JPS6068916A - Preparation of molding - Google Patents

Abstract

PURPOSE:To prevent flashes from projecting on a long member when resin is attached by molding to the end portion of a long member by a method wherein the internal space of a cavity is divided by an interrupting member into two sections and when one of them is filled with resin the interrupting member is removed and all the cavity is filled with resin. CONSTITUTION:An end resin 7 is attached by molding to the end part of a long member 6. The end part of the long member 6 is inserted tightly into the cavity 12 provided by a core 9 and a cavity mold 8 and then an interrupting member 16 is advanced into the internal part of the cavity 12 to divide the internal part of the cavity into two sections and resin is injected from a gate 11 side to fill the internal part of the cavity 12a on the gate side with resin. After filled with resin the interrupting member 16 is retired and the internal part also of the other cavity 12b is filled with resin. In this manner, a large pressure is not applied to resin in the other cavity 12b, injected resin can be prevented from flowing out of the contact part 13 of the mold 8 with the long member 6 and flashes can be prevented from occurring.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to manufacturing capability of molding in which the end portion of a long material is inserted into an injection mold and a terminal resin portion (end cap) is formed by injection molding. In particular, the present invention relates to a method of manufacturing molding θ) used for vehicles.

[Prior art]

Various types of moldings are used for decoration and protection on automobile bodies and the like. Fig. 1 is a perspective view of a section 111I of a side molding cut away as an example, Fig. 2 is a sectional view taken along line A-Δ of 4.1, and Fig. 3 is a sectional view of an injection mold showing a conventional manufacturing method. . The molding 1 includes a metal part 2, a decorative film ls3.4 and a resin part 5.
A long moon [J is cut to a predetermined length, a terminal 46 finger part 7 is formed at the cut end, and the outer surface 1 becomes a decorative surface] and a flat surface that becomes a mounting surface. It has a bottom surface 1b.

The conventional molding manufacturing method uses iron as the core material,
A metal part 2 made of metal foil such as aluminum or stainless steel foil, and decorative films 3 and 4 made of colored or bright resin film are supplied to an extrusion mold, and a long material 6 with a resin part 5 formed by extrusion molding is predetermined. The end portion is inserted into an injection mold consisting of a cavity mold 8 and a core mold 9 as shown in FIG. By injection, the terminal resin part 7 is formed so as to be integrated with the cut end of the elongated material 6.

However, in the conventional molding manufacturing method as described above, it is inevitable that the thickness of the elongated material 6 has an error or variation of about ±0.2 mm. This is not limited to extrusion molded products, but also applies when a metal roll molded product or press molded product is used as the elongated material 6. Therefore, when the thickness of the elongated material 6 is thin, the burr 15 passes through the contact portion 13 with the elongated material 6 of the injection molding mold and enters the relief portion 14.
There is a problem that this burr 15 must be removed manually, and the marks left after removing the burr 15 are unsightly and spoil the appearance.

[Purpose of the invention]

This invention is intended to solve the above-mentioned problems.The cavity is divided by a blocking member, and when the first cavity is almost filled with TAJ fat, the blocking member is opened and the second cavity is opened. To provide a molding manufacturing method that prevents high pressure from being applied to the second cavity by injecting resin into the second cavity, and does not generate burrs even when there are errors or variations in the long material. It is said that

[Structure of the invention]

This invention relates to a method of inserting an end portion of a long material cut into a predetermined length and end shape into an injection mold and forming a terminal resin portion by injection molding. A blocking member is provided in the cavity near the part to block the injected resin, and the cavity is divided into a first cavity and a second cavity, and the first cavity is almost filled with resin.
This method of manufacturing a molding is characterized in that the blocking part set is opened by pressing the button, and the resin is allowed to flow into the second cavity.

[Embodiments of the invention]

Examples of the present invention will be described below. FIG. 4 is a sectional view of an injection molding die showing a manufacturing method according to an embodiment of the present invention, FIG. 5 is a BB sectional view thereof, FIG. 6 is a sectional view of the injection molding die at another point in time, The figure is a sectional view taken along the line CC, and FIG. 8 is a graph showing the pressure and injection amount during injection molding, and the same reference numerals as in FIGS. 1 to 3 indicate the same or corresponding parts.

The injection mold is provided with a plate-shaped blocking member 16 that blocks the injected resin in the cavity 12 near the cut end of the long material 6, and connects the cavity 12 to a first cavity 12a and a second cavity 12b. It is divided. Blocking member 16
protrudes from the core mold 9 toward the cavity mold 8 so as to block almost the entire surface of the cavity 12, and its convex portion J6a
is connected to a rod 18 of a hydraulic cylinder 17 so that it can move forward and backward by opening and closing a hydraulic circuit.

4 and 5 show the state in which the blocking member 16 is advanced, and in this state, the tip 16b of the blocking part 4416 is kept in a small gap 19a so as not to come into contact with the inner surface of the cavity mold 8. It is preferable to leave it as 6 and 7 show a state in which the blocking part set 16 is retracted, and in this state, the blocking member "6" is not completely retracted, and the open latch part 19b formed by its tip 16b and the cavity mold 8 is shown in FIG.
is smaller than the cross-sectional area of the cavity 12 so as to form a constricted portion for the inflow of resin.

The manufacturing method for molding 1 is as follows:
The metal part 2 and the decorative film lz3.4 are fed into an extrusion mold, and the elongated material 6 on which the resin part 5 is formed by extrusion molding is cut into a predetermined length, and the end part is inserted into the cavity mold 8 and It is inserted into an injection mold consisting of a core mold 9 and clamped. At this time, the blocking member 16 is kept in a state in which it is slightly advanced as shown in FIG. 4 and FIG.

The injected resin is blocked by the blocking member 16 and then filled into the first cavity 12a. During this time, some resin leaks through the gap 19a between the blocking member 16 and the cavity mold 8.
There is no problem in flowing into the cavity 12b. When the first cavity 12a is almost full, the hydraulic cylinder 17
When the blocking member 16 is retreated by repeating the
becomes the constriction part, so the resin flows into the second cavity 12 at low pressure.
b and is filled.

As shown in Figure 8, the resin pressure and injection amount during injection molding are set to change stepwise at each point from To to T5, so the injected resin at the point of high pressure is the same. If the injection resin is supplied to the contact part 13, there is a risk that the resin will flow out from the contact part 13, but when the pressure is high, the injected resin is blocked by the blocking member 16 and is not supplied to the contact part 13.

When the first cavity 12a is filled with resin and the injection pressure has decreased to a certain extent, the blocking part 4416 is retreated.
Since the resin flows in through the opening 19b, the pressure of the resin flowing into the second cavity 12b further decreases.

The resin flowing into the second cavity 12b is cooled in the first cavity 12a and has a high viscosity, so that the resin does not flow out from the contact portion 13.

If the holding pressure state of T4 to T5 is maintained as it is, cavity 1
When the resin in 2 hardens and the terminal resin part 7 is integrally formed, but when the second cavity 12b is filled with resin, the hardening of the resin in the part that contacts the contact part 13 is delayed. In this case, the blocking member 16 is further retreated to cause the resin to swell, thereby delaying the increase in pressure until the resin in the contact portion 13 has hardened to some extent.

Although the molding 1 obtained by the above embodiment has no step between the elongated material 6 and the terminal resin portion 7, it is possible to form the cavity 12 as shown in FIG. 3 to manufacture the molding 1 with a step. You can also do this. Moreover, the blocking member 16 may be of other structure, and its 1'+ij
The forward and backward mechanisms can also be modified.

FIG. 9 is a g) rule in which the front part of the site molding manufactured according to another embodiment is cut. In the molding manufacturing method of this embodiment, a metal part 2 made of a metal plate such as a stainless steel plate with an irregular cross section by roll forming or press forming is supplied to an extrusion mold, and a resin part 5 (including a bottom mounting resin part 5a) is supplied to an extrusion mold. ) is extruded to form a long material 6, which is cut into a predetermined size, and then the terminal resin portion 7 is formed by injection molding in the same manner as described above.

FIG. 10 shows a weather fabric manufactured according to still another embodiment.
FIG. 3 is a perspective view of the front section of the strip molding. In the molding manufacturing method of this embodiment, a metal part 2 made of a metal plate made of stainless steel or the like with an irregular cross section by roll forming or press forming is supplied to an extrusion mold, and a resin part 5 (including the lip 5b) is formed by extrusion molding. The formed elongated material 6 is cut into a predetermined size and cut into an end shape having a notch 20, and the end resin portion 7 is formed along the cut end by injection molding in the same manner as described above.

In the following description, the shape and structure of the elongated material 6 can be changed depending on the type of intended molding. The material may be the metal part 2 or only the resin part 5, but it is generally a combination of both, and the decorative film 3.4 may not be used. The metal part 2 may be made of any material such as a stainless steel plate or an aluminum plate, and may be roll-formed or press-formed, or may not be formed. The resin portion 5 is generally extruded from a synthetic resin with high elasticity such as soft vinyl chloride resin. The structure of the injection molding die can also be changed arbitrarily according to the molding to be manufactured, and other similar blocking members may also be used. Furthermore, the present invention is not limited to molding to ZI1 and weather strip molding, but can also be applied to the production of other moldings.
Available for use.

〔Effect of the invention〕

According to the present invention, the cavity is divided by a blocking member,
When the first cavity is almost filled with resin, the blocking member is moved back to allow the resin to flow into the second cavity, which prevents high pressure from being applied to the second cavity and prevents errors in the long material. Paris does not occur even if there is variation. In addition, there is no need to strongly tighten the contact area with the long material, so there is no damage to the outer surface of the molding.
It is possible to produce moldings with excellent appearance.

[Brief explanation of the drawing]

Fig. 1 is a perspective view of the front part of the side molding, Fig. 2 is a cross-sectional view of A=A thereof, Fig. 3 is a cross-sectional view of an injection mold showing the conventional manufacturing method, and Fig. 4 is a cross-sectional view of the injection molding die according to the present invention. A cross-sectional view of an injection mold showing the manufacturing method of one embodiment, FIG. 5 is a cross-sectional view taken along the line 13-B, FIG. 6 is a cross-sectional view of the injection mold at another time, and FIG. 7 is a cross-sectional view taken along the line C-C. FIG. 8 is a graph showing the pressure and injection amount during injection molding, and FIGS. 9 and 10 are perspective views cut away from the front part of moldings manufactured according to other embodiments. In each figure, the same reference numerals indicate the same or equivalent parts, 1 is the molding, 2 is the metal part, 5 is the resin part, 6 is the long material,
7 is a terminal resin part, 8 is a cavity type, 9 is a core type, 12
13 is a cavity, 13 is a contact portion, 15 is a hole, 16 is a blocking member, ] 7 is a hydraulic cylinder. Agent Patent Attorney Sei Yanagihara Figure 4 LB Figure 6 Exit C Figure 5 Figure 7

Claims (1)

[Claims] In a method for forming a resin end portion, a blocking member for blocking the injected resin is provided in the cavity near the cut end of the inserted long material, and the blocking member is provided in the first cavity and the second cavity. A method of manufacturing a molding, which comprises dividing the molding, and opening a blocking member when the first cavity is almost filled with resin to allow the resin to flow into the second cavity. (2) Claim 1 in which the blocking member protrudes from one mold surface toward the other mold surface and is capable of moving forward and backward.
Method for manufacturing the molding described in Section 1. (3) The method of manufacturing a molding according to claim 1 or 2, wherein the opening of the blocking member forms a constriction portion for the inflow of resin. (4) The method for manufacturing a molding according to any one of claims 1 to 3, wherein the elongated material is an extrusion molded product.