JP2010246591A - Inner pot for electromagnetic induction heating electric rice cooker - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To increase the strength of coating of fluorine resin on the inner pot of an electromagnetic induction heating electric rice cooker which prevents sticking or burning of cooked rice to it by coating it with the fluorine resin. <P>SOLUTION: The inner pot of the electromagnetic induction heating electric rice cooker comprises: ceramic on the surfaces of which glaze layers are formed; a metal sprayed coating which is applied to the surface of the glaze layer on its inner peripheral side; a fluorine resin coat layer which is applied to the surface of the metal sprayed coating respectively; and heating members for electromagnetic induction heating which are arranged in predetermined positions on its outer peripheral side. In this case, the adhesion strength of the fluorine resin is increased by applying the fluorine resin coat layer after smoothing the surface of the metal sprayed coating to a predetermined level. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to a structure of an inner pot for an electromagnetic induction heating type electric rice cooker, particularly an inner pot for a ceramic type electromagnetic induction heating type electric rice cooker generally called a clay pot.

  Recently, electromagnetic induction heating provided with an inner pot, a rice cooker main body in which the inner pot is stored, and an induction heating coil that is arranged to face the outer peripheral surface of the inner pot and induction-heats the inner pot. Type electric rice cooker, wherein the inner pot is composed of a highly heat-stored ceramic (ceramic material), and the outer peripheral surface facing the induction heating coil when housed in the rice cooker body of the inner pot An electromagnetic induction heating type electric rice cooker in which an inner pot heating member made of a metal material capable of electromagnetic induction heating is joined to a portion is provided.

  In an inner pan used in such an electromagnetic induction heating type electric rice cooker, for example, a lithium-based crystal is used on the inner peripheral surface side so that the inner peripheral surface side is glossy and smooth and does not cause sticking of rice or scorching. A glassy glaze made of a vitrified glass or the like is applied with a fluororesin (see, for example, Patent Document 1).

  In the inner pot having such a configuration, when the rice cooking operation is started by the ON operation of the rice cooking start switch, a high-frequency current is supplied to the induction heating coil according to a predetermined procedure. And by the alternating magnetic field which generate | occur | produces in the said induction heating coil, the inner pot heating member of the inner pot outer peripheral part facing the same induction heating coil couple | bonds so that electromagnetic induction is possible, and an eddy current flows.

  And the inner pot heating member generates heat by Joule heat due to this eddy current, the heat is transmitted to the inner pot, and the vitreous glaze layer applied to the inner peripheral surface side of the inner pot, or the fluororesin Heat rice and water through the coating layer. At this time, part of the heat is transferred from the bottom part of the inner pot to the side wall part through the inner pot base material, and the entire inner pot is warmed to uniformly heat rice and water.

  Moreover, since a glassy glaze or fluororesin coating is given to the inner peripheral surface of an inner pot, since a certain amount of water generation is ensured, the inner pot to which rice cannot adhere easily is obtained.

  However, in the case of only the above-mentioned glaze layer, aside from the non-water-passing function, it was never satisfactory for avoiding sticking or burning of rice.

  On the other hand, in the case of a configuration coated with a fluororesin, the effect of preventing scorching etc. is much higher than in the case of a glaze layer, but the fluororesin is easily peeled off from the surface of the ceramic substrate and lacks durability and reliability. There was a problem.

  Therefore, in response to such circumstances, for example, the surface of the ceramic pan is roughened by sandblasting, and then an alumina film containing a metal oxide is formed on the top, and fluorine is formed on the upper surface side through the alumina film. There has also been proposed a film in which a fluororesin film is formed by applying and baking a resin (see, for example, Patent Document 2).

  According to such a configuration, since the alumina film is formed after sandblasting the surface of the ceramic pan, the adhesion of the alumina film to the ceramic pan is increased, so the ceramic pan and the fluororesin Can also be improved to some extent.

JP-A-2005-413 JP 2008-279083 A

  However, in the case of the configuration of the above-mentioned Patent Document 2, even if the adhesion between the alumina film and the ceramic pan is improved, alumina is a ceramic to the last, and even if a metal is mixed, a characteristic equivalent to that of a metal cannot be produced. . Therefore, it is difficult to say that the adhesion to the ceramic pan is sufficiently high. In particular, if the target ceramic pan is in an unglazed state, if the surface has a glaze layer, the degree of adhesion is more difficult to improve.

  Further, the fluororesin film is merely applied on the alumina film, and even if it is finally fired, reliable adhesion is not always maintained between the two. Therefore, there still remains a problem that the adhesion state is not stable and is easily peeled off.

  In addition, in order to form a ceramic film such as alumina on the surface of the ceramic pan, it is necessary to perform thermal spraying with a narrow width using an expensive and large-scale thermal spraying machine such as a plasma spraying machine or a metallicon spraying machine. Moreover, it cannot be sprayed using an inexpensive arc sprayer.

  Furthermore, the alumina membrane is more expensive than the glaze layer, and thus the inner pan itself is also expensive when attempting to achieve water-imperviousness of the inner pan body.

  The present invention was made to solve such a problem in the formation of the fluororesin coat layer, and as described above, the base portion of the inner pot is formed of a ceramic, and is formed on the inner peripheral surface of the base of the inner pan. A predetermined glaze layer is formed, and a metal sprayed layer is formed thereon. Then, by applying a predetermined smoothing treatment to the metal sprayed layer and then forming a fluororesin coat layer, the adhesion of the fluororesin to the metal sprayed layer is increased, while preventing sticking and scorching of rice An object of the present invention is to provide an inner pan for an electromagnetic induction heating type electric rice cooker with improved reliability and durability.

  In order to achieve the above object, the present invention is configured with the following problem solving means.

(1) Invention of Claim 1 This invention consists of the ceramics in which the glaze layer was formed in the surface, a metal spray layer on the surface of the glaze layer in the inner peripheral surface side, and a fluororesin coat layer on the surface of the metal spray layer And an inner pot of an electromagnetic induction heating type electric rice cooker in which a heating member for electromagnetic induction heating is provided at a predetermined position on the outer peripheral surface side, wherein the fluororesin coat layer is the metal spray layer It is characterized in that it is provided after the surface is smoothed to a predetermined level.

  According to such a configuration, since the fluororesin coat layer is further formed on the surface of the glaze layer via the metal sprayed layer, it is far from the inner peripheral surface of the rice compared to the case of only the glaze layer. Non-adhesiveness increases, and rice sticking and burning are less likely to occur.

  In addition, since the fluororesin coat layer is formed after the metal sprayed layer is smoothed to a predetermined level, the degree of adhesion is greatly improved compared to the conventional case, and peeling is less likely to occur. Compared with the fluorine coating layer, it is much more reliable.

  Further, the metal sprayed layer has a lower hardness than a ceramic film, and is easy to smooth.

  Further, unlike the ceramic film or the like, the metal sprayed layer can be easily sprayed by a simple and inexpensive arc spraying machine.

(2) Invention of Claim 2 This invention is characterized in that the metal sprayed layer in the configuration of the invention of Claim 1 is an aluminum sprayed layer.

  When aluminum is used as the metal spraying material to form the metal spraying layer as described above, spraying is easy and the hardness is lower than that of the ceramic film. The surface is smoothed.

  Therefore, among various metal materials that can be sprayed by an arc sprayer, aluminum material is optimal.

(3) Invention of Claim 3 This invention is characterized in that the smoothing treatment of the metal sprayed layer in the configuration of the invention of claim 1 or 2 is glass bead shot processing.

  Unlike shot blasting with a metal material such as aluminum, glass bead shots break the glass bead itself when a certain load is applied, so that not only the work surface is scraped but also the work surface is crushed and crushed. A preferred shot effect works.

  Therefore, with the same glass bead shot, shot processing is performed such that only the apex of the convex part of the uneven surface of the uneven aluminum sprayed layer along the uneven surface on the inner peripheral surface of the inner pan body is scraped at a predetermined smoothness level. However, since the concave portion is left in a shape in which the remaining convex portion is almost flat, the engagement effect (anchor effect) due to the penetration of the fluororesin material into the concave portion is not obtained. Demonstrated and improved adhesion.

  In addition, for example, when performing transfer printing (pad printing) for forming a water scale, for example, printing ink tends to adhere to the convex portion and the peripheral portion of the convex portion whose top portion is nearly flat, Ink does not adhere to. Therefore, it is possible to perform clear printing more clearly and without bleeding.

(4) Invention of Claim 4 This invention is characterized in that the metal sprayed layer in the constitution of the invention of Claim 1, 2 or 3 is provided after blasting the glaze layer.

  If it does in this way, the surface of a glaze layer will become a rough surface with an unevenness | corrugation, metal materials, such as sprayed aluminum, will be closely_contact | adhered to a glaze layer reliably, and the bond strength will become high.

  Therefore, the bonding force with the inner peripheral surface of the inner pan of the fluororesin layer provided on the surface of the metal spray layer such as aluminum is also increased.

  As a result of the above, according to the present invention, it is possible to achieve the cooking performance of delicious rice that sticks for a long period of time and does not cause burning, compared to the conventional inner pot.

It is a figure which shows the whole cross-section of the inner pot for electromagnetic induction heating type | formula rice cookers which concern on embodiment of this invention. It is sectional drawing which expands and shows the structure of the bottom wall part of the inner pot. It is sectional drawing which expands and shows the structure of the principal part (A part of FIG. 1) of the bottom wall part of the inner pot.

  1-3 has shown the structure of the inner pot for electromagnetic induction heating type | formula rice cookers which concern on embodiment of this invention.

  This inner pot 1 is an inner pot for rice cooking generally referred to as an earthen pot as already described. For example, the inner pot main body (base body) 1a to 1d shown in FIG. 1 has a high heat-resistant temperature during sintering, It is made of a cordierite-based pottery material with good heat storage during heat retention, and is formed into a bottomed cross-sectional shape having a hill portion 1e and a mouth edge portion 1f as shown.

  A first heating member 2a is provided on the inside of the hill portion 1e of the bottom portion 1a, and a second heating member 2b is provided on a corner portion 1b having a rounded surface shape extending from the hill portion 1e of the bottom portion 1a to the side wall portion 1c. Bonded and integrated.

  Each of the first and second heating members 2a and 2b is capable of self-heating by an eddy current induced by an induction heating coil (work coil) on the electric rice cooker main body (not shown), for example, induction heating such as silver paste. It consists of a sheet.

  And this inner pot 1 is arrange | positioned so as to oppose the said 1st, 2nd heating members 2a and 2b of the electric rice cooker main body which is not shown in figure which the same inner pot 1 is accommodated, and the inner pot 1 accommodated. In the electric rice cooker body of the electromagnetic induction heating type electric rice cooker provided with an induction heating coil for induction heating the inner pot 1 stored therein via the first and second heating members 2a, 2b. Used as a storage set.

  Then, in the state where the inner pot 1 is stored and set in the electric rice cooker body, for example, when the rice cooking operation is started by an ON operation of the rice cooking start switch or the like, a high frequency current is supplied to the induction heating coil according to a predetermined procedure. Then, due to the alternating magnetic field generated in the induction heating coil, the first and second heating members 2a and 2b facing the induction heating coil are coupled so as to be capable of electromagnetic induction, and an eddy current flows.

  The first and second heating members 2a and 2b generate heat due to the Joule heat generated by the eddy current, and the heat is transmitted to the inner pot 1 inside the first and second heating members 2a and 2b. The rice and water in the inner pot 1 are heated. At this time, part of the heat is transferred from the bottom 1a of the inner pot 1 to the corner 1b, from the corner 1b to the side wall 1c, and from the side wall 1c to the opening 1d through the main body (base) of the inner pot 1, The whole of 1 is heated and the rice and water in the inner pot 1 are heated uniformly.

  In addition, a heat retaining heater is provided on the outer periphery of the side wall 1c as necessary. And this side wall part 1c is thicker than the said bottom part 1a and the corner part 1b, and is comprised so that the thermal storage property at the time of heat retention may become high.

  By the way, as described above, even in the case of the conventional inner pot, surface treatment such as glaze application or fluororesin coating is applied to the inner peripheral surface of the inner pot. It is made for the purpose of holding water absorption into the inner pot and the purpose of sticking rice and scorching, but in the case of only the glaze layer, the function of rice I was never satisfied with avoiding stickiness and scorching.

  On the other hand, in the case of a configuration coated with a fluororesin, the effect of preventing scorching etc. is much higher than in the case of a glaze layer, but the fluororesin is easily peeled off from the surface of the ceramic substrate and lacks durability and reliability. There was a problem.

  Therefore, in response to such circumstances, for example, the surface of the ceramic pan is roughened by sandblasting, and then an alumina film containing a metal oxide is formed on the top, and fluorine is formed on the upper surface side through the alumina film. There has also been proposed a film in which a fluororesin film is formed by applying and baking a resin.

  According to such a configuration, since the alumina film is formed after sandblasting the surface of the ceramic pan, the adhesion of the alumina film to the ceramic pan is increased, so the ceramic pan and the fluororesin Can also be improved to some extent.

  However, in the case of this configuration, even if the adhesion between the alumina film and the ceramic pan is improved, alumina is a ceramic to the last, and even if a metal is mixed, a characteristic equivalent to that of a metal cannot be produced. Therefore, it is difficult to say that the adhesion to the ceramic pan is sufficiently high. In particular, if the target ceramic pan is in an unglazed state, if the surface has a glaze layer, the degree of adhesion is more difficult to improve. Further, in the case of the same configuration, the fluororesin film is merely applied on an alumina film that is a ceramic, and even if finally fired, reliable adhesion and bondability between them are not necessarily obtained ( The anchor effect is not always maintained. Therefore, the stability of the fluororesin layer adhesion state is still lacking, and the problem of the fluororesin layer peeling remains.

  In addition, in order to form a ceramic film such as alumina on the surface of the ceramic pan, it is necessary to perform thermal spraying with a narrow width using an expensive and large-scale thermal spraying machine such as a plasma spraying machine or a metallicon spraying machine. Moreover, it cannot be sprayed using an inexpensive arc sprayer.

  Furthermore, the alumina membrane is more expensive than the glaze layer, and thus the inner pan itself is also expensive when attempting to achieve water-imperviousness of the inner pan body. In addition, water permeability is not sufficient.

  The present embodiment was made to solve the above-mentioned problems in forming the fluororesin coat layer. As described above, the base portion of the inner pot 1 is a highly heat-resistant cordierite that represents a clay pot. As a method of effectively preventing sticking and scorching of rice while maintaining non-water permeability of the inner pot 1 by forming a glaze layer 4 on the surface thereof, for example, As shown in FIGS. 2 and 3, the surface of the glaze layer 4 is subjected to a sandblast treatment, and an aluminum metal sprayed layer 5 is formed thereon.

  Then, after a predetermined level of smoothing is applied to the surface of the aluminum sprayed layer 5, the top of the aluminum sprayed layer 5 is left with a concave portion between the convex portion having a substantially flat top and a convex portion. By sequentially forming a fluororesin primer coat layer (first fluororesin coat layer) 6a and a fluororesin topcoat layer (second fluororesin coat layer) 6b, the adhesion and bonding of the fluororesin to the aluminum sprayed layer 5 are achieved. The purpose is to provide an inner pot for an electromagnetic induction heating type electric rice cooker with increased strength and prevention of sticking and scorching of rice while improving its reliability and durability.

  That is, in the inner pot 1 of the present embodiment, as shown in FIGS. 2 and 3, for example, each part of the uncooked inner pot main body (base body) extending from the bottom 1a to the opening 1d of the inner pot 1 shown in FIG. First, a lithianic glaze layer 4 having a desired thickness is formed on both the inner and outer peripheral surfaces (including the heating member 2a and 2b) and the inner pan body at low cost. Realize non-water permeability of the part. Thereafter, a predetermined sandblasting process is performed on the inner peripheral surface side portion (the portion where rice and water are accommodated) to roughen the surface of the glaze layer 4 to a predetermined roughness.

  Then, as a first base treatment for forming the fluororesin coating layers 6a and 6b to be described later, an aluminum metal is sprayed (sprayed) using a simple spraying machine such as an arc spraying machine, and the above An aluminum sprayed layer 5 having a desired thickness along the uneven surface (rough surface) formed by sandblasting on the surface of the glaze layer 4 is formed. The aluminum sprayed layer 5 is produced with good adhesion by effectively adhering to and engaging with the irregular surface portion of the surface of the glaze layer 4 formed by the sandblasting. Then, the surface of the aluminum sprayed layer 5 having the same unevenness is further subjected to a smoothing process by glass bead shot processing as a second base treatment, and the surface is subjected to a predetermined smoothing level, for example, sandblasting as described above. Only the apex of the convex part of the uneven surface of the aluminum sprayed layer 5 with unevenness along the unevenness on the inner pan body side glaze layer 4 is scraped to eliminate random protrusions and increase the curvature of the top part (extremely In other words, it provides a necessary engagement force (anchor effect due to the recess) to the primer coat layer 6a of the fluororesin layer to be coated later, but does not cause unnecessary pinholes due to penetration. And smoothing to such an extent that printing ink can be easily applied during water scale printing.

  Then, a fluororesin primer coat layer (first fluororesin coat layer) 6a is first formed on the aluminum sprayed layer 5 smoothed to such a level by the glass bead shot, and the primer coat layer 6a. Water scales 7, 7, and 7 are pad-printed on the surface of the protrusions. Thereafter, the fluororesin top coat layer 6b (second fluororesin coat layer) is formed thereon with a desired thickness thicker than that of the primer fluororesin layer coat layer 6a, and is baked, so that the rice is stuck and burnt. In addition, the preferred inner pot 1 is configured such that the fluororesin is hardly peeled off and the water scale is clear.

  In this case, the glaze layer 4 is applied after the lithia glaze is applied to the entire inner and outer peripheral surfaces of the unglazed inner pot main bodies (substrates) 1a to 1d after blasting to improve the adhesion. And then dried and then baked. Of course, this blasting process may or may not be performed, but if the glaze layer 4 is formed after the blasting process, the adhesion strength of the glaze layer 4 to the inner pot body is further increased.

Further, as the glass beads for performing the glass bead shot, for example, those mainly composed of silica (SiO ₂ ) having a Mohs hardness of 3 to 8 (more preferably around 5.5) are employed.

  If the hardness is higher than this, the bent aluminum sprayed surface will be cut too much, and conversely if it is too low, the smoothing (cutting) effect will hardly occur.

  Also, unlike shot blasting with a metal material such as aluminum, the glass bead shot described above breaks the glass bead itself when a certain load is applied. A favorable shot effect of hitting and crushing works. Therefore, with the same glass bead shot, only the vicinity of the apex of the convex portion of the uneven surface of the uneven aluminum sprayed layer 5 along the uneven surface on the inner peripheral surface of the inner pan body that has been sandblasted as described above. When the shot processing is performed, the concave portion is not completely smooth as described above, but the concave portion is left in the shape in which the convex portion is nearly flat, and is sufficiently caused by the penetration of the fluororesin material. The engagement effect (anchor effect) due to mutual coupling is exhibited, and the degree of adhesion of each is improved with certainty. In addition, since no pinholes are generated in the fluororesin coat layers 6a and 6b, there is no rust (rust) due to the exposure of the aluminum material on the lower surface side or the penetration of water into the aluminum material part.

  In addition, for example, when performing transfer printing (pad printing) for forming a water scale, for example, printing ink adheres to the convex portion and the peripheral portion of the fluororesin primer coat layer 6a whose top portion is almost flat. On the other hand, the ink does not adhere in the recess (refer to the reference numerals 7, 7... In FIG. 3). Therefore, it is possible to perform clear water scale printing that is clear and has no bleeding more reliably.

  Further, since the glaze layer 4 and the aluminum sprayed layer 5 have different hardnesses (the glaze layer 4 is harder), as described above, the surface of the glaze layer 4 is roughened by a hard sandblasting process, and the aluminum sprayed layer 5. The appropriate thickness of the fluororesin primer coat layer 6a can be achieved more effectively and stably by using appropriate surface treatment methods with appropriate soft glass bead shots and appropriate surface treatment methods. The fluororesin top coat layer 6b can be provided.

  Moreover, the aluminum sprayed layer 5 is easy to bond with the glaze layer 4 of the inner pot 1 and has a lower hardness than a conventional ceramic film made of alumina or the like.

  Further, unlike the conventional ceramic film such as alumina, the aluminum sprayed layer 5 can be easily sprayed by a simple and inexpensive arc spraying machine. Therefore, the manufacturing cost can be reduced.

  DESCRIPTION OF SYMBOLS 1 is an inner pot, 1a is an inner pot bottom part, 1b is an inner pot corner part, 1c is an inner pot side wall part, 1d is an inner pot opening part, 2a is a 1st heating member, 2b is a 2nd heating member, 4 is The glaze layer, 5 is an aluminum sprayed layer, 6a is a fluororesin primer coat layer, and 6b is a fluororesin topcoat layer.

Claims (4)

  It is made of a ceramic product having a glaze layer formed on the surface, and a metal spray layer is provided on the surface of the glaze layer on the inner peripheral surface side, and a fluororesin coat layer is provided on the surface of the metal spray layer, An inner pot of an electromagnetic induction heating type electric rice cooker provided with a heating member for electromagnetic induction heating at a position, wherein the fluororesin coat layer is obtained by smoothing the surface of the metal sprayed layer to a predetermined level. An inner pot for an electromagnetic induction heating type electric rice cooker characterized by being provided with.   2. The inner pot for an electromagnetic induction heating type electric rice cooker according to claim 1, wherein the metal sprayed layer is an aluminum sprayed layer.   The inner pot for an electromagnetic induction heating type electric rice cooker according to claim 1 or 2, wherein the smoothing treatment of the metal sprayed layer is glass bead shot processing.   4. The inner pot for an electromagnetic induction heating electric rice cooker according to claim 1, wherein the metal spray layer is provided after blasting the glaze layer.

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