JPH0126328B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for forming an enlarged-diameter socket at the end of a synthetic resin pipe (hereinafter referred to as a "hole pipe"), which is formed by penetrating a pipe wall with a large number of through holes in the pipe axis direction. The purpose of this is to insert a filler into the hole at the end of the hole tube, which will become the expanded diameter socket, to make it solid and non-porous, thereby forming the expanded diameter socket. To easily form an enlarged diameter socket having a smooth outer circumferential surface and an excellent appearance.

Conventionally, many methods have been proposed for forming an enlarged diameter socket at the end of the hole tube, but since the through hole at the end of the hole tube is easily crushed during diameter expansion, unevenness is created on the outer peripheral surface of the enlarged diameter section. However, there was a problem that the appearance deteriorated.

The present invention was made to solve the above-mentioned problems, and when forming an enlarged diameter socket in a hole tube having a large number of through holes in the tube axis direction through the tube wall, first the end of the hole tube is opened. The outer mold is applied to the outer peripheral surface of the tube, which is heated and softened and located a predetermined distance inward from the end surface of the tube, and is compressed in an annular groove shape to bring the outer wall of the tube wall into close contact with the inner wall to temporarily close the through hole. A filling material is inserted into each hole on the side of the tube end from the blocked part to make it filled and non-porous, and then the outer wall of the temporarily blocked part is restored and expanded by reheating, and then the filling material is inserted into each hole on the side of the tube end from the blocked part, and then the outer wall of the temporarily blocked part is restored and swollen. The present invention relates to a method for forming an expanded diameter socket of a hole tube, which comprises inserting an inner mold into the end of the tube to expand the diameter.

Hereinafter, the present invention will be explained with reference to the drawings.

Figure 1 is a cutaway perspective view of the hole tube, Figure 2 is a cutaway front view of the hole in the hole being temporarily closed, and Figure 3 is a filling of the hole on the end side of the tube than the temporarily closed part. FIG. 4 is a cutaway front view showing the state in which the through hole is restored by opening the temporary blockage after the material has been inserted and filled, and FIG. 4 is a cutaway front view showing the state in which the enlarged diameter socket is formed.

As shown in FIG. 1, the hole pipe P has a large number of through holes 1d in the pipe axis direction formed between the inner wall 1a, outer wall 1b, and partition wall 1c that constitute it, and has an enlarged diameter socket. The formation of the portion is performed as shown in FIGS. 2 to 4.

(1) As shown in Fig. 2, a cylindrical core with an outer diameter that matches the inner circumferential surface of the hole pipe P extends a predetermined length from the end of the hole pipe P into the end that becomes the enlarged diameter socket. The mold 2 is inserted, and the outer end thereof has an inner peripheral surface 3a having a diameter that matches the outer peripheral surface of the core mold, and an annular projection 3b for compression protruding from the same surface toward the center. 2, surround the area closer to the mouth than the inner end of the mold 2, heat the same area to a temperature below the melting point of the synthetic resin to soften it, and press it with the annular protrusion 3b of the outer mold 3. Due to this compression, the outer wall 1b of the hole tube wall is bent inward and the inner wall 1b is bent inward.
Each through hole is temporarily closed by this close contact portion 1e in close contact with a. However, this temporary closure is temporary, and if the same part is later reheated to below the melting point of the resin, the bent shape of the close contact part 1e will return to its original straight pipe shape, and the close contact part will open, temporarily opening the through hole. The closed portion is restored to its original condition.

(2) Insert the filler 4 into each through hole 1d on the tube end side from the part that has been temporarily closed as described above, as shown in FIG. The above-mentioned portion of each through hole 1d is kept in a solid and non-porous state. The filler 4 may be injected with silicone resin, foamed resin, or the like, or a thin rod that matches the diameter of the through hole may be inserted.

(3) After each through hole is filled with the filler 4 to a non-porous state as described above, the temporarily closed part is reheated to a temperature below the melting point of the resin, and this heating causes the close contact part 1e (third (indicated by a chain line in the figure) is restored to its initial straight pipe state (indicated by a solid line in Fig. 3).

(4) As shown in Fig. 4, an enlarged diameter socket part S is formed at the end of the hole tube, where the through hole is filled with a filler so that it is not porous. Form.

The inner mold M includes a tip part _M1 having an outer diameter corresponding to the inner diameter of the Hall tube P, an enlarged diameter part _M3 which has a large diameter via an inclined part M2, and a diameter enlarged part _M3 extending in the circumferential direction from this enlarged diameter part _M3 . It includes a protruding and retracting part _M4 for forming an annular groove that can move forward and backward, and a sliding wedge K that moves on an axis J to operate the protruding and retracting part _M4 . The outer mold N has a tip inner circumference N1 corresponding to the outer circumference of the tip _M1 of the inner die M, and _an inclined inner circumference corresponding to the inclined portion _M2 .
N ₂ and the enlarged diameter inner periphery N ₃ corresponding to the enlarged diameter part M ₃ are the protruding and retracting parts.
An annular groove surface N ₄ corresponding to M ₄ is provided.

In order to form the enlarged diameter socket part with the above mold, the end of the hole pipe P is heated, the protruding and recessed part _M4 of the inner mold M is recessed, and this inner mold M is inserted from the tip part _M1 . The enlarged diameter socket part S having an annular groove is formed by inserting it into the end of the hole tube, surrounding the outside with an outer mold N, and sliding the sliding wedge K to project the recessed part _M4 .

As described above, in forming the expanded diameter socket, the present invention temporarily closes each through hole at the end of the hole tube that will become the expanded diameter socket, thereby extending a certain length from the through hole end to the temporarily closed part. Since the filling material is inserted through the hole, the through hole can be reliably closed. Moreover, after the passage hole is closed, the temporarily closed part is opened to make the tube's outer circumferential surface smooth, and then the tube end expands in diameter with a solid and non-porous state, which prevents the passage hole from being crushed or torn. It is possible to form an enlarged diameter socket with a smooth outer circumferential surface and an excellent appearance.

[Brief explanation of drawings]

Fig. 1 is a cutaway perspective view of the hole tube, Fig. 2 is a cutaway front view of the passageway of the hole tube temporarily closed, and Fig. 3 is a filling material inserted into the temporarily closed passageway to fill it. FIG. 4 is a cutaway front view showing a state in which the through hole is restored by opening the temporary closure after the opening, and FIG. 4 is a cutaway front view showing the state in which the enlarged diameter socket is formed. P is Hall tube, 1a, 1b, 1c, 1d, 1e
are the inner wall, outer wall, partition wall, through hole, and temporary close contact part of the hole tube, 2 is a core mold for temporary closure, 3 is an outer mold, and 4 is
is the filling material, M is the inner mold for expansion, N is the outer mold,
S is an enlarged diameter socket.

Claims (1)

[Claims] 1. When forming an enlarged-diameter socket in a hole tube whose tube wall has a large number of through holes in the tube axis direction, first the end of the hole tube is heated and softened, and the outer circumferential surface of the tube is located a predetermined distance inward from the tube end surface. Apply the outer mold to the tube and compress it in an annular groove shape to bring the outer wall of the tube wall into close contact with the inner wall to temporarily close each hole, and then apply the filling material to each hole on the side of the tube end from this temporarily closed part. After that, the outer wall of the temporarily closed part is restored and expanded by reheating, and then an inner mold is inserted into the end of the pipe in the non-porous state to enlarge the diameter. Features: A method for forming the enlarged diameter socket of a hole tube.