JPH0637331B2 - Baking method for extruded ceramics - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for firing a ceramic molded material, in particular, a ceramic extruded elongate shaped material (hereinafter referred to as a ceramic elongate body) formed into an elongated shape by extrusion molding.

[Prior Art] Generally, a ceramic long body is formed by extruding a ceramic raw material into a long shape, drying it, and then putting it in a furnace and firing it. An extruded ceramic long body is
As shown in FIG. 11, it is deformed in the X direction and the Y direction, and nothing straight is present. Further, the dried product is further deformed due to uneven drying. When such a long body is fired, the shape after firing is inevitably changed.

Therefore, regarding the technology to make long ceramics made by extrusion molding as straight as possible, please see
-25703 publication is known. This is intended to make a straight shape by firing a ceramic long body in a suspended state.

[Problems to be Solved by the Invention] In the above-mentioned conventional technique, firing a ceramic long body in a suspended state has the effect of firing straight, but the firing furnace must be vertically long. Therefore, in order to make the heat distribution above and below the furnace uniform,
Forced circulation of the heat medium is required, and energy for that is required. In addition, since the ceramic long body may shake due to the circulation of the heat medium and the hanging part may be damaged, the shape of the ceramic long body is limited, and the work of suspending the ceramic long body on the upper part of the furnace is performed. There is a problem that is difficult. Further, although this method can be applied to a straight shape, it was not possible to fire an arc or curved shape into an accurate shape.

Therefore, the present invention is to provide a firing method capable of accurately and efficiently producing a long ceramic body having various shapes such as a linear shape, an arc shape, and a curved shape.

[Means for Solving the Problems] The present invention is to extrude a shaped material having a desired cross-sectional shape from a ceramic material, and form the shaped body by a firing jig having at least two supporting surfaces facing different directions. , A ceramic which is supported and heated from below to soften the molded body, the surface shape of the molded body is deformed by its own weight along the supporting surface of the firing jig, and then the ceramic is sintered. It is a method of firing extruded profile.

In the present invention, when it is necessary to dry the ceramic long body prior to firing, the ceramic long body may be placed on the above-mentioned firing jig and dried. Since it does not require heat resistance, it is better to place the ceramic long body on a jig composed of the same shape and inexpensive material, dry it, and place it again on the firing jig after drying and fire it. . Further, in the case of a deformable material such as an arc shape or a curved shape, it is deformed in advance while being pressed substantially along the supporting surface of the jig before this drying.

As the firing jig, Al ₂ O ₃ which is a material having good workability and heat resistance is preferably used. In addition, as a holder for the firing jig, SiC that has high heat resistance and high strength
Is preferably used.

The firing jig is divided into several pieces, and the intervals between the pieces are set so that they do not sag when the elongated ceramic body softens. By doing so, the circulation of the heat medium is improved through the space between the small pieces, and the long ceramic body can be heated uniformly.

Further, as another aspect of the firing jig, the firing jig may have a length substantially equal to that of the elongated ceramic body, and a large number of through holes for passing a heating medium may be provided on the entire surface.

The at least two supporting surfaces facing different directions in the firing jig are typically V-shaped when the outer surface of the elongated ceramic body is rectangular. When the outer surface of the long ceramic body is circular, the lower central part of the arc surface of the supporting surface is formed in an arc shape having a curvature smaller than the curvature of the circular cross section of the long ceramic body before firing. The long ceramic body is supported at two positions on both sides of the arc surface.

[Operation] In the present invention, the long ceramic body is softened by heating prior to sintering, and the outer shape thereof is corrected along the supporting surface of the firing jig, whereby a product having a desired shape can be obtained.

Embodiments Embodiments will be described below with reference to the drawings.

Example 1 FIG. 1 is a perspective view showing a mode of use of a firing jig used in the present invention, and FIG. 2 is a sectional view taken along line II-II of the same.

A long ceramic body 1 is obtained by extruding a shaped material having a desired cross-sectional shape from a ceramic material. This is dried if necessary and placed on the firing jigs 2, 2 ... The firing jig 2 is fitted into the groove 5 on the Al ₂ O ₃ base 4 provided on the SiC base 3 at a predetermined interval.
The firing jig 2 is supported from below by two supporting surfaces 6 and 7 facing different directions as shown in FIG. That is, the supporting surfaces 6 and 7 form a right-angled V shape, the supporting surface 6 is contacted with the short side of the ceramic long body 1, and the supporting surface 7 is contacted with the long side of the ceramic long body 1. Keep it stable.

Then, the ceramic long body 1 placed on the firing jig 2 is placed in a firing furnace as it is and heated. At this heating stage, the ceramic long body 1 is softened and comes into close contact with the supporting surfaces 6 and 7 due to its own weight.
The shape of the part not hitting 6 and 7 is also corrected as a whole. A product having a desired shape can be obtained by sintering this. At this time, the firing jig 2 is A
Since it is only fitted on the l ₂ O ₃ base 4,
When the elongated ceramic body 1 contracts during firing, the firing jig 2 can slide in the groove 5 of the Al ₂ O ₃ base 4 as required.

Embodiment 2 FIGS. 3 and 4 show another embodiment of the firing apparatus,
A long firing jig 8 having V-shaped supporting surfaces 9 and 10 is fitted in a groove 5 on an Al ₂ O ₃ base 4 provided on a SiC base 3 is there. This long baking jig
8 has a through hole 11 for passing a heat medium on the entire surface.

Example 3 In the example shown in FIG.
In an apparatus used for firing a thing having 5 and 15, one supporting surface 13 of the firing jig 12 is provided with irregularities corresponding to the projecting piece 15 on one surface of the long ceramic body. And the protrusion
The recess 14 for receiving 15 has a size capable of accommodating the deformed protrusion 15 in consideration of the amount of deformation of the protrusion 15 due to extrusion molding. That is, the recess 14 has a size commensurate with the amount of distortion of the protrusion 15.

Example 4 FIG. 6 shows an apparatus used for firing a long ceramic body having a circular cross section, and an arc surface is formed on the upper surface of the firing jig 16. The arcuate surface is formed so that the central portion has a small curvature.
Therefore, when the long ceramic body 17 having a circular cross section before firing, which is indicated by the alternate long and short dash line, is placed on the firing jig 16, a gap is formed on the lower bottom surface. In other words, the long ceramic body 17 before firing is supported by the support surfaces 18 and 19 at two points. The long ceramic body 17 'after firing has a circular cross section shown by a solid line. At this time, the long ceramic body 17' has a curvature equal to the central portion of the arc surface and is supported by the central portion.

Embodiment 5 FIGS. 7 to 9 show a firing apparatus for obtaining an arc-shaped elongated ceramic body. The alternate long and short dash line in FIG. 8 indicates the desired degree of curvature of the elongated ceramic body. A circular Al ₂ O ₃ base 20 is obliquely arranged, and a firing jig 21 having two V-shaped support surfaces 22 and 23 is fixed on the base 20 at a predetermined distance. While deforming the extruded ceramic long body along the supporting surfaces 22, 23 of the firing jig 21,
Before firing, it is formed into a curved shape and then fired.

Figures 10a-e illustrate products made according to embodiments of the present invention.

[Effect of the Invention] In the method of the present invention, if a long ceramic body is placed on a supporting surface of a firing jig and heated, an accurate shape along the supporting surface is exhibited. It is possible to obtain a product having an accurate shape, not limited to a curved shape or a curved shape. Further, since the long ceramic body can be fired in a state in which the long body is laid down sideways, the work of placing it on the firing table is easy, and since a furnace with a low height can be used, the heat distribution in the furnace can be reduced. It has the effect of making it easy to make uniform.

Further, the baking apparatus used for such a baking method may be prepared easily, easily and at low cost because it is sufficient to prepare a baking jig having at least two supporting surfaces facing different directions. be able to.

[Brief description of drawings]

FIG. 1 is a perspective view of an embodiment of the firing apparatus, FIG. 2 is a sectional view taken along line II-II of FIG. 1, FIG. 3 is a perspective view of another embodiment, and FIG. 4 is IV- of FIG. IV sectional view, FIG. 5 is a sectional view of an embodiment of an apparatus for firing a material having protrusions, FIG. 6 is a sectional view of an embodiment of an apparatus for firing a material having a circular cross section, and FIG. 7 is an arc-shaped material. FIG. 8 is a sectional view of an embodiment of an apparatus for firing the slag, FIG. 8 is a sectional view taken along the axis of FIG. 7, and FIG.
Sectional views, FIGS. 10A to 10E are perspective views of a product example of the present invention, FIG.
FIG. 1 is a perspective view of the elongated ceramic body after molding. 1 …… Ceramic long body, 2 …… Firing jig 3 …… SiC base, 4 …… Al ₂ O ₃ base 5 …… Groove, 6, 7 …… Supporting surface, 8 …… Firing Jig 9,10 …… Supporting surface, 11 …… Through hole, 12 …… Firing jig 13 …… Supporting surface, 14 …… Concave, 15 …… Projecting piece 16 …… Firing jig 17 …… Firing Previous ceramic elongated body with circular cross section 17 '…… Ceramic elongated body with circular cross section after firing, 18,1
9 …… Supporting surface 20 …… Annular Al ₂ O ₃ base 21 …… Baking jig, 22, 23 …… Supporting surface

Claims (1)

[Claims] 1. A long shaped material having a desired cross-sectional shape is extruded from a ceramic material, and the shaped body is heated while being supported from below by a firing jig having at least two supporting surfaces facing different directions. Then, the molded body is softened, the surface shape of the molded body is deformed by its own weight along the supporting surface of the firing jig, and then the ceramic body is sintered. Method.