JPH0554801B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a formwork for producing concrete piles in which a cylindrical formwork is filled with concrete and the formwork is rotated to perform centrifugal forming.

[Background Art] Conventionally, the formwork 1' for centrifugally forming concrete piles has been formed by semi-cylindrical divided formworks 1a' and 1b' divided into upper and lower halves, as shown in Fig. 8a. , with one split formwork 1a' removed, the eighth
As shown in Figure b, a core reinforcing bar cage is placed inside the other split formwork 1b', and concrete 2 is filled,
One split formwork 1a' is placed over the split formwork 1b', both split formworks 1a' and 1b' are fastened together with flanges 3, both ends of the formwork 1' are closed with end plates, and the formwork 1 ′ was rotated at high speed for centrifugal molding. However, such a conventional example has the following problem.

(1) When filling the inside of the formwork 1' with concrete 2, generally, one divided formwork 1a' is removed and the other half-cylindrical divided formwork 1b' is filled as shown in Figure 8b. Concrete 2 is poured into the concrete 2, but since the required volume of concrete 2 cannot fit into the divided formwork 1b', it has to be poured in a mountain shape, and this filling work is done manually, making it difficult and time consuming. There is. Furthermore, even if the concrete 2 can be poured in a mountain shape, the mountain-shaped concrete 2 may collapse or collapse due to the vibrations of the surrounding processes (particularly due to the vibrations of centrifugal forming) until the split formwork 1a' is closed. There was a problem that the split formwork 1a' could not be closed because it rested on the flange 3.

(2) After the concrete pile has been centrifugally formed and cured, when removing the pile from the formwork 1', remove the divided formwork 1a' and then lift the pile out of the divided formwork 1b', or separate it. The pile is rolled out by inverting the formwork 1b', but since the divided formworks 1a' and 1b' are semi-cylindrical, the contact area between the pile surface and the inner surface of the formwork 1' is large, and the concrete 2 is rolled out. There is a problem in that it adheres closely to the inner surface and is difficult to remove from the mold. Particularly in the case of formwork for manufacturing knot piles and the like having protrusions on the pile body, the formwork itself has an uneven shape, so the contact area becomes larger and larger, making demolding difficult. In addition, when manufacturing PC piles (prestressed concrete piles) using formwork for knotted piles, there is a problem in that there are parts that adhere tightly between the joints of the formwork and the joints of the pile, making it even more difficult to remove the mold. be. Generally, when manufacturing PC piles, a predetermined tension force is applied to the PC bars of the core reinforcing bar cage with concrete filled in the formwork (the reaction force of the tension is transmitted to the formwork via the end plates). After solidifying the pile, that is, when demolding, the tension applied to the formwork is released and tension is applied to the pile, but at this time the pile tends to shrink.
On the other hand, as the formwork tries to stretch, it adheres strongly at the joints.

[Object of the Invention] The present invention has been made in view of the above points, and the objects of the present invention are to make it easy to pour concrete, to easily take out piles after forming, and to make it possible to easily remove the pile after forming. To provide a formwork for producing concrete piles which allows easy disassembly and assembly of the frame.

[Disclosure of the Invention] The formwork for producing concrete piles of the present invention is a formwork for producing concrete piles with cylindrical knots in which a plurality of knotted parts protrude in the circumferential direction at appropriate intervals in the longitudinal direction. The cylindrical formwork is divided into three parts in the circumferential direction including the knot molding part, and a flange is provided on each divided end face to protrude outward.
It is characterized in that at least one flange of a plurality of adjacent flanges is rotatably connected by a hinge at a flange portion located on the outer periphery of the joint molded portion, and as described above. This configuration solves the drawbacks of the conventional example. In other words, by dividing the form into three parts, when pouring concrete, you can open (remove) one divided form and pour the concrete into the two assembled formwork, which is more similar to a cylinder than a semi-cylindrical form. There is no need to pile up concrete in the form of a mountain, making it easier to pour concrete, and when removing the mold,
It is now possible to pull out the formed pile by expanding two separate formworks, making it easier to remove the pile.
In addition, by connecting the flanges at at least one location with a hinge to connect the two divided formworks in a rotatable manner, it is easy to disassemble the pile when taking it out, and it is also easy to assemble it.

The present invention will be explained in detail below with reference to Examples.

In this example, an example of a concrete pile manufacturing formwork for manufacturing PC piles will be described.
As shown in FIGS. 1a and 1b, a concrete pile manufacturing formwork (hereinafter referred to as formwork) 1 has a substantially cylindrical shape, and is divided into three divided formworks 1a and 1 in the circumferential direction.
b, 1c. Split formwork 1a, 1
Flanges 3 are provided in the longitudinal direction on both sides of the circumferential direction of b and 1c, and the flanges 3 are connected together with bolts.
They are assembled by fastening with nuts or rotatably connected with hinges 19. The formwork 1 is formed with knot forming portions 4 extending circumferentially at equal intervals in the longitudinal direction so as to protrude outward, and these knot forming portions 4 form the knots of the pile. ing. This joint forming portion 4 is also divided into three parts in the circumferential direction together with the divided formworks 1a, 1b, and 1c. Further, tires 5 are mounted on the formwork 1 at equal intervals in the longitudinal direction and extending in the circumferential direction, and these tires 5 are also attached to the divided formworks 1a, 1b,
It is divided into three parts along with 1c. Among the divided formworks 1a, 1b, and 1c divided into three, divided formworks 1b and 1c
The two sides are rotatably connected to each other by a hinge 19. The remaining flanges 3 are connected with bolts and nuts. When the flanges 3 are connected to each other by the hinge 19, they are connected at a position on the outer periphery of the joint molded portion 4. End plates 6a are provided at both ends of the formwork 1 in the longitudinal direction.
6b is arranged, and a core reinforcing bar cage 7 is arranged inside the formwork 1 as shown in FIG. The core reinforcing bar cage 7 is comprised of a plurality of main reinforcing bars 7a arranged longitudinally and at intervals in the circumferential direction, and hoop reinforcing bars 7b wound in a coil around the main reinforcing bars 7a. Edge iron plates 8 are installed at both ends of the formwork 1.
are arranged, and the main reinforcing bars 7 of the core reinforcing bar cage 7 are placed on the end iron plate 8.
Both ends of a are inserted. One end of the main reinforcing bar 7a is connected to one end plate 6a with a screw connection,
The other end of the main reinforcing bar 7a is connected to a sliding plate 9 disposed at the other end within the formwork 2 by a screw connection. A screw shaft 10 is provided protruding from the sliding plate 9.
into the end plate 6b and attach the nut 11 to the screw shaft 10.
are screwed together. A device for rotationally driving the formwork 1 includes a drive roller 1 on a drive shaft 13 driven by a motor 12.
4. This drive roller 14
are provided at the same intervals as the tires 5 on the formwork.

The pile 15 is formed in the following manner. As shown in Fig. 3, with one split formwork 1a removed, the remaining two are connected with hinges 19.
The two divided formworks 1b, 1c are assembled and set on the stand 16, the core reinforcing bar cage 7 is set inside the divided formworks 1b, 1c, and in this state, the concrete 2 is dropped from the hopper 17 upwards. Concrete 2 is poured into the divided formworks 1b and 1c through the openings.
At this time, since the disassembled formworks 1b and 1c stand upward from the semi-cylindrical shape, the concrete 2 is sufficiently filled and does not easily spill. Next, split formwork 1
a, connect the flanges 3 together to assemble the formwork 1, set the formwork 1 on the drive roller 14,
Tighten the nut 11 to apply tension to the core reinforcing bar cage 7. Next, the drive shaft 13 is driven to rotate the mold 1 to perform centrifugal molding. After centrifugal molding and curing are completed to form the pile 15, the nut 11 is loosened to release the tension, the divided formwork 1a is removed, and the divided formworks 1b and 1c are opened as shown in FIG.
Pile 15 is taken out by lifting or dropping it. When lifting, use the vacuum lifter 18 as shown in FIGS. 4 and 5 a. When taking out the pile 15, the divided formworks 1b and 1c are
Open the vacuum lifter 1 in the direction of arrow A in figure a.
Lift it up at 8. When taking out the pile 15, the divided formwork 1a is removed and the two divided formworks 1b and 1c are unfolded, so the pile 15 can be easily taken out, even if the pile has knots.
It can also be easily taken out from the PC pile. That is, when the nut 11 is loosened to release the tension, the pile 15 tends to shrink in the longitudinal direction, while the formwork 1 tries to expand in the longitudinal direction, so that the knots of the pile 15 and the knot forming part 4 of the formwork 1 The piles 15 are in close contact with each other and a warp occurs, making it difficult to remove the pile 15 in the case of the conventional two-part formwork 1', but in the case of the three-part formwork 1, the pile 15 can be easily taken out.

In the above embodiment, the formwork 1 was divided into three parts in the circumferential direction to form the three divided formworks 1a, 1b, and 1c, but the divided formworks 1a were not spaced evenly, and the divided formworks 1a were separated from the other divided formworks 1b and 1c. You can make it smaller. Further, in the above embodiment, the flanges 3 protrude in the radial direction, but they may protrude in the horizontal direction as shown in FIG. 6, or in the vertical direction as shown in FIG.

[Effect of the invention] As described above, the present invention divides the cylindrical formwork into three parts in the circumferential direction, so when pouring concrete, one divided formwork is opened (removed) and two divided molds are created. The concrete can be poured with the frame assembled, and the concrete is poured into the divided formwork, which is more cylindrical than semi-cylindrical, so there is no need to pile up concrete, making it easier to pour concrete. Moreover, it does not spill even when filled with a large amount of concrete, and when demolding, the three divided formwork can be expanded and the formed pile can be pulled out, making it easy to remove the pile. Furthermore, even when knotted piles or PC piles are formed, the piles can be easily removed. Further, the present invention divides the cylindrical formwork into three parts in the circumferential direction including the knot molding part, and provides an outwardly projecting flange on each divided end face, so that at least one flange of the plurality of adjacent flanges Since they are rotatably connected by a hinge at the flange portion located on the outer periphery of the joint molding part, at least two of the three divided formworks are rotatably connected by the hinge, When taking out the pile after forming the pile, it is possible to take out the pile by simply opening at least two divided formworks without disassembling it, and the pile can be taken out easily, and the formwork is assembled. In addition, since the number of points where the flanges are connected to each other is reduced, the workability of assembling the formwork is improved.Furthermore, since the flanges are connected with a hinge at the flange part on the outer periphery of the joint forming part, the joints are Even if there is a forming part, when opening and closing the split formwork, the split formwork can be opened without the inner wall surface of the joint forming part of the form coming into contact with the outer circumferential surface of the joint part of the formed pile. It is something that can be done.

[Brief explanation of drawings]

Figures 1a and b are a front view and partially cutaway side view of an embodiment of the present invention, Figure 2 is a partially cutaway front view of the same, and Figure 3 is a side sectional view of the same as the above when concrete is being poured. , Fig. 4 is a side sectional view of the same pile taken out, Figs. 5 a and b are side sectional views and partially cutaway front views illustrating the main parts, and Figs. 6 and 7 are the same formwork as above. A side sectional view showing another shape of, Fig. 8a,
b is a sectional view of a conventional example, where 1 is a formwork, 1a,
1b and 1c are divided formworks, 3 is a flange, 4 is a knot molding part, and 19 is a hinge.

Claims (1)

[Claims] 1. In a cylindrical formwork for producing knotted concrete piles in which a plurality of joint forming portions extending in the circumferential direction are protruded at appropriate intervals in the longitudinal direction, the cylindrical formwork is placed around the circumference including the joint forming portions. It is divided into three parts in the direction, and each divided end face is provided with an outwardly protruding flange, and the flanges at least one of the plurality of adjacent flanges are rotated by a hinge at the flange part located on the outer periphery from the joint molded part. Formwork for manufacturing concrete piles characterized by being freely connected.