JPS6213888B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for forming an end of a synthetic resin extrusion molding to be attached to a single panel of an automobile, fittings, furniture, etc.

Conventionally, a molding body 1 is extruded into a long length, cut into a predetermined length, placed and fixed in an injection mold M as shown in FIGS. 1 and 2, and then molded into a cavity mold M1 and a core mold. A molding terminal forming method in which the end cap part E is integrally formed by injecting and filling molten resin from the side part ML through the spool M4 and the gate M3 into the end cap molding space MS formed by the end cap part M2. Widely used.

However, according to this terminal molding method, a part of the gate portion of the molded terminal end cap E is generated as a burr F, and this burr F has to be cut off after the end cap E is molded. It was hot.

An object of the present invention is to solve the above-mentioned problems by injecting the resin in such a way that a gate portion serving as a resin injection port protrudes from the bottom side of the end cap when injecting the molten resin.

FIGS. 3 to 7 show an embodiment of the method for forming the end of a molding according to the present invention. FIG. 3 is a perspective view of the end of a molding made by the molding end forming method according to the present invention, in which the molding body 1 is made of polyvinyl chloride resin (hereinafter referred to as
It is made by extrusion molding PVC into a long length, and has a two-stage outer surface portion 1a, 1b and both side portions 1c, 1d, and has an approximately C-shaped cross section, and an inner surface with a shape that is almost similar to the outer surface shape. Top part 1e, side parts 1f, 1g
It is integrally molded to have A metal profile material 1h formed by bending a metal strip into a constant cross-sectional shape is integrally buried inside.

Reference numeral E designates an end cap portion which is tapered toward the tip and is integrated at the cut end portion 1j of the molding body 1.

FIG. 4 is a perspective view of the back side of the molding terminal portion.

FIG. 5 is a perspective view of the core member 2 embedded and integrated in the end cap portion E, and is molded from a relatively rigid foamed ABS resin or the like, and includes a main body portion 2a,
It has a protrusion 2b that protrudes to fit into the internal space of the molding body 1. The core member 2 has a substantially similar shape to the end cap E and is manufactured to be small overall, and the main body portion 2a has a bottom surface portion 2c and both side portions 2d and 2e, and both side portions 2d and 2e have cutouts 2f and 2g. The width of the bottom surface 2c is narrower than the width between both sides. Furthermore, protrusions 2h, 2h are formed at predetermined intervals on the bottom surface portion 2c.

The core member 2 thus formed is placed and fixed in an injection mold M as shown in FIG. 7, and the end cap portion E is formed by injecting molten resin. In this case, the mold M is a cavity mold M1
and a core mold M2, and the core member 2 is fixed to the core mold by pins M21 and M22 protruding from the core mold M2. Further, an injection nozzle N is provided on the core mold so that its tip protrudes toward the cavity mold beyond the notch 2f of the core member, and is connected to a hot runner M23 provided on the core mold. With the cavity mold and core mold opened, set the core member, and fit the cut end of the molding body so that the protrusion 2b of the core member 2 is inserted into the internal space of the molding body. When the mold is closed and PVC molten resin compatible with the molding body is injected from the nozzle N, a portion of the resin flows in the Y direction and most of it flows in the X direction in the end cap molding space. It flows and fills along the top of the core member 2 until it reaches the opposite side. While the resin is being filled in this way, the pressure P that tries to lift the core member 2 is greater than the pressure Q that tries to lift it, so the core member remains firmly pressed against the core mold. be. When the mold is opened after the molten resin has cooled and solidified, the nozzle N is opened as shown in Figure 6.
The resin at the tip of the molding body is torn off, and the cut end of the molding body and the end cap are integrated to complete the product.

As explained above, the method for forming the end of molding according to the present invention has the following effects. That is, since the gate portion consisting of the nozzle N is located inside the end cap E, even if a burr F occurs, it does not come out on the outside surface of the end cap E, and therefore processes such as cutting are not required.

[Brief explanation of the drawing]

1 and 2 are views showing an example of a conventional molding end forming method, and FIGS. 3 to 7 are perspective views and sectional views showing an embodiment of a molding end forming method according to the present invention. It is. 1... Molding body, 2... Core member,
E... End cap, N... Nozzle, 2f...
Notch, M21, M22...pin.

Claims (1)

[Claims] 1. A step of placing the end of a molding body with a predetermined cross-sectional shape on the end cap molding space side, which is made up of a cavity mold and a core mold. Molding the end cap portion by filling the molding space with molten synthetic resin through a nozzle that projects into the end cap molding space from the bottom side of the molding. Terminal forming method.