JPH0313965B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a bottle cap that fits onto a bottle mouth and a mold for forming the bottle cap.

BACKGROUND ART Conventionally, bottle caps as shown in FIG. 1 have been widely used, and such bottle caps are manufactured using a mold as shown in the same figure. To explain this bottle lid, a is an outer cylinder, b is an inner cylinder, c is a mouth wall, d is an endless groove formed in the mouth wall, and e is a pouring barrel. f is a tension ring, and by pulling this ring f, the tearing groove d is torn, a through hole is formed in the mouth wall c, and the content liquid is poured out from the bottle mouth (not shown).

Next, the bottle cap is formed using a mold as shown in the figure. In the figure, h is a protruding mold forming one side of the mouth wall c, i is a pin, j is an outer cylinder inner mold,
k and k' are the outer molds of the outer cylinder, l is the outer mold of the pouring tube that forms the pouring tube e, m is the inner mold thereof, and n is the mouth wall mold that forms the other surface of the mouth wall. The molten synthetic resin passes through the passage p of the mouth wall type n, enters the bottle cap forming space from the gate q of the passage P, and is molded.

Next, when taking out the product, the molds are removed in this order: the mouth wall mold n, the inner mold m, the outer mold l, and the outer cylinder k', and the protruding mold h and the outer cylinder inner mold j are integrated. and finally the protruding mold h and pin i.
protrudes and the bottle cap separates from the mold. However, at this time, pinholes often occur in the tearing groove d of the bottle cap, which hinders mass production.

This invention was made to solve such problems, and to describe the structure of the bottle lid of this invention with reference to drawings showing embodiments, in Figs. 3 to 10, an outer cylinder 1 made of synthetic resin is shown. An inner cylinder 2 is provided concentrically with an annular wall 3, and a mouth wall 4 is provided in the inner cylinder 2.
and forming an endless fissure groove 5 in the mouth wall 4,
As a result, in the bottle lid in which the tearing wall 5a is formed inside the tearing groove 5, the remaining wall 5b is formed on the outside, and the tearing member 5c is provided on the upper part of the tearing wall 5a. This bottle lid is characterized in that a remaining wall 5b of the mouth wall 4 is provided with a portion 6 for preventing deformation of the remaining wall against the pressing of the mouth wall 4 during the formation of the bottle lid.

The deformation prevention portion 6 may be a plurality of protrusions provided on the outside of the tear groove 5 within the mouth wall 4 as shown in FIG. The end may be formed at a substantially right angle, or may be formed at an angle as shown in FIG. 5, or may be formed along the cleavage groove 5 as shown in FIG. Alternatively, it may be formed in a concave shape as shown in FIGS. 8 and 9. Alternatively, as shown in FIG. 10, both a concave portion and a protrusion may be formed.

By forming in this manner, pinholes are not generated in the tearing grooves 5 during mold release.

The reason for this is probably that the surface area increases due to the formation of protrusions or recesses, and the force applied to the mouth wall 4 that is pressed by the protrusion is dispersed so that it is not applied to the fissure groove 5. This is probably because the presence of protrusions or recesses makes them less likely to deform than those in the form of a flat plate, compared to those in which no protrusions or recesses are formed.

Next, the structure of the mold for forming the bottle lid is shown in FIG. 2, which shows a protruding mold 8 forming one side of the mouth wall 4 of the bottle lid, which has a mouth wall 4 that blocks the flow of liquid.
and an outer cylindrical inner mold 9 provided on the outside of the protruding mold 8,
an outer cylinder outer mold 10, 10' forming an outer cylinder of the bottle lid;
An outer mold 11 and an inner mold 12 that form the spout of the bottle lid and form a tearing member 5c together with the mouth wall mold 13 described later, and a mouth wall mold 13 that forms the other surface of the mouth wall.
In the bottle cap forming mold, the ejecting die 8 is provided with a groove forming part 8a that forms an endless fissure groove in the mouth wall, and the outer side of the groove forming part 8a of the ejecting die 8 is provided. The mold for forming a bottle cap is characterized in that a forming part 14 of a remaining wall deformation prevention part is provided to prevent the remaining wall 5b from deforming.

Note that 16 in the figure indicates a pin.

The molten synthetic resin is injected into the bottle lid forming space from the passage 17 of the mouth wall mold 13 through a passage (not shown), and is solidified.

When removing a product from this mold, the mold is removed in the same order as the conventional mold. That is, oral wall type 1
3. Inner cylinder mold 12, outer mold 11, outer cylinder outer mold 10'
After removing the outer mold 10', the ejecting mold 8 and the outer cylindrical inner mold 9 are ejected for a certain length.
The bottle lid is removed from the outer cylinder outer mold 10, and then placed in the protruding mold 8.
It is pushed out and taken out.

In this case, the groove forming portion 8 of the extrusion mold 8
By providing a forming portion 14 of a remaining wall deformation prevention portion for preventing deformation of the remaining wall 5b on the outside of the bottle cap, the mouth wall 4 can be prevented from being deformed while the remaining wall 5b of the formed bottle cap is prevented from being deformed. The residual wall 5b can be pressed and protruded, and therefore, the deformation that affects the fissure groove 5 remains very small, so it is possible to prevent pinholes from forming in the fissure groove 5. . Furthermore, when the bottle lid formed by the mold is first opened, when the tearing member 5c is pulled upward, a deformation preventing portion 6 is formed on the remaining wall 5b, and the tearing wall 5a is Since the deformation prevention part 6 is not formed, the remaining wall 5b is prevented from deforming the tearing member 5c.
Since the deformation is extremely small, the stress of tearing is not dispersed over the entire mouth wall 4 but is concentrated in the tearing groove 5, so that tearing occurs immediately and easily, making it easy to tear.

[Brief explanation of the drawing]

Fig. 1 is a sectional view of a conventional bottle cap and a mold for forming a bottle cap, Fig. 2 is a sectional view of a bottle cap and a mold for forming a bottle cap, and Fig. 3 is a sectional view of an embodiment of the present invention. 4 is an enlarged partial view of the essential parts of the bottle cap of FIG. 3, FIG. 5 is a half-sectional view of the bottle cap of another embodiment of the present invention, and FIG. The fourth part of the bottle cap shown in Figure 5
7 is a diagram corresponding to FIG. 4 showing still another embodiment, FIG. 8 is a diagram corresponding to FIG. 5 showing still another embodiment, and FIG. 9 is a diagram corresponding to still another embodiment. FIG. 10 is a diagram corresponding to FIG. 5 showing another embodiment, FIG. 11 is a diagram corresponding to FIG. 5 showing still another embodiment. It is. 1... Outer cylinder, 2... Inner cylinder, 3... Annular wall, 4...
...mouth wall, 5... tear groove, 6... deformation prevention part, 8...
...Extrusion type, 9...Outer cylinder inner type, 10,10'...
. . . Outer tube outer mold, 11 .

Claims (1)

[Scope of Claims] 1. An outer cylinder 1 and an inner cylinder 2 made of synthetic resin are provided concentrically by an annular wall 3, a mouth wall 4 is provided in the inner cylinder 2, and an endless tear is provided in the mouth wall 4. A groove 5 is formed, thereby forming a split wall 5a on the inside of the split groove 5, and a remaining wall 5b on the outside.
The bottle lid is provided with a tearing member 5c on the upper part of the bottle cap, and is characterized in that the remaining wall 5b of the mouth wall 4 is provided with a remaining wall deformation preventing portion 6 against the pressing of the mouth wall 4 during the formation of the bottle cap. A bottle lid. 2. A protruding mold 8 forming one surface of the mouth wall 4 of a bottle lid having a mouth wall 4 that blocks the flow of liquid;
An outer cylinder inner mold 9 provided on the outside of the protruding mold 8, an outer cylinder outer mold 10, 10' that forms the outer cylinder of the bottle lid, and a mouth wall mold 13 that forms the barrel of the bottle lid and will be described later. In the mold for forming a bottle cap, which includes an outer mold 11 and an inner mold 12, which together form the tearing member 5c, and a mouth wall mold 13, which forms the other surface of the mouth wall, the ejecting mold 8 has the A groove forming part 8a forming an endless cleavage groove is provided on the mouth wall, and a remaining wall deformation preventing part is formed on the outside of the groove forming part 8a of the extrusion mold 8 to prevent deformation of the remaining wall 5b. A mold for forming a bottle lid, characterized in that a part 14 is provided.