JP3510004B2 - Core bottom structure of block mold - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a core-type bottom plate structure of a block forming form such as a form for forming a box culvert by horizontal driving. The present invention relates to a structure for preventing a recess formed by air bubbles or water bubbles on a plane formed by a core bottom plate. [0002] The inner surface of a concrete block having a hollow portion such as a box culvert is formed by a core mold supported by an outer mold. Like a box culvert, if the hollow part has a square cross-section, the core mold for molding it will also be square, but when such a block is molded by sideways, it will be molded at the bottom of the core mold There is a problem that dents due to air bubbles and water bubbles occur on the surface. This is, as shown in FIG. 4, the bottom surface 2 of the core mold 21 which becomes a horizontal surface during molding.
Second, the air bubbles and excess water mixed in the concrete milk accumulate to form air bubbles and water bubbles 23, which form a recess on the inner surface of the concrete block formed. Conventionally, in order to avoid this problem, as shown in FIG. 5, a number of small holes 25 are formed in a core-shaped bottom plate 24, and a cloth 26 is attached to the bottom surface of the bottom plate 24 during 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 texture of the cloth 26 and the small holes 25, so that no recess due to the air bubbles and water bubbles 23 occurs. [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 five concrete blocks are formed. In addition, there is a problem that the cloth 26 becomes a consumable and is uneconomical, and that the replacement of the cloth 26 is troublesome. The present invention is a durable and easy-to-handle core type which can prevent convection of air bubbles and water bubbles under the core type bottom plate without requiring complicated work. The goal is to obtain a bottom plate structure. [0006] bottom plate structure of the core type of block molding frame according to the present invention According to an aspect of the place both side surfaces of the lower surface perpendicular
A large number of side surfaces of the elongated strip-shaped plate member 15 processed into a plane having a constant surface roughness are made to pass air and water through each other and cement is removed.
The upper surface is welded and integrated with the reinforcing ribs 16 arranged in the direction perpendicular to the longitudinal direction of the plate members in a state where they are brought into contact with each other so that they do not penetrate, so that the lower surface as a whole is a single molded surface. It is assumed that. The side surfaces of the elongated plate material forming the core-shaped bottom plate 5 are in contact with the side surfaces of adjacent plate materials, and both are in surface contact with each other, but have an airtight or watertight structure. Absent.
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
Is discharged through the abutting portions of the side surfaces. On the other hand, cement, which has a much larger particle size than air or water,
5 and 15 cannot pass through the contact part of the side
Therefore, it does not penetrate into the contact portions between the side surfaces. The contact portion 19 that allows air and water to pass through and does not allow cement to enter is set based on the processed surface roughness of the side surfaces of the plate members 15 and 15 and the degree of close contact between the side surfaces of the plate members. The above-mentioned adhesion degree is a plate material 1 arranged
When the reinforcing ribs 16 are welded to the upper surfaces of the plates 5 and 15, the whole plate material can be clamped by a vise and set by the clamping force. The core mold must be squeezed in order to remove the mold from the molded block, and in order to enable the squeezing, a part of the molding surface of the core mold must be removed or retracted. No. As a structure in this case, if a core type having a structure in which the entire bottom plate 5 configured as described above is removed or retracted is used, manufacture of a core type including the bottom plate 5 having the above structure becomes easy, and Maintenance inspections can be easily performed. FIG. 1 to FIG. 3 show a core mold of a box culvert molding form having a bottom plate structure according to the present invention. As shown in FIG. 3, the core mold 1 has a structure in which the top plate 2 and both side plates 3, 4 are integrated, and the bottom plate 5 is pulled up and retracted. Fitting and disengaging surfaces 6 and 7 (see FIG. 2 for details) are formed between the inner lower ends of the side plates 3 and 4 and both sides of the bottom plate 5. The squeezed portions 8 and 9 in which the reinforcing plate is discontinuous are provided in the shoulder portion, which is the portion connecting the top plate 2 and both side plates. The side plates 3 and 4 can slightly swing with respect to the top plate 2 at the narrowed portions 8 and 9. [0010] Between the left and right side plates 3, 4, a diaphragm device 11 is provided.
Is mounted. This squeezing device is of a toggle type, and expands the side plates on both sides by rotating the crank 12. Brackets 13 and 14 are attached to the inside of the top plate 2 and the bottom plate 5 at opposing portions, respectively.
An unillustrated bottom plate retraction mechanism 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 is formed by arranging a number of strip-shaped plate members 15, 15... It has a structure in which a reinforcing rib 16 is welded, and edge members 17 that form the fitting and disengaging surface with the lower portion of the side plate are welded to both sides thereof. When a box culvert is formed by using a core mold having such a structure, when concrete milk is poured into the mold, air bubbles and water bubbles accumulated at the lower portion of the bottom plate 5 are removed from the side surfaces 18 of the plate members 15, 15. , 18 mutual abutment 19
Through the core, so that no air bubbles or water bubbles accumulate under the bottom plate 5, so that there is no recess on the surface of the block formed by the bottom plate 5 and a clean molding surface is formed. be able to. The water bubbles and bubbles under the core bottom plate 5 are pressurized by the weight of the concrete milk injected into the mold, so that the adjacent plate 1
Abutment portions 19 in which the side surfaces of the 5 are merely in contact with each other
Leaks from. On the other hand, since the cement particles have a much larger diameter than the molecules of air and water, they cannot penetrate into the abutting portions of the plate members 15, 15.
Is not buried by cement. When the concrete in the form has solidified, the bottom plate 5 is pulled up to the inside of the core mold and retracted, and the drawing device 1
1 is loosened, and the core mold 1 is pulled out in a direction perpendicular to the plane of the drawing to release the mold. According to the present invention described above, the trouble of attaching a cloth to the core-shaped bottom plate can be avoided.
Bubbles and water bubbles below the bottom plate of the core can be released, and a concrete block having a rectangular hollow portion such as a box culvert can be formed without forming a recess on the inner forming surface.

[Brief description of the 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 portion of a 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 below a core type bottom plate. FIG. 5 is an enlarged sectional view of a bottom plate in which a cloth is attached to the bottom plate. [Explanation of symbols] 5 Bottom plate 15 sheet material 16 Reinforcement rib 19 Contact part

Claims (1)

(57) Patent Claims 1. A large number of side phases of both sides of the lower surface and perpendicular processed elongated strip-shaped plate material flat <br/> surface of a predetermined surface roughness (15)
Airtight, air and water through each other and cement
The upper surface is welded and integrated with the reinforcing ribs (16) arranged in the direction perpendicular to the longitudinal direction of the plate material in the state of contact with the degree of attachment, so that the lower surface as a whole is a single molded surface The core-shaped bottom plate structure of the block molding form.