JPH0691689A - Method for processing inside surface of hollow member - Google Patents

Abstract

PURPOSE:To reduce processing cost by providing a synthetic resin supply hole to a hollow part at the place fixing a core member so as to pierce the inside and outside surfaces of the hollow member and surrounding the periphery of the supply hole by a mold to inject a synthetic resin material in the supply hole in a molten state and curing the synthetic resin material to integrally mold the core member on the inside surface of the hollow member. CONSTITUTION:A hollow member 1 has such a structure that a core member mounting part 14 forming an inside surface 11 in a stepped state is formed to the area near to the leading end of the hollow part 12 formed into a hollow conical shape by molding of the hollow member 1. A linear synthetic resin supply hole 3 is made in the hollow member 1 from the outside surface 13 of the leading end thereof to the mounting part 14. The supply hole 3 is integrally molded by a mold simultaneously with the hollow member 1. The hollow member 1 is inserted in a mold 4 and a synthetic resin material 6 is injected in the mold 4 in a molten state from a gate 5 to be molded. The mold 4 has the gap A forming a core member 2 along with the core member mounting part 14 formed thereto so that pin-shaped head parts are abutted in the hollow part 12 of the hollow member 1 and a gap B is formed on the entire outside surface of the hollow member 1. Therefore, the core member 2 can be integrally fixed to the hollow member 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for processing the inner surface of a hollow member. More specifically, the present invention relates to an improvement in processing cost and processing speed of a hollow member inner surface processing method such as fixing a core member made of a core holding packing to an inner surface of a hollow member made of a taper member of a mechanical pencil. .

[0002]

2. Description of the Related Art Conventionally, for example, a method shown in FIG. 5 is known as a method for processing the inner surface of a hollow member.

This conventional hollow member inner surface processing method is as follows:
A core member 2 made of a lead holding packing for holding the mechanical lead fed by a knock mechanism on the inner side surface 11 of a hollow member 1 made of a tapered tip member screwed to the tip of the body of a mechanical pencil so as not to fall out. The core member 2 separately molded into a tubular shape with a rubber material or the like is press-fitted into the hollow portion 12 of the hollow member 1 that is molded with a synthetic resin material such as hard ABS resin or acrylic resin. The hollow member 2 is fixed to the inner side surface 11 of the hollow member 1 by fitting. Regarding such a conventional method for processing the inner surface of a hollow member, it is also conceivable that the core member 2 is integrally molded by a so-called two-color molding means after molding the hollow member 1, but a normal metal is used. Hollow member 1 in mold technology
There is a technical background that it is impossible to construct a gate or the like for injecting a synthetic resin material into the narrow hollow portion 12 of FIG.

In such a conventional method for processing the inner surface of a hollow member, the small and precise core member 2 must be separately molded, resulting in a high processing cost and a narrow hollow portion 12 of the hollow member 1. There is a problem that the work of press-fitting the core member 2 is complicated and the processing speed becomes slow.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in consideration of the above-mentioned problems, and an object of the present invention is to provide a method for processing the inner surface of a hollow member which has a low processing cost and does not require a processing time. .

[0006]

In order to solve the aforementioned problems, the hollow member inner surface processing method according to the present invention employs the following means.

That is, according to the first aspect of the present invention, in the method for processing the inner surface of a hollow member, wherein the inner member of the hollow member is fixed to the inner member of the hollow member, the inner member is fixed to the inner member of the hollow member. A synthetic resin material supply hole penetrating from the side surface to the outer surface is preliminarily formed, and at least the outer surface and the inner surface of the hollow member are surrounded by a mold and hardened to bond the synthetic resin material. Is melted and injected, and the core member is adhesively molded on the inner surface of the hollow member with a cured synthetic resin material.

According to a second aspect of the present invention, in the method for processing the inner surface of the hollow member according to the first aspect, a wide range including the periphery of the synthetic resin material supply hole on the outer surface of the hollow member is covered with the synthetic resin material. To do.

[0009]

According to the above-mentioned means, according to the first aspect, the synthetic resin material supply hole is bored to solve the technical problem of the mold in the technical background described above, and the so-called two-color molding means by the mold melts. Since the synthetic resin material is injected into the hollow member from the outer surface side of the hollow member to integrally mold the core member with the hollow member, the inner surface processing method of the hollow member is low in processing cost and does not require processing time. Is solved.

According to the second aspect of the present invention, in the operation of the first aspect, the coating layer of the synthetic resin material integral with the core member is formed on the outer surface of the hollow member.

[0011]

EXAMPLES Examples of the method for processing the inner surface of a hollow member according to the present invention will be described below with reference to FIGS.

1 and 2 show a first embodiment of a method for processing the inner surface of a hollow member according to the present invention.

In this embodiment, like the above-mentioned conventional example,
Hollow member 1 consisting of a taper member at the tip of a mechanical pencil
The core member 2 made of a core holding packing is fixed to the inner surface 11 of the above.

In carrying out this embodiment, first, the hollow member 1 is machined.

As shown in FIG. 1 (A), the hollow member 1 is formed in a hollow spindle shape by molding or the like, and a core member mounting portion 14 having a stepped inner side surface 11 is formed near the tip of the hollow portion 12. However, the synthetic resin material supply hole 3 is linearly formed from the outer surface 13 at the tip to the core member mounting portion 14. The synthetic resin material supply hole 3 can be integrally molded at the same time when the hollow member 1 is molded.

After the synthetic resin material supply hole 3 is machined in the hollow member 1 as described above, the hollow member 1 is put into the mold 4 and the synthetic resin material 6 is removed from the gate 5 as shown in FIG. 1 (B). It is melted and poured, and so-called two-color molding is performed.

The mold 4 used for this molding is configured such that the pin-shaped heads abut against each other inside the hollow portion 12 of the hollow member 1, and together with the core member mounting portion 14 of the hollow member 1, the core member 2 is formed. The formation gap A is formed. Further, a slight gap B is formed on the entire outer surface 13 of the hollow member 1. Therefore, a supply path of the synthetic resin material 6 from the entire outer surface 13 of the hollow member 1 to the inner surface 11 via the synthetic resin material supply hole 3 is formed following the gate 5.

Further, the synthetic resin material 6 used for this molding
Is a substance that is hardened and adhered and fixed to the inner surface 11 of the hollow member 1 so as to function to some extent, for example, the hollow member 1 is A
For BS resin, elastomer or urethane resin is selected.

When the mold 4 is released after the synthetic resin material 5 thus injected is cured, the core member 2 is integrated with the inner surface 11 (core member mounting portion 14) of the hollow member 1. It will be adhesively molded. Therefore, as compared with the case where the core member 2 made of a separate member is molded and mounted as in the conventional example described above, the processing cost is much lower and the processing time is not required. The core member 2 thus formed has a shape such that it is adhered to the inner side surface 11 of the hollow member 1 and its back portion is projected and intruded into the synthetic resin material supply hole 3. The fixing strength to the member 1 becomes considerably high, and even if stress due to sliding of the sharp core is applied, it is not easily detached, and the durability becomes good.

The hardened synthetic resin material 6 forms a thin film 7 on the entire outer surface 13 of the hollow member 1.
As shown in FIG. 2, the thin film 7 can cover the synthetic resin material supply hole 3 to prevent the appearance from being deteriorated, and improve decorativeness and tactile sensation depending on the material, color and the like. Is also possible.

FIG. 3 shows a second embodiment of the method for processing the inner surface of a hollow member according to the present invention.

In this embodiment, the thin film 7 is connected to the hollow member 1
It is provided only on the tip portion of the outer side surface 13 of the.

According to such an embodiment, the purpose of covering the synthetic resin material supply holes 3 with the thin film 7 can be sufficiently achieved, and the core thickness of the mechanical pencil is color-coded by the thin film 7 having the tip ring shape. There is an advantage that it can function as.

FIG. 4 shows a third embodiment of the method for processing the inner surface of a hollow member according to the present invention.

In this embodiment, the synthetic resin material supply holes 3 are arranged in the direction orthogonal to the axial direction of the hollow member 1. Such a disposition structure of the synthetic resin material supply holes 3 is possible depending on the releasing direction of the mold 4.

According to such an embodiment, the synthetic resin material supply hole 3 is shortened, the flowability of the synthetic resin material 6 from the outer surface 13 side to the inner surface 11 side of the hollow member 1 is improved, and the core member is formed. 2 has the advantage that the accuracy is good.

As described above, in addition to the embodiment shown in the drawings, it is effective as a practical use for various machine elements and daily miscellaneous goods, especially small ones.

[0028]

As described above, the method for processing the inner surface of the hollow member according to the present invention has the same features as claims 1 and 2, and the core member is integrally formed with the hollow member by a so-called two-color molding means using a mold. However, unlike the conventional example, since the core member made of another member is not molded and attached, the processing cost is reduced and the processing time is shortened. Further, due to this effect, mass production becomes possible.

Further, in common with claims 1 and 2, since the core member is adhered to the inner surface of the hollow member and the back portion thereof is projected and intruded into the synthetic resin material supply hole, the hollow member is hollow. This has the effect of increasing the fixing strength to the member. Further, this effect brings about an effect of improving durability.

Further, only in claim 2, it is possible to cover the synthetic resin material supply hole to prevent the appearance of the hollow member from being deteriorated in appearance, and to improve the decorative property and tactile sensation of the hollow member. There is an effect that can be done.

[Brief description of drawings]

FIG. 1 is a first method for processing an inner surface of a hollow member according to the present invention.
It is sectional drawing which shows an Example, and shows the process order in order of (A) and (B).

FIG. 2 is an enlarged side view of the released product of FIG.

FIG. 3 is a second method of processing the inner surface of a hollow member according to the present invention.
It is sectional drawing which shows an Example.

FIG. 4 is a third method of processing the inner surface of a hollow member according to the present invention.
It is sectional drawing which shows an Example.

FIG. 5 is a cross-sectional view showing a conventional example.

[Explanation of symbols]

1 Hollow member 11
Inner side surface 12 Hollow part 13 Outer side surface 2 Core member 3 Synthetic resin material supply hole

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification number Office reference number FI technical display location B43K 21/24 6863-2C // B29L 22:00 4F 31:00 4F

Claims (2)

[Claims] 1. A method for processing an inner surface of a hollow member, wherein a core member of a material different from that of the hollow member is fixed to the inner surface of the hollow member, from the inner surface to the outer surface at a position where the core member of the hollow member is fixed. A synthetic resin material supply hole that penetrates is formed in advance, and at least the synthetic resin material supply hole on the outer surface and the inner surface of the hollow member is surrounded by a mold and hardened to be bonded. Then, the inner surface of the hollow member is processed by adhesively molding the core member on the inner surface of the hollow member with the cured synthetic resin material. 2. The hollow member inner surface processing method according to claim 1, wherein a wide range including a synthetic resin material supply hole around the outer surface of the hollow member is covered with the synthetic resin material. Side processing method.