JPH0365783B2 - - Google Patents

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a plastic tube (hereinafter referred to as a "porous plastic tube") having a large number of through holes in the tube wall in the tube axis direction.
Regarding the end closure method (referred to as ).

(Prior art) This type of porous plastic pipe has holes in the pipe wall, which allows for the saving of plastic materials and reduces the weight of the pipe, and by increasing the thickness of the pipe wall. It has the advantage of increasing the rigidity of the

Therefore, in recent years, porous plastic pipes have been used as underground pipes.

In general, the connection between these porous plastic tubes is made by enlarging the diameter of the end of one tube 1' as shown in the half-sectional view in FIG. A port 2' is provided, and the end of the other tube 1' is inserted into the socket 2' and connected in sequence.

However, in the case of a porous plastic tube, there is a through hole 13' that communicates from one end having the socket 2' to the other end inserted into the socket 2' of the other pipe. Inconveniences arise in that fluid within the pipe leaks through the pipe 13' and groundwater such as rainwater flows into the pipe.

In order to solve this problem, a method has conventionally been proposed in which a filler 3' is embedded in a through hole 13' opened in the end face of the socket 2', as shown in a partial cross-sectional view in FIG. However, this method had the disadvantage that complete watertightness could not be obtained.

That is, when rubber or the like is used as the filler 3', when the pipe is subjected to vibrations, shocks, etc., or when the water pressure inside the pipe acts on the back surface of the filler 3' through the through hole 13'. In some cases, the filler 3' escaped from the through hole 13'.

In addition, when a fluid adhesive or the like is used as the filler 3', when the filler 3' is filled into the through hole 13', it simply penetrates into the deep part of the through hole. In some cases, the inside of the filling material 3' was not completely closed off by the filling material 3'.

(Object of the Invention) The present invention solves the problems of the conventional closing method, and when embedding a filler material into a through hole opened in a tube end surface, the filling material is placed at a predetermined distance behind the tube end surface. to prevent the filling material from penetrating deep into the hole, and to prevent the filling material from escaping from the hole after it is embedded in the hole. The open end of the seal is crushed to provide a simple closure method that provides reliable watertightness.

(Structure of the Invention) Hereinafter, a specific structure of the present invention will be explained with reference to the drawings.

FIG. 1 is a half-sectional view of a closing step showing an embodiment of the present invention, FIG. 2 is a partial front view showing an example of a filling material, FIG. 3 is a schematic diagram showing an example of a filling device, and FIG.
The figure is a sectional view of essential parts showing an example of the process of embedding a filler into a through hole, in which reference numeral 1 is a porous plastic tube, 3 is a filler, 4 is an inner mold, and 5 is a divisible ring mold. , 6 are end molds.

The porous plastic tube 1 is a synthetic resin tube made of vinyl chloride resin or the like and has a perfect circular, elliptical, oval, or other appropriate cross-sectional shape.
A large number of through holes 13 communicating in the tube axis direction are provided in the tube wall constituted by the inner peripheral wall 12 and the tube wall.

In the present invention, first, the end of the porous plastic tube 1 is heated and softened, and the inner mold 4 having the enlarged diameter portion 41 is press-fitted into the end of the tube to form the enlarged diameter socket 2. Next, the slide member 43 is moved in the axial direction, and the groove 21 for attaching the rubber ring is formed with the core member 42 expanded in the outer circumferential direction.

After forming the rubber ring type socket 2 in this manner, the link mold 5 is pressed against the tube end outer circumferential wall 11 to partially crush the through hole 13 at a position a predetermined distance rearward from the tube end surface.

This crushing is done by filling material 3 during the next embedding process.
This is to prevent the filler from penetrating into the deep part of the hole 13, so there is no need to crush it until the inside of the hole 13 is completely blocked. In addition, the diameter of the inside of the through hole 13 may be appropriately reduced.

Next, the filler 3 is embedded in the through hole 13 opened in the end face of the socket 2.

As this filler, relatively rigid materials such as rubber and plastic, fluid rubber, silicone resin, and other appropriate adhesives can be used.

In the case of using the former rigid material, the filler 3 may be formed into a rod shape having a cross-sectional shape that matches the through hole 13, and the filler material 3 may be embedded into each through hole 13 one by one. In addition, as shown in FIG. 2, the filling material 3 formed into a spherical shape is connected in a bead shape at intervals corresponding to the through holes 13, 13, .
It is preferable to embed it integrally by applying it to the open end of the holder, since the embedding operation can be performed easily. At this time, the connecting portions 31 connecting the fillers 3 are cut and discarded.

Moreover, when using the latter filling material 3 having fluidity, it is preferable to use a filling apparatus A shown in FIG. 3. This filling device A is connected to an injection device 9 that quantitatively measures and supplies the filling material to the mounting portion 8, and a device at the rear of the mounting portion 8 to remove excess filling material that has protruded from the through hole. The cutting blade 81 is provided, and as shown in FIG. 4, the mounting portion 8 is applied to the opening end surface of the through hole 3, and is sequentially filled into each through hole 13 while moving in the circumferential direction. Embed material 3.

After completing the embedding operation of the filler 3 into the through hole 13 in this way, as shown in FIG.
Press the end mold 6 against the outer circumferential wall 11 of the tube tip, and open the through hole 1.
Squeeze the open end of step 3.

The end of the porous plastic tube is thus completely occluded.

Although FIG. 1 shows an embodiment in which the present invention is applied to the tip of a rubber ring type socket, the present invention is not limited to this embodiment only, and may be applied within the scope of the gist of the present invention. Various configurations can be taken.

For example, it is also possible to apply the present invention to an adhesive type socket shown in FIG. 1 with the rubber ring mounting groove 21 removed, or to the tip of a straight pipe. Also ring type 5,
The end mold 6 may be pressed against the inner circumferential wall 12 from the inside of the tube to crush the through hole 13, or if necessary, the end mold 6 may be pressed from both the outside and inside of the tube to crush the through hole. good. Furthermore, as the filler, a material having rigidity such as rubber and a material having fluidity such as silicone resin may be used in combination.

(Effects of the Invention) As detailed above, the closing method of the present invention involves crushing the through hole in advance at a position a predetermined distance behind the tube end surface, and then embedding a filler into the through hole at the tip end of the tube. Therefore, the inconvenience of the filling material penetrating deep into the through hole does not occur, and the inside of the through hole can be reliably closed with the minimum necessary amount of filling material. Moreover, since the hole opened at the tip of the tube is crushed and the filler is completely sealed inside the hole, even if the tube is subjected to vibrations, shocks, etc., or pressure inside the tube is applied to the filler. The inconvenience of escaping from the through hole does not occur.

[Brief explanation of drawings]

FIG. 1 is a half-sectional view of a closing step showing an embodiment of the present invention, FIG. 2 is a partial front view showing an example of a filling material, FIG. 3 is a schematic diagram showing an example of a filling device, and FIG.
The figure is a sectional view of the main part showing an example of the filling material embedding process, Fig. 5 is a half sectional view showing the connected state of a conventional porous plastic pipe, and Fig. 6 is a sectional view of the main part showing the conventional closed state. . 1...Porous plastic pipe, 11...Outer peripheral wall,
12...Inner peripheral wall, 13...Through hole, 2...Socket, 3
...Filling material, 4...Inner mold, 5...Ring mold, 6...
...edge type.

Claims (1)

[Claims] 1. Heat and soften the end of a plastic tube that has a large number of axial holes in the tube wall, press a ring mold against the outer circumferential wall or inner circumferential wall of the tube end, and place it at a position a predetermined distance behind the tube end surface. The opening end of the through hole is crushed by pressing the end mold against the outer circumferential wall or inner circumferential wall of the tip of the tube. A method for closing the end of a porous plastic tube, which is characterized by crushing the tube.