JPS595562Y2 - injection mold - Google Patents

Description

[Detailed explanation of the idea] This invention relates to an injection mold.

For example, a beer bottle container is provided with a grip part for holding the hand, but it is generally preferable that this grip part has a large roundness on the underside to make it easier to hold the container. It is said that

By the way, the conventional injection mold used to mold the above-mentioned container is shown in Fig. 1 and Fig. 2.
As shown in the figure, a cavity C is formed by closing the fixed mold 1, the male mold 2, and the split mold 3, and when the fixed mold 1 and the male mold 2 are opened, the split mold 3 is opened by the angular pin 4. configured to work.

Furthermore, the tip of a movable member 5 provided in the split mold 3 so as to be able to advance and retreat diagonally downward in a direction away from the side wall of the male mold 2 comes into contact with the side wall of the male mold 2, thereby forming a molded product. The lower side of the grip portion H is rounded.

When releasing a molded product such as a beer bottle container from such an injection mold,
The molded product is removed from the cavity C by separating the male mold 2 and the split mold 3 from the fixed mold 1.

That is, the male mold 2 is moved upward and the fixed mold 1 is
At the same time, the split mold 3 is moved away from the fixed mold 1 and the male mold 2.

At this time, the movable member 5 provided on the split mold 3 retreats obliquely downward in a direction away from the side wall of the male mold 2, and the molded product is damaged in the roundness of the lower side of the grip portion H. It is taken out in such a way that it does not last.

However, in the injection mold as described above, the movable member 5 for forming a roundness on the lower side of the gripping part H is configured to retreat diagonally downward. If it is desired to form a rounded shape in which the tangent line is higher than the forward and backward direction of the movable member 5, an undercut will occur, and as a result, the movable member 5 will cause a sagging phenomenon at the rounded portion of the gripping portion H. However, if this is forcibly removed, the rounded portion may be damaged.

This idea was made in view of the above circumstances, and the movable member that forms the undercut part of the downward facing surface, like the lower side of the grip of a beer bottle container, is spaced directly below the undercut part. The purpose of the present invention is to provide an injection molding die that can easily form a rounded portion of a desired size on the undercut portion.

Hereinafter, a first embodiment of this invention will be described in detail with reference to FIGS. 3 and 4.

In the figure, 10 is a fixed type, 11 is a male type, and 12 is a split type,
These are arranged so as to be openable and closable with each other to form a mold, and the lower surface of the male mold 11 is in contact with the upper surface of the fixed mold 10, and the lower surface and side surfaces of the split mold 12 are in contact with the upper surface of the fixed mold 10.
Cavities C1 and C2 are formed when abutting against the upper surface of the fixed mold 10 and the side surface of the male mold 11.

A cavity 13 having a rectangular cross section is formed in the split mold 12 from the lower part of the cavity C2 (that is, the cavity forming the gripping part H of the molded product).

A movable member 14 for forming a rounded portion on the lower side of the grip portion H is disposed within this gap portion 13.

This movable member 14 is configured to move up and down along a guide member 15 that is suspended from above the split mold 12 into the cavity 13, and also moves between the male mold 11 and the split mold 1.
2 is in close contact with the side wall of the male die 11 when the two are closed.

A cylindrical recess 16 is formed in the movable member 14, and a coil spring 17 is inserted into the recess 16 to constantly press the movable member 14 downward.

Further, the split mold 12 is provided with a return device 18 for returning the movable member 14 to its original state.

This return device 18 connects the gap 13 and the fixed mold 10.
A communication hole 19 is provided in the split mold 12 and communicates perpendicularly with the mold 12. One end surface of the rod 20 is placed in the communication hole 19 in contact with the upper surface of the fixed mold 10, and the other end surface is brought into contact with the lower surface of the movable member 14. The movable member 14 is pushed up against the coil spring 17 by the rod 20 .

Further, an insertion hole (not shown) is provided in the split mold 12, and an angular pin (not shown) fixed to the fixed mold 10 is inserted into the insertion hole. When the split mold 12 moves along the line, the side surface of the split mold 12 separates from the side surface of the male mold 11.

Further, a clearance is provided between the insertion hole of the split mold 12 and the angular pin, and this clearance allows the male mold 11 and the split mold 12 to and are integrally separated from the fixed mold 10 by a distance corresponding to the clearance.

Furthermore, the fixed mold 10 is provided with a push-up device 21 for pushing the split mold 12 upward.

This push-up device 21 has a push-up column 23 having a flange 22 inserted into a hole 24 formed in the fixed mold 10, and the push-up column 23 is inserted into the hole 24 so that the push-up column 23 is inserted into the fixed mold 10.
A spring 25 is arranged to project upward.

Therefore, when the male mold 11 and the split mold 12 integrally open from the fixed mold 10, the movable member 14
It is moved below the cavity C2 by the coil spring 17, and is pushed up by the rod 20 to form the cavity C2 when the molds 10, 11 and 12 are closed.

Incidentally, the split mold 12 and the male mold 11 are provided with inclined surfaces 11a and 12a for separating the upper surface of the split mold 12 and the upper inner surface of the male mold 11, and the inclined surfaces 11a , 12a restrict upward movement of the split mold 12.

Next, the operation of the injection mold constructed as described above will be explained.

First, as shown in FIG. 3, a cavity C1, which is formed by closing the fixed mold 10, the male mold 11, and the split mold 12,
The molding material is injected into C2 and solidified.

At this time, the movable member 14 is held between the fixed positions of the male die 11 and the split die 12 while being supported by the rod 20, thereby forming a downward undercut portion of the grip portion H.

Thereafter, when taking out the molded product from the cavities C1 and C2, the male mold 11 is first moved upward by a drive device (not shown) and separated from the fixed mold 10.

At this time, the split mold 12 is raised together with the male mold 11 by a distance corresponding to the clearance between the split mold 12 and the angular pin (not shown) by the push-up device 21, and the fixed mold 10
distance from.

When the split mold 12 rises in this manner, the movable member 14 is moved downward along the guide member 15 by the coil spring 17.

That is, it moves from the lower part of the grip part H of the molding surface directly below.

Then, when the male mold 11 is further moved upward, the split mold 12 is moved diagonally upward to the right along the angular pin, and as a result, the side surface of the male mold 11 and the side surface of the split mold 12 are 4 are spaced apart as shown in Figure 4.

At this time, since the inclined surface 12a of the split mold 12 is moved along the inclined surface 11a of the male mold 11, the upper surface of the split mold 12 and the inner surface of the male mold 11 are separated.

In addition, when closing the male mold 11 and the split mold 12 to the fixed mold 10, the operation opposite to the above may be performed.

In this case, the rod 20 moves upward with respect to the split mold 12, and the movable member 14 moves relatively upward within the split mold 12 against the coil spring 17, returning to the original position in FIG. Return to position.

Next, a second embodiment of this invention will be described based on FIGS. 5 and 6.

Note that the same parts in the figure as in FIGS. 3 and 4 are denoted by the same reference numerals, and the explanation thereof will be omitted.

This second embodiment differs from the first embodiment only in the return device, and the other features are exactly the same.

That is, the return device 30 of the second embodiment has the split mold 12
A communication hole 31 is provided in the split mold 12 and communicates obliquely with the cavity 13 formed in the upper surface of the fixed mold 10 and the inclined part 10a formed protrudingly on the upper surface of the fixed mold 10. A rod-shaped return member 32 that returns the
is inserted, and one end of the return member 32 is in contact with the lower surface of the movable member 14, and the other end is in contact with the lower surface of the fixed mold 1.
Further, a coil spring 33 is attached to the return member 32, and the coil spring 33 always pushes the return member 32 diagonally downward. .

In addition, numeral 34 in the figure is a stopper member for locking the return member 32 so that it does not come out from the communication hole 31 of the split mold 12.

The operation of the recovery device 30 for the injection mold that has been stolen in this way will be explained.

First, when the male die 11 is moved upward as in the first embodiment, the split die 12 is also moved upward and the fixed die 10 is moved upward.
distance from.

When the split mold 12 moves upward in this way, the return member 32
is pushed out from inside the split mold 12 by the coil spring 33, and the lower end of the return member 32 is pushed out from the inclined part 10 of the fixed mold 10.
The return member 32 is moved together with the split mold 12 along the line a.

As a result, the movable member 14 in the cavity 13 becomes the coil spring 17.
is moved below the cavity C2 similarly to the first embodiment.

Further, when each of the molds 10, 11, 12 is closed, the return member 32 performs an operation opposite to that described above, and the movable member 14
is pushed up to form the cavity C2.

As explained above, according to the injection mold according to the invention, the movable member that molds the undercut portion of the downward facing surface, such as the lower side of the grip of a beer bottle container, can be Since it is configured to be spaced directly below the undercut portion, a rounded portion of a desired size can be easily formed in the undercut portion.

[Brief explanation of drawings]

Fig. 1 is a sectional view of the main part of a conventional injection mold, Fig. 2 is a sectional view showing the mold in an open state, and Fig. 3 is a sectional view of the main part showing the first embodiment of this invention. Fig. 4 is a sectional view showing the mold in an open state, Fig. 5 is a sectional view of main parts showing a second embodiment of this invention, and Fig. 6 is a sectional view showing the mold in an open state. be. 10...Fixed type, 11...Male type, 12
...Split mold, 14...Movable member, 17.
...Coil spring, 1B, 30...Return device.

Claims (1)

[Scope of utility model registration request] Between a fixed mold, a male mold that is located above the fixed mold and opens the mold upward, and a split mold that is located above the fixed mold and tilts away from the male mold and opens the mold upward. , a downward undercut of the molded article by means of a movable member that forms a cavity into which the molding material is injected and that is provided in the male mold and the mold part so as to be sandwiched between fixed positions in each of the mold parts; In an injection mold for molding a part, a movable member is provided at a fixed position of the split mold so as to be movable directly downward from the fixed position, and the split mold is provided with a lower part of the movable member and an upper part of the fixed mold. A rod interposed therebetween is movable up and down, and the length of the rod is set to a length between the lower part of the movable member and the upper part of the fixed mold at the fixed position of the split mold. A mold for injection molding.