JPH0631718A - Forming method for seal of centrifugally molded concrete tube collar - Google Patents

Abstract

PURPOSE:To prevent loss of water stopping effect due to a gap generated between a steel faucet collar to be fixed to an outer periphery of an end of a centrifugally molded concrete tube and a quick-drying semifluid sealing material when the material is fed down from a nozzle to an inner surface of the collar while rotating the collar to form one or a plurality of stringlike circumferential seals on the inner surface of the collar. CONSTITUTION:A collar 1 is rotatably supported to a roller 2, and rotated in a direction of an arrow 3 at a central axis of the collar as a center. A vessel 4 which contains semifluid sealing material 5 has a nozzle 6 at its lower end. When the material contained in the vessel 4 is pressurized, it is continuously fed down from the nozzle 6 in a string state. A section of the nozzle 6 is formed in a semicircular shape, and a dropping direction of the nozzle 6 is decided in a direction in which its long side (diameter) is brought into contact with an inner surface of the collar 1, and operated. As the material 6, one-pack elastic sealant having water expansion properties is employed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of forming a cord-like circumferential seal on the inner surface of a centrifugally molded concrete pipe collar.

[0002]

2. Description of the Related Art FIG. 3 shows the structure of a pipe end of a centrifugally molded concrete pipe. A steel or stainless steel socket collar (joint metal fitting) 1 with a fold 12 is attached to the end of one concrete pipe 11. The collar 1 and the concrete pipe 11 are attached to each other by arranging the collar 1 in a centrifugal molding frame and centrifugally molding the concrete pipe 11, so that the folds 12 are cut into the concrete and fixed. The collar 1 and the concrete pipe 11 are integrated. It is possible to connect the concrete pipes 11 and 21 by inserting an insertion port of another concrete pipe 21 into the receiving collar 1 and sealing with a sealing material 22 and a cushion material 23.

In order to secure the sealing property between the inner surface of the collar 1 and the concrete, as shown in FIG. 3, a circumferential sealing material 5 made of water-expandable rubber is attached to the inner surface of the collar 1. The mounting of the circumferential seal material 5 is performed as follows. FIG. 1 shows a step of attaching the sealing material 5 to the inner surface of the collar 1. The collar 1 is allowed to rotate horizontally, and the semi-fluid sealing material 5 is made to flow down from the nozzle 6 having a circular cross section on the inner surface thereof. The sealing material 5 that has flowed down has a circular cross section and is attached to the inner surface of the collar 1 to form a circumferential sealing material.

[0004]

In this case, as the collar 1 rotates, the sealing material 5 reaches the ceiling together with the inner surface of the collar 1. The seal material 5 that has reached the ceiling is color 1.
Often trying to fall away from the collar, often with collar 1 and seal 5
Adhesion with is partly separated. When the sealing material 5 is dried and hardened and centrifugally molded into a concrete pipe, the concrete subjected to centrifugal force should press the sealing material 5 against the inner surface of the collar 1 to enhance the sealing property between the collar 1 and the concrete. However, in reality, since the sand and the like in the concrete has a larger mass than the seal material 5, the sand and the like show a behavior of being subjected to a centrifugal force larger than that of the seal material 5 and entering the adhesion portion between the collar 1 and the seal material 5, There is a problem that the sealability between the seal material 5 and the collar 1 is impaired.

The present invention aims to solve such problems.

[0006]

DISCLOSURE OF THE INVENTION The present invention is directed to the inner surface of a steel or stainless steel socket collar to be fixed to the outer diameter of a pipe end of a centrifugally molded concrete pipe, while rotating the collar to obtain semi-fluidity. When a string-shaped circumferential seal is formed on the inner surface of the collar by flowing the sealing material of the nozzle from the nozzle, the sealing material outlet cross section of the nozzle has a flat shape with the long side as the base,
A method for forming a seal for a centrifugally-formed concrete pipe collar, characterized in that the nozzle is disposed so that the long side of the cross section of the sealing material flowing out from the nozzle is in contact with the inner surface of the collar, and the sealing material is made to flow down.

[0007]

The sealing material according to the present invention is a rubber-like substance which has semi-fluidity when attached to the inner surface of the collar, can be extruded like a cord from a nozzle, has adhesive force, and has elasticity after drying. . Conventionally, it is common knowledge that such a seal material has a circular cross section and is compressed so as to crush the circle so that the circumference shifts from line contact to surface contact, at which time the sealing performance is improved. However, the circumferential seal on the inner surface of the collar of the centrifugally molded concrete tube, as mentioned above, exhibits a phenomenon contrary to this common sense.

In the present invention, the cross sectional shape of the sealing material nozzle is a flat shape with the long side as the base. Here, the flat shape means a shape whose height in a direction perpendicular to the long side is smaller than the length of the long side, and for example, a semicircular shape, a trapezoidal shape, a rectangular shape, a semielliptic shape, a mountain shape, and the like. Say.
When the nozzle is arranged so that the long side of such a cross-sectional shape is in contact with the collar and the sealing material is made to flow down, the sealing material and the collar are in contact and adhere to each other at the long side. Even if the collar is rotated and the sealing material is positioned on the ceiling of the inner surface of the collar, peeling does not occur. Further, when centrifugally molding concrete, unlike the conventional circular cross section, the sealing material is pressed against the inner surface of the collar without the concrete entering the long side contact portion. Therefore, good sealability can be reliably ensured.

[0009]

EXAMPLE FIG. 1 shows a construction situation of an example of the present invention. The collar covered by the present invention has a diameter of 250 to 2000 mm. Further, FIG. 2 exemplifies the cross-sectional shape of the nozzle tip used for carrying out the present invention. In FIG. 2, (a) is a semi-circle,
(B) is a trapezoid, (c) is a rectangle, (d) is a semi-ellipse, (e)
Is an example of a chevron cross section.

The collar 1 is rotatably supported on the roller 2 and rotates in the direction of arrow 3 about the central axis of the collar. The container 4 accommodating the semi-fluidic sealing material 5 is provided with a nozzle 6 at the lower end, and when the sealing material accommodated in the container 4 is pressurized, it flows like a string from the nozzle 6 continuously.
The cross section of the nozzle 6 was a semicircle shown in FIG. 2A, and the falling direction of the nozzle 6 was determined so that the long side (diameter) 10 of the nozzle 6 contacted the inner surface of the collar 1. As the sealing material 5,
A water-swellable one-component elastic sealant (manufactured by Asahi Denka Kogyo) was used.

The sealing material thus constructed had a very good sealing performance in concrete and a perfect waterproof effect.

[0012]

According to the method of the present invention, the seal of the attachment portion of the receiving collar of the centrifugal concrete tube, which has conventionally been incompletely sealed, was completely sealed, and the watertightness was also perfect.

[Brief description of drawings]

FIG. 1 is an explanatory view showing a construction situation of an embodiment of the present invention.

FIG. 2 is a drawing showing an example of a cross section of a nozzle of an embodiment.

FIG. 3 is a cross-sectional view showing a structure of a pipe end portion of a centrifugally molded concrete pipe.

[Explanation of symbols]

1 Color 2 Roller 3 Arrow 4 Container 5 Sealing Material 6 Nozzle 10 Diameter 11 Concrete Pipe 12 Crease 21 Concrete Pipe 22 Sealing Material 23 Cushioning Material

Claims (1)

[Claims] 1. A collar which is made to flow from a nozzle by causing a quick-drying semi-fluid sealing material to flow down on the inner surface of a steel receiving collar to be fixed to the outer diameter of a pipe end of a centrifugally molded concrete pipe while rotating the collar. When forming a cord-shaped circumferential seal on the inner surface, the nozzle seal material outlet cross section is made flat with the long side as the base, and the nozzle extends in the direction in which the long side of the seal material cross section that flows out from the nozzle contacts the inner surface of the collar. A method for forming a seal for a centrifugally molded concrete pipe collar, characterized in that the seal material is disposed so that the seal material flows down.