JPH08230021A - Parison controller of hollow molder - Google Patents

Abstract

PURPOSE: To provide a parison controller of a hollow molder, with which a high quality parison for a die head suitable for resin, which easily stagnates such as engineering plastic or the like, is obtainable. CONSTITUTION: In a hollow molder, which discharges parison 14 through the die 11 of a resin flow path 12 in a die head 18 by introducing the molten resin 17 extruded from an extruder 15 in the die head 18 through the resin flow path 12, a die 11 is so constituted as to be vertically controllable by an electric motor 1.

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 a method of vertically moving a die by an electric motor so as to obtain a high-quality parison for a resin-type die head in which stagnation is likely to occur such as engineering plastic. By moving the parison, the thickness of the parison is controlled, and the length of the parison is automatically controlled.

[0002]

2. Description of the Related Art Conventionally, as shown in FIG. 4, the parison control of a blow molding machine is such that the resin plasticized by the extruder 31 passes through the gap between the die 35 and the core 36 fixed to the outlet side of the head 34, and the parison is controlled. 37 is extruded. At this time, when the mandrel 38 connected to the core 36 is moved up and down by the signal of the control unit by the actuator 39, the gap changes and the thickness of the parison 37 changes.

[0003]

However, according to the conventional parison control described above, since the core 6 is moved up and down in order to change the gap, the resin flow portion easily stays and the resin burns. It often causes charring, resulting in defective molded products.

In the case of a die head for discharging a plurality of parisons, a chalk or the like is provided at a branch portion of a resin flow path to adjust the flow rate manually in order to equalize the parison length. It is necessary to readjust the resin every time the resin is changed or due to the temperature setting or other factors. At that time, it is dangerous to touch the heater or the like and get burned or electric shock.

Accordingly, the present invention provides a parison controller for a blow molding machine which solves the above problems.

[0006]

According to a first aspect of the present invention, in order to solve the above problems, molten resin extruded from an extruder is introduced into a die head through a resin flow path, and a die in the die head is introduced. In a hollow molding machine for discharging a parison from a gap with a core, the die can be adjusted up and down by an electric motor.

According to a second aspect of the present invention, the molten resin extruded from the extruder is introduced into a die head having a plurality of resin flow paths, and parison is discharged from the gaps between a plurality of sets of dies and cores in the die head. In the machine, the die is vertically adjustable by an electric motor.

According to the third aspect, the molten resin extruded from the extruder is introduced into the die head through a plurality of resin flow paths, and the parison is discharged from the gaps between the plurality of sets of dies and the core in the die head. In the molding machine, a choke and an actuator for driving the choke are provided in each of the resin flow paths near the branch portion.

According to the present invention, the molten resin extruded from the extruder is introduced into the die head through a plurality of resin flow paths, and the parison is discharged from the gaps between the plurality of sets of dies and cores in the die head. In the molding machine, the die is provided to be adjustable up and down by an electric motor, and a choke and an actuator for driving the choke are provided in the resin flow path near the branch portion, respectively, and
A sensor for detecting the length of the parison is provided below the core or the die, and the electric motor, the actuator, and the sensor are electrically connected to a controller to enable program control.

[0010]

[Operation] The change in the thickness of the parison is adjusted by vertically moving the die with an electric motor. Further, the flow rate is adjusted by adjusting the chokes of the plurality of resin flow paths, and the length of the parison is detected by the sensor, whereby the thickness and length of each parison are controlled, so that the height of the parison can be controlled without scorching. You can get a quality parison.

[0011]

Embodiments of the present invention will be described below with reference to the drawings.
As shown in FIG. 1, a speed reducer 2 is connected to an electric motor 1 such as a servomotor, a ball screw 5 is connected to the speed reducer 2 via a coupling 3, and the ball screw 5 is fixed to a fixed base 7a having a thrust bearing 4. , And a nut 6 is engaged with the ball screw 5 to fix the nut 6 to the lifting plate 7.
The elevating plate 7 is non-rotatably guided by the fixed base 7a and suspended so as to be vertically movable. The electric motor 1 is electrically connected to a programmable controller 24.

An appropriate number of rods 8 are suspended from the lifting plate 7. On the other hand, the crosshead 9 and the spider 1
0 and the head 11a are tightly connected and fixed, and the rod 8 is penetrated therethrough so that the lifting plate 7 can be raised and lowered. The die 11 is connected to the lower end of the rod 8. The die 11 is a cylindrical body having a circular hole formed around the core 13, and a cylindrical portion 11b protruding from the circular hole at a required length below the head 11a.
Are fitted.

The crosshead 9, the spider 10, and the head 11a constitute a die head 18.
A resin channel 12 is formed at the center of the resin channel 12, and a core 13 is fixedly supported by the spider 10 at the center near the lowermost end of the resin channel 12 and hangs down. A parison 14 hangs down from the gap between the core 13 and the die 11. .

The parison 14 is one in which the molten resin 17 flows from the extruder 15 and is discharged from the gap between the die 11 and the core 13 through the resin flow path 12 and droops downward. In order to detect the drooping length. In addition, a pair of photocells 16 are arranged below the die 11 at a predetermined height position so as to face each other with the parison 14 in between.

The die head 18 has a plurality of resin flow paths 1.
2 is formed, and the crosshead 9 has a branch portion 2
Although 0 is formed (see FIG. 2), it is clear that the above configuration of the present invention can be adopted even if the branch portion 20 is not provided and the resin flow path 12 is a single die head.

As shown in FIG. 2, at the branch portion 20 in the resin flow passage 12 of the crosshead 9, two resin flow passages 12 are formed from the branch portion 20, and the resin near the branch portion 20 is formed. Choke 2 in each of the channels 12 and 12
The choke 21 is connected to an actuator 22 such as a servomotor, and a sensor 23 is provided on the actuator 22. The sensor 23 is electrically connected to a controller 24.

Next, the operation of the above embodiment will be described.
Molten resin 1 extruded from extruder 15 into branch 20
7 is an actuator 22 according to a signal from the controller 24.
Is activated to move the choke 21 forward and backward to the resin flow path 12, thereby changing the cross-sectional area of the resin flow path 12 and adjusting the flow rate to move the resin flow path 12.
Is discharged as a parison 14 from the gap.

At the time of this discharge, the electric motor 1 is driven by a signal from the controller 24 and the ball screw 5 rotates in either forward or reverse directions, whereby the lift plate 7 can move up and down, so that as shown in FIG. Since the die 11 can move up and down to change the gap G with the core 13, the thickness of the parison 14 can be controlled.

The lower end of the parison 14 is the sensor 16
, The parison cutter (not shown) is activated, and the parison 14 is cut near the die 11 and is received by a molding die (not shown) waiting therebelow.

Thus, the molten resin 17 is controlled by the controller 24.
The flow rate of the parison 14 and the change in the thickness of the parison 14 can be freely controlled.
Can be obtained.

[0021]

According to the present invention described above, the die can be moved up and down by the electric motor to change the gap with the core, and the resin flow can be controlled by the choke of the resin flow path. Also, since the discharge length of the parison is detected by a sensor, it is possible to control the change in the parison wall thickness with less resin stagnation compared to the conventional one, and it is possible to evenly adjust the length of multiple parisons ,
Moreover, since the flow rate is not manually adjusted, there is no danger, and since hydraulic pressure is not used, it is possible to obtain a clean and high-quality parison without oil leakage or oil stains.

[Brief description of drawings]

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

FIG. 2 is a configuration diagram of a resin flow rate adjusting mechanism of the blow molding machine according to the present invention.

FIG. 3 is an operation explanatory diagram

FIG. 4 is a half sectional front view of a main part of a conventional blow molding machine.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Electric motor 2 ... Speed reducer 5 ... Ball screw 6 ... Nut 7 ... Elevating plate 8 ... Rod 9 ... Crosshead 10 ... Spider 11 ... Die 11a ... Head 12 ... Resin flow path 13 ... Core 14 ... Parison 15 ... Extruder 16 ... Sensor 18 ... Die Head 20 ... Branch 21 ... Choke 22 ... Actuator 23 ... Sensor 24 ... Controller

Claims (4)

[Claims] 1. A blow molding machine in which a molten resin extruded from an extruder is introduced into a die head through a resin flow path and a parison is discharged from a gap between a die and a core in the die head, and the die is moved up and down by an electric motor. Adjustable parison controller for blow molding machine. 2. A hollow molding machine in which a molten resin extruded from an extruder is introduced into a die head having a plurality of resin flow paths, and parison is discharged from gaps between a plurality of sets of dies and cores in the die head. A parison controller for a hollow molding machine, characterized in that it can be adjusted up and down with an electric motor. 3. A hollow molding machine in which molten resin extruded from an extruder is introduced into a die head through a plurality of resin flow paths, and parison is discharged from gaps between a plurality of sets of dies and cores in the die head, respectively. A parison controller for a hollow molding machine, wherein a choke and an actuator for driving the choke are provided in the resin flow path near each portion. 4. A hollow molding machine in which molten resin extruded from an extruder is introduced into a die head through a plurality of resin flow paths, and parison is discharged from gaps between a plurality of sets of dies and cores in the die head, A die is provided to be adjustable up and down by an electric motor, a choke and an actuator for driving the choke are provided in the resin flow path near the branch portion, and a sensor for detecting the parison length is provided under the core or the die. A parison controller for a hollow molding machine, wherein the parison controller is provided, and the electric motor, the actuator, and the sensor are electrically connected to a controller to enable program control.