JP2545339Y2 - Resin flow distribution device of blow molding machine - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin flow distribution device for a blow molding machine.

[0002]

2. Description of the Related Art Conventionally, a parison is formed by discharging a molten resin downward in a cylindrical shape, and the parison is sandwiched between a pair of molds and inflated with air to blow-mold a product such as a container. Machines are known.

FIGS. 5 to 7 show an example of the blow molding machine. In the drawings, reference numeral 1 denotes a head of the blow molding machine, 2 denotes a fixed portion integrally fixed to the head 1, and 3 denotes a fixed portion 2 A holder 4 having an upper end attached thereto and extending to a position below a central portion in the head 1 is slidably fitted to the holder 3 and housed in the head 1 and an actuator 5 attached to the fixed portion 2 The plunger 6 is slidably fitted into the center of the holder 3 and supported by an actuator 7 mounted on the fixed part 2 so as to be able to move up and down. The mandrel 9 is formed in an annular slit formed between the mandrel 8 and the discharge port 10 at the lower end of the head 1, and the mandrel 9 is formed at a plurality of places (two places in the illustrated example) in the circumferential direction above the head 1. Perforated inlet 12 shows a resin flow path extending vertically formed in the plunger 4 the outer circumference to correspond to the flow inlet 11, the mandrel 8 with the actuator 7
When the molten resin 13 is introduced by using a material extruder (not shown) from the inflow port 11 after the plunger 4 is raised and the plunger 4 is raised, the introduced molten resin 13 Flowing down the resin flow path 12,
Furthermore, the molten resin 13 is distributed in the circumferential direction by flowing down the downwardly expanding expansion portion 14 formed at the lower portion of the resin flow channel 12, and the distributed molten resin 13 swells to the lower portion of the expansion portion 14. When the plunger 4 is guided down the plunger 4 by flowing down the throttle channel 16 between the overhang portion 15 and the inner peripheral surface of the head 1, and then the plunger 4 is pushed down by the actuator 5, the molten resin 13 is slit. The cylindrical parison 17 is discharged from the outside 9 and extruded.

[0004]

However, in order to form the parison 17 without uneven thickness or bending, it is necessary to distribute the molten resin 13 introduced from each inlet 11 evenly in the circumferential direction. However, no matter how carefully the design of the expansion part 14 and the like is made, since various conditions such as a change in the resin used and a difference in the viscosity of the resin depending on the temperature condition change, for example, the viscosity of the molten resin 13 is designed. Sometimes, when the value becomes lower than the assumed value, the flow of the molten resin 13 may be biased in the circumferential direction, for example, the amount of the resin flowing immediately below the resin flow path 12 increases.

That is, the conventional blow molding machine has no means for externally adjusting the distribution of the molten resin 13 in the circumferential direction. Since the molten resin 13 is not evenly distributed in the circumferential direction due to the above-mentioned conditions, the parison 17 However, it was not possible to cope with the occurrence of uneven thickness or bending.

The present invention has been made in view of the above circumstances, and has as its object to provide a resin flow distribution device of a blow molding machine capable of externally adjusting the distribution of a molten resin in a circumferential direction.

[0007]

According to the present invention, molten resin introduced from inlets formed at a plurality of positions in a circumferential direction of a head is provided.
The molten resin is caused to flow in the circumferential direction by flowing down a vertically extending resin flow path formed on the outer periphery of the plunger in the head, and further flowing down a downwardly divergent extension formed at the lower part of the resin flow path. A resin flow distribution device of a blow molding machine configured to distribute and guide to a position below the plunger, wherein a position immediately below a resin flow path of the expansion portion,
A taper-shaped distribution valve that is widened downward is provided so as to be swingable about a top portion, and a swing mechanism that swings the distribution valve is provided in the plunger. .

[0008]

Therefore, in the present invention, when the distribution valve is swung to a required angle by the swing mechanism, the molten resin introduced from the inlet of the head and flowing down the resin flow path of the plunger can be arbitrarily shifted to the left and right by the distribution valve. Distributed to

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the drawings.

FIGS. 1 to 4 show an embodiment of the present invention, in which parts denoted by the same reference numerals as those in FIGS. 5 to 7 represent the same parts.

In the blow molding machine 18 constructed substantially in the same manner as the blow molding machine shown in FIGS.
At the position just below the resin flow path 12 in the expansion portion 14, the top portion is supported by a swing shaft 20 rotatably held by a bush 19 embedded in the plunger 4 so as to rotate integrally with the top portion, and is wide downward. A distributing valve 21 formed in a tapered shape is provided. Further, a pinion 22 is integrally fitted to a middle portion of the swing shaft 20, and a hole 23 drilled vertically adjacent to the pinion 22 is provided. Oscillation for oscillating the distributing valve 21 by disposing a rack 26 having gear teeth 24 meshed with the pinion 22 at a lower portion and supported by an actuator 25 mounted on the upper end of the plunger 4 so as to be able to move up and down. The swing mechanism 27 constitutes a mechanism 27.
And the distribution valve 21 constitute a resin flow distribution device 28.

When the rack 26 is moved up and down by extending and retracting the actuator 25, the gear teeth 24 of the rack 26 are moved.
The pinion 22 meshed with the shaft is rotated, the distribution valve 21 is swung to a required angle via the swing shaft 20, and the molten resin 13 flowing down the resin flow path 12 is arbitrarily moved left and right by the distribution valve 21. Distributed to

Therefore, according to the above embodiment, the resin flow path 12
The molten resin 13 flowing down can be arbitrarily distributed by adjusting the swinging position of the distribution valve, so that the molten resin 13 can be evenly distributed in the circumferential direction according to various conditions. 17 can be prevented from being uneven or bent.

The resin flow distribution device of the blow molding machine according to the present invention is not limited to the above-described embodiment.
In addition to the rack and pinion system shown in the figure,
A lever type or the like that swings the distribution valve by pushing and pulling a lever protruding from the swing shaft with an actuator may be employed. In the example shown, a blow molding machine for forming a single-layer parison However, it is needless to say that the present invention can be similarly applied to a blow molding machine for forming a multi-layer parison, and that various changes can be made without departing from the gist of the present invention.

[0015]

According to the resin flow distribution device of the blow molding machine of the present invention, the molten resin flowing down the resin flow path can be arbitrarily distributed by adjusting the swing position of the distribution valve. As a result, the molten resin can be evenly distributed in the circumferential direction according to various conditions, and an excellent effect of preventing the parison from being uneven in thickness or bending can be obtained.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention.

FIG. 2 is a view in the direction of arrows II-II in FIG.

FIG. 3 is a view in the direction of arrows III-III in FIG. 1;

FIG. 4 is a view in the direction of arrows IV-IV in FIG. 1;

FIG. 5 is a sectional view showing a conventional example.

6 is a view in the direction of arrows VI-VI in FIG. 5;

FIG. 7 is a view in the direction of arrows VII-VII in FIG. 5;

[Explanation of symbols]

 Reference Signs List 1 head 4 plunger 11 inflow port 12 resin flow path 13 molten resin 14 expansion section 18 blow molding machine 21 distribution valve 27 swing mechanism 28 resin flow distribution device

Claims (1)

(57) [Scope of request for utility model registration] 1. A molten resin introduced from a plurality of inlets formed in a plurality of positions in a circumferential direction of a head is caused to flow down a vertically extending resin flow path formed on an outer periphery of a plunger in the head.
Further, a resin flow distribution of a blow molding machine configured to distribute the molten resin in a circumferential direction and guide the molten resin to a position below the plunger by flowing down a downwardly expanding expansion portion formed at a lower portion of the resin flow path. An apparatus, wherein a distributing valve formed in a tapered shape that widens downward is provided at a position directly below a resin flow path of the expansion part so as to be swingable about a top part, and the dispensing valve is operated to swing. A resin flow distribution device for a blow molding machine, wherein a moving mechanism is provided on the plunger.