JPH0353862Y2 - - Google Patents

Description

[Detailed description of the invention] <Industrial application field> This invention relates to foam molding molds for seats used in vehicles, etc., and is particularly useful when forming holes at appropriate positions on the sheet during molding to prevent resin leakage. Regarding type structure for prevention.

[Prior Art] Recently, when molding a pad for a vehicle seat, the skin material is molded at the same time as the pad is molded so that it is integrated with the surface of the pad. Efforts are being made to reduce assembly man-hours and streamline the process.

Further, in this type of integrally molded skin sheet, holes such as an insertion hole for a headrest and a pivot hole for a rotating hinge portion of the sheet are formed at the same time during molding.

<<Problems to be solved by the invention>> A general problem with this technology is that the foaming resin liquid that makes up the pad leaks onto the surface of the skin material during molding, and in particular leakage from the holes. are significantly more common.

That is, the mold used for this molding conventionally consists of an upper mold 1 and a lower mold 2, as shown in FIG.
Moreover, it has a structure in which a boss portion 3 is provided protrudingly at the hole forming position of the lower mold 2. The molding method using this mold involves fitting a hole 4a formed in a skin material 4 installed on the mold surface of the lower mold 2 into the boss 3, and lowering the upper mold 1 in this state. The pad material is integrated on the back surface of the skin material 4 by engaging the mold 2 and clamping the two molds, and injecting and filling a foamable resin such as a foamed urethane stock solution into the cavity d formed between them. ing.

In the above molding technique, the general surface is such that most of the material on the surface of the skin material 4 is non-breathable;
Further, even if the skin material is made of a breathable material, no problem arises because the problem is solved by laminating a non-breathable backing material.

However, when the skin material 4 is attached to the boss portion 3, the hole 4a formed in the skin material 4,
The foaming resin liquid leaks from the small gap between the boss part 3 and reaches the surface of the skin material 4, and forms the hole 4a.
The molding was done while it was attached to the periphery of the surface. As a countermeasure against this, the hole 4a is brought into close contact with the boss 3 or the hole 4a is covered with tape, but even when such measures are taken, the skin material is not dragged by the molding pressure of the foamed resin. Because of this, a reliable seal cannot be achieved, and there is a high probability that resin will leak.

Therefore, in such cases, it is necessary to deburr the leaked resin, and since it cannot be easily peeled off, post-processing is troublesome.
This was a major factor in reducing work efficiency and product yield.

This idea was made based on the above background, and it is possible to structurally prevent resin leakage from the hole forming position, thereby preventing post-processing and product yield from decreasing due to resin leakage. The purpose is to

<Means for Solving the Problems> In order to achieve the above object, this invention provides a protrusion for positioning the hole formed in the skin material at the hole formation position of the mold surface where the skin material is installed. At the same time, a concave boss portion for forming a hole is provided protrudingly on the other mold surface to fit in an uneven shape on the outer periphery of the positioning protrusion, and the outer periphery of the concave boss portion The gist is that the mold is clamped in a state where the periphery of the back surface of the hole formed in the material is crushed.

《Operation》 During foam molding, the concave boss crushes the back side edge of the hole formed in the skin material, and in this state liquid tightness is maintained, preventing resin leakage from the hole due to foaming pressure. do.

<<Example>> Hereinafter, this example will be described in detail using the drawings.

1 to 3 show a first embodiment of this invention.

In the figure, the foaming mold consists of an upper mold 10 and a lower mold 12, similar to conventional ones, and a foamable resin such as urethane stock solution is filled in a cavity d formed by clamping the two molds. When the resin is injected and filled, it is foamed at an appropriate expansion ratio, and the foamed resin is cured while filling the cavity d, so that a molded product that conforms to the shape of the mold can be obtained.

Prior to foam molding, a skin material 14 is positioned and installed on the mold surface of the lower mold 12. This skin material is
Slab urethane 16b, generally called wading, is laminated on the back side of a skin 16a made of synthetic leather such as PVC, and is pre-processed into a sheet shape according to the mold surface of the lower mold 12 by sewing or the like. Then, a hole 1 is formed at the hole forming position of the molded body.
4a is formed as an opening.

Correspondingly, a positioning protrusion 18 is formed protrudingly at the hole forming position of the lower mold 12, and the skin material 1
4 is installed, it protrudes to the inner peripheral part of the hole 14a and is positioned.

On the other hand, a boss portion 20 for forming a hole, which fits into the positioning protrusion 18 in an uneven manner, is provided on the mold surface of the upper mold 10 in a protruding manner.

In the above configuration, when the upper mold 10 is engaged with the lower mold 12 and the mold is clamped, the boss portion 20 fits into the projection 18 and presses the slab urethane 16b exposed on the back surface of the skin material 14 with its lower surface periphery. Crush, hole 14
Seal the periphery of a liquid-tightly.

Therefore, since foam molding is performed in this state, the resin from the holes in the molded body will not leak to the skin material 16a side, resulting in a molded body with a good appearance.

FIG. 3 shows the holes of a molded body obtained using the above mold. The hole 22a of the pad 22 of the molded body in the figure has a long hole shape, and the hole 1 on the skin material 14 side corresponds to the outer shape of the boss 20.
The diameter is one step larger than the inner diameter of 4a.

The advantages of such a shape are as follows.

In other words, the diameter of the surface side is smaller than the diameter of the inside, which provides greater flexibility when attaching parts that are inserted through it, such as head rest stays, rotating hinges, etc., and also has a good appearance because the inner surface of the hole is not visible. Points for improvement are listed. Furthermore, by impregnating the crushed urethane slab around the hole with the foaming resin liquid, the peripheral edge of the hole hardens, and a reinforcing effect can be expected.

Next, FIGS. 4 and 5 show a second embodiment of this invention.

In the figure, the positioning protrusion 30 and the hole-forming boss part 32 that fits into the protrusion 30 in an uneven manner are cylindrical. Further, a separate slab urethane 34 is positioned and installed on the periphery of the back surface of the hole 14a of the skin material 14. Even with this structure, leakage of the resin to the surface of the molded body is structurally prevented, and the above-mentioned reinforcement hardening at the periphery of the hole can be further improved by impregnating and hardening the slab urethane 34.

<<Effects of the invention>> As explained in detail using the embodiments above, according to the foam mold of this invention, the concave boss portion crushes the periphery of the hole in the skin material during foam molding, and in this state, Since liquid tightness is maintained, resin leakage from the holes due to foaming pressure is prevented.

Therefore, with this invention, there is no need for seal leakage or repair work or molding defects due to seal leakage, as is the case with conventional seals, and it is possible to improve workability and product yield.

In addition, with this design, the inside diameter of the hole is larger than the surface side, so there is greater flexibility in assembling parts that are inserted through it, and since the inside is not visible, the appearance is improved, and the surface periphery of the hole is hardened. Therefore, we can expect a reinforcing effect from this.

[Brief explanation of drawings]

1 to 4 show a first embodiment of this invention, FIG. 1 is a cross-sectional view of essential parts of a foam mold according to this invention, FIG. 2 is a cross-sectional view taken along the - line in FIG. The figure is a partial perspective view showing the hole shape of the obtained foam molded product, Figures 4 and 5 show the second embodiment, Figure 4 is a sectional view of the main part of the foam mold, and Figure 5 is FIG. 4 is a sectional view taken along the - line, and FIG. 6 is a sectional view showing a main part of a hole forming portion in a conventional foaming mold. 10... Upper die, 12... Lower die, 14... Skin material, 14a... Hole, 18, 32... Positioning protrusion, 20, 30... Concave boss, 22... Pad, 22a... ...hole.

Claims (1)

[Scope of utility model registration request] A protrusion for positioning the hole formed in the skin material is formed protrudingly at the hole forming position of the mold surface where the skin material is installed, and an uneven shape is formed on the outer periphery of the positioning projection on the other mold surface. A concave boss part for forming a hole to be fitted is provided protrudingly, and the mold is clamped with the outer periphery of the concave boss part crushing the periphery of the back surface of the hole formed in the skin material. A foam mold for a sheet, which is characterized by being designed to do the following.