JPH0251366B2 - - Google Patents

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention is capable of producing circular pipes, oval pipes, square This invention relates to a method for forming concrete pipes such as pipes.

(Prior art) Currently, a concrete pipe forming method is used in which concrete pipes are compacted by applying vibrations to the outer and middle molds, but this forming method requires the use of underground pits to prevent noise caused by vibrations. After forming, the molded pipe is pulled up to the ground together with the outer mold to remove the middle mold, and the molded pipe covered with the outer mold is moved to a curing place, and the outer mold is removed. After separating the pallet from the mold, the outer mold is pulled up and demolded.

(Problem to be solved by the invention) Therefore, in such a conventional forming method, the press-formed pipe is lifted up with a crane together with the outer mold with a pallet locked at the lower end, and the molding is carried out while the pipe is moved to a curing place. There was a drawback that work was interrupted. Continuous molding of this requires a plurality of outer molds, which is extremely uneconomical. In that case, a crane is required to pull up the molded pipe from the pit and insert the new outer mold into the pit, and a crane to transport it to the curing area and remove the mold. When the pipe is pulled out from the medium size by a crane, in addition to the weight of the formed pipe and the outer mold, frictional resistance between the concrete material and the medium size acts, so in order to ensure safety, it is necessary to design the capacity of the crane to be considerably large. The accompanying drawbacks were that the entire device became larger and more complex, and the failure rate increased.

In view of such conventional concrete pipe forming methods, the present invention relates to a concrete pipe forming method that enables continuous forming using a pair of outer and middle molds, and also simplifies the equipment and reduces the failure rate. be.

(Means for solving the problem) That is, the present invention installs an outer mold in an underground pit, allows the middle mold to move up and down, and places pallets and reinforcing bars in the molding space formed between the middle mold and the outer mold. is inserted to hold the pallet at the lower end of the hollow, then concrete is poured into the molding space and compacted while vibrating the outer mold and the middle mold. After a predetermined amount of concrete has been poured, A molding ring is fitted to the upper end of the molding space and locked to the upper end of the outer mold, and then a push-up mechanism installed in the pit pushes up the middle mold to pressurize the concrete material and form the upper end. After that, the molding ring is removed and the middle mold is further pushed up to remove the outer mold.The pallet is held on the ground and the middle mold is lowered into the outer mold to remove the middle mold and insert it into the outer mold. In this method, the molded pipes held on pallets are moved to a curing area.

(Example) Next, an example of the concrete pipe forming method according to the present invention will be described based on the drawings. A molding space 4 is formed between the molded medium mold 3, and a pallet 5 and reinforcing bars 6 are placed in this molding space 4.
After inserting the pallet 5 to support the lower end of the medium 3, the vibrator 7 installed inside the medium 3
and water in the molding space 4 while vibrating the outer mold 2.
When extremely hard concrete material 8 with a small cement ratio is introduced, the concrete material 8 is gradually compacted from the bottom.

When a predetermined amount of this concrete material 8 is poured and compacted and reaches the upper end of the molding space 4, a molding ring 9 is fitted to the upper end of the molding space 4, and its outer periphery is fastened to the upper end of the outer mold 2 by a metal fitting 10. After locking, the medium size 3 is pushed up by the hydraulic cylinder 13 which is established on the bit 1 and penetrates through the bottom plate 11 of the medium size 3 and connects the tip of the rod to the bottom surface of the top plate 12.
The entire concrete material 8 is pressurized, and the upper end of the concrete material 8 is pressure-formed.

Then, the molding link 9 is unlocked and removed from the molding space 4, and the medium mold 3 is moved by the hydraulic cylinder 13.
If the molded pipe 14 is pushed up further, it will be released from the outer mold 2, held by the middle mold 3 and the pallet 5, and exposed on the ground. After holding the mold horizontally, the hydraulic cylinder 13 is retreated and the middle mold 3 is lowered, and the middle mold 3 is removed from the forming pipe 14.
It is inserted into the mold to handle the next molding. On the other hand, the formed pipe 14 supported on the ground by the support device 15 is moved to a curing place using a traveling crane, an overhead crane, or the like. During this movement, the molding space 4
Pallets 5 and reinforcing bars are set inside, concrete material 8 is poured, and forming continues.

(Effects) As detailed above, the concrete pipe forming method according to the present invention removes the outer mold and the middle mold by only raising and lowering the middle mold from the molded pipe formed in the pit, and It can be pushed up to the ground and immediately moved to a curing place, and at the same time the next molding cycle can be started, continuous molding can be performed using a pair of outer and middle molds. In addition, in the present invention, the medium size is pushed up by the push-up mechanism installed inside the bit, so safety is high.
The entire device is simplified, and the occurrence of failures can be reduced accordingly.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram showing the charging and compaction state of concrete material in one embodiment of the present invention;
The figure is an explanatory diagram showing the state of pressurization of the concrete material and the pressure forming of the upper end in the same example. Figure 3 is an explanatory diagram showing the demolded state of the outer mold in the same example. Figure 4 is the same example. FIG. 1; pit, 2; outer mold, 3; medium mold, 4; molding space, 5; pallet, 6; reinforcing bar, 8; concrete material, 9: molding ring, 13; hydraulic cylinder, 1
4; Molded pipe.

Claims (1)

[Claims] 1. Insert the pallet and reinforcing bars into the molding space formed between the outer mold installed in the underground pit and the middle mold inserted from above into the outer mold, and hold the pallet at the lower end of the middle mold. After that, vibration compaction is performed while concrete material is poured into the molding space from above, and after a predetermined amount of concrete material has been poured, a molding ring is fitted to the upper end of the molding space and it is molded into the outer mold. The mold was locked, and a push-up mechanism installed in the pit pushed up the middle mold to form the upper end while pressurizing the entire concrete material.Then, the lock of the molding ring was released, and the molding ring was removed from the molding space. After that, the middle mold is pushed up together with the pallet and the molding pipe above the outer mold by the push-up mechanism, the pallet is held on the ground, and the middle mold is lowered into the outer mold, thereby removing the middle mold and moving it into the outer mold. A method for forming a concrete pipe characterized by inserting the pipe into a pallet to form a forming space in preparation for the next forming, and moving the formed pipe held on a pallet to a curing place for curing.