JPH0151762B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application This invention relates to a method for measuring the remaining length of a rolled sheet, and more specifically, when feeding a sheet wound into a roll onto a core cylinder, the remaining length of the rolled sheet is measured. The present invention relates to a measuring method capable of measuring the unused remaining length of a rolled sheet in real time.

Conventional technology In corrugated board manufacturing equipment, rolls of core paper and liner wound around a core cylinder are loaded into a mill roll stand, and when operation starts, these base papers and liner are fed from the rolls and continuously supplied to a single facer. This has led to the production of corrugated paperboard. Further, in a web-paper rotary press, printing paper wound into a roll is fed from a paper feed section to a printing device at high speed. In other industries, there is an extremely high demand for the use of rolls, in which long raw fabrics, films, webs, foils, etc. are wound around core tubes, in the production process. , textiles, foils, etc. are collectively referred to as ``sheets'').

In industries that consume such sheets to manufacture desired products, demand for sheets of a predetermined length is anticipated when planning the production of the products. Therefore, it is extremely important to know in advance whether or not the planned demand can be covered by the length of the sheet remaining on the roll set on a mill roll stand etc. in order to formulate an efficient production plan. It's important. However, it is difficult to accurately know the remaining length of a roll sheet, and if you make a mistake in determining this, you may have to stop operation during production on an integrated continuous production line and change the roll. , which could cause major losses in terms of production economy.

Furthermore, when supplying sheets from the rolls, frequent order changes are often required in which rolls of a specific size are removed from the stand and rolls of other sizes are installed and replaced in order to meet the diverse needs of customers. . In such cases, roll sheets that are replaced midway through use are stored in preparation for the next use, but knowing how much unused roll sheet is left is important for inventory management. This is extremely important for management purposes. If this remaining length is not accurately known, when the intermediately used roll is used for the next production, the actual sheet length of the roll will be insufficient compared to the planned sheet length, and the continuous production line will be shortened. This could lead to serious problems such as business suspension.

Problems to be Solved by the Invention In the past, people relied on the experience and intuition of skilled workers to find out how much unused roll sheet length remained. However, as a matter of course, this involves large errors and cannot be adopted under modern production systems. Therefore, instead of such empirical means, there is a known method of calculating the remaining sheet length by, for example, measuring the weight of the rolled sheet with a pressure sensor such as a load cell and converting the length and weight proportionally. ing. However, when the sheet is made of base paper, the weight of the base paper per unit length varies depending on its moisture content and the quality of the base paper rolls that are replaced for each production lot, resulting in large measurement errors. In order to minimize errors, each time the operation starts and during operation,
There is a drawback that frequent manual correction is required.

In addition, as a means for detecting the end of drawing out the roll base paper, the time required for one rotation of the winding roll is taken out in pulses, and the length of the sheet pulled out from the winding roll within the time width defined by the pulse interval is calculated. , a method has been proposed in which a pulse generator that generates one pulse per unit distance is used to take out the paper and count it with a counter, but this method detects the end of the unused roll sheet and detects the end of the unused roll sheet. A major drawback is that the remaining length cannot be measured.

Furthermore, when detecting the remaining amount of roll sheet,
A method of calculating the remaining amount by inputting the sheet thickness as data has also been proposed (for example, Japanese Patent Laid-Open No. 165653/1983). However, it is difficult to separately measure the thickness of the sheet in this way, and practical difficulties have been pointed out, such as the need for a separate thickness measuring device, which increases the installation cost.

In addition, as shown in Special Publication No. 53-47710,
"A first unit coupled to a wound reel of tape-like material.
a pulse oscillator and a second pulse oscillator driven by the tape-like material to be unwound are connected to a circuit arrangement which allows a predetermined reel rotation to determine the duration of the first measuring cycle. and from the number of pulses of the second pulse oscillator emitted during the second measurement period of the same period starting later by a predetermined number of reel rotations, the number of turns is determined by the required formula.
A device for measuring the number of turns of a tape-like material is known. However, even if one attempts to use this device to measure the remaining length of a roll sheet, the above-mentioned publication merely teaches the measurement of the number of turns of a roll sheet, and does not provide any suggestions or suggestions regarding the measurement of the remaining length of a roll sheet. has not been done at all.

Purpose of the Invention The present invention has been devised in view of the above-mentioned drawbacks inherent in the conventional methods and devices for measuring the remaining length of a roll sheet. It is an object of the present invention to provide a method that can achieve highly accurate remaining length measurement without measuring and inputting this as data.

Means for Solving the Invention In order to achieve this object, the method for measuring the remaining length of a roll sheet according to the present invention includes: 1. The outer circumference length at each point of two arbitrary points separated by more than one rotation is determined by the sum of the outer circumference lengths obtained by rotating two or more rotations near each point, and then the outer circumference length of the core tube is determined from the outer circumference length from any one point by the outer circumference length of the core cylinder. Calculate the number of turns up to the outer circumference of the cylinder, set the calculated outer circumference at any one point of the roll sheet and the outer circumference of the core cylinder as the lengths of two parallel sides facing each other, and The method is characterized in that a trapezoid in which the number of turns is a function of height is assumed, and the remaining length of the roll sheet from the arbitrary point to the outer periphery of the core cylinder is calculated by calculating the area of this trapezoid.

EXAMPLES Next, the method for measuring the remaining length of a roll sheet according to the present invention will be described below with reference to preferred examples and the accompanying drawings.

First, in order to contribute to understanding of the method of the present invention, an outline of the principle of measuring the remaining length of a roll sheet will be explained. As shown in FIG.
The circumference of the first round is la, the circumference of the bth week is lb, and the core cylinder 1
Let the circumference of 0 be lc. When the circumferential length of each outer circumference is expanded, a schematic diagram as shown in FIG. 2 is obtained. In addition, in the figure, d indicates the circumferential length difference per one rotation of the roll, and T indicates the number of windings from the bth rotation to the core tube 10, that is, the number of turns.

As can be seen from Fig. 2, the outer diameter of the roll sheet from the a-th round to the b-th round when measurement started is:
If observed every round, it will appear in an arithmetic series. However, it does not become infinitely small from the b-th turn onward, and it draws an arithmetic curve from the b-th turn until it reaches the outer circumference lc of the core tube 10, but the curve ends at the core tube 10. . And, if we consider the diagonally shaded part in Fig. 2 to be a substantially straight line between b and c, then
The circumferences lb and lc are parallel bases, and the height is T
It can be thought of as a trapezoid. Since the area S of a trapezoid is generally calculated as (top side + bottom side) x height/2, in this case as well, the remaining length of the roll sheet at point b should be obtained by calculating the area of the trapezoid. .

In addition, the amount of decrease in the roll outer diameter per one rotation of the roll 12, that is, the circumferential length difference d per one rotation, is calculated by finding a curve that decreases in an arithmetic series between two points from point a to point b. It is calculated by dividing the change by the number of revolutions.

That is, it is determined by d=la-lb/ba.

Therefore, in FIG. 2, the length of the paper from the lbth circumference to the outer circumference lc of the core tube 10 (that is, the unused remaining length of the roll sheet, which is the ultimate measurement target in the present invention) Lb is calculated as described above. Since it is determined by the area of the trapezoid shown with diagonal lines, it is obtained as Lb=T/2(lb+lc).

Here, T (number of turns from the bth turn to the core cylinder 10) = lb-lc/d+1 = lb-lc+d/d ∴Lb=1/2d (lb+lc) (lb-lc+d) ......(1) This is , which is the basic formula for calculating the remaining length of the roll sheet.

By the way, when actually performing specific calculations, the problem is that the sheet thickness is as thin as 0.2 mm to 0.3 mm, so even if the roll sheet rotates once, the roll outer diameter will decrease. This means that the changes are extremely small. Therefore, even if you want to measure the same point, for example, start the measurement one point earlier, and
The curve up to the odd numbered point after 10 rotations may be calculated. For example, the third
In the figure, from the first round of measurement (2m-1)
If the total circumference up to the round is L ₀ , the highly accurate circumference at the m-th round is calculated as = L ₀ /2m-1.

Similarly, from the n+1st round (n+2m-
1) If the total circumference up to the first circumference is Ln, then (n+
m) The highly accurate circumference + of the circumference is calculated as +=Ln/2m−1.

Therefore, the change d in the circumference per revolution is: d=lm/--lm+n/--/(n+m)-m
= 1/2m-1(L ₀ -Ln)/n = (L ₀ -Ln)/(2m-1)n......(2) Therefore, the highly accurate circumference of the (n+2m) round +
2m is +2=+-md=Ln/2m-1-m(L ₀
-Ln)/(2m-1)n=(m+n)Ln-mL ₀ /(2m-1
)n……(3) Therefore, from the (n+2m)th circumference, the outer circumference lc of the core cylinder 10
The remaining length of the roll sheet up to Σln + 2m is calculated using the basic formula (1) previously calculated as Σln + 2m = 1/2d (lb + lc) (lb - lc + d) ...... (4) where lb = + 2 and Equations (2) and (3) of
Since the relationship of the formula holds, d=L ₀ −Ln/(2m−1)n……2 equations, lb=+2=(m+n)Ln−mL ₀ /(2m -1) n...
…Substituting each equation (3), Σln+2m=(2m-1)n/2(L ₀ −Ln)・{(m+n)
Ln−mL ₀ / (2m−1)n+lc} {(m+n)Ln−mL ₀ /(
2m−1)n−lc+L ₀ −Ln/(2m−1)n} =(2m−1)n/2(L ₀ −Ln)・{(m+n)Ln+mL
₀ / (2m-1)n+lc}・{(m+n-1)Ln-(m-
1) L ₀ /(2m-1)n-lc}......(5) In the above equation (5) obtained in this way, m (mth round) and n (nth round) given as constants. ), lc (outer circumference length of the core tube 10), and the values of L ₀ and Ln calculated by the hold circuit described later in connection with FIG. The remaining length of the roll sheet until it reaches the outer circumference lc of the core cylinder 10 is calculated in real time.

An example of a circuit for measuring _L0 and Ln will now be described with reference to FIG. 4. In FIG. 4, reference numeral 14 indicates that each time the roll 12 attached to the mill roll stand 16 rotates once,
A sensor, reference numeral 18, which detects this and generates one pulse, is elastically pressed against the sheet fed out from the roll 12, and generates a pulse train of a constant length per certain length according to the feeding run of the sheet. Each vessel is shown. Note that the M counter in the figure counts the pulses from the sensor 14 after reset 2, and the N counter counts the pulses from the sensor 14 after reset 1.
The L counter counts the pulses from the pulse generator 18 after reset 3.

Now, when measurement starts from the first rotation of the roll sheet, the sensor 14 detects the roll 1
It is detected that the counter 2 rotates once, and then the outputs of reset 1, reset 2, and reset 3 are input from the counting controller (CC) to the N counter, M counter, and L counter, respectively, and all the counters are reset. Next, the N counter and the M counter start counting the number of revolutions of the roll 12 using a pulse sent from the sensor 14, and the L counter starts counting the sheet delivery flow length using a pulse from the pulse generator 18. . After that, when the measured value M of the M counter reaches the preset value of 2m-1,
This is input to the counting controller (CC), and a hold 1 command is output from the counting controller (CC) to the hold circuit 1. As a result, the current count value L of the L counter is held, and this hold value is given to the arithmetic unit (AU) as _L0 .

Next, when the value N of the N counter that continuously counts the output pulses from the sensor 14 reaches n, the counting controller (CC) sends each M
Give the output of reset 2 to the counter and the output of reset 3 to the L counter to reset it once,
Thereafter, the M counter starts counting the output pulses of the sensor 14, and the L counter starts counting the pulses from the pulse generator 18. Then, when the measured value M of the M counter reaches the same preset value of 2m-1, this is input to the counting controller (CC), and another hold is sent from the counting controller (CC). A hold 2 command is output to circuit 2. As a result, L
The count value Ln of the counter at that point in time is held, and this hold value Ln is given to the arithmetic unit (AU).

The arithmetic unit (AU) is given the values m and n of the m-th and n-th turns as well as the outer circumference length lc of the core cylinder 10 in advance as constants, and from the first turn (2m-1 ) Accumulated total lap L up to lap ₀ and n
Total circumference Ln from the first circumference to (n+2m)
is also given as data to the arithmetic unit (AU) by the measurement operation, so all preparations for calculation are now complete.

Therefore, from the counting controller (CC) to the arithmetic unit (AU)
When a calculation start command is given to the calculation unit (AU), the calculation unit (AU) starts calculating the equation (5) obtained earlier, and calculates the sheet length from the (n+2m)th circumference of the roll sheet until it reaches the outer circumference lc of the core cylinder 10. , that is, the remaining length is calculated in real time. The calculated remaining sheet length is displayed on a display as a digital value and recorded by other appropriate means. The sequence of this measurement operation is shown in FIG. 5 as a flowchart.

Effects of the Invention As described above, according to the method according to the present invention, the decrease in the outer circumference of the roll per revolution and the decrease in the outer diameter of the roll per revolution is measured during the unwinding operation of the roll, and the obtained data is used. The remaining length of the roll sheet is calculated by calculating based on a theoretical formula. Even if a roll with an unknown remaining length is set in the equipment and production is started, the remaining sheet length can be calculated after several 10 revolutions. The length can be measured extremely accurately.

Therefore, it is not necessary to obtain data on the sheet thickness and thickness of the roll sheet in advance, and by accurately measuring the remaining length of the roll sheet in this way, the following useful advantages can be obtained. . In other words, whether or not the remaining length of the roll sheet currently set in the equipment is sufficient for the expected required sheet length for the planned production of the product is calculated in real time as a numerical value, so the next roll sheet length can be calculated in real time. Arrangements and other preparations can be made appropriately. This is extremely effective in that it can prevent the unexpected situation of stopping operation for changing rolls in the middle of production in an integrated continuous production line.

Feedback control such as adjustment of the tension applied to the sheet and speed adjustment can be performed according to the remaining length of the roll sheet, so that optimal operating conditions can be obtained at all times.

If there are sheets remaining on a roll after production is completed, the remaining sheet length can be recorded on the roll, making it easier to decide whether the roll can be used as is for the next production.
Inventory management can be performed accurately.

Furthermore, in the method of the present invention, reference data is obtained by measuring the total circumference of the sheet when the roll rotates several tens of times, rather than measuring all the necessary data just by measuring one rotation of the roll. There is no need to use a high-precision pulse generator that generates a large number of pulses per distance, and an inexpensive pulse generator that generates a small number of pulses can be used. Therefore, the counter that counts the generated pulses only needs to be of a low-speed response type, and the arithmetic unit (AU) does not need to be an expensive high-speed processing type, so this method can be implemented at a low cost overall. It is something.

[Brief explanation of drawings]

FIG. 1 is an explanatory perspective view showing measurement points of a sheet wound into a roll, FIGS. 2 and 3 are schematic diagrams for theoretically explaining the measurement method according to the present invention, and FIG.
The figure is a block diagram of a counting control circuit as an embodiment of the measuring method according to the present invention, and FIG. 5 is a flowchart showing the sequence of the measuring operation. 10... core cylinder, 12... roll, 14... sensor, 16... mill roll stand, 18... pulse generator.

[Claims]

1 A pressure control chamber having an output pressure port and a pressure relief port, a moving member movable in a predetermined direction with respect to the pressure relief port, a pressure control chamber provided on the moving member, and having an inlet connected to a source pressure supply source. a source pressure passage whose outlet faces the pressure control chamber; a drive device for moving the movable member to a position according to an input electric signal; and a drive device for moving the movable member to a position in accordance with the input electric signal; a source pressure valve that is movable in the same direction as the movable member and that opens and closes the outlet of the source pressure passage; and a source pressure valve that is movable in the same direction as the moving member with respect to the pressure relief port outside the pressure control chamber and opens and closes the pressure relief port. a pressure relief valve, a pressure relief valve spring that urges the pressure relief valve in a direction to close the pressure relief port, and a pressure relief valve spring that is interposed between the source pressure valve and the pressure relief valve, and that connects the source pressure valve to the outlet of the source pressure passage. An electrical signal-to-pneumatic pressure conversion device comprising: a source pressure valve spring that biases the pressure relief valve in a direction to close the pressure relief port, and at the same time biases the pressure relief valve in a direction to open the pressure relief port.