JPH06218743A - Foaming mold - Google Patents

Abstract

PURPOSE:To facilitate the falling-out of vent refuse and to prevent the generation of a defect due to a gas sump by providing a plurality of gas vent holes composed of slit like slots to one of the upper mold or core mold of a foaming mold. CONSTITUTION:A plurality of gas vent holes composed of slit like slots 11 are provided to the upper mold of a foaming mold. By this constitution, the vent refuse falling out to the outside of the mold from the gas vent holes 11 can be made large and the vent refuse falling out of the holes 11 becomes much and the remaining vent refuse becomes little to be easily pushed out and removed to the outer surface of the upper mold. Therefore, gas can be certainly vented out of the gas vent holes 11 and the generation of the defect caused by a gas sump. can be prevented and the quality of a product can be enhanced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a foam molding die, and more particularly to a foam molding die suitable for use in foam molding of soft urethane. In particular, it facilitates removal of vent waste clogging the gas vent hole, This will improve the product quality.

[0002]

2. Description of the Related Art For example, as a conventional foaming mold composed of an upper mold and a lower mold, as shown in FIG.
Where the lower mold 2 is hinged to one side, the upper mold 1 is generally widely used in which a plurality of gas vent holes, so-called vent holes 3 each having a small diameter of about 2 mm, are formed in a row. Has been done.

Here, each vent hole 3 functions so as to allow the gas generated during foam molding to escape to the outside of the mold, thereby smoothing the flow of the foamed resin material in the mold and improving the product quality. Is.

[0004]

In many cases, however, in the prior art, vent debris which has escaped from the vent hole 3 to the outside of the mold together with the foaming gas adheres to the outer surface of the upper mold and the vent hole 3 is formed. Therefore, in order for the vent holes 3 to exhibit their original functions, it is necessary to remove all vent waste from the respective vent holes 3.

Therefore, conventionally, a wire having a diameter slightly smaller than that of the vent hole 3 is used to extrude and remove the vent waste from the inner surface side of the upper die to the outer surface side by a worker's manual operation, or from the inner surface side of the upper die. It has been common for an operator to blow high-pressure air to each vent hole 3 to extrude and remove vent waste.

However, these operations for all the vent holes 3 have an inconvenience that an extremely large number of man-hours are required, so that in the mass production line of foam-molded products,
Since it is practically impossible to perform the above-mentioned work perfectly, the foam molding die is usually subjected to the next foam molding while leaving some vent waste.
Therefore, there is a high possibility that a foamed molded product may have a defective product due to incomplete degassing.

The present invention has been made as a result of studies aimed at solving the above problems of the prior art, and the object of the present invention is to facilitate the removal of vent waste accompanying mold opening. At the same time, it is another object of the present invention to provide a foam molding die capable of greatly reducing the occurrence rate of defective molding of a foam molded article by facilitating removal of vent waste from each gas vent hole.

[0008]

The foaming mold of the present invention comprises an upper mold and a lower mold, and sometimes a core mold, wherein at least one of the upper mold and the core mold is A plurality of gas vent holes each having a slit-like long hole are formed.

[0009]

In this foam molding die, each gas vent hole is formed as a slit-shaped long hole, and the gas vent function for a plurality of conventional vent holes is exerted so that the gas is released together with the foam gas. In addition to the fact that the weight of one vent waste that escaped from the hole to the outside of the mold is much larger than that of the conventional vent waste, per unit volume of vent waste,
The contact area with the wall surface of the gas vent hole is smaller than that of the conventional technology, and the frictional force between the vent dust and the gas vent hole is reduced. This also contributes greatly to the possibility that vent debris will fall out of the gas vent hole under the action of opening impact on the die, and also the area of high-pressure air blown from the inner surface of the upper die to the gas vent hole will increase. Thus, all of the vent waste remaining in the gas vent hole can be easily and quickly extruded to the outer surface side of the upper mold.

For this reason, even in the mass-production line of foam-molded products, it is possible to reliably remove all the vent dust with a small number of man-hours. Therefore, the appearance quality and internal quality of the foam-molded products can be improved. Both can be kept high all the time.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a foaming mold showing an embodiment of the present invention, which is a schematic perspective view showing a mold for foaming a backrest portion of a rear seat for a passenger car in an open state thereof.

This foaming mold is also constructed by hinge one side of the upper mold 1 to one side of the lower mold 2 as described in the prior art. For example, this can be performed by engaging a turning hook (not shown) provided on the upper mold side with a latching rod (not shown) provided on the lower mold side.

In the illustrated example, the upper die 1 is provided with, for example, 3
A plurality of gas vent holes 11 each having a slit-like straight long hole having a width of mm are formed, and each of these gas vent holes 11 is formed.
Then, the inner surface of the upper mold 1 functioning as a molding surface is communicated with the outer surface thereof, as is apparent from the enlarged sectional view of FIG.

According to the foaming mold having the above-described structure, most of the vent wastes leached from the respective gas vent holes 11 to the outside of the mold fall out of the mold when the mold is opened. Further, by blowing high-pressure air from the inner surface side of the upper mold 1 to the vent dust that does not fall out and remains in the gas vent hole, all of them can be removed easily and quickly.

Therefore, in the subsequent foam molding, all the gas vent holes 11 can be made to function as expected, and as a result, the quality of the foam molded product can always be made excellent. .

By the way, the width is 1380 mm and the height is 48.
In order to mold a 0 mm backrest, a foam mold as shown has a width of 3 mm and a length of about 300.
In the case of forming 18 mm vent holes 11 mm, when the upper mold 1 is opened for demolding the foamed molded product, most of the vent dust falls from the gas vent hole 11, and the remaining vent dust is By blowing high pressure air against it,
All of them could be removed in a very short time.

Therefore, it is possible to greatly reduce the rate of occurrence of defects due to the generation of gas accumulation in the foamed molded product, as compared with the prior art, and to reduce the variation in product weight.
This can also be greatly reduced compared to the prior art.

By the way, when the diameter of the vent holes 3 in the prior art is set to 2 mm and the total opening area of the vent holes 3 is set to be the same as that of the gas vent holes 11 described above, almost all of the foam molded articles are Some product defects occur due to clogging of the vent layer, which is about 5 times that of the foaming mold according to the present invention, and the product weight variation is about ± 10%, which varies depending on the invention molding die. It was about twice.

The present invention has been described above based on the illustrated example. However, in the case of a molding die including a core die, instead of the upper die,
Alternatively, a gas vent hole may be formed in the core die together with the upper die, and the gas vent hole may be extended in a curved shape, a polygonal line shape, or the like.

[0020]

As described above, according to the present invention, it is extremely easy to remove and remove the vent dust based on the action of the gas vent hole formed in at least one of the upper die and the core die, which is a slit-like long hole. As a result, all the gas vent holes can be opened at all times, so that it is possible to prevent the occurrence of defects such as gas accumulation in the foam molded product, and to improve product quality. Can be improved.

[Brief description of drawings]

FIG. 1 is a schematic line perspective view showing an embodiment of the present invention.

FIG. 2 is a sectional view taken along line II-II in FIG.

FIG. 3 is a schematic perspective view showing a conventional example.

[Explanation of symbols]

 1 Upper mold 2 Lower mold 11 Gas vent hole

Claims (1)

[Claims] 1. A foaming mold comprising an upper mold and a lower mold, and sometimes a core mold, wherein at least one of the upper mold and the core mold is a gas vent hole having a slit-like long hole. Foaming mold made by forming a plurality of.