KR101568229B1 - Winding apparatus of web and its controlling method - Google Patents

Abstract

A winding device in which the output of a motor is restricted on the outermost circumference side of a winding roll, which can obtain precise winding characteristics, is disclosed. The winding device adjusts the nip load in the web along the nip roller. At this time, for the winding range in which the winding ratio of the winding roll becomes 80% or more, the nip load increases as the winding ratio increases. In a preferred form, an analysis model is used to optimize the winding tension. In the analytical model, the nip load is set as a variable, and the nip load is also optimized.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a web winding apparatus,

The present invention relates to a web winding apparatus and a control method thereof.

The winding process of the web is widely used in many industrial products such as liquid crystal displays, cellular phones, and printed sheets. The applicant of the present application first proposed a web winding technique of Patent Document 1. In this winding technique, a winding motor for rotating a winding core for winding a web, and a tension adjusting means for adjusting a rotation speed of the winding motor to adjust the tension at the time of winding are provided. The winding of the winding roll (The ratio of the radius of the winding roll at the present point occupying the maximum value (100%) of the preset maximum winding radius of the winding roll) And on the latter side, the winding tension of the web is gradually reduced.

On the other hand, the basic theory of web winding is evolving every year. According to the related basic theory, it is possible to quantitatively grasp the internal stress state of the winding roll on which the web is wound by using an analytical model including a predetermined nonlinear two-phase differential equation. Further, when it becomes possible to quantitatively model the internal stress state of the wind-up roll, various conditions can be optimized when the web is wound. The inventor of the present invention has developed and proposed a technique of calculating the radial stress and the circumferential stress of the winding roll and calculating the optimum winding condition based on the calculation result based on the internal stress analysis model proposed previously Document 1).

[Prior Art Literature]

[Patent Literature]

[Patent Document 1] Patent No. 2825457

[Non-Patent Document]

[Non-Patent Document 1] Hashimoto et al., &Quot; Optimum Winding Tension and Nip-load into Wound Webs for Protecting Wrinkles and Slippage ", published by Japan Institute of Mechanical Engineers, Journal of Advanced Mechanical Design, Systems, and Manufacturing, Vol. 4 (2010) no. 1 pp. 238-248

According to the technique of Patent Document 1, a practical winding characteristic can be obtained with a relatively simple control such as setting a taper ratio (reduction ratio of winding tension) which is very suitable in advance. On the other hand, as revealed by the technique of the non-patent document, the optimum winding control by the precise analysis model is not a simple characteristic that the tension is necessarily received at the rear side.

Here, it is preferable to obtain winding characteristics close to a more accurate analysis model.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and it is an object of the present invention to provide a web winding apparatus and a control method thereof that can obtain accurate and practical winding characteristics based on recent research results.

In order to solve the above problems, the present invention provides a web winding device comprising a winding motor for rotating a winding for winding a web, and a tension adjusting means for adjusting a rotation speed of the winding motor to adjust a tension at the time of winding, A nip roller for pressing the outer periphery of the web wound on the core, a nip load adjusting means for adjusting a nip load on the web by the nip roller, and a winding range for the winding ratio of the winding roll being 80% And a nip load control means for controlling the nip load adjusting means such that the nip load increases as the winding rate increases. Herein, the winding ratio refers to the ratio of the radius of the winding roll at the present point of time to the maximum value (100%) of the winding radius of the winding core set to the initial value (0%) and the outermost radius of the winding roll set in advance. In this embodiment, the nip load is increased as the winding ratio increases, with respect to the winding range in which the winding ratio of the winding roll becomes 80% or more, so that the shortage of the winding tension, which is generated in the latter half of winding, Can be supplemented. Therefore, a very suitable winding property is exhibited, and the internal stress of the winding roll is appropriately distributed. As a result, it is possible to prevent wrinkles and sagging from occurring in addition to the prior art.

A tension function storage means for storing a tension function indicating the winding tension in relation to the radial direction coordinate of the winding core; at least a circumferential stress acting on the winding roll of the web, a frictional force between the layers, A target value storage means for storing an objective function having a critical frictional force as a parameter; an objective function storage means for storing a target frictional force as a parameter, wherein the frictional force is equal to or more than the critical frictional force, A constraint function storage means for storing a constraint function for setting a constraint of an objective function; and an evolution processing means for evolving the tension function until the objective function becomes smaller under the condition set by the constraint function, The nip load control means controls the tension adjusting means based on the winding tension calculated by the advanced tension function And also with, to control the nip load on the basis of a value of when the objective function becomes smaller. In this configuration, the tension function for setting the winding tension can evolve under a predetermined condition, and a very suitable winding tension can be calculated, so that it is possible to wind various webs in a suitable state while preventing wrinkles and sagging.

In a preferred form, the constraint function storage means stores a design variable having the nip load as a parameter as a parameter of the constraint function, and the evolution processing means optimizes the nip load set as a variable. In this form, the pressing force of the nip roller can be more suitably adjusted because the nip load used as an element of the design parameter can be optimized in the process of evolving the tension function. Therefore, the winding tension can be optimized by a precise analysis model. In addition, with respect to the winding range in which the winding ratio of the winding roll is 80% or more, the nip load which increases with the winding ratio increases can be optimized while maintaining the optimum winding tension, .

According to another aspect of the present invention, there is provided a web winding apparatus comprising: a winding motor for rotating a winding core that winds a web; tension adjusting means for adjusting a tension at the time of winding by adjusting a rotation speed of the winding motor; A control method for controlling a web winding apparatus equipped with a nip roller, the method comprising: a winding ratio detecting step of detecting a winding ratio of the winding roll; and a winding ratio detecting step of detecting a winding ratio of the winding roll And a nip load control step of controlling the nip load so as to increase the nip load in accordance with an increasing work.

A tension function defining step for defining a tension function indicating the winding tension in relation to the radial direction coordinate of the winding core with respect to a preferred embodiment; and a tension function definition step for defining at least a friction force between the circumferential stress and the layer acting on the winding roll of the web, An objective function defining step of defining an objective function with a critical frictional force as a parameter; setting a constraint of the objective function such that a minimum value of the radial stress inside the wind-up roll is a positive value and the frictional force is equal to or greater than the critical frictional force An evolution step of evolving the tension function until the objective function becomes smaller under conditions set by the constraint function; and a step of, based on the winding tension calculated by the evolved tension function, The tension adjusting means is controlled, and the nip when the objective function becomes small Wherein the nip load control step controls the tension adjusting means based on the winding tension calculated by the advanced tension function, and the nip load control step controls the tension adjusting means based on the objective function The nip load is controlled based on the value at the time when the load is small.

For a preferred form, the step of defining the constraint function is to define a design variable having the nip load as a parameter as a parameter of the constraint function, and the step of evolving is to optimize the nip load set as a variable.

INDUSTRIAL APPLICABILITY As described above, according to the present invention, since the winding tension of the winding roll is gradually reduced from the predetermined winding ratio on the latter half side, it is possible to obtain a winding roll which is free from winding defects such as wrinkles and deflection . In addition, as for the winding range in which the winding ratio of the winding roll becomes 80% or more, the nip load increases with the increase of the winding ratio, so that the shortage of the winding tension that is generated in the latter half of winding is compensated by the nip load There is a number. Therefore, the internal stress of the wind-up roll is appropriately distributed, exhibiting more suitable winding characteristics. As a result, the present invention achieves a remarkable effect that can prevent wrinkles and sagging from being added to the prior art.

1 is a schematic configuration diagram of a winding device according to an embodiment of the present invention.
Fig. 2 is an explanatory view showing an enlarged main part of Fig.
Fig. 3 is a graph showing the characteristics of the roll tension at each dimensionless roll radius position in the evolution process.
Fig. 4 is a graph showing the characteristics of the nip load at each dimensionless roll radius position in the evolution process.
FIG. 5 is an entity relation (ER) diagram showing a part of the database structure according to the embodiment of FIG.
6 is a diagram showing an example of a screen for executing the optimization program according to the embodiment of FIG.
7 is a diagram showing an example of a screen for executing a web and machine condition setting program according to the embodiment of Fig.
8 is a diagram showing an example of a screen for inputting operation conditions according to the embodiment of FIG.
Fig. 9 is a diagram showing an example of the execution state of the optimization program according to the embodiment of Fig. 1 as an example.
10 is a flow chart showing an example of optimization control processing according to the embodiment of FIG.
11 is a graph showing the winding tension-winding ratio.
Fig. 12A is a graph showing characteristics calculated based on the winding tension in Fig. 11, and is a graph showing the frictional force for each winding ratio. Fig.
Fig. 12B is a graph showing the characteristics calculated based on the winding tension in Fig. 11, and is a graph showing the radial stress for each winding ratio.
Fig. 12C is a graph showing characteristics calculated based on the winding tension in Fig. 11, and is a graph showing the circumferential stress for each winding ratio. Fig.
13 is a graph showing an example of execution of the optimization program according to the embodiment of FIG.
FIG. 14A is a graph showing characteristics that can be obtained based on the winding tension and the nip load in FIG. 13, and is a graph showing the frictional force for each winding ratio. FIG.
Fig. 14B is a graph showing the characteristics that can be obtained based on the winding tension and the nip load in Fig. 13, and is a graph showing the radial stress for each winding ratio.
Fig. 14C is a graph showing the characteristics that can be obtained based on the winding tension and the nip load in Fig. 13, and is a graph showing the circumferential stress for each winding ratio.
15 is a graph showing another example of the optimization program according to the embodiment of FIG.
16 is a graph showing a comparative example using an optimization program according to the embodiment of Fig.
17 is a graph showing another comparative example using the optimization program according to the embodiment of FIG.
18 is a graph showing another comparative example using the optimization program according to the embodiment of Fig. 1
19 is a graph showing an operation example of Fig.
20 is a graph showing an operation example of Fig.
21 is a graph showing an example of the operation in Fig.
22 is a graph showing an operation example of Fig.
23 is a graph showing an operation example of Fig.
24 is a flow chart showing another embodiment of the present invention.

Best Mode for Carrying Out the Invention Hereinafter, the best mode for carrying out the present invention will be described with reference to the accompanying drawings.

1, the winding device 100 shown in the figure is a device for winding a web 10 from a roll 1 of a winding device 101 wound around a web 10, 2, a pair of pinch rollers 3 and a nip roller 4 to the outer periphery of the winding core 5a of the winding roll 5. Although not shown, an edge position control device for preventing a difference in position of the web 10 and a load cell for detecting the winding tension of the web 10 are provided in a path from the roll 1 to the winding roll 5 Respectively.

The nip roller 4 is provided with a nip load adjusting device 6 as nip load controlling means by adjusting the pressing force against the winding roll 5. The nip load adjusting device 6 is embodied as an electropneumatic transducer having a pressurized air source, an air cylinder, a regulator for regulating the output of an air cylinder, and the like, and is disposed between the nip roller 4 and the winding roll 5 The nip load N of the nip 45 formed on the nip 45 can be adjusted.

A motor 7 is connected to the winding core 5a of the winding roll 5 so that the winding core 5a itself rotates to wind the web 10. [

As the web 10, a reactive sheet used in a liquid crystal panel, a display monitor, a cellular phone, a solar cell system, various other products, or a printed matter can be used.

For the control of the nip load adjusting device 6 and the motor 7, the winding device 100 is provided with a control unit 20. The control unit 20 has a storage unit 21, a control unit 22, a motor control unit 23, and a nip load adjustment unit 24 as logical modules. Furthermore, the display unit 25 and the input / output unit 26 are connected to the control unit 20 so that the operator can perform necessary data processing to the input / output unit 26 while viewing the display of the display unit 25. [

The storage unit 21 is a module embodied as a ROM, a RAM, an auxiliary memory, or the like and having an area for storing control programs and parameters for controlling the entire winding device 100.

The control unit 22 has a microprocessor, a storage device, and an input / output interface, reads control programs and data stored in the storage device, and executes the control programs to control the elements constituting the control unit 20 (Nip load adjustment section 24, display section 25, and input / output section 26).

The motor control section 23 is a module for controlling the rotation speed of the motor 7 on the basis of the calculation result of the control section 22. [ In the present embodiment, the motor control unit 23 also serves as a tension adjusting means for adjusting the winding tension Tw of the web 10 through the rotation speed control of the motor 7. [

The nip load adjusting section 24 is a module for adjusting the pressing force by the nip load adjusting device 6 based on the calculation result of the control section 22. [ In the present embodiment, the nip load adjusting section 24 can detect the winding ratio Rr of the winding roll 5 based on the number of revolutions and the operation time of the motor 7. Wherein and the outermost peripheral radius r _max of the take-up rate Rr is, and the radius rc of the winding core (5a) to the initial value (0%), the take-up roll 5 has been set in advance as the maximum (100%), the take-up at the present time Refers to the ratio of the radius r of the rolls 5.

The display unit 25 is a unit embodied by a liquid crystal display or other display device.

The input / output unit 26 is a unit embodied by a pointing device such as a keyboard and a mouse, and an input / output device such as a card reader.

Further, depending on the mode in which the winding device 100 is implemented, it is also possible that the control unit 20 is provided with a communication function so that the control program and data are communicated with the host computer.

Next, the control of the winding tension Tw and the nip load N executed by the control unit 22 in the present embodiment will be described.

First, the main nomenclature used in the following description is shown in Table 1, and the major physical quantity corresponding to FIG. 2 is shown.

2, an interlayer pressure (radially compressive stress) σ _r is always applied to the web 10 at a position of an arbitrary winding radius r of the winding roll 5, and the web 10, And is pressed by each layer of the web 10 at this outer diameter. On the other hand, in the circumferential direction, the circumferential stress? _T acts, but depending on the radial position of the winding roll 5, it can be compressed even if it is pulled. The stress in the width direction of the take-up roll 5 is normally calculated in the same manner. For this stress state,

sign Justice unit C ₀ ~ C ₂ (7) Coefficient of equation E _c Elongation modulus Pa E _mip Elongation modulus of nip roll Pa E _r The radial elongation modulus Pa E _ra Elongation modulus of air layer Pa E _req The radial equivalent elongation modulus Pa E _t Tensile elongation modulus of wound roll Pa E _teq The tangential direction equivalent elongation modulus Pa f (X) Objective function F _cr Critical frictional force with slip N F _i Web interlaminar friction force of winding roll N

Average value of web interlaminar friction force of winding roll N g _i (X) (i = 1 to 2n + 2m + 2) Constraint function h The thickness of the air layer at the time of winding m h ₀ The thickness of the air layer in the outer layer of the roll m N Nip load N N (r) Nip load function N p _a Atmospheric pressure Pa r Any radius of the winding roll m r _c Radius of coverage m r _max Maximum winding diameter of roll m S The outermost radius of the winding roll m t _f Web thickness at any radius during winding ㎛ t _f0 The web thickness at the initial stage at the start of winding ㎛ T _w (r) Coiling tension function N / m T _w0 (r) Initial Coiling Tension Function N / m Δ _i (i = 1 to n) the amount of change from the initial set tension at the i-th node N / m Δ _i (i = 1 to m) the amount of change from the initial nip load at the i-th node N U _w Web winding speed m / s w Width of web m X Design variable vector μ eff Effective friction coefficient between web layers μ s Static friction coefficient between web layers v Circumferential direction σ ff Composite surface roughness between web layers ㎛ σ r Radial stress in the wound roll Pa δσ _r Increment of radial stress Pa σ _t Tangential stress in the wound roll Pa φ Taper ratio of winding tension

It is possible to calculate according to the application of the web winding theory (Hakiel model) described later.

In addition, when the nip roller 4 is used, a nip load N [N] is generated in the nip 45 occurring between the nip roller 4 and the winding roll 5. Specifically, in the form described later, the nip load N also greatly affects the internal stress of the wind-up roll 5. It is preferable to calculate the nip load N by the nip line load divided by the web width, and in the apparatus according to the present embodiment, the specific calculation is calculated by the nip line load. However, for convenience of explanation, It is unified and explained.

The winding apparatus 100 according to the present embodiment shown in Figs. 1 and 2 is called a center drive winding system. It has been confirmed that the analysis of the internal stress in the center drive winding system is effective for the web winding theory called the Hakiel model. However, the Hakiel model does not take into account air entrainment or nip load, and can not be used as it is. Therefore, in the following description, to facilitate understanding of the present embodiment, the extended Hakiel model is used in the case of involving entrainment of air and nip load. The Hakiel model is schematically shown below.

Radial stress in the i-th layer of the winding roll (5) σ _ri is the i + n-th layer from the first layer to obtain the whole added to the stress increment δσ _ri of the respective layers to the (last layer of the winding), formula (1) Lt; / RTI > However, the i-th layer refers to the i-th layer when the layer in the core 5a is the first layer and the layers are sequentially measured toward the outer layer.

(1)

(One)

However, δσ _rij represents the stress increment in the j-th layer when it is wound up to the i-th layer.

The equation governing δσ _rij (in the equation below, subscript i, j is omitted) in equation (1) is given by

(2)

(2)

Equation (2) is an equation that is the basis of winding, and is hereinafter referred to as " winding equation. &Quot; Since the winding equation (2) includes differentials of up to two stages with respect to the variable r and the parameter (E _teq / E _req ) is a function of the nonlinear extensional elastic modulus E _{req in} the r direction, It is an ordinary differential equation. Therefore, in order to solve the winding equation (2), two boundary conditions regarding the outermost layer (r = s) and the innermost layer of the winding roll 5 are required.

Here, when considering the nip load, the boundary conditions are as follows.

(3)

(3)

(3), which takes account of air entrapment, by using the relationship between the stress and strain of the equivalent layer of the thickness (t _f0 + h ₀ ) of the initial web thickness t _f0 plus the air film thickness h ₀ , The elongation modulus E _req and E _teq in the radial direction and in the circumferential direction can be obtained as follows.

(4)

(4)

Where h ₀ is the thickness of the entrained air film,

t _f0 is the web thickness at the beginning of winding.

However, the elongation modulus E _ra of the air layer is given as follows.

5)

5)

Further, for the winding process, the web thickness t _f of an arbitrary winding radius and the thickness h of the air layer are given as follows, respectively.

(6)

(6)

From Eqs. (4) to (6), h ₀ and t _f0 represent the thickness of the air layer and web thickness at the initial stage of winding.

When the air is wound up at the time of winding, slip between the web layers of the winding roll 5 is apt to occur. In order to reduce the amount of entrained air as much as possible to prevent slippage, the central drive winding system using the nip roller 4 is often adopted in the same manner as in the present embodiment. The thickness h ₀ of the air layer in this case can be evaluated by EHL theory (Elastohydrodynamic lubrication theory) between the winding roll 5 and the nip roll. In this embodiment, the results of Hamrock and Dowson (see Hamrock, BJ, and Dowson, D., " Elastohydrodynamic Lubrication of Elliptical Contacts to Materials of Low Modulus I-Fully Flooded conjunction, " ASME J. Lubrication Technology, Vol. 100, 1978, pp. 236-245).

(7)

(7)

However, C ₀ -C ₂ is an experimentally obtained constant.

Based on the equivalent internal stress of the winding roll 5 and using the radial stress? _R required from equations (1) - (7), the circumferential stress? _T is given by the following equation.

(8)

(8)

(Or more) is the web winding theory based on the Hakiel model, and the formulation and verification of the tension equation (2) are now confirmed by a predetermined numerical analysis. As a result of the requirements verification, it was confirmed that the parameter having a large influence in optimizing the roll internal stress, which is the main factor of roll defects, is the winding tension Tw. On the other hand, as for the method of optimizing the winding tension Tw, a method of optimizing the nip load N without further verification has not been examined so far. Thus, in the present embodiment, the winding tension Tw is optimized, and the nip load N is also optimized in the course of the process, so that various winding failures in a trade-off relationship can be suitably eliminated from either side Provide a technique.

First, the tension function Tw (r) and the nip load function N (r), the objective function f (X), the constraint function gi (X) (i = 2 n + 2m + 2 ) Are stored. The tension function Tw (r) calculates the winding tension Tw with respect to the winding radius r. The nip load function N (r) computes the nip load N with respect to the winding radius r. In order to evolve (optimize) the nip load function N (r) of these tension functions Tw (r) and Eq. (10), in this embodiment, the average value of the circumferential stress? _T is used as an objective function, A condition for eliminating various winding failures called star defects, plastic deformation, and telescopes is suitably applied to both of them to optimize the tension and to minimize the objective function The nip load N is also optimized.

The tension force Tw (n) and the nip load function N (r) according to the present embodiment are determined in consideration of the flexibility of the function and ease of handling, Is represented by a cubic spline function related to the radius r, and is stored in the storage unit 21.

(9)

(9)

(10)

(10)

However ,? R is an equal proportion period of the radial coordinate r,

Mi is a shape parameter determined from a condition in which the first derivative at each node position of the curve represented in each section is continuous.

As is clear from (10), in this embodiment, from the winding start point to the outermost circumference of the winding roll is divided into n back sections, and the winding tension Tw of each section and the nip load N (Interpolation). The winding tension Tw and the nip load N are expressed as a function for smoothly connecting the sections in accordance with the setting of Mi in the equations (9) and (10) as conditions. The tension function Tw (r) of the equation (9) and the nip load function N (r) of the equation (10) are optimized (evolved) according to the setting of the objective function and the constraint function. Namely, the minimum value of the circumferential stress in the winding roll 5 is non-negative, and the equations (9) and (10) are evolved so that the average value of the circumferential stress becomes infinitely zero, The nip load N can be obtained.

Referring to Fig. 3, as a method of evolving the tension function Tw (r) of the equation (9), the tension of the shear layer (k step indicated by the solid line) in the evolution process ((k + 1) with respect to functions, secure the r-coordinate of each point P ^(k) (r _i, T _i), and by changing only δT _i the Tw coordinates in the positive direction direction or negative new contact point P ^{(k + 1)} (r _i, T _i + δT _i ). By using the new coordinate values obtained in this form, the function form according to Eq. (9) is corrected and the order is evolved until the value of the objective function f (X) becomes optimal.

Also, with respect to the nip load function N (r) in the equation (10), the shear layer (the k (k) point indicated by the solid line in the evolution process phase), each point P ^(k) for a nip load of a function of (r _i, secure the r-coordinate of N _i), and by changing only δN _ㅑ the N coordinates in the positive direction direction or negative new contact point P ^{(k + 1 )} (r _i , N _i +? N _i ). Using the new coordinate values obtained in this way, the function form is modified by Eq. (10), and the process is evolved in order until the value of the objective function f (X) becomes optimal.

Next, variables of the objective function f (X) will be described.

In the present embodiment, the design variable vector of the objective function f (X) is defined as follows and stored in the storage unit 21.

(11)

(11)

However, the executable area from the winding position to the outermost diameter of the winding roll is divided in the r direction.

ΔT _i represents the difference between the initial tension T _w0 at an arbitrary radial position r _i and the tension during evolution (k stage).

N _i represents the difference between the initial nip load N _{0 at an} arbitrary radial position r _i and the nip load during evolution (step k).

In the present embodiment, the nip load is treated as a variable as is clear from the equation (11). The nip load N is optimized in the process of evolving the nip load function N (r) of the tension function Tw (r) and the equation (10) according to the addition of the parameter of the nip load N to this design parameter vector .

The objective function f (X) stored in the storage unit 21 is defined as follows.

(12)

(12)

However, F _i is the frictional force between webs,

F _cr is the critical frictional force at which slip begins,

σ _t , _ref is the reference value of the circumferential stress.

In the present embodiment, the critical frictional force F _cr is determined experimentally and is, for example, 5 kN. This critical frictional force F _cr is also called a " telescopic condition value " in the following description, because it is a critical value as to whether or not the shape collapse called axial telescoping occurs. In addition, the frictional force F _i and the true measures? _T and _ref are respectively defined as follows.

(13)

(13)

를 부과하는 제약 조건은, 아래와 같이 정의되어서 기억부(21)에 기억되어 있다.On the other hand, design parameters ΔT _i and maximum and minimum load of the nip N, the minimum value of the circumferential stress σ _tmin, and the mean frictional force of the web layers

Is stored in the storage unit 21 as defined below.

(14)

(14)

The constraint function gi (X) (i = 1 to 2n + 2m + 2) is defined and stored in the storage unit 21 as follows.

In summary, the optimization of the winding tension Tw is expressed as follows.

Find X to minimize  f (X)

subject to g _i (X)? 0 (i = 1 to 2n + 2m + 2) (16)

Next, in order to realize the above-described optimization processing, the storage unit 21 stores tables 211 to 221 relating to information for calculating the above-described predictive model. Here, a table refers to a set of data expressed in a two-dimensional matrix (row and column) for a database system.

Hereinafter, a table according to the present embodiment will be described with reference to FIG. In the following description, a table column is referred to as an "attribute", and a set of values for each row of a table (actual values that can be assigned to attributes) is referred to as a "tuple". In Fig. 5, (PK) denotes the primary key and (FK) denotes the foreign key. A primary key is a set of one or more attributes that uniquely identify a tuple in a table. A foreign key is a set of one or more attributes for referring to data of a table having a corresponding primary key in accordance with a value having the same value as the primary key. When a plurality of attributes are represented as a set, they are enclosed in {}. In addition, the arrows in the drawing indicate relationships (relations) between the tables, and the external keys in the table on the end point side of the arrows refer to the primary keys in the table on the origin side of the arrows. Also, the relationship between the primary key and the foreign key is represented by cardinality (the number of tuples) between two tables, and arrows indicate that the starting point is 0 or 1 and the end points are cardinalities. Also, the tables shown in the drawings are logical entities, and the same data group may be physically composed of a plurality of tables, or a plurality of data groups may be composed of the same table. In addition, the attributes set in each table are merely for describing the present embodiment in order to explain the present embodiment, and may have attributes other than those shown in the drawings. The table can be realized, for example, as text data.

5, a web table 211, a core table 212, a nip roller table 214, a winding setting table 215, and an optimization technique table (not shown) are connected to the auxiliary memory device of the storage unit 21, 216 are stored.

The web table 211 is a table for registering the specifications of the web 10 and has a thickness h _f , a width W, a radial elongation modulus E _r , a circumferential elongation modulus E _t , an RMS composite roughness It is possible to register parameters including σ _{f f} , static friction coefficient μ s, radial and lateral ratios υ _tr and circumferential ratios υ _rt .

The core table 212 registers the specification of the core 5a and can register parameters including the elongation modulus E _c , core thickness t _c , core radius r _c , and puff ratio v for each core part number (primary key) .

A nip roller table 214, is to register the specifications of the nip roller 4, each nip roller part number (primary key), the radius of the nip roller 4 r _n, young's modulus E _n, peuah including's ratio υ _n Parameters can be registered.

The winding setting table 215 sets the winding tension (provides an inverse curve) for each winding rate as the winding setting code as a primary key. For example, in the example described below, according to the setting registered in the winding setting table 215, the winding tension Tw becomes a constant value (for example, 150 N) from the start of operation until the winding ratio reaches about 20% , And after the lapse of 20%, the product of the diameter of the winding roll 5 and the winding tension Tw can be set to be constant in response to the increase of the winding ratio.

The optimization method table 216 defines setting conditions for giving concrete conditions when the above-described equations (9) to (15) are processed for the optimization processing to be described later. Taper tension, winding tension, initial values of the nip load, and setting items for selecting whether or not the final value is fixed are registered.

Next, in the present embodiment, as a transaction table for operating the winding device 100, the winding plan table 220, the winding plan specification table 221, the Web product management table 222, the optimum winding table 223, and an optimum nip load table 224 are provided.

The winding plan table 220 stores specifications for managing the plan of the winding process, and items including a date of manufacture, a date of manufacture, and an order code can be registered for each winding plan code (primary key).

The winding plan specification table 221 registers the specifications of the winding roll 5 produced by the winding plan and the general specifications of the processing for each winding plan code and sets the nip roller The number of windings 5, the number of webs 10, the critical friction force F _cr (telescopic condition value), the winding length, the number of turns n, the outermost layer roll radius r _out , Can be registered. The winding plan specification table 221 includes a winding setting table 215 and an external key of the optimization technique table 216 so that the winding setting can be performed for each specification of the winding plan, Can be set. In addition, an attribute for setting the initial taper tension and the initial value of the nip load in the set optimization method is provided.

The web product management table 222 is for managing production conditions of individual concrete products (winding rolls 5) produced for each of the specifications determined by the winding plan specification table 221 and includes a winding plan specification table 221, It is possible to register the date of manufacture by giving priority to a composite key composed of an external key (production plan code, specification code) and serial number for making association.

The optimum winding table 223 sets the specification of the winding tension Tw necessary for the optimum winding control and sets the winding tension TW, the winding speed (motor revolution number) V, the dimensionless roll radius position r / r _c , and the winding ratio Rr can be set. In this optimum winding table 223, the calculation result of the tension function Tw (r) of the equation (9) is registered by optimization processing which will be described later.

The optimum nip load table 224 sets the specification of the nip load N necessary for the optimum winding control and sets the nip load N, the winding speed (motor revolution number) V, the dimensional roll radius position r / r _c , and the winding ratio Rr can be set. In this optimum nip load table 224, the calculation result of the nip load function N (r) of equation (10) is registered by the optimization processing described later. In this embodiment, the optimum winding table 223 and the optimum nip load table 224 can be associated in a one-to-one relationship, and the winding tension Tw at a certain winding ratio and the nip load N are related It is made to know.

According to the use of the tables 211 to 221 as described above, various screens and view tables can be created, and the operator can realize the optimization operation.

Referring to Fig. 6, in this embodiment, a screen 300 for executing an optimization program is provided. This screen is switched from the main menu which is not shown.

On the screen 300, a command button 301 for setting web and machine conditions and a command button 303 for setting a method of optimization calculation based on the set conditions are prepared. The setting results of the optimization calculation are displayed in the text box 304 and the operation speed of the winding device 100 (the number of revolutions of the motor 7) and the nip load N are set in the text boxes 305 and 306 ). ≪ / RTI > When the operator judges that correction is unnecessary, the operator operates the command button 307 for transmission and outputs the setting result to the control unit 20, . The control unit 20 winds the web 10 on the winding roll 5 based on the set result and registers the transaction results in the tables 221 to 224 shown in Fig. In addition, a command button 308 is prepared on the screen 300 so that the user can switch to the main menu or the previous screen, if necessary.

When the command button 301 shown in Fig. 6 is operated, the screen switches to the screen 310 for setting the web and machine conditions.

7, a screen 310 includes a combo box 311 for selecting a part number of the web 10 and a list window 321 for displaying specifications of the web 10 selected in the combo box 311. [ 312 are provided. From the combo box 311, the web part numbers registered in the web table 211 of Fig. 5 are listed up, and the specifications concerning the selected part numbers are displayed in the list window 312. Fig. When it is necessary to register a new part number, the user returns to the main menu and registers the new part number on the registration screen not shown.

The screen 310 has a combo box 313 for selecting the part number of the core 5a and a list window 314 for displaying the specification of the core 5a selected by the combo box 313 . The winding number registered in the winding table 212 in FIG. 5 is listed up from the combo box 313, and each specification relating to the selected part number is displayed in the list window 314. FIG. When it is necessary to register a new part number, the user returns to the main menu and registers from the registration screen not shown.

A combo box 315 for selecting the part number of the nip roller 4 and a list window 316 for displaying the specifications of the nip roller 4 selected by the combo box 315 are provided on the screen 310 . The nip roller number registered in the nip roller table 214 of Fig. 5 is listed up from the combo box 315, and each specification relating to the selected part number is displayed in the list window 316. Fig. When it is necessary to register a new part number, the user returns to the main menu and registers from a registration screen not shown.

The operator confirms the specifications displayed in the list windows 312, 314, and 316, and if there is no change in the displayed contents, the operator operates the command button 317 for execution to switch to the next screen. When the command button 317 is operated, the screen switches to the screen 320 for inputting the operating condition shown in Fig.

Referring to Fig. 8, a screen 320 is provided with a combo box 318 for selecting an optimization technique. The combo box 318 displays the optimization technique code set in the optimization technique table 216 in FIG. 5, and the setting condition in the optimization process can be selected by selecting this code . The screen 320 also has a text box 321 for setting the range of the operation speed and a text box 322 for inputting the telescopic condition value (critical frictional force F _cr ). In the embodiment shown in the drawings, a text box 323 for displaying a predetermined conversion value is prepared by inputting the operation speed.

Text boxes 324a and 324b for setting the upper and lower limits of the winding tension are provided on the screen 320 and the text boxes 325a and 325b indicating the converted values (nip line load) are set to the upper limit value and the lower limit value Respectively.

The screen 320 also has text boxes 326a and 326b for setting the upper and lower limits of the nip load. Values of the text boxes 324a, 324b, 326a, and 326b are registered in the winding plan specification table 221. [ The screen 320 is provided with a text box 326c for inputting the nip load initial value when the nip load is fixed in accordance with the optimization technique. The value entered in this text box 326c is registered in the winding plan specification table 221. [

On the screen 320, an optimization execution button 327 for executing optimization processing is provided based on the set conditions. The operator inputs the above-mentioned specifications into a corresponding text box or the like, and performs optimization processing based on the set conditions as the optimizing execution button 327 is clicked (operated). The display 320 is provided with a display window 328 indicating that the optimization process is being executed and a predetermined message "being calculated" is displayed in the display window 328. Elapsed time: 00: 00: 00 " and the like are displayed. When the optimization processing is completed, the screen is switched to the screen 330 showing the processing result.

9, the screen 330 includes text boxes 324a, 324b, 325a, 325b, 326a and 326b and buttons 327 and 308, which are items of a part of the screen 320, The window 332 is displayed. In the window 332, a graph Tw _INV of the winding tension Tw and a nip load N _INV are displayed based on the calculation result.

Next, optimization processing will be described with reference to Fig.

When the optimization execution button 327 displayed on the screen 320 of Fig. 8 is clicked, the control unit 20 reads necessary data in each table of Fig. 5 (step S101). Next, the control unit 20 initializes the counter variable k to 0 (step S103), and based on the read data, the basic equation 26 and all the expressions related to the basic equation 26, The winding tension TN and the nip load N in the sections r0 to rs are calculated by using the initial taper tension registered in the optimization method table 216 for each of the function TW (r) and the nip load function N (r) (Step S104). In this first step (k = 0), for example, the winding tension TW is set as a linear taper ratio indicated by the imaginary line in Fig. 3, and the nip load N is set as the characteristic indicated by the imaginary line in Fig.

Then, the control unit 20 searches for the minimum value of the k-th objective function f (X) ^(k) under the constraint of the constraint function gi (X) (step S105). Then, the control unit 20, on the basis of which was obtained at this stage design variable vector of the winding tension Tw (ΔTw _{1, 2} ΔTw, ΔTw _3, ··· ΔTw _N), the tension Tw function (r) Evolves the nip load N (r) based on the nip loads N (? L ₁ ,? L ₂ ,? L ₃ , ...? L _m ). Specifically, a new contact point P ^(k) is obtained by fixing the r-coordinate of each contact point P ^(k) and changing the Tw coordinate only in the positive or negative direction by ΔTw _i . For example, when the initial winding tension Tw ₀ indicated by the imaginary line evolves, the tension function Tw (r) evolves to the winding tension Tw _k indicated by the solid line. Also, the same calculation is performed on the nip load N (r ⁾ to obtain a new contact P ^(k) .

Next, the control unit 20 verifies whether or not the searched objective function f (X) is the minimum value (step S107), and if it is not the minimum value, increments the step k (step S108) And when it reaches the minimum value, the process shifts to the control process.

Concretely, the winding tension TW based on the tension function Tw (r) of the equation (9) evolved until the objective function f (X) becomes the minimum and the nip load function N (r) of the equation , Thereby controlling the motor 7 (step S109). As a result, even immediately after winding, it is possible to obtain a winding roll 5 in which neither star defects, plastic deformation nor telescopic is generated even after a temperature change occurs.

Next, several operation examples will be described in order to clarify the operation and effect of the present embodiment.

First, referring to FIG. 11, the characteristics of the winding tension Tw obtained in the development process of the present invention will be described.

When the nip load N is fixed to a predetermined value (N = 50 in the example shown in the figure) and the technique related to Patent Document 1 proposed by the applicant of the present application is used, the characteristic is Tw _cov . In this specification, the winding tension Tw of the web 10 is gradually decreased from about 20% of the winding ratio Rr on the second half side. When the operation condition of the motor 7 is set as the characteristic Tw _cov , the output is restricted as the outputable range M indicated by the virtual line.

The printable range M is calculated in the following order.

In other words, the number of revolutions Nr [rpm] and torque [N · m] of the core 5a are expressed by the following equations.

(17)

(17)

V: Line speed of wound web [m / min]

(18)

(18)

From the equations (17) and (18), the rotation speed Nr and the torque? Of the motor change with an increase in the winding diameter under constant line speed and winding tension.

On the other hand, the horsepower P [kw]

(19)

(19)

(19＇)

(19 ')

Equation (19 ') indicates that the constant output is constant regardless of the change in diameter under a constant speed and a constant tension.

Therefore, from Equation (19 '), the required horsepower of the motor can be requested in the following manner.

(20)

(20)

However, η: Efficiency

 R: Actual horsepower range

Also,

(21)

(21)

, The horsepower is also P = [omega] t, so that various forms can be calculated based on the equation (21).

A calculation example is shown below.

1.5Kw motor 2.2Kw motor Motor torque τ [N · m] 8 12 Reduction ratio
(Determined by winding speed and minimum winding diameter) 1/2 1/2
Outputs of each winding
Winding tension Tw [N] 200 mm 160 240 250 mm 128 192 300 mm 107 160 350 mm 91 137

On the contrary, if the matter applicant first, using the proposed non-patent optimization technique according to the reference 1, to secure the nip force N at the same constant and the characteristic Tw _cov optimizes the winding tension Tw, that particular is, as Tw _opt do. As is clear from the drawing, in the optimized characteristic, when the winding ratio Rr is 70% or more, the winding tension Tw is increased sharply. In such a characteristic, the frictional force F, the radial stress? R, and the circumferential stress? _T shown in Figs. 12A to 12C have good characteristics, and it is possible to avoid the winding failure such as sagging and wrinkles very suitably okay.

However, when the running characteristic of the motor 7 is conventionally set to Tw _cov , when the winding ratio Rr is 100%, the motor output characteristics necessary for obtaining the optimum winding tension are output from the motor 7 It is out of the range of the range M, and it has been found that it is difficult to follow the motor 7 to the characteristic Tw _opt .

Here, the inventors of the present invention examined several comparative examples shown in Fig. 11 in order to approach the operating characteristics of Tw _{cov to} the driving characteristics of the same effect as the optimum characteristic Tw _opt . In the comparative example described below, either nip load N is an integer (N = 50) equal to the characteristic Tw _opt .

The first comparative example Tw _T1 is a case where the wrapping tension Tw after winding is increased to 130% with respect to the optimum characteristic Tw _opt .

The second comparative example Tw _T2 is a case where the optimum winding property Tw _opt is the winding tension Tw after winding down to 80%.

The third comparative example Tw _T3 is a case in which the winding tension is excessively increased in the region where the winding ratio is about 50% with respect to the optimum characteristic Tw _opt .

12A to 12C, it was confirmed that, in the case of the first comparative example Tw _T1 , the frictional force F and the radial stress σr tend to become too high on the front side of the winding ratio Rr.

It was also confirmed that in the case of the second comparative example Tw _T2 , the frictional force F and the radial stress? R tend to be too low on the front side of the winding ratio Rr.

In addition, in the case of the third comparative example Tw _T3 , as a timing at which the winding tension Tw is increased, the frictional force F and the radial stress? R excessively tend to increase excessively.

In addition, the circumferential stress? _T did not become an appropriate value for either of the comparative examples Tw _{T1 to T3} .

From this work, it has been found that it is difficult to obtain characteristics that can be substituted for the characteristic Tw _opt simply from the characteristic Tw _cov by only the operation of the winding tension Tw.

Further, as a subsequent study, it was also confirmed that the increase of the winding tension Tw on the second half side of the winding ratio Rr in the characteristic Tw _opt is effective for avoiding a winding failure called a telescope.

Based on this finding, the inventors of the present invention considered that the nip load N is treated as a variable, and the winding tension Tw and the nip load N are optimized at the same time, so that the winding ratio Rr of the winding tension Tw, To the nip load N. [0060]

As described above, according to the present embodiment, the motor 7 as the winding motor for rotating the winding core 5a for winding the web 10, and the motor 7 for adjusting the rotation speed of the motor 7, And the motor control unit 23 as the tension adjusting means and preferably the winding range of the winding roll 5 formed by winding the web 10 on the winding core 5a from the predetermined winding ratio Rr to the web 10 A nip roller 4 for pressing the outer periphery of the web 10 wound around the core 5a against the web winding device 100 set to reduce the winding tension Tw of the nip roller 4, The nip load adjusting device 6 as the nip load adjusting device for adjusting the nip load N in the nip load adjusting device 6 and the nip load adjusting device 6 for adjusting the nip load N as the winding ratio Rr increases with respect to the winding range where the winding ratio Rr is 80% As a nip load control means for controlling the nip load adjusting device 6 so as to increase the nip load And an adjusting unit 24. The web winding apparatus 100 is a web winding apparatus.

According to the present embodiment, regarding the step S109 of Fig. 10, the winding ratio detection step of detecting the winding ratio Rr of the winding roll 5 and the winding range where the detected winding ratio Rr is 80% A nip load control step is performed in which the nip load N is controlled so as to increase the nip load N as the ratio Rr increases.

For this reason, in the present embodiment, in the latter half of the winding roll 5 in which the winding ratio Rr of the winding roll 5 has been decreased from the predetermined value, the winding tension Tw is gradually decreased so that the winding roll 5 ) Can be obtained. As for the winding range in which the winding ratio Rr of the winding roll 5 is 80% or more, the nip load N increases as the winding ratio Rr increases, so that the winding tension Tw that is generated at the latter half of the winding The shortage can be compensated by the nip load N. Therefore, the more appropriate winding property is exhibited, and the internal stress of the winding roll 5 is appropriately distributed. As a result, it is possible to prevent wrinkles, sagging, and the like from occurring in addition to the conventional art.

In the present embodiment, the tension function storage means for storing the tension function indicating the winding tension Tw with respect to the radial direction coordinate of the core 5a, and the tension function storage means for storing at least the circumferential stress acting on the winding roll 5 of the web 10 an objective function storage means for storing an objective function with parameters σr, a frictional force F between layers, and a critical frictional force _{Fcr at which} slip occurs, and an objective function storage means for storing, as a parameter, a minimum value of radial stress in the winding roll 5, A constraint function storage means for storing a constraint function for setting a constraint of the objective function such that the frictional force F is _{equal to} or greater than the critical frictional force F _cr ; The nip load adjusting section 24 controls the motor control section 23 on the basis of the winding tension Tw calculated by the evolved tension function, On the basis of a value of time to control the nip force N. Therefore, in the present embodiment, the tension function for setting the winding tension Tw can evolve under a predetermined condition, and a very suitable winding tension Tw can be calculated. Therefore, various wafers 10 can be very And can be wound in an appropriate state.

Further, in the present embodiment, the constraint function storage means stores a design variable having the nip load N as a parameter as a parameter of the constraint function, and the evolution processing means optimizes the nip load N as a variable. Therefore, in the present embodiment, it is possible to optimize the nip load N used as an element of the design parameter, so that the pressing force of the nip roller 4 can be more suitably adjusted. Therefore, the winding tension Tw can be optimized by a precise analysis model. Furthermore, with respect to the winding range in which the winding ratio Rr of the winding roll 5 is 80% or more, the nip load N that increases with the increase of the winding ratio Rr can be optimized while maintaining the optimum winding tension Tw, A very suitable winding characteristic can be obtained.

Thus, according to the present embodiment, a winding roll 5 without wrinkle or sagging can be obtained as in the prior art. On the other hand, in the winding range in which the winding ratio Rr of the winding roll 5 is 80% , The nip load N increases as the winding ratio Rr increases, so that the shortage of the winding tension Tw likely to occur at the latter half of winding can be compensated by the nip load N. [ Therefore, the internal stress of the winding roll 5 is appropriately distributed so as to exhibit a more suitable winding characteristic. As a result, a remarkable effect is obtained in which the occurrence of wrinkles and deflections can be prevented in addition to the conventional case.

[Example]

Examples are shown below.

(First Embodiment)

Referring to Fig. 13, in the first embodiment, optimization processing is performed under conditions that can be freely adjusted without fixing the initial value of the winding tension Tw and the nip load N. [ For the first embodiment, the characteristics of the winding tension Tw and the nip load N are Tw _INV and N _INV , respectively. As is apparent from Fig. 13, the winding tension Tw _INV greatly decreases until the winding ratio Rr reaches 20%, gradually decreases after 20%, and gradually increases to approximately 80%. Even in the case where the winding ratio Rr is 100%, the value is substantially equal to the characteristic Tw _cov in the technique related to Patent Document 1, and the gap SH becomes as close to 0 as possible.

Referring to FIG. 14A, the frictional force F in the first embodiment is higher than the critical frictional force F _cr over almost the whole of the reel ratio Rr, and it is confirmed that the frictional force is good. Also, as shown in Fig. 14B, it was confirmed that characteristics similar to the characteristic Tw _opt over the entire region can be obtained for the radial stress. In addition, as shown in Fig. 14C, it was confirmed that even in the circumferential stress, a value of 0 or more can be maintained over the entire area.

As a result, it was confirmed that the optimum winding tension Tw can be obtained by the first embodiment even in a state in which the operating characteristics of the motor 7 are set by the technique related to Patent Document 1.

(Second Embodiment)

Referring to Fig. 15, in the second embodiment, the initial values are fixed and optimization processing is performed for both the winding tension Tw and the nip load N. [ As a result, substantially the same results as those of FIGS. 14A to 14C were obtained. As a result, even when the optimization processing is performed by fixing the initial values of both the winding tension Tw and the nip load N, the optimal winding tension Tw. ≪ / RTI >

(Comparative Example 1)

16, in the first comparative example, a process of fixing the nip load N at a predetermined optimum value (N = 107 N / m in the comparative example shown in the figure) and optimizing only the winding tension Tw was performed.

The result was Tw _cp1 . In the first comparative example, the area outside the output-enabled range M was outside the area where the winding ratio Rr was 100%.

(Comparative Example 2)

17, in the second comparative example, the initial value of the nip load N is fixed, measures are taken to prevent wrinkles at the beginning of the winding, and the nip load N is fixed after the winding ratio is 25% A process of optimizing the winding tension Tw was performed.

The result was Tw _cp2 . In this second comparative example, too, the area outside the output-enabled range M is at a position where the winding ratio Rr is 100%.

(Third Comparative Example)

Referring to Fig. 18, in the third comparative example, the nip load N was fixed to a certain value (N = 100) and the processing for optimizing only the winding tension Tw was performed.

The result was Tw _cp3 . In this third comparative example, too, the area outside the output-enabled range M was at a position where the winding ratio Rr was 100%.

19 to 23 are graphs showing the internal stress of the winding roll 5 based on the characteristics of the first and second embodiments and the first to third comparative examples.

As apparent from these drawings, in any of the cases, the frictional force F, the radial stress? R, and the circumferential stress? _T are very suitable, but in the first and second embodiments, the winding ratio Rr is 100% in respect to the take-up tension Tw _INV in what can be suppressed low, a comparative example of the first to third, it was confirmed that the take-up rate Rr is increased the winding tension Tw - Tw _{CP1 CP3} in a 100% change.

The present invention is not limited to the above-described embodiments.

For example, by using a program such as that shown in Fig. 24, it is possible to approximate optimal control.

Referring to Fig. 24, in the modification shown in Fig. 24, the operation characteristic of the motor 7 is set to the control unit 20 based on the technique of Patent Document 1 (step S200). In addition, a preset winding ratio (preferably 80%) is set as a threshold value. The control unit 20 calculates the winding ratio (step S201), and determines whether or not the calculated winding ratio reaches the threshold value (step S202). If the winding ratio reaches the threshold value, the control unit 20 raises the nip load N at a predetermined ratio corresponding to the winding amount (step S203). In this case, the winding tension Tw is set to the step S200. The control unit 20 determines whether or not the winding amount has been reached, that is, whether or not the winding ratio is 100% (step S204). If the winding amount is not reached, the control unit 20 proceeds to step S203 and repeats the above- , And when the winding amount is reached, the process is terminated. If it is determined in step S202 that the winding ratio has not reached the threshold value, the winding tension is controlled based on the set value set in step S200 (step S205), and the process goes to step S201 and the above-described process is repeated.

In the example shown in Fig. 24, the optimum value calculation is executed for every process depending on the threshold value in step S202 and the increase ratio of the nip load in step S203, based on the experiment or simulation calculation of the optimum value in advance , It is possible to obtain a winding characteristic that is approximately optimum.

It goes without saying that various modifications are possible within the scope of the claims of the present invention.

1: roll 2: guide roller
3: Pinch roller 4: Nip roller
5: Winding roll 5a: Core
6: Nip load adjusting device 7: Motor
10: Web 20: Control Unit
21: storage unit 22:
23: motor control unit 24: nip load adjusting unit
25: display unit 26: input /
45: Nip
100:

Claims (6)

A web winding device comprising a winding motor for rotating a winding core for winding a web and a tension adjusting means for adjusting a rotation speed of the winding motor to adjust a tension at the time of winding,
A nip roller for pressing the outer circumference of the web wound on the core,
Nip load adjusting means for adjusting a nip load in the web by the nip roller,
A nip load control means for controlling the nip load adjusting means so that the nip load is increased as the winding ratio increases for a winding range in which the winding ratio of the winding roll becomes 80%
Tension function storage means for storing a tension function indicating the winding tension in terms of radial direction coordinates of the winding core,
An objective function storage means for storing an objective function having as parameters a circumferential stress acting on at least the winding roll of the web, a frictional force between the layers, and a critical frictional force at which slippage occurs,
Constraint function storage means for storing a constraint function for setting a constraint of the objective function such that a minimum value of a radial stress inside the winding roll is a positive value and the frictional force is equal to or more than the critical frictional force;
And evolution processing means for evolving the tension function until the objective function becomes smaller under the condition of setting the constraint function,
The nip load control means controls the tension adjusting means based on the winding tension calculated by the advanced tension function and controls the nip load based on the value when the objective function becomes small Gt; delete The method according to claim 1,
Wherein the constraint function storage means stores a design variable having the nip load as a parameter as a parameter of the constraint function,
Wherein said evolution processing means optimizes said nip load set as a variable. A web winding device having a nip roller that presses the outer periphery of the web wound around the core to adjust the rotation speed of the winding motor so as to adjust the tension at the time of winding; The control method comprising:
A winding ratio detecting step of detecting a winding ratio of the winding roll;
A nip load control step of controlling the nip load so as to increase the nip load as the winding ratio increases as to the winding range in which the detected winding ratio becomes 80%
A tension function definition step of defining a tension function indicating the winding tension in relation to the radial direction coordinates of the winding core,
An objective function defining step of defining an objective function having at least parameters of a circumferential stress acting on a winding roll of the web, a frictional force between layers, and a critical frictional force generated by slip,
A constraint function definition step of defining a constraint function that sets a constraint of the objective function such that a minimum value of a radial stress in the winding roll is a positive value and the frictional force is equal to or more than the critical frictional force;
An evolution step of evolving the tension function until the objective function becomes smaller under conditions set by the constraint function;
A control step of controlling the tension adjusting means based on the winding tension calculated by the advanced tension function and controlling the nip load of the winding device based on the nip load when the objective function is reduced ,
The nip load control step controls the tension adjusting means based on the winding tension calculated by the advanced tension function and controls the nip load based on the value when the objective function becomes small Of the web winding device. delete The method of claim 4,
Wherein the constraint function definition step defines a design variable having the nip load as a parameter as a parameter of the constraint function,
Wherein the step of evolving optimizes the nip load set as a variable.

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