JPH0440887Y2 - - Google Patents

Description

[Detailed description of the invention] A. Purpose of the invention a. Industrial application field This invention relates to formwork used to manufacture concrete pipes.

b. Prior art and its problems The conventional form 7 for concrete pipes has a structure in which an outer form 7B and an inner form 7C are planted in a base frame 7A. In this case, the inner formwork 7C
The inner edge 7A1 of the base frame 7A that receives the lower end of the base frame 7A has an L-shaped cross section, and is structured to receive the entire lower end surface of the inner form frame 7C from below. Concrete adheres to the corner 7A11. For this reason, when installing the inner formwork, it takes time and effort to remove this adhered concrete. In addition, it takes time and effort to demold the concrete after it hardens and to remove the inner formwork.

B. Structure of the invention a Means for solving the problem The present application attempts to solve the above-mentioned problem with the following structure. That is, the present invention consists of a base frame 2, an outer frame 3, and an inner frame 4, and the base frame 2 has a short cylindrical side wall part 2B on the circumference of a flat circular horizontal plate part 2A. The side wall portion 2B is
At the lower end of the side wall portion 2B, a suitable number of protrusions 2C are arranged in series in a horizontal direction in a comb-tooth shape.
and the protrusion 2C form an inner receiving part 2D for receiving the lower edge of the inner form 4, and an outer receiving part 2H for receiving the lower edge of the outer form 3 is formed on the outer periphery of the horizontal plate part 2A. The outer form frame 3 has a cylindrical shape, and its lower end has a shape that can be attached to and detached from the outer receiving part 2H from above, and the inner form frame 4 has a cylindrical shape. It is configured to be attached and detached from above from above, and to have a distance D between it and the outer formwork for pouring concrete.

b Example of the invention 1 is a formwork for a concrete pipe, which consists of a base frame 2, an outer formwork 3, and an inner formwork 4.

Therefore, in the base frame 2, a short cylindrical side wall portion 2B is continuously provided on the circumference of the flat circular horizontal plate portion 2A,
At the lower end of the side wall portion 2B, an appropriate number of protrusions 2C are arranged in a row in a horizontal direction in a comb-tooth shape. An inner receiving part 2D is formed to receive the inner receiving part 2D. Further, on the outer periphery of the horizontal plate portion 2A, an inclined wall 2E configured as a cylindrical body in the shape of a truncated cone is continuously provided, and on the outer periphery of the lower edge of this inclined wall 2E, a horizontal plate portion 2F is provided continuously. A protrusion 2G is provided on the outer periphery of the upper surface of the plate portion 2F. These inclined walls 2E, horizontal plate portions 2F, and protrusions 2G
An outer receiving portion 2H is formed to receive the lower edge of the outer formwork 3.

On the other hand, the outer frame 3 has a cylindrical shape, and its lower end is configured to be able to be attached to and detached from the outer receiving portion 2H from above.

Further, the inner formwork 4 is attached to and removed from the outer receiving part 2H from above, and is naturally configured to have a predetermined distance D between it and the outer formwork. Concrete is placed in this interval D, and the concrete pipe 8 is manufactured.

In this case, in order to facilitate the removal of the circular frame 4, the following configuration is adopted, for example.

Therefore, in this inner formwork 4, one vertical cut 4C is carved in the side wall 4B of the vertical pipe-shaped inner formwork body 4A,
Receiving edges 4F and 4G having a triangular prism-like cross section on the left and right are attached to the opposing edges 4D and 4E formed by the vertical cuts 4C, facing inward of the inner form frame 4A, and there are no rotations in the inner form frame 4A. A movable vertical shaft 5 is installed, and the vertical notch 4C is inserted into the vertical shaft 5 through an eccentric disk 5A.
An arm 5B that moves forward and backward in the direction is successively provided, and a pressing portion 5C that opens and closes the receiving edges 4F and 4G in the circumferential direction of the inner frame body 4A is provided in a row at the tip of the arm 5B. Therefore, the state of connection between this arm 5B and the above-mentioned pressing part 5C is determined by a bracket 5F having a bolt 5E screwed into a cap nut 5D rotatably connected to the tip of this arm and protruding from the above-mentioned pressing part side. They are connected using pins P.

5G is a small protrusion that projects inward from the pressing part 5C with the center position in the longitudinal direction of the pressing part 5C, and 5H is a band that comes into contact with the inner surface of the small projection, and both ends of this band 5H1 is rotatably connected to a shaft 5I installed in the vicinity of the receiving edges 4F and 4G in the pressing portion 5C.

6 is a mounting bracket protruding from the inner form frame body 4A;
The vertical shaft 5 is rotatably supported by this metal fitting. 6A is a reinforced edge. This inner formwork is
Since it is configured as described above, when the vertical shaft 5 is rotated and the pressing portion is pressed against the inside of the receiving edge, the inner mold frame body 4A is held in a predetermined state. Thereafter, a material such as concrete is filled between the outer formwork 3 and the inner formwork body 4A and cured. When demolding is desired, the vertical shaft is rotated in the opposite direction, and the pressing part is
It is drawn inward of the inner form body 4A by eccentric discs, arms, etc.

As a result, the pressing force on the receiving edges 4F, 4G disappears, so the opposing edges 4D, 4E are slightly drawn inward, and the inside of the concrete pipe 8, which is the product, and the outside of the inner form body 4A are separated. It will peel off. As a result, demolding can be performed easily and reliably.

As the pressing part moves, the small protrusion 5G also moves, and the band 5H is also pulled inward of the pressing part.
Since the pressing portion moves inward evenly in the vertical direction, the above-mentioned peeling action can be made more reliable.

c. Effect Explain along with the effects.

C Effect of the idea After manufacturing the concrete pipe 8, which is the product, the base frame 2
Then, the outer formwork 3 and the inner formwork 4 are taken apart, cleaned, and reassembled to be used as formwork for concrete pipes. In this case, since an appropriate number of protrusions 2C arranged in a comb-teeth pattern are arranged in series on the inner receiving part 2D of the base frame 2, the concrete adhesion phenomenon mentioned at the beginning is unlikely to occur. Moreover, even if it occurs, it is extremely easy to remove it.

[Brief explanation of the drawing]

Figure 1 is a plan view of the conventional model, Figure 2 is A-A
3 is a plan view of the present invention, FIG. 4 is a sectional view taken along line B--B, FIG. 5 is a plan view of another embodiment, and FIG. 6 is an enlarged longitudinal sectional view of the same. 1... Concrete pipe formwork, 2... Base frame, 3
...Outer formwork, 4...Inner formwork.

Claims (1)

[Claims for Utility Model Registration] A formwork for a concrete pipe characterized by comprising a base frame 2, an outer formwork 3, and an inner formwork 4 having the following requirements. A. The base frame 2 has a short cylindrical side wall portion 2B connected to the circumference of the flat circular horizontal plate portion 2A, and the lower end of the side wall portion 2B is connected in a comb-like shape in the horizontal direction. An appropriate number of protrusions 2C are arranged in series, and these side wall portions 2B and the protrusions 2C form an inner receiving portion 2D that receives the lower edge of the inner form 4, and the horizontal plate portion 2A. An outer receiving portion 2H for receiving the lower edge of the outer formwork 3 is formed on the outer periphery. (b) The outer formwork 3 is configured to have a cylindrical shape, and the lower end is configured to be able to be attached to and detached from the outer receiving portion 2H from above. (c) The inner formwork 4 is configured to be attached to and removed from the outer receiving part 2H from above, and to have a distance D between it and the outer formwork for pouring concrete.