JP3346684B2 - Injection mold - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the injection of a stopper with a pull ring which is opened by pulling a pull ring used for a container of food such as fruit juice drink, sake, mirin, etc., or a non-food such as shampoo and fabric softener. The present invention relates to a molding die, and more particularly, to a die structure that can be easily manufactured at a low cost.

[0002]

2. Description of the Related Art Conventionally, as shown in FIG. 5, a pouring cylinder 3 is erected on a pedestal plate 2, and a cutout portion around which a thin film weak wire 4 is provided is provided on the pedestal plate 2 inside the pouring cylinder 3. 5 is provided, and a stopper 1 with a pull ring provided with a support 6 on which a pull ring 7 is attached at a part of the cutout 5 is used for a wide range of use as a spout for food and non-food containers. I have.

[0003] In an injection molding die for molding the plug 1 with a pull ring, as shown in FIG.
The core mold that forms the inside of the pouring cylinder 3 includes a core mold 101 that forms the inside of the pulling ring and a core mold 102 that forms the inside of the pouring cylinder from the outside of the pulling ring. First, the core mold 101 forming the inside of the pull ring was opened, and then the core mold 102 forming the inside of the pouring cylinder from the outside of the pull ring was opened. In the figure,
103 and 104 are cavity molds that form the outside of the pouring tube 3.

[0004]

However, in the conventional mold, the recess forming the tension ring 7 has a core mold 1 in which the inside of the injection cylinder is formed from the outside of the tension ring.
When the core mold 102 is opened, the outside of the tension ring 7 is undercut (trapped in the opening and closing direction of the mold) with respect to the core mold 102 when the core mold 102 is opened. Is pulled in the direction in which the core mold 102 opens, and the support 6 connected to the pull ring 7 and the cutout 5 are also pulled together,
When a force is applied to the ring-shaped thin film weak line 4 provided on the periphery of the cutout portion 5, a pinhole may be generated in the thin film weak line 4, and the thin film weak line 4 may be cut off in some cases. there were.

As shown in FIG. 7, the above-mentioned pulling ring 7 has a structure in which the upper part of the column 6 is cut into a V-shape 8 because the pulling ring 7 is easy to grasp. With such a structure, as shown in FIG. 8, the inner peripheral surface of the core mold 102 that forms the inside of the pouring cylinder from the outside of the pull ring has a complicated shape (particularly, the processing around the V-shaped cut). Need to be applied. The core mold 102
Is formed in a relatively thin cylindrical shape, and it is extremely complicated and difficult to apply a complicated shape to the inner circumferential surface of such a thin cylindrical shape. Therefore, there is a problem that the cost of the mold becomes very expensive.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional problems, and an object of the present invention is to make it easy to manufacture a mold even when a plug having a complicated shape of a pull ring is injection-molded. An object of the present invention is to provide an injection molding die that can be manufactured at low cost.

[0007]

To achieve the above object, according to the Invention The injection molding die of the present invention, erected the dispensing tube 3 to the base plate 2, inside the base plate of the pouring cylinder 3 2. Thin film fragile wire
4 provided cutouts 5 is peripherally provided, a portion on the cut portion 5, in the injection molding die for molding the spout 1 to column 6 erected tensile ring 7 is attached from the molten resin, The core type forming the inside of the pouring cylinder 3 is
A core mold 101 forming the inside of the pull ring, and a core mold 1 forming the inside of the pouring tube 3 from the outside of the pull ring 7
It made 02 Prefecture, to form a ring 7 pulling the peripheral surface of the core mold 101 to form the pull ring 7 inside the recess
101a is provided.

[0008]

According to the injection molding die of the present invention, a concave portion for forming a pull ring is provided on the peripheral surface of the core die forming the inside of the pull ring, and a concave portion is provided on the outer peripheral surface of the cylindrical core die. Processing can be easily performed even in the case of a complicated shape in the case of forming a pull ring provided with a V-cut, and a mold can be easily manufactured.
Cost can be reduced.

According to the injection mold of the present invention,
At the time of opening the mold after molding, when the core mold forming the inside of the tension ring first opens, the molded tension ring is not pulled in the opening direction of the core mold, and then,
When the core mold that forms the inside of the dispensing cylinder from the outside of the pull ring opens, the pull ring does not get caught in that direction and the pull ring is not pulled. Can be prevented.

[0010]

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings.

FIG. 1 is an explanatory view showing the overall structure of an injection molding die according to one embodiment of the present invention, and FIG. 2 is an explanatory view showing the movement of a plate by a hanging pin of the injection molding die in the embodiment. FIG. 3 is a cross-sectional view showing a core type structure forming the inside of the pouring cylinder in the embodiment. FIG. 4 is a perspective view showing a core type structure forming the inside of the pull ring in the embodiment.

First, the overall configuration of the injection mold according to this embodiment will be described.

As shown in FIG. 1, the injection molding die 1
00 is divided into a fixed platen-side mold 110 and a movable platen-side mold 120 from the mold division surface A. The fixed platen-side mold 110 is composed of a fixed-side mounting plate 111 and several plates 112, 113, 11.
4 and a sprue 11, a runner 12, a gate 13 and the like are provided therein. On the other hand, movable platen side mold 1
20 is a movable side mounting plate 121 and several plates 122 to
126, which are fixed to a predetermined plate and fixed to the core dies 101 and 102 and the cavity dies 103 and
4 are stored. Also, the mounting plate and each plate are respectively connected to a predetermined plate with a connecting pin (to be connected at a predetermined interval), a suspension pin (to be connected from a predetermined interval), and a ring (to be connected from a predetermined interval).
Are connected or linked by, for example, The molten resin injected from the injection nozzle of the injection molding machine passes through the sprue 11 and the runner 12 in the mold and is injected into the cavity 14 from the gate 13 to form a plug.

More specifically, the fixed platen side mold 110 includes a sprue 11, a runner 12 and a gate 13.
Plate 114, plate 113, and the like internally provided
The movable platen-side mold 120 is composed of a plate 112 and a fixed-side mounting plate 111, and the movable platen-side mold 120 has plates 126, 125, 123, 122 in which the core mold 101, the core mold 102, the cavity molds 103, 104 and the like are provided. , 124
And the movable side mounting plate 121, and further, the movable side mounting plate 121 and the plate 122 of the movable platen side mold are
The plate 122 and the plate 123 are connected by a suspension pin 21 and connected by a connecting pin (not shown).
4 and the plate 125 are joined by the joining pin 22, the plate 125 and the plate 126 are connected by the hanging pin 23, the plate 126 and the plate 114 are connected by a ring (not shown), and The core mold 101 is attached to 122, and the core mold 10 is attached to the plate 123.
2 is attached, and the cavity mold 1 is
03 is attached, and the cavity mold 104 is attached to the plate 126. The core die 101
Is a core type forming the inside of the tension ring as described above, and the core type 102 is a core type forming the inside of the pouring cylinder from the outside of the tension ring.

Conventionally, as described above, a concave portion for forming a pull ring is provided on the inner peripheral surface of the core mold 102, but the characteristic configuration of the present invention is such a concave portion.
1a is provided on the outer peripheral surface of the core mold 101 (see FIGS. 3 and 4). By doing so, it is only necessary to process the concave portion for forming the pull ring on the outer surface of the cylindrical core mold 101. For example, a pull ring provided with a V-cut as shown in FIG. The processing of the mold becomes very easy even for a complicated shape as in the case of molding. Further, in the present embodiment, when the core mold 101 is opened after the molding, the molded tension ring is prevented from being pulled in the opening direction of the core mold 101 as shown in FIG.
The shape of the recess 101a shown in FIG.
Of course, the shape of 01a is not limited to this.

The operation of opening the mold on the movable platen side after molding by molding a plug with a pull ring using the injection mold thus configured will be described with reference to FIGS. 1 and 2. First, when the movable-side mounting plate 121 moves, the plate 122 connected to the movable-side mounting plate also moves at the same time, and the core mold 101 attached to this plate moves and opens. Further, when the plate 122 moves to a predetermined position, the surface a of the hanging pin 21 comes into contact with the surface b of the plate 123, the plate 123 moves, and the core mold 102 attached to this plate moves and opens.

Further, the e surface of the plate 122 which moves together with the plate 123 abuts on the f surface of the plate 124, the plate 124 moves, and further, the plate 125 joined to this plate moves. The cavity mold 103 attached to the plate moves and opens. Next, when the plate 125 moves to a predetermined position, the c surface of the suspension pin 23 comes into contact with the d surface of the plate 126, the plate 126 moves, and the cavity mold 104 attached to this plate moves and opens. In addition, plate 1
When the plate 26 moves to a predetermined position, the plate 114 of the fixed platen-side mold moves in the mold direction on the movable platen side by a ring (not shown), and the formed plug with a pull ring is released.

The state of molding using the injection mold of the present embodiment was good, and no problem such as generation of pinholes was observed in the thin film brittle line of the molded plug.

[0019]

As described above in detail, according to the injection molding die of the present invention, the cylindrical shape is formed by providing the concave portion for forming the tension ring on the peripheral surface of the core mold forming the inside of the tension ring. Since it is only necessary to perform processing for providing a concave portion on the outer peripheral surface of the core mold, even if it is a complicated shape when forming a pull ring provided with a V cut, the processing can be easily performed, and the production of a mold can be performed. It has an excellent effect that it is easy and the cost can be reduced.

According to the injection molding die of the present invention,
At the time of opening the mold after molding, when the core mold forming the inside of the tension ring first opens, the molded tension ring is not pulled in the opening direction of the core mold, and then,
When the core mold that forms the inside of the pouring cylinder opens from the outside of the pull ring, the pull ring does not catch in that direction and the pull ring does not pull. Instead, an excellent effect of preventing generation of pinholes is achieved.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing the overall structure of an injection mold according to one embodiment of the present invention.

FIG. 2 is an explanatory view showing movement of a plate by a hanging pin of an injection mold in the embodiment.

FIG. 3 is a cross-sectional view showing a core-type structure forming the inside of a pouring cylinder in the embodiment.

FIG. 4 is a perspective view showing a core type structure forming the inside of a tension ring in the embodiment.

FIG. 5 is a cross-sectional view showing a structure of a plug with a pull ring.

FIG. 6 is an explanatory view showing a structure of a main part of a conventional injection mold.

FIG. 7 is a cross-sectional view of a pull ring having a V-cut structure.

FIG. 8 is a perspective view showing a conventional core-type structure that forms the inside of an ejection tube from the outside of a pull ring.

[Explanation of symbols]

 DESCRIPTION OF REFERENCE NUMERALS 1 spout 2 pedestal plate 3 pouring cylinder 4 thin film weak line 5 cutout portion 6 support column 7 pull ring 8 V cut 11 sprue 12 runner 13 gate 14 cavity 21, 23 suspending pin 22 joining pin 100 injection molding die 101, 102 core type 101a Recess 103, 104 Cavity mold 110 Fixed plate side mold 111 Fixed side mounting plate 112, 113, 114 plate 120 Movable plate side die 121 Movable side mounting plate 122, 123, 124, 125, 126 plate

Continuation of front page (56) References JP-A-63-128919 (JP, A) JP-A-2-242754 (JP, A) JP-A-8-164541 (JP, A) JP-A-6-218762 (JP) , A) Japanese Patent Publication No. 35-2690 (JP, B1) Japanese Utility Model Publication No. 2-13140 (JP, Y2) Japanese Utility Model Publication No. 472781 (JP, Y1) (58) Fields surveyed (Int. Cl. ⁷ , DB Name) B29C 45/26 B65D 47/36

Claims (1)

(57) [Claims] 1. A standing the dispensing tube 3 to the base plate 2, to the pouring cylinder base plate 2 inside the 3, the cut portion 5 of the thin film line of weakness 4 is circumferentially provided, the cutouts 5 above Melt the plug 1 on which a column 6 with a pull ring 7 is attached upright
In the injection molding die for molding a resin, the core mold for forming the inner side of the pouring cylinder 3, the core mold 101 to form a ring inner tension, pulling the inner pouring cylinder 3 from the ring 7 outside Consisting of a core mold 102 to be formed,
The pull ring 7 injection mold, characterized in that a recess 101a to form a ring 7 pulling the peripheral surface of the core mold 101 to form the inner.