upper surface of the base plate 11, and is placed on the top plate of a domestic IH cooker and heated. The base plate 11 is square, and includes a main body plate 12 made of aluminum, a heat generating layer 13 provided on the lower surface of the main body plate, and a heat insulating layer 14 formed of a heat insulating material and covering the heat generating layer 13.

  The main body plate 12 is a square plate forming the main part of the base plate 11, and a pair of handles 15 projecting outward are formed on the left and right sides thereof. On the upper surface of the main body plate 12, a square frame enclosure 16 formed along the periphery, a periphery 17 formed inside the frame enclosure 16, and an annular formed further inside than the periphery Groove 18.

  The height position of the upper surface of the main body plate 12 is different in the frame surrounding portion 16, the peripheral edge portion 17, the annular groove 18, and the upper surface central portion 19 of the main body plate 12 surrounded by the annular groove 18. Specifically, it is formed highest at the frame surrounding portion 16, formed lower than the frame surrounding portion 16 at the peripheral edge portion 17, further formed lower than the peripheral edge portion 17 at the upper surface central portion 19, and lowest at the annular groove 18. It is formed. Thus, the upper surface of the base plate 11 has an upper surface central portion 19 that is a recess. As shown in FIG. 5, the recess is a recess having an upper surface central portion 19 as a flat bottom surface and an annular groove 18 as a side surface. The bottom surfaces of the peripheral edge portion 17 and the annular groove 18 are also flat.

  An annular ridge 31 and eight ridges 32 extending radially from the ridge 31 to the periphery of the body plate are formed on the lower surface of the body plate 12. In plan view, the ridge 31 is formed along the annular groove 18, and the width of the ridge 31 is larger than the groove width of the annular groove 18.

  The central portion of the lower surface of the main body plate 12 surrounded by the protrusions 31 is subjected to a ground treatment so as to follow the deformation of the main body plate, and then a ferromagnetic material (iron) is sprayed thereon, and the heat generating layer 13 is provided. The heat generating layer 13 generates heat by electromagnetic induction heating. The thickness of the heat generating layer 13 may be constant, but it is preferable that the center of the heat generating layer 13 is thinner than the peripheral edge in order to realize the deformation appropriately.

  The ridges 32 serve to quickly diffuse the heat of the heat generating layer 13. It also serves to suppress deformation of the peripheral edge of the base plate. By providing the radial protrusions 32, the thickness of the central portion of the main body plate 12 is smaller than the thickness of the peripheral edge portion. That is, the thickness of the base plate 11 is large at the peripheral portion and small at the central portion. The annular groove 18 and the protrusion 31 that coincide in plan view serve as a boundary between the base plate central portion and the base plate peripheral portion.

  From the viewpoint of suitably realizing the deformation, it is preferable that the thickness of the base plate 11 is small. In the present embodiment, it is preferable that the thickness of the central portion of the main body plate is 3 to 5 mm. More preferably, the thickness of the peripheral edge of the main body plate is 6 to 10 mm.

  Thus, the warp deformation of the center portion of the base plate which is changed from the state of FIG. 5 to the state of FIG. It is thought that it will be realized.

  The heat insulation layer 14 provided in the lower surface center part surrounded by the endless protrusion 31 extended over the whole periphery is provided in the lower surface of the heat generating layer 13, and is formed so that it may swell slightly below the protrusion 31. . The material of the heat insulation layer 14 includes a thermoplastic resin or thermosetting resin that is an organic compound, and an inorganic hollow body (foamed perlite) that is an inorganic compound.

  Thermoplastic resins include, for example, acrylic resin (PMMA), polyamide (PA), polybutylene terephthalate (PBT), fluororesin (PTFE) / polyimide (PI), polyetherimide (PEI), polysulfone (PSU), polyetherether Ketone (PEEK), polyphenylene sulfide (PPS), polyethersulfone (PES), polysulfone (PSF), liquid crystal polymer (LCP), or a mixture thereof.

  Thermosetting resins include, for example, silicone resin (SI), modified silicone resin (MS), phenol resin (PF), melamine resin (MF), urea resin (UF), epoxy resin (EP), unsaturated polyester resin (UP ), Or a mixture thereof.

  The inorganic hollow body is a porous solid particle, and includes bubbles and is lightweight. Moreover, since it is an inorganic compound, it is nonflammable and resistant to heat.

  The resin has a lower thermal conductivity than the metal, and the inorganic hollow body contains bubbles, so that the thermal conductivity is low. Thus, the heat insulating layer 14 of this embodiment is excellent in heat insulating performance. The heat insulating layer 14 does not hinder the transmission of magnetic lines of force, adheres firmly to the lower surface of the heat generating layer 13, and deforms following the thermal deformation of the main body plate 12. Further, the heat insulating layer 14 covers and protects the heat generating layer 13.

  The lava plate 21 is a square flat plate cut out from natural lava stone, and the upper and lower surfaces thereof are flat surfaces and contain a large number of bubbles. And it receives heat from the base plate 11 and is heated to a temperature required for cooking such as yakiniku. When the cooking plate 10 is at room temperature, the lower surface of the lava plate 21 comes into contact with the peripheral edge 17 of the base plate 11, but a gap 22 is formed between the upper surface central portion 19 of the base plate 11 and the lower surface of the lava plate 21. In addition, room temperature here means 0 degreeC-40 degreeC. It should be understood that the temperature of the base plate 11 and the lava plate 21 is 0 ° C. to 40 ° C., and there is a gap between the base plate upper surface central portion 19 and the lava plate lower surface central portion.

  In this embodiment, a lava plate 21 is cut out from a lava stone produced from Sakurajima, Kagoshima Prefecture. The lava rocks from Sakurajima are black, more porous than the lava rocks from Mt. Fuji and contain many bubbles that communicate with each other. The lava stones from Sakurajima have a large bubble communication rate. Therefore, the excess oil content of meat can be absorbed well. The lava plate 21 is formed to a thickness of 8 mm to 18 mm. As shown in FIG. 1, the frame surrounding portion 16 has substantially the same size and shape as the outer periphery of the lava plate 21, and the lava plate 21 is positioned on the upper surface of the base plate 11 by the frame surrounding portion 16. Alternatively, as a modification, the lava plate 21 may be made of Mt. Fuji lava stone or other volcanic lava stone.

  Next, the usage state of the cooking plate 10 will be described.

  At room temperature, the lower peripheral edge of the lava plate 21 contacts the peripheral edge 17 of the upper surface of the base plate 11 as shown in FIG. 5, so that the lava plate 21 is stably held by the base plate 11.

  The cooking plate 10 is placed on a top plate of an IH cooker (not shown), and the heat generating layer 13 generates heat by electromagnetic induction heating. Then, the aluminum body plate 12 is quickly heated to a predetermined temperature, while the heat insulating layer 14 suppresses heat transfer from the heat generating layer 13 to the lower side (top plate side).

  The heat insulating layer 14 protects the top plate of the IH cooker from becoming high temperature, and the main body plate 12 efficiently heats the lava plate 21.

  The base plate 11 brought to a predetermined temperature is warped and deformed so that the center part is lifted more than the peripheral part. If it does so, the upper surface center part 19 will contact the lower surface of the lava plate 21, and the clearance gap 22 will close. Thereby, heat conduction is efficiently performed from the main body plate 12 to the lava plate 21. At this time, since the peripheral edge portion 17 remains in contact with the lower surface of the lava plate 21, the peripheral edge portion and the central portion of the lava plate 21 are entirely heated. In addition, during heating, the lower peripheral edge of the lava plate 21 contacts the peripheral edge 17 on the upper surface of the base plate 11 at a plurality of locations as shown in FIG. 6, so that the lava plate 21 is stably held by the base plate 11.

  The cooking plate of this example was placed on the top plate of the IH cooker and heated, and the temperature of each part was measured. The used cooking plate is a square having a thickness of 11 mm at the peripheral edge of the main body plate (including the protrusion 32), a thickness of 4 mm at the central portion of the main body plate, and a length of 290 mm. FIG. 7: is a graph which shows the temperature change of each part in the plate for a cooking of a present Example, and the temperature change of the peripheral part B of the upper surface of the lava plate 100mm away from this center part A and the center part A of the lava plate upper surface. Show.

  The temperature of the lava plate upper surface central portion a was 28 ° C. at the start of heating. At this time, the gap between the lava plate lower surface center and the main body plate upper surface center was 3 mm. The temperature reached 180 ° C. after about 10 minutes from the start of heating by electromagnetic induction heating, and reached 220 ° C. after about 15 minutes from the start of heating. At this time, the gap between the lava plate lower surface center and the main body plate upper surface center was closed.

  The temperature of the lava plate upper surface periphery b was 28 ° C. at the start of heating. At this time, the lower peripheral edge of the lava plate was in contact with the upper peripheral edge of the main body plate. Then, due to electromagnetic induction heating, the temperature reached 140 ° C. after about 10 minutes from the start of heating, and reached 180 ° C. after about 15 minutes from the start of heating. Also at this time, the lower peripheral edge of the lava plate was in contact with the upper peripheral edge of the main body plate. The temperature difference between the lava plate upper surface central portion a and the lava plate upper surface peripheral portion b was 40 ° C. after about 15 minutes had elapsed since the start of heating.

  The temperature of the central portion 19 of the upper surface of the base plate reaches a predetermined temperature after 10 to 15 minutes have elapsed from the start of heating. This predetermined temperature is a temperature at which the upper surface central portion of the lava plate 21 reaches 170 to 220 ° C. suitable for cooking such as grilled meat, and is considered to be a higher temperature (250 to 340 ° C.) at the upper central portion of the base plate. In addition, the temperature rise per unit time in a present Example is influenced by the output of an IH cooker, and is not limited to this experimental result.

  Thus, according to the present Example, it turned out that the temperature of the upper-surface center part of a lava plate can be raised to 220 degreeC in 15 minutes. As is clear from the comparison with the conventional configuration shown in FIG. 13 that is heated at the same output using the same IH cooker as in this example, according to this example shown in FIG. It reaches the temperature required for cooking in a short time. And the temperature difference of the center part a and the peripheral part b is less than the conventional structure shown in FIG. 13, and there is little temperature nonuniformity of the lava plate upper surface. And since it has the heat insulation layer 14, thermal efficiency is good.

  Further, according to the present embodiment, the lava plate 21 is always supported by the base plate 11 while the cooking plate 10 is carried, placed on the top plate, or electromagnetically heated, so that the conventional lava plate is used. Strength, cracks, and chips are less likely to occur. Therefore, thickness can be made smaller than the conventional lava plate.

  On the upper surface of the lava plate 21, an object to be cooked such as meat and vegetables is placed. The lava plate 21 directly cooks the food to be cooked by heat conduction and generates far infrared rays so as to cook the food so as not to damage the umami component. Furthermore, the communication bubbles contained in the lava plate 21 absorb excess oil from the object to be cooked.

  In addition, the protrusion 16e is formed in the outer periphery of the frame surrounding part 16 over the perimeter. Even when the juice of the cooking object overflows from the lava plate 21, the juice is dammed by the ridges 16e. Therefore, it is possible to prevent the top plate from being soiled.

  Next, another embodiment of the present invention will be described. FIG. 8 is a sectional view showing a cooking plate according to another embodiment of the present invention. FIG. 9 is a sectional view showing a cooking plate according to another embodiment heated to a predetermined temperature. Portions common to the above-described embodiment are denoted by the same reference numerals and description thereof is omitted. In addition, FIG. 1 should be applied mutatis mutandis for the plan view of another embodiment, FIG. 2 for the front view, and FIG. 4 for the side view.

  The cooking plate 40 according to another embodiment includes a base plate 41 and a lava plate that is placed on the upper surface of the base plate 41 and whose lower surface is in contact with the peripheral edge 17 of the upper surface of the base plate 41.

  The base plate 41 is an iron magnetic body and generates heat by electromagnetic induction heating. Or it is heated from below with a gas fire. A plurality of protrusions 43 are formed on the peripheral edge of the lower surface of the base plate 41 at equal intervals in the circumferential direction. And there is no protrusion on the lower surface of the base plate. Although the base plate 41 does not have a heat insulating layer, the protrusion 43 comes into contact with the top plate of the IH cooker, so that most of the lower surface of the top plate 41 does not contact the top plate and a gap is formed. This gap plays a role of heat insulation and suppresses heat of the base plate 41 from being conducted to the top plate. The protrusion 43 may be formed of a material having a lower thermal conductivity than iron, such as the same material as the heat insulating layer 14 of the first embodiment described above.

  As shown in FIG. 8, a gap 22 is formed between the central portion 19 of the upper surface of the base plate 41 and the lower surface of the lava plate 21 at room temperature.

  The base plate 41 is deformed by heating, and is warped and deformed so that the central portion 19 is lifted as shown in FIG. When the base plate 41 reaches a predetermined temperature, the gap 22 is closed. This predetermined temperature is a temperature when the central portion of the upper surface of the lava plate 21 is 170 to 220 degrees which is a cooking temperature range such as yakiniku, and the temperature of the central portion of the upper surface of the base plate is further 80 to 120 than the central portion of the upper surface of the lava plate. It is considered high temperature.

  FIG. 10 is a graph showing the temperature change of the cooking plate according to another embodiment. The temperature of the lava plate upper surface central portion a was 28 ° C. at the start of heating. At this time, the gap between the lava plate lower surface center and the main body plate upper surface center was 3 mm. The temperature reached 170 ° C. after about 10 minutes from the start of heating by electromagnetic induction heating, and reached 208 ° C. after about 15 minutes from the start of heating. At this time, the gap between the lava plate lower surface center and the main body plate upper surface center was closed.

  The temperature of the lava plate upper surface periphery b was 28 ° C. at the start of heating. At this time, the lower peripheral edge of the lava plate was in contact with the upper peripheral edge of the main body plate. Then, due to electromagnetic induction heating, the temperature reached 105 ° C. after about 10 minutes from the start of heating, and reached 140 ° C. after about 15 minutes from the start of heating. Also at this time, the lower peripheral edge of the lava plate was in contact with the upper peripheral edge of the main body plate. The temperature difference between the lava plate upper surface central portion a and the lava plate upper surface peripheral edge b was 68 ° C. after about 15 minutes had elapsed since the start of heating.

  As is apparent when referring to FIG. 10 in comparison with FIG. 13, also in the other embodiments shown in FIGS. 8 and 9, the base plate 41 is warped and deformed by heating, and the peripheral portion of the upper surface of the base plate and the center of the upper surface of the base plate 41. Since the part 19 contacts, the lava plate 21 can be efficiently heated as a whole.

  Although the embodiments of the present invention have been described 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 embodiment within the same range or equivalent range as the present invention. For example, the main body plate 12 and the lava plate 21 are not limited to a square but may be other polygons.

  The cooking plate according to the present invention is advantageously used in cooking utensils heated by gas stoves and IH cookers.

  DESCRIPTION OF SYMBOLS 10 Cooking plate, 11 Base plate, 12 Main body plate, 13 Heat generation layer, 14 Heat insulation layer, 15 Handle, 16 Frame enclosure part, 17 Peripheral part, 18 Annular groove, 19 Upper surface center part, 21 Lava plate, 22 Gap, 31 , 32 ridges, 40 cooking plate, 41 base plate, 43 protrusions.

Claims (7)

A base plate;
A lava plate placed on the upper surface of the base plate and having a lower surface in contact with the peripheral edge of the upper surface of the base plate;
A gap is formed between the center of the upper surface of the base plate and the lower surface of the lava plate at room temperature,
The cooking plate is configured such that the base plate is deformed by heating and the gap is closed at a predetermined temperature.   The cooking plate according to claim 1, wherein a concave portion is formed at a central portion of the upper surface of the base plate, and a lower surface of the lava plate is a flat surface.   The cooking plate according to claim 1, wherein the base plate has a heat generating layer that generates heat by electromagnetic induction heating.   The cooking plate according to claim 3, wherein the base plate further includes a heat insulating layer including a resin and an inorganic hollow body below the heat generating layer. The base plate is made of aluminum or an aluminum alloy, and further includes a main body plate provided with the concave portion at the center of the upper surface and provided with a protrusion extending over the entire circumference on the lower surface,
The heat generating layer is made of a ferromagnetic material sprayed on a region surrounded by the protrusions on the lower surface of the main body plate,
The cooking plate according to claim 4, wherein the heat insulating layer is attached to a region surrounded by the protrusions and covers the heat generating layer.   The cooking plate according to claim 5, wherein radially extending protrusions are formed on a peripheral edge of the lower surface of the main body plate. The said lava plate is a plate for cooking in any one of Claims 1-6 which is 12 mm-20 mm in thickness.

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