JPH0243691Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a leakage plate used to block water leaking from a formwork when manufacturing a concrete pipe by centrifugal force forming.

[Prior Art] Generally, concrete pipes are widely used for utility poles, bridge piers, etc., and come in various shapes and sizes.

Traditionally, many of these have been made regardless of their dimensions;
It is manufactured by centrifugal force molding as described in JP-A-60-83811 and JP-A-60-67115.

In this manufacturing method, a concrete pipe formwork consisting of a cylinder and a hollow lid fitted to its end face is rotated at a predetermined speed in the axial direction, and concrete is poured into the mold through one hollow opening. A concrete layer is created by centrifugal force on the inner surface of the frame and then cured at high temperatures to create a concrete pipe.

By the way, the hollow openings of the opposing lids fitted into the cylinder are of the same size, and in order to prevent the amount of moisture in the rotating formwork from becoming too large, the hollow openings at both ends are closed when the height of the lid is exceeded. It spills out of the hollow mouth and is made to be constant.

As the rotational speed of the formwork increases, centrifugal force within the formwork causes components of concrete with high specific gravity to move outward, and muddy water containing a large amount of water with relatively low specific gravity collects on the inside. The muddy water then travels along the inner surface of the concrete, and when it leaks out of the hollow holes in the lid fitted to both ends of the form, it is scattered radially by centrifugal force. At this time, the hollow opening on one side of the formwork is a place where concrete can be poured and concrete spilled from the formwork can be poured, so there is no problem even if muddy water splashes, but the hollow opening on the other side On the entrance side, there are workers working and electrical equipment, so if muddy water splashes around, it can stain the surrounding area or adhere to the equipment. To prevent this, traditionally a leakage plate made of cardboard or plastic plate cut to match the inner surface of the formwork is placed inside the lid to block the leakage of muddy water from the hollow opening. .

[Problems to be solved by the invention] Since the leakage plate cut to fit the inner surface of the formwork is firmly fixed to the formwork, it can effectively prevent muddy water from leaking. Its size is almost the same as the inner surface of the formwork, so when inserting it into the formwork, you have to take the trouble to remove the lid from the formwork and then firmly fit the lid back on after inserting it, which is a hassle. There is a problem with this.

Another problem is that when these leakage plates are cured at high temperatures, they deteriorate or deform, making them unusable.

Therefore, the object of the present invention is to provide a leakage plate that can be easily inserted into a mold without removing the lid, and can be used even after curing at high temperatures.

[Means for solving the problems] The structure of the present invention, which was made to solve the above problems, uses a formwork consisting of a cylinder and a hollow lid fitted to the end face of the cylinder. When manufacturing concrete pipes by centrifugal force forming, this is a disc-shaped leakage plate for manufacturing concrete pipes that is placed inside the lid to prevent moisture from leaking out of the mold from the hollow opening of the lid. The gist of the invention is a leakage plate for manufacturing concrete pipes, comprising: two fan-shaped heat-resistant plates; and a fixing member that fixes one end of each of the heat-resistant plates so as to be rotatable in a plane direction. .

The heat-resistant plate may be made of any material as long as it does not change or deform due to the curing temperature; for example, a metal plate or a ceramic plate can be used.

Further, the fixing member may be any member that fixes the two heat-resistant plates so as to be rotatable in the plane direction, and can be realized by, for example, a combination of rivets, eyelets, bolts, and nuts.

Furthermore, the shape of the two heat-resistant plates may be a semicircular fan shape so that it becomes a disk when expanded to prevent moisture from leaking inside the formwork, but it is also possible to look into the inner surface of the concrete, or to prevent the end surface of the concrete after curing. To make it easier to remove from the container, the inside may be cut out so that it becomes a hollow disk when expanded.
Note that the hollow space of this disc needs to be smaller than the hollow space of the lid.

[Function] In the leakage plate of the present invention, the two heat-resistant plates are configured to rotate in the plane direction around the fixed member, so they can be narrowed and placed inside the lid from the hollow opening. For example, when manufacturing concrete pipes, when the formwork begins to rotate, it begins to gradually expand due to centrifugal force.
It is firmly fixed to the inner surface of the formwork. When the rotation of the formwork reaches a predetermined speed, muddy water containing a large amount of water with a relatively low specific gravity collects on the inner surface of the concrete, travels along the inner surface, is led to the edge, and begins to leak out from the hollow opening. The leakage plate blocks this and prevents muddy water from leaking from the hollow opening.

[Example] An example of the leakage plate for manufacturing concrete pipes of the present invention will be described. The concrete pipe manufactured in this example is used for utility poles.

FIG. 2 is a sectional view showing the formwork of a concrete pipe manufactured by centrifugal force forming and the leakage plate of this embodiment installed inside the formwork.

As shown in the figure, a concrete pipe formwork 1 includes a metal cylinder 2 with flanges 2a formed at both ends,
It is made up of lids 4a and 4b that are fitted onto both ends of the cylinder 2 and secured by tightening bolts 3 to the flange 2a. Furthermore, hollow openings 4ac and 4bc of the same diameter are formed in the opposing lids 4a and 4b.
Furthermore, the leakage plate 5 of this embodiment is arranged inside one lid 4a.

As shown in FIG. 1, this leak-tight plate 5 has an arcuate cutout on the inside, and two fan-shaped tin-plated steel plates 5a (corresponding to the heat-resistant plates mentioned above) and a tin-plated steel plate 5a in the planar direction. It is made up of a rivet 5b (corresponding to the above-mentioned fixing member) attached to its end so as to be rotatably fixed. As shown in FIG. 1a, when two tin-plated steel plates 5a are spread out to form a ring, the inside of the ring formed is covered with lids 4a and 4.
It is smaller than the hollow holes 4ac and 4bc formed in b.
Further, as shown in FIG. 1b, the ends of the two fan-shaped tin-plated steel plates 5a are cut so that when they are narrowed, they become elliptical.

Now, the formwork 1 that accommodates such a leakage plate 5 is as follows.
When manufacturing a concrete pipe, it is installed horizontally on a rotating roller 6 and is rotatable in the axial direction.

Next, the function of the leakage plate 5 of this embodiment will be explained in accordance with the manufacture of a concrete pipe. In advance, the reinforcing bars 7 that will be the core of the concrete pipe are assembled into a cylindrical gaggle, and this is inserted into the cylinder 2, the lid 4b is fitted, and the oval-shaped leak is opened from the hollow opening 4ac of the other lid 4a. A stop plate 5 is inserted and placed between the inside of the lid 4a and the reinforcing bar 7. When the above preparations are completed, the rotating roller 6 is started to rotate the formwork 1, and concrete is started to be poured from one hollow opening 4bc.
Eventually, as the rotation of the formwork 1 becomes faster, the leakage plate 5 begins to gradually expand due to centrifugal force, expands into a ring as shown in FIG. is fixed. The poured concrete also gradually forms a concrete layer 8 on the inner surface of the formwork 1 due to centrifugal force.

As the formwork 1 continues to rotate further and reaches a predetermined speed, the centrifugal force also increases, so components with relatively high specific gravity in the concrete turn outward, and muddy water 8b with a low specific gravity containing a large amount of water collects inward. It's coming. This muddy water 8b travels along the inner surface of the concrete, is guided to both ends of the formwork 1, and is guided to one hollow opening 4.
It leaks from bc, but the other hollow port 4ac is blocked by the leakage plate 5 and does not leak outside. Continue to rotate the formwork 1 at a predetermined speed in this state for a while, and when the concrete in the formwork 1 has hardened to some extent, the formwork 1
Remove the whole thing from the rotating roller 6, and the ambient temperature is about 200.
Cure for several days at ℃ to accelerate concrete hardening. Then, once the concrete has hardened, cover 4
a, 4b and remove the leakage plate 5. At this time, the leakage plate 5 is stuck to the end face due to hardening of the concrete, so insert your hand inside the ring and pull it from the inside. Remove the leakage plate 5 by pulling strongly. After this, since the concrete has contracted due to hardening, it is easily removed from the formwork 1, and the concrete pipe is completed by extruding it as it is.

The removed leakage plate 5 can be used again when manufacturing the next concrete pipe, and if a release agent is applied to the surface of the tin-plated steel plate in advance, it will come off more easily.

As described above, according to the leakage plate 5 of this embodiment, if the two tin-plated steel plates are narrowed and made into an oval shape, it can be inserted into the formwork 1 through the hollow opening 4ac without taking the trouble of removing the lid 4a. When the formwork 1 rotates, it expands into a ring due to centrifugal force and is firmly fixed to the inner surface of the formwork 1, so that muddy water inside the formwork 1 can be prevented from leaking.

In addition, since the leakage plate 5 is made of a tin-plated steel plate, it can be used repeatedly without deformation or deterioration even after being cured at a high temperature of about 200°C, and since tin-plated steel plates are inexpensive, the manufacturing cost can be reduced. can be kept low.

Furthermore, since the leakage plate 5 forms a ring when expanded, the inside of the concrete can be visually observed from the inside, and after the concrete has cured, it can be easily removed by pulling the leakage plate stuck to the end face toward you from the inside.

In addition, in the leakage plate of the above embodiment, two tin-plated steel plates were each formed into a substantially semicircular fan shape, and nothing was provided around them, but the leakage plate of the present invention is shown in FIG. As shown, protrusions 5e may be formed at two locations around the two tin-plated steel plates, and the two tin-plated steel plates 5a' may each be formed into a sector shape larger than a semicircle. When such a leakage plate 5' is used, the area of the overlapping parts 5c and 5d increases when expanded into a ring, so when the formwork is rotated, leakage from inside the formwork to the outside through the gap between the overlapping parts 5c and 5d. The amount of muddy water leaking can be reduced. Furthermore, by providing the protrusion 5e, the friction between the formwork and the leak-tight plate 5' increases and rotational deviation can be prevented, and since the stop position of the formwork is usually fixed, the overlapping portion 5c, when stopped, Leakage plate 5' so that 5d is horizontal
If this is set inside the formwork, when the formwork is rotated to produce a concrete pipe and the formwork is stopped again at its original position, the leakage plate 5' will also stop at its original position. Therefore, when the mold is stopped, muddy water accumulates in the lower part of the formwork, but the overlapping portion 5c of the leakage plate 5'
5d is horizontal and not located below, so muddy water will not leak out from the gap.

[Effects of the invention] As detailed above, if the leakage plate for manufacturing concrete pipes of the invention is used, the leakage plate can be inserted from the hollow opening of the lid without removing the lid, and Since it expands into a disk shape and is firmly fixed to the inner surface of the formwork, leakage of muddy water inside the formwork can be effectively prevented.

In addition, since the leakage plate is made of a heat-resistant plate, even if the entire formwork is cured at high temperatures, it can be used repeatedly without deterioration or deformation.

[Brief explanation of drawings]

1 and 2 show an embodiment of the present invention,
Figure 1 is a plan view showing the configuration of the leakage plate, Figure 2 is a sectional view showing the leakage plate attached to the formwork of a concrete pipe, and Figure 3 is a diagram of another example of the leakage plate. FIG. 3 is a plan view showing the configuration. 1... Formwork, 4a, 4b... Lid, 5, 5'... Leakage plate,
5a, 5a'...Tin plated steel plate, 8...Concrete layer, 8b...Muddy water.

Claims (1)

[Claims for Utility Model Registration] When manufacturing a concrete pipe by centrifugal force forming using a formwork consisting of a cylinder and a hollow lid fitted to the end face of the cylinder, the above-mentioned A leakage plate for manufacturing disc-shaped concrete pipes, which is placed inside the lid to prevent moisture from leaking inside the formwork, and includes two fan-shaped heat-resistant plates, and one end of each of the heat-resistant plates. A leakage plate for manufacturing concrete pipes, comprising: a fixing member for rotatably fixing in a plane direction; and a leakage plate for manufacturing concrete pipes.