JPH071561A - Lip gap adjusting method - Google Patents

Abstract

PURPOSE:To accurately perform the rough adjustment of a lip gap within a short time. CONSTITUTION:The thickness of a film or sheet is measured in the lateral direction thereof and, from the measured deviation, the objective change quantity DELTAyi of a lip gap is calculated and the operation quantity DELTAxi in such a case that all of lip gap adjusting means (die bolts) are set to operation objects is calculated on the basis of the objective change quantity DELTAyi. A specific lip gap adjusting drive means (die bolt) large in the operation quantity DELTAxi is selected and the operation quantity DELTAxi is adjusted so that the change quantity DELTAyci of the lip gap due to the selected means approaches the objective change quantity DELTAyi to perform rough adjustment and, thereafter, precise adjustment is performed by all of the lip gap adjusting means.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a film or sheet molding machine, and more particularly to a method for adjusting a lip gap for adjusting a widthwise thickness of a film or sheet and its distribution to desired values.

[0002]

2. Description of the Related Art Adjustment of a lip gap in a film or sheet molding machine is performed by a lip gap adjusting driving means including a large number of bolts and heaters arranged along the lip. That is, the bolt is rotated manually or automatically, the lip is deformed according to the amount of extension of the bolt to adjust the gap, and the bolt-shaped object is expanded and contracted by the temperature adjustment by the heater, whereby the lip is deformed to reduce the gap. I am adjusting.

Various methods have been proposed in which the amount of operation such as the amount of rotation of the bolt and the temperature of the heater is calculated by a computer and the lip clearance is adjusted more accurately (for example, Japanese Patent Publication No. 60-50133, JP-A-1). -29582
No. 0).

[0004]

By the way, a lip gap adjusting drive means such as a bolt is 50 to 10 along the lip.
Since it is a very large number of 0 or more, it is not preferable to adjust the total number from the rough adjustment stage from the viewpoint of efficiency, and it is possible to select and adjust only a portion having a large deviation from the conventional one. Has been done.

In the rough adjustment stage in which only a part of and unspecified lip gap adjusting driving means is operated, if the method of calculating the operation amount by the computer is applied as it is for all of them, an accurate adjustment can be made. I can't do it. That is, since the lip portion is continuous in the width direction,
The lip adjustments by the respective lip gap adjusting driving means influence each other to cause a predetermined lip gap change. For this reason, when only the specific lip gap adjusting drive means is operated, a desired lip gap change cannot be obtained.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a lip gap adjusting method capable of more accurately performing lip gap adjustment including a rough adjustment step. There is.

[0007]

SUMMARY OF THE INVENTION To achieve the above object, the present invention is to measure the thickness of a film or sheet during molding in the width direction and compare it with a target value. In the method of adjusting the lip gap by determining the amount of change and calculating the operation amount of each lip gap adjusting drive unit based on this target change amount by a predetermined calculation formula, when the deviation is large, the lip gap adjusting drive unit Of these, a specific lip gap adjustment drive means having a large deviation is selected, and a correction amount is added to the operation amount obtained by the above-described calculation formula, so that the specific lip gap adjustment drive means causes a variation amount closer to the target change amount of the lip gap. Is applied to adjust the lip gap and when the deviation becomes small, the lip gap is adjusted by obtaining the manipulated variable by the above calculation formula for all the lip gap adjusting means. It is intended.

[0008]

When the deviation of the film or sheet thickness in the width direction is large, not all the lip gap adjusting driving means are operated, but only the specific lip gap adjusting driving means having a large deviation is adjusted. At this time, the operation amount of the lip gap adjustment drive means is obtained based on a calculation formula for all the lip gap adjustment drive means including conventionally known ones. Since the operation amount obtained by this calculation formula is a value for all the objects, when only a specific lip gap adjustment drive means is adjusted, the change in the lip gap due to the adjustment of the remaining lip gap adjustment drive means is added. Therefore, the target change amount cannot be obtained. Therefore, in consideration of this amount, the value obtained by the above-mentioned calculation formula is corrected to give a variation of the lip gap close to the target variation. As a result, rough adjustment can be performed accurately in a short time. Then, when the deviation becomes small, the adjustment amount from the rough adjustment to the fine adjustment can be performed very accurately by adjusting the total number of the lip gap adjusting driving means by using the operation amount obtained by the above-mentioned calculation formula as it is. .

[0009]

Embodiments of the present invention will be described below with reference to FIGS.
Will be described with reference to. FIG. 1 is a partially cutaway perspective view of a lip portion of a film or sheet molding machine, in which 11 is a fixed lip, 12 is a movable lip, and Y is a lip gap. Although not shown in FIG. As shown in FIG. 2, a plurality of screw holes 13 located above the lip 12 are respectively engaged with die bolts 14 as a lip gap adjusting drive means, and their tips press the upper surface of the movable lip 12 with an appropriate load. It is supposed to do.

When the die bolt 14 is used as the driving means for adjusting the lip gap, the operation amount Δxi of n die bolts is used.
Can be calculated based on the following equation, as disclosed in Japanese Patent Publication No. 60-50133.

[0011]

[Equation 1]

However, Δyi: target change amount of lip gap Y, Δpi: load change amount of die bolt 14, Δpj: Δ
The load change amount of the other die bolt 14 according to the load change amount of pi, fij: displacement characteristic constant matrix of the lip gap Y, k _B :
This is a spring constant for expansion and contraction of the die bolt 14.

The target change amount Δyi in the equation (1) is obtained from the deviation by comparing the thickness of the film or sheet being formed in the width direction with a predetermined target value (thickness). It is a thing.

Using this target change amount Δyi and the displacement characteristic constant matrix fij previously obtained and stored, the multidimensional linear simultaneous equations of equation (1) are solved to obtain the unknown number Δpj.

Next, these solutions Δpj are substituted into Equation (2) as Δpi to calculate the manipulated variable Δxi of each die bolt 14.

If the manipulated variable Δxi calculated by the above method is applied to all die bolts 14, the desired target variation Δyi is obtained.
It is as disclosed in Japanese Patent Publication No. 60-50133.

According to the present invention, in the rough adjustment stage where the deviation is large, all the die bolts 14 are not operated, and m / n pieces are selected and operated from the above calculation result in the descending order of the operation amount Δxi. The ratio m / n can be set appropriately, but is preferably about 1/2 to 1/10.

By the way, using the manipulated variable Δxi obtained from the equations (1) and (2) as it is, the specific die bolt 14
It is not possible to obtain the target variation Δyi by operating only.

FIG. 4 shows a simulation result when all the die bolts 14 are operated. The operation amount Δxi obtained from the target change amount Δyi is the die bolt No. 1 to
It is shown that when applied to all of Nos. 21 and 21, the actual lip change amount Δyci obtained by the simulation is approximately equal to the target change amount Δyi.

However, as shown in FIG. 5, using the same Δxi as in FIG. 2, 6, 11, 1
Even if only five die bolts 6 and 20 are operated, as shown by Δyci in FIG. 5, it is ⅓ of the target change amount Δyi.
Only about 1/2 change amount can be obtained.

As shown in FIG. 4, when all the die bolts are operated, each die bolt is operated by Δxi.
Although the movable lip 12 is changed by causing a load change amount Δpi corresponding to the above, in the case of FIG. 5, the load change amount Δpi of the non-operated die bolt is small in the die bolt adjacent to the operated die bolt, but in the opposite direction. Since the reaction amounts of the movable lip 12 are concentrated on the operated specific die bolts, the load change amount Δpi of this specific die bolt becomes larger than that in the case of FIG. 4, and the deformation of the die bolt becomes large. This is because the (expansion / contraction) amount becomes larger than that in the case of FIG. 4 as well, and the desired variation amount Δyci cannot be obtained.

This will be described with reference to FIG. As shown in FIG. 2B, when the operation amount Δxi is applied to the die bolt 14, the movable lip 12 tries to change by an amount equal to the operation amount Δxi. With this change, a load is applied to the tip of the die bolt 14. The reaction force indicated by the amount of change Δpi acts.

Since the die bolt 14 contracts due to this pressure, that is, the load change amount Δpi, the movable lip 12 actually changes only by δci. This δci is expressed by the following equation (3)
Given in.

[0024]

[Equation 2]

On the other hand, the die bolt 14 adjacent to the operated die bolt 14 has an operation amount Δ, as shown in FIG. 2 (A).
Although xi is zero, since the movable lip 12 is continuous in the width direction, the actual change amount Δy by the simulation of FIG.
As indicated by ci, the change in δci occurs under the influence of the operated die bolt 14. Note that this δci
Is the die bolt 14 No. The value varies depending on
It goes without saying that it is similar to the change amount Δyci and the like.
The load change amount Δpi at this time is as shown in FIG.

Since a certain load is already applied to the die bolt 14 which is not operated, even if the load change amount Δpi is in the opposite direction to that of FIG. Absorb the die bolt 14
The tip of the above is kept in contact with the upper surface of the movable lip 12.

By the way, the actual change amount Δyci calculated from the above equations (1) and (2) and the actual change amount δci obtained from the equation (3) must match. The present embodiment utilizes this displacement characteristic of the movable lip 12, and based on the operation amount Δxi calculated from the equations (1) and (2), the operation amount Δ of the die bolt 14 specified as described above.
xi is appropriately determined, and the load change amount Δpi is also appropriately determined and substituted into equations (1) and (3) to obtain Δyci and δci.
Respectively, and Δpi is corrected by the following equation (4).

[0028]

[Equation 3]

By substituting the corrected Δp′i as a new Δpi into Equations (1) and (3) again, Δyci and δci are obtained, until (Δyci−δci) is within the allowable value. The correction by the equation (4) and the recalculation based on it are repeated (step 1).

If (Δyci-δci) is within the allowable value, the target change amount Δyi and Δyc calculated as described above are obtained.
i is compared, and Δxi is modified by the following equation (5) so that (Δyci−Δyi) is within the allowable value (step 2).

[0031]

[Equation 4]

The corrected Δx'i is set as a new Δxi, and the process returns to step 1 above to correct Δpi.
This is repeated so that (Δyci−Δyi) falls within the allowable value. It should be noted that the correction calculation in step 2 is usually performed once or twice.

When the operation amount Δxi of the specific die bolt 14 is obtained in this way, the operation amount Δxi is given to the die bolt 14 to change the lip gap Y.

FIG. 6 shows the manipulated variable Δ obtained as described above.
xi, the same No. as in FIG. 2,6,11,16,2
The load change amount Δpi and the actual change amount Δyci of the lip gap Y when the five die bolts 0 of 0 are operated are shown. As is apparent from FIG. 6, the actual change amount Δyci is extremely close to the target change amount Δyi.

FIG. 3 is a general flow chart of the process of obtaining the operation amount Δxi of the specific die bolt 14 described above. First, the selection conditions of the operation target die bolt 14, for example, the selection ratio m / n, the presence or absence of selection. A deviation value or the like serving as a criterion for determination is input, and the operation amount Δxi is determined as described above.

In this way, if the deviation is within the predetermined value, the process proceeds to the next step in which all the die bolts 14 are operated.

In the rough adjustment stage using only the specific die bolts 14 described above, lip gap adjustment is performed manually or by automatically rotating the die bolts 14 using a bolt runner or the like to perform a fine adjustment for all die bolts 14. At the stage, a heat displacement type heat bolt may be used.

The above-described embodiment is described in Japanese Examined Patent Publication No. 60-5013.
Although an example according to the lip gap adjusting method disclosed in Japanese Patent Laid-Open No. 3-2, that is, an example in which the die bolt 14 expands and contracts according to the load change amount Δpi has been shown, the lip gap adjusting drive means such as the die bolt 14 causes elastic deformation. When it does not occur or is not affected by elastic deformation, for example,
Various modifications can be made such that the manipulated variable Δxi may be obtained using only equations (1) and (5).

[0039]

As described above, according to the present invention, the rough adjustment of the lip gap can be performed extremely accurately, the adjustment time of the lip gap can be shortened, the occurrence of defective products can be suppressed, and the productivity can be greatly increased. The effect that can be improved.

[Brief description of drawings]

FIG. 1 is a partially cutaway perspective view showing an example of a lip portion of a film or sheet molding machine to which the present invention is applied.

FIG. 2 is a diagram showing a change state of a die bolt and a movable lip of a lip portion shown in FIG.

FIG. 3 is a general flowchart showing an embodiment of a lip gap adjusting method according to the present invention.

FIG. 4 is a diagram showing a target change amount Δyi, an operation amount Δxi, a load change amount Δpi, and a simulation actual change amount Δyci when operating all die bolts.

5 is a diagram corresponding to FIG. 4 when only a specific die bolt is operated using the operation amount Δxi shown in FIG. 4.

FIG. 6 is a diagram corresponding to FIG. 5 in the case where the operation amount Δxi of a specific die bolt is corrected and given according to the present invention.

[Explanation of symbols]

 11 Fixed lip 12 Movable lip 13 Screw hole 14 Die bolt

Claims (1)

[Claims] 1. The thickness of a film or sheet being formed is measured in the width direction and compared with a target value, the target change amount of the lip gap is determined from the deviation, and each lip gap is determined based on the target change amount. In the method of adjusting the lip gap by obtaining the operation amount of the adjustment drive means by a predetermined calculation formula, when the deviation is large, a specific lip gap adjustment drive means having a large deviation is selected from the lip gap adjustment drive means. , The lip gap adjustment is performed by adding a change amount closer to the target change amount of the lip gap by the specific lip gap adjustment drive means by correcting the operation amount obtained by the calculation formula, and the deviation is A lip gap adjusting method characterized in that when the size becomes smaller, the operation amount is calculated by the above-mentioned calculation formula for all the lip gap adjusting means and the lip gap is adjusted.