JPS6321377Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial field of application] The invention is used in wet extrusion molding of a green material for tiles that is planned to be divided into two parts after firing to produce products. This relates to molds.

[Prior art and its problems]

Figure 3 shows the final product, tile 3 with soles.
It is a perspective view showing an example. The tile 3 as a final product is obtained by drying and firing two pieces of the same shape integrally molded with their soles facing each other, and then dividing them into two. In the same figure, 3a is a tile surface that defines the front side contour of the tile 3, and is usually glazed.

FIG. 1 is a perspective view showing a biogenic body 2, which is to be divided into two parts after firing, being integrally extruded from a mold 1. In the extruded biogenic body 2, two identically shaped biogenic bodies 2, which will become future product tiles 3, are arranged symmetrically on both sides of the sole molding space 5 located on the virtual vertical center line. ing. In the same figure, 2a and 2b are parts that will become the tile surface 3a when the biogenic body 2 becomes a product tile 3, and both swell laterally, and the cross-sectional shape of each biogenic body 2 is horizontal. Its posture is almost trapezoidal. Further, in the figure, 2c and 2d are portions that will become the side surfaces of the tile when the biogenic body 2 becomes the product tile 3. The portions located at both longitudinal ends of the sole forming space 5 formed in the center are as follows:
This is a part that temporarily connects the symmetrically arranged biogenic bodies 2 until the time of halving them. The biogenic body 2 is formed by continuously extruding a plasticized kneaded clay with a moisture content of about 20% from the mold 1, and is cut into predetermined dimensions to form one unit of the biogenic body 2. Become. One unit of biological body 2, which is symmetrically arranged and integrally connected, is
After drying, a glaze is applied to the parts 2a and 2b that will become the tile surface in the future (hereinafter referred to as the element surface), and then fired. The dry element body 2 is
During firing, they are stacked in layers as shown in FIG. That is, on top of the temporary joint surface of the unroasted glaze in the dry element body 2 located in the lower stage and the portion 2d that will become the tile side surface in the future, the joint surface of the unroasted glaze in the raw material body 2 located in the upper stage and The portions 2c that will become the tile side surfaces in the future are stacked in two to several stages and charged into the firing furnace. When the firing is completed, the tile is taken out of the oven and divided into two at the sole forming space 5 to obtain the product tile 3 shown in FIG. 3. At that time, the connecting parts of the fired element bodies 2, which were arranged symmetrically,
It is separated from the fired element body 2 and discarded.

As mentioned above, when the biogenic bodies 2 are molded by wet extrusion, the biogenic bodies 2 in a symmetrical arrangement,
The sole forming space 5 interposed between the two is formed by a punched ball 14 mounted in the center of the cavity of the mold 1 (see FIG. 5).
However, around the punched ball 14, there are many irregularities superimposed according to the number of soles to be formed, and this part has a large resistance to the flow of clay during extrusion. becomes. Therefore, the filling density of the clay in the vicinity of the sole forming space 5 in the biomass body 2 is lower than that in the vicinity of the base body surfaces 2a, 2b, which have less irregularities. A portion where the clay filling density is low has a large amount of shrinkage due to firing. Moreover, the greater the degree of unevenness and the greater the number of the unevenness, the longer the extension line of the outline, and the longer the extension line, the greater the amount of shrinkage due to firing. Such shrinkage is accumulated in the vicinity of the element body connecting portions located at both longitudinal ends of the sole forming space 5 and the portions 2c and 2d that will become the tile side surfaces in the future. Therefore, when the biogenic body 2 is fired, it deforms as shown in FIG. That is, the element body connecting portion 6 and the portions 2c and 2d that will become the tile side surfaces in the future are curved inward and recessed, especially the connecting portion 6 located in the middle.
A phenomenon occurred in which the dents were severe. Such a phenomenon has the disadvantage of deteriorating the dimensional accuracy of the product tile 3.

The fact that the element body connecting portion 6 and the portions 2c and 2d that will become the tile side surfaces in the future are recessed inward means that
This also means that the corner angles of the portions transitioning from the surfaces c and 2d to the element surfaces 2a and 2b protrude at acute angles. Therefore, when dry element bodies 2 are stacked and fired as shown in FIG. 2, the acute angles in the lower element bodies 2 and the acute angles in the upper element bodies 2 come into local contact. The weight of the element bodies 2 stacked on the upper tier is intensively loaded on the parts that are in local contact. However, during the firing process, the clay that is the material of the element body 2 is temporarily melted, so that a phenomenon has occurred in which the upper and lower elements 2 are fused to each other at the portions where they are in local contact. If there is fusion bonding between the elements 2, the fused portion may be damaged when the two are separated, resulting in defective products. In addition, the element surfaces 2a and 2b
If the glaze applied to the glaze drips during firing and wraps around the area where it came into contact with the glaze, the fused state will further expand and the damage caused when the glaze is separated will be severe.

As a conventional measure to prevent such defects, as shown in FIG. 2, an insoluble alumina particle layer 4 is interposed in the area where fusion is expected to occur, so that the lower element body 2 and the upper element body 2 are separated from each other. Means was taken to bring the element into indirect contact with the element body 2. Alumina particle layer 4
is formed by mixing alumina particles and water to form a suspension and applying the suspension. If this means is sufficiently effective, mutual fusion of the element bodies 2 can be prevented, and the alumina particle layer 4 can be easily removed after firing. However, the alumina particle layer 4 needs to have a uniform thickness, and the effect will be unstable unless the contact area and deformation due to firing are evenly distributed.
In practice, the situation was such that no reliable effect could be expected in preventing the above-mentioned drawbacks.

[Means for solving problems]

The present invention was created with the aim of solving the above problem, and the solution is as follows:
In a mold for wet extrusion molding of a biomaterial for tiles that is scheduled to be split into two, the mold cavities for molding the main body of the material are symmetrical on both sides of an imaginary center line that bisects the front of the mold. A punching ball for forming the sole of the element body is placed on the virtual center line, and a side part for forming a side part and a connecting part of the body is placed at both end areas in the front longitudinal direction of the punching ball. The voids are arranged symmetrically, and the voids on both sides are expanded by an amount corresponding to the amount of shrinkage deformation during firing of the element body, so that the inner surface of the void is shaped like the bottom of a ship with a flat central surface.

[Effect]

The mold for wet-formed tiles according to the present invention (hereinafter referred to as
In the case of the proposed mold (hereinafter referred to as the mold), there are side gaps arranged symmetrically at both ends in the longitudinal direction of the punched ball installed on the front center line, and the area occupied by the side gaps is an amount corresponding to the amount of shrinkage deformation during firing of the element body. Because it was expanded and the inner surface of the cavity was shaped like the bottom of a ship with a flat central surface,
The bioelement which is extrusion-molded by the present mold and is to be split into two parts is bulged with an allowance for the amount of shrinkage and deformation of the joint part during firing, and the element body is bulged from the side of the element body following the joint part. The corners of the portion transitioning to the surface are chamfered, and their overall surface shape presents a trapezoidal cutout surface corresponding to the bottom-like surface of the inner surface of the cavity in the mold.

Therefore, if the upper element is stacked and fired in the same position on the trapezoidal surface of the joining part and side of the lower element, the trapezoidal surface of the lower element will be flattened and the chamfered corners will be acute. There will be no noticeable deformation. Therefore, the stacked fired bodies do not come into local contact with each other and do not fuse together.
Generation of defective tiles due to fusion separation can be prevented, and product tiles with excellent dimensional accuracy can be obtained.

〔Example〕

EMBODIMENT OF THE INVENTION Hereinafter, the structure of this invention will be explained in more detail based on the Example shown in drawing.

FIG. 5 shows one embodiment of the mold 7 according to the present invention, and is a perspective view seen from the front side. A punched ball 14 for molding the sole of a biogenic body obtained by extrusion molding is installed on the vertically imaginary center line at the front center of the mold 7 of the present invention. Tokitama 1
4, mold cavities 9, 9 for molding the main body of the biological body to be divided into two after firing are arranged symmetrically, and the inner surfaces 7a, 7b of the mold cavities 9, 9 are arranged symmetrically. Shape the surface contour of the resulting biomass. In addition, at both end regions in the longitudinal direction of the punched ball 14, there are a connecting part that temporarily integrates each bioelement body scheduled to be split into two, and lateral gaps 11, 11 that form the side part of each element body. are arranged symmetrically, and the inner surfaces 7c, 7d of the side gaps 11, 11 form the side contours of the joints and sides of the biological body. In the present mold 7, special measures were taken for the shapes of the side gaps 11, 11 and the inner surfaces 7c, 7d of the gaps. As already mentioned, in a biomaterial that is extruded using a mold and is scheduled to be split into two, the entire side part contracts inward during firing and becomes curved, with the two parts being the most concave at the connecting part in the center. Serious. Therefore, in the present mold 7, the side gaps 11, 11 are expanded by the amount of shrinkage deformation of the element body, and the shape of the gap inner surfaces 7c, 7d that outline the side gaps 11, 11 is shaped like a ship's bottom with a flat central surface. did. The reason why the inner surfaces 7c and 7d of the voids are shaped like a ship's bottom with a flat central surface is to ensure stability when stacking the molded bodies during firing, and to take into consideration the amount of shrinkage and deformation of each part during firing. This is to encourage them. In this example,
The dimensional relationship between the central flat surfaces of the bottom-shaped cavity inner surfaces 7c and 7d and the bottom slopes 12 and 12 of both wings is set as follows based on experience. That is, the front width W of each cavity inner surface 7c, 7d is 34 mm, and the width of the central flat surface is
W ₁ was 10 mm, and the width W ₂ of the bottom slopes 12, 12 was each 12 mm. The inclination gradient of the bottom slopes 12, 12 was set to 0.5/12. However, these dimensional relationships are not limited in nature, as they need to vary depending on the type of clay that is the raw material for the biomass, the shape and dimensions of the biomass, firing conditions, etc. In addition, in FIG. 5, 16 is a protrusion.
The scratches 16 form scratches on the sides of the extrusion-molded biomaterial, so that when the fired material is divided into two, the joint can be easily separated. Furthermore, in this embodiment, the cavity inner surface 7
Although the shape of the mold cavities 9, 9 outlined by a, 7b is a horizontal trapezoid, it is needless to say that the shape is not limited to a horizontal trapezoid. That is, it may be rectangular, semicircular, or various other shapes.

Next, the element body molded by the mold 7 configured as described above will be explained.

First, since the biomass that is continuously extruded from the mold 7 is still soft and plastic, it is cut into pieces of predetermined dimensions to obtain one unit of biomass. The cross-sectional shape of the biological body is as shown in FIG.
That is, the biological body 8 has a vertically long sole formation space 1 in the center.
5, and a main body 10, which is contoured in a horizontal trapezoidal shape by element surfaces 8a and 8b on both sides thereof.
10 are arranged symmetrically. Element body surface 8a, 8b
When the biomass 8 becomes a product tile, it becomes the tile surface, so a glaze is applied after drying. In addition, in the longitudinal direction both end regions of the sole forming space 15,
The bulging connecting portions 13, 13 and the side portions of the element body are arranged symmetrically. The surface of the bulge connecting part 13 and the side part of the element body is
It is contoured by element side surfaces 8c, 8d corresponding to the bottom-like cavity inner surfaces 7c, 7d of the mold 7. The side surfaces 8c and 8d of the element body are trapezoidal surfaces with an allowance corresponding to the amount of shrinkage deformation during firing. That is, the bulge connecting portion 13 and its neighboring outer surface are flat surfaces, and the side portions of the element body located on both wings of the bulge connecting portion 13 are sloped surfaces 18, 18, both of which are the element surfaces 8a, 8b. The corner that transitions to is chamfered. Swelling connection part 13
is a part that is separated and discarded when the element body 8 becomes a product tile, and since the side surfaces of the element body become the side surfaces of the product tile, these surfaces are usually not glazed. The bulge connecting portion 13 and the trapezoidal flat surface in its vicinity ensure stability when the element bodies 8 are stacked in layers during firing.

The biogenic body 8 having the shape described above is stacked in stages as shown in FIG. 7 when it is dried and fired. That is, the alumina particle layer 4 is provided on the side surface 8d of the element body 8d which has an upward trapezoidal width of the drying element 8 located in the lower stage, and is overlaid on the element having a trapezoidal downward facing width of the drying element 8 which is to be located in the upper stage. The body sides 8c are stacked one on top of the other. The bulging connecting portion 13 and the side portions of the element body, which were formed into a trapezoidal shape with allowances, shrink and deform as shown in FIG. 8 while the element body 8 is fired, and the overall surface shape becomes uniformly flat. be done. In this case, the element surface 8a,
Since the corner transitioning to 8b was chamfered in advance, that part does not protrude at an acute angle, and therefore the upper element body 8 and the lower element body 8 do not come into local contact. .

[Effect of idea]

The molding according to the present invention has the above-mentioned configuration, and in particular, the shape of the side voids arranged symmetrically at both end regions in the longitudinal direction of the punched ball installed on the front center line corresponds to the amount of shrinkage deformation during firing of the obtained element body. The inner surface of the cavity is shaped like the bottom of a ship with a flat central surface.

Therefore, in the biomass formed by the proposed mold, the joining part where the shrinkage during firing is most likely to accumulate and the side part of the base body where it is to be split into two are swollen with an estimated amount corresponding to the amount of shrinkage deformation during firing. Since the corners of the portion transitioning from the side surface of the element body to the surface of the element body are chamfered, the overall surface shape of the side surface of the element body is a trapezoidal shape. When the body is fired, the trapezoidal surface is uniformly flattened.

Therefore, the element body obtained by the mold according to the present invention has the following effects.

Even if the elements are fired in a stacked state, locally protruding deformed parts will not occur on the mutually overlapping surfaces, and there is no risk of fusion due to contact of locally deformed parts, and there will be no intervening parts on the overlapping surfaces. Even if the alumina particle layer is uneven, and even if the glaze drips, there is no risk of fusion. Therefore, the element body does not suffer from defects due to fusion separation, contributing to improvements in work efficiency and product yield.

Since the bulge portion of the element body with the estimated allowance is offset in accordance with the amount of shrinkage deformation caused by firing, a product tile with excellent dimensional accuracy can be obtained.

[Brief explanation of drawings]

Figures 1 to 4 relate to the prior art, in which Figure 1 is a perspective view showing a mold and the biological body extruded by the mold, and Figure 2 is a front view showing a stacked state of dry element bodies. Figure 3 is a perspective view showing a product tile obtained by dividing the fired element body, Figure 4 is a front view showing the fired element body, and Figures 5 to 8 are related to the present invention. Figure 5 is a perspective view of the mold from the front side.
FIG. 6 is a front view of the biomass body, FIG. 7 is a front view of the dry base body in a stacked state, and FIG. 8 is a front view of the fired base body in a stacked state. 7...Proposed mold, 7a, 7b...Cavity inner surface,
7c, 7d... Gap inner surface, 8... Element body (bio element body, dry element body, fired element body) by the proposed mold, 8a,
8b...Element body surface, 8c, 8d...Element body side surface, 9
... Mold cavity, 11 ... Lateral cavity, 13 ... Swelling connection part, 14 ... Ball-extrusion, 15 ... Sole formation space.

Claims (1)

[Scope of utility model registration request] In a mold for wet extrusion molding of a biomaterial for tiles that is scheduled to be split into two, the mold cavities for molding the main body of the material are symmetrical on both sides of an imaginary center line that bisects the front of the mold. A punching ball for forming the sole of the element body is placed on the virtual center line, and a side part for forming the side part and the connecting part of the body is placed at both end areas in the front longitudinal direction of the punching ball. A wet-formed tile characterized in that the voids are arranged symmetrically, and the voids on both sides are expanded by an amount corresponding to the amount of shrinkage deformation during firing of the element body, so that the inner surface of the void is shaped like the bottom of a ship with a flat central surface. Molding mold.