JPS646260Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a formwork for producing concrete blocks for paving, which are used for laying on sidewalks, parks, plazas, etc.

In recent years, block pieces called so-called interlocking blocks have been increasingly used as this type of concrete block.
The general method of manufacturing it is to mold ready-mixed concrete in a mold, remove it from the mold once it has hardened to a predetermined thickness, and then cure it.
By the way, the molds used for this manufacturing have traditionally been exclusively cast products, but cast products have limitations in the accuracy of mold dimensions and limited durability due to poor toughness. For these reasons, it is unsuitable for the current block formwork, which now requires extremely high dimensional accuracy.

This invention eliminates the above-mentioned drawbacks and is highly durable.
The aim is to provide a formwork that can exhibit high dimensional accuracy, and its gist is that the material is structural steel, the exposed surface of which has been carburized and hardened, and the inner peripheral wall surface has concave and convex parts. In the continuous interlocking block mold, a required number of concave portions with a depth of approximately 0.3 mm and a required length to prevent concrete from falling before curing were placed at required positions on the convex surface of the mold, and were distributed over the entire circumference. This is a formwork for manufacturing concrete blocks for paving, which is characterized by the following.

In addition, in this invention, the depth of the recess for preventing concrete falling before curing is set to approximately 0.3 mm because the depth of the carburized hardened layer on the inner wall surface of the formwork in this invention is usually approximately 1 mm. .

The reason why this recess is provided on the convex surface of the formwork is to improve the workability of carving the recess.

The present invention will be described in detail below with reference to the drawings.

FIG. 1 is a schematic diagram of the formwork for manufacturing concrete blocks for pavement according to the present invention. As shown in FIG. 1, a plurality of hollow portions 2 are provided in one structural steel plate 1. It is something. The shape of the hollow portion 2 may vary depending on the desired shape of the interlocking block. In the formwork of the present invention, the inner wall surface of the hollow part 2 is carburized and hardened to a depth of about 1 mm, and the outermost layer has a hardness of about Hv 700, and even at a depth of 1 mm, it has a hardness of about Hv 400 or more. It is something that you have.

Figure 2 shows an explanatory diagram of only two parts of one hollow part.
FIG. 3 shows an enlarged sectional view taken along the line A-A in FIG. 2. As shown in FIGS. 2 is formed by machining, and then a recess 3 for preventing concrete from falling before curing is carved by a required means such as machining. In addition to the recess shown in FIG. 3, the recess may have a smooth curved corner as shown in FIG. 4. All exposed surfaces are then carburized and hardened. In this case, the size and number of the recessed portions 3 should be appropriately selected depending on the size of the hollow portion 2, but as a result of various experiments, the width (in the vertical direction) is preferably about 5 mm. Moreover, the length (circumferential direction) is approximately 20 to 30 mm per piece, and the number of recesses can be increased depending on the size of the hollow part 2, but the total length (circumferential direction) of the recesses 3 It has been found that it is preferable that the length be about 20 to 30% of the inner circumference of No. 2, and that if it is less than that, the fall prevention effect will be low, and if it is too long, it may leave traces on the final complete product, so it is not desirable. . In addition, the height (position) in the vertical direction at which the recess 3 is carved should be at the bottom of the formwork as a condition that it does not leave much trace on the final product and has the effect of preventing falling. 25-33% of the height of the formwork from the bottom
It was found that a higher position was preferable.
This is also due to the following reason. In other words, the concrete placed in the formwork becomes a convex part due to the concave part 3, and this concave part 3 and the convex part of the concrete fit together to prevent falling, but the concave part If the convex part 3 is located near the bottom surface, if the convex part formed in the concrete becomes uncoupled due to external force such as vibration during transportation, it will be easily released from the formwork, and there will be less fall prevention effect, while the concave part 3 If it is near the top surface, a so-called hanging phenomenon will occur, and the concrete will not be able to support its own weight, causing cracks and the like to occur near the recesses, resulting in product defects.

As described above, according to the present invention, the raw concrete filled in the formwork enters the fall prevention recess carved into the inner wall of the formwork, and once the concrete has hardened to a certain extent, it is cured. The concrete is loaded in several stages on top of the concrete pallet, but during the operation, the convex part of the concrete digs into the concave part to prevent concrete from falling, so the concrete does not fall when it is not needed.
Furthermore, since the formwork of the present invention is machined from structural steel and the entire exposed surface is carburized and hardened, it has the advantage that it is easy to sufficiently improve its dimensional accuracy.

In addition, according to the present invention, it is possible to prevent uncured concrete from falling as described above, but on the other hand, when a concrete block is to be pulled out from the formwork for curing, it can be easily pulled out by pushing it with a plunger. Since the fall prevention protrusion formed on the concrete block has a slight height of approximately 0.3 mm, product defects such as breakage and scratches due to the protrusion do not occur at all.

[Brief explanation of the drawing]

Fig. 1 is a perspective view of the formwork for manufacturing concrete blocks for paving according to the present invention, Fig. 2 is an explanatory view of the main parts thereof, Fig. 3 is an enlarged sectional view taken along the line A-A in Fig. 2, and Fig. 4
The figure is a sectional view of a main part showing another shape of the recessed part of the formwork in the present invention. In the figure, 1: structural steel plate, 2: hollow part, 3: recessed part.

Claims (1)

[Scope of utility model registration request] A mold for interlocking blocks made of structural steel, the inner wall of which has been carburized and hardened, and the inner peripheral wall of which has a continuous concave and convex portion, is characterized in that a required number of recesses, each about 0.3 mm deep and of a required length, for preventing pre-cured concrete from falling are distributed around the entire circumference at required positions on the convex portion.