JPS5924643A - Molding die - Google Patents

Abstract

PURPOSE:To obtain the two-color molding die by a structure wherein the die consists of a bottom force equipped with a slide core, a first top force and a second top force and projections to form engaging holes in an insert are provided at the upper ends of fixed pins of the bottom force or within the first top force. CONSTITUTION:A bottom force 5 is equipped with a slide core 12, which is connected to a pushing-out rod 11 and through which a plurality of the fixed pins 13 are arranged. The pushing-out rod 11 is coupled to a reciprocating drive means such as a cylinder, a cam and the like to make the slide core 12 reciprocatingly shiftable between an insert molding position and a skin molding position. A first top force 6 is equipped with a recess 6a to form a cavity surface for front side of the insert, while a second top force 7 with a recess 7a to form the cavity surface for front side of the skin. The first top force 6 and the second top force 7 are installed on the fixed platens of the injection machines for injecting each material at separate places.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a mold used for continuous two-stage molding (so-called two-color molding) of a polymeric molded product consisting of an insert and a skin.

Here, a steering wheel pad (hereinafter referred to as "wheel pad") will be taken as an example of the above-mentioned polymer material molded article, but the present invention is not limited to this.

Generally, wheel pads are as shown in Figures 1 and 2.
Insert 2 molded from hard synthetic resin such as PP, Al3S, nylon, soft PvC/polyurethane, E,
The structure includes a skin 3 molded from a soft synthetic resin such as PI) M or the like. In this configuration, there is almost no compatibility between the insert and skin materials, so they do not adhere to each other, and it is difficult to obtain them by ordinary two-color molding. Therefore,
Normally, the insert 2 is first molded with an insert molding die so that it has a plurality of locking holes 2a (one in the example shown), and then a locking hole is formed on the back side of the insert 2, and a locking hole is formed in the back side of the insert 2, and a locking hole is formed in the back side of the insert 2. The insert 2 is placed in a mold for molding the skin so that an undercut space is formed in communication with the hole 2a, and then the locking legs 3a are molded integrally with the skin 3 to form the skin l having the above structure. A wheel pad was obtained in which the insert 2 did not peel off.

However, this method required the preparation of two sets of molds and had poor moldability.

In view of the above, an object of the present invention is to provide a molding die capable of obtaining a polymeric material molded product such as a horn pad consisting of an insert and a skin by two-color molding.゛The molding die of the present invention includes a male mold having a slide core that forms the cavity surface on the back side of the insert, a first female mold that forms the cavity surface on the front side of the insert, and a second mold that forms the cavity surface of the skin together with the insert. The male mold is slidable, and the upper end of the fixing bottle or the female mold is provided with a protrusion that forms a soil hole for the insert. An embodiment of the present invention will be described below with reference to the drawings, in which the above object is achieved by a structure in which an undercut space is formed in or communicating with the locking hole.

As shown in FIGS. 3 to 1I, it consists of a male mold 5, a first Illf mold O, and a second female mold 7. Here, the male die 5 includes a slide core /, 2 connected to an extrusion rod I/, and a plurality of slide cores (1 in the illustrated example) penetrating the slide core 12.
A fixed bottle 13 of books) is attached. Extruded rod/
/ is connected to reciprocating drive means such as a cylinder or cam (not shown), allowing the slide core 12 to reciprocate between the insert molding position (back dead center) and the skin molding position (front dead center).

The upper surface 12a of the slide core 12 is shaped to form a cavity surface on the back side of the insert. j fixed hinge 1 At the upper end of the bin, the upper surface 1 of the slide core 12 is placed at the insert molding position (post dead center) (the state shown in Fig. 3) of the slide core 12.
A tapered protrusion 13a that protrudes from 2a and forms a locking hole 2a in the insert 2 is provided.

The first female mold B is provided with four parts 6a that form the cavity surface on the front side of the insert (FIG. 3). On the other hand, the second female mold 7 includes a recess 7a that forms a cavity surface on the front side of the skin (FIG. 1). The first female mold 6 and the second female mold 7 are mounted at different positions on a fixed plate of an injection machine (not shown) for injecting each material. In the illustrated example, 2b is a hole for preventing skin peeling, and is a bottle protruding from the first female die 6 for forming the hole.

Next, a two-color molding method for a wheel pad using the above molding mold will be described. First, as shown in Fig. 3, after positioning the slide core 12 at the bottom dead center and aligning the male mold S with the first female mold B, insert it into the cavity "CI" using the submarine gate method (not shown). The material for molding is injected from the injection machine. After the material in the cavity Cl hardens, the mold is opened, and the male mold 5 is moved to the position where the second female mold 7 is placed, and the slide core 12 is moved to the front dead center position. When pushed out, the gate part is cut out, creating an undercut space A as shown in Figure 1.
The insert 2 having the locking hole 2a is set in the male mold S floating above the mating surface. In this state, after aligning the male die S with the second female die 7, the side gate method (
(not shown), the skin material is injected into the cavity C2 from an injection machine. After the material of Capity C2 has hardened, the mold is opened, and after the mold is released using an ejector turbine (not shown) or the like, the gate part etc. are removed to obtain a wheel pad l as shown in Fig. 1-2. can. As described above, the undercut locking legs 3a are integrally formed on the outer skin 3 of this wheel pad, and are irremovably bonded to the insert 2.

Figures 5-6 show another embodiment of the square-shaped mold of the present invention, in which a protrusion C forming the insert 2vc locking hole 2C is provided on the first female mold side. It is something. Usage mode i It is almost the same as above, but in this case, the locking hole 2C is straight, and as shown in FIG. Space A/
is starting to form.

As described above, the molding die of the present invention enables continuous two-stage molding when molding a polymeric material molded product consisting of an insert and a skin, thereby facilitating high-speed molding. Furthermore, although two female molds are required, only seven male molds are required, resulting in lower mold manufacturing costs and overall lower molding costs. In addition, the molding die of this invention can also be applied to rubber materials.
-! It can also be applied to transfer molding.

[Brief explanation of the drawing]

Fig. 1 is a plan view showing an example of a wheel pad, Fig. 2 is a sectional view taken along the line U-N in Fig. 1, and Figs. FIGS. 5 and 6 are cross-sectional views showing the other side of the molding die of the present invention during insert molding and skin molding, respectively. l...Wheel pad (polymer material molded product), 2...
・Insert, 2F3. ．． 2Q...-locking hole, 3...
・Skin, 3a...Locking leg, j...Male type, ≦...
・First female mold, 6a...Four parts, 6C...Protrusion, 7...
・Second female mold, 7a...Four parts, 1.2...Slide core, /2a,...Top surface, 13...Fixing pin, /3a
... Protrusion, A, Al... Undercut space, CI
, C2...cavity. Figure 1, Figure 3
figure

Claims (1)

[Claims] A mold used for continuous two-stage molding of a polymeric material molded product consisting of an insert and a skin.
a male mold including a slide core forming a side cavity surface; a first female mold forming a front cavity surface of the insert;
and a second female mold forming a cavity surface on the surface side of the epidermis,
The male die is provided with a protrusion that forms a locking hole, and an undercut space is formed in or in communication with the locking hole of the insert by extruding the slide core. A mold for molding with a configuration that allows for