JPS58131041A - Mold injection molding method - Google Patents

Abstract

PURPOSE:To intend the shortening of a molding cycle at an injection molding, by shutting a runner after filling a cavity part to which a specified well part is linked with a molten resin via the runner. CONSTITUTION:An ejector pin 14 for ejecting a molded article molded in a cavity 11 is energized by a spring 15 at its back end side and when a molten resin is forced in, the pin 14 descends so as a well part 16 is formed on its upper part. When the molten resin is forced into the cavity 11 shaped between the cavity plates 3, 5 via a runner 12 and a gate 13, the pin 14 descends against the energizing force of the spring 15 and the resin is filled in the shaped well part 16 too. After a lifting plate 9 is raised and the flow passage of the runner 12 is shut by a slide pin 17, the mold 1 is cooled, then the molten resin solidifies shrinking and at that time the pin 14 is raised by the restoring force of the spring 15 and the shrinkage by solidification of the molded article is compensated by the supply of the resin from the well part 16.

Description

DETAILED DESCRIPTION OF THE INVENTION The following describes a molding method in 61 skin injection molding.

In the conventional injection type, Ili, l seedlings are produced *4. When the EI resin was injected into the cavity, the exit pressure was maintained until the resin was cooled and solidified by a gate at the inlet where the resin flowed.

This is because the collection of the molded product in the cavity is done for the purpose of filling the mold, or if there are many cavities.
kv,''), or in the case of a large molded product, the molding knife becomes longer so that the molding knife does not flare when the injection pressure is maintained.

Therefore, one object of the present invention is to provide a method for injection molding that can shorten the molding time.

According to this invention, after the resin is injected and filled into the cavity h through the filler, by blocking the filler with a sufidobin, the volume expands due to the pressure of the dust during the injection of the tM resin, and the 9M resin is injected. By blocking the funnel, pressure can be applied to the cavity group and maintained by the elastic force of the dripping part, and for this reason, the injection molding machine is required to maintain the injection pressure after resin injection. is no longer necessary, and e
The K molding process can be started, and the molding knife can be shortened by 11 minutes when the injection pressure is maintained.

An embodiment of the present invention having such characteristics will be described in detail below with reference to the drawings.

The drawing shows a mold for injection molding, and the mold l has plate 2 for mounting on the fixed side, cavity plate 8 on the fixed side, sprue A/4, cavity plate 5 on the movable side, base 6, and mounting on the movable side. Board 7,
An ejector plate 8 and a push-up plate 9 are provided, and the ejector plate 8 and the push-up plate 9 are provided so as to be movable in the vertical direction in the gap formed by the base 6, and the push-up plate 9 is provided on the side of the molding machine. It is moved at the tip of the production cylinder lO provided,
The ejector plate 8 is moved at the rear stage of this cylinder lO.A cavity part 11 which becomes a molded product is carved on the separating surface side of the cavity plates 8 and 5 described above, and a runner that leads from the sub-μ4 to this cavity part 11fc. 12 and gate 18
is engraved on the cavity plate 5 on the movable side.

A protruding bottle 14 for protruding the molded product of the above-mentioned cavity portion 5
is held by the above-mentioned ejector plate 9, but the rear part of the arrowed bottle 14 is urged in the ejecting direction by the spring 16, and the ejected bottle 14 can be moved back as much as the spring 15 is compressed. This bottle has 14 s
When retreating, H city 16 is formed in IIkA city ahead of Bin 14 (Figure 1g8).

That is, the above-mentioned reservoir 16 is the cavity tli' 1
When the spring 15 is acting in a state where there is no injection pressure in the bottle 1, its volume is zero, and the resin is injected and filled into the cavity 8jS11, and injection pressure is applied to the tip of the protruding bottle 14, and this bottle 14 is By retreating, the volume expands, and when the injection pressure after injection and filling disappears, the 'g volume contracts due to the elastic force of the spring 150.

The aforementioned runner 12 is equipped with a sealed bin 17 that can completely shut off the runner 12.
The rear end of 7 is held by the aforementioned push-up plate 9.

Further, the above-mentioned push-up plate 9 holds a central bottle 1g' at a position opposite to the spool 4, and this center bottle 18 pushes down the push-up plate 9 by receiving injection pressure at its tip.

At this time, the slide bin 17 is also pushed down, so the runner 12d is in a flowing state, but it is for ejection! /9 When the &9 is pushed up by the runner 10, the tip of the slide bin 17 comes into contact with the flat surface of the cavity plate 8 on the fixed side, and the runner 1
2 at the side of the bottle 17.

Note that 19 is an injection nozzle on the molding machine side.

Resin is injected and filled into the plasticized resin bitty part 11 of the mold 1 configured in this way, and the injection pressure at this time acts on the tip of the ejecting bottle 14 to push down this bottle 14t.
The reservoir portion 16 is also filled with resin.

Tree required for the volume of cavity part 11! When fI is filled, the ejecting sz cylinder G is activated, and its tip pushes up the push-up plate 9, and the tip of the sphoid pin 17 comes into contact with the cavity plate 8, so that the ○@ surface to shut off the runner 12.

When the runner 12 is blocked, the backflow from the cavity part 11 is blocked. It is not necessary to maintain the pressure by the injection pressure from the injection nozzle 19, and the injection nozzle 19 can proceed to the next measuring step of the molding process.

On the other hand, the cavity part 11 protrudes by shutting off the runner 120, and the injection pressure at the tip of the bottle 14 is removed, so the oil 9 l is contracted by the force acting on the linear cylinder 150 at the rear end of the bottle 14, and this pressure causes the contraction of the cavity l'll to close. Pressure replenishment takes place.

After that, when the dart 18 solidifies and the cavity molded product solidifies, the cavity plate 6 is moved,
The YJb product is ejected and removed by the ejector bin 14.

[Brief explanation of the drawing]

The drawings show an embodiment of the invention, and FIG. 1 is a sectional view of a mold. FIG. 2 is a sectional view showing the operating state. FIG. 8 is a partially cutaway sectional view showing the protruding bottle portion. 1...-Gold M 11...Cavity M
S1!・−・Runner “←・Protruding bottle 15
... Sude! 16...1 block...Slide bin Figure 1 Section 2 Figure 3

Claims (1)

[Claims] 1. The '6 spear expands due to injection pressure, and when the injection pressure is removed, the volume contracts due to elastic force ftM! 1st part t cavity 181-
Contrary to the shape, the runner is fully opened in this cavity capital and 4 = 48
A mold injection molding method characterized in that after applying FIk light, it is smoked in a slide bin at a runner assembly.