JPH1016011A - Automatic gate cutting apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate after-treatment for cutting, and to reduce time and expenditure by a method in which the size of a runner is arranged so that the runner can contact the tip surface when a split mold is opened, a molding is moved backward integrally with a core pin after the mold being opened, and a gate is cut by the molding. SOLUTION: The size of a runner 11 is arranged so that the runner 11 can contact the tip surface when a split mold 2 is opened, a molding 13 is moved backward integrally with a core pin 9 after the mold 2 being opened, and a gate 11a is cut by the molding 13. In other words, the runner 11 contacts the front of the mold 2 during injection molding, the mold 2 is opened in the arrow direction, and it is fixed to the mold 2 without falling into a space part formed in the mold 2. Next, when the second movable mold 10 retreats, since the molding 13 shrinks to be embraced by the core pin 9, it retreats with a bush 6, and a flange 7 moves backward in a long channel 8 and stops. At this time, the ring gate 11a is cut automatically by the molding 13. Next, the core pin 9 is extracted from the molding 13, and the molding 13 falls.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic gate cutting apparatus for automatically cutting a gate from a molded product when a molded product formed by a split mold is opened.

[0002]

2. Description of the Related Art FIGS. 10 to 13 show a conventional molding apparatus using a split mold. 50 is a split mold, 51 is a molded product therein,
52 is a runner, 53 is a core pin, and a fixed bush 54
To slide.

Next, the operation will be described. Runner 52
Is located in the space 55 where the split mold 50 is formed when the mold is opened. Therefore, as shown in FIG. 11, when the movable mold 56 is retracted and the core pin 53 comes out of the molded product 51, the molded product 51 falls integrally with the runner 52.

[0004]

In the above prior art, there is a problem that the runner cannot be automatically cut from the molded product, so that it must be cut by post-processing, which increases the time and cost.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems, and to make the runner large enough to be in contact with the front end surface when the split mold is opened, and to form a molded product integrally with the core pin after the split mold is opened. It is characterized in that the gate is retracted and cut from the molded product.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described in detail with reference to the drawings. 1 to 6 show a first embodiment of the present invention. 1 is a fixed side, 2 is a split type, and 3 is an angular pin. Reference numeral 4 denotes a movable side, and a first movable mold 5
The bush 6 is slidably fitted to the
Are slidably inserted in the long groove 8. Reference numeral 9 denotes a core pin that slides in the bush 6, and the lower end thereof is a second movable die 10
It is fixed to. Numeral 11 denotes a runner and 11a denotes a ring gate.
Then, the split mold 2 is opened in the direction of the arrow as shown in FIG. 3, and is locked by the split mold 2 without falling into the space 12 formed in the split mold 2 as shown in FIG. Next, the second movable mold 1
When 0 is retracted by the distance L, the molded product 13 contracts and is held by the core pin 9, so the entire bush 6 is retracted and the flange 7 is retracted.
Stops moving backward in the long groove 8. At this time, the ring gate 11a is automatically cut from the molded product 13. Next, as shown in FIG. 6, the core pin 9 comes out of the molded article 13 and the molded article 1
3 falls.

FIGS. 7 to 9 show a second embodiment of the present invention. Reference numeral 20 denotes a split type, which holds a core pin 21. Reference numeral 22 denotes a runner similar to that of the first embodiment, and reference numeral 22a denotes a pin gate. Since the molded product 23 contracts and is held by the core pin 21, when the movable mold 24 is retracted, the core pin 21 is retracted integrally with the molded product 23, and the pin gate 22a is automatically cut. Next, as shown in FIG. 9, when the mold opening is completed, the molded product 23 falls.

[0008]

According to the present invention, the runner is made large enough to be in contact with the front end face when the split mold is opened, and after the split mold is opened, the molded product is retracted integrally with the core pin to cut the gate from the molded product. Therefore, when the split mold is opened, the ring gate can be automatically cut along with the retraction of the core pin, so that post-processing for cutting is unnecessary, and time and cost can be reduced.

[Brief description of the drawings]

FIG. 1 is a front cross-sectional view of an entire injection molding die according to a first embodiment of the present invention.

FIG. 2 is a front sectional view of a main part of FIG.

FIG. 3 is a front sectional view of FIG. 2 at an initial stage of mold opening.

FIG. 4 is a front sectional view of the middle stage of mold opening of FIG. 2;

FIG. 5 is a front cross-sectional view of FIG. 2 when the mold opening is completed.

FIG. 6 is a front cross-sectional view of the core pin of FIG.

FIG. 7 is a front sectional view at the time of mold injection in a second embodiment of the present invention.

8 is a front sectional view of the mold at the initial stage of FIG. 7;

FIG. 9 is a front sectional view of the molded product of FIG. 7 when the molded product is dropped.

FIG. 10 is a front sectional view of a conventional apparatus at the time of injection molding.

FIG. 11 is a front sectional view of the mold shown in FIG. 10 when the mold is opened.

FIG. 12 is a front sectional view at the time of completion of mold opening of FIG. 10;

FIG. 13 is a front sectional view of the molded article of FIG. 10 when dropped.

[Explanation of symbols]

 Reference Signs List 1 fixed side split type 4 movable side 5 movable type 6 bush 7 flange 8 long groove 9 core pin 11 runner 11a ring gate 12 space portion 20 split type 21 core pin 22 runner 22a pin gate 23 molded product 24 movable type

Claims (1)

[Claims] 1. An automatic gate cutting device in which a runner has a size capable of contacting a tip end surface when a split mold is opened, and after the split mold is opened, a molded product is retracted integrally with a core pin to cut a gate from the molded product.