JPS5839858Y2 - Formwork for centrifugal molding of hollow concrete columns - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a formwork for manufacturing hollow concrete columns such as concrete piles, humid pipes, and columns, and mainly relates to formwork for concrete piles.

The length of concrete piles is determined by JIS 5335 from 7m to 15m in 1m increments, and if necessary, it is possible to manufacture concrete piles shorter than 7m in 1m increments. For frequently used molds, prepare several molds every 1m, and for molds of other dimensions, prepare several types of molds of different lengths, and combine molds of different lengths as necessary to meet the purpose. It is assembled into a formwork of the appropriate length.

However, these joint formworks 10a, 10b, 10C
..., if there is even a slight gap in the joint surface 12 of the joint flange 11, the centrifugal force during centrifugal molding will cause the cement paste to flow out of the mold through this gap, and in the finished product after molding. The quality of the concrete in the area corresponding to the leakage location deteriorates, making it impossible to form a concrete hollow column with the desired strength.

In addition, when joining several formworks, the inner peripheral part of one formwork is made to protrude 13 in the axial direction in a cylindrical shape so that the cores of the several formworks coincide as shown in Fig. 2. , whereas,
The mold that connects in the axial direction has a corresponding circular recess 14.
It is designed to fit into the so-called inro, but
Since the abutting end faces of this fitting part have a narrow area, if the length of the cylindrical protrusion 13 is longer than the other circular recess 14,
Due to the unavoidable imbalance in the tightening force when tightening a pair of flanges with a bold, the abutting surfaces are crushed, the cores are joined at an angle, and a gap is often created at the joint.

Also, in order to prevent this cylindrical protrusion from being crushed, a circular concave 1
If the dimension of the cylindrical protrusion 13 is made shorter than the depth of 4 (see Fig. 2), a gap 15 will be created at the joint, causing burrs to appear on the finished product, which will not only make the product look unsightly and reduce the product value, but also require post-processing. This requires a lot of effort and expense.

Also, instead of the so-called in-rotation process described above, it is possible to make a hole in the flange by reaming and install a dowel pin in the flange of the other member, but the size of the formwork for the concrete hollow column is extremely large. It is almost impossible to precisely ream the flange at the correct position.

Therefore, this invention improves these known drawbacks, and when joining several formworks in the axial direction, the cores of the formworks can be easily aligned, and the joints at the flange part can be easily aligned. It can be completely attached to the two formworks to be used, and there will be no cracks in the gap.

This invention has a joint formwork consisting of several sets of formworks each having at least one rotating wheel and joint flanges at both ends of a unit long formwork that can be divided in the diametrical direction. A groove with a semicircular cross section is
When several sets of formworks, each of which is carved in a concentric circle with the inner diameter of the formwork, and a pair of formworks are combined into a cylindrical shape, it is exactly half-immersed in a circular groove formed by the pair of grooves formed. This formwork for centrifugal forming of a hollow concrete column is characterized by comprising a steel wire seal ring having a cross-sectional shape and a diameter that closely contacts the inner surface of the groove.

The invention will now be explained based on the illustrated representative embodiment.

In the figure, 10a, 10b, and 10C are formworks constituting joint formworks for forming concrete hollow columns, and flanges 11 are provided at both ends in the axial direction. A hole 16 is provided, and these formworks 10a, 10b, 10C are each divided into two in the diametrical direction, and in the disassembled state, have a gutter-like shape with a semicircular arc cross section.

In addition, in this invention, each formwork 10a, 10b,
The number of diametrical divisions of 10 C is the same for this invention, whether it is divided into three or four.

Moreover, each formwork 10a, 10b, 10C...
... is the wheel 17 supported during concrete centrifugal forming.
Each section is provided for at least one copy.

The above is the same as the known one.

In this invention, at least one groove 18 concentric with the inner diameter of the formwork is provided on the butt joint end face 12 of the flanges 11 of each formwork, and the cross-sectional shape of the groove 18 is semicircular.

19 is a seal ring made of steel wire with a thick radius that corresponds to the radius of the cross section of this groove, and in the examples shown in FIGS.
Both sides of the seal ring are flattened to form a flat surface, and the cross-sectional shape is an occluded circular portion 20 with parallel straight portions.

The radius of this ring 19 is made to exactly match the radius of the cross section of the groove 18.

The cross-sectional shape of the seal ring 19 is preferably a perfect circle, an ellipse, a regular hexagon, or a diamond shape with rounded corners, and the cross-sectional shape of the groove 18 is also provided with this in mind.

In this invention, which is stolen as described above, the formwork 1
When assembling one of 0a, 10b, or 10c, by assembling the seal ring 19 half-immersed in the groove 18, the half-split formwork becomes completely cylindrical, and
The seal ring 19 that is half-fitted into the groove 18 and the other half is in a protruding state is inserted into the groove in which the seal ring 19 of the other assembled formwork that is joined to the axially adjacent one is not fitted. By fitting with 18, the centering effect is exhibited.

Also, by inserting the bold 21 into the bolt hole 16 of the flange 11 and tightening it, the seal ring 19 is inserted into the groove 1.
At the same time, since the seal ring 19 is in close contact with the inner surface of the seal ring 19 and has the above-mentioned dimensions, the joint end surfaces 12 of the pair of flanges can be pressed together over the entire surface, and of course there is no gap between the flange joint end surfaces 12 after joining. Formwork groove 18
This seal ring 19 will be press-fitted into the
The circumferential surface of the groove 18 and the inner circumferential surface of the groove 18 are in close contact with each other over the entire length of the ring in the circumferential direction, and exhibit a complete sealing effect, so that cement milk does not leak from the flange joint end surface 12 of the formwork.

In particular, the sealing effect is even more remarkable when the groove 18 is located inside the bolt hole 16 or when it is provided both inside and outside the bolt.

In particular, since each seal ring has an inclined cross-sectional shape such as a perfect circle, ellipse, regular hexagon, or rhombus, the fitting operation is easy.

In addition, when the cross-sectional shape of the seal ring 19 has a straight portion 20a with an occluded circular portion 20 or a recess 20b (see FIG. 5) at the portion that completely immerses into the groove 18, When tightened, the seal ring 19 can be elastically deformed within the groove 18, albeit very slightly, and the contact pressure between the two can be made sufficiently high to allow the seal ring 19 to completely immerse into the groove 18.

In this case, the cross-sectional radius of one seal ring should be made slightly larger (0 to 1%) than the cross-sectional radius of the groove 18, so that when the two flanges 11 are tightened with the bold 21, the joint surfaces of both flanges can be brought into close contact. It is preferable to mold it.

Further, an air vent hole 22 may be provided at the bottom of the groove 18 if necessary.

In short, in the formwork of this invention, formworks 10a, 10b, 10 constituting joint formworks that are continuous in the axial direction
It is easy to align C's together, has an excellent sealing effect to prevent cement leakage, and has the effect of efficiently manufacturing high-quality concrete hollow columns.

In the above example, the seal ring 19 is detachably installed in the groove 18 of the flange 11, but the seal ring 19 is fixed in advance in the groove of one formwork 18 by gluing, brazing, spot welding, etc. Even so, there is nothing that would change this idea.

[Brief explanation of the drawing]

The figures show typical embodiments of this invention, in which Fig. 1 is a side view showing the external appearance of the joint frame, Fig. 2 is a partially jointed side view of a conventional joint, and Fig. 3 is a longitudinal side view of the joint of this invention, FIGS. 4 and 5 are partial longitudinal side views showing other embodiments, and FIG. 6 is a sectional view showing the cross-sectional shape of another seal ring. It is. Symbols in the figure: 10 a, 10 b, 10 C...
...Concrete formwork, 11...Flange, 1
6...Bold hole, 18...Groove, 19
... Seal ring, 20 ... Missing circular portion.

Claims (2)

[Scope of utility model registration request] (1) In a joint formwork consisting of several sets of formworks each having at least one rotating wheel and joining flanges at both ends of a diametrically divisible unit length form, at least several sets of formworks, each of which has a groove with a single semicircular cross section carved concentrically with the inner diameter of the formwork;
Further, when the pair of molds are combined into a cylindrical shape, a steel wire seal ring having a cross-sectional shape and a diameter is exactly half-immersed in the circular groove formed by the pair of grooves and is in close contact with the inner surface of the groove. A formwork for centrifugal forming of hollow concrete columns, characterized by the following: (2) The cross-sectional shape of the seal ring is one of a perfect circle, an ellipse, and a regular hexagon, and the groove of the flange that fits therein is one of a semicircle, a semiellipse, and a semiregular hexagon. A formwork for centrifugal forming of a hollow concrete column according to claim 1 of the above-mentioned utility model registration, characterized by: