JP2005226101A - Firing vessel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent the reduction in the quality of the body to be fired by reducing the contact area with members to be mounted with the body to be fired and thus suppressing the reaction to the body to be fired at the time of firing. <P>SOLUTION: The inner bottom part of a firing vessel body 11 with an almost cubic shape for firing zinc oxide elements is densely filled with a plurality of ceramics balls 12 and is paved therewith so as to arrange their height. The surfaces of the paved spherical ceramics balls 12 are, e.g., erectly mounted with zinc oxide elements 13. By the mounting, the lower edge faces of the zinc oxide elements 13 are contacted with the spherical ceramics balls 12 at point contacts. In this case, at least three parts are made to be point-contacted with the lower edge faces in the zinc oxide elements 13, thus the unstabilization of the zinc oxide elements 13 by being tilted in the firing vessel body 11 is prevented. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a firing container used when firing voltage nonlinear resistors (zinc oxide elements), fine ceramics, electronic ceramic materials, ceramic products, and the like mainly composed of zinc oxide (ZnO).

  Among zinc oxide elements mainly composed of ZnO, fine ceramics, electronic ceramic materials and ceramic products, especially zinc oxide elements include bismuth oxide, antimony oxide, cobalt oxide, manganese oxide, chromium oxide, nickel oxide, It is manufactured from a composition blended with high non-linearity and low heat loss by adding subcomponents such as silicon oxide.

  Usually, these subcomponents are premixed with a ball mill or the like, then mixed with an organic binder and ZnO, and spray-dried with a spray dryer to form a granulated powder having good fluidity.

  The obtained granulated powder is formed into a cylindrical shape by a die press and degreased by temporary firing at 700 ° C to 1000 ° C. Next, a primary insulating material is coated on the side surface of the obtained temporary fired body, and fired again at a temperature of 1000 ° C. to 1300 ° C. for several hours to obtain a fired body.

  Thereafter, the obtained fired body is coated with a secondary insulating material as necessary and baked. Thereafter, both end faces of the fired body are polished, and aluminum electrodes are sprayed on both end faces to complete the zinc oxide element.

  FIG. 3 shows the manufacturing process of the zinc oxide element described above. In the manufacturing process of the zinc oxide element shown in FIG. 3, in the temporary baking, a columnar molded product is erected on the inner bottom surface of the baking container main body for temporary baking and baking is performed.

  After that, when firing the preliminarily fired columnar preliminarily fired product, a means is employed in which a floor plate is placed on the bottom surface inside the firing container body, and the columnar presintered product is erected and fired. Yes. As the baking means, a gas furnace or an electric furnace is used.

In addition, ceramics such as aluminum oxide (Al ₂ O ₃ ), magnesium oxide (MgO), and zirconia oxide (ZrO ₂ ) are used as the material for the firing container main body and the base plate.
JP 05-267010 A

  In the above-described technology, since molded products such as zinc oxide elements, fine ceramics, and electronic ceramics are placed directly on the bottom surface of the firing container body or the floor plate, there is a risk of chemical reaction with the firing container body or the bottom plate at the contact surface. There is a concern about the influence on the properties of molded products such as zinc oxide elements.

  In addition, since the components of the molded product (particularly metal oxide having a low melting point) corrode the firing container body or the bottom plate during firing, there is a risk of accelerating the deterioration of the firing container body and the bottom plate.

  If there are ceramic wastes such as zinc oxide elements or ceramic chips left on the firing container body or flooring, and the molded product is placed on the waste and fired, There is a possibility that it may be adsorbed to the molded product or the shape of the molded product may be deformed to cause product defects.

  In order to solve the above problem, it is desirable that the contact surface between the molded product such as the zinc oxide element and the baking container main body or the floor plate is small. Therefore, there are cases where a firing container body or a floor plate having grooves, ridges, protrusions and the like on the inner bottom surface has been developed and used.

  However, the fired container body processed as described above is more expensive than the unprocessed one, and the processed parts such as protrusions are easily damaged, and the running cost is high. A new problem arises that is disadvantageous in this regard.

  The present invention has been made in view of the above circumstances, and the contact area with the member on which the object to be fired is placed is made as small as possible to suppress the reaction to the object to be fired during firing, thereby reducing the quality of the object to be fired. It is an object of the present invention to provide a firing container capable of preventing the above.

  In order to achieve the above object, according to the first aspect of the present invention, there is provided a container body for firing a body to be fired, and an arrangement and arrangement so as not to move over the entire inner bottom portion of the container body. It is characterized by comprising a ceramic body placed by point contact or line contact.

  The second invention is characterized in that the ceramic body is formed in a spherical or cylindrical shape.

  The third invention is characterized in that the ceramic body is made of a material that is physically and chemically stable with respect to a firing temperature.

  As described above, according to the present invention, a spherical ceramic body, a cylindrical ceramic body, or the like is disposed on the inner bottom surface of the firing container main body so as to be difficult to move, and the fired body is placed thereon. Since firing is performed in a high-temperature furnace or the like, it is possible to perform sintering while suppressing contamination of raw materials such as a firing container body during sintering of the body to be fired.

  In addition, according to the present invention, even if chip waste such as a body to be fired or a firing container main body or other dust enters the container, contact between the body to be fired and waste or dust is difficult to occur. , Deformation can be suppressed.

  Furthermore, since the ceramic body has a spherical or cylindrical shape, the processing is relatively easy, and even if they deteriorate, only the deteriorated ceramic body can be replaced, which is economically advantageous.

  Embodiments of the present invention will be described below with reference to the drawings. FIGS. 1A and 1B are configuration explanatory views showing a first embodiment of the present invention. FIG. 1A is a top view and FIG. 1B is a cross-sectional view taken along the line XX.

  In FIG. 1, reference numeral 11 denotes a substantially cubic firing container main body for firing, for example, a zinc oxide element. The inner bottom portion of the firing container main body 11 is densely filled with a plurality of spherical ceramic balls 12 and has a high height. Align and spread.

  On the spherical ceramic balls 12 laid in this manner, a zinc oxide element 13 which is a fired body, for example, formed in a cylindrical body, is erected and placed. When placed upright in this manner, the lower end surface of the zinc oxide element 13 comes into contact with the spherical ceramic ball 12 in point contact.

  At this time, there are at least three sites that make point contact with the lower end face of the zinc oxide element 13 so that the zinc oxide element 13 does not tilt and become unstable in the baking container body 11.

  For this reason, the diameter of the spherical ceramic ball 12 is determined according to the size of the zinc oxide element 13. The material of the spherical ceramic ball 12 is YSZ (stable zirconia).

  By firing the firing container main body 11 in which the zinc oxide element 13 is erected and placed on the spherical ceramic ball 12 as described above in a gas furnace or an electric furnace, the lower end face of the fired zinc oxide element 13 A lower end face having a uniform color and shape was obtained on the (contact surface with the spherical ceramic ball 12) visually compared to the end face of the zinc oxide element fired with the usual floor plate described in the background art.

  FIG. 2 is a structural explanatory view showing a second embodiment of the present invention, FIG. 2 (a) is a top view, and FIG. 2 (b) is a sectional view taken along the line XX. In addition, the same code | symbol is attached | subjected and demonstrated to the same part as 1st Embodiment.

  In the second embodiment shown in FIG. 2, a plurality of columnar ceramics 21 are arranged side by side on the inner bottom portion of the firing container main body 11 and arranged. For example, the zinc oxide element 13 is placed on the columnar ceramics 21 arranged in this manner, as in the first embodiment.

  Then, although the lower end surface of the zinc oxide element 13 is in linear contact with the cylindrical ceramic 21, the zinc oxide element 13 is placed by arranging the lower end surface so that there are at least two contacts. Stability can be ensured.

  In order to adjust the stability, the diameter of the columnar ceramic 21 is determined according to the size of the zinc oxide element 13. The material of the columnar ceramic 21 is YSZ (stabilized zirconia) as in the first embodiment.

  In the second embodiment configured as described above, even when the zinc oxide element 13 was accommodated in the baking container main body 11 and baked in a gas furnace or the like, the same effects as those of the first embodiment were obtained.

  In the first and second embodiments, the spherical ceramic balls 12 and the columnar ceramics 21 are disposed on the inner bottom of the firing container body 11, and the zinc oxide is disposed on the ceramic balls 12 or the columnar ceramics 21. When the element 13 is placed and fired in a gas furnace or an electric furnace, the heat conduction to the zinc oxide element 13 is a point or line contact in the spherical ceramic ball 12 or the cylindrical ceramic 21, so that the firing container body Since the heat from is difficult to be transmitted, the above-described effects can be obtained.

  However, as described in the background art, when a zinc oxide element is placed directly on a firing container body or a floor board and fired, the heat conduction to the zinc oxide element is directly conducted from the firing container body or the floor board. This is likely to occur, and the zinc oxide element becomes non-uniformly sintered.

  For this reason, in 1st form and 2nd form, there is no local heating from the contact surface of the baking container main body 11 and the zinc oxide element 13, and heating by the convection of air or the radiant heat of the baking container main body wall becomes main. The zinc oxide element 13 is uniformly sintered.

  In the first embodiment and the second embodiment, for example, the zinc oxide element 13 which is a body to be fired is mounted on the spherical ceramic ball 12 or the columnar ceramic 21 provided on the inner bottom portion of the firing container body 11. When firing in a gas furnace or an electric furnace, the zinc oxide element 13 and the spherical ceramic ball 12 are in point contact, and the columnar ceramic 21 is in line contact.

  For this reason, the reactivity of the zinc oxide element is extremely low compared to the case where the zinc oxide element is directly placed on the firing container main body and the bottom plate and baked as described in the background art. Sintering with reduced contamination (contamination) can be performed, erosion due to the components of the zinc oxide element can be reduced, and deterioration of the firing container body, spherical ceramic balls, and cylindrical ceramics themselves can be suppressed.

  Furthermore, since there is a space between the spherical ceramic balls and cylindrical ceramics filled in the firing container body, scraps and dust from the zinc oxide element and firing container body enter the firing container body. However, if it is less than the diameter of the spherical and cylindrical ceramics, it will not fall into the space and come into contact with the zinc oxide element.

  Therefore, in this embodiment, since scraps, dust, and the like do not contact the zinc oxide element, adsorption of the scrap and the zinc oxide element and deformation of the zinc oxide element caused by the adsorption can be suppressed.

  In addition to the above, the processing of spherical ceramic balls and cylindrical ceramics is easier than the firing container main body and floor plate with special processing such as protrusions described in the background art, thereby reducing the initial cost. Can be planned. In addition, when replacing the firing container main body and the floor plate due to deterioration or the like, until now, it was necessary to replace themselves, but in this embodiment, it is only necessary to replace the deteriorated ceramic balls or columnar ceramics. The running cost can be reduced and the amount of waste can be reduced.

  In the above-described embodiment, the zinc oxide element has been described as an example. However, the same effects can be obtained even when the present invention is applied to temporary firing in which fine ceramics, electronic ceramic materials, ceramic products and the like are fired or degreased.

  It is particularly effective for firing ceramics that are cylindrical and have a flat bottom at the bottom, or for firing electronic ceramic materials that do not favor the inclusion of impurities, and uniform sintering (density and crystal uniformity) It is also suitable for a method of firing desirable ceramics.

  The shape of the above-mentioned spherical ceramics may be constituted by a sphere, a disk shape, a polyhedron close to a sphere, or the like as long as it is brought into contact with the object to be fired at a point.

  Moreover, as long as the shape of the columnar ceramics is to be brought into contact with the body to be fired with a line, it may be formed in an n-prism shape (n is 3 or more).

  In addition, it is desirable to use a material that is physically and chemically stable to the firing temperature as the material of the spherical ceramic or the cylindrical ceramic. Specifically, the material contains aluminum oxide, silicon oxide, magnesium oxide, zirconium oxide, calcium oxide, or one or more thereof as a main component.

BRIEF DESCRIPTION OF THE DRAWINGS It is a block diagram which shows 1st Embodiment of this invention, (a) is a top view, (b) is XX sectional drawing. It is a block diagram which shows 2nd Embodiment of this invention, (a) is a top view, (b) is the YY sectional view taken on the line. Manufacturing process explanatory drawing of a zinc oxide element.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 ... Firing container main body 12 ... Spherical ceramic ball 13 ... Zinc oxide element which is to-be-fired body 21 ... Cylindrical ceramics

Claims (3)

A container body for firing the object to be fired;
A ceramic body on which the object to be fired is placed by point contact or line contact, arranged and arranged so as not to move over the entire inner bottom part of the container body,
A firing container comprising: The firing container according to claim 1, wherein the ceramic body is formed in a spherical shape or a cylindrical shape. The firing container according to claim 1, wherein the ceramic body is made of a material that is physically and chemically stable with respect to a firing temperature.

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