JPS643784B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a winding control method for winding a plastic film or the like with high accuracy without using a tension detector in a winding device.

An overview of a conventional winding device will be explained with reference to FIG. 1. A film 1 is taken out as a continuous sheet from a winding machine 13 which is a pre-processing step. Pick up roll 2
is moved in conjunction with a take-up machine 13, the circumferential speed of the take-up roll 2 is the same as the traveling speed of the film, and the roll rotation speed is detected by a rotation speed detector 3.

Further, the tension detector 5 detects the film tension acting on the detection roll 6, and the guide roll 4 and the guide roll 7 set the film path for detecting the tension. The film 1 is wound onto a winding shaft 9, which is driven by a variable speed electric motor 10 via a gear train 11, and the rotational speed of the variable speed electric motor 10 is detected by a rotational speed detector 12. . In addition, 3
3 shows the wound film.

Next, the principle of the conventional winding control method will be briefly explained with reference to FIG. 2. The variable speed motor 10 will be explained as a DC motor. Now, the signal of rotation speed detector 3 is
The take-up speed υ (m/min) is outputted via the amplifier 14. In addition, the winding diameter calculator 15 calculates υ/(π×N×
Calculate a) and output the winding diameter D (m). however,
N (rpm) is the motor rotation speed, and a is the reduction ratio of the gear train 11. Further, the tension reference calculator 16 calculates and outputs a tension reference value F ₀ (Kg). 17, 18, 19,
20 is a volume, which gives the calculation coefficient of the tension reference value F ₀ calculated by the tension reference calculator 16, the volume 17 is the winding shaft diameter D ₀ (m), and the volume 18 is the maximum winding diameter D _MA m), volume 19
gives the taper rate T _P (%), and the volume 20 gives the tension setting value F _S (Kg), respectively.

The tension reference calculator 16 executes the calculation F _S ×(1−T _P /100× D−D ₀ /D _MA X−D ₀ ). The current reference calculator 21 executes the calculation K ₁ ×F ₀ ×D and outputs the current reference value C _R (A). However, K ₁ is a conversion coefficient,
The unit is A/Kg・m. 22 is a tension correction circuit which takes the deviation between the tension reference value F ₀ and the actual tension F (Kg), performs proportional integral calculation, and outputs a tension correction value C _F (A). The tension correction circuit 22 also includes a tension detector 5,
It is composed of an amplifier 23 and a proportional-integral calculator 24.

Now, the output of the amplifier 23 becomes the actual tension F, and the output of the proportional-integral calculator 24 becomes the tension correction value C _F.
The mechanical loss calculator 25 is a fixed mechanical loss setting device 2.
6. Consists of speed proportional mechanical loss calculator 27,
The fixed portion mechanical loss setting device 26 outputs a fixed portion mechanical loss current value C _MF (A).

In addition, the speed proportional mechanical loss calculator 27 calculates K ₂ ×
N calculations are performed and the calculation results are output as a speed proportional mechanical loss current value C _MN (A). However, K ₂ is a conversion coefficient, and the unit is A/rpm. Normally, K ₂ is set as a semi-fixed volume. The adder 28 adds the already explained C _R , C _F , C _MF , and C _MN to obtain the current command value.
Output C _COM .

29 is an amplifier that converts the output of the rotation speed detector 12 into the motor rotation speed N, and the take-up speed υ
is the rotational speed Nυ equivalent to a DC motor by the calculator 30.
Convert to Also, the adder 31 calculates N−Nυ,
Outputs speed command value N _COM . The DC motor control circuit 34 is connected to C _COM or
N _COM is input, and the DC motor 10 is driven by the signal from the DC motor control circuit 34 .

FIG. 3 shows the state in which the film 1 is wound onto the winding shaft 9. First, FIG. 3A shows the state before winding, and the circumferential speed of the winding shaft 9 is driven to match the traveling speed of the film 1. At this time, the changeover switch 32 in FIG. 2 is in the state shown by the broken line. FIG. 3B shows the beginning of winding the film 1, and the cutter 46 operates to cut the film 1 and wind it onto the winding shaft 9.

Further, FIG. 3C shows a state in which the film 33 is being wound, and the film 33 is being wound thicker. FIG. 3D shows a state in which the film 33 wound around the winding shaft 9 reaches a predetermined length and the film 1 and the wound film 33 are separated by the cutter 46. At this time, a new winding shaft 35 has been set. In addition, in FIG. 3 B, C, and D, the changeover switch 32 of FIG.
is in the state shown by the solid line.

Now, FIG. 4 shows the motor rotational speed N that changes according to FIG. 3 A to D. A section 36 in the figure corresponds to FIG. 3A, and the motor rotation speed reaches the tuned rotation speed N ₁ at the same time as startup, and that state is maintained.
Further, a section 37 corresponds to FIG. 3C, and as the wound film 33 becomes thicker, the motor rotation speed N decreases. In addition, from section 36 to section 37
The point 38 at which the line changes to corresponds to FIG. 3B, and the end point 39 of the section 37 corresponds to FIG. 3D.

However, in this conventional control method, the second
Since the conversion coefficient K ₂ of the fixed mechanical loss setter 26 of the mechanical loss calculator 25 and the speed proportional mechanical loss calculator 27 shown in the figure is semi-fixed, it is actually not possible to accurately track the mechanical loss that fluctuates due to changes in mechanical conditions. . Therefore, a tension correction circuit 22 is required, and this tension correction circuit 22 corrects the above-mentioned problems.

The present invention was proposed in order to solve the above-mentioned conventional drawbacks, and when winding a film such as plastic using a variable speed electric motor, the rotational speed of the electric motor measured before each winding start and the electric motor speed of the electric motor Based on the child current, a coefficient for fixed mechanical loss and a coefficient for speed proportional mechanical loss are calculated using a coefficient calculator, and the same coefficient is used, as well as the rotational speed of the motor at the end of winding measured before one cycle, the armature current of the motor, Based on the winding diameter at the end of winding, the coefficient of mechanical loss proportional to the winding weight is calculated by the same calculator, and the mechanical loss value is calculated from moment to moment during each winding operation from the start of winding to the end of winding based on the above coefficients. Calculated by correction calculator,
By correcting, the coefficient of each mechanical loss is updated during the winding operation, and the tension is obtained with high precision without feedback of the actual tension. The purpose is not only to compensate for mechanical loss, but also to automatically compensate for changes in mechanical loss over a long period of time, and to maintain constant tension at all times. It is an object of the present invention to provide a film winding control method that does not require the conventional tension correction circuit.

It has already been explained that the mechanical loss correction during film winding is performed using the fixed mechanical loss current value C _MF (A) and the speed proportional mechanical loss current value C _MN (A). By the way, as the film becomes thicker, the weight W (Kg) of the film 33 wound up increases as shown in FIG. will increase. The weight of the wound film is (D ²
−D ₀ ² ), so here the mechanical loss is expressed as (1)
Approximate by formula.

C _MEC = K _M1 + K _M2 × N + K _M3 (D ² − D ₀ ² ) ...(1) However, K _M1 , K _M2 , K _M3 are coefficients, N is the motor rotation speed (rpm), and D is the winding diameter ( m), D ₀ is the winding shaft diameter (m), and C _MEC is the mechanical loss correction current (A).

Figure 5 is a diagram showing the measurement points of mechanical loss.
Compared to the diagram, section 36 is divided into section 40 and section 41, and section 42 is added after section 37. Section 40 and section 41 are sections corresponding to FIG. 3A, but in section 40, the motor rotation speed is set to _N2 , and in section 41, the motor rotation speed is set to _N1 .

When the motor rotation speed becomes stable in section 40, the motor rotation speed N ₂ and motor armature current C ₂ are measured.
When the motor rotation speed becomes stable in section 41, the motor rotation speed N ₁ and motor armature current C ₁ are measured. In section 42, the changeover switch 32 in FIG. 6, which shows the embodiment of the present invention, controls the motor in the state indicated by the dotted line, and when the motor rotation speed becomes stable, the motor rotation speed changes.
Measure N ₃ , motor armature current C ₃ and winding diameter D ₃ .
However, the motor armature current is determined by the DC motor control circuit 3.
4, the value normally used for the current minor loop is used, and the winding diameter _D3 is the value immediately before the cutter operates at time 39.

N ₂ , C ₂ , N ₁ , C ₁ , N ₃ measured as above,
Using C ₃ and D ₃ , the coefficients K _M1 , K _M2 , and
Calculate K _M3 . Also, N ₂ , C ₂ , N ₁ , and C ₁ are measured values in the state shown in Figure 3 A, and the winding diameter D at this time is D=
D is ₀ . Therefore, by substituting N ₂ , C ₂ , N ₁ , and C ₁ into equation (1), we get C ₂ =K _M1 +K _M2 ×N ₂ ……(2) C ₁ =K _M1 +K _M2 ×N ₁ ……(3 ) is obtained.

Next, by substituting N ₃ , C ₃ , and D ₃ into equation (1), we get C ₃ =K _M1 +K _M2 ×N ₃ +K _M3 (D ₃ ² −D ₀ ² )...(4) Equation (2), ( From formulas 3) and (4), K _M1 = (C ₂ × N ₁ − C ₁ × N ₂ ) / (N ₁ − N ₂ ) ... (5) K _M2 = (C ₁ − C ₂ ) / ( N ₁ −N ₂ ) ...(6) K _M3 = (C ₃ − K _M1 − K _M2 ×N ₃ ) /D ₃ ² −D ₀ ² ) ...(7) However, from Fig. 5, N ₂ , C ₂ , N ₁ , and C ₁ can be measured before winding, but N ₃ , C ₃ , and D ₃ use the values measured at the time of winding before one round. Note that since the coefficients K _M1 , K _M2 , and K _M3 can be determined from equations (5), (6), and (7), mechanical loss correction during winding can be performed using equation (1).

Now, in the winding control system shown in FIG. 6 showing an embodiment of the present invention, a coefficient calculator 43, a mechanical loss correction calculator 44, and an adder 45 are newly provided compared to the conventional system shown in FIG. Tension correction circuit 2 in Figure 2
2. The components other than the mechanical loss calculator 25 and the adder 28 are used as they are in FIG. 6, but since they have already been explained, detailed explanation thereof will be omitted here.

By the way, the coefficient calculator 43 has already been explained (5)
, (6) and (7), and calculate the coefficients K _M1 , K _M2 , K _M3
The mechanical loss correction calculator 44
calculates equation (1) using coefficients K _M1 , K _M2 , K _M3 , winding diameter D, and motor rotation speed N, and outputs a mechanical loss correction value C _MEC . Further, the adder 45 adds the current reference value C _R and the mechanical loss correction value C _MEC to obtain the current command value C _COM
The functions of the other components have already been explained, so a detailed explanation will be omitted.

As explained in detail above, the present invention is configured to automatically measure mechanical loss each time one product is rolled up during production operation, calculate each coefficient in the mechanical loss compensation calculation formula, Since it is an updating method, it has the following advantages. In other words, it is possible to automatically compensate for changes in mechanical loss over a long period of time, eliminating the need for off-line test runs like in the past. A tension detector and accompanying detection rolls, guide rolls, etc. are no longer required.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing an outline of a conventional winding device;
Figure 2 is a block diagram showing the principle of the conventional winding control system, Figure 3 A, B, C, and D are explanatory diagrams showing the state in which the film is wound onto the winding shaft, and Figure 4 is similar to Figure 3. FIG. 5 is a diagram showing the correspondingly varying DC motor rotational speed, FIG. 5 is a diagram showing mechanical loss measurement points, and FIG. 6 is a block diagram of a winding control system showing an embodiment of the present invention. Explanation of the main parts of the figure, 1...Film, 33...
...Wound film, 43...Coefficient calculator,
44... Mechanical loss correction calculator, 45... Adder.

Claims (1)

[Claims] 1. When winding a film such as plastic using a variable speed electric motor, calculate the fixed mechanical loss coefficient and the speed proportional mechanical loss coefficient based on the rotational speed of the motor measured before each winding start and the armature current of the motor. In addition to calculating with a coefficient calculator, the mechanical loss coefficient proportional to the winding weight is calculated based on the same coefficient, the rotation speed of the motor at the end of winding measured before one cycle, the armature current of the motor, and the winding diameter at the end of winding. is calculated by the same calculator, and the mechanical loss value at every moment during each winding operation from the start of winding to the end of winding is calculated and corrected by the mechanical loss correction calculator based on the above-mentioned coefficients. A film winding control method characterized by obtaining a highly accurate tension without feedback of actual tension while updating a mechanical loss coefficient.