JPS5848112Y2 - Steam vents in foam molding equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a steam hole in a foam molding device, and provides a steam hole suitable for preventing water from entering the mold through the steam hole.

A steam hole is installed in a foam molding apparatus in which a mold is filled with foamable thermoplastic resin particles, and steam is used as a heating medium to heat and expand the resin particles and thermally fuse them to each other for molding. As shown in Fig. 1, a slit part 1 (commonly known as core vents) is used, which has a steam slit 2 at its tip and a recessed part 3 at its base end. , 5 and is inserted into the hole.

As is clear from FIGS. 2 and 3, which show the installation state of the slit part 1, the drawbacks of the conventional steam hole mentioned above are:
Water collects in the proximal recess 3 of the slit part 1 located on the upper surface of the mold, and water also collects below the inner surface of the recess 3 of the slit part 1 on the side of the mold, causing the foamed molded product 6 to accumulate. When the foamed molded product 6 is taken out from the mold, the accumulated water enters the mold and adheres to the surface of the foamed molded product 6.

If water easily enters the mold through the steam holes, filling of the raw material is inhibited, so extra cracking is taken and water is blown off before filling.

However, if cracking is increased, the weight of the foamed molded product becomes heavier due to overfilling of the raw material, and both heating time and cooling time become longer, resulting in an increase in product cost.

Furthermore, when removing the foam molded product from the mold, if residual water enters the mold through the steam holes, this water will adhere to the surface of the foam molded product. Another disadvantage was that the drying process of the foamed molded product required a long time.

In view of these conventional drawbacks, the inventor of the present invention conducted various studies and finally succeeded in creating a steam hole that prevents water from penetrating into the mold.

That is, in the present invention, a columnar body having a dish-shaped recess formed at the distal end and passing through a small hole is inserted into the proximal recess of a slit component having a steam slit at the distal end. This article focuses on steam holes in foam molding equipment.

Next, embodiments of the present invention will be described below with reference to the drawings.

Reference numeral 7 is a columnar body having a small hole 71 passing through it in the longitudinal direction, and a dish-shaped recess 72 formed on the tip side.

This columnar body 7 is used by being fitted into the proximal recess 3 of the slit component 1 which is driven into the fitting holes of the mold walls 4 and 5 of the mold. It is preferable to fit it into the proximal recess 3 of the slit component 1 so that it is flush with the outer surfaces of the walls 4 and 5, or protrudes outward from these.

It should be noted that, on the side of the columnar body 7 that is inserted into the proximal recess 3 of the slit component 1, a slip prevention part 73 is formed on the outer periphery by knurling grooves or other processing. This is convenient, and the shape of the columnar body 7 on the side to be fitted into the proximal recess 3 of the slit component 1 is preferably cylindrical, corresponding to the shape of this recess 3. As shown in FIGS. 6 and 7, the entire columnar body 7 may have a cylindrical shape, but one end of the columnar body 7 that protrudes outward from the outer surface of the mold wall 4.5 may be shaped like a cone or polygon. A pyramidal shape such as a pyramid is more preferable because water will not accumulate at the end of the columnar body 7 even when the steam hole is located on the upper surface of the mold.

The above-mentioned conical shapes include those in which the outer peripheral surface of the conical shape is curved inward or outward to bulge or concave (Fig. 8), and truncated conical shapes (Fig. 9). Also included.

Further, a dish-shaped recess 72 is formed on the tip side of the columnar body 7, and this recess 72 plays the role of uniformly diffusing steam into the steam slit 2 of the slit component 1. The dish-shaped shape may be substantially dish-shaped, and includes a truncated cone shape, a conical shape, and the like.

In addition to the case where one small hole 71 is provided in the center of the columnar body 7, it is also possible to provide a plurality of small holes 71 passing through the columnar body 7 in the longitudinal direction (
Figure 7).

In addition, the cross-sectional area of the small holes 71 (or the total sum of the small holes 71 in the case of multiple small holes 71) is such that if the cross-sectional area of the small holes 71 is smaller than the total area of the steam slits 2 of the slits 1, steam will not flow into the mold. Steam slit 2 has the disadvantage of hindering the inflow.
It is desirable that the area be the same as or larger than the total area of the area.

The present invention prevents water from entering the mold by inserting the above-mentioned columnar body into the concave portion on the proximal side of the conventional slit component, so that cracking is not provided during molding. It is now possible to fill the raw material without any foam molding, and it will vary slightly depending on the size and thickness of the foam molded product, but
Since overfilling of raw materials can be prevented, raw material savings of about 5-7% can be achieved.

In addition, the inner surface of the mold can be kept dry and water will not accumulate in the steam holes, so water will not adhere to the foam molded product.
This has excellent effects such as eliminating the need for a drying process for foam molded products.

[Brief explanation of the drawing]

Fig. 1 is a perspective view of a conventional slit part, Fig. 2 is a schematic diagram of a foam molding device with a slit part installed in the front part, Fig. 3 is an enlarged sectional view of the part A in the front part, and Fig. 4 is the present invention. FIG. 5 is a partial cross-sectional view of a foam molding device equipped with steam holes according to the present invention, and FIGS. 6 to 9 are cross-sectional views showing modified examples of the steam holes according to the present invention. It is. In the figure, 1 is a slit component, 7 is a columnar body, 71 is a small hole, and 72 is a dish-shaped recess.

Claims (1)

[Scope of utility model registration request] 1. Steam in a foam molding device in which a columnar body, which is inserted through a small hole and has a dish-shaped recess at its tip, is inserted into a concave portion on the proximal side of a slit part with a steam slit formed at its tip. Hole. 2. A steam hole in a foam molding apparatus according to claim 1, wherein one end of the columnar body is flush with or protrudes outward from the outer surface of the mold wall. 3. A steam hole in a foam molding apparatus according to claim 1, wherein the cross-sectional area of the small hole provided in the columnar body is equal to or larger than the total area of the steam slit.