JPH04201302A - Manufacture of concrete product and concrete form therefor - Google Patents

Abstract

PURPOSE:To enable demolding even if an operator and jig are not put into the inside of a product and the demolding is enabled even if the product is in a complicated shape, by a method wherein an inner form performing concrete molding with an outer form and inner form is made of an elastic material and the demolding is performed by reducing a sectional area of the inner form by pulling the inner form after cure. CONSTITUTION:An outer form 1 and base form 3 are assembled in a body, an inner form 5 is arranged at the center and concrete is placed into a gap surrounded by a form. In addition, a rigid material 6 such as a chain or a wire rope is built in the inner form made of an elastic material. Then a bolt and nut are removed from a form after cure and the outer form 1 is removed. Then a sectional area of the inner form 5 can be reduced by pulling both ends of a link 6a, through which demolding can be performed by peeling an external circumferential surface of the inner form 5 off from the surface of the concrete.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to concrete formwork made of elastic material.

[Conventional technology]

Factory-produced precast concrete products generally use steel formwork. An example thereof will be explained below using the drawings.

Figure 5 is an exploded perspective view, in which 1 is the outer formwork, 2
3 is the inner formwork, and 3 is the base formwork. Each formwork is assembled together with bolts and Nandos. Concrete is poured into the gap surrounded by the formwork, and after hardening, the bolts and Nandos are removed from the formwork. The concrete product 4 is taken out by removing the mold and demolding the formwork.

[Problem to be solved by the invention]

When demolding, the outer formwork can be easily removed, but if the inner formwork is large, workers must enter inside the mold, resulting in very poor working conditions, and for small products, a jig must be inserted. There is a problem in that the size is limited because it is carried out in large quantities.

Further, demolding the inner formwork having a complicated shape requires certain procedures and skill, and if performed by an inexperienced person, there is a problem that the product may be damaged.

[Means to solve problems]

Therefore, the present invention is characterized in that at least the inner formwork of the outer formwork and the inner formwork for forming concrete is made of an elastic material, and after hardening, the molding is performed by reducing the cross-sectional area of the inner formwork. be.

〔Example] An embodiment of the present invention will be described below with reference to the drawings.

Fig. 1 is a sectional view of the inner formwork, Fig. 2 is a sectional view showing an example of the shape, and Fig. 3 is a perspective view showing an example of use.
is an inner formwork made of elastic material, such as rubber, resin, plastic, or foam material.

A rigid material 6 such as a chain or wire rope is embedded within this inner formwork 5. The buried state of this rigid material 6 is as follows.
As shown in the figure, in the case of a chain, the links 6a are not in contact with each other and maintain a spacing S, and an elastic material is interposed between the spacing S. In the case of a wire rope, the structure is such that the links 6a are not in contact with each other but have an elastic material interposed between them. It is buried in a meandering state, and even in this case, links are buried and protrude at the ends.

One or more such rigid members 6 are provided in the inner formwork 5, and the number and position of embedding are determined depending on the cross-sectional shape.

The production of the concrete product 4 using the inner formwork 5 as described above will be explained with reference to FIG.

In the figure, 1 is an outer formwork, 3 is a base formwork, and 5 is an inner formwork. The outer formwork 1 and the base formwork 3 are assembled together with bolts and nuts, and the inner formwork 5 is placed in the center. Then concrete is poured into the gap surrounded by the formwork.

After curing, remove the bolts and nuts from the formwork and remove the outer formwork 1. Therefore, by pulling both ends of the links 6a of the inner formwork 5, the cross-sectional area of the inner formwork 5 can be reduced, and thereby the outer peripheral surface of the inner formwork 5 can be peeled off from the concrete surface and demolded. I can do it. In the case of this embodiment, when the lower surface of the inner formwork 5 is fixed to the base formwork 3, a tensile force is exerted between it and the fixed base formwork 3 by pulling the link 6a on the free end side. The cross-sectional area can be reduced.

FIG. 4 shows another practical example, in which the inner formwork 5 is used horizontally, the end of the inner formwork 5 is fitted into the end plate 8 placed on the base plate 7, and side plates 9 are arranged on both sides. Concrete is poured from the upper opening, and the concrete is poured between the inner formwork 5, the base plate 7, and the side plates 9, and is formed.

After curing, remove the bolts and nuts from the formwork and remove the side plate 9. Therefore, by pulling both ends of the links 6a of the inner formwork 5, the cross-sectional area of the inner formwork 5 can be reduced.
As a result, the outer circumferential surface of the inner formwork 5 can be peeled off from the concrete surface and removed from the mold.

Conversely, mold removal is possible by pressing the inner formwork during molding to increase the cross-sectional area, and releasing the pressure during demolding to return the cross-sectional area to its original state. be.

In the above embodiment, the rigid material 6 buried in the inner formwork 5 is made of a flexible material, but it may also be a rigid material such as shaped steel or a pipe. Even in these cases, there are links protruding from both ends.
This link does not necessarily have to be connected to the buried rigid member 6 including the above embodiments.

Further, the shape of the inner frame 5 is arbitrary, and may be a hollow shape as shown in FIG. 2, or may be formed by combining the inner frames 5.

〔Effect of the invention〕

According to the present invention described in detail above, the inner formwork of the formwork for forming concrete by the outer formwork and the inner formwork is made of an elastic material, and the cross-sectional area of the inner formwork is reduced by pulling the hardened formwork. It is characterized by reducing the size of the product and cutting it out from the mold.It is possible to cut out the shape without putting people or jigs inside the product, and it is possible to cut out the shape of products that are narrow or curved inward. It has the effect that even if it is a shape, it can be cut out.

In addition, by attaching a link to the end of the inner mold, the mold can be pulled out by simply pulling the link when demolding, making it possible to easily mold even extremely small hollow bodies. have

[Brief explanation of the drawing]

Fig. 1 is a sectional view of an inner formwork showing an embodiment of the present invention, Fig. 2 is a sectional view showing an example of the shape, Fig. 3 is a perspective view showing an example of use, and Fig. 4 is an example of another use. FIG. 5 is an exploded perspective view showing a conventional example. 1... Outer formwork 3... Base formwork 4... Concrete product 5... Inner formwork 6... Rigid material patent applicant Shihata Kogyo Co., Ltd. Landex Kogyo Co., Ltd. Haru Uoyo Kamisato Attorney Patent Attorney Takashi Kanakura Motorcycle 5
Watauchi @ Inventor Haruo Kamihira Kaori Jlls, 608-72 Kita-cho, Takamatsu City Landex Industry Co., Ltd. 138-3 Fujii, Kinashi-cho, Takamatsu City

Claims (1)

[Scope of Claims] 1. At least the inner formwork of the outer formwork and inner formwork for concrete molding is made of an elastic material, and after hardening, the molding is performed by reducing the cross-sectional area of the inner formwork. A method for manufacturing concrete products. 2. A formwork for concrete products, characterized in that links are buried in the ends of the inner formwork made of an elastic material, and when the inner formwork is pulled by the links, the cross-sectional area of the inner formwork is reduced.