JPH026003B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a reel that is sequentially replaced and installed on the reel drum of a surf-s reel of a paper making machine such as a paper machine or a coater, and is rotated by pressure contact with the reel drum, and is continuously Measuring the thickness of a rolled paper sheet attached to the Surf-S reel of a paper making machine, where the number of rotations of a spool roll that winds up a paper sheet of a continuous strip to be manufactured is detected to measure the sheet thickness of the paper sheet. It is related to the device, and during operation, the thickness of the paper sheet of the band-shaped continuous body that is being wound on different spool rolls as it runs,
The purpose of this invention is to obtain a device that can measure a running paper sheet without directly contacting it.

As a conventional device for measuring the thickness of a paper sheet, for example, in a paper machine, there is a β-ray thickness meter, which is a device that measures the thickness of paper, which is a continuously running strip. It measures the amount of attenuation of β-rays due to paper, and is expressed in terms of weight per unit area, or basis weight (expressed in units such as g/ ^m2 ), and is also affected by moisture. The actual thickness is measured differently. Of course, the thickness of paper depends on the basis weight, but it also depends on the properties of the papermaking raw materials, especially its freeness, dryness in the dry part, pressure load in the calender part,
It is highly dependent on the contact pressure in the reel part, and direct measurement of thickness has been desired from the viewpoint of papermaking operations. In addition, to directly measure the thickness of running paper, the running paper is narrowed between targets set above and below it, and the thickness is measured, but the targets are not in contact with the running paper. This is not necessarily preferable because paper dust that is slightly peeled off from the paper surface accumulates on the target, causing errors in paper thickness measurement and causing paper breakage, resulting in a decrease in production.

Yet another method for measuring paper thickness is at the reel of a paper machine.

FIG. 1 shows a surf-s reel device 3 among reel devices which are winding devices of a paper machine. The surf-s reel device 3 consists of a reel drum 4 and a spool roll support/pressing device (arm 5 in the illustrated example), and the reel drum 4 moves at a circumferential speed equal to the traveling speed of the paper sheet 1 traveling in the direction of arrow B. The arm 5 is driven to rotate in the direction of arrow C, and during the winding operation of the paper sheet 1 traveling at high speed, the arm 5 rotatably supports the spool roll 6 while moving the spool roll 6 onto the surface of the reel drum 4 ( (SURF-S) to drive the rotation. The spool roll 6 passes through the wound paper sheet 1,
The paper sheet 1 is wound up to form a web 7 while being rotated by the reel drum 4 at the same peripheral speed as the reel drum 4, and is replaced one after another every time a predetermined length is reached. That is, Figure 1 shows the final process of a paper machine, in which liquid pulp and other papermaking raw materials are dehydrated in a wire part and a press part, formed into a sheet, dried in a dry part, and then exited from the dry part. Paper sheet 1 travels in the direction of arrow A as shown in the figure, is pressurized in calendar part 2, and after adjusting the paper thickness, travels in the direction of arrow B.
It travels in the direction and is wound up in the surf-s reel device 3. The winding operation in the surf-s reel device 3 is carried out by pressing the paper with a predetermined contact pressure via the arm 5 onto the surface of the reel drum 4 which is rotationally driven in the direction of arrow C, and the paper is applied to the surface of the rotating spool roll 6. The sheet 1 is wound to form a web 7. The arm 5 is
Although not shown in detail in the illustrated example, a spool roll 6 that is movable on a horizontal plane is rotatable around an arm shaft 8 while being pressed against the surface of the reel drum 4 with a predetermined contact pressure.

As the winding operation progresses, the winding diameter of the web 7 increases to form the web 9, and the spool roll 6 moves to the position of the spool roll 10. During this time, the arm 5 rotates clockwise, and the spool roll 7 is moved from the spool roll 6 to the spool roll 10. When the traveling speed of the paper sheet 1 to be wound up until it reaches the roll 10 is constant, the rotational speed of the spool roll is gradually decreased as the diameter of the paper sheet increases. When the winding length of the paper roll 9 reaches a predetermined length,
The paper sheet 1 is cut on the reel drum 4, and the spool roll 10 with the web 9 wound thereon is removed from the surf-s reel device 3 and replaced by another spool roll that has been previously rotated on the reel drum 4. The leading edge of the cut paper sheet 1 is instantaneously and automatically wrapped around 6, moved to the illustrated position, and then moved to the next winding operation. The above-mentioned spool roll 6 is replaced by the reel drum 4, which always rotates at high speed.
This is done without interrupting the papermaking operation, and no loss of paper sheet 1 occurs during the above-mentioned replacement operation. However, when winding the paper sheet 1 at the beginning of winding onto the spool roll 6 during high-speed operation, or when rewinding due to paper breakage during winding operation, uneven winding and wrinkles may occur in the paper sheet 1 at the beginning of winding. Based on the time of occurrence,
The outer circumferential surface of the web 7 has partial diameter discrepancies in the axial direction, eccentricity, etc.
Since both ends of the spool roll 6 are pressed against the surface of the reel drum 4 by the arm 5 and rotated, uneven rotation of the spool roll 6 and shaft end vibration of both shaft ends of the spool roll 6 relative to the reel drum surface are likely to occur. Also, variations in paper thickness in the running direction of the paper sheet 1,
In particular, slight differences in paper thickness in the width direction are superimposed during winding, resulting in fluctuations in the diameter of the paper roll in the width direction, resulting in uneven rotation of the spool roll 6 and the axes at both ends of the spool roll 6 as described above. Causes edge vibration.

If the winding diameter of the web 7 at a certain moment during the winding operation is _d1 , the winding diameter after a certain time is _d2 , and the number of rotations of the spool roll 6 during this period is C, then 1
The thickness of each paper sheet 1 is determined by d ₂ −d ₁ /2C.

In this sheet thickness measurement method, if the thickness of each paper sheet 1 is not accurate, it is difficult to accurately measure the winding diameter, and the winding paper 7 wound around the spool roll 6 that is replaced one after another may be uneven. If there is,
If the number of rotations of the spool roll 6 is only a few rotations, it may be difficult to accurately measure the winding diameter.
Therefore, the accuracy of measuring the paper sheet thickness at each moment during operation is low, and if the number of rotations C is increased to increase the accuracy, the average paper sheet thickness for C times will be measured. The paper sheet thickness at each moment cannot be measured.

Therefore, it would be desirable to have a paper sheet thickness measuring device that does not have the drawbacks of the prior art described above.

The present invention responds to those demands,
The configuration will be explained below with reference to embodiments shown in the drawings.

As shown in FIG.
This method measures the thickness of the paper sheet 1 during the winding process in the vicinity, and it is calculated by using pulse signals from rotation transmitters at rotating parts such as the calender roll 11, reel drum 4, and spool roll 6. This device measures the change in the winding diameter of the web 7 and the thickness of the paper sheet at approximately each point in time, and is capable of measuring the thickness of the paper sheet without measuring the winding diameter.

Next, the basics of the calculation will be explained. As mentioned above, the rotational speed of the web in the Surf-S Reel device 3, that is, the rotational speed of the spool roll, has slight rotational unevenness, and vibrations at both shaft ends of the spool roll are unavoidable. The calculation must be based on the average radius of the web during multiple rotations. Therefore, when calculating the radius of the paper web, the feature is to obtain the average value during n rotations of the paper web.

If the paper sheet 1 travels a length l while the web 7 having a certain winding radius rotates n times, the average radius r of the web 7 is given by: r=l/2πn (1).

Suppose now that the average radius of the web becomes from r ₁ to r ₂ (r ₁ < r ₂ ), and in each case, during each rotation n ₁ and n ₂ times, the length of the paper sheet increases by l ₁ and l ₂ . If it travels, from equation (1), r ₁ = l ₁ /2πn ₁ ...(2) r ₂ = l ₂ /2πn ₂ ...(3) If the thickness of paper sheet 1 is T, the radius of the paper roll Since T is obtained by dividing the increase in number N by the number of rotations of the web during that period, T is given by the following equation. That is, T=r ₂ − r ₁ /N (2), substituting equations (3), T=(l ₂ /n ₂ −l ₁ /n ₁ )/2πN ...(4) Travel of paper sheet 1 The length l is determined by measuring the number of rotations m of the reel drum 4 that the paper sheet 1 rotates in contact with. That is, reel drum 4
If the radius of is R, then l=2πR・m... (5) If the number of rotations of the reel drum 4 with running length l ₁ is m ₁ and the number of rotations of reel drum 4 with running length l ₂ is m ₂ , then , from equation (5), l ₁ = 2πR・m ₁ ...(6) l ₂ = 2πR・m ₂ ...(7) Substituting equations (6) and (7) into equation (4), T= R/N(m ₂ /n ₂ −m ₁ /n ₁ ) ...(8) Here, since R is constant, m ₁ , m ₂ , n ₁ , n ₂ ,
By measuring N, T at each measurement time can be determined.

Here, if it is measured by a constant number of rotations of n ₁ = n ₂ = n, then T = R/nN (m ₂ - m ₁ )...(9) Here, R/nN is a constant, of which n , N can be set arbitrarily.

However, according to this measurement method, the web 7 is N
Only intermittent data can be obtained with each rotation.

To obtain data continuously, do the following:
That is, the number of rotational pulses m' corresponding to the number of rotations m of the reel drum 4 for every n rotations of the web 7 (assuming that a Q pulse is generated for each rotation of the reel drum, m' = Qm) is sequentially measured. Then, m ₀ ′, m ₁ ′,
Obtaining the data m ₂ ′, m ₃ ′, ... (rolling paper 7
Since _{the diameter of}
m ₃ ′<...) and store these numbers in a storage device or shift register.

Note that from the above equation (9), T=R/nNQ(m ₂ ′−m ₁ ′) ……(9′) is obtained.

For example, N=100, n=10 or N/n=10
Then, when m ₁₀ ′ is obtained, the number of rotations of the web becomes n×10 = N, and at this point, substituting m ₁₀ ′ and the stored m ₀ ′ into the above equation (9′), The sheet thickness T at the time when m ₁₀ ' is obtained is determined. The next time m ₁₁ ′ is obtained, it is conserved as m ₁₁ ′
m ₁ ′, the thickness T at that point can be determined by equation (9′).

By using a storage device or a shift register in this way, if the movement difference is sequentially determined using the stored data, the time for the n constant number of rotations can be calculated with a time delay of the N rotations. Paper sheet thickness data is sequentially obtained at successively close time intervals for each interval.

Based on the above-described calculation basis, the present invention is constructed as follows, as shown in FIG. That is, the roll paper rotation pulse detector 12 attached to the spool roll 6, the reel drum rotation pulse transmitter 13 attached to the reel drum 4, and the selection corresponding to the number of rotations n of the roll paper 7 that can be selected in advance. A preset counter 14 that operates according to the number of winding rotation pulses, a pulse counter 15 that measures the number of pulses m' from the reel drum rotation pulse generator 13 at each pulse interval corresponding to the selected number of winding rotations n, and the pulse counter A storage device (or shift register) 16 for sequentially storing the number of measured pulses m′ [(m _i ′, m′ _i+1 ……m _j ′, ……)] from 15); a computer device; 17. Consists of a constant setter 18 that sends a constant signal corresponding to a preset R/nNQ to the computer device 17, and is stored in the storage device 16 at predetermined time intervals or at desired times. Number of measurement pulses
m′(m _i ′, m′ _i+1 ,...m _j ′,...) (here j=i
+N/n. ) is called up to the computer device 17, and the computer device 17 performs subtraction (m _j ′−m _i ′), etc., and then multiplies the above subtracted value by the constant from the constant setter 18 to obtain the multiplication R/nNQ(m _j ′−m _i '), the paper sheet thickness T between the number of measured pulses m _i ', m' _i+1 , . . . , m _j ' is calculated and output according to the above equation (9).

As mentioned above, the output and display of the paper sheet thickness T according to the present invention requires at least a time delay from the beginning of the generation of the pulse m _i ' to the end of the generation of the pulse m _j ', and the average paper sheet thickness during that time. Although there is a restriction that it is a measurement, it does not detect small ripples that are unnecessary for actual measurement, especially due to uneven rotation of the spool roll, so paper is measured as the average value in the width direction of the paper sheet. The sheet thickness can be measured with stable and high accuracy.

Therefore, by inputting the above-mentioned output paper sheet thickness T value into another automatic control device, it is possible to mix the raw materials, control the supply amount, control the freeness, control the dryness in the dry part, and control the dryness in the calendar part. It is also possible to use it for various automatic controls such as the control of pressurized loads. In addition, in the embodiment shown in FIG. 1, the traveling length l of the paper sheet 1 is determined by measuring the number of rotational pulses m' corresponding to the number of rotations m of the reel drum 4 that the paper sheet 1 contacts and rotates. However, instead of using the reel drum 4, it may be determined by the number of rotation pulses corresponding to the number of rotations of a paper sheet contact roll having a constant radius, which the paper sheet 1 rotates in contact with.

Further, generally, a paper sheet is stretched by applying tension, and its thickness is reduced accordingly, but the diameter of the paper sheet can be more significantly reduced or increased by increasing or decreasing the contact pressure with the reel drum during winding.

In the above-mentioned embodiment as well, the winding stiffness of the web 7 changes depending on the tension applied to the paper sheet 1 between the calendar part 2 and the reel 3 and the contact pressure that presses the web 7 against the reel drum 4, and the diameter of the web changes. This causes a difference in the amount of change, resulting in a difference in the thickness of the paper obtained.

Therefore, depending on the case, it may be necessary to make corrections using external forces such as the tension and contact force.

The tension applied to the paper sheet 1 is determined by the speed difference between the surface speed of the calender roll 11 of the calender part 2 and the surface speed of the reel drum 4 of the reel 3 (this is called a draw). Since the diameter of the calender roll 11 and the diameter of the reel drum 4 are each constant, the number of rotations of the calender roll 11 and the reel drum 4 in the same time are different.
By determining the number of rotations, the difference in surface speed, that is, the draw, can be determined.

The number of rotations of the reel drum 4 is obtained by a reel drum rotation pulse detector 13, and the number of rotations of the calendar roll 11 is obtained by a calendar rotation pulse transmitter 19 attached to the roll 11. Calendar rotation pulse transmitter 19 as shown in FIG.
The draw D is obtained by applying the pulses from the rotation speed and the pulses from the reel drum rotation speed pulse generator 13 to the computer 17 and calculating the difference in circumferential speed between the calender roll 11 and the reel drum 4. Further, the contact force for pressing the web 7 against the reel drum 4 can be determined by detecting the force P exerted by the arm 5 on the spool roll 6, and this force P can be detected by the force detector 20 attached to the arm 5. Alternatively, it can also be obtained by measuring the fluid pressure of a fluid pressure cylinder that applies rotational pressure to the arm 5.

A computer device 1 calculates the values of the draw D and the pressing force P.
In addition to step 7, calculate the sheet thickness T' corrected by a correction formula stored in a predetermined computer device,
It can be output.

Various formats can be considered as the correction formula, and for example, the following format may be used.

T′=K ₁ (α ₁ D/D ₀ +β ₁ ) (α ₂ p/P ₀ +β ₂ )T+K ₂ …(10) However, T′……Correction paper sheet thickness T……Paper sheet thickness before correction D...Draw D ₀ ... Draw reference value P... Pressure force P ₀ ... Pressure force reference value K ₁ , K ₂ , α ₁ , α ₂ , β ₁ , β ₂ ... Constants D ₀ , P ₀ are This is a value determined by operational standards,
K ₁ , K ₂ , α ₁ , α ₂ , β ₁ , and β ₂ are determined in advance from a large amount of operational data, including the type of paper machine, the type of paper produced, and the paper raw materials. Different values are taken depending on the machine speed and other operating conditions, and these constants are stored in advance in a computer device.

The output of this corrected paper sheet thickness value T′ is
As mentioned above, it is of course possible to use the data as input data for automatic control equipment.

The above-mentioned embodiment describes a surf S winding reel as shown in FIG.

Note that the above-mentioned computer device 17 can be a separate computer, but can also be configured by an attached electronic circuit.

Although the embodiments described above are applied to a paper machine, the present invention can also be applied to any apparatus for continuous production of coated paper web sheets, such as a coater.

Since the present invention has the structure described in the claims, by detecting a pulse corresponding to the running length of the paper sheet and a pulse corresponding to the number of rotations of the winding, and storing and calculating the data. , without directly measuring the thickness of a paper sheet that is easily torn, the paper sheet thickness can be calculated as the average value in the width direction of the paper sheet, regardless of the weight per unit area, that is, the basis weight, and the moisture content. This is an excellent invention that allows for accurate measurements, is useful for automatic operation, does not produce errors even in long-term measurements, and does not cause production to be hindered.

[Brief explanation of drawings]

FIG. 1 is a side view schematically showing a paper machine calendar and a surface reel part, and FIG. 2 is a block diagram of a paper sheet thickness measurement process. 1: Paper sheet, 6: Spool roll, 7: Roll paper, 12: Roll paper rotation pulse detector, 13: Reel drum rotation pulse transmitter, 14: Preset counter, 15: Pulse counter, 16: Storage device, 17: Computer Device, 18: Constant setter.

Claims (1)

[Claims] 1. A spool roll that is sequentially replaced and installed on the reel drum of a surf-s reel of a paper manufacturing machine, and is rotated by pressure contact with the reel drum to wind up continuous paper sheets in the form of a continuous band. A web sheet thickness measuring device attached to a surf-s reel of the paper manufacturing machine, which measures the sheet thickness of the paper sheet by detecting the number of rotations of each spool roll. A roll paper rotation pulse detector, a reel drum rotation pulse transmitter that detects the number of rotations of the reel drum, a preset counter that operates at a selected number of roll paper rotation pulses corresponding to a preselectable number of rotations of the roll paper, and the preset counter. Selection from counter A pulse counter that measures the number of pulses from the reel drum rotation pulse transmitter at each roll paper rotation pulse interval, a storage device that sequentially stores and saves the number of measured pulses measured by the pulse counter, a computer device, and a selectable device. The computer device reads the number of measured pulses stored in the storage device, subtracts it, and then multiplies it by the setting constant signal from the constant setting device. and further corrected by the contact pressure force between the web and the reel drum,
A web sheet thickness measuring device on a surf-s reel drum of a paper manufacturing machine, characterized in that the thickness of the paper sheet is sequentially calculated and output during the winding operation.