JPS647566B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The formwork for forming concrete products of the present invention is a concrete forming formwork for immediate demolding whose bottom surface has two-dimensional unevenness with a substantially uniform cross section, wherein the two-dimensional unevenness portions are: It is covered with a bottom plate that is an elastic thin steel plate or a durable hard rubber plate that is easy to bend in two dimensions and easily peeled off from the demolded product, and the bottom plate is the bottom of the formwork that suctions and supports the product in the shape of the two-dimensional unevenness. The adsorption force of the bottom of the formwork is sufficient to deform and hold the base plate, which is originally a flat plate, into the shape of the uneven parts, and the product and the spacing between the base plates when the product is removed from the mold. It is characterized by being weaker than the adhesion force.

When mass-producing concrete products, in addition to the pour molding method, a method is often used in which concrete with a slump value of zero is instantly hardened using vibration and a press and then immediately demolded.

This instant demolding method is highly efficient and has a great economic effect as it does not require leaving a large number of molds in the curing room.
For example, when the bottom surface is uneven as shown in Figure 1, the product and the bottom of the formwork often stick together and cannot be separated, or some concrete remains on the bottom side of the formwork, resulting in product defects. Therefore, products with such shapes have conventionally been considered unsuitable for immediate demolding.
The present invention provides a formwork that can immediately demold even such products.

An embodiment of the present invention is shown in FIGS. 1 and 2. The side plate 1 is substantially vertical (actually has a slight draft angle) and stands around a rectangular substrate or base frame 2, forming a box-shaped frame. On the substrate or base frame 2,
A bottom plate 3 having a two-dimensional unevenness with a substantially uniform cross section is attached to serve as the bottom surface of the formwork.

In this case, the uneven bottom plate 3 has a double structure along the top of the same-shaped receiving plate 3a, as shown in an enlarged view in FIG. ing. A plurality of these magnet pieces 5 are buried at important points on the bottom surface of the formwork so that the bottom plate 6 placed on the bottom plate 3 is pressed so that the magnet pieces 5 are brought into close contact with the entire bottom surface of the formwork. Of course, the magnet piece 5 is housed in the hole 4 so as not to protrude from the bottom surface.

The floor plate 6 is made of an elastic flexible plate, and is preferably made of a flexible elastic material that can be peeled off from one end of the demolded concrete product, such as a thin magnetic stainless steel plate or a tough rubber plate filled with magnetic particles.

The attraction force of the magnet pieces 5 does not need to be stronger than the extent that the bottom plate 6 is curved and brought into close contact with the surface of the bottom plate 3. When demolding the product C immediately, the bottom plate 6 must be released from the magnet 5 of the adsorption part and attached to the product C side and come out of the mold. Normally, there is no need to worry about this, but if the adsorption force is too strong and the bottom plate 6 remains inside the formwork,
Laying the bottom plate 6 becomes a waste.

Concrete is poured into this mold, vibrated as usual using a vibrating device (not shown), pressed down by a press plate 7, and the mold is turned over as shown in FIG. 4 by a reversing device (not shown), whereby the product C falls off. Note that before applying the press plate 7, a receiving plate 8 is placed on the upper surface of the concrete as shown in FIG. 1, so that the fallen product C is placed on the receiving plate 8.

To peel off the bottom plate 6 from this product C, simply peel it off from one end. Unlike the case where the rigid surface and the concrete surface are in close contact, when the flexible and elastic floor plate 6 is lifted with one end with a finger and pulled upside down, it gradually overcomes the adhesion force of the concrete.
It peels off. Since the direction of the peeling force is along the product surface, there is no risk of peeling off the surface layer of unhardened concrete from the inner layer.

The attraction portion of the present invention may be a permanent magnet, or may be a simple electromagnet that generates attraction force only when energized, or may utilize vacuum attraction force. The latter embodiment is shown in FIG. In this case, a suction port 5' is disposed on the bottom plate 3 instead of a magnet, and a space surrounded by the bottom plate 3, the substrate 2, and the side plate 1 is used as a decompression chamber 9. Bottom plate 3 and board 2
A ventilation hole 11 is provided in the frame plate 10 connecting the two, and a hose 12 connected to a vacuum pump is connected to the side plate 1.

If the suction part is not the magnet 5 but the suction port 5',
The bottom plate 6 does not need to be made of magnetic material, and if it is a rubber plate, it does not need to contain magnetic powder. Since the bottom of the formwork according to the present invention only needs to be able to support the bottom plate 6 in a desired shape, the bottom plate 10 shown in FIGS.
It is also possible to simply combine them closely. FIG. 6 is a plan view showing how to bury the magnet pieces 5 in that case. In this case, the gap between the frame plates 10 may be used to push the product down together with the bottom plate during demolding.

In addition, the two-dimensional unevenness on the bottom of the formwork is not limited to the waveforms shown in Figures 1 and 5, but also products with stepped parts as shown in Figure 7.
This invention can also be applied to C′. In this case, a stainless steel plate may be used as the bottom plate 6', with the portion corresponding to the sharp step being stepped in advance and the rest remaining flat. Magnetic stainless steel sheets are most suitable as the bottom plate of this invention because they do not rust and have elasticity, but ordinary steel sheets can also be used. Rubber plates and plastic plates can be used as long as they are strong enough to be used and flexible enough to be turned over.

Although the formwork of the present invention has two-dimensional unevenness with a substantially uniform cross section on the bottom surface, it is not necessary that the entire bottom surface has such unevenness. All you have to do is lay down the floor planks locally in the required area. Furthermore, if the bottom surface has two-dimensional unevenness in two directions, a bottom plate for each can be placed at each position. In the case of a trapezoid with slopes on all sides, the upper surface of the trapezoid has two overlapping bottom plates, so these may be made into a single piece. If there is a small trapezoid in the center, press-form only that part in advance and use a flat plate for the rest. In addition, the material and shape of the bottom plate may be modified depending on the shape of the product.

However, the bottom plate of the present invention is, in principle, a flat single plate that can conform to various irregularities of the product, and this advantage should be taken advantage of.

The idea of laying cloth in a formwork, pouring concrete on top of it, and then peeling off the cloth after removing the mold has been well known for a long time. However, the cloth that wrinkles easily must be laid well, and it is especially difficult to lay on uneven surfaces, and it is easy to move due to the impact of concrete pouring.
It is not put into practical use because it adheres too closely to concrete and is difficult to remove, and it is not durable.

This invention incorporates all the advantages of the above known techniques into a modern instant demolding molding device. The above-mentioned drawbacks can be solved by replacing the sheet with a bed plate, which adds appropriate rigidity, makes it possible to peel it off due to its flexible elasticity, and makes it possible to easily and reliably lay it in the formwork with the suction part.
This prevented movement during concrete pouring.

[Brief explanation of drawings]

Fig. 1 is an elevational sectional view of one embodiment of this invention;
The figure is a plan view, Figure 3 is a partially enlarged view of Figure 1,
Fig. 4 is an explanatory diagram of the state in which the mold is immediately demolded and the bottom plate has begun to be peeled off, Fig. 5 is an elevational view of another embodiment,
FIG. 6 is a plan view of a part of the bottom of the formwork of another embodiment;
FIG. 7 is an explanatory diagram of a product having unevenness including stepped portions and a state in which the bottom plate is removed. 5... Attraction part (magnet piece), 5'... Attraction part (suction hole), 6, 6'... Bottom plate.

Claims (1)

[Scope of Claims] 1. In a concrete molding form for immediate demolding, the bottom surface of which has two-dimensional irregularities with a substantially uniform cross section, the two-dimensional irregularities are easily two-dimensionally bendable and can be easily removed from the demolded product. It is covered with a bottom plate made of an elastic thin steel plate or a durable hard rubber plate that can be easily peeled off, and the bottom plate is easily attached to and removed from the bottom of the formwork that suctions and supports it in the shape of the two-dimensional unevenness. The adsorption force of the bottom of the frame is sufficient to deform and hold the base plate, which is originally a flat plate, into the shape of the uneven portion, and is weaker than the adhesion force between the product and the base plate when the product is demolded. Formwork for.