JP2961453B2 - Optimal tension calculator for printing machines - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printing machine provided with a tension adjusting means capable of adjusting a tension applied to continuous paper, and to an optimum tension calculating device for a printing machine for calculating an optimum tension to be applied to continuous paper. Things.

[0002]

2. Description of the Related Art Conventionally, taking into account the delicate influence on print quality and cutting length in a post-process, the setting of the initial tension on continuous paper is based on paper width, paper thickness, paper basis weight, and paper weight. The optimal tension was empirically estimated from the type of paper and the like, and was set manually.

[0003]

However, according to such a method for setting the optimum tension, it is necessary to rely on the experience of a veteran operator, and it is not possible to recruit an operator with little experience.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above-mentioned problems, and includes a tension detecting means for detecting a tension applied to a continuous sheet, and a rotation amount for detecting a rotation amount of a downstream roll. A detection means is provided, and assuming that the movement of the continuous paper is regulated by stopping the rotation of the upstream roll, the downstream roll is gradually rotated to apply tension to the continuous paper. The relationship between the tension applied to the continuous paper and the elongation of the continuous paper is measured from the rotation amount, and the optimum tension to be applied to the continuous paper is calculated based on the measured value obtained by the measurement.

[0005]

Therefore, according to the present invention, regardless of the type of continuous paper, that is, without inputting detailed data on the characteristics of the continuous paper, the continuous paper (continuous paper to be printed) can be obtained from the relationship between the actual tension and the elongation. The optimal tension to be applied to the paper is automatically calculated.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An apparatus for calculating the optimum tension of a printing machine according to the present invention will be described below in detail.

FIG. 1 is a block diagram showing an embodiment of the optimum tension calculating device, which is shown together with the main components of a printing machine. In the figure, 1-1 and 1-2 are upstream drive rolls, 2-1 and 2-2 are downstream drive rolls, 3 is a driving motor, 4 is a driving shaft driven by the driving motor 3, 5, 6 Is a harmonic drive, 7 is a tension detecting roll, 8 is a tension detector, and 9 is a continuous paper.

The harmonic drive 5 (6) has three axes: an input shaft called a wave generator, an output shaft called a circular spline, and a control shaft called a flexspline. The input shaft is connected to the driving shaft 4 (4). The output shaft is connected to the upstream drive roll 1 (downstream drive roll 2), and the control shaft is connected to a first control motor (not shown) (second control motor).

In the harmonic drive, the output shaft rotates with a slight speed difference from the rotation speed of the input shaft by changing the speed of the control shaft. When the rotation of the input shaft is stopped, the output shaft is connected to the control shaft. It becomes the same rotation speed. FIG. 2 shows the characteristics of the harmonic drive.

According to the printing machine having the above-described configuration, while controlling the rotation of the control shafts of the harmonic drives 5 and 6 while detecting the tension applied to the continuous paper 9 with the tension detector 8, the upstream drive roll is controlled. The tension applied to the continuous paper 9 can be adjusted to a set value by adjusting the speed difference between the first drive roller 1 and the downstream drive roll 2.

An optimum tension calculator 10 is provided for such a printing machine. The optimum tension calculating unit 10 includes a rotation amount command unit 10-1 for pulse-commanding the rotation amount θ (t) to the harmonic drive 6, and a momentary command rotation amount θ (t) of the rotation amount command unit 10-1. And a memory unit 10 for storing the momentarily detected tension T (t) from the tension detector 8
-2, the commanded rotation amount θ (t) and the detected tension T (t) stored in the memory unit 10-2, and the elongation rate γ
(T), elongation δ (t) per unit tension, optimal tension T
_A calculating unit 10-3 for calculating the _SP ; elongation rates γ (t) and δ (t) calculated by the calculating unit 10-3; a detected tension T (t) from the tension detector 8; When the command rotation amount θ (t) from the unit 10-1 is input and δ (t)> δ ₀ or γ (t)> γ ₀ or T (t)> T ₀ , the command rotation amount θ ( Command stop unit 1 for preventing passage of t)
0-4.

Next, the operation of the optimal tension calculator configured as described above will be described. First, as a preceding step, after the continuous paper 9 is threaded, the rotation of the driving motor 3 is stopped with a weak tension such that the continuous paper 9 does not slack.
Further, the harmonic drives 5 and 6 are also stopped.

When the present apparatus is operated from such a state, the command rotation amount θ (t) from the rotation amount command unit 10-1 gradually increases, whereby the control shaft of the harmonic drive 6 gradually rotates. Begin to. That is, the downstream drive roll 2 connected to the output shaft of the harmonic drive 6 gradually starts rotating in a state where the movement of the continuous paper 9 is regulated by the stop of the upstream drive roll 1.

By the gradual rotation of the downstream drive roll 2, the slack of the continuous paper 9 is first absorbed and enters the lost motion area. In this state, backlash and twist of the drive system are absorbed, and the tension on the continuous paper 9 rises.

On the other hand, the momentary command rotation amount θ (t) from the rotation amount command unit 10-1 and the momentary detected tension T (t) from the tension detector 8 are stored in the memory unit 10-2. Is done. The calculation unit 10-3 calculates the command rotation amount θ (t) at the time when the detected tension T (t) from the tension detector 8 rises.
Is the zero starting point, the change in the rotation amount with respect to the change in the tension, that is, Δθ (t) / ΔT (t) = [θ (t + 1) −θ
(T)] / [T (t + 1) -T (t)] is calculated as the elongation rate δ (t) per unit tension every moment. The arithmetic unit 10-3 detects the detected tension T from the tension detector 8.
Using the command rotation amount θ (t) at the time when (t) rises as the zero starting point, the upstream drive roll 1 and the downstream drive roll 2
(The original length of the continuous paper 9 when the tension is zero)
The ratio of the current rotation amount Δθ to θ ₀ , that is, Δ
θ / θ ₀ is calculated as the momentary elongation γ (t).

Then, the elongation rate δ (t) and the elongation rate γ per unit tension at every moment in the arithmetic unit 10-3
(T) is given to the command stopping unit 10-4. In the command stopping unit 10-4, δ (t)> δ ₀ or γ
When (t)> γ ₀ , the passage of the command rotation amount θ (t) is prevented, and the rotation of the downstream drive roll 2 is forcibly stopped.
That is, when the elongation rate δ (t) per unit tension increases rapidly or the overall elongation rate γ (t) exceeds a predetermined value, if the elongation rate continuation is continued further, the continuous paper 9 exceeds the yield point. Then, the rotation of the downstream drive roll 2 is stopped, and the increase in the tension on the continuous paper 9 is interrupted. In the present embodiment, when γ (t) becomes 1% or when δ (t) becomes 0.1 mm, the rotation of the downstream drive roll 2 is forcibly stopped.
Note that the command stopping unit 10-4 also prevents passage of the command rotation amount θ (t) and forcibly rotates the downstream drive roll 2 even when the detected tension T (t) becomes the abnormal value T _0. Stop.

On the other hand, the arithmetic unit 10-3 calculates that δ (t)> δ ₀
Or γ (t)> γ _0, and by averaging the momentary δ (t) until the rotation of the downstream drive roll 2 is forcibly stopped, the continuous paper The average elongation δ per unit tension of No. 9 is calculated. Then, the arithmetic unit 10-3 calculates the tension such that γ becomes 0.3% by calculating backward from the calculated average elongation rate δ, for example, to the optimum tension T.
_Ask as _SP . Note that the optimum tension T _SP may be obtained using γ (t) instead of δ (t).

As described above, according to the present embodiment, the continuous paper 9
Irrespective of the type, ie, without inputting detailed data on the characteristics of the continuous paper 9, the optimum tension T _SP to be applied to the continuous paper 9 is automatically calculated from the relationship between the actual tension and the elongation. , The optimum tension T obtained by this calculation
If the speed difference between the upstream drive roll 1 and the downstream drive roll 2 is adjusted using _SP as a command value, the tension applied to the continuous paper 9 can be automatically adjusted to the optimum tension T _SP . That is, according to the present embodiment, it is possible to automatically set an accurate initial tension for almost all types of continuous paper without depending on the experience of a veteran operator.

In the above-described embodiment, the instantaneous command rotation amount θ (t) of the rotation amount command unit 10-1 is detected as the rotation amount of the downstream drive roll 2.
The actual amount of rotation of the downstream drive roll 2 may be detected and obtained, or the amount of rotation may be detected by fixing the downstream drive roll 2 and reversing the upstream drive roll 1. . In addition, although the tension adjusting means is exemplified by an adjusting means based on a speed difference between two pairs of rolls, it is needless to say that the same effect can be obtained by using other known adjusting means.

Although it is possible to set a sufficiently sufficient initial tension by the optimum tension T _SP obtained as described above, there is a slight difference in how to apply the tension even if the paper has the same elongation depending on the type of continuous paper. Therefore, in this embodiment, in order to further improve the accuracy, the type of continuous paper can be manually input as data, and the calculation of the optimum tension can be corrected according to the type of continuous paper. It has a configuration.

In this embodiment, three types of continuous paper, that is, coated paper, high-quality paper, and reprinted paper, are used as data and can be manually input. However, these types of continuous paper cannot always be clearly classified.

Therefore, as another embodiment, a fuzzy controller is used to give the type of continuous paper as data, and a linear type setting device 11 as shown in FIG. This is made to correspond to an input membership function as shown in FIG. 6B, and the type of the continuous paper can be continuously and manually input as data.

That is, in FIG. 3A, by moving the setting knob 11-1 in the horizontal direction in the figure,
From the left, the type setting of the paper-changed, high-quality paper, and coated paper can be set, and the type setting display sections 11-2 to 11-11 displayed by reference are displayed.
-4 is drawn so that the neighbors overlap each other. It is known that the paper is easy to stretch in the case of paper change, so the expansion is taken a lot, and the coated paper is known to take a small amount.
There are some paper breaks that are very easy to stretch. Therefore, as shown in FIG. 5, an output membership function corresponding to each of fresh paper, high-quality paper, and coated paper is created, and the optimal tension is corrected by the fuzzy rule shown in FIG.

As described above, if the fuzzy controller is used, the type data can be continuously changed from the sheet change to the coated paper, and the type data can be set according to human's intuitive judgment. It becomes possible.

Recently, by fuzzy control,
A method of correcting a print quality and a trimming length by adjusting a printing state including a tension applied to a continuous sheet has been considered. In this case, if the optimum tension obtained by the present embodiment is given as the set value as the tension to be the center, the load on the operator can be further reduced.

[0026]

As is apparent from the above description, according to the present invention, it is possible to print continuous paper to be printed from the relationship between actual tension and elongation without inputting detailed data on the characteristics of the continuous paper. The optimum tension to be applied is automatically calculated, and the tension applied to the continuous paper can be automatically and optimally adjusted using the optimum tension obtained by the calculation as a set value. In this way, the recruitment of less experienced operators becomes possible.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of an optimum tension calculating device for a printing machine according to the present invention.

FIG. 2 is a diagram showing characteristics of a harmonic drive.

FIG. 3 is a plan view of an operation unit and a diagram showing an input membership function in a linear setting device using a fuzzy controller.

FIG. 4 is a diagram showing a fuzzy rule in a linear setting device using a fuzzy controller.

FIG. 5 is a diagram showing an output membership function in a linear setting device using a fuzzy controller.

[Explanation of symbols]

 1 (1-1, 1-2) Upstream drive roller 2 (2-1, 2-2) Downstream drive roller 5 Harmonic drive 6 Harmonic drive 8 Tension detector 9 Continuous paper 10 Optimal tension calculation unit 10-2 Memory Unit 10-1 Rotation amount command unit 10-3 Operation unit 10-4 Command stop unit

Claims (5)

(57) [Claims] 1. A printing machine provided with a tension adjusting means capable of adjusting a tension applied to a continuous paper, wherein a tension detecting means for detecting a tension applied to the continuous paper, and a rotation for detecting an amount of rotation of a downstream roll. An amount detecting means, and assuming that the movement of the continuous paper is regulated by stopping the rotation of the upstream roll, the downstream roll is gradually rotated to apply tension to the continuous paper, and the detection at this time is performed. Optimum tension calculation for measuring the relationship between the tension applied to the continuous paper and the elongation of the continuous paper from the tension and the detected rotation amount, and calculating the optimal tension to be applied to the continuous paper based on the measurement value obtained thereby Means for calculating the optimum tension of a printing machine. 2. The optimum tension calculating device for a printing machine according to claim 1, wherein the optimum tension calculating means corrects the calculation of the optimum tension according to the type of continuous paper given as data. 3. The optimum tension calculating device for a printing machine according to claim 1, wherein the rotation of the downstream roll is obtained by using a harmonic drive device. 4. The optimal tension of a printing machine according to claim 1, wherein the optimal tension calculating means forcibly stops the rotation of the downstream roll when the elongation rate of the continuous paper exceeds a predetermined value. Arithmetic unit. 5. The printing method according to claim 1, wherein the optimum tension calculating means forcibly stops the rotation of the downstream roll when the elongation rate per unit tension of the continuous paper exceeds a predetermined value. Optimal tension calculation device for machines.