JPH0413124B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application) The present invention relates to a method for manufacturing pipes for manufacturing concrete blocks.

(Prior art) Concrete blocks used as revetments or retaining walls have through holes for inserting reinforcing bars during construction and for pouring filler concrete to connect the concrete blocks to each other. There is. FIG. 6 is an example of a concrete block with through holes. 1 in the diagram
is a through hole, which extends through the concrete block in the width direction.

By the way, as shown in FIG. 1, the conventional method for manufacturing concrete blocks equipped with such through-holes involves inserting an iron plate between both walls in the width direction of a box-shaped formwork 10 for manufacturing concrete blocks. Hang the pipes and pour concrete into them. After the concrete hardens, a through hole is created in the concrete block by removing the pipe.

(Problem to be solved by the invention) As mentioned above, in the conventional manufacture of concrete blocks, a steel pipe is passed through the formwork of the concrete block to harden the concrete, but this pipe is made of iron. Therefore, there was a problem that it was extremely heavy and difficult to handle. Conventional concrete block products are large, with long sides of 125 cm, short sides of 80 cm, and a height of about 35 cm, so the pipes used are over 80 cm long and weigh about 50 kg. It was hot too. Therefore, it was something that those without power could not handle.

The present invention provides a method for manufacturing a concrete block manufacturing pipe that is much lighter and easier to handle than conventionally used pipes, and has sufficient strength. The purpose is to

(Means for Solving the Problems) In order to achieve the above object, the present invention has the following configuration.

That is, in a method for manufacturing a pipe for manufacturing concrete blocks, which is supported by being stretched between the side frames of a formwork for manufacturing concrete blocks into which concrete is poured, in order to provide through holes for inserting reinforcing bars or filler concrete during construction,
A tubular body made of a synthetic resin such as vinyl chloride is heated by immersing it in oil heated to 100°C or higher, and a mold with a through-hole for molding with a tapered inner wall surface is inserted into the tubular body. Similarly, the heated tube is immersed in oil and heated in advance, and the heated tube is pushed into the through-hole of the mold, and the outer surface shape of the tube is shaped to follow the shape of the through-hole. The method is characterized in that the mold and the tube are cooled while the tube remains pushed into the mold, and the tube is pulled out from the mold to obtain a pipe of a predetermined shape.

(Embodiments) Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 is a perspective view showing a concrete block manufacturing pipe (hereinafter referred to as pipe) manufactured by the method of the present invention and an example of how this pipe is used.
FIG. 2 shows a cross-sectional view of the pipe 12.

The pipe is made of synthetic resin such as vinyl chloride, and is formed as a hollow tube as shown in FIG. The outer surface of the pipe is tapered so that the diameter gradually increases from one end to the other end.

As shown in FIG. 1, the pipe 12 is installed so as to span between the side frames 14, 14 in the width direction of the formwork 10, and the end of the pipe 12 is inserted into the insertion hole 16 provided in the side frame 14. It is inserted through and supported by the side frame 14.
In the embodiment, three pipes 12 are supported on the side frame 14. Since the pipe 12 has a tapered outer surface, it can be inserted into the formwork 10 from the outside of the large-diameter insertion hole 16. Then, after pouring concrete into the formwork 10 and hardening it, the pipe 12
By pulling out a concrete block as shown in FIG. 6 is obtained. Note that the bottom plate 18 of the formwork 10 and each side frame plate are connected by a hinge,
After the concrete has hardened, the side frames can be expanded to remove the concrete blocks.

Next, a method of manufacturing the pipe 12 will be explained. The outer surface of the pipe 12 is formed into a tapered shape.
It can be easily manufactured using 0. As shown in the cross-sectional view of the mold 20 (FIG. 4), the mold 2
A through hole 22 for forming is formed in the inner wall surface as a tapered surface whose diameter gradually increases from one open end to the other open end.

This mold 20 is made by pushing a straight tube made of commonly used synthetic resin such as vinyl chloride into the through hole 22, so that the tube conforms to the shape of the inner wall of the through hole 22. Transform and form. However, since it is impossible to deform a synthetic resin tube by simply pushing it into the mold at normal temperatures, the tube is first heated to make it deformable, and then the tube is pushed into the mold 20.

In the example, a vinyl chloride pipe is used as the pipe body,
After the vinyl chloride pipe was immersed in oil heated to a temperature of 130° C. or higher and thoroughly heated, the pipe was pushed into the molding through hole 22 of the mold 20. Since the forming through hole 22 is tapered, the tip can be gradually deformed into a tapered shape by pushing the tube from the large diameter side. Note that the mold 20 is also heated in advance by immersing it in hot oil. By heating the mold 20 and the tubular body at a high temperature in this manner, the outer surface shape of the tubular body can be molded to follow the shaping through hole 22. After molding into a predetermined shape, the tubular body is immersed in cold water while being pushed into the mold 20 to cool the entire body, and the molded tubular body is pulled out. By cooling, the tube can be easily pulled out. In this way, a pipe 12 having a tapered outer surface is obtained. Note that if hot water is used to heat the pipe, the heating temperature will be low;
PVC pipes could not be sufficiently deformed.

Note that the tube may have an appropriate diameter according to the diameter of the molding through hole 22, and since it is used in the mold 10, a tube with a certain thickness is used so as to have a predetermined strength.

The above manufacturing method is characterized in that it can be molded by simply heating the tube and the mold with high-temperature oil and then pushing the tube into the mold, making the molding operation extremely easy. The size of the mold 20 or the molding through hole 22 can be set as appropriate, and commonly used vinyl chloride pipes can be suitably used, resulting in low cost.

In addition, since the pipe is made of synthetic resin such as vinyl chloride, it weighs several kilograms, making it much lighter than the iron pipes used in the past. Therefore, it can be easily handled even with a weak tool, is extremely convenient, and can improve workability.

Figure 5 shows that after concrete is hardened with mold 10,
This is a cap used when removing the pipe 12, and is used by covering the end of the pipe 12 in a cap shape. After the concrete has hardened, the pipe 12 is removed from the concrete block by placing the cap and tapping the handle 24.

The present invention has been variously explained above with reference to preferred embodiments, but the present invention is not limited to these embodiments, and it goes without saying that many modifications can be made without departing from the spirit of the invention. That's true.

(Effects of the Invention) According to the method of the present invention, pipes for producing concrete blocks can be easily obtained, the molding operation is easy, and the pipes can be manufactured at low cost using synthetic resin pipes such as vinyl chloride. can. The obtained pipe is lighter than conventional pipes for producing concrete blocks, and has remarkable effects such as being easier to handle when producing concrete blocks.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing the state of use of a concrete block manufacturing pipe obtained by the present invention;
FIG. 2 is a sectional view of the pipe, FIGS. 3 and 4 are a perspective view and a sectional view of the mold, FIG. 5 is a perspective view of the cap, and FIG. 6 is a perspective view of the concrete block. 1... Through hole, 10... Formwork, 12... Pipe, 14... Side frame, 16... Insertion hole, 18... Bottom plate, 20... Molding mold, 22... Molding through hole, 2
4...Nigiri.

Claims (1)

[Scope of Claims] 1. Manufacture of a concrete block manufacturing pipe that is supported by being stretched between the side frames of a concrete block manufacturing form into which concrete is poured in order to provide through holes for inserting reinforcing bars or filler concrete during construction. In this method, a tubular body made of synthetic resin such as vinyl chloride is heated by immersing it in oil heated to over 100°C, and a mold with a tapered inner wall and a through-hole for molding is formed. Like the tube, it is preheated by immersing it in oil, and the heated tube is pushed into the through-hole for molding in the mold, so that the outer surface shape of the tube is shaped into the shape of the through-hole for molding. A pipe for producing a concrete block, characterized in that the pipe is flattened and formed, the mold and the pipe are cooled while the pipe is pushed into the mold, and the pipe is pulled out from the mold to obtain a pipe of a predetermined shape. manufacturing method.