JP2604076B2 - Parison controller for 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 parison controller for a blow molding machine, and more particularly, to reducing the size of the entire apparatus and saving resources by moving a core provided at a discharge port for discharging a parison through a motor. And new improvements to obtain high quality parisons.

[0002]

2. Description of the Related Art There have been various types of parison controllers of this type of blow molding machine which have been used in the past. Among them, a typical one is described in general, as shown in FIGS. 2 and 3. Can be mentioned. That is, what is indicated by reference numeral 1 in FIG. 2 is a crosshead to which the molten resin 4 is supplied from the extruder 2, and the die 3 provided below the crosshead 1 discharges the molten resin 4. Is formed.

The discharge port 5 is formed in an annular shape by a tapered core 6 operably provided at the center of the die 3, and the core 6 has a tapered portion 6a and a linear portion 6b as shown in FIG. By moving the core 6 in the direction of arrow A, the distance between the outer surface 6aA of the tapered portion 6a and the inner wall 5a of the discharge port 5 is freely changed, and the thickness of the extruded parison 12 is increased. Can be changed.

[0004] The core 6 is connected to a rod 7 provided through the top 1 a of the crosshead 1.
The rod 7 is connected to a piston (not shown) of a servo actuator 9 provided above the crosshead 1 via a support 8.

[0005] A hydraulic unit 10 and a control unit 11 are connected to the servo actuator 9.
A memory (not shown) contains a program for program-controlling the servo actuator 9.

Accordingly, by operating the servo actuator 9 in accordance with the program of the control unit 11 to control the vertical movement of the core 6, the thickness of the parison 12 discharged from the discharge port 5 can be freely changed, and the molded product can be formed. Was continuously controlled so as to have a required thickness in accordance with the shape of the device.

[0007]

The parison controller of the conventional blow molding machine has the following problems because it is configured as described above. That is, since the core is moved by hydraulic control, for example, when oil leaks, the parison may be soiled, and the parison is a fatal defect for molding. In addition, the hydraulic unit is expensive and requires a large space, and the motor (3.7 KW) of the hydraulic unit becomes large, making it impossible to achieve energy saving.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and in particular, by moving a core for forming a discharge port for discharging a parison through a motor, miniaturization and saving. It is an object of the present invention to provide a parison controller of a hollow molding machine that is capable of obtaining resources of a parison with high quality.

[0009]

A parison controller of a blow molding machine according to the present invention is configured to move a core provided at a discharge port of a die of a crosshead up and down to thereby increase the thickness of a parison extruded from the discharge port. In the parison controller of the blow molding machine, the rod provided on the crosshead and connected to the core, the entire periphery of the rod and the inner wall of the crosshead can be directly opposed. A formed cylindrical void portion,
A female screw part formed on the upper part of the rod, a rotating rod having a male screw part screwed into the female screw part,
A speed reducer connected to the rotating rod via a thrust bearing, a motor connected to the speed reducer, and a thrust bearing holding mechanism that holds the thrust bearing and is provided between the crosshead and the speed reducer. And a first and second gap formed in the thrust bearing holder and sandwiching the thrust bearing. The core is moved by a motor, and the second gap is formed by the male. It is formed corresponding to the outer peripheral position of the screw portion and the female screw portion.

[0010]

In the parison cutting device of the blow molding machine according to the present invention, the core provided on the die of the crosshead is moved up and down by a motor controlled by a program.
By controlling the rotation of the motor itself with high accuracy, the core can be moved with high accuracy, and the thickness of the parison can be freely controlled.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of a parison cutting device for a blow molding machine according to the present invention will be described below in detail with reference to the drawings. Note that the same or equivalent parts as those in the conventional example will be described using the same reference numerals. FIG. 1 is a block diagram showing a parison controller of a blow molding machine according to the present invention.

In FIG. 1, reference numeral 1 denotes a crosshead to which a molten resin 4 is supplied from an extruder 2, and a die 3 provided below the crosshead 1 Discharge port 5 for discharging the liquid
Are formed.

The discharge port 5 is formed in an annular shape by a core 6 operably provided at the center of the die 3. As shown in FIG. 3, the core 6 integrally includes a tapered portion 6a and a straight portion 6b. By moving the core 6 in the direction of arrow A, the distance between the outer surface 6aA of the tapered portion 6a and the inner wall 5a of the discharge port 5 can be freely changed, and the thickness of the extruded parison 12 can be changed. Can be. The configuration described above is the same as the conventional example.

The core 6 is connected to a rod 7 which penetrates the top 1a of the crosshead 1 and is provided only for up and down movement indicated by an arrow A. Are formed.

The female screw portion 7a has a well-known thrust bearing 2 provided for releasing pressure from resin.
A male screw portion 20Aa of a rotary rod 20A connected to the speed reducer 21 via a wire 0 is screwed into and out of the speed reducer 21, and a rotary shaft 22a of a motor 22 is connected to the speed reducer 21. The motor 22 has a variable speed configuration such as an AC servomotor having a rotation detector 22b such as a rotary encoder, and is connected to the control unit 11 having a memory (not shown) storing a program. . The entire periphery 7b of the rod 7 and the inner wall 1b of the crosshead 1
Are directly opposed to each other, i.e., a cylindrical void portion 33 is formed in a space without any obstacle therebetween, and the thrust bearing 20 is connected to the crosshead 1.
The first and second gap portions 31 and 32 are formed in the thrust bearing holder 30 so as to sandwich the thrust bearing 20. And the second gap 3
2 is formed corresponding to the outer peripheral position of the male screw portion 20Aa and the female screw portion 7a.

Next, a case where the parison controller of the blow molding machine according to the present invention is operated in the above-described configuration will be described. First, when the motor 22 is rotated by the control unit 11 containing a preset program, the rotation of the motor 22 causes the rotation of the male screw portion 20Aa via the reduction gear 21, the thrust bearing 20, and the rotating rod 20A. Since only the rod 7 moves in the direction of the arrow A via the female screw portion 7a and the axial position of the rod 7 is determined, the annular interval of the discharge port 5 due to the movement of the core 6 in the direction of the arrow A can be arbitrarily set. Can be changed.

Therefore, by setting the program of the control section 11 arbitrarily, it is possible to change the required interval between the discharge ports 5 and continuously change the thickness of the parison 12.

The connection between the rod 7 and the rotary shaft 22a of the motor 22 in the above-described embodiment is not limited to the structure of the reduction gear 21 and the thrust bearing 20, but may be, for example, a combination of a step motor and a thrust bearing. It is needless to say that the same operation and effect can be obtained when another configuration is used.

[0019]

The parison controller of the blow molding machine according to the present invention is constructed as described above, so that the following effects can be obtained. In other words, since the core that changes the width of the discharge port formed in the die is moved up and down by a program-controlled motor, compared to the conventional hydraulic configuration, there is no contamination of the parison due to oil leakage, and the molded product is cleaner. Can be easily achieved. Further, as compared with the conventional hydraulic configuration, the cost is greatly reduced, and the space can be significantly reduced. In addition, the capacity as a power source required 3.7 KW in the hydraulic configuration, but was 0.7 in the present invention.
Because it is a KW AC servomotor, it saves a great deal of energy. Furthermore, since the position is detected by the position detector directly connected to the motor, a feedback detector is not required, and the configuration can be simplified and the size can be reduced.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing a parison controller 3 of a blow molding machine according to the present invention.

FIG. 2 is a configuration diagram showing a parison controller of a conventional blow molding machine.

FIG. 3 is an enlarged sectional view showing a main part of FIGS. 1 and 2;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Cross head 1a Top part 1b Inner wall 3 Die 5 Discharge port 6 Core 7 Rod 7a Female screw part 7b All around part 12 Parison 20 Thrust bearing 20A Rotating rod 20Aa Male screw part 22 Motor 20a Rotating shaft 30 Thrust bearing holder 31 First gap Part 32 Second gap

 ──────────────────────────────────────────────────続 き Continuation of front page (72) Inventor Hiroaki Takanashi 2-2-1 Fukuura, Kanazawa-ku, Yokohama-shi, Kanagawa Japan Steel Works Co., Ltd. (56) References JP-A-2-248211 (JP, A) 57-163032 (JP, A) JP 3-5294 (JP, B2) JP 57-14343 (JP, B2) JP 57-27832 (JP, B2) The Society of Polymer Science, Japan Basics of Machining, ”Industrial Research Committee (March 25, 1982), page 289, right column and page 290, left column“ AC Servo Guidance ”Mitsubishi Electric Corporation (January 1989), 1, 3 and Page 17

Claims (1)

(57) [Claims] An outlet (5) of a die (3) of a crosshead (1).
In a parison controller of a blow molding machine in which the thickness of a parison (12) extruded from the discharge port (5) is changed by vertically moving a core (6) provided in the crosshead (1). ), The entire periphery (7b) of the rod (7) and the inner wall (1b) of the crosshead (1) directly face each other. A cylindrical void portion (33) formed in a state in which
(7) A female screw part (7a) formed on the upper part, a rotary rod (20A) having a male screw part (20Aa) screwed into the female screw part (7a), and the rotary rod (20A) A speed reducer (21) connected to the speed reducer (20) through a thrust bearing (20);
1) The motor (22) connected to the thrust bearing
(20) and a thrust bearing holder (3) provided between the crosshead (1) and the speed reducer (21).
0), and first and second gaps (31, 32) provided in the thrust bearing holder (30) and sandwiching the thrust bearing (20), and the core (6 ) Is moved by a motor (22), and the second gap portion (32) is formed corresponding to the outer peripheral position of the male screw portion (20Aa) and the female screw portion (7a). Parison controller for molding machines.