JPH07299860A - Parison controller for blow molding machine - Google Patents

Abstract

PURPOSE:To reduce an entire device in size and save energy by moving a core provided at a discharge opening for discharging a parison through a motor and a link. CONSTITUTION:A core can be moved through a motor 22 and a link 23 provided at a fixed body 1A on a cross head 1. The motor 22 can be reduced in size and the core can be moved quickly.

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 hollow molding machine, and more particularly to downsizing the entire apparatus by moving a core provided at a discharge port for discharging the parison via a motor and a link. It relates to new improvements for energy saving and high quality parison.

[0002]

2. Description of the Related Art As a conventionally used parison controller of this type of hollow molding machine, for example, the structure disclosed in Japanese Patent Laid-Open No. 5-92481 shown in FIG. 4 can be mentioned. That is, reference numeral 1 in FIG. 4 denotes 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 into the die 3. A ring-shaped discharge port 5 for performing the above is formed.

The discharge port 5 is formed in a ring shape by a core 6 operably provided at the center of the die 3, and by moving the core 6 in the direction of arrow A, the meat of the parison 12 to be extruded. The thickness can be changed.

The core 6 is connected to a rod 7 penetrating the top portion 1a of the crosshead 4 and freely movable up and down as shown by an arrow A. The upper portion of the rod 7 has a female screw portion 7a. Are formed.

A well-known thrust bearing 2 is provided on the female screw portion 7a to escape the pressure from the resin.
Rotating rod 20A connected to speed reducer 100 through 0
The male screw portion 20Aa is screwed in and out freely, and the speed reducer 100 is connected to the rotary shaft 22a of the motor 22. 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 a control unit 11 having a memory (not shown) storing a program. .

Next, a case where the parison controller of the conventional blow molding machine is operated in the above-mentioned 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 motor 22 via the speed reducer 100, the thrust bearing 20, and the rotating rod 20A.
When 0Aa is rotated, the rod 7 is passed through the female screw portion 7a.
Since only the rod moves in the direction of arrow A and the axial position of the rod 7 is determined, the ring-shaped interval of the discharge port 5 due to the movement of the core 6 in the direction of arrow A can be arbitrarily changed.

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

[0008]

Since the conventional parison controller of the hollow molding machine is constructed as described above, the following problems exist. That is, since the core is moved by using the speed reducer and the screw shaft, a large-sized motor is required, which goes against energy and space.

The present invention has been made to solve the above problems, and in particular, by moving a core provided at a discharge port for discharging a parison via a motor and a link, It is an object of the present invention to provide a parison controller for a blow molding machine, which achieves high quality parison by miniaturization and resource saving.

[0010]

A parison controller of a blow molding machine according to the present invention is configured so that a core provided at a discharge port of a die of a crosshead is moved up and down to increase the thickness of a parison extruded from the discharge port. In the parison controller of the blow molding machine, the core is moved via a link with a motor provided on a fixed body on the crosshead.

More specifically, a screw body which is rotated by the motor and has a right-handed screw portion and a left-handed screw portion, a right-hand screw nut block screwed to the right-hand screw portion, and a left-hand screw screwed to the left-hand screw portion. It is a configuration including a pair of first and second link pieces that are pivotally supported between the nut blocks and the rods connected to the nut blocks and the core to form the links.

[0012]

In the parison controller of the blow molding machine according to the present invention, since the core provided on the die of the crosshead moves through the motor and the link which are controlled by the program, the capacity of the motor can be made small. In addition to this, highly accurate parison thickness control can be performed.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A preferred embodiment of a parison controller for a blow molding machine according to the present invention will be described in detail below with reference to the drawings. In addition, the same or equivalent portions as those of the conventional example will be described using the same reference numerals. FIG. 1 shows a first embodiment, and the reference numeral 1 in FIG. 1 is a crosshead to which a molten resin 4 is supplied from an extruder 2, and a die provided below the crosshead 1. A ring-shaped ejection port 5 for ejecting the molten resin 4 is formed in 3.

The discharge port 5 is formed in a ring shape by a core 6 operably provided at the center of the die 3, and by moving the core 6 in the direction of arrow A, the meat of the parison 12 to be extruded. The thickness can be changed. The above-mentioned configuration is the same as the conventional example.

The core 6 is connected to a rod 7 penetrating the top portion 1a of the crosshead 1 so as to freely move up and down as indicated by an arrow A, and a pin 20 is provided on the upper portion of the rod 7. A link 23 composed of the first and second link pieces 21 and 21A is pivotally supported in a V shape.

A screw body 28 integrally having a right-hand thread portion 26 and a left-hand thread portion 27 is rotatably provided on an upper portion of the fixed body 1A provided on the upper portion of the crosshead 1 through a pair of bearings 24 and 25. The first link piece 21 is pivotally supported on the right-handed screw nut block 30 which is provided and screwed to the right-handed screw portion 26 via the first shaft support portion 31, and the left-handed screw nut block 32 is provided with the second screw nut block 32. The link piece 21A is the second shaft supporting portion 33.
Is pivoted through.

The screw body 28 is connected via a coupling 40 to a rotary shaft 22b of a motor 22 having a detector 22a provided on the fixed body 1A.

Therefore, in the structure of FIG. 1 described above, when the motor 22 is rotated, the screw body 28 is rotated, and the nut blocks 30 and 32 are moved in mutually different directions via the screw portions 26 and 27, respectively. When the link pieces 21, 21A are moved to the positions shown by the solid line and the dotted line, the core 6 moves up and down via the rod 7 and the gap of the discharge port 5 can be changed.

Next, a second embodiment shown in FIG. 2 will be described. That is, FIG. 2 shows a development of another embodiment of FIG. 1, in which the pin 20 is a slide pin and is engaged with the guide groove 7A of the rod 7, The third link piece 50 and the fourth link piece are provided on the shaft supporting portions 31 and 33.
The link piece 51 is pivotally supported, and the third and fourth link pieces 50, 51 are pivotally supported by the fixing pin 60 of the upper projecting portion 1Aa of the fixed body 1A so that the link pieces 21, 21A, 50,
51 is formed in a rhombic shape so as to be operable. Since the other configurations are the same as those in FIG. 1, the same portions are denoted by the same reference numerals and the description thereof will be omitted.

Therefore, when the motor 22 is rotated in the configuration of FIG. 2, the screw body 28 is rotated and the screw portions 26, 2 are rotated.
7, the nut blocks 30 and 32 move in mutually different directions, and the link pieces 21, 21A, 50, and 51 move to the positions shown by the solid and dotted lines, so that the core 8 moves vertically through the rod 7. The gap of the discharge port 5 can be changed by moving.

Next, FIG. 3 shows a third embodiment. In FIG. 3, a pair of fifth and sixth link pieces connected to the upper part of the rod 7 and bendable via a third shaft supporting portion 80. The link 23 composed of 70 and 71 is pivotally supported by the fixing pin 90 of the fixed body 1A above the crosshead 1. The fifth link piece 70 is rotated by the motor 22 via the speed reducer 100, and each link piece 70, The toggle mechanism 200 is configured by 71. Since the other parts are the same as those in the first and second embodiments, the same parts are designated by the same reference numerals and the description thereof will be omitted.

Therefore, in the above-mentioned configuration, the motor 22
By rotating the toggle mechanism 200 into a bent shape and a linear shape by the rotation, the core 6 can be moved up and down via the rod 7.

[0023]

Since the parison controller of the blow molding machine according to the present invention is configured as described above, the following effects can be obtained. That is, since the rotation of the motor is transmitted to the rod via the link, the core can be moved by a smaller motor as compared with the conventional screw configuration. At the same time, compared to the conventional screw configuration, the core can be moved faster, which is advantageous for molded products with large changes in wall thickness (molded products with a large blow ratio), for quick and highly accurate molding. It can be carried out.

[Brief description of drawings]

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

FIG. 2 is a configuration diagram showing a second embodiment.

FIG. 3 is a configuration diagram showing a third embodiment.

FIG. 4 is a configuration diagram showing a conventional configuration.

[Explanation of symbols]

 1 Crosshead 1A Fixed body 3 Die 5 Discharge port 6 Core 12 Parison 21,21A 1st, 2nd link piece 22 Motor 23 Link 26 Right screw part 27 Left screw part 28 Screw body 30 Right screw nut block 32 Left screw nut block 50,51 3rd, 4th link piece 60 Fixing pin 70,71 5th, 6th link piece 200 Toggle mechanism

Claims (2)

[Claims] 1. A discharge port (5) of a die (3) of a crosshead (1)
In the parison controller of the blow molding machine, the wall thickness of the parison (12) extruded from the discharge port (5) is changed by vertically moving the core (6) provided in the core (6). Is the fixed body (1A) on the crosshead (1)
A parison controller for a blow molding machine, characterized in that the parison controller is configured to move via a motor (22) and a link (23) provided in the. 2. A right-hand screw portion (2) rotated by the motor (22).
6) and a screw body (28) having a left screw part (27), a right screw nut block (30) screwed to the right screw part (26), and a left screw screwed to the left screw part (27). A pair of first nuts (32) that are pivotally supported between the screw nut blocks (32) and the rods (7) connected to the nut blocks (30, 32) and the core (6), The parison controller of the blow molding machine according to claim 1, further comprising a second link piece (21, 21A).