JPS6334900Y2 - - Google Patents

Description

[Detailed description of the invention] This invention relates to an improvement of a molding die having a slide core made of synthetic resin, and is capable of automatically extruding the runner part, gate part, etc. on the slide core when the mold is opened after molding. The purpose is to provide molding molds.

In a conventional molding mold having a slide core made of synthetic resin, especially an injection mold, if a runner and a gate are formed on the slide core, the runner part,
Since the gate section and sprue section also move at the same time, a push spring is attached to the runner section in order to push out the runner section, gate section, and sprue section from the slide core, but the pushing operation becomes uncertain and the runner section and the gate section move. The reliability of automatic extrusion of parts and sprue parts is low, making it difficult to realize fully automated molding.

The present invention has the configuration described in the claims of the utility model registration, so that the runner part, the gate part, and the sprue part can be automatically pushed out from the slide core using the upward movement of the ejector plate. This makes fully automatic molding of synthetic resin possible.

The configuration of the illustrated example will be explained below.

In FIG. 1, a slide core 3 is disposed between an upper mold 1 and a lower mold 2, and a cavity 4 is formed between the upper mold 1 and the slide core 3.

An inclined pin 5 is implanted in the upper mold 1 and is configured to be able to be fitted into and removed from an oblique hole 6 of the slide core 3. When the upper mold 1 is in the lowered position and the mold is closed, the slide core 3 is inserted into the upper mold 1. When the mold is moved forward in the direction of arrow A and the upper mold 1 is raised to open the mold, the slide core 3 can be moved back in the direction of arrow B, and the retraction distance is set in the lower mold 2. The stop bolt 7 restricts the distance to S.

A runner 8 and a gate 9 are on the top surface of the slide core 3.
is formed, and a sprue 10 is formed on the upper mold 1.

Directly below the runner 8 of the slide core 3, a through hole 11 is formed that vertically passes through the slide core 3, and within the hole 11, an extrusion pin 14 whose upper end 12 is always located at the runner bottom portion 13 is inserted vertically. It is slidably inserted.

The through hole 11 in the illustrated example is composed of a small diameter part 15 and a large diameter part 16 below it, and the push-out pin 14 is composed of an upper pin 17 and a lower pin 18. The lower end rests on the enlarged head 19 of the lower pin 18. The lower pin 18 is suspended and supported by a plate 21 embedded and fixed in the lower part of the slide core 3 with bolts 20 at the expanded head 19, and is suspended from the upper and lower penetration grooves of the lower mold 2.
A lower end 22 of the lower pin 18 is made to protrude from the lower surface side of the lower mold 2 through the lower pin 3 .

The length of the vertical through-hole 23 is set so as not to interfere with the push-out pin 14 when it moves along with the slide core 3 over the distance S.

The enlarged lower end 24 of the above-mentioned upper pin 17 and the through hole 1
A coil spring 2 is connected between the upper end of the large diameter portion 16 of
5 is compressed, and the upper pin 17 and the lower pin 1
8, that is, the push-out pin 14 is always connected to the through hole 1.
I am urging you to immerse yourself within 1. Due to the bias of this coil spring 25, the upper end 12 of the push-out pin 14
That is, the upper end of the upper pin 17 is always located at the runner bottom portion 13. In addition, extrusion pin 1
4, that is, the upper pin 17 is slidably and tightly fitted into the through hole 11, that is, the small diameter portion 15.

When the slide core 3 is moved back by the distance S as described above and occupies the position shown in FIG. A push-up pin 27 that moves up and down together with the extractor plate 26 is provided. This push-up pin 27 is
When the slide core 3 occupies the forward position, which is the molding position, the slide core 3 is located at a distance S from the axis of the lower end 22 of the extrusion pin 14, that is, the lower end 22 of the lower pin 18 in the backward direction of the slide core 3. When the lower ejector plate 26 is in the lowered position, the push-up pin 27
When the slide core 3 moves backward, the upper end 28 of the
It is configured so that it can occupy a position lower than the lower end 22 of the push-out pin 14 by a distance l so as not to interfere with the lower end 22.

Further, the upward movement distance of the push-up pin 27 due to the upward movement of the lower ejector plate 26 is longer than the distance l, and the upward movement distance is such that the lower ejector plate 26 is moved along the chain line 2' in the state shown in FIG. The distance is such that when the push-out pin 14 is moved upward to the position indicated by , the upper end 12 of the push-out pin 14 can be raised to the position indicated by the chain line 12'.

In the figure, reference numeral 29 is an upper ejector plate, and reference numeral 30 is an extrusion rod.

The molding die configured as described above operates as follows.

That is, with each member occupying the position shown in FIG. 1, synthetic resin is injected from the sprue 10 and filled into the cavity 4, and after being cooled, the upper mold 1 is moved upward.

Due to this upward movement of the upper die, the slide core 3 is moved backward in the direction of arrow B by the action of the inclined pin 5 and the oblique hole 6, and is stopped at the position where the rear end surface 3' abuts against the stop bolt 7. This situation is shown in FIG.

As mentioned above, since the push-up pin 27 is disposed at a position corresponding to the retraction distance S of the slide core 3, in the state shown in FIG. Then, the upper end 28 of the push-up pin 27 will be located. This second
After reaching the state shown by the solid line in the figure, extrusion rod 3
When the push-up pin 27 is raised via the lower ejector plate 26, the upper end 2
8, the lower end 22 of the ejector pin 14 is pushed, and the ejector pin 14 rises against the elasticity of the coil spring 25, and its upper end 12 rises to the position indicated by the reference numeral 12' in FIG. , the gate portion 9', and the sprue portion 10' are pushed out to the position shown by the chain line in FIG.

After removing the extruded runner section 8', gate section 9', and sprue section 10' and taking out the molded product 31, the extrusion rod 30 is lowered to remove the pressure on the extrusion pin 14 by the push-up pin 27. And, the pin 14 is pushed by the elasticity of the coil spring 25,
It is returned to the old position shown in FIG. 1, and then the upper die 1 is lowered, and the inclined pin 5 is fitted into the oblique hole 6, so that the slide core 3 is also returned to the position shown in FIG.
This is in preparation for the next injection molding.

In the embodiment described above, the return movement of the push-out pin 14 is performed by the elasticity of the coil spring 25.
This structure may be changed to the structure shown in FIG. 3, and the return movement may be made actively by lowering the upper die.

That is, a cavity 33 that opens on the lower surface side is formed in the slide core 32 and is communicated with the through hole 34, and a second through hole 35 is formed in parallel with the through hole 34.
is installed through it.

The upper extrusion pin 36 is inserted into the above-mentioned through hole 34 so as to be slidable up and down, and its enlarged lower end 37 is brought into contact with the enlarged head 39 of the lower extrusion pin 38. It is supported by a first plate 41 fixed with bolts 40, and the lower end 42 of the lower extrusion pin 38 is made to protrude toward the lower surface side of the lower mold 43 through the vertical through groove 44 of the lower mold 43.

Furthermore, insert the push-down pin 45 into the through hole 35,
A second plate 46 is fixed to its lower end with bolts 47, and the enlarged lower end 37 of the upper push-out pin 36 is fitted into a recess 48 on the lower surface of the plate 46.

In addition, during injection molding, the upper end 49 of the upper extrusion pin 36 is located in the same plane as the bottom surface of the runner 50, and the upper end 51 of the push-down pin 45 is located in the same plane as the bottom surface of the runner 50.
It is located in the same plane as the upper surface of 2.

In this embodiment as well, after injection molding, the ejector plate is raised by the operation of the extrusion rod (not shown), and the upward movement of the extrusion pin causes the upper extrusion pin 36 to move upward via the lower extrusion pin 38, and inside the runner 50. The extrusion of the runner section produces the same effect as that of the embodiment shown in FIG.
The push-down pin 45 also moves upward via the second plate 46, and its upper end 51 touches the slide core 3.
Projects upward from the top surface of 2.

In preparation for the next molding, when the upper mold (not shown) is lowered and its lower surface comes into close contact with the upper surface of the slide core 32, the upper end 51 of the push-down pin 45 is pressed by the lower surface of the upper mold, so that the push-down pin 45 is the second
Since the enlarged lower end 37 of the upper ejector pin 36 is lowered through the plate 46, both the upper ejector pin 36 and the lower ejector pin 38 are positively pushed down to their old positions by this operation. In this embodiment, the upper extrusion pin 36 and the slide core 3
This is advantageous when there is a tendency for binding to occur between the two through holes 34 due to galling or the like.

The molding die according to the present invention has the configuration described above,
At a predetermined retreat position of the slide core that retreats in response to mold opening, a pusher that moves up and down together with the ejector plate is placed at a position corresponding to the lower end of the ejector pin built into the core. A raising pin is attached, and the ejecting pin of the slide core occupying the retreated position can be moved upward, so that the runner section, gate section, sprue section, etc. remaining on the slide core can be mechanically removed in response to the mold opening operation after molding. It can be automatically discharged and removed, ensuring reliable extrusion operation, and making fully automatic molding possible.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal cross-sectional view of the main part of an example of the embodiment during molding, FIG. 2 is a longitudinal cross-sectional view of the main part of the mold shown in FIG. 1 when the mold is opened, and FIG. It is a longitudinal cross-sectional view shown at the line position in the figure. 1: Upper mold, 2: Lower mold, 3: Slide core, 8:
Runner, 9: Gate, 10: Sprue, 11: Through hole, 12: Upper end of push-out pin, 13: Bottom portion of runner, 14: Push-out pin, 26: Lower ejector plate, 27: Push-up pin.

Claims (1)

[Scope of utility model registration request] Directly below the runner in the slide core in which the runner and gate are formed, a through hole is provided that vertically passes through the slide core, and within the hole is an extrusion pin whose upper end is always located at the bottom of the runner.
The ejector pin is inserted vertically and slidably so that its upper end can protrude upward from the bottom surface of the runner, and an ejector is inserted at a position corresponding to the lower end of the ejector pin when the slide core occupies a certain retracted position. 1. A synthetic resin molding die, characterized in that a push-up pin is disposed that moves up and down together with the plate, and the push-up pin is moved upward by the upward movement of the push-up pin.