JPH0516336A - Device and method for controlling cutting position - Google Patents

Abstract

PURPOSE:To properly estimate a misregistration amount between a printing position and a cutting position. CONSTITUTION:In a cutting position controller provided with a mark detection head 70 for detecting a mark printed on a web 1; an encoder 62 loaded on a shaft of a folding machine 60 to rotate in synchronism with a saw-tooth cylinder 61; and a cut-off controller 30 controls a cutting position for cutting the web 1 by controlling a compensator roller 21 by a motor 22 based on a detection signal from the mark detection head 70 and a reference pulse signal Ps from the encoder 62, the mark detection head 70 is disposed in the folding machine 60.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cutting position control device for cutting a continuously printed web and a control method therefor, and more particularly, to a register mark printed on the web or a pattern which can be substituted for the register mark automatically. The present invention relates to a cutting position control device and a control method for cutting the same based on this detection signal.

[0002]

2. Description of the Related Art For example, in a rotary printing press, a device as shown in FIG. 4 is used to control the registration between printing on a web and cutting as a subsequent process. In the figure, the web 1 reaches the web path portion 20 via the cooling roller 10. The web path unit 20 has a compensator roller 21 driven by a motor 22,
By moving this and changing the web path length, the registration between printing and cutting is controlled. An optical mark detection head 70 'is installed between the compensator roller 21 of the web path unit 20 and the folding machine 60', and optically detects the control mark attached to the web 1. The web 1 that has passed through the web path unit 20 reaches the folder 60 ′ via the transport roller 80, the web path drag roller 40, and the triangular plate 50.

Here, the cutoff controller 30 '
Is the detection signal from the mark detection head 70 'and the saw cylinder 61.
By comparing with the reference pulse signal P _S from the encoder 62 that rotates in synchronism with the above, the compensator roller 21 is moved by predicting the amount of misregistration between printing and cutting, and the registration between printing and cutting is controlled. Specifically, the reference pulse signal P _S from the encoder 62 is counted by the counter, and when the mark is detected by the mark detection head 70 ′ in the gate having a predetermined width manually set in advance, the counter value is latched. Mark position.

The axial position movement control of the compensator roller 21 is generally performed by so-called PD (proportional / derivative) control.

FIG. 3B is a diagram showing a conventional mark detecting head, wherein (A) is a front view and (A) is a side view. In the past, the automatic gate setting function was provided, but as shown in the figure, since there was only one sensor 72 'for the head, the head was moved left and right for each pattern.

[0006]

FIG. 5 is a diagram for explaining the amount of cut deviation. (A) shows the web 1 on which a pattern and a mark are attached, and (B) is a diagram showing a mark signal for performing the normal cutting when the mark is detected at that time. On the other hand, when the mark signal is detected at the position with respect to the web 1 as shown in (C), the mark is cut before the position to be cut. Further, in the case shown in (D), the cut is made after the position to be cut. In this case, as shown in (F), only one pulse of the encoder is the cut deviation amount. Incidentally, as shown in (G), the pulse count value is reset every time it returns to the mechanical origin.

By the way, in the above-mentioned conventional apparatus, since the position of the mark detecting head 70 'is separated from the position to be actually cut, the cutoff controller 30' is used in that state due to expansion and contraction of the web 1. Even if the compensator roller 21 is controlled, there is a problem that the predicted misregistration amount is not accurate as compared with the actual amount.

That is, in the prior art, since the mark detecting head 70 'is installed in the web path portion 20 about 5 to 7 m upstream from the saw cylinder 61, even if the cutoff position is detected at that position, it is downstream. Then, when the tension and elongation of the web 1 changed, the cut position of the printed book was shifted (shifted by 0.5 to 1.5 mm).

Therefore, the cutoff controller 3
0'manual fine tuning was often required.

The present invention has been made under the circumstances as described above, and an object of the present invention is to provide a cutting position control device and a control method therefor capable of accurately predicting a misregistration amount between printing and cutting. To provide.

[0011]

SUMMARY OF THE INVENTION The present invention relates to a cutting position control device and a control method for automatically extracting a register mark printed on a web or a pattern that can substitute for the register mark and cutting based on this detection signal. The object of the present invention is to detect a mark on a printed web, a mark detection head, an encoder that rotates in synchronization with a saw cylinder, a detection signal from the mark detection head, and an encoder. In a cutting position control device having a controller for controlling a cutting position for cutting the web by controlling a compensator roller based on a reference pulse signal, the mark detection head is provided between the web path drag roller and the saw cylinder. It is achieved by installing in.

Further, the mark detection head detects misregistration by reading the mark on the printed web,
In the cutting position control method for controlling the cutting position of the web by controlling the compensator roller based on the detection signal and the reference pulse signal from the encoder that rotates in synchronization with the saw cylinder, a predetermined register error is detected. This is accomplished by calculating the moving time Δt of the compensator roller by performing the PD calculation according to the equation (3), moving the compensator roller at a constant speed v based on the calculated value, and controlling the cutting position of the web.

[0013]

According to the present invention, by disposing the mark detecting head after the web pass drag roller, it is possible to eliminate the cut deviation in the printing book itself. Further, by adopting the optimum control gain according to the position of the mark detection head, hunting during steady state or overshoot during paster does not occur.

[0014]

Embodiments of the present invention will now be described in detail with reference to the drawings. FIG. 1 is a configuration block diagram of an embodiment of a cutting position control device of the present invention. In the figure, the mark detection head 70 and the cutoff controller 3
Since the part other than the control method in 0 is the same as the conventional one, the description is omitted. In this embodiment, the mark detection head 70 is installed inside the folding machine 60. As a result, the amount of cut deviation, which is substantially equal to the actual amount of cut deviation after cutting, is detected and controlled, so that the cut position of the printed book does not deviate even if the tension or elongation of the web 1 changes.
That is, it is better to detect the misregistration amount between the printing and the cutting position and control the cutting position immediately after the original cutting.
Since it is extremely difficult to detect the cutting position from the cut and fluttered printed matter after cutting, the mark detection head 70 must be installed upstream of the saw cylinder 61. Here, when the mark detection head 70 is separated from the saw cylinder 61, the cut deviation amount detected by the mark detection head 70 and the actual cut deviation amount are such that the web 1 is between the mark detection head and the saw cylinder 61. They do not equal when expanded or contracted. For example, when a certain tension variation occurs, the amount of expansion and contraction of the web 1 increases as the original web length increases. Therefore, the shorter the distance between the mark detection head 70 and the saw cylinder 61, the shorter the distance between the two. Since the amount of expansion and contraction of the web is also small, it is possible to detect an amount close to the actual amount of cut deviation.

In FIG. 2, the mark detecting head 70 is mounted on a folding machine 60.
FIG. 6 is a diagram comparing the cut deviation between the case of the present embodiment installed inside and the case of the related art. As shown in FIG. 2B, in the conventional case, even if the mark detection head 70 is controlled so as to eliminate the cut deviation, the cut deviation may occur in the printing book itself. Manual adjustment was necessary, and in particular, there were many cracks at the time of pasta where the tension fluctuation was large and the growth rates of the old and new fabrics often differed. On the other hand, as shown in FIG. 7A, if the mark detection head 70 installed inside the folder 60 is controlled so as not to have a cut deviation, the mark detection head 70 at the conventional position has a cut deviation. Even when a change is detected, the deviation of the cut does not occur in the printing plate itself because the amount of the web deviation immediately before cutting is controlled and controlled. Therefore, fine adjustment of the controller is not necessary even after the paster or the seam where the expansion rate of the web 1 changes, and the automatic operation becomes possible. It should be noted that the mark detection head 70 can obtain a certain effect if it is installed after the web pass drag roller 40, but since the amount of expansion and contraction of the web 1 is smaller at a position closer to the saw cylinder 61, it is necessary to know the cutoff amount accurately. It is desirable because it can be done.

Next, the mark detecting head adopted in the present invention will be described. FIG. 3A is a diagram showing an example of the mark detection head employed in the cutting position control device of the present invention, where (A) is a front view and (A) is a side view.
In the mark detection head 70, a plurality of light sources 71 and a pair of sensors 72 (16 in the figure) are arranged in a line. The mark detection head 70 automatically searches the optimum pattern edge as a control mark in the pattern and generates a gate. The optimum pattern edge reference includes high density, parallel to the left and right, and a sufficient margin in front of the mark. Further, since the mark detecting head 70 is of the multi-head type as described above, it is not necessary to move the head left and right even if the design changes.

By the way, since the folding machine 60 contains a lot of paper dust, the mark detecting head 70 is equipped with a wiper 73 for effectively cleaning the head in the present invention. Figure 3
In the example shown in (A), the structure is such that the rubber is slid vertically with respect to the detection surface by the solenoid 74 (or air cylinder). The wiper is not limited to the wiper, and may be an airbrush or the like as long as the same effect can be obtained.

Next, a method of controlling the compensator roller 21 based on a specific control calculation will be described. In the present invention, the optimum control gain is obtained for each printing machine based on the following equations 2, 3 and 4, and the control is performed by the equation 1. The equations 2, 3 and 4 are obtained by computer simulation and an actual machine test based on the correlation theory of tension and register (see Japanese Patent Application No. 58-220148).

[0019]

[Formula 1] Δt = K _P · E _K + K _D (E _K −E _K−1 )

[0020]

(2) K _P = f ₁ (x) · f ₂ (v)

[0021]

[Formula 3] K _D = f ₁ (x) · f ₃ (x) · f ₄ (v) ·
f ₅ (R)

[0022]

X = f ₆ (L ₁ , L ₂ , C) where Δt: moving time of the compensator roller 21 K _P : proportional gain K _D : differential gain E _K : current misregistration E _K-1 : Misregistration L ₁ before one revolution of the plate cylinder: Cooling drag 11-Web path drag roller 40 paper path length L ₂ : Web path drag roller 40 / head paper path length v: Moving speed R of compensator roller 21: This machine Rotational speed C: plate cylinder circumference In this way, since the optimum control gain is set for each machine, hunting during steady state or overshoot during pasting does not occur. Therefore, there is little spoiling during pasta.

[0023]

As described above, according to the cutting position control device and the control method thereof of the present invention, since the mark detection head is installed inside the folding machine, the misregistration amount between printing and cutting can be accurately measured. Can be predicted. That is, since the amount of cut deviation, which is substantially equal to the amount of cut deviation after cutting, is detected and controlled, the cut position of the printed book does not shift even if the tension or elongation of the web changes. There is no cut deviation in the printed book itself, and fine adjustment of the controller is not necessary even after the paster or the seam, and automatic operation is possible. Also, since the optimum control gain is set for each machine,
Hunting during steady state and overshoot during pasta do not occur, and there is little cracking during pasta. Furthermore, since the mark detection head is of a multi-head type, it is not necessary to move the head from side to side even if the design changes. Moreover, since the wiper is attached, the head surface does not get dirty even inside the folding machine.

[Brief description of drawings]

FIG. 1 is a configuration block diagram of an embodiment of a cutting position control device of the present invention.

FIG. 2 is a diagram comparing a cutting deviation between an example in which a mark detection head 70 is installed inside a folder 60 and a conventional case.

FIG. 3 is a diagram showing a mark detection head according to the present invention and the related art.

FIG. 4 is a configuration block diagram of an example of a conventional cutting position control device.

FIG. 5 is a diagram for explaining a cut deviation amount.

[Explanation of symbols]

1 Web 10 Cooling roller 11 Cooling drag roller 20 Web Pass Department 21 Compensator Roller 22 motor 30 cut-off controller 40 Web Pass Drag Roller 50 triangular plate 60 folding machine 61 saw body 62 encoder 70 mark detection head 71 light source 72 sensors 73 wiper 74 Solenoid 80 transport rollers

Claims (2)

[Claims] 1. A mark detection head that detects a mark on a printed web, an encoder that rotates in synchronization with a saw cylinder, a detection signal from the mark detection head, and a reference pulse signal from the encoder. In a cutting position control device having a controller for controlling a cutting position for cutting the web by controlling a compensator roller by using a mark detecting head, the mark detecting head is installed between the web path drag roller and the saw cylinder. A cutting position control device characterized by the above. 2. A mark detection head detects misregistration by reading a mark on a printed web, and a compensator based on the detection signal and a reference pulse signal from an encoder rotating in synchronization with the saw cylinder. In the cutting position control method of controlling the cutting position of the web by controlling the roller, the PD calculation shown in the following formula is performed for the detected misregistration to calculate the moving time Δt of the compensator roller, and the calculated value is calculated. Based on the above, the cutting position control method is characterized in that the compensator roller is moved at a constant speed v to control the cutting position of the web. Δt = K _P · E _K + K _D (E _K −E _K−1 ) K _P = f ₁ (x) · f ₂ (v) K _D = f ₁ (x) · f ₃ (x) · f ₄ ( v) ・ f
_{5 (R) x = f 6} (L 1, L 2, C) where, Delta] t: compensator rollers movement time _{K P} of: proportional gain _{K D:} differential gain _{E K:} Current misregistration _{E K-1:} plate Misregistration before one rotation of the cylinder L ₁ : Cooling drag-web path drag roller paper path length L ₂ : Web path drag / head paper path length v: Compensator roller movement speed R: Machine rotation speed C: Plate cylinder Circumference