JPH0544886B2 - - Google Patents

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to irregularly shaped tiles in which a side surface of one tile has a portion where two different surfaces face inward and intersect. This invention relates to a method for molding irregularly shaped tiles in which a convex portion is formed on the mold to partially increase the molding pressure to compensate for the lack of molding pressure caused by the molding.

[Conventional technology]

An example of a tile exhibiting a special decorative pattern is an irregularly shaped tile 1 as shown in FIG. 4. This irregularly shaped tile 1 has four circumferential side surfaces 1a to 1d that are opposed to each other and are formed in a symmetrical shape, so that the uneven surfaces match each other when installed. Thus, each of the four circumferential side surfaces 1a to 1d of the irregularly shaped tile 1 is formed with at least one portion 2 where two different surfaces intersect inwardly. Irregular-shaped tiles 1 having such intersecting portions 2 are formed by wet molding on four circumferential sides 1a to 1.
Since it is not possible to form the unevenness of d, it is manufactured by dry molding. In dry molding, normally, as shown in FIG. 5, a filling space 5 formed by a frame mold 3 and a lower mold 4 is filled with clay 6, and this is pressurized by an upper mold 7 to form a tile molded body. The product is obtained by applying a glaze and firing it.

Incidentally, the irregularly shaped tile 1 exhibiting such a special decorative pattern is used as a paving block by being attached to the surface side of a cement block or the like having the same shape, for example. on the cement block,
By pasting the irregularly shaped tiles 1, it is possible to improve the abrasion resistance and also to obtain an aesthetically excellent paving surface.

[Problem to be solved by the invention]

By the way, in the dry forming method of such irregularly shaped tiles 1, when the clay 6 is pressurized by the lowering of the upper mold 7, forming stress as shown in FIG. 6 is generated in the clay 6. This forming stress is applied from the outside to the inside of the irregularly shaped tile 1, and from each of the four circumferential sides 1a to 1.
It acts in a direction perpendicular to d. Therefore, as shown in FIG. 6, stress is dispersed in different directions at a portion 2 where two different surfaces intersect inwardly, resulting in insufficient molding pressure for the clay in this portion. Therefore, when such a pressure-formed base body is fired, the behavior associated with thermal expansion and contraction of the tile is divided at the portion where the molding pressure is insufficient, and the behavior associated with thermal expansion and contraction occurs individually in each divided region. Then, as shown in Fig. 6, the intersecting part 2
There was a drawback that cracks 8 were generated.

[Means to solve the problem]

The present invention improves and eliminates the above-mentioned conventional problems, and provides a tile forming method that does not leave localized areas of insufficient molding pressure on the tile base during dry pressure forming of tiles. This is what I am trying to do.

Therefore, the means adopted by the present invention to solve the above problem is to provide an irregularly shaped tile in which a side surface of one tile is formed with a portion where two different surfaces face inward and intersect, and the intersecting portion is A convex portion is formed on the molding surface of the mold corresponding to the back side of the mold, so that the molding pressure applied to the clay in the intersecting parts is higher than the molding pressure applied to the clay in the parts other than the intersecting parts, During molding, the lack of molding pressure due to the dispersion of stress generated at the intersecting portion from the outside of the tile to the inside of the tile is compensated for.

[Effect]

Normally, when clay, which is a raw material for a tile base, is dry pressure molded, the stress distribution of the forming pressure acting on the clay acts perpendicularly to each side surface from the outside to the inside of the tile base. Therefore, in the case of irregularly shaped tiles in which two different surfaces face inward and intersect on one tile side surface, local stress dispersion from the intersecting portion occurs, resulting in insufficient forming force. Become.

Therefore, in the present invention, a convex part is formed in the mold corresponding to the intersecting part, so that the molding pressure acting on the clay at the intersecting part is higher than the molding pressure acting on the clay at other parts. That's what I do. As a result, the molding pressure acting on the clay at the intersecting portions is compensated for by the deficiency caused by the locally dispersed stress, and a uniform stress distribution of the molding pressure can be obtained over the entire tile base. Therefore, during thermal expansion and contraction in the subsequent firing process,
No cracks will occur where two different surfaces intersect inward.

〔Example〕

The molding method of the present invention will be described below based on examples shown in the drawings.

1 to 3 relate to one embodiment of the present invention, and FIG. 1 is a partially enlarged vertical cross-sectional view of a mold;
FIG. 2 is a bottom view of the irregularly shaped tile 11, and FIG. 3 is a side view of the same tile 11. It should be noted that, as in the conventional case, the irregularly shaped tiles 11 of this embodiment are attached to the surface side of a cement block or the like of the same shape and used, for example, as a paving block. As shown in FIGS. 2 and 3, the irregularly shaped tile 11 of this embodiment is different from the conventional irregularly shaped tile 1 shown in FIG.
The same planar shape is used, and each of the tile side surfaces 11a to 11d is formed with a portion 12 where two different surfaces intersect inward. In this embodiment, as shown in FIG. 1, the portion of the lower mold 14 corresponding to the intersecting portion 12 is provided with a convex portion having an arcuate inner circumferential surface 19a when viewed from above. A portion 19 is formed. Then, the filling space 15 formed by the frame 13 and the lower mold 14 of such a mold is filled with clay 16, which is the raw material for the tile base, and the upper mold 17 is lowered to pressure-form the clay. As a result, as shown in FIGS. 2 and 3, a recess 20 having an arc-shaped inner circumferential surface 20a is formed in the portion 12 where two different surfaces of the tile back surface 11e intersect inwardly. .

In this way, the intersecting portion 1 of the irregularly shaped tiles 11
By forming a convex part 19 on the part of the lower mold 14 corresponding to 2 and press-molding the clay 16 which is a tile base material, it is possible to compensate for the lack of molding pressure due to stress dispersion to the intersecting part 12. It is possible. This will be explained below. That is, the first
As shown in the figure, when the upper die 17 is lowered and the clay 16 filled into the filling space 15 is pressurized, the tile base is molded from the outside to the inside in the direction indicated by arrow A in Figure 1. Pressure stress is generated, and at the portion 12 where two different surfaces intersect inwardly, insufficient molding pressure occurs due to stress dispersion.
On the other hand, in the part of the lower mold 14 corresponding to the part 12 where two different surfaces face inward and intersect, a convex part 1 is provided.
9 is formed, so this intersecting part 12
The molding pressure of the clay 16 in the region becomes larger than the molding pressure of the clay 16 in other parts, and the increased molding pressure is the insufficient molding pressure due to stress dispersion generated in the intersecting part 12. corresponds to Therefore, the insufficient molding pressure at the intersecting portion 12 due to the dispersion of stress due to the molding pressure indicated by arrow A is caused by locally increasing the molding pressure at the intersecting portion 12 due to the formation of the convex portion 19. It is possible to compensate by In this case, what should be noted is that the inner circumferential surface 19a of the convex portion 19
The molding pressure is formed to have an arc shape when the side is viewed from above, and the stress of the molding pressure shown by arrow A is distributed in a direction perpendicular to the inner circumferential surface 19a, so that it is locally concentrated. It is important to ensure that they do not become dispersed.

Therefore, in the dry-formed tile base as described above, there will be no insufficient molding pressure due to stress dispersion at the part 12 where two different surfaces intersect inward, and thermal expansion and contraction during the firing process will not occur. Since the behavior is performed on the whole tile as a unit and not on parts, the intersecting part 12
No cracks will occur.

The present invention is not limited to the embodiments described above, and can be modified as appropriate. For example, the shape of the irregularly shaped tile 11 may be arbitrarily changed depending on the decorative purpose, and the convex portion 19 of the mold corresponding to the intersecting portion 12 may be formed on the upper mold.

〔Effect of the invention〕

As explained above, in the present invention, when molding an irregularly shaped tile having a portion where two different surfaces intersect inwardly on the side surface of one tile, the stress dispersion from the intersecting portion is This can be compensated for and released by locally increased molding pressure, resulting in a uniform molding pressure stress distribution over the entire tile substrate. Therefore, during the subsequent firing process, no cracks will occur at the intersections. In other words, it is possible to significantly improve the yield.

[Brief explanation of the drawing]

1 to 3 relate to one embodiment of the present invention, and FIG. 1 is a partially enlarged vertical cross-sectional view of a mold;
Figure 2 is a bottom view of the irregularly shaped tile, Figure 3 is a side view of the same, Figures 4 to 6 are related to the prior art, Figure 4 is a plan view of the irregularly shaped tile, and Figure 5 is a mold. FIG. 6 is a partially enlarged view of the tile molding base showing the stress distribution during molding. DESCRIPTION OF SYMBOLS 11... Unusual tile, 11a to 11d... Tile side surface, 12... Intersecting portion, 14... Lower mold, 19... Convex portion.

Claims (1)

[Claims] 1. Regarding an irregularly shaped tile in which a part of one tile side face is formed where two different faces face inward and intersect, a convex part is formed on the molding surface of the mold corresponding to the back side of the intersecting part, The molding pressure applied to the clay in the intersecting parts is set to be higher than the molding pressure applied to the clay in the parts other than the intersecting parts,
1. A method for forming irregularly shaped tiles, characterized in that the insufficient forming pressure is compensated for by dispersing stress generated at the intersecting portions from the outside of the tile to the inside of the tile during forming.