JPH0939034A - Injection molding die - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an injection molding die wherein the die can be easily manufactured at low cost even when a mouth stopper equipped with a complicatedly shaped tension ring is injection molded. SOLUTION: An injecting cylinder is disposed in upright to a base seat plate, and a part to be cut off around which a thin film fragil wire is provided, is provided to the base seat plate inside the injecting cylinder. In an injection molding die for molding a mouth stopper to which a support provided with a tension ring is disposed in upright to a part on the part to be cut off, a core die forming the inside of the injection cylinder is composed of a core die 101 forming an inside of the tension ring, and a core die 102 forming the inside of the injection cylinder from outside the tension ring. A recess part forming the tension ring is provided on a peripheral surface of the core die 101 forming the inside of the tension ring.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to injection of a stopper with a pulling ring for pulling and opening a pulling ring used for a container for foods such as fruit juices, sake, mirin and non-foods such as shampoo and textile softener. The present invention relates to a molding die, and more particularly, to a die structure that can be easily manufactured and can be manufactured at low cost.

[0002]

2. Description of the Related Art Conventionally, as shown in FIG. 5, a pouring tube 3 is erected on a pedestal plate 2, and a pedestal plate 2 inside the pouring tube 3 is provided with a thin film fragile wire 4 around the cutout portion. 5, a plug 1 with a pulling ring in which a strut 6 to which a pulling ring 7 is attached is erected in a part of the cutout 5 is used in a wide range of applications as a spout for food and non-food containers. There is.

In an injection molding die for molding the stopper 1 with a pull ring, as shown in FIG.
The core mold that forms the inside of the dispensing cylinder 3 is composed of a core mold 101 that forms the inside of the pulling ring and a core mold 102 that forms the inside of the dispensing cylinder from the outside of the pulling ring. When opening the mold after molding, 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 tube was opened from the outside of the pull ring. 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 core mold 1 in which the recess forming the pulling ring 7 forms the inside of the pouring tube from the outside of the pulling ring described above.
02 is provided on the inner peripheral surface, and when the core mold 102 is opened, the outside of the pull ring 7 undercuts (hangs in the opening and closing direction of the mold) with respect to the core mold 102. Is pulled in the opening direction of the core mold 102, and the pillar 6 connected to the pull ring 7 and the cutout portion 5 are also pulled together,
A ring-shaped thin film weakening line 4 provided on the periphery of the cutout portion 5 may be subjected to a force to generate a pinhole in the thin film weakening line 4, and in some cases, the thin film weakening line 4 may be cut. there were.

As shown in FIG. 7, the pulling ring 7 has a structure in which the upper portion of the column 6 is cut into a V-shape 8 for the reason that the pulling ring 7 is easy to grip. With such a structure, as shown in FIG. 8, the inner peripheral surface of the core mold 102, which forms the inside of the spout cylinder from the outside of the pull ring, has a complicated shape (particularly the periphery of the V-shaped cut). Need to give. The core mold 102
Is formed in a comparatively thin tubular shape, and therefore it is very complicated and difficult to process such a thin tubular inner peripheral surface into a complicated shape. Therefore, there is a problem that the cost of the mold becomes very expensive.

The present invention has been made in view of the above-mentioned conventional problems, and an object of the present invention is to easily manufacture a mold even when injection-molding a spout having a pull ring having a complicated shape. It is to provide an injection molding die that can be manufactured at low cost.

[0007]

In order to achieve the above object, in the injection molding die of the present invention, a pouring tube is erected on a base plate, and a thin film is formed on the base plate inside the pouring cylinder. Provide a cutout portion around which the line of weakness is provided, and in a part on the cutout portion, in an injection molding die for forming a stopper in which a strut provided with a pull ring is erected, The core mold to be formed is composed of a core mold that forms the inside of the pulling ring and a core mold that forms the inside of the dispensing tube from the outside of the pulling ring, and the pulling ring is provided on the peripheral surface of the core mold that forms the inside of the pulling ring. It is characterized in that a concave portion to be formed is provided.

[0008]

According to the injection molding die of the present invention, a recess is formed in the outer peripheral surface of the cylindrical core die by providing a recess for forming the pull ring on the peripheral surface of the core die forming the inner side of the pull ring. Since it is only necessary to perform processing for, it is possible to easily process even a complicated shape when forming a tension ring provided with a V cut, and it is easy to manufacture a mold,
The cost can be reduced.

According to the injection molding die of the present invention,
At the time of opening the mold after molding, first, when the core mold forming the inside of the tension ring is opened, 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 tube from the outside of the pulling ring opens, the pulling ring does not get caught in that direction and the pulling 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 an embodiment of the present invention, and FIG. 2 is an illustration showing the movement of a plate by a suspension pin of the injection molding die in the embodiment. FIG. 3 is a cross-sectional view showing the structure of a core mold forming the inside of the pouring cylinder in the embodiment, and FIG. 4 is a perspective view showing the structure of the core mold forming the inside of the pulling ring in the embodiment.

First, the overall structure of the injection molding die of this embodiment will be described.

As shown in FIG. 1, the injection molding die 1 is used.
00 is divided into a fixed plate side mold 110 and a movable plate side mold 120 from the mold dividing surface A, and the fixed plate side mold 110 includes a fixed side mounting plate 111 and several plates 112, 113, 11
4 in which a sprue 11, a runner 12, a gate 13 and the like are internally provided. On the other hand, movable plate side mold 1
20 is a movable side mounting plate 121 and several plates 122 to
And the core molds 101, 102 and the cavity molds 103, 10 fixed to a predetermined plate.
4 are stored. In addition, the mounting plate and each plate are respectively a predetermined plate and a coupling pin (which is coupled at a constant interval), a suspension pin (which is coupled from a predetermined spacing position), and a ring (which is coupled from a predetermined spacing position).
Are linked or linked by. 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 the plug.

More specifically, the fixed plate-side mold 110 includes a sprue 11, a runner 12, and a gate 13.
Such as plate 114, plate 113,
The movable plate side mold 120 is composed of a plate 112 and a fixed side mounting plate 111, and the movable plate side mold 120 has plates 126, 125, 123, 122 in which a core mold 101, a core mold 102, cavity molds 103, 104, etc. are installed. , 124
And the movable side mounting plate 121, and the movable side mounting plate 121 and the plate 122 of the movable plate side mold are
The plate 122 and the plate 123 are joined by a joining pin (not shown), and are connected by the hanging pin 21.
4 and the plate 125 are joined by the joining pin 22, the plate 125 and the plate 126 are joined by the hanging pin 23, the plate 126 and the plate 114 are joined by a ring (not shown), and the plate 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 attached to the plate 125.
03, and the cavity mold 104 is attached to the plate 126. The core mold 101
As described above, is a core mold that forms the inside of the pulling ring, and the core mold 102 is a core mold that forms the inside of the dispensing tube from the outside of the pulling ring.

Conventionally, as described above, the recess for forming the pulling ring is provided on the inner peripheral surface of the core mold 102, but the characteristic configuration of the present invention is such a recess 10.
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 pulling ring on the outer surface of the cylindrical core die 101. Therefore, for example, a pulling ring provided with a V cut as shown in FIG. 7 is used. Even if it is a complicated shape such as when molding, the processing of the mold becomes very easy. In addition, in this embodiment, when the core die 101 is opened after molding, the tension ring thus formed is prevented from being pulled in the opening direction of the core die 101 as shown in FIG.
Although the shape of the concave portion 101a is as shown in FIG.
Of course, the shape of 01a is not limited to this.

1 and 2 will be used to explain the operation of the mold opening of the mold on the movable plate side after molding after molding the stopper plug with a pull ring using the mold for injection molding constructed as described above. First, when the movable side mounting plate 121 moves, the plate 122 coupled with the movable side mounting plate simultaneously moves, and the core mold 101 mounted on this plate moves and opens. Further, when the plate 122 moves to a predetermined position, the a-face of the hanging pin 21 contacts the b-face 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 that moves together with the plate 123 comes into contact with the f surface of the plate 124, the plate 124 moves, and the plate 125 joined to this plate also moves. The cavity mold 103 attached to the plate moves and opens. Next, when the plate 125 moves to a predetermined position, the c-plane of the hanging pin 23 contacts the d-plane of the plate 126, the plate 126 moves, and the cavity mold 104 attached to this plate moves and opens. Furthermore, plate 1
When 26 is moved to a predetermined position, the plate (114) of the fixed plate side mold is moved in the mold direction on the movable plate side by a ring (not shown), and the molded stopper with a pull ring is released from the mold.

The injection molding die of this example was in a good molding state, and no problems such as pinholes were found in the thin film brittle wire of the molded plug.

[0019]

As described in detail above, according to the injection molding die of the present invention, by providing a concave portion for forming a pulling ring on the peripheral surface of the core die forming the inside of the pulling ring, a cylindrical shape can be obtained. Since it suffices to perform a process for forming a concave portion on the outer peripheral surface of the core mold, the process can be easily performed even if the pull ring having the V cut is formed, and the mold can be manufactured. It has an excellent effect that it is easy and the cost is low.

According to the injection molding die of the present invention,
At the time of opening the mold after molding, first, when the core mold forming the inside of the tension ring is opened, 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 spout tube 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. There is no such a case, and the excellent effect of preventing the generation of pinholes is achieved.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing an overall structure of an injection molding die according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram showing movement of a plate by means of a hanging pin of the injection molding die in the above embodiment.

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

FIG. 4 is a perspective view showing the structure of a core type forming the inside of the pulling ring in the above 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 molding die.

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

FIG. 8 is a perspective view showing a structure of a core type in which the inside of a dispensing cylinder is formed from the outside of a conventional pulling ring.

[Explanation of symbols] 1 mouth plug 2 pedestal plate 3 spouting cylinder 4 thin film weak wire 5 cutout portion 6 strut 7 pull ring 8 V cut 11 sprue 12 runner 13 gate 14 cavity 21, 23 hanging pin 22 joining pin 100 injection molding type 101, 102 core type 101a concave part 103, 104 cavity type 110 fixed plate side mold 111 fixed side mounting plate 112, 113, 114 plate 120 movable plate side mold 121 movable side mounting plate 122, 123, 124, 125, 126 plate

Claims (1)

[Claims] 1. A pedestal plate is provided with a pouring tube upright, and a pedestal plate inside the pouring tube is provided with a cutout portion around which a thin film weakening line is provided, and a pulling ring is provided on a part of the cutout portion. In an injection-molding die for molding a spout in which an attached strut is erected, a core die that forms the inside of the pouring cylinder,
It consists of a core type that forms the inside of the pulling ring and a core type that forms the inside of the dispensing tube from the outside of the pulling ring.
An injection-molding die, characterized in that a recess for forming a pull ring is provided on a peripheral surface of a core die forming the inside of the pull ring.