JPH08142026A - Mold for concrete product - Google Patents

Abstract

PURPOSE: To obtain a mold for a concrete product low in the adhesiveness with concrete, improving the releasability of the concrete product even if a release agent is not used and capable of easily demolding the concrete product without generating a crack or damage though formed into an integral box shape and having the embossed patterns corresponding to the surface patterns of the concrete product. CONSTITUTION: A mold A formed into an upwardly opened box shape and having the embossed patterns 3 corresponding to the surface patterns of a concrete product or a tile fitting recessed part formed to at least one inner surface thereof is molded by in-mold beads foam molding using a polyolefinic resin. Crevices 6, 6 reaching the vicinity of the bottom part 1 of the mold from the opening edge part thereof are opposedly formed to the mutually opposed side wall parts 2a, 2b of the mold and the groove 8 extending from one side end of the bottom part to the other side end thereof is formed to the rear surface of the bottom part at the corresponding position with the crevices 6, 6 to easily perform the opening operation of the opening part 5 of the mold.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a concrete product used for curbs, paving stones, retaining walls, and the like, particularly a concrete product having a hanging pattern or other uneven pattern on the surface, or a pattern tile on which the concrete is applied. The present invention relates to a molding die for molding concrete products such as blocks.

[0002]

2. Description of the Related Art Conventionally, when molding concrete products such as curbstones for roads and flower beds, paving stones, and concrete blocks with patterns used for retaining walls, concrete molding made of iron or wood A sheet with a concavo-convex pattern made of a material such as silicone rubber or urethane rubber is arranged on the inner surface of the mold, and concrete is poured into the sheet for molding.

However, since the above-mentioned molding die is made of metal or wood, the larger the concrete product is, the heavier it is and the more difficult it is to handle. For example, when the molding die is leaned against the molding product and cured. , Its work was not easy.

In addition, the use of the sheet with the uneven pattern requires a mold for molding the sheet, and a release agent for improving the release property between the sheet and the concrete product. It is indispensable, and there is a problem that the coating work is troublesome and that the release agent remains in the concave and convex portions to cause flaws such as pinholes on the surface of the concrete product.

Further, in recent years, in order to reduce the weight of this type of molding die, a molding die made of Styrofoam has been often used. However, since Styrofoam has a relatively good adhesiveness to concrete, it is also required. A mold release agent needs to be applied, and its elasticity and toughness are poor, and it easily cracks or breaks during die cutting, cannot withstand repeated use, and has to be discarded almost once or several times. It was something I didn't get.

Particularly, in the case of an integral mold having a concave-convex pattern corresponding to the product surface on the inner surface of a box-shaped mold, such as a concrete product molding mold having a concave-convex pattern on the surface, the molding mold is used after hardening of the concrete. It was extremely difficult to die-cut without cracking or breaking so that it could be reused.

There is also a molding die of this kind having an uneven pattern on the inner surface, which is made of non-foamed urethane rubber. However, in the case of this urethane rubber, it is also heavy and difficult to handle, and there is a problem in workability. Moreover, there is a drawback that it is very expensive.

It is an object of the present invention to be lightweight and easy to handle, to have low adhesiveness to concrete, and to provide good releasability of concrete products without the use of a release agent. An object of the present invention is to provide a molding die which can be easily die-cut without causing cracks or damages, even if it has an uneven pattern corresponding to the pattern.

[0009]

A mold for concrete products according to the present invention, which solves the above problems, has a box shape with an opening on the upper surface, and an uneven pattern or a concave portion for tile fitting is formed on at least one surface on the inner surface. And a molded mold,
It is formed by in-mold bead foam molding using a polyolefin resin as a material.

In the above-mentioned forming die, it is particularly preferable that at least one of the side walls facing each other is formed with a crack facing each other from the opening edge portion to the vicinity of the bottom portion. Further, it is more preferable that the bottom surface of the bottom portion is formed with a groove extending from one end to the other end at a position corresponding to the crack in the side wall.

[0011]

According to the above-mentioned molding die of the present invention, the foaming material of the polyolefin resin, which is a constituent material of the molding die, has low adhesiveness to concrete because of its material, and therefore, it is not necessary to use a release agent. Even so, the concrete does not become too tightly adhered and cannot be released.

Moreover, the foam of the polyolefin-based resin has appropriate elasticity and flexibility, and has a toughness as compared with expanded polystyrene. Therefore, when the concrete product is demolded, the opening of the box-shaped molding die is widened so that the concrete product can be easily released without cracking or damage. Moreover, even if there is an uneven pattern on the inner surface of the mold, for example, an uneven pattern corresponding to the surface pattern of the concrete product, there is also a recess for fitting the tile, and the tile is integrally attached to the surface of the concrete product. However, the continuous product can be die-cut easily and without causing damage.

In particular, when a crack extending from the opening edge to the vicinity of the bottom is formed on at least one of the opposing side wall portions so as to face each other, the molding die is provided with the crack portion. The opening can be widened as it opens so that the die cutting of the above-mentioned finished product becomes easier.

Further, when a concave groove is formed on the lower surface of the bottom portion at a position corresponding to the crack as in claim 3, the bottom portion becomes thin at the concave groove portion and is easily bent. The mold expanding operation can be performed more easily.

Since the polyolefin resin foam has a toughness, even if the crack is opened as described above, the crack does not occur from this portion.

[0016]

Embodiments of the present invention will now be described with reference to the drawings.

1 to 4 show an embodiment of a molding die (A) according to the present invention.

This molding die (A) has a bottom portion (1) having a rectangular shape in plan view and side wall portions (2a) (2a)) (2b) (2) on four sides.
By b), it is formed in a vertically long box shape that opens upward, and the inside thereof is a molding space for concrete products. On the inner surface of the box-shaped mold (A), an uneven pattern (3) such as a chipping pattern corresponding to the surface form of the concrete product is provided with side walls (2) facing the bottom (1) and the long side.
a) It is formed on the surface of (2a). (5) shows an opening.

The concavo-convex pattern (3) need only be formed on at least one of the inner surfaces, and for example, one of the facing side wall parts, mainly the long side facing side wall parts (as shown in the drawing). It may be provided on the inner surface of at least one of 2a) and 2c, or may be provided only on the surface of the bottom portion (1).

This molding die (A) is made of a polyolefin resin such as polypropylene or polyethylene or a polyolefin resin such as a polyolefin-based copolymer or the like. It is formed and is reasonably elastic and relatively tough. Among them, the polypropylene foam is slightly harder and more rigid than the polyethylene foam, so that the expansion ratio can be set to a large value and it is economical.

The above-mentioned polyolefin resin foam has a foaming ratio of 2 to 60 times, preferably 3 to 3, in consideration of lightness and strength in use as a mold for concrete products.
It is set to 40 times, particularly preferably 5 to 30 times.
That is, if the expansion ratio is too high, the elasticity and flexibility of the foam itself may be increased, and the surface of the concrete product may be deformed and molded, and if the expansion ratio is decreased, the effect of weight reduction may be obtained. It becomes small, the amount of resin used increases, and it becomes expensive. Therefore, it is preferable to set it in the above range.

In the bead foam molding of the molding die (A) itself, when the male and female dies are separated after molding, the molded article is placed on the male die side due to the uneven pattern (3) on the inner surface of the die. Since it adheres, the molded product is released from the opening side by pressing with a push pin.

In the molding die (A) made of a polyolefin resin foam having the above expansion ratio, the bottom portion (1) and the side wall portions (2a) (2a) (2b) (2b) have a considerable thickness. Even if it is made of steel, it is lighter in weight and easier to handle than a mold made of iron or wood, and has sufficient shape retention strength and surface strength.

Further, the molding die (A) of the illustrated embodiment is
An opening is formed in one of the side walls facing each other, particularly in the central portion of the side walls (2b) (2b) on the short side between the side walls (2a) (2a) having the concave-convex pattern (3) as shown in the figure. The crevices (6) and (6) extending from the edge to the vicinity of the bottom (1) are formed facing each other. In the case of the drawing, the outer surface at the position where the crack is formed is notched (7) into a V shape so that the expanding operation can be easily performed at the time of die cutting after the concrete product is molded.

A concave groove (8) extending from one end to the other end is provided on the lower surface of the bottom portion (4) at a position corresponding to the cracks (6) and (6). It is formed to be a little thin, so that the expanding operation at the crack (6) can be performed more easily.

The cracks (6) and (6) are not limited to those provided in the center of one of the facing side wall portions (2b) and (2b) as shown in the figure, and a plurality of cracks may be provided in the facing side wall portions. It is possible to provide a crack, or in the case of a mold having a large planar shape, a crack can be formed in each of the side wall portions facing each other in both the vertical and horizontal directions.

Further, the concave groove (8) on the lower surface of the bottom portion (1)
With respect to the above, it is possible to implement by providing a plurality of or in both vertical and horizontal directions at positions corresponding to the cracks.

According to the forming die (A) of this embodiment, when the concrete product (B) is formed, the cracks (6) and (6) in the side wall portions (2b) and (2b) are opened by pouring the concrete. To prevent this, use adhesive tape to stop the cracks or band them as necessary. Then, concrete is poured into the space inside the mold to mold it.

When the mold is removed after the concrete is hardened, the opening (5) of the box-shaped mold (A) is expanded by utilizing the elasticity and flexibility of the material. Particularly, the molding die (A) of the embodiment has one side wall portion (2b) (2
Since the cracks (6) and (6) are formed in b) and the concave groove (8) is formed in the bottom (1), it is a box-shaped integral mold (A). Regardless, it can be easily expanded to open the cracks (6) (6) (Fig. 4), so that there is an uneven pattern (3) on the inner surfaces of the side walls (2a) (2a) and the concrete product (B). Despite having the unevenness corresponding to the uneven pattern (3) on the surface, the product (B) can be easily die-cut without damaging the molding die (A).

Moreover, the material has a lower adhesiveness than styrene foam, and the concrete surface easily separates from the mold surface. Therefore, even if a mold release agent is not applied, concrete remains on the inner surface of the mold. Never. Therefore, this molding die (A) can be repeatedly used, for example, can be repeatedly used 30 times or more.

FIGS. 5 and 6 show another embodiment of the molding die (A).

In the molding die (A) of this embodiment, at least one of the inner surfaces of the molding die (A) is provided with a recess (9) for fitting a tile. That is, the concave portion (9) into which the tile (C) can be fitted and mounted on the inner surface of the bottom portion (1) and the inner surface of the side wall portion (2a) on the long side is a vertical and horizontal convex portion (10) corresponding to the joint space. ) Are formed in parallel with each other. The tile fitting recess (9) may be formed on another inner surface so as to correspond to the surface of the tiled concrete product.

The other constructions and materials are basically the same as those in the above-mentioned embodiment, and the same components are designated by the same reference numerals.

In the case of the molding die (A) of this embodiment, the tile (C) is installed in the recess (9) before the concrete is poured. In this way, after pouring concrete in the same manner as above and curing and hardening, the molding die (A) is cracked (6).
When (6) is opened and opened, the tile (C) is integrally attached to the surface of the concrete product and removed from the recess (9), so that the concrete product can be easily die-cut. . This makes it possible to obtain a concrete product in which tiles are attached to the surface. Also,
In order to obtain a box-shaped concrete product (B) used for a retaining wall or the like having a recess in its back as shown in FIG. 7, an inner mold for molding an internal space is combined with the above mold (A). You can use it. This inner mold is also preferably molded from a foam of polyolefin resin as described above. When the concrete product (A) thus formed is used as a retaining wall or the like, the bolt insertion hole (11) for the connection may be formed at a desired location such as the side wall. If necessary, a connecting means for connecting to another structure can be provided.

The planar shape of the molding die is not limited to the rectangular parallelepiped shape shown in the illustrated embodiment, but may be other polygons, polygons with rounded corners, or other concrete products. It can be implemented in various modes depending on the situation.

[0036]

As described above, according to the molding die of the present invention, a polyolefin resin foam is used as a material.
Lightweight and easy to handle, the adhesiveness of concrete is low, concrete products can be easily released without using a release agent, concrete does not remain on the mold surface, and the material is Even if it has a moderate elasticity, flexibility and toughness and forms an integral box shape, it is relatively easy to spread the opening and it does not crack or break. Can be die-cut. Therefore, this molding die can be repeatedly used as many as 30 times or more, which is economical as compared with the case where a foamed styrol product is used.

Particularly, when the side walls facing each other are provided with cracks, and when the bottom surface of the bottom is further provided with a groove, the openings can be easily and easily compared by utilizing the above-mentioned grooves or grooves. Since it can be expanded greatly, it can more easily perform the die-cutting action, and even if it is a concrete product with an uneven pattern on the surface or a concrete product with tiles attached, it is easy to mold without cracking or damage. Can be pulled out. Therefore, the molding work of this type of concrete product can be further simplified, and the molding die can be repeatedly used many times, so that the economical effect thereof becomes great.

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of a molding die of the present invention.

FIG. 2 is a plan view of the same.

FIG. 3 is a sectional view of the above.

FIG. 4 is a cross-sectional view of the same die-cutting state.

FIG. 5 is a perspective view showing an example of another molding die.

FIG. 6 is a sectional view of the same.

FIG. 7 is a perspective view showing a box-shaped concrete product having a recess on the back.

[Explanation of symbols]

 (A) Mold (1) Bottom (2a) (2a) One opposite side wall (2b) (2b) The other opposite side wall (3) Concavo-convex pattern (5) Opening (6) Crack (8) Recessed groove (9) Recess for tile fitting (B) Concrete product (C) Tile

Claims (3)

[Claims] 1. A molding die having a box-like shape having an opening on the upper surface and having an uneven pattern or a concave portion for tile fitting formed on at least one surface of the inner surface, which is obtained by in-mold bead foam molding using a polyolefin resin as a material. Molding mold for concrete products, characterized by being molded. 2. The concrete product molding die according to claim 1, wherein a crack extending from the opening edge portion to the vicinity of the bottom portion is formed so as to face at least one of the opposite side wall portions. 3. The mold for concrete product according to claim 2, wherein a concave groove extending from one side end to the other side end is formed on the lower surface of the bottom portion at a position corresponding to the crack of the side wall portion.