JPH0144680Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a sliding formwork device for vertical upward movement, particularly intermittent upward movement, and to an improvement of a guide tube fitted to a jack rod for upward movement.

Traditionally, sliding form construction methods have been used to erect piers, columns, and box-shaped cores by pouring concrete. As a typical example of this construction method, as shown in Fig. 1, a hydraulic jack 2 is mounted on a mounting base 1, and a pair of yokes 3, 3a are suspended from the mounting base, and are inscribed between the yokes to raise the belly. A pair of weir plates 5, 5a via the
There is a structure in which a support rod 6 for raising the jack is arranged between the weir plates and passing through the mounting base 1 from the jack. When working with a device having this structure, a rod guide pipe 7 is fitted onto the support rod 6 in advance, and concrete 8 is placed around the guide pipe. The height of one concrete pouring is only a few feet, but the next pouring is done following the top surface of the previous pouring. At this time, the concrete begins to solidify within a few minutes between the previous pouring and the next pouring, but if the poured concrete wall surface becomes slightly stiff, the sliding formwork device is connected to the previous pouring through the jacks. Then raise the concrete to the same height and prepare for the next concrete pouring. Concrete is placed at a high height by the above-mentioned repeated operations of concrete pouring and sliding formwork equipment (see Figure 2). In this construction work, since the sliding formwork device is raised before the poured concrete has solidified, a sliding state is always maintained between the rod guide pipe 7 and the concrete surface, so concrete is poured continuously for several days. Even when the formwork device is finally removed from the concrete, no significant friction or sticking occurs between the concrete and the guide pipe due to solidification of the concrete. Therefore, the entire device including the support rod is pulled upward from the poured concrete, and the hole drilled vertically with the guide tube is filled to complete the work. However, in recent years, continuous work as described above is often not possible. For this reason, it has become necessary to carry out intermittent work, for example, after 12 hours of pouring work in a day, the work is stopped, and then the next day the work is repeated for another 12 hours. In this case, edge cutting work (empty slide) between concrete and formwork after pouring is completed.
must be done. At this time, it is easy to remove the adhesion between the concrete and formwork by performing empty sliding over time. However, it is not easy to prevent the guide pipe from tightening due to shrinkage of the concrete, which is extremely difficult, and as a result, loosening the guide pipe from the poured concrete may damage the concrete or impose a strain on the concrete. This often prevents normal sliding work, and it takes a great deal of effort and time to perform edge cutting and sliding after pouring.

The present invention is an improvement of the guide pipe in order to solve the above-mentioned drawbacks, and the present invention is a weir plate that is attached to a pair of yokes 3, 3a that are fixed to the mounting base 1 of the hydraulic jack 2 and hang down, facing inscribed in the guide pipe. A device for intermittently pouring concrete 8 by a sliding form method around a hollow rod guide pipe fitted to a support rod 6 for lifting the jack hanging down from the mounting base between 5 and 5a, The guide tube 10 or 11 is a continuous convex curve in which at least the upper region in the length direction continuing from the upper end thereof is directed downward and the cross-sectional area surrounded by the outer circumference becomes continuously smaller, and the cross-sectional area becomes smaller. It has reached the end. Reference numeral 12 in the drawing indicates a hanging bolt for hanging the rod guide pipe from the mounting base 1. The rod guide tube used in this invention is the third type.
Examples are shown in Figures a and b, where figure a has a hollow downward truncated conical shape and tapers so that the outer diameter becomes thinner from the top to the bottom. The part shown in FIG. 1B has a hollow truncated conical shape from the upper part to a portion 11a, and the part below 11a has a cylindrical shape with the tapered cross section of the truncated cone.

The case where the sliding formwork apparatus of the present invention is operated using the hollow rod guide pipe shown in FIG. 3a will be described. Concrete 8 is first placed between the weir plates 5 and 5a in the usual manner. Immediately before the next pouring, the jack 2 is operated to raise the entire device together with the jack along the support rod 6. At this time, the rod guide tube 10
Since the upper part of the guide tube 10 is gently tapered downward, the relationship of the guide tube 10 to the concrete 8 that was poured last time and is about to solidify while maintaining its shape is the same as the relationship of the tapered bottle stopper to the bottle mouth. It slides upward relatively smoothly. In this case, since the guide pipe is tapered toward the bottom, the concrete part that has already been placed and was previously in contact with the top of the guide pipe will inevitably lose contact with the guide pipe at the bottom. Therefore, the contact surface between the guide tube and the poured concrete is smaller than that of a conventional cylindrical guide tube, and for this reason, the guide tube can easily slide upward as described above. Therefore, when pouring concrete in multiple stages, it is of course easy to raise the sliding formwork device midway between pours, and it is also possible to raise the sliding formwork halfway between pours, and also to raise the sliding formwork halfway between pours.
(Fig.), when the jack is then operated to cut the edge between the concrete and the sliding formwork device and slide it, as mentioned above, the only part that is in close contact with the inner surface of the concrete is near the top of the guide pipe, so Even if the lower concrete that has been poured shrinks, the shrinkage will not affect the guide tube because the lower part of the guide tube is narrower. The sliding formwork device can be raised to the position shown to prepare for pouring the next day.

Rod guide tube 11 having a funnel-shaped outer shape as shown in FIG. 3b
The case where the guide tube 10 is used is also the same as the case where the guide tube 10 is used. The guide tube 11 has a cylindrical shape below the portion 11a, and its outer diameter is the same as the outer diameter of the constricted portion of the funnel 11a. Therefore, during concrete pouring, the newest concrete to be poured is placed above the constriction 11a of the pipe 11, so when sliding the edges after final pouring, the area below the constriction 11a is mainly used for guiding the rod 6. It only touches, but does not come into contact with the poured concrete. Therefore, empty sliding can be easily performed without interfering with the edge cutting slide of the sliding formwork device.

Although the guide tubes 10 and 11 described above are shown as truncated cones, their cross sections do not necessarily have to be circular, but may be curved surfaces with a cross section surrounded by continuous convex curves that are smooth and without recesses, such as an elliptical cross section. There is no problem as long as you have it. In addition, for the conical shape above the constricted portion 11a of the guide tube 11, within the scope of a utility model registration claim, it may be a spherical surface up to a hemisphere, an elliptical surface that is axially symmetrical and less than half the size, or a hollow shape that has a monoplane hyperboloid. It is also possible to use the rod guide tube of the present invention in which solid bodies are arranged symmetrically with respect to the axis of the guide tube and their axes are aligned.

[Brief explanation of the drawing]

Fig. 1 is an elevational view of a conventional sliding formwork device, Fig. 2 is an elevational view with a partial cross section of a conventional rod guide pipe,
Figures 3a and 3b are partial cross-sectional elevational views of the rod guide pipe of the present invention, and Figures 4 and 5 are elevational views of the sliding formwork device of the present invention in use. Fig. 5 shows the state in which the edge cutting slide has been completed after concrete pouring. 1... Mounting base, 6... Support rod, 2... Hydraulic jack, 8... Concrete, 3, 3a... Yoke, 1
0, 11... Guide pipe, 5, 5a... Weir plate.

Claims (1)

[Scope of utility model registration request] A support rod 6 for the jack that hangs down from the mount is fitted between the weir plates 5 and 5a that are attached to the pair of yokes 3 and 3a that are fixed to and hang down from the mount 1 of the hydraulic jack 2 and that are inscribed facing each other. This is a device for intermittently pouring concrete 8 around a hollow guide pipe by a sliding form method, wherein the guide pipe 10 or 11 has at least its upper section in the length direction extending from its upper end facing downward. 1. A vertically movable sliding formwork device, characterized in that it is formed of a continuous convex curved surface whose cross-sectional area surrounding the outer periphery becomes smaller continuously, and which reaches an end with a smaller cross-sectional area.