JPH01226317A - Preparation of molded item - Google Patents

Abstract

PURPOSE:To set stretchedly a member of soft and limp sheet inside a tube-like element by means of insert molding, by supporting solidly a sheet member on the tube-like element and setting stretchedly it in an inner path at the first molding process and covering the sheet member exposed outside at the second molding process. CONSTITUTION:A plurality of notches 14 are formed on the outer circumference of a sheet member 13, which is pinched between a fixed cavity 4 and a movable cavity 5. Under this condition, notches between phisigma-phibeta perforate the upper and lower sides of the sheet member 13 and if a resin is injected, a primary molded item 15 is molded and the outer circumferential part (between phigamma-phisigma) of the sheet member 13 is exposed outside of the primary molded item 15. The position of the primary molded item 15 is held by a projected part of a fixed pin 9 on the secondary molding side and a sleeve pin 11 and if a resin is injected under this condition, the resin is molded so as to wrap the outer circumference of the primary molded item and cover therein the sheet member 13 exposed outside of the outer circumference of the primary molded item.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to a molded body formed into a tubular shape, and to a method for insert molding a flexible sheet-like portion in an internal passageway of the tubular molded body.

<Prior Art> FIG. 8 shows a molded article desired by the present invention. In FIG. 8, 1 is a tubular member, and 2 is a sheet-like member stretched over the internal passage 3 of the tubular member I. In FIG. Said tubular member l
The device allows fluid such as gas to flow through the device, and is made of a resin material.

The sheet-like member 2 is made of a flexible material such as a Teflon sheet, for example.
It is a so-called flexible material, and is provided for the purpose of filtering the fluid passing through the tubular member 1 by keeping water out but allowing air to pass through.

In general, so-called insert molding, in which a non-resin material is placed in a resin molded body at the same time as resin molding, is well known. By the way, to obtain a molded body as shown in Figure 1, if the inserted member is relatively hard (so-called stiff material) such as metal, the sheet-like member to be inserted may be supported with pins, etc. However, as mentioned above, it is not easy to insert mold a flexible sheet-like member 2 without stiffness.In other words, in the case of a flexible sheet-like member 2, the center of the member 2 must be supported with a pin or the like. Even if insert molding is attempted, the outer circumferential portion to be inserted cannot be supported, so the outer circumferential portion to be inserted will be bent due to the inflow of resin. If this happens, not only will the sheet-like member 2 not be firmly supported by the tubular member l, but it is also conceivable that the sheet-like member 2 will separate from the inner surface of the tubular member l, creating a gap.

Therefore, conventionally, instead of installing the sheet-like member 2 inside the tubular member l as shown in FIG. 8, as shown in FIG.
The sheet-like member 2 was installed at the outlet (or inlet) of the tubular member 1 by gluing it or the like.

However, with this method, the work of gluing the sheet-like members 2 together is troublesome and time-consuming, and it is difficult to obtain sufficient strength even if the sheet-like members 2 are bonded together. In addition, when actually using this tubular member, it is necessary to connect an additional pipe to the outlet side (or inlet side) to which the sheet member 2 is glued, which causes problems in terms of time, number of parts, and sealing performance. is likely to occur.

<Problems to be solved by the present invention> The objective is to obtain a molded body as shown in FIG.

<Means for solving the problem> A flexible sheet-like member is attached to a tubular molded body.
When performing insert molding so as to be stretched into the internal passage of the molded body, the molding process consists of a primary molding process and a secondary molding process.

The primary molding step is a step of insert molding the flexible sheet-like member with resin flow holes formed therein so as to be installed within a tubular member having a diameter such that the outer periphery of the sheet-like member is exposed to the outside. be.

The secondary molding step is a step in which resin is integrally molded on the outside of the tubular member molded in the primary molding step to hide the exposed outer periphery of the sheet-like portion inside.

Function> First, in the primary molding step, the sheet-like member is firmly supported by the tubular member and stretched inside the internal passage.

Next, in a secondary molding step, the sheet-like member exposed to the outside is concealed to obtain a molded body as shown in FIG.

<Example> Fig. 1 is a sectional view of a mold used in an example of the present invention, and Fig. 2
Figures 4 through 4 are sectional views of essential parts on the same side.

In FIGS. 1 to 4, 4 is a fixed cavity on the primary molding side, and 5 is a movable cavity on the primary molding side.

6 is a fixed side pin on the primary molding side, and 7 is a movable side pin on the primary molding side. 8 is an ejector sleeve on the primary molding side.

Next, explaining the secondary molding side B, the mold on the secondary molding side B is provided adjacent to the mold for the primary molding process.

9 is a fixed cavity on the secondary molding side, and 10 is a movable cavity on the secondary molding side. 11 is a sleeve pin on the secondary molding side. 12 is an ejector sleeve on the secondary molding side.

The molding method will be explained.

First, the sheet-like member 13 is formed as shown in FIG. φα shown in FIG. 5 corresponds to the inner diameter of the completed molded body (secondary molded body). A plurality of notches 14 are formed on the outer peripheral side of this sheet-like member 13. This notch 14
The inner end diameter φβ is larger than the above-mentioned φα, so that the notch 14 is not exposed to the internal passage. Also, φσ is φβ
This is larger and corresponds to the outer diameter of the primary molded body described later. φγ is the outer diameter of the sheet-like member 13, and the above −
It is larger than the outer diameter of the igneous molded body and smaller than the outer diameter of the secondary molded body (completed body), which will be described later.

The method of primary molding will be explained. First, as shown in FIG. 3, a sheet-like member +3 is held between the fixed cavity 4 and the movable cavity 5 on the -pyroforming side. In this state, the notch between φσ and φβ is the sheet member 13.
The top and bottom are connected. If resin is injected in this state, a primary molded body 15 as shown in FIG. 6 will be molded. This fire-molded body 15 is a resin molded body formed into a tubular shape with an inner diameter α and an outer diameter φσ. (between φγ and φσ) is exposed to the outside of the igneous body 15.

Next, when performing secondary molding, as shown in Figure 2, -
The molded body 15 after fire forming is transferred to the secondary molding side. On the secondary molding side, the fire-formed body 15 is held in position by the protruding portion of the fixing bin 9 and the sleeve bin 11 on the secondary molding side, as shown in FIG. When the resin is injected while being held in this manner, the resin is molded so as to wrap around the outer periphery of the above-mentioned fire-formed body 15, and as shown in FIG. +
3 will be hidden inside. In this case, the exposed sheet-like member 13 will be bent at the outer surface of the primary molded body 15, but since the sheet-like member 13 has already been firmly held by the primary molding, the outer periphery of the exposed sheet-like member 13 will be bent. There is no problem even if some parts are bent.

The secondary molded body 16 thus obtained has the same form as the desired one shown in FIG.

If the molding process is divided into the primary and secondary fire molding processes as described above, the desired molded body shown in Figs. They can be freely adopted, such as by adding a .

<Effects> According to the present invention, a flexible, stiff sheet-like member can be stretched inside a tubular member by insert molding.

Therefore, when tensioning the sheet-like member, it is possible to firmly and without leakage, and variations in mass production can be completely eliminated.

[Brief explanation of the drawing]

Figure 1 is a sectional view of a mold used in an embodiment of the present invention, Figures 2 to 4 are enlarged views of the main parts of the same mold, Figure 5 is a plan view of a sheet-like member, and Figure 6 is a FIG. 7 is a cross-sectional view of a secondary molded body, FIG. 8 is a cross-sectional view of a molded body desired in the present invention, and FIG. 9 is a cross-sectional view of a conventional molded body. 13: Sheet-like member% 15 2nd primary molded body, 16 2nd secondary molded body. Agent Patent Attorney Takeshi Sugiyama (and 1 other person) No.2rJa $3 Figure No.1I No.4rjI

Claims (1)

[Claims] 1. When insert molding a flexible sheet-like member into a tubular molded body so as to stretch it into the internal passage of the molded body, the molding process is performed as follows: It consists of a molding process and a secondary molding process, and the primary molding process converts the flexible sheet-like member in which resin flow holes are formed into a tubular member having a diameter such that the outer periphery of the sheet-like member is exposed to the outside. This is a process of insert molding so that the tubular member is installed inside the tubular member, and the secondary molding process is a process of integrally molding resin on the outside of the tubular member molded in the primary molding process, and inserting the outer periphery of the exposed sheet part inside the tubular member. A method for manufacturing a molded body, which is a concealing process.