JPS59199Y2 - Blow molding equipment for bent thermoplastic resin containers - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a blow molding apparatus for bent thermoplastic resin containers.

In conventional blow molding equipment for curved thermoplastic resin containers,
As shown in FIG. 1 of the accompanying drawings, since the tubular thermoplastic resin 1 is closed in that state without being bent and then blown into the mold, burrs B appear at bent portions A and the like.

Therefore, it is necessary to cut the burr B and the AA' portion of the mouth of the molded product S.

In addition, after cutting the A-A' part of the mouth of the molded product, it is necessary to perform further cutting to make the surface smooth, and after cutting, cutting powder may enter the inside of the molded product S. A process of blowing out the cutting powder using air is required.

Furthermore, since whisker-like burrs remain after removing the burrs, it is necessary to manually finish them with a knife or the like.

Molding bent thermoplastic resin containers using conventional blow molding equipment has the drawback of increasing the manufacturing cost of the containers due to the large number of manual steps.

The object of the present invention is to provide a blow molding device for curved thermoplastic containers that can solve these problems in conventional blow molding devices.

To this end, the present invention automatically bends and deforms the tubular thermoplastic resin in the direction of the center line of the cavity formed in a split mold, and at the same time as the mold is completely closed, a blowing nozzle is introduced from the top of the tubular resin. This method is characterized by blow molding, which eliminates the need for post-processing and reduces manpower.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to FIGS. 2 to 8 of the accompanying drawings showing embodiments thereof.

First, as shown in FIGS. 2 to 4, the device of the present invention attaches one sliding split mold 7 to the upper part of each split mold 6 fixed to each mounting plate 5, and guides fixed thereto. Each sliding split mold 7 is attached via a pin 8 so as to be movable in a direction perpendicular to the dividing surface of each split mold 6, and each sliding split mold 7 is attached to the split mold 6 by a coil spring 9 interposed between them. It is held so that it always protrudes from the dividing surface.

In addition, the sliding split mold 7 is formed with a so-called bag-shaped split mold, that is, a so-called bag in which a part of the inner diameter part is enlarged, and the surplus part of the tubular thermoplastic resin 1 caused by injection of the blowing nozzle is protruded into this part. By doing so, when a bag is not formed, the excess portion of the tubular thermoplastic resin 1 caused by the injection nozzle is prevented from protruding into the boundary between the mouth of the container and the container body, causing so-called carry-in. The bag-like split mold 10 is fixedly attached, and the sliding split mold 7 is first brought together during mold closing, so that when the tubular resin 1 is bent later, the upper part of the tubular resin 1 is It is held so that it cannot be bent.

Further, the lower inner surface of the bag-shaped split mold 10 has an edge so that the opening of the molding surface can be easily removed.

Further, a first air cylinder 11 is pivotally connected to one of the mounting plates 5 at its cylinder end, and the piston rod end thereof is connected to a first arm 1 whose one end is pivotally mounted to the mounting plate 5.
It is pivoted to a part of 2.

At the other end of this first arm 12, at right angles to the splitting plane of the split mold 6, in the example of FIG.
3, or in the example of FIG.
One end of the arm 23 is fixed, and the second arm 13
Or within the dividing plane of the double mold 6 via 23, the double mold 6
It is possible to pivot to a position approximately at the center line of the cavity 6'.

The tip of the second arm 23 is provided with a gripping mechanism that forcibly grips the tubular resin 1 and bends it securely without slipping.

As shown in FIGS. 5 and 6, this knob mechanism has a pair of second air cylinders 20 movably attached to each second arm 23, and a knob at opposite ends of the second air cylinders 200. A cam 24 is pivotally connected by a pin 25 and one end of the cam 24 is attached to the other end of a coil spring 26 attached at one end to the second air cylinder 20, thereby causing the cam 24 to It is constantly indexed via a spring 26 until it hits a stop 27 attached to the air cylinder 2o (FIG. 7), and an opening 2B is formed between the two.

In this configuration, the air port 2 is provided in the second air cylinder 20.
When pressurized air is sent through the second air cylinder 9, the second air cylinder 20 approaches the spring 20 interposed between them until it collides with the sleeve 1 to the collar 31, and at this time, the knob cam 24 A protrusion 32 formed near the pin 25 engages, causing the knob cam 24 to pivot about the pin 25 and close the opening 28 between them (FIG. 8).

Note that when air is removed from both built-in second cylinders 20, the second air cylinders 2 are opened by the action of the opening spring 30.
0 returns to its original position, and an opening 28 is again formed between the knob cams 24 (FIG. 7).

A centering spring 33 is interposed in each of the second air cylinders 20 so that the second air cylinders 20 are always positioned symmetrically with respect to the dividing center plane of the two split molds 6.

In addition, in FIGS. 3 and 4, the second arm 12 is provided with a hook plate 14 instead of the arm 23 provided with the second cylinder 20.
The second arm 13 is shown attached.

The present invention has the above configuration, and its operation will be explained next.

When each split mold 6 is attached to a blow molding device equipped with one or more heads and the tubular thermoplastic resin 1 is extruded between the two split molds 6 from the single or plural heads in an open state, the extruded tubular thermoplastic resin 1 is heated. During the closing of the split molds 6, the plastic resin 1 is first combined with one or more sliding split molds 7 and bag-shaped split molds 10, which are movably attached to the upper part of each split mold 6. caught between them by

In this way, the sliding split mold 7 and the bag-shaped split mold 10 are brought together, sandwiching the upper part of the tubular thermoplastic resin 1, and cutting this with the knife 41 disposed above the split mold 10. At the same time, the first air First arm 12 by cylinder 11
The second air cylinder 20 has a built-in knob cam 24 which operates the second arm 23 and pinches the lower part of the tubular thermoplastic resin 1.
After bending along the center line of the cavity 6' of the mold or mold parts 6 by pinching through the
(see 1' in the figure), completely closed.

When the mold is completely closed, blow molding is performed using the blow nozzle 40.

During this blow molding, the first air cylinder 11 performs a return operation, and the knob cam 24 also returns to its original position by releasing air from the second air cylinder 20.

In this manner, when the blow molding is completed, the split mold 6 is opened, the sliding split mold 7, which was pressed by the coil spring 9 in the middle, is also opened, and the molded product is taken out.

As described above, according to the present invention, when blow molding a bent thermoplastic resin container, the tubular thermoplastic resin is bent along the center line of the cavity formed in a split mold. There are no cracks at the bent portions, so the molded product is clean, and the amount of manpower required for finishing can be significantly reduced, resulting in extremely great effects.

[Brief explanation of the drawing]

Figure 1 is a diagram showing an example of a molded product made by the conventional blow molding method.
Fig. 2 is a schematic plan view showing one embodiment of the present invention, Fig. 3 is a front view seen in the direction of arrow III-III, Fig. 4 is a side sectional view taken along line IV-IV in Fig. 2, FIG. 5 is a partially cutaway side view showing a modified embodiment of the present invention, and FIG.
The sectional view taken along the line I-VI, and FIGS. 7 and 8 are explanatory diagrams of its operation. 1... Tubular thermoplastic resin; 5... Mounting plate: 6...
・Split mold: 6'... Cavity; 7... Sliding split mold; 8... Guide pin; 10... Bag-shaped split mold; 11...
・First air cylinder: 12...First arm: 13,
23... Second arm; 14... Hook plate; 20...
Built-in second air cylinder for the knob mechanism; 24... knob cam; 40... blow nozzle; 41-- cutter.

Claims (1)

[Scope of utility model registration request] A pair of sliding split molds 7 each having a fixed bag-shaped split mold 10 that grips the upper part of the tubular thermoplastic resin 1 to be extruded from the diametrical direction while the mold is being closed; 1 set having a cavity 6' inclined with respect to the center line of the tubular thermoplastic resin 1 to be extruded, in which each sliding split mold 7 is attached to the upper part so as to be slidable toward the tubular thermoplastic resin 1; a split mold 6, a first air cylinder 11 whose cylinder end is pivoted to a mounting plate 5 for fixing the split mold 6, and a piston rod end thereof on the side where the first air cylinder 11 is installed. are pivotally connected to a part thereof, and one end thereof is pivotally connected to each mounting plate 5, and a second arm 23 that is perpendicular thereto and facing each other is fixed to the other end. a pair of first arms 12, second air cylinders 20 movably attached to each second arm 23, and pivoted to opposite ends of each second air cylinder 20; The distal ends are always open via the spring 26, and the proximal ends are pressed against each other by the operation of the second air cylinder 20, thereby closing the distal ends, and the tubular thermoplastic resin 1 is placed between the distal ends. One knob cam 2 each configured to pinch
4 and an opening spring 30 connecting the second air cylinders 20 so as to separate them from each other.