JP3212648B2 - Adjusting the gap between the base of automatic T-die with deckle - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic T-die for forming a plastic sheet or the like, which is provided with a deckle (width adjusting mechanism) having a closing portion for width adjustment at least at one end of an effective portion for extruding a die. The present invention relates to a die gap adjusting method for setting a die bolt operation amount of a T-die.

[0002]

2. Description of the Related Art In recent years, the trend of high-mix low-volume production has been increasing.
As shown in FIG. 1, the side edge of the extrusion gap 12 of the base 10 is closed with a deckle 14 to form a deckle portion 16, and an automatic T-die with a deckle in which the base extrusion effective width portion 18 is variable has been used. I have. The base 10 is provided with a plurality of die bolts 24 on the movable base 22, and the bending of the neck portion 22 a (see FIG. 2) of the movable base 22 is adjusted by pushing and pulling the die bolts. The gap 12 is configured to be adjustable. Also,
Reference numeral 20 is a fixed base, 26 is a base manifold, 28
Indicates a partition.

In this type of automatic T-die, the same applies to a normal (not equipped with deckle) automatic T-die, but in order to achieve the set thickness of the molded sheet and the thickness accuracy in the width direction. It is indispensable to adjust the base gap to a predetermined value. However, since this adjustment interferes with the die bolts, that is, when a specific die bolt is operated, its action spreads not only to a position corresponding to the operated die bolt, but also to a position corresponding to another unoperated die bolt. Difficult and subtle,
Traditionally, it relied on manual experience and intuition. However, this manual operation requires a great deal of time and is dangerous, and it has not been possible to achieve a sufficient adjustment accuracy.

Therefore, the present applicant has previously developed a technique capable of automatically performing the adjustment, and has disclosed a technique disclosed in Japanese Patent No. 132362.
No. 7 was patented and successfully put to practical use. In the following, this patent invention will be briefly described. In FIG. 5, a die bolt 24n (n =
In the operation of (m + 1, m + 2,... n) (see FIG. 1), first, a die corresponding to each die bolt is obtained from a deviation value between a preset target sheet thickness pattern corresponding to each die bolt and an actual sheet thickness during molding. A target gap change amount ΔCi to be changed is determined (first step). Next, from the target gap change amount ΔCi and the mutual proportionality constant f _ij to the die gap change of the die bolt load set theoretically or experimentally in advance, the load change amount Δ to be changed by the die bolt
Find Pj. That is, the following equation (4)

[0005]

(Equation 2)

Is calculated. Further, the load change amount ΔP
j, die bolt spring constant k, and the target gap change amount Δ
Then, the bolt operation amount ΔWi is obtained from Ci. That is, the following equation (5) ΔWi = ΔCi + (ΔPi / k) (5) is calculated (second step). Finally, this bolt operation amount Δ
According to Wi, each die bolt 24n is operated by thermal expansion, a servomotor, or the like. In other words, each die bolt 24n
Is operated via the sum of the target change amount ΔCi of the movable base 22 and the elastic change amount Pj / k of the bolt itself due to the load change.
In this manner, according to the above-described patent invention, the die gap adjustment can be automatically and accurately achieved.

Therefore, it is proposed to apply the above-mentioned patented invention also to a method of adjusting a gap between the bases of an automatic T-die with a deckle. 5 and 6 show the target gap change ΔCn, the load change ΔPn, and the streamline 30 of the molten plastic, respectively, when the patented invention is applied to the automatic T-die with deckle shown in FIG. It is.
Here, the dimension 1 in FIG. 6 indicates the width of the molded sheet, and this sheet width 1 is smaller than the width L of the effective portion 18 by ΔL (with respect to one side of the base), which is caused by the viscoelasticity of the molten plastic. Is what you do.

[0008]

As described above, according to the above patent invention, it is possible to automatically adjust the gap between the base and the automatic T-die with the deckle. However, it has been found that the above technique has the following disadvantages.

That is, the above-mentioned technique applies the above-described patent invention to the die bolts 24n (n = m + 1, m + 2,... N) of the effective width portion 18 and the die bolts 24m (m = 1, 2,. m) (see FIG. 1), which is left unoperated, whereby the flow of molten plastic (streamline 30a) through the manifold 26 behind the deckle 14 has a strong effect on the sheet thickness, Width l
In addition, it has been found that the thickness accuracy in the width direction, particularly the thickness accuracy at the edge in the width direction, is reduced. This can be easily inferred from the fact that the patented invention does not originally have a deckle, that is, is applied to a T-die having a partition wall 28 'at the end of the base (see FIG. 6). But it was.

SUMMARY OF THE INVENTION An object of the present invention is to provide an automatic die with a deckle which can easily calculate the amount of operation of the die bolt to be adjusted by arithmetic operation without lowering the sheet width and thickness accuracy in the width direction. An object of the present invention is to achieve a method of adjusting a gap between bases.

[0011]

In order to achieve the above object, a method of adjusting a gap of a die of an automatic T-die with a deckle according to the present invention comprises a plurality of die bolts for adjusting a gap of a die for forming a plastic sheet or the like. In the method of adjusting the gap of the automatic T-die with a deckle having a deckle part closed at least on one side end of the effective width part of the mouth of the automatic T-die, the gaps corresponding to the die bolts should be changed. For the effective width portion, the target gap change amount is determined from the deviation value between the target sheet thickness pattern set in advance and the actual sheet thickness during molding, while for the deckle portion, the innermost die bolt is located at the end of the effective width portion. The change amount of the outer die bolt is set to be substantially equal to the change amount of the outer die bolt, and the remaining die bolts are set so that the outermost die bolt has a change amount of almost zero. A first step and a load change amount to be changed for each of the die bolts based on the target gap change amount and a predetermined cross-proportional constant to a die gap change of the die bolt load corresponding to the target gap change amount. And a second step of calculating and setting the load change amount, the die bolt spring constant, and the target gap change amount.

In the above method for adjusting the gap between the die, the first step is to divide the die gap of the automatic T-die with the deckle into an effective width portion for discharging a sheet or the like and a deckle portion closed by the deckle. The total number of die bolts is n, the number of die bolts in the deckle is m (n> m), and the thickness of a sheet or the like formed from the effective width portion is measured. In comparison with the thickness, the target gap change amount of the die gap at each die bolt position of the effective portion to be corrected from the deviation is defined as ΔCi (i = m + 1, m + 2,... N), while the die at each die bolt position of the deckle portion .DELTA.Ci (i = 1, 2, 3,... M) is calculated from the following equation (6) to determine the target gap change amount of the gap: .DELTA.Ci = i / _{m.times..DELTA.Cm + 1} (6) Load change of each bolt to obtain target gap change amount ΔCi .DELTA.Pj (j = 1, 2, 3,...)
n), and the cross-proportional constant for the die gap change of the die bolt load set theoretically or experimentally is f _ij, and the following equation (7) which holds between these variables

[0013]

(Equation 3)

The load change amount ΔPj is calculated from
The die bolt operation amount ΔWi is calculated from the following equation (8) based on the calculated load change amount, the spring constant k of the die bolt alone, and the target gap change amount ΔCi of the die gap: ΔWi = ΔCi + (ΔPi / k) (8) It can be set as follows.

[0015]

According to the present invention, in applying a conventional patented invention,
In the first step of determining the target gap change amount, the patent invention is applied as it is to the die bolt (24n) of the effective width portion, while the innermost die bolt is the outermost die bolt of the effective width portion to the die bolt (24m) of the deckle portion. , And the remaining die bolts are gradually reduced so that the outermost die bolt has a change amount of almost zero. Then, in the second step of determining the operation amount of the die bolt, all the die bolts are determined. (24n, 24m)
The method of the patented invention is applied to the invention.

As described above, when adjusting the gap between the bases, the die bolts of the effective width portion and the deckle portion are simultaneously and predeterminedly operated, so that the flow (streamline) of the molten plastic behind the deckle portion in the prior art described above is caused. The disturbance of the sheet edge thickness is substantially eliminated, so that the adjustment of the sheet width and the thickness can be accurately and automatically achieved.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, an embodiment of a method for adjusting a gap of a base of an automatic T-die with a deckle according to the present invention will be described in detail with reference to the accompanying drawings.

First, the configuration of the automatic T-die with deckle is the same as that already described with reference to FIGS.

In the die gap adjusting method according to the present invention, first, in FIGS.
n (n = 1, 2,... n), the target gap change amounts ΔCi (n = 1, 2,.
In the first step for determining n), the above-described patented invention is applied to the effective width portion 18 as it is. That is, each die bolt 24n (n = m + 1, m +) in the effective width portion
2,... N), the sheet thicknesses formed corresponding to these are measured, and this sheet thickness is compared with a sheet thickness pattern in the width direction set as a target in advance.
The target gap change amount ΔCi (i = m +) of the die gap corresponding to each die bolt position of the effective width portion to be corrected from the deviation.
1, m + 2,... N). However, Deckell part 1
6, the target change amount ΔCi (i = 1, 2,...) Of the die gap corresponding to the position of each die bolt 24m (m = 1, 2,... M).
m) is calculated from the following equation (9): ΔCi = i / m × ΔC _{m + 1} (1) That is, the deckle die bolt 24m
The target change amount ΔCi corresponding to the position is set so as to gradually decrease toward 0 from the target change amount ΔC _{m + 1} corresponding to the effective width die bolt 24 _{m + 1} position closest to the deckle portion.

Next, all die bolts 24n (n = 1, 2,...)
n) to determine the manipulated variable ΔWi (i = 1, 2,... n)
In the process, the patented invention is applied as it is. That is, first, the following equation (10)

[0021]

(Equation 4)

Thus, the load change amount ΔPj (j = 1, 2,...) Of each die bolt to obtain the target gap change amount ΔCi.
n) is calculated. Here, f _ij is a constant proportional to the change in die gap of the die bolt load set theoretically or experimentally. Next, the die bolt operation amount Δ (i = 1, 2,... N) corresponding to the load change amount ΔPi is calculated from the following equation (11) ΔWi = ΔCi + (ΔPi / k) (11). Here,
k is the spring constant of the die bolt alone.

Finally, each die bolt 24n is subjected to thermal expansion, a servomotor or the like in accordance with the die bolt operation amount ΔWi.
(N = 1, 2,... N) is operated.

However, according to the adjustment method of the present invention, the die bolt 24n (n = m + 1, m) of the effective width portion is used.
+2,... N) and 24 m (m
= 1, 2,... M), the molten plastic flow (stream line 30a) behind the deckle portion is compensated for, as shown in FIG. Substantially eliminated. As a result, the width l and the thickness of the sheet can be adjusted with high accuracy. It is clear that this adjusting operation is automatically achieved.

The preferred embodiment of the present invention has been described above. However, the present invention is not limited to the above-described embodiment, and many design changes can be made without departing from the spirit of the present invention.

[0026]

As described above, the method for adjusting the gap of the die of the automatic T-die with the deckle according to the present invention comprises the step of extruding the die of the automatic T-die having a plurality of die bolts for adjusting the gap of the die for forming a plastic sheet or the like. In the die gap adjusting method of the automatic T-die with a deckle having a deckle part at least on one side end of the effective width part, a target gap change amount to be changed for each die gap corresponding to each die bolt, Determined from the deviation value between the preset target sheet thickness pattern and the actual sheet thickness during molding, on the other hand, with respect to the deckle portion, the innermost die bolt is determined to be approximately equal to the change amount of the outermost die bolt of the effective width portion, The remaining die bolts have almost zero outermost die bolts
A first step of gradually decreasing the amount of change in the die gap, and setting the operation amount of each die bolt corresponding to the target clearance change amount to the target clearance change amount and a preset die bolt load relative to the die clearance change. And the second step of calculating and setting the load change amount to be changed for each of the die bolts from the above and the load change amount and the die bolt spring constant and the target gap change amount. Is automatically achieved, and in this adjustment, unlike the conventional method, the die bolt in the deckle part can be operated simultaneously with the die bolt in the effective width part. The disturbance in the thickness of the portion is eliminated, and thus the accuracy of the width and thickness of the formed sheet can be improved at the same time.

[Brief description of the drawings]

FIG. 1 is a schematic perspective view illustrating a configuration of a base of an automatic T-die with a deckle.

FIG. 2 is a sectional view of a main part taken along line II-II of FIG. 1;

FIG. 3 is an explanatory diagram showing a target gap change amount and a load change amount with respect to each die bolt of a deckle portion and an effective width portion at the time of adjusting a die gap set according to the present invention.

FIG. 4 is an explanatory view showing a flow state of molten plastic inside a die in the adjustment method of the present invention shown in FIG. 3;

FIG. 5 is an explanatory diagram showing a target gap change amount and a load change amount with respect to a die bolt of an effective width portion in the conventional die gap adjustment.

FIG. 6 is an explanatory diagram showing a flow state of molten plastic inside a die in the conventional adjusting method shown in FIG.

[Explanation of symbols]

Reference Signs List 10 base 12 base gap 14 deckle 16 deckle part 18 effective width part 20 fixed base 22 movable base 22a neck part 24m, 24n die bolt 26 manifold 28 partition wall 30 streamline ΔCm, ΔCn target gap change amount ΔPm, ΔPn
Load change

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-3-53922 (JP, A) JP-A-2-63715 (JP, A) JP-A-2-38022 (JP, A) 50133 (JP, B2) (58) Fields investigated (Int. Cl. ⁷ , DB name) B29C 47/00-47/96

Claims (2)

(57) [Claims] 1. An automatic T-die equipped with a deckle having a deckle portion closed at least at one end of an effective width portion of a die extrusion of an automatic T-die provided with a plurality of die bolts for adjusting a die gap for forming a plastic sheet or the like. In the method of adjusting the die gap of the T die, the target gap change amount to be changed for each die gap corresponding to each die bolt is defined by comparing a preset target sheet thickness pattern with the actual sheet thickness during molding for the effective width portion. From the deviation values, the innermost die bolt of the deckle portion is determined to be almost equal to the change of the outermost die bolt of the effective width portion, and the remaining die bolts are gradually reduced so that the outermost die bolt has a change of almost zero. A first step of setting the operation amount of each die bolt corresponding to the target gap change amount as the target gap change amount in advance. The amount of change in the load of the die bolt to be changed is calculated from the mutual proportional constant of the die bolt load to the change in the die gap, and the second change is calculated and set from the load change, the spring constant of the die bolt, and the target clearance change. Automatic T with deckle characterized by comprising two steps
Die gap adjustment method. 2. The first step is to divide the base gap of an automatic T-die with a deckle into an effective width portion for discharging a sheet or the like and a deckle portion closed by a deckle, and to reduce the total die bolt number of the T-die to n. The number of die bolts in the book and deckle portions is m (n> m), and the thickness of a sheet or the like formed from the effective width portion is measured and compared with the thickness of a sheet or the like in the width direction set in advance as a target. The target clearance change amount of the die clearance at each die bolt position of the effective part to be corrected from the deviation is defined as ΔCi (i = m + 1, m + 2,... N).
.DELTA.Ci (i = 1, 2, 3,... M) is calculated from the following equation (1) to calculate the target gap change amount of the die gap at each die bolt position of the deckle part, and .DELTA.Ci = i / _{m.times..DELTA.Cm + 1} (1) In the second step, the load change amount of each bolt for obtaining the target gap change amount ΔCi is set to ΔPj (j = 1, 2, 3,... N), and the die bolt load set theoretically or experimentally is determined. Let f _ij be a mutual proportionality constant with respect to a change in the base gap, and the following equation (2) that is established between these variables: From the calculated load change, the spring constant k of the die bolt alone, and the target gap change ΔCi of the die gap, the die bolt operation amount ΔW is calculated.
The method according to claim 1, wherein i is calculated from the following equation (3): ΔWi = ΔCi + (ΔPi / k) (3)