JPS5816842Y2 - Undercut processing equipment for container molding molds - Google Patents

Description

[Detailed description of the invention] This invention has at least two protruding pieces that protrude outward from the side wall of the container, and the minus protruding piece is a bent part or folded part that makes a certain angle with the protruding direction. The present invention relates to a rotary undercut processing apparatus for injection molding a container having a structure in which a sliding piece is attached to a movable mold.

The purpose of this invention is to provide an undercut treatment device that can easily handle undercuts caused by bent or folded portions using a rotatable undercut forming piece with a compact structure.

The next object of this invention is to provide an undercut treatment device which is configured to reliably attach a molded container to a movable mold, open the mold, and treat the undercut.

A container having at least two projecting pieces projecting outward from the side wall of the container can be molded with a container molding mold having a slide piece that moves in a direction substantially perpendicular to the moving direction of the movable mold. be.

The lever has at least two protruding pieces that protrude outward from the side wall of the container, and the - protruding piece forms a certain angle with the direction of the protrusion (that is, the direction of movement of the slide piece). A container having a folded portion cannot be molded using a container mold having a slide piece described above.

Therefore, the container having the bent portion or folded portion is molded using a container mold having an undercut molding piece for treating the undercut of the bent portion or folded portion.

However, conventionally, the undercut (Ji) type piece is moved in a linear motion and by means of a slope, a dovetail groove, a guide pin, or a combination thereof so as to cause displacement in two axial directions.

However, in order to cause the undercut forming piece to move linearly and to cause displacement in two axial directions, it is necessary to secure enough space for such movement, and as a result,
Various constraints are often imposed on the shape of the molded product or the structure of the mold.

Further, since the undercut molding piece must naturally be moved by a large movement stroke, there is a drawback that, in addition to the above-mentioned restrictions, the mold structure becomes large and complicated.

Furthermore, undercut molding pieces are usually constructed and assembled so that they move in close relationship with the movement of the movable mold or slide piece, which makes the configuration complicated, the assembly troublesome, and the assembly precision reduced. It's hard to get out.

Furthermore, due to the complexity in which the undercut molding piece moves to follow the movement of the movable mold or the slide piece, it is difficult to increase the speed at which the mold is closed and opened, resulting in various problems.

This invention was made to solve the above-mentioned drawbacks and problems of the conventional technology, and the ultimate purpose of this invention is to solve the problems of the fixed mold, the movable mold, and the parts attached to the movable mold. A mold for molding a container that is intertwined with a slide piece, in particular, a bent portion or a mold having at least two projecting pieces projecting outward from the side wall of the container, with the - projecting piece forming a certain angle with the projecting direction. An undercut treatment device for a container molding die for injection molding a container having a folded part, wherein a large area over a certain range is applied to a portion of the slide surface of the slide piece that includes the bent part or the undercut mold surface of the folded part. The bottom surface of the recess is formed into an inclined surface inclined in the sliding direction of the slide piece, the part that fits into the recess is the same shape and the same size as the recess, and the back surface of the recess is formed into an inclined surface inclined in the sliding direction of the slide piece. An undercut molding piece is formed on a mold clamping slope inclined at the same angle as the slope in the sliding direction of the piece, and has a convex part for undercut molding and a container mold surface of the required range, on the parting surface of the movable mold. A rotary mold for container molding, which is characterized in that it is rotatably installed, and that a drive device that rotates the undercut molding piece directly or indirectly through its rotating shaft is installed in the movable mold. An object of the present invention is to provide an undercut treatment device.

Next, this invention will be explained with reference to illustrated embodiments.

FIG. 1 is a cross-sectional view of a main part of a mold for molding a container to which an undercut treatment device according to an embodiment of the present invention is applied, in a clamped state.

In the figure, 1 is a fixed mold, 2 is a movable mold, and 3 is a slide piece attached to the movable mold 2.

Moreover, 4 in the figure is a container which is a molded product.

Container 4 has an opening edge in the side wall of the container (right edge in the figure).
and protrusion pieces 4 a , 4 b , and 4 C that protrude outward from the middle portion and the bottom portion (left end portion in the figure), respectively.

Moreover, the protruding piece 4C at the opening edge has a folded part 4c' bent at a substantially right angle to the protruding direction of the protruding piece 4C,
This forms a handle portion having a substantially square cross-section.

The folded portion 4C' forms an undercut that makes it impossible for the slide piece 3 to move.

However, the shape of the folded portion 4C' is not limited to the illustrated example.

In other words, if it is a bent part that forms a certain angle with respect to the protruding direction of the protruding piece 4C, or if it has a shape or structure that forms an undercut that makes the slide piece 3 unable to slide, it can be molded in exactly the same way. be.

The protruding piece 4c is a sliding surface portion of the slide piece 3 that is connected to the movable mold 2 in order to deal with the undercut caused by the protruding piece 4c and the folded portion 40'.

A portion of the folded portion 4C' including the undercut mold surface is packed in a certain range, and has a shape and size necessary and sufficient for installing the undercut molding piece 5, as shown in FIG.

However, the size of the range never extends to the adjacent protruding piece 4b.

) is provided with a notch-shaped recess 3a, and an undercut molding piece 5 that fits within this recess 3a is rotatably installed on the parting surface of the movable mold 2.

The bottom surface of the recess 3a is shaped like an inclined surface 3a' that is inclined in the sliding direction of the slide piece 3 (in the direction of arrow C) at an angle necessary and sufficient for clamping the undercoat + molding piece 5.

The undercut forming piece 5 includes an undercut forming convex portion 5a for forming an undercut by the above-mentioned projecting piece 4c and folded piece 4C/, and a forming mold for a necessary area (container side wall, etc.). It has a surface.

This undercut) d-shaped piece 5 and the undercut forming convex portion 5a are the projecting piece 4c of the container 4, the folding piece 4
C' (that is, the undercut formed by these) has a length equal to the longitudinal dimension, and in this undercut forming piece 5, the portion that fits into the recess 3a is similar to the recess 3a. They are formed to have the same shape and size, and the back surface is formed into a mold clamping inclined surface 5C inclined at the same angle (parallel) as the inclined surface 3a' in the sliding direction of the slide piece 3.

The undercut molding piece 5 is rotatably installed on the parting surface of the movable mold 2.

That is, as shown in FIG. 2, a concave groove 15 is formed in the parting surface of the movable mold 2 with a width and depth that allow the shaft 8 of the undercut molding piece 5 to be completely sunk below the parting surface 2a.
, and ``a recess 16 with a shape and depth in which a part of the recess 15 is expanded to receive the rotated undercut forming piece 5.
has been established.

Then, the bearing stand 9 is fixed in the recess 16, the undercut molding piece 5 is positioned at the recess 16, and the shaft 8 fixed through the support arm 5b of the undercut molding piece 5 is fixed to the bearing stand. 9 for rotatable support, and a concave groove 15
It is arranged in the long horizontal direction.

Note that inside the groove 15, there is a groove 1 at a certain distance.
A bearing stand 9' that is completely sunken into the shaft 5 is installed to provide stable support for the shaft 8.

Thus, when the shaft 8 is rotated, the undercut forming piece 5 is also rotated at the same rotation angle in the direction of the arrow D, which is removed from the undercut, or in the opposite direction.

The end of the shaft 8 is made to protrude through the groove 15 to the side surface 2b of the movable mold 2, and a crank lever 7 having an elongated hole 7a is fixedly attached to the end, and is connected to a hydraulic or pneumatic drive device. A piston rod 11 of a fluid pressure cylinder 10 is connected to the piston rod 11, and the undercut forming piece 5 is indirectly rotated by the fluid pressure cylinder 10 via a shaft 8.

The fluid pressure cylinder 10 is installed on the side surface 2b of the movable mold 2, and has a yoke 1 attached to the tip of the piston rod 11.
2 and a crank pin 14 which is passed through a slider 13 which is slidable within the elongated hole 7a.

Therefore, when the piston rod 11 of the fluid pressure cylinder 10 retreats, the undercut forming piece 5 rotates in the mold clamping direction, and when it moves forward, it rotates in the direction of the arrow and comes out of the undercut.

Note that the means for rotating the undercut forming piece 5 is not limited to the illustrated configuration.

For example, rotating the shaft 8 directly by a hydraulic motor or the like;
Alternatively, the shaft 8 may be made as short as necessary, a crank portion may be formed directly on the undercut molding piece 5, a fluid pressure cylinder 11 may be installed in the movable mold 2, and its piston rod may be connected to the crank portion. Similar objectives can be achieved by different configurations, etc.

Next, the operation of the undercut processing device having the above configuration will be explained.

FIG. 3 shows the container 4 in a mold-clamped state after injection molding.

At this time, the front surface 5d of the undercut 14-shaped piece 5 is in contact with the parting surface 2a of the movable mold 2, and the slope 3a' of the slide piece 3 is the mold clamping slope of the undercut molding piece 5. It comes into pressure contact with surface 5C, and its approach (
is strongly backed up by the wedge effect).
Withstands molten resin pressure.

After cooling the container 4, in the mold peeling and mold opening process, the movable mold 2 is first opened and moved back in the direction of arrow A.

As a result, the container 4, which is a molded product, moves together with the movable mold 2 and the slide piece 3 while being held therein.

Next, the slide piece 3 is slid in the direction of arrow C at a certain position during the mold opening process of the movable mold 2 to open the mold.

As a result, the backup to the undercut forming piece 5 is eliminated, and the undercut forming piece 5 becomes able to rotate.

Thereafter, the undercut 1 is moved by the fluid pressure cylinder 10.
4. The shape piece 5 is connected to the undercut molding convex portion 5a of the container 4.
Rotate it in the direction of the puller coming out of the undercut (in the direction of the arrow).

The undercut molding piece 5 is rotated at an angle until the undercut molding convex portion 5a is completely removed from the undercut portion 4C of the molded product 4.

As a result, the container 4 is attached only to the movable mold 2, and finally, the container 4 is pushed out of the molding machine from the movable mold 2 by an ejection device (not shown).

Note that the mold closing and mold clamping processes are performed in the exact opposite order to the above process operations.

That is, first, the undercut molding piece 5 is warped and reversed in the direction of the arrow so that its front surface 5d is in contact with the parting surface 2a of the movable mold 2, and then the slide piece 3 is advanced in the direction opposite to the arrow C. Finally, the movable mold 2 is closed and clamped to the fixed mold 1, and the clamping is completed.

As explained above, this invention is a container molding mold consisting of a fixed mold 1, a movable mold 2, and a slide piece 3 attached to the movable mold 2. At least two protruding pieces 4 a and 4 b
, 4C, and a bent part or folded part 4C' in which the - protruding piece 4C forms a certain angle with the protruding direction.
In an undercut processing device for a container molding die for injection molding, a recess of a certain size over a certain range is formed in a portion of the slide surface of the slide piece 3 that includes the undercut mold surface of the bent portion or folded portion 40'. Set up 3a,
The bottom surface of the recess 3a is formed into an inclined surface 3a' inclined in the sliding direction of the slide piece 3, and the portion that fits into the recess 3a has the same shape as the recess 3a.

It has the same size, and the back surface is formed with a mold clamping slope 5C which is sloped at the same angle as the slope 3a' in the sliding direction of the slide piece 3, and an undercut d elbow convex part 5a and a necessary range of the mold clamping slope 5C. An undercut molding piece 5 having a container mold surface is rotatably installed on the parting surface of the movable mold 2, and a drive device rotates the undercut molding piece 5 directly or indirectly through its rotation shaft. The gist of the present invention is an undercut processing apparatus for a container molding die, which is characterized in that: is installed in the movable die 2, and has the following effects.

■ A container having at least two protruding pieces protruding outward from the side wall of the container, and the negative protruding piece having a bent or folded part that makes a certain angle with the protruding direction, is placed under the container. Can be cut and injection molded.

■ The undercut forming piece has a structure that requires only a simple rotation of the undercut forming convex part in the direction to remove it from the undercut of the molded product, so its movement is extremely simple, and the movement is highly efficient and easy to use. (2) Therefore, this undercut processing device can reduce the space occupied by the movement efficiency of the undercut forming pieces.

■ Conversely, the smaller the space occupied, the greater the degree of freedom in designing the shape of the molded product and the structure of the mold.

■ The undercut forming piece only rotates in a simple manner, and its movement is extremely simple, so the method of driving the undercut forming piece is easy, and it is possible to increase the accuracy of operation and increase the speed of operation. Therefore, there is no risk of trouble.

■ The undercut forming piece is configured to simply rotate its undercut forming protrusion only in the direction of pulling out from the undercut of the molded product, so there is no waste in the movement of the undercut forming piece, and its movement stroke is quite small. It's fine.

(2) Therefore, the means for rotationally driving the undercut forming piece can be made smaller and the space for movement can be reduced.

- The undercut molding piece and the drive device that rotates it are installed only in the movable mold and have a simple configuration, making assembly work easy and achieving high assembly accuracy.

■ The molded container is reliably attached to a movable mold, opened, and undercutted, making it easy and reliable to eject the container.

[Brief explanation of the drawing]

The drawings show an embodiment of this invention; FIG. 1 is a sectional view of the main parts of a mold for molding a container, FIG. 2 is a perspective view of the main parts of an undercut processing device, and FIGS. FIG. 2 is a cross-sectional view of the main parts of the molding die and the undercut processing device showing the mold clamping and mold opening states.

Claims (1)

[Claims for Utility Model Registration] A mold for molding a container consisting of a fixed mold 1, a movable mold 2, and a slide piece 3 attached to the movable mold 2, which protrudes outward from the side wall of the container. at least two protruding pieces 4
a, 4b, 4c, and a bent or folded portion 4C in which the - protruding piece 4C forms a certain angle with the protruding direction.
In an undercut processing device for a container molding die for molding a container 4 having a shape of 1, (a) a constant portion of the sliding surface of the slide piece 3 including the undercut mold surface of the bent portion or folded portion 4C'; A recess 3a of a wide range of sizes is provided, and the bottom surface of the recess 3a is formed into an inclined surface 3a' inclined in the sliding direction of the slide piece 3, and (b) the recess 3a is fitted into the recess 3a. The part has the same shape and the same size as the recess 3a, and the back surface is formed into a mold clamping slope 5C inclined at the same angle as the slope 3a' in the sliding direction of the slide piece 3, and a convex part for undercut molding. 5a and an undercut molding piece 5 having a container mold surface within a necessary range are rotatably installed on the parting surface of the movable mold 2, and (c) the undercut molding piece 5 is connected directly or to its rotation axis. An undercut treatment device for a container molding mold, characterized in that a driving device that indirectly rotates through the movable mold 2 is installed.