KR100730690B1 - Gate cutting machine of injection mold - Google Patents

Abstract

A gate cutting machine of an injection mold is provided to automatically cut a tunnel gate during the injection molding so that an additional process does not need and a cutting surface of the tunnel gate is excellent. A gate cutting machine of an injection mold includes upper and lower pushing plates(10,20), an upper pushing pin(30) including an insertion groove(36) having a rotating lower end installed at the upper pushing plate and a spiral part(34) formed on the bottom, and a tunnel gate (32) penetrating a movable molding plate(63) to communicate a cavity(C) with a runner(R) to supply melted resin injected into the runner to the cavity. A lower pushing pin(40) is fixed to the lower pushing plate to correspond to the insertion groove of the upper pushing plate. A spiral part(44) is formed at the leading end to correspond to the spiral part of the upper pushing pin so as to rotate the upper pushing pin when the lower pushing plate is elevated and lowered. The lower pushing plate is integrated with an ejecting rod(50) and has a penetrating hole(22) formed in the center.

Description

Tunnel gate cutting device of injection mold {GATE CUTTING MACHINE OF INJECTION MOLD}

1 is a cross-sectional view showing an injection molding machine having a tunnel gate cutting device of the injection mold according to the present invention.

2A is a perspective view of the upper mill pin.

2b is a perspective view of the lower mill pin;
Figure 3a to 3b is a block diagram showing the operating state of the injection molding machine having a tunnel gate cutting device of the injection mold according to the present invention.

* Explanation of symbols for main parts of drawings *

10: upper plate 20: lower plate

30: upper mill pin 32: tunnel gate

34: helix 36: insertion groove

40: lower mill pin 44: spiral portion

50: ejecting rod 70: injection molding

The present invention relates to a tunnel gate cutting device of an injection mold, and more particularly, when the improvement is completed, the tunnel gate is cut and afterwards the molding and the cut tunnel gate are simultaneously taken out. The present invention relates to a tunnel gate cutting device of an injection mold that eliminates a process for cutting, thereby improving productivity and greatly reducing a product defect rate.

In general, the mold mold for injection molding the product is formed with one or more cavities for forming the appearance of the product, the runner and the gate for supplying the molten plastic resin to the cavity is installed, the tunnel gate is The molten resin formed in the lower portion of the cavity and injected into the runner through the sprue is supplied to the cavity through the tunnel gate formed in the lower portion of the cavity.

The molded article injection-molded by the mold mold using the tunnel gate is injected into the cavity through the tunnel gate and the runner, and then molded into a product shape according to the shape of the mold mold.

In addition, since the resin injected into the tunnel gate and the runner by the mil pin is taken out integrally with the molded article, the molded product is completed by completely cutting the resin injected into the tunnel gate to remove unnecessary parts.

However, in the related art, since a worker removes a molded product from the mold and the worker manually cuts the tunnel gate of the molded product, the production speed is lowered and causes a defect. A safety issue has occurred.

In addition, when the tunnel gate is not smoothly processed, there is a problem in that a defect such as burr or crack is generated in the product, thereby degrading the quality of the product.

An object of the present invention for solving the problems as described above is to cut the tunnel gate automatically after the improvement of the resin is completed so that the injection is ejected, the tunnel gate of the injection mold to reduce the defective rate of the injection and improve the productivity It is to provide a cutting device.

Features of the present invention for achieving the above object is installed spaced apart from each other during the lifting of the ejecting rod of the injection machine only the lower plate for a certain time and the lower plate is lifted by a certain distance, the upper plate is raised / lower The upper mill pin, which has a mill plate, and an upper end portion of which is cut axially at a position slightly away from the center of the shaft to form a tunnel gate, and a lower end portion is rotatably installed on the upper mill plate to be opened toward the bottom and has an insertion groove formed with a spiral on the inner circumferential surface thereof. The lower part is fixedly installed on the lower mill plate and the upper part is composed of a lower mill pin which is formed in the outer periphery and is inserted into the insertion groove of the upper mill pin to rotate the upper mill pin according to the lifting / lowering movement of the lower mill plate. At the time of lifting the upper plate, the tunnel gate is cut while the upper pin is rotated. It has a tunnel gate cut apparatus for taking out a molded product and cutting tunnel gate at the same time.

An embodiment of the present invention having the above characteristics will be described in more detail with reference to the accompanying drawings.

Figure 1 is a cross-sectional view showing an injection molding machine having a tunnel gate cutting device of the injection mold according to the present invention, Figure 2a is a perspective view of the upper mill pin, Figure 2b is a perspective view of the lower mill pin.

Tunnel gate cutting device of the injection mold according to the present invention, as shown in Fig. 1 to 2b, the upper and lower mill plates 10, 20 operated in two stages, and the lower end portion is rotatable to the upper mill plate 10 Insertion groove 36 having a spiral portion 34 formed on the bottom surface is provided, and the upper end portion is installed so as to penetrate through the movable shaft plate 63, the resin in the molten state injected into the runner (R) cavity (C) Upper mill pin 30 is provided with a tunnel gate 32 for communicating the cavity (C) and the runner (R) to supply to the lower, and the lower mill plate 20 to correspond to the insertion groove 36 of the upper mill plate (10) Fixed to the other end, and the other spiral portion 44 corresponding to the spiral portion 34 of the upper mill pin 30 is formed at the distal end so that the lower mill plate 20 rotates the upper mill pin 30 by screwing when the lower mill plate 20 is raised or lowered. It consists of a lower mill pin 40.
In the above configuration, the lower plate 20 is formed integrally with the ejecting rod 50, the through hole 22 is formed in the center, and the upper plate 10 is the through hole 22 of the lower plate 20 The guide rod 65, which is positioned to be spaced apart from the lower plate 20 by a supporting rod 62 penetrated by a predetermined distance, and is installed through the movable side template 63 of the injection molding machine, is integrally installed. On the outer circumference of the rod 65, a spring 66 is provided between the movable side template 63.

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In addition, the upper mil pin 30 is cut in the axial direction at a position slightly off the center of the shaft to form a tunnel gate 32, the lower end of the insertion groove 36 is formed with a spiral portion 34 on the inner peripheral surface Is formed is fixed to the insertion groove 36 is opened in the upper mill 10 to open toward the lower, the lower mill pin 40 is the lower mill pin is installed fixed to the lower mill 20 and the upper is the upper mill pin Another spiral portion 44 corresponding to the spiral portion 34 of the 30 is formed and inserted into the insertion groove 36 of the upper mill pin 30, according to the lifting / lowering motion of the lower mill plate 20. Rotate the upper mill pin 30 forward / reverse.
3a to 3b is a configuration diagram showing the operating state of the injection molding machine having a tunnel gate cutting device of the injection mold according to the present invention.

3A to 3B, when the weighing is completed first, as shown in FIG. 3A, the movable side template 63 is lowered together with the upper and lower tight plates 10 and 20 to open the injection mold, and then the ejecting rod 50 3 is elevated, the lower mill plate 20 is raised with the spiral parts 34 and 44 of the lower mill pin 40 and the upper mill pin 30 screwed together as shown in FIG. 3B, and the upper mill pin 30 rotates by 180 °. While cutting the tunnel gate 32 as shown in the enlarged view of FIG.
Subsequently, when the ejecting rod 50 is continuously raised and pushed up in the state where the lower plate 20 is interviewed with the upper plate 10, the upper mill pin 30 protrudes and is cut as shown in FIG. 3C. With the injection molding 70 is taken out.

Then, when the ejector is moved in the reverse order after the extraction process is finished, the upper mill plate 10 is restored to its original position by the tension of the spring 66 and the lower mill plate 20 is the original position by the ejecting rod 50 Is restored.

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On the other hand, the tunnel gate cutting device as described above is a tunnel gate is formed in both directions from the runner in general, although not shown, a plurality of upper and lower milpins may be formed in accordance with the number of tunnel gates.

Therefore, according to the present invention, since the tunnel gate is automatically cut during the injection molding operation, there is no need for a separate process for cutting the tunnel gate, and the quality of the tunnel gate cutting surface is excellent, so that the work for processing the tunnel gate cutting surface is performed. Since it is not necessary, productivity is greatly improved, and the defect rate of a product is reduced.

Claims (2)

In the tunnel gate cutting device of the injection mold, When the ejecting rod of the injection machine is lifted apart from each other, the upper and lower mills are lifted only by the lower plate for a predetermined time and the lower plate is lifted by a certain distance. An upper mill pin having a portion of the upper end cut in the axial direction at a position slightly away from the center of the shaft to form a tunnel gate, and the lower end being rotatably installed on the upper mill to be opened toward the lower side and having an insertion groove having a spiral formed on the inner circumferential surface thereof; The lower part is fixedly installed on the lower mill plate, and the upper portion is formed with another spiral portion on the outer periphery, and is inserted into the insertion groove of the upper mill pin so that the lower mill pin rotates the upper mill pin according to the lifting / lowering motion of the lower mill plate. Tunnel gate cutting device of injection mold. According to claim 1, wherein the lower plate is installed integrally with the ejecting rod and the through-hole is formed in the center, the upper plate is installed to be spaced apart from the lower plate by a support rod through the through hole of the lower plate and the injection machine The guide rod is integrally installed through the movable side template, and the tunnel gate cutting device of the injection mold, characterized in that a spring is installed between the movable side template and the outer circumference of the guide rod.

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