JPH08300332A - Bottom plate structure of core mold for block molding form - Google Patents

Abstract

PURPOSE: To obtain the structure in which the handling for releasing air or water bubble under a bottom plate is easy and which has high durability. CONSTITUTION: A bottom plate in which the lower surface is formed in one molding surface as a whole is obtained by welding a reinforcing rib 16 disposed perpendicularly to the length of the slender rectangular plate materials 15 to be integrated in the state that the many materials 15 surface on both sides perpendicularly to the lower surface are brought into contact with the sides to be integrated. At the time of molding a block, since the air or water staging under the bottom plate 5 is pressurized by the own weight of concrete, it is exhausted via the contact part of the sides of the materials 15. On the other hand, the cement having a much larger particle size than that of the air or water cannot pass the contact part of the sides of the materials 15, and hence the air or water does not enter around the contact part of the sides.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a core type bottom plate structure of a block molding form, such as a form for horizontally punching a box culvert, and a flat surface formed by the core type bottom plate. The present invention relates to a structure for preventing dents due to air bubbles and water bubbles.

[0002]

2. Description of the Related Art The inner surface of a concrete block having a hollow portion such as a box culvert is molded by a core mold supported by an outer mold. If the hollow part has a square cross section, such as a box culvert, the core mold that molds it will also be square, but when molding such a block by horizontal casting, it will be molded at the bottom of the core mold. There is a problem that dents are generated on the surface due to air bubbles or water bubbles. As shown in FIG. 4, this is the bottom surface 2 of the core mold 21 that becomes a horizontal surface during molding.
In FIG. 2, air bubbles and excess water mixed in the concrete milk are accumulated to form air bubbles and water bubbles 23, and a recess is formed on the inner surface of the concrete block molded by this.

In order to avoid this problem, conventionally, as shown in FIG. 5, a large number of small holes 25 are punched in a core type bottom plate 24, and a cloth 26 is attached to the bottom surface of the bottom plate 24 at the time of molding. It is carried out. In this way, the air bubbles and water bubbles 23 collected under the core-shaped bottom plate 24 escape through the grain of the cloth 26 and the small holes 25, so that the air bubbles and the water bubbles 23 do not form a recess.

[0004]

However, in the conventional molding method as described above, the durability of the cloth 26 is low, and the cloth 26 must be replaced every time about 5 concrete blocks are molded. 26 is a consumable item, which is uneconomical, and it takes time to replace the cloth 26.

The present invention has a durable and easy-to-use core type which can prevent convection of air bubbles and water bubbles under the bottom plate of the core type without requiring troublesome work. The challenge is to obtain a bottom plate structure.

[0006]

According to the core mold bottom plate structure of the present invention, a large number of elongated strip-shaped plate members 15 each having both side surfaces processed into flat surfaces at right angles to the lower surface are arranged side by side. In the abutting state, the upper surface is welded to and integrated with the reinforcing ribs 16 arranged in the direction perpendicular to the longitudinal direction of the plate materials, so that the lower surface is formed as a single molding surface as a whole. .

[0007]

The side surface of the elongated plate material forming the core type bottom plate 5 is in contact with the side surface of the adjacent plate material, and both are in surface contact with each other, but they are not airtight or watertight.
Therefore, the air and water accumulated under the bottom plate 5 are pressurized by the weight of the concrete, so that the plate members 15, 15
Are discharged through the abutting portions of the side surfaces of each other. On the other hand, cement, which has a much larger particle size than air or water, is
5 and 15 cannot pass through the abutting portions of the side surfaces,
Therefore, they do not penetrate into the abutting portions of the side surfaces. The contact portion 19 that allows air and water to pass therethrough and does not allow cement to enter is set by the processed surface roughness of the side surfaces of the plate materials 15 and 15 and the degree of adhesion between the side surfaces of the plate materials. The above-mentioned degree of adhesion is plate material 1
When the reinforcing ribs 16 are welded to the upper surfaces of the plates 5 and 15, it can be set by clamping the entire aligned plate materials with a vise and setting the clamping force.

The core mold must be squeezed in order to release it from the molded block, and in order to enable this drawing, a part of the molding surface of the core mold must be removed or retracted. I won't. As a structure in this case, if a core mold having a structure in which the entire bottom plate 5 configured as described above is detached or retracted, a core mold having the bottom plate 5 having the above structure can be easily manufactured, and the bottom plate 5 can be easily manufactured. Easy maintenance and inspection.

[0009]

1 to 3 show a core mold of a box culvert molding form having a bottom plate structure of the present invention. As shown in FIG. 3, the core mold 1 has a structure in which a top plate 2 and both side plates 3 and 4 are integrated, and a bottom plate 5 is pulled up and retracted. Fitting and disengaging surfaces 6 and 7 (details are shown in FIG. 2) are formed between the inner lower ends of the side plates 3 and 4 and both sides of the bottom plate 5. The shoulder portions, which are the connecting portions between the top plate 2 and both side plates, are provided with narrowed portions 8 and 9 in which reinforcing plates are discontinuous. The side plates 3 and 4 are slightly swingable with respect to the top plate 2 at the narrowed portions 8 and 9.

A diaphragm device 11 is provided between the left and right side plates 3, 4.
Is mounted. This diaphragm device is of a toggle type, and the side plates on both sides are expanded by rotating the crank 12. Brackets 13 and 14 are mounted inside the top plate 2 and the bottom plate 5, respectively, at portions facing each other.
A retracting mechanism for the bottom plate (not shown) is mounted between the brackets 13 and 14.

The structure of the bottom plate 5 is shown in FIGS. As shown in FIG. 1, the bottom plate 5 has a large number of elongated strip-shaped plate members 15, 15 ... Machined on both sides side by side, which are clamped in the AA direction of FIG. The reinforcing ribs 16 are formed by welding, and the edge members 17 that form the fitting / removing surface with the lower side plate are welded on both sides of the reinforcing ribs 16.

When a box culvert is formed by using the core die having such a structure, when concrete milk is poured into the form, air bubbles and water bubbles accumulated in the lower part of the bottom plate 5 are generated on the side surfaces 18 of the plate members 15, 15. , 18 mutual abutting portion 19
To escape to the inner side of the core mold, so that air bubbles and water bubbles do not accumulate under the bottom plate 5, so that there is no recess on the surface of the block molded by the bottom plate 5 and a clean molding surface is obtained. be able to. Water bubbles and air bubbles under the core type bottom plate 5 are pressurized by the weight of the concrete milk injected into the mold, so that the adjacent plate materials 1
The abutting portion 19 in which the side faces of 5 are merely abutting each other
Leaks from. On the other hand, since the cement particles have a diameter much larger than that of air or water molecules, the cement particles cannot penetrate into the abutting portions of the plate materials 15 and 15, and therefore the abutting portions 19
Is not filled with cement.

When the concrete in the mold is solidified, the bottom plate 5 is pulled up to the inner side of the core mold and retracted, and the expansion device 1
Loosen 1 and pull out the core mold 1 in the direction perpendicular to the plane of the drawing to remove the mold.

[0014]

According to the present invention described above, it is possible to eliminate the trouble of attaching a cloth to the core type bottom plate,
Air bubbles and water bubbles under the bottom plate of the core type can be released, and a concrete block having a rectangular hollow portion like a box culvert can be molded without forming a recess on the inner molding surface.

[Brief description of drawings]

FIG. 1 is a broken perspective view showing a bottom plate structure.

FIG. 2 is an enlarged front view of a connecting portion between a bottom plate and a lower side plate.

FIG. 3 is a front view showing an example of a core type.

FIG. 4 is an explanatory view showing air bubbles and water bubbles under the core type bottom plate.

FIG. 5 is an enlarged cross-sectional view of a bottom plate having a cloth attached to the bottom plate.

[Explanation of symbols]

 5 Bottom plate 15 Plate material 16 Reinforcing rib 19 Abutting part

Claims (1)

[Claims] 1. Reinforcing ribs arranged in a direction perpendicular to the longitudinal direction of a plurality of long and narrow strip-shaped plate members (15) whose both sides are processed into a plane perpendicular to the lower face, with their side faces abutting each other. A core-shaped bottom plate structure of a block molding formwork, characterized in that the upper surface is welded to and integrated with the (16) so that the lower surface becomes one molding surface as a whole.