JPH0140741B2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field to which the Invention Pertains] The present invention relates to a method and device for manipulating the die bolt angle position of a T-die for extrusion molding a plastic sheet, etc., and in particular to a slide lip or a die bolt angle position and a fixing member opposing thereto. The present invention relates to an operating method and apparatus for automatically operating the angular position of a plurality of die bolts provided in the width direction of the slide lip or the like in a pattern of flow path gaps formed by the above.

[Prior art and its problems]

BACKGROUND ART Conventionally, a T-die constructed as shown in FIG. 4 has been known as a T-die constructed so as to be able to adjust thickness unevenness in the sheet width direction during extrusion molding of plastic sheets and the like. That is, FIG. 4 shows a slide-rip type T-die configured to use a slide lip to adjust the gap between the dies for extrusion molding sheets and the like. In FIG. 4, reference numeral 10 indicates a fixed lip, and 12 indicates a sliding lip, and the lip gap 14 formed by these lips 10, 12 defines the thickness of the plastic sheet to be extruded. However,
This slide lip 12 is provided with a plurality of die bolts 16 in the width direction, and these die bolts 1
6 along the sliding surface 20 of the movable die 18 to adjust the lip gap 14 (see FIG. 5).

However, conventional extrusion molding machines that use T-dies equipped with this type of adjustment mechanism use scanning thickness gauges that measure the thickness by reciprocating the measuring head in the width direction of the plastic sheet being extruded. An automatic profile control system is adopted in which the die bolt is operated by a servo motor or the like to set the lip interval of the T-die at an appropriate position.

However, in this case, smooth engagement of each die bolt with a coupling means for operating the die bolt becomes an unavoidable important issue in order to improve control characteristics. From this point of view, various proposals have been made in the past to facilitate engagement by modifying the shape of the head of the die bolt and the socket of the connecting means that engages with the head, such as chamfering. However, the engagement of these conventional coupling means has the following problems.

(1) A clutch mechanism is required to prevent unnecessary rotation of the die bolt due to the torque generated during engagement. In addition, to eliminate play during engagement,
It is necessary to separately provide a low torque motor. This not only complicates the configuration, but also increases the equipment space and manufacturing costs.

(2) Even if the shape of the engaging portion is modified, it is not possible to engage each die bolt in a straight manner. Therefore, an extra correction operation for engagement is required, resulting in a disadvantage that the operation speed, that is, the work efficiency is reduced.

(3) Although the socket of the coupling means can be made rotatable by a certain angle with respect to the drive shaft, the problems of items (1) and (2) above are not solved in this case as well.

[Purpose of the invention]

An object of the present invention is to achieve smooth engagement with a coupling means for adjusting a die bolt with a simple configuration and control operation, and to achieve high precision and high automatic profile control in an extrusion molding machine for plastic sheets, etc. It is an object of the present invention to provide a method and device for efficiently controlling the die bolt angle position of a T-die for extrusion molding of plastic sheets and the like.

[Key points of the invention]

The method of controlling the die bolt angle position of a die for extrusion molding of plastic sheets, etc., according to the present invention, operates a plurality of die bolts using an automatic profile control device to adjust the lip distance and adjust the thickness of the plastic sheet, etc. to be extruded. In the method for adjusting the die bolt angle position of the T-die to be adjusted, the socket is engaged with the required die bolt and rotated, and then the socket is reversed by the play angle from the stop position, and the angular position of the socket is determined as the current angle of each die bolt. It is characterized by detecting the position and updating and storing this data, calculating a profile control signal for each die bolt due to thickness variation based on this updated data, and executing profile control of the die bolt based on this control signal. shall be.

On the other hand, the die bolt angle position operating device of the present invention is equipped with a T-die die bolt that operates a plurality of die bolts by an automatic profile control device to adjust the gap between the lips and the thickness of the extruded plastic sheet, etc. In a die bolt angular position operating device for an extrusion molding die, a socket is engaged with a required die bolt and rotated, and then the angular position of the socket is determined by reversing the socket by an amount of play angle from a stopped position and is used as the current angle of each die bolt. A means for detecting the position and sequentially updating and storing this data, and calculating the thickness data obtained by the thickness gauge of the plastic sheet etc. extruded from the T-die together with data regarding the current angular position of the die bolt, a calculation means for obtaining a rotation angle signal as a profile control signal, and an execution means for engaging a required die bolt and rotating it to perform profile control of the die bolt based on the calculation means, The means are
It is characterized by comprising a pulse motor that rotationally drives the socket, a fluid pressure cylinder that moves the socket forward and backward with respect to the die bolt, and a servo motor that positions the socket with respect to a predetermined die bolt.

[Embodiments of the invention]

Next, a preferred embodiment of the method for controlling the angle position of a die bolt for an extrusion molding die for plastic sheets, etc., according to the present invention will be described in detail in relation to the apparatus with reference to the accompanying drawings.

FIG. 1 shows the configuration and control system of a die bolt angular position operating device used to carry out the method of the present invention. In FIG. 1, reference number 30
4 shows a T-die which is connected to an extrusion molding machine to continuously extrude the plastic sheet S, as in FIG. This T-die 30 is, for example, a fixed lip 3
2 and a slide lip 34, the slide lip 34 is provided with a plurality of die bolts 36 in the width direction, and these die bolts 36 are connected to the movable die 3.
By displacing the lip gap 42 relative to the wall surfaces 40 of 8, the lip gap 42, which defines the thickness of the extruded plastic sheet S, can be configured to be adjustable. Note that the lip gap 4 of the T-die 30
The plastic sheet S extruded from 2 is
The plastic sheet S is suitably delivered via a cast roll 44, and a measuring head of a scanning thickness gauge 46 is provided in part of the delivery path of the plastic sheet S.

On the other hand, a socket 4 as a coupling means that engages with the head of the die bolt of the T-die 30
A drive mechanism 50 with 8 is provided. This drive mechanism 50 has an operation head 52 that holds the socket 48, and a socket drive pulse motor 54, a socket pushing fluid pressure cylinder 56, and a socket engagement detector 58.
and a positioning servo motor 60 for moving the operating head 52 so that the socket 48 is positioned opposite to the plurality of die bolts 36 attached to the T-die 30 side. Incidentally, a detection end portion 62 for performing a detection operation of the socket engagement detector 58 is built inside the socket 48. Drive mechanism 50 configured in this way
In order to perform automatic profile control on the T-die 30 of the extrusion molding machine, the above-mentioned controllers are calculated and controlled by a computer system based on measurement data from the scanning thickness gauge 46. That is,
In the embodiment shown in FIG. 1, the computer system includes a CPU 64, an internal storage device 66,
keyboard 68, external storage device 70, and CRT
Displays 72 are connected and arranged, respectively.

Therefore, the measurement signal from the scanning thickness gauge 46 is input to the CPU 64 via the interface 74, and the detection signal from the socket engagement detector 58 is also input to the CPU 64. On the other hand, predetermined arithmetic control commands are sent from the CPU 64 to the socket driving pulse motor 54 via the pulse motor controller 76, to the positioning servo motor 60 via the servo motor controller 78, and to the electromagnetic switching valve 80. is supplied to a hydraulic cylinder 56 for pushing the socket. In this embodiment, a position detector 82 such as a rotary encoder is provided for the socket driving pulse motor 54 to detect the rotational position of the pulse motor 54 and send this detection signal to the pulse motor controller 76. The configuration is such that the data is input to the CPU 64 as arithmetic processing data via the CPU 64.

Further, in the present invention, the geometric dimensions of the engagement between the head of the die bolt 36 and the socket 48 are set as follows. FIG. 2 shows the engagement relationship between the regular hexagonal die bolt head 36a and the engagement hole 48a of the socket 48 in a neutral position, and FIG.
6a and the engagement hole 48a of the socket 48. From the relationship shown in FIG. 2, the engagement hole 48a of the die bolt head 36a and the socket 48
The relationship between the gap c and the play angle α until engagement is generally expressed by the following equation.

cosβ=(1×c/a)cos(180°/n)...(1) α=180°/n-β...(2) However, n=number of angles of die bolt head 36a For example, as shown in FIG. In the example, n=6, c=
If 0.3 mm and a=9.5 mm, β≒25° and α≒3°.

Next, a basic control method for the apparatus of the present invention having the above configuration will be explained.

First, the operation unit 5 is pressed against the die bolt 36.
The positioning servo motor 60 for moving the die bolt 36 is operated to position the socket 48 at a position facing a predetermined die bolt 36.

Activate the socket drive pulse motor 54,
Based on the data stored in the internal storage device 66 of the computer system, the socket 48 is placed in a substantially neutral position (second position) with respect to the die bolt 36.
(see figure).

The electromagnetic switching valve 80 is operated to move the socket 48 forward and engage the head of the die bolt 36.

Activate the socket drive pulse motor 54,
After the die bolt 36 is rotated (effective angle + α) based on the calculation control command, it is reversed by the play angle α, and the head of the die bolt 36 and the socket 48 are returned to the neutral position. During this time, the angular position of the socket 48 is detected by the position detector 82, etc., and this data is updated and stored as a current value in the internal storage device 66 of the computer system.

The electromagnetic switching valve 80 is operated to move the socket 48 backward and disengage it from the die bolt 36.

In the apparatus of the present invention, the above-mentioned operations are appropriately performed on each die bolt 36 to adjust the lip gap of the T-die, and the extrusion molding machine is operated to continuously extrude a plastic sheet of a predetermined thickness. Furthermore, when a plastic sheet is being extruded, automatic profile control can be achieved by repeating the above operations for the required die bolts 36 based on the measurement data of the scanning thickness gauge.

Particularly, in the present invention, in the control operation, the socket 4 is connected to the head of the die bolt 36.
8 are held in contact with each other by the fluid pressure cylinder 56 at a pressure that can maintain the frictional torque to a minimum, and in this state, the pulse motor 54 is operated to rotate the socket 48 in the tightening direction of the die bolt 36. As a result,
The socket 48 rotates in sliding contact with the head of the die bolt 36, and engagement in its neutral position is achieved within a rotation angle of 360°/n. At this time, the socket 48 moves forward and the state of engagement with the die bolt 36 is confirmed by the engagement detector 58. Furthermore, since the state of engagement between the socket 48 and the die bolt 36 at this time is indeterminate, the socket 48 may be further tightened by at least 2α.
If it is rotated more than this, the engaged state as shown in FIG. 3 will be achieved. The angular position of the die bolt 36 at this time is detected by the position detector 82 or the like as 360°/n from the reference position, and this data is updated and stored in the internal storage device 66 of the computer system. Thereafter, by reversing the socket 48 by α, the state of engagement with the die bolt 36 can be brought to the neutral position as shown in FIG.
Retraction of socket 48 from 6 can be easily accomplished. Note that the current angular position of the die bolt 36 can be easily detected by counting the number of pulses that command the drive of the pulse motor 54 that rotates the socket 48 when the die bolt 36 is engaged with the die bolt 36 using a computer system. I can do it.

〔Effect of the invention〕

As is clear from the embodiments described above, according to the operating method of the present invention, the lip gap of the T-die for extrusion molding can be adjusted in an extrusion molding machine for plastic sheets, etc., which performs automatic profile control with adjustable thickness. The current angular position of each die bolt is updated and memorized by an operating device using a computer system that automatically adjusts each die bolt, and the engagement between the die bolt to be controlled and the socket of the device that operates it is always maintained at the neutral position. Smooth and quick engagement can be achieved in any situation. Therefore, according to the device of the present invention, it is possible to perform automatic profile control quickly and reliably at low cost without employing the flexible structure of the clutch, torque motor, socket, special processing of the engaging parts, etc. as in the past. It can be realized.

Although the preferred embodiments of the present invention have been described above, it goes without saying that various design changes can be made without departing from the spirit of the present invention.

[Brief explanation of drawings]

FIG. 1 is a system diagram of the control system of the operating device used to implement the method for operating the die bolt angle position of a die for extrusion molding of plastic sheets, etc. according to the present invention;
Figures 3 and 3 are explanatory diagrams showing the state of engagement between the head of the die bolt and the socket in the present invention, Figure 4 is a perspective view of the main part of a conventional slide-rip type T-die, and Figure 5 is the same as Figure 4. FIG. 2 is a vertical cross-sectional view of a main part of the T-die shown in FIG. 30...T-die, 32...fixed lip, 34...
...Slide lip, 36...Die bolt, 38...
... Movable die, 40 ... Wall surface, 42 ... Lip gap, 44 ... Cast roll, 46 ... Scanning thickness gauge, 48 ... Socket, 50 ... Drive mechanism, 5
2... Operation head, 54... Pulse motor for driving socket, 56... Fluid pressure cylinder for pushing socket, 58... Socket engagement detector, 60... Servo motor for positioning, 62... Detection end, 64 …
...CPU, 66...Internal storage device, 68...Keyboard, 70...External storage device, 72...CRT
Display, 74...Interface, 76...
...Pulse motor controller, 78... Servo motor controller, 80... Solenoid switching valve, 82... Position detector, S... Plastic sheet.

Claims (1)

[Scope of Claims] 1. A method for adjusting the angle position of a die bolt of a T-die in which a plurality of die bolts are operated by an automatic profile control device to adjust the distance between lips and the thickness of an extruded plastic sheet, etc., comprising: is engaged with the required die bolt and rotated, and then the angular position of the socket, which is reversed by the play angle from the stop position, is detected as the current angular position of each die bolt, and this data is updated and stored. A die bolt angular position operating method for an extrusion molding die, characterized in that a profile control signal for each die bolt due to thickness variation is calculated based on updated data, and profile control of the die bolt is executed based on this control signal. 2. A die bolt angle position operating device for an extrusion molding die equipped with a T-die die bolt, which operates a plurality of die bolts using an automatic profile control device to adjust the distance between lips and adjust the thickness of a plastic sheet, etc. to be extruded. In this step, the socket is engaged with the required die bolt and rotated, and then the angular position of the socket is detected by reversing the socket by the play angle from the stop position as the current angular position of each die bolt, and this data is sequentially updated. The thickness data obtained by the thickness gauge of the plastic sheet etc. extruded from the T-die is calculated together with the data regarding the current angular position of the die bolt, and the rotation angle signal of each die bolt is used as a profile control signal. a calculation means for obtaining
The execution means engages with a required die bolt and rotates it to control the profile of the die bolt based on the calculation means, and the execution means includes a pulse motor that rotationally drives the socket, and a pulse motor that rotationally drives the socket. 1. A die bolt angle position operating device for an extrusion molding die, comprising: a fluid pressure cylinder that moves the socket forward and backward relative to the die bolt; and a servo motor that positions the socket relative to a predetermined die bolt.