JPS58188638A - Mold for injection molding - Google Patents

Abstract

PURPOSE:To obtain the titled mold capable of simplifying mechanism having the ability of molding articles having different shape of cavity with one molding machine, by a method wherein a stationary mold plate is formed to engage a retainer plate in uneven manner corresponding to the convex part of stripper plate. CONSTITUTION:Hot runner system 20, stationary to plate 22 and runner stripper plate 24 are arranged on the cavity side plate surface 48 of injection stage as common part of respective metal mold. Templates 26, 28 and moving head die plate 32 are respectively provided on the moving head plate surface 50. The condition of close fitting between the template 26 and the plate 24 is kept from the finished time of filling to the time when the resin in the gate part of cavity solidifies, and then the resin is cut off by making the plate 24 apart from the die plate 22 with the energized pressure of spring 36 by slightly making the plate surface 50 descend. The template 26 is caused to descend with the dead weight by further making the plate surface 50 descend, and the both molds 26 and 28 are cut off by extruding the template 26 upward with the extruding bar 52 after solidifying by cooling.

Description

DETAILED DESCRIPTION OF THE INVENTION This @ Ming relates to an improvement of a six-plate type injection mold.

A slide or rotary type injection molding machine that performs continuous molding has a mold and its mold opening mechanism at each division position of the index table, and also to prevent large gate marks from forming on the product surface. When using a pinpoint gate, a 5-grae type mold is used to remove the runner and runner pull.

Figure 1 shows a three-grade type mold that has been commonly used in the past.This mold has a runner stripper plate 6, a fixed It is roughly composed of a foot@template 10 and a moving side template 11, and a moving@template 11.
is connected to the movement@mounting plate 15 via the spacer block 15.

Each of the above plates 6 and templates 10 and 11 are fixed m mounting plates 5
The mold opening adjustment links 8, 8 are connected by mold opening adjustment links 8, 8 that project from each other and are positioned mutually by inserting the door bin 5, and adjust the mutual separation position when the mounting plate 15 moves back. There is.

In addition, a locate ring 1 and a sprue bush 2 buried in the lower part are provided in the center of the Joki weir plate 5, and the outer periphery of the tapered tip of the sprue bush 2 penetrates through the plate 6 and is fixed. The tip of the side mold plate 10 is exposed, and its spool is communicated with the mold &10, thereby communicating with the cavities formed in the parting surfaces of the mold plates 10 and 11 via a bin point gate.

Furthermore, in the figure, 4 is a stopper bolt that regulates the distance between the fixed side mounting plate 3 and the plate 6, and 8 is a stopper bolt between the plate 6 and the template 10.
The spring 12.14 interposed is the ejector bin and its plate.

When the movable mold plate 15 is lowered from the position shown in the figure in the molding die configured to have a diameter of 5゜ as described above, the upper ml spring 8
Due to the biasing pressure, the plate 6 and template 10 are first separated,
Tear off the pine resin that accumulates in the sprue from the bin point gate. Next, the link 8 restricts the lowering of the template 10,
The person on the movable template 11 descends to separate the templates 10 and 11, and then the plate 6 descends from the mounting plate to a position where it is regulated by the bolts 4, and in this state, the inside of the sprue is The resin accumulated in the sprue bush 2 is also separated from the sprue bushing 2, making it easy to remove the unnecessary resin. In other words, in this kind of three-plate type mold, the solidified resin accumulated in the glue 2 is removed by separating the plate 6 and the mold plate 10 using a bottle point gate, and then separating the plate from the mounting plate 3. This has the great advantage of eliminating the need for post-molding gate treatment compared to two-plate molds.

However, on the other hand, the structure of the above mold is extremely complicated compared to a two-plate type mold, and especially when applied to a continuous injection molding machine, failure factors increase, durability is poor, and the mold cost is high. becomes extremely ugly. In addition, with this type of structure, there is a large amount of resin that is squeezed into the sprue bushing, so there is a lot of material loss during each molding, and the mold has to be opened a lot, making the equipment larger. Various shortcomings were noted, including an inevitable drop in molding cycles.

The present invention has been made in view of the above-mentioned drawbacks, and its purpose is to provide a mold that is simple in structure, small and compact, and that causes less material loss during each molding process.

Another object of this invention is to perform split molding of Cr.
To provide a mold in which a fixed 41IA mounting plate and a runner stripper plate are shared parts of each mold, and only the injection stage can be installed therein.

In order to achieve the above objects, the present invention has a fixed mounting plate attached to the outer periphery of the tip of a hot runner system of an injection molding machine, and a fixed mounting plate attached to the tip surface of the mounting plate in a detachable manner. A stripper plate whose central part is removably fitted to the tip of the hot runner system and forms a part of a sprue that communicates with the hot runner system in the event of failure, and this stripper plate is always biased toward the separation side. The middle stage of the spring, the positioning bolt that protrudes toward the distal end of the mounting plate, is slidably inserted into the stripper grate, and regulates its separation position; Press the stripper grate to fit it into the hot runner system, and at the same time press the stripper grate to fit it into the hot runner system. Mold clamping,
The present invention provides an injection mold having a mold opening mechanism, and one embodiment of the present invention will be explained in detail below with reference to FIG. 2 and subsequent drawings.

In FIG. 2, the injection molding mold according to the present invention includes a hot runner system 20 attached to the side plate of one leg of the injection molding machine, and a fixed side attached to the lower outer periphery of this hot runner system 20! 22, a runner stripper plate 24 detachably attached to the lower surface of this mounting plate 22, a fixed @ template 26 fitted to the lower part of this plate 24, and a movable plate 26 that engages with this template 26. a side template 28;
It is preferably composed of a moving part (j mounting plate 32) connected to the lower part of the moving side template 28 via a spacer block 50.

The runner stripper plate 24 has a trapezoidal cross-section fitting recess 24 that is removably fitted into the tapered outer peripheral portion 20m of the tip of the nozzle constituting the hot runner system 20.
m is formed in the central part, and the lower part thereof also forms a fitting convex part 24b with a trapezoidal cross section, and the concave and convex part 24m
, 24b to form a sprue portion 24c that communicates with the hot runner system 20.

The stripper plate 24 is inserted into a plurality of positioning stripper bolts 34 screwed onto the lower surface of the mounting plate 22, and is coupled to the mounting plate 22 so as to be able to come into contact with and be separated from the mounting plate 22. The separation position of the bolt head 34 is regulated by the bolt head 34 formed on the protruding front part of the bolt 34. Further, a gap 35 of a certain number is formed between the stripper grate 24 and the mounting plate 22, and a compression coil spring 56 is inserted into the gap 35, and these springs 66 keep the stripper grate 24 constant. It is biased in a direction away from the mounting plate 22. Therefore, when the moving side mounting plate 32 is lowered from the position shown in the figure, the stripper plate 24 is separated from the fixed side mounting plate 22 by the above-mentioned biasing pressure, thereby separating the tip of the hot runner system and the sprue portion 24e.

The shape of the sprue portion 24c is a mouth-shaped cross section so that the resin in the sprue portion 24c is not carried away to the hot runner 20 side when the sprue portion 24c is separated.

The rigid side mold plate 26 has a flange portion 26m formed on its periphery that engages with the upper end of the protruding rod (not shown), and a flange portion 26m that engages with the upper end of the protruding rod (not shown), and a flange portion 26m that engages with the fitting convex portion 24b of the stripper plate 24 on the upper surface of the central portion thereof. A fitting recess 26b is formed in the center of the fitting recess 26b to communicate with the sprue portion 24e, and a pinpoint gate 26d is formed in the lower part of the sprue portion 26c. It communicates with a cavity 58 formed between the parting surface with the movable template 28 through the movable mold plate 28.

Reference numeral 40 indicates a plurality of guide bins that penetrate through the fixed mold plate 26 and protrude from the lower part thereof, and 42 indicates a guide with a pole bearing that is located inside the movable mold plate 28 and allows the guide pin 40 to be slidably inserted therein. The bush 44 is an ejector bin whose upper end passes through the movable mold plate 28 and faces the inner bottom surface of the cavity 58, and 46 is an ejector plate provided at the lower end of the ejector bin 44.

The injection molding mold according to the present invention is constructed as described above, and one molding cycle when this mold is applied to a slide or rotary continuous injection molding machine is shown in Fig. 3 (a). ) to (・) will be used to explain.

First, as shown in Fig. 5 ta+, the hot runner system 2
0. Fixed side installation &22 and runner stripper plate 2
4 is provided on the identification side plate LII of the injection stage as a common part of the molds of friends, and each mold plate 26, 28 and transfer @
@Mounting & 52 is provided on the sliding or rotary type movable side panel surface 50.

In the figure, 52 is the above-mentioned abutting rod which is installed on the board surface 50 of the movable die 1 and comes into contact with the flange portion 261 of the fixed side mold &26.

FIG. 5(a) shows the point in time when the fixed mold plate 26 and the movable mold plate 2δ are combined and positioned at the molding standby position of the injection stage.

At this stage, the mold clamping mechanism (not shown) moves the side plate 1 river 50 mm.
7J<
The mold plate 26 is tightly fitted to the top flash of the stripper plate 24 by its unevenness, and in this state, the melted resin is filled into the cavity, and from the time of completion of filling, the φ millimeter 3
This state is maintained until the resin in #26d is cooled and solidified.

Then, at that point, when the moving side plate @50 lowers slightly,
As shown in FIG. 5(c), the biasing pressure of the spring 36 causes the stripper plate and the plate 24 to
6, the resin is separated between the upper ends of the sprue part 24e of the attachment part 22.

Next, when the movable side panel surface 50 further descends, the stripper grate 22 no longer descends because its lowering position is regulated by the bolts 11g34m, whereas the fixed @ template 26 descends together with the movable side panel dIJ50 due to its own weight. , the two are separated as shown in FIG. 3(d), and as a result of this separation, the resin in the sprue portion 24c of the stripper plate 24 is pulled out and protrudes onto the m plate 26. .

In this state, move side panel 1! [150 further descends, the inside of the cavity 58 is cooled and solidified, and the movable side board surface 50 moves to another stage.

After cooling and solidifying, as shown in Figure 5 (・), the board surface 50
As the gate 2 descends, the abutting rod 52 pushes up the template 26, separating the two ffs 126 and 28.
6d to open the cavity while separating the resin, and then the ejector bin 44 protrudes into the cavity to enable ejection of the molded product, and the resin remaining in the sprue 26d of the template 26 is removed by an appropriate removal means. and - end the forming cycle.

In addition, when the mold according to the present invention is applied to the above-mentioned injection molding machine for continuous molding, a runner stripper plate is fixedly provided on the injection stage and can be shared by each mold plate.

Therefore, in the present invention, if the solid y'sm slab is formed into a shape that corresponds to the convex portion of the stripper plate and is held in an uneven shape, cavities with different shapes can be molded with one molding machine. , when molding many types of molded products with one molding machine, the mold mechanism can be extremely simplified.

As explained above, since the injection mold according to the present invention has the above-described structure, the mechanism is simpler and more compact than the conventional three-plate type mold. As a result, failure factors are reduced, durability is excellent, and the entire device can be downsized, and mold costs can be reduced. Since the runner stripper plate F can be shared, the mold cost can be further reduced.

In addition, the present invention incorporates a hot runner system, and the length of the part of the sprue that passes through the stripper plate and the one-leg side mold plate can be made shorter than before, resulting in less material loss and a shorter molding cycle. In addition, the resin that has cooled and solidified in a part of the sprue is pulled out to the template side and does not remain on the stripper plate (stripper plate), so it has various excellent advantages such as no inconvenience when shared. .

[Brief explanation of the drawing]

FIG. 1 is a vertical sectional view showing a conventional 5-grade type mold structure, and FIG. 2 is a vertical sectional view showing a mold structure according to the present invention.
FIGS. 3(a) to 3(e) are sectional views sequentially illustrating one molding cycle when applied to an injection molding machine for continuous molding according to the present invention. 20...Hot runner system 20a River outer periphery 22...Fixed side mounting plate 24...Runner stripper grate 24c...Sprue part 26...Fixed @ template 26c...Sprue part 26d.・・Pinpoint gate 28・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・ move side mounting plate 54 50...Moving side panel surface %1 Applicant Tateishi Electric Co., Ltd. Figure 3 (Q) (b) (c)
(d) A, 2

Claims (2)

[Claims] (1) A fixing device attached to the outside of the tip of the hot runner system of the injection molding machine [4i, which is detachably attached to the mounting plate and the tip l of this mounting plate, and the center part of the fixing plate is attached to the outside of the hot runner system. A stripper plate that is removably fitted to the tip and has a gel part that communicates with the hot runner system when fitted, a spring means that constantly urges the stripper plate apart, and the mounting plate. A positioning bolt that protrudes toward the tip, is slidably inserted into the stripper plate, and controls its separation position, and engages with the tip g@ surface of the stripper plate to press the stripper plate. This is fitted into the hot runner system, and a fixed side mold plate that communicates with a part of the sprue, a movable side mold plate that engages with this mold plate, and a mold clamping and mold opening mechanism for these mold plates □ are installed. injection mold with (2) A patent for a %copy in which the fixed 41Am plate and runner stripper part are attached to the identification side panel surface of the injection stage, and both mold plates and their mold clamping and mold opening mechanisms are provided on the movable side panel surface. An injection mold according to claim 1.